aops.c 33.9 KB
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/* -*- mode: c; c-basic-offset: 8; -*-
 * vim: noexpandtab sw=8 ts=8 sts=0:
 *
 * Copyright (C) 2002, 2004 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 as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * 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.
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <asm/byteorder.h>
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#include <linux/swap.h>
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#include <linux/pipe_fs_i.h>
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#define MLOG_MASK_PREFIX ML_FILE_IO
#include <cluster/masklog.h>

#include "ocfs2.h"

#include "alloc.h"
#include "aops.h"
#include "dlmglue.h"
#include "extent_map.h"
#include "file.h"
#include "inode.h"
#include "journal.h"
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#include "suballoc.h"
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#include "super.h"
#include "symlink.h"

#include "buffer_head_io.h"

static int ocfs2_symlink_get_block(struct inode *inode, sector_t iblock,
				   struct buffer_head *bh_result, int create)
{
	int err = -EIO;
	int status;
	struct ocfs2_dinode *fe = NULL;
	struct buffer_head *bh = NULL;
	struct buffer_head *buffer_cache_bh = NULL;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	void *kaddr;

	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
		   (unsigned long long)iblock, bh_result, create);

	BUG_ON(ocfs2_inode_is_fast_symlink(inode));

	if ((iblock << inode->i_sb->s_blocksize_bits) > PATH_MAX + 1) {
		mlog(ML_ERROR, "block offset > PATH_MAX: %llu",
		     (unsigned long long)iblock);
		goto bail;
	}

	status = ocfs2_read_block(OCFS2_SB(inode->i_sb),
				  OCFS2_I(inode)->ip_blkno,
				  &bh, OCFS2_BH_CACHED, inode);
	if (status < 0) {
		mlog_errno(status);
		goto bail;
	}
	fe = (struct ocfs2_dinode *) bh->b_data;

	if (!OCFS2_IS_VALID_DINODE(fe)) {
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		mlog(ML_ERROR, "Invalid dinode #%llu: signature = %.*s\n",
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		     (unsigned long long)le64_to_cpu(fe->i_blkno), 7,
		     fe->i_signature);
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		goto bail;
	}

	if ((u64)iblock >= ocfs2_clusters_to_blocks(inode->i_sb,
						    le32_to_cpu(fe->i_clusters))) {
		mlog(ML_ERROR, "block offset is outside the allocated size: "
		     "%llu\n", (unsigned long long)iblock);
		goto bail;
	}

	/* We don't use the page cache to create symlink data, so if
	 * need be, copy it over from the buffer cache. */
	if (!buffer_uptodate(bh_result) && ocfs2_inode_is_new(inode)) {
		u64 blkno = le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) +
			    iblock;
		buffer_cache_bh = sb_getblk(osb->sb, blkno);
		if (!buffer_cache_bh) {
			mlog(ML_ERROR, "couldn't getblock for symlink!\n");
			goto bail;
		}

		/* we haven't locked out transactions, so a commit
		 * could've happened. Since we've got a reference on
		 * the bh, even if it commits while we're doing the
		 * copy, the data is still good. */
		if (buffer_jbd(buffer_cache_bh)
		    && ocfs2_inode_is_new(inode)) {
			kaddr = kmap_atomic(bh_result->b_page, KM_USER0);
			if (!kaddr) {
				mlog(ML_ERROR, "couldn't kmap!\n");
				goto bail;
			}
			memcpy(kaddr + (bh_result->b_size * iblock),
			       buffer_cache_bh->b_data,
			       bh_result->b_size);
			kunmap_atomic(kaddr, KM_USER0);
			set_buffer_uptodate(bh_result);
		}
		brelse(buffer_cache_bh);
	}

	map_bh(bh_result, inode->i_sb,
	       le64_to_cpu(fe->id2.i_list.l_recs[0].e_blkno) + iblock);

	err = 0;

bail:
	if (bh)
		brelse(bh);

	mlog_exit(err);
	return err;
}

static int ocfs2_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh_result, int create)
{
	int err = 0;
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	unsigned int ext_flags;
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	u64 p_blkno, past_eof;
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	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
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	mlog_entry("(0x%p, %llu, 0x%p, %d)\n", inode,
		   (unsigned long long)iblock, bh_result, create);

	if (OCFS2_I(inode)->ip_flags & OCFS2_INODE_SYSTEM_FILE)
		mlog(ML_NOTICE, "get_block on system inode 0x%p (%lu)\n",
		     inode, inode->i_ino);

	if (S_ISLNK(inode->i_mode)) {
		/* this always does I/O for some reason. */
		err = ocfs2_symlink_get_block(inode, iblock, bh_result, create);
		goto bail;
	}

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	err = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno, NULL,
					  &ext_flags);
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	if (err) {
		mlog(ML_ERROR, "Error %d from get_blocks(0x%p, %llu, 1, "
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		     "%llu, NULL)\n", err, inode, (unsigned long long)iblock,
		     (unsigned long long)p_blkno);
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		goto bail;
	}

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	/*
	 * ocfs2 never allocates in this function - the only time we
	 * need to use BH_New is when we're extending i_size on a file
	 * system which doesn't support holes, in which case BH_New
	 * allows block_prepare_write() to zero.
	 */
	mlog_bug_on_msg(create && p_blkno == 0 && ocfs2_sparse_alloc(osb),
			"ino %lu, iblock %llu\n", inode->i_ino,
			(unsigned long long)iblock);

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	/* Treat the unwritten extent as a hole for zeroing purposes. */
	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
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		map_bh(bh_result, inode->i_sb, p_blkno);

	if (!ocfs2_sparse_alloc(osb)) {
		if (p_blkno == 0) {
			err = -EIO;
			mlog(ML_ERROR,
			     "iblock = %llu p_blkno = %llu blkno=(%llu)\n",
			     (unsigned long long)iblock,
			     (unsigned long long)p_blkno,
			     (unsigned long long)OCFS2_I(inode)->ip_blkno);
			mlog(ML_ERROR, "Size %llu, clusters %u\n", (unsigned long long)i_size_read(inode), OCFS2_I(inode)->ip_clusters);
			dump_stack();
		}
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		past_eof = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
		mlog(0, "Inode %lu, past_eof = %llu\n", inode->i_ino,
		     (unsigned long long)past_eof);
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		if (create && (iblock >= past_eof))
			set_buffer_new(bh_result);
	}
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bail:
	if (err < 0)
		err = -EIO;

	mlog_exit(err);
	return err;
}

static int ocfs2_readpage(struct file *file, struct page *page)
{
	struct inode *inode = page->mapping->host;
	loff_t start = (loff_t)page->index << PAGE_CACHE_SHIFT;
	int ret, unlock = 1;

	mlog_entry("(0x%p, %lu)\n", file, (page ? page->index : 0));

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	ret = ocfs2_meta_lock_with_page(inode, NULL, 0, page);
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	if (ret != 0) {
		if (ret == AOP_TRUNCATED_PAGE)
			unlock = 0;
		mlog_errno(ret);
		goto out;
	}

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	if (down_read_trylock(&OCFS2_I(inode)->ip_alloc_sem) == 0) {
		ret = AOP_TRUNCATED_PAGE;
		goto out_meta_unlock;
	}
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	/*
	 * i_size might have just been updated as we grabed the meta lock.  We
	 * might now be discovering a truncate that hit on another node.
	 * block_read_full_page->get_block freaks out if it is asked to read
	 * beyond the end of a file, so we check here.  Callers
	 * (generic_file_read, fault->nopage) are clever enough to check i_size
	 * and notice that the page they just read isn't needed.
	 *
	 * XXX sys_readahead() seems to get that wrong?
	 */
	if (start >= i_size_read(inode)) {
		char *addr = kmap(page);
		memset(addr, 0, PAGE_SIZE);
		flush_dcache_page(page);
		kunmap(page);
		SetPageUptodate(page);
		ret = 0;
		goto out_alloc;
	}

	ret = ocfs2_data_lock_with_page(inode, 0, page);
	if (ret != 0) {
		if (ret == AOP_TRUNCATED_PAGE)
			unlock = 0;
		mlog_errno(ret);
		goto out_alloc;
	}

	ret = block_read_full_page(page, ocfs2_get_block);
	unlock = 0;

	ocfs2_data_unlock(inode, 0);
out_alloc:
	up_read(&OCFS2_I(inode)->ip_alloc_sem);
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out_meta_unlock:
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	ocfs2_meta_unlock(inode, 0);
out:
	if (unlock)
		unlock_page(page);
	mlog_exit(ret);
	return ret;
}

/* Note: Because we don't support holes, our allocation has
 * already happened (allocation writes zeros to the file data)
 * so we don't have to worry about ordered writes in
 * ocfs2_writepage.
 *
 * ->writepage is called during the process of invalidating the page cache
 * during blocked lock processing.  It can't block on any cluster locks
 * to during block mapping.  It's relying on the fact that the block
 * mapping can't have disappeared under the dirty pages that it is
 * being asked to write back.
 */
static int ocfs2_writepage(struct page *page, struct writeback_control *wbc)
{
	int ret;

	mlog_entry("(0x%p)\n", page);

	ret = block_write_full_page(page, ocfs2_get_block, wbc);

	mlog_exit(ret);

	return ret;
}

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/*
 * This is called from ocfs2_write_zero_page() which has handled it's
 * own cluster locking and has ensured allocation exists for those
 * blocks to be written.
 */
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int ocfs2_prepare_write_nolock(struct inode *inode, struct page *page,
			       unsigned from, unsigned to)
{
	int ret;

	down_read(&OCFS2_I(inode)->ip_alloc_sem);

	ret = block_prepare_write(page, from, to, ocfs2_get_block);

	up_read(&OCFS2_I(inode)->ip_alloc_sem);

	return ret;
}

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/* Taken from ext3. We don't necessarily need the full blown
 * functionality yet, but IMHO it's better to cut and paste the whole
 * thing so we can avoid introducing our own bugs (and easily pick up
 * their fixes when they happen) --Mark */
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int walk_page_buffers(	handle_t *handle,
			struct buffer_head *head,
			unsigned from,
			unsigned to,
			int *partial,
			int (*fn)(	handle_t *handle,
					struct buffer_head *bh))
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{
	struct buffer_head *bh;
	unsigned block_start, block_end;
	unsigned blocksize = head->b_size;
	int err, ret = 0;
	struct buffer_head *next;

	for (	bh = head, block_start = 0;
		ret == 0 && (bh != head || !block_start);
	    	block_start = block_end, bh = next)
	{
		next = bh->b_this_page;
		block_end = block_start + blocksize;
		if (block_end <= from || block_start >= to) {
			if (partial && !buffer_uptodate(bh))
				*partial = 1;
			continue;
		}
		err = (*fn)(handle, bh);
		if (!ret)
			ret = err;
	}
	return ret;
}

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handle_t *ocfs2_start_walk_page_trans(struct inode *inode,
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							 struct page *page,
							 unsigned from,
							 unsigned to)
{
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
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	handle_t *handle = NULL;
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	int ret = 0;

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	handle = ocfs2_start_trans(osb, OCFS2_INODE_UPDATE_CREDITS);
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	if (!handle) {
		ret = -ENOMEM;
		mlog_errno(ret);
		goto out;
	}

	if (ocfs2_should_order_data(inode)) {
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		ret = walk_page_buffers(handle,
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					page_buffers(page),
					from, to, NULL,
					ocfs2_journal_dirty_data);
		if (ret < 0) 
			mlog_errno(ret);
	}
out:
	if (ret) {
		if (handle)
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			ocfs2_commit_trans(osb, handle);
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		handle = ERR_PTR(ret);
	}
	return handle;
}

static sector_t ocfs2_bmap(struct address_space *mapping, sector_t block)
{
	sector_t status;
	u64 p_blkno = 0;
	int err = 0;
	struct inode *inode = mapping->host;

	mlog_entry("(block = %llu)\n", (unsigned long long)block);

	/* We don't need to lock journal system files, since they aren't
	 * accessed concurrently from multiple nodes.
	 */
	if (!INODE_JOURNAL(inode)) {
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		err = ocfs2_meta_lock(inode, NULL, 0);
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		if (err) {
			if (err != -ENOENT)
				mlog_errno(err);
			goto bail;
		}
		down_read(&OCFS2_I(inode)->ip_alloc_sem);
	}

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	err = ocfs2_extent_map_get_blocks(inode, block, &p_blkno, NULL, NULL);
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	if (!INODE_JOURNAL(inode)) {
		up_read(&OCFS2_I(inode)->ip_alloc_sem);
		ocfs2_meta_unlock(inode, 0);
	}

	if (err) {
		mlog(ML_ERROR, "get_blocks() failed, block = %llu\n",
		     (unsigned long long)block);
		mlog_errno(err);
		goto bail;
	}


bail:
	status = err ? 0 : p_blkno;

	mlog_exit((int)status);

	return status;
}

/*
 * TODO: Make this into a generic get_blocks function.
 *
 * From do_direct_io in direct-io.c:
 *  "So what we do is to permit the ->get_blocks function to populate
 *   bh.b_size with the size of IO which is permitted at this offset and
 *   this i_blkbits."
 *
 * This function is called directly from get_more_blocks in direct-io.c.
 *
 * called like this: dio->get_blocks(dio->inode, fs_startblk,
 * 					fs_count, map_bh, dio->rw == WRITE);
 */
static int ocfs2_direct_IO_get_blocks(struct inode *inode, sector_t iblock,
				     struct buffer_head *bh_result, int create)
{
	int ret;
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	u64 p_blkno, inode_blocks, contig_blocks;
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	unsigned int ext_flags;
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	unsigned char blocksize_bits = inode->i_sb->s_blocksize_bits;
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	unsigned long max_blocks = bh_result->b_size >> inode->i_blkbits;
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	/* This function won't even be called if the request isn't all
	 * nicely aligned and of the right size, so there's no need
	 * for us to check any of that. */

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	inode_blocks = ocfs2_blocks_for_bytes(inode->i_sb, i_size_read(inode));
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	/*
	 * Any write past EOF is not allowed because we'd be extending.
	 */
	if (create && (iblock + max_blocks) > inode_blocks) {
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		ret = -EIO;
		goto bail;
	}

	/* This figures out the size of the next contiguous block, and
	 * our logical offset */
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	ret = ocfs2_extent_map_get_blocks(inode, iblock, &p_blkno,
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					  &contig_blocks, &ext_flags);
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	if (ret) {
		mlog(ML_ERROR, "get_blocks() failed iblock=%llu\n",
		     (unsigned long long)iblock);
		ret = -EIO;
		goto bail;
	}

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	if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb)) && !p_blkno) {
		ocfs2_error(inode->i_sb,
			    "Inode %llu has a hole at block %llu\n",
			    (unsigned long long)OCFS2_I(inode)->ip_blkno,
			    (unsigned long long)iblock);
		ret = -EROFS;
		goto bail;
	}

	/*
	 * get_more_blocks() expects us to describe a hole by clearing
	 * the mapped bit on bh_result().
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	 *
	 * Consider an unwritten extent as a hole.
491
	 */
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	if (p_blkno && !(ext_flags & OCFS2_EXT_UNWRITTEN))
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		map_bh(bh_result, inode->i_sb, p_blkno);
	else {
		/*
		 * ocfs2_prepare_inode_for_write() should have caught
		 * the case where we'd be filling a hole and triggered
		 * a buffered write instead.
		 */
		if (create) {
			ret = -EIO;
			mlog_errno(ret);
			goto bail;
		}

		clear_buffer_mapped(bh_result);
	}
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	/* make sure we don't map more than max_blocks blocks here as
	   that's all the kernel will handle at this point. */
	if (max_blocks < contig_blocks)
		contig_blocks = max_blocks;
	bh_result->b_size = contig_blocks << blocksize_bits;
bail:
	return ret;
}

/* 
 * ocfs2_dio_end_io is called by the dio core when a dio is finished.  We're
 * particularly interested in the aio/dio case.  Like the core uses
 * i_alloc_sem, we use the rw_lock DLM lock to protect io on one node from
 * truncation on another.
 */
static void ocfs2_dio_end_io(struct kiocb *iocb,
			     loff_t offset,
			     ssize_t bytes,
			     void *private)
{
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	struct inode *inode = iocb->ki_filp->f_path.dentry->d_inode;
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	int level;
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	/* this io's submitter should not have unlocked this before we could */
	BUG_ON(!ocfs2_iocb_is_rw_locked(iocb));
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	ocfs2_iocb_clear_rw_locked(iocb);
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	level = ocfs2_iocb_rw_locked_level(iocb);
	if (!level)
		up_read(&inode->i_alloc_sem);
	ocfs2_rw_unlock(inode, level);
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}

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/*
 * ocfs2_invalidatepage() and ocfs2_releasepage() are shamelessly stolen
 * from ext3.  PageChecked() bits have been removed as OCFS2 does not
 * do journalled data.
 */
static void ocfs2_invalidatepage(struct page *page, unsigned long offset)
{
	journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;

	journal_invalidatepage(journal, page, offset);
}

static int ocfs2_releasepage(struct page *page, gfp_t wait)
{
	journal_t *journal = OCFS2_SB(page->mapping->host->i_sb)->journal->j_journal;

	if (!page_has_buffers(page))
		return 0;
	return journal_try_to_free_buffers(journal, page, wait);
}

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static ssize_t ocfs2_direct_IO(int rw,
			       struct kiocb *iocb,
			       const struct iovec *iov,
			       loff_t offset,
			       unsigned long nr_segs)
{
	struct file *file = iocb->ki_filp;
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	struct inode *inode = file->f_path.dentry->d_inode->i_mapping->host;
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	int ret;

	mlog_entry_void();
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	if (!ocfs2_sparse_alloc(OCFS2_SB(inode->i_sb))) {
		/*
		 * We get PR data locks even for O_DIRECT.  This
		 * allows concurrent O_DIRECT I/O but doesn't let
		 * O_DIRECT with extending and buffered zeroing writes
		 * race.  If they did race then the buffered zeroing
		 * could be written back after the O_DIRECT I/O.  It's
		 * one thing to tell people not to mix buffered and
		 * O_DIRECT writes, but expecting them to understand
		 * that file extension is also an implicit buffered
		 * write is too much.  By getting the PR we force
		 * writeback of the buffered zeroing before
		 * proceeding.
		 */
		ret = ocfs2_data_lock(inode, 0);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
		ocfs2_data_unlock(inode, 0);
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	}

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	ret = blockdev_direct_IO_no_locking(rw, iocb, inode,
					    inode->i_sb->s_bdev, iov, offset,
					    nr_segs, 
					    ocfs2_direct_IO_get_blocks,
					    ocfs2_dio_end_io);
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out:
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	mlog_exit(ret);
	return ret;
}

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static void ocfs2_figure_cluster_boundaries(struct ocfs2_super *osb,
					    u32 cpos,
					    unsigned int *start,
					    unsigned int *end)
{
	unsigned int cluster_start = 0, cluster_end = PAGE_CACHE_SIZE;

	if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits)) {
		unsigned int cpp;

		cpp = 1 << (PAGE_CACHE_SHIFT - osb->s_clustersize_bits);

		cluster_start = cpos % cpp;
		cluster_start = cluster_start << osb->s_clustersize_bits;

		cluster_end = cluster_start + osb->s_clustersize;
	}

	BUG_ON(cluster_start > PAGE_SIZE);
	BUG_ON(cluster_end > PAGE_SIZE);

	if (start)
		*start = cluster_start;
	if (end)
		*end = cluster_end;
}

/*
 * 'from' and 'to' are the region in the page to avoid zeroing.
 *
 * If pagesize > clustersize, this function will avoid zeroing outside
 * of the cluster boundary.
 *
 * from == to == 0 is code for "zero the entire cluster region"
 */
static void ocfs2_clear_page_regions(struct page *page,
				     struct ocfs2_super *osb, u32 cpos,
				     unsigned from, unsigned to)
{
	void *kaddr;
	unsigned int cluster_start, cluster_end;

	ocfs2_figure_cluster_boundaries(osb, cpos, &cluster_start, &cluster_end);

	kaddr = kmap_atomic(page, KM_USER0);

	if (from || to) {
		if (from > cluster_start)
			memset(kaddr + cluster_start, 0, from - cluster_start);
		if (to < cluster_end)
			memset(kaddr + to, 0, cluster_end - to);
	} else {
		memset(kaddr + cluster_start, 0, cluster_end - cluster_start);
	}

	kunmap_atomic(kaddr, KM_USER0);
}

/*
 * Some of this taken from block_prepare_write(). We already have our
 * mapping by now though, and the entire write will be allocating or
 * it won't, so not much need to use BH_New.
 *
 * This will also skip zeroing, which is handled externally.
 */
673 674 675
int ocfs2_map_page_blocks(struct page *page, u64 *p_blkno,
			  struct inode *inode, unsigned int from,
			  unsigned int to, int new)
676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693
{
	int ret = 0;
	struct buffer_head *head, *bh, *wait[2], **wait_bh = wait;
	unsigned int block_end, block_start;
	unsigned int bsize = 1 << inode->i_blkbits;

	if (!page_has_buffers(page))
		create_empty_buffers(page, bsize, 0);

	head = page_buffers(page);
	for (bh = head, block_start = 0; bh != head || !block_start;
	     bh = bh->b_this_page, block_start += bsize) {
		block_end = block_start + bsize;

		/*
		 * Ignore blocks outside of our i/o range -
		 * they may belong to unallocated clusters.
		 */
694
		if (block_start >= to || block_end <= from) {
695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766
			if (PageUptodate(page))
				set_buffer_uptodate(bh);
			continue;
		}

		/*
		 * For an allocating write with cluster size >= page
		 * size, we always write the entire page.
		 */

		if (buffer_new(bh))
			clear_buffer_new(bh);

		if (!buffer_mapped(bh)) {
			map_bh(bh, inode->i_sb, *p_blkno);
			unmap_underlying_metadata(bh->b_bdev, bh->b_blocknr);
		}

		if (PageUptodate(page)) {
			if (!buffer_uptodate(bh))
				set_buffer_uptodate(bh);
		} else if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
		     (block_start < from || block_end > to)) {
			ll_rw_block(READ, 1, &bh);
			*wait_bh++=bh;
		}

		*p_blkno = *p_blkno + 1;
	}

	/*
	 * If we issued read requests - let them complete.
	 */
	while(wait_bh > wait) {
		wait_on_buffer(*--wait_bh);
		if (!buffer_uptodate(*wait_bh))
			ret = -EIO;
	}

	if (ret == 0 || !new)
		return ret;

	/*
	 * If we get -EIO above, zero out any newly allocated blocks
	 * to avoid exposing stale data.
	 */
	bh = head;
	block_start = 0;
	do {
		void *kaddr;

		block_end = block_start + bsize;
		if (block_end <= from)
			goto next_bh;
		if (block_start >= to)
			break;

		kaddr = kmap_atomic(page, KM_USER0);
		memset(kaddr+block_start, 0, bh->b_size);
		flush_dcache_page(page);
		kunmap_atomic(kaddr, KM_USER0);
		set_buffer_uptodate(bh);
		mark_buffer_dirty(bh);

next_bh:
		block_start = block_end;
		bh = bh->b_this_page;
	} while (bh != head);

	return ret;
}

M
Mark Fasheh 已提交
767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834
/*
 * This will copy user data from the buffer page in the splice
 * context.
 *
 * For now, we ignore SPLICE_F_MOVE as that would require some extra
 * communication out all the way to ocfs2_write().
 */
int ocfs2_map_and_write_splice_data(struct inode *inode,
				  struct ocfs2_write_ctxt *wc, u64 *p_blkno,
				  unsigned int *ret_from, unsigned int *ret_to)
{
	int ret;
	unsigned int to, from, cluster_start, cluster_end;
	char *src, *dst;
	struct ocfs2_splice_write_priv *sp = wc->w_private;
	struct pipe_buffer *buf = sp->s_buf;
	unsigned long bytes, src_from;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start,
					&cluster_end);

	from = sp->s_offset;
	src_from = sp->s_buf_offset;
	bytes = wc->w_count;

	if (wc->w_large_pages) {
		/*
		 * For cluster size < page size, we have to
		 * calculate pos within the cluster and obey
		 * the rightmost boundary.
		 */
		bytes = min(bytes, (unsigned long)(osb->s_clustersize
				   - (wc->w_pos & (osb->s_clustersize - 1))));
	}
	to = from + bytes;

	if (wc->w_this_page_new)
		ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
					    cluster_start, cluster_end, 1);
	else
		ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
					    from, to, 0);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	BUG_ON(from > PAGE_CACHE_SIZE);
	BUG_ON(to > PAGE_CACHE_SIZE);
	BUG_ON(from > osb->s_clustersize);
	BUG_ON(to > osb->s_clustersize);

	src = buf->ops->map(sp->s_pipe, buf, 1);
	dst = kmap_atomic(wc->w_this_page, KM_USER1);
	memcpy(dst + from, src + src_from, bytes);
	kunmap_atomic(wc->w_this_page, KM_USER1);
	buf->ops->unmap(sp->s_pipe, buf, src);

	wc->w_finished_copy = 1;

	*ret_from = from;
	*ret_to = to;
out:

	return bytes ? (unsigned int)bytes : ret;
}

835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946
/*
 * This will copy user data from the iovec in the buffered write
 * context.
 */
int ocfs2_map_and_write_user_data(struct inode *inode,
				  struct ocfs2_write_ctxt *wc, u64 *p_blkno,
				  unsigned int *ret_from, unsigned int *ret_to)
{
	int ret;
	unsigned int to, from, cluster_start, cluster_end;
	unsigned long bytes, src_from;
	char *dst;
	struct ocfs2_buffered_write_priv *bp = wc->w_private;
	const struct iovec *cur_iov = bp->b_cur_iov;
	char __user *buf;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);

	ocfs2_figure_cluster_boundaries(osb, wc->w_cpos, &cluster_start,
					&cluster_end);

	buf = cur_iov->iov_base + bp->b_cur_off;
	src_from = (unsigned long)buf & ~PAGE_CACHE_MASK;

	from = wc->w_pos & (PAGE_CACHE_SIZE - 1);

	/*
	 * This is a lot of comparisons, but it reads quite
	 * easily, which is important here.
	 */
	/* Stay within the src page */
	bytes = PAGE_SIZE - src_from;
	/* Stay within the vector */
	bytes = min(bytes,
		    (unsigned long)(cur_iov->iov_len - bp->b_cur_off));
	/* Stay within count */
	bytes = min(bytes, (unsigned long)wc->w_count);
	/*
	 * For clustersize > page size, just stay within
	 * target page, otherwise we have to calculate pos
	 * within the cluster and obey the rightmost
	 * boundary.
	 */
	if (wc->w_large_pages) {
		/*
		 * For cluster size < page size, we have to
		 * calculate pos within the cluster and obey
		 * the rightmost boundary.
		 */
		bytes = min(bytes, (unsigned long)(osb->s_clustersize
				   - (wc->w_pos & (osb->s_clustersize - 1))));
	} else {
		/*
		 * cluster size > page size is the most common
		 * case - we just stay within the target page
		 * boundary.
		 */
		bytes = min(bytes, PAGE_CACHE_SIZE - from);
	}

	to = from + bytes;

	if (wc->w_this_page_new)
		ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
					    cluster_start, cluster_end, 1);
	else
		ret = ocfs2_map_page_blocks(wc->w_this_page, p_blkno, inode,
					    from, to, 0);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}

	BUG_ON(from > PAGE_CACHE_SIZE);
	BUG_ON(to > PAGE_CACHE_SIZE);
	BUG_ON(from > osb->s_clustersize);
	BUG_ON(to > osb->s_clustersize);

	dst = kmap(wc->w_this_page);
	memcpy(dst + from, bp->b_src_buf + src_from, bytes);
	kunmap(wc->w_this_page);

	/*
	 * XXX: This is slow, but simple. The caller of
	 * ocfs2_buffered_write_cluster() is responsible for
	 * passing through the iovecs, so it's difficult to
	 * predict what our next step is in here after our
	 * initial write. A future version should be pushing
	 * that iovec manipulation further down.
	 *
	 * By setting this, we indicate that a copy from user
	 * data was done, and subsequent calls for this
	 * cluster will skip copying more data.
	 */
	wc->w_finished_copy = 1;

	*ret_from = from;
	*ret_to = to;
out:

	return bytes ? (unsigned int)bytes : ret;
}

/*
 * Map, fill and write a page to disk.
 *
 * The work of copying data is done via callback.  Newly allocated
 * pages which don't take user data will be zero'd (set 'new' to
 * indicate an allocating write)
 *
 * Returns a negative error code or the number of bytes copied into
 * the page.
 */
947 948 949
static int ocfs2_write_data_page(struct inode *inode, handle_t *handle,
				 u64 *p_blkno, struct page *page,
				 struct ocfs2_write_ctxt *wc, int new)
950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
{
	int ret, copied = 0;
	unsigned int from = 0, to = 0;
	unsigned int cluster_start, cluster_end;
	unsigned int zero_from = 0, zero_to = 0;

	ocfs2_figure_cluster_boundaries(OCFS2_SB(inode->i_sb), wc->w_cpos,
					&cluster_start, &cluster_end);

	if ((wc->w_pos >> PAGE_CACHE_SHIFT) == page->index
	    && !wc->w_finished_copy) {

		wc->w_this_page = page;
		wc->w_this_page_new = new;
		ret = wc->w_write_data_page(inode, wc, p_blkno, &from, &to);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}

		copied = ret;

		zero_from = from;
		zero_to = to;
		if (new) {
			from = cluster_start;
			to = cluster_end;
		}
	} else {
		/*
		 * If we haven't allocated the new page yet, we
		 * shouldn't be writing it out without copying user
		 * data. This is likely a math error from the caller.
		 */
		BUG_ON(!new);

		from = cluster_start;
		to = cluster_end;

		ret = ocfs2_map_page_blocks(page, p_blkno, inode,
					    cluster_start, cluster_end, 1);
		if (ret) {
			mlog_errno(ret);
			goto out;
		}
	}

	/*
	 * Parts of newly allocated pages need to be zero'd.
	 *
	 * Above, we have also rewritten 'to' and 'from' - as far as
	 * the rest of the function is concerned, the entire cluster
	 * range inside of a page needs to be written.
	 *
	 * We can skip this if the page is up to date - it's already
	 * been zero'd from being read in as a hole.
	 */
	if (new && !PageUptodate(page))
		ocfs2_clear_page_regions(page, OCFS2_SB(inode->i_sb),
					 wc->w_cpos, zero_from, zero_to);

	flush_dcache_page(page);

	if (ocfs2_should_order_data(inode)) {
		ret = walk_page_buffers(handle,
					page_buffers(page),
					from, to, NULL,
					ocfs2_journal_dirty_data);
		if (ret < 0)
			mlog_errno(ret);
	}

	/*
	 * We don't use generic_commit_write() because we need to
	 * handle our own i_size update.
	 */
	ret = block_commit_write(page, from, to);
	if (ret)
		mlog_errno(ret);
out:

	return copied ? copied : ret;
}

/*
 * Do the actual write of some data into an inode. Optionally allocate
 * in order to fulfill the write.
 *
 * cpos is the logical cluster offset within the file to write at
 *
 * 'phys' is the physical mapping of that offset. a 'phys' value of
 * zero indicates that allocation is required. In this case, data_ac
 * and meta_ac should be valid (meta_ac can be null if metadata
 * allocation isn't required).
 */
static ssize_t ocfs2_write(struct file *file, u32 phys, handle_t *handle,
			   struct buffer_head *di_bh,
			   struct ocfs2_alloc_context *data_ac,
			   struct ocfs2_alloc_context *meta_ac,
			   struct ocfs2_write_ctxt *wc)
{
	int ret, i, numpages = 1, new;
	unsigned int copied = 0;
	u32 tmp_pos;
	u64 v_blkno, p_blkno;
	struct address_space *mapping = file->f_mapping;
	struct inode *inode = mapping->host;
	unsigned long index, start;
	struct page **cpages;

	new = phys == 0 ? 1 : 0;

	/*
	 * Figure out how many pages we'll be manipulating here. For
1064 1065
	 * non allocating write, we just change the one
	 * page. Otherwise, we'll need a whole clusters worth.
1066
	 */
1067 1068
	if (new)
		numpages = ocfs2_pages_per_cluster(inode->i_sb);
1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093

	cpages = kzalloc(sizeof(*cpages) * numpages, GFP_NOFS);
	if (!cpages) {
		ret = -ENOMEM;
		mlog_errno(ret);
		return ret;
	}

	/*
	 * Fill our page array first. That way we've grabbed enough so
	 * that we can zero and flush if we error after adding the
	 * extent.
	 */
	if (new) {
		start = ocfs2_align_clusters_to_page_index(inode->i_sb,
							   wc->w_cpos);
		v_blkno = ocfs2_clusters_to_blocks(inode->i_sb, wc->w_cpos);
	} else {
		start = wc->w_pos >> PAGE_CACHE_SHIFT;
		v_blkno = wc->w_pos >> inode->i_sb->s_blocksize_bits;
	}

	for(i = 0; i < numpages; i++) {
		index = start + i;

1094
		cpages[i] = find_or_create_page(mapping, index, GFP_NOFS);
1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128
		if (!cpages[i]) {
			ret = -ENOMEM;
			mlog_errno(ret);
			goto out;
		}
	}

	if (new) {
		/*
		 * This is safe to call with the page locks - it won't take
		 * any additional semaphores or cluster locks.
		 */
		tmp_pos = wc->w_cpos;
		ret = ocfs2_do_extend_allocation(OCFS2_SB(inode->i_sb), inode,
						 &tmp_pos, 1, di_bh, handle,
						 data_ac, meta_ac, NULL);
		/*
		 * This shouldn't happen because we must have already
		 * calculated the correct meta data allocation required. The
		 * internal tree allocation code should know how to increase
		 * transaction credits itself.
		 *
		 * If need be, we could handle -EAGAIN for a
		 * RESTART_TRANS here.
		 */
		mlog_bug_on_msg(ret == -EAGAIN,
				"Inode %llu: EAGAIN return during allocation.\n",
				(unsigned long long)OCFS2_I(inode)->ip_blkno);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}
	}

1129 1130
	ret = ocfs2_extent_map_get_blocks(inode, v_blkno, &p_blkno, NULL,
					  NULL);
1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233
	if (ret < 0) {

		/*
		 * XXX: Should we go readonly here?
		 */

		mlog_errno(ret);
		goto out;
	}

	BUG_ON(p_blkno == 0);

	for(i = 0; i < numpages; i++) {
		ret = ocfs2_write_data_page(inode, handle, &p_blkno, cpages[i],
					    wc, new);
		if (ret < 0) {
			mlog_errno(ret);
			goto out;
		}

		copied += ret;
	}

out:
	for(i = 0; i < numpages; i++) {
		unlock_page(cpages[i]);
		mark_page_accessed(cpages[i]);
		page_cache_release(cpages[i]);
	}
	kfree(cpages);

	return copied ? copied : ret;
}

static void ocfs2_write_ctxt_init(struct ocfs2_write_ctxt *wc,
				  struct ocfs2_super *osb, loff_t pos,
				  size_t count, ocfs2_page_writer *cb,
				  void *cb_priv)
{
	wc->w_count = count;
	wc->w_pos = pos;
	wc->w_cpos = wc->w_pos >> osb->s_clustersize_bits;
	wc->w_finished_copy = 0;

	if (unlikely(PAGE_CACHE_SHIFT > osb->s_clustersize_bits))
		wc->w_large_pages = 1;
	else
		wc->w_large_pages = 0;

	wc->w_write_data_page = cb;
	wc->w_private = cb_priv;
}

/*
 * Write a cluster to an inode. The cluster may not be allocated yet,
 * in which case it will be. This only exists for buffered writes -
 * O_DIRECT takes a more "traditional" path through the kernel.
 *
 * The caller is responsible for incrementing pos, written counts, etc
 *
 * For file systems that don't support sparse files, pre-allocation
 * and page zeroing up until cpos should be done prior to this
 * function call.
 *
 * Callers should be holding i_sem, and the rw cluster lock.
 *
 * Returns the number of user bytes written, or less than zero for
 * error.
 */
ssize_t ocfs2_buffered_write_cluster(struct file *file, loff_t pos,
				     size_t count, ocfs2_page_writer *actor,
				     void *priv)
{
	int ret, credits = OCFS2_INODE_UPDATE_CREDITS;
	ssize_t written = 0;
	u32 phys;
	struct inode *inode = file->f_mapping->host;
	struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
	struct buffer_head *di_bh = NULL;
	struct ocfs2_dinode *di;
	struct ocfs2_alloc_context *data_ac = NULL;
	struct ocfs2_alloc_context *meta_ac = NULL;
	handle_t *handle;
	struct ocfs2_write_ctxt wc;

	ocfs2_write_ctxt_init(&wc, osb, pos, count, actor, priv);

	ret = ocfs2_meta_lock(inode, &di_bh, 1);
	if (ret) {
		mlog_errno(ret);
		goto out;
	}
	di = (struct ocfs2_dinode *)di_bh->b_data;

	/*
	 * Take alloc sem here to prevent concurrent lookups. That way
	 * the mapping, zeroing and tree manipulation within
	 * ocfs2_write() will be safe against ->readpage(). This
	 * should also serve to lock out allocation from a shared
	 * writeable region.
	 */
	down_write(&OCFS2_I(inode)->ip_alloc_sem);

1234
	ret = ocfs2_get_clusters(inode, wc.w_cpos, &phys, NULL, NULL);
1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283
	if (ret) {
		mlog_errno(ret);
		goto out_meta;
	}

	/* phys == 0 means that allocation is required. */
	if (phys == 0) {
		ret = ocfs2_lock_allocators(inode, di, 1, &data_ac, &meta_ac);
		if (ret) {
			mlog_errno(ret);
			goto out_meta;
		}

		credits = ocfs2_calc_extend_credits(inode->i_sb, di, 1);
	}

	ret = ocfs2_data_lock(inode, 1);
	if (ret) {
		mlog_errno(ret);
		goto out_meta;
	}

	handle = ocfs2_start_trans(osb, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		mlog_errno(ret);
		goto out_data;
	}

	written = ocfs2_write(file, phys, handle, di_bh, data_ac,
			      meta_ac, &wc);
	if (written < 0) {
		ret = written;
		mlog_errno(ret);
		goto out_commit;
	}

	ret = ocfs2_journal_access(handle, inode, di_bh,
				   OCFS2_JOURNAL_ACCESS_WRITE);
	if (ret) {
		mlog_errno(ret);
		goto out_commit;
	}

	pos += written;
	if (pos > inode->i_size) {
		i_size_write(inode, pos);
		mark_inode_dirty(inode);
	}
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	inode->i_blocks = ocfs2_inode_sector_count(inode);
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	di->i_size = cpu_to_le64((u64)i_size_read(inode));
	inode->i_mtime = inode->i_ctime = CURRENT_TIME;
	di->i_mtime = di->i_ctime = cpu_to_le64(inode->i_mtime.tv_sec);
	di->i_mtime_nsec = di->i_ctime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);

	ret = ocfs2_journal_dirty(handle, di_bh);
	if (ret)
		mlog_errno(ret);

out_commit:
	ocfs2_commit_trans(osb, handle);

out_data:
	ocfs2_data_unlock(inode, 1);

out_meta:
	up_write(&OCFS2_I(inode)->ip_alloc_sem);
	ocfs2_meta_unlock(inode, 1);

out:
	brelse(di_bh);
	if (data_ac)
		ocfs2_free_alloc_context(data_ac);
	if (meta_ac)
		ocfs2_free_alloc_context(meta_ac);

	return written ? written : ret;
}

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const struct address_space_operations ocfs2_aops = {
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	.readpage	= ocfs2_readpage,
	.writepage	= ocfs2_writepage,
	.bmap		= ocfs2_bmap,
	.sync_page	= block_sync_page,
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	.direct_IO	= ocfs2_direct_IO,
	.invalidatepage	= ocfs2_invalidatepage,
	.releasepage	= ocfs2_releasepage,
	.migratepage	= buffer_migrate_page,
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};