inode.c 195.6 KB
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/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

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#include <linux/kernel.h>
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#include <linux/bio.h>
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#include <linux/buffer_head.h>
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#include <linux/file.h>
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#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/highmem.h>
#include <linux/time.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/backing-dev.h>
#include <linux/mpage.h>
#include <linux/swap.h>
#include <linux/writeback.h>
#include <linux/statfs.h>
#include <linux/compat.h>
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#include <linux/bit_spinlock.h>
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#include <linux/xattr.h>
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#include <linux/posix_acl.h>
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#include <linux/falloc.h>
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#include <linux/slab.h>
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#include "compat.h"
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#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
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#include "volumes.h"
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#include "ordered-data.h"
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#include "xattr.h"
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#include "tree-log.h"
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#include "compression.h"
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#include "locking.h"
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struct btrfs_iget_args {
	u64 ino;
	struct btrfs_root *root;
};

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static const struct inode_operations btrfs_dir_inode_operations;
static const struct inode_operations btrfs_symlink_inode_operations;
static const struct inode_operations btrfs_dir_ro_inode_operations;
static const struct inode_operations btrfs_special_inode_operations;
static const struct inode_operations btrfs_file_inode_operations;
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static const struct address_space_operations btrfs_aops;
static const struct address_space_operations btrfs_symlink_aops;
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static const struct file_operations btrfs_dir_file_operations;
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static struct extent_io_ops btrfs_extent_io_ops;
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static struct kmem_cache *btrfs_inode_cachep;
struct kmem_cache *btrfs_trans_handle_cachep;
struct kmem_cache *btrfs_transaction_cachep;
struct kmem_cache *btrfs_path_cachep;

#define S_SHIFT 12
static unsigned char btrfs_type_by_mode[S_IFMT >> S_SHIFT] = {
	[S_IFREG >> S_SHIFT]	= BTRFS_FT_REG_FILE,
	[S_IFDIR >> S_SHIFT]	= BTRFS_FT_DIR,
	[S_IFCHR >> S_SHIFT]	= BTRFS_FT_CHRDEV,
	[S_IFBLK >> S_SHIFT]	= BTRFS_FT_BLKDEV,
	[S_IFIFO >> S_SHIFT]	= BTRFS_FT_FIFO,
	[S_IFSOCK >> S_SHIFT]	= BTRFS_FT_SOCK,
	[S_IFLNK >> S_SHIFT]	= BTRFS_FT_SYMLINK,
};

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static void btrfs_truncate(struct inode *inode);
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static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
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static noinline int cow_file_range(struct inode *inode,
				   struct page *locked_page,
				   u64 start, u64 end, int *page_started,
				   unsigned long *nr_written, int unlock);
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static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
				     struct inode *inode,  struct inode *dir)
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{
	int err;

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	err = btrfs_init_acl(trans, inode, dir);
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	if (!err)
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		err = btrfs_xattr_security_init(trans, inode, dir);
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	return err;
}

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/*
 * this does all the hard work for inserting an inline extent into
 * the btree.  The caller should have done a btrfs_drop_extents so that
 * no overlapping inline items exist in the btree
 */
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static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
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				struct btrfs_root *root, struct inode *inode,
				u64 start, size_t size, size_t compressed_size,
				struct page **compressed_pages)
{
	struct btrfs_key key;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct page *page = NULL;
	char *kaddr;
	unsigned long ptr;
	struct btrfs_file_extent_item *ei;
	int err = 0;
	int ret;
	size_t cur_size = size;
	size_t datasize;
	unsigned long offset;
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	int compress_type = BTRFS_COMPRESS_NONE;
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	if (compressed_size && compressed_pages) {
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		compress_type = root->fs_info->compress_type;
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		cur_size = compressed_size;
	}

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	path = btrfs_alloc_path();
	if (!path)
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		return -ENOMEM;

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	path->leave_spinning = 1;
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	btrfs_set_trans_block_group(trans, inode);

	key.objectid = inode->i_ino;
	key.offset = start;
	btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
	datasize = btrfs_file_extent_calc_inline_size(cur_size);

	inode_add_bytes(inode, size);
	ret = btrfs_insert_empty_item(trans, root, path, &key,
				      datasize);
	BUG_ON(ret);
	if (ret) {
		err = ret;
		goto fail;
	}
	leaf = path->nodes[0];
	ei = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
	btrfs_set_file_extent_generation(leaf, ei, trans->transid);
	btrfs_set_file_extent_type(leaf, ei, BTRFS_FILE_EXTENT_INLINE);
	btrfs_set_file_extent_encryption(leaf, ei, 0);
	btrfs_set_file_extent_other_encoding(leaf, ei, 0);
	btrfs_set_file_extent_ram_bytes(leaf, ei, size);
	ptr = btrfs_file_extent_inline_start(ei);

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	if (compress_type != BTRFS_COMPRESS_NONE) {
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		struct page *cpage;
		int i = 0;
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		while (compressed_size > 0) {
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			cpage = compressed_pages[i];
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			cur_size = min_t(unsigned long, compressed_size,
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				       PAGE_CACHE_SIZE);

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			kaddr = kmap_atomic(cpage, KM_USER0);
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			write_extent_buffer(leaf, kaddr, ptr, cur_size);
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			kunmap_atomic(kaddr, KM_USER0);
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			i++;
			ptr += cur_size;
			compressed_size -= cur_size;
		}
		btrfs_set_file_extent_compression(leaf, ei,
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						  compress_type);
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	} else {
		page = find_get_page(inode->i_mapping,
				     start >> PAGE_CACHE_SHIFT);
		btrfs_set_file_extent_compression(leaf, ei, 0);
		kaddr = kmap_atomic(page, KM_USER0);
		offset = start & (PAGE_CACHE_SIZE - 1);
		write_extent_buffer(leaf, kaddr + offset, ptr, size);
		kunmap_atomic(kaddr, KM_USER0);
		page_cache_release(page);
	}
	btrfs_mark_buffer_dirty(leaf);
	btrfs_free_path(path);

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	/*
	 * we're an inline extent, so nobody can
	 * extend the file past i_size without locking
	 * a page we already have locked.
	 *
	 * We must do any isize and inode updates
	 * before we unlock the pages.  Otherwise we
	 * could end up racing with unlink.
	 */
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	BTRFS_I(inode)->disk_i_size = inode->i_size;
	btrfs_update_inode(trans, root, inode);
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	return 0;
fail:
	btrfs_free_path(path);
	return err;
}


/*
 * conditionally insert an inline extent into the file.  This
 * does the checks required to make sure the data is small enough
 * to fit as an inline extent.
 */
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static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
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				 struct btrfs_root *root,
				 struct inode *inode, u64 start, u64 end,
				 size_t compressed_size,
				 struct page **compressed_pages)
{
	u64 isize = i_size_read(inode);
	u64 actual_end = min(end + 1, isize);
	u64 inline_len = actual_end - start;
	u64 aligned_end = (end + root->sectorsize - 1) &
			~((u64)root->sectorsize - 1);
	u64 hint_byte;
	u64 data_len = inline_len;
	int ret;

	if (compressed_size)
		data_len = compressed_size;

	if (start > 0 ||
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	    actual_end >= PAGE_CACHE_SIZE ||
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	    data_len >= BTRFS_MAX_INLINE_DATA_SIZE(root) ||
	    (!compressed_size &&
	    (actual_end & (root->sectorsize - 1)) == 0) ||
	    end + 1 < isize ||
	    data_len > root->fs_info->max_inline) {
		return 1;
	}

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	ret = btrfs_drop_extents(trans, inode, start, aligned_end,
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				 &hint_byte, 1);
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	BUG_ON(ret);

	if (isize > actual_end)
		inline_len = min_t(u64, isize, actual_end);
	ret = insert_inline_extent(trans, root, inode, start,
				   inline_len, compressed_size,
				   compressed_pages);
	BUG_ON(ret);
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	btrfs_delalloc_release_metadata(inode, end + 1 - start);
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	btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
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	return 0;
}

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struct async_extent {
	u64 start;
	u64 ram_size;
	u64 compressed_size;
	struct page **pages;
	unsigned long nr_pages;
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	int compress_type;
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	struct list_head list;
};

struct async_cow {
	struct inode *inode;
	struct btrfs_root *root;
	struct page *locked_page;
	u64 start;
	u64 end;
	struct list_head extents;
	struct btrfs_work work;
};

static noinline int add_async_extent(struct async_cow *cow,
				     u64 start, u64 ram_size,
				     u64 compressed_size,
				     struct page **pages,
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				     unsigned long nr_pages,
				     int compress_type)
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{
	struct async_extent *async_extent;

	async_extent = kmalloc(sizeof(*async_extent), GFP_NOFS);
	async_extent->start = start;
	async_extent->ram_size = ram_size;
	async_extent->compressed_size = compressed_size;
	async_extent->pages = pages;
	async_extent->nr_pages = nr_pages;
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	async_extent->compress_type = compress_type;
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	list_add_tail(&async_extent->list, &cow->extents);
	return 0;
}

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/*
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 * we create compressed extents in two phases.  The first
 * phase compresses a range of pages that have already been
 * locked (both pages and state bits are locked).
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 *
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 * This is done inside an ordered work queue, and the compression
 * is spread across many cpus.  The actual IO submission is step
 * two, and the ordered work queue takes care of making sure that
 * happens in the same order things were put onto the queue by
 * writepages and friends.
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 *
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 * If this code finds it can't get good compression, it puts an
 * entry onto the work queue to write the uncompressed bytes.  This
 * makes sure that both compressed inodes and uncompressed inodes
 * are written in the same order that pdflush sent them down.
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 */
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static noinline int compress_file_range(struct inode *inode,
					struct page *locked_page,
					u64 start, u64 end,
					struct async_cow *async_cow,
					int *num_added)
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{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
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	u64 num_bytes;
	u64 blocksize = root->sectorsize;
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	u64 actual_end;
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	u64 isize = i_size_read(inode);
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	int ret = 0;
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	struct page **pages = NULL;
	unsigned long nr_pages;
	unsigned long nr_pages_ret = 0;
	unsigned long total_compressed = 0;
	unsigned long total_in = 0;
	unsigned long max_compressed = 128 * 1024;
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	unsigned long max_uncompressed = 128 * 1024;
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	int i;
	int will_compress;
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	int compress_type = root->fs_info->compress_type;
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	actual_end = min_t(u64, isize, end + 1);
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again:
	will_compress = 0;
	nr_pages = (end >> PAGE_CACHE_SHIFT) - (start >> PAGE_CACHE_SHIFT) + 1;
	nr_pages = min(nr_pages, (128 * 1024UL) / PAGE_CACHE_SIZE);
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	/*
	 * we don't want to send crud past the end of i_size through
	 * compression, that's just a waste of CPU time.  So, if the
	 * end of the file is before the start of our current
	 * requested range of bytes, we bail out to the uncompressed
	 * cleanup code that can deal with all of this.
	 *
	 * It isn't really the fastest way to fix things, but this is a
	 * very uncommon corner.
	 */
	if (actual_end <= start)
		goto cleanup_and_bail_uncompressed;

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	total_compressed = actual_end - start;

	/* we want to make sure that amount of ram required to uncompress
	 * an extent is reasonable, so we limit the total size in ram
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	 * of a compressed extent to 128k.  This is a crucial number
	 * because it also controls how easily we can spread reads across
	 * cpus for decompression.
	 *
	 * We also want to make sure the amount of IO required to do
	 * a random read is reasonably small, so we limit the size of
	 * a compressed extent to 128k.
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	 */
	total_compressed = min(total_compressed, max_uncompressed);
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	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
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	num_bytes = max(blocksize,  num_bytes);
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	total_in = 0;
	ret = 0;
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	/*
	 * we do compression for mount -o compress and when the
	 * inode has not been flagged as nocompress.  This flag can
	 * change at any time if we discover bad compression ratios.
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	 */
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	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
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	    (btrfs_test_opt(root, COMPRESS) ||
	     (BTRFS_I(inode)->force_compress))) {
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		WARN_ON(pages);
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		pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
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		if (BTRFS_I(inode)->force_compress)
			compress_type = BTRFS_I(inode)->force_compress;

		ret = btrfs_compress_pages(compress_type,
					   inode->i_mapping, start,
					   total_compressed, pages,
					   nr_pages, &nr_pages_ret,
					   &total_in,
					   &total_compressed,
					   max_compressed);
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		if (!ret) {
			unsigned long offset = total_compressed &
				(PAGE_CACHE_SIZE - 1);
			struct page *page = pages[nr_pages_ret - 1];
			char *kaddr;

			/* zero the tail end of the last page, we might be
			 * sending it down to disk
			 */
			if (offset) {
				kaddr = kmap_atomic(page, KM_USER0);
				memset(kaddr + offset, 0,
				       PAGE_CACHE_SIZE - offset);
				kunmap_atomic(kaddr, KM_USER0);
			}
			will_compress = 1;
		}
	}
	if (start == 0) {
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		trans = btrfs_join_transaction(root, 1);
		BUG_ON(!trans);
		btrfs_set_trans_block_group(trans, inode);
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		trans->block_rsv = &root->fs_info->delalloc_block_rsv;
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		/* lets try to make an inline extent */
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		if (ret || total_in < (actual_end - start)) {
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			/* we didn't compress the entire range, try
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			 * to make an uncompressed inline extent.
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			 */
			ret = cow_file_range_inline(trans, root, inode,
						    start, end, 0, NULL);
		} else {
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			/* try making a compressed inline extent */
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			ret = cow_file_range_inline(trans, root, inode,
						    start, end,
						    total_compressed, pages);
		}
		if (ret == 0) {
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			/*
			 * inline extent creation worked, we don't need
			 * to create any more async work items.  Unlock
			 * and free up our temp pages.
			 */
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			extent_clear_unlock_delalloc(inode,
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			     &BTRFS_I(inode)->io_tree,
			     start, end, NULL,
			     EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
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			     EXTENT_CLEAR_DELALLOC |
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			     EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
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			btrfs_end_transaction(trans, root);
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			goto free_pages_out;
		}
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		btrfs_end_transaction(trans, root);
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	}

	if (will_compress) {
		/*
		 * we aren't doing an inline extent round the compressed size
		 * up to a block size boundary so the allocator does sane
		 * things
		 */
		total_compressed = (total_compressed + blocksize - 1) &
			~(blocksize - 1);

		/*
		 * one last check to make sure the compression is really a
		 * win, compare the page count read with the blocks on disk
		 */
		total_in = (total_in + PAGE_CACHE_SIZE - 1) &
			~(PAGE_CACHE_SIZE - 1);
		if (total_compressed >= total_in) {
			will_compress = 0;
		} else {
			num_bytes = total_in;
		}
	}
	if (!will_compress && pages) {
		/*
		 * the compression code ran but failed to make things smaller,
		 * free any pages it allocated and our page pointer array
		 */
		for (i = 0; i < nr_pages_ret; i++) {
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			WARN_ON(pages[i]->mapping);
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			page_cache_release(pages[i]);
		}
		kfree(pages);
		pages = NULL;
		total_compressed = 0;
		nr_pages_ret = 0;

		/* flag the file so we don't compress in the future */
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		if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
		    !(BTRFS_I(inode)->force_compress)) {
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			BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
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		}
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	}
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	if (will_compress) {
		*num_added += 1;
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		/* the async work queues will take care of doing actual
		 * allocation on disk for these compressed pages,
		 * and will submit them to the elevator.
		 */
		add_async_extent(async_cow, start, num_bytes,
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				 total_compressed, pages, nr_pages_ret,
				 compress_type);
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		if (start + num_bytes < end) {
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			start += num_bytes;
			pages = NULL;
			cond_resched();
			goto again;
		}
	} else {
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cleanup_and_bail_uncompressed:
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		/*
		 * No compression, but we still need to write the pages in
		 * the file we've been given so far.  redirty the locked
		 * page if it corresponds to our extent and set things up
		 * for the async work queue to run cow_file_range to do
		 * the normal delalloc dance
		 */
		if (page_offset(locked_page) >= start &&
		    page_offset(locked_page) <= end) {
			__set_page_dirty_nobuffers(locked_page);
			/* unlocked later on in the async handlers */
		}
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		add_async_extent(async_cow, start, end - start + 1,
				 0, NULL, 0, BTRFS_COMPRESS_NONE);
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		*num_added += 1;
	}
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out:
	return 0;

free_pages_out:
	for (i = 0; i < nr_pages_ret; i++) {
		WARN_ON(pages[i]->mapping);
		page_cache_release(pages[i]);
	}
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	kfree(pages);
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	goto out;
}

/*
 * phase two of compressed writeback.  This is the ordered portion
 * of the code, which only gets called in the order the work was
 * queued.  We walk all the async extents created by compress_file_range
 * and send them down to the disk.
 */
static noinline int submit_compressed_extents(struct inode *inode,
					      struct async_cow *async_cow)
{
	struct async_extent *async_extent;
	u64 alloc_hint = 0;
	struct btrfs_trans_handle *trans;
	struct btrfs_key ins;
	struct extent_map *em;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct extent_io_tree *io_tree;
562
	int ret = 0;
563 564 565 566 567

	if (list_empty(&async_cow->extents))
		return 0;


C
Chris Mason 已提交
568
	while (!list_empty(&async_cow->extents)) {
569 570 571
		async_extent = list_entry(async_cow->extents.next,
					  struct async_extent, list);
		list_del(&async_extent->list);
C
Chris Mason 已提交
572

573 574
		io_tree = &BTRFS_I(inode)->io_tree;

575
retry:
576 577 578 579 580 581
		/* did the compression code fall back to uncompressed IO? */
		if (!async_extent->pages) {
			int page_started = 0;
			unsigned long nr_written = 0;

			lock_extent(io_tree, async_extent->start,
582 583
					 async_extent->start +
					 async_extent->ram_size - 1, GFP_NOFS);
584 585

			/* allocate blocks */
586 587 588 589 590
			ret = cow_file_range(inode, async_cow->locked_page,
					     async_extent->start,
					     async_extent->start +
					     async_extent->ram_size - 1,
					     &page_started, &nr_written, 0);
591 592 593 594 595 596 597

			/*
			 * if page_started, cow_file_range inserted an
			 * inline extent and took care of all the unlocking
			 * and IO for us.  Otherwise, we need to submit
			 * all those pages down to the drive.
			 */
598
			if (!page_started && !ret)
599 600
				extent_write_locked_range(io_tree,
						  inode, async_extent->start,
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Chris Mason 已提交
601
						  async_extent->start +
602 603 604 605 606 607 608 609 610 611 612 613
						  async_extent->ram_size - 1,
						  btrfs_get_extent,
						  WB_SYNC_ALL);
			kfree(async_extent);
			cond_resched();
			continue;
		}

		lock_extent(io_tree, async_extent->start,
			    async_extent->start + async_extent->ram_size - 1,
			    GFP_NOFS);

614
		trans = btrfs_join_transaction(root, 1);
615 616 617 618 619
		ret = btrfs_reserve_extent(trans, root,
					   async_extent->compressed_size,
					   async_extent->compressed_size,
					   0, alloc_hint,
					   (u64)-1, &ins, 1);
620 621
		btrfs_end_transaction(trans, root);

622 623 624 625 626 627 628 629 630 631 632 633 634 635 636
		if (ret) {
			int i;
			for (i = 0; i < async_extent->nr_pages; i++) {
				WARN_ON(async_extent->pages[i]->mapping);
				page_cache_release(async_extent->pages[i]);
			}
			kfree(async_extent->pages);
			async_extent->nr_pages = 0;
			async_extent->pages = NULL;
			unlock_extent(io_tree, async_extent->start,
				      async_extent->start +
				      async_extent->ram_size - 1, GFP_NOFS);
			goto retry;
		}

637 638 639 640 641 642 643 644
		/*
		 * here we're doing allocation and writeback of the
		 * compressed pages
		 */
		btrfs_drop_extent_cache(inode, async_extent->start,
					async_extent->start +
					async_extent->ram_size - 1, 0);

645 646 647
		em = alloc_extent_map(GFP_NOFS);
		em->start = async_extent->start;
		em->len = async_extent->ram_size;
648
		em->orig_start = em->start;
C
Chris Mason 已提交
649

650 651 652
		em->block_start = ins.objectid;
		em->block_len = ins.offset;
		em->bdev = root->fs_info->fs_devices->latest_bdev;
653
		em->compress_type = async_extent->compress_type;
654 655 656
		set_bit(EXTENT_FLAG_PINNED, &em->flags);
		set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);

C
Chris Mason 已提交
657
		while (1) {
658
			write_lock(&em_tree->lock);
659
			ret = add_extent_mapping(em_tree, em);
660
			write_unlock(&em_tree->lock);
661 662 663 664 665 666 667 668 669
			if (ret != -EEXIST) {
				free_extent_map(em);
				break;
			}
			btrfs_drop_extent_cache(inode, async_extent->start,
						async_extent->start +
						async_extent->ram_size - 1, 0);
		}

670 671 672 673 674 675 676
		ret = btrfs_add_ordered_extent_compress(inode,
						async_extent->start,
						ins.objectid,
						async_extent->ram_size,
						ins.offset,
						BTRFS_ORDERED_COMPRESSED,
						async_extent->compress_type);
677 678 679 680 681 682
		BUG_ON(ret);

		/*
		 * clear dirty, set writeback and unlock the pages.
		 */
		extent_clear_unlock_delalloc(inode,
683 684 685 686 687 688
				&BTRFS_I(inode)->io_tree,
				async_extent->start,
				async_extent->start +
				async_extent->ram_size - 1,
				NULL, EXTENT_CLEAR_UNLOCK_PAGE |
				EXTENT_CLEAR_UNLOCK |
689
				EXTENT_CLEAR_DELALLOC |
690
				EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
691 692

		ret = btrfs_submit_compressed_write(inode,
C
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693 694 695 696 697
				    async_extent->start,
				    async_extent->ram_size,
				    ins.objectid,
				    ins.offset, async_extent->pages,
				    async_extent->nr_pages);
698 699 700 701 702 703 704 705 706 707

		BUG_ON(ret);
		alloc_hint = ins.objectid + ins.offset;
		kfree(async_extent);
		cond_resched();
	}

	return 0;
}

708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739
static u64 get_extent_allocation_hint(struct inode *inode, u64 start,
				      u64 num_bytes)
{
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct extent_map *em;
	u64 alloc_hint = 0;

	read_lock(&em_tree->lock);
	em = search_extent_mapping(em_tree, start, num_bytes);
	if (em) {
		/*
		 * if block start isn't an actual block number then find the
		 * first block in this inode and use that as a hint.  If that
		 * block is also bogus then just don't worry about it.
		 */
		if (em->block_start >= EXTENT_MAP_LAST_BYTE) {
			free_extent_map(em);
			em = search_extent_mapping(em_tree, 0, 0);
			if (em && em->block_start < EXTENT_MAP_LAST_BYTE)
				alloc_hint = em->block_start;
			if (em)
				free_extent_map(em);
		} else {
			alloc_hint = em->block_start;
			free_extent_map(em);
		}
	}
	read_unlock(&em_tree->lock);

	return alloc_hint;
}

740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771
/*
 * when extent_io.c finds a delayed allocation range in the file,
 * the call backs end up in this code.  The basic idea is to
 * allocate extents on disk for the range, and create ordered data structs
 * in ram to track those extents.
 *
 * locked_page is the page that writepage had locked already.  We use
 * it to make sure we don't do extra locks or unlocks.
 *
 * *page_started is set to one if we unlock locked_page and do everything
 * required to start IO on it.  It may be clean and already done with
 * IO when we return.
 */
static noinline int cow_file_range(struct inode *inode,
				   struct page *locked_page,
				   u64 start, u64 end, int *page_started,
				   unsigned long *nr_written,
				   int unlock)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	u64 alloc_hint = 0;
	u64 num_bytes;
	unsigned long ram_size;
	u64 disk_num_bytes;
	u64 cur_alloc_size;
	u64 blocksize = root->sectorsize;
	struct btrfs_key ins;
	struct extent_map *em;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	int ret = 0;

J
Josef Bacik 已提交
772
	BUG_ON(root == root->fs_info->tree_root);
773 774 775
	trans = btrfs_join_transaction(root, 1);
	BUG_ON(!trans);
	btrfs_set_trans_block_group(trans, inode);
776
	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
777 778 779 780 781 782 783 784 785 786 787 788

	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
	num_bytes = max(blocksize,  num_bytes);
	disk_num_bytes = num_bytes;
	ret = 0;

	if (start == 0) {
		/* lets try to make an inline extent */
		ret = cow_file_range_inline(trans, root, inode,
					    start, end, 0, NULL);
		if (ret == 0) {
			extent_clear_unlock_delalloc(inode,
789 790 791 792 793 794 795 796
				     &BTRFS_I(inode)->io_tree,
				     start, end, NULL,
				     EXTENT_CLEAR_UNLOCK_PAGE |
				     EXTENT_CLEAR_UNLOCK |
				     EXTENT_CLEAR_DELALLOC |
				     EXTENT_CLEAR_DIRTY |
				     EXTENT_SET_WRITEBACK |
				     EXTENT_END_WRITEBACK);
797

798 799 800 801 802 803 804 805 806 807 808
			*nr_written = *nr_written +
			     (end - start + PAGE_CACHE_SIZE) / PAGE_CACHE_SIZE;
			*page_started = 1;
			ret = 0;
			goto out;
		}
	}

	BUG_ON(disk_num_bytes >
	       btrfs_super_total_bytes(&root->fs_info->super_copy));

809
	alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
810 811
	btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);

C
Chris Mason 已提交
812
	while (disk_num_bytes > 0) {
813 814
		unsigned long op;

815
		cur_alloc_size = disk_num_bytes;
816
		ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
817
					   root->sectorsize, 0, alloc_hint,
818
					   (u64)-1, &ins, 1);
C
Chris Mason 已提交
819 820
		BUG_ON(ret);

821 822
		em = alloc_extent_map(GFP_NOFS);
		em->start = start;
823
		em->orig_start = em->start;
824 825
		ram_size = ins.offset;
		em->len = ins.offset;
C
Chris Mason 已提交
826

827
		em->block_start = ins.objectid;
C
Chris Mason 已提交
828
		em->block_len = ins.offset;
829
		em->bdev = root->fs_info->fs_devices->latest_bdev;
830
		set_bit(EXTENT_FLAG_PINNED, &em->flags);
C
Chris Mason 已提交
831

C
Chris Mason 已提交
832
		while (1) {
833
			write_lock(&em_tree->lock);
834
			ret = add_extent_mapping(em_tree, em);
835
			write_unlock(&em_tree->lock);
836 837 838 839 840
			if (ret != -EEXIST) {
				free_extent_map(em);
				break;
			}
			btrfs_drop_extent_cache(inode, start,
C
Chris Mason 已提交
841
						start + ram_size - 1, 0);
842 843
		}

844
		cur_alloc_size = ins.offset;
845
		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
846
					       ram_size, cur_alloc_size, 0);
847
		BUG_ON(ret);
C
Chris Mason 已提交
848

849 850 851 852 853 854 855
		if (root->root_key.objectid ==
		    BTRFS_DATA_RELOC_TREE_OBJECTID) {
			ret = btrfs_reloc_clone_csums(inode, start,
						      cur_alloc_size);
			BUG_ON(ret);
		}

C
Chris Mason 已提交
856
		if (disk_num_bytes < cur_alloc_size)
857
			break;
C
Chris Mason 已提交
858

C
Chris Mason 已提交
859 860 861
		/* we're not doing compressed IO, don't unlock the first
		 * page (which the caller expects to stay locked), don't
		 * clear any dirty bits and don't set any writeback bits
862 863 864
		 *
		 * Do set the Private2 bit so we know this page was properly
		 * setup for writepage
C
Chris Mason 已提交
865
		 */
866 867 868 869
		op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
		op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
			EXTENT_SET_PRIVATE2;

C
Chris Mason 已提交
870 871
		extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
					     start, start + ram_size - 1,
872
					     locked_page, op);
C
Chris Mason 已提交
873
		disk_num_bytes -= cur_alloc_size;
874 875 876
		num_bytes -= cur_alloc_size;
		alloc_hint = ins.objectid + ins.offset;
		start += cur_alloc_size;
877 878
	}
out:
879
	ret = 0;
880
	btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
881

882
	return ret;
883
}
C
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884

885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922
/*
 * work queue call back to started compression on a file and pages
 */
static noinline void async_cow_start(struct btrfs_work *work)
{
	struct async_cow *async_cow;
	int num_added = 0;
	async_cow = container_of(work, struct async_cow, work);

	compress_file_range(async_cow->inode, async_cow->locked_page,
			    async_cow->start, async_cow->end, async_cow,
			    &num_added);
	if (num_added == 0)
		async_cow->inode = NULL;
}

/*
 * work queue call back to submit previously compressed pages
 */
static noinline void async_cow_submit(struct btrfs_work *work)
{
	struct async_cow *async_cow;
	struct btrfs_root *root;
	unsigned long nr_pages;

	async_cow = container_of(work, struct async_cow, work);

	root = async_cow->root;
	nr_pages = (async_cow->end - async_cow->start + PAGE_CACHE_SIZE) >>
		PAGE_CACHE_SHIFT;

	atomic_sub(nr_pages, &root->fs_info->async_delalloc_pages);

	if (atomic_read(&root->fs_info->async_delalloc_pages) <
	    5 * 1042 * 1024 &&
	    waitqueue_active(&root->fs_info->async_submit_wait))
		wake_up(&root->fs_info->async_submit_wait);

C
Chris Mason 已提交
923
	if (async_cow->inode)
924 925
		submit_compressed_extents(async_cow->inode, async_cow);
}
C
Chris Mason 已提交
926

927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943
static noinline void async_cow_free(struct btrfs_work *work)
{
	struct async_cow *async_cow;
	async_cow = container_of(work, struct async_cow, work);
	kfree(async_cow);
}

static int cow_file_range_async(struct inode *inode, struct page *locked_page,
				u64 start, u64 end, int *page_started,
				unsigned long *nr_written)
{
	struct async_cow *async_cow;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	unsigned long nr_pages;
	u64 cur_end;
	int limit = 10 * 1024 * 1042;

944 945
	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
			 1, 0, NULL, GFP_NOFS);
C
Chris Mason 已提交
946
	while (start < end) {
947 948 949 950 951 952
		async_cow = kmalloc(sizeof(*async_cow), GFP_NOFS);
		async_cow->inode = inode;
		async_cow->root = root;
		async_cow->locked_page = locked_page;
		async_cow->start = start;

953
		if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978
			cur_end = end;
		else
			cur_end = min(end, start + 512 * 1024 - 1);

		async_cow->end = cur_end;
		INIT_LIST_HEAD(&async_cow->extents);

		async_cow->work.func = async_cow_start;
		async_cow->work.ordered_func = async_cow_submit;
		async_cow->work.ordered_free = async_cow_free;
		async_cow->work.flags = 0;

		nr_pages = (cur_end - start + PAGE_CACHE_SIZE) >>
			PAGE_CACHE_SHIFT;
		atomic_add(nr_pages, &root->fs_info->async_delalloc_pages);

		btrfs_queue_worker(&root->fs_info->delalloc_workers,
				   &async_cow->work);

		if (atomic_read(&root->fs_info->async_delalloc_pages) > limit) {
			wait_event(root->fs_info->async_submit_wait,
			   (atomic_read(&root->fs_info->async_delalloc_pages) <
			    limit));
		}

C
Chris Mason 已提交
979
		while (atomic_read(&root->fs_info->async_submit_draining) &&
980 981 982 983 984 985 986 987 988 989 990
		      atomic_read(&root->fs_info->async_delalloc_pages)) {
			wait_event(root->fs_info->async_submit_wait,
			  (atomic_read(&root->fs_info->async_delalloc_pages) ==
			   0));
		}

		*nr_written += nr_pages;
		start = cur_end + 1;
	}
	*page_started = 1;
	return 0;
991 992
}

C
Chris Mason 已提交
993
static noinline int csum_exist_in_range(struct btrfs_root *root,
994 995 996 997 998 999
					u64 bytenr, u64 num_bytes)
{
	int ret;
	struct btrfs_ordered_sum *sums;
	LIST_HEAD(list);

Y
Yan Zheng 已提交
1000 1001
	ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
				       bytenr + num_bytes - 1, &list);
1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012
	if (ret == 0 && list_empty(&list))
		return 0;

	while (!list_empty(&list)) {
		sums = list_entry(list.next, struct btrfs_ordered_sum, list);
		list_del(&sums->list);
		kfree(sums);
	}
	return 1;
}

C
Chris Mason 已提交
1013 1014 1015 1016 1017 1018 1019
/*
 * when nowcow writeback call back.  This checks for snapshots or COW copies
 * of the extents that exist in the file, and COWs the file as required.
 *
 * If no cow copies or snapshots exist, we write directly to the existing
 * blocks on disk
 */
1020 1021
static noinline int run_delalloc_nocow(struct inode *inode,
				       struct page *locked_page,
1022 1023
			      u64 start, u64 end, int *page_started, int force,
			      unsigned long *nr_written)
1024 1025
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1026
	struct btrfs_trans_handle *trans;
1027 1028
	struct extent_buffer *leaf;
	struct btrfs_path *path;
Y
Yan Zheng 已提交
1029
	struct btrfs_file_extent_item *fi;
1030
	struct btrfs_key found_key;
Y
Yan Zheng 已提交
1031 1032 1033
	u64 cow_start;
	u64 cur_offset;
	u64 extent_end;
1034
	u64 extent_offset;
Y
Yan Zheng 已提交
1035 1036 1037 1038
	u64 disk_bytenr;
	u64 num_bytes;
	int extent_type;
	int ret;
Y
Yan Zheng 已提交
1039
	int type;
Y
Yan Zheng 已提交
1040 1041
	int nocow;
	int check_prev = 1;
J
Josef Bacik 已提交
1042
	bool nolock = false;
1043 1044 1045

	path = btrfs_alloc_path();
	BUG_ON(!path);
J
Josef Bacik 已提交
1046 1047 1048 1049 1050 1051
	if (root == root->fs_info->tree_root) {
		nolock = true;
		trans = btrfs_join_transaction_nolock(root, 1);
	} else {
		trans = btrfs_join_transaction(root, 1);
	}
1052
	BUG_ON(!trans);
1053

Y
Yan Zheng 已提交
1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078
	cow_start = (u64)-1;
	cur_offset = start;
	while (1) {
		ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
					       cur_offset, 0);
		BUG_ON(ret < 0);
		if (ret > 0 && path->slots[0] > 0 && check_prev) {
			leaf = path->nodes[0];
			btrfs_item_key_to_cpu(leaf, &found_key,
					      path->slots[0] - 1);
			if (found_key.objectid == inode->i_ino &&
			    found_key.type == BTRFS_EXTENT_DATA_KEY)
				path->slots[0]--;
		}
		check_prev = 0;
next_slot:
		leaf = path->nodes[0];
		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0)
				BUG_ON(1);
			if (ret > 0)
				break;
			leaf = path->nodes[0];
		}
1079

Y
Yan Zheng 已提交
1080 1081
		nocow = 0;
		disk_bytenr = 0;
1082
		num_bytes = 0;
Y
Yan Zheng 已提交
1083 1084 1085 1086 1087 1088 1089 1090 1091
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

		if (found_key.objectid > inode->i_ino ||
		    found_key.type > BTRFS_EXTENT_DATA_KEY ||
		    found_key.offset > end)
			break;

		if (found_key.offset > cur_offset) {
			extent_end = found_key.offset;
1092
			extent_type = 0;
Y
Yan Zheng 已提交
1093 1094 1095 1096 1097 1098 1099
			goto out_check;
		}

		fi = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_file_extent_item);
		extent_type = btrfs_file_extent_type(leaf, fi);

Y
Yan Zheng 已提交
1100 1101
		if (extent_type == BTRFS_FILE_EXTENT_REG ||
		    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
Y
Yan Zheng 已提交
1102
			disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1103
			extent_offset = btrfs_file_extent_offset(leaf, fi);
Y
Yan Zheng 已提交
1104 1105 1106 1107 1108 1109
			extent_end = found_key.offset +
				btrfs_file_extent_num_bytes(leaf, fi);
			if (extent_end <= start) {
				path->slots[0]++;
				goto next_slot;
			}
1110 1111
			if (disk_bytenr == 0)
				goto out_check;
Y
Yan Zheng 已提交
1112 1113 1114 1115
			if (btrfs_file_extent_compression(leaf, fi) ||
			    btrfs_file_extent_encryption(leaf, fi) ||
			    btrfs_file_extent_other_encoding(leaf, fi))
				goto out_check;
Y
Yan Zheng 已提交
1116 1117
			if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
				goto out_check;
1118
			if (btrfs_extent_readonly(root, disk_bytenr))
Y
Yan Zheng 已提交
1119
				goto out_check;
1120
			if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
1121 1122
						  found_key.offset -
						  extent_offset, disk_bytenr))
1123
				goto out_check;
1124
			disk_bytenr += extent_offset;
1125 1126 1127 1128 1129 1130 1131 1132 1133
			disk_bytenr += cur_offset - found_key.offset;
			num_bytes = min(end + 1, extent_end) - cur_offset;
			/*
			 * force cow if csum exists in the range.
			 * this ensure that csum for a given extent are
			 * either valid or do not exist.
			 */
			if (csum_exist_in_range(root, disk_bytenr, num_bytes))
				goto out_check;
Y
Yan Zheng 已提交
1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154
			nocow = 1;
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
			extent_end = found_key.offset +
				btrfs_file_extent_inline_len(leaf, fi);
			extent_end = ALIGN(extent_end, root->sectorsize);
		} else {
			BUG_ON(1);
		}
out_check:
		if (extent_end <= start) {
			path->slots[0]++;
			goto next_slot;
		}
		if (!nocow) {
			if (cow_start == (u64)-1)
				cow_start = cur_offset;
			cur_offset = extent_end;
			if (cur_offset > end)
				break;
			path->slots[0]++;
			goto next_slot;
1155 1156 1157
		}

		btrfs_release_path(root, path);
Y
Yan Zheng 已提交
1158 1159
		if (cow_start != (u64)-1) {
			ret = cow_file_range(inode, locked_page, cow_start,
1160 1161
					found_key.offset - 1, page_started,
					nr_written, 1);
Y
Yan Zheng 已提交
1162 1163
			BUG_ON(ret);
			cow_start = (u64)-1;
1164
		}
Y
Yan Zheng 已提交
1165

Y
Yan Zheng 已提交
1166 1167 1168 1169 1170 1171
		if (extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
			struct extent_map *em;
			struct extent_map_tree *em_tree;
			em_tree = &BTRFS_I(inode)->extent_tree;
			em = alloc_extent_map(GFP_NOFS);
			em->start = cur_offset;
1172
			em->orig_start = em->start;
Y
Yan Zheng 已提交
1173 1174 1175 1176 1177 1178
			em->len = num_bytes;
			em->block_len = num_bytes;
			em->block_start = disk_bytenr;
			em->bdev = root->fs_info->fs_devices->latest_bdev;
			set_bit(EXTENT_FLAG_PINNED, &em->flags);
			while (1) {
1179
				write_lock(&em_tree->lock);
Y
Yan Zheng 已提交
1180
				ret = add_extent_mapping(em_tree, em);
1181
				write_unlock(&em_tree->lock);
Y
Yan Zheng 已提交
1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192
				if (ret != -EEXIST) {
					free_extent_map(em);
					break;
				}
				btrfs_drop_extent_cache(inode, em->start,
						em->start + em->len - 1, 0);
			}
			type = BTRFS_ORDERED_PREALLOC;
		} else {
			type = BTRFS_ORDERED_NOCOW;
		}
Y
Yan Zheng 已提交
1193 1194

		ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
Y
Yan Zheng 已提交
1195 1196
					       num_bytes, num_bytes, type);
		BUG_ON(ret);
1197

1198 1199 1200 1201 1202 1203 1204
		if (root->root_key.objectid ==
		    BTRFS_DATA_RELOC_TREE_OBJECTID) {
			ret = btrfs_reloc_clone_csums(inode, cur_offset,
						      num_bytes);
			BUG_ON(ret);
		}

Y
Yan Zheng 已提交
1205
		extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1206 1207 1208 1209
				cur_offset, cur_offset + num_bytes - 1,
				locked_page, EXTENT_CLEAR_UNLOCK_PAGE |
				EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
				EXTENT_SET_PRIVATE2);
Y
Yan Zheng 已提交
1210 1211 1212
		cur_offset = extent_end;
		if (cur_offset > end)
			break;
1213
	}
Y
Yan Zheng 已提交
1214 1215 1216 1217 1218 1219
	btrfs_release_path(root, path);

	if (cur_offset <= end && cow_start == (u64)-1)
		cow_start = cur_offset;
	if (cow_start != (u64)-1) {
		ret = cow_file_range(inode, locked_page, cow_start, end,
1220
				     page_started, nr_written, 1);
Y
Yan Zheng 已提交
1221 1222 1223
		BUG_ON(ret);
	}

J
Josef Bacik 已提交
1224 1225 1226 1227 1228 1229 1230
	if (nolock) {
		ret = btrfs_end_transaction_nolock(trans, root);
		BUG_ON(ret);
	} else {
		ret = btrfs_end_transaction(trans, root);
		BUG_ON(ret);
	}
1231
	btrfs_free_path(path);
Y
Yan Zheng 已提交
1232
	return 0;
1233 1234
}

C
Chris Mason 已提交
1235 1236 1237
/*
 * extent_io.c call back to do delayed allocation processing
 */
C
Chris Mason 已提交
1238
static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1239 1240
			      u64 start, u64 end, int *page_started,
			      unsigned long *nr_written)
1241 1242
{
	int ret;
1243
	struct btrfs_root *root = BTRFS_I(inode)->root;
1244

1245
	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
C
Chris Mason 已提交
1246
		ret = run_delalloc_nocow(inode, locked_page, start, end,
C
Chris Mason 已提交
1247
					 page_started, 1, nr_written);
1248
	else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
Y
Yan Zheng 已提交
1249
		ret = run_delalloc_nocow(inode, locked_page, start, end,
C
Chris Mason 已提交
1250
					 page_started, 0, nr_written);
C
Chris Mason 已提交
1251 1252
	else if (!btrfs_test_opt(root, COMPRESS) &&
		 !(BTRFS_I(inode)->force_compress))
1253 1254
		ret = cow_file_range(inode, locked_page, start, end,
				      page_started, nr_written, 1);
1255
	else
1256
		ret = cow_file_range_async(inode, locked_page, start, end,
C
Chris Mason 已提交
1257
					   page_started, nr_written);
1258 1259 1260
	return ret;
}

J
Josef Bacik 已提交
1261
static int btrfs_split_extent_hook(struct inode *inode,
1262
				   struct extent_state *orig, u64 split)
J
Josef Bacik 已提交
1263
{
1264
	/* not delalloc, ignore it */
J
Josef Bacik 已提交
1265 1266 1267
	if (!(orig->state & EXTENT_DELALLOC))
		return 0;

1268
	atomic_inc(&BTRFS_I(inode)->outstanding_extents);
J
Josef Bacik 已提交
1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285
	return 0;
}

/*
 * extent_io.c merge_extent_hook, used to track merged delayed allocation
 * extents so we can keep track of new extents that are just merged onto old
 * extents, such as when we are doing sequential writes, so we can properly
 * account for the metadata space we'll need.
 */
static int btrfs_merge_extent_hook(struct inode *inode,
				   struct extent_state *new,
				   struct extent_state *other)
{
	/* not delalloc, ignore it */
	if (!(other->state & EXTENT_DELALLOC))
		return 0;

1286
	atomic_dec(&BTRFS_I(inode)->outstanding_extents);
J
Josef Bacik 已提交
1287 1288 1289
	return 0;
}

C
Chris Mason 已提交
1290 1291 1292 1293 1294
/*
 * extent_io.c set_bit_hook, used to track delayed allocation
 * bytes in this file, and to maintain the list of inodes that
 * have pending delalloc work to be done.
 */
1295 1296
static int btrfs_set_bit_hook(struct inode *inode,
			      struct extent_state *state, int *bits)
1297
{
J
Josef Bacik 已提交
1298

1299 1300 1301 1302 1303
	/*
	 * set_bit and clear bit hooks normally require _irqsave/restore
	 * but in this case, we are only testeing for the DELALLOC
	 * bit, which is only set or cleared with irqs on
	 */
1304
	if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1305
		struct btrfs_root *root = BTRFS_I(inode)->root;
1306
		u64 len = state->end + 1 - state->start;
J
Josef Bacik 已提交
1307 1308
		int do_list = (root->root_key.objectid !=
			       BTRFS_ROOT_TREE_OBJECTID);
J
Josef Bacik 已提交
1309

1310 1311 1312 1313
		if (*bits & EXTENT_FIRST_DELALLOC)
			*bits &= ~EXTENT_FIRST_DELALLOC;
		else
			atomic_inc(&BTRFS_I(inode)->outstanding_extents);
1314

1315
		spin_lock(&root->fs_info->delalloc_lock);
1316 1317
		BTRFS_I(inode)->delalloc_bytes += len;
		root->fs_info->delalloc_bytes += len;
J
Josef Bacik 已提交
1318
		if (do_list && list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
1319 1320 1321
			list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
				      &root->fs_info->delalloc_inodes);
		}
1322
		spin_unlock(&root->fs_info->delalloc_lock);
1323 1324 1325 1326
	}
	return 0;
}

C
Chris Mason 已提交
1327 1328 1329
/*
 * extent_io.c clear_bit_hook, see set_bit_hook for why
 */
J
Josef Bacik 已提交
1330
static int btrfs_clear_bit_hook(struct inode *inode,
1331
				struct extent_state *state, int *bits)
1332
{
1333 1334 1335 1336 1337
	/*
	 * set_bit and clear bit hooks normally require _irqsave/restore
	 * but in this case, we are only testeing for the DELALLOC
	 * bit, which is only set or cleared with irqs on
	 */
1338
	if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1339
		struct btrfs_root *root = BTRFS_I(inode)->root;
1340
		u64 len = state->end + 1 - state->start;
J
Josef Bacik 已提交
1341 1342
		int do_list = (root->root_key.objectid !=
			       BTRFS_ROOT_TREE_OBJECTID);
1343

1344 1345 1346 1347 1348 1349 1350 1351
		if (*bits & EXTENT_FIRST_DELALLOC)
			*bits &= ~EXTENT_FIRST_DELALLOC;
		else if (!(*bits & EXTENT_DO_ACCOUNTING))
			atomic_dec(&BTRFS_I(inode)->outstanding_extents);

		if (*bits & EXTENT_DO_ACCOUNTING)
			btrfs_delalloc_release_metadata(inode, len);

J
Josef Bacik 已提交
1352 1353
		if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID
		    && do_list)
1354
			btrfs_free_reserved_data_space(inode, len);
J
Josef Bacik 已提交
1355

1356
		spin_lock(&root->fs_info->delalloc_lock);
1357 1358 1359
		root->fs_info->delalloc_bytes -= len;
		BTRFS_I(inode)->delalloc_bytes -= len;

J
Josef Bacik 已提交
1360
		if (do_list && BTRFS_I(inode)->delalloc_bytes == 0 &&
1361 1362 1363
		    !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
			list_del_init(&BTRFS_I(inode)->delalloc_inodes);
		}
1364
		spin_unlock(&root->fs_info->delalloc_lock);
1365 1366 1367 1368
	}
	return 0;
}

C
Chris Mason 已提交
1369 1370 1371 1372
/*
 * extent_io.c merge_bio_hook, this must check the chunk tree to make sure
 * we don't create bios that span stripes or chunks
 */
1373
int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
C
Chris Mason 已提交
1374 1375
			 size_t size, struct bio *bio,
			 unsigned long bio_flags)
1376 1377 1378
{
	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
	struct btrfs_mapping_tree *map_tree;
1379
	u64 logical = (u64)bio->bi_sector << 9;
1380 1381 1382 1383
	u64 length = 0;
	u64 map_length;
	int ret;

1384 1385 1386
	if (bio_flags & EXTENT_BIO_COMPRESSED)
		return 0;

1387
	length = bio->bi_size;
1388 1389
	map_tree = &root->fs_info->mapping_tree;
	map_length = length;
1390
	ret = btrfs_map_block(map_tree, READ, logical,
1391
			      &map_length, NULL, 0);
1392

C
Chris Mason 已提交
1393
	if (map_length < length + size)
1394
		return 1;
1395
	return ret;
1396 1397
}

C
Chris Mason 已提交
1398 1399 1400 1401 1402 1403 1404 1405
/*
 * in order to insert checksums into the metadata in large chunks,
 * we wait until bio submission time.   All the pages in the bio are
 * checksummed and sums are attached onto the ordered extent record.
 *
 * At IO completion time the cums attached on the ordered extent record
 * are inserted into the btree
 */
C
Chris Mason 已提交
1406 1407
static int __btrfs_submit_bio_start(struct inode *inode, int rw,
				    struct bio *bio, int mirror_num,
1408 1409
				    unsigned long bio_flags,
				    u64 bio_offset)
1410 1411 1412
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret = 0;
1413

1414
	ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1415
	BUG_ON(ret);
C
Chris Mason 已提交
1416 1417
	return 0;
}
1418

C
Chris Mason 已提交
1419 1420 1421 1422 1423 1424 1425 1426
/*
 * in order to insert checksums into the metadata in large chunks,
 * we wait until bio submission time.   All the pages in the bio are
 * checksummed and sums are attached onto the ordered extent record.
 *
 * At IO completion time the cums attached on the ordered extent record
 * are inserted into the btree
 */
1427
static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1428 1429
			  int mirror_num, unsigned long bio_flags,
			  u64 bio_offset)
C
Chris Mason 已提交
1430 1431
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1432
	return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1433 1434
}

C
Chris Mason 已提交
1435
/*
1436 1437
 * extent_io.c submission hook. This does the right thing for csum calculation
 * on write, or reading the csums from the tree before a read
C
Chris Mason 已提交
1438
 */
1439
static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1440 1441
			  int mirror_num, unsigned long bio_flags,
			  u64 bio_offset)
1442 1443 1444
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret = 0;
1445
	int skip_sum;
1446

1447
	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1448

J
Josef Bacik 已提交
1449 1450 1451 1452
	if (root == root->fs_info->tree_root)
		ret = btrfs_bio_wq_end_io(root->fs_info, bio, 2);
	else
		ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
1453
	BUG_ON(ret);
1454

1455
	if (!(rw & REQ_WRITE)) {
1456
		if (bio_flags & EXTENT_BIO_COMPRESSED) {
C
Chris Mason 已提交
1457 1458
			return btrfs_submit_compressed_read(inode, bio,
						    mirror_num, bio_flags);
1459 1460
		} else if (!skip_sum)
			btrfs_lookup_bio_sums(root, inode, bio, NULL);
1461
		goto mapit;
1462
	} else if (!skip_sum) {
1463 1464 1465
		/* csum items have already been cloned */
		if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
			goto mapit;
1466 1467
		/* we're doing a write, do the async checksumming */
		return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1468
				   inode, rw, bio, mirror_num,
1469 1470
				   bio_flags, bio_offset,
				   __btrfs_submit_bio_start,
C
Chris Mason 已提交
1471
				   __btrfs_submit_bio_done);
1472 1473
	}

1474
mapit:
1475
	return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1476
}
C
Chris Mason 已提交
1477

C
Chris Mason 已提交
1478 1479 1480 1481
/*
 * given a list of ordered sums record them in the inode.  This happens
 * at IO completion time based on sums calculated at bio submission time.
 */
1482
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1483 1484 1485 1486 1487 1488
			     struct inode *inode, u64 file_offset,
			     struct list_head *list)
{
	struct btrfs_ordered_sum *sum;

	btrfs_set_trans_block_group(trans, inode);
Q
Qinghuang Feng 已提交
1489 1490

	list_for_each_entry(sum, list, list) {
1491 1492
		btrfs_csum_file_blocks(trans,
		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
1493 1494 1495 1496
	}
	return 0;
}

1497 1498
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
			      struct extent_state **cached_state)
1499
{
C
Chris Mason 已提交
1500
	if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1501
		WARN_ON(1);
1502
	return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1503
				   cached_state, GFP_NOFS);
1504 1505
}

C
Chris Mason 已提交
1506
/* see btrfs_writepage_start_hook for details on why this is required */
1507 1508 1509 1510 1511
struct btrfs_writepage_fixup {
	struct page *page;
	struct btrfs_work work;
};

1512
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1513 1514 1515
{
	struct btrfs_writepage_fixup *fixup;
	struct btrfs_ordered_extent *ordered;
1516
	struct extent_state *cached_state = NULL;
1517 1518 1519 1520 1521 1522 1523
	struct page *page;
	struct inode *inode;
	u64 page_start;
	u64 page_end;

	fixup = container_of(work, struct btrfs_writepage_fixup, work);
	page = fixup->page;
C
Chris Mason 已提交
1524
again:
1525 1526 1527 1528 1529 1530 1531 1532 1533 1534
	lock_page(page);
	if (!page->mapping || !PageDirty(page) || !PageChecked(page)) {
		ClearPageChecked(page);
		goto out_page;
	}

	inode = page->mapping->host;
	page_start = page_offset(page);
	page_end = page_offset(page) + PAGE_CACHE_SIZE - 1;

1535 1536
	lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
			 &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1537 1538

	/* already ordered? We're done */
1539
	if (PagePrivate2(page))
1540
		goto out;
C
Chris Mason 已提交
1541 1542 1543

	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
1544 1545
		unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
				     page_end, &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1546 1547 1548 1549
		unlock_page(page);
		btrfs_start_ordered_extent(inode, ordered, 1);
		goto again;
	}
1550

1551
	BUG();
1552
	btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1553 1554
	ClearPageChecked(page);
out:
1555 1556
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
			     &cached_state, GFP_NOFS);
1557 1558 1559
out_page:
	unlock_page(page);
	page_cache_release(page);
1560
	kfree(fixup);
1561 1562 1563 1564 1565 1566 1567 1568
}

/*
 * There are a few paths in the higher layers of the kernel that directly
 * set the page dirty bit without asking the filesystem if it is a
 * good idea.  This causes problems because we want to make sure COW
 * properly happens and the data=ordered rules are followed.
 *
C
Chris Mason 已提交
1569
 * In our case any range that doesn't have the ORDERED bit set
1570 1571 1572 1573
 * hasn't been properly setup for IO.  We kick off an async process
 * to fix it up.  The async helper will wait for ordered extents, set
 * the delalloc bit and make it safe to write the page.
 */
1574
static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1575 1576 1577 1578 1579
{
	struct inode *inode = page->mapping->host;
	struct btrfs_writepage_fixup *fixup;
	struct btrfs_root *root = BTRFS_I(inode)->root;

1580 1581
	/* this page is properly in the ordered list */
	if (TestClearPagePrivate2(page))
1582 1583 1584 1585 1586 1587 1588 1589
		return 0;

	if (PageChecked(page))
		return -EAGAIN;

	fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
	if (!fixup)
		return -EAGAIN;
1590

1591 1592 1593 1594 1595 1596 1597 1598
	SetPageChecked(page);
	page_cache_get(page);
	fixup->work.func = btrfs_writepage_fixup_worker;
	fixup->page = page;
	btrfs_queue_worker(&root->fs_info->fixup_workers, &fixup->work);
	return -EAGAIN;
}

Y
Yan Zheng 已提交
1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616
static int insert_reserved_file_extent(struct btrfs_trans_handle *trans,
				       struct inode *inode, u64 file_pos,
				       u64 disk_bytenr, u64 disk_num_bytes,
				       u64 num_bytes, u64 ram_bytes,
				       u8 compression, u8 encryption,
				       u16 other_encoding, int extent_type)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_file_extent_item *fi;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key ins;
	u64 hint;
	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);

1617
	path->leave_spinning = 1;
C
Chris Mason 已提交
1618 1619 1620 1621 1622 1623 1624 1625 1626 1627

	/*
	 * we may be replacing one extent in the tree with another.
	 * The new extent is pinned in the extent map, and we don't want
	 * to drop it from the cache until it is completely in the btree.
	 *
	 * So, tell btrfs_drop_extents to leave this extent in the cache.
	 * the caller is expected to unpin it and allow it to be merged
	 * with the others.
	 */
Y
Yan, Zheng 已提交
1628 1629
	ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
				 &hint, 0);
Y
Yan Zheng 已提交
1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649
	BUG_ON(ret);

	ins.objectid = inode->i_ino;
	ins.offset = file_pos;
	ins.type = BTRFS_EXTENT_DATA_KEY;
	ret = btrfs_insert_empty_item(trans, root, path, &ins, sizeof(*fi));
	BUG_ON(ret);
	leaf = path->nodes[0];
	fi = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
	btrfs_set_file_extent_generation(leaf, fi, trans->transid);
	btrfs_set_file_extent_type(leaf, fi, extent_type);
	btrfs_set_file_extent_disk_bytenr(leaf, fi, disk_bytenr);
	btrfs_set_file_extent_disk_num_bytes(leaf, fi, disk_num_bytes);
	btrfs_set_file_extent_offset(leaf, fi, 0);
	btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
	btrfs_set_file_extent_ram_bytes(leaf, fi, ram_bytes);
	btrfs_set_file_extent_compression(leaf, fi, compression);
	btrfs_set_file_extent_encryption(leaf, fi, encryption);
	btrfs_set_file_extent_other_encoding(leaf, fi, other_encoding);
1650 1651 1652 1653

	btrfs_unlock_up_safe(path, 1);
	btrfs_set_lock_blocking(leaf);

Y
Yan Zheng 已提交
1654 1655 1656 1657 1658 1659 1660
	btrfs_mark_buffer_dirty(leaf);

	inode_add_bytes(inode, num_bytes);

	ins.objectid = disk_bytenr;
	ins.offset = disk_num_bytes;
	ins.type = BTRFS_EXTENT_ITEM_KEY;
1661 1662 1663
	ret = btrfs_alloc_reserved_file_extent(trans, root,
					root->root_key.objectid,
					inode->i_ino, file_pos, &ins);
Y
Yan Zheng 已提交
1664 1665
	BUG_ON(ret);
	btrfs_free_path(path);
1666

Y
Yan Zheng 已提交
1667 1668 1669
	return 0;
}

1670 1671 1672 1673 1674 1675
/*
 * helper function for btrfs_finish_ordered_io, this
 * just reads in some of the csum leaves to prime them into ram
 * before we start the transaction.  It limits the amount of btree
 * reads required while inside the transaction.
 */
C
Chris Mason 已提交
1676 1677 1678 1679
/* as ordered data IO finishes, this gets called so we can finish
 * an ordered extent if the range of bytes in the file it covers are
 * fully written.
 */
1680
static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1681 1682
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1683
	struct btrfs_trans_handle *trans = NULL;
1684
	struct btrfs_ordered_extent *ordered_extent = NULL;
1685
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1686
	struct extent_state *cached_state = NULL;
1687
	int compress_type = 0;
1688
	int ret;
J
Josef Bacik 已提交
1689
	bool nolock = false;
1690

1691 1692
	ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
					     end - start + 1);
1693
	if (!ret)
1694 1695
		return 0;
	BUG_ON(!ordered_extent);
1696

J
Josef Bacik 已提交
1697 1698
	nolock = (root == root->fs_info->tree_root);

1699 1700 1701 1702
	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered_extent->flags)) {
		BUG_ON(!list_empty(&ordered_extent->list));
		ret = btrfs_ordered_update_i_size(inode, 0, ordered_extent);
		if (!ret) {
J
Josef Bacik 已提交
1703 1704 1705 1706 1707
			if (nolock)
				trans = btrfs_join_transaction_nolock(root, 1);
			else
				trans = btrfs_join_transaction(root, 1);
			BUG_ON(!trans);
1708 1709
			btrfs_set_trans_block_group(trans, inode);
			trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1710 1711 1712 1713 1714
			ret = btrfs_update_inode(trans, root, inode);
			BUG_ON(ret);
		}
		goto out;
	}
1715

1716 1717 1718
	lock_extent_bits(io_tree, ordered_extent->file_offset,
			 ordered_extent->file_offset + ordered_extent->len - 1,
			 0, &cached_state, GFP_NOFS);
1719

J
Josef Bacik 已提交
1720 1721 1722 1723
	if (nolock)
		trans = btrfs_join_transaction_nolock(root, 1);
	else
		trans = btrfs_join_transaction(root, 1);
1724 1725
	btrfs_set_trans_block_group(trans, inode);
	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1726

C
Chris Mason 已提交
1727
	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
1728
		compress_type = ordered_extent->compress_type;
Y
Yan Zheng 已提交
1729
	if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
1730
		BUG_ON(compress_type);
Y
Yan, Zheng 已提交
1731
		ret = btrfs_mark_extent_written(trans, inode,
Y
Yan Zheng 已提交
1732 1733 1734 1735 1736
						ordered_extent->file_offset,
						ordered_extent->file_offset +
						ordered_extent->len);
		BUG_ON(ret);
	} else {
1737
		BUG_ON(root == root->fs_info->tree_root);
Y
Yan Zheng 已提交
1738 1739 1740 1741 1742 1743
		ret = insert_reserved_file_extent(trans, inode,
						ordered_extent->file_offset,
						ordered_extent->start,
						ordered_extent->disk_len,
						ordered_extent->len,
						ordered_extent->len,
1744
						compress_type, 0, 0,
Y
Yan Zheng 已提交
1745
						BTRFS_FILE_EXTENT_REG);
C
Chris Mason 已提交
1746 1747 1748
		unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
				   ordered_extent->file_offset,
				   ordered_extent->len);
Y
Yan Zheng 已提交
1749 1750
		BUG_ON(ret);
	}
1751 1752 1753 1754
	unlock_extent_cached(io_tree, ordered_extent->file_offset,
			     ordered_extent->file_offset +
			     ordered_extent->len - 1, &cached_state, GFP_NOFS);

1755 1756 1757
	add_pending_csums(trans, inode, ordered_extent->file_offset,
			  &ordered_extent->list);

1758 1759 1760 1761
	btrfs_ordered_update_i_size(inode, 0, ordered_extent);
	ret = btrfs_update_inode(trans, root, inode);
	BUG_ON(ret);
out:
J
Josef Bacik 已提交
1762 1763 1764 1765 1766 1767 1768 1769 1770
	if (nolock) {
		if (trans)
			btrfs_end_transaction_nolock(trans, root);
	} else {
		btrfs_delalloc_release_metadata(inode, ordered_extent->len);
		if (trans)
			btrfs_end_transaction(trans, root);
	}

1771 1772 1773 1774 1775 1776 1777 1778
	/* once for us */
	btrfs_put_ordered_extent(ordered_extent);
	/* once for the tree */
	btrfs_put_ordered_extent(ordered_extent);

	return 0;
}

1779
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1780 1781
				struct extent_state *state, int uptodate)
{
1782
	ClearPagePrivate2(page);
1783 1784 1785
	return btrfs_finish_ordered_io(page->mapping->host, start, end);
}

C
Chris Mason 已提交
1786 1787 1788 1789 1790 1791 1792 1793
/*
 * When IO fails, either with EIO or csum verification fails, we
 * try other mirrors that might have a good copy of the data.  This
 * io_failure_record is used to record state as we go through all the
 * mirrors.  If another mirror has good data, the page is set up to date
 * and things continue.  If a good mirror can't be found, the original
 * bio end_io callback is called to indicate things have failed.
 */
1794 1795 1796 1797 1798
struct io_failure_record {
	struct page *page;
	u64 start;
	u64 len;
	u64 logical;
1799
	unsigned long bio_flags;
1800 1801 1802
	int last_mirror;
};

1803
static int btrfs_io_failed_hook(struct bio *failed_bio,
1804 1805
			 struct page *page, u64 start, u64 end,
			 struct extent_state *state)
1806 1807 1808 1809 1810 1811
{
	struct io_failure_record *failrec = NULL;
	u64 private;
	struct extent_map *em;
	struct inode *inode = page->mapping->host;
	struct extent_io_tree *failure_tree = &BTRFS_I(inode)->io_failure_tree;
1812
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1813 1814 1815
	struct bio *bio;
	int num_copies;
	int ret;
1816
	int rw;
1817 1818 1819 1820 1821 1822 1823 1824 1825 1826
	u64 logical;

	ret = get_state_private(failure_tree, start, &private);
	if (ret) {
		failrec = kmalloc(sizeof(*failrec), GFP_NOFS);
		if (!failrec)
			return -ENOMEM;
		failrec->start = start;
		failrec->len = end - start + 1;
		failrec->last_mirror = 0;
1827
		failrec->bio_flags = 0;
1828

1829
		read_lock(&em_tree->lock);
1830 1831 1832 1833 1834
		em = lookup_extent_mapping(em_tree, start, failrec->len);
		if (em->start > start || em->start + em->len < start) {
			free_extent_map(em);
			em = NULL;
		}
1835
		read_unlock(&em_tree->lock);
1836 1837 1838 1839 1840 1841 1842

		if (!em || IS_ERR(em)) {
			kfree(failrec);
			return -EIO;
		}
		logical = start - em->start;
		logical = em->block_start + logical;
1843 1844 1845
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
			logical = em->block_start;
			failrec->bio_flags = EXTENT_BIO_COMPRESSED;
1846 1847
			extent_set_compress_type(&failrec->bio_flags,
						 em->compress_type);
1848
		}
1849 1850 1851 1852
		failrec->logical = logical;
		free_extent_map(em);
		set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
				EXTENT_DIRTY, GFP_NOFS);
1853 1854
		set_state_private(failure_tree, start,
				 (u64)(unsigned long)failrec);
1855
	} else {
1856
		failrec = (struct io_failure_record *)(unsigned long)private;
1857 1858 1859 1860 1861 1862
	}
	num_copies = btrfs_num_copies(
			      &BTRFS_I(inode)->root->fs_info->mapping_tree,
			      failrec->logical, failrec->len);
	failrec->last_mirror++;
	if (!state) {
1863
		spin_lock(&BTRFS_I(inode)->io_tree.lock);
1864 1865 1866 1867 1868
		state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
						    failrec->start,
						    EXTENT_LOCKED);
		if (state && state->start != failrec->start)
			state = NULL;
1869
		spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
	}
	if (!state || failrec->last_mirror > num_copies) {
		set_state_private(failure_tree, failrec->start, 0);
		clear_extent_bits(failure_tree, failrec->start,
				  failrec->start + failrec->len - 1,
				  EXTENT_LOCKED | EXTENT_DIRTY, GFP_NOFS);
		kfree(failrec);
		return -EIO;
	}
	bio = bio_alloc(GFP_NOFS, 1);
	bio->bi_private = state;
	bio->bi_end_io = failed_bio->bi_end_io;
	bio->bi_sector = failrec->logical >> 9;
	bio->bi_bdev = failed_bio->bi_bdev;
1884
	bio->bi_size = 0;
1885

1886
	bio_add_page(bio, page, failrec->len, start - page_offset(page));
1887
	if (failed_bio->bi_rw & REQ_WRITE)
1888 1889 1890 1891 1892
		rw = WRITE;
	else
		rw = READ;

	BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
C
Chris Mason 已提交
1893
						      failrec->last_mirror,
1894
						      failrec->bio_flags, 0);
1895 1896 1897
	return 0;
}

C
Chris Mason 已提交
1898 1899 1900 1901
/*
 * each time an IO finishes, we do a fast check in the IO failure tree
 * to see if we need to process or clean up an io_failure_record
 */
1902
static int btrfs_clean_io_failures(struct inode *inode, u64 start)
1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926
{
	u64 private;
	u64 private_failure;
	struct io_failure_record *failure;
	int ret;

	private = 0;
	if (count_range_bits(&BTRFS_I(inode)->io_failure_tree, &private,
			     (u64)-1, 1, EXTENT_DIRTY)) {
		ret = get_state_private(&BTRFS_I(inode)->io_failure_tree,
					start, &private_failure);
		if (ret == 0) {
			failure = (struct io_failure_record *)(unsigned long)
				   private_failure;
			set_state_private(&BTRFS_I(inode)->io_failure_tree,
					  failure->start, 0);
			clear_extent_bits(&BTRFS_I(inode)->io_failure_tree,
					  failure->start,
					  failure->start + failure->len - 1,
					  EXTENT_DIRTY | EXTENT_LOCKED,
					  GFP_NOFS);
			kfree(failure);
		}
	}
1927 1928 1929
	return 0;
}

C
Chris Mason 已提交
1930 1931 1932 1933 1934
/*
 * when reads are done, we need to check csums to verify the data is correct
 * if there's a match, we allow the bio to finish.  If not, we go through
 * the io_failure_record routines to find good copies
 */
1935
static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1936
			       struct extent_state *state)
1937
{
1938
	size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1939
	struct inode *inode = page->mapping->host;
1940
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1941
	char *kaddr;
1942
	u64 private = ~(u32)0;
1943
	int ret;
1944 1945
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u32 csum = ~(u32)0;
1946

1947 1948 1949 1950
	if (PageChecked(page)) {
		ClearPageChecked(page);
		goto good;
	}
1951 1952

	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1953 1954 1955
		return 0;

	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1956
	    test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1957 1958
		clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
				  GFP_NOFS);
1959
		return 0;
1960
	}
1961

Y
Yan 已提交
1962
	if (state && state->start == start) {
1963 1964 1965 1966 1967
		private = state->private;
		ret = 0;
	} else {
		ret = get_state_private(io_tree, start, &private);
	}
1968
	kaddr = kmap_atomic(page, KM_USER0);
C
Chris Mason 已提交
1969
	if (ret)
1970
		goto zeroit;
C
Chris Mason 已提交
1971

1972 1973
	csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
	btrfs_csum_final(csum, (char *)&csum);
C
Chris Mason 已提交
1974
	if (csum != private)
1975
		goto zeroit;
C
Chris Mason 已提交
1976

1977
	kunmap_atomic(kaddr, KM_USER0);
1978
good:
1979 1980 1981
	/* if the io failure tree for this inode is non-empty,
	 * check to see if we've recovered from a failed IO
	 */
1982
	btrfs_clean_io_failures(inode, start);
1983 1984 1985
	return 0;

zeroit:
C
Chris Mason 已提交
1986 1987 1988 1989 1990 1991
	if (printk_ratelimit()) {
		printk(KERN_INFO "btrfs csum failed ino %lu off %llu csum %u "
		       "private %llu\n", page->mapping->host->i_ino,
		       (unsigned long long)start, csum,
		       (unsigned long long)private);
	}
1992 1993
	memset(kaddr + offset, 1, end - start + 1);
	flush_dcache_page(page);
1994
	kunmap_atomic(kaddr, KM_USER0);
1995 1996
	if (private == 0)
		return 0;
1997
	return -EIO;
1998
}
1999

Y
Yan, Zheng 已提交
2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047
struct delayed_iput {
	struct list_head list;
	struct inode *inode;
};

void btrfs_add_delayed_iput(struct inode *inode)
{
	struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
	struct delayed_iput *delayed;

	if (atomic_add_unless(&inode->i_count, -1, 1))
		return;

	delayed = kmalloc(sizeof(*delayed), GFP_NOFS | __GFP_NOFAIL);
	delayed->inode = inode;

	spin_lock(&fs_info->delayed_iput_lock);
	list_add_tail(&delayed->list, &fs_info->delayed_iputs);
	spin_unlock(&fs_info->delayed_iput_lock);
}

void btrfs_run_delayed_iputs(struct btrfs_root *root)
{
	LIST_HEAD(list);
	struct btrfs_fs_info *fs_info = root->fs_info;
	struct delayed_iput *delayed;
	int empty;

	spin_lock(&fs_info->delayed_iput_lock);
	empty = list_empty(&fs_info->delayed_iputs);
	spin_unlock(&fs_info->delayed_iput_lock);
	if (empty)
		return;

	down_read(&root->fs_info->cleanup_work_sem);
	spin_lock(&fs_info->delayed_iput_lock);
	list_splice_init(&fs_info->delayed_iputs, &list);
	spin_unlock(&fs_info->delayed_iput_lock);

	while (!list_empty(&list)) {
		delayed = list_entry(list.next, struct delayed_iput, list);
		list_del(&delayed->list);
		iput(delayed->inode);
		kfree(delayed);
	}
	up_read(&root->fs_info->cleanup_work_sem);
}

2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164
/*
 * calculate extra metadata reservation when snapshotting a subvolume
 * contains orphan files.
 */
void btrfs_orphan_pre_snapshot(struct btrfs_trans_handle *trans,
				struct btrfs_pending_snapshot *pending,
				u64 *bytes_to_reserve)
{
	struct btrfs_root *root;
	struct btrfs_block_rsv *block_rsv;
	u64 num_bytes;
	int index;

	root = pending->root;
	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
		return;

	block_rsv = root->orphan_block_rsv;

	/* orphan block reservation for the snapshot */
	num_bytes = block_rsv->size;

	/*
	 * after the snapshot is created, COWing tree blocks may use more
	 * space than it frees. So we should make sure there is enough
	 * reserved space.
	 */
	index = trans->transid & 0x1;
	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
		num_bytes += block_rsv->size -
			     (block_rsv->reserved + block_rsv->freed[index]);
	}

	*bytes_to_reserve += num_bytes;
}

void btrfs_orphan_post_snapshot(struct btrfs_trans_handle *trans,
				struct btrfs_pending_snapshot *pending)
{
	struct btrfs_root *root = pending->root;
	struct btrfs_root *snap = pending->snap;
	struct btrfs_block_rsv *block_rsv;
	u64 num_bytes;
	int index;
	int ret;

	if (!root->orphan_block_rsv || list_empty(&root->orphan_list))
		return;

	/* refill source subvolume's orphan block reservation */
	block_rsv = root->orphan_block_rsv;
	index = trans->transid & 0x1;
	if (block_rsv->reserved + block_rsv->freed[index] < block_rsv->size) {
		num_bytes = block_rsv->size -
			    (block_rsv->reserved + block_rsv->freed[index]);
		ret = btrfs_block_rsv_migrate(&pending->block_rsv,
					      root->orphan_block_rsv,
					      num_bytes);
		BUG_ON(ret);
	}

	/* setup orphan block reservation for the snapshot */
	block_rsv = btrfs_alloc_block_rsv(snap);
	BUG_ON(!block_rsv);

	btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
	snap->orphan_block_rsv = block_rsv;

	num_bytes = root->orphan_block_rsv->size;
	ret = btrfs_block_rsv_migrate(&pending->block_rsv,
				      block_rsv, num_bytes);
	BUG_ON(ret);

#if 0
	/* insert orphan item for the snapshot */
	WARN_ON(!root->orphan_item_inserted);
	ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
				       snap->root_key.objectid);
	BUG_ON(ret);
	snap->orphan_item_inserted = 1;
#endif
}

enum btrfs_orphan_cleanup_state {
	ORPHAN_CLEANUP_STARTED	= 1,
	ORPHAN_CLEANUP_DONE	= 2,
};

/*
 * This is called in transaction commmit time. If there are no orphan
 * files in the subvolume, it removes orphan item and frees block_rsv
 * structure.
 */
void btrfs_orphan_commit_root(struct btrfs_trans_handle *trans,
			      struct btrfs_root *root)
{
	int ret;

	if (!list_empty(&root->orphan_list) ||
	    root->orphan_cleanup_state != ORPHAN_CLEANUP_DONE)
		return;

	if (root->orphan_item_inserted &&
	    btrfs_root_refs(&root->root_item) > 0) {
		ret = btrfs_del_orphan_item(trans, root->fs_info->tree_root,
					    root->root_key.objectid);
		BUG_ON(ret);
		root->orphan_item_inserted = 0;
	}

	if (root->orphan_block_rsv) {
		WARN_ON(root->orphan_block_rsv->size > 0);
		btrfs_free_block_rsv(root, root->orphan_block_rsv);
		root->orphan_block_rsv = NULL;
	}
}

2165 2166 2167
/*
 * This creates an orphan entry for the given inode in case something goes
 * wrong in the middle of an unlink/truncate.
2168 2169 2170
 *
 * NOTE: caller of this function should reserve 5 units of metadata for
 *	 this function.
2171 2172 2173 2174
 */
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
2175 2176 2177 2178
	struct btrfs_block_rsv *block_rsv = NULL;
	int reserve = 0;
	int insert = 0;
	int ret;
2179

2180 2181 2182 2183
	if (!root->orphan_block_rsv) {
		block_rsv = btrfs_alloc_block_rsv(root);
		BUG_ON(!block_rsv);
	}
2184

2185 2186 2187 2188 2189 2190
	spin_lock(&root->orphan_lock);
	if (!root->orphan_block_rsv) {
		root->orphan_block_rsv = block_rsv;
	} else if (block_rsv) {
		btrfs_free_block_rsv(root, block_rsv);
		block_rsv = NULL;
2191 2192
	}

2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208
	if (list_empty(&BTRFS_I(inode)->i_orphan)) {
		list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
#if 0
		/*
		 * For proper ENOSPC handling, we should do orphan
		 * cleanup when mounting. But this introduces backward
		 * compatibility issue.
		 */
		if (!xchg(&root->orphan_item_inserted, 1))
			insert = 2;
		else
			insert = 1;
#endif
		insert = 1;
	} else {
		WARN_ON(!BTRFS_I(inode)->orphan_meta_reserved);
2209 2210
	}

2211 2212 2213 2214 2215
	if (!BTRFS_I(inode)->orphan_meta_reserved) {
		BTRFS_I(inode)->orphan_meta_reserved = 1;
		reserve = 1;
	}
	spin_unlock(&root->orphan_lock);
2216

2217 2218
	if (block_rsv)
		btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2219

2220 2221 2222 2223 2224
	/* grab metadata reservation from transaction handle */
	if (reserve) {
		ret = btrfs_orphan_reserve_metadata(trans, inode);
		BUG_ON(ret);
	}
2225

2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238
	/* insert an orphan item to track this unlinked/truncated file */
	if (insert >= 1) {
		ret = btrfs_insert_orphan_item(trans, root, inode->i_ino);
		BUG_ON(ret);
	}

	/* insert an orphan item to track subvolume contains orphan files */
	if (insert >= 2) {
		ret = btrfs_insert_orphan_item(trans, root->fs_info->tree_root,
					       root->root_key.objectid);
		BUG_ON(ret);
	}
	return 0;
2239 2240 2241 2242 2243 2244 2245 2246 2247
}

/*
 * We have done the truncate/delete so we can go ahead and remove the orphan
 * item for this particular inode.
 */
int btrfs_orphan_del(struct btrfs_trans_handle *trans, struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
2248 2249
	int delete_item = 0;
	int release_rsv = 0;
2250 2251
	int ret = 0;

2252 2253 2254 2255
	spin_lock(&root->orphan_lock);
	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
		list_del_init(&BTRFS_I(inode)->i_orphan);
		delete_item = 1;
2256 2257
	}

2258 2259 2260
	if (BTRFS_I(inode)->orphan_meta_reserved) {
		BTRFS_I(inode)->orphan_meta_reserved = 0;
		release_rsv = 1;
2261
	}
2262
	spin_unlock(&root->orphan_lock);
2263

2264 2265 2266 2267
	if (trans && delete_item) {
		ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
		BUG_ON(ret);
	}
2268

2269 2270
	if (release_rsv)
		btrfs_orphan_release_metadata(inode);
2271

2272
	return 0;
2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287
}

/*
 * this cleans up any orphans that may be left on the list from the last use
 * of this root.
 */
void btrfs_orphan_cleanup(struct btrfs_root *root)
{
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_key key, found_key;
	struct btrfs_trans_handle *trans;
	struct inode *inode;
	int ret = 0, nr_unlink = 0, nr_truncate = 0;

2288
	if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2289
		return;
2290 2291 2292

	path = btrfs_alloc_path();
	BUG_ON(!path);
2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335
	path->reada = -1;

	key.objectid = BTRFS_ORPHAN_OBJECTID;
	btrfs_set_key_type(&key, BTRFS_ORPHAN_ITEM_KEY);
	key.offset = (u64)-1;

	while (1) {
		ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
		if (ret < 0) {
			printk(KERN_ERR "Error searching slot for orphan: %d"
			       "\n", ret);
			break;
		}

		/*
		 * if ret == 0 means we found what we were searching for, which
		 * is weird, but possible, so only screw with path if we didnt
		 * find the key and see if we have stuff that matches
		 */
		if (ret > 0) {
			if (path->slots[0] == 0)
				break;
			path->slots[0]--;
		}

		/* pull out the item */
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

		/* make sure the item matches what we want */
		if (found_key.objectid != BTRFS_ORPHAN_OBJECTID)
			break;
		if (btrfs_key_type(&found_key) != BTRFS_ORPHAN_ITEM_KEY)
			break;

		/* release the path since we're done with it */
		btrfs_release_path(root, path);

		/*
		 * this is where we are basically btrfs_lookup, without the
		 * crossing root thing.  we store the inode number in the
		 * offset of the orphan item.
		 */
2336 2337 2338
		found_key.objectid = found_key.offset;
		found_key.type = BTRFS_INODE_ITEM_KEY;
		found_key.offset = 0;
2339
		inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2340
		BUG_ON(IS_ERR(inode));
2341 2342 2343 2344 2345

		/*
		 * add this inode to the orphan list so btrfs_orphan_del does
		 * the proper thing when we hit it
		 */
2346
		spin_lock(&root->orphan_lock);
2347
		list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2348
		spin_unlock(&root->orphan_lock);
2349 2350 2351 2352 2353 2354 2355 2356

		/*
		 * if this is a bad inode, means we actually succeeded in
		 * removing the inode, but not the orphan record, which means
		 * we need to manually delete the orphan since iput will just
		 * do a destroy_inode
		 */
		if (is_bad_inode(inode)) {
2357
			trans = btrfs_start_transaction(root, 0);
2358
			btrfs_orphan_del(trans, inode);
2359
			btrfs_end_transaction(trans, root);
2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374
			iput(inode);
			continue;
		}

		/* if we have links, this was a truncate, lets do that */
		if (inode->i_nlink) {
			nr_truncate++;
			btrfs_truncate(inode);
		} else {
			nr_unlink++;
		}

		/* this will do delete_inode and everything for us */
		iput(inode);
	}
2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386
	btrfs_free_path(path);

	root->orphan_cleanup_state = ORPHAN_CLEANUP_DONE;

	if (root->orphan_block_rsv)
		btrfs_block_rsv_release(root, root->orphan_block_rsv,
					(u64)-1);

	if (root->orphan_block_rsv || root->orphan_item_inserted) {
		trans = btrfs_join_transaction(root, 1);
		btrfs_end_transaction(trans, root);
	}
2387 2388 2389 2390 2391 2392 2393

	if (nr_unlink)
		printk(KERN_INFO "btrfs: unlinked %d orphans\n", nr_unlink);
	if (nr_truncate)
		printk(KERN_INFO "btrfs: truncated %d orphans\n", nr_truncate);
}

2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444
/*
 * very simple check to peek ahead in the leaf looking for xattrs.  If we
 * don't find any xattrs, we know there can't be any acls.
 *
 * slot is the slot the inode is in, objectid is the objectid of the inode
 */
static noinline int acls_after_inode_item(struct extent_buffer *leaf,
					  int slot, u64 objectid)
{
	u32 nritems = btrfs_header_nritems(leaf);
	struct btrfs_key found_key;
	int scanned = 0;

	slot++;
	while (slot < nritems) {
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		/* we found a different objectid, there must not be acls */
		if (found_key.objectid != objectid)
			return 0;

		/* we found an xattr, assume we've got an acl */
		if (found_key.type == BTRFS_XATTR_ITEM_KEY)
			return 1;

		/*
		 * we found a key greater than an xattr key, there can't
		 * be any acls later on
		 */
		if (found_key.type > BTRFS_XATTR_ITEM_KEY)
			return 0;

		slot++;
		scanned++;

		/*
		 * it goes inode, inode backrefs, xattrs, extents,
		 * so if there are a ton of hard links to an inode there can
		 * be a lot of backrefs.  Don't waste time searching too hard,
		 * this is just an optimization
		 */
		if (scanned >= 8)
			break;
	}
	/* we hit the end of the leaf before we found an xattr or
	 * something larger than an xattr.  We have to assume the inode
	 * has acls
	 */
	return 1;
}

C
Chris Mason 已提交
2445 2446 2447
/*
 * read an inode from the btree into the in-memory inode
 */
2448
static void btrfs_read_locked_inode(struct inode *inode)
C
Chris Mason 已提交
2449 2450
{
	struct btrfs_path *path;
2451
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2452
	struct btrfs_inode_item *inode_item;
2453
	struct btrfs_timespec *tspec;
C
Chris Mason 已提交
2454 2455
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key location;
2456
	int maybe_acls;
C
Chris Mason 已提交
2457
	u64 alloc_group_block;
J
Josef Bacik 已提交
2458
	u32 rdev;
C
Chris Mason 已提交
2459 2460 2461 2462 2463
	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
C
Chris Mason 已提交
2464

C
Chris Mason 已提交
2465
	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2466
	if (ret)
C
Chris Mason 已提交
2467 2468
		goto make_bad;

2469 2470 2471 2472 2473 2474 2475 2476
	leaf = path->nodes[0];
	inode_item = btrfs_item_ptr(leaf, path->slots[0],
				    struct btrfs_inode_item);

	inode->i_mode = btrfs_inode_mode(leaf, inode_item);
	inode->i_nlink = btrfs_inode_nlink(leaf, inode_item);
	inode->i_uid = btrfs_inode_uid(leaf, inode_item);
	inode->i_gid = btrfs_inode_gid(leaf, inode_item);
2477
	btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490

	tspec = btrfs_inode_atime(inode_item);
	inode->i_atime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_atime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

	tspec = btrfs_inode_mtime(inode_item);
	inode->i_mtime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_mtime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

	tspec = btrfs_inode_ctime(inode_item);
	inode->i_ctime.tv_sec = btrfs_timespec_sec(leaf, tspec);
	inode->i_ctime.tv_nsec = btrfs_timespec_nsec(leaf, tspec);

2491
	inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2492
	BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2493
	BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2494
	inode->i_generation = BTRFS_I(inode)->generation;
J
Josef Bacik 已提交
2495
	inode->i_rdev = 0;
2496 2497
	rdev = btrfs_inode_rdev(leaf, inode_item);

2498
	BTRFS_I(inode)->index_cnt = (u64)-1;
2499
	BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2500

2501
	alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
2502

2503 2504 2505 2506 2507
	/*
	 * try to precache a NULL acl entry for files that don't have
	 * any xattrs or acls
	 */
	maybe_acls = acls_after_inode_item(leaf, path->slots[0], inode->i_ino);
2508 2509
	if (!maybe_acls)
		cache_no_acl(inode);
2510

2511 2512
	BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
						alloc_group_block, 0);
C
Chris Mason 已提交
2513 2514 2515 2516 2517 2518
	btrfs_free_path(path);
	inode_item = NULL;

	switch (inode->i_mode & S_IFMT) {
	case S_IFREG:
		inode->i_mapping->a_ops = &btrfs_aops;
C
Chris Mason 已提交
2519
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2520
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
		break;
	case S_IFDIR:
		inode->i_fop = &btrfs_dir_file_operations;
		if (root == root->fs_info->tree_root)
			inode->i_op = &btrfs_dir_ro_inode_operations;
		else
			inode->i_op = &btrfs_dir_inode_operations;
		break;
	case S_IFLNK:
		inode->i_op = &btrfs_symlink_inode_operations;
		inode->i_mapping->a_ops = &btrfs_symlink_aops;
C
Chris Mason 已提交
2534
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
2535
		break;
J
Josef Bacik 已提交
2536
	default:
J
Jim Owens 已提交
2537
		inode->i_op = &btrfs_special_inode_operations;
J
Josef Bacik 已提交
2538 2539
		init_special_inode(inode, inode->i_mode, rdev);
		break;
C
Chris Mason 已提交
2540
	}
2541 2542

	btrfs_update_iflags(inode);
C
Chris Mason 已提交
2543 2544 2545 2546 2547 2548 2549
	return;

make_bad:
	btrfs_free_path(path);
	make_bad_inode(inode);
}

C
Chris Mason 已提交
2550 2551 2552
/*
 * given a leaf and an inode, copy the inode fields into the leaf
 */
2553 2554
static void fill_inode_item(struct btrfs_trans_handle *trans,
			    struct extent_buffer *leaf,
2555
			    struct btrfs_inode_item *item,
C
Chris Mason 已提交
2556 2557
			    struct inode *inode)
{
2558 2559
	btrfs_set_inode_uid(leaf, item, inode->i_uid);
	btrfs_set_inode_gid(leaf, item, inode->i_gid);
2560
	btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578
	btrfs_set_inode_mode(leaf, item, inode->i_mode);
	btrfs_set_inode_nlink(leaf, item, inode->i_nlink);

	btrfs_set_timespec_sec(leaf, btrfs_inode_atime(item),
			       inode->i_atime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_atime(item),
				inode->i_atime.tv_nsec);

	btrfs_set_timespec_sec(leaf, btrfs_inode_mtime(item),
			       inode->i_mtime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_mtime(item),
				inode->i_mtime.tv_nsec);

	btrfs_set_timespec_sec(leaf, btrfs_inode_ctime(item),
			       inode->i_ctime.tv_sec);
	btrfs_set_timespec_nsec(leaf, btrfs_inode_ctime(item),
				inode->i_ctime.tv_nsec);

2579
	btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2580
	btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2581
	btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2582
	btrfs_set_inode_transid(leaf, item, trans->transid);
2583
	btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
Y
Yan 已提交
2584
	btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2585
	btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
C
Chris Mason 已提交
2586 2587
}

C
Chris Mason 已提交
2588 2589 2590
/*
 * copy everything in the in-memory inode into the btree.
 */
C
Chris Mason 已提交
2591 2592
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
				struct btrfs_root *root, struct inode *inode)
C
Chris Mason 已提交
2593 2594 2595
{
	struct btrfs_inode_item *inode_item;
	struct btrfs_path *path;
2596
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2597 2598 2599 2600
	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);
2601
	path->leave_spinning = 1;
C
Chris Mason 已提交
2602 2603 2604 2605 2606 2607 2608 2609
	ret = btrfs_lookup_inode(trans, root, path,
				 &BTRFS_I(inode)->location, 1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		goto failed;
	}

2610
	btrfs_unlock_up_safe(path, 1);
2611 2612
	leaf = path->nodes[0];
	inode_item = btrfs_item_ptr(leaf, path->slots[0],
C
Chris Mason 已提交
2613 2614
				  struct btrfs_inode_item);

2615
	fill_inode_item(trans, leaf, inode_item, inode);
2616
	btrfs_mark_buffer_dirty(leaf);
2617
	btrfs_set_inode_last_trans(trans, inode);
C
Chris Mason 已提交
2618 2619 2620 2621 2622 2623 2624
	ret = 0;
failed:
	btrfs_free_path(path);
	return ret;
}


C
Chris Mason 已提交
2625 2626 2627 2628 2629
/*
 * unlink helper that gets used here in inode.c and in the tree logging
 * recovery code.  It remove a link in a directory with a given name, and
 * also drops the back refs in the inode to the directory
 */
2630 2631 2632 2633
int btrfs_unlink_inode(struct btrfs_trans_handle *trans,
		       struct btrfs_root *root,
		       struct inode *dir, struct inode *inode,
		       const char *name, int name_len)
C
Chris Mason 已提交
2634 2635 2636
{
	struct btrfs_path *path;
	int ret = 0;
2637
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2638
	struct btrfs_dir_item *di;
2639
	struct btrfs_key key;
2640
	u64 index;
C
Chris Mason 已提交
2641 2642

	path = btrfs_alloc_path();
2643 2644 2645 2646 2647
	if (!path) {
		ret = -ENOMEM;
		goto err;
	}

2648
	path->leave_spinning = 1;
C
Chris Mason 已提交
2649 2650 2651 2652 2653 2654 2655 2656 2657 2658
	di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
				    name, name_len, -1);
	if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto err;
	}
	if (!di) {
		ret = -ENOENT;
		goto err;
	}
2659 2660
	leaf = path->nodes[0];
	btrfs_dir_item_key_to_cpu(leaf, di, &key);
C
Chris Mason 已提交
2661
	ret = btrfs_delete_one_dir_name(trans, root, path, di);
2662 2663
	if (ret)
		goto err;
C
Chris Mason 已提交
2664 2665
	btrfs_release_path(root, path);

2666
	ret = btrfs_del_inode_ref(trans, root, name, name_len,
2667 2668
				  inode->i_ino,
				  dir->i_ino, &index);
2669
	if (ret) {
C
Chris Mason 已提交
2670
		printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2671
		       "inode %lu parent %lu\n", name_len, name,
2672
		       inode->i_ino, dir->i_ino);
2673 2674 2675
		goto err;
	}

C
Chris Mason 已提交
2676
	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
2677
					 index, name, name_len, -1);
C
Chris Mason 已提交
2678 2679 2680 2681 2682 2683 2684 2685 2686
	if (IS_ERR(di)) {
		ret = PTR_ERR(di);
		goto err;
	}
	if (!di) {
		ret = -ENOENT;
		goto err;
	}
	ret = btrfs_delete_one_dir_name(trans, root, path, di);
2687
	btrfs_release_path(root, path);
C
Chris Mason 已提交
2688

2689 2690
	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
					 inode, dir->i_ino);
C
Chris Mason 已提交
2691
	BUG_ON(ret != 0 && ret != -ENOENT);
2692 2693 2694

	ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
					   dir, index);
2695 2696
	if (ret == -ENOENT)
		ret = 0;
C
Chris Mason 已提交
2697 2698
err:
	btrfs_free_path(path);
2699 2700 2701 2702 2703 2704 2705 2706 2707
	if (ret)
		goto out;

	btrfs_i_size_write(dir, dir->i_size - name_len * 2);
	inode->i_ctime = dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	btrfs_update_inode(trans, root, dir);
	btrfs_drop_nlink(inode);
	ret = btrfs_update_inode(trans, root, inode);
out:
C
Chris Mason 已提交
2708 2709 2710
	return ret;
}

2711 2712 2713
/* helper to check if there is any shared block in the path */
static int check_path_shared(struct btrfs_root *root,
			     struct btrfs_path *path)
C
Chris Mason 已提交
2714
{
2715 2716
	struct extent_buffer *eb;
	int level;
2717
	u64 refs = 1;
2718
	int uninitialized_var(ret);
2719

2720 2721 2722 2723 2724 2725 2726 2727 2728 2729
	for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
		if (!path->nodes[level])
			break;
		eb = path->nodes[level];
		if (!btrfs_block_can_be_shared(root, eb))
			continue;
		ret = btrfs_lookup_extent_info(NULL, root, eb->start, eb->len,
					       &refs, NULL);
		if (refs > 1)
			return 1;
2730
	}
2731
	return ret; /* XXX callers? */
C
Chris Mason 已提交
2732 2733
}

2734 2735 2736 2737 2738 2739 2740 2741 2742
/*
 * helper to start transaction for unlink and rmdir.
 *
 * unlink and rmdir are special in btrfs, they do not always free space.
 * so in enospc case, we should make sure they will free space before
 * allowing them to use the global metadata reservation.
 */
static struct btrfs_trans_handle *__unlink_start_trans(struct inode *dir,
						       struct dentry *dentry)
2743
{
C
Chris Mason 已提交
2744
	struct btrfs_trans_handle *trans;
2745
	struct btrfs_root *root = BTRFS_I(dir)->root;
2746
	struct btrfs_path *path;
2747
	struct btrfs_inode_ref *ref;
2748
	struct btrfs_dir_item *di;
2749
	struct inode *inode = dentry->d_inode;
2750
	u64 index;
2751 2752
	int check_link = 1;
	int err = -ENOSPC;
2753 2754
	int ret;

2755 2756 2757
	trans = btrfs_start_transaction(root, 10);
	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
		return trans;
2758

2759 2760
	if (inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
		return ERR_PTR(-ENOSPC);
2761

2762 2763 2764
	/* check if there is someone else holds reference */
	if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
		return ERR_PTR(-ENOSPC);
2765

2766 2767
	if (atomic_read(&inode->i_count) > 2)
		return ERR_PTR(-ENOSPC);
2768

2769 2770 2771 2772 2773 2774 2775
	if (xchg(&root->fs_info->enospc_unlink, 1))
		return ERR_PTR(-ENOSPC);

	path = btrfs_alloc_path();
	if (!path) {
		root->fs_info->enospc_unlink = 0;
		return ERR_PTR(-ENOMEM);
2776 2777
	}

2778
	trans = btrfs_start_transaction(root, 0);
2779
	if (IS_ERR(trans)) {
2780 2781 2782 2783
		btrfs_free_path(path);
		root->fs_info->enospc_unlink = 0;
		return trans;
	}
2784

2785 2786
	path->skip_locking = 1;
	path->search_commit_root = 1;
2787

2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798
	ret = btrfs_lookup_inode(trans, root, path,
				&BTRFS_I(dir)->location, 0);
	if (ret < 0) {
		err = ret;
		goto out;
	}
	if (ret == 0) {
		if (check_path_shared(root, path))
			goto out;
	} else {
		check_link = 0;
2799
	}
2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905
	btrfs_release_path(root, path);

	ret = btrfs_lookup_inode(trans, root, path,
				&BTRFS_I(inode)->location, 0);
	if (ret < 0) {
		err = ret;
		goto out;
	}
	if (ret == 0) {
		if (check_path_shared(root, path))
			goto out;
	} else {
		check_link = 0;
	}
	btrfs_release_path(root, path);

	if (ret == 0 && S_ISREG(inode->i_mode)) {
		ret = btrfs_lookup_file_extent(trans, root, path,
					       inode->i_ino, (u64)-1, 0);
		if (ret < 0) {
			err = ret;
			goto out;
		}
		BUG_ON(ret == 0);
		if (check_path_shared(root, path))
			goto out;
		btrfs_release_path(root, path);
	}

	if (!check_link) {
		err = 0;
		goto out;
	}

	di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
				dentry->d_name.name, dentry->d_name.len, 0);
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto out;
	}
	if (di) {
		if (check_path_shared(root, path))
			goto out;
	} else {
		err = 0;
		goto out;
	}
	btrfs_release_path(root, path);

	ref = btrfs_lookup_inode_ref(trans, root, path,
				dentry->d_name.name, dentry->d_name.len,
				inode->i_ino, dir->i_ino, 0);
	if (IS_ERR(ref)) {
		err = PTR_ERR(ref);
		goto out;
	}
	BUG_ON(!ref);
	if (check_path_shared(root, path))
		goto out;
	index = btrfs_inode_ref_index(path->nodes[0], ref);
	btrfs_release_path(root, path);

	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino, index,
				dentry->d_name.name, dentry->d_name.len, 0);
	if (IS_ERR(di)) {
		err = PTR_ERR(di);
		goto out;
	}
	BUG_ON(ret == -ENOENT);
	if (check_path_shared(root, path))
		goto out;

	err = 0;
out:
	btrfs_free_path(path);
	if (err) {
		btrfs_end_transaction(trans, root);
		root->fs_info->enospc_unlink = 0;
		return ERR_PTR(err);
	}

	trans->block_rsv = &root->fs_info->global_block_rsv;
	return trans;
}

static void __unlink_end_trans(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root)
{
	if (trans->block_rsv == &root->fs_info->global_block_rsv) {
		BUG_ON(!root->fs_info->enospc_unlink);
		root->fs_info->enospc_unlink = 0;
	}
	btrfs_end_transaction_throttle(trans, root);
}

static int btrfs_unlink(struct inode *dir, struct dentry *dentry)
{
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_trans_handle *trans;
	struct inode *inode = dentry->d_inode;
	int ret;
	unsigned long nr = 0;

	trans = __unlink_start_trans(dir, dentry);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
2906

C
Chris Mason 已提交
2907
	btrfs_set_trans_block_group(trans, dir);
2908 2909 2910

	btrfs_record_unlink_dir(trans, dir, dentry->d_inode, 0);

2911 2912
	ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
				 dentry->d_name.name, dentry->d_name.len);
2913
	BUG_ON(ret);
2914

2915
	if (inode->i_nlink == 0) {
2916
		ret = btrfs_orphan_add(trans, inode);
2917 2918
		BUG_ON(ret);
	}
2919

2920
	nr = trans->blocks_used;
2921
	__unlink_end_trans(trans, root);
2922
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
2923 2924 2925
	return ret;
}

2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987
int btrfs_unlink_subvol(struct btrfs_trans_handle *trans,
			struct btrfs_root *root,
			struct inode *dir, u64 objectid,
			const char *name, int name_len)
{
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
	u64 index;
	int ret;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	di = btrfs_lookup_dir_item(trans, root, path, dir->i_ino,
				   name, name_len, -1);
	BUG_ON(!di || IS_ERR(di));

	leaf = path->nodes[0];
	btrfs_dir_item_key_to_cpu(leaf, di, &key);
	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
	ret = btrfs_delete_one_dir_name(trans, root, path, di);
	BUG_ON(ret);
	btrfs_release_path(root, path);

	ret = btrfs_del_root_ref(trans, root->fs_info->tree_root,
				 objectid, root->root_key.objectid,
				 dir->i_ino, &index, name, name_len);
	if (ret < 0) {
		BUG_ON(ret != -ENOENT);
		di = btrfs_search_dir_index_item(root, path, dir->i_ino,
						 name, name_len);
		BUG_ON(!di || IS_ERR(di));

		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
		btrfs_release_path(root, path);
		index = key.offset;
	}

	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
					 index, name, name_len, -1);
	BUG_ON(!di || IS_ERR(di));

	leaf = path->nodes[0];
	btrfs_dir_item_key_to_cpu(leaf, di, &key);
	WARN_ON(key.type != BTRFS_ROOT_ITEM_KEY || key.objectid != objectid);
	ret = btrfs_delete_one_dir_name(trans, root, path, di);
	BUG_ON(ret);
	btrfs_release_path(root, path);

	btrfs_i_size_write(dir, dir->i_size - name_len * 2);
	dir->i_mtime = dir->i_ctime = CURRENT_TIME;
	ret = btrfs_update_inode(trans, root, dir);
	BUG_ON(ret);

	btrfs_free_path(path);
	return 0;
}

C
Chris Mason 已提交
2988 2989 2990
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
2991
	int err = 0;
C
Chris Mason 已提交
2992 2993
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_trans_handle *trans;
2994
	unsigned long nr = 0;
C
Chris Mason 已提交
2995

2996
	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
2997
	    inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
Y
Yan 已提交
2998 2999
		return -ENOTEMPTY;

3000 3001
	trans = __unlink_start_trans(dir, dentry);
	if (IS_ERR(trans))
3002 3003
		return PTR_ERR(trans);

C
Chris Mason 已提交
3004 3005
	btrfs_set_trans_block_group(trans, dir);

3006 3007 3008 3009 3010 3011 3012 3013
	if (unlikely(inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
		err = btrfs_unlink_subvol(trans, root, dir,
					  BTRFS_I(inode)->location.objectid,
					  dentry->d_name.name,
					  dentry->d_name.len);
		goto out;
	}

3014 3015
	err = btrfs_orphan_add(trans, inode);
	if (err)
3016
		goto out;
3017

C
Chris Mason 已提交
3018
	/* now the directory is empty */
3019 3020
	err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
				 dentry->d_name.name, dentry->d_name.len);
C
Chris Mason 已提交
3021
	if (!err)
3022
		btrfs_i_size_write(inode, 0);
3023
out:
3024
	nr = trans->blocks_used;
3025
	__unlink_end_trans(trans, root);
3026
	btrfs_btree_balance_dirty(root, nr);
3027

C
Chris Mason 已提交
3028 3029 3030
	return err;
}

3031
#if 0
3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059
/*
 * when truncating bytes in a file, it is possible to avoid reading
 * the leaves that contain only checksum items.  This can be the
 * majority of the IO required to delete a large file, but it must
 * be done carefully.
 *
 * The keys in the level just above the leaves are checked to make sure
 * the lowest key in a given leaf is a csum key, and starts at an offset
 * after the new  size.
 *
 * Then the key for the next leaf is checked to make sure it also has
 * a checksum item for the same file.  If it does, we know our target leaf
 * contains only checksum items, and it can be safely freed without reading
 * it.
 *
 * This is just an optimization targeted at large files.  It may do
 * nothing.  It will return 0 unless things went badly.
 */
static noinline int drop_csum_leaves(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
				     struct btrfs_path *path,
				     struct inode *inode, u64 new_size)
{
	struct btrfs_key key;
	int ret;
	int nritems;
	struct btrfs_key found_key;
	struct btrfs_key other_key;
Y
Yan Zheng 已提交
3060 3061 3062
	struct btrfs_leaf_ref *ref;
	u64 leaf_gen;
	u64 leaf_start;
3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155

	path->lowest_level = 1;
	key.objectid = inode->i_ino;
	key.type = BTRFS_CSUM_ITEM_KEY;
	key.offset = new_size;
again:
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
	if (ret < 0)
		goto out;

	if (path->nodes[1] == NULL) {
		ret = 0;
		goto out;
	}
	ret = 0;
	btrfs_node_key_to_cpu(path->nodes[1], &found_key, path->slots[1]);
	nritems = btrfs_header_nritems(path->nodes[1]);

	if (!nritems)
		goto out;

	if (path->slots[1] >= nritems)
		goto next_node;

	/* did we find a key greater than anything we want to delete? */
	if (found_key.objectid > inode->i_ino ||
	   (found_key.objectid == inode->i_ino && found_key.type > key.type))
		goto out;

	/* we check the next key in the node to make sure the leave contains
	 * only checksum items.  This comparison doesn't work if our
	 * leaf is the last one in the node
	 */
	if (path->slots[1] + 1 >= nritems) {
next_node:
		/* search forward from the last key in the node, this
		 * will bring us into the next node in the tree
		 */
		btrfs_node_key_to_cpu(path->nodes[1], &found_key, nritems - 1);

		/* unlikely, but we inc below, so check to be safe */
		if (found_key.offset == (u64)-1)
			goto out;

		/* search_forward needs a path with locks held, do the
		 * search again for the original key.  It is possible
		 * this will race with a balance and return a path that
		 * we could modify, but this drop is just an optimization
		 * and is allowed to miss some leaves.
		 */
		btrfs_release_path(root, path);
		found_key.offset++;

		/* setup a max key for search_forward */
		other_key.offset = (u64)-1;
		other_key.type = key.type;
		other_key.objectid = key.objectid;

		path->keep_locks = 1;
		ret = btrfs_search_forward(root, &found_key, &other_key,
					   path, 0, 0);
		path->keep_locks = 0;
		if (ret || found_key.objectid != key.objectid ||
		    found_key.type != key.type) {
			ret = 0;
			goto out;
		}

		key.offset = found_key.offset;
		btrfs_release_path(root, path);
		cond_resched();
		goto again;
	}

	/* we know there's one more slot after us in the tree,
	 * read that key so we can verify it is also a checksum item
	 */
	btrfs_node_key_to_cpu(path->nodes[1], &other_key, path->slots[1] + 1);

	if (found_key.objectid < inode->i_ino)
		goto next_key;

	if (found_key.type != key.type || found_key.offset < new_size)
		goto next_key;

	/*
	 * if the key for the next leaf isn't a csum key from this objectid,
	 * we can't be sure there aren't good items inside this leaf.
	 * Bail out
	 */
	if (other_key.objectid != inode->i_ino || other_key.type != key.type)
		goto out;

Y
Yan Zheng 已提交
3156 3157
	leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
	leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
3158 3159 3160 3161
	/*
	 * it is safe to delete this leaf, it contains only
	 * csum items from this inode at an offset >= new_size
	 */
Y
Yan Zheng 已提交
3162
	ret = btrfs_del_leaf(trans, root, path, leaf_start);
3163 3164
	BUG_ON(ret);

Y
Yan Zheng 已提交
3165 3166 3167 3168 3169 3170 3171 3172 3173
	if (root->ref_cows && leaf_gen < trans->transid) {
		ref = btrfs_alloc_leaf_ref(root, 0);
		if (ref) {
			ref->root_gen = root->root_key.offset;
			ref->bytenr = leaf_start;
			ref->owner = 0;
			ref->generation = leaf_gen;
			ref->nritems = 0;

3174 3175
			btrfs_sort_leaf_ref(ref);

Y
Yan Zheng 已提交
3176 3177 3178 3179 3180 3181 3182
			ret = btrfs_add_leaf_ref(root, ref, 0);
			WARN_ON(ret);
			btrfs_free_leaf_ref(root, ref);
		} else {
			WARN_ON(1);
		}
	}
3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200
next_key:
	btrfs_release_path(root, path);

	if (other_key.objectid == inode->i_ino &&
	    other_key.type == key.type && other_key.offset > key.offset) {
		key.offset = other_key.offset;
		cond_resched();
		goto again;
	}
	ret = 0;
out:
	/* fixup any changes we've made to the path */
	path->lowest_level = 0;
	path->keep_locks = 0;
	btrfs_release_path(root, path);
	return ret;
}

3201 3202
#endif

C
Chris Mason 已提交
3203 3204 3205
/*
 * this can truncate away extent items, csum items and directory items.
 * It starts at a high offset and removes keys until it can't find
C
Chris Mason 已提交
3206
 * any higher than new_size
C
Chris Mason 已提交
3207 3208 3209
 *
 * csum items that cross the new i_size are truncated to the new size
 * as well.
3210 3211 3212
 *
 * min_type is the minimum key type to truncate down to.  If set to 0, this
 * will kill all the items on this inode, including the INODE_ITEM_KEY.
C
Chris Mason 已提交
3213
 */
3214 3215 3216 3217
int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans,
			       struct btrfs_root *root,
			       struct inode *inode,
			       u64 new_size, u32 min_type)
C
Chris Mason 已提交
3218 3219
{
	struct btrfs_path *path;
3220
	struct extent_buffer *leaf;
C
Chris Mason 已提交
3221
	struct btrfs_file_extent_item *fi;
3222 3223
	struct btrfs_key key;
	struct btrfs_key found_key;
C
Chris Mason 已提交
3224
	u64 extent_start = 0;
3225
	u64 extent_num_bytes = 0;
3226
	u64 extent_offset = 0;
C
Chris Mason 已提交
3227
	u64 item_end = 0;
3228 3229
	u64 mask = root->sectorsize - 1;
	u32 found_type = (u8)-1;
C
Chris Mason 已提交
3230 3231
	int found_extent;
	int del_item;
3232 3233
	int pending_del_nr = 0;
	int pending_del_slot = 0;
3234
	int extent_type = -1;
3235
	int encoding;
3236 3237 3238 3239
	int ret;
	int err = 0;

	BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
C
Chris Mason 已提交
3240

3241
	if (root->ref_cows || root == root->fs_info->tree_root)
3242
		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3243

C
Chris Mason 已提交
3244 3245
	path = btrfs_alloc_path();
	BUG_ON(!path);
J
Julia Lawall 已提交
3246
	path->reada = -1;
3247

C
Chris Mason 已提交
3248 3249
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
3250 3251
	key.type = (u8)-1;

3252
search_again:
3253
	path->leave_spinning = 1;
3254
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3255 3256 3257 3258
	if (ret < 0) {
		err = ret;
		goto out;
	}
C
Chris Mason 已提交
3259

3260
	if (ret > 0) {
3261 3262 3263
		/* there are no items in the tree for us to truncate, we're
		 * done
		 */
3264 3265
		if (path->slots[0] == 0)
			goto out;
3266 3267 3268
		path->slots[0]--;
	}

C
Chris Mason 已提交
3269
	while (1) {
C
Chris Mason 已提交
3270
		fi = NULL;
3271 3272 3273
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		found_type = btrfs_key_type(&found_key);
3274
		encoding = 0;
C
Chris Mason 已提交
3275

3276
		if (found_key.objectid != inode->i_ino)
C
Chris Mason 已提交
3277
			break;
3278

3279
		if (found_type < min_type)
C
Chris Mason 已提交
3280 3281
			break;

3282
		item_end = found_key.offset;
C
Chris Mason 已提交
3283
		if (found_type == BTRFS_EXTENT_DATA_KEY) {
3284
			fi = btrfs_item_ptr(leaf, path->slots[0],
C
Chris Mason 已提交
3285
					    struct btrfs_file_extent_item);
3286
			extent_type = btrfs_file_extent_type(leaf, fi);
3287 3288 3289 3290
			encoding = btrfs_file_extent_compression(leaf, fi);
			encoding |= btrfs_file_extent_encryption(leaf, fi);
			encoding |= btrfs_file_extent_other_encoding(leaf, fi);

3291
			if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3292
				item_end +=
3293
				    btrfs_file_extent_num_bytes(leaf, fi);
3294 3295
			} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
				item_end += btrfs_file_extent_inline_len(leaf,
C
Chris Mason 已提交
3296
									 fi);
C
Chris Mason 已提交
3297
			}
3298
			item_end--;
C
Chris Mason 已提交
3299
		}
3300 3301 3302 3303
		if (found_type > min_type) {
			del_item = 1;
		} else {
			if (item_end < new_size)
3304
				break;
3305 3306 3307 3308
			if (found_key.offset >= new_size)
				del_item = 1;
			else
				del_item = 0;
C
Chris Mason 已提交
3309 3310 3311
		}
		found_extent = 0;
		/* FIXME, shrink the extent if the ref count is only 1 */
3312 3313 3314 3315
		if (found_type != BTRFS_EXTENT_DATA_KEY)
			goto delete;

		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
3316
			u64 num_dec;
3317
			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3318
			if (!del_item && !encoding) {
3319 3320
				u64 orig_num_bytes =
					btrfs_file_extent_num_bytes(leaf, fi);
3321
				extent_num_bytes = new_size -
3322
					found_key.offset + root->sectorsize - 1;
3323 3324
				extent_num_bytes = extent_num_bytes &
					~((u64)root->sectorsize - 1);
3325 3326 3327
				btrfs_set_file_extent_num_bytes(leaf, fi,
							 extent_num_bytes);
				num_dec = (orig_num_bytes -
C
Chris Mason 已提交
3328
					   extent_num_bytes);
3329
				if (root->ref_cows && extent_start != 0)
3330
					inode_sub_bytes(inode, num_dec);
3331
				btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
3332
			} else {
3333 3334 3335
				extent_num_bytes =
					btrfs_file_extent_disk_num_bytes(leaf,
									 fi);
3336 3337 3338
				extent_offset = found_key.offset -
					btrfs_file_extent_offset(leaf, fi);

C
Chris Mason 已提交
3339
				/* FIXME blocksize != 4096 */
C
Chris Mason 已提交
3340
				num_dec = btrfs_file_extent_num_bytes(leaf, fi);
C
Chris Mason 已提交
3341 3342
				if (extent_start != 0) {
					found_extent = 1;
3343
					if (root->ref_cows)
3344
						inode_sub_bytes(inode, num_dec);
3345
				}
C
Chris Mason 已提交
3346
			}
C
Chris Mason 已提交
3347
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
3348 3349 3350 3351 3352 3353 3354 3355
			/*
			 * we can't truncate inline items that have had
			 * special encodings
			 */
			if (!del_item &&
			    btrfs_file_extent_compression(leaf, fi) == 0 &&
			    btrfs_file_extent_encryption(leaf, fi) == 0 &&
			    btrfs_file_extent_other_encoding(leaf, fi) == 0) {
3356 3357 3358
				u32 size = new_size - found_key.offset;

				if (root->ref_cows) {
3359 3360
					inode_sub_bytes(inode, item_end + 1 -
							new_size);
3361 3362 3363
				}
				size =
				    btrfs_file_extent_calc_inline_size(size);
C
Chris Mason 已提交
3364
				ret = btrfs_truncate_item(trans, root, path,
3365
							  size, 1);
C
Chris Mason 已提交
3366
				BUG_ON(ret);
3367
			} else if (root->ref_cows) {
3368 3369
				inode_sub_bytes(inode, item_end + 1 -
						found_key.offset);
C
Chris Mason 已提交
3370
			}
C
Chris Mason 已提交
3371
		}
3372
delete:
C
Chris Mason 已提交
3373
		if (del_item) {
3374 3375 3376 3377 3378 3379 3380 3381 3382 3383
			if (!pending_del_nr) {
				/* no pending yet, add ourselves */
				pending_del_slot = path->slots[0];
				pending_del_nr = 1;
			} else if (pending_del_nr &&
				   path->slots[0] + 1 == pending_del_slot) {
				/* hop on the pending chunk */
				pending_del_nr++;
				pending_del_slot = path->slots[0];
			} else {
C
Chris Mason 已提交
3384
				BUG();
3385
			}
C
Chris Mason 已提交
3386 3387 3388
		} else {
			break;
		}
3389 3390
		if (found_extent && (root->ref_cows ||
				     root == root->fs_info->tree_root)) {
3391
			btrfs_set_path_blocking(path);
C
Chris Mason 已提交
3392
			ret = btrfs_free_extent(trans, root, extent_start,
3393 3394 3395
						extent_num_bytes, 0,
						btrfs_header_owner(leaf),
						inode->i_ino, extent_offset);
C
Chris Mason 已提交
3396 3397
			BUG_ON(ret);
		}
3398

3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414
		if (found_type == BTRFS_INODE_ITEM_KEY)
			break;

		if (path->slots[0] == 0 ||
		    path->slots[0] != pending_del_slot) {
			if (root->ref_cows) {
				err = -EAGAIN;
				goto out;
			}
			if (pending_del_nr) {
				ret = btrfs_del_items(trans, root, path,
						pending_del_slot,
						pending_del_nr);
				BUG_ON(ret);
				pending_del_nr = 0;
			}
3415 3416
			btrfs_release_path(root, path);
			goto search_again;
3417 3418
		} else {
			path->slots[0]--;
3419
		}
C
Chris Mason 已提交
3420
	}
3421
out:
3422 3423 3424
	if (pending_del_nr) {
		ret = btrfs_del_items(trans, root, path, pending_del_slot,
				      pending_del_nr);
3425
		BUG_ON(ret);
3426
	}
C
Chris Mason 已提交
3427
	btrfs_free_path(path);
3428
	return err;
C
Chris Mason 已提交
3429 3430 3431 3432 3433 3434 3435 3436 3437
}

/*
 * taken from block_truncate_page, but does cow as it zeros out
 * any bytes left in the last page in the file.
 */
static int btrfs_truncate_page(struct address_space *mapping, loff_t from)
{
	struct inode *inode = mapping->host;
3438
	struct btrfs_root *root = BTRFS_I(inode)->root;
3439 3440
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct btrfs_ordered_extent *ordered;
3441
	struct extent_state *cached_state = NULL;
3442
	char *kaddr;
3443
	u32 blocksize = root->sectorsize;
C
Chris Mason 已提交
3444 3445 3446 3447
	pgoff_t index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	struct page *page;
	int ret = 0;
3448
	u64 page_start;
3449
	u64 page_end;
C
Chris Mason 已提交
3450 3451 3452

	if ((offset & (blocksize - 1)) == 0)
		goto out;
3453
	ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3454 3455
	if (ret)
		goto out;
C
Chris Mason 已提交
3456 3457

	ret = -ENOMEM;
3458
again:
C
Chris Mason 已提交
3459
	page = grab_cache_page(mapping, index);
3460
	if (!page) {
3461
		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
C
Chris Mason 已提交
3462
		goto out;
3463
	}
3464 3465 3466 3467

	page_start = page_offset(page);
	page_end = page_start + PAGE_CACHE_SIZE - 1;

C
Chris Mason 已提交
3468
	if (!PageUptodate(page)) {
C
Chris Mason 已提交
3469
		ret = btrfs_readpage(NULL, page);
C
Chris Mason 已提交
3470
		lock_page(page);
3471 3472 3473 3474 3475
		if (page->mapping != mapping) {
			unlock_page(page);
			page_cache_release(page);
			goto again;
		}
C
Chris Mason 已提交
3476 3477
		if (!PageUptodate(page)) {
			ret = -EIO;
3478
			goto out_unlock;
C
Chris Mason 已提交
3479 3480
		}
	}
3481
	wait_on_page_writeback(page);
3482

3483 3484
	lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
3485 3486 3487 3488
	set_page_extent_mapped(page);

	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
3489 3490
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
3491 3492
		unlock_page(page);
		page_cache_release(page);
3493
		btrfs_start_ordered_extent(inode, ordered, 1);
3494 3495 3496 3497
		btrfs_put_ordered_extent(ordered);
		goto again;
	}

3498
	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3499
			  EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3500
			  0, 0, &cached_state, GFP_NOFS);
3501

3502 3503
	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
					&cached_state);
J
Josef Bacik 已提交
3504
	if (ret) {
3505 3506
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
3507 3508 3509
		goto out_unlock;
	}

3510 3511 3512 3513 3514 3515 3516
	ret = 0;
	if (offset != PAGE_CACHE_SIZE) {
		kaddr = kmap(page);
		memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
		flush_dcache_page(page);
		kunmap(page);
	}
3517
	ClearPageChecked(page);
3518
	set_page_dirty(page);
3519 3520
	unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
			     GFP_NOFS);
C
Chris Mason 已提交
3521

3522
out_unlock:
3523
	if (ret)
3524
		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
C
Chris Mason 已提交
3525 3526 3527 3528 3529 3530
	unlock_page(page);
	page_cache_release(page);
out:
	return ret;
}

Y
Yan Zheng 已提交
3531
int btrfs_cont_expand(struct inode *inode, loff_t size)
C
Chris Mason 已提交
3532
{
Y
Yan Zheng 已提交
3533 3534 3535
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3536
	struct extent_map *em = NULL;
3537
	struct extent_state *cached_state = NULL;
Y
Yan Zheng 已提交
3538 3539 3540 3541 3542 3543
	u64 mask = root->sectorsize - 1;
	u64 hole_start = (inode->i_size + mask) & ~mask;
	u64 block_end = (size + mask) & ~mask;
	u64 last_byte;
	u64 cur_offset;
	u64 hole_size;
J
Josef Bacik 已提交
3544
	int err = 0;
C
Chris Mason 已提交
3545

Y
Yan Zheng 已提交
3546 3547 3548 3549 3550 3551 3552
	if (size <= hole_start)
		return 0;

	while (1) {
		struct btrfs_ordered_extent *ordered;
		btrfs_wait_ordered_range(inode, hole_start,
					 block_end - hole_start);
3553 3554
		lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
				 &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
3555 3556 3557
		ordered = btrfs_lookup_ordered_extent(inode, hole_start);
		if (!ordered)
			break;
3558 3559
		unlock_extent_cached(io_tree, hole_start, block_end - 1,
				     &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
3560 3561
		btrfs_put_ordered_extent(ordered);
	}
C
Chris Mason 已提交
3562

Y
Yan Zheng 已提交
3563 3564 3565 3566 3567 3568 3569
	cur_offset = hole_start;
	while (1) {
		em = btrfs_get_extent(inode, NULL, 0, cur_offset,
				block_end - cur_offset, 0);
		BUG_ON(IS_ERR(em) || !em);
		last_byte = min(extent_map_end(em), block_end);
		last_byte = (last_byte + mask) & ~mask;
3570
		if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3571
			u64 hint_byte = 0;
Y
Yan Zheng 已提交
3572
			hole_size = last_byte - cur_offset;
J
Josef Bacik 已提交
3573

3574 3575 3576
			trans = btrfs_start_transaction(root, 2);
			if (IS_ERR(trans)) {
				err = PTR_ERR(trans);
J
Josef Bacik 已提交
3577
				break;
3578
			}
3579 3580 3581 3582 3583 3584 3585
			btrfs_set_trans_block_group(trans, inode);

			err = btrfs_drop_extents(trans, inode, cur_offset,
						 cur_offset + hole_size,
						 &hint_byte, 1);
			BUG_ON(err);

Y
Yan Zheng 已提交
3586 3587 3588 3589
			err = btrfs_insert_file_extent(trans, root,
					inode->i_ino, cur_offset, 0,
					0, hole_size, 0, hole_size,
					0, 0, 0);
3590 3591
			BUG_ON(err);

Y
Yan Zheng 已提交
3592 3593
			btrfs_drop_extent_cache(inode, hole_start,
					last_byte - 1, 0);
3594 3595

			btrfs_end_transaction(trans, root);
Y
Yan Zheng 已提交
3596 3597
		}
		free_extent_map(em);
3598
		em = NULL;
Y
Yan Zheng 已提交
3599
		cur_offset = last_byte;
3600
		if (cur_offset >= block_end)
Y
Yan Zheng 已提交
3601 3602
			break;
	}
3603

3604
	free_extent_map(em);
3605 3606
	unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
			     GFP_NOFS);
Y
Yan Zheng 已提交
3607 3608
	return err;
}
C
Chris Mason 已提交
3609

3610 3611 3612 3613 3614 3615 3616 3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630
static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	unsigned long nr;
	int ret;

	if (attr->ia_size == inode->i_size)
		return 0;

	if (attr->ia_size > inode->i_size) {
		unsigned long limit;
		limit = current->signal->rlim[RLIMIT_FSIZE].rlim_cur;
		if (attr->ia_size > inode->i_sb->s_maxbytes)
			return -EFBIG;
		if (limit != RLIM_INFINITY && attr->ia_size > limit) {
			send_sig(SIGXFSZ, current, 0);
			return -EFBIG;
		}
	}

3631 3632 3633
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644 3645 3646 3647 3648 3649 3650 3651 3652 3653

	btrfs_set_trans_block_group(trans, inode);

	ret = btrfs_orphan_add(trans, inode);
	BUG_ON(ret);

	nr = trans->blocks_used;
	btrfs_end_transaction(trans, root);
	btrfs_btree_balance_dirty(root, nr);

	if (attr->ia_size > inode->i_size) {
		ret = btrfs_cont_expand(inode, attr->ia_size);
		if (ret) {
			btrfs_truncate(inode);
			return ret;
		}

		i_size_write(inode, attr->ia_size);
		btrfs_ordered_update_i_size(inode, inode->i_size, NULL);

3654 3655
		trans = btrfs_start_transaction(root, 0);
		BUG_ON(IS_ERR(trans));
3656
		btrfs_set_trans_block_group(trans, inode);
3657 3658
		trans->block_rsv = root->orphan_block_rsv;
		BUG_ON(!trans->block_rsv);
3659 3660 3661 3662 3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678 3679 3680 3681 3682 3683 3684 3685 3686

		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);
		if (inode->i_nlink > 0) {
			ret = btrfs_orphan_del(trans, inode);
			BUG_ON(ret);
		}
		nr = trans->blocks_used;
		btrfs_end_transaction(trans, root);
		btrfs_btree_balance_dirty(root, nr);
		return 0;
	}

	/*
	 * We're truncating a file that used to have good data down to
	 * zero. Make sure it gets into the ordered flush list so that
	 * any new writes get down to disk quickly.
	 */
	if (attr->ia_size == 0)
		BTRFS_I(inode)->ordered_data_close = 1;

	/* we don't support swapfiles, so vmtruncate shouldn't fail */
	ret = vmtruncate(inode, attr->ia_size);
	BUG_ON(ret);

	return 0;
}

Y
Yan Zheng 已提交
3687 3688 3689
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
L
Li Zefan 已提交
3690
	struct btrfs_root *root = BTRFS_I(inode)->root;
Y
Yan Zheng 已提交
3691
	int err;
C
Chris Mason 已提交
3692

L
Li Zefan 已提交
3693 3694 3695
	if (btrfs_root_readonly(root))
		return -EROFS;

Y
Yan Zheng 已提交
3696 3697 3698
	err = inode_change_ok(inode, attr);
	if (err)
		return err;
C
Chris Mason 已提交
3699

3700
	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3701 3702 3703
		err = btrfs_setattr_size(inode, attr);
		if (err)
			return err;
C
Chris Mason 已提交
3704
	}
Y
Yan Zheng 已提交
3705

C
Christoph Hellwig 已提交
3706 3707 3708 3709 3710 3711 3712
	if (attr->ia_valid) {
		setattr_copy(inode, attr);
		mark_inode_dirty(inode);

		if (attr->ia_valid & ATTR_MODE)
			err = btrfs_acl_chmod(inode);
	}
J
Josef Bacik 已提交
3713

C
Chris Mason 已提交
3714 3715
	return err;
}
3716

A
Al Viro 已提交
3717
void btrfs_evict_inode(struct inode *inode)
C
Chris Mason 已提交
3718 3719 3720
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(inode)->root;
3721
	unsigned long nr;
C
Chris Mason 已提交
3722 3723 3724
	int ret;

	truncate_inode_pages(&inode->i_data, 0);
3725 3726
	if (inode->i_nlink && (btrfs_root_refs(&root->root_item) != 0 ||
			       root == root->fs_info->tree_root))
A
Al Viro 已提交
3727 3728
		goto no_delete;

C
Chris Mason 已提交
3729
	if (is_bad_inode(inode)) {
3730
		btrfs_orphan_del(NULL, inode);
C
Chris Mason 已提交
3731 3732
		goto no_delete;
	}
A
Al Viro 已提交
3733
	/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
C
Chris Mason 已提交
3734
	btrfs_wait_ordered_range(inode, 0, (u64)-1);
3735

3736 3737 3738 3739 3740
	if (root->fs_info->log_root_recovering) {
		BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
		goto no_delete;
	}

3741 3742 3743 3744 3745
	if (inode->i_nlink > 0) {
		BUG_ON(btrfs_root_refs(&root->root_item) != 0);
		goto no_delete;
	}

3746
	btrfs_i_size_write(inode, 0);
3747

3748
	while (1) {
3749 3750
		trans = btrfs_start_transaction(root, 0);
		BUG_ON(IS_ERR(trans));
3751
		btrfs_set_trans_block_group(trans, inode);
3752 3753 3754 3755 3756 3757 3758 3759 3760 3761
		trans->block_rsv = root->orphan_block_rsv;

		ret = btrfs_block_rsv_check(trans, root,
					    root->orphan_block_rsv, 0, 5);
		if (ret) {
			BUG_ON(ret != -EAGAIN);
			ret = btrfs_commit_transaction(trans, root);
			BUG_ON(ret);
			continue;
		}
3762

3763
		ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3764 3765
		if (ret != -EAGAIN)
			break;
3766

3767 3768 3769 3770
		nr = trans->blocks_used;
		btrfs_end_transaction(trans, root);
		trans = NULL;
		btrfs_btree_balance_dirty(root, nr);
3771

3772
	}
3773

3774 3775 3776 3777
	if (ret == 0) {
		ret = btrfs_orphan_del(trans, inode);
		BUG_ON(ret);
	}
3778

3779
	nr = trans->blocks_used;
3780
	btrfs_end_transaction(trans, root);
3781
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
3782
no_delete:
A
Al Viro 已提交
3783
	end_writeback(inode);
3784
	return;
C
Chris Mason 已提交
3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795 3796 3797 3798
}

/*
 * this returns the key found in the dir entry in the location pointer.
 * If no dir entries were found, location->objectid is 0.
 */
static int btrfs_inode_by_name(struct inode *dir, struct dentry *dentry,
			       struct btrfs_key *location)
{
	const char *name = dentry->d_name.name;
	int namelen = dentry->d_name.len;
	struct btrfs_dir_item *di;
	struct btrfs_path *path;
	struct btrfs_root *root = BTRFS_I(dir)->root;
Y
Yan 已提交
3799
	int ret = 0;
C
Chris Mason 已提交
3800 3801 3802

	path = btrfs_alloc_path();
	BUG_ON(!path);
3803

C
Chris Mason 已提交
3804 3805
	di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
				    namelen, 0);
Y
Yan 已提交
3806 3807
	if (IS_ERR(di))
		ret = PTR_ERR(di);
C
Chris Mason 已提交
3808 3809

	if (!di || IS_ERR(di))
3810
		goto out_err;
C
Chris Mason 已提交
3811

3812
	btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
C
Chris Mason 已提交
3813 3814 3815
out:
	btrfs_free_path(path);
	return ret;
3816 3817 3818
out_err:
	location->objectid = 0;
	goto out;
C
Chris Mason 已提交
3819 3820 3821 3822 3823 3824 3825 3826
}

/*
 * when we hit a tree root in a directory, the btrfs part of the inode
 * needs to be changed to reflect the root directory of the tree root.  This
 * is kind of like crossing a mount point.
 */
static int fixup_tree_root_location(struct btrfs_root *root,
3827 3828 3829 3830
				    struct inode *dir,
				    struct dentry *dentry,
				    struct btrfs_key *location,
				    struct btrfs_root **sub_root)
C
Chris Mason 已提交
3831
{
3832 3833 3834 3835 3836 3837
	struct btrfs_path *path;
	struct btrfs_root *new_root;
	struct btrfs_root_ref *ref;
	struct extent_buffer *leaf;
	int ret;
	int err = 0;
C
Chris Mason 已提交
3838

3839 3840 3841 3842 3843
	path = btrfs_alloc_path();
	if (!path) {
		err = -ENOMEM;
		goto out;
	}
C
Chris Mason 已提交
3844

3845 3846 3847 3848 3849 3850 3851 3852 3853
	err = -ENOENT;
	ret = btrfs_find_root_ref(root->fs_info->tree_root, path,
				  BTRFS_I(dir)->root->root_key.objectid,
				  location->objectid);
	if (ret) {
		if (ret < 0)
			err = ret;
		goto out;
	}
C
Chris Mason 已提交
3854

3855 3856 3857 3858 3859
	leaf = path->nodes[0];
	ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_root_ref);
	if (btrfs_root_ref_dirid(leaf, ref) != dir->i_ino ||
	    btrfs_root_ref_name_len(leaf, ref) != dentry->d_name.len)
		goto out;
C
Chris Mason 已提交
3860

3861 3862 3863 3864 3865 3866 3867 3868 3869 3870 3871 3872 3873 3874 3875 3876 3877 3878 3879 3880 3881 3882 3883 3884 3885 3886 3887
	ret = memcmp_extent_buffer(leaf, dentry->d_name.name,
				   (unsigned long)(ref + 1),
				   dentry->d_name.len);
	if (ret)
		goto out;

	btrfs_release_path(root->fs_info->tree_root, path);

	new_root = btrfs_read_fs_root_no_name(root->fs_info, location);
	if (IS_ERR(new_root)) {
		err = PTR_ERR(new_root);
		goto out;
	}

	if (btrfs_root_refs(&new_root->root_item) == 0) {
		err = -ENOENT;
		goto out;
	}

	*sub_root = new_root;
	location->objectid = btrfs_root_dirid(&new_root->root_item);
	location->type = BTRFS_INODE_ITEM_KEY;
	location->offset = 0;
	err = 0;
out:
	btrfs_free_path(path);
	return err;
C
Chris Mason 已提交
3888 3889
}

3890 3891 3892 3893
static void inode_tree_add(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_inode *entry;
3894 3895 3896 3897 3898
	struct rb_node **p;
	struct rb_node *parent;
again:
	p = &root->inode_tree.rb_node;
	parent = NULL;
3899

3900 3901 3902
	if (hlist_unhashed(&inode->i_hash))
		return;

3903 3904 3905 3906 3907 3908
	spin_lock(&root->inode_lock);
	while (*p) {
		parent = *p;
		entry = rb_entry(parent, struct btrfs_inode, rb_node);

		if (inode->i_ino < entry->vfs_inode.i_ino)
3909
			p = &parent->rb_left;
3910
		else if (inode->i_ino > entry->vfs_inode.i_ino)
3911
			p = &parent->rb_right;
3912 3913
		else {
			WARN_ON(!(entry->vfs_inode.i_state &
A
Al Viro 已提交
3914
				  (I_WILL_FREE | I_FREEING)));
3915 3916 3917 3918
			rb_erase(parent, &root->inode_tree);
			RB_CLEAR_NODE(parent);
			spin_unlock(&root->inode_lock);
			goto again;
3919 3920 3921 3922 3923 3924 3925 3926 3927 3928
		}
	}
	rb_link_node(&BTRFS_I(inode)->rb_node, parent, p);
	rb_insert_color(&BTRFS_I(inode)->rb_node, &root->inode_tree);
	spin_unlock(&root->inode_lock);
}

static void inode_tree_del(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
3929
	int empty = 0;
3930

3931
	spin_lock(&root->inode_lock);
3932 3933 3934
	if (!RB_EMPTY_NODE(&BTRFS_I(inode)->rb_node)) {
		rb_erase(&BTRFS_I(inode)->rb_node, &root->inode_tree);
		RB_CLEAR_NODE(&BTRFS_I(inode)->rb_node);
3935
		empty = RB_EMPTY_ROOT(&root->inode_tree);
3936
	}
3937
	spin_unlock(&root->inode_lock);
3938

3939 3940 3941 3942 3943 3944 3945 3946
	/*
	 * Free space cache has inodes in the tree root, but the tree root has a
	 * root_refs of 0, so this could end up dropping the tree root as a
	 * snapshot, so we need the extra !root->fs_info->tree_root check to
	 * make sure we don't drop it.
	 */
	if (empty && btrfs_root_refs(&root->root_item) == 0 &&
	    root != root->fs_info->tree_root) {
3947 3948 3949 3950 3951 3952 3953 3954 3955 3956 3957 3958 3959 3960 3961 3962 3963 3964 3965 3966 3967 3968 3969 3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999
		synchronize_srcu(&root->fs_info->subvol_srcu);
		spin_lock(&root->inode_lock);
		empty = RB_EMPTY_ROOT(&root->inode_tree);
		spin_unlock(&root->inode_lock);
		if (empty)
			btrfs_add_dead_root(root);
	}
}

int btrfs_invalidate_inodes(struct btrfs_root *root)
{
	struct rb_node *node;
	struct rb_node *prev;
	struct btrfs_inode *entry;
	struct inode *inode;
	u64 objectid = 0;

	WARN_ON(btrfs_root_refs(&root->root_item) != 0);

	spin_lock(&root->inode_lock);
again:
	node = root->inode_tree.rb_node;
	prev = NULL;
	while (node) {
		prev = node;
		entry = rb_entry(node, struct btrfs_inode, rb_node);

		if (objectid < entry->vfs_inode.i_ino)
			node = node->rb_left;
		else if (objectid > entry->vfs_inode.i_ino)
			node = node->rb_right;
		else
			break;
	}
	if (!node) {
		while (prev) {
			entry = rb_entry(prev, struct btrfs_inode, rb_node);
			if (objectid <= entry->vfs_inode.i_ino) {
				node = prev;
				break;
			}
			prev = rb_next(prev);
		}
	}
	while (node) {
		entry = rb_entry(node, struct btrfs_inode, rb_node);
		objectid = entry->vfs_inode.i_ino + 1;
		inode = igrab(&entry->vfs_inode);
		if (inode) {
			spin_unlock(&root->inode_lock);
			if (atomic_read(&inode->i_count) > 1)
				d_prune_aliases(inode);
			/*
4000
			 * btrfs_drop_inode will have it removed from
4001 4002 4003 4004 4005 4006 4007 4008 4009 4010 4011 4012 4013 4014 4015 4016
			 * the inode cache when its usage count
			 * hits zero.
			 */
			iput(inode);
			cond_resched();
			spin_lock(&root->inode_lock);
			goto again;
		}

		if (cond_resched_lock(&root->inode_lock))
			goto again;

		node = rb_next(node);
	}
	spin_unlock(&root->inode_lock);
	return 0;
4017 4018
}

4019 4020 4021 4022 4023
static int btrfs_init_locked_inode(struct inode *inode, void *p)
{
	struct btrfs_iget_args *args = p;
	inode->i_ino = args->ino;
	BTRFS_I(inode)->root = args->root;
J
Josef Bacik 已提交
4024
	btrfs_set_inode_space_info(args->root, inode);
C
Chris Mason 已提交
4025 4026 4027 4028 4029 4030
	return 0;
}

static int btrfs_find_actor(struct inode *inode, void *opaque)
{
	struct btrfs_iget_args *args = opaque;
C
Chris Mason 已提交
4031 4032
	return args->ino == inode->i_ino &&
		args->root == BTRFS_I(inode)->root;
C
Chris Mason 已提交
4033 4034
}

4035 4036 4037
static struct inode *btrfs_iget_locked(struct super_block *s,
				       u64 objectid,
				       struct btrfs_root *root)
C
Chris Mason 已提交
4038 4039 4040 4041 4042 4043 4044 4045 4046 4047 4048 4049
{
	struct inode *inode;
	struct btrfs_iget_args args;
	args.ino = objectid;
	args.root = root;

	inode = iget5_locked(s, objectid, btrfs_find_actor,
			     btrfs_init_locked_inode,
			     (void *)&args);
	return inode;
}

B
Balaji Rao 已提交
4050 4051 4052 4053
/* Get an inode object given its location and corresponding root.
 * Returns in *is_new if the inode was read from disk
 */
struct inode *btrfs_iget(struct super_block *s, struct btrfs_key *location,
4054
			 struct btrfs_root *root, int *new)
B
Balaji Rao 已提交
4055 4056 4057 4058 4059
{
	struct inode *inode;

	inode = btrfs_iget_locked(s, location->objectid, root);
	if (!inode)
4060
		return ERR_PTR(-ENOMEM);
B
Balaji Rao 已提交
4061 4062 4063 4064 4065

	if (inode->i_state & I_NEW) {
		BTRFS_I(inode)->root = root;
		memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
		btrfs_read_locked_inode(inode);
4066 4067

		inode_tree_add(inode);
B
Balaji Rao 已提交
4068
		unlock_new_inode(inode);
4069 4070
		if (new)
			*new = 1;
B
Balaji Rao 已提交
4071 4072 4073 4074 4075
	}

	return inode;
}

4076 4077 4078 4079 4080 4081 4082 4083 4084 4085 4086 4087 4088 4089 4090 4091 4092 4093 4094 4095 4096 4097
static struct inode *new_simple_dir(struct super_block *s,
				    struct btrfs_key *key,
				    struct btrfs_root *root)
{
	struct inode *inode = new_inode(s);

	if (!inode)
		return ERR_PTR(-ENOMEM);

	BTRFS_I(inode)->root = root;
	memcpy(&BTRFS_I(inode)->location, key, sizeof(*key));
	BTRFS_I(inode)->dummy_inode = 1;

	inode->i_ino = BTRFS_EMPTY_SUBVOL_DIR_OBJECTID;
	inode->i_op = &simple_dir_inode_operations;
	inode->i_fop = &simple_dir_operations;
	inode->i_mode = S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO;
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;

	return inode;
}

4098
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
C
Chris Mason 已提交
4099
{
C
Chris Mason 已提交
4100
	struct inode *inode;
4101
	struct btrfs_root *root = BTRFS_I(dir)->root;
C
Chris Mason 已提交
4102 4103
	struct btrfs_root *sub_root = root;
	struct btrfs_key location;
4104
	int index;
4105
	int ret;
C
Chris Mason 已提交
4106

4107 4108
	dentry->d_op = &btrfs_dentry_operations;

C
Chris Mason 已提交
4109 4110
	if (dentry->d_name.len > BTRFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);
4111

C
Chris Mason 已提交
4112
	ret = btrfs_inode_by_name(dir, dentry, &location);
4113

C
Chris Mason 已提交
4114 4115
	if (ret < 0)
		return ERR_PTR(ret);
4116

4117 4118 4119 4120
	if (location.objectid == 0)
		return NULL;

	if (location.type == BTRFS_INODE_ITEM_KEY) {
4121
		inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4122 4123 4124 4125 4126
		return inode;
	}

	BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);

4127
	index = srcu_read_lock(&root->fs_info->subvol_srcu);
4128 4129 4130 4131 4132 4133 4134 4135
	ret = fixup_tree_root_location(root, dir, dentry,
				       &location, &sub_root);
	if (ret < 0) {
		if (ret != -ENOENT)
			inode = ERR_PTR(ret);
		else
			inode = new_simple_dir(dir->i_sb, &location, sub_root);
	} else {
4136
		inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
C
Chris Mason 已提交
4137
	}
4138 4139
	srcu_read_unlock(&root->fs_info->subvol_srcu, index);

4140 4141 4142 4143 4144 4145 4146
	if (root != sub_root) {
		down_read(&root->fs_info->cleanup_work_sem);
		if (!(inode->i_sb->s_flags & MS_RDONLY))
			btrfs_orphan_cleanup(sub_root);
		up_read(&root->fs_info->cleanup_work_sem);
	}

4147 4148 4149
	return inode;
}

4150 4151 4152 4153
static int btrfs_dentry_delete(struct dentry *dentry)
{
	struct btrfs_root *root;

4154 4155
	if (!dentry->d_inode && !IS_ROOT(dentry))
		dentry = dentry->d_parent;
4156

4157 4158 4159 4160 4161
	if (dentry->d_inode) {
		root = BTRFS_I(dentry->d_inode)->root;
		if (btrfs_root_refs(&root->root_item) == 0)
			return 1;
	}
4162 4163 4164
	return 0;
}

4165 4166 4167 4168 4169 4170 4171 4172
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
				   struct nameidata *nd)
{
	struct inode *inode;

	inode = btrfs_lookup_dentry(dir, dentry);
	if (IS_ERR(inode))
		return ERR_CAST(inode);
4173

C
Chris Mason 已提交
4174 4175 4176 4177 4178 4179 4180
	return d_splice_alias(inode, dentry);
}

static unsigned char btrfs_filetype_table[] = {
	DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK
};

4181 4182
static int btrfs_real_readdir(struct file *filp, void *dirent,
			      filldir_t filldir)
C
Chris Mason 已提交
4183
{
4184
	struct inode *inode = filp->f_dentry->d_inode;
C
Chris Mason 已提交
4185 4186 4187 4188
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
4189
	struct btrfs_key found_key;
C
Chris Mason 已提交
4190 4191 4192
	struct btrfs_path *path;
	int ret;
	u32 nritems;
4193
	struct extent_buffer *leaf;
C
Chris Mason 已提交
4194 4195 4196 4197 4198 4199 4200 4201
	int slot;
	int advance;
	unsigned char d_type;
	int over = 0;
	u32 di_cur;
	u32 di_total;
	u32 di_len;
	int key_type = BTRFS_DIR_INDEX_KEY;
4202 4203 4204
	char tmp_name[32];
	char *name_ptr;
	int name_len;
C
Chris Mason 已提交
4205 4206 4207 4208

	/* FIXME, use a real flag for deciding about the key type */
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;
4209

4210 4211 4212 4213 4214 4215 4216 4217 4218 4219 4220
	/* special case for "." */
	if (filp->f_pos == 0) {
		over = filldir(dirent, ".", 1,
			       1, inode->i_ino,
			       DT_DIR);
		if (over)
			return 0;
		filp->f_pos = 1;
	}
	/* special case for .., just use the back ref */
	if (filp->f_pos == 1) {
4221
		u64 pino = parent_ino(filp->f_path.dentry);
4222
		over = filldir(dirent, "..", 2,
4223
			       2, pino, DT_DIR);
4224
		if (over)
4225
			return 0;
4226 4227
		filp->f_pos = 2;
	}
4228 4229 4230
	path = btrfs_alloc_path();
	path->reada = 2;

C
Chris Mason 已提交
4231 4232
	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
4233
	key.objectid = inode->i_ino;
4234

C
Chris Mason 已提交
4235 4236 4237 4238
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;
	advance = 0;
4239 4240

	while (1) {
4241 4242
		leaf = path->nodes[0];
		nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
4243 4244
		slot = path->slots[0];
		if (advance || slot >= nritems) {
4245
			if (slot >= nritems - 1) {
C
Chris Mason 已提交
4246 4247 4248
				ret = btrfs_next_leaf(root, path);
				if (ret)
					break;
4249 4250
				leaf = path->nodes[0];
				nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
4251 4252 4253 4254 4255 4256
				slot = path->slots[0];
			} else {
				slot++;
				path->slots[0]++;
			}
		}
4257

C
Chris Mason 已提交
4258
		advance = 1;
4259 4260 4261 4262
		item = btrfs_item_nr(leaf, slot);
		btrfs_item_key_to_cpu(leaf, &found_key, slot);

		if (found_key.objectid != key.objectid)
C
Chris Mason 已提交
4263
			break;
4264
		if (btrfs_key_type(&found_key) != key_type)
C
Chris Mason 已提交
4265
			break;
4266
		if (found_key.offset < filp->f_pos)
C
Chris Mason 已提交
4267
			continue;
4268 4269

		filp->f_pos = found_key.offset;
4270

C
Chris Mason 已提交
4271 4272
		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
4273
		di_total = btrfs_item_size(leaf, item);
4274 4275

		while (di_cur < di_total) {
4276 4277 4278
			struct btrfs_key location;

			name_len = btrfs_dir_name_len(leaf, di);
4279
			if (name_len <= sizeof(tmp_name)) {
4280 4281 4282
				name_ptr = tmp_name;
			} else {
				name_ptr = kmalloc(name_len, GFP_NOFS);
4283 4284 4285 4286
				if (!name_ptr) {
					ret = -ENOMEM;
					goto err;
				}
4287 4288 4289 4290 4291 4292
			}
			read_extent_buffer(leaf, name_ptr,
					   (unsigned long)(di + 1), name_len);

			d_type = btrfs_filetype_table[btrfs_dir_type(leaf, di)];
			btrfs_dir_item_key_to_cpu(leaf, di, &location);
4293 4294 4295 4296 4297 4298 4299 4300 4301

			/* is this a reference to our own snapshot? If so
			 * skip it
			 */
			if (location.type == BTRFS_ROOT_ITEM_KEY &&
			    location.objectid == root->root_key.objectid) {
				over = 0;
				goto skip;
			}
4302
			over = filldir(dirent, name_ptr, name_len,
4303
				       found_key.offset, location.objectid,
C
Chris Mason 已提交
4304
				       d_type);
4305

4306
skip:
4307 4308 4309
			if (name_ptr != tmp_name)
				kfree(name_ptr);

C
Chris Mason 已提交
4310 4311
			if (over)
				goto nopos;
J
Josef Bacik 已提交
4312
			di_len = btrfs_dir_name_len(leaf, di) +
4313
				 btrfs_dir_data_len(leaf, di) + sizeof(*di);
C
Chris Mason 已提交
4314 4315 4316 4317
			di_cur += di_len;
			di = (struct btrfs_dir_item *)((char *)di + di_len);
		}
	}
4318 4319

	/* Reached end of directory/root. Bump pos past the last item. */
4320
	if (key_type == BTRFS_DIR_INDEX_KEY)
4321 4322 4323 4324 4325
		/*
		 * 32-bit glibc will use getdents64, but then strtol -
		 * so the last number we can serve is this.
		 */
		filp->f_pos = 0x7fffffff;
4326 4327
	else
		filp->f_pos++;
C
Chris Mason 已提交
4328 4329 4330 4331 4332 4333 4334
nopos:
	ret = 0;
err:
	btrfs_free_path(path);
	return ret;
}

4335
int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
C
Chris Mason 已提交
4336 4337 4338 4339
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	int ret = 0;
4340
	bool nolock = false;
C
Chris Mason 已提交
4341

4342
	if (BTRFS_I(inode)->dummy_inode)
4343 4344
		return 0;

4345 4346 4347
	smp_mb();
	nolock = (root->fs_info->closing && root == root->fs_info->tree_root);

4348
	if (wbc->sync_mode == WB_SYNC_ALL) {
4349 4350 4351 4352
		if (nolock)
			trans = btrfs_join_transaction_nolock(root, 1);
		else
			trans = btrfs_join_transaction(root, 1);
C
Chris Mason 已提交
4353
		btrfs_set_trans_block_group(trans, inode);
4354 4355 4356 4357
		if (nolock)
			ret = btrfs_end_transaction_nolock(trans, root);
		else
			ret = btrfs_commit_transaction(trans, root);
C
Chris Mason 已提交
4358 4359 4360 4361 4362
	}
	return ret;
}

/*
4363
 * This is somewhat expensive, updating the tree every time the
C
Chris Mason 已提交
4364 4365 4366 4367 4368 4369 4370 4371
 * inode changes.  But, it is most likely to find the inode in cache.
 * FIXME, needs more benchmarking...there are no reasons other than performance
 * to keep or drop this code.
 */
void btrfs_dirty_inode(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
4372 4373 4374 4375
	int ret;

	if (BTRFS_I(inode)->dummy_inode)
		return;
C
Chris Mason 已提交
4376

4377
	trans = btrfs_join_transaction(root, 1);
C
Chris Mason 已提交
4378
	btrfs_set_trans_block_group(trans, inode);
4379 4380

	ret = btrfs_update_inode(trans, root, inode);
4381 4382 4383 4384
	if (ret && ret == -ENOSPC) {
		/* whoops, lets try again with the full transaction */
		btrfs_end_transaction(trans, root);
		trans = btrfs_start_transaction(root, 1);
4385 4386 4387 4388 4389 4390 4391 4392
		if (IS_ERR(trans)) {
			if (printk_ratelimit()) {
				printk(KERN_ERR "btrfs: fail to "
				       "dirty  inode %lu error %ld\n",
				       inode->i_ino, PTR_ERR(trans));
			}
			return;
		}
4393
		btrfs_set_trans_block_group(trans, inode);
4394

4395 4396
		ret = btrfs_update_inode(trans, root, inode);
		if (ret) {
4397 4398 4399 4400 4401
			if (printk_ratelimit()) {
				printk(KERN_ERR "btrfs: fail to "
				       "dirty  inode %lu error %d\n",
				       inode->i_ino, ret);
			}
4402 4403
		}
	}
C
Chris Mason 已提交
4404 4405 4406
	btrfs_end_transaction(trans, root);
}

C
Chris Mason 已提交
4407 4408 4409 4410 4411
/*
 * find the highest existing sequence number in a directory
 * and then set the in-memory index_cnt variable to reflect
 * free sequence numbers
 */
4412 4413 4414 4415 4416 4417 4418 4419 4420 4421 4422 4423 4424 4425 4426 4427 4428 4429 4430 4431 4432 4433 4434 4435 4436 4437 4438 4439 4440 4441 4442 4443 4444 4445 4446 4447 4448 4449 4450 4451 4452 4453 4454 4455 4456 4457 4458 4459 4460 4461 4462 4463
static int btrfs_set_inode_index_count(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key key, found_key;
	struct btrfs_path *path;
	struct extent_buffer *leaf;
	int ret;

	key.objectid = inode->i_ino;
	btrfs_set_key_type(&key, BTRFS_DIR_INDEX_KEY);
	key.offset = (u64)-1;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto out;
	/* FIXME: we should be able to handle this */
	if (ret == 0)
		goto out;
	ret = 0;

	/*
	 * MAGIC NUMBER EXPLANATION:
	 * since we search a directory based on f_pos we have to start at 2
	 * since '.' and '..' have f_pos of 0 and 1 respectively, so everybody
	 * else has to start at 2
	 */
	if (path->slots[0] == 0) {
		BTRFS_I(inode)->index_cnt = 2;
		goto out;
	}

	path->slots[0]--;

	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);

	if (found_key.objectid != inode->i_ino ||
	    btrfs_key_type(&found_key) != BTRFS_DIR_INDEX_KEY) {
		BTRFS_I(inode)->index_cnt = 2;
		goto out;
	}

	BTRFS_I(inode)->index_cnt = found_key.offset + 1;
out:
	btrfs_free_path(path);
	return ret;
}

C
Chris Mason 已提交
4464 4465 4466 4467
/*
 * helper to find a free sequence number in a given directory.  This current
 * code is very simple, later versions will do smarter things in the btree
 */
4468
int btrfs_set_inode_index(struct inode *dir, u64 *index)
4469 4470 4471 4472 4473
{
	int ret = 0;

	if (BTRFS_I(dir)->index_cnt == (u64)-1) {
		ret = btrfs_set_inode_index_count(dir);
C
Chris Mason 已提交
4474
		if (ret)
4475 4476 4477
			return ret;
	}

4478
	*index = BTRFS_I(dir)->index_cnt;
4479 4480 4481 4482 4483
	BTRFS_I(dir)->index_cnt++;

	return ret;
}

C
Chris Mason 已提交
4484 4485
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
4486
				     struct inode *dir,
4487
				     const char *name, int name_len,
4488 4489
				     u64 ref_objectid, u64 objectid,
				     u64 alloc_hint, int mode, u64 *index)
C
Chris Mason 已提交
4490 4491
{
	struct inode *inode;
4492
	struct btrfs_inode_item *inode_item;
C
Chris Mason 已提交
4493
	struct btrfs_key *location;
4494
	struct btrfs_path *path;
4495 4496 4497 4498
	struct btrfs_inode_ref *ref;
	struct btrfs_key key[2];
	u32 sizes[2];
	unsigned long ptr;
C
Chris Mason 已提交
4499 4500 4501
	int ret;
	int owner;

4502 4503 4504
	path = btrfs_alloc_path();
	BUG_ON(!path);

C
Chris Mason 已提交
4505 4506 4507 4508
	inode = new_inode(root->fs_info->sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

4509
	if (dir) {
4510
		ret = btrfs_set_inode_index(dir, index);
4511 4512
		if (ret) {
			iput(inode);
4513
			return ERR_PTR(ret);
4514
		}
4515 4516 4517 4518 4519 4520 4521
	}
	/*
	 * index_cnt is ignored for everything but a dir,
	 * btrfs_get_inode_index_count has an explanation for the magic
	 * number
	 */
	BTRFS_I(inode)->index_cnt = 2;
C
Chris Mason 已提交
4522
	BTRFS_I(inode)->root = root;
4523
	BTRFS_I(inode)->generation = trans->transid;
4524
	inode->i_generation = BTRFS_I(inode)->generation;
J
Josef Bacik 已提交
4525
	btrfs_set_inode_space_info(root, inode);
4526

C
Chris Mason 已提交
4527 4528 4529 4530
	if (mode & S_IFDIR)
		owner = 0;
	else
		owner = 1;
4531 4532
	BTRFS_I(inode)->block_group =
			btrfs_find_block_group(root, 0, alloc_hint, owner);
4533 4534 4535 4536 4537 4538 4539 4540 4541 4542 4543 4544

	key[0].objectid = objectid;
	btrfs_set_key_type(&key[0], BTRFS_INODE_ITEM_KEY);
	key[0].offset = 0;

	key[1].objectid = objectid;
	btrfs_set_key_type(&key[1], BTRFS_INODE_REF_KEY);
	key[1].offset = ref_objectid;

	sizes[0] = sizeof(struct btrfs_inode_item);
	sizes[1] = name_len + sizeof(*ref);

4545
	path->leave_spinning = 1;
4546 4547
	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
	if (ret != 0)
4548 4549
		goto fail;

4550
	inode_init_owner(inode, dir, mode);
C
Chris Mason 已提交
4551
	inode->i_ino = objectid;
4552
	inode_set_bytes(inode, 0);
C
Chris Mason 已提交
4553
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4554 4555
	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
				  struct btrfs_inode_item);
4556
	fill_inode_item(trans, path->nodes[0], inode_item, inode);
4557 4558 4559 4560

	ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1,
			     struct btrfs_inode_ref);
	btrfs_set_inode_ref_name_len(path->nodes[0], ref, name_len);
4561
	btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4562 4563 4564
	ptr = (unsigned long)(ref + 1);
	write_extent_buffer(path->nodes[0], name, ptr, name_len);

4565 4566 4567
	btrfs_mark_buffer_dirty(path->nodes[0]);
	btrfs_free_path(path);

C
Chris Mason 已提交
4568 4569 4570 4571 4572
	location = &BTRFS_I(inode)->location;
	location->objectid = objectid;
	location->offset = 0;
	btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);

4573 4574
	btrfs_inherit_iflags(inode, dir);

4575 4576 4577 4578 4579 4580 4581
	if ((mode & S_IFREG)) {
		if (btrfs_test_opt(root, NODATASUM))
			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATASUM;
		if (btrfs_test_opt(root, NODATACOW))
			BTRFS_I(inode)->flags |= BTRFS_INODE_NODATACOW;
	}

C
Chris Mason 已提交
4582
	insert_inode_hash(inode);
4583
	inode_tree_add(inode);
C
Chris Mason 已提交
4584
	return inode;
4585
fail:
4586 4587
	if (dir)
		BTRFS_I(dir)->index_cnt--;
4588
	btrfs_free_path(path);
4589
	iput(inode);
4590
	return ERR_PTR(ret);
C
Chris Mason 已提交
4591 4592 4593 4594 4595 4596 4597
}

static inline u8 btrfs_inode_type(struct inode *inode)
{
	return btrfs_type_by_mode[(inode->i_mode & S_IFMT) >> S_SHIFT];
}

C
Chris Mason 已提交
4598 4599 4600 4601 4602 4603
/*
 * utility function to add 'inode' into 'parent_inode' with
 * a give name and a given sequence number.
 * if 'add_backref' is true, also insert a backref from the
 * inode to the parent directory.
 */
4604 4605 4606
int btrfs_add_link(struct btrfs_trans_handle *trans,
		   struct inode *parent_inode, struct inode *inode,
		   const char *name, int name_len, int add_backref, u64 index)
C
Chris Mason 已提交
4607
{
4608
	int ret = 0;
C
Chris Mason 已提交
4609
	struct btrfs_key key;
4610
	struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4611

4612 4613 4614 4615 4616 4617 4618 4619 4620 4621 4622 4623 4624 4625 4626 4627 4628 4629
	if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
		memcpy(&key, &BTRFS_I(inode)->root->root_key, sizeof(key));
	} else {
		key.objectid = inode->i_ino;
		btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
		key.offset = 0;
	}

	if (unlikely(inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
		ret = btrfs_add_root_ref(trans, root->fs_info->tree_root,
					 key.objectid, root->root_key.objectid,
					 parent_inode->i_ino,
					 index, name, name_len);
	} else if (add_backref) {
		ret = btrfs_insert_inode_ref(trans, root,
					     name, name_len, inode->i_ino,
					     parent_inode->i_ino, index);
	}
C
Chris Mason 已提交
4630 4631

	if (ret == 0) {
4632 4633 4634 4635 4636
		ret = btrfs_insert_dir_item(trans, root, name, name_len,
					    parent_inode->i_ino, &key,
					    btrfs_inode_type(inode), index);
		BUG_ON(ret);

4637
		btrfs_i_size_write(parent_inode, parent_inode->i_size +
4638
				   name_len * 2);
4639
		parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4640
		ret = btrfs_update_inode(trans, root, parent_inode);
C
Chris Mason 已提交
4641 4642 4643 4644 4645
	}
	return ret;
}

static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4646 4647
			    struct inode *dir, struct dentry *dentry,
			    struct inode *inode, int backref, u64 index)
C
Chris Mason 已提交
4648
{
4649 4650 4651
	int err = btrfs_add_link(trans, dir, inode,
				 dentry->d_name.name, dentry->d_name.len,
				 backref, index);
C
Chris Mason 已提交
4652 4653 4654 4655 4656 4657 4658 4659 4660
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	if (err > 0)
		err = -EEXIST;
	return err;
}

J
Josef Bacik 已提交
4661 4662 4663 4664 4665
static int btrfs_mknod(struct inode *dir, struct dentry *dentry,
			int mode, dev_t rdev)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
4666
	struct inode *inode = NULL;
J
Josef Bacik 已提交
4667 4668 4669
	int err;
	int drop_inode = 0;
	u64 objectid;
4670
	unsigned long nr = 0;
4671
	u64 index = 0;
J
Josef Bacik 已提交
4672 4673 4674 4675

	if (!new_valid_dev(rdev))
		return -EINVAL;

4676 4677 4678 4679
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;

J
Josef Bacik 已提交
4680 4681 4682 4683 4684
	/*
	 * 2 for inode item and ref
	 * 2 for dir items
	 * 1 for xattr if selinux is on
	 */
4685 4686 4687
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
4688

J
Josef Bacik 已提交
4689 4690
	btrfs_set_trans_block_group(trans, dir);

4691
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4692
				dentry->d_name.len, dir->i_ino, objectid,
4693
				BTRFS_I(dir)->block_group, mode, &index);
J
Josef Bacik 已提交
4694 4695 4696 4697
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

4698
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4699 4700 4701 4702 4703
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

J
Josef Bacik 已提交
4704
	btrfs_set_trans_block_group(trans, inode);
4705
	err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
J
Josef Bacik 已提交
4706 4707 4708 4709 4710
	if (err)
		drop_inode = 1;
	else {
		inode->i_op = &btrfs_special_inode_operations;
		init_special_inode(inode, inode->i_mode, rdev);
4711
		btrfs_update_inode(trans, root, inode);
J
Josef Bacik 已提交
4712 4713 4714 4715
	}
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
4716
	nr = trans->blocks_used;
4717
	btrfs_end_transaction_throttle(trans, root);
4718
	btrfs_btree_balance_dirty(root, nr);
J
Josef Bacik 已提交
4719 4720 4721 4722 4723 4724 4725
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
	return err;
}

C
Chris Mason 已提交
4726 4727 4728 4729 4730
static int btrfs_create(struct inode *dir, struct dentry *dentry,
			int mode, struct nameidata *nd)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
4731
	struct inode *inode = NULL;
C
Chris Mason 已提交
4732
	int drop_inode = 0;
4733
	int err;
4734
	unsigned long nr = 0;
C
Chris Mason 已提交
4735
	u64 objectid;
4736
	u64 index = 0;
C
Chris Mason 已提交
4737

4738 4739 4740
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;
J
Josef Bacik 已提交
4741 4742 4743 4744 4745
	/*
	 * 2 for inode item and ref
	 * 2 for dir items
	 * 1 for xattr if selinux is on
	 */
4746 4747 4748
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
J
Josef Bacik 已提交
4749

C
Chris Mason 已提交
4750 4751
	btrfs_set_trans_block_group(trans, dir);

4752
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4753 4754
				dentry->d_name.len, dir->i_ino, objectid,
				BTRFS_I(dir)->block_group, mode, &index);
C
Chris Mason 已提交
4755 4756 4757 4758
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

4759
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4760 4761 4762 4763 4764
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

C
Chris Mason 已提交
4765
	btrfs_set_trans_block_group(trans, inode);
4766
	err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
C
Chris Mason 已提交
4767 4768 4769 4770
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
C
Chris Mason 已提交
4771
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
4772 4773
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
4774
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
4775 4776 4777 4778
	}
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
4779
	nr = trans->blocks_used;
4780
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
4781 4782 4783 4784
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
4785
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4786 4787 4788 4789 4790 4791 4792 4793 4794
	return err;
}

static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
		      struct dentry *dentry)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct inode *inode = old_dentry->d_inode;
4795
	u64 index;
4796
	unsigned long nr = 0;
C
Chris Mason 已提交
4797 4798 4799 4800 4801 4802
	int err;
	int drop_inode = 0;

	if (inode->i_nlink == 0)
		return -ENOENT;

4803 4804 4805 4806
	/* do not allow sys_link's with other subvols of the same device */
	if (root->objectid != BTRFS_I(inode)->root->objectid)
		return -EPERM;

J
Josef Bacik 已提交
4807
	btrfs_inc_nlink(inode);
4808
	inode->i_ctime = CURRENT_TIME;
J
Josef Bacik 已提交
4809

4810
	err = btrfs_set_inode_index(dir, &index);
4811 4812 4813
	if (err)
		goto fail;

4814 4815 4816 4817 4818 4819 4820 4821 4822
	/*
	 * 1 item for inode ref
	 * 2 items for dir items
	 */
	trans = btrfs_start_transaction(root, 3);
	if (IS_ERR(trans)) {
		err = PTR_ERR(trans);
		goto fail;
	}
4823

C
Chris Mason 已提交
4824 4825
	btrfs_set_trans_block_group(trans, dir);
	atomic_inc(&inode->i_count);
4826

4827
	err = btrfs_add_nondir(trans, dir, dentry, inode, 1, index);
4828

4829
	if (err) {
4830
		drop_inode = 1;
4831
	} else {
4832
		struct dentry *parent = dget_parent(dentry);
4833 4834 4835
		btrfs_update_inode_block_group(trans, dir);
		err = btrfs_update_inode(trans, root, inode);
		BUG_ON(err);
4836 4837
		btrfs_log_new_name(trans, inode, NULL, parent);
		dput(parent);
4838
	}
C
Chris Mason 已提交
4839

4840
	nr = trans->blocks_used;
4841
	btrfs_end_transaction_throttle(trans, root);
4842
fail:
C
Chris Mason 已提交
4843 4844 4845 4846
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
4847
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4848 4849 4850 4851 4852
	return err;
}

static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
4853
	struct inode *inode = NULL;
C
Chris Mason 已提交
4854 4855 4856 4857
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	int err = 0;
	int drop_on_err = 0;
4858
	u64 objectid = 0;
4859
	u64 index = 0;
4860
	unsigned long nr = 1;
C
Chris Mason 已提交
4861

4862 4863 4864 4865
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;

J
Josef Bacik 已提交
4866 4867 4868 4869 4870
	/*
	 * 2 items for inode and ref
	 * 2 items for dir items
	 * 1 for xattr if selinux is on
	 */
4871 4872 4873
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
J
Josef Bacik 已提交
4874
	btrfs_set_trans_block_group(trans, dir);
C
Chris Mason 已提交
4875

4876
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4877
				dentry->d_name.len, dir->i_ino, objectid,
4878 4879
				BTRFS_I(dir)->block_group, S_IFDIR | mode,
				&index);
C
Chris Mason 已提交
4880 4881 4882 4883
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fail;
	}
4884

C
Chris Mason 已提交
4885
	drop_on_err = 1;
J
Josef Bacik 已提交
4886

4887
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4888 4889 4890
	if (err)
		goto out_fail;

C
Chris Mason 已提交
4891 4892 4893 4894
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
	btrfs_set_trans_block_group(trans, inode);

4895
	btrfs_i_size_write(inode, 0);
C
Chris Mason 已提交
4896 4897 4898
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		goto out_fail;
4899

4900 4901
	err = btrfs_add_link(trans, dir, inode, dentry->d_name.name,
			     dentry->d_name.len, 0, index);
C
Chris Mason 已提交
4902 4903
	if (err)
		goto out_fail;
4904

C
Chris Mason 已提交
4905 4906 4907 4908 4909 4910
	d_instantiate(dentry, inode);
	drop_on_err = 0;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);

out_fail:
4911
	nr = trans->blocks_used;
4912
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
4913 4914
	if (drop_on_err)
		iput(inode);
4915
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4916 4917 4918
	return err;
}

C
Chris Mason 已提交
4919 4920 4921 4922
/* helper for btfs_get_extent.  Given an existing extent in the tree,
 * and an extent that you want to insert, deal with overlap and insert
 * the new extent into the tree.
 */
4923 4924
static int merge_extent_mapping(struct extent_map_tree *em_tree,
				struct extent_map *existing,
4925 4926
				struct extent_map *em,
				u64 map_start, u64 map_len)
4927 4928 4929
{
	u64 start_diff;

4930 4931 4932 4933
	BUG_ON(map_start < em->start || map_start >= extent_map_end(em));
	start_diff = map_start - em->start;
	em->start = map_start;
	em->len = map_len;
C
Chris Mason 已提交
4934 4935
	if (em->block_start < EXTENT_MAP_LAST_BYTE &&
	    !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4936
		em->block_start += start_diff;
C
Chris Mason 已提交
4937 4938
		em->block_len -= start_diff;
	}
4939
	return add_extent_mapping(em_tree, em);
4940 4941
}

C
Chris Mason 已提交
4942 4943 4944 4945 4946 4947 4948 4949 4950 4951 4952
static noinline int uncompress_inline(struct btrfs_path *path,
				      struct inode *inode, struct page *page,
				      size_t pg_offset, u64 extent_offset,
				      struct btrfs_file_extent_item *item)
{
	int ret;
	struct extent_buffer *leaf = path->nodes[0];
	char *tmp;
	size_t max_size;
	unsigned long inline_size;
	unsigned long ptr;
4953
	int compress_type;
C
Chris Mason 已提交
4954 4955

	WARN_ON(pg_offset != 0);
4956
	compress_type = btrfs_file_extent_compression(leaf, item);
C
Chris Mason 已提交
4957 4958 4959 4960 4961 4962 4963 4964
	max_size = btrfs_file_extent_ram_bytes(leaf, item);
	inline_size = btrfs_file_extent_inline_item_len(leaf,
					btrfs_item_nr(leaf, path->slots[0]));
	tmp = kmalloc(inline_size, GFP_NOFS);
	ptr = btrfs_file_extent_inline_start(item);

	read_extent_buffer(leaf, tmp, ptr, inline_size);

4965
	max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
4966 4967
	ret = btrfs_decompress(compress_type, tmp, page,
			       extent_offset, inline_size, max_size);
C
Chris Mason 已提交
4968 4969 4970 4971 4972 4973 4974 4975 4976 4977 4978 4979
	if (ret) {
		char *kaddr = kmap_atomic(page, KM_USER0);
		unsigned long copy_size = min_t(u64,
				  PAGE_CACHE_SIZE - pg_offset,
				  max_size - extent_offset);
		memset(kaddr + pg_offset, 0, copy_size);
		kunmap_atomic(kaddr, KM_USER0);
	}
	kfree(tmp);
	return 0;
}

C
Chris Mason 已提交
4980 4981
/*
 * a bit scary, this does extent mapping from logical file offset to the disk.
C
Chris Mason 已提交
4982 4983
 * the ugly parts come from merging extents from the disk with the in-ram
 * representation.  This gets more complex because of the data=ordered code,
C
Chris Mason 已提交
4984 4985 4986 4987
 * where the in-ram extents might be locked pending data=ordered completion.
 *
 * This also copies inline extents directly into the page.
 */
C
Chris Mason 已提交
4988

4989
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
4990
				    size_t pg_offset, u64 start, u64 len,
4991 4992 4993 4994
				    int create)
{
	int ret;
	int err = 0;
4995
	u64 bytenr;
4996 4997 4998 4999
	u64 extent_start = 0;
	u64 extent_end = 0;
	u64 objectid = inode->i_ino;
	u32 found_type;
5000
	struct btrfs_path *path = NULL;
5001 5002
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_file_extent_item *item;
5003 5004
	struct extent_buffer *leaf;
	struct btrfs_key found_key;
5005 5006
	struct extent_map *em = NULL;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
5007
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
5008
	struct btrfs_trans_handle *trans = NULL;
5009
	int compress_type;
5010 5011

again:
5012
	read_lock(&em_tree->lock);
5013
	em = lookup_extent_mapping(em_tree, start, len);
5014 5015
	if (em)
		em->bdev = root->fs_info->fs_devices->latest_bdev;
5016
	read_unlock(&em_tree->lock);
5017

5018
	if (em) {
5019 5020 5021
		if (em->start > start || em->start + em->len <= start)
			free_extent_map(em);
		else if (em->block_start == EXTENT_MAP_INLINE && page)
5022 5023 5024
			free_extent_map(em);
		else
			goto out;
5025
	}
5026
	em = alloc_extent_map(GFP_NOFS);
5027
	if (!em) {
5028 5029
		err = -ENOMEM;
		goto out;
5030
	}
5031
	em->bdev = root->fs_info->fs_devices->latest_bdev;
5032
	em->start = EXTENT_MAP_HOLE;
5033
	em->orig_start = EXTENT_MAP_HOLE;
5034
	em->len = (u64)-1;
C
Chris Mason 已提交
5035
	em->block_len = (u64)-1;
5036 5037 5038 5039 5040 5041

	if (!path) {
		path = btrfs_alloc_path();
		BUG_ON(!path);
	}

5042 5043
	ret = btrfs_lookup_file_extent(trans, root, path,
				       objectid, start, trans != NULL);
5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054
	if (ret < 0) {
		err = ret;
		goto out;
	}

	if (ret != 0) {
		if (path->slots[0] == 0)
			goto not_found;
		path->slots[0]--;
	}

5055 5056
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0],
5057 5058
			      struct btrfs_file_extent_item);
	/* are we inside the extent that was found? */
5059 5060 5061
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	found_type = btrfs_key_type(&found_key);
	if (found_key.objectid != objectid ||
5062 5063 5064 5065
	    found_type != BTRFS_EXTENT_DATA_KEY) {
		goto not_found;
	}

5066 5067
	found_type = btrfs_file_extent_type(leaf, item);
	extent_start = found_key.offset;
5068
	compress_type = btrfs_file_extent_compression(leaf, item);
Y
Yan Zheng 已提交
5069 5070
	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5071
		extent_end = extent_start +
5072
		       btrfs_file_extent_num_bytes(leaf, item);
Y
Yan Zheng 已提交
5073 5074 5075 5076 5077 5078 5079 5080 5081 5082 5083 5084 5085 5086
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
		size_t size;
		size = btrfs_file_extent_inline_len(leaf, item);
		extent_end = (extent_start + size + root->sectorsize - 1) &
			~((u64)root->sectorsize - 1);
	}

	if (start >= extent_end) {
		path->slots[0]++;
		if (path->slots[0] >= btrfs_header_nritems(leaf)) {
			ret = btrfs_next_leaf(root, path);
			if (ret < 0) {
				err = ret;
				goto out;
5087
			}
Y
Yan Zheng 已提交
5088 5089 5090
			if (ret > 0)
				goto not_found;
			leaf = path->nodes[0];
5091
		}
Y
Yan Zheng 已提交
5092 5093 5094 5095 5096 5097 5098 5099 5100 5101 5102
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		if (found_key.objectid != objectid ||
		    found_key.type != BTRFS_EXTENT_DATA_KEY)
			goto not_found;
		if (start + len <= found_key.offset)
			goto not_found;
		em->start = start;
		em->len = found_key.offset - start;
		goto not_found_em;
	}

Y
Yan Zheng 已提交
5103 5104
	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
Y
Yan Zheng 已提交
5105 5106
		em->start = extent_start;
		em->len = extent_end - extent_start;
5107 5108
		em->orig_start = extent_start -
				 btrfs_file_extent_offset(leaf, item);
5109 5110
		bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
		if (bytenr == 0) {
5111
			em->block_start = EXTENT_MAP_HOLE;
5112 5113
			goto insert;
		}
5114
		if (compress_type != BTRFS_COMPRESS_NONE) {
C
Chris Mason 已提交
5115
			set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5116
			em->compress_type = compress_type;
C
Chris Mason 已提交
5117 5118 5119 5120 5121 5122 5123
			em->block_start = bytenr;
			em->block_len = btrfs_file_extent_disk_num_bytes(leaf,
									 item);
		} else {
			bytenr += btrfs_file_extent_offset(leaf, item);
			em->block_start = bytenr;
			em->block_len = em->len;
Y
Yan Zheng 已提交
5124 5125
			if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
				set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
C
Chris Mason 已提交
5126
		}
5127 5128
		goto insert;
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5129
		unsigned long ptr;
5130
		char *map;
5131 5132 5133
		size_t size;
		size_t extent_offset;
		size_t copy_size;
5134

5135
		em->block_start = EXTENT_MAP_INLINE;
C
Chris Mason 已提交
5136
		if (!page || create) {
5137
			em->start = extent_start;
Y
Yan Zheng 已提交
5138
			em->len = extent_end - extent_start;
5139 5140
			goto out;
		}
5141

Y
Yan Zheng 已提交
5142 5143
		size = btrfs_file_extent_inline_len(leaf, item);
		extent_offset = page_offset(page) + pg_offset - extent_start;
5144
		copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5145 5146
				size - extent_offset);
		em->start = extent_start + extent_offset;
5147 5148
		em->len = (copy_size + root->sectorsize - 1) &
			~((u64)root->sectorsize - 1);
5149
		em->orig_start = EXTENT_MAP_INLINE;
5150
		if (compress_type) {
C
Chris Mason 已提交
5151
			set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5152 5153
			em->compress_type = compress_type;
		}
5154
		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5155
		if (create == 0 && !PageUptodate(page)) {
5156 5157
			if (btrfs_file_extent_compression(leaf, item) !=
			    BTRFS_COMPRESS_NONE) {
C
Chris Mason 已提交
5158 5159 5160 5161 5162 5163 5164 5165
				ret = uncompress_inline(path, inode, page,
							pg_offset,
							extent_offset, item);
				BUG_ON(ret);
			} else {
				map = kmap(page);
				read_extent_buffer(leaf, map + pg_offset, ptr,
						   copy_size);
5166 5167 5168 5169 5170
				if (pg_offset + copy_size < PAGE_CACHE_SIZE) {
					memset(map + pg_offset + copy_size, 0,
					       PAGE_CACHE_SIZE - pg_offset -
					       copy_size);
				}
C
Chris Mason 已提交
5171 5172
				kunmap(page);
			}
5173 5174
			flush_dcache_page(page);
		} else if (create && PageUptodate(page)) {
5175
			WARN_ON(1);
5176 5177 5178 5179 5180
			if (!trans) {
				kunmap(page);
				free_extent_map(em);
				em = NULL;
				btrfs_release_path(root, path);
5181
				trans = btrfs_join_transaction(root, 1);
5182 5183
				goto again;
			}
C
Chris Mason 已提交
5184
			map = kmap(page);
5185
			write_extent_buffer(leaf, map + pg_offset, ptr,
5186
					    copy_size);
C
Chris Mason 已提交
5187
			kunmap(page);
5188
			btrfs_mark_buffer_dirty(leaf);
5189
		}
5190 5191
		set_extent_uptodate(io_tree, em->start,
				    extent_map_end(em) - 1, GFP_NOFS);
5192 5193
		goto insert;
	} else {
C
Chris Mason 已提交
5194
		printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5195 5196 5197 5198
		WARN_ON(1);
	}
not_found:
	em->start = start;
5199
	em->len = len;
5200
not_found_em:
5201
	em->block_start = EXTENT_MAP_HOLE;
Y
Yan Zheng 已提交
5202
	set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5203 5204
insert:
	btrfs_release_path(root, path);
5205
	if (em->start > start || extent_map_end(em) <= start) {
C
Chris Mason 已提交
5206 5207 5208 5209 5210
		printk(KERN_ERR "Btrfs: bad extent! em: [%llu %llu] passed "
		       "[%llu %llu]\n", (unsigned long long)em->start,
		       (unsigned long long)em->len,
		       (unsigned long long)start,
		       (unsigned long long)len);
5211 5212 5213
		err = -EIO;
		goto out;
	}
5214 5215

	err = 0;
5216
	write_lock(&em_tree->lock);
5217
	ret = add_extent_mapping(em_tree, em);
5218 5219 5220 5221
	/* it is possible that someone inserted the extent into the tree
	 * while we had the lock dropped.  It is also possible that
	 * an overlapping map exists in the tree
	 */
5222
	if (ret == -EEXIST) {
5223
		struct extent_map *existing;
5224 5225 5226

		ret = 0;

5227
		existing = lookup_extent_mapping(em_tree, start, len);
5228 5229 5230 5231 5232
		if (existing && (existing->start > start ||
		    existing->start + existing->len <= start)) {
			free_extent_map(existing);
			existing = NULL;
		}
5233 5234 5235 5236 5237
		if (!existing) {
			existing = lookup_extent_mapping(em_tree, em->start,
							 em->len);
			if (existing) {
				err = merge_extent_mapping(em_tree, existing,
5238 5239
							   em, start,
							   root->sectorsize);
5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252
				free_extent_map(existing);
				if (err) {
					free_extent_map(em);
					em = NULL;
				}
			} else {
				err = -EIO;
				free_extent_map(em);
				em = NULL;
			}
		} else {
			free_extent_map(em);
			em = existing;
5253
			err = 0;
5254 5255
		}
	}
5256
	write_unlock(&em_tree->lock);
5257
out:
5258 5259
	if (path)
		btrfs_free_path(path);
5260 5261
	if (trans) {
		ret = btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
5262
		if (!err)
5263 5264 5265 5266 5267 5268 5269 5270 5271
			err = ret;
	}
	if (err) {
		free_extent_map(em);
		return ERR_PTR(err);
	}
	return em;
}

5272 5273 5274 5275 5276 5277 5278 5279 5280 5281 5282 5283 5284 5285 5286 5287 5288 5289 5290 5291 5292 5293 5294 5295 5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308 5309 5310 5311 5312 5313 5314 5315 5316 5317 5318 5319 5320 5321 5322 5323 5324 5325 5326 5327 5328 5329 5330 5331 5332 5333
static struct extent_map *btrfs_new_extent_direct(struct inode *inode,
						  u64 start, u64 len)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	struct extent_map *em;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	struct btrfs_key ins;
	u64 alloc_hint;
	int ret;

	btrfs_drop_extent_cache(inode, start, start + len - 1, 0);

	trans = btrfs_join_transaction(root, 0);
	if (!trans)
		return ERR_PTR(-ENOMEM);

	trans->block_rsv = &root->fs_info->delalloc_block_rsv;

	alloc_hint = get_extent_allocation_hint(inode, start, len);
	ret = btrfs_reserve_extent(trans, root, len, root->sectorsize, 0,
				   alloc_hint, (u64)-1, &ins, 1);
	if (ret) {
		em = ERR_PTR(ret);
		goto out;
	}

	em = alloc_extent_map(GFP_NOFS);
	if (!em) {
		em = ERR_PTR(-ENOMEM);
		goto out;
	}

	em->start = start;
	em->orig_start = em->start;
	em->len = ins.offset;

	em->block_start = ins.objectid;
	em->block_len = ins.offset;
	em->bdev = root->fs_info->fs_devices->latest_bdev;
	set_bit(EXTENT_FLAG_PINNED, &em->flags);

	while (1) {
		write_lock(&em_tree->lock);
		ret = add_extent_mapping(em_tree, em);
		write_unlock(&em_tree->lock);
		if (ret != -EEXIST)
			break;
		btrfs_drop_extent_cache(inode, start, start + em->len - 1, 0);
	}

	ret = btrfs_add_ordered_extent_dio(inode, start, ins.objectid,
					   ins.offset, ins.offset, 0);
	if (ret) {
		btrfs_free_reserved_extent(root, ins.objectid, ins.offset);
		em = ERR_PTR(ret);
	}
out:
	btrfs_end_transaction(trans, root);
	return em;
}

5334 5335 5336 5337 5338 5339 5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352 5353 5354 5355 5356 5357 5358 5359 5360 5361 5362 5363 5364 5365 5366 5367 5368 5369 5370 5371 5372 5373 5374 5375 5376 5377 5378 5379 5380 5381 5382 5383 5384 5385 5386 5387 5388 5389 5390 5391 5392 5393 5394 5395 5396 5397 5398 5399 5400 5401 5402 5403 5404 5405 5406 5407 5408 5409 5410 5411 5412 5413 5414 5415 5416 5417 5418 5419 5420 5421 5422 5423 5424 5425 5426 5427 5428 5429 5430 5431 5432 5433
/*
 * returns 1 when the nocow is safe, < 1 on error, 0 if the
 * block must be cow'd
 */
static noinline int can_nocow_odirect(struct btrfs_trans_handle *trans,
				      struct inode *inode, u64 offset, u64 len)
{
	struct btrfs_path *path;
	int ret;
	struct extent_buffer *leaf;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_file_extent_item *fi;
	struct btrfs_key key;
	u64 disk_bytenr;
	u64 backref_offset;
	u64 extent_end;
	u64 num_bytes;
	int slot;
	int found_type;

	path = btrfs_alloc_path();
	if (!path)
		return -ENOMEM;

	ret = btrfs_lookup_file_extent(trans, root, path, inode->i_ino,
				       offset, 0);
	if (ret < 0)
		goto out;

	slot = path->slots[0];
	if (ret == 1) {
		if (slot == 0) {
			/* can't find the item, must cow */
			ret = 0;
			goto out;
		}
		slot--;
	}
	ret = 0;
	leaf = path->nodes[0];
	btrfs_item_key_to_cpu(leaf, &key, slot);
	if (key.objectid != inode->i_ino ||
	    key.type != BTRFS_EXTENT_DATA_KEY) {
		/* not our file or wrong item type, must cow */
		goto out;
	}

	if (key.offset > offset) {
		/* Wrong offset, must cow */
		goto out;
	}

	fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
	found_type = btrfs_file_extent_type(leaf, fi);
	if (found_type != BTRFS_FILE_EXTENT_REG &&
	    found_type != BTRFS_FILE_EXTENT_PREALLOC) {
		/* not a regular extent, must cow */
		goto out;
	}
	disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
	backref_offset = btrfs_file_extent_offset(leaf, fi);

	extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
	if (extent_end < offset + len) {
		/* extent doesn't include our full range, must cow */
		goto out;
	}

	if (btrfs_extent_readonly(root, disk_bytenr))
		goto out;

	/*
	 * look for other files referencing this extent, if we
	 * find any we must cow
	 */
	if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
				  key.offset - backref_offset, disk_bytenr))
		goto out;

	/*
	 * adjust disk_bytenr and num_bytes to cover just the bytes
	 * in this extent we are about to write.  If there
	 * are any csums in that range we have to cow in order
	 * to keep the csums correct
	 */
	disk_bytenr += backref_offset;
	disk_bytenr += offset - key.offset;
	num_bytes = min(offset + len, extent_end) - offset;
	if (csum_exist_in_range(root, disk_bytenr, num_bytes))
				goto out;
	/*
	 * all of the above have passed, it is safe to overwrite this extent
	 * without cow
	 */
	ret = 1;
out:
	btrfs_free_path(path);
	return ret;
}

5434 5435 5436 5437 5438 5439 5440
static int btrfs_get_blocks_direct(struct inode *inode, sector_t iblock,
				   struct buffer_head *bh_result, int create)
{
	struct extent_map *em;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u64 start = iblock << inode->i_blkbits;
	u64 len = bh_result->b_size;
5441
	struct btrfs_trans_handle *trans;
5442 5443 5444 5445 5446 5447 5448 5449 5450 5451 5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463 5464 5465 5466 5467 5468 5469 5470 5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485

	em = btrfs_get_extent(inode, NULL, 0, start, len, 0);
	if (IS_ERR(em))
		return PTR_ERR(em);

	/*
	 * Ok for INLINE and COMPRESSED extents we need to fallback on buffered
	 * io.  INLINE is special, and we could probably kludge it in here, but
	 * it's still buffered so for safety lets just fall back to the generic
	 * buffered path.
	 *
	 * For COMPRESSED we _have_ to read the entire extent in so we can
	 * decompress it, so there will be buffering required no matter what we
	 * do, so go ahead and fallback to buffered.
	 *
	 * We return -ENOTBLK because thats what makes DIO go ahead and go back
	 * to buffered IO.  Don't blame me, this is the price we pay for using
	 * the generic code.
	 */
	if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) ||
	    em->block_start == EXTENT_MAP_INLINE) {
		free_extent_map(em);
		return -ENOTBLK;
	}

	/* Just a good old fashioned hole, return */
	if (!create && (em->block_start == EXTENT_MAP_HOLE ||
			test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
		free_extent_map(em);
		/* DIO will do one hole at a time, so just unlock a sector */
		unlock_extent(&BTRFS_I(inode)->io_tree, start,
			      start + root->sectorsize - 1, GFP_NOFS);
		return 0;
	}

	/*
	 * We don't allocate a new extent in the following cases
	 *
	 * 1) The inode is marked as NODATACOW.  In this case we'll just use the
	 * existing extent.
	 * 2) The extent is marked as PREALLOC.  We're good to go here and can
	 * just use the extent.
	 *
	 */
5486 5487
	if (!create) {
		len = em->len - (start - em->start);
5488
		goto map;
5489
	}
5490 5491 5492 5493 5494 5495

	if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
	    ((BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW) &&
	     em->block_start != EXTENT_MAP_HOLE)) {
		int type;
		int ret;
5496
		u64 block_start;
5497 5498 5499 5500 5501

		if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
			type = BTRFS_ORDERED_PREALLOC;
		else
			type = BTRFS_ORDERED_NOCOW;
5502
		len = min(len, em->len - (start - em->start));
5503
		block_start = em->block_start + (start - em->start);
5504 5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522

		/*
		 * we're not going to log anything, but we do need
		 * to make sure the current transaction stays open
		 * while we look for nocow cross refs
		 */
		trans = btrfs_join_transaction(root, 0);
		if (!trans)
			goto must_cow;

		if (can_nocow_odirect(trans, inode, start, len) == 1) {
			ret = btrfs_add_ordered_extent_dio(inode, start,
					   block_start, len, len, type);
			btrfs_end_transaction(trans, root);
			if (ret) {
				free_extent_map(em);
				return ret;
			}
			goto unlock;
5523
		}
5524
		btrfs_end_transaction(trans, root);
5525
	}
5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537
must_cow:
	/*
	 * this will cow the extent, reset the len in case we changed
	 * it above
	 */
	len = bh_result->b_size;
	free_extent_map(em);
	em = btrfs_new_extent_direct(inode, start, len);
	if (IS_ERR(em))
		return PTR_ERR(em);
	len = min(len, em->len - (start - em->start));
unlock:
5538 5539 5540
	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
			  EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
			  0, NULL, GFP_NOFS);
5541 5542 5543
map:
	bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
		inode->i_blkbits;
5544
	bh_result->b_size = len;
5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561
	bh_result->b_bdev = em->bdev;
	set_buffer_mapped(bh_result);
	if (create && !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
		set_buffer_new(bh_result);

	free_extent_map(em);

	return 0;
}

struct btrfs_dio_private {
	struct inode *inode;
	u64 logical_offset;
	u64 disk_bytenr;
	u64 bytes;
	u32 *csums;
	void *private;
M
Miao Xie 已提交
5562 5563 5564 5565 5566 5567 5568 5569

	/* number of bios pending for this dio */
	atomic_t pending_bios;

	/* IO errors */
	int errors;

	struct bio *orig_bio;
5570 5571 5572 5573
};

static void btrfs_endio_direct_read(struct bio *bio, int err)
{
M
Miao Xie 已提交
5574
	struct btrfs_dio_private *dip = bio->bi_private;
5575 5576 5577 5578 5579 5580 5581 5582 5583 5584 5585 5586 5587 5588 5589 5590 5591 5592 5593 5594 5595 5596 5597 5598 5599 5600 5601 5602 5603 5604 5605 5606 5607 5608 5609 5610 5611 5612 5613 5614 5615 5616 5617 5618 5619 5620 5621 5622 5623 5624 5625 5626 5627 5628 5629
	struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
	struct bio_vec *bvec = bio->bi_io_vec;
	struct inode *inode = dip->inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u64 start;
	u32 *private = dip->csums;

	start = dip->logical_offset;
	do {
		if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)) {
			struct page *page = bvec->bv_page;
			char *kaddr;
			u32 csum = ~(u32)0;
			unsigned long flags;

			local_irq_save(flags);
			kaddr = kmap_atomic(page, KM_IRQ0);
			csum = btrfs_csum_data(root, kaddr + bvec->bv_offset,
					       csum, bvec->bv_len);
			btrfs_csum_final(csum, (char *)&csum);
			kunmap_atomic(kaddr, KM_IRQ0);
			local_irq_restore(flags);

			flush_dcache_page(bvec->bv_page);
			if (csum != *private) {
				printk(KERN_ERR "btrfs csum failed ino %lu off"
				      " %llu csum %u private %u\n",
				      inode->i_ino, (unsigned long long)start,
				      csum, *private);
				err = -EIO;
			}
		}

		start += bvec->bv_len;
		private++;
		bvec++;
	} while (bvec <= bvec_end);

	unlock_extent(&BTRFS_I(inode)->io_tree, dip->logical_offset,
		      dip->logical_offset + dip->bytes - 1, GFP_NOFS);
	bio->bi_private = dip->private;

	kfree(dip->csums);
	kfree(dip);
	dio_end_io(bio, err);
}

static void btrfs_endio_direct_write(struct bio *bio, int err)
{
	struct btrfs_dio_private *dip = bio->bi_private;
	struct inode *inode = dip->inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	struct btrfs_ordered_extent *ordered = NULL;
	struct extent_state *cached_state = NULL;
5630 5631
	u64 ordered_offset = dip->logical_offset;
	u64 ordered_bytes = dip->bytes;
5632 5633 5634 5635
	int ret;

	if (err)
		goto out_done;
5636 5637 5638 5639
again:
	ret = btrfs_dec_test_first_ordered_pending(inode, &ordered,
						   &ordered_offset,
						   ordered_bytes);
5640
	if (!ret)
5641
		goto out_test;
5642 5643 5644 5645 5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658 5659 5660 5661 5662 5663 5664 5665 5666 5667 5668 5669 5670 5671 5672 5673 5674 5675 5676 5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687 5688 5689 5690 5691 5692 5693 5694 5695 5696 5697 5698 5699 5700

	BUG_ON(!ordered);

	trans = btrfs_join_transaction(root, 1);
	if (!trans) {
		err = -ENOMEM;
		goto out;
	}
	trans->block_rsv = &root->fs_info->delalloc_block_rsv;

	if (test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags)) {
		ret = btrfs_ordered_update_i_size(inode, 0, ordered);
		if (!ret)
			ret = btrfs_update_inode(trans, root, inode);
		err = ret;
		goto out;
	}

	lock_extent_bits(&BTRFS_I(inode)->io_tree, ordered->file_offset,
			 ordered->file_offset + ordered->len - 1, 0,
			 &cached_state, GFP_NOFS);

	if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
		ret = btrfs_mark_extent_written(trans, inode,
						ordered->file_offset,
						ordered->file_offset +
						ordered->len);
		if (ret) {
			err = ret;
			goto out_unlock;
		}
	} else {
		ret = insert_reserved_file_extent(trans, inode,
						  ordered->file_offset,
						  ordered->start,
						  ordered->disk_len,
						  ordered->len,
						  ordered->len,
						  0, 0, 0,
						  BTRFS_FILE_EXTENT_REG);
		unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
				   ordered->file_offset, ordered->len);
		if (ret) {
			err = ret;
			WARN_ON(1);
			goto out_unlock;
		}
	}

	add_pending_csums(trans, inode, ordered->file_offset, &ordered->list);
	btrfs_ordered_update_i_size(inode, 0, ordered);
	btrfs_update_inode(trans, root, inode);
out_unlock:
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, ordered->file_offset,
			     ordered->file_offset + ordered->len - 1,
			     &cached_state, GFP_NOFS);
out:
	btrfs_delalloc_release_metadata(inode, ordered->len);
	btrfs_end_transaction(trans, root);
5701
	ordered_offset = ordered->file_offset + ordered->len;
5702 5703
	btrfs_put_ordered_extent(ordered);
	btrfs_put_ordered_extent(ordered);
5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714

out_test:
	/*
	 * our bio might span multiple ordered extents.  If we haven't
	 * completed the accounting for the whole dio, go back and try again
	 */
	if (ordered_offset < dip->logical_offset + dip->bytes) {
		ordered_bytes = dip->logical_offset + dip->bytes -
			ordered_offset;
		goto again;
	}
5715 5716 5717 5718 5719 5720 5721 5722
out_done:
	bio->bi_private = dip->private;

	kfree(dip->csums);
	kfree(dip);
	dio_end_io(bio, err);
}

5723 5724 5725 5726 5727 5728 5729 5730 5731 5732 5733
static int __btrfs_submit_bio_start_direct_io(struct inode *inode, int rw,
				    struct bio *bio, int mirror_num,
				    unsigned long bio_flags, u64 offset)
{
	int ret;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	ret = btrfs_csum_one_bio(root, inode, bio, offset, 1);
	BUG_ON(ret);
	return 0;
}

M
Miao Xie 已提交
5734 5735 5736 5737 5738 5739
static void btrfs_end_dio_bio(struct bio *bio, int err)
{
	struct btrfs_dio_private *dip = bio->bi_private;

	if (err) {
		printk(KERN_ERR "btrfs direct IO failed ino %lu rw %lu "
J
Jan Beulich 已提交
5740 5741 5742
		      "sector %#Lx len %u err no %d\n",
		      dip->inode->i_ino, bio->bi_rw,
		      (unsigned long long)bio->bi_sector, bio->bi_size, err);
M
Miao Xie 已提交
5743 5744 5745 5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781 5782 5783 5784 5785 5786 5787 5788 5789 5790 5791 5792 5793 5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819 5820 5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831 5832 5833 5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845 5846 5847 5848 5849 5850 5851 5852 5853 5854 5855 5856 5857 5858 5859 5860 5861 5862 5863 5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876 5877 5878 5879 5880 5881 5882 5883 5884 5885 5886 5887 5888 5889 5890 5891 5892 5893 5894 5895 5896 5897 5898 5899 5900 5901 5902 5903
		dip->errors = 1;

		/*
		 * before atomic variable goto zero, we must make sure
		 * dip->errors is perceived to be set.
		 */
		smp_mb__before_atomic_dec();
	}

	/* if there are more bios still pending for this dio, just exit */
	if (!atomic_dec_and_test(&dip->pending_bios))
		goto out;

	if (dip->errors)
		bio_io_error(dip->orig_bio);
	else {
		set_bit(BIO_UPTODATE, &dip->orig_bio->bi_flags);
		bio_endio(dip->orig_bio, 0);
	}
out:
	bio_put(bio);
}

static struct bio *btrfs_dio_bio_alloc(struct block_device *bdev,
				       u64 first_sector, gfp_t gfp_flags)
{
	int nr_vecs = bio_get_nr_vecs(bdev);
	return btrfs_bio_alloc(bdev, first_sector, nr_vecs, gfp_flags);
}

static inline int __btrfs_submit_dio_bio(struct bio *bio, struct inode *inode,
					 int rw, u64 file_offset, int skip_sum,
					 u32 *csums)
{
	int write = rw & REQ_WRITE;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;

	bio_get(bio);
	ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
	if (ret)
		goto err;

	if (write && !skip_sum) {
		ret = btrfs_wq_submit_bio(root->fs_info,
				   inode, rw, bio, 0, 0,
				   file_offset,
				   __btrfs_submit_bio_start_direct_io,
				   __btrfs_submit_bio_done);
		goto err;
	} else if (!skip_sum)
		btrfs_lookup_bio_sums_dio(root, inode, bio,
					  file_offset, csums);

	ret = btrfs_map_bio(root, rw, bio, 0, 1);
err:
	bio_put(bio);
	return ret;
}

static int btrfs_submit_direct_hook(int rw, struct btrfs_dio_private *dip,
				    int skip_sum)
{
	struct inode *inode = dip->inode;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_mapping_tree *map_tree = &root->fs_info->mapping_tree;
	struct bio *bio;
	struct bio *orig_bio = dip->orig_bio;
	struct bio_vec *bvec = orig_bio->bi_io_vec;
	u64 start_sector = orig_bio->bi_sector;
	u64 file_offset = dip->logical_offset;
	u64 submit_len = 0;
	u64 map_length;
	int nr_pages = 0;
	u32 *csums = dip->csums;
	int ret = 0;

	bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev, start_sector, GFP_NOFS);
	if (!bio)
		return -ENOMEM;
	bio->bi_private = dip;
	bio->bi_end_io = btrfs_end_dio_bio;
	atomic_inc(&dip->pending_bios);

	map_length = orig_bio->bi_size;
	ret = btrfs_map_block(map_tree, READ, start_sector << 9,
			      &map_length, NULL, 0);
	if (ret) {
		bio_put(bio);
		return -EIO;
	}

	while (bvec <= (orig_bio->bi_io_vec + orig_bio->bi_vcnt - 1)) {
		if (unlikely(map_length < submit_len + bvec->bv_len ||
		    bio_add_page(bio, bvec->bv_page, bvec->bv_len,
				 bvec->bv_offset) < bvec->bv_len)) {
			/*
			 * inc the count before we submit the bio so
			 * we know the end IO handler won't happen before
			 * we inc the count. Otherwise, the dip might get freed
			 * before we're done setting it up
			 */
			atomic_inc(&dip->pending_bios);
			ret = __btrfs_submit_dio_bio(bio, inode, rw,
						     file_offset, skip_sum,
						     csums);
			if (ret) {
				bio_put(bio);
				atomic_dec(&dip->pending_bios);
				goto out_err;
			}

			if (!skip_sum)
				csums = csums + nr_pages;
			start_sector += submit_len >> 9;
			file_offset += submit_len;

			submit_len = 0;
			nr_pages = 0;

			bio = btrfs_dio_bio_alloc(orig_bio->bi_bdev,
						  start_sector, GFP_NOFS);
			if (!bio)
				goto out_err;
			bio->bi_private = dip;
			bio->bi_end_io = btrfs_end_dio_bio;

			map_length = orig_bio->bi_size;
			ret = btrfs_map_block(map_tree, READ, start_sector << 9,
					      &map_length, NULL, 0);
			if (ret) {
				bio_put(bio);
				goto out_err;
			}
		} else {
			submit_len += bvec->bv_len;
			nr_pages ++;
			bvec++;
		}
	}

	ret = __btrfs_submit_dio_bio(bio, inode, rw, file_offset, skip_sum,
				     csums);
	if (!ret)
		return 0;

	bio_put(bio);
out_err:
	dip->errors = 1;
	/*
	 * before atomic variable goto zero, we must
	 * make sure dip->errors is perceived to be set.
	 */
	smp_mb__before_atomic_dec();
	if (atomic_dec_and_test(&dip->pending_bios))
		bio_io_error(dip->orig_bio);

	/* bio_end_io() will handle error, so we needn't return it */
	return 0;
}

5904 5905 5906 5907 5908 5909 5910
static void btrfs_submit_direct(int rw, struct bio *bio, struct inode *inode,
				loff_t file_offset)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_dio_private *dip;
	struct bio_vec *bvec = bio->bi_io_vec;
	int skip_sum;
5911
	int write = rw & REQ_WRITE;
5912 5913 5914 5915 5916 5917 5918 5919 5920 5921 5922 5923 5924 5925 5926 5927 5928 5929 5930 5931 5932 5933 5934 5935 5936 5937 5938 5939 5940
	int ret = 0;

	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;

	dip = kmalloc(sizeof(*dip), GFP_NOFS);
	if (!dip) {
		ret = -ENOMEM;
		goto free_ordered;
	}
	dip->csums = NULL;

	if (!skip_sum) {
		dip->csums = kmalloc(sizeof(u32) * bio->bi_vcnt, GFP_NOFS);
		if (!dip->csums) {
			ret = -ENOMEM;
			goto free_ordered;
		}
	}

	dip->private = bio->bi_private;
	dip->inode = inode;
	dip->logical_offset = file_offset;

	dip->bytes = 0;
	do {
		dip->bytes += bvec->bv_len;
		bvec++;
	} while (bvec <= (bio->bi_io_vec + bio->bi_vcnt - 1));

5941
	dip->disk_bytenr = (u64)bio->bi_sector << 9;
5942
	bio->bi_private = dip;
M
Miao Xie 已提交
5943 5944 5945
	dip->errors = 0;
	dip->orig_bio = bio;
	atomic_set(&dip->pending_bios, 0);
5946 5947 5948 5949 5950 5951

	if (write)
		bio->bi_end_io = btrfs_endio_direct_write;
	else
		bio->bi_end_io = btrfs_endio_direct_read;

M
Miao Xie 已提交
5952 5953
	ret = btrfs_submit_direct_hook(rw, dip, skip_sum);
	if (!ret)
5954
		return;
5955 5956 5957 5958 5959 5960 5961
free_ordered:
	/*
	 * If this is a write, we need to clean up the reserved space and kill
	 * the ordered extent.
	 */
	if (write) {
		struct btrfs_ordered_extent *ordered;
5962
		ordered = btrfs_lookup_ordered_extent(inode, file_offset);
5963 5964 5965 5966 5967 5968 5969 5970 5971 5972
		if (!test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags) &&
		    !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags))
			btrfs_free_reserved_extent(root, ordered->start,
						   ordered->disk_len);
		btrfs_put_ordered_extent(ordered);
		btrfs_put_ordered_extent(ordered);
	}
	bio_endio(bio, ret);
}

C
Chris Mason 已提交
5973 5974 5975 5976 5977 5978 5979 5980 5981 5982 5983 5984 5985 5986 5987 5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998
static ssize_t check_direct_IO(struct btrfs_root *root, int rw, struct kiocb *iocb,
			const struct iovec *iov, loff_t offset,
			unsigned long nr_segs)
{
	int seg;
	size_t size;
	unsigned long addr;
	unsigned blocksize_mask = root->sectorsize - 1;
	ssize_t retval = -EINVAL;
	loff_t end = offset;

	if (offset & blocksize_mask)
		goto out;

	/* Check the memory alignment.  Blocks cannot straddle pages */
	for (seg = 0; seg < nr_segs; seg++) {
		addr = (unsigned long)iov[seg].iov_base;
		size = iov[seg].iov_len;
		end += size;
		if ((addr & blocksize_mask) || (size & blocksize_mask)) 
			goto out;
	}
	retval = 0;
out:
	return retval;
}
5999 6000 6001 6002
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
			const struct iovec *iov, loff_t offset,
			unsigned long nr_segs)
{
6003 6004 6005
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	struct btrfs_ordered_extent *ordered;
6006
	struct extent_state *cached_state = NULL;
6007 6008
	u64 lockstart, lockend;
	ssize_t ret;
6009 6010
	int writing = rw & WRITE;
	int write_bits = 0;
6011
	size_t count = iov_length(iov, nr_segs);
6012

C
Chris Mason 已提交
6013 6014 6015 6016 6017
	if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
			    offset, nr_segs)) {
		return 0;
	}

6018
	lockstart = offset;
6019 6020 6021 6022 6023 6024 6025
	lockend = offset + count - 1;

	if (writing) {
		ret = btrfs_delalloc_reserve_space(inode, count);
		if (ret)
			goto out;
	}
6026

6027
	while (1) {
6028 6029
		lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				 0, &cached_state, GFP_NOFS);
6030 6031 6032 6033 6034 6035 6036 6037 6038
		/*
		 * We're concerned with the entire range that we're going to be
		 * doing DIO to, so we need to make sure theres no ordered
		 * extents in this range.
		 */
		ordered = btrfs_lookup_ordered_range(inode, lockstart,
						     lockend - lockstart + 1);
		if (!ordered)
			break;
6039 6040
		unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				     &cached_state, GFP_NOFS);
6041 6042 6043 6044 6045
		btrfs_start_ordered_extent(inode, ordered, 1);
		btrfs_put_ordered_extent(ordered);
		cond_resched();
	}

6046 6047 6048 6049 6050 6051 6052 6053 6054 6055 6056 6057 6058 6059 6060 6061 6062 6063 6064 6065
	/*
	 * we don't use btrfs_set_extent_delalloc because we don't want
	 * the dirty or uptodate bits
	 */
	if (writing) {
		write_bits = EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING;
		ret = set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				     EXTENT_DELALLOC, 0, NULL, &cached_state,
				     GFP_NOFS);
		if (ret) {
			clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
					 lockend, EXTENT_LOCKED | write_bits,
					 1, 0, &cached_state, GFP_NOFS);
			goto out;
		}
	}

	free_extent_state(cached_state);
	cached_state = NULL;

C
Chris Mason 已提交
6066 6067 6068 6069
	ret = __blockdev_direct_IO(rw, iocb, inode,
		   BTRFS_I(inode)->root->fs_info->fs_devices->latest_bdev,
		   iov, offset, nr_segs, btrfs_get_blocks_direct, NULL,
		   btrfs_submit_direct, 0);
6070 6071

	if (ret < 0 && ret != -EIOCBQUEUED) {
6072 6073 6074 6075
		clear_extent_bit(&BTRFS_I(inode)->io_tree, offset,
			      offset + iov_length(iov, nr_segs) - 1,
			      EXTENT_LOCKED | write_bits, 1, 0,
			      &cached_state, GFP_NOFS);
6076 6077 6078 6079 6080
	} else if (ret >= 0 && ret < iov_length(iov, nr_segs)) {
		/*
		 * We're falling back to buffered, unlock the section we didn't
		 * do IO on.
		 */
6081 6082 6083 6084
		clear_extent_bit(&BTRFS_I(inode)->io_tree, offset + ret,
			      offset + iov_length(iov, nr_segs) - 1,
			      EXTENT_LOCKED | write_bits, 1, 0,
			      &cached_state, GFP_NOFS);
6085
	}
6086 6087
out:
	free_extent_state(cached_state);
6088
	return ret;
6089 6090
}

Y
Yehuda Sadeh 已提交
6091 6092 6093 6094 6095 6096
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
		__u64 start, __u64 len)
{
	return extent_fiemap(inode, fieinfo, start, len, btrfs_get_extent);
}

6097
int btrfs_readpage(struct file *file, struct page *page)
C
Chris Mason 已提交
6098
{
6099 6100
	struct extent_io_tree *tree;
	tree = &BTRFS_I(page->mapping->host)->io_tree;
6101
	return extent_read_full_page(tree, page, btrfs_get_extent);
C
Chris Mason 已提交
6102
}
6103

6104
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
C
Chris Mason 已提交
6105
{
6106
	struct extent_io_tree *tree;
6107 6108 6109 6110 6111 6112 6113


	if (current->flags & PF_MEMALLOC) {
		redirty_page_for_writepage(wbc, page);
		unlock_page(page);
		return 0;
	}
6114
	tree = &BTRFS_I(page->mapping->host)->io_tree;
6115
	return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
C
Chris Mason 已提交
6116 6117
}

6118 6119
int btrfs_writepages(struct address_space *mapping,
		     struct writeback_control *wbc)
C
Chris Mason 已提交
6120
{
6121
	struct extent_io_tree *tree;
6122

6123
	tree = &BTRFS_I(mapping->host)->io_tree;
C
Chris Mason 已提交
6124 6125 6126
	return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}

C
Chris Mason 已提交
6127 6128 6129 6130
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
		struct list_head *pages, unsigned nr_pages)
{
6131 6132
	struct extent_io_tree *tree;
	tree = &BTRFS_I(mapping->host)->io_tree;
C
Chris Mason 已提交
6133 6134 6135
	return extent_readpages(tree, mapping, pages, nr_pages,
				btrfs_get_extent);
}
6136
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
C
Chris Mason 已提交
6137
{
6138 6139
	struct extent_io_tree *tree;
	struct extent_map_tree *map;
6140
	int ret;
6141

6142 6143
	tree = &BTRFS_I(page->mapping->host)->io_tree;
	map = &BTRFS_I(page->mapping->host)->extent_tree;
6144
	ret = try_release_extent_mapping(map, tree, page, gfp_flags);
6145 6146 6147 6148
	if (ret == 1) {
		ClearPagePrivate(page);
		set_page_private(page, 0);
		page_cache_release(page);
C
Chris Mason 已提交
6149
	}
6150
	return ret;
C
Chris Mason 已提交
6151 6152
}

6153 6154
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
6155 6156
	if (PageWriteback(page) || PageDirty(page))
		return 0;
6157
	return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
6158 6159
}

6160
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
C
Chris Mason 已提交
6161
{
6162
	struct extent_io_tree *tree;
6163
	struct btrfs_ordered_extent *ordered;
6164
	struct extent_state *cached_state = NULL;
6165 6166
	u64 page_start = page_offset(page);
	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
C
Chris Mason 已提交
6167

6168 6169 6170 6171 6172 6173 6174 6175

	/*
	 * we have the page locked, so new writeback can't start,
	 * and the dirty bit won't be cleared while we are here.
	 *
	 * Wait for IO on this page so that we can safely clear
	 * the PagePrivate2 bit and do ordered accounting
	 */
6176
	wait_on_page_writeback(page);
6177

6178
	tree = &BTRFS_I(page->mapping->host)->io_tree;
6179 6180 6181 6182
	if (offset) {
		btrfs_releasepage(page, GFP_NOFS);
		return;
	}
6183 6184
	lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
6185 6186 6187
	ordered = btrfs_lookup_ordered_extent(page->mapping->host,
					   page_offset(page));
	if (ordered) {
6188 6189 6190 6191
		/*
		 * IO on this page will never be started, so we need
		 * to account for any ordered extents now
		 */
6192 6193
		clear_extent_bit(tree, page_start, page_end,
				 EXTENT_DIRTY | EXTENT_DELALLOC |
6194
				 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
6195
				 &cached_state, GFP_NOFS);
6196 6197 6198 6199 6200 6201 6202 6203
		/*
		 * whoever cleared the private bit is responsible
		 * for the finish_ordered_io
		 */
		if (TestClearPagePrivate2(page)) {
			btrfs_finish_ordered_io(page->mapping->host,
						page_start, page_end);
		}
6204
		btrfs_put_ordered_extent(ordered);
6205 6206 6207
		cached_state = NULL;
		lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
				 GFP_NOFS);
6208 6209
	}
	clear_extent_bit(tree, page_start, page_end,
6210
		 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
6211
		 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
6212 6213
	__btrfs_releasepage(page, GFP_NOFS);

C
Chris Mason 已提交
6214
	ClearPageChecked(page);
6215 6216 6217 6218 6219
	if (PagePrivate(page)) {
		ClearPagePrivate(page);
		set_page_private(page, 0);
		page_cache_release(page);
	}
C
Chris Mason 已提交
6220 6221
}

C
Chris Mason 已提交
6222 6223 6224 6225 6226 6227 6228 6229 6230 6231 6232 6233 6234 6235 6236
/*
 * btrfs_page_mkwrite() is not allowed to change the file size as it gets
 * called from a page fault handler when a page is first dirtied. Hence we must
 * be careful to check for EOF conditions here. We set the page up correctly
 * for a written page which means we get ENOSPC checking when writing into
 * holes and correct delalloc and unwritten extent mapping on filesystems that
 * support these features.
 *
 * We are not allowed to take the i_mutex here so we have to play games to
 * protect against truncate races as the page could now be beyond EOF.  Because
 * vmtruncate() writes the inode size before removing pages, once we have the
 * page lock we can determine safely if the page is beyond EOF. If it is not
 * beyond EOF, then the page is guaranteed safe against truncation until we
 * unlock the page.
 */
6237
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
C
Chris Mason 已提交
6238
{
6239
	struct page *page = vmf->page;
6240
	struct inode *inode = fdentry(vma->vm_file)->d_inode;
6241
	struct btrfs_root *root = BTRFS_I(inode)->root;
6242 6243
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct btrfs_ordered_extent *ordered;
6244
	struct extent_state *cached_state = NULL;
6245 6246
	char *kaddr;
	unsigned long zero_start;
C
Chris Mason 已提交
6247
	loff_t size;
6248
	int ret;
6249
	u64 page_start;
6250
	u64 page_end;
C
Chris Mason 已提交
6251

6252
	ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6253 6254 6255 6256 6257
	if (ret) {
		if (ret == -ENOMEM)
			ret = VM_FAULT_OOM;
		else /* -ENOSPC, -EIO, etc */
			ret = VM_FAULT_SIGBUS;
6258
		goto out;
6259
	}
6260

6261
	ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6262
again:
C
Chris Mason 已提交
6263 6264
	lock_page(page);
	size = i_size_read(inode);
6265 6266
	page_start = page_offset(page);
	page_end = page_start + PAGE_CACHE_SIZE - 1;
6267

C
Chris Mason 已提交
6268
	if ((page->mapping != inode->i_mapping) ||
6269
	    (page_start >= size)) {
C
Chris Mason 已提交
6270 6271 6272
		/* page got truncated out from underneath us */
		goto out_unlock;
	}
6273 6274
	wait_on_page_writeback(page);

6275 6276
	lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
6277 6278
	set_page_extent_mapped(page);

6279 6280 6281 6282
	/*
	 * we can't set the delalloc bits if there are pending ordered
	 * extents.  Drop our locks and wait for them to finish
	 */
6283 6284
	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
6285 6286
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
6287
		unlock_page(page);
6288
		btrfs_start_ordered_extent(inode, ordered, 1);
6289 6290 6291 6292
		btrfs_put_ordered_extent(ordered);
		goto again;
	}

J
Josef Bacik 已提交
6293 6294 6295 6296 6297 6298 6299
	/*
	 * XXX - page_mkwrite gets called every time the page is dirtied, even
	 * if it was already dirty, so for space accounting reasons we need to
	 * clear any delalloc bits for the range we are fixing to save.  There
	 * is probably a better way to do this, but for now keep consistent with
	 * prepare_pages in the normal write path.
	 */
6300
	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6301
			  EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6302
			  0, 0, &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
6303

6304 6305
	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
					&cached_state);
J
Josef Bacik 已提交
6306
	if (ret) {
6307 6308
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
6309 6310 6311
		ret = VM_FAULT_SIGBUS;
		goto out_unlock;
	}
6312
	ret = 0;
C
Chris Mason 已提交
6313 6314

	/* page is wholly or partially inside EOF */
6315
	if (page_start + PAGE_CACHE_SIZE > size)
6316
		zero_start = size & ~PAGE_CACHE_MASK;
C
Chris Mason 已提交
6317
	else
6318
		zero_start = PAGE_CACHE_SIZE;
C
Chris Mason 已提交
6319

6320 6321 6322 6323 6324 6325
	if (zero_start != PAGE_CACHE_SIZE) {
		kaddr = kmap(page);
		memset(kaddr + zero_start, 0, PAGE_CACHE_SIZE - zero_start);
		flush_dcache_page(page);
		kunmap(page);
	}
6326
	ClearPageChecked(page);
6327
	set_page_dirty(page);
6328
	SetPageUptodate(page);
6329

6330 6331 6332
	BTRFS_I(inode)->last_trans = root->fs_info->generation;
	BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;

6333
	unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
C
Chris Mason 已提交
6334 6335

out_unlock:
6336 6337
	if (!ret)
		return VM_FAULT_LOCKED;
C
Chris Mason 已提交
6338
	unlock_page(page);
6339
	btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6340
out:
C
Chris Mason 已提交
6341 6342 6343
	return ret;
}

C
Chris Mason 已提交
6344 6345 6346 6347 6348
static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;
	struct btrfs_trans_handle *trans;
6349
	unsigned long nr;
6350
	u64 mask = root->sectorsize - 1;
C
Chris Mason 已提交
6351

6352 6353
	if (!S_ISREG(inode->i_mode)) {
		WARN_ON(1);
C
Chris Mason 已提交
6354
		return;
6355
	}
C
Chris Mason 已提交
6356

6357 6358 6359
	ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
	if (ret)
		return;
6360

C
Chris Mason 已提交
6361
	btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6362
	btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
C
Chris Mason 已提交
6363

6364 6365
	trans = btrfs_start_transaction(root, 0);
	BUG_ON(IS_ERR(trans));
6366
	btrfs_set_trans_block_group(trans, inode);
6367
	trans->block_rsv = root->orphan_block_rsv;
6368 6369 6370 6371 6372 6373 6374 6375 6376 6377 6378 6379 6380 6381 6382 6383 6384 6385 6386 6387 6388

	/*
	 * setattr is responsible for setting the ordered_data_close flag,
	 * but that is only tested during the last file release.  That
	 * could happen well after the next commit, leaving a great big
	 * window where new writes may get lost if someone chooses to write
	 * to this file after truncating to zero
	 *
	 * The inode doesn't have any dirty data here, and so if we commit
	 * this is a noop.  If someone immediately starts writing to the inode
	 * it is very likely we'll catch some of their writes in this
	 * transaction, and the commit will find this file on the ordered
	 * data list with good things to send down.
	 *
	 * This is a best effort solution, there is still a window where
	 * using truncate to replace the contents of the file will
	 * end up with a zero length file after a crash.
	 */
	if (inode->i_size == 0 && BTRFS_I(inode)->ordered_data_close)
		btrfs_add_ordered_operation(trans, root, inode);

6389
	while (1) {
6390 6391 6392 6393 6394 6395 6396 6397 6398 6399 6400 6401 6402 6403 6404 6405 6406
		if (!trans) {
			trans = btrfs_start_transaction(root, 0);
			BUG_ON(IS_ERR(trans));
			btrfs_set_trans_block_group(trans, inode);
			trans->block_rsv = root->orphan_block_rsv;
		}

		ret = btrfs_block_rsv_check(trans, root,
					    root->orphan_block_rsv, 0, 5);
		if (ret) {
			BUG_ON(ret != -EAGAIN);
			ret = btrfs_commit_transaction(trans, root);
			BUG_ON(ret);
			trans = NULL;
			continue;
		}

6407 6408 6409 6410 6411
		ret = btrfs_truncate_inode_items(trans, root, inode,
						 inode->i_size,
						 BTRFS_EXTENT_DATA_KEY);
		if (ret != -EAGAIN)
			break;
C
Chris Mason 已提交
6412

6413 6414
		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);
6415

6416 6417
		nr = trans->blocks_used;
		btrfs_end_transaction(trans, root);
6418
		trans = NULL;
6419 6420 6421 6422 6423 6424 6425 6426 6427
		btrfs_btree_balance_dirty(root, nr);
	}

	if (ret == 0 && inode->i_nlink > 0) {
		ret = btrfs_orphan_del(trans, inode);
		BUG_ON(ret);
	}

	ret = btrfs_update_inode(trans, root, inode);
6428 6429 6430
	BUG_ON(ret);

	nr = trans->blocks_used;
6431
	ret = btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
6432
	BUG_ON(ret);
6433
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
6434 6435
}

C
Chris Mason 已提交
6436 6437 6438
/*
 * create a new subvolume directory/inode (helper for the ioctl).
 */
6439
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6440
			     struct btrfs_root *new_root,
6441
			     u64 new_dirid, u64 alloc_hint)
C
Chris Mason 已提交
6442 6443
{
	struct inode *inode;
6444
	int err;
6445
	u64 index = 0;
C
Chris Mason 已提交
6446

6447
	inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
6448
				new_dirid, alloc_hint, S_IFDIR | 0700, &index);
6449
	if (IS_ERR(inode))
C
Christoph Hellwig 已提交
6450
		return PTR_ERR(inode);
C
Chris Mason 已提交
6451 6452 6453 6454
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;

	inode->i_nlink = 1;
6455
	btrfs_i_size_write(inode, 0);
6456

6457 6458
	err = btrfs_update_inode(trans, new_root, inode);
	BUG_ON(err);
6459

6460
	iput(inode);
6461
	return 0;
C
Chris Mason 已提交
6462 6463
}

C
Chris Mason 已提交
6464 6465 6466
/* helper function for file defrag and space balancing.  This
 * forces readahead on a given range of bytes in an inode
 */
6467
unsigned long btrfs_force_ra(struct address_space *mapping,
6468 6469 6470
			      struct file_ra_state *ra, struct file *file,
			      pgoff_t offset, pgoff_t last_index)
{
6471
	pgoff_t req_size = last_index - offset + 1;
6472 6473 6474 6475 6476

	page_cache_sync_readahead(mapping, ra, file, offset, req_size);
	return offset + req_size;
}

C
Chris Mason 已提交
6477 6478 6479
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
	struct btrfs_inode *ei;
Y
Yan, Zheng 已提交
6480
	struct inode *inode;
C
Chris Mason 已提交
6481 6482 6483 6484

	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;
Y
Yan, Zheng 已提交
6485 6486 6487 6488 6489

	ei->root = NULL;
	ei->space_info = NULL;
	ei->generation = 0;
	ei->sequence = 0;
6490
	ei->last_trans = 0;
6491
	ei->last_sub_trans = 0;
6492
	ei->logged_trans = 0;
Y
Yan, Zheng 已提交
6493 6494 6495 6496 6497 6498 6499
	ei->delalloc_bytes = 0;
	ei->reserved_bytes = 0;
	ei->disk_i_size = 0;
	ei->flags = 0;
	ei->index_cnt = (u64)-1;
	ei->last_unlink_trans = 0;

6500
	spin_lock_init(&ei->accounting_lock);
6501
	atomic_set(&ei->outstanding_extents, 0);
6502
	ei->reserved_extents = 0;
Y
Yan, Zheng 已提交
6503 6504

	ei->ordered_data_close = 0;
6505
	ei->orphan_meta_reserved = 0;
Y
Yan, Zheng 已提交
6506
	ei->dummy_inode = 0;
6507
	ei->force_compress = BTRFS_COMPRESS_NONE;
Y
Yan, Zheng 已提交
6508 6509 6510 6511 6512 6513

	inode = &ei->vfs_inode;
	extent_map_tree_init(&ei->extent_tree, GFP_NOFS);
	extent_io_tree_init(&ei->io_tree, &inode->i_data, GFP_NOFS);
	extent_io_tree_init(&ei->io_failure_tree, &inode->i_data, GFP_NOFS);
	mutex_init(&ei->log_mutex);
6514
	btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6515
	INIT_LIST_HEAD(&ei->i_orphan);
Y
Yan, Zheng 已提交
6516
	INIT_LIST_HEAD(&ei->delalloc_inodes);
6517
	INIT_LIST_HEAD(&ei->ordered_operations);
Y
Yan, Zheng 已提交
6518 6519 6520
	RB_CLEAR_NODE(&ei->rb_node);

	return inode;
C
Chris Mason 已提交
6521 6522 6523 6524
}

void btrfs_destroy_inode(struct inode *inode)
{
6525
	struct btrfs_ordered_extent *ordered;
6526 6527
	struct btrfs_root *root = BTRFS_I(inode)->root;

C
Chris Mason 已提交
6528 6529
	WARN_ON(!list_empty(&inode->i_dentry));
	WARN_ON(inode->i_data.nrpages);
6530 6531
	WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents));
	WARN_ON(BTRFS_I(inode)->reserved_extents);
C
Chris Mason 已提交
6532

6533 6534 6535 6536 6537 6538 6539 6540
	/*
	 * This can happen where we create an inode, but somebody else also
	 * created the same inode and we need to destroy the one we already
	 * created.
	 */
	if (!root)
		goto free;

6541 6542 6543 6544 6545 6546 6547 6548 6549 6550 6551
	/*
	 * Make sure we're properly removed from the ordered operation
	 * lists.
	 */
	smp_mb();
	if (!list_empty(&BTRFS_I(inode)->ordered_operations)) {
		spin_lock(&root->fs_info->ordered_extent_lock);
		list_del_init(&BTRFS_I(inode)->ordered_operations);
		spin_unlock(&root->fs_info->ordered_extent_lock);
	}

6552 6553 6554 6555 6556 6557 6558 6559 6560 6561 6562 6563 6564 6565 6566
	if (root == root->fs_info->tree_root) {
		struct btrfs_block_group_cache *block_group;

		block_group = btrfs_lookup_block_group(root->fs_info,
						BTRFS_I(inode)->block_group);
		if (block_group && block_group->inode == inode) {
			spin_lock(&block_group->lock);
			block_group->inode = NULL;
			spin_unlock(&block_group->lock);
			btrfs_put_block_group(block_group);
		} else if (block_group) {
			btrfs_put_block_group(block_group);
		}
	}

6567
	spin_lock(&root->orphan_lock);
6568
	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6569 6570 6571
		printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
		       inode->i_ino);
		list_del_init(&BTRFS_I(inode)->i_orphan);
6572
	}
6573
	spin_unlock(&root->orphan_lock);
6574

C
Chris Mason 已提交
6575
	while (1) {
6576 6577 6578 6579
		ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
		if (!ordered)
			break;
		else {
C
Chris Mason 已提交
6580 6581 6582 6583
			printk(KERN_ERR "btrfs found ordered "
			       "extent %llu %llu on inode cleanup\n",
			       (unsigned long long)ordered->file_offset,
			       (unsigned long long)ordered->len);
6584 6585 6586 6587 6588
			btrfs_remove_ordered_extent(inode, ordered);
			btrfs_put_ordered_extent(ordered);
			btrfs_put_ordered_extent(ordered);
		}
	}
6589
	inode_tree_del(inode);
6590
	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6591
free:
C
Chris Mason 已提交
6592 6593 6594
	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}

6595
int btrfs_drop_inode(struct inode *inode)
6596 6597
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
6598

6599 6600
	if (btrfs_root_refs(&root->root_item) == 0 &&
	    root != root->fs_info->tree_root)
6601
		return 1;
6602
	else
6603
		return generic_drop_inode(inode);
6604 6605
}

6606
static void init_once(void *foo)
C
Chris Mason 已提交
6607 6608 6609 6610 6611 6612 6613 6614 6615 6616 6617 6618 6619 6620 6621 6622 6623 6624 6625 6626
{
	struct btrfs_inode *ei = (struct btrfs_inode *) foo;

	inode_init_once(&ei->vfs_inode);
}

void btrfs_destroy_cachep(void)
{
	if (btrfs_inode_cachep)
		kmem_cache_destroy(btrfs_inode_cachep);
	if (btrfs_trans_handle_cachep)
		kmem_cache_destroy(btrfs_trans_handle_cachep);
	if (btrfs_transaction_cachep)
		kmem_cache_destroy(btrfs_transaction_cachep);
	if (btrfs_path_cachep)
		kmem_cache_destroy(btrfs_path_cachep);
}

int btrfs_init_cachep(void)
{
6627 6628 6629
	btrfs_inode_cachep = kmem_cache_create("btrfs_inode_cache",
			sizeof(struct btrfs_inode), 0,
			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, init_once);
C
Chris Mason 已提交
6630 6631
	if (!btrfs_inode_cachep)
		goto fail;
6632 6633 6634 6635

	btrfs_trans_handle_cachep = kmem_cache_create("btrfs_trans_handle_cache",
			sizeof(struct btrfs_trans_handle), 0,
			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
C
Chris Mason 已提交
6636 6637
	if (!btrfs_trans_handle_cachep)
		goto fail;
6638 6639 6640 6641

	btrfs_transaction_cachep = kmem_cache_create("btrfs_transaction_cache",
			sizeof(struct btrfs_transaction), 0,
			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
C
Chris Mason 已提交
6642 6643
	if (!btrfs_transaction_cachep)
		goto fail;
6644 6645 6646 6647

	btrfs_path_cachep = kmem_cache_create("btrfs_path_cache",
			sizeof(struct btrfs_path), 0,
			SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD, NULL);
C
Chris Mason 已提交
6648 6649
	if (!btrfs_path_cachep)
		goto fail;
6650

C
Chris Mason 已提交
6651 6652 6653 6654 6655 6656 6657 6658 6659 6660 6661
	return 0;
fail:
	btrfs_destroy_cachep();
	return -ENOMEM;
}

static int btrfs_getattr(struct vfsmount *mnt,
			 struct dentry *dentry, struct kstat *stat)
{
	struct inode *inode = dentry->d_inode;
	generic_fillattr(inode, stat);
6662
	stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
C
Chris Mason 已提交
6663
	stat->blksize = PAGE_CACHE_SIZE;
6664 6665
	stat->blocks = (inode_get_bytes(inode) +
			BTRFS_I(inode)->delalloc_bytes) >> 9;
C
Chris Mason 已提交
6666 6667 6668
	return 0;
}

C
Chris Mason 已提交
6669 6670
static int btrfs_rename(struct inode *old_dir, struct dentry *old_dentry,
			   struct inode *new_dir, struct dentry *new_dentry)
C
Chris Mason 已提交
6671 6672 6673
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(old_dir)->root;
6674
	struct btrfs_root *dest = BTRFS_I(new_dir)->root;
C
Chris Mason 已提交
6675 6676 6677
	struct inode *new_inode = new_dentry->d_inode;
	struct inode *old_inode = old_dentry->d_inode;
	struct timespec ctime = CURRENT_TIME;
6678
	u64 index = 0;
6679
	u64 root_objectid;
C
Chris Mason 已提交
6680 6681
	int ret;

6682 6683 6684
	if (new_dir->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
		return -EPERM;

6685 6686
	/* we only allow rename subvolume link between subvolumes */
	if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6687 6688
		return -EXDEV;

6689 6690
	if (old_inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID ||
	    (new_inode && new_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID))
C
Chris Mason 已提交
6691
		return -ENOTEMPTY;
6692

6693 6694 6695
	if (S_ISDIR(old_inode->i_mode) && new_inode &&
	    new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
		return -ENOTEMPTY;
6696 6697 6698 6699 6700
	/*
	 * we're using rename to replace one file with another.
	 * and the replacement file is large.  Start IO on it now so
	 * we don't add too much work to the end of the transaction
	 */
6701
	if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
6702 6703 6704
	    old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
		filemap_flush(old_inode->i_mapping);

6705 6706 6707
	/* close the racy window with snapshot create/destroy ioctl */
	if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
		down_read(&root->fs_info->subvol_sem);
6708 6709 6710 6711 6712 6713 6714 6715 6716 6717 6718
	/*
	 * We want to reserve the absolute worst case amount of items.  So if
	 * both inodes are subvols and we need to unlink them then that would
	 * require 4 item modifications, but if they are both normal inodes it
	 * would require 5 item modifications, so we'll assume their normal
	 * inodes.  So 5 * 2 is 10, plus 1 for the new link, so 11 total items
	 * should cover the worst case number of items we'll modify.
	 */
	trans = btrfs_start_transaction(root, 20);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
6719

6720
	btrfs_set_trans_block_group(trans, new_dir);
6721

6722 6723
	if (dest != root)
		btrfs_record_root_in_trans(trans, dest);
6724

6725 6726 6727
	ret = btrfs_set_inode_index(new_dir, &index);
	if (ret)
		goto out_fail;
6728

6729
	if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
6730 6731 6732
		/* force full log commit if subvolume involved. */
		root->fs_info->last_trans_log_full_commit = trans->transid;
	} else {
6733 6734 6735 6736 6737 6738 6739
		ret = btrfs_insert_inode_ref(trans, dest,
					     new_dentry->d_name.name,
					     new_dentry->d_name.len,
					     old_inode->i_ino,
					     new_dir->i_ino, index);
		if (ret)
			goto out_fail;
6740 6741 6742 6743 6744 6745 6746 6747 6748
		/*
		 * this is an ugly little race, but the rename is required
		 * to make sure that if we crash, the inode is either at the
		 * old name or the new one.  pinning the log transaction lets
		 * us make sure we don't allow a log commit to come in after
		 * we unlink the name but before we add the new name back in.
		 */
		btrfs_pin_log_trans(root);
	}
6749 6750 6751 6752 6753 6754 6755 6756 6757
	/*
	 * make sure the inode gets flushed if it is replacing
	 * something.
	 */
	if (new_inode && new_inode->i_size &&
	    old_inode && S_ISREG(old_inode->i_mode)) {
		btrfs_add_ordered_operation(trans, root, old_inode);
	}

C
Chris Mason 已提交
6758 6759 6760
	old_dir->i_ctime = old_dir->i_mtime = ctime;
	new_dir->i_ctime = new_dir->i_mtime = ctime;
	old_inode->i_ctime = ctime;
6761

6762 6763 6764
	if (old_dentry->d_parent != new_dentry->d_parent)
		btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);

6765 6766 6767 6768 6769 6770 6771 6772 6773 6774 6775 6776 6777
	if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
		root_objectid = BTRFS_I(old_inode)->root->root_key.objectid;
		ret = btrfs_unlink_subvol(trans, root, old_dir, root_objectid,
					old_dentry->d_name.name,
					old_dentry->d_name.len);
	} else {
		btrfs_inc_nlink(old_dentry->d_inode);
		ret = btrfs_unlink_inode(trans, root, old_dir,
					 old_dentry->d_inode,
					 old_dentry->d_name.name,
					 old_dentry->d_name.len);
	}
	BUG_ON(ret);
C
Chris Mason 已提交
6778 6779 6780

	if (new_inode) {
		new_inode->i_ctime = CURRENT_TIME;
6781 6782 6783 6784 6785 6786 6787 6788 6789 6790 6791 6792 6793 6794 6795
		if (unlikely(new_inode->i_ino ==
			     BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)) {
			root_objectid = BTRFS_I(new_inode)->location.objectid;
			ret = btrfs_unlink_subvol(trans, dest, new_dir,
						root_objectid,
						new_dentry->d_name.name,
						new_dentry->d_name.len);
			BUG_ON(new_inode->i_nlink == 0);
		} else {
			ret = btrfs_unlink_inode(trans, dest, new_dir,
						 new_dentry->d_inode,
						 new_dentry->d_name.name,
						 new_dentry->d_name.len);
		}
		BUG_ON(ret);
6796
		if (new_inode->i_nlink == 0) {
6797
			ret = btrfs_orphan_add(trans, new_dentry->d_inode);
6798
			BUG_ON(ret);
6799
		}
C
Chris Mason 已提交
6800
	}
6801

6802 6803
	ret = btrfs_add_link(trans, new_dir, old_inode,
			     new_dentry->d_name.name,
6804
			     new_dentry->d_name.len, 0, index);
6805
	BUG_ON(ret);
C
Chris Mason 已提交
6806

6807
	if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
6808 6809 6810
		struct dentry *parent = dget_parent(new_dentry);
		btrfs_log_new_name(trans, old_inode, old_dir, parent);
		dput(parent);
6811 6812
		btrfs_end_log_trans(root);
	}
C
Chris Mason 已提交
6813
out_fail:
6814
	btrfs_end_transaction_throttle(trans, root);
6815

6816 6817
	if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
		up_read(&root->fs_info->subvol_sem);
J
Josef Bacik 已提交
6818

C
Chris Mason 已提交
6819 6820 6821
	return ret;
}

C
Chris Mason 已提交
6822 6823 6824 6825
/*
 * some fairly slow code that needs optimization. This walks the list
 * of all the inodes with pending delalloc and forces them to disk.
 */
Y
Yan, Zheng 已提交
6826
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
6827 6828 6829
{
	struct list_head *head = &root->fs_info->delalloc_inodes;
	struct btrfs_inode *binode;
6830
	struct inode *inode;
6831

Y
Yan Zheng 已提交
6832 6833 6834
	if (root->fs_info->sb->s_flags & MS_RDONLY)
		return -EROFS;

6835
	spin_lock(&root->fs_info->delalloc_lock);
C
Chris Mason 已提交
6836
	while (!list_empty(head)) {
6837 6838
		binode = list_entry(head->next, struct btrfs_inode,
				    delalloc_inodes);
6839 6840 6841
		inode = igrab(&binode->vfs_inode);
		if (!inode)
			list_del_init(&binode->delalloc_inodes);
6842
		spin_unlock(&root->fs_info->delalloc_lock);
6843
		if (inode) {
6844
			filemap_flush(inode->i_mapping);
Y
Yan, Zheng 已提交
6845 6846 6847 6848
			if (delay_iput)
				btrfs_add_delayed_iput(inode);
			else
				iput(inode);
6849 6850
		}
		cond_resched();
6851
		spin_lock(&root->fs_info->delalloc_lock);
6852
	}
6853
	spin_unlock(&root->fs_info->delalloc_lock);
6854 6855 6856 6857 6858 6859

	/* the filemap_flush will queue IO into the worker threads, but
	 * we have to make sure the IO is actually started and that
	 * ordered extents get created before we return
	 */
	atomic_inc(&root->fs_info->async_submit_draining);
C
Chris Mason 已提交
6860
	while (atomic_read(&root->fs_info->nr_async_submits) ||
6861
	      atomic_read(&root->fs_info->async_delalloc_pages)) {
6862
		wait_event(root->fs_info->async_submit_wait,
6863 6864
		   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
		    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
6865 6866
	}
	atomic_dec(&root->fs_info->async_submit_draining);
6867 6868 6869
	return 0;
}

J
Josef Bacik 已提交
6870 6871
int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput,
				   int sync)
6872 6873 6874 6875 6876 6877 6878 6879 6880 6881 6882 6883 6884 6885 6886 6887 6888 6889 6890 6891 6892
{
	struct btrfs_inode *binode;
	struct inode *inode = NULL;

	spin_lock(&root->fs_info->delalloc_lock);
	while (!list_empty(&root->fs_info->delalloc_inodes)) {
		binode = list_entry(root->fs_info->delalloc_inodes.next,
				    struct btrfs_inode, delalloc_inodes);
		inode = igrab(&binode->vfs_inode);
		if (inode) {
			list_move_tail(&binode->delalloc_inodes,
				       &root->fs_info->delalloc_inodes);
			break;
		}

		list_del_init(&binode->delalloc_inodes);
		cond_resched_lock(&root->fs_info->delalloc_lock);
	}
	spin_unlock(&root->fs_info->delalloc_lock);

	if (inode) {
J
Josef Bacik 已提交
6893 6894 6895 6896 6897 6898 6899 6900 6901 6902 6903 6904 6905 6906 6907 6908 6909 6910 6911 6912
		if (sync) {
			filemap_write_and_wait(inode->i_mapping);
			/*
			 * We have to do this because compression doesn't
			 * actually set PG_writeback until it submits the pages
			 * for IO, which happens in an async thread, so we could
			 * race and not actually wait for any writeback pages
			 * because they've not been submitted yet.  Technically
			 * this could still be the case for the ordered stuff
			 * since the async thread may not have started to do its
			 * work yet.  If this becomes the case then we need to
			 * figure out a way to make sure that in writepage we
			 * wait for any async pages to be submitted before
			 * returning so that fdatawait does what its supposed to
			 * do.
			 */
			btrfs_wait_ordered_range(inode, 0, (u64)-1);
		} else {
			filemap_flush(inode->i_mapping);
		}
6913 6914 6915 6916 6917 6918 6919 6920 6921
		if (delay_iput)
			btrfs_add_delayed_iput(inode);
		else
			iput(inode);
		return 1;
	}
	return 0;
}

C
Chris Mason 已提交
6922 6923 6924 6925 6926 6927 6928
static int btrfs_symlink(struct inode *dir, struct dentry *dentry,
			 const char *symname)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_path *path;
	struct btrfs_key key;
6929
	struct inode *inode = NULL;
C
Chris Mason 已提交
6930 6931 6932
	int err;
	int drop_inode = 0;
	u64 objectid;
6933
	u64 index = 0 ;
C
Chris Mason 已提交
6934 6935
	int name_len;
	int datasize;
6936
	unsigned long ptr;
C
Chris Mason 已提交
6937
	struct btrfs_file_extent_item *ei;
6938
	struct extent_buffer *leaf;
6939
	unsigned long nr = 0;
C
Chris Mason 已提交
6940 6941 6942 6943

	name_len = strlen(symname) + 1;
	if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
		return -ENAMETOOLONG;
6944

6945 6946 6947
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;
J
Josef Bacik 已提交
6948 6949 6950 6951 6952
	/*
	 * 2 items for inode item and ref
	 * 2 items for dir items
	 * 1 item for xattr if selinux is on
	 */
6953 6954 6955
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
6956

C
Chris Mason 已提交
6957 6958
	btrfs_set_trans_block_group(trans, dir);

6959
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6960
				dentry->d_name.len, dir->i_ino, objectid,
6961 6962
				BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
				&index);
C
Chris Mason 已提交
6963 6964 6965 6966
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

6967
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
6968 6969 6970 6971 6972
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

C
Chris Mason 已提交
6973
	btrfs_set_trans_block_group(trans, inode);
6974
	err = btrfs_add_nondir(trans, dir, dentry, inode, 0, index);
C
Chris Mason 已提交
6975 6976 6977 6978
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
C
Chris Mason 已提交
6979
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
6980 6981
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
6982
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
6983 6984 6985 6986 6987 6988 6989 6990 6991 6992 6993 6994 6995 6996
	}
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
	if (drop_inode)
		goto out_unlock;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	key.objectid = inode->i_ino;
	key.offset = 0;
	btrfs_set_key_type(&key, BTRFS_EXTENT_DATA_KEY);
	datasize = btrfs_file_extent_calc_inline_size(name_len);
	err = btrfs_insert_empty_item(trans, root, path, &key,
				      datasize);
6997 6998 6999 7000
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}
7001 7002 7003 7004 7005
	leaf = path->nodes[0];
	ei = btrfs_item_ptr(leaf, path->slots[0],
			    struct btrfs_file_extent_item);
	btrfs_set_file_extent_generation(leaf, ei, trans->transid);
	btrfs_set_file_extent_type(leaf, ei,
C
Chris Mason 已提交
7006
				   BTRFS_FILE_EXTENT_INLINE);
C
Chris Mason 已提交
7007 7008 7009 7010 7011
	btrfs_set_file_extent_encryption(leaf, ei, 0);
	btrfs_set_file_extent_compression(leaf, ei, 0);
	btrfs_set_file_extent_other_encoding(leaf, ei, 0);
	btrfs_set_file_extent_ram_bytes(leaf, ei, name_len);

C
Chris Mason 已提交
7012
	ptr = btrfs_file_extent_inline_start(ei);
7013 7014
	write_extent_buffer(leaf, symname, ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
7015
	btrfs_free_path(path);
7016

C
Chris Mason 已提交
7017 7018
	inode->i_op = &btrfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &btrfs_symlink_aops;
C
Chris Mason 已提交
7019
	inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
Y
Yan Zheng 已提交
7020
	inode_set_bytes(inode, name_len);
7021
	btrfs_i_size_write(inode, name_len - 1);
7022 7023 7024
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
7025 7026

out_unlock:
7027
	nr = trans->blocks_used;
7028
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
7029 7030 7031 7032
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
7033
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
7034 7035
	return err;
}
7036

7037 7038 7039 7040
static int __btrfs_prealloc_file_range(struct inode *inode, int mode,
				       u64 start, u64 num_bytes, u64 min_size,
				       loff_t actual_len, u64 *alloc_hint,
				       struct btrfs_trans_handle *trans)
Y
Yan Zheng 已提交
7041 7042 7043 7044
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key ins;
	u64 cur_offset = start;
7045
	u64 i_size;
Y
Yan Zheng 已提交
7046
	int ret = 0;
7047
	bool own_trans = true;
Y
Yan Zheng 已提交
7048

7049 7050
	if (trans)
		own_trans = false;
Y
Yan Zheng 已提交
7051
	while (num_bytes > 0) {
7052 7053 7054 7055 7056 7057
		if (own_trans) {
			trans = btrfs_start_transaction(root, 3);
			if (IS_ERR(trans)) {
				ret = PTR_ERR(trans);
				break;
			}
7058 7059
		}

7060 7061
		ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
					   0, *alloc_hint, (u64)-1, &ins, 1);
7062
		if (ret) {
7063 7064
			if (own_trans)
				btrfs_end_transaction(trans, root);
7065
			break;
Y
Yan Zheng 已提交
7066
		}
7067

Y
Yan Zheng 已提交
7068 7069 7070
		ret = insert_reserved_file_extent(trans, inode,
						  cur_offset, ins.objectid,
						  ins.offset, ins.offset,
Y
Yan, Zheng 已提交
7071
						  ins.offset, 0, 0, 0,
Y
Yan Zheng 已提交
7072 7073
						  BTRFS_FILE_EXTENT_PREALLOC);
		BUG_ON(ret);
C
Chris Mason 已提交
7074 7075
		btrfs_drop_extent_cache(inode, cur_offset,
					cur_offset + ins.offset -1, 0);
7076

Y
Yan Zheng 已提交
7077 7078
		num_bytes -= ins.offset;
		cur_offset += ins.offset;
7079
		*alloc_hint = ins.objectid + ins.offset;
7080

Y
Yan Zheng 已提交
7081
		inode->i_ctime = CURRENT_TIME;
7082
		BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
Y
Yan Zheng 已提交
7083
		if (!(mode & FALLOC_FL_KEEP_SIZE) &&
7084 7085
		    (actual_len > inode->i_size) &&
		    (cur_offset > inode->i_size)) {
7086
			if (cur_offset > actual_len)
7087
				i_size = actual_len;
7088
			else
7089 7090 7091
				i_size = cur_offset;
			i_size_write(inode, i_size);
			btrfs_ordered_update_i_size(inode, i_size, NULL);
7092 7093
		}

Y
Yan Zheng 已提交
7094 7095 7096
		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);

7097 7098
		if (own_trans)
			btrfs_end_transaction(trans, root);
7099
	}
Y
Yan Zheng 已提交
7100 7101 7102
	return ret;
}

7103 7104 7105 7106 7107 7108 7109 7110 7111 7112 7113 7114 7115 7116 7117 7118 7119 7120
int btrfs_prealloc_file_range(struct inode *inode, int mode,
			      u64 start, u64 num_bytes, u64 min_size,
			      loff_t actual_len, u64 *alloc_hint)
{
	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
					   min_size, actual_len, alloc_hint,
					   NULL);
}

int btrfs_prealloc_file_range_trans(struct inode *inode,
				    struct btrfs_trans_handle *trans, int mode,
				    u64 start, u64 num_bytes, u64 min_size,
				    loff_t actual_len, u64 *alloc_hint)
{
	return __btrfs_prealloc_file_range(inode, mode, start, num_bytes,
					   min_size, actual_len, alloc_hint, trans);
}

Y
Yan Zheng 已提交
7121 7122 7123
static long btrfs_fallocate(struct inode *inode, int mode,
			    loff_t offset, loff_t len)
{
7124
	struct extent_state *cached_state = NULL;
Y
Yan Zheng 已提交
7125 7126 7127 7128 7129
	u64 cur_offset;
	u64 last_byte;
	u64 alloc_start;
	u64 alloc_end;
	u64 alloc_hint = 0;
7130
	u64 locked_end;
Y
Yan Zheng 已提交
7131 7132 7133 7134 7135 7136 7137
	u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
	struct extent_map *em;
	int ret;

	alloc_start = offset & ~mask;
	alloc_end =  (offset + len + mask) & ~mask;

7138 7139 7140 7141 7142 7143
	/*
	 * wait for ordered IO before we have any locks.  We'll loop again
	 * below with the locks held.
	 */
	btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);

Y
Yan Zheng 已提交
7144
	mutex_lock(&inode->i_mutex);
7145 7146 7147 7148
	ret = inode_newsize_ok(inode, alloc_end);
	if (ret)
		goto out;

Y
Yan Zheng 已提交
7149 7150 7151 7152 7153 7154
	if (alloc_start > inode->i_size) {
		ret = btrfs_cont_expand(inode, alloc_start);
		if (ret)
			goto out;
	}

7155
	ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
7156 7157 7158
	if (ret)
		goto out;

7159
	locked_end = alloc_end - 1;
Y
Yan Zheng 已提交
7160 7161
	while (1) {
		struct btrfs_ordered_extent *ordered;
7162 7163 7164 7165

		/* the extent lock is ordered inside the running
		 * transaction
		 */
7166 7167
		lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
				 locked_end, 0, &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
7168 7169 7170 7171 7172 7173
		ordered = btrfs_lookup_first_ordered_extent(inode,
							    alloc_end - 1);
		if (ordered &&
		    ordered->file_offset + ordered->len > alloc_start &&
		    ordered->file_offset < alloc_end) {
			btrfs_put_ordered_extent(ordered);
7174 7175 7176
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
					     alloc_start, locked_end,
					     &cached_state, GFP_NOFS);
7177 7178 7179 7180
			/*
			 * we can't wait on the range with the transaction
			 * running or with the extent lock held
			 */
Y
Yan Zheng 已提交
7181 7182 7183 7184 7185 7186 7187 7188 7189 7190 7191 7192 7193 7194 7195 7196
			btrfs_wait_ordered_range(inode, alloc_start,
						 alloc_end - alloc_start);
		} else {
			if (ordered)
				btrfs_put_ordered_extent(ordered);
			break;
		}
	}

	cur_offset = alloc_start;
	while (1) {
		em = btrfs_get_extent(inode, NULL, 0, cur_offset,
				      alloc_end - cur_offset, 0);
		BUG_ON(IS_ERR(em) || !em);
		last_byte = min(extent_map_end(em), alloc_end);
		last_byte = (last_byte + mask) & ~mask;
7197 7198 7199
		if (em->block_start == EXTENT_MAP_HOLE ||
		    (cur_offset >= inode->i_size &&
		     !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
J
Josef Bacik 已提交
7200
			ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
7201 7202 7203 7204
							last_byte - cur_offset,
							1 << inode->i_blkbits,
							offset + len,
							&alloc_hint);
Y
Yan Zheng 已提交
7205 7206 7207 7208 7209 7210 7211 7212 7213 7214 7215 7216 7217
			if (ret < 0) {
				free_extent_map(em);
				break;
			}
		}
		free_extent_map(em);

		cur_offset = last_byte;
		if (cur_offset >= alloc_end) {
			ret = 0;
			break;
		}
	}
7218 7219
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
			     &cached_state, GFP_NOFS);
7220

7221
	btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
Y
Yan Zheng 已提交
7222 7223 7224 7225 7226
out:
	mutex_unlock(&inode->i_mutex);
	return ret;
}

7227 7228 7229 7230 7231
static int btrfs_set_page_dirty(struct page *page)
{
	return __set_page_dirty_nobuffers(page);
}

7232
static int btrfs_permission(struct inode *inode, int mask)
Y
Yan 已提交
7233
{
L
Li Zefan 已提交
7234 7235 7236 7237
	struct btrfs_root *root = BTRFS_I(inode)->root;

	if (btrfs_root_readonly(root) && (mask & MAY_WRITE))
		return -EROFS;
7238
	if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
Y
Yan 已提交
7239
		return -EACCES;
J
Josef Bacik 已提交
7240
	return generic_permission(inode, mask, btrfs_check_acl);
Y
Yan 已提交
7241
}
C
Chris Mason 已提交
7242

7243
static const struct inode_operations btrfs_dir_inode_operations = {
7244
	.getattr	= btrfs_getattr,
C
Chris Mason 已提交
7245 7246 7247 7248 7249 7250 7251 7252 7253
	.lookup		= btrfs_lookup,
	.create		= btrfs_create,
	.unlink		= btrfs_unlink,
	.link		= btrfs_link,
	.mkdir		= btrfs_mkdir,
	.rmdir		= btrfs_rmdir,
	.rename		= btrfs_rename,
	.symlink	= btrfs_symlink,
	.setattr	= btrfs_setattr,
J
Josef Bacik 已提交
7254
	.mknod		= btrfs_mknod,
7255 7256
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
7257
	.listxattr	= btrfs_listxattr,
7258
	.removexattr	= btrfs_removexattr,
Y
Yan 已提交
7259
	.permission	= btrfs_permission,
C
Chris Mason 已提交
7260
};
7261
static const struct inode_operations btrfs_dir_ro_inode_operations = {
C
Chris Mason 已提交
7262
	.lookup		= btrfs_lookup,
Y
Yan 已提交
7263
	.permission	= btrfs_permission,
C
Chris Mason 已提交
7264
};
7265

7266
static const struct file_operations btrfs_dir_file_operations = {
C
Chris Mason 已提交
7267 7268
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
7269
	.readdir	= btrfs_real_readdir,
C
Christoph Hellwig 已提交
7270
	.unlocked_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
7271
#ifdef CONFIG_COMPAT
C
Christoph Hellwig 已提交
7272
	.compat_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
7273
#endif
S
Sage Weil 已提交
7274
	.release        = btrfs_release_file,
7275
	.fsync		= btrfs_sync_file,
C
Chris Mason 已提交
7276 7277
};

7278
static struct extent_io_ops btrfs_extent_io_ops = {
7279
	.fill_delalloc = run_delalloc_range,
7280
	.submit_bio_hook = btrfs_submit_bio_hook,
7281
	.merge_bio_hook = btrfs_merge_bio_hook,
7282
	.readpage_end_io_hook = btrfs_readpage_end_io_hook,
7283
	.writepage_end_io_hook = btrfs_writepage_end_io_hook,
7284
	.writepage_start_hook = btrfs_writepage_start_hook,
7285
	.readpage_io_failed_hook = btrfs_io_failed_hook,
C
Chris Mason 已提交
7286 7287
	.set_bit_hook = btrfs_set_bit_hook,
	.clear_bit_hook = btrfs_clear_bit_hook,
J
Josef Bacik 已提交
7288 7289
	.merge_extent_hook = btrfs_merge_extent_hook,
	.split_extent_hook = btrfs_split_extent_hook,
7290 7291
};

7292 7293 7294 7295 7296 7297 7298 7299 7300 7301 7302 7303
/*
 * btrfs doesn't support the bmap operation because swapfiles
 * use bmap to make a mapping of extents in the file.  They assume
 * these extents won't change over the life of the file and they
 * use the bmap result to do IO directly to the drive.
 *
 * the btrfs bmap call would return logical addresses that aren't
 * suitable for IO and they also will change frequently as COW
 * operations happen.  So, swapfile + btrfs == corruption.
 *
 * For now we're avoiding this by dropping bmap.
 */
7304
static const struct address_space_operations btrfs_aops = {
C
Chris Mason 已提交
7305 7306
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
7307
	.writepages	= btrfs_writepages,
C
Chris Mason 已提交
7308
	.readpages	= btrfs_readpages,
C
Chris Mason 已提交
7309
	.sync_page	= block_sync_page,
7310
	.direct_IO	= btrfs_direct_IO,
7311 7312
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
7313
	.set_page_dirty	= btrfs_set_page_dirty,
7314
	.error_remove_page = generic_error_remove_page,
C
Chris Mason 已提交
7315 7316
};

7317
static const struct address_space_operations btrfs_symlink_aops = {
C
Chris Mason 已提交
7318 7319
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
7320 7321
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
C
Chris Mason 已提交
7322 7323
};

7324
static const struct inode_operations btrfs_file_inode_operations = {
C
Chris Mason 已提交
7325 7326 7327
	.truncate	= btrfs_truncate,
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
7328 7329
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
7330
	.listxattr      = btrfs_listxattr,
7331
	.removexattr	= btrfs_removexattr,
Y
Yan 已提交
7332
	.permission	= btrfs_permission,
Y
Yan Zheng 已提交
7333
	.fallocate	= btrfs_fallocate,
Y
Yehuda Sadeh 已提交
7334
	.fiemap		= btrfs_fiemap,
C
Chris Mason 已提交
7335
};
7336
static const struct inode_operations btrfs_special_inode_operations = {
J
Josef Bacik 已提交
7337 7338
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
Y
Yan 已提交
7339
	.permission	= btrfs_permission,
7340 7341
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
7342
	.listxattr	= btrfs_listxattr,
7343
	.removexattr	= btrfs_removexattr,
J
Josef Bacik 已提交
7344
};
7345
static const struct inode_operations btrfs_symlink_inode_operations = {
C
Chris Mason 已提交
7346 7347 7348
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_link,
7349
	.getattr	= btrfs_getattr,
Y
Yan 已提交
7350
	.permission	= btrfs_permission,
J
Jim Owens 已提交
7351 7352 7353 7354
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
	.listxattr	= btrfs_listxattr,
	.removexattr	= btrfs_removexattr,
C
Chris Mason 已提交
7355
};
7356

7357
const struct dentry_operations btrfs_dentry_operations = {
7358 7359
	.d_delete	= btrfs_dentry_delete,
};