->permission() sanitizing: don't pass flags to ->check_acl()
[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/time.h>
26 #include <linux/highuid.h>
27 #include <linux/pagemap.h>
28 #include <linux/quotaops.h>
29 #include <linux/module.h>
30 #include <linux/writeback.h>
31 #include <linux/buffer_head.h>
32 #include <linux/mpage.h>
33 #include <linux/fiemap.h>
34 #include <linux/namei.h>
35 #include "ext2.h"
36 #include "acl.h"
37 #include "xip.h"
38
39 MODULE_AUTHOR("Remy Card and others");
40 MODULE_DESCRIPTION("Second Extended Filesystem");
41 MODULE_LICENSE("GPL");
42
43 static int __ext2_write_inode(struct inode *inode, int do_sync);
44
45 /*
46  * Test whether an inode is a fast symlink.
47  */
48 static inline int ext2_inode_is_fast_symlink(struct inode *inode)
49 {
50         int ea_blocks = EXT2_I(inode)->i_file_acl ?
51                 (inode->i_sb->s_blocksize >> 9) : 0;
52
53         return (S_ISLNK(inode->i_mode) &&
54                 inode->i_blocks - ea_blocks == 0);
55 }
56
57 static void ext2_truncate_blocks(struct inode *inode, loff_t offset);
58
59 static void ext2_write_failed(struct address_space *mapping, loff_t to)
60 {
61         struct inode *inode = mapping->host;
62
63         if (to > inode->i_size) {
64                 truncate_pagecache(inode, to, inode->i_size);
65                 ext2_truncate_blocks(inode, inode->i_size);
66         }
67 }
68
69 /*
70  * Called at the last iput() if i_nlink is zero.
71  */
72 void ext2_evict_inode(struct inode * inode)
73 {
74         struct ext2_block_alloc_info *rsv;
75         int want_delete = 0;
76
77         if (!inode->i_nlink && !is_bad_inode(inode)) {
78                 want_delete = 1;
79                 dquot_initialize(inode);
80         } else {
81                 dquot_drop(inode);
82         }
83
84         truncate_inode_pages(&inode->i_data, 0);
85
86         if (want_delete) {
87                 /* set dtime */
88                 EXT2_I(inode)->i_dtime  = get_seconds();
89                 mark_inode_dirty(inode);
90                 __ext2_write_inode(inode, inode_needs_sync(inode));
91                 /* truncate to 0 */
92                 inode->i_size = 0;
93                 if (inode->i_blocks)
94                         ext2_truncate_blocks(inode, 0);
95         }
96
97         invalidate_inode_buffers(inode);
98         end_writeback(inode);
99
100         ext2_discard_reservation(inode);
101         rsv = EXT2_I(inode)->i_block_alloc_info;
102         EXT2_I(inode)->i_block_alloc_info = NULL;
103         if (unlikely(rsv))
104                 kfree(rsv);
105
106         if (want_delete)
107                 ext2_free_inode(inode);
108 }
109
110 typedef struct {
111         __le32  *p;
112         __le32  key;
113         struct buffer_head *bh;
114 } Indirect;
115
116 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
117 {
118         p->key = *(p->p = v);
119         p->bh = bh;
120 }
121
122 static inline int verify_chain(Indirect *from, Indirect *to)
123 {
124         while (from <= to && from->key == *from->p)
125                 from++;
126         return (from > to);
127 }
128
129 /**
130  *      ext2_block_to_path - parse the block number into array of offsets
131  *      @inode: inode in question (we are only interested in its superblock)
132  *      @i_block: block number to be parsed
133  *      @offsets: array to store the offsets in
134  *      @boundary: set this non-zero if the referred-to block is likely to be
135  *             followed (on disk) by an indirect block.
136  *      To store the locations of file's data ext2 uses a data structure common
137  *      for UNIX filesystems - tree of pointers anchored in the inode, with
138  *      data blocks at leaves and indirect blocks in intermediate nodes.
139  *      This function translates the block number into path in that tree -
140  *      return value is the path length and @offsets[n] is the offset of
141  *      pointer to (n+1)th node in the nth one. If @block is out of range
142  *      (negative or too large) warning is printed and zero returned.
143  *
144  *      Note: function doesn't find node addresses, so no IO is needed. All
145  *      we need to know is the capacity of indirect blocks (taken from the
146  *      inode->i_sb).
147  */
148
149 /*
150  * Portability note: the last comparison (check that we fit into triple
151  * indirect block) is spelled differently, because otherwise on an
152  * architecture with 32-bit longs and 8Kb pages we might get into trouble
153  * if our filesystem had 8Kb blocks. We might use long long, but that would
154  * kill us on x86. Oh, well, at least the sign propagation does not matter -
155  * i_block would have to be negative in the very beginning, so we would not
156  * get there at all.
157  */
158
159 static int ext2_block_to_path(struct inode *inode,
160                         long i_block, int offsets[4], int *boundary)
161 {
162         int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
163         int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
164         const long direct_blocks = EXT2_NDIR_BLOCKS,
165                 indirect_blocks = ptrs,
166                 double_blocks = (1 << (ptrs_bits * 2));
167         int n = 0;
168         int final = 0;
169
170         if (i_block < 0) {
171                 ext2_msg(inode->i_sb, KERN_WARNING,
172                         "warning: %s: block < 0", __func__);
173         } else if (i_block < direct_blocks) {
174                 offsets[n++] = i_block;
175                 final = direct_blocks;
176         } else if ( (i_block -= direct_blocks) < indirect_blocks) {
177                 offsets[n++] = EXT2_IND_BLOCK;
178                 offsets[n++] = i_block;
179                 final = ptrs;
180         } else if ((i_block -= indirect_blocks) < double_blocks) {
181                 offsets[n++] = EXT2_DIND_BLOCK;
182                 offsets[n++] = i_block >> ptrs_bits;
183                 offsets[n++] = i_block & (ptrs - 1);
184                 final = ptrs;
185         } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
186                 offsets[n++] = EXT2_TIND_BLOCK;
187                 offsets[n++] = i_block >> (ptrs_bits * 2);
188                 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
189                 offsets[n++] = i_block & (ptrs - 1);
190                 final = ptrs;
191         } else {
192                 ext2_msg(inode->i_sb, KERN_WARNING,
193                         "warning: %s: block is too big", __func__);
194         }
195         if (boundary)
196                 *boundary = final - 1 - (i_block & (ptrs - 1));
197
198         return n;
199 }
200
201 /**
202  *      ext2_get_branch - read the chain of indirect blocks leading to data
203  *      @inode: inode in question
204  *      @depth: depth of the chain (1 - direct pointer, etc.)
205  *      @offsets: offsets of pointers in inode/indirect blocks
206  *      @chain: place to store the result
207  *      @err: here we store the error value
208  *
209  *      Function fills the array of triples <key, p, bh> and returns %NULL
210  *      if everything went OK or the pointer to the last filled triple
211  *      (incomplete one) otherwise. Upon the return chain[i].key contains
212  *      the number of (i+1)-th block in the chain (as it is stored in memory,
213  *      i.e. little-endian 32-bit), chain[i].p contains the address of that
214  *      number (it points into struct inode for i==0 and into the bh->b_data
215  *      for i>0) and chain[i].bh points to the buffer_head of i-th indirect
216  *      block for i>0 and NULL for i==0. In other words, it holds the block
217  *      numbers of the chain, addresses they were taken from (and where we can
218  *      verify that chain did not change) and buffer_heads hosting these
219  *      numbers.
220  *
221  *      Function stops when it stumbles upon zero pointer (absent block)
222  *              (pointer to last triple returned, *@err == 0)
223  *      or when it gets an IO error reading an indirect block
224  *              (ditto, *@err == -EIO)
225  *      or when it notices that chain had been changed while it was reading
226  *              (ditto, *@err == -EAGAIN)
227  *      or when it reads all @depth-1 indirect blocks successfully and finds
228  *      the whole chain, all way to the data (returns %NULL, *err == 0).
229  */
230 static Indirect *ext2_get_branch(struct inode *inode,
231                                  int depth,
232                                  int *offsets,
233                                  Indirect chain[4],
234                                  int *err)
235 {
236         struct super_block *sb = inode->i_sb;
237         Indirect *p = chain;
238         struct buffer_head *bh;
239
240         *err = 0;
241         /* i_data is not going away, no lock needed */
242         add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
243         if (!p->key)
244                 goto no_block;
245         while (--depth) {
246                 bh = sb_bread(sb, le32_to_cpu(p->key));
247                 if (!bh)
248                         goto failure;
249                 read_lock(&EXT2_I(inode)->i_meta_lock);
250                 if (!verify_chain(chain, p))
251                         goto changed;
252                 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
253                 read_unlock(&EXT2_I(inode)->i_meta_lock);
254                 if (!p->key)
255                         goto no_block;
256         }
257         return NULL;
258
259 changed:
260         read_unlock(&EXT2_I(inode)->i_meta_lock);
261         brelse(bh);
262         *err = -EAGAIN;
263         goto no_block;
264 failure:
265         *err = -EIO;
266 no_block:
267         return p;
268 }
269
270 /**
271  *      ext2_find_near - find a place for allocation with sufficient locality
272  *      @inode: owner
273  *      @ind: descriptor of indirect block.
274  *
275  *      This function returns the preferred place for block allocation.
276  *      It is used when heuristic for sequential allocation fails.
277  *      Rules are:
278  *        + if there is a block to the left of our position - allocate near it.
279  *        + if pointer will live in indirect block - allocate near that block.
280  *        + if pointer will live in inode - allocate in the same cylinder group.
281  *
282  * In the latter case we colour the starting block by the callers PID to
283  * prevent it from clashing with concurrent allocations for a different inode
284  * in the same block group.   The PID is used here so that functionally related
285  * files will be close-by on-disk.
286  *
287  *      Caller must make sure that @ind is valid and will stay that way.
288  */
289
290 static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
291 {
292         struct ext2_inode_info *ei = EXT2_I(inode);
293         __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
294         __le32 *p;
295         ext2_fsblk_t bg_start;
296         ext2_fsblk_t colour;
297
298         /* Try to find previous block */
299         for (p = ind->p - 1; p >= start; p--)
300                 if (*p)
301                         return le32_to_cpu(*p);
302
303         /* No such thing, so let's try location of indirect block */
304         if (ind->bh)
305                 return ind->bh->b_blocknr;
306
307         /*
308          * It is going to be referred from inode itself? OK, just put it into
309          * the same cylinder group then.
310          */
311         bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
312         colour = (current->pid % 16) *
313                         (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
314         return bg_start + colour;
315 }
316
317 /**
318  *      ext2_find_goal - find a preferred place for allocation.
319  *      @inode: owner
320  *      @block:  block we want
321  *      @partial: pointer to the last triple within a chain
322  *
323  *      Returns preferred place for a block (the goal).
324  */
325
326 static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
327                                           Indirect *partial)
328 {
329         struct ext2_block_alloc_info *block_i;
330
331         block_i = EXT2_I(inode)->i_block_alloc_info;
332
333         /*
334          * try the heuristic for sequential allocation,
335          * failing that at least try to get decent locality.
336          */
337         if (block_i && (block == block_i->last_alloc_logical_block + 1)
338                 && (block_i->last_alloc_physical_block != 0)) {
339                 return block_i->last_alloc_physical_block + 1;
340         }
341
342         return ext2_find_near(inode, partial);
343 }
344
345 /**
346  *      ext2_blks_to_allocate: Look up the block map and count the number
347  *      of direct blocks need to be allocated for the given branch.
348  *
349  *      @branch: chain of indirect blocks
350  *      @k: number of blocks need for indirect blocks
351  *      @blks: number of data blocks to be mapped.
352  *      @blocks_to_boundary:  the offset in the indirect block
353  *
354  *      return the total number of blocks to be allocate, including the
355  *      direct and indirect blocks.
356  */
357 static int
358 ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
359                 int blocks_to_boundary)
360 {
361         unsigned long count = 0;
362
363         /*
364          * Simple case, [t,d]Indirect block(s) has not allocated yet
365          * then it's clear blocks on that path have not allocated
366          */
367         if (k > 0) {
368                 /* right now don't hanel cross boundary allocation */
369                 if (blks < blocks_to_boundary + 1)
370                         count += blks;
371                 else
372                         count += blocks_to_boundary + 1;
373                 return count;
374         }
375
376         count++;
377         while (count < blks && count <= blocks_to_boundary
378                 && le32_to_cpu(*(branch[0].p + count)) == 0) {
379                 count++;
380         }
381         return count;
382 }
383
384 /**
385  *      ext2_alloc_blocks: multiple allocate blocks needed for a branch
386  *      @indirect_blks: the number of blocks need to allocate for indirect
387  *                      blocks
388  *
389  *      @new_blocks: on return it will store the new block numbers for
390  *      the indirect blocks(if needed) and the first direct block,
391  *      @blks:  on return it will store the total number of allocated
392  *              direct blocks
393  */
394 static int ext2_alloc_blocks(struct inode *inode,
395                         ext2_fsblk_t goal, int indirect_blks, int blks,
396                         ext2_fsblk_t new_blocks[4], int *err)
397 {
398         int target, i;
399         unsigned long count = 0;
400         int index = 0;
401         ext2_fsblk_t current_block = 0;
402         int ret = 0;
403
404         /*
405          * Here we try to allocate the requested multiple blocks at once,
406          * on a best-effort basis.
407          * To build a branch, we should allocate blocks for
408          * the indirect blocks(if not allocated yet), and at least
409          * the first direct block of this branch.  That's the
410          * minimum number of blocks need to allocate(required)
411          */
412         target = blks + indirect_blks;
413
414         while (1) {
415                 count = target;
416                 /* allocating blocks for indirect blocks and direct blocks */
417                 current_block = ext2_new_blocks(inode,goal,&count,err);
418                 if (*err)
419                         goto failed_out;
420
421                 target -= count;
422                 /* allocate blocks for indirect blocks */
423                 while (index < indirect_blks && count) {
424                         new_blocks[index++] = current_block++;
425                         count--;
426                 }
427
428                 if (count > 0)
429                         break;
430         }
431
432         /* save the new block number for the first direct block */
433         new_blocks[index] = current_block;
434
435         /* total number of blocks allocated for direct blocks */
436         ret = count;
437         *err = 0;
438         return ret;
439 failed_out:
440         for (i = 0; i <index; i++)
441                 ext2_free_blocks(inode, new_blocks[i], 1);
442         if (index)
443                 mark_inode_dirty(inode);
444         return ret;
445 }
446
447 /**
448  *      ext2_alloc_branch - allocate and set up a chain of blocks.
449  *      @inode: owner
450  *      @num: depth of the chain (number of blocks to allocate)
451  *      @offsets: offsets (in the blocks) to store the pointers to next.
452  *      @branch: place to store the chain in.
453  *
454  *      This function allocates @num blocks, zeroes out all but the last one,
455  *      links them into chain and (if we are synchronous) writes them to disk.
456  *      In other words, it prepares a branch that can be spliced onto the
457  *      inode. It stores the information about that chain in the branch[], in
458  *      the same format as ext2_get_branch() would do. We are calling it after
459  *      we had read the existing part of chain and partial points to the last
460  *      triple of that (one with zero ->key). Upon the exit we have the same
461  *      picture as after the successful ext2_get_block(), except that in one
462  *      place chain is disconnected - *branch->p is still zero (we did not
463  *      set the last link), but branch->key contains the number that should
464  *      be placed into *branch->p to fill that gap.
465  *
466  *      If allocation fails we free all blocks we've allocated (and forget
467  *      their buffer_heads) and return the error value the from failed
468  *      ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
469  *      as described above and return 0.
470  */
471
472 static int ext2_alloc_branch(struct inode *inode,
473                         int indirect_blks, int *blks, ext2_fsblk_t goal,
474                         int *offsets, Indirect *branch)
475 {
476         int blocksize = inode->i_sb->s_blocksize;
477         int i, n = 0;
478         int err = 0;
479         struct buffer_head *bh;
480         int num;
481         ext2_fsblk_t new_blocks[4];
482         ext2_fsblk_t current_block;
483
484         num = ext2_alloc_blocks(inode, goal, indirect_blks,
485                                 *blks, new_blocks, &err);
486         if (err)
487                 return err;
488
489         branch[0].key = cpu_to_le32(new_blocks[0]);
490         /*
491          * metadata blocks and data blocks are allocated.
492          */
493         for (n = 1; n <= indirect_blks;  n++) {
494                 /*
495                  * Get buffer_head for parent block, zero it out
496                  * and set the pointer to new one, then send
497                  * parent to disk.
498                  */
499                 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
500                 branch[n].bh = bh;
501                 lock_buffer(bh);
502                 memset(bh->b_data, 0, blocksize);
503                 branch[n].p = (__le32 *) bh->b_data + offsets[n];
504                 branch[n].key = cpu_to_le32(new_blocks[n]);
505                 *branch[n].p = branch[n].key;
506                 if ( n == indirect_blks) {
507                         current_block = new_blocks[n];
508                         /*
509                          * End of chain, update the last new metablock of
510                          * the chain to point to the new allocated
511                          * data blocks numbers
512                          */
513                         for (i=1; i < num; i++)
514                                 *(branch[n].p + i) = cpu_to_le32(++current_block);
515                 }
516                 set_buffer_uptodate(bh);
517                 unlock_buffer(bh);
518                 mark_buffer_dirty_inode(bh, inode);
519                 /* We used to sync bh here if IS_SYNC(inode).
520                  * But we now rely upon generic_write_sync()
521                  * and b_inode_buffers.  But not for directories.
522                  */
523                 if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
524                         sync_dirty_buffer(bh);
525         }
526         *blks = num;
527         return err;
528 }
529
530 /**
531  * ext2_splice_branch - splice the allocated branch onto inode.
532  * @inode: owner
533  * @block: (logical) number of block we are adding
534  * @where: location of missing link
535  * @num:   number of indirect blocks we are adding
536  * @blks:  number of direct blocks we are adding
537  *
538  * This function fills the missing link and does all housekeeping needed in
539  * inode (->i_blocks, etc.). In case of success we end up with the full
540  * chain to new block and return 0.
541  */
542 static void ext2_splice_branch(struct inode *inode,
543                         long block, Indirect *where, int num, int blks)
544 {
545         int i;
546         struct ext2_block_alloc_info *block_i;
547         ext2_fsblk_t current_block;
548
549         block_i = EXT2_I(inode)->i_block_alloc_info;
550
551         /* XXX LOCKING probably should have i_meta_lock ?*/
552         /* That's it */
553
554         *where->p = where->key;
555
556         /*
557          * Update the host buffer_head or inode to point to more just allocated
558          * direct blocks blocks
559          */
560         if (num == 0 && blks > 1) {
561                 current_block = le32_to_cpu(where->key) + 1;
562                 for (i = 1; i < blks; i++)
563                         *(where->p + i ) = cpu_to_le32(current_block++);
564         }
565
566         /*
567          * update the most recently allocated logical & physical block
568          * in i_block_alloc_info, to assist find the proper goal block for next
569          * allocation
570          */
571         if (block_i) {
572                 block_i->last_alloc_logical_block = block + blks - 1;
573                 block_i->last_alloc_physical_block =
574                                 le32_to_cpu(where[num].key) + blks - 1;
575         }
576
577         /* We are done with atomic stuff, now do the rest of housekeeping */
578
579         /* had we spliced it onto indirect block? */
580         if (where->bh)
581                 mark_buffer_dirty_inode(where->bh, inode);
582
583         inode->i_ctime = CURRENT_TIME_SEC;
584         mark_inode_dirty(inode);
585 }
586
587 /*
588  * Allocation strategy is simple: if we have to allocate something, we will
589  * have to go the whole way to leaf. So let's do it before attaching anything
590  * to tree, set linkage between the newborn blocks, write them if sync is
591  * required, recheck the path, free and repeat if check fails, otherwise
592  * set the last missing link (that will protect us from any truncate-generated
593  * removals - all blocks on the path are immune now) and possibly force the
594  * write on the parent block.
595  * That has a nice additional property: no special recovery from the failed
596  * allocations is needed - we simply release blocks and do not touch anything
597  * reachable from inode.
598  *
599  * `handle' can be NULL if create == 0.
600  *
601  * return > 0, # of blocks mapped or allocated.
602  * return = 0, if plain lookup failed.
603  * return < 0, error case.
604  */
605 static int ext2_get_blocks(struct inode *inode,
606                            sector_t iblock, unsigned long maxblocks,
607                            struct buffer_head *bh_result,
608                            int create)
609 {
610         int err = -EIO;
611         int offsets[4];
612         Indirect chain[4];
613         Indirect *partial;
614         ext2_fsblk_t goal;
615         int indirect_blks;
616         int blocks_to_boundary = 0;
617         int depth;
618         struct ext2_inode_info *ei = EXT2_I(inode);
619         int count = 0;
620         ext2_fsblk_t first_block = 0;
621
622         depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
623
624         if (depth == 0)
625                 return (err);
626
627         partial = ext2_get_branch(inode, depth, offsets, chain, &err);
628         /* Simplest case - block found, no allocation needed */
629         if (!partial) {
630                 first_block = le32_to_cpu(chain[depth - 1].key);
631                 clear_buffer_new(bh_result); /* What's this do? */
632                 count++;
633                 /*map more blocks*/
634                 while (count < maxblocks && count <= blocks_to_boundary) {
635                         ext2_fsblk_t blk;
636
637                         if (!verify_chain(chain, chain + depth - 1)) {
638                                 /*
639                                  * Indirect block might be removed by
640                                  * truncate while we were reading it.
641                                  * Handling of that case: forget what we've
642                                  * got now, go to reread.
643                                  */
644                                 err = -EAGAIN;
645                                 count = 0;
646                                 break;
647                         }
648                         blk = le32_to_cpu(*(chain[depth-1].p + count));
649                         if (blk == first_block + count)
650                                 count++;
651                         else
652                                 break;
653                 }
654                 if (err != -EAGAIN)
655                         goto got_it;
656         }
657
658         /* Next simple case - plain lookup or failed read of indirect block */
659         if (!create || err == -EIO)
660                 goto cleanup;
661
662         mutex_lock(&ei->truncate_mutex);
663         /*
664          * If the indirect block is missing while we are reading
665          * the chain(ext2_get_branch() returns -EAGAIN err), or
666          * if the chain has been changed after we grab the semaphore,
667          * (either because another process truncated this branch, or
668          * another get_block allocated this branch) re-grab the chain to see if
669          * the request block has been allocated or not.
670          *
671          * Since we already block the truncate/other get_block
672          * at this point, we will have the current copy of the chain when we
673          * splice the branch into the tree.
674          */
675         if (err == -EAGAIN || !verify_chain(chain, partial)) {
676                 while (partial > chain) {
677                         brelse(partial->bh);
678                         partial--;
679                 }
680                 partial = ext2_get_branch(inode, depth, offsets, chain, &err);
681                 if (!partial) {
682                         count++;
683                         mutex_unlock(&ei->truncate_mutex);
684                         if (err)
685                                 goto cleanup;
686                         clear_buffer_new(bh_result);
687                         goto got_it;
688                 }
689         }
690
691         /*
692          * Okay, we need to do block allocation.  Lazily initialize the block
693          * allocation info here if necessary
694         */
695         if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
696                 ext2_init_block_alloc_info(inode);
697
698         goal = ext2_find_goal(inode, iblock, partial);
699
700         /* the number of blocks need to allocate for [d,t]indirect blocks */
701         indirect_blks = (chain + depth) - partial - 1;
702         /*
703          * Next look up the indirect map to count the totoal number of
704          * direct blocks to allocate for this branch.
705          */
706         count = ext2_blks_to_allocate(partial, indirect_blks,
707                                         maxblocks, blocks_to_boundary);
708         /*
709          * XXX ???? Block out ext2_truncate while we alter the tree
710          */
711         err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
712                                 offsets + (partial - chain), partial);
713
714         if (err) {
715                 mutex_unlock(&ei->truncate_mutex);
716                 goto cleanup;
717         }
718
719         if (ext2_use_xip(inode->i_sb)) {
720                 /*
721                  * we need to clear the block
722                  */
723                 err = ext2_clear_xip_target (inode,
724                         le32_to_cpu(chain[depth-1].key));
725                 if (err) {
726                         mutex_unlock(&ei->truncate_mutex);
727                         goto cleanup;
728                 }
729         }
730
731         ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
732         mutex_unlock(&ei->truncate_mutex);
733         set_buffer_new(bh_result);
734 got_it:
735         map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
736         if (count > blocks_to_boundary)
737                 set_buffer_boundary(bh_result);
738         err = count;
739         /* Clean up and exit */
740         partial = chain + depth - 1;    /* the whole chain */
741 cleanup:
742         while (partial > chain) {
743                 brelse(partial->bh);
744                 partial--;
745         }
746         return err;
747 }
748
749 int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
750 {
751         unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
752         int ret = ext2_get_blocks(inode, iblock, max_blocks,
753                               bh_result, create);
754         if (ret > 0) {
755                 bh_result->b_size = (ret << inode->i_blkbits);
756                 ret = 0;
757         }
758         return ret;
759
760 }
761
762 int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
763                 u64 start, u64 len)
764 {
765         return generic_block_fiemap(inode, fieinfo, start, len,
766                                     ext2_get_block);
767 }
768
769 static int ext2_writepage(struct page *page, struct writeback_control *wbc)
770 {
771         return block_write_full_page(page, ext2_get_block, wbc);
772 }
773
774 static int ext2_readpage(struct file *file, struct page *page)
775 {
776         return mpage_readpage(page, ext2_get_block);
777 }
778
779 static int
780 ext2_readpages(struct file *file, struct address_space *mapping,
781                 struct list_head *pages, unsigned nr_pages)
782 {
783         return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
784 }
785
786 static int
787 ext2_write_begin(struct file *file, struct address_space *mapping,
788                 loff_t pos, unsigned len, unsigned flags,
789                 struct page **pagep, void **fsdata)
790 {
791         int ret;
792
793         ret = block_write_begin(mapping, pos, len, flags, pagep,
794                                 ext2_get_block);
795         if (ret < 0)
796                 ext2_write_failed(mapping, pos + len);
797         return ret;
798 }
799
800 static int ext2_write_end(struct file *file, struct address_space *mapping,
801                         loff_t pos, unsigned len, unsigned copied,
802                         struct page *page, void *fsdata)
803 {
804         int ret;
805
806         ret = generic_write_end(file, mapping, pos, len, copied, page, fsdata);
807         if (ret < len)
808                 ext2_write_failed(mapping, pos + len);
809         return ret;
810 }
811
812 static int
813 ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
814                 loff_t pos, unsigned len, unsigned flags,
815                 struct page **pagep, void **fsdata)
816 {
817         int ret;
818
819         ret = nobh_write_begin(mapping, pos, len, flags, pagep, fsdata,
820                                ext2_get_block);
821         if (ret < 0)
822                 ext2_write_failed(mapping, pos + len);
823         return ret;
824 }
825
826 static int ext2_nobh_writepage(struct page *page,
827                         struct writeback_control *wbc)
828 {
829         return nobh_writepage(page, ext2_get_block, wbc);
830 }
831
832 static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
833 {
834         return generic_block_bmap(mapping,block,ext2_get_block);
835 }
836
837 static ssize_t
838 ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
839                         loff_t offset, unsigned long nr_segs)
840 {
841         struct file *file = iocb->ki_filp;
842         struct address_space *mapping = file->f_mapping;
843         struct inode *inode = mapping->host;
844         ssize_t ret;
845
846         ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev,
847                                 iov, offset, nr_segs, ext2_get_block, NULL);
848         if (ret < 0 && (rw & WRITE))
849                 ext2_write_failed(mapping, offset + iov_length(iov, nr_segs));
850         return ret;
851 }
852
853 static int
854 ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
855 {
856         return mpage_writepages(mapping, wbc, ext2_get_block);
857 }
858
859 const struct address_space_operations ext2_aops = {
860         .readpage               = ext2_readpage,
861         .readpages              = ext2_readpages,
862         .writepage              = ext2_writepage,
863         .write_begin            = ext2_write_begin,
864         .write_end              = ext2_write_end,
865         .bmap                   = ext2_bmap,
866         .direct_IO              = ext2_direct_IO,
867         .writepages             = ext2_writepages,
868         .migratepage            = buffer_migrate_page,
869         .is_partially_uptodate  = block_is_partially_uptodate,
870         .error_remove_page      = generic_error_remove_page,
871 };
872
873 const struct address_space_operations ext2_aops_xip = {
874         .bmap                   = ext2_bmap,
875         .get_xip_mem            = ext2_get_xip_mem,
876 };
877
878 const struct address_space_operations ext2_nobh_aops = {
879         .readpage               = ext2_readpage,
880         .readpages              = ext2_readpages,
881         .writepage              = ext2_nobh_writepage,
882         .write_begin            = ext2_nobh_write_begin,
883         .write_end              = nobh_write_end,
884         .bmap                   = ext2_bmap,
885         .direct_IO              = ext2_direct_IO,
886         .writepages             = ext2_writepages,
887         .migratepage            = buffer_migrate_page,
888         .error_remove_page      = generic_error_remove_page,
889 };
890
891 /*
892  * Probably it should be a library function... search for first non-zero word
893  * or memcmp with zero_page, whatever is better for particular architecture.
894  * Linus?
895  */
896 static inline int all_zeroes(__le32 *p, __le32 *q)
897 {
898         while (p < q)
899                 if (*p++)
900                         return 0;
901         return 1;
902 }
903
904 /**
905  *      ext2_find_shared - find the indirect blocks for partial truncation.
906  *      @inode:   inode in question
907  *      @depth:   depth of the affected branch
908  *      @offsets: offsets of pointers in that branch (see ext2_block_to_path)
909  *      @chain:   place to store the pointers to partial indirect blocks
910  *      @top:     place to the (detached) top of branch
911  *
912  *      This is a helper function used by ext2_truncate().
913  *
914  *      When we do truncate() we may have to clean the ends of several indirect
915  *      blocks but leave the blocks themselves alive. Block is partially
916  *      truncated if some data below the new i_size is referred from it (and
917  *      it is on the path to the first completely truncated data block, indeed).
918  *      We have to free the top of that path along with everything to the right
919  *      of the path. Since no allocation past the truncation point is possible
920  *      until ext2_truncate() finishes, we may safely do the latter, but top
921  *      of branch may require special attention - pageout below the truncation
922  *      point might try to populate it.
923  *
924  *      We atomically detach the top of branch from the tree, store the block
925  *      number of its root in *@top, pointers to buffer_heads of partially
926  *      truncated blocks - in @chain[].bh and pointers to their last elements
927  *      that should not be removed - in @chain[].p. Return value is the pointer
928  *      to last filled element of @chain.
929  *
930  *      The work left to caller to do the actual freeing of subtrees:
931  *              a) free the subtree starting from *@top
932  *              b) free the subtrees whose roots are stored in
933  *                      (@chain[i].p+1 .. end of @chain[i].bh->b_data)
934  *              c) free the subtrees growing from the inode past the @chain[0].p
935  *                      (no partially truncated stuff there).
936  */
937
938 static Indirect *ext2_find_shared(struct inode *inode,
939                                 int depth,
940                                 int offsets[4],
941                                 Indirect chain[4],
942                                 __le32 *top)
943 {
944         Indirect *partial, *p;
945         int k, err;
946
947         *top = 0;
948         for (k = depth; k > 1 && !offsets[k-1]; k--)
949                 ;
950         partial = ext2_get_branch(inode, k, offsets, chain, &err);
951         if (!partial)
952                 partial = chain + k-1;
953         /*
954          * If the branch acquired continuation since we've looked at it -
955          * fine, it should all survive and (new) top doesn't belong to us.
956          */
957         write_lock(&EXT2_I(inode)->i_meta_lock);
958         if (!partial->key && *partial->p) {
959                 write_unlock(&EXT2_I(inode)->i_meta_lock);
960                 goto no_top;
961         }
962         for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
963                 ;
964         /*
965          * OK, we've found the last block that must survive. The rest of our
966          * branch should be detached before unlocking. However, if that rest
967          * of branch is all ours and does not grow immediately from the inode
968          * it's easier to cheat and just decrement partial->p.
969          */
970         if (p == chain + k - 1 && p > chain) {
971                 p->p--;
972         } else {
973                 *top = *p->p;
974                 *p->p = 0;
975         }
976         write_unlock(&EXT2_I(inode)->i_meta_lock);
977
978         while(partial > p)
979         {
980                 brelse(partial->bh);
981                 partial--;
982         }
983 no_top:
984         return partial;
985 }
986
987 /**
988  *      ext2_free_data - free a list of data blocks
989  *      @inode: inode we are dealing with
990  *      @p:     array of block numbers
991  *      @q:     points immediately past the end of array
992  *
993  *      We are freeing all blocks referred from that array (numbers are
994  *      stored as little-endian 32-bit) and updating @inode->i_blocks
995  *      appropriately.
996  */
997 static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
998 {
999         unsigned long block_to_free = 0, count = 0;
1000         unsigned long nr;
1001
1002         for ( ; p < q ; p++) {
1003                 nr = le32_to_cpu(*p);
1004                 if (nr) {
1005                         *p = 0;
1006                         /* accumulate blocks to free if they're contiguous */
1007                         if (count == 0)
1008                                 goto free_this;
1009                         else if (block_to_free == nr - count)
1010                                 count++;
1011                         else {
1012                                 ext2_free_blocks (inode, block_to_free, count);
1013                                 mark_inode_dirty(inode);
1014                         free_this:
1015                                 block_to_free = nr;
1016                                 count = 1;
1017                         }
1018                 }
1019         }
1020         if (count > 0) {
1021                 ext2_free_blocks (inode, block_to_free, count);
1022                 mark_inode_dirty(inode);
1023         }
1024 }
1025
1026 /**
1027  *      ext2_free_branches - free an array of branches
1028  *      @inode: inode we are dealing with
1029  *      @p:     array of block numbers
1030  *      @q:     pointer immediately past the end of array
1031  *      @depth: depth of the branches to free
1032  *
1033  *      We are freeing all blocks referred from these branches (numbers are
1034  *      stored as little-endian 32-bit) and updating @inode->i_blocks
1035  *      appropriately.
1036  */
1037 static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
1038 {
1039         struct buffer_head * bh;
1040         unsigned long nr;
1041
1042         if (depth--) {
1043                 int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1044                 for ( ; p < q ; p++) {
1045                         nr = le32_to_cpu(*p);
1046                         if (!nr)
1047                                 continue;
1048                         *p = 0;
1049                         bh = sb_bread(inode->i_sb, nr);
1050                         /*
1051                          * A read failure? Report error and clear slot
1052                          * (should be rare).
1053                          */ 
1054                         if (!bh) {
1055                                 ext2_error(inode->i_sb, "ext2_free_branches",
1056                                         "Read failure, inode=%ld, block=%ld",
1057                                         inode->i_ino, nr);
1058                                 continue;
1059                         }
1060                         ext2_free_branches(inode,
1061                                            (__le32*)bh->b_data,
1062                                            (__le32*)bh->b_data + addr_per_block,
1063                                            depth);
1064                         bforget(bh);
1065                         ext2_free_blocks(inode, nr, 1);
1066                         mark_inode_dirty(inode);
1067                 }
1068         } else
1069                 ext2_free_data(inode, p, q);
1070 }
1071
1072 static void __ext2_truncate_blocks(struct inode *inode, loff_t offset)
1073 {
1074         __le32 *i_data = EXT2_I(inode)->i_data;
1075         struct ext2_inode_info *ei = EXT2_I(inode);
1076         int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1077         int offsets[4];
1078         Indirect chain[4];
1079         Indirect *partial;
1080         __le32 nr = 0;
1081         int n;
1082         long iblock;
1083         unsigned blocksize;
1084         blocksize = inode->i_sb->s_blocksize;
1085         iblock = (offset + blocksize-1) >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
1086
1087         n = ext2_block_to_path(inode, iblock, offsets, NULL);
1088         if (n == 0)
1089                 return;
1090
1091         /*
1092          * From here we block out all ext2_get_block() callers who want to
1093          * modify the block allocation tree.
1094          */
1095         mutex_lock(&ei->truncate_mutex);
1096
1097         if (n == 1) {
1098                 ext2_free_data(inode, i_data+offsets[0],
1099                                         i_data + EXT2_NDIR_BLOCKS);
1100                 goto do_indirects;
1101         }
1102
1103         partial = ext2_find_shared(inode, n, offsets, chain, &nr);
1104         /* Kill the top of shared branch (already detached) */
1105         if (nr) {
1106                 if (partial == chain)
1107                         mark_inode_dirty(inode);
1108                 else
1109                         mark_buffer_dirty_inode(partial->bh, inode);
1110                 ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
1111         }
1112         /* Clear the ends of indirect blocks on the shared branch */
1113         while (partial > chain) {
1114                 ext2_free_branches(inode,
1115                                    partial->p + 1,
1116                                    (__le32*)partial->bh->b_data+addr_per_block,
1117                                    (chain+n-1) - partial);
1118                 mark_buffer_dirty_inode(partial->bh, inode);
1119                 brelse (partial->bh);
1120                 partial--;
1121         }
1122 do_indirects:
1123         /* Kill the remaining (whole) subtrees */
1124         switch (offsets[0]) {
1125                 default:
1126                         nr = i_data[EXT2_IND_BLOCK];
1127                         if (nr) {
1128                                 i_data[EXT2_IND_BLOCK] = 0;
1129                                 mark_inode_dirty(inode);
1130                                 ext2_free_branches(inode, &nr, &nr+1, 1);
1131                         }
1132                 case EXT2_IND_BLOCK:
1133                         nr = i_data[EXT2_DIND_BLOCK];
1134                         if (nr) {
1135                                 i_data[EXT2_DIND_BLOCK] = 0;
1136                                 mark_inode_dirty(inode);
1137                                 ext2_free_branches(inode, &nr, &nr+1, 2);
1138                         }
1139                 case EXT2_DIND_BLOCK:
1140                         nr = i_data[EXT2_TIND_BLOCK];
1141                         if (nr) {
1142                                 i_data[EXT2_TIND_BLOCK] = 0;
1143                                 mark_inode_dirty(inode);
1144                                 ext2_free_branches(inode, &nr, &nr+1, 3);
1145                         }
1146                 case EXT2_TIND_BLOCK:
1147                         ;
1148         }
1149
1150         ext2_discard_reservation(inode);
1151
1152         mutex_unlock(&ei->truncate_mutex);
1153 }
1154
1155 static void ext2_truncate_blocks(struct inode *inode, loff_t offset)
1156 {
1157         /*
1158          * XXX: it seems like a bug here that we don't allow
1159          * IS_APPEND inode to have blocks-past-i_size trimmed off.
1160          * review and fix this.
1161          *
1162          * Also would be nice to be able to handle IO errors and such,
1163          * but that's probably too much to ask.
1164          */
1165         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1166             S_ISLNK(inode->i_mode)))
1167                 return;
1168         if (ext2_inode_is_fast_symlink(inode))
1169                 return;
1170         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1171                 return;
1172         __ext2_truncate_blocks(inode, offset);
1173 }
1174
1175 static int ext2_setsize(struct inode *inode, loff_t newsize)
1176 {
1177         int error;
1178
1179         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1180             S_ISLNK(inode->i_mode)))
1181                 return -EINVAL;
1182         if (ext2_inode_is_fast_symlink(inode))
1183                 return -EINVAL;
1184         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1185                 return -EPERM;
1186
1187         if (mapping_is_xip(inode->i_mapping))
1188                 error = xip_truncate_page(inode->i_mapping, newsize);
1189         else if (test_opt(inode->i_sb, NOBH))
1190                 error = nobh_truncate_page(inode->i_mapping,
1191                                 newsize, ext2_get_block);
1192         else
1193                 error = block_truncate_page(inode->i_mapping,
1194                                 newsize, ext2_get_block);
1195         if (error)
1196                 return error;
1197
1198         truncate_setsize(inode, newsize);
1199         __ext2_truncate_blocks(inode, newsize);
1200
1201         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
1202         if (inode_needs_sync(inode)) {
1203                 sync_mapping_buffers(inode->i_mapping);
1204                 sync_inode_metadata(inode, 1);
1205         } else {
1206                 mark_inode_dirty(inode);
1207         }
1208
1209         return 0;
1210 }
1211
1212 static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1213                                         struct buffer_head **p)
1214 {
1215         struct buffer_head * bh;
1216         unsigned long block_group;
1217         unsigned long block;
1218         unsigned long offset;
1219         struct ext2_group_desc * gdp;
1220
1221         *p = NULL;
1222         if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1223             ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1224                 goto Einval;
1225
1226         block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1227         gdp = ext2_get_group_desc(sb, block_group, NULL);
1228         if (!gdp)
1229                 goto Egdp;
1230         /*
1231          * Figure out the offset within the block group inode table
1232          */
1233         offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1234         block = le32_to_cpu(gdp->bg_inode_table) +
1235                 (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1236         if (!(bh = sb_bread(sb, block)))
1237                 goto Eio;
1238
1239         *p = bh;
1240         offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1241         return (struct ext2_inode *) (bh->b_data + offset);
1242
1243 Einval:
1244         ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1245                    (unsigned long) ino);
1246         return ERR_PTR(-EINVAL);
1247 Eio:
1248         ext2_error(sb, "ext2_get_inode",
1249                    "unable to read inode block - inode=%lu, block=%lu",
1250                    (unsigned long) ino, block);
1251 Egdp:
1252         return ERR_PTR(-EIO);
1253 }
1254
1255 void ext2_set_inode_flags(struct inode *inode)
1256 {
1257         unsigned int flags = EXT2_I(inode)->i_flags;
1258
1259         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
1260         if (flags & EXT2_SYNC_FL)
1261                 inode->i_flags |= S_SYNC;
1262         if (flags & EXT2_APPEND_FL)
1263                 inode->i_flags |= S_APPEND;
1264         if (flags & EXT2_IMMUTABLE_FL)
1265                 inode->i_flags |= S_IMMUTABLE;
1266         if (flags & EXT2_NOATIME_FL)
1267                 inode->i_flags |= S_NOATIME;
1268         if (flags & EXT2_DIRSYNC_FL)
1269                 inode->i_flags |= S_DIRSYNC;
1270 }
1271
1272 /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
1273 void ext2_get_inode_flags(struct ext2_inode_info *ei)
1274 {
1275         unsigned int flags = ei->vfs_inode.i_flags;
1276
1277         ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
1278                         EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
1279         if (flags & S_SYNC)
1280                 ei->i_flags |= EXT2_SYNC_FL;
1281         if (flags & S_APPEND)
1282                 ei->i_flags |= EXT2_APPEND_FL;
1283         if (flags & S_IMMUTABLE)
1284                 ei->i_flags |= EXT2_IMMUTABLE_FL;
1285         if (flags & S_NOATIME)
1286                 ei->i_flags |= EXT2_NOATIME_FL;
1287         if (flags & S_DIRSYNC)
1288                 ei->i_flags |= EXT2_DIRSYNC_FL;
1289 }
1290
1291 struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
1292 {
1293         struct ext2_inode_info *ei;
1294         struct buffer_head * bh;
1295         struct ext2_inode *raw_inode;
1296         struct inode *inode;
1297         long ret = -EIO;
1298         int n;
1299
1300         inode = iget_locked(sb, ino);
1301         if (!inode)
1302                 return ERR_PTR(-ENOMEM);
1303         if (!(inode->i_state & I_NEW))
1304                 return inode;
1305
1306         ei = EXT2_I(inode);
1307         ei->i_block_alloc_info = NULL;
1308
1309         raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1310         if (IS_ERR(raw_inode)) {
1311                 ret = PTR_ERR(raw_inode);
1312                 goto bad_inode;
1313         }
1314
1315         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1316         inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1317         inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1318         if (!(test_opt (inode->i_sb, NO_UID32))) {
1319                 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1320                 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1321         }
1322         inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
1323         inode->i_size = le32_to_cpu(raw_inode->i_size);
1324         inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
1325         inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
1326         inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
1327         inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1328         ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1329         /* We now have enough fields to check if the inode was active or not.
1330          * This is needed because nfsd might try to access dead inodes
1331          * the test is that same one that e2fsck uses
1332          * NeilBrown 1999oct15
1333          */
1334         if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
1335                 /* this inode is deleted */
1336                 brelse (bh);
1337                 ret = -ESTALE;
1338                 goto bad_inode;
1339         }
1340         inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1341         ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1342         ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1343         ei->i_frag_no = raw_inode->i_frag;
1344         ei->i_frag_size = raw_inode->i_fsize;
1345         ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1346         ei->i_dir_acl = 0;
1347         if (S_ISREG(inode->i_mode))
1348                 inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1349         else
1350                 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1351         ei->i_dtime = 0;
1352         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1353         ei->i_state = 0;
1354         ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1355         ei->i_dir_start_lookup = 0;
1356
1357         /*
1358          * NOTE! The in-memory inode i_data array is in little-endian order
1359          * even on big-endian machines: we do NOT byteswap the block numbers!
1360          */
1361         for (n = 0; n < EXT2_N_BLOCKS; n++)
1362                 ei->i_data[n] = raw_inode->i_block[n];
1363
1364         if (S_ISREG(inode->i_mode)) {
1365                 inode->i_op = &ext2_file_inode_operations;
1366                 if (ext2_use_xip(inode->i_sb)) {
1367                         inode->i_mapping->a_ops = &ext2_aops_xip;
1368                         inode->i_fop = &ext2_xip_file_operations;
1369                 } else if (test_opt(inode->i_sb, NOBH)) {
1370                         inode->i_mapping->a_ops = &ext2_nobh_aops;
1371                         inode->i_fop = &ext2_file_operations;
1372                 } else {
1373                         inode->i_mapping->a_ops = &ext2_aops;
1374                         inode->i_fop = &ext2_file_operations;
1375                 }
1376         } else if (S_ISDIR(inode->i_mode)) {
1377                 inode->i_op = &ext2_dir_inode_operations;
1378                 inode->i_fop = &ext2_dir_operations;
1379                 if (test_opt(inode->i_sb, NOBH))
1380                         inode->i_mapping->a_ops = &ext2_nobh_aops;
1381                 else
1382                         inode->i_mapping->a_ops = &ext2_aops;
1383         } else if (S_ISLNK(inode->i_mode)) {
1384                 if (ext2_inode_is_fast_symlink(inode)) {
1385                         inode->i_op = &ext2_fast_symlink_inode_operations;
1386                         nd_terminate_link(ei->i_data, inode->i_size,
1387                                 sizeof(ei->i_data) - 1);
1388                 } else {
1389                         inode->i_op = &ext2_symlink_inode_operations;
1390                         if (test_opt(inode->i_sb, NOBH))
1391                                 inode->i_mapping->a_ops = &ext2_nobh_aops;
1392                         else
1393                                 inode->i_mapping->a_ops = &ext2_aops;
1394                 }
1395         } else {
1396                 inode->i_op = &ext2_special_inode_operations;
1397                 if (raw_inode->i_block[0])
1398                         init_special_inode(inode, inode->i_mode,
1399                            old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1400                 else 
1401                         init_special_inode(inode, inode->i_mode,
1402                            new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1403         }
1404         brelse (bh);
1405         ext2_set_inode_flags(inode);
1406         unlock_new_inode(inode);
1407         return inode;
1408         
1409 bad_inode:
1410         iget_failed(inode);
1411         return ERR_PTR(ret);
1412 }
1413
1414 static int __ext2_write_inode(struct inode *inode, int do_sync)
1415 {
1416         struct ext2_inode_info *ei = EXT2_I(inode);
1417         struct super_block *sb = inode->i_sb;
1418         ino_t ino = inode->i_ino;
1419         uid_t uid = inode->i_uid;
1420         gid_t gid = inode->i_gid;
1421         struct buffer_head * bh;
1422         struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1423         int n;
1424         int err = 0;
1425
1426         if (IS_ERR(raw_inode))
1427                 return -EIO;
1428
1429         /* For fields not not tracking in the in-memory inode,
1430          * initialise them to zero for new inodes. */
1431         if (ei->i_state & EXT2_STATE_NEW)
1432                 memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1433
1434         ext2_get_inode_flags(ei);
1435         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1436         if (!(test_opt(sb, NO_UID32))) {
1437                 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1438                 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1439 /*
1440  * Fix up interoperability with old kernels. Otherwise, old inodes get
1441  * re-used with the upper 16 bits of the uid/gid intact
1442  */
1443                 if (!ei->i_dtime) {
1444                         raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1445                         raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1446                 } else {
1447                         raw_inode->i_uid_high = 0;
1448                         raw_inode->i_gid_high = 0;
1449                 }
1450         } else {
1451                 raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1452                 raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1453                 raw_inode->i_uid_high = 0;
1454                 raw_inode->i_gid_high = 0;
1455         }
1456         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1457         raw_inode->i_size = cpu_to_le32(inode->i_size);
1458         raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1459         raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1460         raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1461
1462         raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1463         raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1464         raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1465         raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1466         raw_inode->i_frag = ei->i_frag_no;
1467         raw_inode->i_fsize = ei->i_frag_size;
1468         raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1469         if (!S_ISREG(inode->i_mode))
1470                 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1471         else {
1472                 raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1473                 if (inode->i_size > 0x7fffffffULL) {
1474                         if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1475                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1476                             EXT2_SB(sb)->s_es->s_rev_level ==
1477                                         cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1478                                /* If this is the first large file
1479                                 * created, add a flag to the superblock.
1480                                 */
1481                                 spin_lock(&EXT2_SB(sb)->s_lock);
1482                                 ext2_update_dynamic_rev(sb);
1483                                 EXT2_SET_RO_COMPAT_FEATURE(sb,
1484                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1485                                 spin_unlock(&EXT2_SB(sb)->s_lock);
1486                                 ext2_write_super(sb);
1487                         }
1488                 }
1489         }
1490         
1491         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1492         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1493                 if (old_valid_dev(inode->i_rdev)) {
1494                         raw_inode->i_block[0] =
1495                                 cpu_to_le32(old_encode_dev(inode->i_rdev));
1496                         raw_inode->i_block[1] = 0;
1497                 } else {
1498                         raw_inode->i_block[0] = 0;
1499                         raw_inode->i_block[1] =
1500                                 cpu_to_le32(new_encode_dev(inode->i_rdev));
1501                         raw_inode->i_block[2] = 0;
1502                 }
1503         } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1504                 raw_inode->i_block[n] = ei->i_data[n];
1505         mark_buffer_dirty(bh);
1506         if (do_sync) {
1507                 sync_dirty_buffer(bh);
1508                 if (buffer_req(bh) && !buffer_uptodate(bh)) {
1509                         printk ("IO error syncing ext2 inode [%s:%08lx]\n",
1510                                 sb->s_id, (unsigned long) ino);
1511                         err = -EIO;
1512                 }
1513         }
1514         ei->i_state &= ~EXT2_STATE_NEW;
1515         brelse (bh);
1516         return err;
1517 }
1518
1519 int ext2_write_inode(struct inode *inode, struct writeback_control *wbc)
1520 {
1521         return __ext2_write_inode(inode, wbc->sync_mode == WB_SYNC_ALL);
1522 }
1523
1524 int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
1525 {
1526         struct inode *inode = dentry->d_inode;
1527         int error;
1528
1529         error = inode_change_ok(inode, iattr);
1530         if (error)
1531                 return error;
1532
1533         if (is_quota_modification(inode, iattr))
1534                 dquot_initialize(inode);
1535         if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
1536             (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
1537                 error = dquot_transfer(inode, iattr);
1538                 if (error)
1539                         return error;
1540         }
1541         if (iattr->ia_valid & ATTR_SIZE && iattr->ia_size != inode->i_size) {
1542                 error = ext2_setsize(inode, iattr->ia_size);
1543                 if (error)
1544                         return error;
1545         }
1546         setattr_copy(inode, iattr);
1547         if (iattr->ia_valid & ATTR_MODE)
1548                 error = ext2_acl_chmod(inode);
1549         mark_inode_dirty(inode);
1550
1551         return error;
1552 }