inode.c 176.5 KB
Newer Older
1
// SPDX-License-Identifier: GPL-2.0
2
/*
3
 *  linux/fs/ext4/inode.c
4 5 6 7 8 9 10 11 12 13 14 15 16 17 18
 *
 * Copyright (C) 1992, 1993, 1994, 1995
 * Remy Card (card@masi.ibp.fr)
 * Laboratoire MASI - Institut Blaise Pascal
 * Universite Pierre et Marie Curie (Paris VI)
 *
 *  from
 *
 *  linux/fs/minix/inode.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *
 *  64-bit file support on 64-bit platforms by Jakub Jelinek
 *	(jj@sunsite.ms.mff.cuni.cz)
 *
19
 *  Assorted race fixes, rewrite of ext4_get_block() by Al Viro, 2000
20 21 22 23 24 25
 */

#include <linux/fs.h>
#include <linux/time.h>
#include <linux/highuid.h>
#include <linux/pagemap.h>
26
#include <linux/dax.h>
27 28 29 30
#include <linux/quotaops.h>
#include <linux/string.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
31
#include <linux/pagevec.h>
32
#include <linux/mpage.h>
33
#include <linux/namei.h>
34 35
#include <linux/uio.h>
#include <linux/bio.h>
36
#include <linux/workqueue.h>
37
#include <linux/kernel.h>
38
#include <linux/printk.h>
39
#include <linux/slab.h>
40
#include <linux/bitops.h>
41
#include <linux/iomap.h>
42
#include <linux/iversion.h>
43

44
#include "ext4_jbd2.h"
45 46
#include "xattr.h"
#include "acl.h"
47
#include "truncate.h"
48

49 50
#include <trace/events/ext4.h>

51 52
#define MPAGE_DA_EXTENT_TAIL 0x01

53 54 55 56 57
static __u32 ext4_inode_csum(struct inode *inode, struct ext4_inode *raw,
			      struct ext4_inode_info *ei)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
	__u32 csum;
58 59 60
	__u16 dummy_csum = 0;
	int offset = offsetof(struct ext4_inode, i_checksum_lo);
	unsigned int csum_size = sizeof(dummy_csum);
61

62 63 64 65 66
	csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)raw, offset);
	csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum, csum_size);
	offset += csum_size;
	csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
			   EXT4_GOOD_OLD_INODE_SIZE - offset);
67

68 69 70 71 72 73 74 75 76 77
	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
		offset = offsetof(struct ext4_inode, i_checksum_hi);
		csum = ext4_chksum(sbi, csum, (__u8 *)raw +
				   EXT4_GOOD_OLD_INODE_SIZE,
				   offset - EXT4_GOOD_OLD_INODE_SIZE);
		if (EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi)) {
			csum = ext4_chksum(sbi, csum, (__u8 *)&dummy_csum,
					   csum_size);
			offset += csum_size;
		}
78 79
		csum = ext4_chksum(sbi, csum, (__u8 *)raw + offset,
				   EXT4_INODE_SIZE(inode->i_sb) - offset);
80 81 82 83 84 85 86 87 88 89 90 91
	}

	return csum;
}

static int ext4_inode_csum_verify(struct inode *inode, struct ext4_inode *raw,
				  struct ext4_inode_info *ei)
{
	__u32 provided, calculated;

	if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
	    cpu_to_le32(EXT4_OS_LINUX) ||
92
	    !ext4_has_metadata_csum(inode->i_sb))
93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112
		return 1;

	provided = le16_to_cpu(raw->i_checksum_lo);
	calculated = ext4_inode_csum(inode, raw, ei);
	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
		provided |= ((__u32)le16_to_cpu(raw->i_checksum_hi)) << 16;
	else
		calculated &= 0xFFFF;

	return provided == calculated;
}

static void ext4_inode_csum_set(struct inode *inode, struct ext4_inode *raw,
				struct ext4_inode_info *ei)
{
	__u32 csum;

	if (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
	    cpu_to_le32(EXT4_OS_LINUX) ||
113
	    !ext4_has_metadata_csum(inode->i_sb))
114 115 116 117 118 119 120 121 122
		return;

	csum = ext4_inode_csum(inode, raw, ei);
	raw->i_checksum_lo = cpu_to_le16(csum & 0xFFFF);
	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
	    EXT4_FITS_IN_INODE(raw, ei, i_checksum_hi))
		raw->i_checksum_hi = cpu_to_le16(csum >> 16);
}

123 124 125
static inline int ext4_begin_ordered_truncate(struct inode *inode,
					      loff_t new_size)
{
126
	trace_ext4_begin_ordered_truncate(inode, new_size);
127 128 129 130 131 132 133 134 135 136 137
	/*
	 * If jinode is zero, then we never opened the file for
	 * writing, so there's no need to call
	 * jbd2_journal_begin_ordered_truncate() since there's no
	 * outstanding writes we need to flush.
	 */
	if (!EXT4_I(inode)->jinode)
		return 0;
	return jbd2_journal_begin_ordered_truncate(EXT4_JOURNAL(inode),
						   EXT4_I(inode)->jinode,
						   new_size);
138 139
}

140 141
static void ext4_invalidatepage(struct page *page, unsigned int offset,
				unsigned int length);
142 143
static int __ext4_journalled_writepage(struct page *page, unsigned int len);
static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh);
T
Tahsin Erdogan 已提交
144 145
static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
				  int pextents);
146

147 148
/*
 * Test whether an inode is a fast symlink.
149
 * A fast symlink has its symlink data stored in ext4_inode_info->i_data.
150
 */
151
int ext4_inode_is_fast_symlink(struct inode *inode)
152
{
153 154
	return S_ISLNK(inode->i_mode) && inode->i_size &&
	       (inode->i_size < EXT4_N_BLOCKS * 4);
155 156 157 158 159 160 161
}

/*
 * Restart the transaction associated with *handle.  This does a commit,
 * so before we call here everything must be consistently dirtied against
 * this transaction.
 */
162
int ext4_truncate_restart_trans(handle_t *handle, struct inode *inode,
163
				 int nblocks)
164
{
165 166 167
	int ret;

	/*
168
	 * Drop i_data_sem to avoid deadlock with ext4_map_blocks.  At this
169 170 171 172
	 * moment, get_block can be called only for blocks inside i_size since
	 * page cache has been already dropped and writes are blocked by
	 * i_mutex. So we can safely drop the i_data_sem here.
	 */
173
	BUG_ON(EXT4_JOURNAL(inode) == NULL);
174
	jbd_debug(2, "restarting handle %p\n", handle);
175
	up_write(&EXT4_I(inode)->i_data_sem);
176
	ret = ext4_journal_restart(handle, nblocks);
177
	down_write(&EXT4_I(inode)->i_data_sem);
178
	ext4_discard_preallocations(inode);
179 180

	return ret;
181 182 183 184 185
}

/*
 * Called at the last iput() if i_nlink is zero.
 */
A
Al Viro 已提交
186
void ext4_evict_inode(struct inode *inode)
187 188
{
	handle_t *handle;
189
	int err;
A
Andreas Dilger 已提交
190
	int extra_credits = 3;
191
	struct ext4_xattr_inode_array *ea_inode_array = NULL;
192

193
	trace_ext4_evict_inode(inode);
194

A
Al Viro 已提交
195
	if (inode->i_nlink) {
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213
		/*
		 * When journalling data dirty buffers are tracked only in the
		 * journal. So although mm thinks everything is clean and
		 * ready for reaping the inode might still have some pages to
		 * write in the running transaction or waiting to be
		 * checkpointed. Thus calling jbd2_journal_invalidatepage()
		 * (via truncate_inode_pages()) to discard these buffers can
		 * cause data loss. Also even if we did not discard these
		 * buffers, we would have no way to find them after the inode
		 * is reaped and thus user could see stale data if he tries to
		 * read them before the transaction is checkpointed. So be
		 * careful and force everything to disk here... We use
		 * ei->i_datasync_tid to store the newest transaction
		 * containing inode's data.
		 *
		 * Note that directories do not have this problem because they
		 * don't use page cache.
		 */
214 215
		if (inode->i_ino != EXT4_JOURNAL_INO &&
		    ext4_should_journal_data(inode) &&
216 217
		    (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
		    inode->i_data.nrpages) {
218 219 220
			journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
			tid_t commit_tid = EXT4_I(inode)->i_datasync_tid;

221
			jbd2_complete_transaction(journal, commit_tid);
222 223
			filemap_write_and_wait(&inode->i_data);
		}
224
		truncate_inode_pages_final(&inode->i_data);
J
Jan Kara 已提交
225

A
Al Viro 已提交
226 227 228
		goto no_delete;
	}

229 230 231
	if (is_bad_inode(inode))
		goto no_delete;
	dquot_initialize(inode);
232

233 234
	if (ext4_should_order_data(inode))
		ext4_begin_ordered_truncate(inode, 0);
235
	truncate_inode_pages_final(&inode->i_data);
236

237 238 239 240 241
	/*
	 * Protect us against freezing - iput() caller didn't have to have any
	 * protection against it
	 */
	sb_start_intwrite(inode->i_sb);
A
Andreas Dilger 已提交
242

243 244 245 246 247
	if (!IS_NOQUOTA(inode))
		extra_credits += EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb);

	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE,
				 ext4_blocks_for_truncate(inode)+extra_credits);
248
	if (IS_ERR(handle)) {
249
		ext4_std_error(inode->i_sb, PTR_ERR(handle));
250 251 252 253 254
		/*
		 * If we're going to skip the normal cleanup, we still need to
		 * make sure that the in-core orphan linked list is properly
		 * cleaned up.
		 */
255
		ext4_orphan_del(NULL, inode);
256
		sb_end_intwrite(inode->i_sb);
257 258
		goto no_delete;
	}
259

260
	if (IS_SYNC(inode))
261
		ext4_handle_sync(handle);
262 263 264 265 266 267 268 269 270 271

	/*
	 * Set inode->i_size to 0 before calling ext4_truncate(). We need
	 * special handling of symlinks here because i_size is used to
	 * determine whether ext4_inode_info->i_data contains symlink data or
	 * block mappings. Setting i_size to 0 will remove its fast symlink
	 * status. Erase i_data so that it becomes a valid empty block map.
	 */
	if (ext4_inode_is_fast_symlink(inode))
		memset(EXT4_I(inode)->i_data, 0, sizeof(EXT4_I(inode)->i_data));
272
	inode->i_size = 0;
273 274
	err = ext4_mark_inode_dirty(handle, inode);
	if (err) {
275
		ext4_warning(inode->i_sb,
276 277 278
			     "couldn't mark inode dirty (err %d)", err);
		goto stop_handle;
	}
279 280 281 282 283 284 285 286 287
	if (inode->i_blocks) {
		err = ext4_truncate(inode);
		if (err) {
			ext4_error(inode->i_sb,
				   "couldn't truncate inode %lu (err %d)",
				   inode->i_ino, err);
			goto stop_handle;
		}
	}
288

289 290 291 292 293 294 295 296 297 298 299
	/* Remove xattr references. */
	err = ext4_xattr_delete_inode(handle, inode, &ea_inode_array,
				      extra_credits);
	if (err) {
		ext4_warning(inode->i_sb, "xattr delete (err %d)", err);
stop_handle:
		ext4_journal_stop(handle);
		ext4_orphan_del(NULL, inode);
		sb_end_intwrite(inode->i_sb);
		ext4_xattr_inode_array_free(ea_inode_array);
		goto no_delete;
300 301
	}

302
	/*
303
	 * Kill off the orphan record which ext4_truncate created.
304
	 * AKPM: I think this can be inside the above `if'.
305
	 * Note that ext4_orphan_del() has to be able to cope with the
306
	 * deletion of a non-existent orphan - this is because we don't
307
	 * know if ext4_truncate() actually created an orphan record.
308 309
	 * (Well, we could do this if we need to, but heck - it works)
	 */
310 311
	ext4_orphan_del(handle, inode);
	EXT4_I(inode)->i_dtime	= get_seconds();
312 313 314 315 316 317 318 319

	/*
	 * One subtle ordering requirement: if anything has gone wrong
	 * (transaction abort, IO errors, whatever), then we can still
	 * do these next steps (the fs will already have been marked as
	 * having errors), but we can't free the inode if the mark_dirty
	 * fails.
	 */
320
	if (ext4_mark_inode_dirty(handle, inode))
321
		/* If that failed, just do the required in-core inode clear. */
A
Al Viro 已提交
322
		ext4_clear_inode(inode);
323
	else
324 325
		ext4_free_inode(handle, inode);
	ext4_journal_stop(handle);
326
	sb_end_intwrite(inode->i_sb);
327
	ext4_xattr_inode_array_free(ea_inode_array);
328 329
	return;
no_delete:
A
Al Viro 已提交
330
	ext4_clear_inode(inode);	/* We must guarantee clearing of inode... */
331 332
}

333 334
#ifdef CONFIG_QUOTA
qsize_t *ext4_get_reserved_space(struct inode *inode)
335
{
336
	return &EXT4_I(inode)->i_reserved_quota;
337
}
338
#endif
339

340 341 342 343
/*
 * Called with i_data_sem down, which is important since we can call
 * ext4_discard_preallocations() from here.
 */
344 345
void ext4_da_update_reserve_space(struct inode *inode,
					int used, int quota_claim)
346 347
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
348 349 350
	struct ext4_inode_info *ei = EXT4_I(inode);

	spin_lock(&ei->i_block_reservation_lock);
351
	trace_ext4_da_update_reserve_space(inode, used, quota_claim);
352
	if (unlikely(used > ei->i_reserved_data_blocks)) {
353
		ext4_warning(inode->i_sb, "%s: ino %lu, used %d "
354
			 "with only %d reserved data blocks",
355 356 357 358 359
			 __func__, inode->i_ino, used,
			 ei->i_reserved_data_blocks);
		WARN_ON(1);
		used = ei->i_reserved_data_blocks;
	}
360

361 362
	/* Update per-inode reservations */
	ei->i_reserved_data_blocks -= used;
363
	percpu_counter_sub(&sbi->s_dirtyclusters_counter, used);
364

365
	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
366

367 368
	/* Update quota subsystem for data blocks */
	if (quota_claim)
369
		dquot_claim_block(inode, EXT4_C2B(sbi, used));
370
	else {
371 372 373
		/*
		 * We did fallocate with an offset that is already delayed
		 * allocated. So on delayed allocated writeback we should
374
		 * not re-claim the quota for fallocated blocks.
375
		 */
376
		dquot_release_reservation_block(inode, EXT4_C2B(sbi, used));
377
	}
378 379 380 381 382 383

	/*
	 * If we have done all the pending block allocations and if
	 * there aren't any writers on the inode, we can discard the
	 * inode's preallocations.
	 */
384 385
	if ((ei->i_reserved_data_blocks == 0) &&
	    (atomic_read(&inode->i_writecount) == 0))
386
		ext4_discard_preallocations(inode);
387 388
}

389
static int __check_block_validity(struct inode *inode, const char *func,
390 391
				unsigned int line,
				struct ext4_map_blocks *map)
392
{
393 394
	if (!ext4_data_block_valid(EXT4_SB(inode->i_sb), map->m_pblk,
				   map->m_len)) {
395 396 397 398
		ext4_error_inode(inode, func, line, map->m_pblk,
				 "lblock %lu mapped to illegal pblock "
				 "(length %d)", (unsigned long) map->m_lblk,
				 map->m_len);
399
		return -EFSCORRUPTED;
400 401 402 403
	}
	return 0;
}

J
Jan Kara 已提交
404 405 406 407 408 409
int ext4_issue_zeroout(struct inode *inode, ext4_lblk_t lblk, ext4_fsblk_t pblk,
		       ext4_lblk_t len)
{
	int ret;

	if (ext4_encrypted_inode(inode))
410
		return fscrypt_zeroout_range(inode, lblk, pblk, len);
J
Jan Kara 已提交
411 412 413 414 415 416 417 418

	ret = sb_issue_zeroout(inode->i_sb, pblk, len, GFP_NOFS);
	if (ret > 0)
		ret = 0;

	return ret;
}

419
#define check_block_validity(inode, map)	\
420
	__check_block_validity((inode), __func__, __LINE__, (map))
421

422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438
#ifdef ES_AGGRESSIVE_TEST
static void ext4_map_blocks_es_recheck(handle_t *handle,
				       struct inode *inode,
				       struct ext4_map_blocks *es_map,
				       struct ext4_map_blocks *map,
				       int flags)
{
	int retval;

	map->m_flags = 0;
	/*
	 * There is a race window that the result is not the same.
	 * e.g. xfstests #223 when dioread_nolock enables.  The reason
	 * is that we lookup a block mapping in extent status tree with
	 * out taking i_data_sem.  So at the time the unwritten extent
	 * could be converted.
	 */
439
	down_read(&EXT4_I(inode)->i_data_sem);
440 441 442 443 444 445 446
	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
		retval = ext4_ext_map_blocks(handle, inode, map, flags &
					     EXT4_GET_BLOCKS_KEEP_SIZE);
	} else {
		retval = ext4_ind_map_blocks(handle, inode, map, flags &
					     EXT4_GET_BLOCKS_KEEP_SIZE);
	}
447
	up_read((&EXT4_I(inode)->i_data_sem));
448 449 450 451 452 453 454 455

	/*
	 * We don't check m_len because extent will be collpased in status
	 * tree.  So the m_len might not equal.
	 */
	if (es_map->m_lblk != map->m_lblk ||
	    es_map->m_flags != map->m_flags ||
	    es_map->m_pblk != map->m_pblk) {
456
		printk("ES cache assertion failed for inode: %lu "
457 458 459 460 461 462 463 464 465 466
		       "es_cached ex [%d/%d/%llu/%x] != "
		       "found ex [%d/%d/%llu/%x] retval %d flags %x\n",
		       inode->i_ino, es_map->m_lblk, es_map->m_len,
		       es_map->m_pblk, es_map->m_flags, map->m_lblk,
		       map->m_len, map->m_pblk, map->m_flags,
		       retval, flags);
	}
}
#endif /* ES_AGGRESSIVE_TEST */

467
/*
468
 * The ext4_map_blocks() function tries to look up the requested blocks,
469
 * and returns if the blocks are already mapped.
470 471 472 473 474
 *
 * Otherwise it takes the write lock of the i_data_sem and allocate blocks
 * and store the allocated blocks in the result buffer head and mark it
 * mapped.
 *
475 476
 * If file type is extents based, it will call ext4_ext_map_blocks(),
 * Otherwise, call with ext4_ind_map_blocks() to handle indirect mapping
477 478
 * based files
 *
479 480 481
 * On success, it returns the number of blocks being mapped or allocated.  if
 * create==0 and the blocks are pre-allocated and unwritten, the resulting @map
 * is marked as unwritten. If the create == 1, it will mark @map as mapped.
482 483
 *
 * It returns 0 if plain look up failed (blocks have not been allocated), in
484 485
 * that case, @map is returned as unmapped but we still do fill map->m_len to
 * indicate the length of a hole starting at map->m_lblk.
486 487 488
 *
 * It returns the error in case of allocation failure.
 */
489 490
int ext4_map_blocks(handle_t *handle, struct inode *inode,
		    struct ext4_map_blocks *map, int flags)
491
{
492
	struct extent_status es;
493
	int retval;
494
	int ret = 0;
495 496 497 498 499
#ifdef ES_AGGRESSIVE_TEST
	struct ext4_map_blocks orig_map;

	memcpy(&orig_map, map, sizeof(*map));
#endif
500

501 502 503 504
	map->m_flags = 0;
	ext_debug("ext4_map_blocks(): inode %lu, flag %d, max_blocks %u,"
		  "logical block %lu\n", inode->i_ino, flags, map->m_len,
		  (unsigned long) map->m_lblk);
505

506 507 508 509 510 511
	/*
	 * ext4_map_blocks returns an int, and m_len is an unsigned int
	 */
	if (unlikely(map->m_len > INT_MAX))
		map->m_len = INT_MAX;

512 513
	/* We can handle the block number less than EXT_MAX_BLOCKS */
	if (unlikely(map->m_lblk >= EXT_MAX_BLOCKS))
514
		return -EFSCORRUPTED;
515

516 517 518 519 520 521 522 523 524 525 526 527
	/* Lookup extent status tree firstly */
	if (ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
		if (ext4_es_is_written(&es) || ext4_es_is_unwritten(&es)) {
			map->m_pblk = ext4_es_pblock(&es) +
					map->m_lblk - es.es_lblk;
			map->m_flags |= ext4_es_is_written(&es) ?
					EXT4_MAP_MAPPED : EXT4_MAP_UNWRITTEN;
			retval = es.es_len - (map->m_lblk - es.es_lblk);
			if (retval > map->m_len)
				retval = map->m_len;
			map->m_len = retval;
		} else if (ext4_es_is_delayed(&es) || ext4_es_is_hole(&es)) {
528 529 530 531 532
			map->m_pblk = 0;
			retval = es.es_len - (map->m_lblk - es.es_lblk);
			if (retval > map->m_len)
				retval = map->m_len;
			map->m_len = retval;
533 534 535 536
			retval = 0;
		} else {
			BUG_ON(1);
		}
537 538 539 540
#ifdef ES_AGGRESSIVE_TEST
		ext4_map_blocks_es_recheck(handle, inode, map,
					   &orig_map, flags);
#endif
541 542 543
		goto found;
	}

544
	/*
545 546
	 * Try to see if we can get the block without requesting a new
	 * file system block.
547
	 */
548
	down_read(&EXT4_I(inode)->i_data_sem);
549
	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
550 551
		retval = ext4_ext_map_blocks(handle, inode, map, flags &
					     EXT4_GET_BLOCKS_KEEP_SIZE);
552
	} else {
553 554
		retval = ext4_ind_map_blocks(handle, inode, map, flags &
					     EXT4_GET_BLOCKS_KEEP_SIZE);
555
	}
556
	if (retval > 0) {
557
		unsigned int status;
558

559 560 561 562 563 564
		if (unlikely(retval != map->m_len)) {
			ext4_warning(inode->i_sb,
				     "ES len assertion failed for inode "
				     "%lu: retval %d != map->m_len %d",
				     inode->i_ino, retval, map->m_len);
			WARN_ON(1);
565 566
		}

567 568 569
		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
570
		    !(status & EXTENT_STATUS_WRITTEN) &&
571 572 573 574 575 576 577 578
		    ext4_find_delalloc_range(inode, map->m_lblk,
					     map->m_lblk + map->m_len - 1))
			status |= EXTENT_STATUS_DELAYED;
		ret = ext4_es_insert_extent(inode, map->m_lblk,
					    map->m_len, map->m_pblk, status);
		if (ret < 0)
			retval = ret;
	}
579
	up_read((&EXT4_I(inode)->i_data_sem));
580

581
found:
582
	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
583
		ret = check_block_validity(inode, map);
584 585 586 587
		if (ret != 0)
			return ret;
	}

588
	/* If it is only a block(s) look up */
589
	if ((flags & EXT4_GET_BLOCKS_CREATE) == 0)
590 591 592 593 594 595
		return retval;

	/*
	 * Returns if the blocks have already allocated
	 *
	 * Note that if blocks have been preallocated
596
	 * ext4_ext_get_block() returns the create = 0
597 598
	 * with buffer head unmapped.
	 */
599
	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED)
600 601 602 603 604 605 606
		/*
		 * If we need to convert extent to unwritten
		 * we continue and do the actual work in
		 * ext4_ext_map_blocks()
		 */
		if (!(flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN))
			return retval;
607

608
	/*
609 610
	 * Here we clear m_flags because after allocating an new extent,
	 * it will be set again.
611
	 */
612
	map->m_flags &= ~EXT4_MAP_FLAGS;
613

614
	/*
615
	 * New blocks allocate and/or writing to unwritten extent
616
	 * will possibly result in updating i_data, so we take
617
	 * the write lock of i_data_sem, and call get_block()
618
	 * with create == 1 flag.
619
	 */
620
	down_write(&EXT4_I(inode)->i_data_sem);
621

622 623 624 625
	/*
	 * We need to check for EXT4 here because migrate
	 * could have changed the inode type in between
	 */
626
	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
627
		retval = ext4_ext_map_blocks(handle, inode, map, flags);
628
	} else {
629
		retval = ext4_ind_map_blocks(handle, inode, map, flags);
630

631
		if (retval > 0 && map->m_flags & EXT4_MAP_NEW) {
632 633 634 635 636
			/*
			 * We allocated new blocks which will result in
			 * i_data's format changing.  Force the migrate
			 * to fail by clearing migrate flags
			 */
637
			ext4_clear_inode_state(inode, EXT4_STATE_EXT_MIGRATE);
638
		}
639

640 641 642 643 644 645 646
		/*
		 * Update reserved blocks/metadata blocks after successful
		 * block allocation which had been deferred till now. We don't
		 * support fallocate for non extent files. So we can update
		 * reserve space here.
		 */
		if ((retval > 0) &&
647
			(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE))
648 649
			ext4_da_update_reserve_space(inode, retval, 1);
	}
650

651
	if (retval > 0) {
652
		unsigned int status;
653

654 655 656 657 658 659
		if (unlikely(retval != map->m_len)) {
			ext4_warning(inode->i_sb,
				     "ES len assertion failed for inode "
				     "%lu: retval %d != map->m_len %d",
				     inode->i_ino, retval, map->m_len);
			WARN_ON(1);
660 661
		}

662 663 664
		/*
		 * We have to zeroout blocks before inserting them into extent
		 * status tree. Otherwise someone could look them up there and
665 666 667
		 * use them before they are really zeroed. We also have to
		 * unmap metadata before zeroing as otherwise writeback can
		 * overwrite zeros with stale data from block device.
668 669 670 671
		 */
		if (flags & EXT4_GET_BLOCKS_ZERO &&
		    map->m_flags & EXT4_MAP_MAPPED &&
		    map->m_flags & EXT4_MAP_NEW) {
672 673
			clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk,
					   map->m_len);
674 675 676 677 678 679 680 681
			ret = ext4_issue_zeroout(inode, map->m_lblk,
						 map->m_pblk, map->m_len);
			if (ret) {
				retval = ret;
				goto out_sem;
			}
		}

682 683 684 685 686 687 688
		/*
		 * If the extent has been zeroed out, we don't need to update
		 * extent status tree.
		 */
		if ((flags & EXT4_GET_BLOCKS_PRE_IO) &&
		    ext4_es_lookup_extent(inode, map->m_lblk, &es)) {
			if (ext4_es_is_written(&es))
689
				goto out_sem;
690
		}
691 692 693
		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
		if (!(flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) &&
694
		    !(status & EXTENT_STATUS_WRITTEN) &&
695 696 697 698 699
		    ext4_find_delalloc_range(inode, map->m_lblk,
					     map->m_lblk + map->m_len - 1))
			status |= EXTENT_STATUS_DELAYED;
		ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
					    map->m_pblk, status);
700
		if (ret < 0) {
701
			retval = ret;
702 703
			goto out_sem;
		}
704 705
	}

706
out_sem:
707
	up_write((&EXT4_I(inode)->i_data_sem));
708
	if (retval > 0 && map->m_flags & EXT4_MAP_MAPPED) {
709
		ret = check_block_validity(inode, map);
710 711
		if (ret != 0)
			return ret;
J
Jan Kara 已提交
712 713 714 715 716 717 718 719 720

		/*
		 * Inodes with freshly allocated blocks where contents will be
		 * visible after transaction commit must be on transaction's
		 * ordered data list.
		 */
		if (map->m_flags & EXT4_MAP_NEW &&
		    !(map->m_flags & EXT4_MAP_UNWRITTEN) &&
		    !(flags & EXT4_GET_BLOCKS_ZERO) &&
T
Tahsin Erdogan 已提交
721
		    !ext4_is_quota_file(inode) &&
J
Jan Kara 已提交
722
		    ext4_should_order_data(inode)) {
723 724 725 726
			if (flags & EXT4_GET_BLOCKS_IO_SUBMIT)
				ret = ext4_jbd2_inode_add_wait(handle, inode);
			else
				ret = ext4_jbd2_inode_add_write(handle, inode);
J
Jan Kara 已提交
727 728 729
			if (ret)
				return ret;
		}
730
	}
731 732 733
	return retval;
}

J
Jan Kara 已提交
734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761
/*
 * Update EXT4_MAP_FLAGS in bh->b_state. For buffer heads attached to pages
 * we have to be careful as someone else may be manipulating b_state as well.
 */
static void ext4_update_bh_state(struct buffer_head *bh, unsigned long flags)
{
	unsigned long old_state;
	unsigned long new_state;

	flags &= EXT4_MAP_FLAGS;

	/* Dummy buffer_head? Set non-atomically. */
	if (!bh->b_page) {
		bh->b_state = (bh->b_state & ~EXT4_MAP_FLAGS) | flags;
		return;
	}
	/*
	 * Someone else may be modifying b_state. Be careful! This is ugly but
	 * once we get rid of using bh as a container for mapping information
	 * to pass to / from get_block functions, this can go away.
	 */
	do {
		old_state = READ_ONCE(bh->b_state);
		new_state = (old_state & ~EXT4_MAP_FLAGS) | flags;
	} while (unlikely(
		 cmpxchg(&bh->b_state, old_state, new_state) != old_state));
}

762 763
static int _ext4_get_block(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh, int flags)
764
{
765
	struct ext4_map_blocks map;
766
	int ret = 0;
767

T
Tao Ma 已提交
768 769 770
	if (ext4_has_inline_data(inode))
		return -ERANGE;

771 772 773
	map.m_lblk = iblock;
	map.m_len = bh->b_size >> inode->i_blkbits;

774 775
	ret = ext4_map_blocks(ext4_journal_current_handle(), inode, &map,
			      flags);
J
Jan Kara 已提交
776
	if (ret > 0) {
777
		map_bh(bh, inode->i_sb, map.m_pblk);
J
Jan Kara 已提交
778
		ext4_update_bh_state(bh, map.m_flags);
779
		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
J
Jan Kara 已提交
780
		ret = 0;
781 782 783
	} else if (ret == 0) {
		/* hole case, need to fill in bh->b_size */
		bh->b_size = inode->i_sb->s_blocksize * map.m_len;
784 785 786 787
	}
	return ret;
}

788 789 790 791 792 793 794
int ext4_get_block(struct inode *inode, sector_t iblock,
		   struct buffer_head *bh, int create)
{
	return _ext4_get_block(inode, iblock, bh,
			       create ? EXT4_GET_BLOCKS_CREATE : 0);
}

795 796 797 798 799 800 801 802 803 804 805 806 807 808
/*
 * Get block function used when preparing for buffered write if we require
 * creating an unwritten extent if blocks haven't been allocated.  The extent
 * will be converted to written after the IO is complete.
 */
int ext4_get_block_unwritten(struct inode *inode, sector_t iblock,
			     struct buffer_head *bh_result, int create)
{
	ext4_debug("ext4_get_block_unwritten: inode %lu, create flag %d\n",
		   inode->i_ino, create);
	return _ext4_get_block(inode, iblock, bh_result,
			       EXT4_GET_BLOCKS_IO_CREATE_EXT);
}

809 810 811
/* Maximum number of blocks we map for direct IO at once. */
#define DIO_MAX_BLOCKS 4096

812 813 814 815 816 817 818
/*
 * Get blocks function for the cases that need to start a transaction -
 * generally difference cases of direct IO and DAX IO. It also handles retries
 * in case of ENOSPC.
 */
static int ext4_get_block_trans(struct inode *inode, sector_t iblock,
				struct buffer_head *bh_result, int flags)
819 820
{
	int dio_credits;
821 822 823
	handle_t *handle;
	int retries = 0;
	int ret;
824 825 826 827 828 829

	/* Trim mapping request to maximum we can map at once for DIO */
	if (bh_result->b_size >> inode->i_blkbits > DIO_MAX_BLOCKS)
		bh_result->b_size = DIO_MAX_BLOCKS << inode->i_blkbits;
	dio_credits = ext4_chunk_trans_blocks(inode,
				      bh_result->b_size >> inode->i_blkbits);
830 831 832 833 834 835 836 837 838 839 840
retry:
	handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS, dio_credits);
	if (IS_ERR(handle))
		return PTR_ERR(handle);

	ret = _ext4_get_block(inode, iblock, bh_result, flags);
	ext4_journal_stop(handle);

	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry;
	return ret;
841 842
}

843 844 845 846
/* Get block function for DIO reads and writes to inodes without extents */
int ext4_dio_get_block(struct inode *inode, sector_t iblock,
		       struct buffer_head *bh, int create)
{
847 848 849
	/* We don't expect handle for direct IO */
	WARN_ON_ONCE(ext4_journal_current_handle());

850 851 852
	if (!create)
		return _ext4_get_block(inode, iblock, bh, 0);
	return ext4_get_block_trans(inode, iblock, bh, EXT4_GET_BLOCKS_CREATE);
853 854 855
}

/*
856
 * Get block function for AIO DIO writes when we create unwritten extent if
857 858 859
 * blocks are not allocated yet. The extent will be converted to written
 * after IO is complete.
 */
860 861
static int ext4_dio_get_block_unwritten_async(struct inode *inode,
		sector_t iblock, struct buffer_head *bh_result,	int create)
862
{
863 864 865 866 867
	int ret;

	/* We don't expect handle for direct IO */
	WARN_ON_ONCE(ext4_journal_current_handle());

868 869
	ret = ext4_get_block_trans(inode, iblock, bh_result,
				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
870

871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887
	/*
	 * When doing DIO using unwritten extents, we need io_end to convert
	 * unwritten extents to written on IO completion. We allocate io_end
	 * once we spot unwritten extent and store it in b_private. Generic
	 * DIO code keeps b_private set and furthermore passes the value to
	 * our completion callback in 'private' argument.
	 */
	if (!ret && buffer_unwritten(bh_result)) {
		if (!bh_result->b_private) {
			ext4_io_end_t *io_end;

			io_end = ext4_init_io_end(inode, GFP_KERNEL);
			if (!io_end)
				return -ENOMEM;
			bh_result->b_private = io_end;
			ext4_set_io_unwritten_flag(inode, io_end);
		}
888 889 890 891
		set_buffer_defer_completion(bh_result);
	}

	return ret;
892 893
}

894 895 896
/*
 * Get block function for non-AIO DIO writes when we create unwritten extent if
 * blocks are not allocated yet. The extent will be converted to written
897
 * after IO is complete by ext4_direct_IO_write().
898 899 900 901 902 903 904 905 906
 */
static int ext4_dio_get_block_unwritten_sync(struct inode *inode,
		sector_t iblock, struct buffer_head *bh_result,	int create)
{
	int ret;

	/* We don't expect handle for direct IO */
	WARN_ON_ONCE(ext4_journal_current_handle());

907 908
	ret = ext4_get_block_trans(inode, iblock, bh_result,
				   EXT4_GET_BLOCKS_IO_CREATE_EXT);
909 910 911

	/*
	 * Mark inode as having pending DIO writes to unwritten extents.
912
	 * ext4_direct_IO_write() checks this flag and converts extents to
913 914 915 916 917 918 919 920
	 * written.
	 */
	if (!ret && buffer_unwritten(bh_result))
		ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);

	return ret;
}

921 922 923 924 925 926 927
static int ext4_dio_get_block_overwrite(struct inode *inode, sector_t iblock,
		   struct buffer_head *bh_result, int create)
{
	int ret;

	ext4_debug("ext4_dio_get_block_overwrite: inode %lu, create flag %d\n",
		   inode->i_ino, create);
928 929 930
	/* We don't expect handle for direct IO */
	WARN_ON_ONCE(ext4_journal_current_handle());

931 932 933 934 935
	ret = _ext4_get_block(inode, iblock, bh_result, 0);
	/*
	 * Blocks should have been preallocated! ext4_file_write_iter() checks
	 * that.
	 */
936
	WARN_ON_ONCE(!buffer_mapped(bh_result) || buffer_unwritten(bh_result));
937 938 939 940 941

	return ret;
}


942 943 944
/*
 * `handle' can be NULL if create is zero
 */
945
struct buffer_head *ext4_getblk(handle_t *handle, struct inode *inode,
946
				ext4_lblk_t block, int map_flags)
947
{
948 949
	struct ext4_map_blocks map;
	struct buffer_head *bh;
950
	int create = map_flags & EXT4_GET_BLOCKS_CREATE;
951
	int err;
952 953 954

	J_ASSERT(handle != NULL || create == 0);

955 956
	map.m_lblk = block;
	map.m_len = 1;
957
	err = ext4_map_blocks(handle, inode, &map, map_flags);
958

959 960
	if (err == 0)
		return create ? ERR_PTR(-ENOSPC) : NULL;
961
	if (err < 0)
962
		return ERR_PTR(err);
963 964

	bh = sb_getblk(inode->i_sb, map.m_pblk);
965 966
	if (unlikely(!bh))
		return ERR_PTR(-ENOMEM);
967 968 969
	if (map.m_flags & EXT4_MAP_NEW) {
		J_ASSERT(create != 0);
		J_ASSERT(handle != NULL);
970

971 972 973 974 975 976 977 978 979
		/*
		 * Now that we do not always journal data, we should
		 * keep in mind whether this should always journal the
		 * new buffer as metadata.  For now, regular file
		 * writes use ext4_get_block instead, so it's not a
		 * problem.
		 */
		lock_buffer(bh);
		BUFFER_TRACE(bh, "call get_create_access");
980 981 982 983 984 985
		err = ext4_journal_get_create_access(handle, bh);
		if (unlikely(err)) {
			unlock_buffer(bh);
			goto errout;
		}
		if (!buffer_uptodate(bh)) {
986 987
			memset(bh->b_data, 0, inode->i_sb->s_blocksize);
			set_buffer_uptodate(bh);
988
		}
989 990 991
		unlock_buffer(bh);
		BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
		err = ext4_handle_dirty_metadata(handle, inode, bh);
992 993 994
		if (unlikely(err))
			goto errout;
	} else
995 996
		BUFFER_TRACE(bh, "not a new buffer");
	return bh;
997 998 999
errout:
	brelse(bh);
	return ERR_PTR(err);
1000 1001
}

1002
struct buffer_head *ext4_bread(handle_t *handle, struct inode *inode,
1003
			       ext4_lblk_t block, int map_flags)
1004
{
1005
	struct buffer_head *bh;
1006

1007
	bh = ext4_getblk(handle, inode, block, map_flags);
1008
	if (IS_ERR(bh))
1009
		return bh;
1010
	if (!bh || buffer_uptodate(bh))
1011
		return bh;
1012
	ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1, &bh);
1013 1014 1015 1016
	wait_on_buffer(bh);
	if (buffer_uptodate(bh))
		return bh;
	put_bh(bh);
1017
	return ERR_PTR(-EIO);
1018 1019
}

1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063
/* Read a contiguous batch of blocks. */
int ext4_bread_batch(struct inode *inode, ext4_lblk_t block, int bh_count,
		     bool wait, struct buffer_head **bhs)
{
	int i, err;

	for (i = 0; i < bh_count; i++) {
		bhs[i] = ext4_getblk(NULL, inode, block + i, 0 /* map_flags */);
		if (IS_ERR(bhs[i])) {
			err = PTR_ERR(bhs[i]);
			bh_count = i;
			goto out_brelse;
		}
	}

	for (i = 0; i < bh_count; i++)
		/* Note that NULL bhs[i] is valid because of holes. */
		if (bhs[i] && !buffer_uptodate(bhs[i]))
			ll_rw_block(REQ_OP_READ, REQ_META | REQ_PRIO, 1,
				    &bhs[i]);

	if (!wait)
		return 0;

	for (i = 0; i < bh_count; i++)
		if (bhs[i])
			wait_on_buffer(bhs[i]);

	for (i = 0; i < bh_count; i++) {
		if (bhs[i] && !buffer_uptodate(bhs[i])) {
			err = -EIO;
			goto out_brelse;
		}
	}
	return 0;

out_brelse:
	for (i = 0; i < bh_count; i++) {
		brelse(bhs[i]);
		bhs[i] = NULL;
	}
	return err;
}

1064 1065 1066 1067 1068 1069 1070
int ext4_walk_page_buffers(handle_t *handle,
			   struct buffer_head *head,
			   unsigned from,
			   unsigned to,
			   int *partial,
			   int (*fn)(handle_t *handle,
				     struct buffer_head *bh))
1071 1072 1073 1074 1075 1076 1077
{
	struct buffer_head *bh;
	unsigned block_start, block_end;
	unsigned blocksize = head->b_size;
	int err, ret = 0;
	struct buffer_head *next;

1078 1079
	for (bh = head, block_start = 0;
	     ret == 0 && (bh != head || !block_start);
1080
	     block_start = block_end, bh = next) {
1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097
		next = bh->b_this_page;
		block_end = block_start + blocksize;
		if (block_end <= from || block_start >= to) {
			if (partial && !buffer_uptodate(bh))
				*partial = 1;
			continue;
		}
		err = (*fn)(handle, bh);
		if (!ret)
			ret = err;
	}
	return ret;
}

/*
 * To preserve ordering, it is essential that the hole instantiation and
 * the data write be encapsulated in a single transaction.  We cannot
1098
 * close off a transaction and start a new one between the ext4_get_block()
1099
 * and the commit_write().  So doing the jbd2_journal_start at the start of
1100 1101
 * prepare_write() is the right place.
 *
1102 1103 1104 1105
 * Also, this function can nest inside ext4_writepage().  In that case, we
 * *know* that ext4_writepage() has generated enough buffer credits to do the
 * whole page.  So we won't block on the journal in that case, which is good,
 * because the caller may be PF_MEMALLOC.
1106
 *
1107
 * By accident, ext4 can be reentered when a transaction is open via
1108 1109 1110 1111 1112 1113
 * quota file writes.  If we were to commit the transaction while thus
 * reentered, there can be a deadlock - we would be holding a quota
 * lock, and the commit would never complete if another thread had a
 * transaction open and was blocking on the quota lock - a ranking
 * violation.
 *
1114
 * So what we do is to rely on the fact that jbd2_journal_stop/journal_start
1115 1116 1117 1118
 * will _not_ run commit under these circumstances because handle->h_ref
 * is elevated.  We'll still have enough credits for the tiny quotafile
 * write.
 */
1119 1120
int do_journal_get_write_access(handle_t *handle,
				struct buffer_head *bh)
1121
{
1122 1123 1124
	int dirty = buffer_dirty(bh);
	int ret;

1125 1126
	if (!buffer_mapped(bh) || buffer_freed(bh))
		return 0;
1127
	/*
C
Christoph Hellwig 已提交
1128
	 * __block_write_begin() could have dirtied some buffers. Clean
1129 1130
	 * the dirty bit as jbd2_journal_get_write_access() could complain
	 * otherwise about fs integrity issues. Setting of the dirty bit
C
Christoph Hellwig 已提交
1131
	 * by __block_write_begin() isn't a real problem here as we clear
1132 1133 1134 1135 1136
	 * the bit before releasing a page lock and thus writeback cannot
	 * ever write the buffer.
	 */
	if (dirty)
		clear_buffer_dirty(bh);
1137
	BUFFER_TRACE(bh, "get write access");
1138 1139 1140 1141
	ret = ext4_journal_get_write_access(handle, bh);
	if (!ret && dirty)
		ret = ext4_handle_dirty_metadata(handle, NULL, bh);
	return ret;
1142 1143
}

1144 1145 1146 1147
#ifdef CONFIG_EXT4_FS_ENCRYPTION
static int ext4_block_write_begin(struct page *page, loff_t pos, unsigned len,
				  get_block_t *get_block)
{
1148
	unsigned from = pos & (PAGE_SIZE - 1);
1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159
	unsigned to = from + len;
	struct inode *inode = page->mapping->host;
	unsigned block_start, block_end;
	sector_t block;
	int err = 0;
	unsigned blocksize = inode->i_sb->s_blocksize;
	unsigned bbits;
	struct buffer_head *bh, *head, *wait[2], **wait_bh = wait;
	bool decrypt = false;

	BUG_ON(!PageLocked(page));
1160 1161
	BUG_ON(from > PAGE_SIZE);
	BUG_ON(to > PAGE_SIZE);
1162 1163 1164 1165 1166 1167
	BUG_ON(from > to);

	if (!page_has_buffers(page))
		create_empty_buffers(page, blocksize, 0);
	head = page_buffers(page);
	bbits = ilog2(blocksize);
1168
	block = (sector_t)page->index << (PAGE_SHIFT - bbits);
1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187

	for (bh = head, block_start = 0; bh != head || !block_start;
	    block++, block_start = block_end, bh = bh->b_this_page) {
		block_end = block_start + blocksize;
		if (block_end <= from || block_start >= to) {
			if (PageUptodate(page)) {
				if (!buffer_uptodate(bh))
					set_buffer_uptodate(bh);
			}
			continue;
		}
		if (buffer_new(bh))
			clear_buffer_new(bh);
		if (!buffer_mapped(bh)) {
			WARN_ON(bh->b_size != blocksize);
			err = get_block(inode, block, bh, 1);
			if (err)
				break;
			if (buffer_new(bh)) {
1188
				clean_bdev_bh_alias(bh);
1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208
				if (PageUptodate(page)) {
					clear_buffer_new(bh);
					set_buffer_uptodate(bh);
					mark_buffer_dirty(bh);
					continue;
				}
				if (block_end > to || block_start < from)
					zero_user_segments(page, to, block_end,
							   block_start, from);
				continue;
			}
		}
		if (PageUptodate(page)) {
			if (!buffer_uptodate(bh))
				set_buffer_uptodate(bh);
			continue;
		}
		if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
		    !buffer_unwritten(bh) &&
		    (block_start < from || block_end > to)) {
1209
			ll_rw_block(REQ_OP_READ, 0, 1, &bh);
1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225
			*wait_bh++ = bh;
			decrypt = ext4_encrypted_inode(inode) &&
				S_ISREG(inode->i_mode);
		}
	}
	/*
	 * If we issued read requests, let them complete.
	 */
	while (wait_bh > wait) {
		wait_on_buffer(*--wait_bh);
		if (!buffer_uptodate(*wait_bh))
			err = -EIO;
	}
	if (unlikely(err))
		page_zero_new_buffers(page, from, to);
	else if (decrypt)
1226
		err = fscrypt_decrypt_page(page->mapping->host, page,
1227
				PAGE_SIZE, 0, page->index);
1228 1229 1230 1231
	return err;
}
#endif

N
Nick Piggin 已提交
1232
static int ext4_write_begin(struct file *file, struct address_space *mapping,
1233 1234
			    loff_t pos, unsigned len, unsigned flags,
			    struct page **pagep, void **fsdata)
1235
{
1236
	struct inode *inode = mapping->host;
1237
	int ret, needed_blocks;
1238 1239
	handle_t *handle;
	int retries = 0;
1240
	struct page *page;
1241
	pgoff_t index;
1242
	unsigned from, to;
N
Nick Piggin 已提交
1243

1244 1245 1246
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

1247
	trace_ext4_write_begin(inode, pos, len, flags);
1248 1249 1250 1251 1252
	/*
	 * Reserve one block more for addition to orphan list in case
	 * we allocate blocks but write fails for some reason
	 */
	needed_blocks = ext4_writepage_trans_blocks(inode) + 1;
1253 1254
	index = pos >> PAGE_SHIFT;
	from = pos & (PAGE_SIZE - 1);
1255
	to = from + len;
1256

1257 1258 1259 1260
	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
		ret = ext4_try_to_write_inline_data(mapping, inode, pos, len,
						    flags, pagep);
		if (ret < 0)
1261 1262 1263
			return ret;
		if (ret == 1)
			return 0;
1264 1265
	}

1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279
	/*
	 * grab_cache_page_write_begin() can take a long time if the
	 * system is thrashing due to memory pressure, or if the page
	 * is being written back.  So grab it first before we start
	 * the transaction handle.  This also allows us to allocate
	 * the page (if needed) without using GFP_NOFS.
	 */
retry_grab:
	page = grab_cache_page_write_begin(mapping, index, flags);
	if (!page)
		return -ENOMEM;
	unlock_page(page);

retry_journal:
1280
	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE, needed_blocks);
1281
	if (IS_ERR(handle)) {
1282
		put_page(page);
1283
		return PTR_ERR(handle);
1284
	}
1285

1286 1287 1288 1289
	lock_page(page);
	if (page->mapping != mapping) {
		/* The page got truncated from under us */
		unlock_page(page);
1290
		put_page(page);
1291
		ext4_journal_stop(handle);
1292
		goto retry_grab;
1293
	}
1294 1295
	/* In case writeback began while the page was unlocked */
	wait_for_stable_page(page);
1296

1297 1298 1299
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	if (ext4_should_dioread_nolock(inode))
		ret = ext4_block_write_begin(page, pos, len,
1300
					     ext4_get_block_unwritten);
1301 1302 1303 1304
	else
		ret = ext4_block_write_begin(page, pos, len,
					     ext4_get_block);
#else
1305
	if (ext4_should_dioread_nolock(inode))
1306 1307
		ret = __block_write_begin(page, pos, len,
					  ext4_get_block_unwritten);
1308
	else
1309
		ret = __block_write_begin(page, pos, len, ext4_get_block);
1310
#endif
N
Nick Piggin 已提交
1311
	if (!ret && ext4_should_journal_data(inode)) {
1312 1313 1314
		ret = ext4_walk_page_buffers(handle, page_buffers(page),
					     from, to, NULL,
					     do_journal_get_write_access);
1315
	}
N
Nick Piggin 已提交
1316 1317

	if (ret) {
1318
		unlock_page(page);
1319
		/*
1320
		 * __block_write_begin may have instantiated a few blocks
1321 1322
		 * outside i_size.  Trim these off again. Don't need
		 * i_size_read because we hold i_mutex.
1323 1324 1325
		 *
		 * Add inode to orphan list in case we crash before
		 * truncate finishes
1326
		 */
1327
		if (pos + len > inode->i_size && ext4_can_truncate(inode))
1328 1329 1330 1331
			ext4_orphan_add(handle, inode);

		ext4_journal_stop(handle);
		if (pos + len > inode->i_size) {
1332
			ext4_truncate_failed_write(inode);
1333
			/*
1334
			 * If truncate failed early the inode might
1335 1336 1337 1338 1339 1340 1341
			 * still be on the orphan list; we need to
			 * make sure the inode is removed from the
			 * orphan list in that case.
			 */
			if (inode->i_nlink)
				ext4_orphan_del(NULL, inode);
		}
N
Nick Piggin 已提交
1342

1343 1344 1345
		if (ret == -ENOSPC &&
		    ext4_should_retry_alloc(inode->i_sb, &retries))
			goto retry_journal;
1346
		put_page(page);
1347 1348 1349
		return ret;
	}
	*pagep = page;
1350 1351 1352
	return ret;
}

N
Nick Piggin 已提交
1353 1354
/* For write_end() in data=journal mode */
static int write_end_fn(handle_t *handle, struct buffer_head *bh)
1355
{
1356
	int ret;
1357 1358 1359
	if (!buffer_mapped(bh) || buffer_freed(bh))
		return 0;
	set_buffer_uptodate(bh);
1360 1361 1362 1363
	ret = ext4_handle_dirty_metadata(handle, NULL, bh);
	clear_buffer_meta(bh);
	clear_buffer_prio(bh);
	return ret;
1364 1365
}

1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376
/*
 * We need to pick up the new inode size which generic_commit_write gave us
 * `file' can be NULL - eg, when called from page_symlink().
 *
 * ext4 never places buffers on inode->i_mapping->private_list.  metadata
 * buffers are managed internally.
 */
static int ext4_write_end(struct file *file,
			  struct address_space *mapping,
			  loff_t pos, unsigned len, unsigned copied,
			  struct page *page, void *fsdata)
1377 1378
{
	handle_t *handle = ext4_journal_current_handle();
1379
	struct inode *inode = mapping->host;
1380
	loff_t old_size = inode->i_size;
1381 1382 1383 1384
	int ret = 0, ret2;
	int i_size_changed = 0;

	trace_ext4_write_end(inode, pos, len, copied);
1385 1386 1387
	if (ext4_has_inline_data(inode)) {
		ret = ext4_write_inline_data_end(inode, pos, len,
						 copied, page);
1388 1389 1390
		if (ret < 0) {
			unlock_page(page);
			put_page(page);
1391
			goto errout;
1392
		}
1393 1394
		copied = ret;
	} else
1395 1396
		copied = block_write_end(file, mapping, pos,
					 len, copied, page, fsdata);
1397
	/*
1398
	 * it's important to update i_size while still holding page lock:
1399 1400
	 * page writeout could otherwise come in and zero beyond i_size.
	 */
1401
	i_size_changed = ext4_update_inode_size(inode, pos + copied);
1402
	unlock_page(page);
1403
	put_page(page);
1404

1405 1406
	if (old_size < pos)
		pagecache_isize_extended(inode, old_size, pos);
1407 1408 1409 1410 1411 1412 1413 1414 1415
	/*
	 * Don't mark the inode dirty under page lock. First, it unnecessarily
	 * makes the holding time of page lock longer. Second, it forces lock
	 * ordering of page lock and transaction start for journaling
	 * filesystems.
	 */
	if (i_size_changed)
		ext4_mark_inode_dirty(handle, inode);

1416
	if (pos + len > inode->i_size && ext4_can_truncate(inode))
1417 1418 1419 1420 1421
		/* if we have allocated more blocks and copied
		 * less. We will have blocks allocated outside
		 * inode->i_size. So truncate them
		 */
		ext4_orphan_add(handle, inode);
1422
errout:
1423
	ret2 = ext4_journal_stop(handle);
1424 1425
	if (!ret)
		ret = ret2;
N
Nick Piggin 已提交
1426

1427
	if (pos + len > inode->i_size) {
1428
		ext4_truncate_failed_write(inode);
1429
		/*
1430
		 * If truncate failed early the inode might still be
1431 1432 1433 1434 1435 1436 1437
		 * on the orphan list; we need to make sure the inode
		 * is removed from the orphan list in that case.
		 */
		if (inode->i_nlink)
			ext4_orphan_del(NULL, inode);
	}

N
Nick Piggin 已提交
1438
	return ret ? ret : copied;
1439 1440
}

1441 1442 1443 1444 1445
/*
 * This is a private version of page_zero_new_buffers() which doesn't
 * set the buffer to be dirty, since in data=journalled mode we need
 * to call ext4_handle_dirty_metadata() instead.
 */
1446 1447 1448
static void ext4_journalled_zero_new_buffers(handle_t *handle,
					    struct page *page,
					    unsigned from, unsigned to)
1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464
{
	unsigned int block_start = 0, block_end;
	struct buffer_head *head, *bh;

	bh = head = page_buffers(page);
	do {
		block_end = block_start + bh->b_size;
		if (buffer_new(bh)) {
			if (block_end > from && block_start < to) {
				if (!PageUptodate(page)) {
					unsigned start, size;

					start = max(from, block_start);
					size = min(to, block_end) - start;

					zero_user(page, start, size);
1465
					write_end_fn(handle, bh);
1466 1467 1468 1469 1470 1471 1472 1473 1474
				}
				clear_buffer_new(bh);
			}
		}
		block_start = block_end;
		bh = bh->b_this_page;
	} while (bh != head);
}

N
Nick Piggin 已提交
1475
static int ext4_journalled_write_end(struct file *file,
1476 1477 1478
				     struct address_space *mapping,
				     loff_t pos, unsigned len, unsigned copied,
				     struct page *page, void *fsdata)
1479
{
1480
	handle_t *handle = ext4_journal_current_handle();
N
Nick Piggin 已提交
1481
	struct inode *inode = mapping->host;
1482
	loff_t old_size = inode->i_size;
1483 1484
	int ret = 0, ret2;
	int partial = 0;
N
Nick Piggin 已提交
1485
	unsigned from, to;
1486
	int size_changed = 0;
1487

1488
	trace_ext4_journalled_write_end(inode, pos, len, copied);
1489
	from = pos & (PAGE_SIZE - 1);
N
Nick Piggin 已提交
1490 1491
	to = from + len;

1492 1493
	BUG_ON(!ext4_handle_valid(handle));

1494 1495 1496 1497 1498 1499 1500 1501 1502 1503
	if (ext4_has_inline_data(inode)) {
		ret = ext4_write_inline_data_end(inode, pos, len,
						 copied, page);
		if (ret < 0) {
			unlock_page(page);
			put_page(page);
			goto errout;
		}
		copied = ret;
	} else if (unlikely(copied < len) && !PageUptodate(page)) {
1504 1505 1506 1507 1508 1509
		copied = 0;
		ext4_journalled_zero_new_buffers(handle, page, from, to);
	} else {
		if (unlikely(copied < len))
			ext4_journalled_zero_new_buffers(handle, page,
							 from + copied, to);
1510
		ret = ext4_walk_page_buffers(handle, page_buffers(page), from,
1511 1512
					     from + copied, &partial,
					     write_end_fn);
1513 1514 1515
		if (!partial)
			SetPageUptodate(page);
	}
1516
	size_changed = ext4_update_inode_size(inode, pos + copied);
1517
	ext4_set_inode_state(inode, EXT4_STATE_JDATA);
1518
	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
1519
	unlock_page(page);
1520
	put_page(page);
1521

1522 1523 1524
	if (old_size < pos)
		pagecache_isize_extended(inode, old_size, pos);

1525
	if (size_changed) {
1526
		ret2 = ext4_mark_inode_dirty(handle, inode);
1527 1528 1529
		if (!ret)
			ret = ret2;
	}
N
Nick Piggin 已提交
1530

1531
	if (pos + len > inode->i_size && ext4_can_truncate(inode))
1532 1533 1534 1535 1536 1537
		/* if we have allocated more blocks and copied
		 * less. We will have blocks allocated outside
		 * inode->i_size. So truncate them
		 */
		ext4_orphan_add(handle, inode);

1538
errout:
1539
	ret2 = ext4_journal_stop(handle);
1540 1541
	if (!ret)
		ret = ret2;
1542
	if (pos + len > inode->i_size) {
1543
		ext4_truncate_failed_write(inode);
1544
		/*
1545
		 * If truncate failed early the inode might still be
1546 1547 1548 1549 1550 1551
		 * on the orphan list; we need to make sure the inode
		 * is removed from the orphan list in that case.
		 */
		if (inode->i_nlink)
			ext4_orphan_del(NULL, inode);
	}
N
Nick Piggin 已提交
1552 1553

	return ret ? ret : copied;
1554
}
1555

1556
/*
1557
 * Reserve space for a single cluster
1558
 */
1559
static int ext4_da_reserve_space(struct inode *inode)
1560
{
1561
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1562
	struct ext4_inode_info *ei = EXT4_I(inode);
1563
	int ret;
1564 1565 1566 1567 1568 1569 1570 1571 1572

	/*
	 * We will charge metadata quota at writeout time; this saves
	 * us from metadata over-estimation, though we may go over by
	 * a small amount in the end.  Here we just reserve for data.
	 */
	ret = dquot_reserve_block(inode, EXT4_C2B(sbi, 1));
	if (ret)
		return ret;
1573

1574
	spin_lock(&ei->i_block_reservation_lock);
1575
	if (ext4_claim_free_clusters(sbi, 1, 0)) {
1576 1577
		spin_unlock(&ei->i_block_reservation_lock);
		dquot_release_reservation_block(inode, EXT4_C2B(sbi, 1));
1578 1579
		return -ENOSPC;
	}
1580
	ei->i_reserved_data_blocks++;
1581
	trace_ext4_da_reserve_space(inode);
1582
	spin_unlock(&ei->i_block_reservation_lock);
1583

1584 1585 1586
	return 0;       /* success */
}

1587
static void ext4_da_release_space(struct inode *inode, int to_free)
1588 1589
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1590
	struct ext4_inode_info *ei = EXT4_I(inode);
1591

1592 1593 1594
	if (!to_free)
		return;		/* Nothing to release, exit */

1595
	spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1596

L
Li Zefan 已提交
1597
	trace_ext4_da_release_space(inode, to_free);
1598
	if (unlikely(to_free > ei->i_reserved_data_blocks)) {
1599
		/*
1600 1601 1602 1603
		 * if there aren't enough reserved blocks, then the
		 * counter is messed up somewhere.  Since this
		 * function is called from invalidate page, it's
		 * harmless to return without any action.
1604
		 */
1605
		ext4_warning(inode->i_sb, "ext4_da_release_space: "
1606
			 "ino %lu, to_free %d with only %d reserved "
1607
			 "data blocks", inode->i_ino, to_free,
1608 1609 1610
			 ei->i_reserved_data_blocks);
		WARN_ON(1);
		to_free = ei->i_reserved_data_blocks;
1611
	}
1612
	ei->i_reserved_data_blocks -= to_free;
1613

1614
	/* update fs dirty data blocks counter */
1615
	percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
1616 1617

	spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1618

1619
	dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
1620 1621 1622
}

static void ext4_da_page_release_reservation(struct page *page,
1623 1624
					     unsigned int offset,
					     unsigned int length)
1625
{
1626
	int to_release = 0, contiguous_blks = 0;
1627 1628
	struct buffer_head *head, *bh;
	unsigned int curr_off = 0;
1629 1630
	struct inode *inode = page->mapping->host;
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1631
	unsigned int stop = offset + length;
1632
	int num_clusters;
1633
	ext4_fsblk_t lblk;
1634

1635
	BUG_ON(stop > PAGE_SIZE || stop < length);
1636

1637 1638 1639 1640 1641
	head = page_buffers(page);
	bh = head;
	do {
		unsigned int next_off = curr_off + bh->b_size;

1642 1643 1644
		if (next_off > stop)
			break;

1645 1646
		if ((offset <= curr_off) && (buffer_delay(bh))) {
			to_release++;
1647
			contiguous_blks++;
1648
			clear_buffer_delay(bh);
1649 1650
		} else if (contiguous_blks) {
			lblk = page->index <<
1651
			       (PAGE_SHIFT - inode->i_blkbits);
1652 1653 1654 1655
			lblk += (curr_off >> inode->i_blkbits) -
				contiguous_blks;
			ext4_es_remove_extent(inode, lblk, contiguous_blks);
			contiguous_blks = 0;
1656 1657 1658
		}
		curr_off = next_off;
	} while ((bh = bh->b_this_page) != head);
1659

1660
	if (contiguous_blks) {
1661
		lblk = page->index << (PAGE_SHIFT - inode->i_blkbits);
1662 1663
		lblk += (curr_off >> inode->i_blkbits) - contiguous_blks;
		ext4_es_remove_extent(inode, lblk, contiguous_blks);
1664 1665
	}

1666 1667 1668 1669
	/* If we have released all the blocks belonging to a cluster, then we
	 * need to release the reserved space for that cluster. */
	num_clusters = EXT4_NUM_B2C(sbi, to_release);
	while (num_clusters > 0) {
1670
		lblk = (page->index << (PAGE_SHIFT - inode->i_blkbits)) +
1671 1672
			((num_clusters - 1) << sbi->s_cluster_bits);
		if (sbi->s_cluster_ratio == 1 ||
1673
		    !ext4_find_delalloc_cluster(inode, lblk))
1674 1675 1676 1677
			ext4_da_release_space(inode, 1);

		num_clusters--;
	}
1678
}
1679

1680 1681 1682 1683
/*
 * Delayed allocation stuff
 */

J
Jan Kara 已提交
1684 1685 1686
struct mpage_da_data {
	struct inode *inode;
	struct writeback_control *wbc;
1687

J
Jan Kara 已提交
1688 1689 1690
	pgoff_t first_page;	/* The first page to write */
	pgoff_t next_page;	/* Current page to examine */
	pgoff_t last_page;	/* Last page to examine */
1691
	/*
J
Jan Kara 已提交
1692 1693 1694
	 * Extent to map - this can be after first_page because that can be
	 * fully mapped. We somewhat abuse m_flags to store whether the extent
	 * is delalloc or unwritten.
1695
	 */
J
Jan Kara 已提交
1696 1697
	struct ext4_map_blocks map;
	struct ext4_io_submit io_submit;	/* IO submission data */
1698
	unsigned int do_map:1;
J
Jan Kara 已提交
1699
};
1700

J
Jan Kara 已提交
1701 1702
static void mpage_release_unused_pages(struct mpage_da_data *mpd,
				       bool invalidate)
1703 1704 1705 1706 1707 1708
{
	int nr_pages, i;
	pgoff_t index, end;
	struct pagevec pvec;
	struct inode *inode = mpd->inode;
	struct address_space *mapping = inode->i_mapping;
J
Jan Kara 已提交
1709 1710 1711 1712

	/* This is necessary when next_page == 0. */
	if (mpd->first_page >= mpd->next_page)
		return;
1713

1714 1715
	index = mpd->first_page;
	end   = mpd->next_page - 1;
J
Jan Kara 已提交
1716 1717
	if (invalidate) {
		ext4_lblk_t start, last;
1718 1719
		start = index << (PAGE_SHIFT - inode->i_blkbits);
		last = end << (PAGE_SHIFT - inode->i_blkbits);
J
Jan Kara 已提交
1720 1721
		ext4_es_remove_extent(inode, start, last - start + 1);
	}
1722

1723
	pagevec_init(&pvec);
1724
	while (index <= end) {
1725
		nr_pages = pagevec_lookup_range(&pvec, mapping, &index, end);
1726 1727 1728 1729
		if (nr_pages == 0)
			break;
		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];
1730

1731 1732
			BUG_ON(!PageLocked(page));
			BUG_ON(PageWriteback(page));
J
Jan Kara 已提交
1733
			if (invalidate) {
1734 1735
				if (page_mapped(page))
					clear_page_dirty_for_io(page);
1736
				block_invalidatepage(page, 0, PAGE_SIZE);
J
Jan Kara 已提交
1737 1738
				ClearPageUptodate(page);
			}
1739 1740
			unlock_page(page);
		}
1741
		pagevec_release(&pvec);
1742 1743 1744
	}
}

1745 1746 1747
static void ext4_print_free_blocks(struct inode *inode)
{
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
1748
	struct super_block *sb = inode->i_sb;
1749
	struct ext4_inode_info *ei = EXT4_I(inode);
1750 1751

	ext4_msg(sb, KERN_CRIT, "Total free blocks count %lld",
1752
	       EXT4_C2B(EXT4_SB(inode->i_sb),
1753
			ext4_count_free_clusters(sb)));
1754 1755
	ext4_msg(sb, KERN_CRIT, "Free/Dirty block details");
	ext4_msg(sb, KERN_CRIT, "free_blocks=%lld",
1756
	       (long long) EXT4_C2B(EXT4_SB(sb),
1757
		percpu_counter_sum(&sbi->s_freeclusters_counter)));
1758
	ext4_msg(sb, KERN_CRIT, "dirty_blocks=%lld",
1759
	       (long long) EXT4_C2B(EXT4_SB(sb),
1760
		percpu_counter_sum(&sbi->s_dirtyclusters_counter)));
1761 1762
	ext4_msg(sb, KERN_CRIT, "Block reservation details");
	ext4_msg(sb, KERN_CRIT, "i_reserved_data_blocks=%u",
1763
		 ei->i_reserved_data_blocks);
1764 1765 1766
	return;
}

1767
static int ext4_bh_delay_or_unwritten(handle_t *handle, struct buffer_head *bh)
1768
{
1769
	return (buffer_delay(bh) || buffer_unwritten(bh)) && buffer_dirty(bh);
1770 1771
}

1772 1773 1774 1775 1776 1777 1778 1779 1780 1781
/*
 * This function is grabs code from the very beginning of
 * ext4_map_blocks, but assumes that the caller is from delayed write
 * time. This function looks up the requested blocks and sets the
 * buffer delay bit under the protection of i_data_sem.
 */
static int ext4_da_map_blocks(struct inode *inode, sector_t iblock,
			      struct ext4_map_blocks *map,
			      struct buffer_head *bh)
{
1782
	struct extent_status es;
1783 1784
	int retval;
	sector_t invalid_block = ~((sector_t) 0xffff);
1785 1786 1787 1788 1789
#ifdef ES_AGGRESSIVE_TEST
	struct ext4_map_blocks orig_map;

	memcpy(&orig_map, map, sizeof(*map));
#endif
1790 1791 1792 1793 1794 1795 1796 1797

	if (invalid_block < ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es))
		invalid_block = ~0;

	map->m_flags = 0;
	ext_debug("ext4_da_map_blocks(): inode %lu, max_blocks %u,"
		  "logical block %lu\n", inode->i_ino, map->m_len,
		  (unsigned long) map->m_lblk);
1798 1799 1800 1801 1802

	/* Lookup extent status tree firstly */
	if (ext4_es_lookup_extent(inode, iblock, &es)) {
		if (ext4_es_is_hole(&es)) {
			retval = 0;
1803
			down_read(&EXT4_I(inode)->i_data_sem);
1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829
			goto add_delayed;
		}

		/*
		 * Delayed extent could be allocated by fallocate.
		 * So we need to check it.
		 */
		if (ext4_es_is_delayed(&es) && !ext4_es_is_unwritten(&es)) {
			map_bh(bh, inode->i_sb, invalid_block);
			set_buffer_new(bh);
			set_buffer_delay(bh);
			return 0;
		}

		map->m_pblk = ext4_es_pblock(&es) + iblock - es.es_lblk;
		retval = es.es_len - (iblock - es.es_lblk);
		if (retval > map->m_len)
			retval = map->m_len;
		map->m_len = retval;
		if (ext4_es_is_written(&es))
			map->m_flags |= EXT4_MAP_MAPPED;
		else if (ext4_es_is_unwritten(&es))
			map->m_flags |= EXT4_MAP_UNWRITTEN;
		else
			BUG_ON(1);

1830 1831 1832
#ifdef ES_AGGRESSIVE_TEST
		ext4_map_blocks_es_recheck(NULL, inode, map, &orig_map, 0);
#endif
1833 1834 1835
		return retval;
	}

1836 1837 1838 1839
	/*
	 * Try to see if we can get the block without requesting a new
	 * file system block.
	 */
1840
	down_read(&EXT4_I(inode)->i_data_sem);
1841
	if (ext4_has_inline_data(inode))
1842
		retval = 0;
1843
	else if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
1844
		retval = ext4_ext_map_blocks(NULL, inode, map, 0);
1845
	else
1846
		retval = ext4_ind_map_blocks(NULL, inode, map, 0);
1847

1848
add_delayed:
1849
	if (retval == 0) {
1850
		int ret;
1851 1852 1853 1854
		/*
		 * XXX: __block_prepare_write() unmaps passed block,
		 * is it OK?
		 */
1855 1856 1857 1858 1859
		/*
		 * If the block was allocated from previously allocated cluster,
		 * then we don't need to reserve it again. However we still need
		 * to reserve metadata for every block we're going to write.
		 */
1860
		if (EXT4_SB(inode->i_sb)->s_cluster_ratio == 1 ||
1861
		    !ext4_find_delalloc_cluster(inode, map->m_lblk)) {
1862
			ret = ext4_da_reserve_space(inode);
1863
			if (ret) {
1864
				/* not enough space to reserve */
1865
				retval = ret;
1866
				goto out_unlock;
1867
			}
1868 1869
		}

1870 1871 1872 1873
		ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
					    ~0, EXTENT_STATUS_DELAYED);
		if (ret) {
			retval = ret;
1874
			goto out_unlock;
1875
		}
1876

1877 1878 1879
		map_bh(bh, inode->i_sb, invalid_block);
		set_buffer_new(bh);
		set_buffer_delay(bh);
1880 1881
	} else if (retval > 0) {
		int ret;
1882
		unsigned int status;
1883

1884 1885 1886 1887 1888 1889
		if (unlikely(retval != map->m_len)) {
			ext4_warning(inode->i_sb,
				     "ES len assertion failed for inode "
				     "%lu: retval %d != map->m_len %d",
				     inode->i_ino, retval, map->m_len);
			WARN_ON(1);
1890 1891
		}

1892 1893 1894 1895 1896 1897
		status = map->m_flags & EXT4_MAP_UNWRITTEN ?
				EXTENT_STATUS_UNWRITTEN : EXTENT_STATUS_WRITTEN;
		ret = ext4_es_insert_extent(inode, map->m_lblk, map->m_len,
					    map->m_pblk, status);
		if (ret != 0)
			retval = ret;
1898 1899 1900 1901 1902 1903 1904 1905
	}

out_unlock:
	up_read((&EXT4_I(inode)->i_data_sem));

	return retval;
}

1906
/*
1907
 * This is a special get_block_t callback which is used by
1908 1909
 * ext4_da_write_begin().  It will either return mapped block or
 * reserve space for a single block.
1910 1911 1912 1913 1914 1915 1916
 *
 * For delayed buffer_head we have BH_Mapped, BH_New, BH_Delay set.
 * We also have b_blocknr = -1 and b_bdev initialized properly
 *
 * For unwritten buffer_head we have BH_Mapped, BH_New, BH_Unwritten set.
 * We also have b_blocknr = physicalblock mapping unwritten extent and b_bdev
 * initialized properly.
1917
 */
1918 1919
int ext4_da_get_block_prep(struct inode *inode, sector_t iblock,
			   struct buffer_head *bh, int create)
1920
{
1921
	struct ext4_map_blocks map;
1922 1923 1924
	int ret = 0;

	BUG_ON(create == 0);
1925 1926 1927 1928
	BUG_ON(bh->b_size != inode->i_sb->s_blocksize);

	map.m_lblk = iblock;
	map.m_len = 1;
1929 1930 1931 1932 1933 1934

	/*
	 * first, we need to know whether the block is allocated already
	 * preallocated blocks are unmapped but should treated
	 * the same as allocated blocks.
	 */
1935 1936
	ret = ext4_da_map_blocks(inode, iblock, &map, bh);
	if (ret <= 0)
1937
		return ret;
1938

1939
	map_bh(bh, inode->i_sb, map.m_pblk);
J
Jan Kara 已提交
1940
	ext4_update_bh_state(bh, map.m_flags);
1941 1942 1943 1944 1945 1946 1947 1948 1949

	if (buffer_unwritten(bh)) {
		/* A delayed write to unwritten bh should be marked
		 * new and mapped.  Mapped ensures that we don't do
		 * get_block multiple times when we write to the same
		 * offset and new ensures that we do proper zero out
		 * for partial write.
		 */
		set_buffer_new(bh);
1950
		set_buffer_mapped(bh);
1951 1952
	}
	return 0;
1953
}
1954

1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971
static int bget_one(handle_t *handle, struct buffer_head *bh)
{
	get_bh(bh);
	return 0;
}

static int bput_one(handle_t *handle, struct buffer_head *bh)
{
	put_bh(bh);
	return 0;
}

static int __ext4_journalled_writepage(struct page *page,
				       unsigned int len)
{
	struct address_space *mapping = page->mapping;
	struct inode *inode = mapping->host;
1972
	struct buffer_head *page_bufs = NULL;
1973
	handle_t *handle = NULL;
1974 1975 1976
	int ret = 0, err = 0;
	int inline_data = ext4_has_inline_data(inode);
	struct buffer_head *inode_bh = NULL;
1977

1978
	ClearPageChecked(page);
1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994

	if (inline_data) {
		BUG_ON(page->index != 0);
		BUG_ON(len > ext4_get_max_inline_size(inode));
		inode_bh = ext4_journalled_write_inline_data(inode, len, page);
		if (inode_bh == NULL)
			goto out;
	} else {
		page_bufs = page_buffers(page);
		if (!page_bufs) {
			BUG();
			goto out;
		}
		ext4_walk_page_buffers(handle, page_bufs, 0, len,
				       NULL, bget_one);
	}
1995 1996 1997 1998 1999 2000
	/*
	 * We need to release the page lock before we start the
	 * journal, so grab a reference so the page won't disappear
	 * out from under us.
	 */
	get_page(page);
2001 2002
	unlock_page(page);

2003 2004
	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
				    ext4_writepage_trans_blocks(inode));
2005 2006
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
2007 2008
		put_page(page);
		goto out_no_pagelock;
2009
	}
2010 2011
	BUG_ON(!ext4_handle_valid(handle));

2012 2013 2014 2015 2016 2017 2018 2019 2020
	lock_page(page);
	put_page(page);
	if (page->mapping != mapping) {
		/* The page got truncated from under us */
		ext4_journal_stop(handle);
		ret = 0;
		goto out;
	}

2021
	if (inline_data) {
2022
		BUFFER_TRACE(inode_bh, "get write access");
2023
		ret = ext4_journal_get_write_access(handle, inode_bh);
2024

2025 2026 2027 2028 2029 2030 2031 2032 2033
		err = ext4_handle_dirty_metadata(handle, inode, inode_bh);

	} else {
		ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
					     do_journal_get_write_access);

		err = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
					     write_end_fn);
	}
2034 2035
	if (ret == 0)
		ret = err;
2036
	EXT4_I(inode)->i_datasync_tid = handle->h_transaction->t_tid;
2037 2038 2039 2040
	err = ext4_journal_stop(handle);
	if (!ret)
		ret = err;

2041
	if (!ext4_has_inline_data(inode))
2042
		ext4_walk_page_buffers(NULL, page_bufs, 0, len,
2043
				       NULL, bput_one);
2044
	ext4_set_inode_state(inode, EXT4_STATE_JDATA);
2045
out:
2046 2047
	unlock_page(page);
out_no_pagelock:
2048
	brelse(inode_bh);
2049 2050 2051
	return ret;
}

2052
/*
2053 2054 2055 2056
 * Note that we don't need to start a transaction unless we're journaling data
 * because we should have holes filled from ext4_page_mkwrite(). We even don't
 * need to file the inode to the transaction's list in ordered mode because if
 * we are writing back data added by write(), the inode is already there and if
L
Lucas De Marchi 已提交
2057
 * we are writing back data modified via mmap(), no one guarantees in which
2058 2059 2060 2061
 * transaction the data will hit the disk. In case we are journaling data, we
 * cannot start transaction directly because transaction start ranks above page
 * lock so we have to do some magic.
 *
2062
 * This function can get called via...
2063
 *   - ext4_writepages after taking page lock (have journal handle)
2064
 *   - journal_submit_inode_data_buffers (no journal handle)
2065
 *   - shrink_page_list via the kswapd/direct reclaim (no journal handle)
2066
 *   - grab_page_cache when doing write_begin (have journal handle)
2067 2068 2069 2070 2071 2072 2073 2074 2075
 *
 * We don't do any block allocation in this function. If we have page with
 * multiple blocks we need to write those buffer_heads that are mapped. This
 * is important for mmaped based write. So if we do with blocksize 1K
 * truncate(f, 1024);
 * a = mmap(f, 0, 4096);
 * a[0] = 'a';
 * truncate(f, 4096);
 * we have in the page first buffer_head mapped via page_mkwrite call back
2076
 * but other buffer_heads would be unmapped but dirty (dirty done via the
2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091
 * do_wp_page). So writepage should write the first block. If we modify
 * the mmap area beyond 1024 we will again get a page_fault and the
 * page_mkwrite callback will do the block allocation and mark the
 * buffer_heads mapped.
 *
 * We redirty the page if we have any buffer_heads that is either delay or
 * unwritten in the page.
 *
 * We can get recursively called as show below.
 *
 *	ext4_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
 *		ext4_writepage()
 *
 * But since we don't do any block allocation we should not deadlock.
 * Page also have the dirty flag cleared so we don't get recurive page_lock.
2092
 */
2093
static int ext4_writepage(struct page *page,
2094
			  struct writeback_control *wbc)
2095
{
2096
	int ret = 0;
2097
	loff_t size;
2098
	unsigned int len;
2099
	struct buffer_head *page_bufs = NULL;
2100
	struct inode *inode = page->mapping->host;
2101
	struct ext4_io_submit io_submit;
2102
	bool keep_towrite = false;
2103

2104 2105 2106 2107 2108 2109
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb)))) {
		ext4_invalidatepage(page, 0, PAGE_SIZE);
		unlock_page(page);
		return -EIO;
	}

L
Lukas Czerner 已提交
2110
	trace_ext4_writepage(page);
2111
	size = i_size_read(inode);
2112 2113
	if (page->index == size >> PAGE_SHIFT)
		len = size & ~PAGE_MASK;
2114
	else
2115
		len = PAGE_SIZE;
2116

T
Theodore Ts'o 已提交
2117 2118
	page_bufs = page_buffers(page);
	/*
2119 2120 2121 2122 2123
	 * We cannot do block allocation or other extent handling in this
	 * function. If there are buffers needing that, we have to redirty
	 * the page. But we may reach here when we do a journal commit via
	 * journal_submit_inode_data_buffers() and in that case we must write
	 * allocated buffers to achieve data=ordered mode guarantees.
2124 2125 2126 2127 2128 2129 2130 2131 2132 2133
	 *
	 * Also, if there is only one buffer per page (the fs block
	 * size == the page size), if one buffer needs block
	 * allocation or needs to modify the extent tree to clear the
	 * unwritten flag, we know that the page can't be written at
	 * all, so we might as well refuse the write immediately.
	 * Unfortunately if the block size != page size, we can't as
	 * easily detect this case using ext4_walk_page_buffers(), but
	 * for the extremely common case, this is an optimization that
	 * skips a useless round trip through ext4_bio_write_page().
T
Theodore Ts'o 已提交
2134
	 */
2135 2136
	if (ext4_walk_page_buffers(NULL, page_bufs, 0, len, NULL,
				   ext4_bh_delay_or_unwritten)) {
2137
		redirty_page_for_writepage(wbc, page);
2138
		if ((current->flags & PF_MEMALLOC) ||
2139
		    (inode->i_sb->s_blocksize == PAGE_SIZE)) {
2140 2141 2142 2143 2144 2145 2146
			/*
			 * For memory cleaning there's no point in writing only
			 * some buffers. So just bail out. Warn if we came here
			 * from direct reclaim.
			 */
			WARN_ON_ONCE((current->flags & (PF_MEMALLOC|PF_KSWAPD))
							== PF_MEMALLOC);
2147 2148 2149
			unlock_page(page);
			return 0;
		}
2150
		keep_towrite = true;
T
Theodore Ts'o 已提交
2151
	}
2152

2153
	if (PageChecked(page) && ext4_should_journal_data(inode))
2154 2155 2156 2157
		/*
		 * It's mmapped pagecache.  Add buffers and journal it.  There
		 * doesn't seem much point in redirtying the page here.
		 */
2158
		return __ext4_journalled_writepage(page, len);
2159

J
Jan Kara 已提交
2160 2161 2162 2163 2164 2165 2166
	ext4_io_submit_init(&io_submit, wbc);
	io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
	if (!io_submit.io_end) {
		redirty_page_for_writepage(wbc, page);
		unlock_page(page);
		return -ENOMEM;
	}
2167
	ret = ext4_bio_write_page(&io_submit, page, len, wbc, keep_towrite);
2168
	ext4_io_submit(&io_submit);
J
Jan Kara 已提交
2169 2170
	/* Drop io_end reference we got from init */
	ext4_put_io_end_defer(io_submit.io_end);
2171 2172 2173
	return ret;
}

2174 2175 2176
static int mpage_submit_page(struct mpage_da_data *mpd, struct page *page)
{
	int len;
2177
	loff_t size;
2178 2179 2180
	int err;

	BUG_ON(page->index != mpd->first_page);
2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195
	clear_page_dirty_for_io(page);
	/*
	 * We have to be very careful here!  Nothing protects writeback path
	 * against i_size changes and the page can be writeably mapped into
	 * page tables. So an application can be growing i_size and writing
	 * data through mmap while writeback runs. clear_page_dirty_for_io()
	 * write-protects our page in page tables and the page cannot get
	 * written to again until we release page lock. So only after
	 * clear_page_dirty_for_io() we are safe to sample i_size for
	 * ext4_bio_write_page() to zero-out tail of the written page. We rely
	 * on the barrier provided by TestClearPageDirty in
	 * clear_page_dirty_for_io() to make sure i_size is really sampled only
	 * after page tables are updated.
	 */
	size = i_size_read(mpd->inode);
2196 2197
	if (page->index == size >> PAGE_SHIFT)
		len = size & ~PAGE_MASK;
2198
	else
2199
		len = PAGE_SIZE;
2200
	err = ext4_bio_write_page(&mpd->io_submit, page, len, mpd->wbc, false);
2201 2202 2203 2204 2205 2206 2207
	if (!err)
		mpd->wbc->nr_to_write--;
	mpd->first_page++;

	return err;
}

J
Jan Kara 已提交
2208 2209
#define BH_FLAGS ((1 << BH_Unwritten) | (1 << BH_Delay))

2210
/*
2211 2212
 * mballoc gives us at most this number of blocks...
 * XXX: That seems to be only a limitation of ext4_mb_normalize_request().
2213
 * The rest of mballoc seems to handle chunks up to full group size.
2214
 */
2215
#define MAX_WRITEPAGES_EXTENT_LEN 2048
2216

J
Jan Kara 已提交
2217 2218 2219 2220 2221
/*
 * mpage_add_bh_to_extent - try to add bh to extent of blocks to map
 *
 * @mpd - extent of blocks
 * @lblk - logical number of the block in the file
2222
 * @bh - buffer head we want to add to the extent
J
Jan Kara 已提交
2223
 *
2224 2225 2226 2227 2228 2229
 * The function is used to collect contig. blocks in the same state. If the
 * buffer doesn't require mapping for writeback and we haven't started the
 * extent of buffers to map yet, the function returns 'true' immediately - the
 * caller can write the buffer right away. Otherwise the function returns true
 * if the block has been added to the extent, false if the block couldn't be
 * added.
J
Jan Kara 已提交
2230
 */
2231 2232
static bool mpage_add_bh_to_extent(struct mpage_da_data *mpd, ext4_lblk_t lblk,
				   struct buffer_head *bh)
J
Jan Kara 已提交
2233 2234 2235
{
	struct ext4_map_blocks *map = &mpd->map;

2236 2237 2238 2239 2240 2241 2242 2243
	/* Buffer that doesn't need mapping for writeback? */
	if (!buffer_dirty(bh) || !buffer_mapped(bh) ||
	    (!buffer_delay(bh) && !buffer_unwritten(bh))) {
		/* So far no extent to map => we write the buffer right away */
		if (map->m_len == 0)
			return true;
		return false;
	}
J
Jan Kara 已提交
2244 2245 2246

	/* First block in the extent? */
	if (map->m_len == 0) {
2247 2248 2249
		/* We cannot map unless handle is started... */
		if (!mpd->do_map)
			return false;
J
Jan Kara 已提交
2250 2251
		map->m_lblk = lblk;
		map->m_len = 1;
2252 2253
		map->m_flags = bh->b_state & BH_FLAGS;
		return true;
J
Jan Kara 已提交
2254 2255
	}

2256 2257 2258 2259
	/* Don't go larger than mballoc is willing to allocate */
	if (map->m_len >= MAX_WRITEPAGES_EXTENT_LEN)
		return false;

J
Jan Kara 已提交
2260 2261
	/* Can we merge the block to our big extent? */
	if (lblk == map->m_lblk + map->m_len &&
2262
	    (bh->b_state & BH_FLAGS) == map->m_flags) {
J
Jan Kara 已提交
2263
		map->m_len++;
2264
		return true;
J
Jan Kara 已提交
2265
	}
2266
	return false;
J
Jan Kara 已提交
2267 2268
}

2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288
/*
 * mpage_process_page_bufs - submit page buffers for IO or add them to extent
 *
 * @mpd - extent of blocks for mapping
 * @head - the first buffer in the page
 * @bh - buffer we should start processing from
 * @lblk - logical number of the block in the file corresponding to @bh
 *
 * Walk through page buffers from @bh upto @head (exclusive) and either submit
 * the page for IO if all buffers in this page were mapped and there's no
 * accumulated extent of buffers to map or add buffers in the page to the
 * extent of buffers to map. The function returns 1 if the caller can continue
 * by processing the next page, 0 if it should stop adding buffers to the
 * extent to map because we cannot extend it anymore. It can also return value
 * < 0 in case of error during IO submission.
 */
static int mpage_process_page_bufs(struct mpage_da_data *mpd,
				   struct buffer_head *head,
				   struct buffer_head *bh,
				   ext4_lblk_t lblk)
J
Jan Kara 已提交
2289 2290
{
	struct inode *inode = mpd->inode;
2291
	int err;
F
Fabian Frederick 已提交
2292
	ext4_lblk_t blocks = (i_size_read(inode) + i_blocksize(inode) - 1)
J
Jan Kara 已提交
2293 2294 2295 2296 2297
							>> inode->i_blkbits;

	do {
		BUG_ON(buffer_locked(bh));

2298
		if (lblk >= blocks || !mpage_add_bh_to_extent(mpd, lblk, bh)) {
J
Jan Kara 已提交
2299 2300
			/* Found extent to map? */
			if (mpd->map.m_len)
2301
				return 0;
2302 2303 2304
			/* Buffer needs mapping and handle is not started? */
			if (!mpd->do_map)
				return 0;
2305
			/* Everything mapped so far and we hit EOF */
2306
			break;
J
Jan Kara 已提交
2307 2308
		}
	} while (lblk++, (bh = bh->b_this_page) != head);
2309 2310 2311 2312 2313 2314 2315
	/* So far everything mapped? Submit the page for IO. */
	if (mpd->map.m_len == 0) {
		err = mpage_submit_page(mpd, head->b_page);
		if (err < 0)
			return err;
	}
	return lblk < blocks;
J
Jan Kara 已提交
2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326
}

/*
 * mpage_map_buffers - update buffers corresponding to changed extent and
 *		       submit fully mapped pages for IO
 *
 * @mpd - description of extent to map, on return next extent to map
 *
 * Scan buffers corresponding to changed extent (we expect corresponding pages
 * to be already locked) and update buffer state according to new extent state.
 * We map delalloc buffers to their physical location, clear unwritten bits,
2327
 * and mark buffers as uninit when we perform writes to unwritten extents
J
Jan Kara 已提交
2328 2329 2330 2331 2332 2333 2334 2335 2336 2337
 * and do extent conversion after IO is finished. If the last page is not fully
 * mapped, we update @map to the next extent in the last page that needs
 * mapping. Otherwise we submit the page for IO.
 */
static int mpage_map_and_submit_buffers(struct mpage_da_data *mpd)
{
	struct pagevec pvec;
	int nr_pages, i;
	struct inode *inode = mpd->inode;
	struct buffer_head *head, *bh;
2338
	int bpp_bits = PAGE_SHIFT - inode->i_blkbits;
J
Jan Kara 已提交
2339 2340 2341 2342 2343 2344 2345 2346 2347 2348
	pgoff_t start, end;
	ext4_lblk_t lblk;
	sector_t pblock;
	int err;

	start = mpd->map.m_lblk >> bpp_bits;
	end = (mpd->map.m_lblk + mpd->map.m_len - 1) >> bpp_bits;
	lblk = start << bpp_bits;
	pblock = mpd->map.m_pblk;

2349
	pagevec_init(&pvec);
J
Jan Kara 已提交
2350
	while (start <= end) {
2351
		nr_pages = pagevec_lookup_range(&pvec, inode->i_mapping,
2352
						&start, end);
J
Jan Kara 已提交
2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368
		if (nr_pages == 0)
			break;
		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];

			bh = head = page_buffers(page);
			do {
				if (lblk < mpd->map.m_lblk)
					continue;
				if (lblk >= mpd->map.m_lblk + mpd->map.m_len) {
					/*
					 * Buffer after end of mapped extent.
					 * Find next buffer in the page to map.
					 */
					mpd->map.m_len = 0;
					mpd->map.m_flags = 0;
2369 2370 2371 2372 2373 2374 2375 2376 2377
					/*
					 * FIXME: If dioread_nolock supports
					 * blocksize < pagesize, we need to make
					 * sure we add size mapped so far to
					 * io_end->size as the following call
					 * can submit the page for IO.
					 */
					err = mpage_process_page_bufs(mpd, head,
								      bh, lblk);
J
Jan Kara 已提交
2378
					pagevec_release(&pvec);
2379 2380 2381
					if (err > 0)
						err = 0;
					return err;
J
Jan Kara 已提交
2382 2383 2384 2385 2386 2387
				}
				if (buffer_delay(bh)) {
					clear_buffer_delay(bh);
					bh->b_blocknr = pblock++;
				}
				clear_buffer_unwritten(bh);
2388
			} while (lblk++, (bh = bh->b_this_page) != head);
J
Jan Kara 已提交
2389 2390 2391 2392 2393 2394

			/*
			 * FIXME: This is going to break if dioread_nolock
			 * supports blocksize < pagesize as we will try to
			 * convert potentially unmapped parts of inode.
			 */
2395
			mpd->io_submit.io_end->size += PAGE_SIZE;
J
Jan Kara 已提交
2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415
			/* Page fully mapped - let IO run! */
			err = mpage_submit_page(mpd, page);
			if (err < 0) {
				pagevec_release(&pvec);
				return err;
			}
		}
		pagevec_release(&pvec);
	}
	/* Extent fully mapped and matches with page boundary. We are done. */
	mpd->map.m_len = 0;
	mpd->map.m_flags = 0;
	return 0;
}

static int mpage_map_one_extent(handle_t *handle, struct mpage_da_data *mpd)
{
	struct inode *inode = mpd->inode;
	struct ext4_map_blocks *map = &mpd->map;
	int get_blocks_flags;
2416
	int err, dioread_nolock;
J
Jan Kara 已提交
2417 2418 2419 2420

	trace_ext4_da_write_pages_extent(inode, map);
	/*
	 * Call ext4_map_blocks() to allocate any delayed allocation blocks, or
2421
	 * to convert an unwritten extent to be initialized (in the case
J
Jan Kara 已提交
2422 2423 2424 2425 2426 2427 2428
	 * where we have written into one or more preallocated blocks).  It is
	 * possible that we're going to need more metadata blocks than
	 * previously reserved. However we must not fail because we're in
	 * writeback and there is nothing we can do about it so it might result
	 * in data loss.  So use reserved blocks to allocate metadata if
	 * possible.
	 *
2429 2430 2431 2432
	 * We pass in the magic EXT4_GET_BLOCKS_DELALLOC_RESERVE if
	 * the blocks in question are delalloc blocks.  This indicates
	 * that the blocks and quotas has already been checked when
	 * the data was copied into the page cache.
J
Jan Kara 已提交
2433 2434
	 */
	get_blocks_flags = EXT4_GET_BLOCKS_CREATE |
2435 2436
			   EXT4_GET_BLOCKS_METADATA_NOFAIL |
			   EXT4_GET_BLOCKS_IO_SUBMIT;
2437 2438
	dioread_nolock = ext4_should_dioread_nolock(inode);
	if (dioread_nolock)
J
Jan Kara 已提交
2439 2440 2441 2442 2443 2444 2445
		get_blocks_flags |= EXT4_GET_BLOCKS_IO_CREATE_EXT;
	if (map->m_flags & (1 << BH_Delay))
		get_blocks_flags |= EXT4_GET_BLOCKS_DELALLOC_RESERVE;

	err = ext4_map_blocks(handle, inode, map, get_blocks_flags);
	if (err < 0)
		return err;
2446
	if (dioread_nolock && (map->m_flags & EXT4_MAP_UNWRITTEN)) {
2447 2448 2449 2450 2451
		if (!mpd->io_submit.io_end->handle &&
		    ext4_handle_valid(handle)) {
			mpd->io_submit.io_end->handle = handle->h_rsv_handle;
			handle->h_rsv_handle = NULL;
		}
J
Jan Kara 已提交
2452
		ext4_set_io_unwritten_flag(inode, mpd->io_submit.io_end);
2453
	}
J
Jan Kara 已提交
2454 2455 2456

	BUG_ON(map->m_len == 0);
	if (map->m_flags & EXT4_MAP_NEW) {
2457 2458
		clean_bdev_aliases(inode->i_sb->s_bdev, map->m_pblk,
				   map->m_len);
J
Jan Kara 已提交
2459 2460 2461 2462 2463 2464 2465 2466 2467 2468
	}
	return 0;
}

/*
 * mpage_map_and_submit_extent - map extent starting at mpd->lblk of length
 *				 mpd->len and submit pages underlying it for IO
 *
 * @handle - handle for journal operations
 * @mpd - extent to map
2469 2470 2471
 * @give_up_on_write - we set this to true iff there is a fatal error and there
 *                     is no hope of writing the data. The caller should discard
 *                     dirty pages to avoid infinite loops.
J
Jan Kara 已提交
2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483
 *
 * The function maps extent starting at mpd->lblk of length mpd->len. If it is
 * delayed, blocks are allocated, if it is unwritten, we may need to convert
 * them to initialized or split the described range from larger unwritten
 * extent. Note that we need not map all the described range since allocation
 * can return less blocks or the range is covered by more unwritten extents. We
 * cannot map more because we are limited by reserved transaction credits. On
 * the other hand we always make sure that the last touched page is fully
 * mapped so that it can be written out (and thus forward progress is
 * guaranteed). After mapping we submit all mapped pages for IO.
 */
static int mpage_map_and_submit_extent(handle_t *handle,
2484 2485
				       struct mpage_da_data *mpd,
				       bool *give_up_on_write)
J
Jan Kara 已提交
2486 2487 2488 2489 2490
{
	struct inode *inode = mpd->inode;
	struct ext4_map_blocks *map = &mpd->map;
	int err;
	loff_t disksize;
2491
	int progress = 0;
J
Jan Kara 已提交
2492 2493 2494

	mpd->io_submit.io_end->offset =
				((loff_t)map->m_lblk) << inode->i_blkbits;
2495
	do {
J
Jan Kara 已提交
2496 2497 2498 2499
		err = mpage_map_one_extent(handle, mpd);
		if (err < 0) {
			struct super_block *sb = inode->i_sb;

2500 2501
			if (ext4_forced_shutdown(EXT4_SB(sb)) ||
			    EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)
2502
				goto invalidate_dirty_pages;
J
Jan Kara 已提交
2503
			/*
2504 2505 2506
			 * Let the uper layers retry transient errors.
			 * In the case of ENOSPC, if ext4_count_free_blocks()
			 * is non-zero, a commit should free up blocks.
J
Jan Kara 已提交
2507
			 */
2508
			if ((err == -ENOMEM) ||
2509 2510 2511
			    (err == -ENOSPC && ext4_count_free_clusters(sb))) {
				if (progress)
					goto update_disksize;
2512
				return err;
2513
			}
2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527
			ext4_msg(sb, KERN_CRIT,
				 "Delayed block allocation failed for "
				 "inode %lu at logical offset %llu with"
				 " max blocks %u with error %d",
				 inode->i_ino,
				 (unsigned long long)map->m_lblk,
				 (unsigned)map->m_len, -err);
			ext4_msg(sb, KERN_CRIT,
				 "This should not happen!! Data will "
				 "be lost\n");
			if (err == -ENOSPC)
				ext4_print_free_blocks(inode);
		invalidate_dirty_pages:
			*give_up_on_write = true;
J
Jan Kara 已提交
2528 2529
			return err;
		}
2530
		progress = 1;
J
Jan Kara 已提交
2531 2532 2533 2534 2535 2536
		/*
		 * Update buffer state, submit mapped pages, and get us new
		 * extent to map
		 */
		err = mpage_map_and_submit_buffers(mpd);
		if (err < 0)
2537
			goto update_disksize;
2538
	} while (map->m_len);
J
Jan Kara 已提交
2539

2540
update_disksize:
2541 2542 2543 2544
	/*
	 * Update on-disk size after IO is submitted.  Races with
	 * truncate are avoided by checking i_size under i_data_sem.
	 */
2545
	disksize = ((loff_t)mpd->first_page) << PAGE_SHIFT;
J
Jan Kara 已提交
2546 2547
	if (disksize > EXT4_I(inode)->i_disksize) {
		int err2;
2548 2549 2550 2551 2552 2553 2554 2555 2556
		loff_t i_size;

		down_write(&EXT4_I(inode)->i_data_sem);
		i_size = i_size_read(inode);
		if (disksize > i_size)
			disksize = i_size;
		if (disksize > EXT4_I(inode)->i_disksize)
			EXT4_I(inode)->i_disksize = disksize;
		up_write(&EXT4_I(inode)->i_data_sem);
2557
		err2 = ext4_mark_inode_dirty(handle, inode);
J
Jan Kara 已提交
2558 2559 2560 2561 2562 2563 2564 2565 2566 2567
		if (err2)
			ext4_error(inode->i_sb,
				   "Failed to mark inode %lu dirty",
				   inode->i_ino);
		if (!err)
			err = err2;
	}
	return err;
}

2568 2569
/*
 * Calculate the total number of credits to reserve for one writepages
2570
 * iteration. This is called from ext4_writepages(). We map an extent of
2571
 * up to MAX_WRITEPAGES_EXTENT_LEN blocks and then we go on and finish mapping
2572 2573 2574
 * the last partial page. So in total we can map MAX_WRITEPAGES_EXTENT_LEN +
 * bpp - 1 blocks in bpp different extents.
 */
2575 2576
static int ext4_da_writepages_trans_blocks(struct inode *inode)
{
2577
	int bpp = ext4_journal_blocks_per_page(inode);
2578

2579 2580
	return ext4_meta_trans_blocks(inode,
				MAX_WRITEPAGES_EXTENT_LEN + bpp - 1, bpp);
2581
}
2582

2583
/*
J
Jan Kara 已提交
2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599
 * mpage_prepare_extent_to_map - find & lock contiguous range of dirty pages
 * 				 and underlying extent to map
 *
 * @mpd - where to look for pages
 *
 * Walk dirty pages in the mapping. If they are fully mapped, submit them for
 * IO immediately. When we find a page which isn't mapped we start accumulating
 * extent of buffers underlying these pages that needs mapping (formed by
 * either delayed or unwritten buffers). We also lock the pages containing
 * these buffers. The extent found is returned in @mpd structure (starting at
 * mpd->lblk with length mpd->len blocks).
 *
 * Note that this function can attach bios to one io_end structure which are
 * neither logically nor physically contiguous. Although it may seem as an
 * unnecessary complication, it is actually inevitable in blocksize < pagesize
 * case as we need to track IO to all buffers underlying a page in one io_end.
2600
 */
J
Jan Kara 已提交
2601
static int mpage_prepare_extent_to_map(struct mpage_da_data *mpd)
2602
{
J
Jan Kara 已提交
2603 2604 2605
	struct address_space *mapping = mpd->inode->i_mapping;
	struct pagevec pvec;
	unsigned int nr_pages;
2606
	long left = mpd->wbc->nr_to_write;
J
Jan Kara 已提交
2607 2608 2609 2610 2611 2612 2613
	pgoff_t index = mpd->first_page;
	pgoff_t end = mpd->last_page;
	int tag;
	int i, err = 0;
	int blkbits = mpd->inode->i_blkbits;
	ext4_lblk_t lblk;
	struct buffer_head *head;
2614

J
Jan Kara 已提交
2615
	if (mpd->wbc->sync_mode == WB_SYNC_ALL || mpd->wbc->tagged_writepages)
2616 2617 2618 2619
		tag = PAGECACHE_TAG_TOWRITE;
	else
		tag = PAGECACHE_TAG_DIRTY;

2620
	pagevec_init(&pvec);
J
Jan Kara 已提交
2621 2622
	mpd->map.m_len = 0;
	mpd->next_page = index;
2623
	while (index <= end) {
J
Jan Kara 已提交
2624
		nr_pages = pagevec_lookup_range_tag(&pvec, mapping, &index, end,
2625
				tag);
2626
		if (nr_pages == 0)
J
Jan Kara 已提交
2627
			goto out;
2628 2629 2630 2631

		for (i = 0; i < nr_pages; i++) {
			struct page *page = pvec.pages[i];

2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642
			/*
			 * Accumulated enough dirty pages? This doesn't apply
			 * to WB_SYNC_ALL mode. For integrity sync we have to
			 * keep going because someone may be concurrently
			 * dirtying pages, and we might have synced a lot of
			 * newly appeared dirty pages, but have not synced all
			 * of the old dirty pages.
			 */
			if (mpd->wbc->sync_mode == WB_SYNC_NONE && left <= 0)
				goto out;

J
Jan Kara 已提交
2643 2644 2645
			/* If we can't merge this page, we are done. */
			if (mpd->map.m_len > 0 && mpd->next_page != page->index)
				goto out;
2646

2647 2648
			lock_page(page);
			/*
J
Jan Kara 已提交
2649 2650 2651 2652 2653
			 * If the page is no longer dirty, or its mapping no
			 * longer corresponds to inode we are writing (which
			 * means it has been truncated or invalidated), or the
			 * page is already under writeback and we are not doing
			 * a data integrity writeback, skip the page
2654
			 */
2655 2656
			if (!PageDirty(page) ||
			    (PageWriteback(page) &&
J
Jan Kara 已提交
2657
			     (mpd->wbc->sync_mode == WB_SYNC_NONE)) ||
2658
			    unlikely(page->mapping != mapping)) {
2659 2660 2661 2662
				unlock_page(page);
				continue;
			}

2663
			wait_on_page_writeback(page);
2664 2665
			BUG_ON(PageWriteback(page));

J
Jan Kara 已提交
2666
			if (mpd->map.m_len == 0)
2667 2668
				mpd->first_page = page->index;
			mpd->next_page = page->index + 1;
2669
			/* Add all dirty buffers to mpd */
J
Jan Kara 已提交
2670
			lblk = ((ext4_lblk_t)page->index) <<
2671
				(PAGE_SHIFT - blkbits);
2672
			head = page_buffers(page);
2673 2674
			err = mpage_process_page_bufs(mpd, head, head, lblk);
			if (err <= 0)
J
Jan Kara 已提交
2675
				goto out;
2676
			err = 0;
2677
			left--;
2678 2679 2680 2681
		}
		pagevec_release(&pvec);
		cond_resched();
	}
2682
	return 0;
2683 2684
out:
	pagevec_release(&pvec);
J
Jan Kara 已提交
2685
	return err;
2686 2687
}

2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698
static int __writepage(struct page *page, struct writeback_control *wbc,
		       void *data)
{
	struct address_space *mapping = data;
	int ret = ext4_writepage(page, wbc);
	mapping_set_error(mapping, ret);
	return ret;
}

static int ext4_writepages(struct address_space *mapping,
			   struct writeback_control *wbc)
2699
{
J
Jan Kara 已提交
2700 2701
	pgoff_t	writeback_index = 0;
	long nr_to_write = wbc->nr_to_write;
2702
	int range_whole = 0;
J
Jan Kara 已提交
2703
	int cycled = 1;
2704
	handle_t *handle = NULL;
2705
	struct mpage_da_data mpd;
2706
	struct inode *inode = mapping->host;
2707
	int needed_blocks, rsv_blocks = 0, ret = 0;
2708
	struct ext4_sb_info *sbi = EXT4_SB(mapping->host->i_sb);
J
Jan Kara 已提交
2709
	bool done;
S
Shaohua Li 已提交
2710
	struct blk_plug plug;
2711
	bool give_up_on_write = false;
2712

2713 2714 2715
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

2716
	percpu_down_read(&sbi->s_journal_flag_rwsem);
2717
	trace_ext4_writepages(inode, wbc);
2718

2719 2720 2721 2722 2723
	if (dax_mapping(mapping)) {
		ret = dax_writeback_mapping_range(mapping, inode->i_sb->s_bdev,
						  wbc);
		goto out_writepages;
	}
2724

2725 2726 2727 2728 2729
	/*
	 * No pages to write? This is mainly a kludge to avoid starting
	 * a transaction for special inodes like journal inode on last iput()
	 * because that could violate lock ordering on umount
	 */
2730
	if (!mapping->nrpages || !mapping_tagged(mapping, PAGECACHE_TAG_DIRTY))
2731
		goto out_writepages;
2732

2733 2734 2735 2736 2737 2738
	if (ext4_should_journal_data(inode)) {
		struct blk_plug plug;

		blk_start_plug(&plug);
		ret = write_cache_pages(mapping, wbc, __writepage, mapping);
		blk_finish_plug(&plug);
2739
		goto out_writepages;
2740 2741
	}

2742 2743 2744 2745
	/*
	 * If the filesystem has aborted, it is read-only, so return
	 * right away instead of dumping stack traces later on that
	 * will obscure the real source of the problem.  We test
2746
	 * EXT4_MF_FS_ABORTED instead of sb->s_flag's SB_RDONLY because
2747
	 * the latter could be true if the filesystem is mounted
2748
	 * read-only, and in that case, ext4_writepages should
2749 2750 2751
	 * *never* be called, so if that ever happens, we would want
	 * the stack trace.
	 */
2752 2753
	if (unlikely(ext4_forced_shutdown(EXT4_SB(mapping->host->i_sb)) ||
		     sbi->s_mount_flags & EXT4_MF_FS_ABORTED)) {
2754 2755 2756
		ret = -EROFS;
		goto out_writepages;
	}
2757

2758 2759
	if (ext4_should_dioread_nolock(inode)) {
		/*
2760
		 * We may need to convert up to one extent per block in
2761 2762
		 * the page and we may dirty the inode.
		 */
2763
		rsv_blocks = 1 + (PAGE_SIZE >> inode->i_blkbits);
2764 2765
	}

J
Jan Kara 已提交
2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783
	/*
	 * If we have inline data and arrive here, it means that
	 * we will soon create the block for the 1st page, so
	 * we'd better clear the inline data here.
	 */
	if (ext4_has_inline_data(inode)) {
		/* Just inode will be modified... */
		handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
			goto out_writepages;
		}
		BUG_ON(ext4_test_inode_state(inode,
				EXT4_STATE_MAY_INLINE_DATA));
		ext4_destroy_inline_data(handle, inode);
		ext4_journal_stop(handle);
	}

2784 2785
	if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX)
		range_whole = 1;
2786

2787
	if (wbc->range_cyclic) {
J
Jan Kara 已提交
2788 2789
		writeback_index = mapping->writeback_index;
		if (writeback_index)
2790
			cycled = 0;
J
Jan Kara 已提交
2791 2792
		mpd.first_page = writeback_index;
		mpd.last_page = -1;
2793
	} else {
2794 2795
		mpd.first_page = wbc->range_start >> PAGE_SHIFT;
		mpd.last_page = wbc->range_end >> PAGE_SHIFT;
2796
	}
2797

J
Jan Kara 已提交
2798 2799 2800
	mpd.inode = inode;
	mpd.wbc = wbc;
	ext4_io_submit_init(&mpd.io_submit, wbc);
2801
retry:
2802
	if (wbc->sync_mode == WB_SYNC_ALL || wbc->tagged_writepages)
J
Jan Kara 已提交
2803 2804
		tag_pages_for_writeback(mapping, mpd.first_page, mpd.last_page);
	done = false;
S
Shaohua Li 已提交
2805
	blk_start_plug(&plug);
2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828

	/*
	 * First writeback pages that don't need mapping - we can avoid
	 * starting a transaction unnecessarily and also avoid being blocked
	 * in the block layer on device congestion while having transaction
	 * started.
	 */
	mpd.do_map = 0;
	mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
	if (!mpd.io_submit.io_end) {
		ret = -ENOMEM;
		goto unplug;
	}
	ret = mpage_prepare_extent_to_map(&mpd);
	/* Submit prepared bio */
	ext4_io_submit(&mpd.io_submit);
	ext4_put_io_end_defer(mpd.io_submit.io_end);
	mpd.io_submit.io_end = NULL;
	/* Unlock pages we didn't use */
	mpage_release_unused_pages(&mpd, false);
	if (ret < 0)
		goto unplug;

J
Jan Kara 已提交
2829 2830 2831 2832 2833 2834 2835
	while (!done && mpd.first_page <= mpd.last_page) {
		/* For each extent of pages we use new io_end */
		mpd.io_submit.io_end = ext4_init_io_end(inode, GFP_KERNEL);
		if (!mpd.io_submit.io_end) {
			ret = -ENOMEM;
			break;
		}
2836 2837

		/*
J
Jan Kara 已提交
2838 2839 2840 2841 2842
		 * We have two constraints: We find one extent to map and we
		 * must always write out whole page (makes a difference when
		 * blocksize < pagesize) so that we don't block on IO when we
		 * try to write out the rest of the page. Journalled mode is
		 * not supported by delalloc.
2843 2844
		 */
		BUG_ON(ext4_should_journal_data(inode));
2845
		needed_blocks = ext4_da_writepages_trans_blocks(inode);
2846

J
Jan Kara 已提交
2847
		/* start a new transaction */
2848 2849
		handle = ext4_journal_start_with_reserve(inode,
				EXT4_HT_WRITE_PAGE, needed_blocks, rsv_blocks);
2850 2851
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
2852
			ext4_msg(inode->i_sb, KERN_CRIT, "%s: jbd2_start: "
2853
			       "%ld pages, ino %lu; err %d", __func__,
2854
				wbc->nr_to_write, inode->i_ino, ret);
J
Jan Kara 已提交
2855 2856
			/* Release allocated io_end */
			ext4_put_io_end(mpd.io_submit.io_end);
2857
			mpd.io_submit.io_end = NULL;
J
Jan Kara 已提交
2858
			break;
2859
		}
2860
		mpd.do_map = 1;
2861

J
Jan Kara 已提交
2862 2863 2864 2865
		trace_ext4_da_write_pages(inode, mpd.first_page, mpd.wbc);
		ret = mpage_prepare_extent_to_map(&mpd);
		if (!ret) {
			if (mpd.map.m_len)
2866 2867
				ret = mpage_map_and_submit_extent(handle, &mpd,
					&give_up_on_write);
J
Jan Kara 已提交
2868 2869 2870 2871 2872 2873 2874 2875 2876
			else {
				/*
				 * We scanned the whole range (or exhausted
				 * nr_to_write), submitted what was mapped and
				 * didn't find anything needing mapping. We are
				 * done.
				 */
				done = true;
			}
2877
		}
2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890
		/*
		 * Caution: If the handle is synchronous,
		 * ext4_journal_stop() can wait for transaction commit
		 * to finish which may depend on writeback of pages to
		 * complete or on page lock to be released.  In that
		 * case, we have to wait until after after we have
		 * submitted all the IO, released page locks we hold,
		 * and dropped io_end reference (for extent conversion
		 * to be able to complete) before stopping the handle.
		 */
		if (!ext4_handle_valid(handle) || handle->h_sync == 0) {
			ext4_journal_stop(handle);
			handle = NULL;
2891
			mpd.do_map = 0;
2892
		}
J
Jan Kara 已提交
2893 2894 2895
		/* Submit prepared bio */
		ext4_io_submit(&mpd.io_submit);
		/* Unlock pages we didn't use */
2896
		mpage_release_unused_pages(&mpd, give_up_on_write);
2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908
		/*
		 * Drop our io_end reference we got from init. We have
		 * to be careful and use deferred io_end finishing if
		 * we are still holding the transaction as we can
		 * release the last reference to io_end which may end
		 * up doing unwritten extent conversion.
		 */
		if (handle) {
			ext4_put_io_end_defer(mpd.io_submit.io_end);
			ext4_journal_stop(handle);
		} else
			ext4_put_io_end(mpd.io_submit.io_end);
2909
		mpd.io_submit.io_end = NULL;
J
Jan Kara 已提交
2910 2911 2912 2913

		if (ret == -ENOSPC && sbi->s_journal) {
			/*
			 * Commit the transaction which would
2914 2915 2916
			 * free blocks released in the transaction
			 * and try again
			 */
2917
			jbd2_journal_force_commit_nested(sbi->s_journal);
2918
			ret = 0;
J
Jan Kara 已提交
2919 2920 2921 2922
			continue;
		}
		/* Fatal error - ENOMEM, EIO... */
		if (ret)
2923
			break;
2924
	}
2925
unplug:
S
Shaohua Li 已提交
2926
	blk_finish_plug(&plug);
2927
	if (!ret && !cycled && wbc->nr_to_write > 0) {
2928
		cycled = 1;
J
Jan Kara 已提交
2929 2930
		mpd.last_page = writeback_index - 1;
		mpd.first_page = 0;
2931 2932
		goto retry;
	}
2933 2934 2935 2936

	/* Update index */
	if (wbc->range_cyclic || (range_whole && wbc->nr_to_write > 0))
		/*
J
Jan Kara 已提交
2937
		 * Set the writeback_index so that range_cyclic
2938 2939
		 * mode will write it back later
		 */
J
Jan Kara 已提交
2940
		mapping->writeback_index = mpd.first_page;
2941

2942
out_writepages:
2943 2944
	trace_ext4_writepages_result(inode, wbc, ret,
				     nr_to_write - wbc->nr_to_write);
2945
	percpu_up_read(&sbi->s_journal_flag_rwsem);
2946
	return ret;
2947 2948
}

2949 2950
static int ext4_nonda_switch(struct super_block *sb)
{
2951
	s64 free_clusters, dirty_clusters;
2952 2953 2954 2955 2956
	struct ext4_sb_info *sbi = EXT4_SB(sb);

	/*
	 * switch to non delalloc mode if we are running low
	 * on free block. The free block accounting via percpu
2957
	 * counters can get slightly wrong with percpu_counter_batch getting
2958 2959 2960 2961
	 * accumulated on each CPU without updating global counters
	 * Delalloc need an accurate free block accounting. So switch
	 * to non delalloc when we are near to error range.
	 */
2962 2963 2964 2965
	free_clusters =
		percpu_counter_read_positive(&sbi->s_freeclusters_counter);
	dirty_clusters =
		percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
2966 2967 2968
	/*
	 * Start pushing delalloc when 1/2 of free blocks are dirty.
	 */
2969
	if (dirty_clusters && (free_clusters < 2 * dirty_clusters))
2970
		try_to_writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
2971

2972 2973
	if (2 * free_clusters < 3 * dirty_clusters ||
	    free_clusters < (dirty_clusters + EXT4_FREECLUSTERS_WATERMARK)) {
2974
		/*
2975 2976
		 * free block count is less than 150% of dirty blocks
		 * or free blocks is less than watermark
2977 2978 2979 2980 2981 2982
		 */
		return 1;
	}
	return 0;
}

2983 2984 2985
/* We always reserve for an inode update; the superblock could be there too */
static int ext4_da_write_credits(struct inode *inode, loff_t pos, unsigned len)
{
2986
	if (likely(ext4_has_feature_large_file(inode->i_sb)))
2987 2988 2989 2990 2991 2992 2993 2994 2995
		return 1;

	if (pos + len <= 0x7fffffffULL)
		return 1;

	/* We might need to update the superblock to set LARGE_FILE */
	return 2;
}

2996
static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
2997 2998
			       loff_t pos, unsigned len, unsigned flags,
			       struct page **pagep, void **fsdata)
2999
{
3000
	int ret, retries = 0;
3001 3002 3003 3004 3005
	struct page *page;
	pgoff_t index;
	struct inode *inode = mapping->host;
	handle_t *handle;

3006 3007 3008
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

3009
	index = pos >> PAGE_SHIFT;
3010

3011 3012
	if (ext4_nonda_switch(inode->i_sb) ||
	    S_ISLNK(inode->i_mode)) {
3013 3014 3015 3016 3017
		*fsdata = (void *)FALL_BACK_TO_NONDELALLOC;
		return ext4_write_begin(file, mapping, pos,
					len, flags, pagep, fsdata);
	}
	*fsdata = (void *)0;
3018
	trace_ext4_da_write_begin(inode, pos, len, flags);
3019 3020 3021 3022 3023 3024

	if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA)) {
		ret = ext4_da_write_inline_data_begin(mapping, inode,
						      pos, len, flags,
						      pagep, fsdata);
		if (ret < 0)
3025 3026 3027
			return ret;
		if (ret == 1)
			return 0;
3028 3029
	}

3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042
	/*
	 * grab_cache_page_write_begin() can take a long time if the
	 * system is thrashing due to memory pressure, or if the page
	 * is being written back.  So grab it first before we start
	 * the transaction handle.  This also allows us to allocate
	 * the page (if needed) without using GFP_NOFS.
	 */
retry_grab:
	page = grab_cache_page_write_begin(mapping, index, flags);
	if (!page)
		return -ENOMEM;
	unlock_page(page);

3043 3044 3045 3046 3047 3048
	/*
	 * With delayed allocation, we don't log the i_disksize update
	 * if there is delayed block allocation. But we still need
	 * to journalling the i_disksize update if writes to the end
	 * of file which has an already mapped buffer.
	 */
3049
retry_journal:
3050 3051
	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
				ext4_da_write_credits(inode, pos, len));
3052
	if (IS_ERR(handle)) {
3053
		put_page(page);
3054
		return PTR_ERR(handle);
3055 3056
	}

3057 3058 3059 3060
	lock_page(page);
	if (page->mapping != mapping) {
		/* The page got truncated from under us */
		unlock_page(page);
3061
		put_page(page);
3062
		ext4_journal_stop(handle);
3063
		goto retry_grab;
3064
	}
3065
	/* In case writeback began while the page was unlocked */
3066
	wait_for_stable_page(page);
3067

3068 3069 3070 3071
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	ret = ext4_block_write_begin(page, pos, len,
				     ext4_da_get_block_prep);
#else
3072
	ret = __block_write_begin(page, pos, len, ext4_da_get_block_prep);
3073
#endif
3074 3075 3076
	if (ret < 0) {
		unlock_page(page);
		ext4_journal_stop(handle);
3077 3078 3079 3080 3081 3082
		/*
		 * block_write_begin may have instantiated a few blocks
		 * outside i_size.  Trim these off again. Don't need
		 * i_size_read because we hold i_mutex.
		 */
		if (pos + len > inode->i_size)
3083
			ext4_truncate_failed_write(inode);
3084 3085 3086 3087 3088

		if (ret == -ENOSPC &&
		    ext4_should_retry_alloc(inode->i_sb, &retries))
			goto retry_journal;

3089
		put_page(page);
3090
		return ret;
3091 3092
	}

3093
	*pagep = page;
3094 3095 3096
	return ret;
}

3097 3098 3099 3100 3101
/*
 * Check if we should update i_disksize
 * when write to the end of file but not require block allocation
 */
static int ext4_da_should_update_i_disksize(struct page *page,
3102
					    unsigned long offset)
3103 3104 3105 3106 3107 3108 3109 3110 3111
{
	struct buffer_head *bh;
	struct inode *inode = page->mapping->host;
	unsigned int idx;
	int i;

	bh = page_buffers(page);
	idx = offset >> inode->i_blkbits;

3112
	for (i = 0; i < idx; i++)
3113 3114
		bh = bh->b_this_page;

3115
	if (!buffer_mapped(bh) || (buffer_delay(bh)) || buffer_unwritten(bh))
3116 3117 3118 3119
		return 0;
	return 1;
}

3120
static int ext4_da_write_end(struct file *file,
3121 3122 3123
			     struct address_space *mapping,
			     loff_t pos, unsigned len, unsigned copied,
			     struct page *page, void *fsdata)
3124 3125 3126 3127 3128
{
	struct inode *inode = mapping->host;
	int ret = 0, ret2;
	handle_t *handle = ext4_journal_current_handle();
	loff_t new_i_size;
3129
	unsigned long start, end;
3130 3131
	int write_mode = (int)(unsigned long)fsdata;

3132 3133 3134
	if (write_mode == FALL_BACK_TO_NONDELALLOC)
		return ext4_write_end(file, mapping, pos,
				      len, copied, page, fsdata);
3135

3136
	trace_ext4_da_write_end(inode, pos, len, copied);
3137
	start = pos & (PAGE_SIZE - 1);
3138
	end = start + copied - 1;
3139 3140 3141 3142 3143 3144 3145

	/*
	 * generic_write_end() will run mark_inode_dirty() if i_size
	 * changes.  So let's piggyback the i_disksize mark_inode_dirty
	 * into that.
	 */
	new_i_size = pos + copied;
3146
	if (copied && new_i_size > EXT4_I(inode)->i_disksize) {
3147 3148
		if (ext4_has_inline_data(inode) ||
		    ext4_da_should_update_i_disksize(page, end)) {
3149
			ext4_update_i_disksize(inode, new_i_size);
3150 3151 3152 3153 3154
			/* We need to mark inode dirty even if
			 * new_i_size is less that inode->i_size
			 * bu greater than i_disksize.(hint delalloc)
			 */
			ext4_mark_inode_dirty(handle, inode);
3155
		}
3156
	}
3157 3158 3159 3160 3161 3162 3163 3164

	if (write_mode != CONVERT_INLINE_DATA &&
	    ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) &&
	    ext4_has_inline_data(inode))
		ret2 = ext4_da_write_inline_data_end(inode, pos, len, copied,
						     page);
	else
		ret2 = generic_write_end(file, mapping, pos, len, copied,
3165
							page, fsdata);
3166

3167 3168 3169 3170 3171 3172 3173 3174 3175 3176
	copied = ret2;
	if (ret2 < 0)
		ret = ret2;
	ret2 = ext4_journal_stop(handle);
	if (!ret)
		ret = ret2;

	return ret ? ret : copied;
}

3177 3178
static void ext4_da_invalidatepage(struct page *page, unsigned int offset,
				   unsigned int length)
3179 3180 3181 3182 3183 3184 3185 3186
{
	/*
	 * Drop reserved blocks
	 */
	BUG_ON(!PageLocked(page));
	if (!page_has_buffers(page))
		goto out;

3187
	ext4_da_page_release_reservation(page, offset, length);
3188 3189

out:
3190
	ext4_invalidatepage(page, offset, length);
3191 3192 3193 3194

	return;
}

3195 3196 3197 3198 3199
/*
 * Force all delayed allocation blocks to be allocated for a given inode.
 */
int ext4_alloc_da_blocks(struct inode *inode)
{
3200 3201
	trace_ext4_alloc_da_blocks(inode);

3202
	if (!EXT4_I(inode)->i_reserved_data_blocks)
3203 3204 3205 3206 3207 3208 3209 3210
		return 0;

	/*
	 * We do something simple for now.  The filemap_flush() will
	 * also start triggering a write of the data blocks, which is
	 * not strictly speaking necessary (and for users of
	 * laptop_mode, not even desirable).  However, to do otherwise
	 * would require replicating code paths in:
3211
	 *
3212
	 * ext4_writepages() ->
3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223
	 *    write_cache_pages() ---> (via passed in callback function)
	 *        __mpage_da_writepage() -->
	 *           mpage_add_bh_to_extent()
	 *           mpage_da_map_blocks()
	 *
	 * The problem is that write_cache_pages(), located in
	 * mm/page-writeback.c, marks pages clean in preparation for
	 * doing I/O, which is not desirable if we're not planning on
	 * doing I/O at all.
	 *
	 * We could call write_cache_pages(), and then redirty all of
3224
	 * the pages by calling redirty_page_for_writepage() but that
3225 3226
	 * would be ugly in the extreme.  So instead we would need to
	 * replicate parts of the code in the above functions,
L
Lucas De Marchi 已提交
3227
	 * simplifying them because we wouldn't actually intend to
3228 3229 3230
	 * write out the pages, but rather only collect contiguous
	 * logical block extents, call the multi-block allocator, and
	 * then update the buffer heads with the block allocations.
3231
	 *
3232 3233 3234 3235 3236 3237
	 * For now, though, we'll cheat by calling filemap_flush(),
	 * which will map the blocks, and start the I/O, but not
	 * actually wait for the I/O to complete.
	 */
	return filemap_flush(inode->i_mapping);
}
3238

3239 3240 3241 3242 3243
/*
 * bmap() is special.  It gets used by applications such as lilo and by
 * the swapper to find the on-disk block of a specific piece of data.
 *
 * Naturally, this is dangerous if the block concerned is still in the
3244
 * journal.  If somebody makes a swapfile on an ext4 data-journaling
3245 3246 3247 3248 3249 3250 3251 3252
 * filesystem and enables swap, then they may get a nasty shock when the
 * data getting swapped to that swapfile suddenly gets overwritten by
 * the original zero's written out previously to the journal and
 * awaiting writeback in the kernel's buffer cache.
 *
 * So, if we see any bmap calls here on a modified, data-journaled file,
 * take extra steps to flush any blocks which might be in the cache.
 */
3253
static sector_t ext4_bmap(struct address_space *mapping, sector_t block)
3254 3255 3256 3257 3258
{
	struct inode *inode = mapping->host;
	journal_t *journal;
	int err;

T
Tao Ma 已提交
3259 3260 3261 3262 3263 3264
	/*
	 * We can get here for an inline file via the FIBMAP ioctl
	 */
	if (ext4_has_inline_data(inode))
		return 0;

3265 3266 3267 3268 3269 3270 3271 3272 3273 3274
	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY) &&
			test_opt(inode->i_sb, DELALLOC)) {
		/*
		 * With delalloc we want to sync the file
		 * so that we can make sure we allocate
		 * blocks for file
		 */
		filemap_write_and_wait(mapping);
	}

3275 3276
	if (EXT4_JOURNAL(inode) &&
	    ext4_test_inode_state(inode, EXT4_STATE_JDATA)) {
3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287
		/*
		 * This is a REALLY heavyweight approach, but the use of
		 * bmap on dirty files is expected to be extremely rare:
		 * only if we run lilo or swapon on a freshly made file
		 * do we expect this to happen.
		 *
		 * (bmap requires CAP_SYS_RAWIO so this does not
		 * represent an unprivileged user DOS attack --- we'd be
		 * in trouble if mortal users could trigger this path at
		 * will.)
		 *
3288
		 * NB. EXT4_STATE_JDATA is not set on files other than
3289 3290 3291 3292 3293 3294
		 * regular files.  If somebody wants to bmap a directory
		 * or symlink and gets confused because the buffer
		 * hasn't yet been flushed to disk, they deserve
		 * everything they get.
		 */

3295
		ext4_clear_inode_state(inode, EXT4_STATE_JDATA);
3296
		journal = EXT4_JOURNAL(inode);
3297 3298 3299
		jbd2_journal_lock_updates(journal);
		err = jbd2_journal_flush(journal);
		jbd2_journal_unlock_updates(journal);
3300 3301 3302 3303 3304

		if (err)
			return 0;
	}

3305
	return generic_block_bmap(mapping, block, ext4_get_block);
3306 3307
}

3308
static int ext4_readpage(struct file *file, struct page *page)
3309
{
T
Tao Ma 已提交
3310 3311 3312
	int ret = -EAGAIN;
	struct inode *inode = page->mapping->host;

3313
	trace_ext4_readpage(page);
T
Tao Ma 已提交
3314 3315 3316 3317 3318

	if (ext4_has_inline_data(inode))
		ret = ext4_readpage_inline(inode, page);

	if (ret == -EAGAIN)
3319
		return ext4_mpage_readpages(page->mapping, NULL, page, 1);
T
Tao Ma 已提交
3320 3321

	return ret;
3322 3323 3324
}

static int
3325
ext4_readpages(struct file *file, struct address_space *mapping,
3326 3327
		struct list_head *pages, unsigned nr_pages)
{
T
Tao Ma 已提交
3328 3329 3330 3331 3332 3333
	struct inode *inode = mapping->host;

	/* If the file has inline data, no need to do readpages. */
	if (ext4_has_inline_data(inode))
		return 0;

3334
	return ext4_mpage_readpages(mapping, pages, NULL, nr_pages);
3335 3336
}

3337 3338
static void ext4_invalidatepage(struct page *page, unsigned int offset,
				unsigned int length)
3339
{
3340
	trace_ext4_invalidatepage(page, offset, length);
3341

3342 3343 3344
	/* No journalling happens on data buffers when this function is used */
	WARN_ON(page_has_buffers(page) && buffer_jbd(page_buffers(page)));

3345
	block_invalidatepage(page, offset, length);
3346 3347
}

3348
static int __ext4_journalled_invalidatepage(struct page *page,
3349 3350
					    unsigned int offset,
					    unsigned int length)
3351 3352 3353
{
	journal_t *journal = EXT4_JOURNAL(page->mapping->host);

3354
	trace_ext4_journalled_invalidatepage(page, offset, length);
3355

3356 3357 3358
	/*
	 * If it's a full truncate we just forget about the pending dirtying
	 */
3359
	if (offset == 0 && length == PAGE_SIZE)
3360 3361
		ClearPageChecked(page);

3362
	return jbd2_journal_invalidatepage(journal, page, offset, length);
3363 3364 3365 3366
}

/* Wrapper for aops... */
static void ext4_journalled_invalidatepage(struct page *page,
3367 3368
					   unsigned int offset,
					   unsigned int length)
3369
{
3370
	WARN_ON(__ext4_journalled_invalidatepage(page, offset, length) < 0);
3371 3372
}

3373
static int ext4_releasepage(struct page *page, gfp_t wait)
3374
{
3375
	journal_t *journal = EXT4_JOURNAL(page->mapping->host);
3376

3377 3378
	trace_ext4_releasepage(page);

3379 3380
	/* Page has dirty journalled data -> cannot release */
	if (PageChecked(page))
3381
		return 0;
3382 3383 3384 3385
	if (journal)
		return jbd2_journal_try_to_free_buffers(journal, page, wait);
	else
		return try_to_free_buffers(page);
3386 3387
}

3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400
static bool ext4_inode_datasync_dirty(struct inode *inode)
{
	journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;

	if (journal)
		return !jbd2_transaction_committed(journal,
					EXT4_I(inode)->i_datasync_tid);
	/* Any metadata buffers to write? */
	if (!list_empty(&inode->i_mapping->private_list))
		return true;
	return inode->i_state & I_DIRTY_DATASYNC;
}

3401 3402 3403
static int ext4_iomap_begin(struct inode *inode, loff_t offset, loff_t length,
			    unsigned flags, struct iomap *iomap)
{
3404
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3405 3406 3407 3408
	unsigned int blkbits = inode->i_blkbits;
	unsigned long first_block = offset >> blkbits;
	unsigned long last_block = (offset + length - 1) >> blkbits;
	struct ext4_map_blocks map;
3409
	bool delalloc = false;
3410 3411
	int ret;

3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425

	if (flags & IOMAP_REPORT) {
		if (ext4_has_inline_data(inode)) {
			ret = ext4_inline_data_iomap(inode, iomap);
			if (ret != -EAGAIN) {
				if (ret == 0 && offset >= iomap->length)
					ret = -ENOENT;
				return ret;
			}
		}
	} else {
		if (WARN_ON_ONCE(ext4_has_inline_data(inode)))
			return -ERANGE;
	}
3426 3427 3428 3429

	map.m_lblk = first_block;
	map.m_len = last_block - first_block + 1;

3430
	if (flags & IOMAP_REPORT) {
J
Jan Kara 已提交
3431
		ret = ext4_map_blocks(NULL, inode, &map, 0);
3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456
		if (ret < 0)
			return ret;

		if (ret == 0) {
			ext4_lblk_t end = map.m_lblk + map.m_len - 1;
			struct extent_status es;

			ext4_es_find_delayed_extent_range(inode, map.m_lblk, end, &es);

			if (!es.es_len || es.es_lblk > end) {
				/* entire range is a hole */
			} else if (es.es_lblk > map.m_lblk) {
				/* range starts with a hole */
				map.m_len = es.es_lblk - map.m_lblk;
			} else {
				ext4_lblk_t offs = 0;

				if (es.es_lblk < map.m_lblk)
					offs = map.m_lblk - es.es_lblk;
				map.m_lblk = es.es_lblk + offs;
				map.m_len = es.es_len - offs;
				delalloc = true;
			}
		}
	} else if (flags & IOMAP_WRITE) {
J
Jan Kara 已提交
3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487
		int dio_credits;
		handle_t *handle;
		int retries = 0;

		/* Trim mapping request to maximum we can map at once for DIO */
		if (map.m_len > DIO_MAX_BLOCKS)
			map.m_len = DIO_MAX_BLOCKS;
		dio_credits = ext4_chunk_trans_blocks(inode, map.m_len);
retry:
		/*
		 * Either we allocate blocks and then we don't get unwritten
		 * extent so we have reserved enough credits, or the blocks
		 * are already allocated and unwritten and in that case
		 * extent conversion fits in the credits as well.
		 */
		handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
					    dio_credits);
		if (IS_ERR(handle))
			return PTR_ERR(handle);

		ret = ext4_map_blocks(handle, inode, &map,
				      EXT4_GET_BLOCKS_CREATE_ZERO);
		if (ret < 0) {
			ext4_journal_stop(handle);
			if (ret == -ENOSPC &&
			    ext4_should_retry_alloc(inode->i_sb, &retries))
				goto retry;
			return ret;
		}

		/*
3488
		 * If we added blocks beyond i_size, we need to make sure they
J
Jan Kara 已提交
3489
		 * will get truncated if we crash before updating i_size in
3490 3491 3492 3493 3494
		 * ext4_iomap_end(). For faults we don't need to do that (and
		 * even cannot because for orphan list operations inode_lock is
		 * required) - if we happen to instantiate block beyond i_size,
		 * it is because we race with truncate which has already added
		 * the inode to the orphan list.
J
Jan Kara 已提交
3495
		 */
3496 3497
		if (!(flags & IOMAP_FAULT) && first_block + map.m_len >
		    (i_size_read(inode) + (1 << blkbits) - 1) >> blkbits) {
J
Jan Kara 已提交
3498 3499 3500 3501 3502 3503 3504 3505 3506
			int err;

			err = ext4_orphan_add(handle, inode);
			if (err < 0) {
				ext4_journal_stop(handle);
				return err;
			}
		}
		ext4_journal_stop(handle);
3507 3508 3509 3510
	} else {
		ret = ext4_map_blocks(NULL, inode, &map, 0);
		if (ret < 0)
			return ret;
J
Jan Kara 已提交
3511
	}
3512 3513

	iomap->flags = 0;
3514
	if (ext4_inode_datasync_dirty(inode))
3515
		iomap->flags |= IOMAP_F_DIRTY;
3516 3517
	iomap->bdev = inode->i_sb->s_bdev;
	iomap->dax_dev = sbi->s_daxdev;
3518
	iomap->offset = first_block << blkbits;
3519
	iomap->length = (u64)map.m_len << blkbits;
3520 3521

	if (ret == 0) {
3522
		iomap->type = delalloc ? IOMAP_DELALLOC : IOMAP_HOLE;
3523
		iomap->addr = IOMAP_NULL_ADDR;
3524 3525 3526 3527 3528 3529 3530 3531 3532
	} else {
		if (map.m_flags & EXT4_MAP_MAPPED) {
			iomap->type = IOMAP_MAPPED;
		} else if (map.m_flags & EXT4_MAP_UNWRITTEN) {
			iomap->type = IOMAP_UNWRITTEN;
		} else {
			WARN_ON_ONCE(1);
			return -EIO;
		}
3533
		iomap->addr = (u64)map.m_pblk << blkbits;
3534 3535 3536 3537
	}

	if (map.m_flags & EXT4_MAP_NEW)
		iomap->flags |= IOMAP_F_NEW;
3538

3539 3540 3541
	return 0;
}

J
Jan Kara 已提交
3542 3543 3544 3545 3546 3547 3548 3549
static int ext4_iomap_end(struct inode *inode, loff_t offset, loff_t length,
			  ssize_t written, unsigned flags, struct iomap *iomap)
{
	int ret = 0;
	handle_t *handle;
	int blkbits = inode->i_blkbits;
	bool truncate = false;

3550
	if (!(flags & IOMAP_WRITE) || (flags & IOMAP_FAULT))
J
Jan Kara 已提交
3551 3552 3553 3554 3555 3556 3557 3558 3559 3560 3561 3562 3563 3564 3565 3566 3567 3568 3569 3570 3571 3572 3573 3574 3575 3576 3577 3578 3579 3580 3581 3582 3583 3584 3585 3586 3587 3588 3589 3590 3591 3592 3593
		return 0;

	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		goto orphan_del;
	}
	if (ext4_update_inode_size(inode, offset + written))
		ext4_mark_inode_dirty(handle, inode);
	/*
	 * We may need to truncate allocated but not written blocks beyond EOF.
	 */
	if (iomap->offset + iomap->length > 
	    ALIGN(inode->i_size, 1 << blkbits)) {
		ext4_lblk_t written_blk, end_blk;

		written_blk = (offset + written) >> blkbits;
		end_blk = (offset + length) >> blkbits;
		if (written_blk < end_blk && ext4_can_truncate(inode))
			truncate = true;
	}
	/*
	 * Remove inode from orphan list if we were extending a inode and
	 * everything went fine.
	 */
	if (!truncate && inode->i_nlink &&
	    !list_empty(&EXT4_I(inode)->i_orphan))
		ext4_orphan_del(handle, inode);
	ext4_journal_stop(handle);
	if (truncate) {
		ext4_truncate_failed_write(inode);
orphan_del:
		/*
		 * If truncate failed early the inode might still be on the
		 * orphan list; we need to make sure the inode is removed from
		 * the orphan list in that case.
		 */
		if (inode->i_nlink)
			ext4_orphan_del(NULL, inode);
	}
	return ret;
}

3594
const struct iomap_ops ext4_iomap_ops = {
3595
	.iomap_begin		= ext4_iomap_begin,
J
Jan Kara 已提交
3596
	.iomap_end		= ext4_iomap_end,
3597 3598
};

3599
static int ext4_end_io_dio(struct kiocb *iocb, loff_t offset,
3600
			    ssize_t size, void *private)
3601
{
3602
        ext4_io_end_t *io_end = private;
3603

J
Jan Kara 已提交
3604
	/* if not async direct IO just return */
3605
	if (!io_end)
3606
		return 0;
3607

3608
	ext_debug("ext4_end_io_dio(): io_end 0x%p "
3609
		  "for inode %lu, iocb 0x%p, offset %llu, size %zd\n",
3610
		  io_end, io_end->inode->i_ino, iocb, offset, size);
3611

3612 3613 3614 3615 3616 3617 3618 3619
	/*
	 * Error during AIO DIO. We cannot convert unwritten extents as the
	 * data was not written. Just clear the unwritten flag and drop io_end.
	 */
	if (size <= 0) {
		ext4_clear_io_unwritten_flag(io_end);
		size = 0;
	}
3620 3621
	io_end->offset = offset;
	io_end->size = size;
3622
	ext4_put_io_end(io_end);
3623 3624

	return 0;
3625
}
3626

3627
/*
J
Jan Kara 已提交
3628 3629 3630
 * Handling of direct IO writes.
 *
 * For ext4 extent files, ext4 will do direct-io write even to holes,
3631 3632 3633
 * preallocated extents, and those write extend the file, no need to
 * fall back to buffered IO.
 *
3634
 * For holes, we fallocate those blocks, mark them as unwritten
3635
 * If those blocks were preallocated, we mark sure they are split, but
3636
 * still keep the range to write as unwritten.
3637
 *
3638
 * The unwritten extents will be converted to written when DIO is completed.
3639
 * For async direct IO, since the IO may still pending when return, we
L
Lucas De Marchi 已提交
3640
 * set up an end_io call back function, which will do the conversion
3641
 * when async direct IO completed.
3642 3643 3644 3645 3646 3647
 *
 * If the O_DIRECT write will extend the file then add this inode to the
 * orphan list.  So recovery will truncate it back to the original size
 * if the machine crashes during the write.
 *
 */
3648
static ssize_t ext4_direct_IO_write(struct kiocb *iocb, struct iov_iter *iter)
3649 3650 3651
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
J
Jan Kara 已提交
3652
	struct ext4_inode_info *ei = EXT4_I(inode);
3653
	ssize_t ret;
3654
	loff_t offset = iocb->ki_pos;
3655
	size_t count = iov_iter_count(iter);
3656 3657 3658
	int overwrite = 0;
	get_block_t *get_block_func = NULL;
	int dio_flags = 0;
3659
	loff_t final_size = offset + count;
J
Jan Kara 已提交
3660 3661
	int orphan = 0;
	handle_t *handle;
3662

J
Jan Kara 已提交
3663 3664 3665 3666 3667 3668 3669 3670 3671 3672 3673 3674 3675 3676 3677 3678
	if (final_size > inode->i_size) {
		/* Credits for sb + inode write */
		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
		if (IS_ERR(handle)) {
			ret = PTR_ERR(handle);
			goto out;
		}
		ret = ext4_orphan_add(handle, inode);
		if (ret) {
			ext4_journal_stop(handle);
			goto out;
		}
		orphan = 1;
		ei->i_disksize = inode->i_size;
		ext4_journal_stop(handle);
	}
3679

3680
	BUG_ON(iocb->private == NULL);
3681

3682 3683 3684 3685 3686
	/*
	 * Make all waiters for direct IO properly wait also for extent
	 * conversion. This also disallows race between truncate() and
	 * overwrite DIO as i_dio_count needs to be incremented under i_mutex.
	 */
J
Jan Kara 已提交
3687
	inode_dio_begin(inode);
3688

3689 3690
	/* If we do a overwrite dio, i_mutex locking can be released */
	overwrite = *((int *)iocb->private);
3691

3692
	if (overwrite)
A
Al Viro 已提交
3693
		inode_unlock(inode);
3694

3695
	/*
J
Jan Kara 已提交
3696
	 * For extent mapped files we could direct write to holes and fallocate.
3697
	 *
3698 3699 3700
	 * Allocated blocks to fill the hole are marked as unwritten to prevent
	 * parallel buffered read to expose the stale data before DIO complete
	 * the data IO.
3701
	 *
3702 3703
	 * As to previously fallocated extents, ext4 get_block will just simply
	 * mark the buffer mapped but still keep the extents unwritten.
3704
	 *
3705 3706 3707 3708
	 * For non AIO case, we will convert those unwritten extents to written
	 * after return back from blockdev_direct_IO. That way we save us from
	 * allocating io_end structure and also the overhead of offloading
	 * the extent convertion to a workqueue.
3709 3710 3711 3712 3713 3714 3715
	 *
	 * For async DIO, the conversion needs to be deferred when the
	 * IO is completed. The ext4 end_io callback function will be
	 * called to take care of the conversion work.  Here for async
	 * case, we allocate an io_end structure to hook to the iocb.
	 */
	iocb->private = NULL;
3716
	if (overwrite)
3717
		get_block_func = ext4_dio_get_block_overwrite;
3718
	else if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) ||
F
Fabian Frederick 已提交
3719
		   round_down(offset, i_blocksize(inode)) >= inode->i_size) {
J
Jan Kara 已提交
3720 3721 3722
		get_block_func = ext4_dio_get_block;
		dio_flags = DIO_LOCKING | DIO_SKIP_HOLES;
	} else if (is_sync_kiocb(iocb)) {
3723 3724
		get_block_func = ext4_dio_get_block_unwritten_sync;
		dio_flags = DIO_LOCKING;
3725
	} else {
3726
		get_block_func = ext4_dio_get_block_unwritten_async;
3727 3728
		dio_flags = DIO_LOCKING;
	}
3729 3730 3731
	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,
				   get_block_func, ext4_end_io_dio, NULL,
				   dio_flags);
3732

J
Jan Kara 已提交
3733
	if (ret > 0 && !overwrite && ext4_test_inode_state(inode,
3734 3735 3736 3737 3738 3739
						EXT4_STATE_DIO_UNWRITTEN)) {
		int err;
		/*
		 * for non AIO case, since the IO is already
		 * completed, we could do the conversion right here
		 */
3740
		err = ext4_convert_unwritten_extents(NULL, inode,
3741 3742 3743 3744 3745
						     offset, ret);
		if (err < 0)
			ret = err;
		ext4_clear_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
	}
3746

J
Jan Kara 已提交
3747
	inode_dio_end(inode);
3748
	/* take i_mutex locking again if we do a ovewrite dio */
3749
	if (overwrite)
A
Al Viro 已提交
3750
		inode_lock(inode);
3751

J
Jan Kara 已提交
3752 3753 3754 3755 3756 3757 3758 3759 3760 3761 3762 3763 3764 3765 3766 3767 3768 3769 3770 3771 3772 3773 3774 3775 3776 3777 3778 3779 3780 3781 3782 3783 3784 3785 3786 3787 3788 3789 3790 3791 3792 3793 3794 3795
	if (ret < 0 && final_size > inode->i_size)
		ext4_truncate_failed_write(inode);

	/* Handle extending of i_size after direct IO write */
	if (orphan) {
		int err;

		/* Credits for sb + inode write */
		handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
		if (IS_ERR(handle)) {
			/* This is really bad luck. We've written the data
			 * but cannot extend i_size. Bail out and pretend
			 * the write failed... */
			ret = PTR_ERR(handle);
			if (inode->i_nlink)
				ext4_orphan_del(NULL, inode);

			goto out;
		}
		if (inode->i_nlink)
			ext4_orphan_del(handle, inode);
		if (ret > 0) {
			loff_t end = offset + ret;
			if (end > inode->i_size) {
				ei->i_disksize = end;
				i_size_write(inode, end);
				/*
				 * We're going to return a positive `ret'
				 * here due to non-zero-length I/O, so there's
				 * no way of reporting error returns from
				 * ext4_mark_inode_dirty() to userspace.  So
				 * ignore it.
				 */
				ext4_mark_inode_dirty(handle, inode);
			}
		}
		err = ext4_journal_stop(handle);
		if (ret == 0)
			ret = err;
	}
out:
	return ret;
}

3796
static ssize_t ext4_direct_IO_read(struct kiocb *iocb, struct iov_iter *iter)
J
Jan Kara 已提交
3797
{
J
Jan Kara 已提交
3798 3799
	struct address_space *mapping = iocb->ki_filp->f_mapping;
	struct inode *inode = mapping->host;
3800
	size_t count = iov_iter_count(iter);
J
Jan Kara 已提交
3801 3802
	ssize_t ret;

J
Jan Kara 已提交
3803 3804 3805 3806 3807 3808
	/*
	 * Shared inode_lock is enough for us - it protects against concurrent
	 * writes & truncates and since we take care of writing back page cache,
	 * we are protected against page writeback as well.
	 */
	inode_lock_shared(inode);
3809
	ret = filemap_write_and_wait_range(mapping, iocb->ki_pos,
3810
					   iocb->ki_pos + count - 1);
3811 3812 3813 3814
	if (ret)
		goto out_unlock;
	ret = __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev,
				   iter, ext4_dio_get_block, NULL, NULL, 0);
J
Jan Kara 已提交
3815 3816
out_unlock:
	inode_unlock_shared(inode);
3817
	return ret;
3818 3819
}

3820
static ssize_t ext4_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
3821 3822 3823
{
	struct file *file = iocb->ki_filp;
	struct inode *inode = file->f_mapping->host;
3824
	size_t count = iov_iter_count(iter);
3825
	loff_t offset = iocb->ki_pos;
3826
	ssize_t ret;
3827

3828 3829 3830 3831 3832
#ifdef CONFIG_EXT4_FS_ENCRYPTION
	if (ext4_encrypted_inode(inode) && S_ISREG(inode->i_mode))
		return 0;
#endif

3833 3834 3835 3836 3837 3838
	/*
	 * If we are doing data journalling we don't support O_DIRECT
	 */
	if (ext4_should_journal_data(inode))
		return 0;

T
Tao Ma 已提交
3839 3840 3841 3842
	/* Let buffer I/O handle the inline data case. */
	if (ext4_has_inline_data(inode))
		return 0;

3843 3844 3845 3846
	/* DAX uses iomap path now */
	if (WARN_ON_ONCE(IS_DAX(inode)))
		return 0;

3847
	trace_ext4_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
J
Jan Kara 已提交
3848
	if (iov_iter_rw(iter) == READ)
3849
		ret = ext4_direct_IO_read(iocb, iter);
3850
	else
3851
		ret = ext4_direct_IO_write(iocb, iter);
3852
	trace_ext4_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret);
3853
	return ret;
3854 3855
}

3856
/*
3857
 * Pages can be marked dirty completely asynchronously from ext4's journalling
3858 3859 3860 3861 3862 3863 3864 3865 3866 3867 3868
 * activity.  By filemap_sync_pte(), try_to_unmap_one(), etc.  We cannot do
 * much here because ->set_page_dirty is called under VFS locks.  The page is
 * not necessarily locked.
 *
 * We cannot just dirty the page and leave attached buffers clean, because the
 * buffers' dirty state is "definitive".  We cannot just set the buffers dirty
 * or jbddirty because all the journalling code will explode.
 *
 * So what we do is to mark the page "pending dirty" and next time writepage
 * is called, propagate that into the buffers appropriately.
 */
3869
static int ext4_journalled_set_page_dirty(struct page *page)
3870 3871 3872 3873 3874
{
	SetPageChecked(page);
	return __set_page_dirty_nobuffers(page);
}

3875 3876 3877 3878 3879 3880 3881
static int ext4_set_page_dirty(struct page *page)
{
	WARN_ON_ONCE(!PageLocked(page) && !PageDirty(page));
	WARN_ON_ONCE(!page_has_buffers(page));
	return __set_page_dirty_buffers(page);
}

3882
static const struct address_space_operations ext4_aops = {
3883 3884
	.readpage		= ext4_readpage,
	.readpages		= ext4_readpages,
3885
	.writepage		= ext4_writepage,
3886
	.writepages		= ext4_writepages,
3887
	.write_begin		= ext4_write_begin,
3888
	.write_end		= ext4_write_end,
3889
	.set_page_dirty		= ext4_set_page_dirty,
3890 3891 3892 3893 3894 3895
	.bmap			= ext4_bmap,
	.invalidatepage		= ext4_invalidatepage,
	.releasepage		= ext4_releasepage,
	.direct_IO		= ext4_direct_IO,
	.migratepage		= buffer_migrate_page,
	.is_partially_uptodate  = block_is_partially_uptodate,
3896
	.error_remove_page	= generic_error_remove_page,
3897 3898
};

3899
static const struct address_space_operations ext4_journalled_aops = {
3900 3901
	.readpage		= ext4_readpage,
	.readpages		= ext4_readpages,
3902
	.writepage		= ext4_writepage,
3903
	.writepages		= ext4_writepages,
3904 3905 3906 3907
	.write_begin		= ext4_write_begin,
	.write_end		= ext4_journalled_write_end,
	.set_page_dirty		= ext4_journalled_set_page_dirty,
	.bmap			= ext4_bmap,
3908
	.invalidatepage		= ext4_journalled_invalidatepage,
3909
	.releasepage		= ext4_releasepage,
3910
	.direct_IO		= ext4_direct_IO,
3911
	.is_partially_uptodate  = block_is_partially_uptodate,
3912
	.error_remove_page	= generic_error_remove_page,
3913 3914
};

3915
static const struct address_space_operations ext4_da_aops = {
3916 3917
	.readpage		= ext4_readpage,
	.readpages		= ext4_readpages,
3918
	.writepage		= ext4_writepage,
3919
	.writepages		= ext4_writepages,
3920 3921
	.write_begin		= ext4_da_write_begin,
	.write_end		= ext4_da_write_end,
3922
	.set_page_dirty		= ext4_set_page_dirty,
3923 3924 3925 3926 3927 3928
	.bmap			= ext4_bmap,
	.invalidatepage		= ext4_da_invalidatepage,
	.releasepage		= ext4_releasepage,
	.direct_IO		= ext4_direct_IO,
	.migratepage		= buffer_migrate_page,
	.is_partially_uptodate  = block_is_partially_uptodate,
3929
	.error_remove_page	= generic_error_remove_page,
3930 3931
};

3932
void ext4_set_aops(struct inode *inode)
3933
{
3934 3935 3936 3937 3938
	switch (ext4_inode_journal_mode(inode)) {
	case EXT4_INODE_ORDERED_DATA_MODE:
	case EXT4_INODE_WRITEBACK_DATA_MODE:
		break;
	case EXT4_INODE_JOURNAL_DATA_MODE:
3939
		inode->i_mapping->a_ops = &ext4_journalled_aops;
3940
		return;
3941 3942 3943
	default:
		BUG();
	}
3944 3945 3946 3947
	if (test_opt(inode->i_sb, DELALLOC))
		inode->i_mapping->a_ops = &ext4_da_aops;
	else
		inode->i_mapping->a_ops = &ext4_aops;
3948 3949
}

R
Ross Zwisler 已提交
3950
static int __ext4_block_zero_page_range(handle_t *handle,
3951 3952
		struct address_space *mapping, loff_t from, loff_t length)
{
3953 3954
	ext4_fsblk_t index = from >> PAGE_SHIFT;
	unsigned offset = from & (PAGE_SIZE-1);
R
Ross Zwisler 已提交
3955
	unsigned blocksize, pos;
3956 3957 3958 3959 3960 3961
	ext4_lblk_t iblock;
	struct inode *inode = mapping->host;
	struct buffer_head *bh;
	struct page *page;
	int err = 0;

3962
	page = find_or_create_page(mapping, from >> PAGE_SHIFT,
3963
				   mapping_gfp_constraint(mapping, ~__GFP_FS));
3964 3965 3966 3967 3968
	if (!page)
		return -ENOMEM;

	blocksize = inode->i_sb->s_blocksize;

3969
	iblock = index << (PAGE_SHIFT - inode->i_sb->s_blocksize_bits);
3970 3971 3972 3973 3974 3975 3976 3977 3978 3979 3980 3981 3982 3983 3984 3985 3986 3987 3988 3989 3990 3991 3992 3993 3994 3995 3996 3997 3998 3999 4000 4001

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

	/* Find the buffer that contains "offset" */
	bh = page_buffers(page);
	pos = blocksize;
	while (offset >= pos) {
		bh = bh->b_this_page;
		iblock++;
		pos += blocksize;
	}
	if (buffer_freed(bh)) {
		BUFFER_TRACE(bh, "freed: skip");
		goto unlock;
	}
	if (!buffer_mapped(bh)) {
		BUFFER_TRACE(bh, "unmapped");
		ext4_get_block(inode, iblock, bh, 0);
		/* unmapped? It's a hole - nothing to do */
		if (!buffer_mapped(bh)) {
			BUFFER_TRACE(bh, "still unmapped");
			goto unlock;
		}
	}

	/* Ok, it's mapped. Make sure it's up-to-date */
	if (PageUptodate(page))
		set_buffer_uptodate(bh);

	if (!buffer_uptodate(bh)) {
		err = -EIO;
4002
		ll_rw_block(REQ_OP_READ, 0, 1, &bh);
4003 4004 4005 4006
		wait_on_buffer(bh);
		/* Uhhuh. Read error. Complain and punt. */
		if (!buffer_uptodate(bh))
			goto unlock;
4007 4008 4009
		if (S_ISREG(inode->i_mode) &&
		    ext4_encrypted_inode(inode)) {
			/* We expect the key to be set. */
4010
			BUG_ON(!fscrypt_has_encryption_key(inode));
4011
			BUG_ON(blocksize != PAGE_SIZE);
4012
			WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host,
4013
						page, PAGE_SIZE, 0, page->index));
4014
		}
4015 4016 4017 4018 4019 4020 4021 4022 4023 4024 4025 4026
	}
	if (ext4_should_journal_data(inode)) {
		BUFFER_TRACE(bh, "get write access");
		err = ext4_journal_get_write_access(handle, bh);
		if (err)
			goto unlock;
	}
	zero_user(page, offset, length);
	BUFFER_TRACE(bh, "zeroed end of block");

	if (ext4_should_journal_data(inode)) {
		err = ext4_handle_dirty_metadata(handle, inode, bh);
4027
	} else {
4028
		err = 0;
4029
		mark_buffer_dirty(bh);
J
Jan Kara 已提交
4030
		if (ext4_should_order_data(inode))
4031
			err = ext4_jbd2_inode_add_write(handle, inode);
4032
	}
4033 4034 4035

unlock:
	unlock_page(page);
4036
	put_page(page);
4037 4038 4039
	return err;
}

R
Ross Zwisler 已提交
4040 4041 4042 4043 4044 4045 4046 4047 4048 4049 4050
/*
 * ext4_block_zero_page_range() zeros out a mapping of length 'length'
 * starting from file offset 'from'.  The range to be zero'd must
 * be contained with in one block.  If the specified range exceeds
 * the end of the block it will be shortened to end of the block
 * that cooresponds to 'from'
 */
static int ext4_block_zero_page_range(handle_t *handle,
		struct address_space *mapping, loff_t from, loff_t length)
{
	struct inode *inode = mapping->host;
4051
	unsigned offset = from & (PAGE_SIZE-1);
R
Ross Zwisler 已提交
4052 4053 4054 4055 4056 4057 4058 4059 4060 4061
	unsigned blocksize = inode->i_sb->s_blocksize;
	unsigned max = blocksize - (offset & (blocksize - 1));

	/*
	 * correct length if it does not fall between
	 * 'from' and the end of the block
	 */
	if (length > max || length < 0)
		length = max;

4062 4063 4064 4065
	if (IS_DAX(inode)) {
		return iomap_zero_range(inode, from, length, NULL,
					&ext4_iomap_ops);
	}
R
Ross Zwisler 已提交
4066 4067 4068
	return __ext4_block_zero_page_range(handle, mapping, from, length);
}

4069 4070 4071 4072 4073 4074
/*
 * ext4_block_truncate_page() zeroes out a mapping from file offset `from'
 * up to the end of the block which corresponds to `from'.
 * This required during truncate. We need to physically zero the tail end
 * of that block so it doesn't yield old data if the file is later grown.
 */
4075
static int ext4_block_truncate_page(handle_t *handle,
4076 4077
		struct address_space *mapping, loff_t from)
{
4078
	unsigned offset = from & (PAGE_SIZE-1);
4079 4080 4081 4082
	unsigned length;
	unsigned blocksize;
	struct inode *inode = mapping->host;

4083 4084 4085 4086
	/* If we are processing an encrypted inode during orphan list handling */
	if (ext4_encrypted_inode(inode) && !fscrypt_has_encryption_key(inode))
		return 0;

4087 4088 4089 4090 4091 4092
	blocksize = inode->i_sb->s_blocksize;
	length = blocksize - (offset & (blocksize - 1));

	return ext4_block_zero_page_range(handle, mapping, from, length);
}

4093 4094 4095 4096 4097
int ext4_zero_partial_blocks(handle_t *handle, struct inode *inode,
			     loff_t lstart, loff_t length)
{
	struct super_block *sb = inode->i_sb;
	struct address_space *mapping = inode->i_mapping;
4098
	unsigned partial_start, partial_end;
4099 4100 4101 4102
	ext4_fsblk_t start, end;
	loff_t byte_end = (lstart + length - 1);
	int err = 0;

4103 4104 4105
	partial_start = lstart & (sb->s_blocksize - 1);
	partial_end = byte_end & (sb->s_blocksize - 1);

4106 4107 4108 4109
	start = lstart >> sb->s_blocksize_bits;
	end = byte_end >> sb->s_blocksize_bits;

	/* Handle partial zero within the single block */
4110 4111
	if (start == end &&
	    (partial_start || (partial_end != sb->s_blocksize - 1))) {
4112 4113 4114 4115 4116
		err = ext4_block_zero_page_range(handle, mapping,
						 lstart, length);
		return err;
	}
	/* Handle partial zero out on the start of the range */
4117
	if (partial_start) {
4118 4119 4120 4121 4122 4123
		err = ext4_block_zero_page_range(handle, mapping,
						 lstart, sb->s_blocksize);
		if (err)
			return err;
	}
	/* Handle partial zero out on the end of the range */
4124
	if (partial_end != sb->s_blocksize - 1)
4125
		err = ext4_block_zero_page_range(handle, mapping,
4126 4127
						 byte_end - partial_end,
						 partial_end + 1);
4128 4129 4130
	return err;
}

4131 4132 4133 4134 4135 4136 4137 4138 4139 4140 4141
int ext4_can_truncate(struct inode *inode)
{
	if (S_ISREG(inode->i_mode))
		return 1;
	if (S_ISDIR(inode->i_mode))
		return 1;
	if (S_ISLNK(inode->i_mode))
		return !ext4_inode_is_fast_symlink(inode);
	return 0;
}

4142 4143 4144 4145 4146 4147 4148 4149 4150 4151 4152 4153
/*
 * We have to make sure i_disksize gets properly updated before we truncate
 * page cache due to hole punching or zero range. Otherwise i_disksize update
 * can get lost as it may have been postponed to submission of writeback but
 * that will never happen after we truncate page cache.
 */
int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset,
				      loff_t len)
{
	handle_t *handle;
	loff_t size = i_size_read(inode);

A
Al Viro 已提交
4154
	WARN_ON(!inode_is_locked(inode));
4155 4156 4157 4158 4159 4160 4161 4162 4163 4164 4165 4166 4167 4168 4169 4170
	if (offset > size || offset + len < size)
		return 0;

	if (EXT4_I(inode)->i_disksize >= size)
		return 0;

	handle = ext4_journal_start(inode, EXT4_HT_MISC, 1);
	if (IS_ERR(handle))
		return PTR_ERR(handle);
	ext4_update_i_disksize(inode, size);
	ext4_mark_inode_dirty(handle, inode);
	ext4_journal_stop(handle);

	return 0;
}

4171
/*
4172
 * ext4_punch_hole: punches a hole in a file by releasing the blocks
4173 4174 4175 4176 4177 4178
 * associated with the given offset and length
 *
 * @inode:  File inode
 * @offset: The offset where the hole will begin
 * @len:    The length of the hole
 *
4179
 * Returns: 0 on success or negative on failure
4180 4181
 */

4182
int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length)
4183
{
T
Theodore Ts'o 已提交
4184 4185 4186
	struct super_block *sb = inode->i_sb;
	ext4_lblk_t first_block, stop_block;
	struct address_space *mapping = inode->i_mapping;
4187
	loff_t first_block_offset, last_block_offset;
T
Theodore Ts'o 已提交
4188 4189 4190 4191
	handle_t *handle;
	unsigned int credits;
	int ret = 0;

4192
	if (!S_ISREG(inode->i_mode))
4193
		return -EOPNOTSUPP;
4194

4195
	trace_ext4_punch_hole(inode, offset, length, 0);
4196

T
Theodore Ts'o 已提交
4197 4198 4199 4200
	/*
	 * Write out all dirty pages to avoid race conditions
	 * Then release them.
	 */
4201
	if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
T
Theodore Ts'o 已提交
4202 4203 4204 4205 4206 4207
		ret = filemap_write_and_wait_range(mapping, offset,
						   offset + length - 1);
		if (ret)
			return ret;
	}

A
Al Viro 已提交
4208
	inode_lock(inode);
4209

T
Theodore Ts'o 已提交
4210 4211 4212 4213 4214 4215 4216 4217 4218 4219
	/* No need to punch hole beyond i_size */
	if (offset >= inode->i_size)
		goto out_mutex;

	/*
	 * If the hole extends beyond i_size, set the hole
	 * to end after the page that contains i_size
	 */
	if (offset + length > inode->i_size) {
		length = inode->i_size +
4220
		   PAGE_SIZE - (inode->i_size & (PAGE_SIZE - 1)) -
T
Theodore Ts'o 已提交
4221 4222 4223
		   offset;
	}

4224 4225 4226 4227 4228 4229 4230 4231 4232 4233 4234 4235
	if (offset & (sb->s_blocksize - 1) ||
	    (offset + length) & (sb->s_blocksize - 1)) {
		/*
		 * Attach jinode to inode for jbd2 if we do any zeroing of
		 * partial block
		 */
		ret = ext4_inode_attach_jinode(inode);
		if (ret < 0)
			goto out_mutex;

	}

4236 4237 4238 4239 4240 4241 4242 4243 4244
	/* Wait all existing dio workers, newcomers will block on i_mutex */
	ext4_inode_block_unlocked_dio(inode);
	inode_dio_wait(inode);

	/*
	 * Prevent page faults from reinstantiating pages we have released from
	 * page cache.
	 */
	down_write(&EXT4_I(inode)->i_mmap_sem);
4245 4246
	first_block_offset = round_up(offset, sb->s_blocksize);
	last_block_offset = round_down((offset + length), sb->s_blocksize) - 1;
T
Theodore Ts'o 已提交
4247

4248
	/* Now release the pages and zero block aligned part of pages*/
4249 4250 4251 4252
	if (last_block_offset > first_block_offset) {
		ret = ext4_update_disksize_before_punch(inode, offset, length);
		if (ret)
			goto out_dio;
4253 4254
		truncate_pagecache_range(inode, first_block_offset,
					 last_block_offset);
4255
	}
T
Theodore Ts'o 已提交
4256 4257 4258 4259 4260 4261 4262 4263 4264 4265 4266 4267

	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
		credits = ext4_writepage_trans_blocks(inode);
	else
		credits = ext4_blocks_for_truncate(inode);
	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
	if (IS_ERR(handle)) {
		ret = PTR_ERR(handle);
		ext4_std_error(sb, ret);
		goto out_dio;
	}

4268 4269 4270 4271
	ret = ext4_zero_partial_blocks(handle, inode, offset,
				       length);
	if (ret)
		goto out_stop;
T
Theodore Ts'o 已提交
4272 4273 4274 4275 4276 4277 4278 4279 4280 4281 4282 4283 4284 4285 4286 4287 4288 4289 4290 4291 4292 4293 4294

	first_block = (offset + sb->s_blocksize - 1) >>
		EXT4_BLOCK_SIZE_BITS(sb);
	stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);

	/* If there are no blocks to remove, return now */
	if (first_block >= stop_block)
		goto out_stop;

	down_write(&EXT4_I(inode)->i_data_sem);
	ext4_discard_preallocations(inode);

	ret = ext4_es_remove_extent(inode, first_block,
				    stop_block - first_block);
	if (ret) {
		up_write(&EXT4_I(inode)->i_data_sem);
		goto out_stop;
	}

	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
		ret = ext4_ext_remove_space(inode, first_block,
					    stop_block - 1);
	else
4295
		ret = ext4_ind_remove_space(handle, inode, first_block,
T
Theodore Ts'o 已提交
4296 4297
					    stop_block);

T
Theodore Ts'o 已提交
4298
	up_write(&EXT4_I(inode)->i_data_sem);
T
Theodore Ts'o 已提交
4299 4300
	if (IS_SYNC(inode))
		ext4_handle_sync(handle);
4301

4302
	inode->i_mtime = inode->i_ctime = current_time(inode);
T
Theodore Ts'o 已提交
4303
	ext4_mark_inode_dirty(handle, inode);
4304 4305
	if (ret >= 0)
		ext4_update_inode_fsync_trans(handle, inode, 1);
T
Theodore Ts'o 已提交
4306 4307 4308
out_stop:
	ext4_journal_stop(handle);
out_dio:
4309
	up_write(&EXT4_I(inode)->i_mmap_sem);
T
Theodore Ts'o 已提交
4310 4311
	ext4_inode_resume_unlocked_dio(inode);
out_mutex:
A
Al Viro 已提交
4312
	inode_unlock(inode);
T
Theodore Ts'o 已提交
4313
	return ret;
4314 4315
}

4316 4317 4318 4319 4320 4321 4322 4323 4324 4325 4326 4327 4328 4329 4330 4331 4332 4333 4334 4335 4336 4337 4338 4339 4340
int ext4_inode_attach_jinode(struct inode *inode)
{
	struct ext4_inode_info *ei = EXT4_I(inode);
	struct jbd2_inode *jinode;

	if (ei->jinode || !EXT4_SB(inode->i_sb)->s_journal)
		return 0;

	jinode = jbd2_alloc_inode(GFP_KERNEL);
	spin_lock(&inode->i_lock);
	if (!ei->jinode) {
		if (!jinode) {
			spin_unlock(&inode->i_lock);
			return -ENOMEM;
		}
		ei->jinode = jinode;
		jbd2_journal_init_jbd_inode(ei->jinode, inode);
		jinode = NULL;
	}
	spin_unlock(&inode->i_lock);
	if (unlikely(jinode != NULL))
		jbd2_free_inode(jinode);
	return 0;
}

4341
/*
4342
 * ext4_truncate()
4343
 *
4344 4345
 * We block out ext4_get_block() block instantiations across the entire
 * transaction, and VFS/VM ensures that ext4_truncate() cannot run
4346 4347
 * simultaneously on behalf of the same inode.
 *
4348
 * As we work through the truncate and commit bits of it to the journal there
4349 4350 4351 4352 4353 4354 4355 4356 4357 4358 4359 4360 4361
 * is one core, guiding principle: the file's tree must always be consistent on
 * disk.  We must be able to restart the truncate after a crash.
 *
 * The file's tree may be transiently inconsistent in memory (although it
 * probably isn't), but whenever we close off and commit a journal transaction,
 * the contents of (the filesystem + the journal) must be consistent and
 * restartable.  It's pretty simple, really: bottom up, right to left (although
 * left-to-right works OK too).
 *
 * Note that at recovery time, journal replay occurs *before* the restart of
 * truncate against the orphan inode list.
 *
 * The committed inode has the new, desired i_size (which is the same as
4362
 * i_disksize in this case).  After a crash, ext4_orphan_cleanup() will see
4363
 * that this inode's truncate did not complete and it will again call
4364 4365
 * ext4_truncate() to have another go.  So there will be instantiated blocks
 * to the right of the truncation point in a crashed ext4 filesystem.  But
4366
 * that's fine - as long as they are linked from the inode, the post-crash
4367
 * ext4_truncate() run will find them and release them.
4368
 */
4369
int ext4_truncate(struct inode *inode)
4370
{
T
Theodore Ts'o 已提交
4371 4372
	struct ext4_inode_info *ei = EXT4_I(inode);
	unsigned int credits;
4373
	int err = 0;
T
Theodore Ts'o 已提交
4374 4375 4376
	handle_t *handle;
	struct address_space *mapping = inode->i_mapping;

4377 4378
	/*
	 * There is a possibility that we're either freeing the inode
M
Matthew Wilcox 已提交
4379
	 * or it's a completely new inode. In those cases we might not
4380 4381 4382
	 * have i_mutex locked because it's not necessary.
	 */
	if (!(inode->i_state & (I_NEW|I_FREEING)))
A
Al Viro 已提交
4383
		WARN_ON(!inode_is_locked(inode));
4384 4385
	trace_ext4_truncate_enter(inode);

4386
	if (!ext4_can_truncate(inode))
4387
		return 0;
4388

4389
	ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4390

4391
	if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
4392
		ext4_set_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
4393

4394 4395 4396
	if (ext4_has_inline_data(inode)) {
		int has_inline = 1;

4397 4398 4399
		err = ext4_inline_data_truncate(inode, &has_inline);
		if (err)
			return err;
4400
		if (has_inline)
4401
			return 0;
4402 4403
	}

4404 4405 4406
	/* If we zero-out tail of the page, we have to create jinode for jbd2 */
	if (inode->i_size & (inode->i_sb->s_blocksize - 1)) {
		if (ext4_inode_attach_jinode(inode) < 0)
4407
			return 0;
4408 4409
	}

T
Theodore Ts'o 已提交
4410 4411 4412 4413 4414 4415
	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
		credits = ext4_writepage_trans_blocks(inode);
	else
		credits = ext4_blocks_for_truncate(inode);

	handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
4416 4417
	if (IS_ERR(handle))
		return PTR_ERR(handle);
T
Theodore Ts'o 已提交
4418

4419 4420
	if (inode->i_size & (inode->i_sb->s_blocksize - 1))
		ext4_block_truncate_page(handle, mapping, inode->i_size);
T
Theodore Ts'o 已提交
4421 4422 4423 4424 4425 4426 4427 4428 4429 4430

	/*
	 * We add the inode to the orphan list, so that if this
	 * truncate spans multiple transactions, and we crash, we will
	 * resume the truncate when the filesystem recovers.  It also
	 * marks the inode dirty, to catch the new size.
	 *
	 * Implication: the file must always be in a sane, consistent
	 * truncatable state while each transaction commits.
	 */
4431 4432
	err = ext4_orphan_add(handle, inode);
	if (err)
T
Theodore Ts'o 已提交
4433 4434 4435 4436 4437 4438
		goto out_stop;

	down_write(&EXT4_I(inode)->i_data_sem);

	ext4_discard_preallocations(inode);

4439
	if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4440
		err = ext4_ext_truncate(handle, inode);
4441
	else
T
Theodore Ts'o 已提交
4442 4443 4444
		ext4_ind_truncate(handle, inode);

	up_write(&ei->i_data_sem);
4445 4446
	if (err)
		goto out_stop;
T
Theodore Ts'o 已提交
4447 4448 4449 4450 4451 4452 4453 4454 4455

	if (IS_SYNC(inode))
		ext4_handle_sync(handle);

out_stop:
	/*
	 * If this was a simple ftruncate() and the file will remain alive,
	 * then we need to clear up the orphan record which we created above.
	 * However, if this was a real unlink then we were called by
4456
	 * ext4_evict_inode(), and we allow that function to clean up the
T
Theodore Ts'o 已提交
4457 4458 4459 4460 4461
	 * orphan info for us.
	 */
	if (inode->i_nlink)
		ext4_orphan_del(handle, inode);

4462
	inode->i_mtime = inode->i_ctime = current_time(inode);
T
Theodore Ts'o 已提交
4463 4464
	ext4_mark_inode_dirty(handle, inode);
	ext4_journal_stop(handle);
4465

4466
	trace_ext4_truncate_exit(inode);
4467
	return err;
4468 4469 4470
}

/*
4471
 * ext4_get_inode_loc returns with an extra refcount against the inode's
4472 4473 4474 4475
 * underlying buffer_head on success. If 'in_mem' is true, we have all
 * data in memory that is needed to recreate the on-disk version of this
 * inode.
 */
4476 4477
static int __ext4_get_inode_loc(struct inode *inode,
				struct ext4_iloc *iloc, int in_mem)
4478
{
4479 4480 4481 4482 4483 4484
	struct ext4_group_desc	*gdp;
	struct buffer_head	*bh;
	struct super_block	*sb = inode->i_sb;
	ext4_fsblk_t		block;
	int			inodes_per_block, inode_offset;

A
Aneesh Kumar K.V 已提交
4485
	iloc->bh = NULL;
4486
	if (!ext4_valid_inum(sb, inode->i_ino))
4487
		return -EFSCORRUPTED;
4488

4489 4490 4491
	iloc->block_group = (inode->i_ino - 1) / EXT4_INODES_PER_GROUP(sb);
	gdp = ext4_get_group_desc(sb, iloc->block_group, NULL);
	if (!gdp)
4492 4493
		return -EIO;

4494 4495 4496
	/*
	 * Figure out the offset within the block group inode table
	 */
4497
	inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
4498 4499 4500 4501 4502 4503
	inode_offset = ((inode->i_ino - 1) %
			EXT4_INODES_PER_GROUP(sb));
	block = ext4_inode_table(sb, gdp) + (inode_offset / inodes_per_block);
	iloc->offset = (inode_offset % inodes_per_block) * EXT4_INODE_SIZE(sb);

	bh = sb_getblk(sb, block);
4504
	if (unlikely(!bh))
4505
		return -ENOMEM;
4506 4507
	if (!buffer_uptodate(bh)) {
		lock_buffer(bh);
4508 4509 4510 4511 4512 4513 4514 4515 4516 4517

		/*
		 * If the buffer has the write error flag, we have failed
		 * to write out another inode in the same block.  In this
		 * case, we don't have to read the block because we may
		 * read the old inode data successfully.
		 */
		if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
			set_buffer_uptodate(bh);

4518 4519 4520 4521 4522 4523 4524 4525 4526 4527 4528 4529 4530
		if (buffer_uptodate(bh)) {
			/* someone brought it uptodate while we waited */
			unlock_buffer(bh);
			goto has_buffer;
		}

		/*
		 * If we have all information of the inode in memory and this
		 * is the only valid inode in the block, we need not read the
		 * block.
		 */
		if (in_mem) {
			struct buffer_head *bitmap_bh;
4531
			int i, start;
4532

4533
			start = inode_offset & ~(inodes_per_block - 1);
4534

4535 4536
			/* Is the inode bitmap in cache? */
			bitmap_bh = sb_getblk(sb, ext4_inode_bitmap(sb, gdp));
4537
			if (unlikely(!bitmap_bh))
4538 4539 4540 4541 4542 4543 4544 4545 4546 4547 4548
				goto make_io;

			/*
			 * If the inode bitmap isn't in cache then the
			 * optimisation may end up performing two reads instead
			 * of one, so skip it.
			 */
			if (!buffer_uptodate(bitmap_bh)) {
				brelse(bitmap_bh);
				goto make_io;
			}
4549
			for (i = start; i < start + inodes_per_block; i++) {
4550 4551
				if (i == inode_offset)
					continue;
4552
				if (ext4_test_bit(i, bitmap_bh->b_data))
4553 4554 4555
					break;
			}
			brelse(bitmap_bh);
4556
			if (i == start + inodes_per_block) {
4557 4558 4559 4560 4561 4562 4563 4564 4565
				/* all other inodes are free, so skip I/O */
				memset(bh->b_data, 0, bh->b_size);
				set_buffer_uptodate(bh);
				unlock_buffer(bh);
				goto has_buffer;
			}
		}

make_io:
4566 4567 4568 4569 4570 4571 4572
		/*
		 * If we need to do any I/O, try to pre-readahead extra
		 * blocks from the inode table.
		 */
		if (EXT4_SB(sb)->s_inode_readahead_blks) {
			ext4_fsblk_t b, end, table;
			unsigned num;
4573
			__u32 ra_blks = EXT4_SB(sb)->s_inode_readahead_blks;
4574 4575

			table = ext4_inode_table(sb, gdp);
T
Theodore Ts'o 已提交
4576
			/* s_inode_readahead_blks is always a power of 2 */
4577
			b = block & ~((ext4_fsblk_t) ra_blks - 1);
4578 4579
			if (table > b)
				b = table;
4580
			end = b + ra_blks;
4581
			num = EXT4_INODES_PER_GROUP(sb);
4582
			if (ext4_has_group_desc_csum(sb))
4583
				num -= ext4_itable_unused_count(sb, gdp);
4584 4585 4586 4587 4588 4589 4590
			table += num / inodes_per_block;
			if (end > table)
				end = table;
			while (b <= end)
				sb_breadahead(sb, b++);
		}

4591 4592 4593 4594 4595
		/*
		 * There are other valid inodes in the buffer, this inode
		 * has in-inode xattrs, or we don't have this inode in memory.
		 * Read the block from disk.
		 */
4596
		trace_ext4_load_inode(inode);
4597 4598
		get_bh(bh);
		bh->b_end_io = end_buffer_read_sync;
4599
		submit_bh(REQ_OP_READ, REQ_META | REQ_PRIO, bh);
4600 4601
		wait_on_buffer(bh);
		if (!buffer_uptodate(bh)) {
4602 4603
			EXT4_ERROR_INODE_BLOCK(inode, block,
					       "unable to read itable block");
4604 4605 4606 4607 4608 4609 4610 4611 4612
			brelse(bh);
			return -EIO;
		}
	}
has_buffer:
	iloc->bh = bh;
	return 0;
}

4613
int ext4_get_inode_loc(struct inode *inode, struct ext4_iloc *iloc)
4614 4615
{
	/* We have all inode data except xattrs in memory here. */
4616
	return __ext4_get_inode_loc(inode, iloc,
4617
		!ext4_test_inode_state(inode, EXT4_STATE_XATTR));
4618 4619
}

R
Ross Zwisler 已提交
4620 4621 4622 4623 4624 4625 4626 4627 4628 4629 4630 4631 4632 4633 4634
static bool ext4_should_use_dax(struct inode *inode)
{
	if (!test_opt(inode->i_sb, DAX))
		return false;
	if (!S_ISREG(inode->i_mode))
		return false;
	if (ext4_should_journal_data(inode))
		return false;
	if (ext4_has_inline_data(inode))
		return false;
	if (ext4_encrypted_inode(inode))
		return false;
	return true;
}

4635
void ext4_set_inode_flags(struct inode *inode)
4636
{
4637
	unsigned int flags = EXT4_I(inode)->i_flags;
4638
	unsigned int new_fl = 0;
4639

4640
	if (flags & EXT4_SYNC_FL)
4641
		new_fl |= S_SYNC;
4642
	if (flags & EXT4_APPEND_FL)
4643
		new_fl |= S_APPEND;
4644
	if (flags & EXT4_IMMUTABLE_FL)
4645
		new_fl |= S_IMMUTABLE;
4646
	if (flags & EXT4_NOATIME_FL)
4647
		new_fl |= S_NOATIME;
4648
	if (flags & EXT4_DIRSYNC_FL)
4649
		new_fl |= S_DIRSYNC;
R
Ross Zwisler 已提交
4650
	if (ext4_should_use_dax(inode))
R
Ross Zwisler 已提交
4651
		new_fl |= S_DAX;
4652 4653
	if (flags & EXT4_ENCRYPT_FL)
		new_fl |= S_ENCRYPTED;
4654
	inode_set_flags(inode, new_fl,
4655 4656
			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|
			S_ENCRYPTED);
4657 4658
}

4659
static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,
4660
				  struct ext4_inode_info *ei)
4661 4662
{
	blkcnt_t i_blocks ;
A
Aneesh Kumar K.V 已提交
4663 4664
	struct inode *inode = &(ei->vfs_inode);
	struct super_block *sb = inode->i_sb;
4665

4666
	if (ext4_has_feature_huge_file(sb)) {
4667 4668 4669
		/* we are using combined 48 bit field */
		i_blocks = ((u64)le16_to_cpu(raw_inode->i_blocks_high)) << 32 |
					le32_to_cpu(raw_inode->i_blocks_lo);
4670
		if (ext4_test_inode_flag(inode, EXT4_INODE_HUGE_FILE)) {
A
Aneesh Kumar K.V 已提交
4671 4672 4673 4674 4675
			/* i_blocks represent file system block size */
			return i_blocks  << (inode->i_blkbits - 9);
		} else {
			return i_blocks;
		}
4676 4677 4678 4679
	} else {
		return le32_to_cpu(raw_inode->i_blocks_lo);
	}
}
4680

4681 4682 4683 4684 4685 4686
static inline void ext4_iget_extra_inode(struct inode *inode,
					 struct ext4_inode *raw_inode,
					 struct ext4_inode_info *ei)
{
	__le32 *magic = (void *)raw_inode +
			EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize;
4687 4688 4689
	if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize + sizeof(__le32) <=
	    EXT4_INODE_SIZE(inode->i_sb) &&
	    *magic == cpu_to_le32(EXT4_XATTR_MAGIC)) {
4690
		ext4_set_inode_state(inode, EXT4_STATE_XATTR);
4691
		ext4_find_inline_data_nolock(inode);
4692 4693
	} else
		EXT4_I(inode)->i_inline_off = 0;
4694 4695
}

L
Li Xi 已提交
4696 4697
int ext4_get_projid(struct inode *inode, kprojid_t *projid)
{
K
Kaho Ng 已提交
4698
	if (!ext4_has_feature_project(inode->i_sb))
L
Li Xi 已提交
4699 4700 4701 4702 4703
		return -EOPNOTSUPP;
	*projid = EXT4_I(inode)->i_projid;
	return 0;
}

4704
struct inode *ext4_iget(struct super_block *sb, unsigned long ino)
4705
{
4706 4707
	struct ext4_iloc iloc;
	struct ext4_inode *raw_inode;
4708 4709
	struct ext4_inode_info *ei;
	struct inode *inode;
4710
	journal_t *journal = EXT4_SB(sb)->s_journal;
4711
	long ret;
4712
	loff_t size;
4713
	int block;
4714 4715
	uid_t i_uid;
	gid_t i_gid;
L
Li Xi 已提交
4716
	projid_t i_projid;
4717

4718 4719 4720 4721 4722 4723 4724
	inode = iget_locked(sb, ino);
	if (!inode)
		return ERR_PTR(-ENOMEM);
	if (!(inode->i_state & I_NEW))
		return inode;

	ei = EXT4_I(inode);
4725
	iloc.bh = NULL;
4726

4727 4728
	ret = __ext4_get_inode_loc(inode, &iloc, 0);
	if (ret < 0)
4729
		goto bad_inode;
4730
	raw_inode = ext4_raw_inode(&iloc);
4731 4732 4733 4734

	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
		ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
		if (EXT4_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
4735 4736 4737 4738 4739 4740
			EXT4_INODE_SIZE(inode->i_sb) ||
		    (ei->i_extra_isize & 3)) {
			EXT4_ERROR_INODE(inode,
					 "bad extra_isize %u (inode size %u)",
					 ei->i_extra_isize,
					 EXT4_INODE_SIZE(inode->i_sb));
4741
			ret = -EFSCORRUPTED;
4742 4743 4744 4745 4746 4747
			goto bad_inode;
		}
	} else
		ei->i_extra_isize = 0;

	/* Precompute checksum seed for inode metadata */
4748
	if (ext4_has_metadata_csum(sb)) {
4749 4750 4751 4752 4753 4754 4755 4756 4757 4758 4759 4760
		struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
		__u32 csum;
		__le32 inum = cpu_to_le32(inode->i_ino);
		__le32 gen = raw_inode->i_generation;
		csum = ext4_chksum(sbi, sbi->s_csum_seed, (__u8 *)&inum,
				   sizeof(inum));
		ei->i_csum_seed = ext4_chksum(sbi, csum, (__u8 *)&gen,
					      sizeof(gen));
	}

	if (!ext4_inode_csum_verify(inode, raw_inode, ei)) {
		EXT4_ERROR_INODE(inode, "checksum invalid");
4761
		ret = -EFSBADCRC;
4762 4763 4764
		goto bad_inode;
	}

4765
	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
4766 4767
	i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
	i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
K
Kaho Ng 已提交
4768
	if (ext4_has_feature_project(sb) &&
L
Li Xi 已提交
4769 4770 4771 4772 4773 4774
	    EXT4_INODE_SIZE(sb) > EXT4_GOOD_OLD_INODE_SIZE &&
	    EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
		i_projid = (projid_t)le32_to_cpu(raw_inode->i_projid);
	else
		i_projid = EXT4_DEF_PROJID;

4775
	if (!(test_opt(inode->i_sb, NO_UID32))) {
4776 4777
		i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
		i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
4778
	}
4779 4780
	i_uid_write(inode, i_uid);
	i_gid_write(inode, i_gid);
L
Li Xi 已提交
4781
	ei->i_projid = make_kprojid(&init_user_ns, i_projid);
M
Miklos Szeredi 已提交
4782
	set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
4783

4784
	ext4_clear_state_flags(ei);	/* Only relevant on 32-bit archs */
4785
	ei->i_inline_off = 0;
4786 4787 4788 4789 4790 4791 4792 4793
	ei->i_dir_start_lookup = 0;
	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
	/* We now have enough fields to check if the inode was active or not.
	 * This is needed because nfsd might try to access dead inodes
	 * the test is that same one that e2fsck uses
	 * NeilBrown 1999oct15
	 */
	if (inode->i_nlink == 0) {
4794 4795 4796
		if ((inode->i_mode == 0 ||
		     !(EXT4_SB(inode->i_sb)->s_mount_state & EXT4_ORPHAN_FS)) &&
		    ino != EXT4_BOOT_LOADER_INO) {
4797
			/* this inode is deleted */
4798
			ret = -ESTALE;
4799 4800 4801 4802 4803
			goto bad_inode;
		}
		/* The only unlinked inodes we let through here have
		 * valid i_mode and are being read by the orphan
		 * recovery code: that's fine, we're about to complete
4804 4805 4806
		 * the process of deleting those.
		 * OR it is the EXT4_BOOT_LOADER_INO which is
		 * not initialized on a new filesystem. */
4807 4808
	}
	ei->i_flags = le32_to_cpu(raw_inode->i_flags);
4809
	inode->i_blocks = ext4_inode_blocks(raw_inode, ei);
4810
	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl_lo);
4811
	if (ext4_has_feature_64bit(sb))
B
Badari Pulavarty 已提交
4812 4813
		ei->i_file_acl |=
			((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
A
Artem Blagodarenko 已提交
4814
	inode->i_size = ext4_isize(sb, raw_inode);
4815 4816 4817 4818 4819
	if ((size = i_size_read(inode)) < 0) {
		EXT4_ERROR_INODE(inode, "bad i_size value: %lld", size);
		ret = -EFSCORRUPTED;
		goto bad_inode;
	}
4820
	ei->i_disksize = inode->i_size;
4821 4822 4823
#ifdef CONFIG_QUOTA
	ei->i_reserved_quota = 0;
#endif
4824 4825
	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
	ei->i_block_group = iloc.block_group;
4826
	ei->i_last_alloc_group = ~0;
4827 4828 4829 4830
	/*
	 * NOTE! The in-memory inode i_data array is in little-endian order
	 * even on big-endian machines: we do NOT byteswap the block numbers!
	 */
4831
	for (block = 0; block < EXT4_N_BLOCKS; block++)
4832 4833 4834
		ei->i_data[block] = raw_inode->i_block[block];
	INIT_LIST_HEAD(&ei->i_orphan);

4835 4836 4837 4838 4839 4840 4841 4842 4843 4844 4845
	/*
	 * Set transaction id's of transactions that have to be committed
	 * to finish f[data]sync. We set them to currently running transaction
	 * as we cannot be sure that the inode or some of its metadata isn't
	 * part of the transaction - the inode could have been reclaimed and
	 * now it is reread from disk.
	 */
	if (journal) {
		transaction_t *transaction;
		tid_t tid;

4846
		read_lock(&journal->j_state_lock);
4847 4848 4849 4850 4851 4852 4853 4854
		if (journal->j_running_transaction)
			transaction = journal->j_running_transaction;
		else
			transaction = journal->j_committing_transaction;
		if (transaction)
			tid = transaction->t_tid;
		else
			tid = journal->j_commit_sequence;
4855
		read_unlock(&journal->j_state_lock);
4856 4857 4858 4859
		ei->i_sync_tid = tid;
		ei->i_datasync_tid = tid;
	}

4860
	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
4861 4862
		if (ei->i_extra_isize == 0) {
			/* The extra space is currently unused. Use it. */
4863
			BUILD_BUG_ON(sizeof(struct ext4_inode) & 3);
4864 4865
			ei->i_extra_isize = sizeof(struct ext4_inode) -
					    EXT4_GOOD_OLD_INODE_SIZE;
4866
		} else {
4867
			ext4_iget_extra_inode(inode, raw_inode, ei);
4868
		}
4869
	}
4870

K
Kalpak Shah 已提交
4871 4872 4873 4874 4875
	EXT4_INODE_GET_XTIME(i_ctime, inode, raw_inode);
	EXT4_INODE_GET_XTIME(i_mtime, inode, raw_inode);
	EXT4_INODE_GET_XTIME(i_atime, inode, raw_inode);
	EXT4_EINODE_GET_XTIME(i_crtime, ei, raw_inode);

4876
	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
J
Jeff Layton 已提交
4877 4878
		u64 ivers = le32_to_cpu(raw_inode->i_disk_version);

4879 4880
		if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE) {
			if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
J
Jeff Layton 已提交
4881
				ivers |=
4882 4883
		    (__u64)(le32_to_cpu(raw_inode->i_version_hi)) << 32;
		}
J
Jeff Layton 已提交
4884
		inode_set_iversion_queried(inode, ivers);
4885 4886
	}

4887
	ret = 0;
4888
	if (ei->i_file_acl &&
4889
	    !ext4_data_block_valid(EXT4_SB(sb), ei->i_file_acl, 1)) {
4890 4891
		EXT4_ERROR_INODE(inode, "bad extended attribute block %llu",
				 ei->i_file_acl);
4892
		ret = -EFSCORRUPTED;
4893
		goto bad_inode;
4894 4895 4896 4897 4898 4899 4900 4901 4902 4903 4904 4905 4906
	} else if (!ext4_has_inline_data(inode)) {
		if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
			if ((S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
			    (S_ISLNK(inode->i_mode) &&
			     !ext4_inode_is_fast_symlink(inode))))
				/* Validate extent which is part of inode */
				ret = ext4_ext_check_inode(inode);
		} else if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
			   (S_ISLNK(inode->i_mode) &&
			    !ext4_inode_is_fast_symlink(inode))) {
			/* Validate block references which are part of inode */
			ret = ext4_ind_check_inode(inode);
		}
4907
	}
4908
	if (ret)
4909
		goto bad_inode;
4910

4911
	if (S_ISREG(inode->i_mode)) {
4912
		inode->i_op = &ext4_file_inode_operations;
4913
		inode->i_fop = &ext4_file_operations;
4914
		ext4_set_aops(inode);
4915
	} else if (S_ISDIR(inode->i_mode)) {
4916 4917
		inode->i_op = &ext4_dir_inode_operations;
		inode->i_fop = &ext4_dir_operations;
4918
	} else if (S_ISLNK(inode->i_mode)) {
4919 4920 4921 4922
		if (ext4_encrypted_inode(inode)) {
			inode->i_op = &ext4_encrypted_symlink_inode_operations;
			ext4_set_aops(inode);
		} else if (ext4_inode_is_fast_symlink(inode)) {
A
Al Viro 已提交
4923
			inode->i_link = (char *)ei->i_data;
4924
			inode->i_op = &ext4_fast_symlink_inode_operations;
4925 4926 4927
			nd_terminate_link(ei->i_data, inode->i_size,
				sizeof(ei->i_data) - 1);
		} else {
4928 4929
			inode->i_op = &ext4_symlink_inode_operations;
			ext4_set_aops(inode);
4930
		}
4931
		inode_nohighmem(inode);
4932 4933
	} else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
	      S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
4934
		inode->i_op = &ext4_special_inode_operations;
4935 4936 4937 4938 4939 4940
		if (raw_inode->i_block[0])
			init_special_inode(inode, inode->i_mode,
			   old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
		else
			init_special_inode(inode, inode->i_mode,
			   new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
4941 4942
	} else if (ino == EXT4_BOOT_LOADER_INO) {
		make_bad_inode(inode);
4943
	} else {
4944
		ret = -EFSCORRUPTED;
4945
		EXT4_ERROR_INODE(inode, "bogus i_mode (%o)", inode->i_mode);
4946
		goto bad_inode;
4947
	}
4948
	brelse(iloc.bh);
4949
	ext4_set_inode_flags(inode);
T
Tahsin Erdogan 已提交
4950

4951 4952
	unlock_new_inode(inode);
	return inode;
4953 4954

bad_inode:
4955
	brelse(iloc.bh);
4956 4957
	iget_failed(inode);
	return ERR_PTR(ret);
4958 4959
}

4960 4961 4962
struct inode *ext4_iget_normal(struct super_block *sb, unsigned long ino)
{
	if (ino < EXT4_FIRST_INO(sb) && ino != EXT4_ROOT_INO)
4963
		return ERR_PTR(-EFSCORRUPTED);
4964 4965 4966
	return ext4_iget(sb, ino);
}

4967 4968 4969 4970 4971 4972 4973 4974 4975 4976
static int ext4_inode_blocks_set(handle_t *handle,
				struct ext4_inode *raw_inode,
				struct ext4_inode_info *ei)
{
	struct inode *inode = &(ei->vfs_inode);
	u64 i_blocks = inode->i_blocks;
	struct super_block *sb = inode->i_sb;

	if (i_blocks <= ~0U) {
		/*
4977
		 * i_blocks can be represented in a 32 bit variable
4978 4979
		 * as multiple of 512 bytes
		 */
A
Aneesh Kumar K.V 已提交
4980
		raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
4981
		raw_inode->i_blocks_high = 0;
4982
		ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4983 4984
		return 0;
	}
4985
	if (!ext4_has_feature_huge_file(sb))
4986 4987 4988
		return -EFBIG;

	if (i_blocks <= 0xffffffffffffULL) {
4989 4990 4991 4992
		/*
		 * i_blocks can be represented in a 48 bit variable
		 * as multiple of 512 bytes
		 */
A
Aneesh Kumar K.V 已提交
4993
		raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
4994
		raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
4995
		ext4_clear_inode_flag(inode, EXT4_INODE_HUGE_FILE);
4996
	} else {
4997
		ext4_set_inode_flag(inode, EXT4_INODE_HUGE_FILE);
A
Aneesh Kumar K.V 已提交
4998 4999 5000 5001
		/* i_block is stored in file system block size */
		i_blocks = i_blocks >> (inode->i_blkbits - 9);
		raw_inode->i_blocks_lo   = cpu_to_le32(i_blocks);
		raw_inode->i_blocks_high = cpu_to_le16(i_blocks >> 32);
5002
	}
5003
	return 0;
5004 5005
}

5006 5007 5008 5009 5010 5011 5012 5013 5014 5015 5016 5017 5018 5019 5020 5021 5022 5023 5024 5025 5026 5027 5028 5029 5030 5031 5032 5033 5034 5035 5036 5037 5038 5039 5040 5041 5042 5043 5044 5045 5046 5047 5048 5049 5050 5051 5052 5053 5054 5055
struct other_inode {
	unsigned long		orig_ino;
	struct ext4_inode	*raw_inode;
};

static int other_inode_match(struct inode * inode, unsigned long ino,
			     void *data)
{
	struct other_inode *oi = (struct other_inode *) data;

	if ((inode->i_ino != ino) ||
	    (inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW |
			       I_DIRTY_SYNC | I_DIRTY_DATASYNC)) ||
	    ((inode->i_state & I_DIRTY_TIME) == 0))
		return 0;
	spin_lock(&inode->i_lock);
	if (((inode->i_state & (I_FREEING | I_WILL_FREE | I_NEW |
				I_DIRTY_SYNC | I_DIRTY_DATASYNC)) == 0) &&
	    (inode->i_state & I_DIRTY_TIME)) {
		struct ext4_inode_info	*ei = EXT4_I(inode);

		inode->i_state &= ~(I_DIRTY_TIME | I_DIRTY_TIME_EXPIRED);
		spin_unlock(&inode->i_lock);

		spin_lock(&ei->i_raw_lock);
		EXT4_INODE_SET_XTIME(i_ctime, inode, oi->raw_inode);
		EXT4_INODE_SET_XTIME(i_mtime, inode, oi->raw_inode);
		EXT4_INODE_SET_XTIME(i_atime, inode, oi->raw_inode);
		ext4_inode_csum_set(inode, oi->raw_inode, ei);
		spin_unlock(&ei->i_raw_lock);
		trace_ext4_other_inode_update_time(inode, oi->orig_ino);
		return -1;
	}
	spin_unlock(&inode->i_lock);
	return -1;
}

/*
 * Opportunistically update the other time fields for other inodes in
 * the same inode table block.
 */
static void ext4_update_other_inodes_time(struct super_block *sb,
					  unsigned long orig_ino, char *buf)
{
	struct other_inode oi;
	unsigned long ino;
	int i, inodes_per_block = EXT4_SB(sb)->s_inodes_per_block;
	int inode_size = EXT4_INODE_SIZE(sb);

	oi.orig_ino = orig_ino;
5056 5057 5058 5059 5060 5061
	/*
	 * Calculate the first inode in the inode table block.  Inode
	 * numbers are one-based.  That is, the first inode in a block
	 * (assuming 4k blocks and 256 byte inodes) is (n*16 + 1).
	 */
	ino = ((orig_ino - 1) & ~(inodes_per_block - 1)) + 1;
5062 5063 5064 5065 5066 5067 5068 5069
	for (i = 0; i < inodes_per_block; i++, ino++, buf += inode_size) {
		if (ino == orig_ino)
			continue;
		oi.raw_inode = (struct ext4_inode *) buf;
		(void) find_inode_nowait(sb, ino, other_inode_match, &oi);
	}
}

5070 5071 5072 5073 5074 5075 5076
/*
 * Post the struct inode info into an on-disk inode location in the
 * buffer-cache.  This gobbles the caller's reference to the
 * buffer_head in the inode location struct.
 *
 * The caller must have write access to iloc->bh.
 */
5077
static int ext4_do_update_inode(handle_t *handle,
5078
				struct inode *inode,
5079
				struct ext4_iloc *iloc)
5080
{
5081 5082
	struct ext4_inode *raw_inode = ext4_raw_inode(iloc);
	struct ext4_inode_info *ei = EXT4_I(inode);
5083
	struct buffer_head *bh = iloc->bh;
5084
	struct super_block *sb = inode->i_sb;
5085
	int err = 0, rc, block;
5086
	int need_datasync = 0, set_large_file = 0;
5087 5088
	uid_t i_uid;
	gid_t i_gid;
L
Li Xi 已提交
5089
	projid_t i_projid;
5090

5091 5092 5093
	spin_lock(&ei->i_raw_lock);

	/* For fields not tracked in the in-memory inode,
5094
	 * initialise them to zero for new inodes. */
5095
	if (ext4_test_inode_state(inode, EXT4_STATE_NEW))
5096
		memset(raw_inode, 0, EXT4_SB(inode->i_sb)->s_inode_size);
5097 5098

	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
5099 5100
	i_uid = i_uid_read(inode);
	i_gid = i_gid_read(inode);
L
Li Xi 已提交
5101
	i_projid = from_kprojid(&init_user_ns, ei->i_projid);
5102
	if (!(test_opt(inode->i_sb, NO_UID32))) {
5103 5104
		raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
		raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
5105 5106 5107 5108
/*
 * Fix up interoperability with old kernels. Otherwise, old inodes get
 * re-used with the upper 16 bits of the uid/gid intact
 */
5109 5110 5111 5112
		if (ei->i_dtime && list_empty(&ei->i_orphan)) {
			raw_inode->i_uid_high = 0;
			raw_inode->i_gid_high = 0;
		} else {
5113
			raw_inode->i_uid_high =
5114
				cpu_to_le16(high_16_bits(i_uid));
5115
			raw_inode->i_gid_high =
5116
				cpu_to_le16(high_16_bits(i_gid));
5117 5118
		}
	} else {
5119 5120
		raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(i_uid));
		raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(i_gid));
5121 5122 5123 5124
		raw_inode->i_uid_high = 0;
		raw_inode->i_gid_high = 0;
	}
	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
K
Kalpak Shah 已提交
5125 5126 5127 5128 5129 5130

	EXT4_INODE_SET_XTIME(i_ctime, inode, raw_inode);
	EXT4_INODE_SET_XTIME(i_mtime, inode, raw_inode);
	EXT4_INODE_SET_XTIME(i_atime, inode, raw_inode);
	EXT4_EINODE_SET_XTIME(i_crtime, ei, raw_inode);

5131 5132
	err = ext4_inode_blocks_set(handle, raw_inode, ei);
	if (err) {
5133
		spin_unlock(&ei->i_raw_lock);
5134
		goto out_brelse;
5135
	}
5136
	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
5137
	raw_inode->i_flags = cpu_to_le32(ei->i_flags & 0xFFFFFFFF);
5138
	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT)))
B
Badari Pulavarty 已提交
5139 5140
		raw_inode->i_file_acl_high =
			cpu_to_le16(ei->i_file_acl >> 32);
5141
	raw_inode->i_file_acl_lo = cpu_to_le32(ei->i_file_acl);
A
Artem Blagodarenko 已提交
5142
	if (ei->i_disksize != ext4_isize(inode->i_sb, raw_inode)) {
5143 5144 5145
		ext4_isize_set(raw_inode, ei->i_disksize);
		need_datasync = 1;
	}
5146
	if (ei->i_disksize > 0x7fffffffULL) {
5147
		if (!ext4_has_feature_large_file(sb) ||
5148
				EXT4_SB(sb)->s_es->s_rev_level ==
5149 5150
		    cpu_to_le32(EXT4_GOOD_OLD_REV))
			set_large_file = 1;
5151 5152 5153 5154 5155 5156 5157 5158 5159 5160 5161 5162 5163
	}
	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
		if (old_valid_dev(inode->i_rdev)) {
			raw_inode->i_block[0] =
				cpu_to_le32(old_encode_dev(inode->i_rdev));
			raw_inode->i_block[1] = 0;
		} else {
			raw_inode->i_block[0] = 0;
			raw_inode->i_block[1] =
				cpu_to_le32(new_encode_dev(inode->i_rdev));
			raw_inode->i_block[2] = 0;
		}
5164
	} else if (!ext4_has_inline_data(inode)) {
5165 5166
		for (block = 0; block < EXT4_N_BLOCKS; block++)
			raw_inode->i_block[block] = ei->i_data[block];
5167
	}
5168

5169
	if (likely(!test_opt2(inode->i_sb, HURD_COMPAT))) {
J
Jeff Layton 已提交
5170 5171 5172
		u64 ivers = inode_peek_iversion(inode);

		raw_inode->i_disk_version = cpu_to_le32(ivers);
5173 5174 5175
		if (ei->i_extra_isize) {
			if (EXT4_FITS_IN_INODE(raw_inode, ei, i_version_hi))
				raw_inode->i_version_hi =
J
Jeff Layton 已提交
5176
					cpu_to_le32(ivers >> 32);
5177 5178 5179
			raw_inode->i_extra_isize =
				cpu_to_le16(ei->i_extra_isize);
		}
5180
	}
L
Li Xi 已提交
5181

K
Kaho Ng 已提交
5182
	BUG_ON(!ext4_has_feature_project(inode->i_sb) &&
L
Li Xi 已提交
5183 5184 5185 5186 5187 5188
	       i_projid != EXT4_DEF_PROJID);

	if (EXT4_INODE_SIZE(inode->i_sb) > EXT4_GOOD_OLD_INODE_SIZE &&
	    EXT4_FITS_IN_INODE(raw_inode, ei, i_projid))
		raw_inode->i_projid = cpu_to_le32(i_projid);

5189
	ext4_inode_csum_set(inode, raw_inode, ei);
5190
	spin_unlock(&ei->i_raw_lock);
5191
	if (inode->i_sb->s_flags & SB_LAZYTIME)
5192 5193
		ext4_update_other_inodes_time(inode->i_sb, inode->i_ino,
					      bh->b_data);
5194

5195
	BUFFER_TRACE(bh, "call ext4_handle_dirty_metadata");
5196
	rc = ext4_handle_dirty_metadata(handle, NULL, bh);
5197 5198
	if (!err)
		err = rc;
5199
	ext4_clear_inode_state(inode, EXT4_STATE_NEW);
5200
	if (set_large_file) {
5201
		BUFFER_TRACE(EXT4_SB(sb)->s_sbh, "get write access");
5202 5203 5204 5205
		err = ext4_journal_get_write_access(handle, EXT4_SB(sb)->s_sbh);
		if (err)
			goto out_brelse;
		ext4_update_dynamic_rev(sb);
5206
		ext4_set_feature_large_file(sb);
5207 5208 5209
		ext4_handle_sync(handle);
		err = ext4_handle_dirty_super(handle, sb);
	}
5210
	ext4_update_inode_fsync_trans(handle, inode, need_datasync);
5211
out_brelse:
5212
	brelse(bh);
5213
	ext4_std_error(inode->i_sb, err);
5214 5215 5216 5217
	return err;
}

/*
5218
 * ext4_write_inode()
5219 5220 5221
 *
 * We are called from a few places:
 *
5222
 * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
5223
 *   Here, there will be no transaction running. We wait for any running
5224
 *   transaction to commit.
5225
 *
5226 5227
 * - Within flush work (sys_sync(), kupdate and such).
 *   We wait on commit, if told to.
5228
 *
5229 5230
 * - Within iput_final() -> write_inode_now()
 *   We wait on commit, if told to.
5231 5232 5233
 *
 * In all cases it is actually safe for us to return without doing anything,
 * because the inode has been copied into a raw inode buffer in
5234 5235
 * ext4_mark_inode_dirty().  This is a correctness thing for WB_SYNC_ALL
 * writeback.
5236 5237 5238 5239 5240 5241 5242 5243 5244 5245 5246
 *
 * Note that we are absolutely dependent upon all inode dirtiers doing the
 * right thing: they *must* call mark_inode_dirty() after dirtying info in
 * which we are interested.
 *
 * It would be a bug for them to not do this.  The code:
 *
 *	mark_inode_dirty(inode)
 *	stuff();
 *	inode->i_size = expr;
 *
5247 5248 5249
 * is in error because write_inode() could occur while `stuff()' is running,
 * and the new i_size will be lost.  Plus the inode will no longer be on the
 * superblock's dirty inode list.
5250
 */
5251
int ext4_write_inode(struct inode *inode, struct writeback_control *wbc)
5252
{
5253 5254
	int err;

5255
	if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
5256 5257
		return 0;

5258 5259 5260 5261 5262 5263
	if (EXT4_SB(inode->i_sb)->s_journal) {
		if (ext4_journal_current_handle()) {
			jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
			dump_stack();
			return -EIO;
		}
5264

5265 5266 5267 5268 5269 5270
		/*
		 * No need to force transaction in WB_SYNC_NONE mode. Also
		 * ext4_sync_fs() will force the commit after everything is
		 * written.
		 */
		if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
5271 5272 5273 5274 5275
			return 0;

		err = ext4_force_commit(inode->i_sb);
	} else {
		struct ext4_iloc iloc;
5276

5277
		err = __ext4_get_inode_loc(inode, &iloc, 0);
5278 5279
		if (err)
			return err;
5280 5281 5282 5283 5284
		/*
		 * sync(2) will flush the whole buffer cache. No need to do
		 * it here separately for each inode.
		 */
		if (wbc->sync_mode == WB_SYNC_ALL && !wbc->for_sync)
5285 5286
			sync_dirty_buffer(iloc.bh);
		if (buffer_req(iloc.bh) && !buffer_uptodate(iloc.bh)) {
5287 5288
			EXT4_ERROR_INODE_BLOCK(inode, iloc.bh->b_blocknr,
					 "IO error syncing inode");
5289 5290
			err = -EIO;
		}
5291
		brelse(iloc.bh);
5292 5293
	}
	return err;
5294 5295
}

5296 5297 5298 5299 5300 5301 5302 5303 5304 5305 5306 5307 5308
/*
 * In data=journal mode ext4_journalled_invalidatepage() may fail to invalidate
 * buffers that are attached to a page stradding i_size and are undergoing
 * commit. In that case we have to wait for commit to finish and try again.
 */
static void ext4_wait_for_tail_page_commit(struct inode *inode)
{
	struct page *page;
	unsigned offset;
	journal_t *journal = EXT4_SB(inode->i_sb)->s_journal;
	tid_t commit_tid = 0;
	int ret;

5309
	offset = inode->i_size & (PAGE_SIZE - 1);
5310 5311
	/*
	 * All buffers in the last page remain valid? Then there's nothing to
5312
	 * do. We do the check mainly to optimize the common PAGE_SIZE ==
5313 5314
	 * blocksize case
	 */
F
Fabian Frederick 已提交
5315
	if (offset > PAGE_SIZE - i_blocksize(inode))
5316 5317 5318
		return;
	while (1) {
		page = find_lock_page(inode->i_mapping,
5319
				      inode->i_size >> PAGE_SHIFT);
5320 5321
		if (!page)
			return;
5322
		ret = __ext4_journalled_invalidatepage(page, offset,
5323
						PAGE_SIZE - offset);
5324
		unlock_page(page);
5325
		put_page(page);
5326 5327 5328 5329 5330 5331 5332 5333 5334 5335 5336 5337
		if (ret != -EBUSY)
			return;
		commit_tid = 0;
		read_lock(&journal->j_state_lock);
		if (journal->j_committing_transaction)
			commit_tid = journal->j_committing_transaction->t_tid;
		read_unlock(&journal->j_state_lock);
		if (commit_tid)
			jbd2_log_wait_commit(journal, commit_tid);
	}
}

5338
/*
5339
 * ext4_setattr()
5340 5341 5342 5343 5344 5345 5346 5347 5348 5349 5350 5351 5352
 *
 * Called from notify_change.
 *
 * We want to trap VFS attempts to truncate the file as soon as
 * possible.  In particular, we want to make sure that when the VFS
 * shrinks i_size, we put the inode on the orphan list and modify
 * i_disksize immediately, so that during the subsequent flushing of
 * dirty pages and freeing of disk blocks, we can guarantee that any
 * commit will leave the blocks being flushed in an unused state on
 * disk.  (On recovery, the inode will get truncated and the blocks will
 * be freed, so we have a strong guarantee that no future commit will
 * leave these blocks visible to the user.)
 *
5353 5354 5355 5356 5357 5358 5359 5360
 * Another thing we have to assure is that if we are in ordered mode
 * and inode is still attached to the committing transaction, we must
 * we start writeout of all the dirty pages which are being truncated.
 * This way we are sure that all the data written in the previous
 * transaction are already on disk (truncate waits for pages under
 * writeback).
 *
 * Called with inode->i_mutex down.
5361
 */
5362
int ext4_setattr(struct dentry *dentry, struct iattr *attr)
5363
{
5364
	struct inode *inode = d_inode(dentry);
5365
	int error, rc = 0;
5366
	int orphan = 0;
5367 5368
	const unsigned int ia_valid = attr->ia_valid;

5369 5370 5371
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

5372
	error = setattr_prepare(dentry, attr);
5373 5374 5375
	if (error)
		return error;

5376 5377 5378 5379
	error = fscrypt_prepare_setattr(dentry, attr);
	if (error)
		return error;

5380 5381 5382 5383 5384
	if (is_quota_modification(inode, attr)) {
		error = dquot_initialize(inode);
		if (error)
			return error;
	}
5385 5386
	if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
	    (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
5387 5388 5389 5390
		handle_t *handle;

		/* (user+group)*(old+new) structure, inode write (sb,
		 * inode block, ? - but truncate inode update has it) */
5391 5392 5393
		handle = ext4_journal_start(inode, EXT4_HT_QUOTA,
			(EXT4_MAXQUOTAS_INIT_BLOCKS(inode->i_sb) +
			 EXT4_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)) + 3);
5394 5395 5396 5397
		if (IS_ERR(handle)) {
			error = PTR_ERR(handle);
			goto err_out;
		}
5398 5399 5400 5401 5402

		/* dquot_transfer() calls back ext4_get_inode_usage() which
		 * counts xattr inode references.
		 */
		down_read(&EXT4_I(inode)->xattr_sem);
5403
		error = dquot_transfer(inode, attr);
5404 5405
		up_read(&EXT4_I(inode)->xattr_sem);

5406
		if (error) {
5407
			ext4_journal_stop(handle);
5408 5409 5410 5411 5412 5413 5414 5415
			return error;
		}
		/* Update corresponding info in inode so that everything is in
		 * one transaction */
		if (attr->ia_valid & ATTR_UID)
			inode->i_uid = attr->ia_uid;
		if (attr->ia_valid & ATTR_GID)
			inode->i_gid = attr->ia_gid;
5416 5417
		error = ext4_mark_inode_dirty(handle, inode);
		ext4_journal_stop(handle);
5418 5419
	}

5420
	if (attr->ia_valid & ATTR_SIZE) {
5421
		handle_t *handle;
5422 5423
		loff_t oldsize = inode->i_size;
		int shrink = (attr->ia_size <= inode->i_size);
5424

5425
		if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
5426 5427
			struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);

5428 5429
			if (attr->ia_size > sbi->s_bitmap_maxbytes)
				return -EFBIG;
5430
		}
5431 5432
		if (!S_ISREG(inode->i_mode))
			return -EINVAL;
C
Christoph Hellwig 已提交
5433 5434 5435 5436

		if (IS_I_VERSION(inode) && attr->ia_size != inode->i_size)
			inode_inc_iversion(inode);

5437
		if (ext4_should_order_data(inode) &&
5438
		    (attr->ia_size < inode->i_size)) {
5439
			error = ext4_begin_ordered_truncate(inode,
5440
							    attr->ia_size);
5441 5442 5443 5444
			if (error)
				goto err_out;
		}
		if (attr->ia_size != inode->i_size) {
5445 5446 5447 5448 5449
			handle = ext4_journal_start(inode, EXT4_HT_INODE, 3);
			if (IS_ERR(handle)) {
				error = PTR_ERR(handle);
				goto err_out;
			}
5450
			if (ext4_handle_valid(handle) && shrink) {
5451 5452 5453
				error = ext4_orphan_add(handle, inode);
				orphan = 1;
			}
E
Eryu Guan 已提交
5454 5455 5456 5457 5458
			/*
			 * Update c/mtime on truncate up, ext4_truncate() will
			 * update c/mtime in shrink case below
			 */
			if (!shrink) {
5459
				inode->i_mtime = current_time(inode);
E
Eryu Guan 已提交
5460 5461
				inode->i_ctime = inode->i_mtime;
			}
5462
			down_write(&EXT4_I(inode)->i_data_sem);
5463 5464 5465 5466
			EXT4_I(inode)->i_disksize = attr->ia_size;
			rc = ext4_mark_inode_dirty(handle, inode);
			if (!error)
				error = rc;
5467 5468 5469 5470 5471 5472 5473 5474
			/*
			 * We have to update i_size under i_data_sem together
			 * with i_disksize to avoid races with writeback code
			 * running ext4_wb_update_i_disksize().
			 */
			if (!error)
				i_size_write(inode, attr->ia_size);
			up_write(&EXT4_I(inode)->i_data_sem);
5475 5476
			ext4_journal_stop(handle);
			if (error) {
5477 5478
				if (orphan)
					ext4_orphan_del(NULL, inode);
5479 5480
				goto err_out;
			}
5481
		}
5482 5483
		if (!shrink)
			pagecache_isize_extended(inode, oldsize, inode->i_size);
5484

5485 5486 5487 5488 5489 5490 5491 5492 5493 5494 5495 5496
		/*
		 * Blocks are going to be removed from the inode. Wait
		 * for dio in flight.  Temporarily disable
		 * dioread_nolock to prevent livelock.
		 */
		if (orphan) {
			if (!ext4_should_journal_data(inode)) {
				ext4_inode_block_unlocked_dio(inode);
				inode_dio_wait(inode);
				ext4_inode_resume_unlocked_dio(inode);
			} else
				ext4_wait_for_tail_page_commit(inode);
5497
		}
5498
		down_write(&EXT4_I(inode)->i_mmap_sem);
5499 5500 5501 5502
		/*
		 * Truncate pagecache after we've waited for commit
		 * in data=journal mode to make pages freeable.
		 */
R
Ross Zwisler 已提交
5503
		truncate_pagecache(inode, inode->i_size);
5504 5505 5506 5507 5508
		if (shrink) {
			rc = ext4_truncate(inode);
			if (rc)
				error = rc;
		}
5509
		up_write(&EXT4_I(inode)->i_mmap_sem);
5510
	}
5511

5512
	if (!error) {
C
Christoph Hellwig 已提交
5513 5514 5515 5516 5517 5518 5519 5520
		setattr_copy(inode, attr);
		mark_inode_dirty(inode);
	}

	/*
	 * If the call to ext4_truncate failed to get a transaction handle at
	 * all, we need to clean up the in-core orphan list manually.
	 */
5521
	if (orphan && inode->i_nlink)
5522
		ext4_orphan_del(NULL, inode);
5523

5524
	if (!error && (ia_valid & ATTR_MODE))
5525
		rc = posix_acl_chmod(inode, inode->i_mode);
5526 5527

err_out:
5528
	ext4_std_error(inode->i_sb, error);
5529 5530 5531 5532 5533
	if (!error)
		error = rc;
	return error;
}

5534 5535
int ext4_getattr(const struct path *path, struct kstat *stat,
		 u32 request_mask, unsigned int query_flags)
5536
{
D
David Howells 已提交
5537 5538 5539 5540 5541 5542 5543 5544 5545 5546 5547 5548 5549 5550 5551 5552 5553 5554 5555 5556 5557 5558
	struct inode *inode = d_inode(path->dentry);
	struct ext4_inode *raw_inode;
	struct ext4_inode_info *ei = EXT4_I(inode);
	unsigned int flags;

	if (EXT4_FITS_IN_INODE(raw_inode, ei, i_crtime)) {
		stat->result_mask |= STATX_BTIME;
		stat->btime.tv_sec = ei->i_crtime.tv_sec;
		stat->btime.tv_nsec = ei->i_crtime.tv_nsec;
	}

	flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
	if (flags & EXT4_APPEND_FL)
		stat->attributes |= STATX_ATTR_APPEND;
	if (flags & EXT4_COMPR_FL)
		stat->attributes |= STATX_ATTR_COMPRESSED;
	if (flags & EXT4_ENCRYPT_FL)
		stat->attributes |= STATX_ATTR_ENCRYPTED;
	if (flags & EXT4_IMMUTABLE_FL)
		stat->attributes |= STATX_ATTR_IMMUTABLE;
	if (flags & EXT4_NODUMP_FL)
		stat->attributes |= STATX_ATTR_NODUMP;
5559

5560 5561 5562 5563 5564 5565
	stat->attributes_mask |= (STATX_ATTR_APPEND |
				  STATX_ATTR_COMPRESSED |
				  STATX_ATTR_ENCRYPTED |
				  STATX_ATTR_IMMUTABLE |
				  STATX_ATTR_NODUMP);

5566
	generic_fillattr(inode, stat);
D
David Howells 已提交
5567 5568 5569 5570 5571 5572 5573 5574 5575 5576
	return 0;
}

int ext4_file_getattr(const struct path *path, struct kstat *stat,
		      u32 request_mask, unsigned int query_flags)
{
	struct inode *inode = d_inode(path->dentry);
	u64 delalloc_blocks;

	ext4_getattr(path, stat, request_mask, query_flags);
5577

5578 5579 5580 5581
	/*
	 * If there is inline data in the inode, the inode will normally not
	 * have data blocks allocated (it may have an external xattr block).
	 * Report at least one sector for such files, so tools like tar, rsync,
T
Theodore Ts'o 已提交
5582
	 * others don't incorrectly think the file is completely sparse.
5583 5584 5585 5586
	 */
	if (unlikely(ext4_has_inline_data(inode)))
		stat->blocks += (stat->size + 511) >> 9;

5587 5588 5589 5590 5591 5592 5593 5594 5595 5596
	/*
	 * We can't update i_blocks if the block allocation is delayed
	 * otherwise in the case of system crash before the real block
	 * allocation is done, we will have i_blocks inconsistent with
	 * on-disk file blocks.
	 * We always keep i_blocks updated together with real
	 * allocation. But to not confuse with user, stat
	 * will return the blocks that include the delayed allocation
	 * blocks for this file.
	 */
5597
	delalloc_blocks = EXT4_C2B(EXT4_SB(inode->i_sb),
5598 5599
				   EXT4_I(inode)->i_reserved_data_blocks);
	stat->blocks += delalloc_blocks << (inode->i_sb->s_blocksize_bits - 9);
5600 5601
	return 0;
}
5602

5603 5604
static int ext4_index_trans_blocks(struct inode *inode, int lblocks,
				   int pextents)
5605
{
5606
	if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5607 5608
		return ext4_ind_trans_blocks(inode, lblocks);
	return ext4_ext_index_trans_blocks(inode, pextents);
5609
}
5610

5611
/*
5612 5613 5614
 * Account for index blocks, block groups bitmaps and block group
 * descriptor blocks if modify datablocks and index blocks
 * worse case, the indexs blocks spread over different block groups
5615
 *
5616
 * If datablocks are discontiguous, they are possible to spread over
5617
 * different block groups too. If they are contiguous, with flexbg,
5618
 * they could still across block group boundary.
5619
 *
5620 5621
 * Also account for superblock, inode, quota and xattr blocks
 */
T
Tahsin Erdogan 已提交
5622
static int ext4_meta_trans_blocks(struct inode *inode, int lblocks,
5623
				  int pextents)
5624
{
5625 5626
	ext4_group_t groups, ngroups = ext4_get_groups_count(inode->i_sb);
	int gdpblocks;
5627 5628 5629 5630
	int idxblocks;
	int ret = 0;

	/*
5631 5632
	 * How many index blocks need to touch to map @lblocks logical blocks
	 * to @pextents physical extents?
5633
	 */
5634
	idxblocks = ext4_index_trans_blocks(inode, lblocks, pextents);
5635 5636 5637 5638 5639 5640 5641

	ret = idxblocks;

	/*
	 * Now let's see how many group bitmaps and group descriptors need
	 * to account
	 */
5642
	groups = idxblocks + pextents;
5643
	gdpblocks = groups;
5644 5645
	if (groups > ngroups)
		groups = ngroups;
5646 5647 5648 5649 5650 5651 5652 5653 5654 5655 5656 5657 5658
	if (groups > EXT4_SB(inode->i_sb)->s_gdb_count)
		gdpblocks = EXT4_SB(inode->i_sb)->s_gdb_count;

	/* bitmaps and block group descriptor blocks */
	ret += groups + gdpblocks;

	/* Blocks for super block, inode, quota and xattr blocks */
	ret += EXT4_META_TRANS_BLOCKS(inode->i_sb);

	return ret;
}

/*
L
Lucas De Marchi 已提交
5659
 * Calculate the total number of credits to reserve to fit
5660 5661
 * the modification of a single pages into a single transaction,
 * which may include multiple chunks of block allocations.
5662
 *
5663
 * This could be called via ext4_write_begin()
5664
 *
5665
 * We need to consider the worse case, when
5666
 * one new block per extent.
5667
 */
A
Alex Tomas 已提交
5668
int ext4_writepage_trans_blocks(struct inode *inode)
5669
{
5670
	int bpp = ext4_journal_blocks_per_page(inode);
5671 5672
	int ret;

5673
	ret = ext4_meta_trans_blocks(inode, bpp, bpp);
A
Alex Tomas 已提交
5674

5675
	/* Account for data blocks for journalled mode */
5676
	if (ext4_should_journal_data(inode))
5677
		ret += bpp;
5678 5679
	return ret;
}
5680 5681 5682 5683 5684

/*
 * Calculate the journal credits for a chunk of data modification.
 *
 * This is called from DIO, fallocate or whoever calling
5685
 * ext4_map_blocks() to map/allocate a chunk of contiguous disk blocks.
5686 5687 5688 5689 5690 5691 5692 5693 5694
 *
 * journal buffers for data blocks are not included here, as DIO
 * and fallocate do no need to journal data buffers.
 */
int ext4_chunk_trans_blocks(struct inode *inode, int nrblocks)
{
	return ext4_meta_trans_blocks(inode, nrblocks, 1);
}

5695
/*
5696
 * The caller must have previously called ext4_reserve_inode_write().
5697 5698
 * Give this, we know that the caller already has write access to iloc->bh.
 */
5699
int ext4_mark_iloc_dirty(handle_t *handle,
5700
			 struct inode *inode, struct ext4_iloc *iloc)
5701 5702 5703
{
	int err = 0;

5704 5705 5706
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

5707
	if (IS_I_VERSION(inode))
5708 5709
		inode_inc_iversion(inode);

5710 5711 5712
	/* the do_update_inode consumes one bh->b_count */
	get_bh(iloc->bh);

5713
	/* ext4_do_update_inode() does jbd2_journal_dirty_metadata */
5714
	err = ext4_do_update_inode(handle, inode, iloc);
5715 5716 5717 5718 5719 5720 5721 5722 5723 5724
	put_bh(iloc->bh);
	return err;
}

/*
 * On success, We end up with an outstanding reference count against
 * iloc->bh.  This _must_ be cleaned up later.
 */

int
5725 5726
ext4_reserve_inode_write(handle_t *handle, struct inode *inode,
			 struct ext4_iloc *iloc)
5727
{
5728 5729
	int err;

5730 5731 5732
	if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
		return -EIO;

5733 5734 5735 5736 5737 5738 5739
	err = ext4_get_inode_loc(inode, iloc);
	if (!err) {
		BUFFER_TRACE(iloc->bh, "get_write_access");
		err = ext4_journal_get_write_access(handle, iloc->bh);
		if (err) {
			brelse(iloc->bh);
			iloc->bh = NULL;
5740 5741
		}
	}
5742
	ext4_std_error(inode->i_sb, err);
5743 5744 5745
	return err;
}

5746 5747 5748 5749 5750 5751 5752 5753 5754 5755 5756 5757 5758 5759 5760 5761 5762 5763 5764 5765 5766 5767 5768 5769 5770 5771 5772 5773 5774 5775 5776 5777 5778 5779 5780 5781
static int __ext4_expand_extra_isize(struct inode *inode,
				     unsigned int new_extra_isize,
				     struct ext4_iloc *iloc,
				     handle_t *handle, int *no_expand)
{
	struct ext4_inode *raw_inode;
	struct ext4_xattr_ibody_header *header;
	int error;

	raw_inode = ext4_raw_inode(iloc);

	header = IHDR(inode, raw_inode);

	/* No extended attributes present */
	if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
	    header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
		memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
		       EXT4_I(inode)->i_extra_isize, 0,
		       new_extra_isize - EXT4_I(inode)->i_extra_isize);
		EXT4_I(inode)->i_extra_isize = new_extra_isize;
		return 0;
	}

	/* try to expand with EAs present */
	error = ext4_expand_extra_isize_ea(inode, new_extra_isize,
					   raw_inode, handle);
	if (error) {
		/*
		 * Inode size expansion failed; don't try again
		 */
		*no_expand = 1;
	}

	return error;
}

5782 5783 5784 5785
/*
 * Expand an inode by new_extra_isize bytes.
 * Returns 0 on success or negative error number on failure.
 */
5786 5787 5788 5789
static int ext4_try_to_expand_extra_isize(struct inode *inode,
					  unsigned int new_extra_isize,
					  struct ext4_iloc iloc,
					  handle_t *handle)
5790
{
5791 5792
	int no_expand;
	int error;
5793

5794 5795 5796 5797 5798 5799 5800 5801 5802 5803 5804 5805 5806 5807 5808 5809
	if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND))
		return -EOVERFLOW;

	/*
	 * In nojournal mode, we can immediately attempt to expand
	 * the inode.  When journaled, we first need to obtain extra
	 * buffer credits since we may write into the EA block
	 * with this same handle. If journal_extend fails, then it will
	 * only result in a minor loss of functionality for that inode.
	 * If this is felt to be critical, then e2fsck should be run to
	 * force a large enough s_min_extra_isize.
	 */
	if (ext4_handle_valid(handle) &&
	    jbd2_journal_extend(handle,
				EXT4_DATA_TRANS_BLOCKS(inode->i_sb)) != 0)
		return -ENOSPC;
5810

5811
	if (ext4_write_trylock_xattr(inode, &no_expand) == 0)
5812
		return -EBUSY;
5813

5814 5815 5816
	error = __ext4_expand_extra_isize(inode, new_extra_isize, &iloc,
					  handle, &no_expand);
	ext4_write_unlock_xattr(inode, &no_expand);
5817

5818 5819
	return error;
}
5820

5821 5822 5823 5824 5825 5826 5827 5828 5829 5830 5831
int ext4_expand_extra_isize(struct inode *inode,
			    unsigned int new_extra_isize,
			    struct ext4_iloc *iloc)
{
	handle_t *handle;
	int no_expand;
	int error, rc;

	if (ext4_test_inode_state(inode, EXT4_STATE_NO_EXPAND)) {
		brelse(iloc->bh);
		return -EOVERFLOW;
5832 5833
	}

5834 5835 5836 5837 5838 5839 5840 5841 5842 5843 5844 5845
	handle = ext4_journal_start(inode, EXT4_HT_INODE,
				    EXT4_DATA_TRANS_BLOCKS(inode->i_sb));
	if (IS_ERR(handle)) {
		error = PTR_ERR(handle);
		brelse(iloc->bh);
		return error;
	}

	ext4_write_lock_xattr(inode, &no_expand);

	BUFFER_TRACE(iloc.bh, "get_write_access");
	error = ext4_journal_get_write_access(handle, iloc->bh);
5846
	if (error) {
5847 5848
		brelse(iloc->bh);
		goto out_stop;
5849
	}
5850

5851 5852 5853 5854 5855 5856 5857 5858 5859 5860
	error = __ext4_expand_extra_isize(inode, new_extra_isize, iloc,
					  handle, &no_expand);

	rc = ext4_mark_iloc_dirty(handle, inode, iloc);
	if (!error)
		error = rc;

	ext4_write_unlock_xattr(inode, &no_expand);
out_stop:
	ext4_journal_stop(handle);
5861
	return error;
5862 5863
}

5864 5865 5866 5867 5868 5869 5870 5871 5872 5873 5874 5875 5876
/*
 * What we do here is to mark the in-core inode as clean with respect to inode
 * dirtiness (it may still be data-dirty).
 * This means that the in-core inode may be reaped by prune_icache
 * without having to perform any I/O.  This is a very good thing,
 * because *any* task may call prune_icache - even ones which
 * have a transaction open against a different journal.
 *
 * Is this cheating?  Not really.  Sure, we haven't written the
 * inode out, but prune_icache isn't a user-visible syncing function.
 * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
 * we start and wait on commits.
 */
5877
int ext4_mark_inode_dirty(handle_t *handle, struct inode *inode)
5878
{
5879
	struct ext4_iloc iloc;
5880
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5881
	int err;
5882 5883

	might_sleep();
5884
	trace_ext4_mark_inode_dirty(inode, _RET_IP_);
5885
	err = ext4_reserve_inode_write(handle, inode, &iloc);
5886 5887
	if (err)
		return err;
5888 5889 5890 5891 5892

	if (EXT4_I(inode)->i_extra_isize < sbi->s_want_extra_isize)
		ext4_try_to_expand_extra_isize(inode, sbi->s_want_extra_isize,
					       iloc, handle);

5893
	return ext4_mark_iloc_dirty(handle, inode, &iloc);
5894 5895 5896
}

/*
5897
 * ext4_dirty_inode() is called from __mark_inode_dirty()
5898 5899 5900 5901 5902
 *
 * We're really interested in the case where a file is being extended.
 * i_size has been changed by generic_commit_write() and we thus need
 * to include the updated inode in the current transaction.
 *
5903
 * Also, dquot_alloc_block() will always dirty the inode when blocks
5904 5905 5906 5907 5908
 * are allocated to the file.
 *
 * If the inode is marked synchronous, we don't honour that here - doing
 * so would cause a commit on atime updates, which we don't bother doing.
 * We handle synchronous inodes at the highest possible level.
5909 5910 5911 5912
 *
 * If only the I_DIRTY_TIME flag is set, we can skip everything.  If
 * I_DIRTY_TIME and I_DIRTY_SYNC is set, the only inode fields we need
 * to copy into the on-disk inode structure are the timestamp files.
5913
 */
5914
void ext4_dirty_inode(struct inode *inode, int flags)
5915 5916 5917
{
	handle_t *handle;

5918 5919
	if (flags == I_DIRTY_TIME)
		return;
5920
	handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
5921 5922
	if (IS_ERR(handle))
		goto out;
5923 5924 5925

	ext4_mark_inode_dirty(handle, inode);

5926
	ext4_journal_stop(handle);
5927 5928 5929 5930 5931 5932 5933 5934
out:
	return;
}

#if 0
/*
 * Bind an inode's backing buffer_head into this transaction, to prevent
 * it from being flushed to disk early.  Unlike
5935
 * ext4_reserve_inode_write, this leaves behind no bh reference and
5936 5937 5938
 * returns no iloc structure, so the caller needs to repeat the iloc
 * lookup to mark the inode dirty later.
 */
5939
static int ext4_pin_inode(handle_t *handle, struct inode *inode)
5940
{
5941
	struct ext4_iloc iloc;
5942 5943 5944

	int err = 0;
	if (handle) {
5945
		err = ext4_get_inode_loc(inode, &iloc);
5946 5947
		if (!err) {
			BUFFER_TRACE(iloc.bh, "get_write_access");
5948
			err = jbd2_journal_get_write_access(handle, iloc.bh);
5949
			if (!err)
5950
				err = ext4_handle_dirty_metadata(handle,
5951
								 NULL,
5952
								 iloc.bh);
5953 5954 5955
			brelse(iloc.bh);
		}
	}
5956
	ext4_std_error(inode->i_sb, err);
5957 5958 5959 5960
	return err;
}
#endif

5961
int ext4_change_inode_journal_flag(struct inode *inode, int val)
5962 5963 5964 5965
{
	journal_t *journal;
	handle_t *handle;
	int err;
5966
	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5967 5968 5969 5970 5971 5972 5973 5974 5975 5976 5977

	/*
	 * We have to be very careful here: changing a data block's
	 * journaling status dynamically is dangerous.  If we write a
	 * data block to the journal, change the status and then delete
	 * that block, we risk forgetting to revoke the old log record
	 * from the journal and so a subsequent replay can corrupt data.
	 * So, first we make sure that the journal is empty and that
	 * nobody is changing anything.
	 */

5978
	journal = EXT4_JOURNAL(inode);
5979 5980
	if (!journal)
		return 0;
5981
	if (is_journal_aborted(journal))
5982 5983
		return -EROFS;

5984 5985 5986 5987
	/* Wait for all existing dio workers */
	ext4_inode_block_unlocked_dio(inode);
	inode_dio_wait(inode);

5988 5989 5990 5991 5992 5993 5994 5995 5996 5997 5998 5999 6000 6001 6002 6003 6004 6005
	/*
	 * Before flushing the journal and switching inode's aops, we have
	 * to flush all dirty data the inode has. There can be outstanding
	 * delayed allocations, there can be unwritten extents created by
	 * fallocate or buffered writes in dioread_nolock mode covered by
	 * dirty data which can be converted only after flushing the dirty
	 * data (and journalled aops don't know how to handle these cases).
	 */
	if (val) {
		down_write(&EXT4_I(inode)->i_mmap_sem);
		err = filemap_write_and_wait(inode->i_mapping);
		if (err < 0) {
			up_write(&EXT4_I(inode)->i_mmap_sem);
			ext4_inode_resume_unlocked_dio(inode);
			return err;
		}
	}

6006
	percpu_down_write(&sbi->s_journal_flag_rwsem);
6007
	jbd2_journal_lock_updates(journal);
6008 6009 6010 6011 6012 6013 6014 6015 6016 6017

	/*
	 * OK, there are no updates running now, and all cached data is
	 * synced to disk.  We are now in a completely consistent state
	 * which doesn't have anything in the journal, and we know that
	 * no filesystem updates are running, so it is safe to modify
	 * the inode's in-core data-journaling state flag now.
	 */

	if (val)
6018
		ext4_set_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
6019
	else {
6020 6021 6022
		err = jbd2_journal_flush(journal);
		if (err < 0) {
			jbd2_journal_unlock_updates(journal);
6023
			percpu_up_write(&sbi->s_journal_flag_rwsem);
6024 6025 6026
			ext4_inode_resume_unlocked_dio(inode);
			return err;
		}
6027
		ext4_clear_inode_flag(inode, EXT4_INODE_JOURNAL_DATA);
6028
	}
6029
	ext4_set_aops(inode);
6030

6031
	jbd2_journal_unlock_updates(journal);
6032 6033
	percpu_up_write(&sbi->s_journal_flag_rwsem);

6034 6035
	if (val)
		up_write(&EXT4_I(inode)->i_mmap_sem);
6036
	ext4_inode_resume_unlocked_dio(inode);
6037 6038 6039

	/* Finally we can mark the inode as dirty. */

6040
	handle = ext4_journal_start(inode, EXT4_HT_INODE, 1);
6041 6042 6043
	if (IS_ERR(handle))
		return PTR_ERR(handle);

6044
	err = ext4_mark_inode_dirty(handle, inode);
6045
	ext4_handle_sync(handle);
6046 6047
	ext4_journal_stop(handle);
	ext4_std_error(inode->i_sb, err);
6048 6049 6050

	return err;
}
6051 6052 6053 6054 6055 6056

static int ext4_bh_unmapped(handle_t *handle, struct buffer_head *bh)
{
	return !buffer_mapped(bh);
}

6057
int ext4_page_mkwrite(struct vm_fault *vmf)
6058
{
6059
	struct vm_area_struct *vma = vmf->vma;
6060
	struct page *page = vmf->page;
6061 6062
	loff_t size;
	unsigned long len;
6063
	int ret;
6064
	struct file *file = vma->vm_file;
A
Al Viro 已提交
6065
	struct inode *inode = file_inode(file);
6066
	struct address_space *mapping = inode->i_mapping;
6067 6068 6069
	handle_t *handle;
	get_block_t *get_block;
	int retries = 0;
6070

6071
	sb_start_pagefault(inode->i_sb);
6072
	file_update_time(vma->vm_file);
6073 6074

	down_read(&EXT4_I(inode)->i_mmap_sem);
6075 6076 6077 6078 6079

	ret = ext4_convert_inline_data(inode);
	if (ret)
		goto out_ret;

6080 6081 6082 6083 6084
	/* Delalloc case is easy... */
	if (test_opt(inode->i_sb, DELALLOC) &&
	    !ext4_should_journal_data(inode) &&
	    !ext4_nonda_switch(inode->i_sb)) {
		do {
6085
			ret = block_page_mkwrite(vma, vmf,
6086 6087 6088 6089
						   ext4_da_get_block_prep);
		} while (ret == -ENOSPC &&
		       ext4_should_retry_alloc(inode->i_sb, &retries));
		goto out_ret;
6090
	}
6091 6092

	lock_page(page);
6093 6094 6095 6096 6097 6098
	size = i_size_read(inode);
	/* Page got truncated from under us? */
	if (page->mapping != mapping || page_offset(page) > size) {
		unlock_page(page);
		ret = VM_FAULT_NOPAGE;
		goto out;
6099
	}
6100

6101 6102
	if (page->index == size >> PAGE_SHIFT)
		len = size & ~PAGE_MASK;
6103
	else
6104
		len = PAGE_SIZE;
6105
	/*
6106 6107
	 * Return if we have all the buffers mapped. This avoids the need to do
	 * journal_start/journal_stop which can block and take a long time
6108
	 */
6109
	if (page_has_buffers(page)) {
6110 6111 6112
		if (!ext4_walk_page_buffers(NULL, page_buffers(page),
					    0, len, NULL,
					    ext4_bh_unmapped)) {
6113
			/* Wait so that we don't change page under IO */
6114
			wait_for_stable_page(page);
6115 6116
			ret = VM_FAULT_LOCKED;
			goto out;
6117
		}
6118
	}
6119
	unlock_page(page);
6120 6121
	/* OK, we need to fill the hole... */
	if (ext4_should_dioread_nolock(inode))
6122
		get_block = ext4_get_block_unwritten;
6123 6124 6125
	else
		get_block = ext4_get_block;
retry_alloc:
6126 6127
	handle = ext4_journal_start(inode, EXT4_HT_WRITE_PAGE,
				    ext4_writepage_trans_blocks(inode));
6128
	if (IS_ERR(handle)) {
6129
		ret = VM_FAULT_SIGBUS;
6130 6131
		goto out;
	}
6132
	ret = block_page_mkwrite(vma, vmf, get_block);
6133
	if (!ret && ext4_should_journal_data(inode)) {
6134
		if (ext4_walk_page_buffers(handle, page_buffers(page), 0,
6135
			  PAGE_SIZE, NULL, do_journal_get_write_access)) {
6136 6137
			unlock_page(page);
			ret = VM_FAULT_SIGBUS;
6138
			ext4_journal_stop(handle);
6139 6140 6141 6142 6143 6144 6145 6146 6147 6148
			goto out;
		}
		ext4_set_inode_state(inode, EXT4_STATE_JDATA);
	}
	ext4_journal_stop(handle);
	if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
		goto retry_alloc;
out_ret:
	ret = block_page_mkwrite_return(ret);
out:
6149
	up_read(&EXT4_I(inode)->i_mmap_sem);
6150
	sb_end_pagefault(inode->i_sb);
6151 6152
	return ret;
}
6153

6154
int ext4_filemap_fault(struct vm_fault *vmf)
6155
{
6156
	struct inode *inode = file_inode(vmf->vma->vm_file);
6157 6158 6159
	int err;

	down_read(&EXT4_I(inode)->i_mmap_sem);
6160
	err = filemap_fault(vmf);
6161 6162 6163 6164
	up_read(&EXT4_I(inode)->i_mmap_sem);

	return err;
}