fs: restore nobh
[linux-2.6.git] / fs / ext2 / inode.c
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         truncate_inode_pages(&inode->i_data, 0);
75
76         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;
88 no_delete:
89         clear_inode(inode);     /* We must guarantee clearing of inode... */
90 }
91
92 void 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
110 static 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
147 typedef struct {
148         __le32  *p;
149         __le32  key;
150         struct buffer_head *bh;
151 } Indirect;
152
153 static 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
159 static 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
196 static 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  */
264 static 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
293 changed:
294         read_unlock(&EXT2_I(inode)->i_meta_lock);
295         brelse(bh);
296         *err = -EAGAIN;
297         goto no_block;
298 failure:
299         *err = -EIO;
300 no_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
324 static 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
365 static 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
418 static 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);
443                 if (!bh) {
444                         err = -EIO;
445                         break;
446                 }
447                 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
491 static 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
525 changed:
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
547 int 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
561 reread:
562         partial = ext2_get_branch(inode, depth, offsets, chain, &err);
563
564         /* Simplest case - block found, no allocation needed */
565         if (!partial) {
566 got_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) {
577 cleanup:
578                 while (partial > chain) {
579                         brelse(partial->bh);
580                         partial--;
581                 }
582 out:
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
604         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
614         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
620 changed:
621         while (partial > chain) {
622                 brelse(partial->bh);
623                 partial--;
624         }
625         goto reread;
626 }
627
628 static int ext2_writepage(struct page *page, struct writeback_control *wbc)
629 {
630         return block_write_full_page(page, ext2_get_block, wbc);
631 }
632
633 static int ext2_readpage(struct file *file, struct page *page)
634 {
635         return mpage_readpage(page, ext2_get_block);
636 }
637
638 static int
639 ext2_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
645 int __ext2_write_begin(struct file *file, struct address_space *mapping,
646                 loff_t pos, unsigned len, unsigned flags,
647                 struct page **pagep, void **fsdata)
648 {
649         return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
650                                                         ext2_get_block);
651 }
652
653 static int
654 ext2_write_begin(struct file *file, struct address_space *mapping,
655                 loff_t pos, unsigned len, unsigned flags,
656                 struct page **pagep, void **fsdata)
657 {
658         *pagep = NULL;
659         return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
660 }
661
662 static int
663 ext2_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
676 static int ext2_nobh_writepage(struct page *page,
677                         struct writeback_control *wbc)
678 {
679         return nobh_writepage(page, ext2_get_block, wbc);
680 }
681
682 static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
683 {
684         return generic_block_bmap(mapping,block,ext2_get_block);
685 }
686
687 static ssize_t
688 ext2_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,
695                                 offset, nr_segs, ext2_get_block, NULL);
696 }
697
698 static int
699 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
700 {
701         return mpage_writepages(mapping, wbc, ext2_get_block);
702 }
703
704 const struct address_space_operations ext2_aops = {
705         .readpage               = ext2_readpage,
706         .readpages              = ext2_readpages,
707         .writepage              = ext2_writepage,
708         .sync_page              = block_sync_page,
709         .write_begin            = ext2_write_begin,
710         .write_end              = generic_write_end,
711         .bmap                   = ext2_bmap,
712         .direct_IO              = ext2_direct_IO,
713         .writepages             = ext2_writepages,
714         .migratepage            = buffer_migrate_page,
715 };
716
717 const struct address_space_operations ext2_aops_xip = {
718         .bmap                   = ext2_bmap,
719         .get_xip_page           = ext2_get_xip_page,
720 };
721
722 const struct address_space_operations ext2_nobh_aops = {
723         .readpage               = ext2_readpage,
724         .readpages              = ext2_readpages,
725         .writepage              = ext2_nobh_writepage,
726         .sync_page              = block_sync_page,
727         .write_begin            = ext2_nobh_write_begin,
728         .write_end              = nobh_write_end,
729         .bmap                   = ext2_bmap,
730         .direct_IO              = ext2_direct_IO,
731         .writepages             = ext2_writepages,
732         .migratepage            = buffer_migrate_page,
733 };
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  */
740 static 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
782 static 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         }
827 no_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  */
841 static 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  */
881 static 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
916 void 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
942         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))
945                 nobh_truncate_page(inode->i_mapping,
946                                 inode->i_size, ext2_get_block);
947         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         }
980 do_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
1016 static 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
1047 Einval:
1048         ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1049                    (unsigned long) ino);
1050         return ERR_PTR(-EINVAL);
1051 Eio:
1052         ext2_error(sb, "ext2_get_inode",
1053                    "unable to read inode block - inode=%lu, block=%lu",
1054                    (unsigned long) ino, block);
1055 Egdp:
1056         return ERR_PTR(-EIO);
1057 }
1058
1059 void 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
1076 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
1077 void 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
1095 void 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);
1119         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);
1122         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         }
1134         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;
1163                 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)) {
1167                         inode->i_mapping->a_ops = &ext2_nobh_aops;
1168                         inode->i_fop = &ext2_file_operations;
1169                 } else {
1170                         inode->i_mapping->a_ops = &ext2_aops;
1171                         inode->i_fop = &ext2_file_operations;
1172                 }
1173         } 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         
1203 bad_inode:
1204         make_bad_inode(inode);
1205         return;
1206 }
1207
1208 static 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
1228         ext2_get_inode_flags(ei);
1229         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
1313 int ext2_write_inode(struct inode *inode, int wait)
1314 {
1315         return ext2_update_inode(inode, wait);
1316 }
1317
1318 int 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
1327 int 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 }