[PATCH] ext3: inode numbers are unsigned long
[linux-2.6.git] / fs / ext3 / inode.c
1 /*
2  *  linux/fs/ext3/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@redhat.com), 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 ext3_get_block() by Al Viro, 2000
23  */
24
25 #include <linux/module.h>
26 #include <linux/fs.h>
27 #include <linux/time.h>
28 #include <linux/ext3_jbd.h>
29 #include <linux/jbd.h>
30 #include <linux/smp_lock.h>
31 #include <linux/highuid.h>
32 #include <linux/pagemap.h>
33 #include <linux/quotaops.h>
34 #include <linux/string.h>
35 #include <linux/buffer_head.h>
36 #include <linux/writeback.h>
37 #include <linux/mpage.h>
38 #include <linux/uio.h>
39 #include "xattr.h"
40 #include "acl.h"
41
42 static int ext3_writepage_trans_blocks(struct inode *inode);
43
44 /*
45  * Test whether an inode is a fast symlink.
46  */
47 static int ext3_inode_is_fast_symlink(struct inode *inode)
48 {
49         int ea_blocks = EXT3_I(inode)->i_file_acl ?
50                 (inode->i_sb->s_blocksize >> 9) : 0;
51
52         return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
53 }
54
55 /*
56  * The ext3 forget function must perform a revoke if we are freeing data
57  * which has been journaled.  Metadata (eg. indirect blocks) must be
58  * revoked in all cases.
59  *
60  * "bh" may be NULL: a metadata block may have been freed from memory
61  * but there may still be a record of it in the journal, and that record
62  * still needs to be revoked.
63  */
64 int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
65                         struct buffer_head *bh, ext3_fsblk_t blocknr)
66 {
67         int err;
68
69         might_sleep();
70
71         BUFFER_TRACE(bh, "enter");
72
73         jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
74                   "data mode %lx\n",
75                   bh, is_metadata, inode->i_mode,
76                   test_opt(inode->i_sb, DATA_FLAGS));
77
78         /* Never use the revoke function if we are doing full data
79          * journaling: there is no need to, and a V1 superblock won't
80          * support it.  Otherwise, only skip the revoke on un-journaled
81          * data blocks. */
82
83         if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
84             (!is_metadata && !ext3_should_journal_data(inode))) {
85                 if (bh) {
86                         BUFFER_TRACE(bh, "call journal_forget");
87                         return ext3_journal_forget(handle, bh);
88                 }
89                 return 0;
90         }
91
92         /*
93          * data!=journal && (is_metadata || should_journal_data(inode))
94          */
95         BUFFER_TRACE(bh, "call ext3_journal_revoke");
96         err = ext3_journal_revoke(handle, blocknr, bh);
97         if (err)
98                 ext3_abort(inode->i_sb, __FUNCTION__,
99                            "error %d when attempting revoke", err);
100         BUFFER_TRACE(bh, "exit");
101         return err;
102 }
103
104 /*
105  * Work out how many blocks we need to proceed with the next chunk of a
106  * truncate transaction.
107  */
108 static unsigned long blocks_for_truncate(struct inode *inode)
109 {
110         unsigned long needed;
111
112         needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
113
114         /* Give ourselves just enough room to cope with inodes in which
115          * i_blocks is corrupt: we've seen disk corruptions in the past
116          * which resulted in random data in an inode which looked enough
117          * like a regular file for ext3 to try to delete it.  Things
118          * will go a bit crazy if that happens, but at least we should
119          * try not to panic the whole kernel. */
120         if (needed < 2)
121                 needed = 2;
122
123         /* But we need to bound the transaction so we don't overflow the
124          * journal. */
125         if (needed > EXT3_MAX_TRANS_DATA)
126                 needed = EXT3_MAX_TRANS_DATA;
127
128         return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
129 }
130
131 /*
132  * Truncate transactions can be complex and absolutely huge.  So we need to
133  * be able to restart the transaction at a conventient checkpoint to make
134  * sure we don't overflow the journal.
135  *
136  * start_transaction gets us a new handle for a truncate transaction,
137  * and extend_transaction tries to extend the existing one a bit.  If
138  * extend fails, we need to propagate the failure up and restart the
139  * transaction in the top-level truncate loop. --sct
140  */
141 static handle_t *start_transaction(struct inode *inode)
142 {
143         handle_t *result;
144
145         result = ext3_journal_start(inode, blocks_for_truncate(inode));
146         if (!IS_ERR(result))
147                 return result;
148
149         ext3_std_error(inode->i_sb, PTR_ERR(result));
150         return result;
151 }
152
153 /*
154  * Try to extend this transaction for the purposes of truncation.
155  *
156  * Returns 0 if we managed to create more room.  If we can't create more
157  * room, and the transaction must be restarted we return 1.
158  */
159 static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
160 {
161         if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
162                 return 0;
163         if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
164                 return 0;
165         return 1;
166 }
167
168 /*
169  * Restart the transaction associated with *handle.  This does a commit,
170  * so before we call here everything must be consistently dirtied against
171  * this transaction.
172  */
173 static int ext3_journal_test_restart(handle_t *handle, struct inode *inode)
174 {
175         jbd_debug(2, "restarting handle %p\n", handle);
176         return ext3_journal_restart(handle, blocks_for_truncate(inode));
177 }
178
179 /*
180  * Called at the last iput() if i_nlink is zero.
181  */
182 void ext3_delete_inode (struct inode * inode)
183 {
184         handle_t *handle;
185
186         truncate_inode_pages(&inode->i_data, 0);
187
188         if (is_bad_inode(inode))
189                 goto no_delete;
190
191         handle = start_transaction(inode);
192         if (IS_ERR(handle)) {
193                 /*
194                  * If we're going to skip the normal cleanup, we still need to
195                  * make sure that the in-core orphan linked list is properly
196                  * cleaned up.
197                  */
198                 ext3_orphan_del(NULL, inode);
199                 goto no_delete;
200         }
201
202         if (IS_SYNC(inode))
203                 handle->h_sync = 1;
204         inode->i_size = 0;
205         if (inode->i_blocks)
206                 ext3_truncate(inode);
207         /*
208          * Kill off the orphan record which ext3_truncate created.
209          * AKPM: I think this can be inside the above `if'.
210          * Note that ext3_orphan_del() has to be able to cope with the
211          * deletion of a non-existent orphan - this is because we don't
212          * know if ext3_truncate() actually created an orphan record.
213          * (Well, we could do this if we need to, but heck - it works)
214          */
215         ext3_orphan_del(handle, inode);
216         EXT3_I(inode)->i_dtime  = get_seconds();
217
218         /*
219          * One subtle ordering requirement: if anything has gone wrong
220          * (transaction abort, IO errors, whatever), then we can still
221          * do these next steps (the fs will already have been marked as
222          * having errors), but we can't free the inode if the mark_dirty
223          * fails.
224          */
225         if (ext3_mark_inode_dirty(handle, inode))
226                 /* If that failed, just do the required in-core inode clear. */
227                 clear_inode(inode);
228         else
229                 ext3_free_inode(handle, inode);
230         ext3_journal_stop(handle);
231         return;
232 no_delete:
233         clear_inode(inode);     /* We must guarantee clearing of inode... */
234 }
235
236 typedef struct {
237         __le32  *p;
238         __le32  key;
239         struct buffer_head *bh;
240 } Indirect;
241
242 static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
243 {
244         p->key = *(p->p = v);
245         p->bh = bh;
246 }
247
248 static int verify_chain(Indirect *from, Indirect *to)
249 {
250         while (from <= to && from->key == *from->p)
251                 from++;
252         return (from > to);
253 }
254
255 /**
256  *      ext3_block_to_path - parse the block number into array of offsets
257  *      @inode: inode in question (we are only interested in its superblock)
258  *      @i_block: block number to be parsed
259  *      @offsets: array to store the offsets in
260  *      @boundary: set this non-zero if the referred-to block is likely to be
261  *             followed (on disk) by an indirect block.
262  *
263  *      To store the locations of file's data ext3 uses a data structure common
264  *      for UNIX filesystems - tree of pointers anchored in the inode, with
265  *      data blocks at leaves and indirect blocks in intermediate nodes.
266  *      This function translates the block number into path in that tree -
267  *      return value is the path length and @offsets[n] is the offset of
268  *      pointer to (n+1)th node in the nth one. If @block is out of range
269  *      (negative or too large) warning is printed and zero returned.
270  *
271  *      Note: function doesn't find node addresses, so no IO is needed. All
272  *      we need to know is the capacity of indirect blocks (taken from the
273  *      inode->i_sb).
274  */
275
276 /*
277  * Portability note: the last comparison (check that we fit into triple
278  * indirect block) is spelled differently, because otherwise on an
279  * architecture with 32-bit longs and 8Kb pages we might get into trouble
280  * if our filesystem had 8Kb blocks. We might use long long, but that would
281  * kill us on x86. Oh, well, at least the sign propagation does not matter -
282  * i_block would have to be negative in the very beginning, so we would not
283  * get there at all.
284  */
285
286 static int ext3_block_to_path(struct inode *inode,
287                         long i_block, int offsets[4], int *boundary)
288 {
289         int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
290         int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
291         const long direct_blocks = EXT3_NDIR_BLOCKS,
292                 indirect_blocks = ptrs,
293                 double_blocks = (1 << (ptrs_bits * 2));
294         int n = 0;
295         int final = 0;
296
297         if (i_block < 0) {
298                 ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
299         } else if (i_block < direct_blocks) {
300                 offsets[n++] = i_block;
301                 final = direct_blocks;
302         } else if ( (i_block -= direct_blocks) < indirect_blocks) {
303                 offsets[n++] = EXT3_IND_BLOCK;
304                 offsets[n++] = i_block;
305                 final = ptrs;
306         } else if ((i_block -= indirect_blocks) < double_blocks) {
307                 offsets[n++] = EXT3_DIND_BLOCK;
308                 offsets[n++] = i_block >> ptrs_bits;
309                 offsets[n++] = i_block & (ptrs - 1);
310                 final = ptrs;
311         } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
312                 offsets[n++] = EXT3_TIND_BLOCK;
313                 offsets[n++] = i_block >> (ptrs_bits * 2);
314                 offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
315                 offsets[n++] = i_block & (ptrs - 1);
316                 final = ptrs;
317         } else {
318                 ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
319         }
320         if (boundary)
321                 *boundary = final - 1 - (i_block & (ptrs - 1));
322         return n;
323 }
324
325 /**
326  *      ext3_get_branch - read the chain of indirect blocks leading to data
327  *      @inode: inode in question
328  *      @depth: depth of the chain (1 - direct pointer, etc.)
329  *      @offsets: offsets of pointers in inode/indirect blocks
330  *      @chain: place to store the result
331  *      @err: here we store the error value
332  *
333  *      Function fills the array of triples <key, p, bh> and returns %NULL
334  *      if everything went OK or the pointer to the last filled triple
335  *      (incomplete one) otherwise. Upon the return chain[i].key contains
336  *      the number of (i+1)-th block in the chain (as it is stored in memory,
337  *      i.e. little-endian 32-bit), chain[i].p contains the address of that
338  *      number (it points into struct inode for i==0 and into the bh->b_data
339  *      for i>0) and chain[i].bh points to the buffer_head of i-th indirect
340  *      block for i>0 and NULL for i==0. In other words, it holds the block
341  *      numbers of the chain, addresses they were taken from (and where we can
342  *      verify that chain did not change) and buffer_heads hosting these
343  *      numbers.
344  *
345  *      Function stops when it stumbles upon zero pointer (absent block)
346  *              (pointer to last triple returned, *@err == 0)
347  *      or when it gets an IO error reading an indirect block
348  *              (ditto, *@err == -EIO)
349  *      or when it notices that chain had been changed while it was reading
350  *              (ditto, *@err == -EAGAIN)
351  *      or when it reads all @depth-1 indirect blocks successfully and finds
352  *      the whole chain, all way to the data (returns %NULL, *err == 0).
353  */
354 static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
355                                  Indirect chain[4], int *err)
356 {
357         struct super_block *sb = inode->i_sb;
358         Indirect *p = chain;
359         struct buffer_head *bh;
360
361         *err = 0;
362         /* i_data is not going away, no lock needed */
363         add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
364         if (!p->key)
365                 goto no_block;
366         while (--depth) {
367                 bh = sb_bread(sb, le32_to_cpu(p->key));
368                 if (!bh)
369                         goto failure;
370                 /* Reader: pointers */
371                 if (!verify_chain(chain, p))
372                         goto changed;
373                 add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
374                 /* Reader: end */
375                 if (!p->key)
376                         goto no_block;
377         }
378         return NULL;
379
380 changed:
381         brelse(bh);
382         *err = -EAGAIN;
383         goto no_block;
384 failure:
385         *err = -EIO;
386 no_block:
387         return p;
388 }
389
390 /**
391  *      ext3_find_near - find a place for allocation with sufficient locality
392  *      @inode: owner
393  *      @ind: descriptor of indirect block.
394  *
395  *      This function returns the prefered place for block allocation.
396  *      It is used when heuristic for sequential allocation fails.
397  *      Rules are:
398  *        + if there is a block to the left of our position - allocate near it.
399  *        + if pointer will live in indirect block - allocate near that block.
400  *        + if pointer will live in inode - allocate in the same
401  *          cylinder group.
402  *
403  * In the latter case we colour the starting block by the callers PID to
404  * prevent it from clashing with concurrent allocations for a different inode
405  * in the same block group.   The PID is used here so that functionally related
406  * files will be close-by on-disk.
407  *
408  *      Caller must make sure that @ind is valid and will stay that way.
409  */
410 static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
411 {
412         struct ext3_inode_info *ei = EXT3_I(inode);
413         __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
414         __le32 *p;
415         ext3_fsblk_t bg_start;
416         ext3_grpblk_t colour;
417
418         /* Try to find previous block */
419         for (p = ind->p - 1; p >= start; p--) {
420                 if (*p)
421                         return le32_to_cpu(*p);
422         }
423
424         /* No such thing, so let's try location of indirect block */
425         if (ind->bh)
426                 return ind->bh->b_blocknr;
427
428         /*
429          * It is going to be referred to from the inode itself? OK, just put it
430          * into the same cylinder group then.
431          */
432         bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
433         colour = (current->pid % 16) *
434                         (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
435         return bg_start + colour;
436 }
437
438 /**
439  *      ext3_find_goal - find a prefered place for allocation.
440  *      @inode: owner
441  *      @block:  block we want
442  *      @chain:  chain of indirect blocks
443  *      @partial: pointer to the last triple within a chain
444  *      @goal:  place to store the result.
445  *
446  *      Normally this function find the prefered place for block allocation,
447  *      stores it in *@goal and returns zero.
448  */
449
450 static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
451                 Indirect chain[4], Indirect *partial)
452 {
453         struct ext3_block_alloc_info *block_i;
454
455         block_i =  EXT3_I(inode)->i_block_alloc_info;
456
457         /*
458          * try the heuristic for sequential allocation,
459          * failing that at least try to get decent locality.
460          */
461         if (block_i && (block == block_i->last_alloc_logical_block + 1)
462                 && (block_i->last_alloc_physical_block != 0)) {
463                 return block_i->last_alloc_physical_block + 1;
464         }
465
466         return ext3_find_near(inode, partial);
467 }
468
469 /**
470  *      ext3_blks_to_allocate: Look up the block map and count the number
471  *      of direct blocks need to be allocated for the given branch.
472  *
473  *      @branch: chain of indirect blocks
474  *      @k: number of blocks need for indirect blocks
475  *      @blks: number of data blocks to be mapped.
476  *      @blocks_to_boundary:  the offset in the indirect block
477  *
478  *      return the total number of blocks to be allocate, including the
479  *      direct and indirect blocks.
480  */
481 static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
482                 int blocks_to_boundary)
483 {
484         unsigned long count = 0;
485
486         /*
487          * Simple case, [t,d]Indirect block(s) has not allocated yet
488          * then it's clear blocks on that path have not allocated
489          */
490         if (k > 0) {
491                 /* right now we don't handle cross boundary allocation */
492                 if (blks < blocks_to_boundary + 1)
493                         count += blks;
494                 else
495                         count += blocks_to_boundary + 1;
496                 return count;
497         }
498
499         count++;
500         while (count < blks && count <= blocks_to_boundary &&
501                 le32_to_cpu(*(branch[0].p + count)) == 0) {
502                 count++;
503         }
504         return count;
505 }
506
507 /**
508  *      ext3_alloc_blocks: multiple allocate blocks needed for a branch
509  *      @indirect_blks: the number of blocks need to allocate for indirect
510  *                      blocks
511  *
512  *      @new_blocks: on return it will store the new block numbers for
513  *      the indirect blocks(if needed) and the first direct block,
514  *      @blks:  on return it will store the total number of allocated
515  *              direct blocks
516  */
517 static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
518                         ext3_fsblk_t goal, int indirect_blks, int blks,
519                         ext3_fsblk_t new_blocks[4], int *err)
520 {
521         int target, i;
522         unsigned long count = 0;
523         int index = 0;
524         ext3_fsblk_t current_block = 0;
525         int ret = 0;
526
527         /*
528          * Here we try to allocate the requested multiple blocks at once,
529          * on a best-effort basis.
530          * To build a branch, we should allocate blocks for
531          * the indirect blocks(if not allocated yet), and at least
532          * the first direct block of this branch.  That's the
533          * minimum number of blocks need to allocate(required)
534          */
535         target = blks + indirect_blks;
536
537         while (1) {
538                 count = target;
539                 /* allocating blocks for indirect blocks and direct blocks */
540                 current_block = ext3_new_blocks(handle,inode,goal,&count,err);
541                 if (*err)
542                         goto failed_out;
543
544                 target -= count;
545                 /* allocate blocks for indirect blocks */
546                 while (index < indirect_blks && count) {
547                         new_blocks[index++] = current_block++;
548                         count--;
549                 }
550
551                 if (count > 0)
552                         break;
553         }
554
555         /* save the new block number for the first direct block */
556         new_blocks[index] = current_block;
557
558         /* total number of blocks allocated for direct blocks */
559         ret = count;
560         *err = 0;
561         return ret;
562 failed_out:
563         for (i = 0; i <index; i++)
564                 ext3_free_blocks(handle, inode, new_blocks[i], 1);
565         return ret;
566 }
567
568 /**
569  *      ext3_alloc_branch - allocate and set up a chain of blocks.
570  *      @inode: owner
571  *      @indirect_blks: number of allocated indirect blocks
572  *      @blks: number of allocated direct blocks
573  *      @offsets: offsets (in the blocks) to store the pointers to next.
574  *      @branch: place to store the chain in.
575  *
576  *      This function allocates blocks, zeroes out all but the last one,
577  *      links them into chain and (if we are synchronous) writes them to disk.
578  *      In other words, it prepares a branch that can be spliced onto the
579  *      inode. It stores the information about that chain in the branch[], in
580  *      the same format as ext3_get_branch() would do. We are calling it after
581  *      we had read the existing part of chain and partial points to the last
582  *      triple of that (one with zero ->key). Upon the exit we have the same
583  *      picture as after the successful ext3_get_block(), except that in one
584  *      place chain is disconnected - *branch->p is still zero (we did not
585  *      set the last link), but branch->key contains the number that should
586  *      be placed into *branch->p to fill that gap.
587  *
588  *      If allocation fails we free all blocks we've allocated (and forget
589  *      their buffer_heads) and return the error value the from failed
590  *      ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
591  *      as described above and return 0.
592  */
593 static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
594                         int indirect_blks, int *blks, ext3_fsblk_t goal,
595                         int *offsets, Indirect *branch)
596 {
597         int blocksize = inode->i_sb->s_blocksize;
598         int i, n = 0;
599         int err = 0;
600         struct buffer_head *bh;
601         int num;
602         ext3_fsblk_t new_blocks[4];
603         ext3_fsblk_t current_block;
604
605         num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
606                                 *blks, new_blocks, &err);
607         if (err)
608                 return err;
609
610         branch[0].key = cpu_to_le32(new_blocks[0]);
611         /*
612          * metadata blocks and data blocks are allocated.
613          */
614         for (n = 1; n <= indirect_blks;  n++) {
615                 /*
616                  * Get buffer_head for parent block, zero it out
617                  * and set the pointer to new one, then send
618                  * parent to disk.
619                  */
620                 bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
621                 branch[n].bh = bh;
622                 lock_buffer(bh);
623                 BUFFER_TRACE(bh, "call get_create_access");
624                 err = ext3_journal_get_create_access(handle, bh);
625                 if (err) {
626                         unlock_buffer(bh);
627                         brelse(bh);
628                         goto failed;
629                 }
630
631                 memset(bh->b_data, 0, blocksize);
632                 branch[n].p = (__le32 *) bh->b_data + offsets[n];
633                 branch[n].key = cpu_to_le32(new_blocks[n]);
634                 *branch[n].p = branch[n].key;
635                 if ( n == indirect_blks) {
636                         current_block = new_blocks[n];
637                         /*
638                          * End of chain, update the last new metablock of
639                          * the chain to point to the new allocated
640                          * data blocks numbers
641                          */
642                         for (i=1; i < num; i++)
643                                 *(branch[n].p + i) = cpu_to_le32(++current_block);
644                 }
645                 BUFFER_TRACE(bh, "marking uptodate");
646                 set_buffer_uptodate(bh);
647                 unlock_buffer(bh);
648
649                 BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
650                 err = ext3_journal_dirty_metadata(handle, bh);
651                 if (err)
652                         goto failed;
653         }
654         *blks = num;
655         return err;
656 failed:
657         /* Allocation failed, free what we already allocated */
658         for (i = 1; i <= n ; i++) {
659                 BUFFER_TRACE(branch[i].bh, "call journal_forget");
660                 ext3_journal_forget(handle, branch[i].bh);
661         }
662         for (i = 0; i <indirect_blks; i++)
663                 ext3_free_blocks(handle, inode, new_blocks[i], 1);
664
665         ext3_free_blocks(handle, inode, new_blocks[i], num);
666
667         return err;
668 }
669
670 /**
671  * ext3_splice_branch - splice the allocated branch onto inode.
672  * @inode: owner
673  * @block: (logical) number of block we are adding
674  * @chain: chain of indirect blocks (with a missing link - see
675  *      ext3_alloc_branch)
676  * @where: location of missing link
677  * @num:   number of indirect blocks we are adding
678  * @blks:  number of direct blocks we are adding
679  *
680  * This function fills the missing link and does all housekeeping needed in
681  * inode (->i_blocks, etc.). In case of success we end up with the full
682  * chain to new block and return 0.
683  */
684 static int ext3_splice_branch(handle_t *handle, struct inode *inode,
685                         long block, Indirect *where, int num, int blks)
686 {
687         int i;
688         int err = 0;
689         struct ext3_block_alloc_info *block_i;
690         ext3_fsblk_t current_block;
691
692         block_i = EXT3_I(inode)->i_block_alloc_info;
693         /*
694          * If we're splicing into a [td]indirect block (as opposed to the
695          * inode) then we need to get write access to the [td]indirect block
696          * before the splice.
697          */
698         if (where->bh) {
699                 BUFFER_TRACE(where->bh, "get_write_access");
700                 err = ext3_journal_get_write_access(handle, where->bh);
701                 if (err)
702                         goto err_out;
703         }
704         /* That's it */
705
706         *where->p = where->key;
707
708         /*
709          * Update the host buffer_head or inode to point to more just allocated
710          * direct blocks blocks
711          */
712         if (num == 0 && blks > 1) {
713                 current_block = le32_to_cpu(where->key) + 1;
714                 for (i = 1; i < blks; i++)
715                         *(where->p + i ) = cpu_to_le32(current_block++);
716         }
717
718         /*
719          * update the most recently allocated logical & physical block
720          * in i_block_alloc_info, to assist find the proper goal block for next
721          * allocation
722          */
723         if (block_i) {
724                 block_i->last_alloc_logical_block = block + blks - 1;
725                 block_i->last_alloc_physical_block =
726                                 le32_to_cpu(where[num].key) + blks - 1;
727         }
728
729         /* We are done with atomic stuff, now do the rest of housekeeping */
730
731         inode->i_ctime = CURRENT_TIME_SEC;
732         ext3_mark_inode_dirty(handle, inode);
733
734         /* had we spliced it onto indirect block? */
735         if (where->bh) {
736                 /*
737                  * If we spliced it onto an indirect block, we haven't
738                  * altered the inode.  Note however that if it is being spliced
739                  * onto an indirect block at the very end of the file (the
740                  * file is growing) then we *will* alter the inode to reflect
741                  * the new i_size.  But that is not done here - it is done in
742                  * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
743                  */
744                 jbd_debug(5, "splicing indirect only\n");
745                 BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
746                 err = ext3_journal_dirty_metadata(handle, where->bh);
747                 if (err)
748                         goto err_out;
749         } else {
750                 /*
751                  * OK, we spliced it into the inode itself on a direct block.
752                  * Inode was dirtied above.
753                  */
754                 jbd_debug(5, "splicing direct\n");
755         }
756         return err;
757
758 err_out:
759         for (i = 1; i <= num; i++) {
760                 BUFFER_TRACE(where[i].bh, "call journal_forget");
761                 ext3_journal_forget(handle, where[i].bh);
762                 ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
763         }
764         ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
765
766         return err;
767 }
768
769 /*
770  * Allocation strategy is simple: if we have to allocate something, we will
771  * have to go the whole way to leaf. So let's do it before attaching anything
772  * to tree, set linkage between the newborn blocks, write them if sync is
773  * required, recheck the path, free and repeat if check fails, otherwise
774  * set the last missing link (that will protect us from any truncate-generated
775  * removals - all blocks on the path are immune now) and possibly force the
776  * write on the parent block.
777  * That has a nice additional property: no special recovery from the failed
778  * allocations is needed - we simply release blocks and do not touch anything
779  * reachable from inode.
780  *
781  * `handle' can be NULL if create == 0.
782  *
783  * The BKL may not be held on entry here.  Be sure to take it early.
784  * return > 0, # of blocks mapped or allocated.
785  * return = 0, if plain lookup failed.
786  * return < 0, error case.
787  */
788 int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
789                 sector_t iblock, unsigned long maxblocks,
790                 struct buffer_head *bh_result,
791                 int create, int extend_disksize)
792 {
793         int err = -EIO;
794         int offsets[4];
795         Indirect chain[4];
796         Indirect *partial;
797         ext3_fsblk_t goal;
798         int indirect_blks;
799         int blocks_to_boundary = 0;
800         int depth;
801         struct ext3_inode_info *ei = EXT3_I(inode);
802         int count = 0;
803         ext3_fsblk_t first_block = 0;
804
805
806         J_ASSERT(handle != NULL || create == 0);
807         depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
808
809         if (depth == 0)
810                 goto out;
811
812         partial = ext3_get_branch(inode, depth, offsets, chain, &err);
813
814         /* Simplest case - block found, no allocation needed */
815         if (!partial) {
816                 first_block = le32_to_cpu(chain[depth - 1].key);
817                 clear_buffer_new(bh_result);
818                 count++;
819                 /*map more blocks*/
820                 while (count < maxblocks && count <= blocks_to_boundary) {
821                         ext3_fsblk_t blk;
822
823                         if (!verify_chain(chain, partial)) {
824                                 /*
825                                  * Indirect block might be removed by
826                                  * truncate while we were reading it.
827                                  * Handling of that case: forget what we've
828                                  * got now. Flag the err as EAGAIN, so it
829                                  * will reread.
830                                  */
831                                 err = -EAGAIN;
832                                 count = 0;
833                                 break;
834                         }
835                         blk = le32_to_cpu(*(chain[depth-1].p + count));
836
837                         if (blk == first_block + count)
838                                 count++;
839                         else
840                                 break;
841                 }
842                 if (err != -EAGAIN)
843                         goto got_it;
844         }
845
846         /* Next simple case - plain lookup or failed read of indirect block */
847         if (!create || err == -EIO)
848                 goto cleanup;
849
850         mutex_lock(&ei->truncate_mutex);
851
852         /*
853          * If the indirect block is missing while we are reading
854          * the chain(ext3_get_branch() returns -EAGAIN err), or
855          * if the chain has been changed after we grab the semaphore,
856          * (either because another process truncated this branch, or
857          * another get_block allocated this branch) re-grab the chain to see if
858          * the request block has been allocated or not.
859          *
860          * Since we already block the truncate/other get_block
861          * at this point, we will have the current copy of the chain when we
862          * splice the branch into the tree.
863          */
864         if (err == -EAGAIN || !verify_chain(chain, partial)) {
865                 while (partial > chain) {
866                         brelse(partial->bh);
867                         partial--;
868                 }
869                 partial = ext3_get_branch(inode, depth, offsets, chain, &err);
870                 if (!partial) {
871                         count++;
872                         mutex_unlock(&ei->truncate_mutex);
873                         if (err)
874                                 goto cleanup;
875                         clear_buffer_new(bh_result);
876                         goto got_it;
877                 }
878         }
879
880         /*
881          * Okay, we need to do block allocation.  Lazily initialize the block
882          * allocation info here if necessary
883         */
884         if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
885                 ext3_init_block_alloc_info(inode);
886
887         goal = ext3_find_goal(inode, iblock, chain, partial);
888
889         /* the number of blocks need to allocate for [d,t]indirect blocks */
890         indirect_blks = (chain + depth) - partial - 1;
891
892         /*
893          * Next look up the indirect map to count the totoal number of
894          * direct blocks to allocate for this branch.
895          */
896         count = ext3_blks_to_allocate(partial, indirect_blks,
897                                         maxblocks, blocks_to_boundary);
898         /*
899          * Block out ext3_truncate while we alter the tree
900          */
901         err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
902                                 offsets + (partial - chain), partial);
903
904         /*
905          * The ext3_splice_branch call will free and forget any buffers
906          * on the new chain if there is a failure, but that risks using
907          * up transaction credits, especially for bitmaps where the
908          * credits cannot be returned.  Can we handle this somehow?  We
909          * may need to return -EAGAIN upwards in the worst case.  --sct
910          */
911         if (!err)
912                 err = ext3_splice_branch(handle, inode, iblock,
913                                         partial, indirect_blks, count);
914         /*
915          * i_disksize growing is protected by truncate_mutex.  Don't forget to
916          * protect it if you're about to implement concurrent
917          * ext3_get_block() -bzzz
918         */
919         if (!err && extend_disksize && inode->i_size > ei->i_disksize)
920                 ei->i_disksize = inode->i_size;
921         mutex_unlock(&ei->truncate_mutex);
922         if (err)
923                 goto cleanup;
924
925         set_buffer_new(bh_result);
926 got_it:
927         map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
928         if (count > blocks_to_boundary)
929                 set_buffer_boundary(bh_result);
930         err = count;
931         /* Clean up and exit */
932         partial = chain + depth - 1;    /* the whole chain */
933 cleanup:
934         while (partial > chain) {
935                 BUFFER_TRACE(partial->bh, "call brelse");
936                 brelse(partial->bh);
937                 partial--;
938         }
939         BUFFER_TRACE(bh_result, "returned");
940 out:
941         return err;
942 }
943
944 #define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32)
945
946 static int ext3_get_block(struct inode *inode, sector_t iblock,
947                         struct buffer_head *bh_result, int create)
948 {
949         handle_t *handle = journal_current_handle();
950         int ret = 0;
951         unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
952
953         if (!create)
954                 goto get_block;         /* A read */
955
956         if (max_blocks == 1)
957                 goto get_block;         /* A single block get */
958
959         if (handle->h_transaction->t_state == T_LOCKED) {
960                 /*
961                  * Huge direct-io writes can hold off commits for long
962                  * periods of time.  Let this commit run.
963                  */
964                 ext3_journal_stop(handle);
965                 handle = ext3_journal_start(inode, DIO_CREDITS);
966                 if (IS_ERR(handle))
967                         ret = PTR_ERR(handle);
968                 goto get_block;
969         }
970
971         if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) {
972                 /*
973                  * Getting low on buffer credits...
974                  */
975                 ret = ext3_journal_extend(handle, DIO_CREDITS);
976                 if (ret > 0) {
977                         /*
978                          * Couldn't extend the transaction.  Start a new one.
979                          */
980                         ret = ext3_journal_restart(handle, DIO_CREDITS);
981                 }
982         }
983
984 get_block:
985         if (ret == 0) {
986                 ret = ext3_get_blocks_handle(handle, inode, iblock,
987                                         max_blocks, bh_result, create, 0);
988                 if (ret > 0) {
989                         bh_result->b_size = (ret << inode->i_blkbits);
990                         ret = 0;
991                 }
992         }
993         return ret;
994 }
995
996 /*
997  * `handle' can be NULL if create is zero
998  */
999 struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
1000                                 long block, int create, int *errp)
1001 {
1002         struct buffer_head dummy;
1003         int fatal = 0, err;
1004
1005         J_ASSERT(handle != NULL || create == 0);
1006
1007         dummy.b_state = 0;
1008         dummy.b_blocknr = -1000;
1009         buffer_trace_init(&dummy.b_history);
1010         err = ext3_get_blocks_handle(handle, inode, block, 1,
1011                                         &dummy, create, 1);
1012         /*
1013          * ext3_get_blocks_handle() returns number of blocks
1014          * mapped. 0 in case of a HOLE.
1015          */
1016         if (err > 0) {
1017                 if (err > 1)
1018                         WARN_ON(1);
1019                 err = 0;
1020         }
1021         *errp = err;
1022         if (!err && buffer_mapped(&dummy)) {
1023                 struct buffer_head *bh;
1024                 bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
1025                 if (!bh) {
1026                         *errp = -EIO;
1027                         goto err;
1028                 }
1029                 if (buffer_new(&dummy)) {
1030                         J_ASSERT(create != 0);
1031                         J_ASSERT(handle != 0);
1032
1033                         /*
1034                          * Now that we do not always journal data, we should
1035                          * keep in mind whether this should always journal the
1036                          * new buffer as metadata.  For now, regular file
1037                          * writes use ext3_get_block instead, so it's not a
1038                          * problem.
1039                          */
1040                         lock_buffer(bh);
1041                         BUFFER_TRACE(bh, "call get_create_access");
1042                         fatal = ext3_journal_get_create_access(handle, bh);
1043                         if (!fatal && !buffer_uptodate(bh)) {
1044                                 memset(bh->b_data,0,inode->i_sb->s_blocksize);
1045                                 set_buffer_uptodate(bh);
1046                         }
1047                         unlock_buffer(bh);
1048                         BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1049                         err = ext3_journal_dirty_metadata(handle, bh);
1050                         if (!fatal)
1051                                 fatal = err;
1052                 } else {
1053                         BUFFER_TRACE(bh, "not a new buffer");
1054                 }
1055                 if (fatal) {
1056                         *errp = fatal;
1057                         brelse(bh);
1058                         bh = NULL;
1059                 }
1060                 return bh;
1061         }
1062 err:
1063         return NULL;
1064 }
1065
1066 struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
1067                                int block, int create, int *err)
1068 {
1069         struct buffer_head * bh;
1070
1071         bh = ext3_getblk(handle, inode, block, create, err);
1072         if (!bh)
1073                 return bh;
1074         if (buffer_uptodate(bh))
1075                 return bh;
1076         ll_rw_block(READ, 1, &bh);
1077         wait_on_buffer(bh);
1078         if (buffer_uptodate(bh))
1079                 return bh;
1080         put_bh(bh);
1081         *err = -EIO;
1082         return NULL;
1083 }
1084
1085 static int walk_page_buffers(   handle_t *handle,
1086                                 struct buffer_head *head,
1087                                 unsigned from,
1088                                 unsigned to,
1089                                 int *partial,
1090                                 int (*fn)(      handle_t *handle,
1091                                                 struct buffer_head *bh))
1092 {
1093         struct buffer_head *bh;
1094         unsigned block_start, block_end;
1095         unsigned blocksize = head->b_size;
1096         int err, ret = 0;
1097         struct buffer_head *next;
1098
1099         for (   bh = head, block_start = 0;
1100                 ret == 0 && (bh != head || !block_start);
1101                 block_start = block_end, bh = next)
1102         {
1103                 next = bh->b_this_page;
1104                 block_end = block_start + blocksize;
1105                 if (block_end <= from || block_start >= to) {
1106                         if (partial && !buffer_uptodate(bh))
1107                                 *partial = 1;
1108                         continue;
1109                 }
1110                 err = (*fn)(handle, bh);
1111                 if (!ret)
1112                         ret = err;
1113         }
1114         return ret;
1115 }
1116
1117 /*
1118  * To preserve ordering, it is essential that the hole instantiation and
1119  * the data write be encapsulated in a single transaction.  We cannot
1120  * close off a transaction and start a new one between the ext3_get_block()
1121  * and the commit_write().  So doing the journal_start at the start of
1122  * prepare_write() is the right place.
1123  *
1124  * Also, this function can nest inside ext3_writepage() ->
1125  * block_write_full_page(). In that case, we *know* that ext3_writepage()
1126  * has generated enough buffer credits to do the whole page.  So we won't
1127  * block on the journal in that case, which is good, because the caller may
1128  * be PF_MEMALLOC.
1129  *
1130  * By accident, ext3 can be reentered when a transaction is open via
1131  * quota file writes.  If we were to commit the transaction while thus
1132  * reentered, there can be a deadlock - we would be holding a quota
1133  * lock, and the commit would never complete if another thread had a
1134  * transaction open and was blocking on the quota lock - a ranking
1135  * violation.
1136  *
1137  * So what we do is to rely on the fact that journal_stop/journal_start
1138  * will _not_ run commit under these circumstances because handle->h_ref
1139  * is elevated.  We'll still have enough credits for the tiny quotafile
1140  * write.
1141  */
1142 static int do_journal_get_write_access(handle_t *handle,
1143                                         struct buffer_head *bh)
1144 {
1145         if (!buffer_mapped(bh) || buffer_freed(bh))
1146                 return 0;
1147         return ext3_journal_get_write_access(handle, bh);
1148 }
1149
1150 static int ext3_prepare_write(struct file *file, struct page *page,
1151                               unsigned from, unsigned to)
1152 {
1153         struct inode *inode = page->mapping->host;
1154         int ret, needed_blocks = ext3_writepage_trans_blocks(inode);
1155         handle_t *handle;
1156         int retries = 0;
1157
1158 retry:
1159         handle = ext3_journal_start(inode, needed_blocks);
1160         if (IS_ERR(handle)) {
1161                 ret = PTR_ERR(handle);
1162                 goto out;
1163         }
1164         if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1165                 ret = nobh_prepare_write(page, from, to, ext3_get_block);
1166         else
1167                 ret = block_prepare_write(page, from, to, ext3_get_block);
1168         if (ret)
1169                 goto prepare_write_failed;
1170
1171         if (ext3_should_journal_data(inode)) {
1172                 ret = walk_page_buffers(handle, page_buffers(page),
1173                                 from, to, NULL, do_journal_get_write_access);
1174         }
1175 prepare_write_failed:
1176         if (ret)
1177                 ext3_journal_stop(handle);
1178         if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
1179                 goto retry;
1180 out:
1181         return ret;
1182 }
1183
1184 int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
1185 {
1186         int err = journal_dirty_data(handle, bh);
1187         if (err)
1188                 ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__,
1189                                                 bh, handle,err);
1190         return err;
1191 }
1192
1193 /* For commit_write() in data=journal mode */
1194 static int commit_write_fn(handle_t *handle, struct buffer_head *bh)
1195 {
1196         if (!buffer_mapped(bh) || buffer_freed(bh))
1197                 return 0;
1198         set_buffer_uptodate(bh);
1199         return ext3_journal_dirty_metadata(handle, bh);
1200 }
1201
1202 /*
1203  * We need to pick up the new inode size which generic_commit_write gave us
1204  * `file' can be NULL - eg, when called from page_symlink().
1205  *
1206  * ext3 never places buffers on inode->i_mapping->private_list.  metadata
1207  * buffers are managed internally.
1208  */
1209 static int ext3_ordered_commit_write(struct file *file, struct page *page,
1210                              unsigned from, unsigned to)
1211 {
1212         handle_t *handle = ext3_journal_current_handle();
1213         struct inode *inode = page->mapping->host;
1214         int ret = 0, ret2;
1215
1216         ret = walk_page_buffers(handle, page_buffers(page),
1217                 from, to, NULL, ext3_journal_dirty_data);
1218
1219         if (ret == 0) {
1220                 /*
1221                  * generic_commit_write() will run mark_inode_dirty() if i_size
1222                  * changes.  So let's piggyback the i_disksize mark_inode_dirty
1223                  * into that.
1224                  */
1225                 loff_t new_i_size;
1226
1227                 new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1228                 if (new_i_size > EXT3_I(inode)->i_disksize)
1229                         EXT3_I(inode)->i_disksize = new_i_size;
1230                 ret = generic_commit_write(file, page, from, to);
1231         }
1232         ret2 = ext3_journal_stop(handle);
1233         if (!ret)
1234                 ret = ret2;
1235         return ret;
1236 }
1237
1238 static int ext3_writeback_commit_write(struct file *file, struct page *page,
1239                              unsigned from, unsigned to)
1240 {
1241         handle_t *handle = ext3_journal_current_handle();
1242         struct inode *inode = page->mapping->host;
1243         int ret = 0, ret2;
1244         loff_t new_i_size;
1245
1246         new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1247         if (new_i_size > EXT3_I(inode)->i_disksize)
1248                 EXT3_I(inode)->i_disksize = new_i_size;
1249
1250         if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1251                 ret = nobh_commit_write(file, page, from, to);
1252         else
1253                 ret = generic_commit_write(file, page, from, to);
1254
1255         ret2 = ext3_journal_stop(handle);
1256         if (!ret)
1257                 ret = ret2;
1258         return ret;
1259 }
1260
1261 static int ext3_journalled_commit_write(struct file *file,
1262                         struct page *page, unsigned from, unsigned to)
1263 {
1264         handle_t *handle = ext3_journal_current_handle();
1265         struct inode *inode = page->mapping->host;
1266         int ret = 0, ret2;
1267         int partial = 0;
1268         loff_t pos;
1269
1270         /*
1271          * Here we duplicate the generic_commit_write() functionality
1272          */
1273         pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to;
1274
1275         ret = walk_page_buffers(handle, page_buffers(page), from,
1276                                 to, &partial, commit_write_fn);
1277         if (!partial)
1278                 SetPageUptodate(page);
1279         if (pos > inode->i_size)
1280                 i_size_write(inode, pos);
1281         EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1282         if (inode->i_size > EXT3_I(inode)->i_disksize) {
1283                 EXT3_I(inode)->i_disksize = inode->i_size;
1284                 ret2 = ext3_mark_inode_dirty(handle, inode);
1285                 if (!ret)
1286                         ret = ret2;
1287         }
1288         ret2 = ext3_journal_stop(handle);
1289         if (!ret)
1290                 ret = ret2;
1291         return ret;
1292 }
1293
1294 /*
1295  * bmap() is special.  It gets used by applications such as lilo and by
1296  * the swapper to find the on-disk block of a specific piece of data.
1297  *
1298  * Naturally, this is dangerous if the block concerned is still in the
1299  * journal.  If somebody makes a swapfile on an ext3 data-journaling
1300  * filesystem and enables swap, then they may get a nasty shock when the
1301  * data getting swapped to that swapfile suddenly gets overwritten by
1302  * the original zero's written out previously to the journal and
1303  * awaiting writeback in the kernel's buffer cache.
1304  *
1305  * So, if we see any bmap calls here on a modified, data-journaled file,
1306  * take extra steps to flush any blocks which might be in the cache.
1307  */
1308 static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
1309 {
1310         struct inode *inode = mapping->host;
1311         journal_t *journal;
1312         int err;
1313
1314         if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) {
1315                 /*
1316                  * This is a REALLY heavyweight approach, but the use of
1317                  * bmap on dirty files is expected to be extremely rare:
1318                  * only if we run lilo or swapon on a freshly made file
1319                  * do we expect this to happen.
1320                  *
1321                  * (bmap requires CAP_SYS_RAWIO so this does not
1322                  * represent an unprivileged user DOS attack --- we'd be
1323                  * in trouble if mortal users could trigger this path at
1324                  * will.)
1325                  *
1326                  * NB. EXT3_STATE_JDATA is not set on files other than
1327                  * regular files.  If somebody wants to bmap a directory
1328                  * or symlink and gets confused because the buffer
1329                  * hasn't yet been flushed to disk, they deserve
1330                  * everything they get.
1331                  */
1332
1333                 EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA;
1334                 journal = EXT3_JOURNAL(inode);
1335                 journal_lock_updates(journal);
1336                 err = journal_flush(journal);
1337                 journal_unlock_updates(journal);
1338
1339                 if (err)
1340                         return 0;
1341         }
1342
1343         return generic_block_bmap(mapping,block,ext3_get_block);
1344 }
1345
1346 static int bget_one(handle_t *handle, struct buffer_head *bh)
1347 {
1348         get_bh(bh);
1349         return 0;
1350 }
1351
1352 static int bput_one(handle_t *handle, struct buffer_head *bh)
1353 {
1354         put_bh(bh);
1355         return 0;
1356 }
1357
1358 static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
1359 {
1360         if (buffer_mapped(bh))
1361                 return ext3_journal_dirty_data(handle, bh);
1362         return 0;
1363 }
1364
1365 /*
1366  * Note that we always start a transaction even if we're not journalling
1367  * data.  This is to preserve ordering: any hole instantiation within
1368  * __block_write_full_page -> ext3_get_block() should be journalled
1369  * along with the data so we don't crash and then get metadata which
1370  * refers to old data.
1371  *
1372  * In all journalling modes block_write_full_page() will start the I/O.
1373  *
1374  * Problem:
1375  *
1376  *      ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() ->
1377  *              ext3_writepage()
1378  *
1379  * Similar for:
1380  *
1381  *      ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ...
1382  *
1383  * Same applies to ext3_get_block().  We will deadlock on various things like
1384  * lock_journal and i_truncate_mutex.
1385  *
1386  * Setting PF_MEMALLOC here doesn't work - too many internal memory
1387  * allocations fail.
1388  *
1389  * 16May01: If we're reentered then journal_current_handle() will be
1390  *          non-zero. We simply *return*.
1391  *
1392  * 1 July 2001: @@@ FIXME:
1393  *   In journalled data mode, a data buffer may be metadata against the
1394  *   current transaction.  But the same file is part of a shared mapping
1395  *   and someone does a writepage() on it.
1396  *
1397  *   We will move the buffer onto the async_data list, but *after* it has
1398  *   been dirtied. So there's a small window where we have dirty data on
1399  *   BJ_Metadata.
1400  *
1401  *   Note that this only applies to the last partial page in the file.  The
1402  *   bit which block_write_full_page() uses prepare/commit for.  (That's
1403  *   broken code anyway: it's wrong for msync()).
1404  *
1405  *   It's a rare case: affects the final partial page, for journalled data
1406  *   where the file is subject to bith write() and writepage() in the same
1407  *   transction.  To fix it we'll need a custom block_write_full_page().
1408  *   We'll probably need that anyway for journalling writepage() output.
1409  *
1410  * We don't honour synchronous mounts for writepage().  That would be
1411  * disastrous.  Any write() or metadata operation will sync the fs for
1412  * us.
1413  *
1414  * AKPM2: if all the page's buffers are mapped to disk and !data=journal,
1415  * we don't need to open a transaction here.
1416  */
1417 static int ext3_ordered_writepage(struct page *page,
1418                                 struct writeback_control *wbc)
1419 {
1420         struct inode *inode = page->mapping->host;
1421         struct buffer_head *page_bufs;
1422         handle_t *handle = NULL;
1423         int ret = 0;
1424         int err;
1425
1426         J_ASSERT(PageLocked(page));
1427
1428         /*
1429          * We give up here if we're reentered, because it might be for a
1430          * different filesystem.
1431          */
1432         if (ext3_journal_current_handle())
1433                 goto out_fail;
1434
1435         handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1436
1437         if (IS_ERR(handle)) {
1438                 ret = PTR_ERR(handle);
1439                 goto out_fail;
1440         }
1441
1442         if (!page_has_buffers(page)) {
1443                 create_empty_buffers(page, inode->i_sb->s_blocksize,
1444                                 (1 << BH_Dirty)|(1 << BH_Uptodate));
1445         }
1446         page_bufs = page_buffers(page);
1447         walk_page_buffers(handle, page_bufs, 0,
1448                         PAGE_CACHE_SIZE, NULL, bget_one);
1449
1450         ret = block_write_full_page(page, ext3_get_block, wbc);
1451
1452         /*
1453          * The page can become unlocked at any point now, and
1454          * truncate can then come in and change things.  So we
1455          * can't touch *page from now on.  But *page_bufs is
1456          * safe due to elevated refcount.
1457          */
1458
1459         /*
1460          * And attach them to the current transaction.  But only if
1461          * block_write_full_page() succeeded.  Otherwise they are unmapped,
1462          * and generally junk.
1463          */
1464         if (ret == 0) {
1465                 err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
1466                                         NULL, journal_dirty_data_fn);
1467                 if (!ret)
1468                         ret = err;
1469         }
1470         walk_page_buffers(handle, page_bufs, 0,
1471                         PAGE_CACHE_SIZE, NULL, bput_one);
1472         err = ext3_journal_stop(handle);
1473         if (!ret)
1474                 ret = err;
1475         return ret;
1476
1477 out_fail:
1478         redirty_page_for_writepage(wbc, page);
1479         unlock_page(page);
1480         return ret;
1481 }
1482
1483 static int ext3_writeback_writepage(struct page *page,
1484                                 struct writeback_control *wbc)
1485 {
1486         struct inode *inode = page->mapping->host;
1487         handle_t *handle = NULL;
1488         int ret = 0;
1489         int err;
1490
1491         if (ext3_journal_current_handle())
1492                 goto out_fail;
1493
1494         handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1495         if (IS_ERR(handle)) {
1496                 ret = PTR_ERR(handle);
1497                 goto out_fail;
1498         }
1499
1500         if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode))
1501                 ret = nobh_writepage(page, ext3_get_block, wbc);
1502         else
1503                 ret = block_write_full_page(page, ext3_get_block, wbc);
1504
1505         err = ext3_journal_stop(handle);
1506         if (!ret)
1507                 ret = err;
1508         return ret;
1509
1510 out_fail:
1511         redirty_page_for_writepage(wbc, page);
1512         unlock_page(page);
1513         return ret;
1514 }
1515
1516 static int ext3_journalled_writepage(struct page *page,
1517                                 struct writeback_control *wbc)
1518 {
1519         struct inode *inode = page->mapping->host;
1520         handle_t *handle = NULL;
1521         int ret = 0;
1522         int err;
1523
1524         if (ext3_journal_current_handle())
1525                 goto no_write;
1526
1527         handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
1528         if (IS_ERR(handle)) {
1529                 ret = PTR_ERR(handle);
1530                 goto no_write;
1531         }
1532
1533         if (!page_has_buffers(page) || PageChecked(page)) {
1534                 /*
1535                  * It's mmapped pagecache.  Add buffers and journal it.  There
1536                  * doesn't seem much point in redirtying the page here.
1537                  */
1538                 ClearPageChecked(page);
1539                 ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE,
1540                                         ext3_get_block);
1541                 if (ret != 0) {
1542                         ext3_journal_stop(handle);
1543                         goto out_unlock;
1544                 }
1545                 ret = walk_page_buffers(handle, page_buffers(page), 0,
1546                         PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
1547
1548                 err = walk_page_buffers(handle, page_buffers(page), 0,
1549                                 PAGE_CACHE_SIZE, NULL, commit_write_fn);
1550                 if (ret == 0)
1551                         ret = err;
1552                 EXT3_I(inode)->i_state |= EXT3_STATE_JDATA;
1553                 unlock_page(page);
1554         } else {
1555                 /*
1556                  * It may be a page full of checkpoint-mode buffers.  We don't
1557                  * really know unless we go poke around in the buffer_heads.
1558                  * But block_write_full_page will do the right thing.
1559                  */
1560                 ret = block_write_full_page(page, ext3_get_block, wbc);
1561         }
1562         err = ext3_journal_stop(handle);
1563         if (!ret)
1564                 ret = err;
1565 out:
1566         return ret;
1567
1568 no_write:
1569         redirty_page_for_writepage(wbc, page);
1570 out_unlock:
1571         unlock_page(page);
1572         goto out;
1573 }
1574
1575 static int ext3_readpage(struct file *file, struct page *page)
1576 {
1577         return mpage_readpage(page, ext3_get_block);
1578 }
1579
1580 static int
1581 ext3_readpages(struct file *file, struct address_space *mapping,
1582                 struct list_head *pages, unsigned nr_pages)
1583 {
1584         return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
1585 }
1586
1587 static void ext3_invalidatepage(struct page *page, unsigned long offset)
1588 {
1589         journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1590
1591         /*
1592          * If it's a full truncate we just forget about the pending dirtying
1593          */
1594         if (offset == 0)
1595                 ClearPageChecked(page);
1596
1597         journal_invalidatepage(journal, page, offset);
1598 }
1599
1600 static int ext3_releasepage(struct page *page, gfp_t wait)
1601 {
1602         journal_t *journal = EXT3_JOURNAL(page->mapping->host);
1603
1604         WARN_ON(PageChecked(page));
1605         if (!page_has_buffers(page))
1606                 return 0;
1607         return journal_try_to_free_buffers(journal, page, wait);
1608 }
1609
1610 /*
1611  * If the O_DIRECT write will extend the file then add this inode to the
1612  * orphan list.  So recovery will truncate it back to the original size
1613  * if the machine crashes during the write.
1614  *
1615  * If the O_DIRECT write is intantiating holes inside i_size and the machine
1616  * crashes then stale disk data _may_ be exposed inside the file.
1617  */
1618 static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb,
1619                         const struct iovec *iov, loff_t offset,
1620                         unsigned long nr_segs)
1621 {
1622         struct file *file = iocb->ki_filp;
1623         struct inode *inode = file->f_mapping->host;
1624         struct ext3_inode_info *ei = EXT3_I(inode);
1625         handle_t *handle = NULL;
1626         ssize_t ret;
1627         int orphan = 0;
1628         size_t count = iov_length(iov, nr_segs);
1629
1630         if (rw == WRITE) {
1631                 loff_t final_size = offset + count;
1632
1633                 handle = ext3_journal_start(inode, DIO_CREDITS);
1634                 if (IS_ERR(handle)) {
1635                         ret = PTR_ERR(handle);
1636                         goto out;
1637                 }
1638                 if (final_size > inode->i_size) {
1639                         ret = ext3_orphan_add(handle, inode);
1640                         if (ret)
1641                                 goto out_stop;
1642                         orphan = 1;
1643                         ei->i_disksize = inode->i_size;
1644                 }
1645         }
1646
1647         ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
1648                                  offset, nr_segs,
1649                                  ext3_get_block, NULL);
1650
1651         /*
1652          * Reacquire the handle: ext3_get_block() can restart the transaction
1653          */
1654         handle = journal_current_handle();
1655
1656 out_stop:
1657         if (handle) {
1658                 int err;
1659
1660                 if (orphan && inode->i_nlink)
1661                         ext3_orphan_del(handle, inode);
1662                 if (orphan && ret > 0) {
1663                         loff_t end = offset + ret;
1664                         if (end > inode->i_size) {
1665                                 ei->i_disksize = end;
1666                                 i_size_write(inode, end);
1667                                 /*
1668                                  * We're going to return a positive `ret'
1669                                  * here due to non-zero-length I/O, so there's
1670                                  * no way of reporting error returns from
1671                                  * ext3_mark_inode_dirty() to userspace.  So
1672                                  * ignore it.
1673                                  */
1674                                 ext3_mark_inode_dirty(handle, inode);
1675                         }
1676                 }
1677                 err = ext3_journal_stop(handle);
1678                 if (ret == 0)
1679                         ret = err;
1680         }
1681 out:
1682         return ret;
1683 }
1684
1685 /*
1686  * Pages can be marked dirty completely asynchronously from ext3's journalling
1687  * activity.  By filemap_sync_pte(), try_to_unmap_one(), etc.  We cannot do
1688  * much here because ->set_page_dirty is called under VFS locks.  The page is
1689  * not necessarily locked.
1690  *
1691  * We cannot just dirty the page and leave attached buffers clean, because the
1692  * buffers' dirty state is "definitive".  We cannot just set the buffers dirty
1693  * or jbddirty because all the journalling code will explode.
1694  *
1695  * So what we do is to mark the page "pending dirty" and next time writepage
1696  * is called, propagate that into the buffers appropriately.
1697  */
1698 static int ext3_journalled_set_page_dirty(struct page *page)
1699 {
1700         SetPageChecked(page);
1701         return __set_page_dirty_nobuffers(page);
1702 }
1703
1704 static const struct address_space_operations ext3_ordered_aops = {
1705         .readpage       = ext3_readpage,
1706         .readpages      = ext3_readpages,
1707         .writepage      = ext3_ordered_writepage,
1708         .sync_page      = block_sync_page,
1709         .prepare_write  = ext3_prepare_write,
1710         .commit_write   = ext3_ordered_commit_write,
1711         .bmap           = ext3_bmap,
1712         .invalidatepage = ext3_invalidatepage,
1713         .releasepage    = ext3_releasepage,
1714         .direct_IO      = ext3_direct_IO,
1715         .migratepage    = buffer_migrate_page,
1716 };
1717
1718 static const struct address_space_operations ext3_writeback_aops = {
1719         .readpage       = ext3_readpage,
1720         .readpages      = ext3_readpages,
1721         .writepage      = ext3_writeback_writepage,
1722         .sync_page      = block_sync_page,
1723         .prepare_write  = ext3_prepare_write,
1724         .commit_write   = ext3_writeback_commit_write,
1725         .bmap           = ext3_bmap,
1726         .invalidatepage = ext3_invalidatepage,
1727         .releasepage    = ext3_releasepage,
1728         .direct_IO      = ext3_direct_IO,
1729         .migratepage    = buffer_migrate_page,
1730 };
1731
1732 static const struct address_space_operations ext3_journalled_aops = {
1733         .readpage       = ext3_readpage,
1734         .readpages      = ext3_readpages,
1735         .writepage      = ext3_journalled_writepage,
1736         .sync_page      = block_sync_page,
1737         .prepare_write  = ext3_prepare_write,
1738         .commit_write   = ext3_journalled_commit_write,
1739         .set_page_dirty = ext3_journalled_set_page_dirty,
1740         .bmap           = ext3_bmap,
1741         .invalidatepage = ext3_invalidatepage,
1742         .releasepage    = ext3_releasepage,
1743 };
1744
1745 void ext3_set_aops(struct inode *inode)
1746 {
1747         if (ext3_should_order_data(inode))
1748                 inode->i_mapping->a_ops = &ext3_ordered_aops;
1749         else if (ext3_should_writeback_data(inode))
1750                 inode->i_mapping->a_ops = &ext3_writeback_aops;
1751         else
1752                 inode->i_mapping->a_ops = &ext3_journalled_aops;
1753 }
1754
1755 /*
1756  * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
1757  * up to the end of the block which corresponds to `from'.
1758  * This required during truncate. We need to physically zero the tail end
1759  * of that block so it doesn't yield old data if the file is later grown.
1760  */
1761 static int ext3_block_truncate_page(handle_t *handle, struct page *page,
1762                 struct address_space *mapping, loff_t from)
1763 {
1764         ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
1765         unsigned offset = from & (PAGE_CACHE_SIZE-1);
1766         unsigned blocksize, iblock, length, pos;
1767         struct inode *inode = mapping->host;
1768         struct buffer_head *bh;
1769         int err = 0;
1770         void *kaddr;
1771
1772         blocksize = inode->i_sb->s_blocksize;
1773         length = blocksize - (offset & (blocksize - 1));
1774         iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
1775
1776         /*
1777          * For "nobh" option,  we can only work if we don't need to
1778          * read-in the page - otherwise we create buffers to do the IO.
1779          */
1780         if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) &&
1781              ext3_should_writeback_data(inode) && PageUptodate(page)) {
1782                 kaddr = kmap_atomic(page, KM_USER0);
1783                 memset(kaddr + offset, 0, length);
1784                 flush_dcache_page(page);
1785                 kunmap_atomic(kaddr, KM_USER0);
1786                 set_page_dirty(page);
1787                 goto unlock;
1788         }
1789
1790         if (!page_has_buffers(page))
1791                 create_empty_buffers(page, blocksize, 0);
1792
1793         /* Find the buffer that contains "offset" */
1794         bh = page_buffers(page);
1795         pos = blocksize;
1796         while (offset >= pos) {
1797                 bh = bh->b_this_page;
1798                 iblock++;
1799                 pos += blocksize;
1800         }
1801
1802         err = 0;
1803         if (buffer_freed(bh)) {
1804                 BUFFER_TRACE(bh, "freed: skip");
1805                 goto unlock;
1806         }
1807
1808         if (!buffer_mapped(bh)) {
1809                 BUFFER_TRACE(bh, "unmapped");
1810                 ext3_get_block(inode, iblock, bh, 0);
1811                 /* unmapped? It's a hole - nothing to do */
1812                 if (!buffer_mapped(bh)) {
1813                         BUFFER_TRACE(bh, "still unmapped");
1814                         goto unlock;
1815                 }
1816         }
1817
1818         /* Ok, it's mapped. Make sure it's up-to-date */
1819         if (PageUptodate(page))
1820                 set_buffer_uptodate(bh);
1821
1822         if (!buffer_uptodate(bh)) {
1823                 err = -EIO;
1824                 ll_rw_block(READ, 1, &bh);
1825                 wait_on_buffer(bh);
1826                 /* Uhhuh. Read error. Complain and punt. */
1827                 if (!buffer_uptodate(bh))
1828                         goto unlock;
1829         }
1830
1831         if (ext3_should_journal_data(inode)) {
1832                 BUFFER_TRACE(bh, "get write access");
1833                 err = ext3_journal_get_write_access(handle, bh);
1834                 if (err)
1835                         goto unlock;
1836         }
1837
1838         kaddr = kmap_atomic(page, KM_USER0);
1839         memset(kaddr + offset, 0, length);
1840         flush_dcache_page(page);
1841         kunmap_atomic(kaddr, KM_USER0);
1842
1843         BUFFER_TRACE(bh, "zeroed end of block");
1844
1845         err = 0;
1846         if (ext3_should_journal_data(inode)) {
1847                 err = ext3_journal_dirty_metadata(handle, bh);
1848         } else {
1849                 if (ext3_should_order_data(inode))
1850                         err = ext3_journal_dirty_data(handle, bh);
1851                 mark_buffer_dirty(bh);
1852         }
1853
1854 unlock:
1855         unlock_page(page);
1856         page_cache_release(page);
1857         return err;
1858 }
1859
1860 /*
1861  * Probably it should be a library function... search for first non-zero word
1862  * or memcmp with zero_page, whatever is better for particular architecture.
1863  * Linus?
1864  */
1865 static inline int all_zeroes(__le32 *p, __le32 *q)
1866 {
1867         while (p < q)
1868                 if (*p++)
1869                         return 0;
1870         return 1;
1871 }
1872
1873 /**
1874  *      ext3_find_shared - find the indirect blocks for partial truncation.
1875  *      @inode:   inode in question
1876  *      @depth:   depth of the affected branch
1877  *      @offsets: offsets of pointers in that branch (see ext3_block_to_path)
1878  *      @chain:   place to store the pointers to partial indirect blocks
1879  *      @top:     place to the (detached) top of branch
1880  *
1881  *      This is a helper function used by ext3_truncate().
1882  *
1883  *      When we do truncate() we may have to clean the ends of several
1884  *      indirect blocks but leave the blocks themselves alive. Block is
1885  *      partially truncated if some data below the new i_size is refered
1886  *      from it (and it is on the path to the first completely truncated
1887  *      data block, indeed).  We have to free the top of that path along
1888  *      with everything to the right of the path. Since no allocation
1889  *      past the truncation point is possible until ext3_truncate()
1890  *      finishes, we may safely do the latter, but top of branch may
1891  *      require special attention - pageout below the truncation point
1892  *      might try to populate it.
1893  *
1894  *      We atomically detach the top of branch from the tree, store the
1895  *      block number of its root in *@top, pointers to buffer_heads of
1896  *      partially truncated blocks - in @chain[].bh and pointers to
1897  *      their last elements that should not be removed - in
1898  *      @chain[].p. Return value is the pointer to last filled element
1899  *      of @chain.
1900  *
1901  *      The work left to caller to do the actual freeing of subtrees:
1902  *              a) free the subtree starting from *@top
1903  *              b) free the subtrees whose roots are stored in
1904  *                      (@chain[i].p+1 .. end of @chain[i].bh->b_data)
1905  *              c) free the subtrees growing from the inode past the @chain[0].
1906  *                      (no partially truncated stuff there).  */
1907
1908 static Indirect *ext3_find_shared(struct inode *inode, int depth,
1909                         int offsets[4], Indirect chain[4], __le32 *top)
1910 {
1911         Indirect *partial, *p;
1912         int k, err;
1913
1914         *top = 0;
1915         /* Make k index the deepest non-null offest + 1 */
1916         for (k = depth; k > 1 && !offsets[k-1]; k--)
1917                 ;
1918         partial = ext3_get_branch(inode, k, offsets, chain, &err);
1919         /* Writer: pointers */
1920         if (!partial)
1921                 partial = chain + k-1;
1922         /*
1923          * If the branch acquired continuation since we've looked at it -
1924          * fine, it should all survive and (new) top doesn't belong to us.
1925          */
1926         if (!partial->key && *partial->p)
1927                 /* Writer: end */
1928                 goto no_top;
1929         for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
1930                 ;
1931         /*
1932          * OK, we've found the last block that must survive. The rest of our
1933          * branch should be detached before unlocking. However, if that rest
1934          * of branch is all ours and does not grow immediately from the inode
1935          * it's easier to cheat and just decrement partial->p.
1936          */
1937         if (p == chain + k - 1 && p > chain) {
1938                 p->p--;
1939         } else {
1940                 *top = *p->p;
1941                 /* Nope, don't do this in ext3.  Must leave the tree intact */
1942 #if 0
1943                 *p->p = 0;
1944 #endif
1945         }
1946         /* Writer: end */
1947
1948         while(partial > p) {
1949                 brelse(partial->bh);
1950                 partial--;
1951         }
1952 no_top:
1953         return partial;
1954 }
1955
1956 /*
1957  * Zero a number of block pointers in either an inode or an indirect block.
1958  * If we restart the transaction we must again get write access to the
1959  * indirect block for further modification.
1960  *
1961  * We release `count' blocks on disk, but (last - first) may be greater
1962  * than `count' because there can be holes in there.
1963  */
1964 static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
1965                 struct buffer_head *bh, ext3_fsblk_t block_to_free,
1966                 unsigned long count, __le32 *first, __le32 *last)
1967 {
1968         __le32 *p;
1969         if (try_to_extend_transaction(handle, inode)) {
1970                 if (bh) {
1971                         BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
1972                         ext3_journal_dirty_metadata(handle, bh);
1973                 }
1974                 ext3_mark_inode_dirty(handle, inode);
1975                 ext3_journal_test_restart(handle, inode);
1976                 if (bh) {
1977                         BUFFER_TRACE(bh, "retaking write access");
1978                         ext3_journal_get_write_access(handle, bh);
1979                 }
1980         }
1981
1982         /*
1983          * Any buffers which are on the journal will be in memory. We find
1984          * them on the hash table so journal_revoke() will run journal_forget()
1985          * on them.  We've already detached each block from the file, so
1986          * bforget() in journal_forget() should be safe.
1987          *
1988          * AKPM: turn on bforget in journal_forget()!!!
1989          */
1990         for (p = first; p < last; p++) {
1991                 u32 nr = le32_to_cpu(*p);
1992                 if (nr) {
1993                         struct buffer_head *bh;
1994
1995                         *p = 0;
1996                         bh = sb_find_get_block(inode->i_sb, nr);
1997                         ext3_forget(handle, 0, inode, bh, nr);
1998                 }
1999         }
2000
2001         ext3_free_blocks(handle, inode, block_to_free, count);
2002 }
2003
2004 /**
2005  * ext3_free_data - free a list of data blocks
2006  * @handle:     handle for this transaction
2007  * @inode:      inode we are dealing with
2008  * @this_bh:    indirect buffer_head which contains *@first and *@last
2009  * @first:      array of block numbers
2010  * @last:       points immediately past the end of array
2011  *
2012  * We are freeing all blocks refered from that array (numbers are stored as
2013  * little-endian 32-bit) and updating @inode->i_blocks appropriately.
2014  *
2015  * We accumulate contiguous runs of blocks to free.  Conveniently, if these
2016  * blocks are contiguous then releasing them at one time will only affect one
2017  * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
2018  * actually use a lot of journal space.
2019  *
2020  * @this_bh will be %NULL if @first and @last point into the inode's direct
2021  * block pointers.
2022  */
2023 static void ext3_free_data(handle_t *handle, struct inode *inode,
2024                            struct buffer_head *this_bh,
2025                            __le32 *first, __le32 *last)
2026 {
2027         ext3_fsblk_t block_to_free = 0;    /* Starting block # of a run */
2028         unsigned long count = 0;            /* Number of blocks in the run */
2029         __le32 *block_to_free_p = NULL;     /* Pointer into inode/ind
2030                                                corresponding to
2031                                                block_to_free */
2032         ext3_fsblk_t nr;                    /* Current block # */
2033         __le32 *p;                          /* Pointer into inode/ind
2034                                                for current block */
2035         int err;
2036
2037         if (this_bh) {                          /* For indirect block */
2038                 BUFFER_TRACE(this_bh, "get_write_access");
2039                 err = ext3_journal_get_write_access(handle, this_bh);
2040                 /* Important: if we can't update the indirect pointers
2041                  * to the blocks, we can't free them. */
2042                 if (err)
2043                         return;
2044         }
2045
2046         for (p = first; p < last; p++) {
2047                 nr = le32_to_cpu(*p);
2048                 if (nr) {
2049                         /* accumulate blocks to free if they're contiguous */
2050                         if (count == 0) {
2051                                 block_to_free = nr;
2052                                 block_to_free_p = p;
2053                                 count = 1;
2054                         } else if (nr == block_to_free + count) {
2055                                 count++;
2056                         } else {
2057                                 ext3_clear_blocks(handle, inode, this_bh,
2058                                                   block_to_free,
2059                                                   count, block_to_free_p, p);
2060                                 block_to_free = nr;
2061                                 block_to_free_p = p;
2062                                 count = 1;
2063                         }
2064                 }
2065         }
2066
2067         if (count > 0)
2068                 ext3_clear_blocks(handle, inode, this_bh, block_to_free,
2069                                   count, block_to_free_p, p);
2070
2071         if (this_bh) {
2072                 BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
2073                 ext3_journal_dirty_metadata(handle, this_bh);
2074         }
2075 }
2076
2077 /**
2078  *      ext3_free_branches - free an array of branches
2079  *      @handle: JBD handle for this transaction
2080  *      @inode: inode we are dealing with
2081  *      @parent_bh: the buffer_head which contains *@first and *@last
2082  *      @first: array of block numbers
2083  *      @last:  pointer immediately past the end of array
2084  *      @depth: depth of the branches to free
2085  *
2086  *      We are freeing all blocks refered from these branches (numbers are
2087  *      stored as little-endian 32-bit) and updating @inode->i_blocks
2088  *      appropriately.
2089  */
2090 static void ext3_free_branches(handle_t *handle, struct inode *inode,
2091                                struct buffer_head *parent_bh,
2092                                __le32 *first, __le32 *last, int depth)
2093 {
2094         ext3_fsblk_t nr;
2095         __le32 *p;
2096
2097         if (is_handle_aborted(handle))
2098                 return;
2099
2100         if (depth--) {
2101                 struct buffer_head *bh;
2102                 int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2103                 p = last;
2104                 while (--p >= first) {
2105                         nr = le32_to_cpu(*p);
2106                         if (!nr)
2107                                 continue;               /* A hole */
2108
2109                         /* Go read the buffer for the next level down */
2110                         bh = sb_bread(inode->i_sb, nr);
2111
2112                         /*
2113                          * A read failure? Report error and clear slot
2114                          * (should be rare).
2115                          */
2116                         if (!bh) {
2117                                 ext3_error(inode->i_sb, "ext3_free_branches",
2118                                            "Read failure, inode=%lu, block="E3FSBLK,
2119                                            inode->i_ino, nr);
2120                                 continue;
2121                         }
2122
2123                         /* This zaps the entire block.  Bottom up. */
2124                         BUFFER_TRACE(bh, "free child branches");
2125                         ext3_free_branches(handle, inode, bh,
2126                                            (__le32*)bh->b_data,
2127                                            (__le32*)bh->b_data + addr_per_block,
2128                                            depth);
2129
2130                         /*
2131                          * We've probably journalled the indirect block several
2132                          * times during the truncate.  But it's no longer
2133                          * needed and we now drop it from the transaction via
2134                          * journal_revoke().
2135                          *
2136                          * That's easy if it's exclusively part of this
2137                          * transaction.  But if it's part of the committing
2138                          * transaction then journal_forget() will simply
2139                          * brelse() it.  That means that if the underlying
2140                          * block is reallocated in ext3_get_block(),
2141                          * unmap_underlying_metadata() will find this block
2142                          * and will try to get rid of it.  damn, damn.
2143                          *
2144                          * If this block has already been committed to the
2145                          * journal, a revoke record will be written.  And
2146                          * revoke records must be emitted *before* clearing
2147                          * this block's bit in the bitmaps.
2148                          */
2149                         ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
2150
2151                         /*
2152                          * Everything below this this pointer has been
2153                          * released.  Now let this top-of-subtree go.
2154                          *
2155                          * We want the freeing of this indirect block to be
2156                          * atomic in the journal with the updating of the
2157                          * bitmap block which owns it.  So make some room in
2158                          * the journal.
2159                          *
2160                          * We zero the parent pointer *after* freeing its
2161                          * pointee in the bitmaps, so if extend_transaction()
2162                          * for some reason fails to put the bitmap changes and
2163                          * the release into the same transaction, recovery
2164                          * will merely complain about releasing a free block,
2165                          * rather than leaking blocks.
2166                          */
2167                         if (is_handle_aborted(handle))
2168                                 return;
2169                         if (try_to_extend_transaction(handle, inode)) {
2170                                 ext3_mark_inode_dirty(handle, inode);
2171                                 ext3_journal_test_restart(handle, inode);
2172                         }
2173
2174                         ext3_free_blocks(handle, inode, nr, 1);
2175
2176                         if (parent_bh) {
2177                                 /*
2178                                  * The block which we have just freed is
2179                                  * pointed to by an indirect block: journal it
2180                                  */
2181                                 BUFFER_TRACE(parent_bh, "get_write_access");
2182                                 if (!ext3_journal_get_write_access(handle,
2183                                                                    parent_bh)){
2184                                         *p = 0;
2185                                         BUFFER_TRACE(parent_bh,
2186                                         "call ext3_journal_dirty_metadata");
2187                                         ext3_journal_dirty_metadata(handle,
2188                                                                     parent_bh);
2189                                 }
2190                         }
2191                 }
2192         } else {
2193                 /* We have reached the bottom of the tree. */
2194                 BUFFER_TRACE(parent_bh, "free data blocks");
2195                 ext3_free_data(handle, inode, parent_bh, first, last);
2196         }
2197 }
2198
2199 /*
2200  * ext3_truncate()
2201  *
2202  * We block out ext3_get_block() block instantiations across the entire
2203  * transaction, and VFS/VM ensures that ext3_truncate() cannot run
2204  * simultaneously on behalf of the same inode.
2205  *
2206  * As we work through the truncate and commmit bits of it to the journal there
2207  * is one core, guiding principle: the file's tree must always be consistent on
2208  * disk.  We must be able to restart the truncate after a crash.
2209  *
2210  * The file's tree may be transiently inconsistent in memory (although it
2211  * probably isn't), but whenever we close off and commit a journal transaction,
2212  * the contents of (the filesystem + the journal) must be consistent and
2213  * restartable.  It's pretty simple, really: bottom up, right to left (although
2214  * left-to-right works OK too).
2215  *
2216  * Note that at recovery time, journal replay occurs *before* the restart of
2217  * truncate against the orphan inode list.
2218  *
2219  * The committed inode has the new, desired i_size (which is the same as
2220  * i_disksize in this case).  After a crash, ext3_orphan_cleanup() will see
2221  * that this inode's truncate did not complete and it will again call
2222  * ext3_truncate() to have another go.  So there will be instantiated blocks
2223  * to the right of the truncation point in a crashed ext3 filesystem.  But
2224  * that's fine - as long as they are linked from the inode, the post-crash
2225  * ext3_truncate() run will find them and release them.
2226  */
2227 void ext3_truncate(struct inode *inode)
2228 {
2229         handle_t *handle;
2230         struct ext3_inode_info *ei = EXT3_I(inode);
2231         __le32 *i_data = ei->i_data;
2232         int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
2233         struct address_space *mapping = inode->i_mapping;
2234         int offsets[4];
2235         Indirect chain[4];
2236         Indirect *partial;
2237         __le32 nr = 0;
2238         int n;
2239         long last_block;
2240         unsigned blocksize = inode->i_sb->s_blocksize;
2241         struct page *page;
2242
2243         if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
2244             S_ISLNK(inode->i_mode)))
2245                 return;
2246         if (ext3_inode_is_fast_symlink(inode))
2247                 return;
2248         if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
2249                 return;
2250
2251         /*
2252          * We have to lock the EOF page here, because lock_page() nests
2253          * outside journal_start().
2254          */
2255         if ((inode->i_size & (blocksize - 1)) == 0) {
2256                 /* Block boundary? Nothing to do */
2257                 page = NULL;
2258         } else {
2259                 page = grab_cache_page(mapping,
2260                                 inode->i_size >> PAGE_CACHE_SHIFT);
2261                 if (!page)
2262                         return;
2263         }
2264
2265         handle = start_transaction(inode);
2266         if (IS_ERR(handle)) {
2267                 if (page) {
2268                         clear_highpage(page);
2269                         flush_dcache_page(page);
2270                         unlock_page(page);
2271                         page_cache_release(page);
2272                 }
2273                 return;         /* AKPM: return what? */
2274         }
2275
2276         last_block = (inode->i_size + blocksize-1)
2277                                         >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
2278
2279         if (page)
2280                 ext3_block_truncate_page(handle, page, mapping, inode->i_size);
2281
2282         n = ext3_block_to_path(inode, last_block, offsets, NULL);
2283         if (n == 0)
2284                 goto out_stop;  /* error */
2285
2286         /*
2287          * OK.  This truncate is going to happen.  We add the inode to the
2288          * orphan list, so that if this truncate spans multiple transactions,
2289          * and we crash, we will resume the truncate when the filesystem
2290          * recovers.  It also marks the inode dirty, to catch the new size.
2291          *
2292          * Implication: the file must always be in a sane, consistent
2293          * truncatable state while each transaction commits.
2294          */
2295         if (ext3_orphan_add(handle, inode))
2296                 goto out_stop;
2297
2298         /*
2299          * The orphan list entry will now protect us from any crash which
2300          * occurs before the truncate completes, so it is now safe to propagate
2301          * the new, shorter inode size (held for now in i_size) into the
2302          * on-disk inode. We do this via i_disksize, which is the value which
2303          * ext3 *really* writes onto the disk inode.
2304          */
2305         ei->i_disksize = inode->i_size;
2306
2307         /*
2308          * From here we block out all ext3_get_block() callers who want to
2309          * modify the block allocation tree.
2310          */
2311         mutex_lock(&ei->truncate_mutex);
2312
2313         if (n == 1) {           /* direct blocks */
2314                 ext3_free_data(handle, inode, NULL, i_data+offsets[0],
2315                                i_data + EXT3_NDIR_BLOCKS);
2316                 goto do_indirects;
2317         }
2318
2319         partial = ext3_find_shared(inode, n, offsets, chain, &nr);
2320         /* Kill the top of shared branch (not detached) */
2321         if (nr) {
2322                 if (partial == chain) {
2323                         /* Shared branch grows from the inode */
2324                         ext3_free_branches(handle, inode, NULL,
2325                                            &nr, &nr+1, (chain+n-1) - partial);
2326                         *partial->p = 0;
2327                         /*
2328                          * We mark the inode dirty prior to restart,
2329                          * and prior to stop.  No need for it here.
2330                          */
2331                 } else {
2332                         /* Shared branch grows from an indirect block */
2333                         BUFFER_TRACE(partial->bh, "get_write_access");
2334                         ext3_free_branches(handle, inode, partial->bh,
2335                                         partial->p,
2336                                         partial->p+1, (chain+n-1) - partial);
2337                 }
2338         }
2339         /* Clear the ends of indirect blocks on the shared branch */
2340         while (partial > chain) {
2341                 ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
2342                                    (__le32*)partial->bh->b_data+addr_per_block,
2343                                    (chain+n-1) - partial);
2344                 BUFFER_TRACE(partial->bh, "call brelse");
2345                 brelse (partial->bh);
2346                 partial--;
2347         }
2348 do_indirects:
2349         /* Kill the remaining (whole) subtrees */
2350         switch (offsets[0]) {
2351         default:
2352                 nr = i_data[EXT3_IND_BLOCK];
2353                 if (nr) {
2354                         ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
2355                         i_data[EXT3_IND_BLOCK] = 0;
2356                 }
2357         case EXT3_IND_BLOCK:
2358                 nr = i_data[EXT3_DIND_BLOCK];
2359                 if (nr) {
2360                         ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
2361                         i_data[EXT3_DIND_BLOCK] = 0;
2362                 }
2363         case EXT3_DIND_BLOCK:
2364                 nr = i_data[EXT3_TIND_BLOCK];
2365                 if (nr) {
2366                         ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
2367                         i_data[EXT3_TIND_BLOCK] = 0;
2368                 }
2369         case EXT3_TIND_BLOCK:
2370                 ;
2371         }
2372
2373         ext3_discard_reservation(inode);
2374
2375         mutex_unlock(&ei->truncate_mutex);
2376         inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
2377         ext3_mark_inode_dirty(handle, inode);
2378
2379         /*
2380          * In a multi-transaction truncate, we only make the final transaction
2381          * synchronous
2382          */
2383         if (IS_SYNC(inode))
2384                 handle->h_sync = 1;
2385 out_stop:
2386         /*
2387          * If this was a simple ftruncate(), and the file will remain alive
2388          * then we need to clear up the orphan record which we created above.
2389          * However, if this was a real unlink then we were called by
2390          * ext3_delete_inode(), and we allow that function to clean up the
2391          * orphan info for us.
2392          */
2393         if (inode->i_nlink)
2394                 ext3_orphan_del(handle, inode);
2395
2396         ext3_journal_stop(handle);
2397 }
2398
2399 static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
2400                 unsigned long ino, struct ext3_iloc *iloc)
2401 {
2402         unsigned long desc, group_desc, block_group;
2403         unsigned long offset;
2404         ext3_fsblk_t block;
2405         struct buffer_head *bh;
2406         struct ext3_group_desc * gdp;
2407
2408         if (!ext3_valid_inum(sb, ino)) {
2409                 /*
2410                  * This error is already checked for in namei.c unless we are
2411                  * looking at an NFS filehandle, in which case no error
2412                  * report is needed
2413                  */
2414                 return 0;
2415         }
2416
2417         block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
2418         if (block_group >= EXT3_SB(sb)->s_groups_count) {
2419                 ext3_error(sb,"ext3_get_inode_block","group >= groups count");
2420                 return 0;
2421         }
2422         smp_rmb();
2423         group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb);
2424         desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1);
2425         bh = EXT3_SB(sb)->s_group_desc[group_desc];
2426         if (!bh) {
2427                 ext3_error (sb, "ext3_get_inode_block",
2428                             "Descriptor not loaded");
2429                 return 0;
2430         }
2431
2432         gdp = (struct ext3_group_desc *)bh->b_data;
2433         /*
2434          * Figure out the offset within the block group inode table
2435          */
2436         offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
2437                 EXT3_INODE_SIZE(sb);
2438         block = le32_to_cpu(gdp[desc].bg_inode_table) +
2439                 (offset >> EXT3_BLOCK_SIZE_BITS(sb));
2440
2441         iloc->block_group = block_group;
2442         iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
2443         return block;
2444 }
2445
2446 /*
2447  * ext3_get_inode_loc returns with an extra refcount against the inode's
2448  * underlying buffer_head on success. If 'in_mem' is true, we have all
2449  * data in memory that is needed to recreate the on-disk version of this
2450  * inode.
2451  */
2452 static int __ext3_get_inode_loc(struct inode *inode,
2453                                 struct ext3_iloc *iloc, int in_mem)
2454 {
2455         ext3_fsblk_t block;
2456         struct buffer_head *bh;
2457
2458         block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
2459         if (!block)
2460                 return -EIO;
2461
2462         bh = sb_getblk(inode->i_sb, block);
2463         if (!bh) {
2464                 ext3_error (inode->i_sb, "ext3_get_inode_loc",
2465                                 "unable to read inode block - "
2466                                 "inode=%lu, block="E3FSBLK,
2467                                  inode->i_ino, block);
2468                 return -EIO;
2469         }
2470         if (!buffer_uptodate(bh)) {
2471                 lock_buffer(bh);
2472                 if (buffer_uptodate(bh)) {
2473                         /* someone brought it uptodate while we waited */
2474                         unlock_buffer(bh);
2475                         goto has_buffer;
2476                 }
2477
2478                 /*
2479                  * If we have all information of the inode in memory and this
2480                  * is the only valid inode in the block, we need not read the
2481                  * block.
2482                  */
2483                 if (in_mem) {
2484                         struct buffer_head *bitmap_bh;
2485                         struct ext3_group_desc *desc;
2486                         int inodes_per_buffer;
2487                         int inode_offset, i;
2488                         int block_group;
2489                         int start;
2490
2491                         block_group = (inode->i_ino - 1) /
2492                                         EXT3_INODES_PER_GROUP(inode->i_sb);
2493                         inodes_per_buffer = bh->b_size /
2494                                 EXT3_INODE_SIZE(inode->i_sb);
2495                         inode_offset = ((inode->i_ino - 1) %
2496                                         EXT3_INODES_PER_GROUP(inode->i_sb));
2497                         start = inode_offset & ~(inodes_per_buffer - 1);
2498
2499                         /* Is the inode bitmap in cache? */
2500                         desc = ext3_get_group_desc(inode->i_sb,
2501                                                 block_group, NULL);
2502                         if (!desc)
2503                                 goto make_io;
2504
2505                         bitmap_bh = sb_getblk(inode->i_sb,
2506                                         le32_to_cpu(desc->bg_inode_bitmap));
2507                         if (!bitmap_bh)
2508                                 goto make_io;
2509
2510                         /*
2511                          * If the inode bitmap isn't in cache then the
2512                          * optimisation may end up performing two reads instead
2513                          * of one, so skip it.
2514                          */
2515                         if (!buffer_uptodate(bitmap_bh)) {
2516                                 brelse(bitmap_bh);
2517                                 goto make_io;
2518                         }
2519                         for (i = start; i < start + inodes_per_buffer; i++) {
2520                                 if (i == inode_offset)
2521                                         continue;
2522                                 if (ext3_test_bit(i, bitmap_bh->b_data))
2523                                         break;
2524                         }
2525                         brelse(bitmap_bh);
2526                         if (i == start + inodes_per_buffer) {
2527                                 /* all other inodes are free, so skip I/O */
2528                                 memset(bh->b_data, 0, bh->b_size);
2529                                 set_buffer_uptodate(bh);
2530                                 unlock_buffer(bh);
2531                                 goto has_buffer;
2532                         }
2533                 }
2534
2535 make_io:
2536                 /*
2537                  * There are other valid inodes in the buffer, this inode
2538                  * has in-inode xattrs, or we don't have this inode in memory.
2539                  * Read the block from disk.
2540                  */
2541                 get_bh(bh);
2542                 bh->b_end_io = end_buffer_read_sync;
2543                 submit_bh(READ, bh);
2544                 wait_on_buffer(bh);
2545                 if (!buffer_uptodate(bh)) {
2546                         ext3_error(inode->i_sb, "ext3_get_inode_loc",
2547                                         "unable to read inode block - "
2548                                         "inode=%lu, block="E3FSBLK,
2549                                         inode->i_ino, block);
2550                         brelse(bh);
2551                         return -EIO;
2552                 }
2553         }
2554 has_buffer:
2555         iloc->bh = bh;
2556         return 0;
2557 }
2558
2559 int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
2560 {
2561         /* We have all inode data except xattrs in memory here. */
2562         return __ext3_get_inode_loc(inode, iloc,
2563                 !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR));
2564 }
2565
2566 void ext3_set_inode_flags(struct inode *inode)
2567 {
2568         unsigned int flags = EXT3_I(inode)->i_flags;
2569
2570         inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
2571         if (flags & EXT3_SYNC_FL)
2572                 inode->i_flags |= S_SYNC;
2573         if (flags & EXT3_APPEND_FL)
2574                 inode->i_flags |= S_APPEND;
2575         if (flags & EXT3_IMMUTABLE_FL)
2576                 inode->i_flags |= S_IMMUTABLE;
2577         if (flags & EXT3_NOATIME_FL)
2578                 inode->i_flags |= S_NOATIME;
2579         if (flags & EXT3_DIRSYNC_FL)
2580                 inode->i_flags |= S_DIRSYNC;
2581 }
2582
2583 void ext3_read_inode(struct inode * inode)
2584 {
2585         struct ext3_iloc iloc;
2586         struct ext3_inode *raw_inode;
2587         struct ext3_inode_info *ei = EXT3_I(inode);
2588         struct buffer_head *bh;
2589         int block;
2590
2591 #ifdef CONFIG_EXT3_FS_POSIX_ACL
2592         ei->i_acl = EXT3_ACL_NOT_CACHED;
2593         ei->i_default_acl = EXT3_ACL_NOT_CACHED;
2594 #endif
2595         ei->i_block_alloc_info = NULL;
2596
2597         if (__ext3_get_inode_loc(inode, &iloc, 0))
2598                 goto bad_inode;
2599         bh = iloc.bh;
2600         raw_inode = ext3_raw_inode(&iloc);
2601         inode->i_mode = le16_to_cpu(raw_inode->i_mode);
2602         inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
2603         inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
2604         if(!(test_opt (inode->i_sb, NO_UID32))) {
2605                 inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
2606                 inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
2607         }
2608         inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
2609         inode->i_size = le32_to_cpu(raw_inode->i_size);
2610         inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime);
2611         inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime);
2612         inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime);
2613         inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
2614
2615         ei->i_state = 0;
2616         ei->i_dir_start_lookup = 0;
2617         ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
2618         /* We now have enough fields to check if the inode was active or not.
2619          * This is needed because nfsd might try to access dead inodes
2620          * the test is that same one that e2fsck uses
2621          * NeilBrown 1999oct15
2622          */
2623         if (inode->i_nlink == 0) {
2624                 if (inode->i_mode == 0 ||
2625                     !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
2626                         /* this inode is deleted */
2627                         brelse (bh);
2628                         goto bad_inode;
2629                 }
2630                 /* The only unlinked inodes we let through here have
2631                  * valid i_mode and are being read by the orphan
2632                  * recovery code: that's fine, we're about to complete
2633                  * the process of deleting those. */
2634         }
2635         inode->i_blksize = PAGE_SIZE;   /* This is the optimal IO size
2636                                          * (for stat), not the fs block
2637                                          * size */  
2638         inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
2639         ei->i_flags = le32_to_cpu(raw_inode->i_flags);
2640 #ifdef EXT3_FRAGMENTS
2641         ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
2642         ei->i_frag_no = raw_inode->i_frag;
2643         ei->i_frag_size = raw_inode->i_fsize;
2644 #endif
2645         ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
2646         if (!S_ISREG(inode->i_mode)) {
2647                 ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
2648         } else {
2649                 inode->i_size |=
2650                         ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
2651         }
2652         ei->i_disksize = inode->i_size;
2653         inode->i_generation = le32_to_cpu(raw_inode->i_generation);
2654         ei->i_block_group = iloc.block_group;
2655         /*
2656          * NOTE! The in-memory inode i_data array is in little-endian order
2657          * even on big-endian machines: we do NOT byteswap the block numbers!
2658          */
2659         for (block = 0; block < EXT3_N_BLOCKS; block++)
2660                 ei->i_data[block] = raw_inode->i_block[block];
2661         INIT_LIST_HEAD(&ei->i_orphan);
2662
2663         if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
2664             EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
2665                 /*
2666                  * When mke2fs creates big inodes it does not zero out
2667                  * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
2668                  * so ignore those first few inodes.
2669                  */
2670                 ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
2671                 if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
2672                     EXT3_INODE_SIZE(inode->i_sb))
2673                         goto bad_inode;
2674                 if (ei->i_extra_isize == 0) {
2675                         /* The extra space is currently unused. Use it. */
2676                         ei->i_extra_isize = sizeof(struct ext3_inode) -
2677                                             EXT3_GOOD_OLD_INODE_SIZE;
2678                 } else {
2679                         __le32 *magic = (void *)raw_inode +
2680                                         EXT3_GOOD_OLD_INODE_SIZE +
2681                                         ei->i_extra_isize;
2682                         if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
2683                                  ei->i_state |= EXT3_STATE_XATTR;
2684                 }
2685         } else
2686                 ei->i_extra_isize = 0;
2687
2688         if (S_ISREG(inode->i_mode)) {
2689                 inode->i_op = &ext3_file_inode_operations;
2690                 inode->i_fop = &ext3_file_operations;
2691                 ext3_set_aops(inode);
2692         } else if (S_ISDIR(inode->i_mode)) {
2693                 inode->i_op = &ext3_dir_inode_operations;
2694                 inode->i_fop = &ext3_dir_operations;
2695         } else if (S_ISLNK(inode->i_mode)) {
2696                 if (ext3_inode_is_fast_symlink(inode))
2697                         inode->i_op = &ext3_fast_symlink_inode_operations;
2698                 else {
2699                         inode->i_op = &ext3_symlink_inode_operations;
2700                         ext3_set_aops(inode);
2701                 }
2702         } else {
2703                 inode->i_op = &ext3_special_inode_operations;
2704                 if (raw_inode->i_block[0])
2705                         init_special_inode(inode, inode->i_mode,
2706                            old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
2707                 else
2708                         init_special_inode(inode, inode->i_mode,
2709                            new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
2710         }
2711         brelse (iloc.bh);
2712         ext3_set_inode_flags(inode);
2713         return;
2714
2715 bad_inode:
2716         make_bad_inode(inode);
2717         return;
2718 }
2719
2720 /*
2721  * Post the struct inode info into an on-disk inode location in the
2722  * buffer-cache.  This gobbles the caller's reference to the
2723  * buffer_head in the inode location struct.
2724  *
2725  * The caller must have write access to iloc->bh.
2726  */
2727 static int ext3_do_update_inode(handle_t *handle,
2728                                 struct inode *inode,
2729                                 struct ext3_iloc *iloc)
2730 {
2731         struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
2732         struct ext3_inode_info *ei = EXT3_I(inode);
2733         struct buffer_head *bh = iloc->bh;
2734         int err = 0, rc, block;
2735
2736         /* For fields not not tracking in the in-memory inode,
2737          * initialise them to zero for new inodes. */
2738         if (ei->i_state & EXT3_STATE_NEW)
2739                 memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
2740
2741         raw_inode->i_mode = cpu_to_le16(inode->i_mode);
2742         if(!(test_opt(inode->i_sb, NO_UID32))) {
2743                 raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid));
2744                 raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid));
2745 /*
2746  * Fix up interoperability with old kernels. Otherwise, old inodes get
2747  * re-used with the upper 16 bits of the uid/gid intact
2748  */
2749                 if(!ei->i_dtime) {
2750                         raw_inode->i_uid_high =
2751                                 cpu_to_le16(high_16_bits(inode->i_uid));
2752                         raw_inode->i_gid_high =
2753                                 cpu_to_le16(high_16_bits(inode->i_gid));
2754                 } else {
2755                         raw_inode->i_uid_high = 0;
2756                         raw_inode->i_gid_high = 0;
2757                 }
2758         } else {
2759                 raw_inode->i_uid_low =
2760                         cpu_to_le16(fs_high2lowuid(inode->i_uid));
2761                 raw_inode->i_gid_low =
2762                         cpu_to_le16(fs_high2lowgid(inode->i_gid));
2763                 raw_inode->i_uid_high = 0;
2764                 raw_inode->i_gid_high = 0;
2765         }
2766         raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
2767         raw_inode->i_size = cpu_to_le32(ei->i_disksize);
2768         raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
2769         raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
2770         raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
2771         raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
2772         raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
2773         raw_inode->i_flags = cpu_to_le32(ei->i_flags);
2774 #ifdef EXT3_FRAGMENTS
2775         raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
2776         raw_inode->i_frag = ei->i_frag_no;
2777         raw_inode->i_fsize = ei->i_frag_size;
2778 #endif
2779         raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
2780         if (!S_ISREG(inode->i_mode)) {
2781                 raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
2782         } else {
2783                 raw_inode->i_size_high =
2784                         cpu_to_le32(ei->i_disksize >> 32);
2785                 if (ei->i_disksize > 0x7fffffffULL) {
2786                         struct super_block *sb = inode->i_sb;
2787                         if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
2788                                         EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
2789                             EXT3_SB(sb)->s_es->s_rev_level ==
2790                                         cpu_to_le32(EXT3_GOOD_OLD_REV)) {
2791                                /* If this is the first large file
2792                                 * created, add a flag to the superblock.
2793                                 */
2794                                 err = ext3_journal_get_write_access(handle,
2795                                                 EXT3_SB(sb)->s_sbh);
2796                                 if (err)
2797                                         goto out_brelse;
2798                                 ext3_update_dynamic_rev(sb);
2799                                 EXT3_SET_RO_COMPAT_FEATURE(sb,
2800                                         EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
2801                                 sb->s_dirt = 1;
2802                                 handle->h_sync = 1;
2803                                 err = ext3_journal_dirty_metadata(handle,
2804                                                 EXT3_SB(sb)->s_sbh);
2805                         }
2806                 }
2807         }
2808         raw_inode->i_generation = cpu_to_le32(inode->i_generation);
2809         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
2810                 if (old_valid_dev(inode->i_rdev)) {
2811                         raw_inode->i_block[0] =
2812                                 cpu_to_le32(old_encode_dev(inode->i_rdev));
2813                         raw_inode->i_block[1] = 0;
2814                 } else {
2815                         raw_inode->i_block[0] = 0;
2816                         raw_inode->i_block[1] =
2817                                 cpu_to_le32(new_encode_dev(inode->i_rdev));
2818                         raw_inode->i_block[2] = 0;
2819                 }
2820         } else for (block = 0; block < EXT3_N_BLOCKS; block++)
2821                 raw_inode->i_block[block] = ei->i_data[block];
2822
2823         if (ei->i_extra_isize)
2824                 raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
2825
2826         BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
2827         rc = ext3_journal_dirty_metadata(handle, bh);
2828         if (!err)
2829                 err = rc;
2830         ei->i_state &= ~EXT3_STATE_NEW;
2831
2832 out_brelse:
2833         brelse (bh);
2834         ext3_std_error(inode->i_sb, err);
2835         return err;
2836 }
2837
2838 /*
2839  * ext3_write_inode()
2840  *
2841  * We are called from a few places:
2842  *
2843  * - Within generic_file_write() for O_SYNC files.
2844  *   Here, there will be no transaction running. We wait for any running
2845  *   trasnaction to commit.
2846  *
2847  * - Within sys_sync(), kupdate and such.
2848  *   We wait on commit, if tol to.
2849  *
2850  * - Within prune_icache() (PF_MEMALLOC == true)
2851  *   Here we simply return.  We can't afford to block kswapd on the
2852  *   journal commit.
2853  *
2854  * In all cases it is actually safe for us to return without doing anything,
2855  * because the inode has been copied into a raw inode buffer in
2856  * ext3_mark_inode_dirty().  This is a correctness thing for O_SYNC and for
2857  * knfsd.
2858  *
2859  * Note that we are absolutely dependent upon all inode dirtiers doing the
2860  * right thing: they *must* call mark_inode_dirty() after dirtying info in
2861  * which we are interested.
2862  *
2863  * It would be a bug for them to not do this.  The code:
2864  *
2865  *      mark_inode_dirty(inode)
2866  *      stuff();
2867  *      inode->i_size = expr;
2868  *
2869  * is in error because a kswapd-driven write_inode() could occur while
2870  * `stuff()' is running, and the new i_size will be lost.  Plus the inode
2871  * will no longer be on the superblock's dirty inode list.
2872  */
2873 int ext3_write_inode(struct inode *inode, int wait)
2874 {
2875         if (current->flags & PF_MEMALLOC)
2876                 return 0;
2877
2878         if (ext3_journal_current_handle()) {
2879                 jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n");
2880                 dump_stack();
2881                 return -EIO;
2882         }
2883
2884         if (!wait)
2885                 return 0;
2886
2887         return ext3_force_commit(inode->i_sb);
2888 }
2889
2890 /*
2891  * ext3_setattr()
2892  *
2893  * Called from notify_change.
2894  *
2895  * We want to trap VFS attempts to truncate the file as soon as
2896  * possible.  In particular, we want to make sure that when the VFS
2897  * shrinks i_size, we put the inode on the orphan list and modify
2898  * i_disksize immediately, so that during the subsequent flushing of
2899  * dirty pages and freeing of disk blocks, we can guarantee that any
2900  * commit will leave the blocks being flushed in an unused state on
2901  * disk.  (On recovery, the inode will get truncated and the blocks will
2902  * be freed, so we have a strong guarantee that no future commit will
2903  * leave these blocks visible to the user.)
2904  *
2905  * Called with inode->sem down.
2906  */
2907 int ext3_setattr(struct dentry *dentry, struct iattr *attr)
2908 {
2909         struct inode *inode = dentry->d_inode;
2910         int error, rc = 0;
2911         const unsigned int ia_valid = attr->ia_valid;
2912
2913         error = inode_change_ok(inode, attr);
2914         if (error)
2915                 return error;
2916
2917         if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) ||
2918                 (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) {
2919                 handle_t *handle;
2920
2921                 /* (user+group)*(old+new) structure, inode write (sb,
2922                  * inode block, ? - but truncate inode update has it) */
2923                 handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+
2924                                         EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3);
2925                 if (IS_ERR(handle)) {
2926                         error = PTR_ERR(handle);
2927                         goto err_out;
2928                 }
2929                 error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0;
2930                 if (error) {
2931                         ext3_journal_stop(handle);
2932                         return error;
2933                 }
2934                 /* Update corresponding info in inode so that everything is in
2935                  * one transaction */
2936                 if (attr->ia_valid & ATTR_UID)
2937                         inode->i_uid = attr->ia_uid;
2938                 if (attr->ia_valid & ATTR_GID)
2939                         inode->i_gid = attr->ia_gid;
2940                 error = ext3_mark_inode_dirty(handle, inode);
2941                 ext3_journal_stop(handle);
2942         }
2943
2944         if (S_ISREG(inode->i_mode) &&
2945             attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
2946                 handle_t *handle;
2947
2948                 handle = ext3_journal_start(inode, 3);
2949                 if (IS_ERR(handle)) {
2950                         error = PTR_ERR(handle);
2951                         goto err_out;
2952                 }
2953
2954                 error = ext3_orphan_add(handle, inode);
2955                 EXT3_I(inode)->i_disksize = attr->ia_size;
2956                 rc = ext3_mark_inode_dirty(handle, inode);
2957                 if (!error)
2958                         error = rc;
2959                 ext3_journal_stop(handle);
2960         }
2961
2962         rc = inode_setattr(inode, attr);
2963
2964         /* If inode_setattr's call to ext3_truncate failed to get a
2965          * transaction handle at all, we need to clean up the in-core
2966          * orphan list manually. */
2967         if (inode->i_nlink)
2968                 ext3_orphan_del(NULL, inode);
2969
2970         if (!rc && (ia_valid & ATTR_MODE))
2971                 rc = ext3_acl_chmod(inode);
2972
2973 err_out:
2974         ext3_std_error(inode->i_sb, error);
2975         if (!error)
2976                 error = rc;
2977         return error;
2978 }
2979
2980
2981 /*
2982  * How many blocks doth make a writepage()?
2983  *
2984  * With N blocks per page, it may be:
2985  * N data blocks
2986  * 2 indirect block
2987  * 2 dindirect
2988  * 1 tindirect
2989  * N+5 bitmap blocks (from the above)
2990  * N+5 group descriptor summary blocks
2991  * 1 inode block
2992  * 1 superblock.
2993  * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
2994  *
2995  * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
2996  *
2997  * With ordered or writeback data it's the same, less the N data blocks.
2998  *
2999  * If the inode's direct blocks can hold an integral number of pages then a
3000  * page cannot straddle two indirect blocks, and we can only touch one indirect
3001  * and dindirect block, and the "5" above becomes "3".
3002  *
3003  * This still overestimates under most circumstances.  If we were to pass the
3004  * start and end offsets in here as well we could do block_to_path() on each
3005  * block and work out the exact number of indirects which are touched.  Pah.
3006  */
3007
3008 static int ext3_writepage_trans_blocks(struct inode *inode)
3009 {
3010         int bpp = ext3_journal_blocks_per_page(inode);
3011         int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
3012         int ret;
3013
3014         if (ext3_should_journal_data(inode))
3015                 ret = 3 * (bpp + indirects) + 2;
3016         else
3017                 ret = 2 * (bpp + indirects) + 2;
3018
3019 #ifdef CONFIG_QUOTA
3020         /* We know that structure was already allocated during DQUOT_INIT so
3021          * we will be updating only the data blocks + inodes */
3022         ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb);
3023 #endif
3024
3025         return ret;
3026 }
3027
3028 /*
3029  * The caller must have previously called ext3_reserve_inode_write().
3030  * Give this, we know that the caller already has write access to iloc->bh.
3031  */
3032 int ext3_mark_iloc_dirty(handle_t *handle,
3033                 struct inode *inode, struct ext3_iloc *iloc)
3034 {
3035         int err = 0;
3036
3037         /* the do_update_inode consumes one bh->b_count */
3038         get_bh(iloc->bh);
3039
3040         /* ext3_do_update_inode() does journal_dirty_metadata */
3041         err = ext3_do_update_inode(handle, inode, iloc);
3042         put_bh(iloc->bh);
3043         return err;
3044 }
3045
3046 /*
3047  * On success, We end up with an outstanding reference count against
3048  * iloc->bh.  This _must_ be cleaned up later.
3049  */
3050
3051 int
3052 ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
3053                          struct ext3_iloc *iloc)
3054 {
3055         int err = 0;
3056         if (handle) {
3057                 err = ext3_get_inode_loc(inode, iloc);
3058                 if (!err) {
3059                         BUFFER_TRACE(iloc->bh, "get_write_access");
3060                         err = ext3_journal_get_write_access(handle, iloc->bh);
3061                         if (err) {
3062                                 brelse(iloc->bh);
3063                                 iloc->bh = NULL;
3064                         }
3065                 }
3066         }
3067         ext3_std_error(inode->i_sb, err);
3068         return err;
3069 }
3070
3071 /*
3072  * What we do here is to mark the in-core inode as clean with respect to inode
3073  * dirtiness (it may still be data-dirty).
3074  * This means that the in-core inode may be reaped by prune_icache
3075  * without having to perform any I/O.  This is a very good thing,
3076  * because *any* task may call prune_icache - even ones which
3077  * have a transaction open against a different journal.
3078  *
3079  * Is this cheating?  Not really.  Sure, we haven't written the
3080  * inode out, but prune_icache isn't a user-visible syncing function.
3081  * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
3082  * we start and wait on commits.
3083  *
3084  * Is this efficient/effective?  Well, we're being nice to the system
3085  * by cleaning up our inodes proactively so they can be reaped
3086  * without I/O.  But we are potentially leaving up to five seconds'
3087  * worth of inodes floating about which prune_icache wants us to
3088  * write out.  One way to fix that would be to get prune_icache()
3089  * to do a write_super() to free up some memory.  It has the desired
3090  * effect.
3091  */
3092 int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
3093 {
3094         struct ext3_iloc iloc;
3095         int err;
3096
3097         might_sleep();
3098         err = ext3_reserve_inode_write(handle, inode, &iloc);
3099         if (!err)
3100                 err = ext3_mark_iloc_dirty(handle, inode, &iloc);
3101         return err;
3102 }
3103
3104 /*
3105  * ext3_dirty_inode() is called from __mark_inode_dirty()
3106  *
3107  * We're really interested in the case where a file is being extended.
3108  * i_size has been changed by generic_commit_write() and we thus need
3109  * to include the updated inode in the current transaction.
3110  *
3111  * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks
3112  * are allocated to the file.
3113  *
3114  * If the inode is marked synchronous, we don't honour that here - doing
3115  * so would cause a commit on atime updates, which we don't bother doing.
3116  * We handle synchronous inodes at the highest possible level.
3117  */
3118 void ext3_dirty_inode(struct inode *inode)
3119 {
3120         handle_t *current_handle = ext3_journal_current_handle();
3121         handle_t *handle;
3122
3123         handle = ext3_journal_start(inode, 2);
3124         if (IS_ERR(handle))
3125                 goto out;
3126         if (current_handle &&
3127                 current_handle->h_transaction != handle->h_transaction) {
3128                 /* This task has a transaction open against a different fs */
3129                 printk(KERN_EMERG "%s: transactions do not match!\n",
3130                        __FUNCTION__);
3131         } else {
3132                 jbd_debug(5, "marking dirty.  outer handle=%p\n",
3133                                 current_handle);
3134                 ext3_mark_inode_dirty(handle, inode);
3135         }
3136         ext3_journal_stop(handle);
3137 out:
3138         return;
3139 }
3140
3141 #if 0
3142 /*
3143  * Bind an inode's backing buffer_head into this transaction, to prevent
3144  * it from being flushed to disk early.  Unlike
3145  * ext3_reserve_inode_write, this leaves behind no bh reference and
3146  * returns no iloc structure, so the caller needs to repeat the iloc
3147  * lookup to mark the inode dirty later.
3148  */
3149 static int ext3_pin_inode(handle_t *handle, struct inode *inode)
3150 {
3151         struct ext3_iloc iloc;
3152
3153         int err = 0;
3154         if (handle) {
3155                 err = ext3_get_inode_loc(inode, &iloc);
3156                 if (!err) {
3157                         BUFFER_TRACE(iloc.bh, "get_write_access");
3158                         err = journal_get_write_access(handle, iloc.bh);
3159                         if (!err)
3160                                 err = ext3_journal_dirty_metadata(handle,
3161                                                                   iloc.bh);
3162                         brelse(iloc.bh);
3163                 }
3164         }
3165         ext3_std_error(inode->i_sb, err);
3166         return err;
3167 }
3168 #endif
3169
3170 int ext3_change_inode_journal_flag(struct inode *inode, int val)
3171 {
3172         journal_t *journal;
3173         handle_t *handle;
3174         int err;
3175
3176         /*
3177          * We have to be very careful here: changing a data block's
3178          * journaling status dynamically is dangerous.  If we write a
3179          * data block to the journal, change the status and then delete
3180          * that block, we risk forgetting to revoke the old log record
3181          * from the journal and so a subsequent replay can corrupt data.
3182          * So, first we make sure that the journal is empty and that
3183          * nobody is changing anything.
3184          */
3185
3186         journal = EXT3_JOURNAL(inode);
3187         if (is_journal_aborted(journal) || IS_RDONLY(inode))
3188                 return -EROFS;
3189
3190         journal_lock_updates(journal);
3191         journal_flush(journal);
3192
3193         /*
3194          * OK, there are no updates running now, and all cached data is
3195          * synced to disk.  We are now in a completely consistent state
3196          * which doesn't have anything in the journal, and we know that
3197          * no filesystem updates are running, so it is safe to modify
3198          * the inode's in-core data-journaling state flag now.
3199          */
3200
3201         if (val)
3202                 EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
3203         else
3204                 EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
3205         ext3_set_aops(inode);
3206
3207         journal_unlock_updates(journal);
3208
3209         /* Finally we can mark the inode as dirty. */
3210
3211         handle = ext3_journal_start(inode, 1);
3212         if (IS_ERR(handle))
3213                 return PTR_ERR(handle);
3214
3215         err = ext3_mark_inode_dirty(handle, inode);
3216         handle->h_sync = 1;
3217         ext3_journal_stop(handle);
3218         ext3_std_error(inode->i_sb, err);
3219
3220         return err;
3221 }