inode.c 186.8 KB
Newer Older
C
Chris Mason 已提交
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
/*
 * 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.
 */

19
#include <linux/kernel.h>
20
#include <linux/bio.h>
C
Chris Mason 已提交
21
#include <linux/buffer_head.h>
S
Sage Weil 已提交
22
#include <linux/file.h>
C
Chris Mason 已提交
23 24 25 26 27 28 29 30 31 32 33 34
#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>
C
Chris Mason 已提交
35
#include <linux/bit_spinlock.h>
J
Josef Bacik 已提交
36
#include <linux/xattr.h>
J
Josef Bacik 已提交
37
#include <linux/posix_acl.h>
Y
Yan Zheng 已提交
38
#include <linux/falloc.h>
39
#include <linux/slab.h>
C
Chris Mason 已提交
40
#include "compat.h"
C
Chris Mason 已提交
41 42 43 44 45 46
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
47
#include "volumes.h"
48
#include "ordered-data.h"
49
#include "xattr.h"
50
#include "tree-log.h"
C
Chris Mason 已提交
51
#include "compression.h"
52
#include "locking.h"
C
Chris Mason 已提交
53 54 55 56 57 58

struct btrfs_iget_args {
	u64 ino;
	struct btrfs_root *root;
};

59 60 61 62 63
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;
64 65
static const struct address_space_operations btrfs_aops;
static const struct address_space_operations btrfs_symlink_aops;
66
static const struct file_operations btrfs_dir_file_operations;
67
static struct extent_io_ops btrfs_extent_io_ops;
C
Chris Mason 已提交
68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84

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,
};

85
static void btrfs_truncate(struct inode *inode);
C
Chris Mason 已提交
86
static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end);
87 88 89 90
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);
91

92 93
static int btrfs_init_inode_security(struct btrfs_trans_handle *trans,
				     struct inode *inode,  struct inode *dir)
J
Jim Owens 已提交
94 95 96
{
	int err;

97
	err = btrfs_init_acl(trans, inode, dir);
J
Jim Owens 已提交
98
	if (!err)
99
		err = btrfs_xattr_security_init(trans, inode, dir);
J
Jim Owens 已提交
100 101 102
	return err;
}

C
Chris Mason 已提交
103 104 105 106 107
/*
 * 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
 */
C
Chris Mason 已提交
108
static noinline int insert_inline_extent(struct btrfs_trans_handle *trans,
C
Chris Mason 已提交
109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131
				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;
	int use_compress = 0;

	if (compressed_size && compressed_pages) {
		use_compress = 1;
		cur_size = compressed_size;
	}

C
Chris Mason 已提交
132 133
	path = btrfs_alloc_path();
	if (!path)
C
Chris Mason 已提交
134 135
		return -ENOMEM;

136
	path->leave_spinning = 1;
C
Chris Mason 已提交
137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164
	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);

	if (use_compress) {
		struct page *cpage;
		int i = 0;
C
Chris Mason 已提交
165
		while (compressed_size > 0) {
C
Chris Mason 已提交
166
			cpage = compressed_pages[i];
167
			cur_size = min_t(unsigned long, compressed_size,
C
Chris Mason 已提交
168 169
				       PAGE_CACHE_SIZE);

170
			kaddr = kmap_atomic(cpage, KM_USER0);
C
Chris Mason 已提交
171
			write_extent_buffer(leaf, kaddr, ptr, cur_size);
172
			kunmap_atomic(kaddr, KM_USER0);
C
Chris Mason 已提交
173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192

			i++;
			ptr += cur_size;
			compressed_size -= cur_size;
		}
		btrfs_set_file_extent_compression(leaf, ei,
						  BTRFS_COMPRESS_ZLIB);
	} 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);

193 194 195 196 197 198 199 200 201
	/*
	 * 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.
	 */
C
Chris Mason 已提交
202 203
	BTRFS_I(inode)->disk_i_size = inode->i_size;
	btrfs_update_inode(trans, root, inode);
204

C
Chris Mason 已提交
205 206 207 208 209 210 211 212 213 214 215 216
	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.
 */
217
static noinline int cow_file_range_inline(struct btrfs_trans_handle *trans,
C
Chris Mason 已提交
218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235
				 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 ||
C
Chris Mason 已提交
236
	    actual_end >= PAGE_CACHE_SIZE ||
C
Chris Mason 已提交
237 238 239 240 241 242 243 244
	    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;
	}

Y
Yan, Zheng 已提交
245
	ret = btrfs_drop_extents(trans, inode, start, aligned_end,
C
Chris Mason 已提交
246
				 &hint_byte, 1);
C
Chris Mason 已提交
247 248 249 250 251 252 253 254
	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);
255
	btrfs_delalloc_release_metadata(inode, end + 1 - start);
C
Chris Mason 已提交
256
	btrfs_drop_extent_cache(inode, start, aligned_end - 1, 0);
C
Chris Mason 已提交
257 258 259
	return 0;
}

260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296
struct async_extent {
	u64 start;
	u64 ram_size;
	u64 compressed_size;
	struct page **pages;
	unsigned long nr_pages;
	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,
				     unsigned long nr_pages)
{
	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;
	list_add_tail(&async_extent->list, &cow->extents);
	return 0;
}

C
Chris Mason 已提交
297
/*
298 299 300
 * 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).
C
Chris Mason 已提交
301
 *
302 303 304 305 306
 * 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.
C
Chris Mason 已提交
307
 *
308 309 310 311
 * 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.
C
Chris Mason 已提交
312
 */
313 314 315 316 317
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)
318 319 320
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
321
	u64 num_bytes;
C
Chris Mason 已提交
322 323
	u64 orig_start;
	u64 disk_num_bytes;
324
	u64 blocksize = root->sectorsize;
C
Chris Mason 已提交
325
	u64 actual_end;
326
	u64 isize = i_size_read(inode);
327
	int ret = 0;
C
Chris Mason 已提交
328 329 330 331 332 333
	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;
334
	unsigned long max_uncompressed = 128 * 1024;
C
Chris Mason 已提交
335 336
	int i;
	int will_compress;
337

C
Chris Mason 已提交
338 339
	orig_start = start;

340
	actual_end = min_t(u64, isize, end + 1);
C
Chris Mason 已提交
341 342 343 344
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);
345

346 347 348 349 350 351 352 353 354 355 356 357 358
	/*
	 * 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;

C
Chris Mason 已提交
359 360 361 362
	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
363 364 365 366 367 368 369
	 * 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.
C
Chris Mason 已提交
370 371
	 */
	total_compressed = min(total_compressed, max_uncompressed);
372
	num_bytes = (end - start + blocksize) & ~(blocksize - 1);
373
	num_bytes = max(blocksize,  num_bytes);
C
Chris Mason 已提交
374 375 376
	disk_num_bytes = num_bytes;
	total_in = 0;
	ret = 0;
377

378 379 380 381
	/*
	 * 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.
C
Chris Mason 已提交
382
	 */
383
	if (!(BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS) &&
C
Chris Mason 已提交
384 385
	    (btrfs_test_opt(root, COMPRESS) ||
	     (BTRFS_I(inode)->force_compress))) {
C
Chris Mason 已提交
386
		WARN_ON(pages);
387
		pages = kzalloc(sizeof(struct page *) * nr_pages, GFP_NOFS);
C
Chris Mason 已提交
388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414

		ret = btrfs_zlib_compress_pages(inode->i_mapping, start,
						total_compressed, pages,
						nr_pages, &nr_pages_ret,
						&total_in,
						&total_compressed,
						max_compressed);

		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) {
415 416 417
		trans = btrfs_join_transaction(root, 1);
		BUG_ON(!trans);
		btrfs_set_trans_block_group(trans, inode);
418
		trans->block_rsv = &root->fs_info->delalloc_block_rsv;
419

C
Chris Mason 已提交
420
		/* lets try to make an inline extent */
421
		if (ret || total_in < (actual_end - start)) {
C
Chris Mason 已提交
422
			/* we didn't compress the entire range, try
423
			 * to make an uncompressed inline extent.
C
Chris Mason 已提交
424 425 426 427
			 */
			ret = cow_file_range_inline(trans, root, inode,
						    start, end, 0, NULL);
		} else {
428
			/* try making a compressed inline extent */
C
Chris Mason 已提交
429 430 431 432 433
			ret = cow_file_range_inline(trans, root, inode,
						    start, end,
						    total_compressed, pages);
		}
		if (ret == 0) {
434 435 436 437 438
			/*
			 * inline extent creation worked, we don't need
			 * to create any more async work items.  Unlock
			 * and free up our temp pages.
			 */
C
Chris Mason 已提交
439
			extent_clear_unlock_delalloc(inode,
440 441 442
			     &BTRFS_I(inode)->io_tree,
			     start, end, NULL,
			     EXTENT_CLEAR_UNLOCK_PAGE | EXTENT_CLEAR_DIRTY |
443
			     EXTENT_CLEAR_DELALLOC |
444
			     EXTENT_SET_WRITEBACK | EXTENT_END_WRITEBACK);
445 446

			btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
447 448
			goto free_pages_out;
		}
449
		btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479
	}

	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 {
			disk_num_bytes = total_compressed;
			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++) {
C
Chris Mason 已提交
480
			WARN_ON(pages[i]->mapping);
C
Chris Mason 已提交
481 482 483 484 485 486 487 488
			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 */
C
Chris Mason 已提交
489 490
		if (!btrfs_test_opt(root, FORCE_COMPRESS) &&
		    !(BTRFS_I(inode)->force_compress)) {
C
Chris Mason 已提交
491
			BTRFS_I(inode)->flags |= BTRFS_INODE_NOCOMPRESS;
C
Chris Mason 已提交
492
		}
C
Chris Mason 已提交
493
	}
494 495
	if (will_compress) {
		*num_added += 1;
C
Chris Mason 已提交
496

497 498 499 500 501 502
		/* 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,
				 total_compressed, pages, nr_pages_ret);
503

504
		if (start + num_bytes < end && start + num_bytes < actual_end) {
505 506 507 508 509 510
			start += num_bytes;
			pages = NULL;
			cond_resched();
			goto again;
		}
	} else {
511
cleanup_and_bail_uncompressed:
512 513 514 515 516 517 518 519 520 521 522 523 524 525 526
		/*
		 * 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 */
		}
		add_async_extent(async_cow, start, end - start + 1, 0, NULL, 0);
		*num_added += 1;
	}
527

528 529 530 531 532 533 534 535
out:
	return 0;

free_pages_out:
	for (i = 0; i < nr_pages_ret; i++) {
		WARN_ON(pages[i]->mapping);
		page_cache_release(pages[i]);
	}
C
Chris Mason 已提交
536
	kfree(pages);
537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557

	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;
558
	int ret = 0;
559 560 561 562 563

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


C
Chris Mason 已提交
564
	while (!list_empty(&async_cow->extents)) {
565 566 567
		async_extent = list_entry(async_cow->extents.next,
					  struct async_extent, list);
		list_del(&async_extent->list);
C
Chris Mason 已提交
568

569 570
		io_tree = &BTRFS_I(inode)->io_tree;

571
retry:
572 573 574 575 576 577
		/* 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,
578 579
					 async_extent->start +
					 async_extent->ram_size - 1, GFP_NOFS);
580 581

			/* allocate blocks */
582 583 584 585 586
			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);
587 588 589 590 591 592 593

			/*
			 * 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.
			 */
594
			if (!page_started && !ret)
595 596
				extent_write_locked_range(io_tree,
						  inode, async_extent->start,
C
Chris Mason 已提交
597
						  async_extent->start +
598 599 600 601 602 603 604 605 606 607 608 609
						  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);

610
		trans = btrfs_join_transaction(root, 1);
611 612 613 614 615
		ret = btrfs_reserve_extent(trans, root,
					   async_extent->compressed_size,
					   async_extent->compressed_size,
					   0, alloc_hint,
					   (u64)-1, &ins, 1);
616 617
		btrfs_end_transaction(trans, root);

618 619 620 621 622 623 624 625 626 627 628 629 630 631 632
		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;
		}

633 634 635 636 637 638 639 640
		/*
		 * 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);

641 642 643
		em = alloc_extent_map(GFP_NOFS);
		em->start = async_extent->start;
		em->len = async_extent->ram_size;
644
		em->orig_start = em->start;
C
Chris Mason 已提交
645

646 647 648 649 650 651
		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);
		set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);

C
Chris Mason 已提交
652
		while (1) {
653
			write_lock(&em_tree->lock);
654
			ret = add_extent_mapping(em_tree, em);
655
			write_unlock(&em_tree->lock);
656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675
			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);
		}

		ret = btrfs_add_ordered_extent(inode, async_extent->start,
					       ins.objectid,
					       async_extent->ram_size,
					       ins.offset,
					       BTRFS_ORDERED_COMPRESSED);
		BUG_ON(ret);

		/*
		 * clear dirty, set writeback and unlock the pages.
		 */
		extent_clear_unlock_delalloc(inode,
676 677 678 679 680 681
				&BTRFS_I(inode)->io_tree,
				async_extent->start,
				async_extent->start +
				async_extent->ram_size - 1,
				NULL, EXTENT_CLEAR_UNLOCK_PAGE |
				EXTENT_CLEAR_UNLOCK |
682
				EXTENT_CLEAR_DELALLOC |
683
				EXTENT_CLEAR_DIRTY | EXTENT_SET_WRITEBACK);
684 685

		ret = btrfs_submit_compressed_write(inode,
C
Chris Mason 已提交
686 687 688 689 690
				    async_extent->start,
				    async_extent->ram_size,
				    ins.objectid,
				    ins.offset, async_extent->pages,
				    async_extent->nr_pages);
691 692 693 694 695 696 697 698 699 700

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

	return 0;
}

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
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;
}

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
/*
 * 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;
	u64 actual_end;
761
	u64 isize = i_size_read(inode);
762 763 764 765 766 767 768 769
	struct btrfs_key ins;
	struct extent_map *em;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
	int ret = 0;

	trans = btrfs_join_transaction(root, 1);
	BUG_ON(!trans);
	btrfs_set_trans_block_group(trans, inode);
770
	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
771

772
	actual_end = min_t(u64, isize, end + 1);
773 774 775 776 777 778 779 780 781 782 783 784

	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,
785 786 787 788 789 790 791 792
				     &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);
793

794 795 796 797 798 799 800 801 802 803 804
			*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));

805
	alloc_hint = get_extent_allocation_hint(inode, start, num_bytes);
806 807
	btrfs_drop_extent_cache(inode, start, start + num_bytes - 1, 0);

C
Chris Mason 已提交
808
	while (disk_num_bytes > 0) {
809 810
		unsigned long op;

811
		cur_alloc_size = disk_num_bytes;
812
		ret = btrfs_reserve_extent(trans, root, cur_alloc_size,
813
					   root->sectorsize, 0, alloc_hint,
814
					   (u64)-1, &ins, 1);
C
Chris Mason 已提交
815 816
		BUG_ON(ret);

817 818
		em = alloc_extent_map(GFP_NOFS);
		em->start = start;
819
		em->orig_start = em->start;
820 821
		ram_size = ins.offset;
		em->len = ins.offset;
C
Chris Mason 已提交
822

823
		em->block_start = ins.objectid;
C
Chris Mason 已提交
824
		em->block_len = ins.offset;
825
		em->bdev = root->fs_info->fs_devices->latest_bdev;
826
		set_bit(EXTENT_FLAG_PINNED, &em->flags);
C
Chris Mason 已提交
827

C
Chris Mason 已提交
828
		while (1) {
829
			write_lock(&em_tree->lock);
830
			ret = add_extent_mapping(em_tree, em);
831
			write_unlock(&em_tree->lock);
832 833 834 835 836
			if (ret != -EEXIST) {
				free_extent_map(em);
				break;
			}
			btrfs_drop_extent_cache(inode, start,
C
Chris Mason 已提交
837
						start + ram_size - 1, 0);
838 839
		}

840
		cur_alloc_size = ins.offset;
841
		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,
842
					       ram_size, cur_alloc_size, 0);
843
		BUG_ON(ret);
C
Chris Mason 已提交
844

845 846 847 848 849 850 851
		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
852
		if (disk_num_bytes < cur_alloc_size)
853
			break;
C
Chris Mason 已提交
854

C
Chris Mason 已提交
855 856 857
		/* 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
858 859 860
		 *
		 * Do set the Private2 bit so we know this page was properly
		 * setup for writepage
C
Chris Mason 已提交
861
		 */
862 863 864 865
		op = unlock ? EXTENT_CLEAR_UNLOCK_PAGE : 0;
		op |= EXTENT_CLEAR_UNLOCK | EXTENT_CLEAR_DELALLOC |
			EXTENT_SET_PRIVATE2;

C
Chris Mason 已提交
866 867
		extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
					     start, start + ram_size - 1,
868
					     locked_page, op);
C
Chris Mason 已提交
869
		disk_num_bytes -= cur_alloc_size;
870 871 872
		num_bytes -= cur_alloc_size;
		alloc_hint = ins.objectid + ins.offset;
		start += cur_alloc_size;
873 874
	}
out:
875
	ret = 0;
876
	btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
877

878
	return ret;
879
}
C
Chris Mason 已提交
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
/*
 * 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
919
	if (async_cow->inode)
920 921
		submit_compressed_extents(async_cow->inode, async_cow);
}
C
Chris Mason 已提交
922

923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939
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;

940 941
	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, end, EXTENT_LOCKED,
			 1, 0, NULL, GFP_NOFS);
C
Chris Mason 已提交
942
	while (start < end) {
943 944 945 946 947 948
		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;

949
		if (BTRFS_I(inode)->flags & BTRFS_INODE_NOCOMPRESS)
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
			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
975
		while (atomic_read(&root->fs_info->async_submit_draining) &&
976 977 978 979 980 981 982 983 984 985 986
		      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;
987 988
}

C
Chris Mason 已提交
989
static noinline int csum_exist_in_range(struct btrfs_root *root,
990 991 992 993 994 995
					u64 bytenr, u64 num_bytes)
{
	int ret;
	struct btrfs_ordered_sum *sums;
	LIST_HEAD(list);

Y
Yan Zheng 已提交
996 997
	ret = btrfs_lookup_csums_range(root->fs_info->csum_root, bytenr,
				       bytenr + num_bytes - 1, &list);
998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008
	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
1009 1010 1011 1012 1013 1014 1015
/*
 * 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
 */
1016 1017
static noinline int run_delalloc_nocow(struct inode *inode,
				       struct page *locked_page,
1018 1019
			      u64 start, u64 end, int *page_started, int force,
			      unsigned long *nr_written)
1020 1021
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1022
	struct btrfs_trans_handle *trans;
1023 1024
	struct extent_buffer *leaf;
	struct btrfs_path *path;
Y
Yan Zheng 已提交
1025
	struct btrfs_file_extent_item *fi;
1026
	struct btrfs_key found_key;
Y
Yan Zheng 已提交
1027 1028 1029
	u64 cow_start;
	u64 cur_offset;
	u64 extent_end;
1030
	u64 extent_offset;
Y
Yan Zheng 已提交
1031 1032 1033 1034
	u64 disk_bytenr;
	u64 num_bytes;
	int extent_type;
	int ret;
Y
Yan Zheng 已提交
1035
	int type;
Y
Yan Zheng 已提交
1036 1037
	int nocow;
	int check_prev = 1;
1038 1039 1040

	path = btrfs_alloc_path();
	BUG_ON(!path);
1041 1042
	trans = btrfs_join_transaction(root, 1);
	BUG_ON(!trans);
1043

Y
Yan Zheng 已提交
1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068
	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];
		}
1069

Y
Yan Zheng 已提交
1070 1071
		nocow = 0;
		disk_bytenr = 0;
1072
		num_bytes = 0;
Y
Yan Zheng 已提交
1073 1074 1075 1076 1077 1078 1079 1080 1081
		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;
1082
			extent_type = 0;
Y
Yan Zheng 已提交
1083 1084 1085 1086 1087 1088 1089
			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
1090 1091
		if (extent_type == BTRFS_FILE_EXTENT_REG ||
		    extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
Y
Yan Zheng 已提交
1092
			disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1093
			extent_offset = btrfs_file_extent_offset(leaf, fi);
Y
Yan Zheng 已提交
1094 1095 1096 1097 1098 1099
			extent_end = found_key.offset +
				btrfs_file_extent_num_bytes(leaf, fi);
			if (extent_end <= start) {
				path->slots[0]++;
				goto next_slot;
			}
1100 1101
			if (disk_bytenr == 0)
				goto out_check;
Y
Yan Zheng 已提交
1102 1103 1104 1105
			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
1106 1107
			if (extent_type == BTRFS_FILE_EXTENT_REG && !force)
				goto out_check;
1108
			if (btrfs_extent_readonly(root, disk_bytenr))
Y
Yan Zheng 已提交
1109
				goto out_check;
1110
			if (btrfs_cross_ref_exist(trans, root, inode->i_ino,
1111 1112
						  found_key.offset -
						  extent_offset, disk_bytenr))
1113
				goto out_check;
1114
			disk_bytenr += extent_offset;
1115 1116 1117 1118 1119 1120 1121 1122 1123
			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
1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144
			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;
1145 1146 1147
		}

		btrfs_release_path(root, path);
Y
Yan Zheng 已提交
1148 1149
		if (cow_start != (u64)-1) {
			ret = cow_file_range(inode, locked_page, cow_start,
1150 1151
					found_key.offset - 1, page_started,
					nr_written, 1);
Y
Yan Zheng 已提交
1152 1153
			BUG_ON(ret);
			cow_start = (u64)-1;
1154
		}
Y
Yan Zheng 已提交
1155

Y
Yan Zheng 已提交
1156 1157 1158 1159 1160 1161
		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;
1162
			em->orig_start = em->start;
Y
Yan Zheng 已提交
1163 1164 1165 1166 1167 1168
			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) {
1169
				write_lock(&em_tree->lock);
Y
Yan Zheng 已提交
1170
				ret = add_extent_mapping(em_tree, em);
1171
				write_unlock(&em_tree->lock);
Y
Yan Zheng 已提交
1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182
				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
1183 1184

		ret = btrfs_add_ordered_extent(inode, cur_offset, disk_bytenr,
Y
Yan Zheng 已提交
1185 1186
					       num_bytes, num_bytes, type);
		BUG_ON(ret);
1187

1188 1189 1190 1191 1192 1193 1194
		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
1195
		extent_clear_unlock_delalloc(inode, &BTRFS_I(inode)->io_tree,
1196 1197 1198 1199
				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
1200 1201 1202
		cur_offset = extent_end;
		if (cur_offset > end)
			break;
1203
	}
Y
Yan Zheng 已提交
1204 1205 1206 1207 1208 1209
	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,
1210
				     page_started, nr_written, 1);
Y
Yan Zheng 已提交
1211 1212 1213 1214 1215
		BUG_ON(ret);
	}

	ret = btrfs_end_transaction(trans, root);
	BUG_ON(ret);
1216
	btrfs_free_path(path);
Y
Yan Zheng 已提交
1217
	return 0;
1218 1219
}

C
Chris Mason 已提交
1220 1221 1222
/*
 * extent_io.c call back to do delayed allocation processing
 */
C
Chris Mason 已提交
1223
static int run_delalloc_range(struct inode *inode, struct page *locked_page,
1224 1225
			      u64 start, u64 end, int *page_started,
			      unsigned long *nr_written)
1226 1227
{
	int ret;
1228
	struct btrfs_root *root = BTRFS_I(inode)->root;
1229

1230
	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATACOW)
C
Chris Mason 已提交
1231
		ret = run_delalloc_nocow(inode, locked_page, start, end,
C
Chris Mason 已提交
1232
					 page_started, 1, nr_written);
1233
	else if (BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)
Y
Yan Zheng 已提交
1234
		ret = run_delalloc_nocow(inode, locked_page, start, end,
C
Chris Mason 已提交
1235
					 page_started, 0, nr_written);
C
Chris Mason 已提交
1236 1237
	else if (!btrfs_test_opt(root, COMPRESS) &&
		 !(BTRFS_I(inode)->force_compress))
1238 1239
		ret = cow_file_range(inode, locked_page, start, end,
				      page_started, nr_written, 1);
1240
	else
1241
		ret = cow_file_range_async(inode, locked_page, start, end,
C
Chris Mason 已提交
1242
					   page_started, nr_written);
1243 1244 1245
	return ret;
}

J
Josef Bacik 已提交
1246
static int btrfs_split_extent_hook(struct inode *inode,
1247
				   struct extent_state *orig, u64 split)
J
Josef Bacik 已提交
1248
{
1249
	/* not delalloc, ignore it */
J
Josef Bacik 已提交
1250 1251 1252
	if (!(orig->state & EXTENT_DELALLOC))
		return 0;

1253
	atomic_inc(&BTRFS_I(inode)->outstanding_extents);
J
Josef Bacik 已提交
1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270
	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;

1271
	atomic_dec(&BTRFS_I(inode)->outstanding_extents);
J
Josef Bacik 已提交
1272 1273 1274
	return 0;
}

C
Chris Mason 已提交
1275 1276 1277 1278 1279
/*
 * 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.
 */
1280 1281
static int btrfs_set_bit_hook(struct inode *inode,
			      struct extent_state *state, int *bits)
1282
{
J
Josef Bacik 已提交
1283

1284 1285 1286 1287 1288
	/*
	 * 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
	 */
1289
	if (!(state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1290
		struct btrfs_root *root = BTRFS_I(inode)->root;
1291
		u64 len = state->end + 1 - state->start;
J
Josef Bacik 已提交
1292

1293 1294 1295 1296
		if (*bits & EXTENT_FIRST_DELALLOC)
			*bits &= ~EXTENT_FIRST_DELALLOC;
		else
			atomic_inc(&BTRFS_I(inode)->outstanding_extents);
1297

1298
		spin_lock(&root->fs_info->delalloc_lock);
1299 1300
		BTRFS_I(inode)->delalloc_bytes += len;
		root->fs_info->delalloc_bytes += len;
1301 1302 1303 1304
		if (list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
			list_add_tail(&BTRFS_I(inode)->delalloc_inodes,
				      &root->fs_info->delalloc_inodes);
		}
1305
		spin_unlock(&root->fs_info->delalloc_lock);
1306 1307 1308 1309
	}
	return 0;
}

C
Chris Mason 已提交
1310 1311 1312
/*
 * extent_io.c clear_bit_hook, see set_bit_hook for why
 */
J
Josef Bacik 已提交
1313
static int btrfs_clear_bit_hook(struct inode *inode,
1314
				struct extent_state *state, int *bits)
1315
{
1316 1317 1318 1319 1320
	/*
	 * 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
	 */
1321
	if ((state->state & EXTENT_DELALLOC) && (*bits & EXTENT_DELALLOC)) {
1322
		struct btrfs_root *root = BTRFS_I(inode)->root;
1323
		u64 len = state->end + 1 - state->start;
1324

1325 1326 1327 1328 1329 1330 1331 1332 1333 1334
		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);

		if (root->root_key.objectid != BTRFS_DATA_RELOC_TREE_OBJECTID)
			btrfs_free_reserved_data_space(inode, len);
J
Josef Bacik 已提交
1335

1336
		spin_lock(&root->fs_info->delalloc_lock);
1337 1338 1339
		root->fs_info->delalloc_bytes -= len;
		BTRFS_I(inode)->delalloc_bytes -= len;

1340 1341 1342 1343
		if (BTRFS_I(inode)->delalloc_bytes == 0 &&
		    !list_empty(&BTRFS_I(inode)->delalloc_inodes)) {
			list_del_init(&BTRFS_I(inode)->delalloc_inodes);
		}
1344
		spin_unlock(&root->fs_info->delalloc_lock);
1345 1346 1347 1348
	}
	return 0;
}

C
Chris Mason 已提交
1349 1350 1351 1352
/*
 * 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
 */
1353
int btrfs_merge_bio_hook(struct page *page, unsigned long offset,
C
Chris Mason 已提交
1354 1355
			 size_t size, struct bio *bio,
			 unsigned long bio_flags)
1356 1357 1358
{
	struct btrfs_root *root = BTRFS_I(page->mapping->host)->root;
	struct btrfs_mapping_tree *map_tree;
1359
	u64 logical = (u64)bio->bi_sector << 9;
1360 1361 1362 1363
	u64 length = 0;
	u64 map_length;
	int ret;

1364 1365 1366
	if (bio_flags & EXTENT_BIO_COMPRESSED)
		return 0;

1367
	length = bio->bi_size;
1368 1369
	map_tree = &root->fs_info->mapping_tree;
	map_length = length;
1370
	ret = btrfs_map_block(map_tree, READ, logical,
1371
			      &map_length, NULL, 0);
1372

C
Chris Mason 已提交
1373
	if (map_length < length + size)
1374 1375 1376 1377
		return 1;
	return 0;
}

C
Chris Mason 已提交
1378 1379 1380 1381 1382 1383 1384 1385
/*
 * 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
1386 1387
static int __btrfs_submit_bio_start(struct inode *inode, int rw,
				    struct bio *bio, int mirror_num,
1388 1389
				    unsigned long bio_flags,
				    u64 bio_offset)
1390 1391 1392
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret = 0;
1393

1394
	ret = btrfs_csum_one_bio(root, inode, bio, 0, 0);
1395
	BUG_ON(ret);
C
Chris Mason 已提交
1396 1397
	return 0;
}
1398

C
Chris Mason 已提交
1399 1400 1401 1402 1403 1404 1405 1406
/*
 * 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
 */
1407
static int __btrfs_submit_bio_done(struct inode *inode, int rw, struct bio *bio,
1408 1409
			  int mirror_num, unsigned long bio_flags,
			  u64 bio_offset)
C
Chris Mason 已提交
1410 1411
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1412
	return btrfs_map_bio(root, rw, bio, mirror_num, 1);
1413 1414
}

C
Chris Mason 已提交
1415
/*
1416 1417
 * 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
1418
 */
1419
static int btrfs_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
1420 1421
			  int mirror_num, unsigned long bio_flags,
			  u64 bio_offset)
1422 1423 1424
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret = 0;
1425
	int skip_sum;
1426

1427
	skip_sum = BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM;
1428

1429 1430
	ret = btrfs_bio_wq_end_io(root->fs_info, bio, 0);
	BUG_ON(ret);
1431

1432
	if (!(rw & (1 << BIO_RW))) {
1433
		if (bio_flags & EXTENT_BIO_COMPRESSED) {
C
Chris Mason 已提交
1434 1435
			return btrfs_submit_compressed_read(inode, bio,
						    mirror_num, bio_flags);
1436 1437
		} else if (!skip_sum)
			btrfs_lookup_bio_sums(root, inode, bio, NULL);
1438
		goto mapit;
1439
	} else if (!skip_sum) {
1440 1441 1442
		/* csum items have already been cloned */
		if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID)
			goto mapit;
1443 1444
		/* we're doing a write, do the async checksumming */
		return btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
1445
				   inode, rw, bio, mirror_num,
1446 1447
				   bio_flags, bio_offset,
				   __btrfs_submit_bio_start,
C
Chris Mason 已提交
1448
				   __btrfs_submit_bio_done);
1449 1450
	}

1451
mapit:
1452
	return btrfs_map_bio(root, rw, bio, mirror_num, 0);
1453
}
C
Chris Mason 已提交
1454

C
Chris Mason 已提交
1455 1456 1457 1458
/*
 * 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.
 */
1459
static noinline int add_pending_csums(struct btrfs_trans_handle *trans,
1460 1461 1462 1463 1464 1465
			     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
1466 1467

	list_for_each_entry(sum, list, list) {
1468 1469
		btrfs_csum_file_blocks(trans,
		       BTRFS_I(inode)->root->fs_info->csum_root, sum);
1470 1471 1472 1473
	}
	return 0;
}

1474 1475
int btrfs_set_extent_delalloc(struct inode *inode, u64 start, u64 end,
			      struct extent_state **cached_state)
1476
{
C
Chris Mason 已提交
1477
	if ((end & (PAGE_CACHE_SIZE - 1)) == 0)
1478
		WARN_ON(1);
1479
	return set_extent_delalloc(&BTRFS_I(inode)->io_tree, start, end,
1480
				   cached_state, GFP_NOFS);
1481 1482
}

C
Chris Mason 已提交
1483
/* see btrfs_writepage_start_hook for details on why this is required */
1484 1485 1486 1487 1488
struct btrfs_writepage_fixup {
	struct page *page;
	struct btrfs_work work;
};

1489
static void btrfs_writepage_fixup_worker(struct btrfs_work *work)
1490 1491 1492
{
	struct btrfs_writepage_fixup *fixup;
	struct btrfs_ordered_extent *ordered;
1493
	struct extent_state *cached_state = NULL;
1494 1495 1496 1497 1498 1499 1500
	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
1501
again:
1502 1503 1504 1505 1506 1507 1508 1509 1510 1511
	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;

1512 1513
	lock_extent_bits(&BTRFS_I(inode)->io_tree, page_start, page_end, 0,
			 &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1514 1515

	/* already ordered? We're done */
1516
	if (PagePrivate2(page))
1517
		goto out;
C
Chris Mason 已提交
1518 1519 1520

	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
1521 1522
		unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start,
				     page_end, &cached_state, GFP_NOFS);
C
Chris Mason 已提交
1523 1524 1525 1526
		unlock_page(page);
		btrfs_start_ordered_extent(inode, ordered, 1);
		goto again;
	}
1527

1528
	BUG();
1529
	btrfs_set_extent_delalloc(inode, page_start, page_end, &cached_state);
1530 1531
	ClearPageChecked(page);
out:
1532 1533
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, page_start, page_end,
			     &cached_state, GFP_NOFS);
1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544
out_page:
	unlock_page(page);
	page_cache_release(page);
}

/*
 * 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
1545
 * In our case any range that doesn't have the ORDERED bit set
1546 1547 1548 1549
 * 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.
 */
1550
static int btrfs_writepage_start_hook(struct page *page, u64 start, u64 end)
1551 1552 1553 1554 1555
{
	struct inode *inode = page->mapping->host;
	struct btrfs_writepage_fixup *fixup;
	struct btrfs_root *root = BTRFS_I(inode)->root;

1556 1557
	/* this page is properly in the ordered list */
	if (TestClearPagePrivate2(page))
1558 1559 1560 1561 1562 1563 1564 1565
		return 0;

	if (PageChecked(page))
		return -EAGAIN;

	fixup = kzalloc(sizeof(*fixup), GFP_NOFS);
	if (!fixup)
		return -EAGAIN;
1566

1567 1568 1569 1570 1571 1572 1573 1574
	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
1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592
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);

1593
	path->leave_spinning = 1;
C
Chris Mason 已提交
1594 1595 1596 1597 1598 1599 1600 1601 1602 1603

	/*
	 * 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
1604 1605
	ret = btrfs_drop_extents(trans, inode, file_pos, file_pos + num_bytes,
				 &hint, 0);
Y
Yan Zheng 已提交
1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625
	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);
1626 1627 1628 1629

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

Y
Yan Zheng 已提交
1630 1631 1632 1633 1634 1635 1636
	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;
1637 1638 1639
	ret = btrfs_alloc_reserved_file_extent(trans, root,
					root->root_key.objectid,
					inode->i_ino, file_pos, &ins);
Y
Yan Zheng 已提交
1640 1641
	BUG_ON(ret);
	btrfs_free_path(path);
1642

Y
Yan Zheng 已提交
1643 1644 1645
	return 0;
}

1646 1647 1648 1649 1650 1651
/*
 * 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
1652 1653 1654 1655
/* 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.
 */
1656
static int btrfs_finish_ordered_io(struct inode *inode, u64 start, u64 end)
1657 1658
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
1659
	struct btrfs_trans_handle *trans = NULL;
1660
	struct btrfs_ordered_extent *ordered_extent = NULL;
1661
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1662
	struct extent_state *cached_state = NULL;
Y
Yan Zheng 已提交
1663
	int compressed = 0;
1664 1665
	int ret;

1666 1667
	ret = btrfs_dec_test_ordered_pending(inode, &ordered_extent, start,
					     end - start + 1);
1668
	if (!ret)
1669 1670
		return 0;
	BUG_ON(!ordered_extent);
1671

1672 1673 1674 1675 1676
	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) {
			trans = btrfs_join_transaction(root, 1);
1677 1678
			btrfs_set_trans_block_group(trans, inode);
			trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1679 1680 1681 1682 1683
			ret = btrfs_update_inode(trans, root, inode);
			BUG_ON(ret);
		}
		goto out;
	}
1684

1685 1686 1687
	lock_extent_bits(io_tree, ordered_extent->file_offset,
			 ordered_extent->file_offset + ordered_extent->len - 1,
			 0, &cached_state, GFP_NOFS);
1688

1689
	trans = btrfs_join_transaction(root, 1);
1690 1691
	btrfs_set_trans_block_group(trans, inode);
	trans->block_rsv = &root->fs_info->delalloc_block_rsv;
1692

C
Chris Mason 已提交
1693
	if (test_bit(BTRFS_ORDERED_COMPRESSED, &ordered_extent->flags))
Y
Yan Zheng 已提交
1694 1695 1696
		compressed = 1;
	if (test_bit(BTRFS_ORDERED_PREALLOC, &ordered_extent->flags)) {
		BUG_ON(compressed);
Y
Yan, Zheng 已提交
1697
		ret = btrfs_mark_extent_written(trans, inode,
Y
Yan Zheng 已提交
1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710
						ordered_extent->file_offset,
						ordered_extent->file_offset +
						ordered_extent->len);
		BUG_ON(ret);
	} else {
		ret = insert_reserved_file_extent(trans, inode,
						ordered_extent->file_offset,
						ordered_extent->start,
						ordered_extent->disk_len,
						ordered_extent->len,
						ordered_extent->len,
						compressed, 0, 0,
						BTRFS_FILE_EXTENT_REG);
C
Chris Mason 已提交
1711 1712 1713
		unpin_extent_cache(&BTRFS_I(inode)->extent_tree,
				   ordered_extent->file_offset,
				   ordered_extent->len);
Y
Yan Zheng 已提交
1714 1715
		BUG_ON(ret);
	}
1716 1717 1718 1719
	unlock_extent_cached(io_tree, ordered_extent->file_offset,
			     ordered_extent->file_offset +
			     ordered_extent->len - 1, &cached_state, GFP_NOFS);

1720 1721 1722
	add_pending_csums(trans, inode, ordered_extent->file_offset,
			  &ordered_extent->list);

1723 1724 1725 1726
	btrfs_ordered_update_i_size(inode, 0, ordered_extent);
	ret = btrfs_update_inode(trans, root, inode);
	BUG_ON(ret);
out:
1727 1728 1729
	btrfs_delalloc_release_metadata(inode, ordered_extent->len);
	if (trans)
		btrfs_end_transaction(trans, root);
1730 1731 1732 1733 1734 1735 1736 1737
	/* once for us */
	btrfs_put_ordered_extent(ordered_extent);
	/* once for the tree */
	btrfs_put_ordered_extent(ordered_extent);

	return 0;
}

1738
static int btrfs_writepage_end_io_hook(struct page *page, u64 start, u64 end,
1739 1740
				struct extent_state *state, int uptodate)
{
1741
	ClearPagePrivate2(page);
1742 1743 1744
	return btrfs_finish_ordered_io(page->mapping->host, start, end);
}

C
Chris Mason 已提交
1745 1746 1747 1748 1749 1750 1751 1752
/*
 * 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.
 */
1753 1754 1755 1756 1757
struct io_failure_record {
	struct page *page;
	u64 start;
	u64 len;
	u64 logical;
1758
	unsigned long bio_flags;
1759 1760 1761
	int last_mirror;
};

1762
static int btrfs_io_failed_hook(struct bio *failed_bio,
1763 1764
			 struct page *page, u64 start, u64 end,
			 struct extent_state *state)
1765 1766 1767 1768 1769 1770
{
	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;
1771
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1772 1773 1774
	struct bio *bio;
	int num_copies;
	int ret;
1775
	int rw;
1776 1777 1778 1779 1780 1781 1782 1783 1784 1785
	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;
1786
		failrec->bio_flags = 0;
1787

1788
		read_lock(&em_tree->lock);
1789 1790 1791 1792 1793
		em = lookup_extent_mapping(em_tree, start, failrec->len);
		if (em->start > start || em->start + em->len < start) {
			free_extent_map(em);
			em = NULL;
		}
1794
		read_unlock(&em_tree->lock);
1795 1796 1797 1798 1799 1800 1801

		if (!em || IS_ERR(em)) {
			kfree(failrec);
			return -EIO;
		}
		logical = start - em->start;
		logical = em->block_start + logical;
1802 1803 1804 1805
		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
			logical = em->block_start;
			failrec->bio_flags = EXTENT_BIO_COMPRESSED;
		}
1806 1807 1808 1809
		failrec->logical = logical;
		free_extent_map(em);
		set_extent_bits(failure_tree, start, end, EXTENT_LOCKED |
				EXTENT_DIRTY, GFP_NOFS);
1810 1811
		set_state_private(failure_tree, start,
				 (u64)(unsigned long)failrec);
1812
	} else {
1813
		failrec = (struct io_failure_record *)(unsigned long)private;
1814 1815 1816 1817 1818 1819
	}
	num_copies = btrfs_num_copies(
			      &BTRFS_I(inode)->root->fs_info->mapping_tree,
			      failrec->logical, failrec->len);
	failrec->last_mirror++;
	if (!state) {
1820
		spin_lock(&BTRFS_I(inode)->io_tree.lock);
1821 1822 1823 1824 1825
		state = find_first_extent_bit_state(&BTRFS_I(inode)->io_tree,
						    failrec->start,
						    EXTENT_LOCKED);
		if (state && state->start != failrec->start)
			state = NULL;
1826
		spin_unlock(&BTRFS_I(inode)->io_tree.lock);
1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840
	}
	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;
1841
	bio->bi_size = 0;
1842

1843
	bio_add_page(bio, page, failrec->len, start - page_offset(page));
1844 1845 1846 1847 1848 1849
	if (failed_bio->bi_rw & (1 << BIO_RW))
		rw = WRITE;
	else
		rw = READ;

	BTRFS_I(inode)->io_tree.ops->submit_bio_hook(inode, rw, bio,
C
Chris Mason 已提交
1850
						      failrec->last_mirror,
1851
						      failrec->bio_flags, 0);
1852 1853 1854
	return 0;
}

C
Chris Mason 已提交
1855 1856 1857 1858
/*
 * 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
 */
1859
static int btrfs_clean_io_failures(struct inode *inode, u64 start)
1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883
{
	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);
		}
	}
1884 1885 1886
	return 0;
}

C
Chris Mason 已提交
1887 1888 1889 1890 1891
/*
 * 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
 */
1892
static int btrfs_readpage_end_io_hook(struct page *page, u64 start, u64 end,
1893
			       struct extent_state *state)
1894
{
1895
	size_t offset = start - ((u64)page->index << PAGE_CACHE_SHIFT);
1896
	struct inode *inode = page->mapping->host;
1897
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
1898
	char *kaddr;
1899
	u64 private = ~(u32)0;
1900
	int ret;
1901 1902
	struct btrfs_root *root = BTRFS_I(inode)->root;
	u32 csum = ~(u32)0;
1903

1904 1905 1906 1907
	if (PageChecked(page)) {
		ClearPageChecked(page);
		goto good;
	}
1908 1909

	if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM)
1910 1911 1912
		return 0;

	if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID &&
1913
	    test_range_bit(io_tree, start, end, EXTENT_NODATASUM, 1, NULL)) {
1914 1915
		clear_extent_bits(io_tree, start, end, EXTENT_NODATASUM,
				  GFP_NOFS);
1916
		return 0;
1917
	}
1918

Y
Yan 已提交
1919
	if (state && state->start == start) {
1920 1921 1922 1923 1924
		private = state->private;
		ret = 0;
	} else {
		ret = get_state_private(io_tree, start, &private);
	}
1925
	kaddr = kmap_atomic(page, KM_USER0);
C
Chris Mason 已提交
1926
	if (ret)
1927
		goto zeroit;
C
Chris Mason 已提交
1928

1929 1930
	csum = btrfs_csum_data(root, kaddr + offset, csum,  end - start + 1);
	btrfs_csum_final(csum, (char *)&csum);
C
Chris Mason 已提交
1931
	if (csum != private)
1932
		goto zeroit;
C
Chris Mason 已提交
1933

1934
	kunmap_atomic(kaddr, KM_USER0);
1935
good:
1936 1937 1938
	/* if the io failure tree for this inode is non-empty,
	 * check to see if we've recovered from a failed IO
	 */
1939
	btrfs_clean_io_failures(inode, start);
1940 1941 1942
	return 0;

zeroit:
C
Chris Mason 已提交
1943 1944 1945 1946 1947 1948
	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);
	}
1949 1950
	memset(kaddr + offset, 1, end - start + 1);
	flush_dcache_page(page);
1951
	kunmap_atomic(kaddr, KM_USER0);
1952 1953
	if (private == 0)
		return 0;
1954
	return -EIO;
1955
}
1956

Y
Yan, Zheng 已提交
1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004
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);
}

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 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
/*
 * 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;
	}
}

2122 2123 2124
/*
 * This creates an orphan entry for the given inode in case something goes
 * wrong in the middle of an unlink/truncate.
2125 2126 2127
 *
 * NOTE: caller of this function should reserve 5 units of metadata for
 *	 this function.
2128 2129 2130 2131
 */
int btrfs_orphan_add(struct btrfs_trans_handle *trans, struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
2132 2133 2134 2135
	struct btrfs_block_rsv *block_rsv = NULL;
	int reserve = 0;
	int insert = 0;
	int ret;
2136

2137 2138 2139 2140
	if (!root->orphan_block_rsv) {
		block_rsv = btrfs_alloc_block_rsv(root);
		BUG_ON(!block_rsv);
	}
2141

2142 2143 2144 2145 2146 2147
	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;
2148 2149
	}

2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165
	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);
2166 2167
	}

2168 2169 2170 2171 2172
	if (!BTRFS_I(inode)->orphan_meta_reserved) {
		BTRFS_I(inode)->orphan_meta_reserved = 1;
		reserve = 1;
	}
	spin_unlock(&root->orphan_lock);
2173

2174 2175
	if (block_rsv)
		btrfs_add_durable_block_rsv(root->fs_info, block_rsv);
2176

2177 2178 2179 2180 2181
	/* grab metadata reservation from transaction handle */
	if (reserve) {
		ret = btrfs_orphan_reserve_metadata(trans, inode);
		BUG_ON(ret);
	}
2182

2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195
	/* 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;
2196 2197 2198 2199 2200 2201 2202 2203 2204
}

/*
 * 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;
2205 2206
	int delete_item = 0;
	int release_rsv = 0;
2207 2208
	int ret = 0;

2209 2210 2211 2212
	spin_lock(&root->orphan_lock);
	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
		list_del_init(&BTRFS_I(inode)->i_orphan);
		delete_item = 1;
2213 2214
	}

2215 2216 2217
	if (BTRFS_I(inode)->orphan_meta_reserved) {
		BTRFS_I(inode)->orphan_meta_reserved = 0;
		release_rsv = 1;
2218
	}
2219
	spin_unlock(&root->orphan_lock);
2220

2221 2222 2223 2224
	if (trans && delete_item) {
		ret = btrfs_del_orphan_item(trans, root, inode->i_ino);
		BUG_ON(ret);
	}
2225

2226 2227
	if (release_rsv)
		btrfs_orphan_release_metadata(inode);
2228

2229
	return 0;
2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245
}

/*
 * 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_item *item;
	struct btrfs_key key, found_key;
	struct btrfs_trans_handle *trans;
	struct inode *inode;
	int ret = 0, nr_unlink = 0, nr_truncate = 0;

2246
	if (cmpxchg(&root->orphan_cleanup_state, 0, ORPHAN_CLEANUP_STARTED))
2247
		return;
2248 2249 2250

	path = btrfs_alloc_path();
	BUG_ON(!path);
2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294
	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];
		item = btrfs_item_nr(leaf, path->slots[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.
		 */
2295 2296 2297
		found_key.objectid = found_key.offset;
		found_key.type = BTRFS_INODE_ITEM_KEY;
		found_key.offset = 0;
2298
		inode = btrfs_iget(root->fs_info->sb, &found_key, root, NULL);
2299
		BUG_ON(IS_ERR(inode));
2300 2301 2302 2303 2304

		/*
		 * add this inode to the orphan list so btrfs_orphan_del does
		 * the proper thing when we hit it
		 */
2305
		spin_lock(&root->orphan_lock);
2306
		list_add(&BTRFS_I(inode)->i_orphan, &root->orphan_list);
2307
		spin_unlock(&root->orphan_lock);
2308 2309 2310 2311 2312 2313 2314 2315

		/*
		 * 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)) {
2316
			trans = btrfs_start_transaction(root, 0);
2317
			btrfs_orphan_del(trans, inode);
2318
			btrfs_end_transaction(trans, root);
2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333
			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);
	}
2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345
	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);
	}
2346 2347 2348 2349 2350 2351 2352

	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);
}

2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403
/*
 * 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
2404 2405 2406
/*
 * read an inode from the btree into the in-memory inode
 */
2407
static void btrfs_read_locked_inode(struct inode *inode)
C
Chris Mason 已提交
2408 2409
{
	struct btrfs_path *path;
2410
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2411
	struct btrfs_inode_item *inode_item;
2412
	struct btrfs_timespec *tspec;
C
Chris Mason 已提交
2413 2414
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key location;
2415
	int maybe_acls;
C
Chris Mason 已提交
2416
	u64 alloc_group_block;
J
Josef Bacik 已提交
2417
	u32 rdev;
C
Chris Mason 已提交
2418 2419 2420 2421 2422
	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);
	memcpy(&location, &BTRFS_I(inode)->location, sizeof(location));
C
Chris Mason 已提交
2423

C
Chris Mason 已提交
2424
	ret = btrfs_lookup_inode(NULL, root, path, &location, 0);
2425
	if (ret)
C
Chris Mason 已提交
2426 2427
		goto make_bad;

2428 2429 2430 2431 2432 2433 2434 2435
	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);
2436
	btrfs_i_size_write(inode, btrfs_inode_size(leaf, inode_item));
2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449

	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);

2450
	inode_set_bytes(inode, btrfs_inode_nbytes(leaf, inode_item));
2451
	BTRFS_I(inode)->generation = btrfs_inode_generation(leaf, inode_item);
2452
	BTRFS_I(inode)->sequence = btrfs_inode_sequence(leaf, inode_item);
2453
	inode->i_generation = BTRFS_I(inode)->generation;
J
Josef Bacik 已提交
2454
	inode->i_rdev = 0;
2455 2456
	rdev = btrfs_inode_rdev(leaf, inode_item);

2457
	BTRFS_I(inode)->index_cnt = (u64)-1;
2458
	BTRFS_I(inode)->flags = btrfs_inode_flags(leaf, inode_item);
2459

2460
	alloc_group_block = btrfs_inode_block_group(leaf, inode_item);
2461

2462 2463 2464 2465 2466
	/*
	 * 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);
2467 2468
	if (!maybe_acls)
		cache_no_acl(inode);
2469

2470 2471
	BTRFS_I(inode)->block_group = btrfs_find_block_group(root, 0,
						alloc_group_block, 0);
C
Chris Mason 已提交
2472 2473 2474 2475 2476 2477
	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
2478
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
2479
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492
		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
2493
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
2494
		break;
J
Josef Bacik 已提交
2495
	default:
J
Jim Owens 已提交
2496
		inode->i_op = &btrfs_special_inode_operations;
J
Josef Bacik 已提交
2497 2498
		init_special_inode(inode, inode->i_mode, rdev);
		break;
C
Chris Mason 已提交
2499
	}
2500 2501

	btrfs_update_iflags(inode);
C
Chris Mason 已提交
2502 2503 2504 2505 2506 2507 2508
	return;

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

C
Chris Mason 已提交
2509 2510 2511
/*
 * given a leaf and an inode, copy the inode fields into the leaf
 */
2512 2513
static void fill_inode_item(struct btrfs_trans_handle *trans,
			    struct extent_buffer *leaf,
2514
			    struct btrfs_inode_item *item,
C
Chris Mason 已提交
2515 2516
			    struct inode *inode)
{
2517 2518
	btrfs_set_inode_uid(leaf, item, inode->i_uid);
	btrfs_set_inode_gid(leaf, item, inode->i_gid);
2519
	btrfs_set_inode_size(leaf, item, BTRFS_I(inode)->disk_i_size);
2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537
	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);

2538
	btrfs_set_inode_nbytes(leaf, item, inode_get_bytes(inode));
2539
	btrfs_set_inode_generation(leaf, item, BTRFS_I(inode)->generation);
2540
	btrfs_set_inode_sequence(leaf, item, BTRFS_I(inode)->sequence);
2541
	btrfs_set_inode_transid(leaf, item, trans->transid);
2542
	btrfs_set_inode_rdev(leaf, item, inode->i_rdev);
Y
Yan 已提交
2543
	btrfs_set_inode_flags(leaf, item, BTRFS_I(inode)->flags);
2544
	btrfs_set_inode_block_group(leaf, item, BTRFS_I(inode)->block_group);
C
Chris Mason 已提交
2545 2546
}

C
Chris Mason 已提交
2547 2548 2549
/*
 * copy everything in the in-memory inode into the btree.
 */
C
Chris Mason 已提交
2550 2551
noinline int btrfs_update_inode(struct btrfs_trans_handle *trans,
				struct btrfs_root *root, struct inode *inode)
C
Chris Mason 已提交
2552 2553 2554
{
	struct btrfs_inode_item *inode_item;
	struct btrfs_path *path;
2555
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2556 2557 2558 2559
	int ret;

	path = btrfs_alloc_path();
	BUG_ON(!path);
2560
	path->leave_spinning = 1;
C
Chris Mason 已提交
2561 2562 2563 2564 2565 2566 2567 2568
	ret = btrfs_lookup_inode(trans, root, path,
				 &BTRFS_I(inode)->location, 1);
	if (ret) {
		if (ret > 0)
			ret = -ENOENT;
		goto failed;
	}

2569
	btrfs_unlock_up_safe(path, 1);
2570 2571
	leaf = path->nodes[0];
	inode_item = btrfs_item_ptr(leaf, path->slots[0],
C
Chris Mason 已提交
2572 2573
				  struct btrfs_inode_item);

2574
	fill_inode_item(trans, leaf, inode_item, inode);
2575
	btrfs_mark_buffer_dirty(leaf);
2576
	btrfs_set_inode_last_trans(trans, inode);
C
Chris Mason 已提交
2577 2578 2579 2580 2581 2582 2583
	ret = 0;
failed:
	btrfs_free_path(path);
	return ret;
}


C
Chris Mason 已提交
2584 2585 2586 2587 2588
/*
 * 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
 */
2589 2590 2591 2592
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
2593 2594 2595
{
	struct btrfs_path *path;
	int ret = 0;
2596
	struct extent_buffer *leaf;
C
Chris Mason 已提交
2597
	struct btrfs_dir_item *di;
2598
	struct btrfs_key key;
2599
	u64 index;
C
Chris Mason 已提交
2600 2601

	path = btrfs_alloc_path();
2602 2603 2604 2605 2606
	if (!path) {
		ret = -ENOMEM;
		goto err;
	}

2607
	path->leave_spinning = 1;
C
Chris Mason 已提交
2608 2609 2610 2611 2612 2613 2614 2615 2616 2617
	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;
	}
2618 2619
	leaf = path->nodes[0];
	btrfs_dir_item_key_to_cpu(leaf, di, &key);
C
Chris Mason 已提交
2620
	ret = btrfs_delete_one_dir_name(trans, root, path, di);
2621 2622
	if (ret)
		goto err;
C
Chris Mason 已提交
2623 2624
	btrfs_release_path(root, path);

2625
	ret = btrfs_del_inode_ref(trans, root, name, name_len,
2626 2627
				  inode->i_ino,
				  dir->i_ino, &index);
2628
	if (ret) {
C
Chris Mason 已提交
2629
		printk(KERN_INFO "btrfs failed to delete reference to %.*s, "
2630
		       "inode %lu parent %lu\n", name_len, name,
2631
		       inode->i_ino, dir->i_ino);
2632 2633 2634
		goto err;
	}

C
Chris Mason 已提交
2635
	di = btrfs_lookup_dir_index_item(trans, root, path, dir->i_ino,
2636
					 index, name, name_len, -1);
C
Chris Mason 已提交
2637 2638 2639 2640 2641 2642 2643 2644 2645
	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);
2646
	btrfs_release_path(root, path);
C
Chris Mason 已提交
2647

2648 2649
	ret = btrfs_del_inode_ref_in_log(trans, root, name, name_len,
					 inode, dir->i_ino);
C
Chris Mason 已提交
2650
	BUG_ON(ret != 0 && ret != -ENOENT);
2651 2652 2653 2654

	ret = btrfs_del_dir_entries_in_log(trans, root, name, name_len,
					   dir, index);
	BUG_ON(ret);
C
Chris Mason 已提交
2655 2656
err:
	btrfs_free_path(path);
2657 2658 2659 2660 2661 2662 2663 2664 2665
	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
2666 2667 2668
	return ret;
}

2669 2670 2671
/* 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
2672
{
2673 2674
	struct extent_buffer *eb;
	int level;
C
Chris Mason 已提交
2675
	int ret;
2676
	u64 refs = 1;
2677

2678 2679 2680 2681 2682 2683 2684 2685 2686 2687
	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;
2688
	}
2689
	return 0;
C
Chris Mason 已提交
2690 2691
}

2692 2693 2694 2695 2696 2697 2698 2699 2700
/*
 * 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)
2701
{
C
Chris Mason 已提交
2702
	struct btrfs_trans_handle *trans;
2703
	struct btrfs_root *root = BTRFS_I(dir)->root;
2704
	struct btrfs_path *path;
2705
	struct btrfs_inode_ref *ref;
2706
	struct btrfs_dir_item *di;
2707
	struct inode *inode = dentry->d_inode;
2708
	u64 index;
2709 2710
	int check_link = 1;
	int err = -ENOSPC;
2711 2712
	int ret;

2713 2714 2715
	trans = btrfs_start_transaction(root, 10);
	if (!IS_ERR(trans) || PTR_ERR(trans) != -ENOSPC)
		return trans;
2716

2717 2718
	if (inode->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
		return ERR_PTR(-ENOSPC);
2719

2720 2721 2722
	/* check if there is someone else holds reference */
	if (S_ISDIR(inode->i_mode) && atomic_read(&inode->i_count) > 1)
		return ERR_PTR(-ENOSPC);
2723

2724 2725
	if (atomic_read(&inode->i_count) > 2)
		return ERR_PTR(-ENOSPC);
2726

2727 2728 2729 2730 2731 2732 2733
	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);
2734 2735
	}

2736
	trans = btrfs_start_transaction(root, 0);
2737
	if (IS_ERR(trans)) {
2738 2739 2740 2741
		btrfs_free_path(path);
		root->fs_info->enospc_unlink = 0;
		return trans;
	}
2742

2743 2744
	path->skip_locking = 1;
	path->search_commit_root = 1;
2745

2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756
	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;
2757
	}
2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 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
	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);
2864

C
Chris Mason 已提交
2865
	btrfs_set_trans_block_group(trans, dir);
2866 2867 2868

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

2869 2870
	ret = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
				 dentry->d_name.name, dentry->d_name.len);
2871
	BUG_ON(ret);
2872

2873
	if (inode->i_nlink == 0) {
2874
		ret = btrfs_orphan_add(trans, inode);
2875 2876
		BUG_ON(ret);
	}
2877

2878
	nr = trans->blocks_used;
2879
	__unlink_end_trans(trans, root);
2880
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
2881 2882 2883
	return ret;
}

2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946
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);
	dir->i_sb->s_dirt = 1;

	btrfs_free_path(path);
	return 0;
}

C
Chris Mason 已提交
2947 2948 2949
static int btrfs_rmdir(struct inode *dir, struct dentry *dentry)
{
	struct inode *inode = dentry->d_inode;
2950
	int err = 0;
C
Chris Mason 已提交
2951 2952
	struct btrfs_root *root = BTRFS_I(dir)->root;
	struct btrfs_trans_handle *trans;
2953
	unsigned long nr = 0;
C
Chris Mason 已提交
2954

2955
	if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
2956
	    inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
Y
Yan 已提交
2957 2958
		return -ENOTEMPTY;

2959 2960
	trans = __unlink_start_trans(dir, dentry);
	if (IS_ERR(trans))
2961 2962
		return PTR_ERR(trans);

C
Chris Mason 已提交
2963 2964
	btrfs_set_trans_block_group(trans, dir);

2965 2966 2967 2968 2969 2970 2971 2972
	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;
	}

2973 2974
	err = btrfs_orphan_add(trans, inode);
	if (err)
2975
		goto out;
2976

C
Chris Mason 已提交
2977
	/* now the directory is empty */
2978 2979
	err = btrfs_unlink_inode(trans, root, dir, dentry->d_inode,
				 dentry->d_name.name, dentry->d_name.len);
C
Chris Mason 已提交
2980
	if (!err)
2981
		btrfs_i_size_write(inode, 0);
2982
out:
2983
	nr = trans->blocks_used;
2984
	__unlink_end_trans(trans, root);
2985
	btrfs_btree_balance_dirty(root, nr);
2986

C
Chris Mason 已提交
2987 2988 2989
	return err;
}

2990
#if 0
2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018
/*
 * 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
3019 3020 3021
	struct btrfs_leaf_ref *ref;
	u64 leaf_gen;
	u64 leaf_start;
3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 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 3060 3061 3062 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

	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
3115 3116
	leaf_start = btrfs_node_blockptr(path->nodes[1], path->slots[1]);
	leaf_gen = btrfs_node_ptr_generation(path->nodes[1], path->slots[1]);
3117 3118 3119 3120
	/*
	 * 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
3121
	ret = btrfs_del_leaf(trans, root, path, leaf_start);
3122 3123
	BUG_ON(ret);

Y
Yan Zheng 已提交
3124 3125 3126 3127 3128 3129 3130 3131 3132
	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;

3133 3134
			btrfs_sort_leaf_ref(ref);

Y
Yan Zheng 已提交
3135 3136 3137 3138 3139 3140 3141
			ret = btrfs_add_leaf_ref(root, ref, 0);
			WARN_ON(ret);
			btrfs_free_leaf_ref(root, ref);
		} else {
			WARN_ON(1);
		}
	}
3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159
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;
}

3160 3161
#endif

C
Chris Mason 已提交
3162 3163 3164
/*
 * 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
3165
 * any higher than new_size
C
Chris Mason 已提交
3166 3167 3168
 *
 * csum items that cross the new i_size are truncated to the new size
 * as well.
3169 3170 3171
 *
 * 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
3172
 */
3173 3174 3175 3176
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
3177 3178
{
	struct btrfs_path *path;
3179
	struct extent_buffer *leaf;
C
Chris Mason 已提交
3180
	struct btrfs_file_extent_item *fi;
3181 3182
	struct btrfs_key key;
	struct btrfs_key found_key;
C
Chris Mason 已提交
3183
	u64 extent_start = 0;
3184
	u64 extent_num_bytes = 0;
3185
	u64 extent_offset = 0;
C
Chris Mason 已提交
3186
	u64 item_end = 0;
3187 3188
	u64 mask = root->sectorsize - 1;
	u32 found_type = (u8)-1;
C
Chris Mason 已提交
3189 3190
	int found_extent;
	int del_item;
3191 3192
	int pending_del_nr = 0;
	int pending_del_slot = 0;
3193
	int extent_type = -1;
3194
	int encoding;
3195 3196 3197 3198
	int ret;
	int err = 0;

	BUG_ON(new_size > 0 && min_type != BTRFS_EXTENT_DATA_KEY);
C
Chris Mason 已提交
3199

3200
	if (root->ref_cows)
3201
		btrfs_drop_extent_cache(inode, new_size & (~mask), (u64)-1, 0);
3202

C
Chris Mason 已提交
3203 3204
	path = btrfs_alloc_path();
	BUG_ON(!path);
J
Julia Lawall 已提交
3205
	path->reada = -1;
3206

C
Chris Mason 已提交
3207 3208
	key.objectid = inode->i_ino;
	key.offset = (u64)-1;
3209 3210
	key.type = (u8)-1;

3211
search_again:
3212
	path->leave_spinning = 1;
3213
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
3214 3215 3216 3217
	if (ret < 0) {
		err = ret;
		goto out;
	}
C
Chris Mason 已提交
3218

3219
	if (ret > 0) {
3220 3221 3222
		/* there are no items in the tree for us to truncate, we're
		 * done
		 */
3223 3224
		if (path->slots[0] == 0)
			goto out;
3225 3226 3227
		path->slots[0]--;
	}

C
Chris Mason 已提交
3228
	while (1) {
C
Chris Mason 已提交
3229
		fi = NULL;
3230 3231 3232
		leaf = path->nodes[0];
		btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
		found_type = btrfs_key_type(&found_key);
3233
		encoding = 0;
C
Chris Mason 已提交
3234

3235
		if (found_key.objectid != inode->i_ino)
C
Chris Mason 已提交
3236
			break;
3237

3238
		if (found_type < min_type)
C
Chris Mason 已提交
3239 3240
			break;

3241
		item_end = found_key.offset;
C
Chris Mason 已提交
3242
		if (found_type == BTRFS_EXTENT_DATA_KEY) {
3243
			fi = btrfs_item_ptr(leaf, path->slots[0],
C
Chris Mason 已提交
3244
					    struct btrfs_file_extent_item);
3245
			extent_type = btrfs_file_extent_type(leaf, fi);
3246 3247 3248 3249
			encoding = btrfs_file_extent_compression(leaf, fi);
			encoding |= btrfs_file_extent_encryption(leaf, fi);
			encoding |= btrfs_file_extent_other_encoding(leaf, fi);

3250
			if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
3251
				item_end +=
3252
				    btrfs_file_extent_num_bytes(leaf, fi);
3253 3254
			} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
				item_end += btrfs_file_extent_inline_len(leaf,
C
Chris Mason 已提交
3255
									 fi);
C
Chris Mason 已提交
3256
			}
3257
			item_end--;
C
Chris Mason 已提交
3258
		}
3259 3260 3261 3262
		if (found_type > min_type) {
			del_item = 1;
		} else {
			if (item_end < new_size)
3263
				break;
3264 3265 3266 3267
			if (found_key.offset >= new_size)
				del_item = 1;
			else
				del_item = 0;
C
Chris Mason 已提交
3268 3269 3270
		}
		found_extent = 0;
		/* FIXME, shrink the extent if the ref count is only 1 */
3271 3272 3273 3274
		if (found_type != BTRFS_EXTENT_DATA_KEY)
			goto delete;

		if (extent_type != BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
3275
			u64 num_dec;
3276
			extent_start = btrfs_file_extent_disk_bytenr(leaf, fi);
3277
			if (!del_item && !encoding) {
3278 3279
				u64 orig_num_bytes =
					btrfs_file_extent_num_bytes(leaf, fi);
3280
				extent_num_bytes = new_size -
3281
					found_key.offset + root->sectorsize - 1;
3282 3283
				extent_num_bytes = extent_num_bytes &
					~((u64)root->sectorsize - 1);
3284 3285 3286
				btrfs_set_file_extent_num_bytes(leaf, fi,
							 extent_num_bytes);
				num_dec = (orig_num_bytes -
C
Chris Mason 已提交
3287
					   extent_num_bytes);
3288
				if (root->ref_cows && extent_start != 0)
3289
					inode_sub_bytes(inode, num_dec);
3290
				btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
3291
			} else {
3292 3293 3294
				extent_num_bytes =
					btrfs_file_extent_disk_num_bytes(leaf,
									 fi);
3295 3296 3297
				extent_offset = found_key.offset -
					btrfs_file_extent_offset(leaf, fi);

C
Chris Mason 已提交
3298
				/* FIXME blocksize != 4096 */
C
Chris Mason 已提交
3299
				num_dec = btrfs_file_extent_num_bytes(leaf, fi);
C
Chris Mason 已提交
3300 3301
				if (extent_start != 0) {
					found_extent = 1;
3302
					if (root->ref_cows)
3303
						inode_sub_bytes(inode, num_dec);
3304
				}
C
Chris Mason 已提交
3305
			}
C
Chris Mason 已提交
3306
		} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
C
Chris Mason 已提交
3307 3308 3309 3310 3311 3312 3313 3314
			/*
			 * 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) {
3315 3316 3317
				u32 size = new_size - found_key.offset;

				if (root->ref_cows) {
3318 3319
					inode_sub_bytes(inode, item_end + 1 -
							new_size);
3320 3321 3322
				}
				size =
				    btrfs_file_extent_calc_inline_size(size);
C
Chris Mason 已提交
3323
				ret = btrfs_truncate_item(trans, root, path,
3324
							  size, 1);
C
Chris Mason 已提交
3325
				BUG_ON(ret);
3326
			} else if (root->ref_cows) {
3327 3328
				inode_sub_bytes(inode, item_end + 1 -
						found_key.offset);
C
Chris Mason 已提交
3329
			}
C
Chris Mason 已提交
3330
		}
3331
delete:
C
Chris Mason 已提交
3332
		if (del_item) {
3333 3334 3335 3336 3337 3338 3339 3340 3341 3342
			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
3343
				BUG();
3344
			}
C
Chris Mason 已提交
3345 3346 3347
		} else {
			break;
		}
3348
		if (found_extent && root->ref_cows) {
3349
			btrfs_set_path_blocking(path);
C
Chris Mason 已提交
3350
			ret = btrfs_free_extent(trans, root, extent_start,
3351 3352 3353
						extent_num_bytes, 0,
						btrfs_header_owner(leaf),
						inode->i_ino, extent_offset);
C
Chris Mason 已提交
3354 3355
			BUG_ON(ret);
		}
3356

3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372
		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;
			}
3373 3374
			btrfs_release_path(root, path);
			goto search_again;
3375 3376
		} else {
			path->slots[0]--;
3377
		}
C
Chris Mason 已提交
3378
	}
3379
out:
3380 3381 3382
	if (pending_del_nr) {
		ret = btrfs_del_items(trans, root, path, pending_del_slot,
				      pending_del_nr);
3383
		BUG_ON(ret);
3384
	}
C
Chris Mason 已提交
3385
	btrfs_free_path(path);
3386
	return err;
C
Chris Mason 已提交
3387 3388 3389 3390 3391 3392 3393 3394 3395
}

/*
 * 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;
3396
	struct btrfs_root *root = BTRFS_I(inode)->root;
3397 3398
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct btrfs_ordered_extent *ordered;
3399
	struct extent_state *cached_state = NULL;
3400
	char *kaddr;
3401
	u32 blocksize = root->sectorsize;
C
Chris Mason 已提交
3402 3403 3404 3405
	pgoff_t index = from >> PAGE_CACHE_SHIFT;
	unsigned offset = from & (PAGE_CACHE_SIZE-1);
	struct page *page;
	int ret = 0;
3406
	u64 page_start;
3407
	u64 page_end;
C
Chris Mason 已提交
3408 3409 3410

	if ((offset & (blocksize - 1)) == 0)
		goto out;
3411
	ret = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
3412 3413
	if (ret)
		goto out;
C
Chris Mason 已提交
3414 3415

	ret = -ENOMEM;
3416
again:
C
Chris Mason 已提交
3417
	page = grab_cache_page(mapping, index);
3418
	if (!page) {
3419
		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
C
Chris Mason 已提交
3420
		goto out;
3421
	}
3422 3423 3424 3425

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

C
Chris Mason 已提交
3426
	if (!PageUptodate(page)) {
C
Chris Mason 已提交
3427
		ret = btrfs_readpage(NULL, page);
C
Chris Mason 已提交
3428
		lock_page(page);
3429 3430 3431 3432 3433
		if (page->mapping != mapping) {
			unlock_page(page);
			page_cache_release(page);
			goto again;
		}
C
Chris Mason 已提交
3434 3435
		if (!PageUptodate(page)) {
			ret = -EIO;
3436
			goto out_unlock;
C
Chris Mason 已提交
3437 3438
		}
	}
3439
	wait_on_page_writeback(page);
3440

3441 3442
	lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
3443 3444 3445 3446
	set_page_extent_mapped(page);

	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
3447 3448
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
3449 3450
		unlock_page(page);
		page_cache_release(page);
3451
		btrfs_start_ordered_extent(inode, ordered, 1);
3452 3453 3454 3455
		btrfs_put_ordered_extent(ordered);
		goto again;
	}

3456
	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
3457
			  EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
3458
			  0, 0, &cached_state, GFP_NOFS);
3459

3460 3461
	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
					&cached_state);
J
Josef Bacik 已提交
3462
	if (ret) {
3463 3464
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
3465 3466 3467
		goto out_unlock;
	}

3468 3469 3470 3471 3472 3473 3474
	ret = 0;
	if (offset != PAGE_CACHE_SIZE) {
		kaddr = kmap(page);
		memset(kaddr + offset, 0, PAGE_CACHE_SIZE - offset);
		flush_dcache_page(page);
		kunmap(page);
	}
3475
	ClearPageChecked(page);
3476
	set_page_dirty(page);
3477 3478
	unlock_extent_cached(io_tree, page_start, page_end, &cached_state,
			     GFP_NOFS);
C
Chris Mason 已提交
3479

3480
out_unlock:
3481
	if (ret)
3482
		btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
C
Chris Mason 已提交
3483 3484 3485 3486 3487 3488
	unlock_page(page);
	page_cache_release(page);
out:
	return ret;
}

Y
Yan Zheng 已提交
3489
int btrfs_cont_expand(struct inode *inode, loff_t size)
C
Chris Mason 已提交
3490
{
Y
Yan Zheng 已提交
3491 3492 3493
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
3494
	struct extent_map *em = NULL;
3495
	struct extent_state *cached_state = NULL;
Y
Yan Zheng 已提交
3496 3497 3498 3499 3500 3501
	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
3502
	int err = 0;
C
Chris Mason 已提交
3503

Y
Yan Zheng 已提交
3504 3505 3506 3507 3508 3509 3510
	if (size <= hole_start)
		return 0;

	while (1) {
		struct btrfs_ordered_extent *ordered;
		btrfs_wait_ordered_range(inode, hole_start,
					 block_end - hole_start);
3511 3512
		lock_extent_bits(io_tree, hole_start, block_end - 1, 0,
				 &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
3513 3514 3515
		ordered = btrfs_lookup_ordered_extent(inode, hole_start);
		if (!ordered)
			break;
3516 3517
		unlock_extent_cached(io_tree, hole_start, block_end - 1,
				     &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
3518 3519
		btrfs_put_ordered_extent(ordered);
	}
C
Chris Mason 已提交
3520

Y
Yan Zheng 已提交
3521 3522 3523 3524 3525 3526 3527
	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;
3528
		if (!test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3529
			u64 hint_byte = 0;
Y
Yan Zheng 已提交
3530
			hole_size = last_byte - cur_offset;
J
Josef Bacik 已提交
3531

3532 3533 3534
			trans = btrfs_start_transaction(root, 2);
			if (IS_ERR(trans)) {
				err = PTR_ERR(trans);
J
Josef Bacik 已提交
3535
				break;
3536
			}
3537 3538 3539 3540 3541 3542 3543
			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
3544 3545 3546 3547
			err = btrfs_insert_file_extent(trans, root,
					inode->i_ino, cur_offset, 0,
					0, hole_size, 0, hole_size,
					0, 0, 0);
3548 3549
			BUG_ON(err);

Y
Yan Zheng 已提交
3550 3551
			btrfs_drop_extent_cache(inode, hole_start,
					last_byte - 1, 0);
3552 3553

			btrfs_end_transaction(trans, root);
Y
Yan Zheng 已提交
3554 3555
		}
		free_extent_map(em);
3556
		em = NULL;
Y
Yan Zheng 已提交
3557
		cur_offset = last_byte;
3558
		if (cur_offset >= block_end)
Y
Yan Zheng 已提交
3559 3560
			break;
	}
3561

3562
	free_extent_map(em);
3563 3564
	unlock_extent_cached(io_tree, hole_start, block_end - 1, &cached_state,
			     GFP_NOFS);
Y
Yan Zheng 已提交
3565 3566
	return err;
}
C
Chris Mason 已提交
3567

3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588
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;
		}
	}

3589 3590 3591
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
3592 3593 3594 3595 3596 3597 3598 3599 3600 3601 3602 3603 3604 3605 3606 3607 3608 3609 3610 3611

	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);

3612 3613
		trans = btrfs_start_transaction(root, 0);
		BUG_ON(IS_ERR(trans));
3614
		btrfs_set_trans_block_group(trans, inode);
3615 3616
		trans->block_rsv = root->orphan_block_rsv;
		BUG_ON(!trans->block_rsv);
3617 3618 3619 3620 3621 3622 3623 3624 3625 3626 3627 3628 3629 3630 3631 3632 3633 3634 3635 3636 3637 3638 3639 3640 3641 3642 3643 3644

		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
3645 3646 3647 3648
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	int err;
C
Chris Mason 已提交
3649

Y
Yan Zheng 已提交
3650 3651 3652
	err = inode_change_ok(inode, attr);
	if (err)
		return err;
C
Chris Mason 已提交
3653

3654
	if (S_ISREG(inode->i_mode) && (attr->ia_valid & ATTR_SIZE)) {
3655 3656 3657
		err = btrfs_setattr_size(inode, attr);
		if (err)
			return err;
C
Chris Mason 已提交
3658
	}
3659
	attr->ia_valid &= ~ATTR_SIZE;
Y
Yan Zheng 已提交
3660

3661 3662
	if (attr->ia_valid)
		err = inode_setattr(inode, attr);
J
Josef Bacik 已提交
3663 3664 3665

	if (!err && ((attr->ia_valid & ATTR_MODE)))
		err = btrfs_acl_chmod(inode);
C
Chris Mason 已提交
3666 3667
	return err;
}
3668

C
Chris Mason 已提交
3669 3670 3671 3672
void btrfs_delete_inode(struct inode *inode)
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(inode)->root;
3673
	unsigned long nr;
C
Chris Mason 已提交
3674 3675 3676 3677
	int ret;

	truncate_inode_pages(&inode->i_data, 0);
	if (is_bad_inode(inode)) {
3678
		btrfs_orphan_del(NULL, inode);
C
Chris Mason 已提交
3679 3680
		goto no_delete;
	}
C
Chris Mason 已提交
3681
	btrfs_wait_ordered_range(inode, 0, (u64)-1);
3682

3683 3684 3685 3686 3687
	if (root->fs_info->log_root_recovering) {
		BUG_ON(!list_empty(&BTRFS_I(inode)->i_orphan));
		goto no_delete;
	}

3688 3689 3690 3691 3692
	if (inode->i_nlink > 0) {
		BUG_ON(btrfs_root_refs(&root->root_item) != 0);
		goto no_delete;
	}

3693
	btrfs_i_size_write(inode, 0);
3694

3695
	while (1) {
3696 3697
		trans = btrfs_start_transaction(root, 0);
		BUG_ON(IS_ERR(trans));
3698
		btrfs_set_trans_block_group(trans, inode);
3699 3700 3701 3702 3703 3704 3705 3706 3707 3708
		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;
		}
3709

3710
		ret = btrfs_truncate_inode_items(trans, root, inode, 0, 0);
3711 3712
		if (ret != -EAGAIN)
			break;
3713

3714 3715 3716 3717
		nr = trans->blocks_used;
		btrfs_end_transaction(trans, root);
		trans = NULL;
		btrfs_btree_balance_dirty(root, nr);
3718

3719
	}
3720

3721 3722 3723 3724
	if (ret == 0) {
		ret = btrfs_orphan_del(trans, inode);
		BUG_ON(ret);
	}
3725

3726
	nr = trans->blocks_used;
3727
	btrfs_end_transaction(trans, root);
3728
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
3729 3730
no_delete:
	clear_inode(inode);
3731
	return;
C
Chris Mason 已提交
3732 3733 3734 3735 3736 3737 3738 3739 3740 3741 3742 3743 3744 3745
}

/*
 * 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
3746
	int ret = 0;
C
Chris Mason 已提交
3747 3748 3749

	path = btrfs_alloc_path();
	BUG_ON(!path);
3750

C
Chris Mason 已提交
3751 3752
	di = btrfs_lookup_dir_item(NULL, root, path, dir->i_ino, name,
				    namelen, 0);
Y
Yan 已提交
3753 3754
	if (IS_ERR(di))
		ret = PTR_ERR(di);
C
Chris Mason 已提交
3755 3756

	if (!di || IS_ERR(di))
3757
		goto out_err;
C
Chris Mason 已提交
3758

3759
	btrfs_dir_item_key_to_cpu(path->nodes[0], di, location);
C
Chris Mason 已提交
3760 3761 3762
out:
	btrfs_free_path(path);
	return ret;
3763 3764 3765
out_err:
	location->objectid = 0;
	goto out;
C
Chris Mason 已提交
3766 3767 3768 3769 3770 3771 3772 3773
}

/*
 * 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,
3774 3775 3776 3777
				    struct inode *dir,
				    struct dentry *dentry,
				    struct btrfs_key *location,
				    struct btrfs_root **sub_root)
C
Chris Mason 已提交
3778
{
3779 3780 3781 3782 3783 3784
	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
3785

3786 3787 3788 3789 3790
	path = btrfs_alloc_path();
	if (!path) {
		err = -ENOMEM;
		goto out;
	}
C
Chris Mason 已提交
3791

3792 3793 3794 3795 3796 3797 3798 3799 3800
	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
3801

3802 3803 3804 3805 3806
	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
3807

3808 3809 3810 3811 3812 3813 3814 3815 3816 3817 3818 3819 3820 3821 3822 3823 3824 3825 3826 3827 3828 3829 3830 3831 3832 3833 3834
	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
3835 3836
}

3837 3838 3839 3840
static void inode_tree_add(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_inode *entry;
3841 3842 3843 3844 3845
	struct rb_node **p;
	struct rb_node *parent;
again:
	p = &root->inode_tree.rb_node;
	parent = NULL;
3846

3847 3848 3849
	if (hlist_unhashed(&inode->i_hash))
		return;

3850 3851 3852 3853 3854 3855
	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)
3856
			p = &parent->rb_left;
3857
		else if (inode->i_ino > entry->vfs_inode.i_ino)
3858
			p = &parent->rb_right;
3859 3860 3861
		else {
			WARN_ON(!(entry->vfs_inode.i_state &
				  (I_WILL_FREE | I_FREEING | I_CLEAR)));
3862 3863 3864 3865
			rb_erase(parent, &root->inode_tree);
			RB_CLEAR_NODE(parent);
			spin_unlock(&root->inode_lock);
			goto again;
3866 3867 3868 3869 3870 3871 3872 3873 3874 3875
		}
	}
	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;
3876
	int empty = 0;
3877

3878
	spin_lock(&root->inode_lock);
3879 3880 3881
	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);
3882
		empty = RB_EMPTY_ROOT(&root->inode_tree);
3883
	}
3884
	spin_unlock(&root->inode_lock);
3885 3886 3887 3888 3889 3890 3891 3892 3893 3894 3895 3896 3897 3898 3899 3900 3901 3902 3903 3904 3905 3906 3907 3908 3909 3910 3911 3912 3913 3914 3915 3916 3917 3918 3919 3920 3921 3922 3923 3924 3925 3926 3927 3928 3929 3930 3931 3932 3933 3934 3935 3936 3937 3938 3939 3940 3941 3942 3943 3944 3945 3946 3947 3948 3949 3950 3951 3952 3953 3954 3955 3956

	if (empty && btrfs_root_refs(&root->root_item) == 0) {
		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);
			/*
			 * btrfs_drop_inode will remove it from
			 * 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;
3957 3958
}

3959 3960 3961 3962 3963
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
3964
	btrfs_set_inode_space_info(args->root, inode);
C
Chris Mason 已提交
3965 3966 3967 3968 3969 3970
	return 0;
}

static int btrfs_find_actor(struct inode *inode, void *opaque)
{
	struct btrfs_iget_args *args = opaque;
C
Chris Mason 已提交
3971 3972
	return args->ino == inode->i_ino &&
		args->root == BTRFS_I(inode)->root;
C
Chris Mason 已提交
3973 3974
}

3975 3976 3977
static struct inode *btrfs_iget_locked(struct super_block *s,
				       u64 objectid,
				       struct btrfs_root *root)
C
Chris Mason 已提交
3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989
{
	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
3990 3991 3992 3993
/* 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,
3994
			 struct btrfs_root *root, int *new)
B
Balaji Rao 已提交
3995 3996 3997 3998 3999
{
	struct inode *inode;

	inode = btrfs_iget_locked(s, location->objectid, root);
	if (!inode)
4000
		return ERR_PTR(-ENOMEM);
B
Balaji Rao 已提交
4001 4002 4003 4004 4005

	if (inode->i_state & I_NEW) {
		BTRFS_I(inode)->root = root;
		memcpy(&BTRFS_I(inode)->location, location, sizeof(*location));
		btrfs_read_locked_inode(inode);
4006 4007

		inode_tree_add(inode);
B
Balaji Rao 已提交
4008
		unlock_new_inode(inode);
4009 4010
		if (new)
			*new = 1;
B
Balaji Rao 已提交
4011 4012 4013 4014 4015
	}

	return inode;
}

4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026 4027 4028 4029 4030 4031 4032 4033 4034 4035 4036 4037
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;
}

4038
struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry)
C
Chris Mason 已提交
4039
{
C
Chris Mason 已提交
4040
	struct inode *inode;
4041
	struct btrfs_root *root = BTRFS_I(dir)->root;
C
Chris Mason 已提交
4042 4043
	struct btrfs_root *sub_root = root;
	struct btrfs_key location;
4044
	int index;
4045
	int ret;
C
Chris Mason 已提交
4046

4047 4048
	dentry->d_op = &btrfs_dentry_operations;

C
Chris Mason 已提交
4049 4050
	if (dentry->d_name.len > BTRFS_NAME_LEN)
		return ERR_PTR(-ENAMETOOLONG);
4051

C
Chris Mason 已提交
4052
	ret = btrfs_inode_by_name(dir, dentry, &location);
4053

C
Chris Mason 已提交
4054 4055
	if (ret < 0)
		return ERR_PTR(ret);
4056

4057 4058 4059 4060
	if (location.objectid == 0)
		return NULL;

	if (location.type == BTRFS_INODE_ITEM_KEY) {
4061
		inode = btrfs_iget(dir->i_sb, &location, root, NULL);
4062 4063 4064 4065 4066
		return inode;
	}

	BUG_ON(location.type != BTRFS_ROOT_ITEM_KEY);

4067
	index = srcu_read_lock(&root->fs_info->subvol_srcu);
4068 4069 4070 4071 4072 4073 4074 4075
	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 {
4076
		inode = btrfs_iget(dir->i_sb, &location, sub_root, NULL);
C
Chris Mason 已提交
4077
	}
4078 4079
	srcu_read_unlock(&root->fs_info->subvol_srcu, index);

4080 4081 4082 4083 4084 4085 4086
	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);
	}

4087 4088 4089
	return inode;
}

4090 4091 4092 4093
static int btrfs_dentry_delete(struct dentry *dentry)
{
	struct btrfs_root *root;

4094 4095
	if (!dentry->d_inode && !IS_ROOT(dentry))
		dentry = dentry->d_parent;
4096

4097 4098 4099 4100 4101
	if (dentry->d_inode) {
		root = BTRFS_I(dentry->d_inode)->root;
		if (btrfs_root_refs(&root->root_item) == 0)
			return 1;
	}
4102 4103 4104
	return 0;
}

4105 4106 4107 4108 4109 4110 4111 4112
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);
4113

C
Chris Mason 已提交
4114 4115 4116 4117 4118 4119 4120
	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
};

4121 4122
static int btrfs_real_readdir(struct file *filp, void *dirent,
			      filldir_t filldir)
C
Chris Mason 已提交
4123
{
4124
	struct inode *inode = filp->f_dentry->d_inode;
C
Chris Mason 已提交
4125 4126 4127 4128
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_item *item;
	struct btrfs_dir_item *di;
	struct btrfs_key key;
4129
	struct btrfs_key found_key;
C
Chris Mason 已提交
4130 4131 4132
	struct btrfs_path *path;
	int ret;
	u32 nritems;
4133
	struct extent_buffer *leaf;
C
Chris Mason 已提交
4134 4135 4136 4137 4138 4139 4140 4141
	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;
4142 4143 4144
	char tmp_name[32];
	char *name_ptr;
	int name_len;
C
Chris Mason 已提交
4145 4146 4147 4148

	/* FIXME, use a real flag for deciding about the key type */
	if (root->fs_info->tree_root == root)
		key_type = BTRFS_DIR_ITEM_KEY;
4149

4150 4151 4152 4153 4154 4155 4156 4157 4158 4159 4160
	/* 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) {
4161
		u64 pino = parent_ino(filp->f_path.dentry);
4162
		over = filldir(dirent, "..", 2,
4163
			       2, pino, DT_DIR);
4164
		if (over)
4165
			return 0;
4166 4167
		filp->f_pos = 2;
	}
4168 4169 4170
	path = btrfs_alloc_path();
	path->reada = 2;

C
Chris Mason 已提交
4171 4172
	btrfs_set_key_type(&key, key_type);
	key.offset = filp->f_pos;
4173
	key.objectid = inode->i_ino;
4174

C
Chris Mason 已提交
4175 4176 4177 4178
	ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
	if (ret < 0)
		goto err;
	advance = 0;
4179 4180

	while (1) {
4181 4182
		leaf = path->nodes[0];
		nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
4183 4184
		slot = path->slots[0];
		if (advance || slot >= nritems) {
4185
			if (slot >= nritems - 1) {
C
Chris Mason 已提交
4186 4187 4188
				ret = btrfs_next_leaf(root, path);
				if (ret)
					break;
4189 4190
				leaf = path->nodes[0];
				nritems = btrfs_header_nritems(leaf);
C
Chris Mason 已提交
4191 4192 4193 4194 4195 4196
				slot = path->slots[0];
			} else {
				slot++;
				path->slots[0]++;
			}
		}
4197

C
Chris Mason 已提交
4198
		advance = 1;
4199 4200 4201 4202
		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
4203
			break;
4204
		if (btrfs_key_type(&found_key) != key_type)
C
Chris Mason 已提交
4205
			break;
4206
		if (found_key.offset < filp->f_pos)
C
Chris Mason 已提交
4207
			continue;
4208 4209

		filp->f_pos = found_key.offset;
4210

C
Chris Mason 已提交
4211 4212
		di = btrfs_item_ptr(leaf, slot, struct btrfs_dir_item);
		di_cur = 0;
4213
		di_total = btrfs_item_size(leaf, item);
4214 4215

		while (di_cur < di_total) {
4216 4217 4218
			struct btrfs_key location;

			name_len = btrfs_dir_name_len(leaf, di);
4219
			if (name_len <= sizeof(tmp_name)) {
4220 4221 4222
				name_ptr = tmp_name;
			} else {
				name_ptr = kmalloc(name_len, GFP_NOFS);
4223 4224 4225 4226
				if (!name_ptr) {
					ret = -ENOMEM;
					goto err;
				}
4227 4228 4229 4230 4231 4232
			}
			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);
4233 4234 4235 4236 4237 4238 4239 4240 4241

			/* 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;
			}
4242
			over = filldir(dirent, name_ptr, name_len,
4243
				       found_key.offset, location.objectid,
C
Chris Mason 已提交
4244
				       d_type);
4245

4246
skip:
4247 4248 4249
			if (name_ptr != tmp_name)
				kfree(name_ptr);

C
Chris Mason 已提交
4250 4251
			if (over)
				goto nopos;
J
Josef Bacik 已提交
4252
			di_len = btrfs_dir_name_len(leaf, di) +
4253
				 btrfs_dir_data_len(leaf, di) + sizeof(*di);
C
Chris Mason 已提交
4254 4255 4256 4257
			di_cur += di_len;
			di = (struct btrfs_dir_item *)((char *)di + di_len);
		}
	}
4258 4259

	/* Reached end of directory/root. Bump pos past the last item. */
4260
	if (key_type == BTRFS_DIR_INDEX_KEY)
4261 4262 4263 4264 4265
		/*
		 * 32-bit glibc will use getdents64, but then strtol -
		 * so the last number we can serve is this.
		 */
		filp->f_pos = 0x7fffffff;
4266 4267
	else
		filp->f_pos++;
C
Chris Mason 已提交
4268 4269 4270 4271 4272 4273 4274
nopos:
	ret = 0;
err:
	btrfs_free_path(path);
	return ret;
}

4275
int btrfs_write_inode(struct inode *inode, struct writeback_control *wbc)
C
Chris Mason 已提交
4276 4277 4278 4279 4280
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_trans_handle *trans;
	int ret = 0;

4281
	if (BTRFS_I(inode)->dummy_inode)
4282 4283
		return 0;

4284
	if (wbc->sync_mode == WB_SYNC_ALL) {
4285
		trans = btrfs_join_transaction(root, 1);
C
Chris Mason 已提交
4286 4287 4288 4289 4290 4291 4292
		btrfs_set_trans_block_group(trans, inode);
		ret = btrfs_commit_transaction(trans, root);
	}
	return ret;
}

/*
4293
 * This is somewhat expensive, updating the tree every time the
C
Chris Mason 已提交
4294 4295 4296 4297 4298 4299 4300 4301
 * 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;
4302 4303 4304 4305
	int ret;

	if (BTRFS_I(inode)->dummy_inode)
		return;
C
Chris Mason 已提交
4306

4307
	trans = btrfs_join_transaction(root, 1);
C
Chris Mason 已提交
4308
	btrfs_set_trans_block_group(trans, inode);
4309 4310

	ret = btrfs_update_inode(trans, root, inode);
4311 4312 4313 4314
	if (ret && ret == -ENOSPC) {
		/* whoops, lets try again with the full transaction */
		btrfs_end_transaction(trans, root);
		trans = btrfs_start_transaction(root, 1);
4315 4316 4317 4318 4319 4320 4321 4322
		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;
		}
4323
		btrfs_set_trans_block_group(trans, inode);
4324

4325 4326
		ret = btrfs_update_inode(trans, root, inode);
		if (ret) {
4327 4328 4329 4330 4331
			if (printk_ratelimit()) {
				printk(KERN_ERR "btrfs: fail to "
				       "dirty  inode %lu error %d\n",
				       inode->i_ino, ret);
			}
4332 4333
		}
	}
C
Chris Mason 已提交
4334 4335 4336
	btrfs_end_transaction(trans, root);
}

C
Chris Mason 已提交
4337 4338 4339 4340 4341
/*
 * find the highest existing sequence number in a directory
 * and then set the in-memory index_cnt variable to reflect
 * free sequence numbers
 */
4342 4343 4344 4345 4346 4347 4348 4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361 4362 4363 4364 4365 4366 4367 4368 4369 4370 4371 4372 4373 4374 4375 4376 4377 4378 4379 4380 4381 4382 4383 4384 4385 4386 4387 4388 4389 4390 4391 4392 4393
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
4394 4395 4396 4397
/*
 * 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
 */
4398
int btrfs_set_inode_index(struct inode *dir, u64 *index)
4399 4400 4401 4402 4403
{
	int ret = 0;

	if (BTRFS_I(dir)->index_cnt == (u64)-1) {
		ret = btrfs_set_inode_index_count(dir);
C
Chris Mason 已提交
4404
		if (ret)
4405 4406 4407
			return ret;
	}

4408
	*index = BTRFS_I(dir)->index_cnt;
4409 4410 4411 4412 4413
	BTRFS_I(dir)->index_cnt++;

	return ret;
}

C
Chris Mason 已提交
4414 4415
static struct inode *btrfs_new_inode(struct btrfs_trans_handle *trans,
				     struct btrfs_root *root,
4416
				     struct inode *dir,
4417
				     const char *name, int name_len,
4418 4419
				     u64 ref_objectid, u64 objectid,
				     u64 alloc_hint, int mode, u64 *index)
C
Chris Mason 已提交
4420 4421
{
	struct inode *inode;
4422
	struct btrfs_inode_item *inode_item;
C
Chris Mason 已提交
4423
	struct btrfs_key *location;
4424
	struct btrfs_path *path;
4425 4426 4427 4428
	struct btrfs_inode_ref *ref;
	struct btrfs_key key[2];
	u32 sizes[2];
	unsigned long ptr;
C
Chris Mason 已提交
4429 4430 4431
	int ret;
	int owner;

4432 4433 4434
	path = btrfs_alloc_path();
	BUG_ON(!path);

C
Chris Mason 已提交
4435 4436 4437 4438
	inode = new_inode(root->fs_info->sb);
	if (!inode)
		return ERR_PTR(-ENOMEM);

4439
	if (dir) {
4440
		ret = btrfs_set_inode_index(dir, index);
4441 4442
		if (ret) {
			iput(inode);
4443
			return ERR_PTR(ret);
4444
		}
4445 4446 4447 4448 4449 4450 4451
	}
	/*
	 * 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
4452
	BTRFS_I(inode)->root = root;
4453
	BTRFS_I(inode)->generation = trans->transid;
J
Josef Bacik 已提交
4454
	btrfs_set_inode_space_info(root, inode);
4455

C
Chris Mason 已提交
4456 4457 4458 4459
	if (mode & S_IFDIR)
		owner = 0;
	else
		owner = 1;
4460 4461
	BTRFS_I(inode)->block_group =
			btrfs_find_block_group(root, 0, alloc_hint, owner);
4462 4463 4464 4465 4466 4467 4468 4469 4470 4471 4472 4473

	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);

4474
	path->leave_spinning = 1;
4475 4476
	ret = btrfs_insert_empty_items(trans, root, path, key, sizes, 2);
	if (ret != 0)
4477 4478
		goto fail;

4479
	inode_init_owner(inode, dir, mode);
C
Chris Mason 已提交
4480
	inode->i_ino = objectid;
4481
	inode_set_bytes(inode, 0);
C
Chris Mason 已提交
4482
	inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME;
4483 4484
	inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
				  struct btrfs_inode_item);
4485
	fill_inode_item(trans, path->nodes[0], inode_item, inode);
4486 4487 4488 4489

	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);
4490
	btrfs_set_inode_ref_index(path->nodes[0], ref, *index);
4491 4492 4493
	ptr = (unsigned long)(ref + 1);
	write_extent_buffer(path->nodes[0], name, ptr, name_len);

4494 4495 4496
	btrfs_mark_buffer_dirty(path->nodes[0]);
	btrfs_free_path(path);

C
Chris Mason 已提交
4497 4498 4499 4500 4501
	location = &BTRFS_I(inode)->location;
	location->objectid = objectid;
	location->offset = 0;
	btrfs_set_key_type(location, BTRFS_INODE_ITEM_KEY);

4502 4503
	btrfs_inherit_iflags(inode, dir);

4504 4505 4506 4507 4508 4509 4510
	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
4511
	insert_inode_hash(inode);
4512
	inode_tree_add(inode);
C
Chris Mason 已提交
4513
	return inode;
4514
fail:
4515 4516
	if (dir)
		BTRFS_I(dir)->index_cnt--;
4517
	btrfs_free_path(path);
4518
	iput(inode);
4519
	return ERR_PTR(ret);
C
Chris Mason 已提交
4520 4521 4522 4523 4524 4525 4526
}

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
4527 4528 4529 4530 4531 4532
/*
 * 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.
 */
4533 4534 4535
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
4536
{
4537
	int ret = 0;
C
Chris Mason 已提交
4538
	struct btrfs_key key;
4539
	struct btrfs_root *root = BTRFS_I(parent_inode)->root;
4540

4541 4542 4543 4544 4545 4546 4547 4548 4549 4550 4551 4552 4553 4554 4555 4556 4557 4558
	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
4559 4560

	if (ret == 0) {
4561 4562 4563 4564 4565
		ret = btrfs_insert_dir_item(trans, root, name, name_len,
					    parent_inode->i_ino, &key,
					    btrfs_inode_type(inode), index);
		BUG_ON(ret);

4566
		btrfs_i_size_write(parent_inode, parent_inode->i_size +
4567
				   name_len * 2);
4568
		parent_inode->i_mtime = parent_inode->i_ctime = CURRENT_TIME;
4569
		ret = btrfs_update_inode(trans, root, parent_inode);
C
Chris Mason 已提交
4570 4571 4572 4573 4574
	}
	return ret;
}

static int btrfs_add_nondir(struct btrfs_trans_handle *trans,
4575
			    struct dentry *dentry, struct inode *inode,
4576
			    int backref, u64 index)
C
Chris Mason 已提交
4577
{
4578 4579 4580
	int err = btrfs_add_link(trans, dentry->d_parent->d_inode,
				 inode, dentry->d_name.name,
				 dentry->d_name.len, backref, index);
C
Chris Mason 已提交
4581 4582 4583 4584 4585 4586 4587 4588 4589
	if (!err) {
		d_instantiate(dentry, inode);
		return 0;
	}
	if (err > 0)
		err = -EEXIST;
	return err;
}

J
Josef Bacik 已提交
4590 4591 4592 4593 4594
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;
4595
	struct inode *inode = NULL;
J
Josef Bacik 已提交
4596 4597 4598
	int err;
	int drop_inode = 0;
	u64 objectid;
4599
	unsigned long nr = 0;
4600
	u64 index = 0;
J
Josef Bacik 已提交
4601 4602 4603 4604

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

4605 4606 4607 4608
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;

J
Josef Bacik 已提交
4609 4610 4611 4612 4613
	/*
	 * 2 for inode item and ref
	 * 2 for dir items
	 * 1 for xattr if selinux is on
	 */
4614 4615 4616
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
4617

J
Josef Bacik 已提交
4618 4619
	btrfs_set_trans_block_group(trans, dir);

4620
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4621 4622
				dentry->d_name.len,
				dentry->d_parent->d_inode->i_ino, objectid,
4623
				BTRFS_I(dir)->block_group, mode, &index);
J
Josef Bacik 已提交
4624 4625 4626 4627
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

4628
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4629 4630 4631 4632 4633
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

J
Josef Bacik 已提交
4634
	btrfs_set_trans_block_group(trans, inode);
4635
	err = btrfs_add_nondir(trans, dentry, inode, 0, index);
J
Josef Bacik 已提交
4636 4637 4638 4639 4640
	if (err)
		drop_inode = 1;
	else {
		inode->i_op = &btrfs_special_inode_operations;
		init_special_inode(inode, inode->i_mode, rdev);
4641
		btrfs_update_inode(trans, root, inode);
J
Josef Bacik 已提交
4642 4643 4644 4645
	}
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
4646
	nr = trans->blocks_used;
4647
	btrfs_end_transaction_throttle(trans, root);
4648
	btrfs_btree_balance_dirty(root, nr);
J
Josef Bacik 已提交
4649 4650 4651 4652 4653 4654 4655
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
	return err;
}

C
Chris Mason 已提交
4656 4657 4658 4659 4660
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;
4661
	struct inode *inode = NULL;
C
Chris Mason 已提交
4662
	int drop_inode = 0;
4663
	int err;
4664
	unsigned long nr = 0;
C
Chris Mason 已提交
4665
	u64 objectid;
4666
	u64 index = 0;
C
Chris Mason 已提交
4667

4668 4669 4670
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;
J
Josef Bacik 已提交
4671 4672 4673 4674 4675
	/*
	 * 2 for inode item and ref
	 * 2 for dir items
	 * 1 for xattr if selinux is on
	 */
4676 4677 4678
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
J
Josef Bacik 已提交
4679

C
Chris Mason 已提交
4680 4681
	btrfs_set_trans_block_group(trans, dir);

4682
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4683 4684
				dentry->d_name.len,
				dentry->d_parent->d_inode->i_ino,
4685 4686
				objectid, BTRFS_I(dir)->block_group, mode,
				&index);
C
Chris Mason 已提交
4687 4688 4689 4690
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

4691
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4692 4693 4694 4695 4696
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

C
Chris Mason 已提交
4697
	btrfs_set_trans_block_group(trans, inode);
4698
	err = btrfs_add_nondir(trans, dentry, inode, 0, index);
C
Chris Mason 已提交
4699 4700 4701 4702
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
C
Chris Mason 已提交
4703
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
4704 4705
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
4706
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
4707 4708 4709 4710
	}
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);
out_unlock:
4711
	nr = trans->blocks_used;
4712
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
4713 4714 4715 4716
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
4717
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4718 4719 4720 4721 4722 4723 4724 4725 4726
	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;
4727
	u64 index;
4728
	unsigned long nr = 0;
C
Chris Mason 已提交
4729 4730 4731 4732 4733 4734
	int err;
	int drop_inode = 0;

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

4735 4736 4737 4738
	/* 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
4739 4740
	btrfs_inc_nlink(inode);

4741
	err = btrfs_set_inode_index(dir, &index);
4742 4743 4744
	if (err)
		goto fail;

4745 4746 4747 4748 4749 4750 4751 4752 4753
	/*
	 * 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;
	}
4754

C
Chris Mason 已提交
4755 4756
	btrfs_set_trans_block_group(trans, dir);
	atomic_inc(&inode->i_count);
4757

4758
	err = btrfs_add_nondir(trans, dentry, inode, 1, index);
4759

4760
	if (err) {
4761
		drop_inode = 1;
4762 4763 4764 4765 4766 4767
	} else {
		btrfs_update_inode_block_group(trans, dir);
		err = btrfs_update_inode(trans, root, inode);
		BUG_ON(err);
		btrfs_log_new_name(trans, inode, NULL, dentry->d_parent);
	}
C
Chris Mason 已提交
4768

4769
	nr = trans->blocks_used;
4770
	btrfs_end_transaction_throttle(trans, root);
4771
fail:
C
Chris Mason 已提交
4772 4773 4774 4775
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
4776
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4777 4778 4779 4780 4781
	return err;
}

static int btrfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
4782
	struct inode *inode = NULL;
C
Chris Mason 已提交
4783 4784 4785 4786
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(dir)->root;
	int err = 0;
	int drop_on_err = 0;
4787
	u64 objectid = 0;
4788
	u64 index = 0;
4789
	unsigned long nr = 1;
C
Chris Mason 已提交
4790

4791 4792 4793 4794
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;

J
Josef Bacik 已提交
4795 4796 4797 4798 4799
	/*
	 * 2 items for inode and ref
	 * 2 items for dir items
	 * 1 for xattr if selinux is on
	 */
4800 4801 4802
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
J
Josef Bacik 已提交
4803
	btrfs_set_trans_block_group(trans, dir);
C
Chris Mason 已提交
4804

4805
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
4806 4807
				dentry->d_name.len,
				dentry->d_parent->d_inode->i_ino, objectid,
4808 4809
				BTRFS_I(dir)->block_group, S_IFDIR | mode,
				&index);
C
Chris Mason 已提交
4810 4811 4812 4813
	if (IS_ERR(inode)) {
		err = PTR_ERR(inode);
		goto out_fail;
	}
4814

C
Chris Mason 已提交
4815
	drop_on_err = 1;
J
Josef Bacik 已提交
4816

4817
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
4818 4819 4820
	if (err)
		goto out_fail;

C
Chris Mason 已提交
4821 4822 4823 4824
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;
	btrfs_set_trans_block_group(trans, inode);

4825
	btrfs_i_size_write(inode, 0);
C
Chris Mason 已提交
4826 4827 4828
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		goto out_fail;
4829

4830 4831 4832
	err = btrfs_add_link(trans, dentry->d_parent->d_inode,
				 inode, dentry->d_name.name,
				 dentry->d_name.len, 0, index);
C
Chris Mason 已提交
4833 4834
	if (err)
		goto out_fail;
4835

C
Chris Mason 已提交
4836 4837 4838 4839 4840 4841
	d_instantiate(dentry, inode);
	drop_on_err = 0;
	btrfs_update_inode_block_group(trans, inode);
	btrfs_update_inode_block_group(trans, dir);

out_fail:
4842
	nr = trans->blocks_used;
4843
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
4844 4845
	if (drop_on_err)
		iput(inode);
4846
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
4847 4848 4849
	return err;
}

C
Chris Mason 已提交
4850 4851 4852 4853
/* 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.
 */
4854 4855
static int merge_extent_mapping(struct extent_map_tree *em_tree,
				struct extent_map *existing,
4856 4857
				struct extent_map *em,
				u64 map_start, u64 map_len)
4858 4859 4860
{
	u64 start_diff;

4861 4862 4863 4864
	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
4865 4866
	if (em->block_start < EXTENT_MAP_LAST_BYTE &&
	    !test_bit(EXTENT_FLAG_COMPRESSED, &em->flags)) {
4867
		em->block_start += start_diff;
C
Chris Mason 已提交
4868 4869
		em->block_len -= start_diff;
	}
4870
	return add_extent_mapping(em_tree, em);
4871 4872
}

C
Chris Mason 已提交
4873 4874 4875 4876 4877 4878 4879 4880 4881 4882 4883 4884 4885 4886 4887 4888 4889 4890 4891 4892 4893
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;

	WARN_ON(pg_offset != 0);
	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);

4894
	max_size = min_t(unsigned long, PAGE_CACHE_SIZE, max_size);
C
Chris Mason 已提交
4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906 4907 4908
	ret = btrfs_zlib_decompress(tmp, page, extent_offset,
				    inline_size, max_size);
	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
4909 4910
/*
 * a bit scary, this does extent mapping from logical file offset to the disk.
C
Chris Mason 已提交
4911 4912
 * 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
4913 4914 4915 4916
 * 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
4917

4918
struct extent_map *btrfs_get_extent(struct inode *inode, struct page *page,
4919
				    size_t pg_offset, u64 start, u64 len,
4920 4921 4922 4923
				    int create)
{
	int ret;
	int err = 0;
4924
	u64 bytenr;
4925 4926 4927 4928
	u64 extent_start = 0;
	u64 extent_end = 0;
	u64 objectid = inode->i_ino;
	u32 found_type;
4929
	struct btrfs_path *path = NULL;
4930 4931
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_file_extent_item *item;
4932 4933
	struct extent_buffer *leaf;
	struct btrfs_key found_key;
4934 4935
	struct extent_map *em = NULL;
	struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
4936
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
4937
	struct btrfs_trans_handle *trans = NULL;
C
Chris Mason 已提交
4938
	int compressed;
4939 4940

again:
4941
	read_lock(&em_tree->lock);
4942
	em = lookup_extent_mapping(em_tree, start, len);
4943 4944
	if (em)
		em->bdev = root->fs_info->fs_devices->latest_bdev;
4945
	read_unlock(&em_tree->lock);
4946

4947
	if (em) {
4948 4949 4950
		if (em->start > start || em->start + em->len <= start)
			free_extent_map(em);
		else if (em->block_start == EXTENT_MAP_INLINE && page)
4951 4952 4953
			free_extent_map(em);
		else
			goto out;
4954
	}
4955
	em = alloc_extent_map(GFP_NOFS);
4956
	if (!em) {
4957 4958
		err = -ENOMEM;
		goto out;
4959
	}
4960
	em->bdev = root->fs_info->fs_devices->latest_bdev;
4961
	em->start = EXTENT_MAP_HOLE;
4962
	em->orig_start = EXTENT_MAP_HOLE;
4963
	em->len = (u64)-1;
C
Chris Mason 已提交
4964
	em->block_len = (u64)-1;
4965 4966 4967 4968 4969 4970

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

4971 4972
	ret = btrfs_lookup_file_extent(trans, root, path,
				       objectid, start, trans != NULL);
4973 4974 4975 4976 4977 4978 4979 4980 4981 4982 4983
	if (ret < 0) {
		err = ret;
		goto out;
	}

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

4984 4985
	leaf = path->nodes[0];
	item = btrfs_item_ptr(leaf, path->slots[0],
4986 4987
			      struct btrfs_file_extent_item);
	/* are we inside the extent that was found? */
4988 4989 4990
	btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]);
	found_type = btrfs_key_type(&found_key);
	if (found_key.objectid != objectid ||
4991 4992 4993 4994
	    found_type != BTRFS_EXTENT_DATA_KEY) {
		goto not_found;
	}

4995 4996
	found_type = btrfs_file_extent_type(leaf, item);
	extent_start = found_key.offset;
C
Chris Mason 已提交
4997
	compressed = btrfs_file_extent_compression(leaf, item);
Y
Yan Zheng 已提交
4998 4999
	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
5000
		extent_end = extent_start +
5001
		       btrfs_file_extent_num_bytes(leaf, item);
Y
Yan Zheng 已提交
5002 5003 5004 5005 5006 5007 5008 5009 5010 5011 5012 5013 5014 5015
	} 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;
5016
			}
Y
Yan Zheng 已提交
5017 5018 5019
			if (ret > 0)
				goto not_found;
			leaf = path->nodes[0];
5020
		}
Y
Yan Zheng 已提交
5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031
		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
5032 5033
	if (found_type == BTRFS_FILE_EXTENT_REG ||
	    found_type == BTRFS_FILE_EXTENT_PREALLOC) {
Y
Yan Zheng 已提交
5034 5035
		em->start = extent_start;
		em->len = extent_end - extent_start;
5036 5037
		em->orig_start = extent_start -
				 btrfs_file_extent_offset(leaf, item);
5038 5039
		bytenr = btrfs_file_extent_disk_bytenr(leaf, item);
		if (bytenr == 0) {
5040
			em->block_start = EXTENT_MAP_HOLE;
5041 5042
			goto insert;
		}
C
Chris Mason 已提交
5043 5044 5045 5046 5047 5048 5049 5050 5051
		if (compressed) {
			set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
			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
5052 5053
			if (found_type == BTRFS_FILE_EXTENT_PREALLOC)
				set_bit(EXTENT_FLAG_PREALLOC, &em->flags);
C
Chris Mason 已提交
5054
		}
5055 5056
		goto insert;
	} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
5057
		unsigned long ptr;
5058
		char *map;
5059 5060 5061
		size_t size;
		size_t extent_offset;
		size_t copy_size;
5062

5063
		em->block_start = EXTENT_MAP_INLINE;
C
Chris Mason 已提交
5064
		if (!page || create) {
5065
			em->start = extent_start;
Y
Yan Zheng 已提交
5066
			em->len = extent_end - extent_start;
5067 5068
			goto out;
		}
5069

Y
Yan Zheng 已提交
5070 5071
		size = btrfs_file_extent_inline_len(leaf, item);
		extent_offset = page_offset(page) + pg_offset - extent_start;
5072
		copy_size = min_t(u64, PAGE_CACHE_SIZE - pg_offset,
5073 5074
				size - extent_offset);
		em->start = extent_start + extent_offset;
5075 5076
		em->len = (copy_size + root->sectorsize - 1) &
			~((u64)root->sectorsize - 1);
5077
		em->orig_start = EXTENT_MAP_INLINE;
C
Chris Mason 已提交
5078 5079
		if (compressed)
			set_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
5080
		ptr = btrfs_file_extent_inline_start(item) + extent_offset;
5081
		if (create == 0 && !PageUptodate(page)) {
C
Chris Mason 已提交
5082 5083 5084 5085 5086 5087 5088 5089 5090 5091
			if (btrfs_file_extent_compression(leaf, item) ==
			    BTRFS_COMPRESS_ZLIB) {
				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);
5092 5093 5094 5095 5096
				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
5097 5098
				kunmap(page);
			}
5099 5100
			flush_dcache_page(page);
		} else if (create && PageUptodate(page)) {
5101
			WARN_ON(1);
5102 5103 5104 5105 5106
			if (!trans) {
				kunmap(page);
				free_extent_map(em);
				em = NULL;
				btrfs_release_path(root, path);
5107
				trans = btrfs_join_transaction(root, 1);
5108 5109
				goto again;
			}
C
Chris Mason 已提交
5110
			map = kmap(page);
5111
			write_extent_buffer(leaf, map + pg_offset, ptr,
5112
					    copy_size);
C
Chris Mason 已提交
5113
			kunmap(page);
5114
			btrfs_mark_buffer_dirty(leaf);
5115
		}
5116 5117
		set_extent_uptodate(io_tree, em->start,
				    extent_map_end(em) - 1, GFP_NOFS);
5118 5119
		goto insert;
	} else {
C
Chris Mason 已提交
5120
		printk(KERN_ERR "btrfs unknown found_type %d\n", found_type);
5121 5122 5123 5124
		WARN_ON(1);
	}
not_found:
	em->start = start;
5125
	em->len = len;
5126
not_found_em:
5127
	em->block_start = EXTENT_MAP_HOLE;
Y
Yan Zheng 已提交
5128
	set_bit(EXTENT_FLAG_VACANCY, &em->flags);
5129 5130
insert:
	btrfs_release_path(root, path);
5131
	if (em->start > start || extent_map_end(em) <= start) {
C
Chris Mason 已提交
5132 5133 5134 5135 5136
		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);
5137 5138 5139
		err = -EIO;
		goto out;
	}
5140 5141

	err = 0;
5142
	write_lock(&em_tree->lock);
5143
	ret = add_extent_mapping(em_tree, em);
5144 5145 5146 5147
	/* 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
	 */
5148
	if (ret == -EEXIST) {
5149
		struct extent_map *existing;
5150 5151 5152

		ret = 0;

5153
		existing = lookup_extent_mapping(em_tree, start, len);
5154 5155 5156 5157 5158
		if (existing && (existing->start > start ||
		    existing->start + existing->len <= start)) {
			free_extent_map(existing);
			existing = NULL;
		}
5159 5160 5161 5162 5163
		if (!existing) {
			existing = lookup_extent_mapping(em_tree, em->start,
							 em->len);
			if (existing) {
				err = merge_extent_mapping(em_tree, existing,
5164 5165
							   em, start,
							   root->sectorsize);
5166 5167 5168 5169 5170 5171 5172 5173 5174 5175 5176 5177 5178
				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;
5179
			err = 0;
5180 5181
		}
	}
5182
	write_unlock(&em_tree->lock);
5183
out:
5184 5185
	if (path)
		btrfs_free_path(path);
5186 5187
	if (trans) {
		ret = btrfs_end_transaction(trans, root);
C
Chris Mason 已提交
5188
		if (!err)
5189 5190 5191 5192 5193 5194 5195 5196 5197
			err = ret;
	}
	if (err) {
		free_extent_map(em);
		return ERR_PTR(err);
	}
	return em;
}

5198 5199 5200 5201 5202 5203 5204 5205 5206 5207 5208 5209 5210 5211 5212 5213 5214 5215 5216 5217 5218 5219 5220 5221 5222 5223 5224 5225 5226 5227 5228 5229 5230 5231 5232 5233 5234 5235 5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246 5247 5248 5249 5250 5251 5252 5253 5254 5255 5256 5257 5258 5259
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;
}

5260 5261 5262 5263 5264 5265 5266 5267 5268 5269 5270 5271 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 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
/*
 * 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;
}

5360 5361 5362 5363 5364 5365 5366
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;
5367
	struct btrfs_trans_handle *trans;
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

	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.
	 *
	 */
5412 5413
	if (!create) {
		len = em->len - (start - em->start);
5414
		goto map;
5415
	}
5416 5417 5418 5419 5420 5421

	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;
5422
		u64 block_start;
5423 5424 5425 5426 5427

		if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
			type = BTRFS_ORDERED_PREALLOC;
		else
			type = BTRFS_ORDERED_NOCOW;
5428
		len = min(len, em->len - (start - em->start));
5429
		block_start = em->block_start + (start - em->start);
5430 5431 5432 5433 5434 5435 5436 5437 5438 5439 5440 5441 5442 5443 5444 5445 5446 5447 5448

		/*
		 * 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;
5449
		}
5450
		btrfs_end_transaction(trans, root);
5451
	}
5452 5453 5454 5455 5456 5457 5458 5459 5460 5461 5462 5463
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:
5464 5465 5466
	clear_extent_bit(&BTRFS_I(inode)->io_tree, start, start + len - 1,
			  EXTENT_LOCKED | EXTENT_DELALLOC | EXTENT_DIRTY, 1,
			  0, NULL, GFP_NOFS);
5467 5468 5469
map:
	bh_result->b_blocknr = (em->block_start + (start - em->start)) >>
		inode->i_blkbits;
5470
	bh_result->b_size = len;
5471 5472 5473 5474 5475 5476 5477 5478 5479 5480 5481 5482 5483 5484 5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496 5497 5498 5499 5500 5501 5502 5503 5504 5505 5506 5507 5508 5509 5510 5511 5512 5513 5514 5515 5516 5517 5518 5519 5520 5521 5522 5523 5524 5525 5526 5527 5528 5529 5530 5531 5532 5533 5534 5535 5536 5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558 5559 5560 5561 5562 5563 5564 5565 5566 5567 5568 5569 5570 5571 5572 5573 5574 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
	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;
};

static void btrfs_endio_direct_read(struct bio *bio, int err)
{
	struct bio_vec *bvec_end = bio->bi_io_vec + bio->bi_vcnt - 1;
	struct bio_vec *bvec = bio->bi_io_vec;
	struct btrfs_dio_private *dip = bio->bi_private;
	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;
	int ret;

	if (err)
		goto out_done;

	ret = btrfs_dec_test_ordered_pending(inode, &ordered,
					     dip->logical_offset, dip->bytes);
	if (!ret)
		goto out_done;

	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);
	btrfs_put_ordered_extent(ordered);
	btrfs_put_ordered_extent(ordered);
out_done:
	bio->bi_private = dip->private;

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

5626 5627 5628 5629 5630 5631 5632 5633 5634 5635 5636
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;
}

5637 5638 5639 5640 5641 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
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;
	u64 start;
	int skip_sum;
	int write = rw & (1 << BIO_RW);
	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;

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

5676
	dip->disk_bytenr = (u64)bio->bi_sector << 9;
5677 5678 5679 5680 5681 5682 5683 5684 5685 5686 5687
	bio->bi_private = dip;

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

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

5688 5689 5690 5691 5692 5693 5694 5695 5696 5697
	if (write && !skip_sum) {
		ret = btrfs_wq_submit_bio(BTRFS_I(inode)->root->fs_info,
				   inode, rw, bio, 0, 0,
				   dip->logical_offset,
				   __btrfs_submit_bio_start_direct_io,
				   __btrfs_submit_bio_done);
		if (ret)
			goto out_err;
		return;
	} else if (!skip_sum)
5698 5699 5700
		btrfs_lookup_bio_sums_dio(root, inode, bio,
					  dip->logical_offset, dip->csums);

5701
	ret = btrfs_map_bio(root, rw, bio, 0, 1);
5702 5703 5704 5705 5706 5707 5708 5709 5710 5711 5712 5713 5714 5715 5716 5717 5718 5719 5720 5721 5722 5723 5724 5725 5726
	if (ret)
		goto out_err;
	return;
out_err:
	kfree(dip->csums);
	kfree(dip);
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;
		ordered = btrfs_lookup_ordered_extent(inode,
						      dip->logical_offset);
		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
5727 5728 5729 5730 5731 5732 5733 5734 5735 5736 5737 5738 5739 5740 5741 5742 5743 5744 5745 5746 5747 5748 5749 5750 5751 5752
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;
}
5753 5754 5755 5756
static ssize_t btrfs_direct_IO(int rw, struct kiocb *iocb,
			const struct iovec *iov, loff_t offset,
			unsigned long nr_segs)
{
5757 5758 5759
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
	struct btrfs_ordered_extent *ordered;
5760
	struct extent_state *cached_state = NULL;
5761 5762
	u64 lockstart, lockend;
	ssize_t ret;
5763 5764
	int writing = rw & WRITE;
	int write_bits = 0;
5765
	size_t count = iov_length(iov, nr_segs);
5766

C
Chris Mason 已提交
5767 5768 5769 5770 5771
	if (check_direct_IO(BTRFS_I(inode)->root, rw, iocb, iov,
			    offset, nr_segs)) {
		return 0;
	}

5772
	lockstart = offset;
5773 5774 5775 5776 5777 5778 5779
	lockend = offset + count - 1;

	if (writing) {
		ret = btrfs_delalloc_reserve_space(inode, count);
		if (ret)
			goto out;
	}
5780

5781
	while (1) {
5782 5783
		lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				 0, &cached_state, GFP_NOFS);
5784 5785 5786 5787 5788 5789 5790 5791 5792
		/*
		 * 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;
5793 5794
		unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
				     &cached_state, GFP_NOFS);
5795 5796 5797 5798 5799
		btrfs_start_ordered_extent(inode, ordered, 1);
		btrfs_put_ordered_extent(ordered);
		cond_resched();
	}

5800 5801 5802 5803 5804 5805 5806 5807 5808 5809 5810 5811 5812 5813 5814 5815 5816 5817 5818 5819
	/*
	 * 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
5820 5821 5822 5823
	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);
5824 5825

	if (ret < 0 && ret != -EIOCBQUEUED) {
5826 5827 5828 5829
		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);
5830 5831 5832 5833 5834
	} 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.
		 */
5835 5836 5837 5838
		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);
5839
	}
5840 5841
out:
	free_extent_state(cached_state);
5842
	return ret;
5843 5844
}

Y
Yehuda Sadeh 已提交
5845 5846 5847 5848 5849 5850
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);
}

5851
int btrfs_readpage(struct file *file, struct page *page)
C
Chris Mason 已提交
5852
{
5853 5854
	struct extent_io_tree *tree;
	tree = &BTRFS_I(page->mapping->host)->io_tree;
5855
	return extent_read_full_page(tree, page, btrfs_get_extent);
C
Chris Mason 已提交
5856
}
5857

5858
static int btrfs_writepage(struct page *page, struct writeback_control *wbc)
C
Chris Mason 已提交
5859
{
5860
	struct extent_io_tree *tree;
5861 5862 5863 5864 5865 5866 5867


	if (current->flags & PF_MEMALLOC) {
		redirty_page_for_writepage(wbc, page);
		unlock_page(page);
		return 0;
	}
5868
	tree = &BTRFS_I(page->mapping->host)->io_tree;
5869
	return extent_write_full_page(tree, page, btrfs_get_extent, wbc);
C
Chris Mason 已提交
5870 5871
}

5872 5873
int btrfs_writepages(struct address_space *mapping,
		     struct writeback_control *wbc)
C
Chris Mason 已提交
5874
{
5875
	struct extent_io_tree *tree;
5876

5877
	tree = &BTRFS_I(mapping->host)->io_tree;
C
Chris Mason 已提交
5878 5879 5880
	return extent_writepages(tree, mapping, btrfs_get_extent, wbc);
}

C
Chris Mason 已提交
5881 5882 5883 5884
static int
btrfs_readpages(struct file *file, struct address_space *mapping,
		struct list_head *pages, unsigned nr_pages)
{
5885 5886
	struct extent_io_tree *tree;
	tree = &BTRFS_I(mapping->host)->io_tree;
C
Chris Mason 已提交
5887 5888 5889
	return extent_readpages(tree, mapping, pages, nr_pages,
				btrfs_get_extent);
}
5890
static int __btrfs_releasepage(struct page *page, gfp_t gfp_flags)
C
Chris Mason 已提交
5891
{
5892 5893
	struct extent_io_tree *tree;
	struct extent_map_tree *map;
5894
	int ret;
5895

5896 5897
	tree = &BTRFS_I(page->mapping->host)->io_tree;
	map = &BTRFS_I(page->mapping->host)->extent_tree;
5898
	ret = try_release_extent_mapping(map, tree, page, gfp_flags);
5899 5900 5901 5902
	if (ret == 1) {
		ClearPagePrivate(page);
		set_page_private(page, 0);
		page_cache_release(page);
C
Chris Mason 已提交
5903
	}
5904
	return ret;
C
Chris Mason 已提交
5905 5906
}

5907 5908
static int btrfs_releasepage(struct page *page, gfp_t gfp_flags)
{
5909 5910
	if (PageWriteback(page) || PageDirty(page))
		return 0;
5911
	return __btrfs_releasepage(page, gfp_flags & GFP_NOFS);
5912 5913
}

5914
static void btrfs_invalidatepage(struct page *page, unsigned long offset)
C
Chris Mason 已提交
5915
{
5916
	struct extent_io_tree *tree;
5917
	struct btrfs_ordered_extent *ordered;
5918
	struct extent_state *cached_state = NULL;
5919 5920
	u64 page_start = page_offset(page);
	u64 page_end = page_start + PAGE_CACHE_SIZE - 1;
C
Chris Mason 已提交
5921

5922 5923 5924 5925 5926 5927 5928 5929

	/*
	 * 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
	 */
5930
	wait_on_page_writeback(page);
5931

5932
	tree = &BTRFS_I(page->mapping->host)->io_tree;
5933 5934 5935 5936
	if (offset) {
		btrfs_releasepage(page, GFP_NOFS);
		return;
	}
5937 5938
	lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
5939 5940 5941
	ordered = btrfs_lookup_ordered_extent(page->mapping->host,
					   page_offset(page));
	if (ordered) {
5942 5943 5944 5945
		/*
		 * IO on this page will never be started, so we need
		 * to account for any ordered extents now
		 */
5946 5947
		clear_extent_bit(tree, page_start, page_end,
				 EXTENT_DIRTY | EXTENT_DELALLOC |
5948
				 EXTENT_LOCKED | EXTENT_DO_ACCOUNTING, 1, 0,
5949
				 &cached_state, GFP_NOFS);
5950 5951 5952 5953 5954 5955 5956 5957
		/*
		 * 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);
		}
5958
		btrfs_put_ordered_extent(ordered);
5959 5960 5961
		cached_state = NULL;
		lock_extent_bits(tree, page_start, page_end, 0, &cached_state,
				 GFP_NOFS);
5962 5963
	}
	clear_extent_bit(tree, page_start, page_end,
5964
		 EXTENT_LOCKED | EXTENT_DIRTY | EXTENT_DELALLOC |
5965
		 EXTENT_DO_ACCOUNTING, 1, 1, &cached_state, GFP_NOFS);
5966 5967
	__btrfs_releasepage(page, GFP_NOFS);

C
Chris Mason 已提交
5968
	ClearPageChecked(page);
5969 5970 5971 5972 5973
	if (PagePrivate(page)) {
		ClearPagePrivate(page);
		set_page_private(page, 0);
		page_cache_release(page);
	}
C
Chris Mason 已提交
5974 5975
}

C
Chris Mason 已提交
5976 5977 5978 5979 5980 5981 5982 5983 5984 5985 5986 5987 5988 5989 5990
/*
 * 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.
 */
5991
int btrfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
C
Chris Mason 已提交
5992
{
5993
	struct page *page = vmf->page;
5994
	struct inode *inode = fdentry(vma->vm_file)->d_inode;
5995
	struct btrfs_root *root = BTRFS_I(inode)->root;
5996 5997
	struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
	struct btrfs_ordered_extent *ordered;
5998
	struct extent_state *cached_state = NULL;
5999 6000
	char *kaddr;
	unsigned long zero_start;
C
Chris Mason 已提交
6001
	loff_t size;
6002
	int ret;
6003
	u64 page_start;
6004
	u64 page_end;
C
Chris Mason 已提交
6005

6006
	ret  = btrfs_delalloc_reserve_space(inode, PAGE_CACHE_SIZE);
6007 6008 6009 6010 6011
	if (ret) {
		if (ret == -ENOMEM)
			ret = VM_FAULT_OOM;
		else /* -ENOSPC, -EIO, etc */
			ret = VM_FAULT_SIGBUS;
6012
		goto out;
6013
	}
6014

6015
	ret = VM_FAULT_NOPAGE; /* make the VM retry the fault */
6016
again:
C
Chris Mason 已提交
6017 6018
	lock_page(page);
	size = i_size_read(inode);
6019 6020
	page_start = page_offset(page);
	page_end = page_start + PAGE_CACHE_SIZE - 1;
6021

C
Chris Mason 已提交
6022
	if ((page->mapping != inode->i_mapping) ||
6023
	    (page_start >= size)) {
C
Chris Mason 已提交
6024 6025 6026
		/* page got truncated out from underneath us */
		goto out_unlock;
	}
6027 6028
	wait_on_page_writeback(page);

6029 6030
	lock_extent_bits(io_tree, page_start, page_end, 0, &cached_state,
			 GFP_NOFS);
6031 6032
	set_page_extent_mapped(page);

6033 6034 6035 6036
	/*
	 * we can't set the delalloc bits if there are pending ordered
	 * extents.  Drop our locks and wait for them to finish
	 */
6037 6038
	ordered = btrfs_lookup_ordered_extent(inode, page_start);
	if (ordered) {
6039 6040
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
6041
		unlock_page(page);
6042
		btrfs_start_ordered_extent(inode, ordered, 1);
6043 6044 6045 6046
		btrfs_put_ordered_extent(ordered);
		goto again;
	}

J
Josef Bacik 已提交
6047 6048 6049 6050 6051 6052 6053
	/*
	 * 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.
	 */
6054
	clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, page_end,
6055
			  EXTENT_DIRTY | EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING,
6056
			  0, 0, &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
6057

6058 6059
	ret = btrfs_set_extent_delalloc(inode, page_start, page_end,
					&cached_state);
J
Josef Bacik 已提交
6060
	if (ret) {
6061 6062
		unlock_extent_cached(io_tree, page_start, page_end,
				     &cached_state, GFP_NOFS);
J
Josef Bacik 已提交
6063 6064 6065
		ret = VM_FAULT_SIGBUS;
		goto out_unlock;
	}
6066
	ret = 0;
C
Chris Mason 已提交
6067 6068

	/* page is wholly or partially inside EOF */
6069
	if (page_start + PAGE_CACHE_SIZE > size)
6070
		zero_start = size & ~PAGE_CACHE_MASK;
C
Chris Mason 已提交
6071
	else
6072
		zero_start = PAGE_CACHE_SIZE;
C
Chris Mason 已提交
6073

6074 6075 6076 6077 6078 6079
	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);
	}
6080
	ClearPageChecked(page);
6081
	set_page_dirty(page);
6082
	SetPageUptodate(page);
6083

6084 6085 6086
	BTRFS_I(inode)->last_trans = root->fs_info->generation;
	BTRFS_I(inode)->last_sub_trans = BTRFS_I(inode)->root->log_transid;

6087
	unlock_extent_cached(io_tree, page_start, page_end, &cached_state, GFP_NOFS);
C
Chris Mason 已提交
6088 6089

out_unlock:
6090 6091
	if (!ret)
		return VM_FAULT_LOCKED;
C
Chris Mason 已提交
6092
	unlock_page(page);
6093
	btrfs_delalloc_release_space(inode, PAGE_CACHE_SIZE);
6094
out:
C
Chris Mason 已提交
6095 6096 6097
	return ret;
}

C
Chris Mason 已提交
6098 6099 6100 6101 6102
static void btrfs_truncate(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	int ret;
	struct btrfs_trans_handle *trans;
6103
	unsigned long nr;
6104
	u64 mask = root->sectorsize - 1;
C
Chris Mason 已提交
6105

6106 6107
	if (!S_ISREG(inode->i_mode)) {
		WARN_ON(1);
C
Chris Mason 已提交
6108
		return;
6109
	}
C
Chris Mason 已提交
6110

6111 6112 6113
	ret = btrfs_truncate_page(inode->i_mapping, inode->i_size);
	if (ret)
		return;
6114

C
Chris Mason 已提交
6115
	btrfs_wait_ordered_range(inode, inode->i_size & (~mask), (u64)-1);
6116
	btrfs_ordered_update_i_size(inode, inode->i_size, NULL);
C
Chris Mason 已提交
6117

6118 6119
	trans = btrfs_start_transaction(root, 0);
	BUG_ON(IS_ERR(trans));
6120
	btrfs_set_trans_block_group(trans, inode);
6121
	trans->block_rsv = root->orphan_block_rsv;
6122 6123 6124 6125 6126 6127 6128 6129 6130 6131 6132 6133 6134 6135 6136 6137 6138 6139 6140 6141 6142

	/*
	 * 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);

6143
	while (1) {
6144 6145 6146 6147 6148 6149 6150 6151 6152 6153 6154 6155 6156 6157 6158 6159 6160
		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;
		}

6161 6162 6163 6164 6165
		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
6166

6167 6168
		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);
6169

6170 6171
		nr = trans->blocks_used;
		btrfs_end_transaction(trans, root);
6172
		trans = NULL;
6173 6174 6175 6176 6177 6178 6179 6180 6181
		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);
6182 6183 6184
	BUG_ON(ret);

	nr = trans->blocks_used;
6185
	ret = btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
6186
	BUG_ON(ret);
6187
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
6188 6189
}

C
Chris Mason 已提交
6190 6191 6192
/*
 * create a new subvolume directory/inode (helper for the ioctl).
 */
6193
int btrfs_create_subvol_root(struct btrfs_trans_handle *trans,
6194
			     struct btrfs_root *new_root,
6195
			     u64 new_dirid, u64 alloc_hint)
C
Chris Mason 已提交
6196 6197
{
	struct inode *inode;
6198
	int err;
6199
	u64 index = 0;
C
Chris Mason 已提交
6200

6201
	inode = btrfs_new_inode(trans, new_root, NULL, "..", 2, new_dirid,
6202
				new_dirid, alloc_hint, S_IFDIR | 0700, &index);
6203
	if (IS_ERR(inode))
C
Christoph Hellwig 已提交
6204
		return PTR_ERR(inode);
C
Chris Mason 已提交
6205 6206 6207 6208
	inode->i_op = &btrfs_dir_inode_operations;
	inode->i_fop = &btrfs_dir_file_operations;

	inode->i_nlink = 1;
6209
	btrfs_i_size_write(inode, 0);
6210

6211 6212
	err = btrfs_update_inode(trans, new_root, inode);
	BUG_ON(err);
6213

6214
	iput(inode);
6215
	return 0;
C
Chris Mason 已提交
6216 6217
}

C
Chris Mason 已提交
6218 6219 6220
/* helper function for file defrag and space balancing.  This
 * forces readahead on a given range of bytes in an inode
 */
6221
unsigned long btrfs_force_ra(struct address_space *mapping,
6222 6223 6224
			      struct file_ra_state *ra, struct file *file,
			      pgoff_t offset, pgoff_t last_index)
{
6225
	pgoff_t req_size = last_index - offset + 1;
6226 6227 6228 6229 6230

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

C
Chris Mason 已提交
6231 6232 6233
struct inode *btrfs_alloc_inode(struct super_block *sb)
{
	struct btrfs_inode *ei;
Y
Yan, Zheng 已提交
6234
	struct inode *inode;
C
Chris Mason 已提交
6235 6236 6237 6238

	ei = kmem_cache_alloc(btrfs_inode_cachep, GFP_NOFS);
	if (!ei)
		return NULL;
Y
Yan, Zheng 已提交
6239 6240 6241 6242 6243

	ei->root = NULL;
	ei->space_info = NULL;
	ei->generation = 0;
	ei->sequence = 0;
6244
	ei->last_trans = 0;
6245
	ei->last_sub_trans = 0;
6246
	ei->logged_trans = 0;
Y
Yan, Zheng 已提交
6247 6248 6249 6250 6251 6252 6253
	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;

6254
	spin_lock_init(&ei->accounting_lock);
6255
	atomic_set(&ei->outstanding_extents, 0);
6256
	ei->reserved_extents = 0;
Y
Yan, Zheng 已提交
6257 6258

	ei->ordered_data_close = 0;
6259
	ei->orphan_meta_reserved = 0;
Y
Yan, Zheng 已提交
6260 6261 6262 6263 6264 6265 6266 6267
	ei->dummy_inode = 0;
	ei->force_compress = 0;

	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);
6268
	btrfs_ordered_inode_tree_init(&ei->ordered_tree);
6269
	INIT_LIST_HEAD(&ei->i_orphan);
Y
Yan, Zheng 已提交
6270
	INIT_LIST_HEAD(&ei->delalloc_inodes);
6271
	INIT_LIST_HEAD(&ei->ordered_operations);
Y
Yan, Zheng 已提交
6272 6273 6274
	RB_CLEAR_NODE(&ei->rb_node);

	return inode;
C
Chris Mason 已提交
6275 6276 6277 6278
}

void btrfs_destroy_inode(struct inode *inode)
{
6279
	struct btrfs_ordered_extent *ordered;
6280 6281
	struct btrfs_root *root = BTRFS_I(inode)->root;

C
Chris Mason 已提交
6282 6283
	WARN_ON(!list_empty(&inode->i_dentry));
	WARN_ON(inode->i_data.nrpages);
6284 6285
	WARN_ON(atomic_read(&BTRFS_I(inode)->outstanding_extents));
	WARN_ON(BTRFS_I(inode)->reserved_extents);
C
Chris Mason 已提交
6286

6287 6288 6289 6290 6291 6292 6293 6294
	/*
	 * 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;

6295 6296 6297 6298 6299 6300 6301 6302 6303 6304 6305
	/*
	 * 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);
	}

6306
	spin_lock(&root->orphan_lock);
6307
	if (!list_empty(&BTRFS_I(inode)->i_orphan)) {
6308 6309 6310
		printk(KERN_INFO "BTRFS: inode %lu still on the orphan list\n",
		       inode->i_ino);
		list_del_init(&BTRFS_I(inode)->i_orphan);
6311
	}
6312
	spin_unlock(&root->orphan_lock);
6313

C
Chris Mason 已提交
6314
	while (1) {
6315 6316 6317 6318
		ordered = btrfs_lookup_first_ordered_extent(inode, (u64)-1);
		if (!ordered)
			break;
		else {
C
Chris Mason 已提交
6319 6320 6321 6322
			printk(KERN_ERR "btrfs found ordered "
			       "extent %llu %llu on inode cleanup\n",
			       (unsigned long long)ordered->file_offset,
			       (unsigned long long)ordered->len);
6323 6324 6325 6326 6327
			btrfs_remove_ordered_extent(inode, ordered);
			btrfs_put_ordered_extent(ordered);
			btrfs_put_ordered_extent(ordered);
		}
	}
6328
	inode_tree_del(inode);
6329
	btrfs_drop_extent_cache(inode, 0, (u64)-1, 0);
6330
free:
C
Chris Mason 已提交
6331 6332 6333
	kmem_cache_free(btrfs_inode_cachep, BTRFS_I(inode));
}

6334 6335 6336 6337 6338 6339 6340 6341 6342
void btrfs_drop_inode(struct inode *inode)
{
	struct btrfs_root *root = BTRFS_I(inode)->root;
	if (inode->i_nlink > 0 && btrfs_root_refs(&root->root_item) == 0)
		generic_delete_inode(inode);
	else
		generic_drop_inode(inode);
}

6343
static void init_once(void *foo)
C
Chris Mason 已提交
6344 6345 6346 6347 6348 6349 6350 6351 6352 6353 6354 6355 6356 6357 6358 6359 6360 6361 6362 6363
{
	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)
{
6364 6365 6366
	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
6367 6368
	if (!btrfs_inode_cachep)
		goto fail;
6369 6370 6371 6372

	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
6373 6374
	if (!btrfs_trans_handle_cachep)
		goto fail;
6375 6376 6377 6378

	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
6379 6380
	if (!btrfs_transaction_cachep)
		goto fail;
6381 6382 6383 6384

	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
6385 6386
	if (!btrfs_path_cachep)
		goto fail;
6387

C
Chris Mason 已提交
6388 6389 6390 6391 6392 6393 6394 6395 6396 6397 6398
	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);
6399
	stat->dev = BTRFS_I(inode)->root->anon_super.s_dev;
C
Chris Mason 已提交
6400
	stat->blksize = PAGE_CACHE_SIZE;
6401 6402
	stat->blocks = (inode_get_bytes(inode) +
			BTRFS_I(inode)->delalloc_bytes) >> 9;
C
Chris Mason 已提交
6403 6404 6405
	return 0;
}

C
Chris Mason 已提交
6406 6407
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
6408 6409 6410
{
	struct btrfs_trans_handle *trans;
	struct btrfs_root *root = BTRFS_I(old_dir)->root;
6411
	struct btrfs_root *dest = BTRFS_I(new_dir)->root;
C
Chris Mason 已提交
6412 6413 6414
	struct inode *new_inode = new_dentry->d_inode;
	struct inode *old_inode = old_dentry->d_inode;
	struct timespec ctime = CURRENT_TIME;
6415
	u64 index = 0;
6416
	u64 root_objectid;
C
Chris Mason 已提交
6417 6418
	int ret;

6419 6420 6421
	if (new_dir->i_ino == BTRFS_EMPTY_SUBVOL_DIR_OBJECTID)
		return -EPERM;

6422 6423
	/* we only allow rename subvolume link between subvolumes */
	if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID && root != dest)
6424 6425
		return -EXDEV;

6426 6427
	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
6428
		return -ENOTEMPTY;
6429

6430 6431 6432
	if (S_ISDIR(old_inode->i_mode) && new_inode &&
	    new_inode->i_size > BTRFS_EMPTY_DIR_SIZE)
		return -ENOTEMPTY;
6433 6434 6435 6436 6437
	/*
	 * 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
	 */
6438
	if (new_inode && S_ISREG(old_inode->i_mode) && new_inode->i_size &&
6439 6440 6441
	    old_inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
		filemap_flush(old_inode->i_mapping);

6442 6443 6444
	/* 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);
6445 6446 6447 6448 6449 6450 6451 6452 6453 6454 6455
	/*
	 * 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);
6456

6457
	btrfs_set_trans_block_group(trans, new_dir);
6458

6459 6460
	if (dest != root)
		btrfs_record_root_in_trans(trans, dest);
6461

6462 6463 6464
	ret = btrfs_set_inode_index(new_dir, &index);
	if (ret)
		goto out_fail;
6465

6466
	if (unlikely(old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)) {
6467 6468 6469
		/* force full log commit if subvolume involved. */
		root->fs_info->last_trans_log_full_commit = trans->transid;
	} else {
6470 6471 6472 6473 6474 6475 6476
		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;
6477 6478 6479 6480 6481 6482 6483 6484 6485
		/*
		 * 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);
	}
6486 6487 6488 6489 6490 6491 6492 6493 6494
	/*
	 * 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
6495 6496 6497
	old_dir->i_ctime = old_dir->i_mtime = ctime;
	new_dir->i_ctime = new_dir->i_mtime = ctime;
	old_inode->i_ctime = ctime;
6498

6499 6500 6501
	if (old_dentry->d_parent != new_dentry->d_parent)
		btrfs_record_unlink_dir(trans, old_dir, old_inode, 1);

6502 6503 6504 6505 6506 6507 6508 6509 6510 6511 6512 6513 6514
	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
6515 6516 6517

	if (new_inode) {
		new_inode->i_ctime = CURRENT_TIME;
6518 6519 6520 6521 6522 6523 6524 6525 6526 6527 6528 6529 6530 6531 6532
		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);
6533
		if (new_inode->i_nlink == 0) {
6534
			ret = btrfs_orphan_add(trans, new_dentry->d_inode);
6535
			BUG_ON(ret);
6536
		}
C
Chris Mason 已提交
6537
	}
6538

6539 6540
	ret = btrfs_add_link(trans, new_dir, old_inode,
			     new_dentry->d_name.name,
6541
			     new_dentry->d_name.len, 0, index);
6542
	BUG_ON(ret);
C
Chris Mason 已提交
6543

6544 6545 6546 6547 6548
	if (old_inode->i_ino != BTRFS_FIRST_FREE_OBJECTID) {
		btrfs_log_new_name(trans, old_inode, old_dir,
				   new_dentry->d_parent);
		btrfs_end_log_trans(root);
	}
C
Chris Mason 已提交
6549
out_fail:
6550
	btrfs_end_transaction_throttle(trans, root);
6551

6552 6553
	if (old_inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
		up_read(&root->fs_info->subvol_sem);
J
Josef Bacik 已提交
6554

C
Chris Mason 已提交
6555 6556 6557
	return ret;
}

C
Chris Mason 已提交
6558 6559 6560 6561
/*
 * 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
6562
int btrfs_start_delalloc_inodes(struct btrfs_root *root, int delay_iput)
6563 6564 6565
{
	struct list_head *head = &root->fs_info->delalloc_inodes;
	struct btrfs_inode *binode;
6566
	struct inode *inode;
6567

Y
Yan Zheng 已提交
6568 6569 6570
	if (root->fs_info->sb->s_flags & MS_RDONLY)
		return -EROFS;

6571
	spin_lock(&root->fs_info->delalloc_lock);
C
Chris Mason 已提交
6572
	while (!list_empty(head)) {
6573 6574
		binode = list_entry(head->next, struct btrfs_inode,
				    delalloc_inodes);
6575 6576 6577
		inode = igrab(&binode->vfs_inode);
		if (!inode)
			list_del_init(&binode->delalloc_inodes);
6578
		spin_unlock(&root->fs_info->delalloc_lock);
6579
		if (inode) {
6580
			filemap_flush(inode->i_mapping);
Y
Yan, Zheng 已提交
6581 6582 6583 6584
			if (delay_iput)
				btrfs_add_delayed_iput(inode);
			else
				iput(inode);
6585 6586
		}
		cond_resched();
6587
		spin_lock(&root->fs_info->delalloc_lock);
6588
	}
6589
	spin_unlock(&root->fs_info->delalloc_lock);
6590 6591 6592 6593 6594 6595

	/* 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
6596
	while (atomic_read(&root->fs_info->nr_async_submits) ||
6597
	      atomic_read(&root->fs_info->async_delalloc_pages)) {
6598
		wait_event(root->fs_info->async_submit_wait,
6599 6600
		   (atomic_read(&root->fs_info->nr_async_submits) == 0 &&
		    atomic_read(&root->fs_info->async_delalloc_pages) == 0));
6601 6602
	}
	atomic_dec(&root->fs_info->async_submit_draining);
6603 6604 6605
	return 0;
}

6606 6607 6608 6609 6610 6611 6612 6613 6614 6615 6616 6617 6618 6619 6620 6621 6622 6623 6624 6625 6626 6627 6628 6629 6630 6631 6632 6633 6634 6635 6636 6637
int btrfs_start_one_delalloc_inode(struct btrfs_root *root, int delay_iput)
{
	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) {
		write_inode_now(inode, 0);
		if (delay_iput)
			btrfs_add_delayed_iput(inode);
		else
			iput(inode);
		return 1;
	}
	return 0;
}

C
Chris Mason 已提交
6638 6639 6640 6641 6642 6643 6644
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;
6645
	struct inode *inode = NULL;
C
Chris Mason 已提交
6646 6647 6648
	int err;
	int drop_inode = 0;
	u64 objectid;
6649
	u64 index = 0 ;
C
Chris Mason 已提交
6650 6651
	int name_len;
	int datasize;
6652
	unsigned long ptr;
C
Chris Mason 已提交
6653
	struct btrfs_file_extent_item *ei;
6654
	struct extent_buffer *leaf;
6655
	unsigned long nr = 0;
C
Chris Mason 已提交
6656 6657 6658 6659

	name_len = strlen(symname) + 1;
	if (name_len > BTRFS_MAX_INLINE_DATA_SIZE(root))
		return -ENAMETOOLONG;
6660

6661 6662 6663
	err = btrfs_find_free_objectid(NULL, root, dir->i_ino, &objectid);
	if (err)
		return err;
J
Josef Bacik 已提交
6664 6665 6666 6667 6668
	/*
	 * 2 items for inode item and ref
	 * 2 items for dir items
	 * 1 item for xattr if selinux is on
	 */
6669 6670 6671
	trans = btrfs_start_transaction(root, 5);
	if (IS_ERR(trans))
		return PTR_ERR(trans);
6672

C
Chris Mason 已提交
6673 6674
	btrfs_set_trans_block_group(trans, dir);

6675
	inode = btrfs_new_inode(trans, root, dir, dentry->d_name.name,
6676 6677
				dentry->d_name.len,
				dentry->d_parent->d_inode->i_ino, objectid,
6678 6679
				BTRFS_I(dir)->block_group, S_IFLNK|S_IRWXUGO,
				&index);
C
Chris Mason 已提交
6680 6681 6682 6683
	err = PTR_ERR(inode);
	if (IS_ERR(inode))
		goto out_unlock;

6684
	err = btrfs_init_inode_security(trans, inode, dir);
J
Josef Bacik 已提交
6685 6686 6687 6688 6689
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}

C
Chris Mason 已提交
6690
	btrfs_set_trans_block_group(trans, inode);
6691
	err = btrfs_add_nondir(trans, dentry, inode, 0, index);
C
Chris Mason 已提交
6692 6693 6694 6695
	if (err)
		drop_inode = 1;
	else {
		inode->i_mapping->a_ops = &btrfs_aops;
C
Chris Mason 已提交
6696
		inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
C
Chris Mason 已提交
6697 6698
		inode->i_fop = &btrfs_file_operations;
		inode->i_op = &btrfs_file_inode_operations;
6699
		BTRFS_I(inode)->io_tree.ops = &btrfs_extent_io_ops;
C
Chris Mason 已提交
6700 6701 6702 6703 6704 6705 6706 6707 6708 6709 6710 6711 6712 6713
	}
	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);
6714 6715 6716 6717
	if (err) {
		drop_inode = 1;
		goto out_unlock;
	}
6718 6719 6720 6721 6722
	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
6723
				   BTRFS_FILE_EXTENT_INLINE);
C
Chris Mason 已提交
6724 6725 6726 6727 6728
	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
6729
	ptr = btrfs_file_extent_inline_start(ei);
6730 6731
	write_extent_buffer(leaf, symname, ptr, name_len);
	btrfs_mark_buffer_dirty(leaf);
C
Chris Mason 已提交
6732
	btrfs_free_path(path);
6733

C
Chris Mason 已提交
6734 6735
	inode->i_op = &btrfs_symlink_inode_operations;
	inode->i_mapping->a_ops = &btrfs_symlink_aops;
C
Chris Mason 已提交
6736
	inode->i_mapping->backing_dev_info = &root->fs_info->bdi;
Y
Yan Zheng 已提交
6737
	inode_set_bytes(inode, name_len);
6738
	btrfs_i_size_write(inode, name_len - 1);
6739 6740 6741
	err = btrfs_update_inode(trans, root, inode);
	if (err)
		drop_inode = 1;
C
Chris Mason 已提交
6742 6743

out_unlock:
6744
	nr = trans->blocks_used;
6745
	btrfs_end_transaction_throttle(trans, root);
C
Chris Mason 已提交
6746 6747 6748 6749
	if (drop_inode) {
		inode_dec_link_count(inode);
		iput(inode);
	}
6750
	btrfs_btree_balance_dirty(root, nr);
C
Chris Mason 已提交
6751 6752
	return err;
}
6753

6754 6755 6756
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)
Y
Yan Zheng 已提交
6757
{
6758
	struct btrfs_trans_handle *trans;
Y
Yan Zheng 已提交
6759 6760 6761 6762 6763 6764
	struct btrfs_root *root = BTRFS_I(inode)->root;
	struct btrfs_key ins;
	u64 cur_offset = start;
	int ret = 0;

	while (num_bytes > 0) {
6765 6766 6767 6768
		trans = btrfs_start_transaction(root, 3);
		if (IS_ERR(trans)) {
			ret = PTR_ERR(trans);
			break;
6769 6770
		}

6771 6772
		ret = btrfs_reserve_extent(trans, root, num_bytes, min_size,
					   0, *alloc_hint, (u64)-1, &ins, 1);
6773
		if (ret) {
6774 6775
			btrfs_end_transaction(trans, root);
			break;
Y
Yan Zheng 已提交
6776
		}
6777

Y
Yan Zheng 已提交
6778 6779 6780
		ret = insert_reserved_file_extent(trans, inode,
						  cur_offset, ins.objectid,
						  ins.offset, ins.offset,
Y
Yan, Zheng 已提交
6781
						  ins.offset, 0, 0, 0,
Y
Yan Zheng 已提交
6782 6783
						  BTRFS_FILE_EXTENT_PREALLOC);
		BUG_ON(ret);
C
Chris Mason 已提交
6784 6785
		btrfs_drop_extent_cache(inode, cur_offset,
					cur_offset + ins.offset -1, 0);
6786

Y
Yan Zheng 已提交
6787 6788
		num_bytes -= ins.offset;
		cur_offset += ins.offset;
6789
		*alloc_hint = ins.objectid + ins.offset;
6790

Y
Yan Zheng 已提交
6791
		inode->i_ctime = CURRENT_TIME;
6792
		BTRFS_I(inode)->flags |= BTRFS_INODE_PREALLOC;
Y
Yan Zheng 已提交
6793
		if (!(mode & FALLOC_FL_KEEP_SIZE) &&
6794 6795
		    (actual_len > inode->i_size) &&
		    (cur_offset > inode->i_size)) {
6796
			if (cur_offset > actual_len)
6797
				i_size_write(inode, actual_len);
6798
			else
6799 6800 6801
				i_size_write(inode, cur_offset);
			i_size_write(inode, cur_offset);
			btrfs_ordered_update_i_size(inode, cur_offset, NULL);
6802 6803
		}

Y
Yan Zheng 已提交
6804 6805 6806
		ret = btrfs_update_inode(trans, root, inode);
		BUG_ON(ret);

6807 6808
		btrfs_end_transaction(trans, root);
	}
Y
Yan Zheng 已提交
6809 6810 6811 6812 6813 6814
	return ret;
}

static long btrfs_fallocate(struct inode *inode, int mode,
			    loff_t offset, loff_t len)
{
6815
	struct extent_state *cached_state = NULL;
Y
Yan Zheng 已提交
6816 6817 6818 6819 6820
	u64 cur_offset;
	u64 last_byte;
	u64 alloc_start;
	u64 alloc_end;
	u64 alloc_hint = 0;
6821
	u64 locked_end;
Y
Yan Zheng 已提交
6822 6823 6824 6825 6826 6827 6828
	u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
	struct extent_map *em;
	int ret;

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

6829 6830 6831 6832 6833 6834
	/*
	 * 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
6835 6836 6837 6838 6839 6840 6841
	mutex_lock(&inode->i_mutex);
	if (alloc_start > inode->i_size) {
		ret = btrfs_cont_expand(inode, alloc_start);
		if (ret)
			goto out;
	}

6842
	ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
6843 6844 6845
	if (ret)
		goto out;

6846
	locked_end = alloc_end - 1;
Y
Yan Zheng 已提交
6847 6848
	while (1) {
		struct btrfs_ordered_extent *ordered;
6849 6850 6851 6852

		/* the extent lock is ordered inside the running
		 * transaction
		 */
6853 6854
		lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
				 locked_end, 0, &cached_state, GFP_NOFS);
Y
Yan Zheng 已提交
6855 6856 6857 6858 6859 6860
		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);
6861 6862 6863
			unlock_extent_cached(&BTRFS_I(inode)->io_tree,
					     alloc_start, locked_end,
					     &cached_state, GFP_NOFS);
6864 6865 6866 6867
			/*
			 * we can't wait on the range with the transaction
			 * running or with the extent lock held
			 */
Y
Yan Zheng 已提交
6868 6869 6870 6871 6872 6873 6874 6875 6876 6877 6878 6879 6880 6881 6882 6883
			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;
6884 6885 6886
		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
6887
			ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
6888 6889 6890 6891
							last_byte - cur_offset,
							1 << inode->i_blkbits,
							offset + len,
							&alloc_hint);
Y
Yan Zheng 已提交
6892 6893 6894 6895 6896 6897 6898 6899 6900 6901 6902 6903 6904
			if (ret < 0) {
				free_extent_map(em);
				break;
			}
		}
		free_extent_map(em);

		cur_offset = last_byte;
		if (cur_offset >= alloc_end) {
			ret = 0;
			break;
		}
	}
6905 6906
	unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
			     &cached_state, GFP_NOFS);
6907

6908
	btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
Y
Yan Zheng 已提交
6909 6910 6911 6912 6913
out:
	mutex_unlock(&inode->i_mutex);
	return ret;
}

6914 6915 6916 6917 6918
static int btrfs_set_page_dirty(struct page *page)
{
	return __set_page_dirty_nobuffers(page);
}

6919
static int btrfs_permission(struct inode *inode, int mask)
Y
Yan 已提交
6920
{
6921
	if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
Y
Yan 已提交
6922
		return -EACCES;
J
Josef Bacik 已提交
6923
	return generic_permission(inode, mask, btrfs_check_acl);
Y
Yan 已提交
6924
}
C
Chris Mason 已提交
6925

6926
static const struct inode_operations btrfs_dir_inode_operations = {
6927
	.getattr	= btrfs_getattr,
C
Chris Mason 已提交
6928 6929 6930 6931 6932 6933 6934 6935 6936
	.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
6937
	.mknod		= btrfs_mknod,
6938 6939
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
6940
	.listxattr	= btrfs_listxattr,
6941
	.removexattr	= btrfs_removexattr,
Y
Yan 已提交
6942
	.permission	= btrfs_permission,
C
Chris Mason 已提交
6943
};
6944
static const struct inode_operations btrfs_dir_ro_inode_operations = {
C
Chris Mason 已提交
6945
	.lookup		= btrfs_lookup,
Y
Yan 已提交
6946
	.permission	= btrfs_permission,
C
Chris Mason 已提交
6947
};
6948

6949
static const struct file_operations btrfs_dir_file_operations = {
C
Chris Mason 已提交
6950 6951
	.llseek		= generic_file_llseek,
	.read		= generic_read_dir,
6952
	.readdir	= btrfs_real_readdir,
C
Christoph Hellwig 已提交
6953
	.unlocked_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
6954
#ifdef CONFIG_COMPAT
C
Christoph Hellwig 已提交
6955
	.compat_ioctl	= btrfs_ioctl,
C
Chris Mason 已提交
6956
#endif
S
Sage Weil 已提交
6957
	.release        = btrfs_release_file,
6958
	.fsync		= btrfs_sync_file,
C
Chris Mason 已提交
6959 6960
};

6961
static struct extent_io_ops btrfs_extent_io_ops = {
6962
	.fill_delalloc = run_delalloc_range,
6963
	.submit_bio_hook = btrfs_submit_bio_hook,
6964
	.merge_bio_hook = btrfs_merge_bio_hook,
6965
	.readpage_end_io_hook = btrfs_readpage_end_io_hook,
6966
	.writepage_end_io_hook = btrfs_writepage_end_io_hook,
6967
	.writepage_start_hook = btrfs_writepage_start_hook,
6968
	.readpage_io_failed_hook = btrfs_io_failed_hook,
C
Chris Mason 已提交
6969 6970
	.set_bit_hook = btrfs_set_bit_hook,
	.clear_bit_hook = btrfs_clear_bit_hook,
J
Josef Bacik 已提交
6971 6972
	.merge_extent_hook = btrfs_merge_extent_hook,
	.split_extent_hook = btrfs_split_extent_hook,
6973 6974
};

6975 6976 6977 6978 6979 6980 6981 6982 6983 6984 6985 6986
/*
 * 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.
 */
6987
static const struct address_space_operations btrfs_aops = {
C
Chris Mason 已提交
6988 6989
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
6990
	.writepages	= btrfs_writepages,
C
Chris Mason 已提交
6991
	.readpages	= btrfs_readpages,
C
Chris Mason 已提交
6992
	.sync_page	= block_sync_page,
6993
	.direct_IO	= btrfs_direct_IO,
6994 6995
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
6996
	.set_page_dirty	= btrfs_set_page_dirty,
6997
	.error_remove_page = generic_error_remove_page,
C
Chris Mason 已提交
6998 6999
};

7000
static const struct address_space_operations btrfs_symlink_aops = {
C
Chris Mason 已提交
7001 7002
	.readpage	= btrfs_readpage,
	.writepage	= btrfs_writepage,
C
Chris Mason 已提交
7003 7004
	.invalidatepage = btrfs_invalidatepage,
	.releasepage	= btrfs_releasepage,
C
Chris Mason 已提交
7005 7006
};

7007
static const struct inode_operations btrfs_file_inode_operations = {
C
Chris Mason 已提交
7008 7009 7010
	.truncate	= btrfs_truncate,
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
7011 7012
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
7013
	.listxattr      = btrfs_listxattr,
7014
	.removexattr	= btrfs_removexattr,
Y
Yan 已提交
7015
	.permission	= btrfs_permission,
Y
Yan Zheng 已提交
7016
	.fallocate	= btrfs_fallocate,
Y
Yehuda Sadeh 已提交
7017
	.fiemap		= btrfs_fiemap,
C
Chris Mason 已提交
7018
};
7019
static const struct inode_operations btrfs_special_inode_operations = {
J
Josef Bacik 已提交
7020 7021
	.getattr	= btrfs_getattr,
	.setattr	= btrfs_setattr,
Y
Yan 已提交
7022
	.permission	= btrfs_permission,
7023 7024
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
J
Josef Bacik 已提交
7025
	.listxattr	= btrfs_listxattr,
7026
	.removexattr	= btrfs_removexattr,
J
Josef Bacik 已提交
7027
};
7028
static const struct inode_operations btrfs_symlink_inode_operations = {
C
Chris Mason 已提交
7029 7030 7031
	.readlink	= generic_readlink,
	.follow_link	= page_follow_link_light,
	.put_link	= page_put_link,
Y
Yan 已提交
7032
	.permission	= btrfs_permission,
J
Jim Owens 已提交
7033 7034 7035 7036
	.setxattr	= btrfs_setxattr,
	.getxattr	= btrfs_getxattr,
	.listxattr	= btrfs_listxattr,
	.removexattr	= btrfs_removexattr,
C
Chris Mason 已提交
7037
};
7038

7039
const struct dentry_operations btrfs_dentry_operations = {
7040 7041
	.d_delete	= btrfs_dentry_delete,
};