xref: /linux/fs/ext2/inode.c (revision d67b569f5f620c0fb95d5212642746b7ba9d29e4)
1 /*
2  *  linux/fs/ext2/inode.c
3  *
4  * Copyright (C) 1992, 1993, 1994, 1995
5  * Remy Card (card@masi.ibp.fr)
6  * Laboratoire MASI - Institut Blaise Pascal
7  * Universite Pierre et Marie Curie (Paris VI)
8  *
9  *  from
10  *
11  *  linux/fs/minix/inode.c
12  *
13  *  Copyright (C) 1991, 1992  Linus Torvalds
14  *
15  *  Goal-directed block allocation by Stephen Tweedie
16  * 	(sct@dcs.ed.ac.uk), 1993, 1998
17  *  Big-endian to little-endian byte-swapping/bitmaps by
18  *        David S. Miller (davem@caip.rutgers.edu), 1995
19  *  64-bit file support on 64-bit platforms by Jakub Jelinek
20  * 	(jj@sunsite.ms.mff.cuni.cz)
21  *
22  *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
23  */
24 
25 #include <linux/smp_lock.h>
26 #include <linux/time.h>
27 #include <linux/highuid.h>
28 #include <linux/pagemap.h>
29 #include <linux/quotaops.h>
30 #include <linux/module.h>
31 #include <linux/writeback.h>
32 #include <linux/buffer_head.h>
33 #include <linux/mpage.h>
34 #include "ext2.h"
35 #include "acl.h"
36 #include "xip.h"
37 
38 MODULE_AUTHOR("Remy Card and others");
39 MODULE_DESCRIPTION("Second Extended Filesystem");
40 MODULE_LICENSE("GPL");
41 
42 static int ext2_update_inode(struct inode * inode, int do_sync);
43 
44 /*
45  * Test whether an inode is a fast symlink.
46  */
47 static inline int ext2_inode_is_fast_symlink(struct inode *inode)
48 {
49 	int ea_blocks = EXT2_I(inode)->i_file_acl ?
50 		(inode->i_sb->s_blocksize >> 9) : 0;
51 
52 	return (S_ISLNK(inode->i_mode) &&
53 		inode->i_blocks - ea_blocks == 0);
54 }
55 
56 /*
57  * Called at each iput().
58  *
59  * The inode may be "bad" if ext2_read_inode() saw an error from
60  * ext2_get_inode(), so we need to check that to avoid freeing random disk
61  * blocks.
62  */
63 void ext2_put_inode(struct inode *inode)
64 {
65 	if (!is_bad_inode(inode))
66 		ext2_discard_prealloc(inode);
67 }
68 
69 /*
70  * Called at the last iput() if i_nlink is zero.
71  */
72 void ext2_delete_inode (struct inode * inode)
73 {
74 	if (is_bad_inode(inode))
75 		goto no_delete;
76 	EXT2_I(inode)->i_dtime	= get_seconds();
77 	mark_inode_dirty(inode);
78 	ext2_update_inode(inode, inode_needs_sync(inode));
79 
80 	inode->i_size = 0;
81 	if (inode->i_blocks)
82 		ext2_truncate (inode);
83 	ext2_free_inode (inode);
84 
85 	return;
86 no_delete:
87 	clear_inode(inode);	/* We must guarantee clearing of inode... */
88 }
89 
90 void ext2_discard_prealloc (struct inode * inode)
91 {
92 #ifdef EXT2_PREALLOCATE
93 	struct ext2_inode_info *ei = EXT2_I(inode);
94 	write_lock(&ei->i_meta_lock);
95 	if (ei->i_prealloc_count) {
96 		unsigned short total = ei->i_prealloc_count;
97 		unsigned long block = ei->i_prealloc_block;
98 		ei->i_prealloc_count = 0;
99 		ei->i_prealloc_block = 0;
100 		write_unlock(&ei->i_meta_lock);
101 		ext2_free_blocks (inode, block, total);
102 		return;
103 	} else
104 		write_unlock(&ei->i_meta_lock);
105 #endif
106 }
107 
108 static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err)
109 {
110 #ifdef EXT2FS_DEBUG
111 	static unsigned long alloc_hits, alloc_attempts;
112 #endif
113 	unsigned long result;
114 
115 
116 #ifdef EXT2_PREALLOCATE
117 	struct ext2_inode_info *ei = EXT2_I(inode);
118 	write_lock(&ei->i_meta_lock);
119 	if (ei->i_prealloc_count &&
120 	    (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block))
121 	{
122 		result = ei->i_prealloc_block++;
123 		ei->i_prealloc_count--;
124 		write_unlock(&ei->i_meta_lock);
125 		ext2_debug ("preallocation hit (%lu/%lu).\n",
126 			    ++alloc_hits, ++alloc_attempts);
127 	} else {
128 		write_unlock(&ei->i_meta_lock);
129 		ext2_discard_prealloc (inode);
130 		ext2_debug ("preallocation miss (%lu/%lu).\n",
131 			    alloc_hits, ++alloc_attempts);
132 		if (S_ISREG(inode->i_mode))
133 			result = ext2_new_block (inode, goal,
134 				 &ei->i_prealloc_count,
135 				 &ei->i_prealloc_block, err);
136 		else
137 			result = ext2_new_block(inode, goal, NULL, NULL, err);
138 	}
139 #else
140 	result = ext2_new_block (inode, goal, 0, 0, err);
141 #endif
142 	return result;
143 }
144 
145 typedef struct {
146 	__le32	*p;
147 	__le32	key;
148 	struct buffer_head *bh;
149 } Indirect;
150 
151 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
152 {
153 	p->key = *(p->p = v);
154 	p->bh = bh;
155 }
156 
157 static inline int verify_chain(Indirect *from, Indirect *to)
158 {
159 	while (from <= to && from->key == *from->p)
160 		from++;
161 	return (from > to);
162 }
163 
164 /**
165  *	ext2_block_to_path - parse the block number into array of offsets
166  *	@inode: inode in question (we are only interested in its superblock)
167  *	@i_block: block number to be parsed
168  *	@offsets: array to store the offsets in
169  *      @boundary: set this non-zero if the referred-to block is likely to be
170  *             followed (on disk) by an indirect block.
171  *	To store the locations of file's data ext2 uses a data structure common
172  *	for UNIX filesystems - tree of pointers anchored in the inode, with
173  *	data blocks at leaves and indirect blocks in intermediate nodes.
174  *	This function translates the block number into path in that tree -
175  *	return value is the path length and @offsets[n] is the offset of
176  *	pointer to (n+1)th node in the nth one. If @block is out of range
177  *	(negative or too large) warning is printed and zero returned.
178  *
179  *	Note: function doesn't find node addresses, so no IO is needed. All
180  *	we need to know is the capacity of indirect blocks (taken from the
181  *	inode->i_sb).
182  */
183 
184 /*
185  * Portability note: the last comparison (check that we fit into triple
186  * indirect block) is spelled differently, because otherwise on an
187  * architecture with 32-bit longs and 8Kb pages we might get into trouble
188  * if our filesystem had 8Kb blocks. We might use long long, but that would
189  * kill us on x86. Oh, well, at least the sign propagation does not matter -
190  * i_block would have to be negative in the very beginning, so we would not
191  * get there at all.
192  */
193 
194 static int ext2_block_to_path(struct inode *inode,
195 			long i_block, int offsets[4], int *boundary)
196 {
197 	int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
198 	int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
199 	const long direct_blocks = EXT2_NDIR_BLOCKS,
200 		indirect_blocks = ptrs,
201 		double_blocks = (1 << (ptrs_bits * 2));
202 	int n = 0;
203 	int final = 0;
204 
205 	if (i_block < 0) {
206 		ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0");
207 	} else if (i_block < direct_blocks) {
208 		offsets[n++] = i_block;
209 		final = direct_blocks;
210 	} else if ( (i_block -= direct_blocks) < indirect_blocks) {
211 		offsets[n++] = EXT2_IND_BLOCK;
212 		offsets[n++] = i_block;
213 		final = ptrs;
214 	} else if ((i_block -= indirect_blocks) < double_blocks) {
215 		offsets[n++] = EXT2_DIND_BLOCK;
216 		offsets[n++] = i_block >> ptrs_bits;
217 		offsets[n++] = i_block & (ptrs - 1);
218 		final = ptrs;
219 	} else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
220 		offsets[n++] = EXT2_TIND_BLOCK;
221 		offsets[n++] = i_block >> (ptrs_bits * 2);
222 		offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
223 		offsets[n++] = i_block & (ptrs - 1);
224 		final = ptrs;
225 	} else {
226 		ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
227 	}
228 	if (boundary)
229 		*boundary = (i_block & (ptrs - 1)) == (final - 1);
230 	return n;
231 }
232 
233 /**
234  *	ext2_get_branch - read the chain of indirect blocks leading to data
235  *	@inode: inode in question
236  *	@depth: depth of the chain (1 - direct pointer, etc.)
237  *	@offsets: offsets of pointers in inode/indirect blocks
238  *	@chain: place to store the result
239  *	@err: here we store the error value
240  *
241  *	Function fills the array of triples <key, p, bh> and returns %NULL
242  *	if everything went OK or the pointer to the last filled triple
243  *	(incomplete one) otherwise. Upon the return chain[i].key contains
244  *	the number of (i+1)-th block in the chain (as it is stored in memory,
245  *	i.e. little-endian 32-bit), chain[i].p contains the address of that
246  *	number (it points into struct inode for i==0 and into the bh->b_data
247  *	for i>0) and chain[i].bh points to the buffer_head of i-th indirect
248  *	block for i>0 and NULL for i==0. In other words, it holds the block
249  *	numbers of the chain, addresses they were taken from (and where we can
250  *	verify that chain did not change) and buffer_heads hosting these
251  *	numbers.
252  *
253  *	Function stops when it stumbles upon zero pointer (absent block)
254  *		(pointer to last triple returned, *@err == 0)
255  *	or when it gets an IO error reading an indirect block
256  *		(ditto, *@err == -EIO)
257  *	or when it notices that chain had been changed while it was reading
258  *		(ditto, *@err == -EAGAIN)
259  *	or when it reads all @depth-1 indirect blocks successfully and finds
260  *	the whole chain, all way to the data (returns %NULL, *err == 0).
261  */
262 static Indirect *ext2_get_branch(struct inode *inode,
263 				 int depth,
264 				 int *offsets,
265 				 Indirect chain[4],
266 				 int *err)
267 {
268 	struct super_block *sb = inode->i_sb;
269 	Indirect *p = chain;
270 	struct buffer_head *bh;
271 
272 	*err = 0;
273 	/* i_data is not going away, no lock needed */
274 	add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
275 	if (!p->key)
276 		goto no_block;
277 	while (--depth) {
278 		bh = sb_bread(sb, le32_to_cpu(p->key));
279 		if (!bh)
280 			goto failure;
281 		read_lock(&EXT2_I(inode)->i_meta_lock);
282 		if (!verify_chain(chain, p))
283 			goto changed;
284 		add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
285 		read_unlock(&EXT2_I(inode)->i_meta_lock);
286 		if (!p->key)
287 			goto no_block;
288 	}
289 	return NULL;
290 
291 changed:
292 	read_unlock(&EXT2_I(inode)->i_meta_lock);
293 	brelse(bh);
294 	*err = -EAGAIN;
295 	goto no_block;
296 failure:
297 	*err = -EIO;
298 no_block:
299 	return p;
300 }
301 
302 /**
303  *	ext2_find_near - find a place for allocation with sufficient locality
304  *	@inode: owner
305  *	@ind: descriptor of indirect block.
306  *
307  *	This function returns the prefered place for block allocation.
308  *	It is used when heuristic for sequential allocation fails.
309  *	Rules are:
310  *	  + if there is a block to the left of our position - allocate near it.
311  *	  + if pointer will live in indirect block - allocate near that block.
312  *	  + if pointer will live in inode - allocate in the same cylinder group.
313  *
314  * In the latter case we colour the starting block by the callers PID to
315  * prevent it from clashing with concurrent allocations for a different inode
316  * in the same block group.   The PID is used here so that functionally related
317  * files will be close-by on-disk.
318  *
319  *	Caller must make sure that @ind is valid and will stay that way.
320  */
321 
322 static unsigned long ext2_find_near(struct inode *inode, Indirect *ind)
323 {
324 	struct ext2_inode_info *ei = EXT2_I(inode);
325 	__le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
326 	__le32 *p;
327 	unsigned long bg_start;
328 	unsigned long colour;
329 
330 	/* Try to find previous block */
331 	for (p = ind->p - 1; p >= start; p--)
332 		if (*p)
333 			return le32_to_cpu(*p);
334 
335 	/* No such thing, so let's try location of indirect block */
336 	if (ind->bh)
337 		return ind->bh->b_blocknr;
338 
339 	/*
340 	 * It is going to be refered from inode itself? OK, just put it into
341 	 * the same cylinder group then.
342 	 */
343 	bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
344 		le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block);
345 	colour = (current->pid % 16) *
346 			(EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
347 	return bg_start + colour;
348 }
349 
350 /**
351  *	ext2_find_goal - find a prefered place for allocation.
352  *	@inode: owner
353  *	@block:  block we want
354  *	@chain:  chain of indirect blocks
355  *	@partial: pointer to the last triple within a chain
356  *	@goal:	place to store the result.
357  *
358  *	Normally this function find the prefered place for block allocation,
359  *	stores it in *@goal and returns zero. If the branch had been changed
360  *	under us we return -EAGAIN.
361  */
362 
363 static inline int ext2_find_goal(struct inode *inode,
364 				 long block,
365 				 Indirect chain[4],
366 				 Indirect *partial,
367 				 unsigned long *goal)
368 {
369 	struct ext2_inode_info *ei = EXT2_I(inode);
370 	write_lock(&ei->i_meta_lock);
371 	if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) {
372 		ei->i_next_alloc_block++;
373 		ei->i_next_alloc_goal++;
374 	}
375 	if (verify_chain(chain, partial)) {
376 		/*
377 		 * try the heuristic for sequential allocation,
378 		 * failing that at least try to get decent locality.
379 		 */
380 		if (block == ei->i_next_alloc_block)
381 			*goal = ei->i_next_alloc_goal;
382 		if (!*goal)
383 			*goal = ext2_find_near(inode, partial);
384 		write_unlock(&ei->i_meta_lock);
385 		return 0;
386 	}
387 	write_unlock(&ei->i_meta_lock);
388 	return -EAGAIN;
389 }
390 
391 /**
392  *	ext2_alloc_branch - allocate and set up a chain of blocks.
393  *	@inode: owner
394  *	@num: depth of the chain (number of blocks to allocate)
395  *	@offsets: offsets (in the blocks) to store the pointers to next.
396  *	@branch: place to store the chain in.
397  *
398  *	This function allocates @num blocks, zeroes out all but the last one,
399  *	links them into chain and (if we are synchronous) writes them to disk.
400  *	In other words, it prepares a branch that can be spliced onto the
401  *	inode. It stores the information about that chain in the branch[], in
402  *	the same format as ext2_get_branch() would do. We are calling it after
403  *	we had read the existing part of chain and partial points to the last
404  *	triple of that (one with zero ->key). Upon the exit we have the same
405  *	picture as after the successful ext2_get_block(), excpet that in one
406  *	place chain is disconnected - *branch->p is still zero (we did not
407  *	set the last link), but branch->key contains the number that should
408  *	be placed into *branch->p to fill that gap.
409  *
410  *	If allocation fails we free all blocks we've allocated (and forget
411  *	their buffer_heads) and return the error value the from failed
412  *	ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
413  *	as described above and return 0.
414  */
415 
416 static int ext2_alloc_branch(struct inode *inode,
417 			     int num,
418 			     unsigned long goal,
419 			     int *offsets,
420 			     Indirect *branch)
421 {
422 	int blocksize = inode->i_sb->s_blocksize;
423 	int n = 0;
424 	int err;
425 	int i;
426 	int parent = ext2_alloc_block(inode, goal, &err);
427 
428 	branch[0].key = cpu_to_le32(parent);
429 	if (parent) for (n = 1; n < num; n++) {
430 		struct buffer_head *bh;
431 		/* Allocate the next block */
432 		int nr = ext2_alloc_block(inode, parent, &err);
433 		if (!nr)
434 			break;
435 		branch[n].key = cpu_to_le32(nr);
436 		/*
437 		 * Get buffer_head for parent block, zero it out and set
438 		 * the pointer to new one, then send parent to disk.
439 		 */
440 		bh = sb_getblk(inode->i_sb, parent);
441 		lock_buffer(bh);
442 		memset(bh->b_data, 0, blocksize);
443 		branch[n].bh = bh;
444 		branch[n].p = (__le32 *) bh->b_data + offsets[n];
445 		*branch[n].p = branch[n].key;
446 		set_buffer_uptodate(bh);
447 		unlock_buffer(bh);
448 		mark_buffer_dirty_inode(bh, inode);
449 		/* We used to sync bh here if IS_SYNC(inode).
450 		 * But we now rely upon generic_osync_inode()
451 		 * and b_inode_buffers.  But not for directories.
452 		 */
453 		if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
454 			sync_dirty_buffer(bh);
455 		parent = nr;
456 	}
457 	if (n == num)
458 		return 0;
459 
460 	/* Allocation failed, free what we already allocated */
461 	for (i = 1; i < n; i++)
462 		bforget(branch[i].bh);
463 	for (i = 0; i < n; i++)
464 		ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1);
465 	return err;
466 }
467 
468 /**
469  *	ext2_splice_branch - splice the allocated branch onto inode.
470  *	@inode: owner
471  *	@block: (logical) number of block we are adding
472  *	@chain: chain of indirect blocks (with a missing link - see
473  *		ext2_alloc_branch)
474  *	@where: location of missing link
475  *	@num:   number of blocks we are adding
476  *
477  *	This function verifies that chain (up to the missing link) had not
478  *	changed, fills the missing link and does all housekeeping needed in
479  *	inode (->i_blocks, etc.). In case of success we end up with the full
480  *	chain to new block and return 0. Otherwise (== chain had been changed)
481  *	we free the new blocks (forgetting their buffer_heads, indeed) and
482  *	return -EAGAIN.
483  */
484 
485 static inline int ext2_splice_branch(struct inode *inode,
486 				     long block,
487 				     Indirect chain[4],
488 				     Indirect *where,
489 				     int num)
490 {
491 	struct ext2_inode_info *ei = EXT2_I(inode);
492 	int i;
493 
494 	/* Verify that place we are splicing to is still there and vacant */
495 
496 	write_lock(&ei->i_meta_lock);
497 	if (!verify_chain(chain, where-1) || *where->p)
498 		goto changed;
499 
500 	/* That's it */
501 
502 	*where->p = where->key;
503 	ei->i_next_alloc_block = block;
504 	ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key);
505 
506 	write_unlock(&ei->i_meta_lock);
507 
508 	/* We are done with atomic stuff, now do the rest of housekeeping */
509 
510 	inode->i_ctime = CURRENT_TIME_SEC;
511 
512 	/* had we spliced it onto indirect block? */
513 	if (where->bh)
514 		mark_buffer_dirty_inode(where->bh, inode);
515 
516 	mark_inode_dirty(inode);
517 	return 0;
518 
519 changed:
520 	write_unlock(&ei->i_meta_lock);
521 	for (i = 1; i < num; i++)
522 		bforget(where[i].bh);
523 	for (i = 0; i < num; i++)
524 		ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1);
525 	return -EAGAIN;
526 }
527 
528 /*
529  * Allocation strategy is simple: if we have to allocate something, we will
530  * have to go the whole way to leaf. So let's do it before attaching anything
531  * to tree, set linkage between the newborn blocks, write them if sync is
532  * required, recheck the path, free and repeat if check fails, otherwise
533  * set the last missing link (that will protect us from any truncate-generated
534  * removals - all blocks on the path are immune now) and possibly force the
535  * write on the parent block.
536  * That has a nice additional property: no special recovery from the failed
537  * allocations is needed - we simply release blocks and do not touch anything
538  * reachable from inode.
539  */
540 
541 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
542 {
543 	int err = -EIO;
544 	int offsets[4];
545 	Indirect chain[4];
546 	Indirect *partial;
547 	unsigned long goal;
548 	int left;
549 	int boundary = 0;
550 	int depth = ext2_block_to_path(inode, iblock, offsets, &boundary);
551 
552 	if (depth == 0)
553 		goto out;
554 
555 reread:
556 	partial = ext2_get_branch(inode, depth, offsets, chain, &err);
557 
558 	/* Simplest case - block found, no allocation needed */
559 	if (!partial) {
560 got_it:
561 		map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
562 		if (boundary)
563 			set_buffer_boundary(bh_result);
564 		/* Clean up and exit */
565 		partial = chain+depth-1; /* the whole chain */
566 		goto cleanup;
567 	}
568 
569 	/* Next simple case - plain lookup or failed read of indirect block */
570 	if (!create || err == -EIO) {
571 cleanup:
572 		while (partial > chain) {
573 			brelse(partial->bh);
574 			partial--;
575 		}
576 out:
577 		return err;
578 	}
579 
580 	/*
581 	 * Indirect block might be removed by truncate while we were
582 	 * reading it. Handling of that case (forget what we've got and
583 	 * reread) is taken out of the main path.
584 	 */
585 	if (err == -EAGAIN)
586 		goto changed;
587 
588 	goal = 0;
589 	if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0)
590 		goto changed;
591 
592 	left = (chain + depth) - partial;
593 	err = ext2_alloc_branch(inode, left, goal,
594 					offsets+(partial-chain), partial);
595 	if (err)
596 		goto cleanup;
597 
598 	if (ext2_use_xip(inode->i_sb)) {
599 		/*
600 		 * we need to clear the block
601 		 */
602 		err = ext2_clear_xip_target (inode,
603 			le32_to_cpu(chain[depth-1].key));
604 		if (err)
605 			goto cleanup;
606 	}
607 
608 	if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0)
609 		goto changed;
610 
611 	set_buffer_new(bh_result);
612 	goto got_it;
613 
614 changed:
615 	while (partial > chain) {
616 		brelse(partial->bh);
617 		partial--;
618 	}
619 	goto reread;
620 }
621 
622 static int ext2_writepage(struct page *page, struct writeback_control *wbc)
623 {
624 	return block_write_full_page(page, ext2_get_block, wbc);
625 }
626 
627 static int ext2_readpage(struct file *file, struct page *page)
628 {
629 	return mpage_readpage(page, ext2_get_block);
630 }
631 
632 static int
633 ext2_readpages(struct file *file, struct address_space *mapping,
634 		struct list_head *pages, unsigned nr_pages)
635 {
636 	return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
637 }
638 
639 static int
640 ext2_prepare_write(struct file *file, struct page *page,
641 			unsigned from, unsigned to)
642 {
643 	return block_prepare_write(page,from,to,ext2_get_block);
644 }
645 
646 static int
647 ext2_nobh_prepare_write(struct file *file, struct page *page,
648 			unsigned from, unsigned to)
649 {
650 	return nobh_prepare_write(page,from,to,ext2_get_block);
651 }
652 
653 static int ext2_nobh_writepage(struct page *page,
654 			struct writeback_control *wbc)
655 {
656 	return nobh_writepage(page, ext2_get_block, wbc);
657 }
658 
659 static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
660 {
661 	return generic_block_bmap(mapping,block,ext2_get_block);
662 }
663 
664 static int
665 ext2_get_blocks(struct inode *inode, sector_t iblock, unsigned long max_blocks,
666 			struct buffer_head *bh_result, int create)
667 {
668 	int ret;
669 
670 	ret = ext2_get_block(inode, iblock, bh_result, create);
671 	if (ret == 0)
672 		bh_result->b_size = (1 << inode->i_blkbits);
673 	return ret;
674 }
675 
676 static ssize_t
677 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
678 			loff_t offset, unsigned long nr_segs)
679 {
680 	struct file *file = iocb->ki_filp;
681 	struct inode *inode = file->f_mapping->host;
682 
683 	return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
684 				offset, nr_segs, ext2_get_blocks, NULL);
685 }
686 
687 static int
688 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
689 {
690 	return mpage_writepages(mapping, wbc, ext2_get_block);
691 }
692 
693 struct address_space_operations ext2_aops = {
694 	.readpage		= ext2_readpage,
695 	.readpages		= ext2_readpages,
696 	.writepage		= ext2_writepage,
697 	.sync_page		= block_sync_page,
698 	.prepare_write		= ext2_prepare_write,
699 	.commit_write		= generic_commit_write,
700 	.bmap			= ext2_bmap,
701 	.direct_IO		= ext2_direct_IO,
702 	.writepages		= ext2_writepages,
703 };
704 
705 struct address_space_operations ext2_aops_xip = {
706 	.bmap			= ext2_bmap,
707 	.get_xip_page		= ext2_get_xip_page,
708 };
709 
710 struct address_space_operations ext2_nobh_aops = {
711 	.readpage		= ext2_readpage,
712 	.readpages		= ext2_readpages,
713 	.writepage		= ext2_nobh_writepage,
714 	.sync_page		= block_sync_page,
715 	.prepare_write		= ext2_nobh_prepare_write,
716 	.commit_write		= nobh_commit_write,
717 	.bmap			= ext2_bmap,
718 	.direct_IO		= ext2_direct_IO,
719 	.writepages		= ext2_writepages,
720 };
721 
722 /*
723  * Probably it should be a library function... search for first non-zero word
724  * or memcmp with zero_page, whatever is better for particular architecture.
725  * Linus?
726  */
727 static inline int all_zeroes(__le32 *p, __le32 *q)
728 {
729 	while (p < q)
730 		if (*p++)
731 			return 0;
732 	return 1;
733 }
734 
735 /**
736  *	ext2_find_shared - find the indirect blocks for partial truncation.
737  *	@inode:	  inode in question
738  *	@depth:	  depth of the affected branch
739  *	@offsets: offsets of pointers in that branch (see ext2_block_to_path)
740  *	@chain:	  place to store the pointers to partial indirect blocks
741  *	@top:	  place to the (detached) top of branch
742  *
743  *	This is a helper function used by ext2_truncate().
744  *
745  *	When we do truncate() we may have to clean the ends of several indirect
746  *	blocks but leave the blocks themselves alive. Block is partially
747  *	truncated if some data below the new i_size is refered from it (and
748  *	it is on the path to the first completely truncated data block, indeed).
749  *	We have to free the top of that path along with everything to the right
750  *	of the path. Since no allocation past the truncation point is possible
751  *	until ext2_truncate() finishes, we may safely do the latter, but top
752  *	of branch may require special attention - pageout below the truncation
753  *	point might try to populate it.
754  *
755  *	We atomically detach the top of branch from the tree, store the block
756  *	number of its root in *@top, pointers to buffer_heads of partially
757  *	truncated blocks - in @chain[].bh and pointers to their last elements
758  *	that should not be removed - in @chain[].p. Return value is the pointer
759  *	to last filled element of @chain.
760  *
761  *	The work left to caller to do the actual freeing of subtrees:
762  *		a) free the subtree starting from *@top
763  *		b) free the subtrees whose roots are stored in
764  *			(@chain[i].p+1 .. end of @chain[i].bh->b_data)
765  *		c) free the subtrees growing from the inode past the @chain[0].p
766  *			(no partially truncated stuff there).
767  */
768 
769 static Indirect *ext2_find_shared(struct inode *inode,
770 				int depth,
771 				int offsets[4],
772 				Indirect chain[4],
773 				__le32 *top)
774 {
775 	Indirect *partial, *p;
776 	int k, err;
777 
778 	*top = 0;
779 	for (k = depth; k > 1 && !offsets[k-1]; k--)
780 		;
781 	partial = ext2_get_branch(inode, k, offsets, chain, &err);
782 	if (!partial)
783 		partial = chain + k-1;
784 	/*
785 	 * If the branch acquired continuation since we've looked at it -
786 	 * fine, it should all survive and (new) top doesn't belong to us.
787 	 */
788 	write_lock(&EXT2_I(inode)->i_meta_lock);
789 	if (!partial->key && *partial->p) {
790 		write_unlock(&EXT2_I(inode)->i_meta_lock);
791 		goto no_top;
792 	}
793 	for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
794 		;
795 	/*
796 	 * OK, we've found the last block that must survive. The rest of our
797 	 * branch should be detached before unlocking. However, if that rest
798 	 * of branch is all ours and does not grow immediately from the inode
799 	 * it's easier to cheat and just decrement partial->p.
800 	 */
801 	if (p == chain + k - 1 && p > chain) {
802 		p->p--;
803 	} else {
804 		*top = *p->p;
805 		*p->p = 0;
806 	}
807 	write_unlock(&EXT2_I(inode)->i_meta_lock);
808 
809 	while(partial > p)
810 	{
811 		brelse(partial->bh);
812 		partial--;
813 	}
814 no_top:
815 	return partial;
816 }
817 
818 /**
819  *	ext2_free_data - free a list of data blocks
820  *	@inode:	inode we are dealing with
821  *	@p:	array of block numbers
822  *	@q:	points immediately past the end of array
823  *
824  *	We are freeing all blocks refered from that array (numbers are
825  *	stored as little-endian 32-bit) and updating @inode->i_blocks
826  *	appropriately.
827  */
828 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
829 {
830 	unsigned long block_to_free = 0, count = 0;
831 	unsigned long nr;
832 
833 	for ( ; p < q ; p++) {
834 		nr = le32_to_cpu(*p);
835 		if (nr) {
836 			*p = 0;
837 			/* accumulate blocks to free if they're contiguous */
838 			if (count == 0)
839 				goto free_this;
840 			else if (block_to_free == nr - count)
841 				count++;
842 			else {
843 				mark_inode_dirty(inode);
844 				ext2_free_blocks (inode, block_to_free, count);
845 			free_this:
846 				block_to_free = nr;
847 				count = 1;
848 			}
849 		}
850 	}
851 	if (count > 0) {
852 		mark_inode_dirty(inode);
853 		ext2_free_blocks (inode, block_to_free, count);
854 	}
855 }
856 
857 /**
858  *	ext2_free_branches - free an array of branches
859  *	@inode:	inode we are dealing with
860  *	@p:	array of block numbers
861  *	@q:	pointer immediately past the end of array
862  *	@depth:	depth of the branches to free
863  *
864  *	We are freeing all blocks refered from these branches (numbers are
865  *	stored as little-endian 32-bit) and updating @inode->i_blocks
866  *	appropriately.
867  */
868 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
869 {
870 	struct buffer_head * bh;
871 	unsigned long nr;
872 
873 	if (depth--) {
874 		int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
875 		for ( ; p < q ; p++) {
876 			nr = le32_to_cpu(*p);
877 			if (!nr)
878 				continue;
879 			*p = 0;
880 			bh = sb_bread(inode->i_sb, nr);
881 			/*
882 			 * A read failure? Report error and clear slot
883 			 * (should be rare).
884 			 */
885 			if (!bh) {
886 				ext2_error(inode->i_sb, "ext2_free_branches",
887 					"Read failure, inode=%ld, block=%ld",
888 					inode->i_ino, nr);
889 				continue;
890 			}
891 			ext2_free_branches(inode,
892 					   (__le32*)bh->b_data,
893 					   (__le32*)bh->b_data + addr_per_block,
894 					   depth);
895 			bforget(bh);
896 			ext2_free_blocks(inode, nr, 1);
897 			mark_inode_dirty(inode);
898 		}
899 	} else
900 		ext2_free_data(inode, p, q);
901 }
902 
903 void ext2_truncate (struct inode * inode)
904 {
905 	__le32 *i_data = EXT2_I(inode)->i_data;
906 	int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
907 	int offsets[4];
908 	Indirect chain[4];
909 	Indirect *partial;
910 	__le32 nr = 0;
911 	int n;
912 	long iblock;
913 	unsigned blocksize;
914 
915 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
916 	    S_ISLNK(inode->i_mode)))
917 		return;
918 	if (ext2_inode_is_fast_symlink(inode))
919 		return;
920 	if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
921 		return;
922 
923 	ext2_discard_prealloc(inode);
924 
925 	blocksize = inode->i_sb->s_blocksize;
926 	iblock = (inode->i_size + blocksize-1)
927 					>> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
928 
929 	if (mapping_is_xip(inode->i_mapping))
930 		xip_truncate_page(inode->i_mapping, inode->i_size);
931 	else if (test_opt(inode->i_sb, NOBH))
932 		nobh_truncate_page(inode->i_mapping, inode->i_size);
933 	else
934 		block_truncate_page(inode->i_mapping,
935 				inode->i_size, ext2_get_block);
936 
937 	n = ext2_block_to_path(inode, iblock, offsets, NULL);
938 	if (n == 0)
939 		return;
940 
941 	if (n == 1) {
942 		ext2_free_data(inode, i_data+offsets[0],
943 					i_data + EXT2_NDIR_BLOCKS);
944 		goto do_indirects;
945 	}
946 
947 	partial = ext2_find_shared(inode, n, offsets, chain, &nr);
948 	/* Kill the top of shared branch (already detached) */
949 	if (nr) {
950 		if (partial == chain)
951 			mark_inode_dirty(inode);
952 		else
953 			mark_buffer_dirty_inode(partial->bh, inode);
954 		ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
955 	}
956 	/* Clear the ends of indirect blocks on the shared branch */
957 	while (partial > chain) {
958 		ext2_free_branches(inode,
959 				   partial->p + 1,
960 				   (__le32*)partial->bh->b_data+addr_per_block,
961 				   (chain+n-1) - partial);
962 		mark_buffer_dirty_inode(partial->bh, inode);
963 		brelse (partial->bh);
964 		partial--;
965 	}
966 do_indirects:
967 	/* Kill the remaining (whole) subtrees */
968 	switch (offsets[0]) {
969 		default:
970 			nr = i_data[EXT2_IND_BLOCK];
971 			if (nr) {
972 				i_data[EXT2_IND_BLOCK] = 0;
973 				mark_inode_dirty(inode);
974 				ext2_free_branches(inode, &nr, &nr+1, 1);
975 			}
976 		case EXT2_IND_BLOCK:
977 			nr = i_data[EXT2_DIND_BLOCK];
978 			if (nr) {
979 				i_data[EXT2_DIND_BLOCK] = 0;
980 				mark_inode_dirty(inode);
981 				ext2_free_branches(inode, &nr, &nr+1, 2);
982 			}
983 		case EXT2_DIND_BLOCK:
984 			nr = i_data[EXT2_TIND_BLOCK];
985 			if (nr) {
986 				i_data[EXT2_TIND_BLOCK] = 0;
987 				mark_inode_dirty(inode);
988 				ext2_free_branches(inode, &nr, &nr+1, 3);
989 			}
990 		case EXT2_TIND_BLOCK:
991 			;
992 	}
993 	inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
994 	if (inode_needs_sync(inode)) {
995 		sync_mapping_buffers(inode->i_mapping);
996 		ext2_sync_inode (inode);
997 	} else {
998 		mark_inode_dirty(inode);
999 	}
1000 }
1001 
1002 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1003 					struct buffer_head **p)
1004 {
1005 	struct buffer_head * bh;
1006 	unsigned long block_group;
1007 	unsigned long block;
1008 	unsigned long offset;
1009 	struct ext2_group_desc * gdp;
1010 
1011 	*p = NULL;
1012 	if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1013 	    ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1014 		goto Einval;
1015 
1016 	block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1017 	gdp = ext2_get_group_desc(sb, block_group, &bh);
1018 	if (!gdp)
1019 		goto Egdp;
1020 	/*
1021 	 * Figure out the offset within the block group inode table
1022 	 */
1023 	offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1024 	block = le32_to_cpu(gdp->bg_inode_table) +
1025 		(offset >> EXT2_BLOCK_SIZE_BITS(sb));
1026 	if (!(bh = sb_bread(sb, block)))
1027 		goto Eio;
1028 
1029 	*p = bh;
1030 	offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1031 	return (struct ext2_inode *) (bh->b_data + offset);
1032 
1033 Einval:
1034 	ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1035 		   (unsigned long) ino);
1036 	return ERR_PTR(-EINVAL);
1037 Eio:
1038 	ext2_error(sb, "ext2_get_inode",
1039 		   "unable to read inode block - inode=%lu, block=%lu",
1040 		   (unsigned long) ino, block);
1041 Egdp:
1042 	return ERR_PTR(-EIO);
1043 }
1044 
1045 void ext2_set_inode_flags(struct inode *inode)
1046 {
1047 	unsigned int flags = EXT2_I(inode)->i_flags;
1048 
1049 	inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
1050 	if (flags & EXT2_SYNC_FL)
1051 		inode->i_flags |= S_SYNC;
1052 	if (flags & EXT2_APPEND_FL)
1053 		inode->i_flags |= S_APPEND;
1054 	if (flags & EXT2_IMMUTABLE_FL)
1055 		inode->i_flags |= S_IMMUTABLE;
1056 	if (flags & EXT2_NOATIME_FL)
1057 		inode->i_flags |= S_NOATIME;
1058 	if (flags & EXT2_DIRSYNC_FL)
1059 		inode->i_flags |= S_DIRSYNC;
1060 }
1061 
1062 void ext2_read_inode (struct inode * inode)
1063 {
1064 	struct ext2_inode_info *ei = EXT2_I(inode);
1065 	ino_t ino = inode->i_ino;
1066 	struct buffer_head * bh;
1067 	struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1068 	int n;
1069 
1070 #ifdef CONFIG_EXT2_FS_POSIX_ACL
1071 	ei->i_acl = EXT2_ACL_NOT_CACHED;
1072 	ei->i_default_acl = EXT2_ACL_NOT_CACHED;
1073 #endif
1074 	if (IS_ERR(raw_inode))
1075  		goto bad_inode;
1076 
1077 	inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1078 	inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1079 	inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1080 	if (!(test_opt (inode->i_sb, NO_UID32))) {
1081 		inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1082 		inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1083 	}
1084 	inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
1085 	inode->i_size = le32_to_cpu(raw_inode->i_size);
1086 	inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
1087 	inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
1088 	inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
1089 	inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1090 	ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1091 	/* We now have enough fields to check if the inode was active or not.
1092 	 * This is needed because nfsd might try to access dead inodes
1093 	 * the test is that same one that e2fsck uses
1094 	 * NeilBrown 1999oct15
1095 	 */
1096 	if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
1097 		/* this inode is deleted */
1098 		brelse (bh);
1099 		goto bad_inode;
1100 	}
1101 	inode->i_blksize = PAGE_SIZE;	/* This is the optimal IO size (for stat), not the fs block size */
1102 	inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1103 	ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1104 	ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1105 	ei->i_frag_no = raw_inode->i_frag;
1106 	ei->i_frag_size = raw_inode->i_fsize;
1107 	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1108 	ei->i_dir_acl = 0;
1109 	if (S_ISREG(inode->i_mode))
1110 		inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1111 	else
1112 		ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1113 	ei->i_dtime = 0;
1114 	inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1115 	ei->i_state = 0;
1116 	ei->i_next_alloc_block = 0;
1117 	ei->i_next_alloc_goal = 0;
1118 	ei->i_prealloc_count = 0;
1119 	ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1120 	ei->i_dir_start_lookup = 0;
1121 
1122 	/*
1123 	 * NOTE! The in-memory inode i_data array is in little-endian order
1124 	 * even on big-endian machines: we do NOT byteswap the block numbers!
1125 	 */
1126 	for (n = 0; n < EXT2_N_BLOCKS; n++)
1127 		ei->i_data[n] = raw_inode->i_block[n];
1128 
1129 	if (S_ISREG(inode->i_mode)) {
1130 		inode->i_op = &ext2_file_inode_operations;
1131 		if (ext2_use_xip(inode->i_sb)) {
1132 			inode->i_mapping->a_ops = &ext2_aops_xip;
1133 			inode->i_fop = &ext2_xip_file_operations;
1134 		} else if (test_opt(inode->i_sb, NOBH)) {
1135 			inode->i_mapping->a_ops = &ext2_nobh_aops;
1136 			inode->i_fop = &ext2_file_operations;
1137 		} else {
1138 			inode->i_mapping->a_ops = &ext2_aops;
1139 			inode->i_fop = &ext2_file_operations;
1140 		}
1141 	} else if (S_ISDIR(inode->i_mode)) {
1142 		inode->i_op = &ext2_dir_inode_operations;
1143 		inode->i_fop = &ext2_dir_operations;
1144 		if (test_opt(inode->i_sb, NOBH))
1145 			inode->i_mapping->a_ops = &ext2_nobh_aops;
1146 		else
1147 			inode->i_mapping->a_ops = &ext2_aops;
1148 	} else if (S_ISLNK(inode->i_mode)) {
1149 		if (ext2_inode_is_fast_symlink(inode))
1150 			inode->i_op = &ext2_fast_symlink_inode_operations;
1151 		else {
1152 			inode->i_op = &ext2_symlink_inode_operations;
1153 			if (test_opt(inode->i_sb, NOBH))
1154 				inode->i_mapping->a_ops = &ext2_nobh_aops;
1155 			else
1156 				inode->i_mapping->a_ops = &ext2_aops;
1157 		}
1158 	} else {
1159 		inode->i_op = &ext2_special_inode_operations;
1160 		if (raw_inode->i_block[0])
1161 			init_special_inode(inode, inode->i_mode,
1162 			   old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1163 		else
1164 			init_special_inode(inode, inode->i_mode,
1165 			   new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1166 	}
1167 	brelse (bh);
1168 	ext2_set_inode_flags(inode);
1169 	return;
1170 
1171 bad_inode:
1172 	make_bad_inode(inode);
1173 	return;
1174 }
1175 
1176 static int ext2_update_inode(struct inode * inode, int do_sync)
1177 {
1178 	struct ext2_inode_info *ei = EXT2_I(inode);
1179 	struct super_block *sb = inode->i_sb;
1180 	ino_t ino = inode->i_ino;
1181 	uid_t uid = inode->i_uid;
1182 	gid_t gid = inode->i_gid;
1183 	struct buffer_head * bh;
1184 	struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1185 	int n;
1186 	int err = 0;
1187 
1188 	if (IS_ERR(raw_inode))
1189  		return -EIO;
1190 
1191 	/* For fields not not tracking in the in-memory inode,
1192 	 * initialise them to zero for new inodes. */
1193 	if (ei->i_state & EXT2_STATE_NEW)
1194 		memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1195 
1196 	raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1197 	if (!(test_opt(sb, NO_UID32))) {
1198 		raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1199 		raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1200 /*
1201  * Fix up interoperability with old kernels. Otherwise, old inodes get
1202  * re-used with the upper 16 bits of the uid/gid intact
1203  */
1204 		if (!ei->i_dtime) {
1205 			raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1206 			raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1207 		} else {
1208 			raw_inode->i_uid_high = 0;
1209 			raw_inode->i_gid_high = 0;
1210 		}
1211 	} else {
1212 		raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1213 		raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1214 		raw_inode->i_uid_high = 0;
1215 		raw_inode->i_gid_high = 0;
1216 	}
1217 	raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1218 	raw_inode->i_size = cpu_to_le32(inode->i_size);
1219 	raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1220 	raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1221 	raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1222 
1223 	raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1224 	raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1225 	raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1226 	raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1227 	raw_inode->i_frag = ei->i_frag_no;
1228 	raw_inode->i_fsize = ei->i_frag_size;
1229 	raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1230 	if (!S_ISREG(inode->i_mode))
1231 		raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1232 	else {
1233 		raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1234 		if (inode->i_size > 0x7fffffffULL) {
1235 			if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1236 					EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1237 			    EXT2_SB(sb)->s_es->s_rev_level ==
1238 					cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1239 			       /* If this is the first large file
1240 				* created, add a flag to the superblock.
1241 				*/
1242 				lock_kernel();
1243 				ext2_update_dynamic_rev(sb);
1244 				EXT2_SET_RO_COMPAT_FEATURE(sb,
1245 					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1246 				unlock_kernel();
1247 				ext2_write_super(sb);
1248 			}
1249 		}
1250 	}
1251 
1252 	raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1253 	if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1254 		if (old_valid_dev(inode->i_rdev)) {
1255 			raw_inode->i_block[0] =
1256 				cpu_to_le32(old_encode_dev(inode->i_rdev));
1257 			raw_inode->i_block[1] = 0;
1258 		} else {
1259 			raw_inode->i_block[0] = 0;
1260 			raw_inode->i_block[1] =
1261 				cpu_to_le32(new_encode_dev(inode->i_rdev));
1262 			raw_inode->i_block[2] = 0;
1263 		}
1264 	} else for (n = 0; n < EXT2_N_BLOCKS; n++)
1265 		raw_inode->i_block[n] = ei->i_data[n];
1266 	mark_buffer_dirty(bh);
1267 	if (do_sync) {
1268 		sync_dirty_buffer(bh);
1269 		if (buffer_req(bh) && !buffer_uptodate(bh)) {
1270 			printk ("IO error syncing ext2 inode [%s:%08lx]\n",
1271 				sb->s_id, (unsigned long) ino);
1272 			err = -EIO;
1273 		}
1274 	}
1275 	ei->i_state &= ~EXT2_STATE_NEW;
1276 	brelse (bh);
1277 	return err;
1278 }
1279 
1280 int ext2_write_inode(struct inode *inode, int wait)
1281 {
1282 	return ext2_update_inode(inode, wait);
1283 }
1284 
1285 int ext2_sync_inode(struct inode *inode)
1286 {
1287 	struct writeback_control wbc = {
1288 		.sync_mode = WB_SYNC_ALL,
1289 		.nr_to_write = 0,	/* sys_fsync did this */
1290 	};
1291 	return sync_inode(inode, &wbc);
1292 }
1293 
1294 int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
1295 {
1296 	struct inode *inode = dentry->d_inode;
1297 	int error;
1298 
1299 	error = inode_change_ok(inode, iattr);
1300 	if (error)
1301 		return error;
1302 	if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
1303 	    (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
1304 		error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0;
1305 		if (error)
1306 			return error;
1307 	}
1308 	error = inode_setattr(inode, iattr);
1309 	if (!error && (iattr->ia_valid & ATTR_MODE))
1310 		error = ext2_acl_chmod(inode);
1311 	return error;
1312 }
1313