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1da177e4 LT |
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 inline 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) && | |
53 | inode->i_blocks - ea_blocks == 0); | |
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 | ||
65 | int ext3_forget(handle_t *handle, int is_metadata, | |
66 | struct inode *inode, struct buffer_head *bh, | |
67 | int blocknr) | |
68 | { | |
69 | int err; | |
70 | ||
71 | might_sleep(); | |
72 | ||
73 | BUFFER_TRACE(bh, "enter"); | |
74 | ||
75 | jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, " | |
76 | "data mode %lx\n", | |
77 | bh, is_metadata, inode->i_mode, | |
78 | test_opt(inode->i_sb, DATA_FLAGS)); | |
79 | ||
80 | /* Never use the revoke function if we are doing full data | |
81 | * journaling: there is no need to, and a V1 superblock won't | |
82 | * support it. Otherwise, only skip the revoke on un-journaled | |
83 | * data blocks. */ | |
84 | ||
85 | if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA || | |
86 | (!is_metadata && !ext3_should_journal_data(inode))) { | |
87 | if (bh) { | |
88 | BUFFER_TRACE(bh, "call journal_forget"); | |
89 | return ext3_journal_forget(handle, bh); | |
90 | } | |
91 | return 0; | |
92 | } | |
93 | ||
94 | /* | |
95 | * data!=journal && (is_metadata || should_journal_data(inode)) | |
96 | */ | |
97 | BUFFER_TRACE(bh, "call ext3_journal_revoke"); | |
98 | err = ext3_journal_revoke(handle, blocknr, bh); | |
99 | if (err) | |
100 | ext3_abort(inode->i_sb, __FUNCTION__, | |
101 | "error %d when attempting revoke", err); | |
102 | BUFFER_TRACE(bh, "exit"); | |
103 | return err; | |
104 | } | |
105 | ||
106 | /* | |
107 | * Work out how many blocks we need to progress with the next chunk of a | |
108 | * truncate transaction. | |
109 | */ | |
110 | ||
111 | static unsigned long blocks_for_truncate(struct inode *inode) | |
112 | { | |
113 | unsigned long needed; | |
114 | ||
115 | needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); | |
116 | ||
117 | /* Give ourselves just enough room to cope with inodes in which | |
118 | * i_blocks is corrupt: we've seen disk corruptions in the past | |
119 | * which resulted in random data in an inode which looked enough | |
120 | * like a regular file for ext3 to try to delete it. Things | |
121 | * will go a bit crazy if that happens, but at least we should | |
122 | * try not to panic the whole kernel. */ | |
123 | if (needed < 2) | |
124 | needed = 2; | |
125 | ||
126 | /* But we need to bound the transaction so we don't overflow the | |
127 | * journal. */ | |
128 | if (needed > EXT3_MAX_TRANS_DATA) | |
129 | needed = EXT3_MAX_TRANS_DATA; | |
130 | ||
1f54587b | 131 | return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
1da177e4 LT |
132 | } |
133 | ||
134 | /* | |
135 | * Truncate transactions can be complex and absolutely huge. So we need to | |
136 | * be able to restart the transaction at a conventient checkpoint to make | |
137 | * sure we don't overflow the journal. | |
138 | * | |
139 | * start_transaction gets us a new handle for a truncate transaction, | |
140 | * and extend_transaction tries to extend the existing one a bit. If | |
141 | * extend fails, we need to propagate the failure up and restart the | |
142 | * transaction in the top-level truncate loop. --sct | |
143 | */ | |
144 | ||
145 | static handle_t *start_transaction(struct inode *inode) | |
146 | { | |
147 | handle_t *result; | |
148 | ||
149 | result = ext3_journal_start(inode, blocks_for_truncate(inode)); | |
150 | if (!IS_ERR(result)) | |
151 | return result; | |
152 | ||
153 | ext3_std_error(inode->i_sb, PTR_ERR(result)); | |
154 | return result; | |
155 | } | |
156 | ||
157 | /* | |
158 | * Try to extend this transaction for the purposes of truncation. | |
159 | * | |
160 | * Returns 0 if we managed to create more room. If we can't create more | |
161 | * room, and the transaction must be restarted we return 1. | |
162 | */ | |
163 | static int try_to_extend_transaction(handle_t *handle, struct inode *inode) | |
164 | { | |
165 | if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS) | |
166 | return 0; | |
167 | if (!ext3_journal_extend(handle, blocks_for_truncate(inode))) | |
168 | return 0; | |
169 | return 1; | |
170 | } | |
171 | ||
172 | /* | |
173 | * Restart the transaction associated with *handle. This does a commit, | |
174 | * so before we call here everything must be consistently dirtied against | |
175 | * this transaction. | |
176 | */ | |
177 | static int ext3_journal_test_restart(handle_t *handle, struct inode *inode) | |
178 | { | |
179 | jbd_debug(2, "restarting handle %p\n", handle); | |
180 | return ext3_journal_restart(handle, blocks_for_truncate(inode)); | |
181 | } | |
182 | ||
183 | /* | |
184 | * Called at the last iput() if i_nlink is zero. | |
185 | */ | |
186 | void ext3_delete_inode (struct inode * inode) | |
187 | { | |
188 | handle_t *handle; | |
189 | ||
fef26658 MF |
190 | truncate_inode_pages(&inode->i_data, 0); |
191 | ||
1da177e4 LT |
192 | if (is_bad_inode(inode)) |
193 | goto no_delete; | |
194 | ||
195 | handle = start_transaction(inode); | |
196 | if (IS_ERR(handle)) { | |
197 | /* If we're going to skip the normal cleanup, we still | |
198 | * need to make sure that the in-core orphan linked list | |
199 | * is properly cleaned up. */ | |
200 | ext3_orphan_del(NULL, inode); | |
201 | goto no_delete; | |
202 | } | |
203 | ||
204 | if (IS_SYNC(inode)) | |
205 | handle->h_sync = 1; | |
206 | inode->i_size = 0; | |
207 | if (inode->i_blocks) | |
208 | ext3_truncate(inode); | |
209 | /* | |
210 | * Kill off the orphan record which ext3_truncate created. | |
211 | * AKPM: I think this can be inside the above `if'. | |
212 | * Note that ext3_orphan_del() has to be able to cope with the | |
213 | * deletion of a non-existent orphan - this is because we don't | |
214 | * know if ext3_truncate() actually created an orphan record. | |
215 | * (Well, we could do this if we need to, but heck - it works) | |
216 | */ | |
217 | ext3_orphan_del(handle, inode); | |
218 | EXT3_I(inode)->i_dtime = get_seconds(); | |
219 | ||
220 | /* | |
221 | * One subtle ordering requirement: if anything has gone wrong | |
222 | * (transaction abort, IO errors, whatever), then we can still | |
223 | * do these next steps (the fs will already have been marked as | |
224 | * having errors), but we can't free the inode if the mark_dirty | |
225 | * fails. | |
226 | */ | |
227 | if (ext3_mark_inode_dirty(handle, inode)) | |
228 | /* If that failed, just do the required in-core inode clear. */ | |
229 | clear_inode(inode); | |
230 | else | |
231 | ext3_free_inode(handle, inode); | |
232 | ext3_journal_stop(handle); | |
233 | return; | |
234 | no_delete: | |
235 | clear_inode(inode); /* We must guarantee clearing of inode... */ | |
236 | } | |
237 | ||
238 | static int ext3_alloc_block (handle_t *handle, | |
239 | struct inode * inode, unsigned long goal, int *err) | |
240 | { | |
241 | unsigned long result; | |
242 | ||
243 | result = ext3_new_block(handle, inode, goal, err); | |
244 | return result; | |
245 | } | |
246 | ||
247 | ||
248 | typedef struct { | |
249 | __le32 *p; | |
250 | __le32 key; | |
251 | struct buffer_head *bh; | |
252 | } Indirect; | |
253 | ||
254 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) | |
255 | { | |
256 | p->key = *(p->p = v); | |
257 | p->bh = bh; | |
258 | } | |
259 | ||
260 | static inline int verify_chain(Indirect *from, Indirect *to) | |
261 | { | |
262 | while (from <= to && from->key == *from->p) | |
263 | from++; | |
264 | return (from > to); | |
265 | } | |
266 | ||
267 | /** | |
268 | * ext3_block_to_path - parse the block number into array of offsets | |
269 | * @inode: inode in question (we are only interested in its superblock) | |
270 | * @i_block: block number to be parsed | |
271 | * @offsets: array to store the offsets in | |
272 | * @boundary: set this non-zero if the referred-to block is likely to be | |
273 | * followed (on disk) by an indirect block. | |
274 | * | |
275 | * To store the locations of file's data ext3 uses a data structure common | |
276 | * for UNIX filesystems - tree of pointers anchored in the inode, with | |
277 | * data blocks at leaves and indirect blocks in intermediate nodes. | |
278 | * This function translates the block number into path in that tree - | |
279 | * return value is the path length and @offsets[n] is the offset of | |
280 | * pointer to (n+1)th node in the nth one. If @block is out of range | |
281 | * (negative or too large) warning is printed and zero returned. | |
282 | * | |
283 | * Note: function doesn't find node addresses, so no IO is needed. All | |
284 | * we need to know is the capacity of indirect blocks (taken from the | |
285 | * inode->i_sb). | |
286 | */ | |
287 | ||
288 | /* | |
289 | * Portability note: the last comparison (check that we fit into triple | |
290 | * indirect block) is spelled differently, because otherwise on an | |
291 | * architecture with 32-bit longs and 8Kb pages we might get into trouble | |
292 | * if our filesystem had 8Kb blocks. We might use long long, but that would | |
293 | * kill us on x86. Oh, well, at least the sign propagation does not matter - | |
294 | * i_block would have to be negative in the very beginning, so we would not | |
295 | * get there at all. | |
296 | */ | |
297 | ||
298 | static int ext3_block_to_path(struct inode *inode, | |
299 | long i_block, int offsets[4], int *boundary) | |
300 | { | |
301 | int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
302 | int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb); | |
303 | const long direct_blocks = EXT3_NDIR_BLOCKS, | |
304 | indirect_blocks = ptrs, | |
305 | double_blocks = (1 << (ptrs_bits * 2)); | |
306 | int n = 0; | |
307 | int final = 0; | |
308 | ||
309 | if (i_block < 0) { | |
310 | ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0"); | |
311 | } else if (i_block < direct_blocks) { | |
312 | offsets[n++] = i_block; | |
313 | final = direct_blocks; | |
314 | } else if ( (i_block -= direct_blocks) < indirect_blocks) { | |
315 | offsets[n++] = EXT3_IND_BLOCK; | |
316 | offsets[n++] = i_block; | |
317 | final = ptrs; | |
318 | } else if ((i_block -= indirect_blocks) < double_blocks) { | |
319 | offsets[n++] = EXT3_DIND_BLOCK; | |
320 | offsets[n++] = i_block >> ptrs_bits; | |
321 | offsets[n++] = i_block & (ptrs - 1); | |
322 | final = ptrs; | |
323 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { | |
324 | offsets[n++] = EXT3_TIND_BLOCK; | |
325 | offsets[n++] = i_block >> (ptrs_bits * 2); | |
326 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); | |
327 | offsets[n++] = i_block & (ptrs - 1); | |
328 | final = ptrs; | |
329 | } else { | |
330 | ext3_warning (inode->i_sb, "ext3_block_to_path", "block > big"); | |
331 | } | |
332 | if (boundary) | |
333 | *boundary = (i_block & (ptrs - 1)) == (final - 1); | |
334 | return n; | |
335 | } | |
336 | ||
337 | /** | |
338 | * ext3_get_branch - read the chain of indirect blocks leading to data | |
339 | * @inode: inode in question | |
340 | * @depth: depth of the chain (1 - direct pointer, etc.) | |
341 | * @offsets: offsets of pointers in inode/indirect blocks | |
342 | * @chain: place to store the result | |
343 | * @err: here we store the error value | |
344 | * | |
345 | * Function fills the array of triples <key, p, bh> and returns %NULL | |
346 | * if everything went OK or the pointer to the last filled triple | |
347 | * (incomplete one) otherwise. Upon the return chain[i].key contains | |
348 | * the number of (i+1)-th block in the chain (as it is stored in memory, | |
349 | * i.e. little-endian 32-bit), chain[i].p contains the address of that | |
350 | * number (it points into struct inode for i==0 and into the bh->b_data | |
351 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect | |
352 | * block for i>0 and NULL for i==0. In other words, it holds the block | |
353 | * numbers of the chain, addresses they were taken from (and where we can | |
354 | * verify that chain did not change) and buffer_heads hosting these | |
355 | * numbers. | |
356 | * | |
357 | * Function stops when it stumbles upon zero pointer (absent block) | |
358 | * (pointer to last triple returned, *@err == 0) | |
359 | * or when it gets an IO error reading an indirect block | |
360 | * (ditto, *@err == -EIO) | |
361 | * or when it notices that chain had been changed while it was reading | |
362 | * (ditto, *@err == -EAGAIN) | |
363 | * or when it reads all @depth-1 indirect blocks successfully and finds | |
364 | * the whole chain, all way to the data (returns %NULL, *err == 0). | |
365 | */ | |
366 | static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets, | |
367 | Indirect chain[4], int *err) | |
368 | { | |
369 | struct super_block *sb = inode->i_sb; | |
370 | Indirect *p = chain; | |
371 | struct buffer_head *bh; | |
372 | ||
373 | *err = 0; | |
374 | /* i_data is not going away, no lock needed */ | |
375 | add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets); | |
376 | if (!p->key) | |
377 | goto no_block; | |
378 | while (--depth) { | |
379 | bh = sb_bread(sb, le32_to_cpu(p->key)); | |
380 | if (!bh) | |
381 | goto failure; | |
382 | /* Reader: pointers */ | |
383 | if (!verify_chain(chain, p)) | |
384 | goto changed; | |
385 | add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); | |
386 | /* Reader: end */ | |
387 | if (!p->key) | |
388 | goto no_block; | |
389 | } | |
390 | return NULL; | |
391 | ||
392 | changed: | |
393 | brelse(bh); | |
394 | *err = -EAGAIN; | |
395 | goto no_block; | |
396 | failure: | |
397 | *err = -EIO; | |
398 | no_block: | |
399 | return p; | |
400 | } | |
401 | ||
402 | /** | |
403 | * ext3_find_near - find a place for allocation with sufficient locality | |
404 | * @inode: owner | |
405 | * @ind: descriptor of indirect block. | |
406 | * | |
407 | * This function returns the prefered place for block allocation. | |
408 | * It is used when heuristic for sequential allocation fails. | |
409 | * Rules are: | |
410 | * + if there is a block to the left of our position - allocate near it. | |
411 | * + if pointer will live in indirect block - allocate near that block. | |
412 | * + if pointer will live in inode - allocate in the same | |
413 | * cylinder group. | |
414 | * | |
415 | * In the latter case we colour the starting block by the callers PID to | |
416 | * prevent it from clashing with concurrent allocations for a different inode | |
417 | * in the same block group. The PID is used here so that functionally related | |
418 | * files will be close-by on-disk. | |
419 | * | |
420 | * Caller must make sure that @ind is valid and will stay that way. | |
421 | */ | |
422 | ||
423 | static unsigned long ext3_find_near(struct inode *inode, Indirect *ind) | |
424 | { | |
425 | struct ext3_inode_info *ei = EXT3_I(inode); | |
426 | __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data; | |
427 | __le32 *p; | |
428 | unsigned long bg_start; | |
429 | unsigned long colour; | |
430 | ||
431 | /* Try to find previous block */ | |
432 | for (p = ind->p - 1; p >= start; p--) | |
433 | if (*p) | |
434 | return le32_to_cpu(*p); | |
435 | ||
436 | /* No such thing, so let's try location of indirect block */ | |
437 | if (ind->bh) | |
438 | return ind->bh->b_blocknr; | |
439 | ||
440 | /* | |
441 | * It is going to be refered from inode itself? OK, just put it into | |
442 | * the same cylinder group then. | |
443 | */ | |
444 | bg_start = (ei->i_block_group * EXT3_BLOCKS_PER_GROUP(inode->i_sb)) + | |
445 | le32_to_cpu(EXT3_SB(inode->i_sb)->s_es->s_first_data_block); | |
446 | colour = (current->pid % 16) * | |
447 | (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
448 | return bg_start + colour; | |
449 | } | |
450 | ||
451 | /** | |
452 | * ext3_find_goal - find a prefered place for allocation. | |
453 | * @inode: owner | |
454 | * @block: block we want | |
455 | * @chain: chain of indirect blocks | |
456 | * @partial: pointer to the last triple within a chain | |
457 | * @goal: place to store the result. | |
458 | * | |
459 | * Normally this function find the prefered place for block allocation, | |
fe55c452 | 460 | * stores it in *@goal and returns zero. |
1da177e4 LT |
461 | */ |
462 | ||
fe55c452 MC |
463 | static unsigned long ext3_find_goal(struct inode *inode, long block, |
464 | Indirect chain[4], Indirect *partial) | |
1da177e4 LT |
465 | { |
466 | struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info; | |
467 | ||
468 | /* | |
469 | * try the heuristic for sequential allocation, | |
470 | * failing that at least try to get decent locality. | |
471 | */ | |
472 | if (block_i && (block == block_i->last_alloc_logical_block + 1) | |
473 | && (block_i->last_alloc_physical_block != 0)) { | |
fe55c452 | 474 | return block_i->last_alloc_physical_block + 1; |
1da177e4 LT |
475 | } |
476 | ||
fe55c452 | 477 | return ext3_find_near(inode, partial); |
1da177e4 LT |
478 | } |
479 | ||
480 | /** | |
481 | * ext3_alloc_branch - allocate and set up a chain of blocks. | |
482 | * @inode: owner | |
483 | * @num: depth of the chain (number of blocks to allocate) | |
484 | * @offsets: offsets (in the blocks) to store the pointers to next. | |
485 | * @branch: place to store the chain in. | |
486 | * | |
487 | * This function allocates @num blocks, zeroes out all but the last one, | |
488 | * links them into chain and (if we are synchronous) writes them to disk. | |
489 | * In other words, it prepares a branch that can be spliced onto the | |
490 | * inode. It stores the information about that chain in the branch[], in | |
491 | * the same format as ext3_get_branch() would do. We are calling it after | |
492 | * we had read the existing part of chain and partial points to the last | |
493 | * triple of that (one with zero ->key). Upon the exit we have the same | |
494 | * picture as after the successful ext3_get_block(), excpet that in one | |
495 | * place chain is disconnected - *branch->p is still zero (we did not | |
496 | * set the last link), but branch->key contains the number that should | |
497 | * be placed into *branch->p to fill that gap. | |
498 | * | |
499 | * If allocation fails we free all blocks we've allocated (and forget | |
500 | * their buffer_heads) and return the error value the from failed | |
501 | * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain | |
502 | * as described above and return 0. | |
503 | */ | |
504 | ||
505 | static int ext3_alloc_branch(handle_t *handle, struct inode *inode, | |
506 | int num, | |
507 | unsigned long goal, | |
508 | int *offsets, | |
509 | Indirect *branch) | |
510 | { | |
511 | int blocksize = inode->i_sb->s_blocksize; | |
512 | int n = 0, keys = 0; | |
513 | int err = 0; | |
514 | int i; | |
515 | int parent = ext3_alloc_block(handle, inode, goal, &err); | |
516 | ||
517 | branch[0].key = cpu_to_le32(parent); | |
518 | if (parent) { | |
519 | for (n = 1; n < num; n++) { | |
520 | struct buffer_head *bh; | |
521 | /* Allocate the next block */ | |
522 | int nr = ext3_alloc_block(handle, inode, parent, &err); | |
523 | if (!nr) | |
524 | break; | |
525 | branch[n].key = cpu_to_le32(nr); | |
526 | keys = n+1; | |
527 | ||
528 | /* | |
529 | * Get buffer_head for parent block, zero it out | |
530 | * and set the pointer to new one, then send | |
531 | * parent to disk. | |
532 | */ | |
533 | bh = sb_getblk(inode->i_sb, parent); | |
534 | branch[n].bh = bh; | |
535 | lock_buffer(bh); | |
536 | BUFFER_TRACE(bh, "call get_create_access"); | |
537 | err = ext3_journal_get_create_access(handle, bh); | |
538 | if (err) { | |
539 | unlock_buffer(bh); | |
540 | brelse(bh); | |
541 | break; | |
542 | } | |
543 | ||
544 | memset(bh->b_data, 0, blocksize); | |
545 | branch[n].p = (__le32*) bh->b_data + offsets[n]; | |
546 | *branch[n].p = branch[n].key; | |
547 | BUFFER_TRACE(bh, "marking uptodate"); | |
548 | set_buffer_uptodate(bh); | |
549 | unlock_buffer(bh); | |
550 | ||
551 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
552 | err = ext3_journal_dirty_metadata(handle, bh); | |
553 | if (err) | |
554 | break; | |
555 | ||
556 | parent = nr; | |
557 | } | |
558 | } | |
559 | if (n == num) | |
560 | return 0; | |
561 | ||
562 | /* Allocation failed, free what we already allocated */ | |
563 | for (i = 1; i < keys; i++) { | |
564 | BUFFER_TRACE(branch[i].bh, "call journal_forget"); | |
565 | ext3_journal_forget(handle, branch[i].bh); | |
566 | } | |
567 | for (i = 0; i < keys; i++) | |
568 | ext3_free_blocks(handle, inode, le32_to_cpu(branch[i].key), 1); | |
569 | return err; | |
570 | } | |
571 | ||
572 | /** | |
573 | * ext3_splice_branch - splice the allocated branch onto inode. | |
574 | * @inode: owner | |
575 | * @block: (logical) number of block we are adding | |
576 | * @chain: chain of indirect blocks (with a missing link - see | |
577 | * ext3_alloc_branch) | |
578 | * @where: location of missing link | |
579 | * @num: number of blocks we are adding | |
580 | * | |
fe55c452 | 581 | * This function fills the missing link and does all housekeeping needed in |
1da177e4 | 582 | * inode (->i_blocks, etc.). In case of success we end up with the full |
fe55c452 | 583 | * chain to new block and return 0. |
1da177e4 LT |
584 | */ |
585 | ||
586 | static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block, | |
587 | Indirect chain[4], Indirect *where, int num) | |
588 | { | |
589 | int i; | |
590 | int err = 0; | |
591 | struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info; | |
592 | ||
593 | /* | |
594 | * If we're splicing into a [td]indirect block (as opposed to the | |
595 | * inode) then we need to get write access to the [td]indirect block | |
596 | * before the splice. | |
597 | */ | |
598 | if (where->bh) { | |
599 | BUFFER_TRACE(where->bh, "get_write_access"); | |
600 | err = ext3_journal_get_write_access(handle, where->bh); | |
601 | if (err) | |
602 | goto err_out; | |
603 | } | |
1da177e4 LT |
604 | /* That's it */ |
605 | ||
606 | *where->p = where->key; | |
607 | ||
608 | /* | |
609 | * update the most recently allocated logical & physical block | |
610 | * in i_block_alloc_info, to assist find the proper goal block for next | |
611 | * allocation | |
612 | */ | |
613 | if (block_i) { | |
614 | block_i->last_alloc_logical_block = block; | |
615 | block_i->last_alloc_physical_block = le32_to_cpu(where[num-1].key); | |
616 | } | |
617 | ||
618 | /* We are done with atomic stuff, now do the rest of housekeeping */ | |
619 | ||
620 | inode->i_ctime = CURRENT_TIME_SEC; | |
621 | ext3_mark_inode_dirty(handle, inode); | |
622 | ||
623 | /* had we spliced it onto indirect block? */ | |
624 | if (where->bh) { | |
625 | /* | |
626 | * akpm: If we spliced it onto an indirect block, we haven't | |
627 | * altered the inode. Note however that if it is being spliced | |
628 | * onto an indirect block at the very end of the file (the | |
629 | * file is growing) then we *will* alter the inode to reflect | |
630 | * the new i_size. But that is not done here - it is done in | |
631 | * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode. | |
632 | */ | |
633 | jbd_debug(5, "splicing indirect only\n"); | |
634 | BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata"); | |
635 | err = ext3_journal_dirty_metadata(handle, where->bh); | |
636 | if (err) | |
637 | goto err_out; | |
638 | } else { | |
639 | /* | |
640 | * OK, we spliced it into the inode itself on a direct block. | |
641 | * Inode was dirtied above. | |
642 | */ | |
643 | jbd_debug(5, "splicing direct\n"); | |
644 | } | |
645 | return err; | |
646 | ||
1da177e4 LT |
647 | err_out: |
648 | for (i = 1; i < num; i++) { | |
649 | BUFFER_TRACE(where[i].bh, "call journal_forget"); | |
650 | ext3_journal_forget(handle, where[i].bh); | |
651 | } | |
1da177e4 LT |
652 | return err; |
653 | } | |
654 | ||
655 | /* | |
656 | * Allocation strategy is simple: if we have to allocate something, we will | |
657 | * have to go the whole way to leaf. So let's do it before attaching anything | |
658 | * to tree, set linkage between the newborn blocks, write them if sync is | |
659 | * required, recheck the path, free and repeat if check fails, otherwise | |
660 | * set the last missing link (that will protect us from any truncate-generated | |
661 | * removals - all blocks on the path are immune now) and possibly force the | |
662 | * write on the parent block. | |
663 | * That has a nice additional property: no special recovery from the failed | |
664 | * allocations is needed - we simply release blocks and do not touch anything | |
665 | * reachable from inode. | |
666 | * | |
667 | * akpm: `handle' can be NULL if create == 0. | |
668 | * | |
669 | * The BKL may not be held on entry here. Be sure to take it early. | |
670 | */ | |
671 | ||
672 | static int | |
673 | ext3_get_block_handle(handle_t *handle, struct inode *inode, sector_t iblock, | |
674 | struct buffer_head *bh_result, int create, int extend_disksize) | |
675 | { | |
676 | int err = -EIO; | |
677 | int offsets[4]; | |
678 | Indirect chain[4]; | |
679 | Indirect *partial; | |
680 | unsigned long goal; | |
681 | int left; | |
682 | int boundary = 0; | |
fe55c452 | 683 | const int depth = ext3_block_to_path(inode, iblock, offsets, &boundary); |
1da177e4 LT |
684 | struct ext3_inode_info *ei = EXT3_I(inode); |
685 | ||
686 | J_ASSERT(handle != NULL || create == 0); | |
687 | ||
688 | if (depth == 0) | |
689 | goto out; | |
690 | ||
1da177e4 LT |
691 | partial = ext3_get_branch(inode, depth, offsets, chain, &err); |
692 | ||
693 | /* Simplest case - block found, no allocation needed */ | |
694 | if (!partial) { | |
695 | clear_buffer_new(bh_result); | |
fe55c452 | 696 | goto got_it; |
1da177e4 LT |
697 | } |
698 | ||
699 | /* Next simple case - plain lookup or failed read of indirect block */ | |
fe55c452 MC |
700 | if (!create || err == -EIO) |
701 | goto cleanup; | |
702 | ||
703 | down(&ei->truncate_sem); | |
704 | ||
705 | /* | |
706 | * If the indirect block is missing while we are reading | |
707 | * the chain(ext3_get_branch() returns -EAGAIN err), or | |
708 | * if the chain has been changed after we grab the semaphore, | |
709 | * (either because another process truncated this branch, or | |
710 | * another get_block allocated this branch) re-grab the chain to see if | |
711 | * the request block has been allocated or not. | |
712 | * | |
713 | * Since we already block the truncate/other get_block | |
714 | * at this point, we will have the current copy of the chain when we | |
715 | * splice the branch into the tree. | |
716 | */ | |
717 | if (err == -EAGAIN || !verify_chain(chain, partial)) { | |
1da177e4 | 718 | while (partial > chain) { |
1da177e4 LT |
719 | brelse(partial->bh); |
720 | partial--; | |
721 | } | |
fe55c452 MC |
722 | partial = ext3_get_branch(inode, depth, offsets, chain, &err); |
723 | if (!partial) { | |
724 | up(&ei->truncate_sem); | |
725 | if (err) | |
726 | goto cleanup; | |
727 | clear_buffer_new(bh_result); | |
728 | goto got_it; | |
729 | } | |
1da177e4 LT |
730 | } |
731 | ||
732 | /* | |
fe55c452 MC |
733 | * Okay, we need to do block allocation. Lazily initialize the block |
734 | * allocation info here if necessary | |
735 | */ | |
736 | if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) | |
1da177e4 | 737 | ext3_init_block_alloc_info(inode); |
1da177e4 | 738 | |
fe55c452 | 739 | goal = ext3_find_goal(inode, iblock, chain, partial); |
1da177e4 LT |
740 | |
741 | left = (chain + depth) - partial; | |
742 | ||
743 | /* | |
744 | * Block out ext3_truncate while we alter the tree | |
745 | */ | |
746 | err = ext3_alloc_branch(handle, inode, left, goal, | |
fe55c452 | 747 | offsets + (partial - chain), partial); |
1da177e4 | 748 | |
fe55c452 MC |
749 | /* |
750 | * The ext3_splice_branch call will free and forget any buffers | |
1da177e4 LT |
751 | * on the new chain if there is a failure, but that risks using |
752 | * up transaction credits, especially for bitmaps where the | |
753 | * credits cannot be returned. Can we handle this somehow? We | |
fe55c452 MC |
754 | * may need to return -EAGAIN upwards in the worst case. --sct |
755 | */ | |
1da177e4 LT |
756 | if (!err) |
757 | err = ext3_splice_branch(handle, inode, iblock, chain, | |
758 | partial, left); | |
fe55c452 MC |
759 | /* |
760 | * i_disksize growing is protected by truncate_sem. Don't forget to | |
761 | * protect it if you're about to implement concurrent | |
762 | * ext3_get_block() -bzzz | |
763 | */ | |
1da177e4 LT |
764 | if (!err && extend_disksize && inode->i_size > ei->i_disksize) |
765 | ei->i_disksize = inode->i_size; | |
766 | up(&ei->truncate_sem); | |
1da177e4 LT |
767 | if (err) |
768 | goto cleanup; | |
769 | ||
770 | set_buffer_new(bh_result); | |
fe55c452 MC |
771 | got_it: |
772 | map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); | |
773 | if (boundary) | |
774 | set_buffer_boundary(bh_result); | |
775 | /* Clean up and exit */ | |
776 | partial = chain + depth - 1; /* the whole chain */ | |
777 | cleanup: | |
1da177e4 | 778 | while (partial > chain) { |
fe55c452 | 779 | BUFFER_TRACE(partial->bh, "call brelse"); |
1da177e4 LT |
780 | brelse(partial->bh); |
781 | partial--; | |
782 | } | |
fe55c452 MC |
783 | BUFFER_TRACE(bh_result, "returned"); |
784 | out: | |
785 | return err; | |
1da177e4 LT |
786 | } |
787 | ||
788 | static int ext3_get_block(struct inode *inode, sector_t iblock, | |
789 | struct buffer_head *bh_result, int create) | |
790 | { | |
791 | handle_t *handle = NULL; | |
792 | int ret; | |
793 | ||
794 | if (create) { | |
795 | handle = ext3_journal_current_handle(); | |
796 | J_ASSERT(handle != 0); | |
797 | } | |
798 | ret = ext3_get_block_handle(handle, inode, iblock, | |
799 | bh_result, create, 1); | |
800 | return ret; | |
801 | } | |
802 | ||
803 | #define DIO_CREDITS (EXT3_RESERVE_TRANS_BLOCKS + 32) | |
804 | ||
805 | static int | |
806 | ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock, | |
807 | unsigned long max_blocks, struct buffer_head *bh_result, | |
808 | int create) | |
809 | { | |
810 | handle_t *handle = journal_current_handle(); | |
811 | int ret = 0; | |
812 | ||
813 | if (!handle) | |
814 | goto get_block; /* A read */ | |
815 | ||
816 | if (handle->h_transaction->t_state == T_LOCKED) { | |
817 | /* | |
818 | * Huge direct-io writes can hold off commits for long | |
819 | * periods of time. Let this commit run. | |
820 | */ | |
821 | ext3_journal_stop(handle); | |
822 | handle = ext3_journal_start(inode, DIO_CREDITS); | |
823 | if (IS_ERR(handle)) | |
824 | ret = PTR_ERR(handle); | |
825 | goto get_block; | |
826 | } | |
827 | ||
828 | if (handle->h_buffer_credits <= EXT3_RESERVE_TRANS_BLOCKS) { | |
829 | /* | |
830 | * Getting low on buffer credits... | |
831 | */ | |
832 | ret = ext3_journal_extend(handle, DIO_CREDITS); | |
833 | if (ret > 0) { | |
834 | /* | |
835 | * Couldn't extend the transaction. Start a new one. | |
836 | */ | |
837 | ret = ext3_journal_restart(handle, DIO_CREDITS); | |
838 | } | |
839 | } | |
840 | ||
841 | get_block: | |
842 | if (ret == 0) | |
843 | ret = ext3_get_block_handle(handle, inode, iblock, | |
844 | bh_result, create, 0); | |
845 | bh_result->b_size = (1 << inode->i_blkbits); | |
846 | return ret; | |
847 | } | |
848 | ||
1da177e4 LT |
849 | /* |
850 | * `handle' can be NULL if create is zero | |
851 | */ | |
852 | struct buffer_head *ext3_getblk(handle_t *handle, struct inode * inode, | |
853 | long block, int create, int * errp) | |
854 | { | |
855 | struct buffer_head dummy; | |
856 | int fatal = 0, err; | |
857 | ||
858 | J_ASSERT(handle != NULL || create == 0); | |
859 | ||
860 | dummy.b_state = 0; | |
861 | dummy.b_blocknr = -1000; | |
862 | buffer_trace_init(&dummy.b_history); | |
863 | *errp = ext3_get_block_handle(handle, inode, block, &dummy, create, 1); | |
864 | if (!*errp && buffer_mapped(&dummy)) { | |
865 | struct buffer_head *bh; | |
866 | bh = sb_getblk(inode->i_sb, dummy.b_blocknr); | |
867 | if (buffer_new(&dummy)) { | |
868 | J_ASSERT(create != 0); | |
869 | J_ASSERT(handle != 0); | |
870 | ||
871 | /* Now that we do not always journal data, we | |
872 | should keep in mind whether this should | |
873 | always journal the new buffer as metadata. | |
874 | For now, regular file writes use | |
875 | ext3_get_block instead, so it's not a | |
876 | problem. */ | |
877 | lock_buffer(bh); | |
878 | BUFFER_TRACE(bh, "call get_create_access"); | |
879 | fatal = ext3_journal_get_create_access(handle, bh); | |
880 | if (!fatal && !buffer_uptodate(bh)) { | |
881 | memset(bh->b_data, 0, inode->i_sb->s_blocksize); | |
882 | set_buffer_uptodate(bh); | |
883 | } | |
884 | unlock_buffer(bh); | |
885 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
886 | err = ext3_journal_dirty_metadata(handle, bh); | |
887 | if (!fatal) | |
888 | fatal = err; | |
889 | } else { | |
890 | BUFFER_TRACE(bh, "not a new buffer"); | |
891 | } | |
892 | if (fatal) { | |
893 | *errp = fatal; | |
894 | brelse(bh); | |
895 | bh = NULL; | |
896 | } | |
897 | return bh; | |
898 | } | |
899 | return NULL; | |
900 | } | |
901 | ||
902 | struct buffer_head *ext3_bread(handle_t *handle, struct inode * inode, | |
903 | int block, int create, int *err) | |
904 | { | |
905 | struct buffer_head * bh; | |
906 | ||
907 | bh = ext3_getblk(handle, inode, block, create, err); | |
908 | if (!bh) | |
909 | return bh; | |
910 | if (buffer_uptodate(bh)) | |
911 | return bh; | |
912 | ll_rw_block(READ, 1, &bh); | |
913 | wait_on_buffer(bh); | |
914 | if (buffer_uptodate(bh)) | |
915 | return bh; | |
916 | put_bh(bh); | |
917 | *err = -EIO; | |
918 | return NULL; | |
919 | } | |
920 | ||
921 | static int walk_page_buffers( handle_t *handle, | |
922 | struct buffer_head *head, | |
923 | unsigned from, | |
924 | unsigned to, | |
925 | int *partial, | |
926 | int (*fn)( handle_t *handle, | |
927 | struct buffer_head *bh)) | |
928 | { | |
929 | struct buffer_head *bh; | |
930 | unsigned block_start, block_end; | |
931 | unsigned blocksize = head->b_size; | |
932 | int err, ret = 0; | |
933 | struct buffer_head *next; | |
934 | ||
935 | for ( bh = head, block_start = 0; | |
936 | ret == 0 && (bh != head || !block_start); | |
937 | block_start = block_end, bh = next) | |
938 | { | |
939 | next = bh->b_this_page; | |
940 | block_end = block_start + blocksize; | |
941 | if (block_end <= from || block_start >= to) { | |
942 | if (partial && !buffer_uptodate(bh)) | |
943 | *partial = 1; | |
944 | continue; | |
945 | } | |
946 | err = (*fn)(handle, bh); | |
947 | if (!ret) | |
948 | ret = err; | |
949 | } | |
950 | return ret; | |
951 | } | |
952 | ||
953 | /* | |
954 | * To preserve ordering, it is essential that the hole instantiation and | |
955 | * the data write be encapsulated in a single transaction. We cannot | |
956 | * close off a transaction and start a new one between the ext3_get_block() | |
957 | * and the commit_write(). So doing the journal_start at the start of | |
958 | * prepare_write() is the right place. | |
959 | * | |
960 | * Also, this function can nest inside ext3_writepage() -> | |
961 | * block_write_full_page(). In that case, we *know* that ext3_writepage() | |
962 | * has generated enough buffer credits to do the whole page. So we won't | |
963 | * block on the journal in that case, which is good, because the caller may | |
964 | * be PF_MEMALLOC. | |
965 | * | |
966 | * By accident, ext3 can be reentered when a transaction is open via | |
967 | * quota file writes. If we were to commit the transaction while thus | |
968 | * reentered, there can be a deadlock - we would be holding a quota | |
969 | * lock, and the commit would never complete if another thread had a | |
970 | * transaction open and was blocking on the quota lock - a ranking | |
971 | * violation. | |
972 | * | |
973 | * So what we do is to rely on the fact that journal_stop/journal_start | |
974 | * will _not_ run commit under these circumstances because handle->h_ref | |
975 | * is elevated. We'll still have enough credits for the tiny quotafile | |
976 | * write. | |
977 | */ | |
978 | ||
979 | static int do_journal_get_write_access(handle_t *handle, | |
980 | struct buffer_head *bh) | |
981 | { | |
982 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
983 | return 0; | |
984 | return ext3_journal_get_write_access(handle, bh); | |
985 | } | |
986 | ||
987 | static int ext3_prepare_write(struct file *file, struct page *page, | |
988 | unsigned from, unsigned to) | |
989 | { | |
990 | struct inode *inode = page->mapping->host; | |
991 | int ret, needed_blocks = ext3_writepage_trans_blocks(inode); | |
992 | handle_t *handle; | |
993 | int retries = 0; | |
994 | ||
995 | retry: | |
996 | handle = ext3_journal_start(inode, needed_blocks); | |
997 | if (IS_ERR(handle)) { | |
998 | ret = PTR_ERR(handle); | |
999 | goto out; | |
1000 | } | |
1001 | if (test_opt(inode->i_sb, NOBH)) | |
1002 | ret = nobh_prepare_write(page, from, to, ext3_get_block); | |
1003 | else | |
1004 | ret = block_prepare_write(page, from, to, ext3_get_block); | |
1005 | if (ret) | |
1006 | goto prepare_write_failed; | |
1007 | ||
1008 | if (ext3_should_journal_data(inode)) { | |
1009 | ret = walk_page_buffers(handle, page_buffers(page), | |
1010 | from, to, NULL, do_journal_get_write_access); | |
1011 | } | |
1012 | prepare_write_failed: | |
1013 | if (ret) | |
1014 | ext3_journal_stop(handle); | |
1015 | if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) | |
1016 | goto retry; | |
1017 | out: | |
1018 | return ret; | |
1019 | } | |
1020 | ||
1021 | int | |
1022 | ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh) | |
1023 | { | |
1024 | int err = journal_dirty_data(handle, bh); | |
1025 | if (err) | |
1026 | ext3_journal_abort_handle(__FUNCTION__, __FUNCTION__, | |
1027 | bh, handle,err); | |
1028 | return err; | |
1029 | } | |
1030 | ||
1031 | /* For commit_write() in data=journal mode */ | |
1032 | static int commit_write_fn(handle_t *handle, struct buffer_head *bh) | |
1033 | { | |
1034 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
1035 | return 0; | |
1036 | set_buffer_uptodate(bh); | |
1037 | return ext3_journal_dirty_metadata(handle, bh); | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * We need to pick up the new inode size which generic_commit_write gave us | |
1042 | * `file' can be NULL - eg, when called from page_symlink(). | |
1043 | * | |
1044 | * ext3 never places buffers on inode->i_mapping->private_list. metadata | |
1045 | * buffers are managed internally. | |
1046 | */ | |
1047 | ||
1048 | static int ext3_ordered_commit_write(struct file *file, struct page *page, | |
1049 | unsigned from, unsigned to) | |
1050 | { | |
1051 | handle_t *handle = ext3_journal_current_handle(); | |
1052 | struct inode *inode = page->mapping->host; | |
1053 | int ret = 0, ret2; | |
1054 | ||
1055 | ret = walk_page_buffers(handle, page_buffers(page), | |
1056 | from, to, NULL, ext3_journal_dirty_data); | |
1057 | ||
1058 | if (ret == 0) { | |
1059 | /* | |
1060 | * generic_commit_write() will run mark_inode_dirty() if i_size | |
1061 | * changes. So let's piggyback the i_disksize mark_inode_dirty | |
1062 | * into that. | |
1063 | */ | |
1064 | loff_t new_i_size; | |
1065 | ||
1066 | new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
1067 | if (new_i_size > EXT3_I(inode)->i_disksize) | |
1068 | EXT3_I(inode)->i_disksize = new_i_size; | |
1069 | ret = generic_commit_write(file, page, from, to); | |
1070 | } | |
1071 | ret2 = ext3_journal_stop(handle); | |
1072 | if (!ret) | |
1073 | ret = ret2; | |
1074 | return ret; | |
1075 | } | |
1076 | ||
1077 | static int ext3_writeback_commit_write(struct file *file, struct page *page, | |
1078 | unsigned from, unsigned to) | |
1079 | { | |
1080 | handle_t *handle = ext3_journal_current_handle(); | |
1081 | struct inode *inode = page->mapping->host; | |
1082 | int ret = 0, ret2; | |
1083 | loff_t new_i_size; | |
1084 | ||
1085 | new_i_size = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
1086 | if (new_i_size > EXT3_I(inode)->i_disksize) | |
1087 | EXT3_I(inode)->i_disksize = new_i_size; | |
1088 | ||
1089 | if (test_opt(inode->i_sb, NOBH)) | |
1090 | ret = nobh_commit_write(file, page, from, to); | |
1091 | else | |
1092 | ret = generic_commit_write(file, page, from, to); | |
1093 | ||
1094 | ret2 = ext3_journal_stop(handle); | |
1095 | if (!ret) | |
1096 | ret = ret2; | |
1097 | return ret; | |
1098 | } | |
1099 | ||
1100 | static int ext3_journalled_commit_write(struct file *file, | |
1101 | struct page *page, unsigned from, unsigned to) | |
1102 | { | |
1103 | handle_t *handle = ext3_journal_current_handle(); | |
1104 | struct inode *inode = page->mapping->host; | |
1105 | int ret = 0, ret2; | |
1106 | int partial = 0; | |
1107 | loff_t pos; | |
1108 | ||
1109 | /* | |
1110 | * Here we duplicate the generic_commit_write() functionality | |
1111 | */ | |
1112 | pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; | |
1113 | ||
1114 | ret = walk_page_buffers(handle, page_buffers(page), from, | |
1115 | to, &partial, commit_write_fn); | |
1116 | if (!partial) | |
1117 | SetPageUptodate(page); | |
1118 | if (pos > inode->i_size) | |
1119 | i_size_write(inode, pos); | |
1120 | EXT3_I(inode)->i_state |= EXT3_STATE_JDATA; | |
1121 | if (inode->i_size > EXT3_I(inode)->i_disksize) { | |
1122 | EXT3_I(inode)->i_disksize = inode->i_size; | |
1123 | ret2 = ext3_mark_inode_dirty(handle, inode); | |
1124 | if (!ret) | |
1125 | ret = ret2; | |
1126 | } | |
1127 | ret2 = ext3_journal_stop(handle); | |
1128 | if (!ret) | |
1129 | ret = ret2; | |
1130 | return ret; | |
1131 | } | |
1132 | ||
1133 | /* | |
1134 | * bmap() is special. It gets used by applications such as lilo and by | |
1135 | * the swapper to find the on-disk block of a specific piece of data. | |
1136 | * | |
1137 | * Naturally, this is dangerous if the block concerned is still in the | |
1138 | * journal. If somebody makes a swapfile on an ext3 data-journaling | |
1139 | * filesystem and enables swap, then they may get a nasty shock when the | |
1140 | * data getting swapped to that swapfile suddenly gets overwritten by | |
1141 | * the original zero's written out previously to the journal and | |
1142 | * awaiting writeback in the kernel's buffer cache. | |
1143 | * | |
1144 | * So, if we see any bmap calls here on a modified, data-journaled file, | |
1145 | * take extra steps to flush any blocks which might be in the cache. | |
1146 | */ | |
1147 | static sector_t ext3_bmap(struct address_space *mapping, sector_t block) | |
1148 | { | |
1149 | struct inode *inode = mapping->host; | |
1150 | journal_t *journal; | |
1151 | int err; | |
1152 | ||
1153 | if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) { | |
1154 | /* | |
1155 | * This is a REALLY heavyweight approach, but the use of | |
1156 | * bmap on dirty files is expected to be extremely rare: | |
1157 | * only if we run lilo or swapon on a freshly made file | |
1158 | * do we expect this to happen. | |
1159 | * | |
1160 | * (bmap requires CAP_SYS_RAWIO so this does not | |
1161 | * represent an unprivileged user DOS attack --- we'd be | |
1162 | * in trouble if mortal users could trigger this path at | |
1163 | * will.) | |
1164 | * | |
1165 | * NB. EXT3_STATE_JDATA is not set on files other than | |
1166 | * regular files. If somebody wants to bmap a directory | |
1167 | * or symlink and gets confused because the buffer | |
1168 | * hasn't yet been flushed to disk, they deserve | |
1169 | * everything they get. | |
1170 | */ | |
1171 | ||
1172 | EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA; | |
1173 | journal = EXT3_JOURNAL(inode); | |
1174 | journal_lock_updates(journal); | |
1175 | err = journal_flush(journal); | |
1176 | journal_unlock_updates(journal); | |
1177 | ||
1178 | if (err) | |
1179 | return 0; | |
1180 | } | |
1181 | ||
1182 | return generic_block_bmap(mapping,block,ext3_get_block); | |
1183 | } | |
1184 | ||
1185 | static int bget_one(handle_t *handle, struct buffer_head *bh) | |
1186 | { | |
1187 | get_bh(bh); | |
1188 | return 0; | |
1189 | } | |
1190 | ||
1191 | static int bput_one(handle_t *handle, struct buffer_head *bh) | |
1192 | { | |
1193 | put_bh(bh); | |
1194 | return 0; | |
1195 | } | |
1196 | ||
1197 | static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh) | |
1198 | { | |
1199 | if (buffer_mapped(bh)) | |
1200 | return ext3_journal_dirty_data(handle, bh); | |
1201 | return 0; | |
1202 | } | |
1203 | ||
1204 | /* | |
1205 | * Note that we always start a transaction even if we're not journalling | |
1206 | * data. This is to preserve ordering: any hole instantiation within | |
1207 | * __block_write_full_page -> ext3_get_block() should be journalled | |
1208 | * along with the data so we don't crash and then get metadata which | |
1209 | * refers to old data. | |
1210 | * | |
1211 | * In all journalling modes block_write_full_page() will start the I/O. | |
1212 | * | |
1213 | * Problem: | |
1214 | * | |
1215 | * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> | |
1216 | * ext3_writepage() | |
1217 | * | |
1218 | * Similar for: | |
1219 | * | |
1220 | * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ... | |
1221 | * | |
1222 | * Same applies to ext3_get_block(). We will deadlock on various things like | |
1223 | * lock_journal and i_truncate_sem. | |
1224 | * | |
1225 | * Setting PF_MEMALLOC here doesn't work - too many internal memory | |
1226 | * allocations fail. | |
1227 | * | |
1228 | * 16May01: If we're reentered then journal_current_handle() will be | |
1229 | * non-zero. We simply *return*. | |
1230 | * | |
1231 | * 1 July 2001: @@@ FIXME: | |
1232 | * In journalled data mode, a data buffer may be metadata against the | |
1233 | * current transaction. But the same file is part of a shared mapping | |
1234 | * and someone does a writepage() on it. | |
1235 | * | |
1236 | * We will move the buffer onto the async_data list, but *after* it has | |
1237 | * been dirtied. So there's a small window where we have dirty data on | |
1238 | * BJ_Metadata. | |
1239 | * | |
1240 | * Note that this only applies to the last partial page in the file. The | |
1241 | * bit which block_write_full_page() uses prepare/commit for. (That's | |
1242 | * broken code anyway: it's wrong for msync()). | |
1243 | * | |
1244 | * It's a rare case: affects the final partial page, for journalled data | |
1245 | * where the file is subject to bith write() and writepage() in the same | |
1246 | * transction. To fix it we'll need a custom block_write_full_page(). | |
1247 | * We'll probably need that anyway for journalling writepage() output. | |
1248 | * | |
1249 | * We don't honour synchronous mounts for writepage(). That would be | |
1250 | * disastrous. Any write() or metadata operation will sync the fs for | |
1251 | * us. | |
1252 | * | |
1253 | * AKPM2: if all the page's buffers are mapped to disk and !data=journal, | |
1254 | * we don't need to open a transaction here. | |
1255 | */ | |
1256 | static int ext3_ordered_writepage(struct page *page, | |
1257 | struct writeback_control *wbc) | |
1258 | { | |
1259 | struct inode *inode = page->mapping->host; | |
1260 | struct buffer_head *page_bufs; | |
1261 | handle_t *handle = NULL; | |
1262 | int ret = 0; | |
1263 | int err; | |
1264 | ||
1265 | J_ASSERT(PageLocked(page)); | |
1266 | ||
1267 | /* | |
1268 | * We give up here if we're reentered, because it might be for a | |
1269 | * different filesystem. | |
1270 | */ | |
1271 | if (ext3_journal_current_handle()) | |
1272 | goto out_fail; | |
1273 | ||
1274 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1275 | ||
1276 | if (IS_ERR(handle)) { | |
1277 | ret = PTR_ERR(handle); | |
1278 | goto out_fail; | |
1279 | } | |
1280 | ||
1281 | if (!page_has_buffers(page)) { | |
1282 | create_empty_buffers(page, inode->i_sb->s_blocksize, | |
1283 | (1 << BH_Dirty)|(1 << BH_Uptodate)); | |
1284 | } | |
1285 | page_bufs = page_buffers(page); | |
1286 | walk_page_buffers(handle, page_bufs, 0, | |
1287 | PAGE_CACHE_SIZE, NULL, bget_one); | |
1288 | ||
1289 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1290 | ||
1291 | /* | |
1292 | * The page can become unlocked at any point now, and | |
1293 | * truncate can then come in and change things. So we | |
1294 | * can't touch *page from now on. But *page_bufs is | |
1295 | * safe due to elevated refcount. | |
1296 | */ | |
1297 | ||
1298 | /* | |
1299 | * And attach them to the current transaction. But only if | |
1300 | * block_write_full_page() succeeded. Otherwise they are unmapped, | |
1301 | * and generally junk. | |
1302 | */ | |
1303 | if (ret == 0) { | |
1304 | err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, | |
1305 | NULL, journal_dirty_data_fn); | |
1306 | if (!ret) | |
1307 | ret = err; | |
1308 | } | |
1309 | walk_page_buffers(handle, page_bufs, 0, | |
1310 | PAGE_CACHE_SIZE, NULL, bput_one); | |
1311 | err = ext3_journal_stop(handle); | |
1312 | if (!ret) | |
1313 | ret = err; | |
1314 | return ret; | |
1315 | ||
1316 | out_fail: | |
1317 | redirty_page_for_writepage(wbc, page); | |
1318 | unlock_page(page); | |
1319 | return ret; | |
1320 | } | |
1321 | ||
1da177e4 LT |
1322 | static int ext3_writeback_writepage(struct page *page, |
1323 | struct writeback_control *wbc) | |
1324 | { | |
1325 | struct inode *inode = page->mapping->host; | |
1326 | handle_t *handle = NULL; | |
1327 | int ret = 0; | |
1328 | int err; | |
1329 | ||
1330 | if (ext3_journal_current_handle()) | |
1331 | goto out_fail; | |
1332 | ||
1333 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1334 | if (IS_ERR(handle)) { | |
1335 | ret = PTR_ERR(handle); | |
1336 | goto out_fail; | |
1337 | } | |
1338 | ||
1339 | if (test_opt(inode->i_sb, NOBH)) | |
1340 | ret = nobh_writepage(page, ext3_get_block, wbc); | |
1341 | else | |
1342 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1343 | ||
1344 | err = ext3_journal_stop(handle); | |
1345 | if (!ret) | |
1346 | ret = err; | |
1347 | return ret; | |
1348 | ||
1349 | out_fail: | |
1350 | redirty_page_for_writepage(wbc, page); | |
1351 | unlock_page(page); | |
1352 | return ret; | |
1353 | } | |
1354 | ||
1355 | static int ext3_journalled_writepage(struct page *page, | |
1356 | struct writeback_control *wbc) | |
1357 | { | |
1358 | struct inode *inode = page->mapping->host; | |
1359 | handle_t *handle = NULL; | |
1360 | int ret = 0; | |
1361 | int err; | |
1362 | ||
1363 | if (ext3_journal_current_handle()) | |
1364 | goto no_write; | |
1365 | ||
1366 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1367 | if (IS_ERR(handle)) { | |
1368 | ret = PTR_ERR(handle); | |
1369 | goto no_write; | |
1370 | } | |
1371 | ||
1372 | if (!page_has_buffers(page) || PageChecked(page)) { | |
1373 | /* | |
1374 | * It's mmapped pagecache. Add buffers and journal it. There | |
1375 | * doesn't seem much point in redirtying the page here. | |
1376 | */ | |
1377 | ClearPageChecked(page); | |
1378 | ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, | |
1379 | ext3_get_block); | |
1380 | if (ret != 0) | |
1381 | goto out_unlock; | |
1382 | ret = walk_page_buffers(handle, page_buffers(page), 0, | |
1383 | PAGE_CACHE_SIZE, NULL, do_journal_get_write_access); | |
1384 | ||
1385 | err = walk_page_buffers(handle, page_buffers(page), 0, | |
1386 | PAGE_CACHE_SIZE, NULL, commit_write_fn); | |
1387 | if (ret == 0) | |
1388 | ret = err; | |
1389 | EXT3_I(inode)->i_state |= EXT3_STATE_JDATA; | |
1390 | unlock_page(page); | |
1391 | } else { | |
1392 | /* | |
1393 | * It may be a page full of checkpoint-mode buffers. We don't | |
1394 | * really know unless we go poke around in the buffer_heads. | |
1395 | * But block_write_full_page will do the right thing. | |
1396 | */ | |
1397 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1398 | } | |
1399 | err = ext3_journal_stop(handle); | |
1400 | if (!ret) | |
1401 | ret = err; | |
1402 | out: | |
1403 | return ret; | |
1404 | ||
1405 | no_write: | |
1406 | redirty_page_for_writepage(wbc, page); | |
1407 | out_unlock: | |
1408 | unlock_page(page); | |
1409 | goto out; | |
1410 | } | |
1411 | ||
1412 | static int ext3_readpage(struct file *file, struct page *page) | |
1413 | { | |
1414 | return mpage_readpage(page, ext3_get_block); | |
1415 | } | |
1416 | ||
1417 | static int | |
1418 | ext3_readpages(struct file *file, struct address_space *mapping, | |
1419 | struct list_head *pages, unsigned nr_pages) | |
1420 | { | |
1421 | return mpage_readpages(mapping, pages, nr_pages, ext3_get_block); | |
1422 | } | |
1423 | ||
1424 | static int ext3_invalidatepage(struct page *page, unsigned long offset) | |
1425 | { | |
1426 | journal_t *journal = EXT3_JOURNAL(page->mapping->host); | |
1427 | ||
1428 | /* | |
1429 | * If it's a full truncate we just forget about the pending dirtying | |
1430 | */ | |
1431 | if (offset == 0) | |
1432 | ClearPageChecked(page); | |
1433 | ||
1434 | return journal_invalidatepage(journal, page, offset); | |
1435 | } | |
1436 | ||
27496a8c | 1437 | static int ext3_releasepage(struct page *page, gfp_t wait) |
1da177e4 LT |
1438 | { |
1439 | journal_t *journal = EXT3_JOURNAL(page->mapping->host); | |
1440 | ||
1441 | WARN_ON(PageChecked(page)); | |
1442 | if (!page_has_buffers(page)) | |
1443 | return 0; | |
1444 | return journal_try_to_free_buffers(journal, page, wait); | |
1445 | } | |
1446 | ||
1447 | /* | |
1448 | * If the O_DIRECT write will extend the file then add this inode to the | |
1449 | * orphan list. So recovery will truncate it back to the original size | |
1450 | * if the machine crashes during the write. | |
1451 | * | |
1452 | * If the O_DIRECT write is intantiating holes inside i_size and the machine | |
1453 | * crashes then stale disk data _may_ be exposed inside the file. | |
1454 | */ | |
1455 | static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb, | |
1456 | const struct iovec *iov, loff_t offset, | |
1457 | unsigned long nr_segs) | |
1458 | { | |
1459 | struct file *file = iocb->ki_filp; | |
1460 | struct inode *inode = file->f_mapping->host; | |
1461 | struct ext3_inode_info *ei = EXT3_I(inode); | |
1462 | handle_t *handle = NULL; | |
1463 | ssize_t ret; | |
1464 | int orphan = 0; | |
1465 | size_t count = iov_length(iov, nr_segs); | |
1466 | ||
1467 | if (rw == WRITE) { | |
1468 | loff_t final_size = offset + count; | |
1469 | ||
1470 | handle = ext3_journal_start(inode, DIO_CREDITS); | |
1471 | if (IS_ERR(handle)) { | |
1472 | ret = PTR_ERR(handle); | |
1473 | goto out; | |
1474 | } | |
1475 | if (final_size > inode->i_size) { | |
1476 | ret = ext3_orphan_add(handle, inode); | |
1477 | if (ret) | |
1478 | goto out_stop; | |
1479 | orphan = 1; | |
1480 | ei->i_disksize = inode->i_size; | |
1481 | } | |
1482 | } | |
1483 | ||
1484 | ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, | |
1485 | offset, nr_segs, | |
1486 | ext3_direct_io_get_blocks, NULL); | |
1487 | ||
1488 | /* | |
1489 | * Reacquire the handle: ext3_direct_io_get_block() can restart the | |
1490 | * transaction | |
1491 | */ | |
1492 | handle = journal_current_handle(); | |
1493 | ||
1494 | out_stop: | |
1495 | if (handle) { | |
1496 | int err; | |
1497 | ||
1498 | if (orphan && inode->i_nlink) | |
1499 | ext3_orphan_del(handle, inode); | |
1500 | if (orphan && ret > 0) { | |
1501 | loff_t end = offset + ret; | |
1502 | if (end > inode->i_size) { | |
1503 | ei->i_disksize = end; | |
1504 | i_size_write(inode, end); | |
1505 | /* | |
1506 | * We're going to return a positive `ret' | |
1507 | * here due to non-zero-length I/O, so there's | |
1508 | * no way of reporting error returns from | |
1509 | * ext3_mark_inode_dirty() to userspace. So | |
1510 | * ignore it. | |
1511 | */ | |
1512 | ext3_mark_inode_dirty(handle, inode); | |
1513 | } | |
1514 | } | |
1515 | err = ext3_journal_stop(handle); | |
1516 | if (ret == 0) | |
1517 | ret = err; | |
1518 | } | |
1519 | out: | |
1520 | return ret; | |
1521 | } | |
1522 | ||
1523 | /* | |
1524 | * Pages can be marked dirty completely asynchronously from ext3's journalling | |
1525 | * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do | |
1526 | * much here because ->set_page_dirty is called under VFS locks. The page is | |
1527 | * not necessarily locked. | |
1528 | * | |
1529 | * We cannot just dirty the page and leave attached buffers clean, because the | |
1530 | * buffers' dirty state is "definitive". We cannot just set the buffers dirty | |
1531 | * or jbddirty because all the journalling code will explode. | |
1532 | * | |
1533 | * So what we do is to mark the page "pending dirty" and next time writepage | |
1534 | * is called, propagate that into the buffers appropriately. | |
1535 | */ | |
1536 | static int ext3_journalled_set_page_dirty(struct page *page) | |
1537 | { | |
1538 | SetPageChecked(page); | |
1539 | return __set_page_dirty_nobuffers(page); | |
1540 | } | |
1541 | ||
1542 | static struct address_space_operations ext3_ordered_aops = { | |
1543 | .readpage = ext3_readpage, | |
1544 | .readpages = ext3_readpages, | |
1545 | .writepage = ext3_ordered_writepage, | |
1546 | .sync_page = block_sync_page, | |
1547 | .prepare_write = ext3_prepare_write, | |
1548 | .commit_write = ext3_ordered_commit_write, | |
1549 | .bmap = ext3_bmap, | |
1550 | .invalidatepage = ext3_invalidatepage, | |
1551 | .releasepage = ext3_releasepage, | |
1552 | .direct_IO = ext3_direct_IO, | |
1553 | }; | |
1554 | ||
1555 | static struct address_space_operations ext3_writeback_aops = { | |
1556 | .readpage = ext3_readpage, | |
1557 | .readpages = ext3_readpages, | |
1558 | .writepage = ext3_writeback_writepage, | |
1da177e4 LT |
1559 | .sync_page = block_sync_page, |
1560 | .prepare_write = ext3_prepare_write, | |
1561 | .commit_write = ext3_writeback_commit_write, | |
1562 | .bmap = ext3_bmap, | |
1563 | .invalidatepage = ext3_invalidatepage, | |
1564 | .releasepage = ext3_releasepage, | |
1565 | .direct_IO = ext3_direct_IO, | |
1566 | }; | |
1567 | ||
1568 | static struct address_space_operations ext3_journalled_aops = { | |
1569 | .readpage = ext3_readpage, | |
1570 | .readpages = ext3_readpages, | |
1571 | .writepage = ext3_journalled_writepage, | |
1572 | .sync_page = block_sync_page, | |
1573 | .prepare_write = ext3_prepare_write, | |
1574 | .commit_write = ext3_journalled_commit_write, | |
1575 | .set_page_dirty = ext3_journalled_set_page_dirty, | |
1576 | .bmap = ext3_bmap, | |
1577 | .invalidatepage = ext3_invalidatepage, | |
1578 | .releasepage = ext3_releasepage, | |
1579 | }; | |
1580 | ||
1581 | void ext3_set_aops(struct inode *inode) | |
1582 | { | |
1583 | if (ext3_should_order_data(inode)) | |
1584 | inode->i_mapping->a_ops = &ext3_ordered_aops; | |
1585 | else if (ext3_should_writeback_data(inode)) | |
1586 | inode->i_mapping->a_ops = &ext3_writeback_aops; | |
1587 | else | |
1588 | inode->i_mapping->a_ops = &ext3_journalled_aops; | |
1589 | } | |
1590 | ||
1591 | /* | |
1592 | * ext3_block_truncate_page() zeroes out a mapping from file offset `from' | |
1593 | * up to the end of the block which corresponds to `from'. | |
1594 | * This required during truncate. We need to physically zero the tail end | |
1595 | * of that block so it doesn't yield old data if the file is later grown. | |
1596 | */ | |
1597 | static int ext3_block_truncate_page(handle_t *handle, struct page *page, | |
1598 | struct address_space *mapping, loff_t from) | |
1599 | { | |
1600 | unsigned long index = from >> PAGE_CACHE_SHIFT; | |
1601 | unsigned offset = from & (PAGE_CACHE_SIZE-1); | |
1602 | unsigned blocksize, iblock, length, pos; | |
1603 | struct inode *inode = mapping->host; | |
1604 | struct buffer_head *bh; | |
1605 | int err = 0; | |
1606 | void *kaddr; | |
1607 | ||
1608 | blocksize = inode->i_sb->s_blocksize; | |
1609 | length = blocksize - (offset & (blocksize - 1)); | |
1610 | iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1611 | ||
1612 | /* | |
1613 | * For "nobh" option, we can only work if we don't need to | |
1614 | * read-in the page - otherwise we create buffers to do the IO. | |
1615 | */ | |
1616 | if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH)) { | |
1617 | if (PageUptodate(page)) { | |
1618 | kaddr = kmap_atomic(page, KM_USER0); | |
1619 | memset(kaddr + offset, 0, length); | |
1620 | flush_dcache_page(page); | |
1621 | kunmap_atomic(kaddr, KM_USER0); | |
1622 | set_page_dirty(page); | |
1623 | goto unlock; | |
1624 | } | |
1625 | } | |
1626 | ||
1627 | if (!page_has_buffers(page)) | |
1628 | create_empty_buffers(page, blocksize, 0); | |
1629 | ||
1630 | /* Find the buffer that contains "offset" */ | |
1631 | bh = page_buffers(page); | |
1632 | pos = blocksize; | |
1633 | while (offset >= pos) { | |
1634 | bh = bh->b_this_page; | |
1635 | iblock++; | |
1636 | pos += blocksize; | |
1637 | } | |
1638 | ||
1639 | err = 0; | |
1640 | if (buffer_freed(bh)) { | |
1641 | BUFFER_TRACE(bh, "freed: skip"); | |
1642 | goto unlock; | |
1643 | } | |
1644 | ||
1645 | if (!buffer_mapped(bh)) { | |
1646 | BUFFER_TRACE(bh, "unmapped"); | |
1647 | ext3_get_block(inode, iblock, bh, 0); | |
1648 | /* unmapped? It's a hole - nothing to do */ | |
1649 | if (!buffer_mapped(bh)) { | |
1650 | BUFFER_TRACE(bh, "still unmapped"); | |
1651 | goto unlock; | |
1652 | } | |
1653 | } | |
1654 | ||
1655 | /* Ok, it's mapped. Make sure it's up-to-date */ | |
1656 | if (PageUptodate(page)) | |
1657 | set_buffer_uptodate(bh); | |
1658 | ||
1659 | if (!buffer_uptodate(bh)) { | |
1660 | err = -EIO; | |
1661 | ll_rw_block(READ, 1, &bh); | |
1662 | wait_on_buffer(bh); | |
1663 | /* Uhhuh. Read error. Complain and punt. */ | |
1664 | if (!buffer_uptodate(bh)) | |
1665 | goto unlock; | |
1666 | } | |
1667 | ||
1668 | if (ext3_should_journal_data(inode)) { | |
1669 | BUFFER_TRACE(bh, "get write access"); | |
1670 | err = ext3_journal_get_write_access(handle, bh); | |
1671 | if (err) | |
1672 | goto unlock; | |
1673 | } | |
1674 | ||
1675 | kaddr = kmap_atomic(page, KM_USER0); | |
1676 | memset(kaddr + offset, 0, length); | |
1677 | flush_dcache_page(page); | |
1678 | kunmap_atomic(kaddr, KM_USER0); | |
1679 | ||
1680 | BUFFER_TRACE(bh, "zeroed end of block"); | |
1681 | ||
1682 | err = 0; | |
1683 | if (ext3_should_journal_data(inode)) { | |
1684 | err = ext3_journal_dirty_metadata(handle, bh); | |
1685 | } else { | |
1686 | if (ext3_should_order_data(inode)) | |
1687 | err = ext3_journal_dirty_data(handle, bh); | |
1688 | mark_buffer_dirty(bh); | |
1689 | } | |
1690 | ||
1691 | unlock: | |
1692 | unlock_page(page); | |
1693 | page_cache_release(page); | |
1694 | return err; | |
1695 | } | |
1696 | ||
1697 | /* | |
1698 | * Probably it should be a library function... search for first non-zero word | |
1699 | * or memcmp with zero_page, whatever is better for particular architecture. | |
1700 | * Linus? | |
1701 | */ | |
1702 | static inline int all_zeroes(__le32 *p, __le32 *q) | |
1703 | { | |
1704 | while (p < q) | |
1705 | if (*p++) | |
1706 | return 0; | |
1707 | return 1; | |
1708 | } | |
1709 | ||
1710 | /** | |
1711 | * ext3_find_shared - find the indirect blocks for partial truncation. | |
1712 | * @inode: inode in question | |
1713 | * @depth: depth of the affected branch | |
1714 | * @offsets: offsets of pointers in that branch (see ext3_block_to_path) | |
1715 | * @chain: place to store the pointers to partial indirect blocks | |
1716 | * @top: place to the (detached) top of branch | |
1717 | * | |
1718 | * This is a helper function used by ext3_truncate(). | |
1719 | * | |
1720 | * When we do truncate() we may have to clean the ends of several | |
1721 | * indirect blocks but leave the blocks themselves alive. Block is | |
1722 | * partially truncated if some data below the new i_size is refered | |
1723 | * from it (and it is on the path to the first completely truncated | |
1724 | * data block, indeed). We have to free the top of that path along | |
1725 | * with everything to the right of the path. Since no allocation | |
1726 | * past the truncation point is possible until ext3_truncate() | |
1727 | * finishes, we may safely do the latter, but top of branch may | |
1728 | * require special attention - pageout below the truncation point | |
1729 | * might try to populate it. | |
1730 | * | |
1731 | * We atomically detach the top of branch from the tree, store the | |
1732 | * block number of its root in *@top, pointers to buffer_heads of | |
1733 | * partially truncated blocks - in @chain[].bh and pointers to | |
1734 | * their last elements that should not be removed - in | |
1735 | * @chain[].p. Return value is the pointer to last filled element | |
1736 | * of @chain. | |
1737 | * | |
1738 | * The work left to caller to do the actual freeing of subtrees: | |
1739 | * a) free the subtree starting from *@top | |
1740 | * b) free the subtrees whose roots are stored in | |
1741 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) | |
1742 | * c) free the subtrees growing from the inode past the @chain[0]. | |
1743 | * (no partially truncated stuff there). */ | |
1744 | ||
1745 | static Indirect *ext3_find_shared(struct inode *inode, | |
1746 | int depth, | |
1747 | int offsets[4], | |
1748 | Indirect chain[4], | |
1749 | __le32 *top) | |
1750 | { | |
1751 | Indirect *partial, *p; | |
1752 | int k, err; | |
1753 | ||
1754 | *top = 0; | |
1755 | /* Make k index the deepest non-null offest + 1 */ | |
1756 | for (k = depth; k > 1 && !offsets[k-1]; k--) | |
1757 | ; | |
1758 | partial = ext3_get_branch(inode, k, offsets, chain, &err); | |
1759 | /* Writer: pointers */ | |
1760 | if (!partial) | |
1761 | partial = chain + k-1; | |
1762 | /* | |
1763 | * If the branch acquired continuation since we've looked at it - | |
1764 | * fine, it should all survive and (new) top doesn't belong to us. | |
1765 | */ | |
1766 | if (!partial->key && *partial->p) | |
1767 | /* Writer: end */ | |
1768 | goto no_top; | |
1769 | for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) | |
1770 | ; | |
1771 | /* | |
1772 | * OK, we've found the last block that must survive. The rest of our | |
1773 | * branch should be detached before unlocking. However, if that rest | |
1774 | * of branch is all ours and does not grow immediately from the inode | |
1775 | * it's easier to cheat and just decrement partial->p. | |
1776 | */ | |
1777 | if (p == chain + k - 1 && p > chain) { | |
1778 | p->p--; | |
1779 | } else { | |
1780 | *top = *p->p; | |
1781 | /* Nope, don't do this in ext3. Must leave the tree intact */ | |
1782 | #if 0 | |
1783 | *p->p = 0; | |
1784 | #endif | |
1785 | } | |
1786 | /* Writer: end */ | |
1787 | ||
1788 | while(partial > p) | |
1789 | { | |
1790 | brelse(partial->bh); | |
1791 | partial--; | |
1792 | } | |
1793 | no_top: | |
1794 | return partial; | |
1795 | } | |
1796 | ||
1797 | /* | |
1798 | * Zero a number of block pointers in either an inode or an indirect block. | |
1799 | * If we restart the transaction we must again get write access to the | |
1800 | * indirect block for further modification. | |
1801 | * | |
1802 | * We release `count' blocks on disk, but (last - first) may be greater | |
1803 | * than `count' because there can be holes in there. | |
1804 | */ | |
1805 | static void | |
1806 | ext3_clear_blocks(handle_t *handle, struct inode *inode, struct buffer_head *bh, | |
1807 | unsigned long block_to_free, unsigned long count, | |
1808 | __le32 *first, __le32 *last) | |
1809 | { | |
1810 | __le32 *p; | |
1811 | if (try_to_extend_transaction(handle, inode)) { | |
1812 | if (bh) { | |
1813 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
1814 | ext3_journal_dirty_metadata(handle, bh); | |
1815 | } | |
1816 | ext3_mark_inode_dirty(handle, inode); | |
1817 | ext3_journal_test_restart(handle, inode); | |
1818 | if (bh) { | |
1819 | BUFFER_TRACE(bh, "retaking write access"); | |
1820 | ext3_journal_get_write_access(handle, bh); | |
1821 | } | |
1822 | } | |
1823 | ||
1824 | /* | |
1825 | * Any buffers which are on the journal will be in memory. We find | |
1826 | * them on the hash table so journal_revoke() will run journal_forget() | |
1827 | * on them. We've already detached each block from the file, so | |
1828 | * bforget() in journal_forget() should be safe. | |
1829 | * | |
1830 | * AKPM: turn on bforget in journal_forget()!!! | |
1831 | */ | |
1832 | for (p = first; p < last; p++) { | |
1833 | u32 nr = le32_to_cpu(*p); | |
1834 | if (nr) { | |
1835 | struct buffer_head *bh; | |
1836 | ||
1837 | *p = 0; | |
1838 | bh = sb_find_get_block(inode->i_sb, nr); | |
1839 | ext3_forget(handle, 0, inode, bh, nr); | |
1840 | } | |
1841 | } | |
1842 | ||
1843 | ext3_free_blocks(handle, inode, block_to_free, count); | |
1844 | } | |
1845 | ||
1846 | /** | |
1847 | * ext3_free_data - free a list of data blocks | |
1848 | * @handle: handle for this transaction | |
1849 | * @inode: inode we are dealing with | |
1850 | * @this_bh: indirect buffer_head which contains *@first and *@last | |
1851 | * @first: array of block numbers | |
1852 | * @last: points immediately past the end of array | |
1853 | * | |
1854 | * We are freeing all blocks refered from that array (numbers are stored as | |
1855 | * little-endian 32-bit) and updating @inode->i_blocks appropriately. | |
1856 | * | |
1857 | * We accumulate contiguous runs of blocks to free. Conveniently, if these | |
1858 | * blocks are contiguous then releasing them at one time will only affect one | |
1859 | * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't | |
1860 | * actually use a lot of journal space. | |
1861 | * | |
1862 | * @this_bh will be %NULL if @first and @last point into the inode's direct | |
1863 | * block pointers. | |
1864 | */ | |
1865 | static void ext3_free_data(handle_t *handle, struct inode *inode, | |
1866 | struct buffer_head *this_bh, | |
1867 | __le32 *first, __le32 *last) | |
1868 | { | |
1869 | unsigned long block_to_free = 0; /* Starting block # of a run */ | |
1870 | unsigned long count = 0; /* Number of blocks in the run */ | |
1871 | __le32 *block_to_free_p = NULL; /* Pointer into inode/ind | |
1872 | corresponding to | |
1873 | block_to_free */ | |
1874 | unsigned long nr; /* Current block # */ | |
1875 | __le32 *p; /* Pointer into inode/ind | |
1876 | for current block */ | |
1877 | int err; | |
1878 | ||
1879 | if (this_bh) { /* For indirect block */ | |
1880 | BUFFER_TRACE(this_bh, "get_write_access"); | |
1881 | err = ext3_journal_get_write_access(handle, this_bh); | |
1882 | /* Important: if we can't update the indirect pointers | |
1883 | * to the blocks, we can't free them. */ | |
1884 | if (err) | |
1885 | return; | |
1886 | } | |
1887 | ||
1888 | for (p = first; p < last; p++) { | |
1889 | nr = le32_to_cpu(*p); | |
1890 | if (nr) { | |
1891 | /* accumulate blocks to free if they're contiguous */ | |
1892 | if (count == 0) { | |
1893 | block_to_free = nr; | |
1894 | block_to_free_p = p; | |
1895 | count = 1; | |
1896 | } else if (nr == block_to_free + count) { | |
1897 | count++; | |
1898 | } else { | |
1899 | ext3_clear_blocks(handle, inode, this_bh, | |
1900 | block_to_free, | |
1901 | count, block_to_free_p, p); | |
1902 | block_to_free = nr; | |
1903 | block_to_free_p = p; | |
1904 | count = 1; | |
1905 | } | |
1906 | } | |
1907 | } | |
1908 | ||
1909 | if (count > 0) | |
1910 | ext3_clear_blocks(handle, inode, this_bh, block_to_free, | |
1911 | count, block_to_free_p, p); | |
1912 | ||
1913 | if (this_bh) { | |
1914 | BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata"); | |
1915 | ext3_journal_dirty_metadata(handle, this_bh); | |
1916 | } | |
1917 | } | |
1918 | ||
1919 | /** | |
1920 | * ext3_free_branches - free an array of branches | |
1921 | * @handle: JBD handle for this transaction | |
1922 | * @inode: inode we are dealing with | |
1923 | * @parent_bh: the buffer_head which contains *@first and *@last | |
1924 | * @first: array of block numbers | |
1925 | * @last: pointer immediately past the end of array | |
1926 | * @depth: depth of the branches to free | |
1927 | * | |
1928 | * We are freeing all blocks refered from these branches (numbers are | |
1929 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
1930 | * appropriately. | |
1931 | */ | |
1932 | static void ext3_free_branches(handle_t *handle, struct inode *inode, | |
1933 | struct buffer_head *parent_bh, | |
1934 | __le32 *first, __le32 *last, int depth) | |
1935 | { | |
1936 | unsigned long nr; | |
1937 | __le32 *p; | |
1938 | ||
1939 | if (is_handle_aborted(handle)) | |
1940 | return; | |
1941 | ||
1942 | if (depth--) { | |
1943 | struct buffer_head *bh; | |
1944 | int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
1945 | p = last; | |
1946 | while (--p >= first) { | |
1947 | nr = le32_to_cpu(*p); | |
1948 | if (!nr) | |
1949 | continue; /* A hole */ | |
1950 | ||
1951 | /* Go read the buffer for the next level down */ | |
1952 | bh = sb_bread(inode->i_sb, nr); | |
1953 | ||
1954 | /* | |
1955 | * A read failure? Report error and clear slot | |
1956 | * (should be rare). | |
1957 | */ | |
1958 | if (!bh) { | |
1959 | ext3_error(inode->i_sb, "ext3_free_branches", | |
1960 | "Read failure, inode=%ld, block=%ld", | |
1961 | inode->i_ino, nr); | |
1962 | continue; | |
1963 | } | |
1964 | ||
1965 | /* This zaps the entire block. Bottom up. */ | |
1966 | BUFFER_TRACE(bh, "free child branches"); | |
1967 | ext3_free_branches(handle, inode, bh, | |
1968 | (__le32*)bh->b_data, | |
1969 | (__le32*)bh->b_data + addr_per_block, | |
1970 | depth); | |
1971 | ||
1972 | /* | |
1973 | * We've probably journalled the indirect block several | |
1974 | * times during the truncate. But it's no longer | |
1975 | * needed and we now drop it from the transaction via | |
1976 | * journal_revoke(). | |
1977 | * | |
1978 | * That's easy if it's exclusively part of this | |
1979 | * transaction. But if it's part of the committing | |
1980 | * transaction then journal_forget() will simply | |
1981 | * brelse() it. That means that if the underlying | |
1982 | * block is reallocated in ext3_get_block(), | |
1983 | * unmap_underlying_metadata() will find this block | |
1984 | * and will try to get rid of it. damn, damn. | |
1985 | * | |
1986 | * If this block has already been committed to the | |
1987 | * journal, a revoke record will be written. And | |
1988 | * revoke records must be emitted *before* clearing | |
1989 | * this block's bit in the bitmaps. | |
1990 | */ | |
1991 | ext3_forget(handle, 1, inode, bh, bh->b_blocknr); | |
1992 | ||
1993 | /* | |
1994 | * Everything below this this pointer has been | |
1995 | * released. Now let this top-of-subtree go. | |
1996 | * | |
1997 | * We want the freeing of this indirect block to be | |
1998 | * atomic in the journal with the updating of the | |
1999 | * bitmap block which owns it. So make some room in | |
2000 | * the journal. | |
2001 | * | |
2002 | * We zero the parent pointer *after* freeing its | |
2003 | * pointee in the bitmaps, so if extend_transaction() | |
2004 | * for some reason fails to put the bitmap changes and | |
2005 | * the release into the same transaction, recovery | |
2006 | * will merely complain about releasing a free block, | |
2007 | * rather than leaking blocks. | |
2008 | */ | |
2009 | if (is_handle_aborted(handle)) | |
2010 | return; | |
2011 | if (try_to_extend_transaction(handle, inode)) { | |
2012 | ext3_mark_inode_dirty(handle, inode); | |
2013 | ext3_journal_test_restart(handle, inode); | |
2014 | } | |
2015 | ||
2016 | ext3_free_blocks(handle, inode, nr, 1); | |
2017 | ||
2018 | if (parent_bh) { | |
2019 | /* | |
2020 | * The block which we have just freed is | |
2021 | * pointed to by an indirect block: journal it | |
2022 | */ | |
2023 | BUFFER_TRACE(parent_bh, "get_write_access"); | |
2024 | if (!ext3_journal_get_write_access(handle, | |
2025 | parent_bh)){ | |
2026 | *p = 0; | |
2027 | BUFFER_TRACE(parent_bh, | |
2028 | "call ext3_journal_dirty_metadata"); | |
2029 | ext3_journal_dirty_metadata(handle, | |
2030 | parent_bh); | |
2031 | } | |
2032 | } | |
2033 | } | |
2034 | } else { | |
2035 | /* We have reached the bottom of the tree. */ | |
2036 | BUFFER_TRACE(parent_bh, "free data blocks"); | |
2037 | ext3_free_data(handle, inode, parent_bh, first, last); | |
2038 | } | |
2039 | } | |
2040 | ||
2041 | /* | |
2042 | * ext3_truncate() | |
2043 | * | |
2044 | * We block out ext3_get_block() block instantiations across the entire | |
2045 | * transaction, and VFS/VM ensures that ext3_truncate() cannot run | |
2046 | * simultaneously on behalf of the same inode. | |
2047 | * | |
2048 | * As we work through the truncate and commmit bits of it to the journal there | |
2049 | * is one core, guiding principle: the file's tree must always be consistent on | |
2050 | * disk. We must be able to restart the truncate after a crash. | |
2051 | * | |
2052 | * The file's tree may be transiently inconsistent in memory (although it | |
2053 | * probably isn't), but whenever we close off and commit a journal transaction, | |
2054 | * the contents of (the filesystem + the journal) must be consistent and | |
2055 | * restartable. It's pretty simple, really: bottom up, right to left (although | |
2056 | * left-to-right works OK too). | |
2057 | * | |
2058 | * Note that at recovery time, journal replay occurs *before* the restart of | |
2059 | * truncate against the orphan inode list. | |
2060 | * | |
2061 | * The committed inode has the new, desired i_size (which is the same as | |
2062 | * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see | |
2063 | * that this inode's truncate did not complete and it will again call | |
2064 | * ext3_truncate() to have another go. So there will be instantiated blocks | |
2065 | * to the right of the truncation point in a crashed ext3 filesystem. But | |
2066 | * that's fine - as long as they are linked from the inode, the post-crash | |
2067 | * ext3_truncate() run will find them and release them. | |
2068 | */ | |
2069 | ||
2070 | void ext3_truncate(struct inode * inode) | |
2071 | { | |
2072 | handle_t *handle; | |
2073 | struct ext3_inode_info *ei = EXT3_I(inode); | |
2074 | __le32 *i_data = ei->i_data; | |
2075 | int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
2076 | struct address_space *mapping = inode->i_mapping; | |
2077 | int offsets[4]; | |
2078 | Indirect chain[4]; | |
2079 | Indirect *partial; | |
2080 | __le32 nr = 0; | |
2081 | int n; | |
2082 | long last_block; | |
2083 | unsigned blocksize = inode->i_sb->s_blocksize; | |
2084 | struct page *page; | |
2085 | ||
2086 | if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || | |
2087 | S_ISLNK(inode->i_mode))) | |
2088 | return; | |
2089 | if (ext3_inode_is_fast_symlink(inode)) | |
2090 | return; | |
2091 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
2092 | return; | |
2093 | ||
2094 | /* | |
2095 | * We have to lock the EOF page here, because lock_page() nests | |
2096 | * outside journal_start(). | |
2097 | */ | |
2098 | if ((inode->i_size & (blocksize - 1)) == 0) { | |
2099 | /* Block boundary? Nothing to do */ | |
2100 | page = NULL; | |
2101 | } else { | |
2102 | page = grab_cache_page(mapping, | |
2103 | inode->i_size >> PAGE_CACHE_SHIFT); | |
2104 | if (!page) | |
2105 | return; | |
2106 | } | |
2107 | ||
2108 | handle = start_transaction(inode); | |
2109 | if (IS_ERR(handle)) { | |
2110 | if (page) { | |
2111 | clear_highpage(page); | |
2112 | flush_dcache_page(page); | |
2113 | unlock_page(page); | |
2114 | page_cache_release(page); | |
2115 | } | |
2116 | return; /* AKPM: return what? */ | |
2117 | } | |
2118 | ||
2119 | last_block = (inode->i_size + blocksize-1) | |
2120 | >> EXT3_BLOCK_SIZE_BITS(inode->i_sb); | |
2121 | ||
2122 | if (page) | |
2123 | ext3_block_truncate_page(handle, page, mapping, inode->i_size); | |
2124 | ||
2125 | n = ext3_block_to_path(inode, last_block, offsets, NULL); | |
2126 | if (n == 0) | |
2127 | goto out_stop; /* error */ | |
2128 | ||
2129 | /* | |
2130 | * OK. This truncate is going to happen. We add the inode to the | |
2131 | * orphan list, so that if this truncate spans multiple transactions, | |
2132 | * and we crash, we will resume the truncate when the filesystem | |
2133 | * recovers. It also marks the inode dirty, to catch the new size. | |
2134 | * | |
2135 | * Implication: the file must always be in a sane, consistent | |
2136 | * truncatable state while each transaction commits. | |
2137 | */ | |
2138 | if (ext3_orphan_add(handle, inode)) | |
2139 | goto out_stop; | |
2140 | ||
2141 | /* | |
2142 | * The orphan list entry will now protect us from any crash which | |
2143 | * occurs before the truncate completes, so it is now safe to propagate | |
2144 | * the new, shorter inode size (held for now in i_size) into the | |
2145 | * on-disk inode. We do this via i_disksize, which is the value which | |
2146 | * ext3 *really* writes onto the disk inode. | |
2147 | */ | |
2148 | ei->i_disksize = inode->i_size; | |
2149 | ||
2150 | /* | |
2151 | * From here we block out all ext3_get_block() callers who want to | |
2152 | * modify the block allocation tree. | |
2153 | */ | |
2154 | down(&ei->truncate_sem); | |
2155 | ||
2156 | if (n == 1) { /* direct blocks */ | |
2157 | ext3_free_data(handle, inode, NULL, i_data+offsets[0], | |
2158 | i_data + EXT3_NDIR_BLOCKS); | |
2159 | goto do_indirects; | |
2160 | } | |
2161 | ||
2162 | partial = ext3_find_shared(inode, n, offsets, chain, &nr); | |
2163 | /* Kill the top of shared branch (not detached) */ | |
2164 | if (nr) { | |
2165 | if (partial == chain) { | |
2166 | /* Shared branch grows from the inode */ | |
2167 | ext3_free_branches(handle, inode, NULL, | |
2168 | &nr, &nr+1, (chain+n-1) - partial); | |
2169 | *partial->p = 0; | |
2170 | /* | |
2171 | * We mark the inode dirty prior to restart, | |
2172 | * and prior to stop. No need for it here. | |
2173 | */ | |
2174 | } else { | |
2175 | /* Shared branch grows from an indirect block */ | |
2176 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
2177 | ext3_free_branches(handle, inode, partial->bh, | |
2178 | partial->p, | |
2179 | partial->p+1, (chain+n-1) - partial); | |
2180 | } | |
2181 | } | |
2182 | /* Clear the ends of indirect blocks on the shared branch */ | |
2183 | while (partial > chain) { | |
2184 | ext3_free_branches(handle, inode, partial->bh, partial->p + 1, | |
2185 | (__le32*)partial->bh->b_data+addr_per_block, | |
2186 | (chain+n-1) - partial); | |
2187 | BUFFER_TRACE(partial->bh, "call brelse"); | |
2188 | brelse (partial->bh); | |
2189 | partial--; | |
2190 | } | |
2191 | do_indirects: | |
2192 | /* Kill the remaining (whole) subtrees */ | |
2193 | switch (offsets[0]) { | |
2194 | default: | |
2195 | nr = i_data[EXT3_IND_BLOCK]; | |
2196 | if (nr) { | |
2197 | ext3_free_branches(handle, inode, NULL, | |
2198 | &nr, &nr+1, 1); | |
2199 | i_data[EXT3_IND_BLOCK] = 0; | |
2200 | } | |
2201 | case EXT3_IND_BLOCK: | |
2202 | nr = i_data[EXT3_DIND_BLOCK]; | |
2203 | if (nr) { | |
2204 | ext3_free_branches(handle, inode, NULL, | |
2205 | &nr, &nr+1, 2); | |
2206 | i_data[EXT3_DIND_BLOCK] = 0; | |
2207 | } | |
2208 | case EXT3_DIND_BLOCK: | |
2209 | nr = i_data[EXT3_TIND_BLOCK]; | |
2210 | if (nr) { | |
2211 | ext3_free_branches(handle, inode, NULL, | |
2212 | &nr, &nr+1, 3); | |
2213 | i_data[EXT3_TIND_BLOCK] = 0; | |
2214 | } | |
2215 | case EXT3_TIND_BLOCK: | |
2216 | ; | |
2217 | } | |
2218 | ||
2219 | ext3_discard_reservation(inode); | |
2220 | ||
2221 | up(&ei->truncate_sem); | |
2222 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; | |
2223 | ext3_mark_inode_dirty(handle, inode); | |
2224 | ||
2225 | /* In a multi-transaction truncate, we only make the final | |
2226 | * transaction synchronous */ | |
2227 | if (IS_SYNC(inode)) | |
2228 | handle->h_sync = 1; | |
2229 | out_stop: | |
2230 | /* | |
2231 | * If this was a simple ftruncate(), and the file will remain alive | |
2232 | * then we need to clear up the orphan record which we created above. | |
2233 | * However, if this was a real unlink then we were called by | |
2234 | * ext3_delete_inode(), and we allow that function to clean up the | |
2235 | * orphan info for us. | |
2236 | */ | |
2237 | if (inode->i_nlink) | |
2238 | ext3_orphan_del(handle, inode); | |
2239 | ||
2240 | ext3_journal_stop(handle); | |
2241 | } | |
2242 | ||
2243 | static unsigned long ext3_get_inode_block(struct super_block *sb, | |
2244 | unsigned long ino, struct ext3_iloc *iloc) | |
2245 | { | |
2246 | unsigned long desc, group_desc, block_group; | |
2247 | unsigned long offset, block; | |
2248 | struct buffer_head *bh; | |
2249 | struct ext3_group_desc * gdp; | |
2250 | ||
2251 | ||
2252 | if ((ino != EXT3_ROOT_INO && | |
2253 | ino != EXT3_JOURNAL_INO && | |
2254 | ino != EXT3_RESIZE_INO && | |
2255 | ino < EXT3_FIRST_INO(sb)) || | |
2256 | ino > le32_to_cpu( | |
2257 | EXT3_SB(sb)->s_es->s_inodes_count)) { | |
2258 | ext3_error (sb, "ext3_get_inode_block", | |
2259 | "bad inode number: %lu", ino); | |
2260 | return 0; | |
2261 | } | |
2262 | block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); | |
2263 | if (block_group >= EXT3_SB(sb)->s_groups_count) { | |
2264 | ext3_error (sb, "ext3_get_inode_block", | |
2265 | "group >= groups count"); | |
2266 | return 0; | |
2267 | } | |
2268 | smp_rmb(); | |
2269 | group_desc = block_group >> EXT3_DESC_PER_BLOCK_BITS(sb); | |
2270 | desc = block_group & (EXT3_DESC_PER_BLOCK(sb) - 1); | |
2271 | bh = EXT3_SB(sb)->s_group_desc[group_desc]; | |
2272 | if (!bh) { | |
2273 | ext3_error (sb, "ext3_get_inode_block", | |
2274 | "Descriptor not loaded"); | |
2275 | return 0; | |
2276 | } | |
2277 | ||
2278 | gdp = (struct ext3_group_desc *) bh->b_data; | |
2279 | /* | |
2280 | * Figure out the offset within the block group inode table | |
2281 | */ | |
2282 | offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) * | |
2283 | EXT3_INODE_SIZE(sb); | |
2284 | block = le32_to_cpu(gdp[desc].bg_inode_table) + | |
2285 | (offset >> EXT3_BLOCK_SIZE_BITS(sb)); | |
2286 | ||
2287 | iloc->block_group = block_group; | |
2288 | iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1); | |
2289 | return block; | |
2290 | } | |
2291 | ||
2292 | /* | |
2293 | * ext3_get_inode_loc returns with an extra refcount against the inode's | |
2294 | * underlying buffer_head on success. If 'in_mem' is true, we have all | |
2295 | * data in memory that is needed to recreate the on-disk version of this | |
2296 | * inode. | |
2297 | */ | |
2298 | static int __ext3_get_inode_loc(struct inode *inode, | |
2299 | struct ext3_iloc *iloc, int in_mem) | |
2300 | { | |
2301 | unsigned long block; | |
2302 | struct buffer_head *bh; | |
2303 | ||
2304 | block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc); | |
2305 | if (!block) | |
2306 | return -EIO; | |
2307 | ||
2308 | bh = sb_getblk(inode->i_sb, block); | |
2309 | if (!bh) { | |
2310 | ext3_error (inode->i_sb, "ext3_get_inode_loc", | |
2311 | "unable to read inode block - " | |
2312 | "inode=%lu, block=%lu", inode->i_ino, block); | |
2313 | return -EIO; | |
2314 | } | |
2315 | if (!buffer_uptodate(bh)) { | |
2316 | lock_buffer(bh); | |
2317 | if (buffer_uptodate(bh)) { | |
2318 | /* someone brought it uptodate while we waited */ | |
2319 | unlock_buffer(bh); | |
2320 | goto has_buffer; | |
2321 | } | |
2322 | ||
2323 | /* | |
2324 | * If we have all information of the inode in memory and this | |
2325 | * is the only valid inode in the block, we need not read the | |
2326 | * block. | |
2327 | */ | |
2328 | if (in_mem) { | |
2329 | struct buffer_head *bitmap_bh; | |
2330 | struct ext3_group_desc *desc; | |
2331 | int inodes_per_buffer; | |
2332 | int inode_offset, i; | |
2333 | int block_group; | |
2334 | int start; | |
2335 | ||
2336 | block_group = (inode->i_ino - 1) / | |
2337 | EXT3_INODES_PER_GROUP(inode->i_sb); | |
2338 | inodes_per_buffer = bh->b_size / | |
2339 | EXT3_INODE_SIZE(inode->i_sb); | |
2340 | inode_offset = ((inode->i_ino - 1) % | |
2341 | EXT3_INODES_PER_GROUP(inode->i_sb)); | |
2342 | start = inode_offset & ~(inodes_per_buffer - 1); | |
2343 | ||
2344 | /* Is the inode bitmap in cache? */ | |
2345 | desc = ext3_get_group_desc(inode->i_sb, | |
2346 | block_group, NULL); | |
2347 | if (!desc) | |
2348 | goto make_io; | |
2349 | ||
2350 | bitmap_bh = sb_getblk(inode->i_sb, | |
2351 | le32_to_cpu(desc->bg_inode_bitmap)); | |
2352 | if (!bitmap_bh) | |
2353 | goto make_io; | |
2354 | ||
2355 | /* | |
2356 | * If the inode bitmap isn't in cache then the | |
2357 | * optimisation may end up performing two reads instead | |
2358 | * of one, so skip it. | |
2359 | */ | |
2360 | if (!buffer_uptodate(bitmap_bh)) { | |
2361 | brelse(bitmap_bh); | |
2362 | goto make_io; | |
2363 | } | |
2364 | for (i = start; i < start + inodes_per_buffer; i++) { | |
2365 | if (i == inode_offset) | |
2366 | continue; | |
2367 | if (ext3_test_bit(i, bitmap_bh->b_data)) | |
2368 | break; | |
2369 | } | |
2370 | brelse(bitmap_bh); | |
2371 | if (i == start + inodes_per_buffer) { | |
2372 | /* all other inodes are free, so skip I/O */ | |
2373 | memset(bh->b_data, 0, bh->b_size); | |
2374 | set_buffer_uptodate(bh); | |
2375 | unlock_buffer(bh); | |
2376 | goto has_buffer; | |
2377 | } | |
2378 | } | |
2379 | ||
2380 | make_io: | |
2381 | /* | |
2382 | * There are other valid inodes in the buffer, this inode | |
2383 | * has in-inode xattrs, or we don't have this inode in memory. | |
2384 | * Read the block from disk. | |
2385 | */ | |
2386 | get_bh(bh); | |
2387 | bh->b_end_io = end_buffer_read_sync; | |
2388 | submit_bh(READ, bh); | |
2389 | wait_on_buffer(bh); | |
2390 | if (!buffer_uptodate(bh)) { | |
2391 | ext3_error(inode->i_sb, "ext3_get_inode_loc", | |
2392 | "unable to read inode block - " | |
2393 | "inode=%lu, block=%lu", | |
2394 | inode->i_ino, block); | |
2395 | brelse(bh); | |
2396 | return -EIO; | |
2397 | } | |
2398 | } | |
2399 | has_buffer: | |
2400 | iloc->bh = bh; | |
2401 | return 0; | |
2402 | } | |
2403 | ||
2404 | int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc) | |
2405 | { | |
2406 | /* We have all inode data except xattrs in memory here. */ | |
2407 | return __ext3_get_inode_loc(inode, iloc, | |
2408 | !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR)); | |
2409 | } | |
2410 | ||
2411 | void ext3_set_inode_flags(struct inode *inode) | |
2412 | { | |
2413 | unsigned int flags = EXT3_I(inode)->i_flags; | |
2414 | ||
2415 | inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); | |
2416 | if (flags & EXT3_SYNC_FL) | |
2417 | inode->i_flags |= S_SYNC; | |
2418 | if (flags & EXT3_APPEND_FL) | |
2419 | inode->i_flags |= S_APPEND; | |
2420 | if (flags & EXT3_IMMUTABLE_FL) | |
2421 | inode->i_flags |= S_IMMUTABLE; | |
2422 | if (flags & EXT3_NOATIME_FL) | |
2423 | inode->i_flags |= S_NOATIME; | |
2424 | if (flags & EXT3_DIRSYNC_FL) | |
2425 | inode->i_flags |= S_DIRSYNC; | |
2426 | } | |
2427 | ||
2428 | void ext3_read_inode(struct inode * inode) | |
2429 | { | |
2430 | struct ext3_iloc iloc; | |
2431 | struct ext3_inode *raw_inode; | |
2432 | struct ext3_inode_info *ei = EXT3_I(inode); | |
2433 | struct buffer_head *bh; | |
2434 | int block; | |
2435 | ||
2436 | #ifdef CONFIG_EXT3_FS_POSIX_ACL | |
2437 | ei->i_acl = EXT3_ACL_NOT_CACHED; | |
2438 | ei->i_default_acl = EXT3_ACL_NOT_CACHED; | |
2439 | #endif | |
2440 | ei->i_block_alloc_info = NULL; | |
2441 | ||
2442 | if (__ext3_get_inode_loc(inode, &iloc, 0)) | |
2443 | goto bad_inode; | |
2444 | bh = iloc.bh; | |
2445 | raw_inode = ext3_raw_inode(&iloc); | |
2446 | inode->i_mode = le16_to_cpu(raw_inode->i_mode); | |
2447 | inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); | |
2448 | inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); | |
2449 | if(!(test_opt (inode->i_sb, NO_UID32))) { | |
2450 | inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; | |
2451 | inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; | |
2452 | } | |
2453 | inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); | |
2454 | inode->i_size = le32_to_cpu(raw_inode->i_size); | |
2455 | inode->i_atime.tv_sec = le32_to_cpu(raw_inode->i_atime); | |
2456 | inode->i_ctime.tv_sec = le32_to_cpu(raw_inode->i_ctime); | |
2457 | inode->i_mtime.tv_sec = le32_to_cpu(raw_inode->i_mtime); | |
2458 | inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0; | |
2459 | ||
2460 | ei->i_state = 0; | |
2461 | ei->i_dir_start_lookup = 0; | |
2462 | ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); | |
2463 | /* We now have enough fields to check if the inode was active or not. | |
2464 | * This is needed because nfsd might try to access dead inodes | |
2465 | * the test is that same one that e2fsck uses | |
2466 | * NeilBrown 1999oct15 | |
2467 | */ | |
2468 | if (inode->i_nlink == 0) { | |
2469 | if (inode->i_mode == 0 || | |
2470 | !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) { | |
2471 | /* this inode is deleted */ | |
2472 | brelse (bh); | |
2473 | goto bad_inode; | |
2474 | } | |
2475 | /* The only unlinked inodes we let through here have | |
2476 | * valid i_mode and are being read by the orphan | |
2477 | * recovery code: that's fine, we're about to complete | |
2478 | * the process of deleting those. */ | |
2479 | } | |
2480 | inode->i_blksize = PAGE_SIZE; /* This is the optimal IO size | |
2481 | * (for stat), not the fs block | |
2482 | * size */ | |
2483 | inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); | |
2484 | ei->i_flags = le32_to_cpu(raw_inode->i_flags); | |
2485 | #ifdef EXT3_FRAGMENTS | |
2486 | ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); | |
2487 | ei->i_frag_no = raw_inode->i_frag; | |
2488 | ei->i_frag_size = raw_inode->i_fsize; | |
2489 | #endif | |
2490 | ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); | |
2491 | if (!S_ISREG(inode->i_mode)) { | |
2492 | ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); | |
2493 | } else { | |
2494 | inode->i_size |= | |
2495 | ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; | |
2496 | } | |
2497 | ei->i_disksize = inode->i_size; | |
2498 | inode->i_generation = le32_to_cpu(raw_inode->i_generation); | |
2499 | ei->i_block_group = iloc.block_group; | |
2500 | /* | |
2501 | * NOTE! The in-memory inode i_data array is in little-endian order | |
2502 | * even on big-endian machines: we do NOT byteswap the block numbers! | |
2503 | */ | |
2504 | for (block = 0; block < EXT3_N_BLOCKS; block++) | |
2505 | ei->i_data[block] = raw_inode->i_block[block]; | |
2506 | INIT_LIST_HEAD(&ei->i_orphan); | |
2507 | ||
2508 | if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 && | |
2509 | EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) { | |
2510 | /* | |
2511 | * When mke2fs creates big inodes it does not zero out | |
2512 | * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE, | |
2513 | * so ignore those first few inodes. | |
2514 | */ | |
2515 | ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); | |
2516 | if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > | |
2517 | EXT3_INODE_SIZE(inode->i_sb)) | |
2518 | goto bad_inode; | |
2519 | if (ei->i_extra_isize == 0) { | |
2520 | /* The extra space is currently unused. Use it. */ | |
2521 | ei->i_extra_isize = sizeof(struct ext3_inode) - | |
2522 | EXT3_GOOD_OLD_INODE_SIZE; | |
2523 | } else { | |
2524 | __le32 *magic = (void *)raw_inode + | |
2525 | EXT3_GOOD_OLD_INODE_SIZE + | |
2526 | ei->i_extra_isize; | |
2527 | if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC)) | |
2528 | ei->i_state |= EXT3_STATE_XATTR; | |
2529 | } | |
2530 | } else | |
2531 | ei->i_extra_isize = 0; | |
2532 | ||
2533 | if (S_ISREG(inode->i_mode)) { | |
2534 | inode->i_op = &ext3_file_inode_operations; | |
2535 | inode->i_fop = &ext3_file_operations; | |
2536 | ext3_set_aops(inode); | |
2537 | } else if (S_ISDIR(inode->i_mode)) { | |
2538 | inode->i_op = &ext3_dir_inode_operations; | |
2539 | inode->i_fop = &ext3_dir_operations; | |
2540 | } else if (S_ISLNK(inode->i_mode)) { | |
2541 | if (ext3_inode_is_fast_symlink(inode)) | |
2542 | inode->i_op = &ext3_fast_symlink_inode_operations; | |
2543 | else { | |
2544 | inode->i_op = &ext3_symlink_inode_operations; | |
2545 | ext3_set_aops(inode); | |
2546 | } | |
2547 | } else { | |
2548 | inode->i_op = &ext3_special_inode_operations; | |
2549 | if (raw_inode->i_block[0]) | |
2550 | init_special_inode(inode, inode->i_mode, | |
2551 | old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); | |
2552 | else | |
2553 | init_special_inode(inode, inode->i_mode, | |
2554 | new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); | |
2555 | } | |
2556 | brelse (iloc.bh); | |
2557 | ext3_set_inode_flags(inode); | |
2558 | return; | |
2559 | ||
2560 | bad_inode: | |
2561 | make_bad_inode(inode); | |
2562 | return; | |
2563 | } | |
2564 | ||
2565 | /* | |
2566 | * Post the struct inode info into an on-disk inode location in the | |
2567 | * buffer-cache. This gobbles the caller's reference to the | |
2568 | * buffer_head in the inode location struct. | |
2569 | * | |
2570 | * The caller must have write access to iloc->bh. | |
2571 | */ | |
2572 | static int ext3_do_update_inode(handle_t *handle, | |
2573 | struct inode *inode, | |
2574 | struct ext3_iloc *iloc) | |
2575 | { | |
2576 | struct ext3_inode *raw_inode = ext3_raw_inode(iloc); | |
2577 | struct ext3_inode_info *ei = EXT3_I(inode); | |
2578 | struct buffer_head *bh = iloc->bh; | |
2579 | int err = 0, rc, block; | |
2580 | ||
2581 | /* For fields not not tracking in the in-memory inode, | |
2582 | * initialise them to zero for new inodes. */ | |
2583 | if (ei->i_state & EXT3_STATE_NEW) | |
2584 | memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size); | |
2585 | ||
2586 | raw_inode->i_mode = cpu_to_le16(inode->i_mode); | |
2587 | if(!(test_opt(inode->i_sb, NO_UID32))) { | |
2588 | raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid)); | |
2589 | raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid)); | |
2590 | /* | |
2591 | * Fix up interoperability with old kernels. Otherwise, old inodes get | |
2592 | * re-used with the upper 16 bits of the uid/gid intact | |
2593 | */ | |
2594 | if(!ei->i_dtime) { | |
2595 | raw_inode->i_uid_high = | |
2596 | cpu_to_le16(high_16_bits(inode->i_uid)); | |
2597 | raw_inode->i_gid_high = | |
2598 | cpu_to_le16(high_16_bits(inode->i_gid)); | |
2599 | } else { | |
2600 | raw_inode->i_uid_high = 0; | |
2601 | raw_inode->i_gid_high = 0; | |
2602 | } | |
2603 | } else { | |
2604 | raw_inode->i_uid_low = | |
2605 | cpu_to_le16(fs_high2lowuid(inode->i_uid)); | |
2606 | raw_inode->i_gid_low = | |
2607 | cpu_to_le16(fs_high2lowgid(inode->i_gid)); | |
2608 | raw_inode->i_uid_high = 0; | |
2609 | raw_inode->i_gid_high = 0; | |
2610 | } | |
2611 | raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); | |
2612 | raw_inode->i_size = cpu_to_le32(ei->i_disksize); | |
2613 | raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); | |
2614 | raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); | |
2615 | raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); | |
2616 | raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); | |
2617 | raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); | |
2618 | raw_inode->i_flags = cpu_to_le32(ei->i_flags); | |
2619 | #ifdef EXT3_FRAGMENTS | |
2620 | raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); | |
2621 | raw_inode->i_frag = ei->i_frag_no; | |
2622 | raw_inode->i_fsize = ei->i_frag_size; | |
2623 | #endif | |
2624 | raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); | |
2625 | if (!S_ISREG(inode->i_mode)) { | |
2626 | raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); | |
2627 | } else { | |
2628 | raw_inode->i_size_high = | |
2629 | cpu_to_le32(ei->i_disksize >> 32); | |
2630 | if (ei->i_disksize > 0x7fffffffULL) { | |
2631 | struct super_block *sb = inode->i_sb; | |
2632 | if (!EXT3_HAS_RO_COMPAT_FEATURE(sb, | |
2633 | EXT3_FEATURE_RO_COMPAT_LARGE_FILE) || | |
2634 | EXT3_SB(sb)->s_es->s_rev_level == | |
2635 | cpu_to_le32(EXT3_GOOD_OLD_REV)) { | |
2636 | /* If this is the first large file | |
2637 | * created, add a flag to the superblock. | |
2638 | */ | |
2639 | err = ext3_journal_get_write_access(handle, | |
2640 | EXT3_SB(sb)->s_sbh); | |
2641 | if (err) | |
2642 | goto out_brelse; | |
2643 | ext3_update_dynamic_rev(sb); | |
2644 | EXT3_SET_RO_COMPAT_FEATURE(sb, | |
2645 | EXT3_FEATURE_RO_COMPAT_LARGE_FILE); | |
2646 | sb->s_dirt = 1; | |
2647 | handle->h_sync = 1; | |
2648 | err = ext3_journal_dirty_metadata(handle, | |
2649 | EXT3_SB(sb)->s_sbh); | |
2650 | } | |
2651 | } | |
2652 | } | |
2653 | raw_inode->i_generation = cpu_to_le32(inode->i_generation); | |
2654 | if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { | |
2655 | if (old_valid_dev(inode->i_rdev)) { | |
2656 | raw_inode->i_block[0] = | |
2657 | cpu_to_le32(old_encode_dev(inode->i_rdev)); | |
2658 | raw_inode->i_block[1] = 0; | |
2659 | } else { | |
2660 | raw_inode->i_block[0] = 0; | |
2661 | raw_inode->i_block[1] = | |
2662 | cpu_to_le32(new_encode_dev(inode->i_rdev)); | |
2663 | raw_inode->i_block[2] = 0; | |
2664 | } | |
2665 | } else for (block = 0; block < EXT3_N_BLOCKS; block++) | |
2666 | raw_inode->i_block[block] = ei->i_data[block]; | |
2667 | ||
ff87b37d | 2668 | if (ei->i_extra_isize) |
1da177e4 LT |
2669 | raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); |
2670 | ||
2671 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
2672 | rc = ext3_journal_dirty_metadata(handle, bh); | |
2673 | if (!err) | |
2674 | err = rc; | |
2675 | ei->i_state &= ~EXT3_STATE_NEW; | |
2676 | ||
2677 | out_brelse: | |
2678 | brelse (bh); | |
2679 | ext3_std_error(inode->i_sb, err); | |
2680 | return err; | |
2681 | } | |
2682 | ||
2683 | /* | |
2684 | * ext3_write_inode() | |
2685 | * | |
2686 | * We are called from a few places: | |
2687 | * | |
2688 | * - Within generic_file_write() for O_SYNC files. | |
2689 | * Here, there will be no transaction running. We wait for any running | |
2690 | * trasnaction to commit. | |
2691 | * | |
2692 | * - Within sys_sync(), kupdate and such. | |
2693 | * We wait on commit, if tol to. | |
2694 | * | |
2695 | * - Within prune_icache() (PF_MEMALLOC == true) | |
2696 | * Here we simply return. We can't afford to block kswapd on the | |
2697 | * journal commit. | |
2698 | * | |
2699 | * In all cases it is actually safe for us to return without doing anything, | |
2700 | * because the inode has been copied into a raw inode buffer in | |
2701 | * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for | |
2702 | * knfsd. | |
2703 | * | |
2704 | * Note that we are absolutely dependent upon all inode dirtiers doing the | |
2705 | * right thing: they *must* call mark_inode_dirty() after dirtying info in | |
2706 | * which we are interested. | |
2707 | * | |
2708 | * It would be a bug for them to not do this. The code: | |
2709 | * | |
2710 | * mark_inode_dirty(inode) | |
2711 | * stuff(); | |
2712 | * inode->i_size = expr; | |
2713 | * | |
2714 | * is in error because a kswapd-driven write_inode() could occur while | |
2715 | * `stuff()' is running, and the new i_size will be lost. Plus the inode | |
2716 | * will no longer be on the superblock's dirty inode list. | |
2717 | */ | |
2718 | int ext3_write_inode(struct inode *inode, int wait) | |
2719 | { | |
2720 | if (current->flags & PF_MEMALLOC) | |
2721 | return 0; | |
2722 | ||
2723 | if (ext3_journal_current_handle()) { | |
2724 | jbd_debug(0, "called recursively, non-PF_MEMALLOC!\n"); | |
2725 | dump_stack(); | |
2726 | return -EIO; | |
2727 | } | |
2728 | ||
2729 | if (!wait) | |
2730 | return 0; | |
2731 | ||
2732 | return ext3_force_commit(inode->i_sb); | |
2733 | } | |
2734 | ||
2735 | /* | |
2736 | * ext3_setattr() | |
2737 | * | |
2738 | * Called from notify_change. | |
2739 | * | |
2740 | * We want to trap VFS attempts to truncate the file as soon as | |
2741 | * possible. In particular, we want to make sure that when the VFS | |
2742 | * shrinks i_size, we put the inode on the orphan list and modify | |
2743 | * i_disksize immediately, so that during the subsequent flushing of | |
2744 | * dirty pages and freeing of disk blocks, we can guarantee that any | |
2745 | * commit will leave the blocks being flushed in an unused state on | |
2746 | * disk. (On recovery, the inode will get truncated and the blocks will | |
2747 | * be freed, so we have a strong guarantee that no future commit will | |
2748 | * leave these blocks visible to the user.) | |
2749 | * | |
2750 | * Called with inode->sem down. | |
2751 | */ | |
2752 | int ext3_setattr(struct dentry *dentry, struct iattr *attr) | |
2753 | { | |
2754 | struct inode *inode = dentry->d_inode; | |
2755 | int error, rc = 0; | |
2756 | const unsigned int ia_valid = attr->ia_valid; | |
2757 | ||
2758 | error = inode_change_ok(inode, attr); | |
2759 | if (error) | |
2760 | return error; | |
2761 | ||
2762 | if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || | |
2763 | (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) { | |
2764 | handle_t *handle; | |
2765 | ||
2766 | /* (user+group)*(old+new) structure, inode write (sb, | |
2767 | * inode block, ? - but truncate inode update has it) */ | |
1f54587b JK |
2768 | handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+ |
2769 | EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3); | |
1da177e4 LT |
2770 | if (IS_ERR(handle)) { |
2771 | error = PTR_ERR(handle); | |
2772 | goto err_out; | |
2773 | } | |
2774 | error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0; | |
2775 | if (error) { | |
2776 | ext3_journal_stop(handle); | |
2777 | return error; | |
2778 | } | |
2779 | /* Update corresponding info in inode so that everything is in | |
2780 | * one transaction */ | |
2781 | if (attr->ia_valid & ATTR_UID) | |
2782 | inode->i_uid = attr->ia_uid; | |
2783 | if (attr->ia_valid & ATTR_GID) | |
2784 | inode->i_gid = attr->ia_gid; | |
2785 | error = ext3_mark_inode_dirty(handle, inode); | |
2786 | ext3_journal_stop(handle); | |
2787 | } | |
2788 | ||
2789 | if (S_ISREG(inode->i_mode) && | |
2790 | attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) { | |
2791 | handle_t *handle; | |
2792 | ||
2793 | handle = ext3_journal_start(inode, 3); | |
2794 | if (IS_ERR(handle)) { | |
2795 | error = PTR_ERR(handle); | |
2796 | goto err_out; | |
2797 | } | |
2798 | ||
2799 | error = ext3_orphan_add(handle, inode); | |
2800 | EXT3_I(inode)->i_disksize = attr->ia_size; | |
2801 | rc = ext3_mark_inode_dirty(handle, inode); | |
2802 | if (!error) | |
2803 | error = rc; | |
2804 | ext3_journal_stop(handle); | |
2805 | } | |
2806 | ||
2807 | rc = inode_setattr(inode, attr); | |
2808 | ||
2809 | /* If inode_setattr's call to ext3_truncate failed to get a | |
2810 | * transaction handle at all, we need to clean up the in-core | |
2811 | * orphan list manually. */ | |
2812 | if (inode->i_nlink) | |
2813 | ext3_orphan_del(NULL, inode); | |
2814 | ||
2815 | if (!rc && (ia_valid & ATTR_MODE)) | |
2816 | rc = ext3_acl_chmod(inode); | |
2817 | ||
2818 | err_out: | |
2819 | ext3_std_error(inode->i_sb, error); | |
2820 | if (!error) | |
2821 | error = rc; | |
2822 | return error; | |
2823 | } | |
2824 | ||
2825 | ||
2826 | /* | |
2827 | * akpm: how many blocks doth make a writepage()? | |
2828 | * | |
2829 | * With N blocks per page, it may be: | |
2830 | * N data blocks | |
2831 | * 2 indirect block | |
2832 | * 2 dindirect | |
2833 | * 1 tindirect | |
2834 | * N+5 bitmap blocks (from the above) | |
2835 | * N+5 group descriptor summary blocks | |
2836 | * 1 inode block | |
2837 | * 1 superblock. | |
2838 | * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files | |
2839 | * | |
2840 | * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS | |
2841 | * | |
2842 | * With ordered or writeback data it's the same, less the N data blocks. | |
2843 | * | |
2844 | * If the inode's direct blocks can hold an integral number of pages then a | |
2845 | * page cannot straddle two indirect blocks, and we can only touch one indirect | |
2846 | * and dindirect block, and the "5" above becomes "3". | |
2847 | * | |
2848 | * This still overestimates under most circumstances. If we were to pass the | |
2849 | * start and end offsets in here as well we could do block_to_path() on each | |
2850 | * block and work out the exact number of indirects which are touched. Pah. | |
2851 | */ | |
2852 | ||
2853 | static int ext3_writepage_trans_blocks(struct inode *inode) | |
2854 | { | |
2855 | int bpp = ext3_journal_blocks_per_page(inode); | |
2856 | int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3; | |
2857 | int ret; | |
2858 | ||
2859 | if (ext3_should_journal_data(inode)) | |
2860 | ret = 3 * (bpp + indirects) + 2; | |
2861 | else | |
2862 | ret = 2 * (bpp + indirects) + 2; | |
2863 | ||
2864 | #ifdef CONFIG_QUOTA | |
2865 | /* We know that structure was already allocated during DQUOT_INIT so | |
2866 | * we will be updating only the data blocks + inodes */ | |
1f54587b | 2867 | ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb); |
1da177e4 LT |
2868 | #endif |
2869 | ||
2870 | return ret; | |
2871 | } | |
2872 | ||
2873 | /* | |
2874 | * The caller must have previously called ext3_reserve_inode_write(). | |
2875 | * Give this, we know that the caller already has write access to iloc->bh. | |
2876 | */ | |
2877 | int ext3_mark_iloc_dirty(handle_t *handle, | |
2878 | struct inode *inode, struct ext3_iloc *iloc) | |
2879 | { | |
2880 | int err = 0; | |
2881 | ||
2882 | /* the do_update_inode consumes one bh->b_count */ | |
2883 | get_bh(iloc->bh); | |
2884 | ||
2885 | /* ext3_do_update_inode() does journal_dirty_metadata */ | |
2886 | err = ext3_do_update_inode(handle, inode, iloc); | |
2887 | put_bh(iloc->bh); | |
2888 | return err; | |
2889 | } | |
2890 | ||
2891 | /* | |
2892 | * On success, We end up with an outstanding reference count against | |
2893 | * iloc->bh. This _must_ be cleaned up later. | |
2894 | */ | |
2895 | ||
2896 | int | |
2897 | ext3_reserve_inode_write(handle_t *handle, struct inode *inode, | |
2898 | struct ext3_iloc *iloc) | |
2899 | { | |
2900 | int err = 0; | |
2901 | if (handle) { | |
2902 | err = ext3_get_inode_loc(inode, iloc); | |
2903 | if (!err) { | |
2904 | BUFFER_TRACE(iloc->bh, "get_write_access"); | |
2905 | err = ext3_journal_get_write_access(handle, iloc->bh); | |
2906 | if (err) { | |
2907 | brelse(iloc->bh); | |
2908 | iloc->bh = NULL; | |
2909 | } | |
2910 | } | |
2911 | } | |
2912 | ext3_std_error(inode->i_sb, err); | |
2913 | return err; | |
2914 | } | |
2915 | ||
2916 | /* | |
2917 | * akpm: What we do here is to mark the in-core inode as clean | |
2918 | * with respect to inode dirtiness (it may still be data-dirty). | |
2919 | * This means that the in-core inode may be reaped by prune_icache | |
2920 | * without having to perform any I/O. This is a very good thing, | |
2921 | * because *any* task may call prune_icache - even ones which | |
2922 | * have a transaction open against a different journal. | |
2923 | * | |
2924 | * Is this cheating? Not really. Sure, we haven't written the | |
2925 | * inode out, but prune_icache isn't a user-visible syncing function. | |
2926 | * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) | |
2927 | * we start and wait on commits. | |
2928 | * | |
2929 | * Is this efficient/effective? Well, we're being nice to the system | |
2930 | * by cleaning up our inodes proactively so they can be reaped | |
2931 | * without I/O. But we are potentially leaving up to five seconds' | |
2932 | * worth of inodes floating about which prune_icache wants us to | |
2933 | * write out. One way to fix that would be to get prune_icache() | |
2934 | * to do a write_super() to free up some memory. It has the desired | |
2935 | * effect. | |
2936 | */ | |
2937 | int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode) | |
2938 | { | |
2939 | struct ext3_iloc iloc; | |
2940 | int err; | |
2941 | ||
2942 | might_sleep(); | |
2943 | err = ext3_reserve_inode_write(handle, inode, &iloc); | |
2944 | if (!err) | |
2945 | err = ext3_mark_iloc_dirty(handle, inode, &iloc); | |
2946 | return err; | |
2947 | } | |
2948 | ||
2949 | /* | |
2950 | * akpm: ext3_dirty_inode() is called from __mark_inode_dirty() | |
2951 | * | |
2952 | * We're really interested in the case where a file is being extended. | |
2953 | * i_size has been changed by generic_commit_write() and we thus need | |
2954 | * to include the updated inode in the current transaction. | |
2955 | * | |
2956 | * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks | |
2957 | * are allocated to the file. | |
2958 | * | |
2959 | * If the inode is marked synchronous, we don't honour that here - doing | |
2960 | * so would cause a commit on atime updates, which we don't bother doing. | |
2961 | * We handle synchronous inodes at the highest possible level. | |
2962 | */ | |
2963 | void ext3_dirty_inode(struct inode *inode) | |
2964 | { | |
2965 | handle_t *current_handle = ext3_journal_current_handle(); | |
2966 | handle_t *handle; | |
2967 | ||
2968 | handle = ext3_journal_start(inode, 2); | |
2969 | if (IS_ERR(handle)) | |
2970 | goto out; | |
2971 | if (current_handle && | |
2972 | current_handle->h_transaction != handle->h_transaction) { | |
2973 | /* This task has a transaction open against a different fs */ | |
2974 | printk(KERN_EMERG "%s: transactions do not match!\n", | |
2975 | __FUNCTION__); | |
2976 | } else { | |
2977 | jbd_debug(5, "marking dirty. outer handle=%p\n", | |
2978 | current_handle); | |
2979 | ext3_mark_inode_dirty(handle, inode); | |
2980 | } | |
2981 | ext3_journal_stop(handle); | |
2982 | out: | |
2983 | return; | |
2984 | } | |
2985 | ||
2986 | #ifdef AKPM | |
2987 | /* | |
2988 | * Bind an inode's backing buffer_head into this transaction, to prevent | |
2989 | * it from being flushed to disk early. Unlike | |
2990 | * ext3_reserve_inode_write, this leaves behind no bh reference and | |
2991 | * returns no iloc structure, so the caller needs to repeat the iloc | |
2992 | * lookup to mark the inode dirty later. | |
2993 | */ | |
2994 | static inline int | |
2995 | ext3_pin_inode(handle_t *handle, struct inode *inode) | |
2996 | { | |
2997 | struct ext3_iloc iloc; | |
2998 | ||
2999 | int err = 0; | |
3000 | if (handle) { | |
3001 | err = ext3_get_inode_loc(inode, &iloc); | |
3002 | if (!err) { | |
3003 | BUFFER_TRACE(iloc.bh, "get_write_access"); | |
3004 | err = journal_get_write_access(handle, iloc.bh); | |
3005 | if (!err) | |
3006 | err = ext3_journal_dirty_metadata(handle, | |
3007 | iloc.bh); | |
3008 | brelse(iloc.bh); | |
3009 | } | |
3010 | } | |
3011 | ext3_std_error(inode->i_sb, err); | |
3012 | return err; | |
3013 | } | |
3014 | #endif | |
3015 | ||
3016 | int ext3_change_inode_journal_flag(struct inode *inode, int val) | |
3017 | { | |
3018 | journal_t *journal; | |
3019 | handle_t *handle; | |
3020 | int err; | |
3021 | ||
3022 | /* | |
3023 | * We have to be very careful here: changing a data block's | |
3024 | * journaling status dynamically is dangerous. If we write a | |
3025 | * data block to the journal, change the status and then delete | |
3026 | * that block, we risk forgetting to revoke the old log record | |
3027 | * from the journal and so a subsequent replay can corrupt data. | |
3028 | * So, first we make sure that the journal is empty and that | |
3029 | * nobody is changing anything. | |
3030 | */ | |
3031 | ||
3032 | journal = EXT3_JOURNAL(inode); | |
3033 | if (is_journal_aborted(journal) || IS_RDONLY(inode)) | |
3034 | return -EROFS; | |
3035 | ||
3036 | journal_lock_updates(journal); | |
3037 | journal_flush(journal); | |
3038 | ||
3039 | /* | |
3040 | * OK, there are no updates running now, and all cached data is | |
3041 | * synced to disk. We are now in a completely consistent state | |
3042 | * which doesn't have anything in the journal, and we know that | |
3043 | * no filesystem updates are running, so it is safe to modify | |
3044 | * the inode's in-core data-journaling state flag now. | |
3045 | */ | |
3046 | ||
3047 | if (val) | |
3048 | EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL; | |
3049 | else | |
3050 | EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL; | |
3051 | ext3_set_aops(inode); | |
3052 | ||
3053 | journal_unlock_updates(journal); | |
3054 | ||
3055 | /* Finally we can mark the inode as dirty. */ | |
3056 | ||
3057 | handle = ext3_journal_start(inode, 1); | |
3058 | if (IS_ERR(handle)) | |
3059 | return PTR_ERR(handle); | |
3060 | ||
3061 | err = ext3_mark_inode_dirty(handle, inode); | |
3062 | handle->h_sync = 1; | |
3063 | ext3_journal_stop(handle); | |
3064 | ext3_std_error(inode->i_sb, err); | |
3065 | ||
3066 | return err; | |
3067 | } |