blob: 1b102a1ccebb373761b02194cc2b138a2f194cf0 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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"
Carsten Otte6d791252005-06-23 22:05:26 -070036#include "xip.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
38MODULE_AUTHOR("Remy Card and others");
39MODULE_DESCRIPTION("Second Extended Filesystem");
40MODULE_LICENSE("GPL");
41
42static int ext2_update_inode(struct inode * inode, int do_sync);
43
44/*
45 * Test whether an inode is a fast symlink.
46 */
47static 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/*
Bernard Blackhame072c6f2005-04-16 15:25:45 -070057 * 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 */
63void ext2_put_inode(struct inode *inode)
64{
65 if (!is_bad_inode(inode))
66 ext2_discard_prealloc(inode);
67}
68
69/*
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 * Called at the last iput() if i_nlink is zero.
71 */
72void ext2_delete_inode (struct inode * inode)
73{
Mark Fashehfef26652005-09-09 13:01:31 -070074 truncate_inode_pages(&inode->i_data, 0);
75
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 if (is_bad_inode(inode))
77 goto no_delete;
78 EXT2_I(inode)->i_dtime = get_seconds();
79 mark_inode_dirty(inode);
80 ext2_update_inode(inode, inode_needs_sync(inode));
81
82 inode->i_size = 0;
83 if (inode->i_blocks)
84 ext2_truncate (inode);
85 ext2_free_inode (inode);
86
87 return;
88no_delete:
89 clear_inode(inode); /* We must guarantee clearing of inode... */
90}
91
92void ext2_discard_prealloc (struct inode * inode)
93{
94#ifdef EXT2_PREALLOCATE
95 struct ext2_inode_info *ei = EXT2_I(inode);
96 write_lock(&ei->i_meta_lock);
97 if (ei->i_prealloc_count) {
98 unsigned short total = ei->i_prealloc_count;
99 unsigned long block = ei->i_prealloc_block;
100 ei->i_prealloc_count = 0;
101 ei->i_prealloc_block = 0;
102 write_unlock(&ei->i_meta_lock);
103 ext2_free_blocks (inode, block, total);
104 return;
105 } else
106 write_unlock(&ei->i_meta_lock);
107#endif
108}
109
110static int ext2_alloc_block (struct inode * inode, unsigned long goal, int *err)
111{
112#ifdef EXT2FS_DEBUG
113 static unsigned long alloc_hits, alloc_attempts;
114#endif
115 unsigned long result;
116
117
118#ifdef EXT2_PREALLOCATE
119 struct ext2_inode_info *ei = EXT2_I(inode);
120 write_lock(&ei->i_meta_lock);
121 if (ei->i_prealloc_count &&
122 (goal == ei->i_prealloc_block || goal + 1 == ei->i_prealloc_block))
123 {
124 result = ei->i_prealloc_block++;
125 ei->i_prealloc_count--;
126 write_unlock(&ei->i_meta_lock);
127 ext2_debug ("preallocation hit (%lu/%lu).\n",
128 ++alloc_hits, ++alloc_attempts);
129 } else {
130 write_unlock(&ei->i_meta_lock);
131 ext2_discard_prealloc (inode);
132 ext2_debug ("preallocation miss (%lu/%lu).\n",
133 alloc_hits, ++alloc_attempts);
134 if (S_ISREG(inode->i_mode))
135 result = ext2_new_block (inode, goal,
136 &ei->i_prealloc_count,
137 &ei->i_prealloc_block, err);
138 else
139 result = ext2_new_block(inode, goal, NULL, NULL, err);
140 }
141#else
142 result = ext2_new_block (inode, goal, 0, 0, err);
143#endif
144 return result;
145}
146
147typedef struct {
148 __le32 *p;
149 __le32 key;
150 struct buffer_head *bh;
151} Indirect;
152
153static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
154{
155 p->key = *(p->p = v);
156 p->bh = bh;
157}
158
159static inline int verify_chain(Indirect *from, Indirect *to)
160{
161 while (from <= to && from->key == *from->p)
162 from++;
163 return (from > to);
164}
165
166/**
167 * ext2_block_to_path - parse the block number into array of offsets
168 * @inode: inode in question (we are only interested in its superblock)
169 * @i_block: block number to be parsed
170 * @offsets: array to store the offsets in
171 * @boundary: set this non-zero if the referred-to block is likely to be
172 * followed (on disk) by an indirect block.
173 * To store the locations of file's data ext2 uses a data structure common
174 * for UNIX filesystems - tree of pointers anchored in the inode, with
175 * data blocks at leaves and indirect blocks in intermediate nodes.
176 * This function translates the block number into path in that tree -
177 * return value is the path length and @offsets[n] is the offset of
178 * pointer to (n+1)th node in the nth one. If @block is out of range
179 * (negative or too large) warning is printed and zero returned.
180 *
181 * Note: function doesn't find node addresses, so no IO is needed. All
182 * we need to know is the capacity of indirect blocks (taken from the
183 * inode->i_sb).
184 */
185
186/*
187 * Portability note: the last comparison (check that we fit into triple
188 * indirect block) is spelled differently, because otherwise on an
189 * architecture with 32-bit longs and 8Kb pages we might get into trouble
190 * if our filesystem had 8Kb blocks. We might use long long, but that would
191 * kill us on x86. Oh, well, at least the sign propagation does not matter -
192 * i_block would have to be negative in the very beginning, so we would not
193 * get there at all.
194 */
195
196static int ext2_block_to_path(struct inode *inode,
197 long i_block, int offsets[4], int *boundary)
198{
199 int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
200 int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
201 const long direct_blocks = EXT2_NDIR_BLOCKS,
202 indirect_blocks = ptrs,
203 double_blocks = (1 << (ptrs_bits * 2));
204 int n = 0;
205 int final = 0;
206
207 if (i_block < 0) {
208 ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0");
209 } else if (i_block < direct_blocks) {
210 offsets[n++] = i_block;
211 final = direct_blocks;
212 } else if ( (i_block -= direct_blocks) < indirect_blocks) {
213 offsets[n++] = EXT2_IND_BLOCK;
214 offsets[n++] = i_block;
215 final = ptrs;
216 } else if ((i_block -= indirect_blocks) < double_blocks) {
217 offsets[n++] = EXT2_DIND_BLOCK;
218 offsets[n++] = i_block >> ptrs_bits;
219 offsets[n++] = i_block & (ptrs - 1);
220 final = ptrs;
221 } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
222 offsets[n++] = EXT2_TIND_BLOCK;
223 offsets[n++] = i_block >> (ptrs_bits * 2);
224 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
225 offsets[n++] = i_block & (ptrs - 1);
226 final = ptrs;
227 } else {
228 ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big");
229 }
230 if (boundary)
231 *boundary = (i_block & (ptrs - 1)) == (final - 1);
232 return n;
233}
234
235/**
236 * ext2_get_branch - read the chain of indirect blocks leading to data
237 * @inode: inode in question
238 * @depth: depth of the chain (1 - direct pointer, etc.)
239 * @offsets: offsets of pointers in inode/indirect blocks
240 * @chain: place to store the result
241 * @err: here we store the error value
242 *
243 * Function fills the array of triples <key, p, bh> and returns %NULL
244 * if everything went OK or the pointer to the last filled triple
245 * (incomplete one) otherwise. Upon the return chain[i].key contains
246 * the number of (i+1)-th block in the chain (as it is stored in memory,
247 * i.e. little-endian 32-bit), chain[i].p contains the address of that
248 * number (it points into struct inode for i==0 and into the bh->b_data
249 * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
250 * block for i>0 and NULL for i==0. In other words, it holds the block
251 * numbers of the chain, addresses they were taken from (and where we can
252 * verify that chain did not change) and buffer_heads hosting these
253 * numbers.
254 *
255 * Function stops when it stumbles upon zero pointer (absent block)
256 * (pointer to last triple returned, *@err == 0)
257 * or when it gets an IO error reading an indirect block
258 * (ditto, *@err == -EIO)
259 * or when it notices that chain had been changed while it was reading
260 * (ditto, *@err == -EAGAIN)
261 * or when it reads all @depth-1 indirect blocks successfully and finds
262 * the whole chain, all way to the data (returns %NULL, *err == 0).
263 */
264static Indirect *ext2_get_branch(struct inode *inode,
265 int depth,
266 int *offsets,
267 Indirect chain[4],
268 int *err)
269{
270 struct super_block *sb = inode->i_sb;
271 Indirect *p = chain;
272 struct buffer_head *bh;
273
274 *err = 0;
275 /* i_data is not going away, no lock needed */
276 add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
277 if (!p->key)
278 goto no_block;
279 while (--depth) {
280 bh = sb_bread(sb, le32_to_cpu(p->key));
281 if (!bh)
282 goto failure;
283 read_lock(&EXT2_I(inode)->i_meta_lock);
284 if (!verify_chain(chain, p))
285 goto changed;
286 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
287 read_unlock(&EXT2_I(inode)->i_meta_lock);
288 if (!p->key)
289 goto no_block;
290 }
291 return NULL;
292
293changed:
294 read_unlock(&EXT2_I(inode)->i_meta_lock);
295 brelse(bh);
296 *err = -EAGAIN;
297 goto no_block;
298failure:
299 *err = -EIO;
300no_block:
301 return p;
302}
303
304/**
305 * ext2_find_near - find a place for allocation with sufficient locality
306 * @inode: owner
307 * @ind: descriptor of indirect block.
308 *
309 * This function returns the prefered place for block allocation.
310 * It is used when heuristic for sequential allocation fails.
311 * Rules are:
312 * + if there is a block to the left of our position - allocate near it.
313 * + if pointer will live in indirect block - allocate near that block.
314 * + if pointer will live in inode - allocate in the same cylinder group.
315 *
316 * In the latter case we colour the starting block by the callers PID to
317 * prevent it from clashing with concurrent allocations for a different inode
318 * in the same block group. The PID is used here so that functionally related
319 * files will be close-by on-disk.
320 *
321 * Caller must make sure that @ind is valid and will stay that way.
322 */
323
324static unsigned long ext2_find_near(struct inode *inode, Indirect *ind)
325{
326 struct ext2_inode_info *ei = EXT2_I(inode);
327 __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
328 __le32 *p;
329 unsigned long bg_start;
330 unsigned long colour;
331
332 /* Try to find previous block */
333 for (p = ind->p - 1; p >= start; p--)
334 if (*p)
335 return le32_to_cpu(*p);
336
337 /* No such thing, so let's try location of indirect block */
338 if (ind->bh)
339 return ind->bh->b_blocknr;
340
341 /*
342 * It is going to be refered from inode itself? OK, just put it into
343 * the same cylinder group then.
344 */
345 bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) +
346 le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block);
347 colour = (current->pid % 16) *
348 (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
349 return bg_start + colour;
350}
351
352/**
353 * ext2_find_goal - find a prefered place for allocation.
354 * @inode: owner
355 * @block: block we want
356 * @chain: chain of indirect blocks
357 * @partial: pointer to the last triple within a chain
358 * @goal: place to store the result.
359 *
360 * Normally this function find the prefered place for block allocation,
361 * stores it in *@goal and returns zero. If the branch had been changed
362 * under us we return -EAGAIN.
363 */
364
365static inline int ext2_find_goal(struct inode *inode,
366 long block,
367 Indirect chain[4],
368 Indirect *partial,
369 unsigned long *goal)
370{
371 struct ext2_inode_info *ei = EXT2_I(inode);
372 write_lock(&ei->i_meta_lock);
373 if ((block == ei->i_next_alloc_block + 1) && ei->i_next_alloc_goal) {
374 ei->i_next_alloc_block++;
375 ei->i_next_alloc_goal++;
376 }
377 if (verify_chain(chain, partial)) {
378 /*
379 * try the heuristic for sequential allocation,
380 * failing that at least try to get decent locality.
381 */
382 if (block == ei->i_next_alloc_block)
383 *goal = ei->i_next_alloc_goal;
384 if (!*goal)
385 *goal = ext2_find_near(inode, partial);
386 write_unlock(&ei->i_meta_lock);
387 return 0;
388 }
389 write_unlock(&ei->i_meta_lock);
390 return -EAGAIN;
391}
392
393/**
394 * ext2_alloc_branch - allocate and set up a chain of blocks.
395 * @inode: owner
396 * @num: depth of the chain (number of blocks to allocate)
397 * @offsets: offsets (in the blocks) to store the pointers to next.
398 * @branch: place to store the chain in.
399 *
400 * This function allocates @num blocks, zeroes out all but the last one,
401 * links them into chain and (if we are synchronous) writes them to disk.
402 * In other words, it prepares a branch that can be spliced onto the
403 * inode. It stores the information about that chain in the branch[], in
404 * the same format as ext2_get_branch() would do. We are calling it after
405 * we had read the existing part of chain and partial points to the last
406 * triple of that (one with zero ->key). Upon the exit we have the same
407 * picture as after the successful ext2_get_block(), excpet that in one
408 * place chain is disconnected - *branch->p is still zero (we did not
409 * set the last link), but branch->key contains the number that should
410 * be placed into *branch->p to fill that gap.
411 *
412 * If allocation fails we free all blocks we've allocated (and forget
413 * their buffer_heads) and return the error value the from failed
414 * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
415 * as described above and return 0.
416 */
417
418static int ext2_alloc_branch(struct inode *inode,
419 int num,
420 unsigned long goal,
421 int *offsets,
422 Indirect *branch)
423{
424 int blocksize = inode->i_sb->s_blocksize;
425 int n = 0;
426 int err;
427 int i;
428 int parent = ext2_alloc_block(inode, goal, &err);
429
430 branch[0].key = cpu_to_le32(parent);
431 if (parent) for (n = 1; n < num; n++) {
432 struct buffer_head *bh;
433 /* Allocate the next block */
434 int nr = ext2_alloc_block(inode, parent, &err);
435 if (!nr)
436 break;
437 branch[n].key = cpu_to_le32(nr);
438 /*
439 * Get buffer_head for parent block, zero it out and set
440 * the pointer to new one, then send parent to disk.
441 */
442 bh = sb_getblk(inode->i_sb, parent);
Glauber de Oliveira Costa2973dfd2005-10-30 15:03:05 -0800443 if (!bh) {
444 err = -EIO;
445 break;
446 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 lock_buffer(bh);
448 memset(bh->b_data, 0, blocksize);
449 branch[n].bh = bh;
450 branch[n].p = (__le32 *) bh->b_data + offsets[n];
451 *branch[n].p = branch[n].key;
452 set_buffer_uptodate(bh);
453 unlock_buffer(bh);
454 mark_buffer_dirty_inode(bh, inode);
455 /* We used to sync bh here if IS_SYNC(inode).
456 * But we now rely upon generic_osync_inode()
457 * and b_inode_buffers. But not for directories.
458 */
459 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
460 sync_dirty_buffer(bh);
461 parent = nr;
462 }
463 if (n == num)
464 return 0;
465
466 /* Allocation failed, free what we already allocated */
467 for (i = 1; i < n; i++)
468 bforget(branch[i].bh);
469 for (i = 0; i < n; i++)
470 ext2_free_blocks(inode, le32_to_cpu(branch[i].key), 1);
471 return err;
472}
473
474/**
475 * ext2_splice_branch - splice the allocated branch onto inode.
476 * @inode: owner
477 * @block: (logical) number of block we are adding
478 * @chain: chain of indirect blocks (with a missing link - see
479 * ext2_alloc_branch)
480 * @where: location of missing link
481 * @num: number of blocks we are adding
482 *
483 * This function verifies that chain (up to the missing link) had not
484 * changed, fills the missing link and does all housekeeping needed in
485 * inode (->i_blocks, etc.). In case of success we end up with the full
486 * chain to new block and return 0. Otherwise (== chain had been changed)
487 * we free the new blocks (forgetting their buffer_heads, indeed) and
488 * return -EAGAIN.
489 */
490
491static inline int ext2_splice_branch(struct inode *inode,
492 long block,
493 Indirect chain[4],
494 Indirect *where,
495 int num)
496{
497 struct ext2_inode_info *ei = EXT2_I(inode);
498 int i;
499
500 /* Verify that place we are splicing to is still there and vacant */
501
502 write_lock(&ei->i_meta_lock);
503 if (!verify_chain(chain, where-1) || *where->p)
504 goto changed;
505
506 /* That's it */
507
508 *where->p = where->key;
509 ei->i_next_alloc_block = block;
510 ei->i_next_alloc_goal = le32_to_cpu(where[num-1].key);
511
512 write_unlock(&ei->i_meta_lock);
513
514 /* We are done with atomic stuff, now do the rest of housekeeping */
515
516 inode->i_ctime = CURRENT_TIME_SEC;
517
518 /* had we spliced it onto indirect block? */
519 if (where->bh)
520 mark_buffer_dirty_inode(where->bh, inode);
521
522 mark_inode_dirty(inode);
523 return 0;
524
525changed:
526 write_unlock(&ei->i_meta_lock);
527 for (i = 1; i < num; i++)
528 bforget(where[i].bh);
529 for (i = 0; i < num; i++)
530 ext2_free_blocks(inode, le32_to_cpu(where[i].key), 1);
531 return -EAGAIN;
532}
533
534/*
535 * Allocation strategy is simple: if we have to allocate something, we will
536 * have to go the whole way to leaf. So let's do it before attaching anything
537 * to tree, set linkage between the newborn blocks, write them if sync is
538 * required, recheck the path, free and repeat if check fails, otherwise
539 * set the last missing link (that will protect us from any truncate-generated
540 * removals - all blocks on the path are immune now) and possibly force the
541 * write on the parent block.
542 * That has a nice additional property: no special recovery from the failed
543 * allocations is needed - we simply release blocks and do not touch anything
544 * reachable from inode.
545 */
546
547int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
548{
549 int err = -EIO;
550 int offsets[4];
551 Indirect chain[4];
552 Indirect *partial;
553 unsigned long goal;
554 int left;
555 int boundary = 0;
556 int depth = ext2_block_to_path(inode, iblock, offsets, &boundary);
557
558 if (depth == 0)
559 goto out;
560
561reread:
562 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
563
564 /* Simplest case - block found, no allocation needed */
565 if (!partial) {
566got_it:
567 map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
568 if (boundary)
569 set_buffer_boundary(bh_result);
570 /* Clean up and exit */
571 partial = chain+depth-1; /* the whole chain */
572 goto cleanup;
573 }
574
575 /* Next simple case - plain lookup or failed read of indirect block */
576 if (!create || err == -EIO) {
577cleanup:
578 while (partial > chain) {
579 brelse(partial->bh);
580 partial--;
581 }
582out:
583 return err;
584 }
585
586 /*
587 * Indirect block might be removed by truncate while we were
588 * reading it. Handling of that case (forget what we've got and
589 * reread) is taken out of the main path.
590 */
591 if (err == -EAGAIN)
592 goto changed;
593
594 goal = 0;
595 if (ext2_find_goal(inode, iblock, chain, partial, &goal) < 0)
596 goto changed;
597
598 left = (chain + depth) - partial;
599 err = ext2_alloc_branch(inode, left, goal,
600 offsets+(partial-chain), partial);
601 if (err)
602 goto cleanup;
603
Carsten Otte6d791252005-06-23 22:05:26 -0700604 if (ext2_use_xip(inode->i_sb)) {
605 /*
606 * we need to clear the block
607 */
608 err = ext2_clear_xip_target (inode,
609 le32_to_cpu(chain[depth-1].key));
610 if (err)
611 goto cleanup;
612 }
613
Linus Torvalds1da177e2005-04-16 15:20:36 -0700614 if (ext2_splice_branch(inode, iblock, chain, partial, left) < 0)
615 goto changed;
616
617 set_buffer_new(bh_result);
618 goto got_it;
619
620changed:
621 while (partial > chain) {
622 brelse(partial->bh);
623 partial--;
624 }
625 goto reread;
626}
627
628static int ext2_writepage(struct page *page, struct writeback_control *wbc)
629{
630 return block_write_full_page(page, ext2_get_block, wbc);
631}
632
633static int ext2_readpage(struct file *file, struct page *page)
634{
635 return mpage_readpage(page, ext2_get_block);
636}
637
638static int
639ext2_readpages(struct file *file, struct address_space *mapping,
640 struct list_head *pages, unsigned nr_pages)
641{
642 return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
643}
644
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700645int __ext2_write_begin(struct file *file, struct address_space *mapping,
646 loff_t pos, unsigned len, unsigned flags,
647 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700648{
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700649 return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
650 ext2_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651}
652
653static int
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700654ext2_write_begin(struct file *file, struct address_space *mapping,
655 loff_t pos, unsigned len, unsigned flags,
656 struct page **pagep, void **fsdata)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700657{
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700658 *pagep = NULL;
659 return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660}
661
Nick Piggin03158cd2007-10-16 01:25:25 -0700662static int
663ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
664 loff_t pos, unsigned len, unsigned flags,
665 struct page **pagep, void **fsdata)
666{
667 /*
668 * Dir-in-pagecache still uses ext2_write_begin. Would have to rework
669 * directory handling code to pass around offsets rather than struct
670 * pages in order to make this work easily.
671 */
672 return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
673 ext2_get_block);
674}
675
Linus Torvalds1da177e2005-04-16 15:20:36 -0700676static int ext2_nobh_writepage(struct page *page,
677 struct writeback_control *wbc)
678{
679 return nobh_writepage(page, ext2_get_block, wbc);
680}
681
682static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
683{
684 return generic_block_bmap(mapping,block,ext2_get_block);
685}
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687static ssize_t
688ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
689 loff_t offset, unsigned long nr_segs)
690{
691 struct file *file = iocb->ki_filp;
692 struct inode *inode = file->f_mapping->host;
693
694 return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
Badari Pulavarty1d8fa7a2006-03-26 01:38:02 -0800695 offset, nr_segs, ext2_get_block, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696}
697
698static int
699ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
700{
701 return mpage_writepages(mapping, wbc, ext2_get_block);
702}
703
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700704const struct address_space_operations ext2_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700705 .readpage = ext2_readpage,
706 .readpages = ext2_readpages,
707 .writepage = ext2_writepage,
708 .sync_page = block_sync_page,
Nick Pigginf34fb6e2007-10-16 01:25:04 -0700709 .write_begin = ext2_write_begin,
710 .write_end = generic_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700711 .bmap = ext2_bmap,
712 .direct_IO = ext2_direct_IO,
713 .writepages = ext2_writepages,
Christoph Lametere965f962006-02-01 03:05:41 -0800714 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715};
716
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700717const struct address_space_operations ext2_aops_xip = {
Carsten Otte6d791252005-06-23 22:05:26 -0700718 .bmap = ext2_bmap,
719 .get_xip_page = ext2_get_xip_page,
720};
721
Christoph Hellwigf5e54d62006-06-28 04:26:44 -0700722const struct address_space_operations ext2_nobh_aops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723 .readpage = ext2_readpage,
724 .readpages = ext2_readpages,
725 .writepage = ext2_nobh_writepage,
726 .sync_page = block_sync_page,
Nick Piggin03158cd2007-10-16 01:25:25 -0700727 .write_begin = ext2_nobh_write_begin,
728 .write_end = nobh_write_end,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 .bmap = ext2_bmap,
730 .direct_IO = ext2_direct_IO,
731 .writepages = ext2_writepages,
Christoph Lametere965f962006-02-01 03:05:41 -0800732 .migratepage = buffer_migrate_page,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733};
734
735/*
736 * Probably it should be a library function... search for first non-zero word
737 * or memcmp with zero_page, whatever is better for particular architecture.
738 * Linus?
739 */
740static inline int all_zeroes(__le32 *p, __le32 *q)
741{
742 while (p < q)
743 if (*p++)
744 return 0;
745 return 1;
746}
747
748/**
749 * ext2_find_shared - find the indirect blocks for partial truncation.
750 * @inode: inode in question
751 * @depth: depth of the affected branch
752 * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
753 * @chain: place to store the pointers to partial indirect blocks
754 * @top: place to the (detached) top of branch
755 *
756 * This is a helper function used by ext2_truncate().
757 *
758 * When we do truncate() we may have to clean the ends of several indirect
759 * blocks but leave the blocks themselves alive. Block is partially
760 * truncated if some data below the new i_size is refered from it (and
761 * it is on the path to the first completely truncated data block, indeed).
762 * We have to free the top of that path along with everything to the right
763 * of the path. Since no allocation past the truncation point is possible
764 * until ext2_truncate() finishes, we may safely do the latter, but top
765 * of branch may require special attention - pageout below the truncation
766 * point might try to populate it.
767 *
768 * We atomically detach the top of branch from the tree, store the block
769 * number of its root in *@top, pointers to buffer_heads of partially
770 * truncated blocks - in @chain[].bh and pointers to their last elements
771 * that should not be removed - in @chain[].p. Return value is the pointer
772 * to last filled element of @chain.
773 *
774 * The work left to caller to do the actual freeing of subtrees:
775 * a) free the subtree starting from *@top
776 * b) free the subtrees whose roots are stored in
777 * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
778 * c) free the subtrees growing from the inode past the @chain[0].p
779 * (no partially truncated stuff there).
780 */
781
782static Indirect *ext2_find_shared(struct inode *inode,
783 int depth,
784 int offsets[4],
785 Indirect chain[4],
786 __le32 *top)
787{
788 Indirect *partial, *p;
789 int k, err;
790
791 *top = 0;
792 for (k = depth; k > 1 && !offsets[k-1]; k--)
793 ;
794 partial = ext2_get_branch(inode, k, offsets, chain, &err);
795 if (!partial)
796 partial = chain + k-1;
797 /*
798 * If the branch acquired continuation since we've looked at it -
799 * fine, it should all survive and (new) top doesn't belong to us.
800 */
801 write_lock(&EXT2_I(inode)->i_meta_lock);
802 if (!partial->key && *partial->p) {
803 write_unlock(&EXT2_I(inode)->i_meta_lock);
804 goto no_top;
805 }
806 for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
807 ;
808 /*
809 * OK, we've found the last block that must survive. The rest of our
810 * branch should be detached before unlocking. However, if that rest
811 * of branch is all ours and does not grow immediately from the inode
812 * it's easier to cheat and just decrement partial->p.
813 */
814 if (p == chain + k - 1 && p > chain) {
815 p->p--;
816 } else {
817 *top = *p->p;
818 *p->p = 0;
819 }
820 write_unlock(&EXT2_I(inode)->i_meta_lock);
821
822 while(partial > p)
823 {
824 brelse(partial->bh);
825 partial--;
826 }
827no_top:
828 return partial;
829}
830
831/**
832 * ext2_free_data - free a list of data blocks
833 * @inode: inode we are dealing with
834 * @p: array of block numbers
835 * @q: points immediately past the end of array
836 *
837 * We are freeing all blocks refered from that array (numbers are
838 * stored as little-endian 32-bit) and updating @inode->i_blocks
839 * appropriately.
840 */
841static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
842{
843 unsigned long block_to_free = 0, count = 0;
844 unsigned long nr;
845
846 for ( ; p < q ; p++) {
847 nr = le32_to_cpu(*p);
848 if (nr) {
849 *p = 0;
850 /* accumulate blocks to free if they're contiguous */
851 if (count == 0)
852 goto free_this;
853 else if (block_to_free == nr - count)
854 count++;
855 else {
856 mark_inode_dirty(inode);
857 ext2_free_blocks (inode, block_to_free, count);
858 free_this:
859 block_to_free = nr;
860 count = 1;
861 }
862 }
863 }
864 if (count > 0) {
865 mark_inode_dirty(inode);
866 ext2_free_blocks (inode, block_to_free, count);
867 }
868}
869
870/**
871 * ext2_free_branches - free an array of branches
872 * @inode: inode we are dealing with
873 * @p: array of block numbers
874 * @q: pointer immediately past the end of array
875 * @depth: depth of the branches to free
876 *
877 * We are freeing all blocks refered from these branches (numbers are
878 * stored as little-endian 32-bit) and updating @inode->i_blocks
879 * appropriately.
880 */
881static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
882{
883 struct buffer_head * bh;
884 unsigned long nr;
885
886 if (depth--) {
887 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
888 for ( ; p < q ; p++) {
889 nr = le32_to_cpu(*p);
890 if (!nr)
891 continue;
892 *p = 0;
893 bh = sb_bread(inode->i_sb, nr);
894 /*
895 * A read failure? Report error and clear slot
896 * (should be rare).
897 */
898 if (!bh) {
899 ext2_error(inode->i_sb, "ext2_free_branches",
900 "Read failure, inode=%ld, block=%ld",
901 inode->i_ino, nr);
902 continue;
903 }
904 ext2_free_branches(inode,
905 (__le32*)bh->b_data,
906 (__le32*)bh->b_data + addr_per_block,
907 depth);
908 bforget(bh);
909 ext2_free_blocks(inode, nr, 1);
910 mark_inode_dirty(inode);
911 }
912 } else
913 ext2_free_data(inode, p, q);
914}
915
916void ext2_truncate (struct inode * inode)
917{
918 __le32 *i_data = EXT2_I(inode)->i_data;
919 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
920 int offsets[4];
921 Indirect chain[4];
922 Indirect *partial;
923 __le32 nr = 0;
924 int n;
925 long iblock;
926 unsigned blocksize;
927
928 if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
929 S_ISLNK(inode->i_mode)))
930 return;
931 if (ext2_inode_is_fast_symlink(inode))
932 return;
933 if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
934 return;
935
936 ext2_discard_prealloc(inode);
937
938 blocksize = inode->i_sb->s_blocksize;
939 iblock = (inode->i_size + blocksize-1)
940 >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
941
Carsten Otte6d791252005-06-23 22:05:26 -0700942 if (mapping_is_xip(inode->i_mapping))
943 xip_truncate_page(inode->i_mapping, inode->i_size);
944 else if (test_opt(inode->i_sb, NOBH))
Nick Piggin03158cd2007-10-16 01:25:25 -0700945 nobh_truncate_page(inode->i_mapping,
946 inode->i_size, ext2_get_block);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700947 else
948 block_truncate_page(inode->i_mapping,
949 inode->i_size, ext2_get_block);
950
951 n = ext2_block_to_path(inode, iblock, offsets, NULL);
952 if (n == 0)
953 return;
954
955 if (n == 1) {
956 ext2_free_data(inode, i_data+offsets[0],
957 i_data + EXT2_NDIR_BLOCKS);
958 goto do_indirects;
959 }
960
961 partial = ext2_find_shared(inode, n, offsets, chain, &nr);
962 /* Kill the top of shared branch (already detached) */
963 if (nr) {
964 if (partial == chain)
965 mark_inode_dirty(inode);
966 else
967 mark_buffer_dirty_inode(partial->bh, inode);
968 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
969 }
970 /* Clear the ends of indirect blocks on the shared branch */
971 while (partial > chain) {
972 ext2_free_branches(inode,
973 partial->p + 1,
974 (__le32*)partial->bh->b_data+addr_per_block,
975 (chain+n-1) - partial);
976 mark_buffer_dirty_inode(partial->bh, inode);
977 brelse (partial->bh);
978 partial--;
979 }
980do_indirects:
981 /* Kill the remaining (whole) subtrees */
982 switch (offsets[0]) {
983 default:
984 nr = i_data[EXT2_IND_BLOCK];
985 if (nr) {
986 i_data[EXT2_IND_BLOCK] = 0;
987 mark_inode_dirty(inode);
988 ext2_free_branches(inode, &nr, &nr+1, 1);
989 }
990 case EXT2_IND_BLOCK:
991 nr = i_data[EXT2_DIND_BLOCK];
992 if (nr) {
993 i_data[EXT2_DIND_BLOCK] = 0;
994 mark_inode_dirty(inode);
995 ext2_free_branches(inode, &nr, &nr+1, 2);
996 }
997 case EXT2_DIND_BLOCK:
998 nr = i_data[EXT2_TIND_BLOCK];
999 if (nr) {
1000 i_data[EXT2_TIND_BLOCK] = 0;
1001 mark_inode_dirty(inode);
1002 ext2_free_branches(inode, &nr, &nr+1, 3);
1003 }
1004 case EXT2_TIND_BLOCK:
1005 ;
1006 }
1007 inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
1008 if (inode_needs_sync(inode)) {
1009 sync_mapping_buffers(inode->i_mapping);
1010 ext2_sync_inode (inode);
1011 } else {
1012 mark_inode_dirty(inode);
1013 }
1014}
1015
1016static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1017 struct buffer_head **p)
1018{
1019 struct buffer_head * bh;
1020 unsigned long block_group;
1021 unsigned long block;
1022 unsigned long offset;
1023 struct ext2_group_desc * gdp;
1024
1025 *p = NULL;
1026 if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1027 ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1028 goto Einval;
1029
1030 block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1031 gdp = ext2_get_group_desc(sb, block_group, &bh);
1032 if (!gdp)
1033 goto Egdp;
1034 /*
1035 * Figure out the offset within the block group inode table
1036 */
1037 offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1038 block = le32_to_cpu(gdp->bg_inode_table) +
1039 (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1040 if (!(bh = sb_bread(sb, block)))
1041 goto Eio;
1042
1043 *p = bh;
1044 offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1045 return (struct ext2_inode *) (bh->b_data + offset);
1046
1047Einval:
1048 ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1049 (unsigned long) ino);
1050 return ERR_PTR(-EINVAL);
1051Eio:
1052 ext2_error(sb, "ext2_get_inode",
1053 "unable to read inode block - inode=%lu, block=%lu",
1054 (unsigned long) ino, block);
1055Egdp:
1056 return ERR_PTR(-EIO);
1057}
1058
1059void ext2_set_inode_flags(struct inode *inode)
1060{
1061 unsigned int flags = EXT2_I(inode)->i_flags;
1062
1063 inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
1064 if (flags & EXT2_SYNC_FL)
1065 inode->i_flags |= S_SYNC;
1066 if (flags & EXT2_APPEND_FL)
1067 inode->i_flags |= S_APPEND;
1068 if (flags & EXT2_IMMUTABLE_FL)
1069 inode->i_flags |= S_IMMUTABLE;
1070 if (flags & EXT2_NOATIME_FL)
1071 inode->i_flags |= S_NOATIME;
1072 if (flags & EXT2_DIRSYNC_FL)
1073 inode->i_flags |= S_DIRSYNC;
1074}
1075
Jan Kara4f99ed62007-05-08 00:31:04 -07001076/* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
1077void ext2_get_inode_flags(struct ext2_inode_info *ei)
1078{
1079 unsigned int flags = ei->vfs_inode.i_flags;
1080
1081 ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
1082 EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
1083 if (flags & S_SYNC)
1084 ei->i_flags |= EXT2_SYNC_FL;
1085 if (flags & S_APPEND)
1086 ei->i_flags |= EXT2_APPEND_FL;
1087 if (flags & S_IMMUTABLE)
1088 ei->i_flags |= EXT2_IMMUTABLE_FL;
1089 if (flags & S_NOATIME)
1090 ei->i_flags |= EXT2_NOATIME_FL;
1091 if (flags & S_DIRSYNC)
1092 ei->i_flags |= EXT2_DIRSYNC_FL;
1093}
1094
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095void ext2_read_inode (struct inode * inode)
1096{
1097 struct ext2_inode_info *ei = EXT2_I(inode);
1098 ino_t ino = inode->i_ino;
1099 struct buffer_head * bh;
1100 struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1101 int n;
1102
1103#ifdef CONFIG_EXT2_FS_POSIX_ACL
1104 ei->i_acl = EXT2_ACL_NOT_CACHED;
1105 ei->i_default_acl = EXT2_ACL_NOT_CACHED;
1106#endif
1107 if (IS_ERR(raw_inode))
1108 goto bad_inode;
1109
1110 inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1111 inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1112 inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1113 if (!(test_opt (inode->i_sb, NO_UID32))) {
1114 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1115 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1116 }
1117 inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
1118 inode->i_size = le32_to_cpu(raw_inode->i_size);
Markus Rechberger4d7bf112007-05-08 00:23:39 -07001119 inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
1120 inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
1121 inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1123 ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1124 /* We now have enough fields to check if the inode was active or not.
1125 * This is needed because nfsd might try to access dead inodes
1126 * the test is that same one that e2fsck uses
1127 * NeilBrown 1999oct15
1128 */
1129 if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
1130 /* this inode is deleted */
1131 brelse (bh);
1132 goto bad_inode;
1133 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134 inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1135 ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1136 ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1137 ei->i_frag_no = raw_inode->i_frag;
1138 ei->i_frag_size = raw_inode->i_fsize;
1139 ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1140 ei->i_dir_acl = 0;
1141 if (S_ISREG(inode->i_mode))
1142 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1143 else
1144 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1145 ei->i_dtime = 0;
1146 inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1147 ei->i_state = 0;
1148 ei->i_next_alloc_block = 0;
1149 ei->i_next_alloc_goal = 0;
1150 ei->i_prealloc_count = 0;
1151 ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1152 ei->i_dir_start_lookup = 0;
1153
1154 /*
1155 * NOTE! The in-memory inode i_data array is in little-endian order
1156 * even on big-endian machines: we do NOT byteswap the block numbers!
1157 */
1158 for (n = 0; n < EXT2_N_BLOCKS; n++)
1159 ei->i_data[n] = raw_inode->i_block[n];
1160
1161 if (S_ISREG(inode->i_mode)) {
1162 inode->i_op = &ext2_file_inode_operations;
Carsten Otte6d791252005-06-23 22:05:26 -07001163 if (ext2_use_xip(inode->i_sb)) {
1164 inode->i_mapping->a_ops = &ext2_aops_xip;
1165 inode->i_fop = &ext2_xip_file_operations;
1166 } else if (test_opt(inode->i_sb, NOBH)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001167 inode->i_mapping->a_ops = &ext2_nobh_aops;
Carsten Otte6d791252005-06-23 22:05:26 -07001168 inode->i_fop = &ext2_file_operations;
1169 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -07001170 inode->i_mapping->a_ops = &ext2_aops;
Carsten Otte6d791252005-06-23 22:05:26 -07001171 inode->i_fop = &ext2_file_operations;
1172 }
Linus Torvalds1da177e2005-04-16 15:20:36 -07001173 } else if (S_ISDIR(inode->i_mode)) {
1174 inode->i_op = &ext2_dir_inode_operations;
1175 inode->i_fop = &ext2_dir_operations;
1176 if (test_opt(inode->i_sb, NOBH))
1177 inode->i_mapping->a_ops = &ext2_nobh_aops;
1178 else
1179 inode->i_mapping->a_ops = &ext2_aops;
1180 } else if (S_ISLNK(inode->i_mode)) {
1181 if (ext2_inode_is_fast_symlink(inode))
1182 inode->i_op = &ext2_fast_symlink_inode_operations;
1183 else {
1184 inode->i_op = &ext2_symlink_inode_operations;
1185 if (test_opt(inode->i_sb, NOBH))
1186 inode->i_mapping->a_ops = &ext2_nobh_aops;
1187 else
1188 inode->i_mapping->a_ops = &ext2_aops;
1189 }
1190 } else {
1191 inode->i_op = &ext2_special_inode_operations;
1192 if (raw_inode->i_block[0])
1193 init_special_inode(inode, inode->i_mode,
1194 old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1195 else
1196 init_special_inode(inode, inode->i_mode,
1197 new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1198 }
1199 brelse (bh);
1200 ext2_set_inode_flags(inode);
1201 return;
1202
1203bad_inode:
1204 make_bad_inode(inode);
1205 return;
1206}
1207
1208static int ext2_update_inode(struct inode * inode, int do_sync)
1209{
1210 struct ext2_inode_info *ei = EXT2_I(inode);
1211 struct super_block *sb = inode->i_sb;
1212 ino_t ino = inode->i_ino;
1213 uid_t uid = inode->i_uid;
1214 gid_t gid = inode->i_gid;
1215 struct buffer_head * bh;
1216 struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1217 int n;
1218 int err = 0;
1219
1220 if (IS_ERR(raw_inode))
1221 return -EIO;
1222
1223 /* For fields not not tracking in the in-memory inode,
1224 * initialise them to zero for new inodes. */
1225 if (ei->i_state & EXT2_STATE_NEW)
1226 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1227
Jan Kara4f99ed62007-05-08 00:31:04 -07001228 ext2_get_inode_flags(ei);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001229 raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1230 if (!(test_opt(sb, NO_UID32))) {
1231 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1232 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1233/*
1234 * Fix up interoperability with old kernels. Otherwise, old inodes get
1235 * re-used with the upper 16 bits of the uid/gid intact
1236 */
1237 if (!ei->i_dtime) {
1238 raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1239 raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1240 } else {
1241 raw_inode->i_uid_high = 0;
1242 raw_inode->i_gid_high = 0;
1243 }
1244 } else {
1245 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1246 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1247 raw_inode->i_uid_high = 0;
1248 raw_inode->i_gid_high = 0;
1249 }
1250 raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1251 raw_inode->i_size = cpu_to_le32(inode->i_size);
1252 raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1253 raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1254 raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1255
1256 raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1257 raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1258 raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1259 raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1260 raw_inode->i_frag = ei->i_frag_no;
1261 raw_inode->i_fsize = ei->i_frag_size;
1262 raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1263 if (!S_ISREG(inode->i_mode))
1264 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1265 else {
1266 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1267 if (inode->i_size > 0x7fffffffULL) {
1268 if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1269 EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1270 EXT2_SB(sb)->s_es->s_rev_level ==
1271 cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1272 /* If this is the first large file
1273 * created, add a flag to the superblock.
1274 */
1275 lock_kernel();
1276 ext2_update_dynamic_rev(sb);
1277 EXT2_SET_RO_COMPAT_FEATURE(sb,
1278 EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1279 unlock_kernel();
1280 ext2_write_super(sb);
1281 }
1282 }
1283 }
1284
1285 raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1286 if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1287 if (old_valid_dev(inode->i_rdev)) {
1288 raw_inode->i_block[0] =
1289 cpu_to_le32(old_encode_dev(inode->i_rdev));
1290 raw_inode->i_block[1] = 0;
1291 } else {
1292 raw_inode->i_block[0] = 0;
1293 raw_inode->i_block[1] =
1294 cpu_to_le32(new_encode_dev(inode->i_rdev));
1295 raw_inode->i_block[2] = 0;
1296 }
1297 } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1298 raw_inode->i_block[n] = ei->i_data[n];
1299 mark_buffer_dirty(bh);
1300 if (do_sync) {
1301 sync_dirty_buffer(bh);
1302 if (buffer_req(bh) && !buffer_uptodate(bh)) {
1303 printk ("IO error syncing ext2 inode [%s:%08lx]\n",
1304 sb->s_id, (unsigned long) ino);
1305 err = -EIO;
1306 }
1307 }
1308 ei->i_state &= ~EXT2_STATE_NEW;
1309 brelse (bh);
1310 return err;
1311}
1312
1313int ext2_write_inode(struct inode *inode, int wait)
1314{
1315 return ext2_update_inode(inode, wait);
1316}
1317
1318int ext2_sync_inode(struct inode *inode)
1319{
1320 struct writeback_control wbc = {
1321 .sync_mode = WB_SYNC_ALL,
1322 .nr_to_write = 0, /* sys_fsync did this */
1323 };
1324 return sync_inode(inode, &wbc);
1325}
1326
1327int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
1328{
1329 struct inode *inode = dentry->d_inode;
1330 int error;
1331
1332 error = inode_change_ok(inode, iattr);
1333 if (error)
1334 return error;
1335 if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
1336 (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
1337 error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0;
1338 if (error)
1339 return error;
1340 }
1341 error = inode_setattr(inode, iattr);
1342 if (!error && (iattr->ia_valid & ATTR_MODE))
1343 error = ext2_acl_chmod(inode);
1344 return error;
1345}