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Commit | Line | Data |
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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 | |
e9ad5620 | 16 | * (sct@redhat.com), 1993, 1998 |
1da177e4 LT |
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 | |
e9ad5620 | 20 | * (jj@sunsite.ms.mff.cuni.cz) |
1da177e4 LT |
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> | |
1da177e4 LT |
30 | #include <linux/highuid.h> |
31 | #include <linux/pagemap.h> | |
32 | #include <linux/quotaops.h> | |
33 | #include <linux/string.h> | |
34 | #include <linux/buffer_head.h> | |
35 | #include <linux/writeback.h> | |
36 | #include <linux/mpage.h> | |
37 | #include <linux/uio.h> | |
caa38fb0 | 38 | #include <linux/bio.h> |
68c9d702 | 39 | #include <linux/fiemap.h> |
b5ed3112 | 40 | #include <linux/namei.h> |
1da177e4 LT |
41 | #include "xattr.h" |
42 | #include "acl.h" | |
43 | ||
44 | static int ext3_writepage_trans_blocks(struct inode *inode); | |
45 | ||
46 | /* | |
47 | * Test whether an inode is a fast symlink. | |
48 | */ | |
d6859bfc | 49 | static int ext3_inode_is_fast_symlink(struct inode *inode) |
1da177e4 LT |
50 | { |
51 | int ea_blocks = EXT3_I(inode)->i_file_acl ? | |
52 | (inode->i_sb->s_blocksize >> 9) : 0; | |
53 | ||
d6859bfc | 54 | return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0); |
1da177e4 LT |
55 | } |
56 | ||
d6859bfc AM |
57 | /* |
58 | * The ext3 forget function must perform a revoke if we are freeing data | |
1da177e4 | 59 | * which has been journaled. Metadata (eg. indirect blocks) must be |
ae6ddcc5 | 60 | * revoked in all cases. |
1da177e4 LT |
61 | * |
62 | * "bh" may be NULL: a metadata block may have been freed from memory | |
63 | * but there may still be a record of it in the journal, and that record | |
64 | * still needs to be revoked. | |
65 | */ | |
d6859bfc | 66 | int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode, |
1c2bf374 | 67 | struct buffer_head *bh, ext3_fsblk_t blocknr) |
1da177e4 LT |
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) | |
e05b6b52 | 100 | ext3_abort(inode->i_sb, __func__, |
1da177e4 LT |
101 | "error %d when attempting revoke", err); |
102 | BUFFER_TRACE(bh, "exit"); | |
103 | return err; | |
104 | } | |
105 | ||
106 | /* | |
d6859bfc | 107 | * Work out how many blocks we need to proceed with the next chunk of a |
1da177e4 LT |
108 | * truncate transaction. |
109 | */ | |
ae6ddcc5 | 110 | static unsigned long blocks_for_truncate(struct inode *inode) |
1da177e4 LT |
111 | { |
112 | unsigned long needed; | |
113 | ||
114 | needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9); | |
115 | ||
116 | /* Give ourselves just enough room to cope with inodes in which | |
117 | * i_blocks is corrupt: we've seen disk corruptions in the past | |
118 | * which resulted in random data in an inode which looked enough | |
119 | * like a regular file for ext3 to try to delete it. Things | |
120 | * will go a bit crazy if that happens, but at least we should | |
121 | * try not to panic the whole kernel. */ | |
122 | if (needed < 2) | |
123 | needed = 2; | |
124 | ||
125 | /* But we need to bound the transaction so we don't overflow the | |
126 | * journal. */ | |
ae6ddcc5 | 127 | if (needed > EXT3_MAX_TRANS_DATA) |
1da177e4 LT |
128 | needed = EXT3_MAX_TRANS_DATA; |
129 | ||
1f54587b | 130 | return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed; |
1da177e4 LT |
131 | } |
132 | ||
ae6ddcc5 | 133 | /* |
1da177e4 LT |
134 | * Truncate transactions can be complex and absolutely huge. So we need to |
135 | * be able to restart the transaction at a conventient checkpoint to make | |
136 | * sure we don't overflow the journal. | |
137 | * | |
138 | * start_transaction gets us a new handle for a truncate transaction, | |
139 | * and extend_transaction tries to extend the existing one a bit. If | |
140 | * extend fails, we need to propagate the failure up and restart the | |
ae6ddcc5 | 141 | * transaction in the top-level truncate loop. --sct |
1da177e4 | 142 | */ |
ae6ddcc5 | 143 | static handle_t *start_transaction(struct inode *inode) |
1da177e4 LT |
144 | { |
145 | handle_t *result; | |
146 | ||
147 | result = ext3_journal_start(inode, blocks_for_truncate(inode)); | |
148 | if (!IS_ERR(result)) | |
149 | return result; | |
150 | ||
151 | ext3_std_error(inode->i_sb, PTR_ERR(result)); | |
152 | return result; | |
153 | } | |
154 | ||
155 | /* | |
156 | * Try to extend this transaction for the purposes of truncation. | |
157 | * | |
158 | * Returns 0 if we managed to create more room. If we can't create more | |
159 | * room, and the transaction must be restarted we return 1. | |
160 | */ | |
161 | static int try_to_extend_transaction(handle_t *handle, struct inode *inode) | |
162 | { | |
163 | if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS) | |
164 | return 0; | |
165 | if (!ext3_journal_extend(handle, blocks_for_truncate(inode))) | |
166 | return 0; | |
167 | return 1; | |
168 | } | |
169 | ||
170 | /* | |
171 | * Restart the transaction associated with *handle. This does a commit, | |
172 | * so before we call here everything must be consistently dirtied against | |
173 | * this transaction. | |
174 | */ | |
175 | static int ext3_journal_test_restart(handle_t *handle, struct inode *inode) | |
176 | { | |
177 | jbd_debug(2, "restarting handle %p\n", handle); | |
178 | return ext3_journal_restart(handle, blocks_for_truncate(inode)); | |
179 | } | |
180 | ||
181 | /* | |
182 | * Called at the last iput() if i_nlink is zero. | |
183 | */ | |
184 | void ext3_delete_inode (struct inode * inode) | |
185 | { | |
186 | handle_t *handle; | |
187 | ||
fef26658 MF |
188 | truncate_inode_pages(&inode->i_data, 0); |
189 | ||
1da177e4 LT |
190 | if (is_bad_inode(inode)) |
191 | goto no_delete; | |
192 | ||
193 | handle = start_transaction(inode); | |
194 | if (IS_ERR(handle)) { | |
d6859bfc AM |
195 | /* |
196 | * If we're going to skip the normal cleanup, we still need to | |
197 | * make sure that the in-core orphan linked list is properly | |
198 | * cleaned up. | |
199 | */ | |
1da177e4 LT |
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 | ||
ae6ddcc5 | 220 | /* |
1da177e4 LT |
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 | |
ae6ddcc5 | 225 | * fails. |
1da177e4 LT |
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 | ||
1da177e4 LT |
238 | typedef struct { |
239 | __le32 *p; | |
240 | __le32 key; | |
241 | struct buffer_head *bh; | |
242 | } Indirect; | |
243 | ||
244 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) | |
245 | { | |
246 | p->key = *(p->p = v); | |
247 | p->bh = bh; | |
248 | } | |
249 | ||
d6859bfc | 250 | static int verify_chain(Indirect *from, Indirect *to) |
1da177e4 LT |
251 | { |
252 | while (from <= to && from->key == *from->p) | |
253 | from++; | |
254 | return (from > to); | |
255 | } | |
256 | ||
257 | /** | |
258 | * ext3_block_to_path - parse the block number into array of offsets | |
259 | * @inode: inode in question (we are only interested in its superblock) | |
260 | * @i_block: block number to be parsed | |
261 | * @offsets: array to store the offsets in | |
262 | * @boundary: set this non-zero if the referred-to block is likely to be | |
263 | * followed (on disk) by an indirect block. | |
264 | * | |
265 | * To store the locations of file's data ext3 uses a data structure common | |
266 | * for UNIX filesystems - tree of pointers anchored in the inode, with | |
267 | * data blocks at leaves and indirect blocks in intermediate nodes. | |
268 | * This function translates the block number into path in that tree - | |
269 | * return value is the path length and @offsets[n] is the offset of | |
270 | * pointer to (n+1)th node in the nth one. If @block is out of range | |
271 | * (negative or too large) warning is printed and zero returned. | |
272 | * | |
273 | * Note: function doesn't find node addresses, so no IO is needed. All | |
274 | * we need to know is the capacity of indirect blocks (taken from the | |
275 | * inode->i_sb). | |
276 | */ | |
277 | ||
278 | /* | |
279 | * Portability note: the last comparison (check that we fit into triple | |
280 | * indirect block) is spelled differently, because otherwise on an | |
281 | * architecture with 32-bit longs and 8Kb pages we might get into trouble | |
282 | * if our filesystem had 8Kb blocks. We might use long long, but that would | |
283 | * kill us on x86. Oh, well, at least the sign propagation does not matter - | |
284 | * i_block would have to be negative in the very beginning, so we would not | |
285 | * get there at all. | |
286 | */ | |
287 | ||
288 | static int ext3_block_to_path(struct inode *inode, | |
289 | long i_block, int offsets[4], int *boundary) | |
290 | { | |
291 | int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
292 | int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb); | |
293 | const long direct_blocks = EXT3_NDIR_BLOCKS, | |
294 | indirect_blocks = ptrs, | |
295 | double_blocks = (1 << (ptrs_bits * 2)); | |
296 | int n = 0; | |
297 | int final = 0; | |
298 | ||
299 | if (i_block < 0) { | |
300 | ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0"); | |
301 | } else if (i_block < direct_blocks) { | |
302 | offsets[n++] = i_block; | |
303 | final = direct_blocks; | |
304 | } else if ( (i_block -= direct_blocks) < indirect_blocks) { | |
305 | offsets[n++] = EXT3_IND_BLOCK; | |
306 | offsets[n++] = i_block; | |
307 | final = ptrs; | |
308 | } else if ((i_block -= indirect_blocks) < double_blocks) { | |
309 | offsets[n++] = EXT3_DIND_BLOCK; | |
310 | offsets[n++] = i_block >> ptrs_bits; | |
311 | offsets[n++] = i_block & (ptrs - 1); | |
312 | final = ptrs; | |
313 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { | |
314 | offsets[n++] = EXT3_TIND_BLOCK; | |
315 | offsets[n++] = i_block >> (ptrs_bits * 2); | |
316 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); | |
317 | offsets[n++] = i_block & (ptrs - 1); | |
318 | final = ptrs; | |
319 | } else { | |
d6859bfc | 320 | ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big"); |
1da177e4 LT |
321 | } |
322 | if (boundary) | |
89747d36 | 323 | *boundary = final - 1 - (i_block & (ptrs - 1)); |
1da177e4 LT |
324 | return n; |
325 | } | |
326 | ||
327 | /** | |
328 | * ext3_get_branch - read the chain of indirect blocks leading to data | |
329 | * @inode: inode in question | |
330 | * @depth: depth of the chain (1 - direct pointer, etc.) | |
331 | * @offsets: offsets of pointers in inode/indirect blocks | |
332 | * @chain: place to store the result | |
333 | * @err: here we store the error value | |
334 | * | |
335 | * Function fills the array of triples <key, p, bh> and returns %NULL | |
336 | * if everything went OK or the pointer to the last filled triple | |
337 | * (incomplete one) otherwise. Upon the return chain[i].key contains | |
338 | * the number of (i+1)-th block in the chain (as it is stored in memory, | |
339 | * i.e. little-endian 32-bit), chain[i].p contains the address of that | |
340 | * number (it points into struct inode for i==0 and into the bh->b_data | |
341 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect | |
342 | * block for i>0 and NULL for i==0. In other words, it holds the block | |
343 | * numbers of the chain, addresses they were taken from (and where we can | |
344 | * verify that chain did not change) and buffer_heads hosting these | |
345 | * numbers. | |
346 | * | |
347 | * Function stops when it stumbles upon zero pointer (absent block) | |
348 | * (pointer to last triple returned, *@err == 0) | |
349 | * or when it gets an IO error reading an indirect block | |
350 | * (ditto, *@err == -EIO) | |
351 | * or when it notices that chain had been changed while it was reading | |
352 | * (ditto, *@err == -EAGAIN) | |
353 | * or when it reads all @depth-1 indirect blocks successfully and finds | |
354 | * the whole chain, all way to the data (returns %NULL, *err == 0). | |
355 | */ | |
356 | static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets, | |
357 | Indirect chain[4], int *err) | |
358 | { | |
359 | struct super_block *sb = inode->i_sb; | |
360 | Indirect *p = chain; | |
361 | struct buffer_head *bh; | |
362 | ||
363 | *err = 0; | |
364 | /* i_data is not going away, no lock needed */ | |
365 | add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets); | |
366 | if (!p->key) | |
367 | goto no_block; | |
368 | while (--depth) { | |
369 | bh = sb_bread(sb, le32_to_cpu(p->key)); | |
370 | if (!bh) | |
371 | goto failure; | |
372 | /* Reader: pointers */ | |
373 | if (!verify_chain(chain, p)) | |
374 | goto changed; | |
375 | add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); | |
376 | /* Reader: end */ | |
377 | if (!p->key) | |
378 | goto no_block; | |
379 | } | |
380 | return NULL; | |
381 | ||
382 | changed: | |
383 | brelse(bh); | |
384 | *err = -EAGAIN; | |
385 | goto no_block; | |
386 | failure: | |
387 | *err = -EIO; | |
388 | no_block: | |
389 | return p; | |
390 | } | |
391 | ||
392 | /** | |
393 | * ext3_find_near - find a place for allocation with sufficient locality | |
394 | * @inode: owner | |
395 | * @ind: descriptor of indirect block. | |
396 | * | |
1cc8dcf5 | 397 | * This function returns the preferred place for block allocation. |
1da177e4 LT |
398 | * It is used when heuristic for sequential allocation fails. |
399 | * Rules are: | |
400 | * + if there is a block to the left of our position - allocate near it. | |
401 | * + if pointer will live in indirect block - allocate near that block. | |
402 | * + if pointer will live in inode - allocate in the same | |
ae6ddcc5 | 403 | * cylinder group. |
1da177e4 LT |
404 | * |
405 | * In the latter case we colour the starting block by the callers PID to | |
406 | * prevent it from clashing with concurrent allocations for a different inode | |
407 | * in the same block group. The PID is used here so that functionally related | |
408 | * files will be close-by on-disk. | |
409 | * | |
410 | * Caller must make sure that @ind is valid and will stay that way. | |
411 | */ | |
43d23f90 | 412 | static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind) |
1da177e4 LT |
413 | { |
414 | struct ext3_inode_info *ei = EXT3_I(inode); | |
415 | __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data; | |
416 | __le32 *p; | |
43d23f90 MC |
417 | ext3_fsblk_t bg_start; |
418 | ext3_grpblk_t colour; | |
1da177e4 LT |
419 | |
420 | /* Try to find previous block */ | |
d6859bfc | 421 | for (p = ind->p - 1; p >= start; p--) { |
1da177e4 LT |
422 | if (*p) |
423 | return le32_to_cpu(*p); | |
d6859bfc | 424 | } |
1da177e4 LT |
425 | |
426 | /* No such thing, so let's try location of indirect block */ | |
427 | if (ind->bh) | |
428 | return ind->bh->b_blocknr; | |
429 | ||
430 | /* | |
d6859bfc AM |
431 | * It is going to be referred to from the inode itself? OK, just put it |
432 | * into the same cylinder group then. | |
1da177e4 | 433 | */ |
43d23f90 | 434 | bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group); |
1da177e4 LT |
435 | colour = (current->pid % 16) * |
436 | (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
437 | return bg_start + colour; | |
438 | } | |
439 | ||
440 | /** | |
1cc8dcf5 | 441 | * ext3_find_goal - find a preferred place for allocation. |
1da177e4 LT |
442 | * @inode: owner |
443 | * @block: block we want | |
1da177e4 | 444 | * @partial: pointer to the last triple within a chain |
1da177e4 | 445 | * |
1cc8dcf5 | 446 | * Normally this function find the preferred place for block allocation, |
fb01bfda | 447 | * returns it. |
1da177e4 LT |
448 | */ |
449 | ||
43d23f90 | 450 | static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block, |
fb01bfda | 451 | Indirect *partial) |
1da177e4 | 452 | { |
d6859bfc AM |
453 | struct ext3_block_alloc_info *block_i; |
454 | ||
455 | block_i = EXT3_I(inode)->i_block_alloc_info; | |
1da177e4 LT |
456 | |
457 | /* | |
458 | * try the heuristic for sequential allocation, | |
459 | * failing that at least try to get decent locality. | |
460 | */ | |
461 | if (block_i && (block == block_i->last_alloc_logical_block + 1) | |
462 | && (block_i->last_alloc_physical_block != 0)) { | |
fe55c452 | 463 | return block_i->last_alloc_physical_block + 1; |
1da177e4 LT |
464 | } |
465 | ||
fe55c452 | 466 | return ext3_find_near(inode, partial); |
1da177e4 | 467 | } |
d6859bfc | 468 | |
b47b2478 MC |
469 | /** |
470 | * ext3_blks_to_allocate: Look up the block map and count the number | |
471 | * of direct blocks need to be allocated for the given branch. | |
472 | * | |
e9ad5620 | 473 | * @branch: chain of indirect blocks |
b47b2478 MC |
474 | * @k: number of blocks need for indirect blocks |
475 | * @blks: number of data blocks to be mapped. | |
476 | * @blocks_to_boundary: the offset in the indirect block | |
477 | * | |
478 | * return the total number of blocks to be allocate, including the | |
479 | * direct and indirect blocks. | |
480 | */ | |
d6859bfc | 481 | static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks, |
b47b2478 MC |
482 | int blocks_to_boundary) |
483 | { | |
484 | unsigned long count = 0; | |
485 | ||
486 | /* | |
487 | * Simple case, [t,d]Indirect block(s) has not allocated yet | |
488 | * then it's clear blocks on that path have not allocated | |
489 | */ | |
490 | if (k > 0) { | |
d6859bfc | 491 | /* right now we don't handle cross boundary allocation */ |
b47b2478 MC |
492 | if (blks < blocks_to_boundary + 1) |
493 | count += blks; | |
494 | else | |
495 | count += blocks_to_boundary + 1; | |
496 | return count; | |
497 | } | |
498 | ||
499 | count++; | |
500 | while (count < blks && count <= blocks_to_boundary && | |
501 | le32_to_cpu(*(branch[0].p + count)) == 0) { | |
502 | count++; | |
503 | } | |
504 | return count; | |
505 | } | |
506 | ||
507 | /** | |
508 | * ext3_alloc_blocks: multiple allocate blocks needed for a branch | |
509 | * @indirect_blks: the number of blocks need to allocate for indirect | |
510 | * blocks | |
511 | * | |
512 | * @new_blocks: on return it will store the new block numbers for | |
513 | * the indirect blocks(if needed) and the first direct block, | |
514 | * @blks: on return it will store the total number of allocated | |
515 | * direct blocks | |
516 | */ | |
517 | static int ext3_alloc_blocks(handle_t *handle, struct inode *inode, | |
43d23f90 MC |
518 | ext3_fsblk_t goal, int indirect_blks, int blks, |
519 | ext3_fsblk_t new_blocks[4], int *err) | |
b47b2478 MC |
520 | { |
521 | int target, i; | |
522 | unsigned long count = 0; | |
523 | int index = 0; | |
43d23f90 | 524 | ext3_fsblk_t current_block = 0; |
b47b2478 MC |
525 | int ret = 0; |
526 | ||
527 | /* | |
528 | * Here we try to allocate the requested multiple blocks at once, | |
529 | * on a best-effort basis. | |
530 | * To build a branch, we should allocate blocks for | |
531 | * the indirect blocks(if not allocated yet), and at least | |
532 | * the first direct block of this branch. That's the | |
533 | * minimum number of blocks need to allocate(required) | |
534 | */ | |
535 | target = blks + indirect_blks; | |
536 | ||
537 | while (1) { | |
538 | count = target; | |
539 | /* allocating blocks for indirect blocks and direct blocks */ | |
d6859bfc | 540 | current_block = ext3_new_blocks(handle,inode,goal,&count,err); |
b47b2478 MC |
541 | if (*err) |
542 | goto failed_out; | |
543 | ||
544 | target -= count; | |
545 | /* allocate blocks for indirect blocks */ | |
546 | while (index < indirect_blks && count) { | |
547 | new_blocks[index++] = current_block++; | |
548 | count--; | |
549 | } | |
550 | ||
551 | if (count > 0) | |
552 | break; | |
553 | } | |
554 | ||
555 | /* save the new block number for the first direct block */ | |
556 | new_blocks[index] = current_block; | |
557 | ||
558 | /* total number of blocks allocated for direct blocks */ | |
559 | ret = count; | |
560 | *err = 0; | |
561 | return ret; | |
562 | failed_out: | |
563 | for (i = 0; i <index; i++) | |
564 | ext3_free_blocks(handle, inode, new_blocks[i], 1); | |
565 | return ret; | |
566 | } | |
1da177e4 LT |
567 | |
568 | /** | |
569 | * ext3_alloc_branch - allocate and set up a chain of blocks. | |
570 | * @inode: owner | |
b47b2478 MC |
571 | * @indirect_blks: number of allocated indirect blocks |
572 | * @blks: number of allocated direct blocks | |
1da177e4 LT |
573 | * @offsets: offsets (in the blocks) to store the pointers to next. |
574 | * @branch: place to store the chain in. | |
575 | * | |
b47b2478 | 576 | * This function allocates blocks, zeroes out all but the last one, |
1da177e4 LT |
577 | * links them into chain and (if we are synchronous) writes them to disk. |
578 | * In other words, it prepares a branch that can be spliced onto the | |
579 | * inode. It stores the information about that chain in the branch[], in | |
580 | * the same format as ext3_get_branch() would do. We are calling it after | |
581 | * we had read the existing part of chain and partial points to the last | |
582 | * triple of that (one with zero ->key). Upon the exit we have the same | |
5b116879 | 583 | * picture as after the successful ext3_get_block(), except that in one |
1da177e4 LT |
584 | * place chain is disconnected - *branch->p is still zero (we did not |
585 | * set the last link), but branch->key contains the number that should | |
586 | * be placed into *branch->p to fill that gap. | |
587 | * | |
588 | * If allocation fails we free all blocks we've allocated (and forget | |
589 | * their buffer_heads) and return the error value the from failed | |
590 | * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain | |
591 | * as described above and return 0. | |
592 | */ | |
1da177e4 | 593 | static int ext3_alloc_branch(handle_t *handle, struct inode *inode, |
43d23f90 | 594 | int indirect_blks, int *blks, ext3_fsblk_t goal, |
b47b2478 | 595 | int *offsets, Indirect *branch) |
1da177e4 LT |
596 | { |
597 | int blocksize = inode->i_sb->s_blocksize; | |
b47b2478 | 598 | int i, n = 0; |
1da177e4 | 599 | int err = 0; |
b47b2478 MC |
600 | struct buffer_head *bh; |
601 | int num; | |
43d23f90 MC |
602 | ext3_fsblk_t new_blocks[4]; |
603 | ext3_fsblk_t current_block; | |
1da177e4 | 604 | |
b47b2478 MC |
605 | num = ext3_alloc_blocks(handle, inode, goal, indirect_blks, |
606 | *blks, new_blocks, &err); | |
607 | if (err) | |
608 | return err; | |
1da177e4 | 609 | |
b47b2478 MC |
610 | branch[0].key = cpu_to_le32(new_blocks[0]); |
611 | /* | |
612 | * metadata blocks and data blocks are allocated. | |
613 | */ | |
614 | for (n = 1; n <= indirect_blks; n++) { | |
615 | /* | |
616 | * Get buffer_head for parent block, zero it out | |
617 | * and set the pointer to new one, then send | |
618 | * parent to disk. | |
619 | */ | |
620 | bh = sb_getblk(inode->i_sb, new_blocks[n-1]); | |
621 | branch[n].bh = bh; | |
622 | lock_buffer(bh); | |
623 | BUFFER_TRACE(bh, "call get_create_access"); | |
624 | err = ext3_journal_get_create_access(handle, bh); | |
625 | if (err) { | |
1da177e4 | 626 | unlock_buffer(bh); |
b47b2478 MC |
627 | brelse(bh); |
628 | goto failed; | |
629 | } | |
1da177e4 | 630 | |
b47b2478 MC |
631 | memset(bh->b_data, 0, blocksize); |
632 | branch[n].p = (__le32 *) bh->b_data + offsets[n]; | |
633 | branch[n].key = cpu_to_le32(new_blocks[n]); | |
634 | *branch[n].p = branch[n].key; | |
635 | if ( n == indirect_blks) { | |
636 | current_block = new_blocks[n]; | |
637 | /* | |
638 | * End of chain, update the last new metablock of | |
639 | * the chain to point to the new allocated | |
640 | * data blocks numbers | |
641 | */ | |
642 | for (i=1; i < num; i++) | |
643 | *(branch[n].p + i) = cpu_to_le32(++current_block); | |
1da177e4 | 644 | } |
b47b2478 MC |
645 | BUFFER_TRACE(bh, "marking uptodate"); |
646 | set_buffer_uptodate(bh); | |
647 | unlock_buffer(bh); | |
1da177e4 | 648 | |
b47b2478 MC |
649 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); |
650 | err = ext3_journal_dirty_metadata(handle, bh); | |
651 | if (err) | |
652 | goto failed; | |
653 | } | |
654 | *blks = num; | |
655 | return err; | |
656 | failed: | |
1da177e4 | 657 | /* Allocation failed, free what we already allocated */ |
b47b2478 | 658 | for (i = 1; i <= n ; i++) { |
1da177e4 LT |
659 | BUFFER_TRACE(branch[i].bh, "call journal_forget"); |
660 | ext3_journal_forget(handle, branch[i].bh); | |
661 | } | |
b47b2478 MC |
662 | for (i = 0; i <indirect_blks; i++) |
663 | ext3_free_blocks(handle, inode, new_blocks[i], 1); | |
664 | ||
665 | ext3_free_blocks(handle, inode, new_blocks[i], num); | |
666 | ||
1da177e4 LT |
667 | return err; |
668 | } | |
669 | ||
670 | /** | |
d6859bfc AM |
671 | * ext3_splice_branch - splice the allocated branch onto inode. |
672 | * @inode: owner | |
673 | * @block: (logical) number of block we are adding | |
674 | * @chain: chain of indirect blocks (with a missing link - see | |
675 | * ext3_alloc_branch) | |
676 | * @where: location of missing link | |
677 | * @num: number of indirect blocks we are adding | |
678 | * @blks: number of direct blocks we are adding | |
679 | * | |
680 | * This function fills the missing link and does all housekeeping needed in | |
681 | * inode (->i_blocks, etc.). In case of success we end up with the full | |
682 | * chain to new block and return 0. | |
1da177e4 | 683 | */ |
d6859bfc AM |
684 | static int ext3_splice_branch(handle_t *handle, struct inode *inode, |
685 | long block, Indirect *where, int num, int blks) | |
1da177e4 LT |
686 | { |
687 | int i; | |
688 | int err = 0; | |
d6859bfc | 689 | struct ext3_block_alloc_info *block_i; |
43d23f90 | 690 | ext3_fsblk_t current_block; |
d6859bfc AM |
691 | |
692 | block_i = EXT3_I(inode)->i_block_alloc_info; | |
1da177e4 LT |
693 | /* |
694 | * If we're splicing into a [td]indirect block (as opposed to the | |
695 | * inode) then we need to get write access to the [td]indirect block | |
696 | * before the splice. | |
697 | */ | |
698 | if (where->bh) { | |
699 | BUFFER_TRACE(where->bh, "get_write_access"); | |
700 | err = ext3_journal_get_write_access(handle, where->bh); | |
701 | if (err) | |
702 | goto err_out; | |
703 | } | |
1da177e4 LT |
704 | /* That's it */ |
705 | ||
706 | *where->p = where->key; | |
d6859bfc AM |
707 | |
708 | /* | |
709 | * Update the host buffer_head or inode to point to more just allocated | |
710 | * direct blocks blocks | |
711 | */ | |
b47b2478 | 712 | if (num == 0 && blks > 1) { |
5dea5176 | 713 | current_block = le32_to_cpu(where->key) + 1; |
b47b2478 MC |
714 | for (i = 1; i < blks; i++) |
715 | *(where->p + i ) = cpu_to_le32(current_block++); | |
716 | } | |
1da177e4 LT |
717 | |
718 | /* | |
719 | * update the most recently allocated logical & physical block | |
720 | * in i_block_alloc_info, to assist find the proper goal block for next | |
721 | * allocation | |
722 | */ | |
723 | if (block_i) { | |
b47b2478 | 724 | block_i->last_alloc_logical_block = block + blks - 1; |
d6859bfc | 725 | block_i->last_alloc_physical_block = |
5dea5176 | 726 | le32_to_cpu(where[num].key) + blks - 1; |
1da177e4 LT |
727 | } |
728 | ||
729 | /* We are done with atomic stuff, now do the rest of housekeeping */ | |
730 | ||
731 | inode->i_ctime = CURRENT_TIME_SEC; | |
732 | ext3_mark_inode_dirty(handle, inode); | |
733 | ||
734 | /* had we spliced it onto indirect block? */ | |
735 | if (where->bh) { | |
736 | /* | |
d6859bfc | 737 | * If we spliced it onto an indirect block, we haven't |
1da177e4 LT |
738 | * altered the inode. Note however that if it is being spliced |
739 | * onto an indirect block at the very end of the file (the | |
740 | * file is growing) then we *will* alter the inode to reflect | |
741 | * the new i_size. But that is not done here - it is done in | |
742 | * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode. | |
743 | */ | |
744 | jbd_debug(5, "splicing indirect only\n"); | |
745 | BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata"); | |
746 | err = ext3_journal_dirty_metadata(handle, where->bh); | |
ae6ddcc5 | 747 | if (err) |
1da177e4 LT |
748 | goto err_out; |
749 | } else { | |
750 | /* | |
751 | * OK, we spliced it into the inode itself on a direct block. | |
752 | * Inode was dirtied above. | |
753 | */ | |
754 | jbd_debug(5, "splicing direct\n"); | |
755 | } | |
756 | return err; | |
757 | ||
1da177e4 | 758 | err_out: |
b47b2478 | 759 | for (i = 1; i <= num; i++) { |
1da177e4 LT |
760 | BUFFER_TRACE(where[i].bh, "call journal_forget"); |
761 | ext3_journal_forget(handle, where[i].bh); | |
d6859bfc | 762 | ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1); |
1da177e4 | 763 | } |
b47b2478 MC |
764 | ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks); |
765 | ||
1da177e4 LT |
766 | return err; |
767 | } | |
768 | ||
769 | /* | |
770 | * Allocation strategy is simple: if we have to allocate something, we will | |
771 | * have to go the whole way to leaf. So let's do it before attaching anything | |
772 | * to tree, set linkage between the newborn blocks, write them if sync is | |
773 | * required, recheck the path, free and repeat if check fails, otherwise | |
774 | * set the last missing link (that will protect us from any truncate-generated | |
775 | * removals - all blocks on the path are immune now) and possibly force the | |
776 | * write on the parent block. | |
777 | * That has a nice additional property: no special recovery from the failed | |
778 | * allocations is needed - we simply release blocks and do not touch anything | |
779 | * reachable from inode. | |
780 | * | |
d6859bfc | 781 | * `handle' can be NULL if create == 0. |
1da177e4 LT |
782 | * |
783 | * The BKL may not be held on entry here. Be sure to take it early. | |
89747d36 MC |
784 | * return > 0, # of blocks mapped or allocated. |
785 | * return = 0, if plain lookup failed. | |
786 | * return < 0, error case. | |
1da177e4 | 787 | */ |
d6859bfc AM |
788 | int ext3_get_blocks_handle(handle_t *handle, struct inode *inode, |
789 | sector_t iblock, unsigned long maxblocks, | |
790 | struct buffer_head *bh_result, | |
89747d36 | 791 | int create, int extend_disksize) |
1da177e4 LT |
792 | { |
793 | int err = -EIO; | |
794 | int offsets[4]; | |
795 | Indirect chain[4]; | |
796 | Indirect *partial; | |
43d23f90 | 797 | ext3_fsblk_t goal; |
b47b2478 | 798 | int indirect_blks; |
89747d36 MC |
799 | int blocks_to_boundary = 0; |
800 | int depth; | |
1da177e4 | 801 | struct ext3_inode_info *ei = EXT3_I(inode); |
89747d36 | 802 | int count = 0; |
43d23f90 | 803 | ext3_fsblk_t first_block = 0; |
89747d36 | 804 | |
1da177e4 LT |
805 | |
806 | J_ASSERT(handle != NULL || create == 0); | |
d6859bfc | 807 | depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary); |
1da177e4 LT |
808 | |
809 | if (depth == 0) | |
810 | goto out; | |
811 | ||
1da177e4 LT |
812 | partial = ext3_get_branch(inode, depth, offsets, chain, &err); |
813 | ||
814 | /* Simplest case - block found, no allocation needed */ | |
815 | if (!partial) { | |
5dea5176 | 816 | first_block = le32_to_cpu(chain[depth - 1].key); |
1da177e4 | 817 | clear_buffer_new(bh_result); |
89747d36 MC |
818 | count++; |
819 | /*map more blocks*/ | |
820 | while (count < maxblocks && count <= blocks_to_boundary) { | |
43d23f90 | 821 | ext3_fsblk_t blk; |
5dea5176 | 822 | |
89747d36 MC |
823 | if (!verify_chain(chain, partial)) { |
824 | /* | |
825 | * Indirect block might be removed by | |
826 | * truncate while we were reading it. | |
827 | * Handling of that case: forget what we've | |
828 | * got now. Flag the err as EAGAIN, so it | |
829 | * will reread. | |
830 | */ | |
831 | err = -EAGAIN; | |
832 | count = 0; | |
833 | break; | |
834 | } | |
5dea5176 MC |
835 | blk = le32_to_cpu(*(chain[depth-1].p + count)); |
836 | ||
837 | if (blk == first_block + count) | |
89747d36 MC |
838 | count++; |
839 | else | |
840 | break; | |
841 | } | |
842 | if (err != -EAGAIN) | |
843 | goto got_it; | |
1da177e4 LT |
844 | } |
845 | ||
846 | /* Next simple case - plain lookup or failed read of indirect block */ | |
fe55c452 MC |
847 | if (!create || err == -EIO) |
848 | goto cleanup; | |
849 | ||
97461518 | 850 | mutex_lock(&ei->truncate_mutex); |
fe55c452 MC |
851 | |
852 | /* | |
853 | * If the indirect block is missing while we are reading | |
854 | * the chain(ext3_get_branch() returns -EAGAIN err), or | |
855 | * if the chain has been changed after we grab the semaphore, | |
856 | * (either because another process truncated this branch, or | |
857 | * another get_block allocated this branch) re-grab the chain to see if | |
858 | * the request block has been allocated or not. | |
859 | * | |
860 | * Since we already block the truncate/other get_block | |
861 | * at this point, we will have the current copy of the chain when we | |
862 | * splice the branch into the tree. | |
863 | */ | |
864 | if (err == -EAGAIN || !verify_chain(chain, partial)) { | |
1da177e4 | 865 | while (partial > chain) { |
1da177e4 LT |
866 | brelse(partial->bh); |
867 | partial--; | |
868 | } | |
fe55c452 MC |
869 | partial = ext3_get_branch(inode, depth, offsets, chain, &err); |
870 | if (!partial) { | |
89747d36 | 871 | count++; |
97461518 | 872 | mutex_unlock(&ei->truncate_mutex); |
fe55c452 MC |
873 | if (err) |
874 | goto cleanup; | |
875 | clear_buffer_new(bh_result); | |
876 | goto got_it; | |
877 | } | |
1da177e4 LT |
878 | } |
879 | ||
880 | /* | |
fe55c452 MC |
881 | * Okay, we need to do block allocation. Lazily initialize the block |
882 | * allocation info here if necessary | |
883 | */ | |
884 | if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) | |
1da177e4 | 885 | ext3_init_block_alloc_info(inode); |
1da177e4 | 886 | |
fb01bfda | 887 | goal = ext3_find_goal(inode, iblock, partial); |
1da177e4 | 888 | |
b47b2478 MC |
889 | /* the number of blocks need to allocate for [d,t]indirect blocks */ |
890 | indirect_blks = (chain + depth) - partial - 1; | |
1da177e4 | 891 | |
b47b2478 MC |
892 | /* |
893 | * Next look up the indirect map to count the totoal number of | |
894 | * direct blocks to allocate for this branch. | |
895 | */ | |
896 | count = ext3_blks_to_allocate(partial, indirect_blks, | |
897 | maxblocks, blocks_to_boundary); | |
1da177e4 LT |
898 | /* |
899 | * Block out ext3_truncate while we alter the tree | |
900 | */ | |
b47b2478 | 901 | err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal, |
fe55c452 | 902 | offsets + (partial - chain), partial); |
1da177e4 | 903 | |
fe55c452 MC |
904 | /* |
905 | * The ext3_splice_branch call will free and forget any buffers | |
1da177e4 LT |
906 | * on the new chain if there is a failure, but that risks using |
907 | * up transaction credits, especially for bitmaps where the | |
908 | * credits cannot be returned. Can we handle this somehow? We | |
fe55c452 MC |
909 | * may need to return -EAGAIN upwards in the worst case. --sct |
910 | */ | |
1da177e4 | 911 | if (!err) |
b47b2478 MC |
912 | err = ext3_splice_branch(handle, inode, iblock, |
913 | partial, indirect_blks, count); | |
fe55c452 | 914 | /* |
97461518 | 915 | * i_disksize growing is protected by truncate_mutex. Don't forget to |
fe55c452 MC |
916 | * protect it if you're about to implement concurrent |
917 | * ext3_get_block() -bzzz | |
918 | */ | |
1da177e4 LT |
919 | if (!err && extend_disksize && inode->i_size > ei->i_disksize) |
920 | ei->i_disksize = inode->i_size; | |
97461518 | 921 | mutex_unlock(&ei->truncate_mutex); |
1da177e4 LT |
922 | if (err) |
923 | goto cleanup; | |
924 | ||
925 | set_buffer_new(bh_result); | |
fe55c452 MC |
926 | got_it: |
927 | map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); | |
20acaa18 | 928 | if (count > blocks_to_boundary) |
fe55c452 | 929 | set_buffer_boundary(bh_result); |
89747d36 | 930 | err = count; |
fe55c452 MC |
931 | /* Clean up and exit */ |
932 | partial = chain + depth - 1; /* the whole chain */ | |
933 | cleanup: | |
1da177e4 | 934 | while (partial > chain) { |
fe55c452 | 935 | BUFFER_TRACE(partial->bh, "call brelse"); |
1da177e4 LT |
936 | brelse(partial->bh); |
937 | partial--; | |
938 | } | |
fe55c452 MC |
939 | BUFFER_TRACE(bh_result, "returned"); |
940 | out: | |
941 | return err; | |
1da177e4 LT |
942 | } |
943 | ||
bd1939de JK |
944 | /* Maximum number of blocks we map for direct IO at once. */ |
945 | #define DIO_MAX_BLOCKS 4096 | |
946 | /* | |
947 | * Number of credits we need for writing DIO_MAX_BLOCKS: | |
948 | * We need sb + group descriptor + bitmap + inode -> 4 | |
949 | * For B blocks with A block pointers per block we need: | |
950 | * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect). | |
951 | * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25. | |
952 | */ | |
953 | #define DIO_CREDITS 25 | |
1da177e4 | 954 | |
f91a2ad2 BP |
955 | static int ext3_get_block(struct inode *inode, sector_t iblock, |
956 | struct buffer_head *bh_result, int create) | |
1da177e4 | 957 | { |
3e4fdaf8 | 958 | handle_t *handle = ext3_journal_current_handle(); |
bd1939de | 959 | int ret = 0, started = 0; |
1d8fa7a2 | 960 | unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; |
1da177e4 | 961 | |
bd1939de JK |
962 | if (create && !handle) { /* Direct IO write... */ |
963 | if (max_blocks > DIO_MAX_BLOCKS) | |
964 | max_blocks = DIO_MAX_BLOCKS; | |
965 | handle = ext3_journal_start(inode, DIO_CREDITS + | |
966 | 2 * EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb)); | |
967 | if (IS_ERR(handle)) { | |
1da177e4 | 968 | ret = PTR_ERR(handle); |
bd1939de | 969 | goto out; |
1da177e4 | 970 | } |
bd1939de | 971 | started = 1; |
1da177e4 LT |
972 | } |
973 | ||
bd1939de | 974 | ret = ext3_get_blocks_handle(handle, inode, iblock, |
89747d36 | 975 | max_blocks, bh_result, create, 0); |
bd1939de JK |
976 | if (ret > 0) { |
977 | bh_result->b_size = (ret << inode->i_blkbits); | |
978 | ret = 0; | |
89747d36 | 979 | } |
bd1939de JK |
980 | if (started) |
981 | ext3_journal_stop(handle); | |
982 | out: | |
1da177e4 LT |
983 | return ret; |
984 | } | |
985 | ||
68c9d702 JB |
986 | int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo, |
987 | u64 start, u64 len) | |
988 | { | |
989 | return generic_block_fiemap(inode, fieinfo, start, len, | |
990 | ext3_get_block); | |
991 | } | |
992 | ||
1da177e4 LT |
993 | /* |
994 | * `handle' can be NULL if create is zero | |
995 | */ | |
d6859bfc AM |
996 | struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode, |
997 | long block, int create, int *errp) | |
1da177e4 LT |
998 | { |
999 | struct buffer_head dummy; | |
1000 | int fatal = 0, err; | |
1001 | ||
1002 | J_ASSERT(handle != NULL || create == 0); | |
1003 | ||
1004 | dummy.b_state = 0; | |
1005 | dummy.b_blocknr = -1000; | |
1006 | buffer_trace_init(&dummy.b_history); | |
89747d36 MC |
1007 | err = ext3_get_blocks_handle(handle, inode, block, 1, |
1008 | &dummy, create, 1); | |
3665d0e5 BP |
1009 | /* |
1010 | * ext3_get_blocks_handle() returns number of blocks | |
1011 | * mapped. 0 in case of a HOLE. | |
1012 | */ | |
1013 | if (err > 0) { | |
1014 | if (err > 1) | |
1015 | WARN_ON(1); | |
89747d36 | 1016 | err = 0; |
89747d36 MC |
1017 | } |
1018 | *errp = err; | |
1019 | if (!err && buffer_mapped(&dummy)) { | |
1da177e4 LT |
1020 | struct buffer_head *bh; |
1021 | bh = sb_getblk(inode->i_sb, dummy.b_blocknr); | |
2973dfdb GOC |
1022 | if (!bh) { |
1023 | *errp = -EIO; | |
1024 | goto err; | |
1025 | } | |
1da177e4 LT |
1026 | if (buffer_new(&dummy)) { |
1027 | J_ASSERT(create != 0); | |
c80544dc | 1028 | J_ASSERT(handle != NULL); |
1da177e4 | 1029 | |
d6859bfc AM |
1030 | /* |
1031 | * Now that we do not always journal data, we should | |
1032 | * keep in mind whether this should always journal the | |
1033 | * new buffer as metadata. For now, regular file | |
1034 | * writes use ext3_get_block instead, so it's not a | |
1035 | * problem. | |
1036 | */ | |
1da177e4 LT |
1037 | lock_buffer(bh); |
1038 | BUFFER_TRACE(bh, "call get_create_access"); | |
1039 | fatal = ext3_journal_get_create_access(handle, bh); | |
1040 | if (!fatal && !buffer_uptodate(bh)) { | |
d6859bfc | 1041 | memset(bh->b_data,0,inode->i_sb->s_blocksize); |
1da177e4 LT |
1042 | set_buffer_uptodate(bh); |
1043 | } | |
1044 | unlock_buffer(bh); | |
1045 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
1046 | err = ext3_journal_dirty_metadata(handle, bh); | |
1047 | if (!fatal) | |
1048 | fatal = err; | |
1049 | } else { | |
1050 | BUFFER_TRACE(bh, "not a new buffer"); | |
1051 | } | |
1052 | if (fatal) { | |
1053 | *errp = fatal; | |
1054 | brelse(bh); | |
1055 | bh = NULL; | |
1056 | } | |
1057 | return bh; | |
1058 | } | |
2973dfdb | 1059 | err: |
1da177e4 LT |
1060 | return NULL; |
1061 | } | |
1062 | ||
d6859bfc | 1063 | struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode, |
1da177e4 LT |
1064 | int block, int create, int *err) |
1065 | { | |
1066 | struct buffer_head * bh; | |
1067 | ||
1068 | bh = ext3_getblk(handle, inode, block, create, err); | |
1069 | if (!bh) | |
1070 | return bh; | |
1071 | if (buffer_uptodate(bh)) | |
1072 | return bh; | |
caa38fb0 | 1073 | ll_rw_block(READ_META, 1, &bh); |
1da177e4 LT |
1074 | wait_on_buffer(bh); |
1075 | if (buffer_uptodate(bh)) | |
1076 | return bh; | |
1077 | put_bh(bh); | |
1078 | *err = -EIO; | |
1079 | return NULL; | |
1080 | } | |
1081 | ||
1082 | static int walk_page_buffers( handle_t *handle, | |
1083 | struct buffer_head *head, | |
1084 | unsigned from, | |
1085 | unsigned to, | |
1086 | int *partial, | |
1087 | int (*fn)( handle_t *handle, | |
1088 | struct buffer_head *bh)) | |
1089 | { | |
1090 | struct buffer_head *bh; | |
1091 | unsigned block_start, block_end; | |
1092 | unsigned blocksize = head->b_size; | |
1093 | int err, ret = 0; | |
1094 | struct buffer_head *next; | |
1095 | ||
1096 | for ( bh = head, block_start = 0; | |
1097 | ret == 0 && (bh != head || !block_start); | |
e9ad5620 | 1098 | block_start = block_end, bh = next) |
1da177e4 LT |
1099 | { |
1100 | next = bh->b_this_page; | |
1101 | block_end = block_start + blocksize; | |
1102 | if (block_end <= from || block_start >= to) { | |
1103 | if (partial && !buffer_uptodate(bh)) | |
1104 | *partial = 1; | |
1105 | continue; | |
1106 | } | |
1107 | err = (*fn)(handle, bh); | |
1108 | if (!ret) | |
1109 | ret = err; | |
1110 | } | |
1111 | return ret; | |
1112 | } | |
1113 | ||
1114 | /* | |
1115 | * To preserve ordering, it is essential that the hole instantiation and | |
1116 | * the data write be encapsulated in a single transaction. We cannot | |
1117 | * close off a transaction and start a new one between the ext3_get_block() | |
1118 | * and the commit_write(). So doing the journal_start at the start of | |
1119 | * prepare_write() is the right place. | |
1120 | * | |
1121 | * Also, this function can nest inside ext3_writepage() -> | |
1122 | * block_write_full_page(). In that case, we *know* that ext3_writepage() | |
1123 | * has generated enough buffer credits to do the whole page. So we won't | |
1124 | * block on the journal in that case, which is good, because the caller may | |
1125 | * be PF_MEMALLOC. | |
1126 | * | |
1127 | * By accident, ext3 can be reentered when a transaction is open via | |
1128 | * quota file writes. If we were to commit the transaction while thus | |
1129 | * reentered, there can be a deadlock - we would be holding a quota | |
1130 | * lock, and the commit would never complete if another thread had a | |
1131 | * transaction open and was blocking on the quota lock - a ranking | |
1132 | * violation. | |
1133 | * | |
1134 | * So what we do is to rely on the fact that journal_stop/journal_start | |
1135 | * will _not_ run commit under these circumstances because handle->h_ref | |
1136 | * is elevated. We'll still have enough credits for the tiny quotafile | |
ae6ddcc5 | 1137 | * write. |
1da177e4 | 1138 | */ |
d6859bfc AM |
1139 | static int do_journal_get_write_access(handle_t *handle, |
1140 | struct buffer_head *bh) | |
1da177e4 LT |
1141 | { |
1142 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
1143 | return 0; | |
1144 | return ext3_journal_get_write_access(handle, bh); | |
1145 | } | |
1146 | ||
f4fc66a8 NP |
1147 | static int ext3_write_begin(struct file *file, struct address_space *mapping, |
1148 | loff_t pos, unsigned len, unsigned flags, | |
1149 | struct page **pagep, void **fsdata) | |
1da177e4 | 1150 | { |
f4fc66a8 | 1151 | struct inode *inode = mapping->host; |
1aa9b4b9 | 1152 | int ret, needed_blocks = ext3_writepage_trans_blocks(inode); |
1da177e4 LT |
1153 | handle_t *handle; |
1154 | int retries = 0; | |
f4fc66a8 NP |
1155 | struct page *page; |
1156 | pgoff_t index; | |
1157 | unsigned from, to; | |
1158 | ||
1159 | index = pos >> PAGE_CACHE_SHIFT; | |
1160 | from = pos & (PAGE_CACHE_SIZE - 1); | |
1161 | to = from + len; | |
1da177e4 LT |
1162 | |
1163 | retry: | |
54566b2c | 1164 | page = grab_cache_page_write_begin(mapping, index, flags); |
f4fc66a8 NP |
1165 | if (!page) |
1166 | return -ENOMEM; | |
1167 | *pagep = page; | |
1168 | ||
1da177e4 | 1169 | handle = ext3_journal_start(inode, needed_blocks); |
1aa9b4b9 | 1170 | if (IS_ERR(handle)) { |
f4fc66a8 NP |
1171 | unlock_page(page); |
1172 | page_cache_release(page); | |
1aa9b4b9 AM |
1173 | ret = PTR_ERR(handle); |
1174 | goto out; | |
1175 | } | |
f4fc66a8 NP |
1176 | ret = block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
1177 | ext3_get_block); | |
1da177e4 | 1178 | if (ret) |
f4fc66a8 | 1179 | goto write_begin_failed; |
1da177e4 LT |
1180 | |
1181 | if (ext3_should_journal_data(inode)) { | |
1182 | ret = walk_page_buffers(handle, page_buffers(page), | |
1183 | from, to, NULL, do_journal_get_write_access); | |
1184 | } | |
f4fc66a8 NP |
1185 | write_begin_failed: |
1186 | if (ret) { | |
1aa9b4b9 | 1187 | ext3_journal_stop(handle); |
f4fc66a8 NP |
1188 | unlock_page(page); |
1189 | page_cache_release(page); | |
5ec8b75e AK |
1190 | /* |
1191 | * block_write_begin may have instantiated a few blocks | |
1192 | * outside i_size. Trim these off again. Don't need | |
1193 | * i_size_read because we hold i_mutex. | |
1194 | */ | |
1195 | if (pos + len > inode->i_size) | |
1196 | vmtruncate(inode, inode->i_size); | |
f4fc66a8 | 1197 | } |
1da177e4 LT |
1198 | if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) |
1199 | goto retry; | |
1aa9b4b9 | 1200 | out: |
1da177e4 LT |
1201 | return ret; |
1202 | } | |
1203 | ||
f4fc66a8 | 1204 | |
d6859bfc | 1205 | int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh) |
1da177e4 LT |
1206 | { |
1207 | int err = journal_dirty_data(handle, bh); | |
1208 | if (err) | |
e05b6b52 | 1209 | ext3_journal_abort_handle(__func__, __func__, |
f4fc66a8 | 1210 | bh, handle, err); |
1da177e4 LT |
1211 | return err; |
1212 | } | |
1213 | ||
f4fc66a8 NP |
1214 | /* For write_end() in data=journal mode */ |
1215 | static int write_end_fn(handle_t *handle, struct buffer_head *bh) | |
1da177e4 LT |
1216 | { |
1217 | if (!buffer_mapped(bh) || buffer_freed(bh)) | |
1218 | return 0; | |
1219 | set_buffer_uptodate(bh); | |
1220 | return ext3_journal_dirty_metadata(handle, bh); | |
1221 | } | |
1222 | ||
f4fc66a8 NP |
1223 | /* |
1224 | * Generic write_end handler for ordered and writeback ext3 journal modes. | |
1225 | * We can't use generic_write_end, because that unlocks the page and we need to | |
1226 | * unlock the page after ext3_journal_stop, but ext3_journal_stop must run | |
1227 | * after block_write_end. | |
1228 | */ | |
1229 | static int ext3_generic_write_end(struct file *file, | |
1230 | struct address_space *mapping, | |
1231 | loff_t pos, unsigned len, unsigned copied, | |
1232 | struct page *page, void *fsdata) | |
1233 | { | |
1234 | struct inode *inode = file->f_mapping->host; | |
1235 | ||
1236 | copied = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
1237 | ||
1238 | if (pos+copied > inode->i_size) { | |
1239 | i_size_write(inode, pos+copied); | |
1240 | mark_inode_dirty(inode); | |
1241 | } | |
1242 | ||
1243 | return copied; | |
1244 | } | |
1245 | ||
1da177e4 LT |
1246 | /* |
1247 | * We need to pick up the new inode size which generic_commit_write gave us | |
1248 | * `file' can be NULL - eg, when called from page_symlink(). | |
1249 | * | |
1250 | * ext3 never places buffers on inode->i_mapping->private_list. metadata | |
1251 | * buffers are managed internally. | |
1252 | */ | |
f4fc66a8 NP |
1253 | static int ext3_ordered_write_end(struct file *file, |
1254 | struct address_space *mapping, | |
1255 | loff_t pos, unsigned len, unsigned copied, | |
1256 | struct page *page, void *fsdata) | |
1da177e4 LT |
1257 | { |
1258 | handle_t *handle = ext3_journal_current_handle(); | |
f4fc66a8 NP |
1259 | struct inode *inode = file->f_mapping->host; |
1260 | unsigned from, to; | |
1da177e4 LT |
1261 | int ret = 0, ret2; |
1262 | ||
f4fc66a8 NP |
1263 | from = pos & (PAGE_CACHE_SIZE - 1); |
1264 | to = from + len; | |
1265 | ||
1da177e4 LT |
1266 | ret = walk_page_buffers(handle, page_buffers(page), |
1267 | from, to, NULL, ext3_journal_dirty_data); | |
1268 | ||
1269 | if (ret == 0) { | |
1270 | /* | |
f4fc66a8 | 1271 | * generic_write_end() will run mark_inode_dirty() if i_size |
1da177e4 LT |
1272 | * changes. So let's piggyback the i_disksize mark_inode_dirty |
1273 | * into that. | |
1274 | */ | |
1275 | loff_t new_i_size; | |
1276 | ||
f4fc66a8 | 1277 | new_i_size = pos + copied; |
1da177e4 LT |
1278 | if (new_i_size > EXT3_I(inode)->i_disksize) |
1279 | EXT3_I(inode)->i_disksize = new_i_size; | |
7c2f3d6f | 1280 | ret2 = ext3_generic_write_end(file, mapping, pos, len, copied, |
f4fc66a8 | 1281 | page, fsdata); |
7c2f3d6f RK |
1282 | copied = ret2; |
1283 | if (ret2 < 0) | |
1284 | ret = ret2; | |
1da177e4 LT |
1285 | } |
1286 | ret2 = ext3_journal_stop(handle); | |
1287 | if (!ret) | |
1288 | ret = ret2; | |
f4fc66a8 NP |
1289 | unlock_page(page); |
1290 | page_cache_release(page); | |
1291 | ||
1292 | return ret ? ret : copied; | |
1da177e4 LT |
1293 | } |
1294 | ||
f4fc66a8 NP |
1295 | static int ext3_writeback_write_end(struct file *file, |
1296 | struct address_space *mapping, | |
1297 | loff_t pos, unsigned len, unsigned copied, | |
1298 | struct page *page, void *fsdata) | |
1da177e4 LT |
1299 | { |
1300 | handle_t *handle = ext3_journal_current_handle(); | |
f4fc66a8 | 1301 | struct inode *inode = file->f_mapping->host; |
1da177e4 LT |
1302 | int ret = 0, ret2; |
1303 | loff_t new_i_size; | |
1304 | ||
f4fc66a8 | 1305 | new_i_size = pos + copied; |
1da177e4 LT |
1306 | if (new_i_size > EXT3_I(inode)->i_disksize) |
1307 | EXT3_I(inode)->i_disksize = new_i_size; | |
1308 | ||
7c2f3d6f | 1309 | ret2 = ext3_generic_write_end(file, mapping, pos, len, copied, |
f4fc66a8 | 1310 | page, fsdata); |
7c2f3d6f RK |
1311 | copied = ret2; |
1312 | if (ret2 < 0) | |
1313 | ret = ret2; | |
1da177e4 LT |
1314 | |
1315 | ret2 = ext3_journal_stop(handle); | |
1316 | if (!ret) | |
1317 | ret = ret2; | |
f4fc66a8 NP |
1318 | unlock_page(page); |
1319 | page_cache_release(page); | |
1320 | ||
1321 | return ret ? ret : copied; | |
1da177e4 LT |
1322 | } |
1323 | ||
f4fc66a8 NP |
1324 | static int ext3_journalled_write_end(struct file *file, |
1325 | struct address_space *mapping, | |
1326 | loff_t pos, unsigned len, unsigned copied, | |
1327 | struct page *page, void *fsdata) | |
1da177e4 LT |
1328 | { |
1329 | handle_t *handle = ext3_journal_current_handle(); | |
f4fc66a8 | 1330 | struct inode *inode = mapping->host; |
1da177e4 LT |
1331 | int ret = 0, ret2; |
1332 | int partial = 0; | |
f4fc66a8 | 1333 | unsigned from, to; |
1da177e4 | 1334 | |
f4fc66a8 NP |
1335 | from = pos & (PAGE_CACHE_SIZE - 1); |
1336 | to = from + len; | |
1337 | ||
1338 | if (copied < len) { | |
1339 | if (!PageUptodate(page)) | |
1340 | copied = 0; | |
1341 | page_zero_new_buffers(page, from+copied, to); | |
1342 | } | |
1da177e4 LT |
1343 | |
1344 | ret = walk_page_buffers(handle, page_buffers(page), from, | |
f4fc66a8 | 1345 | to, &partial, write_end_fn); |
1da177e4 LT |
1346 | if (!partial) |
1347 | SetPageUptodate(page); | |
f4fc66a8 NP |
1348 | if (pos+copied > inode->i_size) |
1349 | i_size_write(inode, pos+copied); | |
1da177e4 LT |
1350 | EXT3_I(inode)->i_state |= EXT3_STATE_JDATA; |
1351 | if (inode->i_size > EXT3_I(inode)->i_disksize) { | |
1352 | EXT3_I(inode)->i_disksize = inode->i_size; | |
1353 | ret2 = ext3_mark_inode_dirty(handle, inode); | |
ae6ddcc5 | 1354 | if (!ret) |
1da177e4 LT |
1355 | ret = ret2; |
1356 | } | |
f4fc66a8 | 1357 | |
1da177e4 LT |
1358 | ret2 = ext3_journal_stop(handle); |
1359 | if (!ret) | |
1360 | ret = ret2; | |
f4fc66a8 NP |
1361 | unlock_page(page); |
1362 | page_cache_release(page); | |
1363 | ||
1364 | return ret ? ret : copied; | |
1da177e4 LT |
1365 | } |
1366 | ||
ae6ddcc5 | 1367 | /* |
1da177e4 LT |
1368 | * bmap() is special. It gets used by applications such as lilo and by |
1369 | * the swapper to find the on-disk block of a specific piece of data. | |
1370 | * | |
1371 | * Naturally, this is dangerous if the block concerned is still in the | |
1372 | * journal. If somebody makes a swapfile on an ext3 data-journaling | |
1373 | * filesystem and enables swap, then they may get a nasty shock when the | |
1374 | * data getting swapped to that swapfile suddenly gets overwritten by | |
1375 | * the original zero's written out previously to the journal and | |
ae6ddcc5 | 1376 | * awaiting writeback in the kernel's buffer cache. |
1da177e4 LT |
1377 | * |
1378 | * So, if we see any bmap calls here on a modified, data-journaled file, | |
ae6ddcc5 | 1379 | * take extra steps to flush any blocks which might be in the cache. |
1da177e4 LT |
1380 | */ |
1381 | static sector_t ext3_bmap(struct address_space *mapping, sector_t block) | |
1382 | { | |
1383 | struct inode *inode = mapping->host; | |
1384 | journal_t *journal; | |
1385 | int err; | |
1386 | ||
1387 | if (EXT3_I(inode)->i_state & EXT3_STATE_JDATA) { | |
ae6ddcc5 | 1388 | /* |
1da177e4 LT |
1389 | * This is a REALLY heavyweight approach, but the use of |
1390 | * bmap on dirty files is expected to be extremely rare: | |
1391 | * only if we run lilo or swapon on a freshly made file | |
ae6ddcc5 | 1392 | * do we expect this to happen. |
1da177e4 LT |
1393 | * |
1394 | * (bmap requires CAP_SYS_RAWIO so this does not | |
1395 | * represent an unprivileged user DOS attack --- we'd be | |
1396 | * in trouble if mortal users could trigger this path at | |
ae6ddcc5 | 1397 | * will.) |
1da177e4 LT |
1398 | * |
1399 | * NB. EXT3_STATE_JDATA is not set on files other than | |
1400 | * regular files. If somebody wants to bmap a directory | |
1401 | * or symlink and gets confused because the buffer | |
1402 | * hasn't yet been flushed to disk, they deserve | |
1403 | * everything they get. | |
1404 | */ | |
1405 | ||
1406 | EXT3_I(inode)->i_state &= ~EXT3_STATE_JDATA; | |
1407 | journal = EXT3_JOURNAL(inode); | |
1408 | journal_lock_updates(journal); | |
1409 | err = journal_flush(journal); | |
1410 | journal_unlock_updates(journal); | |
1411 | ||
1412 | if (err) | |
1413 | return 0; | |
1414 | } | |
1415 | ||
1416 | return generic_block_bmap(mapping,block,ext3_get_block); | |
1417 | } | |
1418 | ||
1419 | static int bget_one(handle_t *handle, struct buffer_head *bh) | |
1420 | { | |
1421 | get_bh(bh); | |
1422 | return 0; | |
1423 | } | |
1424 | ||
1425 | static int bput_one(handle_t *handle, struct buffer_head *bh) | |
1426 | { | |
1427 | put_bh(bh); | |
1428 | return 0; | |
1429 | } | |
1430 | ||
1431 | static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh) | |
1432 | { | |
1433 | if (buffer_mapped(bh)) | |
1434 | return ext3_journal_dirty_data(handle, bh); | |
1435 | return 0; | |
1436 | } | |
1437 | ||
1438 | /* | |
1439 | * Note that we always start a transaction even if we're not journalling | |
1440 | * data. This is to preserve ordering: any hole instantiation within | |
1441 | * __block_write_full_page -> ext3_get_block() should be journalled | |
1442 | * along with the data so we don't crash and then get metadata which | |
1443 | * refers to old data. | |
1444 | * | |
1445 | * In all journalling modes block_write_full_page() will start the I/O. | |
1446 | * | |
1447 | * Problem: | |
1448 | * | |
1449 | * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> | |
1450 | * ext3_writepage() | |
1451 | * | |
1452 | * Similar for: | |
1453 | * | |
1454 | * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ... | |
1455 | * | |
1456 | * Same applies to ext3_get_block(). We will deadlock on various things like | |
97461518 | 1457 | * lock_journal and i_truncate_mutex. |
1da177e4 LT |
1458 | * |
1459 | * Setting PF_MEMALLOC here doesn't work - too many internal memory | |
1460 | * allocations fail. | |
1461 | * | |
1462 | * 16May01: If we're reentered then journal_current_handle() will be | |
1463 | * non-zero. We simply *return*. | |
1464 | * | |
1465 | * 1 July 2001: @@@ FIXME: | |
1466 | * In journalled data mode, a data buffer may be metadata against the | |
1467 | * current transaction. But the same file is part of a shared mapping | |
1468 | * and someone does a writepage() on it. | |
1469 | * | |
1470 | * We will move the buffer onto the async_data list, but *after* it has | |
1471 | * been dirtied. So there's a small window where we have dirty data on | |
1472 | * BJ_Metadata. | |
1473 | * | |
1474 | * Note that this only applies to the last partial page in the file. The | |
1475 | * bit which block_write_full_page() uses prepare/commit for. (That's | |
1476 | * broken code anyway: it's wrong for msync()). | |
1477 | * | |
1478 | * It's a rare case: affects the final partial page, for journalled data | |
1479 | * where the file is subject to bith write() and writepage() in the same | |
1480 | * transction. To fix it we'll need a custom block_write_full_page(). | |
1481 | * We'll probably need that anyway for journalling writepage() output. | |
1482 | * | |
1483 | * We don't honour synchronous mounts for writepage(). That would be | |
1484 | * disastrous. Any write() or metadata operation will sync the fs for | |
1485 | * us. | |
1486 | * | |
1487 | * AKPM2: if all the page's buffers are mapped to disk and !data=journal, | |
1488 | * we don't need to open a transaction here. | |
1489 | */ | |
1490 | static int ext3_ordered_writepage(struct page *page, | |
d6859bfc | 1491 | struct writeback_control *wbc) |
1da177e4 LT |
1492 | { |
1493 | struct inode *inode = page->mapping->host; | |
1494 | struct buffer_head *page_bufs; | |
1495 | handle_t *handle = NULL; | |
1496 | int ret = 0; | |
1497 | int err; | |
1498 | ||
1499 | J_ASSERT(PageLocked(page)); | |
1500 | ||
1501 | /* | |
1502 | * We give up here if we're reentered, because it might be for a | |
1503 | * different filesystem. | |
1504 | */ | |
1505 | if (ext3_journal_current_handle()) | |
1506 | goto out_fail; | |
1507 | ||
1508 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1509 | ||
1510 | if (IS_ERR(handle)) { | |
1511 | ret = PTR_ERR(handle); | |
1512 | goto out_fail; | |
1513 | } | |
1514 | ||
1515 | if (!page_has_buffers(page)) { | |
1516 | create_empty_buffers(page, inode->i_sb->s_blocksize, | |
1517 | (1 << BH_Dirty)|(1 << BH_Uptodate)); | |
1518 | } | |
1519 | page_bufs = page_buffers(page); | |
1520 | walk_page_buffers(handle, page_bufs, 0, | |
1521 | PAGE_CACHE_SIZE, NULL, bget_one); | |
1522 | ||
1523 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1524 | ||
1525 | /* | |
1526 | * The page can become unlocked at any point now, and | |
1527 | * truncate can then come in and change things. So we | |
1528 | * can't touch *page from now on. But *page_bufs is | |
1529 | * safe due to elevated refcount. | |
1530 | */ | |
1531 | ||
1532 | /* | |
ae6ddcc5 | 1533 | * And attach them to the current transaction. But only if |
1da177e4 LT |
1534 | * block_write_full_page() succeeded. Otherwise they are unmapped, |
1535 | * and generally junk. | |
1536 | */ | |
1537 | if (ret == 0) { | |
1538 | err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, | |
1539 | NULL, journal_dirty_data_fn); | |
1540 | if (!ret) | |
1541 | ret = err; | |
1542 | } | |
1543 | walk_page_buffers(handle, page_bufs, 0, | |
1544 | PAGE_CACHE_SIZE, NULL, bput_one); | |
1545 | err = ext3_journal_stop(handle); | |
1546 | if (!ret) | |
1547 | ret = err; | |
1548 | return ret; | |
1549 | ||
1550 | out_fail: | |
1551 | redirty_page_for_writepage(wbc, page); | |
1552 | unlock_page(page); | |
1553 | return ret; | |
1554 | } | |
1555 | ||
1da177e4 LT |
1556 | static int ext3_writeback_writepage(struct page *page, |
1557 | struct writeback_control *wbc) | |
1558 | { | |
1559 | struct inode *inode = page->mapping->host; | |
1560 | handle_t *handle = NULL; | |
1561 | int ret = 0; | |
1562 | int err; | |
1563 | ||
1564 | if (ext3_journal_current_handle()) | |
1565 | goto out_fail; | |
1566 | ||
1567 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1568 | if (IS_ERR(handle)) { | |
1569 | ret = PTR_ERR(handle); | |
1570 | goto out_fail; | |
1571 | } | |
1572 | ||
0e31f51d | 1573 | if (test_opt(inode->i_sb, NOBH) && ext3_should_writeback_data(inode)) |
1da177e4 LT |
1574 | ret = nobh_writepage(page, ext3_get_block, wbc); |
1575 | else | |
1576 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1577 | ||
1578 | err = ext3_journal_stop(handle); | |
1579 | if (!ret) | |
1580 | ret = err; | |
1581 | return ret; | |
1582 | ||
1583 | out_fail: | |
1584 | redirty_page_for_writepage(wbc, page); | |
1585 | unlock_page(page); | |
1586 | return ret; | |
1587 | } | |
1588 | ||
1589 | static int ext3_journalled_writepage(struct page *page, | |
1590 | struct writeback_control *wbc) | |
1591 | { | |
1592 | struct inode *inode = page->mapping->host; | |
1593 | handle_t *handle = NULL; | |
1594 | int ret = 0; | |
1595 | int err; | |
1596 | ||
1597 | if (ext3_journal_current_handle()) | |
1598 | goto no_write; | |
1599 | ||
1600 | handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); | |
1601 | if (IS_ERR(handle)) { | |
1602 | ret = PTR_ERR(handle); | |
1603 | goto no_write; | |
1604 | } | |
1605 | ||
1606 | if (!page_has_buffers(page) || PageChecked(page)) { | |
1607 | /* | |
1608 | * It's mmapped pagecache. Add buffers and journal it. There | |
1609 | * doesn't seem much point in redirtying the page here. | |
1610 | */ | |
1611 | ClearPageChecked(page); | |
1612 | ret = block_prepare_write(page, 0, PAGE_CACHE_SIZE, | |
1613 | ext3_get_block); | |
ab4eb43c DL |
1614 | if (ret != 0) { |
1615 | ext3_journal_stop(handle); | |
1da177e4 | 1616 | goto out_unlock; |
ab4eb43c | 1617 | } |
1da177e4 LT |
1618 | ret = walk_page_buffers(handle, page_buffers(page), 0, |
1619 | PAGE_CACHE_SIZE, NULL, do_journal_get_write_access); | |
1620 | ||
1621 | err = walk_page_buffers(handle, page_buffers(page), 0, | |
f4fc66a8 | 1622 | PAGE_CACHE_SIZE, NULL, write_end_fn); |
1da177e4 LT |
1623 | if (ret == 0) |
1624 | ret = err; | |
1625 | EXT3_I(inode)->i_state |= EXT3_STATE_JDATA; | |
1626 | unlock_page(page); | |
1627 | } else { | |
1628 | /* | |
1629 | * It may be a page full of checkpoint-mode buffers. We don't | |
1630 | * really know unless we go poke around in the buffer_heads. | |
1631 | * But block_write_full_page will do the right thing. | |
1632 | */ | |
1633 | ret = block_write_full_page(page, ext3_get_block, wbc); | |
1634 | } | |
1635 | err = ext3_journal_stop(handle); | |
1636 | if (!ret) | |
1637 | ret = err; | |
1638 | out: | |
1639 | return ret; | |
1640 | ||
1641 | no_write: | |
1642 | redirty_page_for_writepage(wbc, page); | |
1643 | out_unlock: | |
1644 | unlock_page(page); | |
1645 | goto out; | |
1646 | } | |
1647 | ||
1648 | static int ext3_readpage(struct file *file, struct page *page) | |
1649 | { | |
1650 | return mpage_readpage(page, ext3_get_block); | |
1651 | } | |
1652 | ||
1653 | static int | |
1654 | ext3_readpages(struct file *file, struct address_space *mapping, | |
1655 | struct list_head *pages, unsigned nr_pages) | |
1656 | { | |
1657 | return mpage_readpages(mapping, pages, nr_pages, ext3_get_block); | |
1658 | } | |
1659 | ||
2ff28e22 | 1660 | static void ext3_invalidatepage(struct page *page, unsigned long offset) |
1da177e4 LT |
1661 | { |
1662 | journal_t *journal = EXT3_JOURNAL(page->mapping->host); | |
1663 | ||
1664 | /* | |
1665 | * If it's a full truncate we just forget about the pending dirtying | |
1666 | */ | |
1667 | if (offset == 0) | |
1668 | ClearPageChecked(page); | |
1669 | ||
2ff28e22 | 1670 | journal_invalidatepage(journal, page, offset); |
1da177e4 LT |
1671 | } |
1672 | ||
27496a8c | 1673 | static int ext3_releasepage(struct page *page, gfp_t wait) |
1da177e4 LT |
1674 | { |
1675 | journal_t *journal = EXT3_JOURNAL(page->mapping->host); | |
1676 | ||
1677 | WARN_ON(PageChecked(page)); | |
1678 | if (!page_has_buffers(page)) | |
1679 | return 0; | |
1680 | return journal_try_to_free_buffers(journal, page, wait); | |
1681 | } | |
1682 | ||
1683 | /* | |
1684 | * If the O_DIRECT write will extend the file then add this inode to the | |
1685 | * orphan list. So recovery will truncate it back to the original size | |
1686 | * if the machine crashes during the write. | |
1687 | * | |
1688 | * If the O_DIRECT write is intantiating holes inside i_size and the machine | |
bd1939de JK |
1689 | * crashes then stale disk data _may_ be exposed inside the file. But current |
1690 | * VFS code falls back into buffered path in that case so we are safe. | |
1da177e4 LT |
1691 | */ |
1692 | static ssize_t ext3_direct_IO(int rw, struct kiocb *iocb, | |
1693 | const struct iovec *iov, loff_t offset, | |
1694 | unsigned long nr_segs) | |
1695 | { | |
1696 | struct file *file = iocb->ki_filp; | |
1697 | struct inode *inode = file->f_mapping->host; | |
1698 | struct ext3_inode_info *ei = EXT3_I(inode); | |
bd1939de | 1699 | handle_t *handle; |
1da177e4 LT |
1700 | ssize_t ret; |
1701 | int orphan = 0; | |
1702 | size_t count = iov_length(iov, nr_segs); | |
1703 | ||
1704 | if (rw == WRITE) { | |
1705 | loff_t final_size = offset + count; | |
1706 | ||
1da177e4 | 1707 | if (final_size > inode->i_size) { |
bd1939de JK |
1708 | /* Credits for sb + inode write */ |
1709 | handle = ext3_journal_start(inode, 2); | |
1710 | if (IS_ERR(handle)) { | |
1711 | ret = PTR_ERR(handle); | |
1712 | goto out; | |
1713 | } | |
1da177e4 | 1714 | ret = ext3_orphan_add(handle, inode); |
bd1939de JK |
1715 | if (ret) { |
1716 | ext3_journal_stop(handle); | |
1717 | goto out; | |
1718 | } | |
1da177e4 LT |
1719 | orphan = 1; |
1720 | ei->i_disksize = inode->i_size; | |
bd1939de | 1721 | ext3_journal_stop(handle); |
1da177e4 LT |
1722 | } |
1723 | } | |
1724 | ||
ae6ddcc5 | 1725 | ret = blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, |
1da177e4 | 1726 | offset, nr_segs, |
f91a2ad2 | 1727 | ext3_get_block, NULL); |
1da177e4 | 1728 | |
bd1939de | 1729 | if (orphan) { |
1da177e4 LT |
1730 | int err; |
1731 | ||
bd1939de JK |
1732 | /* Credits for sb + inode write */ |
1733 | handle = ext3_journal_start(inode, 2); | |
1734 | if (IS_ERR(handle)) { | |
1735 | /* This is really bad luck. We've written the data | |
1736 | * but cannot extend i_size. Bail out and pretend | |
1737 | * the write failed... */ | |
1738 | ret = PTR_ERR(handle); | |
1739 | goto out; | |
1740 | } | |
1741 | if (inode->i_nlink) | |
1da177e4 | 1742 | ext3_orphan_del(handle, inode); |
bd1939de | 1743 | if (ret > 0) { |
1da177e4 LT |
1744 | loff_t end = offset + ret; |
1745 | if (end > inode->i_size) { | |
1746 | ei->i_disksize = end; | |
1747 | i_size_write(inode, end); | |
1748 | /* | |
1749 | * We're going to return a positive `ret' | |
1750 | * here due to non-zero-length I/O, so there's | |
1751 | * no way of reporting error returns from | |
1752 | * ext3_mark_inode_dirty() to userspace. So | |
1753 | * ignore it. | |
1754 | */ | |
1755 | ext3_mark_inode_dirty(handle, inode); | |
1756 | } | |
1757 | } | |
1758 | err = ext3_journal_stop(handle); | |
1759 | if (ret == 0) | |
1760 | ret = err; | |
1761 | } | |
1762 | out: | |
1763 | return ret; | |
1764 | } | |
1765 | ||
1766 | /* | |
1767 | * Pages can be marked dirty completely asynchronously from ext3's journalling | |
1768 | * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do | |
1769 | * much here because ->set_page_dirty is called under VFS locks. The page is | |
1770 | * not necessarily locked. | |
1771 | * | |
1772 | * We cannot just dirty the page and leave attached buffers clean, because the | |
1773 | * buffers' dirty state is "definitive". We cannot just set the buffers dirty | |
1774 | * or jbddirty because all the journalling code will explode. | |
1775 | * | |
1776 | * So what we do is to mark the page "pending dirty" and next time writepage | |
1777 | * is called, propagate that into the buffers appropriately. | |
1778 | */ | |
1779 | static int ext3_journalled_set_page_dirty(struct page *page) | |
1780 | { | |
1781 | SetPageChecked(page); | |
1782 | return __set_page_dirty_nobuffers(page); | |
1783 | } | |
1784 | ||
f5e54d6e | 1785 | static const struct address_space_operations ext3_ordered_aops = { |
8ab22b9a HH |
1786 | .readpage = ext3_readpage, |
1787 | .readpages = ext3_readpages, | |
1788 | .writepage = ext3_ordered_writepage, | |
1789 | .sync_page = block_sync_page, | |
1790 | .write_begin = ext3_write_begin, | |
1791 | .write_end = ext3_ordered_write_end, | |
1792 | .bmap = ext3_bmap, | |
1793 | .invalidatepage = ext3_invalidatepage, | |
1794 | .releasepage = ext3_releasepage, | |
1795 | .direct_IO = ext3_direct_IO, | |
1796 | .migratepage = buffer_migrate_page, | |
1797 | .is_partially_uptodate = block_is_partially_uptodate, | |
1da177e4 LT |
1798 | }; |
1799 | ||
f5e54d6e | 1800 | static const struct address_space_operations ext3_writeback_aops = { |
8ab22b9a HH |
1801 | .readpage = ext3_readpage, |
1802 | .readpages = ext3_readpages, | |
1803 | .writepage = ext3_writeback_writepage, | |
1804 | .sync_page = block_sync_page, | |
1805 | .write_begin = ext3_write_begin, | |
1806 | .write_end = ext3_writeback_write_end, | |
1807 | .bmap = ext3_bmap, | |
1808 | .invalidatepage = ext3_invalidatepage, | |
1809 | .releasepage = ext3_releasepage, | |
1810 | .direct_IO = ext3_direct_IO, | |
1811 | .migratepage = buffer_migrate_page, | |
1812 | .is_partially_uptodate = block_is_partially_uptodate, | |
1da177e4 LT |
1813 | }; |
1814 | ||
f5e54d6e | 1815 | static const struct address_space_operations ext3_journalled_aops = { |
8ab22b9a HH |
1816 | .readpage = ext3_readpage, |
1817 | .readpages = ext3_readpages, | |
1818 | .writepage = ext3_journalled_writepage, | |
1819 | .sync_page = block_sync_page, | |
1820 | .write_begin = ext3_write_begin, | |
1821 | .write_end = ext3_journalled_write_end, | |
1822 | .set_page_dirty = ext3_journalled_set_page_dirty, | |
1823 | .bmap = ext3_bmap, | |
1824 | .invalidatepage = ext3_invalidatepage, | |
1825 | .releasepage = ext3_releasepage, | |
1826 | .is_partially_uptodate = block_is_partially_uptodate, | |
1da177e4 LT |
1827 | }; |
1828 | ||
1829 | void ext3_set_aops(struct inode *inode) | |
1830 | { | |
1831 | if (ext3_should_order_data(inode)) | |
1832 | inode->i_mapping->a_ops = &ext3_ordered_aops; | |
1833 | else if (ext3_should_writeback_data(inode)) | |
1834 | inode->i_mapping->a_ops = &ext3_writeback_aops; | |
1835 | else | |
1836 | inode->i_mapping->a_ops = &ext3_journalled_aops; | |
1837 | } | |
1838 | ||
1839 | /* | |
1840 | * ext3_block_truncate_page() zeroes out a mapping from file offset `from' | |
1841 | * up to the end of the block which corresponds to `from'. | |
1842 | * This required during truncate. We need to physically zero the tail end | |
1843 | * of that block so it doesn't yield old data if the file is later grown. | |
1844 | */ | |
1845 | static int ext3_block_truncate_page(handle_t *handle, struct page *page, | |
1846 | struct address_space *mapping, loff_t from) | |
1847 | { | |
43d23f90 | 1848 | ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT; |
1da177e4 LT |
1849 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
1850 | unsigned blocksize, iblock, length, pos; | |
1851 | struct inode *inode = mapping->host; | |
1852 | struct buffer_head *bh; | |
1853 | int err = 0; | |
1da177e4 LT |
1854 | |
1855 | blocksize = inode->i_sb->s_blocksize; | |
1856 | length = blocksize - (offset & (blocksize - 1)); | |
1857 | iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); | |
1858 | ||
1859 | /* | |
1860 | * For "nobh" option, we can only work if we don't need to | |
1861 | * read-in the page - otherwise we create buffers to do the IO. | |
1862 | */ | |
cd6ef84e BP |
1863 | if (!page_has_buffers(page) && test_opt(inode->i_sb, NOBH) && |
1864 | ext3_should_writeback_data(inode) && PageUptodate(page)) { | |
eebd2aa3 | 1865 | zero_user(page, offset, length); |
cd6ef84e BP |
1866 | set_page_dirty(page); |
1867 | goto unlock; | |
1da177e4 LT |
1868 | } |
1869 | ||
1870 | if (!page_has_buffers(page)) | |
1871 | create_empty_buffers(page, blocksize, 0); | |
1872 | ||
1873 | /* Find the buffer that contains "offset" */ | |
1874 | bh = page_buffers(page); | |
1875 | pos = blocksize; | |
1876 | while (offset >= pos) { | |
1877 | bh = bh->b_this_page; | |
1878 | iblock++; | |
1879 | pos += blocksize; | |
1880 | } | |
1881 | ||
1882 | err = 0; | |
1883 | if (buffer_freed(bh)) { | |
1884 | BUFFER_TRACE(bh, "freed: skip"); | |
1885 | goto unlock; | |
1886 | } | |
1887 | ||
1888 | if (!buffer_mapped(bh)) { | |
1889 | BUFFER_TRACE(bh, "unmapped"); | |
1890 | ext3_get_block(inode, iblock, bh, 0); | |
1891 | /* unmapped? It's a hole - nothing to do */ | |
1892 | if (!buffer_mapped(bh)) { | |
1893 | BUFFER_TRACE(bh, "still unmapped"); | |
1894 | goto unlock; | |
1895 | } | |
1896 | } | |
1897 | ||
1898 | /* Ok, it's mapped. Make sure it's up-to-date */ | |
1899 | if (PageUptodate(page)) | |
1900 | set_buffer_uptodate(bh); | |
1901 | ||
1902 | if (!buffer_uptodate(bh)) { | |
1903 | err = -EIO; | |
1904 | ll_rw_block(READ, 1, &bh); | |
1905 | wait_on_buffer(bh); | |
1906 | /* Uhhuh. Read error. Complain and punt. */ | |
1907 | if (!buffer_uptodate(bh)) | |
1908 | goto unlock; | |
1909 | } | |
1910 | ||
1911 | if (ext3_should_journal_data(inode)) { | |
1912 | BUFFER_TRACE(bh, "get write access"); | |
1913 | err = ext3_journal_get_write_access(handle, bh); | |
1914 | if (err) | |
1915 | goto unlock; | |
1916 | } | |
1917 | ||
eebd2aa3 | 1918 | zero_user(page, offset, length); |
1da177e4 LT |
1919 | BUFFER_TRACE(bh, "zeroed end of block"); |
1920 | ||
1921 | err = 0; | |
1922 | if (ext3_should_journal_data(inode)) { | |
1923 | err = ext3_journal_dirty_metadata(handle, bh); | |
1924 | } else { | |
1925 | if (ext3_should_order_data(inode)) | |
1926 | err = ext3_journal_dirty_data(handle, bh); | |
1927 | mark_buffer_dirty(bh); | |
1928 | } | |
1929 | ||
1930 | unlock: | |
1931 | unlock_page(page); | |
1932 | page_cache_release(page); | |
1933 | return err; | |
1934 | } | |
1935 | ||
1936 | /* | |
1937 | * Probably it should be a library function... search for first non-zero word | |
1938 | * or memcmp with zero_page, whatever is better for particular architecture. | |
1939 | * Linus? | |
1940 | */ | |
1941 | static inline int all_zeroes(__le32 *p, __le32 *q) | |
1942 | { | |
1943 | while (p < q) | |
1944 | if (*p++) | |
1945 | return 0; | |
1946 | return 1; | |
1947 | } | |
1948 | ||
1949 | /** | |
1950 | * ext3_find_shared - find the indirect blocks for partial truncation. | |
1951 | * @inode: inode in question | |
1952 | * @depth: depth of the affected branch | |
1953 | * @offsets: offsets of pointers in that branch (see ext3_block_to_path) | |
1954 | * @chain: place to store the pointers to partial indirect blocks | |
1955 | * @top: place to the (detached) top of branch | |
1956 | * | |
1957 | * This is a helper function used by ext3_truncate(). | |
1958 | * | |
1959 | * When we do truncate() we may have to clean the ends of several | |
1960 | * indirect blocks but leave the blocks themselves alive. Block is | |
1961 | * partially truncated if some data below the new i_size is refered | |
1962 | * from it (and it is on the path to the first completely truncated | |
1963 | * data block, indeed). We have to free the top of that path along | |
1964 | * with everything to the right of the path. Since no allocation | |
1965 | * past the truncation point is possible until ext3_truncate() | |
1966 | * finishes, we may safely do the latter, but top of branch may | |
1967 | * require special attention - pageout below the truncation point | |
1968 | * might try to populate it. | |
1969 | * | |
1970 | * We atomically detach the top of branch from the tree, store the | |
1971 | * block number of its root in *@top, pointers to buffer_heads of | |
1972 | * partially truncated blocks - in @chain[].bh and pointers to | |
1973 | * their last elements that should not be removed - in | |
1974 | * @chain[].p. Return value is the pointer to last filled element | |
1975 | * of @chain. | |
1976 | * | |
1977 | * The work left to caller to do the actual freeing of subtrees: | |
1978 | * a) free the subtree starting from *@top | |
1979 | * b) free the subtrees whose roots are stored in | |
1980 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) | |
1981 | * c) free the subtrees growing from the inode past the @chain[0]. | |
1982 | * (no partially truncated stuff there). */ | |
1983 | ||
d6859bfc AM |
1984 | static Indirect *ext3_find_shared(struct inode *inode, int depth, |
1985 | int offsets[4], Indirect chain[4], __le32 *top) | |
1da177e4 LT |
1986 | { |
1987 | Indirect *partial, *p; | |
1988 | int k, err; | |
1989 | ||
1990 | *top = 0; | |
1991 | /* Make k index the deepest non-null offest + 1 */ | |
1992 | for (k = depth; k > 1 && !offsets[k-1]; k--) | |
1993 | ; | |
1994 | partial = ext3_get_branch(inode, k, offsets, chain, &err); | |
1995 | /* Writer: pointers */ | |
1996 | if (!partial) | |
1997 | partial = chain + k-1; | |
1998 | /* | |
1999 | * If the branch acquired continuation since we've looked at it - | |
2000 | * fine, it should all survive and (new) top doesn't belong to us. | |
2001 | */ | |
2002 | if (!partial->key && *partial->p) | |
2003 | /* Writer: end */ | |
2004 | goto no_top; | |
2005 | for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) | |
2006 | ; | |
2007 | /* | |
2008 | * OK, we've found the last block that must survive. The rest of our | |
2009 | * branch should be detached before unlocking. However, if that rest | |
2010 | * of branch is all ours and does not grow immediately from the inode | |
2011 | * it's easier to cheat and just decrement partial->p. | |
2012 | */ | |
2013 | if (p == chain + k - 1 && p > chain) { | |
2014 | p->p--; | |
2015 | } else { | |
2016 | *top = *p->p; | |
2017 | /* Nope, don't do this in ext3. Must leave the tree intact */ | |
2018 | #if 0 | |
2019 | *p->p = 0; | |
2020 | #endif | |
2021 | } | |
2022 | /* Writer: end */ | |
2023 | ||
d6859bfc | 2024 | while(partial > p) { |
1da177e4 LT |
2025 | brelse(partial->bh); |
2026 | partial--; | |
2027 | } | |
2028 | no_top: | |
2029 | return partial; | |
2030 | } | |
2031 | ||
2032 | /* | |
2033 | * Zero a number of block pointers in either an inode or an indirect block. | |
2034 | * If we restart the transaction we must again get write access to the | |
2035 | * indirect block for further modification. | |
2036 | * | |
2037 | * We release `count' blocks on disk, but (last - first) may be greater | |
2038 | * than `count' because there can be holes in there. | |
2039 | */ | |
d6859bfc | 2040 | static void ext3_clear_blocks(handle_t *handle, struct inode *inode, |
43d23f90 | 2041 | struct buffer_head *bh, ext3_fsblk_t block_to_free, |
d6859bfc | 2042 | unsigned long count, __le32 *first, __le32 *last) |
1da177e4 LT |
2043 | { |
2044 | __le32 *p; | |
2045 | if (try_to_extend_transaction(handle, inode)) { | |
2046 | if (bh) { | |
2047 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
2048 | ext3_journal_dirty_metadata(handle, bh); | |
2049 | } | |
2050 | ext3_mark_inode_dirty(handle, inode); | |
2051 | ext3_journal_test_restart(handle, inode); | |
2052 | if (bh) { | |
2053 | BUFFER_TRACE(bh, "retaking write access"); | |
2054 | ext3_journal_get_write_access(handle, bh); | |
2055 | } | |
2056 | } | |
2057 | ||
2058 | /* | |
2059 | * Any buffers which are on the journal will be in memory. We find | |
2060 | * them on the hash table so journal_revoke() will run journal_forget() | |
2061 | * on them. We've already detached each block from the file, so | |
2062 | * bforget() in journal_forget() should be safe. | |
2063 | * | |
2064 | * AKPM: turn on bforget in journal_forget()!!! | |
2065 | */ | |
2066 | for (p = first; p < last; p++) { | |
2067 | u32 nr = le32_to_cpu(*p); | |
2068 | if (nr) { | |
2069 | struct buffer_head *bh; | |
2070 | ||
2071 | *p = 0; | |
2072 | bh = sb_find_get_block(inode->i_sb, nr); | |
2073 | ext3_forget(handle, 0, inode, bh, nr); | |
2074 | } | |
2075 | } | |
2076 | ||
2077 | ext3_free_blocks(handle, inode, block_to_free, count); | |
2078 | } | |
2079 | ||
2080 | /** | |
2081 | * ext3_free_data - free a list of data blocks | |
2082 | * @handle: handle for this transaction | |
2083 | * @inode: inode we are dealing with | |
2084 | * @this_bh: indirect buffer_head which contains *@first and *@last | |
2085 | * @first: array of block numbers | |
2086 | * @last: points immediately past the end of array | |
2087 | * | |
2088 | * We are freeing all blocks refered from that array (numbers are stored as | |
2089 | * little-endian 32-bit) and updating @inode->i_blocks appropriately. | |
2090 | * | |
2091 | * We accumulate contiguous runs of blocks to free. Conveniently, if these | |
2092 | * blocks are contiguous then releasing them at one time will only affect one | |
2093 | * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't | |
2094 | * actually use a lot of journal space. | |
2095 | * | |
2096 | * @this_bh will be %NULL if @first and @last point into the inode's direct | |
2097 | * block pointers. | |
2098 | */ | |
2099 | static void ext3_free_data(handle_t *handle, struct inode *inode, | |
2100 | struct buffer_head *this_bh, | |
2101 | __le32 *first, __le32 *last) | |
2102 | { | |
43d23f90 | 2103 | ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */ |
ae6ddcc5 | 2104 | unsigned long count = 0; /* Number of blocks in the run */ |
1da177e4 LT |
2105 | __le32 *block_to_free_p = NULL; /* Pointer into inode/ind |
2106 | corresponding to | |
2107 | block_to_free */ | |
43d23f90 | 2108 | ext3_fsblk_t nr; /* Current block # */ |
1da177e4 LT |
2109 | __le32 *p; /* Pointer into inode/ind |
2110 | for current block */ | |
2111 | int err; | |
2112 | ||
2113 | if (this_bh) { /* For indirect block */ | |
2114 | BUFFER_TRACE(this_bh, "get_write_access"); | |
2115 | err = ext3_journal_get_write_access(handle, this_bh); | |
2116 | /* Important: if we can't update the indirect pointers | |
2117 | * to the blocks, we can't free them. */ | |
2118 | if (err) | |
2119 | return; | |
2120 | } | |
2121 | ||
2122 | for (p = first; p < last; p++) { | |
2123 | nr = le32_to_cpu(*p); | |
2124 | if (nr) { | |
2125 | /* accumulate blocks to free if they're contiguous */ | |
2126 | if (count == 0) { | |
2127 | block_to_free = nr; | |
2128 | block_to_free_p = p; | |
2129 | count = 1; | |
2130 | } else if (nr == block_to_free + count) { | |
2131 | count++; | |
2132 | } else { | |
ae6ddcc5 | 2133 | ext3_clear_blocks(handle, inode, this_bh, |
1da177e4 LT |
2134 | block_to_free, |
2135 | count, block_to_free_p, p); | |
2136 | block_to_free = nr; | |
2137 | block_to_free_p = p; | |
2138 | count = 1; | |
2139 | } | |
2140 | } | |
2141 | } | |
2142 | ||
2143 | if (count > 0) | |
2144 | ext3_clear_blocks(handle, inode, this_bh, block_to_free, | |
2145 | count, block_to_free_p, p); | |
2146 | ||
2147 | if (this_bh) { | |
2148 | BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata"); | |
3ccc3167 DG |
2149 | |
2150 | /* | |
2151 | * The buffer head should have an attached journal head at this | |
2152 | * point. However, if the data is corrupted and an indirect | |
2153 | * block pointed to itself, it would have been detached when | |
2154 | * the block was cleared. Check for this instead of OOPSing. | |
2155 | */ | |
2156 | if (bh2jh(this_bh)) | |
2157 | ext3_journal_dirty_metadata(handle, this_bh); | |
2158 | else | |
2159 | ext3_error(inode->i_sb, "ext3_free_data", | |
2160 | "circular indirect block detected, " | |
2161 | "inode=%lu, block=%llu", | |
2162 | inode->i_ino, | |
2163 | (unsigned long long)this_bh->b_blocknr); | |
1da177e4 LT |
2164 | } |
2165 | } | |
2166 | ||
2167 | /** | |
2168 | * ext3_free_branches - free an array of branches | |
2169 | * @handle: JBD handle for this transaction | |
2170 | * @inode: inode we are dealing with | |
2171 | * @parent_bh: the buffer_head which contains *@first and *@last | |
2172 | * @first: array of block numbers | |
2173 | * @last: pointer immediately past the end of array | |
2174 | * @depth: depth of the branches to free | |
2175 | * | |
2176 | * We are freeing all blocks refered from these branches (numbers are | |
2177 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
2178 | * appropriately. | |
2179 | */ | |
2180 | static void ext3_free_branches(handle_t *handle, struct inode *inode, | |
2181 | struct buffer_head *parent_bh, | |
2182 | __le32 *first, __le32 *last, int depth) | |
2183 | { | |
43d23f90 | 2184 | ext3_fsblk_t nr; |
1da177e4 LT |
2185 | __le32 *p; |
2186 | ||
2187 | if (is_handle_aborted(handle)) | |
2188 | return; | |
2189 | ||
2190 | if (depth--) { | |
2191 | struct buffer_head *bh; | |
2192 | int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
2193 | p = last; | |
2194 | while (--p >= first) { | |
2195 | nr = le32_to_cpu(*p); | |
2196 | if (!nr) | |
2197 | continue; /* A hole */ | |
2198 | ||
2199 | /* Go read the buffer for the next level down */ | |
2200 | bh = sb_bread(inode->i_sb, nr); | |
2201 | ||
2202 | /* | |
2203 | * A read failure? Report error and clear slot | |
2204 | * (should be rare). | |
2205 | */ | |
2206 | if (!bh) { | |
2207 | ext3_error(inode->i_sb, "ext3_free_branches", | |
eee194e7 | 2208 | "Read failure, inode=%lu, block="E3FSBLK, |
1da177e4 LT |
2209 | inode->i_ino, nr); |
2210 | continue; | |
2211 | } | |
2212 | ||
2213 | /* This zaps the entire block. Bottom up. */ | |
2214 | BUFFER_TRACE(bh, "free child branches"); | |
2215 | ext3_free_branches(handle, inode, bh, | |
2216 | (__le32*)bh->b_data, | |
2217 | (__le32*)bh->b_data + addr_per_block, | |
2218 | depth); | |
2219 | ||
2220 | /* | |
2221 | * We've probably journalled the indirect block several | |
2222 | * times during the truncate. But it's no longer | |
2223 | * needed and we now drop it from the transaction via | |
2224 | * journal_revoke(). | |
2225 | * | |
2226 | * That's easy if it's exclusively part of this | |
2227 | * transaction. But if it's part of the committing | |
2228 | * transaction then journal_forget() will simply | |
2229 | * brelse() it. That means that if the underlying | |
2230 | * block is reallocated in ext3_get_block(), | |
2231 | * unmap_underlying_metadata() will find this block | |
2232 | * and will try to get rid of it. damn, damn. | |
2233 | * | |
2234 | * If this block has already been committed to the | |
2235 | * journal, a revoke record will be written. And | |
2236 | * revoke records must be emitted *before* clearing | |
2237 | * this block's bit in the bitmaps. | |
2238 | */ | |
2239 | ext3_forget(handle, 1, inode, bh, bh->b_blocknr); | |
2240 | ||
2241 | /* | |
2242 | * Everything below this this pointer has been | |
2243 | * released. Now let this top-of-subtree go. | |
2244 | * | |
2245 | * We want the freeing of this indirect block to be | |
2246 | * atomic in the journal with the updating of the | |
2247 | * bitmap block which owns it. So make some room in | |
2248 | * the journal. | |
2249 | * | |
2250 | * We zero the parent pointer *after* freeing its | |
2251 | * pointee in the bitmaps, so if extend_transaction() | |
2252 | * for some reason fails to put the bitmap changes and | |
2253 | * the release into the same transaction, recovery | |
2254 | * will merely complain about releasing a free block, | |
2255 | * rather than leaking blocks. | |
2256 | */ | |
2257 | if (is_handle_aborted(handle)) | |
2258 | return; | |
2259 | if (try_to_extend_transaction(handle, inode)) { | |
2260 | ext3_mark_inode_dirty(handle, inode); | |
2261 | ext3_journal_test_restart(handle, inode); | |
2262 | } | |
2263 | ||
2264 | ext3_free_blocks(handle, inode, nr, 1); | |
2265 | ||
2266 | if (parent_bh) { | |
2267 | /* | |
2268 | * The block which we have just freed is | |
2269 | * pointed to by an indirect block: journal it | |
2270 | */ | |
2271 | BUFFER_TRACE(parent_bh, "get_write_access"); | |
2272 | if (!ext3_journal_get_write_access(handle, | |
2273 | parent_bh)){ | |
2274 | *p = 0; | |
2275 | BUFFER_TRACE(parent_bh, | |
2276 | "call ext3_journal_dirty_metadata"); | |
ae6ddcc5 | 2277 | ext3_journal_dirty_metadata(handle, |
1da177e4 LT |
2278 | parent_bh); |
2279 | } | |
2280 | } | |
2281 | } | |
2282 | } else { | |
2283 | /* We have reached the bottom of the tree. */ | |
2284 | BUFFER_TRACE(parent_bh, "free data blocks"); | |
2285 | ext3_free_data(handle, inode, parent_bh, first, last); | |
2286 | } | |
2287 | } | |
2288 | ||
ae76dd9a DG |
2289 | int ext3_can_truncate(struct inode *inode) |
2290 | { | |
2291 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
2292 | return 0; | |
2293 | if (S_ISREG(inode->i_mode)) | |
2294 | return 1; | |
2295 | if (S_ISDIR(inode->i_mode)) | |
2296 | return 1; | |
2297 | if (S_ISLNK(inode->i_mode)) | |
2298 | return !ext3_inode_is_fast_symlink(inode); | |
2299 | return 0; | |
2300 | } | |
2301 | ||
1da177e4 LT |
2302 | /* |
2303 | * ext3_truncate() | |
2304 | * | |
2305 | * We block out ext3_get_block() block instantiations across the entire | |
2306 | * transaction, and VFS/VM ensures that ext3_truncate() cannot run | |
2307 | * simultaneously on behalf of the same inode. | |
2308 | * | |
2309 | * As we work through the truncate and commmit bits of it to the journal there | |
2310 | * is one core, guiding principle: the file's tree must always be consistent on | |
2311 | * disk. We must be able to restart the truncate after a crash. | |
2312 | * | |
2313 | * The file's tree may be transiently inconsistent in memory (although it | |
2314 | * probably isn't), but whenever we close off and commit a journal transaction, | |
2315 | * the contents of (the filesystem + the journal) must be consistent and | |
2316 | * restartable. It's pretty simple, really: bottom up, right to left (although | |
2317 | * left-to-right works OK too). | |
2318 | * | |
2319 | * Note that at recovery time, journal replay occurs *before* the restart of | |
2320 | * truncate against the orphan inode list. | |
2321 | * | |
2322 | * The committed inode has the new, desired i_size (which is the same as | |
2323 | * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see | |
2324 | * that this inode's truncate did not complete and it will again call | |
2325 | * ext3_truncate() to have another go. So there will be instantiated blocks | |
2326 | * to the right of the truncation point in a crashed ext3 filesystem. But | |
2327 | * that's fine - as long as they are linked from the inode, the post-crash | |
2328 | * ext3_truncate() run will find them and release them. | |
2329 | */ | |
d6859bfc | 2330 | void ext3_truncate(struct inode *inode) |
1da177e4 LT |
2331 | { |
2332 | handle_t *handle; | |
2333 | struct ext3_inode_info *ei = EXT3_I(inode); | |
2334 | __le32 *i_data = ei->i_data; | |
2335 | int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb); | |
2336 | struct address_space *mapping = inode->i_mapping; | |
2337 | int offsets[4]; | |
2338 | Indirect chain[4]; | |
2339 | Indirect *partial; | |
2340 | __le32 nr = 0; | |
2341 | int n; | |
2342 | long last_block; | |
2343 | unsigned blocksize = inode->i_sb->s_blocksize; | |
2344 | struct page *page; | |
2345 | ||
ae76dd9a | 2346 | if (!ext3_can_truncate(inode)) |
1da177e4 LT |
2347 | return; |
2348 | ||
f7ab34ea TT |
2349 | if (inode->i_size == 0 && ext3_should_writeback_data(inode)) |
2350 | ei->i_state |= EXT3_STATE_FLUSH_ON_CLOSE; | |
2351 | ||
1da177e4 LT |
2352 | /* |
2353 | * We have to lock the EOF page here, because lock_page() nests | |
2354 | * outside journal_start(). | |
2355 | */ | |
2356 | if ((inode->i_size & (blocksize - 1)) == 0) { | |
2357 | /* Block boundary? Nothing to do */ | |
2358 | page = NULL; | |
2359 | } else { | |
2360 | page = grab_cache_page(mapping, | |
2361 | inode->i_size >> PAGE_CACHE_SHIFT); | |
2362 | if (!page) | |
2363 | return; | |
2364 | } | |
2365 | ||
2366 | handle = start_transaction(inode); | |
2367 | if (IS_ERR(handle)) { | |
2368 | if (page) { | |
2369 | clear_highpage(page); | |
2370 | flush_dcache_page(page); | |
2371 | unlock_page(page); | |
2372 | page_cache_release(page); | |
2373 | } | |
2374 | return; /* AKPM: return what? */ | |
2375 | } | |
2376 | ||
2377 | last_block = (inode->i_size + blocksize-1) | |
2378 | >> EXT3_BLOCK_SIZE_BITS(inode->i_sb); | |
2379 | ||
2380 | if (page) | |
2381 | ext3_block_truncate_page(handle, page, mapping, inode->i_size); | |
2382 | ||
2383 | n = ext3_block_to_path(inode, last_block, offsets, NULL); | |
2384 | if (n == 0) | |
2385 | goto out_stop; /* error */ | |
2386 | ||
2387 | /* | |
2388 | * OK. This truncate is going to happen. We add the inode to the | |
2389 | * orphan list, so that if this truncate spans multiple transactions, | |
2390 | * and we crash, we will resume the truncate when the filesystem | |
2391 | * recovers. It also marks the inode dirty, to catch the new size. | |
2392 | * | |
2393 | * Implication: the file must always be in a sane, consistent | |
2394 | * truncatable state while each transaction commits. | |
2395 | */ | |
2396 | if (ext3_orphan_add(handle, inode)) | |
2397 | goto out_stop; | |
2398 | ||
2399 | /* | |
2400 | * The orphan list entry will now protect us from any crash which | |
2401 | * occurs before the truncate completes, so it is now safe to propagate | |
2402 | * the new, shorter inode size (held for now in i_size) into the | |
2403 | * on-disk inode. We do this via i_disksize, which is the value which | |
2404 | * ext3 *really* writes onto the disk inode. | |
2405 | */ | |
2406 | ei->i_disksize = inode->i_size; | |
2407 | ||
2408 | /* | |
2409 | * From here we block out all ext3_get_block() callers who want to | |
2410 | * modify the block allocation tree. | |
2411 | */ | |
97461518 | 2412 | mutex_lock(&ei->truncate_mutex); |
1da177e4 LT |
2413 | |
2414 | if (n == 1) { /* direct blocks */ | |
2415 | ext3_free_data(handle, inode, NULL, i_data+offsets[0], | |
2416 | i_data + EXT3_NDIR_BLOCKS); | |
2417 | goto do_indirects; | |
2418 | } | |
2419 | ||
2420 | partial = ext3_find_shared(inode, n, offsets, chain, &nr); | |
2421 | /* Kill the top of shared branch (not detached) */ | |
2422 | if (nr) { | |
2423 | if (partial == chain) { | |
2424 | /* Shared branch grows from the inode */ | |
2425 | ext3_free_branches(handle, inode, NULL, | |
2426 | &nr, &nr+1, (chain+n-1) - partial); | |
2427 | *partial->p = 0; | |
2428 | /* | |
2429 | * We mark the inode dirty prior to restart, | |
2430 | * and prior to stop. No need for it here. | |
2431 | */ | |
2432 | } else { | |
2433 | /* Shared branch grows from an indirect block */ | |
2434 | BUFFER_TRACE(partial->bh, "get_write_access"); | |
2435 | ext3_free_branches(handle, inode, partial->bh, | |
2436 | partial->p, | |
2437 | partial->p+1, (chain+n-1) - partial); | |
2438 | } | |
2439 | } | |
2440 | /* Clear the ends of indirect blocks on the shared branch */ | |
2441 | while (partial > chain) { | |
2442 | ext3_free_branches(handle, inode, partial->bh, partial->p + 1, | |
2443 | (__le32*)partial->bh->b_data+addr_per_block, | |
2444 | (chain+n-1) - partial); | |
2445 | BUFFER_TRACE(partial->bh, "call brelse"); | |
2446 | brelse (partial->bh); | |
2447 | partial--; | |
2448 | } | |
2449 | do_indirects: | |
2450 | /* Kill the remaining (whole) subtrees */ | |
2451 | switch (offsets[0]) { | |
d6859bfc AM |
2452 | default: |
2453 | nr = i_data[EXT3_IND_BLOCK]; | |
2454 | if (nr) { | |
2455 | ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1); | |
2456 | i_data[EXT3_IND_BLOCK] = 0; | |
2457 | } | |
2458 | case EXT3_IND_BLOCK: | |
2459 | nr = i_data[EXT3_DIND_BLOCK]; | |
2460 | if (nr) { | |
2461 | ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2); | |
2462 | i_data[EXT3_DIND_BLOCK] = 0; | |
2463 | } | |
2464 | case EXT3_DIND_BLOCK: | |
2465 | nr = i_data[EXT3_TIND_BLOCK]; | |
2466 | if (nr) { | |
2467 | ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3); | |
2468 | i_data[EXT3_TIND_BLOCK] = 0; | |
2469 | } | |
2470 | case EXT3_TIND_BLOCK: | |
2471 | ; | |
1da177e4 LT |
2472 | } |
2473 | ||
2474 | ext3_discard_reservation(inode); | |
2475 | ||
97461518 | 2476 | mutex_unlock(&ei->truncate_mutex); |
1da177e4 LT |
2477 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; |
2478 | ext3_mark_inode_dirty(handle, inode); | |
2479 | ||
d6859bfc AM |
2480 | /* |
2481 | * In a multi-transaction truncate, we only make the final transaction | |
2482 | * synchronous | |
2483 | */ | |
1da177e4 LT |
2484 | if (IS_SYNC(inode)) |
2485 | handle->h_sync = 1; | |
2486 | out_stop: | |
2487 | /* | |
2488 | * If this was a simple ftruncate(), and the file will remain alive | |
2489 | * then we need to clear up the orphan record which we created above. | |
2490 | * However, if this was a real unlink then we were called by | |
2491 | * ext3_delete_inode(), and we allow that function to clean up the | |
2492 | * orphan info for us. | |
2493 | */ | |
2494 | if (inode->i_nlink) | |
2495 | ext3_orphan_del(handle, inode); | |
2496 | ||
2497 | ext3_journal_stop(handle); | |
2498 | } | |
2499 | ||
43d23f90 | 2500 | static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb, |
1da177e4 LT |
2501 | unsigned long ino, struct ext3_iloc *iloc) |
2502 | { | |
e0e369a7 | 2503 | unsigned long block_group; |
43d23f90 MC |
2504 | unsigned long offset; |
2505 | ext3_fsblk_t block; | |
e0e369a7 | 2506 | struct ext3_group_desc *gdp; |
1da177e4 | 2507 | |
2ccb48eb NB |
2508 | if (!ext3_valid_inum(sb, ino)) { |
2509 | /* | |
2510 | * This error is already checked for in namei.c unless we are | |
2511 | * looking at an NFS filehandle, in which case no error | |
2512 | * report is needed | |
2513 | */ | |
1da177e4 LT |
2514 | return 0; |
2515 | } | |
2ccb48eb | 2516 | |
1da177e4 | 2517 | block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb); |
e0e369a7 AM |
2518 | gdp = ext3_get_group_desc(sb, block_group, NULL); |
2519 | if (!gdp) | |
1da177e4 | 2520 | return 0; |
1da177e4 LT |
2521 | /* |
2522 | * Figure out the offset within the block group inode table | |
2523 | */ | |
2524 | offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) * | |
2525 | EXT3_INODE_SIZE(sb); | |
e0e369a7 | 2526 | block = le32_to_cpu(gdp->bg_inode_table) + |
1da177e4 LT |
2527 | (offset >> EXT3_BLOCK_SIZE_BITS(sb)); |
2528 | ||
2529 | iloc->block_group = block_group; | |
2530 | iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1); | |
2531 | return block; | |
2532 | } | |
2533 | ||
2534 | /* | |
2535 | * ext3_get_inode_loc returns with an extra refcount against the inode's | |
2536 | * underlying buffer_head on success. If 'in_mem' is true, we have all | |
2537 | * data in memory that is needed to recreate the on-disk version of this | |
2538 | * inode. | |
2539 | */ | |
2540 | static int __ext3_get_inode_loc(struct inode *inode, | |
2541 | struct ext3_iloc *iloc, int in_mem) | |
2542 | { | |
43d23f90 | 2543 | ext3_fsblk_t block; |
1da177e4 LT |
2544 | struct buffer_head *bh; |
2545 | ||
2546 | block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc); | |
2547 | if (!block) | |
2548 | return -EIO; | |
2549 | ||
2550 | bh = sb_getblk(inode->i_sb, block); | |
2551 | if (!bh) { | |
2552 | ext3_error (inode->i_sb, "ext3_get_inode_loc", | |
2553 | "unable to read inode block - " | |
43d23f90 MC |
2554 | "inode=%lu, block="E3FSBLK, |
2555 | inode->i_ino, block); | |
1da177e4 LT |
2556 | return -EIO; |
2557 | } | |
2558 | if (!buffer_uptodate(bh)) { | |
2559 | lock_buffer(bh); | |
95450f5a HK |
2560 | |
2561 | /* | |
2562 | * If the buffer has the write error flag, we have failed | |
2563 | * to write out another inode in the same block. In this | |
2564 | * case, we don't have to read the block because we may | |
2565 | * read the old inode data successfully. | |
2566 | */ | |
2567 | if (buffer_write_io_error(bh) && !buffer_uptodate(bh)) | |
2568 | set_buffer_uptodate(bh); | |
2569 | ||
1da177e4 LT |
2570 | if (buffer_uptodate(bh)) { |
2571 | /* someone brought it uptodate while we waited */ | |
2572 | unlock_buffer(bh); | |
2573 | goto has_buffer; | |
2574 | } | |
2575 | ||
2576 | /* | |
2577 | * If we have all information of the inode in memory and this | |
2578 | * is the only valid inode in the block, we need not read the | |
2579 | * block. | |
2580 | */ | |
2581 | if (in_mem) { | |
2582 | struct buffer_head *bitmap_bh; | |
2583 | struct ext3_group_desc *desc; | |
2584 | int inodes_per_buffer; | |
2585 | int inode_offset, i; | |
2586 | int block_group; | |
2587 | int start; | |
2588 | ||
2589 | block_group = (inode->i_ino - 1) / | |
2590 | EXT3_INODES_PER_GROUP(inode->i_sb); | |
2591 | inodes_per_buffer = bh->b_size / | |
2592 | EXT3_INODE_SIZE(inode->i_sb); | |
2593 | inode_offset = ((inode->i_ino - 1) % | |
2594 | EXT3_INODES_PER_GROUP(inode->i_sb)); | |
2595 | start = inode_offset & ~(inodes_per_buffer - 1); | |
2596 | ||
2597 | /* Is the inode bitmap in cache? */ | |
2598 | desc = ext3_get_group_desc(inode->i_sb, | |
2599 | block_group, NULL); | |
2600 | if (!desc) | |
2601 | goto make_io; | |
2602 | ||
2603 | bitmap_bh = sb_getblk(inode->i_sb, | |
2604 | le32_to_cpu(desc->bg_inode_bitmap)); | |
2605 | if (!bitmap_bh) | |
2606 | goto make_io; | |
2607 | ||
2608 | /* | |
2609 | * If the inode bitmap isn't in cache then the | |
2610 | * optimisation may end up performing two reads instead | |
2611 | * of one, so skip it. | |
2612 | */ | |
2613 | if (!buffer_uptodate(bitmap_bh)) { | |
2614 | brelse(bitmap_bh); | |
2615 | goto make_io; | |
2616 | } | |
2617 | for (i = start; i < start + inodes_per_buffer; i++) { | |
2618 | if (i == inode_offset) | |
2619 | continue; | |
2620 | if (ext3_test_bit(i, bitmap_bh->b_data)) | |
2621 | break; | |
2622 | } | |
2623 | brelse(bitmap_bh); | |
2624 | if (i == start + inodes_per_buffer) { | |
2625 | /* all other inodes are free, so skip I/O */ | |
2626 | memset(bh->b_data, 0, bh->b_size); | |
2627 | set_buffer_uptodate(bh); | |
2628 | unlock_buffer(bh); | |
2629 | goto has_buffer; | |
2630 | } | |
2631 | } | |
2632 | ||
2633 | make_io: | |
2634 | /* | |
2635 | * There are other valid inodes in the buffer, this inode | |
2636 | * has in-inode xattrs, or we don't have this inode in memory. | |
2637 | * Read the block from disk. | |
2638 | */ | |
2639 | get_bh(bh); | |
2640 | bh->b_end_io = end_buffer_read_sync; | |
caa38fb0 | 2641 | submit_bh(READ_META, bh); |
1da177e4 LT |
2642 | wait_on_buffer(bh); |
2643 | if (!buffer_uptodate(bh)) { | |
2644 | ext3_error(inode->i_sb, "ext3_get_inode_loc", | |
2645 | "unable to read inode block - " | |
43d23f90 | 2646 | "inode=%lu, block="E3FSBLK, |
1da177e4 LT |
2647 | inode->i_ino, block); |
2648 | brelse(bh); | |
2649 | return -EIO; | |
2650 | } | |
2651 | } | |
2652 | has_buffer: | |
2653 | iloc->bh = bh; | |
2654 | return 0; | |
2655 | } | |
2656 | ||
2657 | int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc) | |
2658 | { | |
2659 | /* We have all inode data except xattrs in memory here. */ | |
2660 | return __ext3_get_inode_loc(inode, iloc, | |
2661 | !(EXT3_I(inode)->i_state & EXT3_STATE_XATTR)); | |
2662 | } | |
2663 | ||
2664 | void ext3_set_inode_flags(struct inode *inode) | |
2665 | { | |
2666 | unsigned int flags = EXT3_I(inode)->i_flags; | |
2667 | ||
2668 | inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); | |
2669 | if (flags & EXT3_SYNC_FL) | |
2670 | inode->i_flags |= S_SYNC; | |
2671 | if (flags & EXT3_APPEND_FL) | |
2672 | inode->i_flags |= S_APPEND; | |
2673 | if (flags & EXT3_IMMUTABLE_FL) | |
2674 | inode->i_flags |= S_IMMUTABLE; | |
2675 | if (flags & EXT3_NOATIME_FL) | |
2676 | inode->i_flags |= S_NOATIME; | |
2677 | if (flags & EXT3_DIRSYNC_FL) | |
2678 | inode->i_flags |= S_DIRSYNC; | |
2679 | } | |
2680 | ||
28be5abb JK |
2681 | /* Propagate flags from i_flags to EXT3_I(inode)->i_flags */ |
2682 | void ext3_get_inode_flags(struct ext3_inode_info *ei) | |
2683 | { | |
2684 | unsigned int flags = ei->vfs_inode.i_flags; | |
2685 | ||
2686 | ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL| | |
2687 | EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL); | |
2688 | if (flags & S_SYNC) | |
2689 | ei->i_flags |= EXT3_SYNC_FL; | |
2690 | if (flags & S_APPEND) | |
2691 | ei->i_flags |= EXT3_APPEND_FL; | |
2692 | if (flags & S_IMMUTABLE) | |
2693 | ei->i_flags |= EXT3_IMMUTABLE_FL; | |
2694 | if (flags & S_NOATIME) | |
2695 | ei->i_flags |= EXT3_NOATIME_FL; | |
2696 | if (flags & S_DIRSYNC) | |
2697 | ei->i_flags |= EXT3_DIRSYNC_FL; | |
2698 | } | |
2699 | ||
473043dc | 2700 | struct inode *ext3_iget(struct super_block *sb, unsigned long ino) |
1da177e4 LT |
2701 | { |
2702 | struct ext3_iloc iloc; | |
2703 | struct ext3_inode *raw_inode; | |
473043dc | 2704 | struct ext3_inode_info *ei; |
1da177e4 | 2705 | struct buffer_head *bh; |
473043dc DH |
2706 | struct inode *inode; |
2707 | long ret; | |
1da177e4 LT |
2708 | int block; |
2709 | ||
473043dc DH |
2710 | inode = iget_locked(sb, ino); |
2711 | if (!inode) | |
2712 | return ERR_PTR(-ENOMEM); | |
2713 | if (!(inode->i_state & I_NEW)) | |
2714 | return inode; | |
2715 | ||
2716 | ei = EXT3_I(inode); | |
1da177e4 LT |
2717 | #ifdef CONFIG_EXT3_FS_POSIX_ACL |
2718 | ei->i_acl = EXT3_ACL_NOT_CACHED; | |
2719 | ei->i_default_acl = EXT3_ACL_NOT_CACHED; | |
2720 | #endif | |
2721 | ei->i_block_alloc_info = NULL; | |
2722 | ||
473043dc DH |
2723 | ret = __ext3_get_inode_loc(inode, &iloc, 0); |
2724 | if (ret < 0) | |
1da177e4 LT |
2725 | goto bad_inode; |
2726 | bh = iloc.bh; | |
2727 | raw_inode = ext3_raw_inode(&iloc); | |
2728 | inode->i_mode = le16_to_cpu(raw_inode->i_mode); | |
2729 | inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); | |
2730 | inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); | |
2731 | if(!(test_opt (inode->i_sb, NO_UID32))) { | |
2732 | inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; | |
2733 | inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; | |
2734 | } | |
2735 | inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); | |
2736 | inode->i_size = le32_to_cpu(raw_inode->i_size); | |
4d7bf11d MR |
2737 | inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); |
2738 | inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); | |
2739 | inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); | |
1da177e4 LT |
2740 | inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0; |
2741 | ||
2742 | ei->i_state = 0; | |
2743 | ei->i_dir_start_lookup = 0; | |
2744 | ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); | |
2745 | /* We now have enough fields to check if the inode was active or not. | |
2746 | * This is needed because nfsd might try to access dead inodes | |
2747 | * the test is that same one that e2fsck uses | |
2748 | * NeilBrown 1999oct15 | |
2749 | */ | |
2750 | if (inode->i_nlink == 0) { | |
2751 | if (inode->i_mode == 0 || | |
2752 | !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) { | |
2753 | /* this inode is deleted */ | |
2754 | brelse (bh); | |
473043dc | 2755 | ret = -ESTALE; |
1da177e4 LT |
2756 | goto bad_inode; |
2757 | } | |
2758 | /* The only unlinked inodes we let through here have | |
2759 | * valid i_mode and are being read by the orphan | |
2760 | * recovery code: that's fine, we're about to complete | |
2761 | * the process of deleting those. */ | |
2762 | } | |
1da177e4 LT |
2763 | inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); |
2764 | ei->i_flags = le32_to_cpu(raw_inode->i_flags); | |
2765 | #ifdef EXT3_FRAGMENTS | |
2766 | ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); | |
2767 | ei->i_frag_no = raw_inode->i_frag; | |
2768 | ei->i_frag_size = raw_inode->i_fsize; | |
2769 | #endif | |
2770 | ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); | |
2771 | if (!S_ISREG(inode->i_mode)) { | |
2772 | ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); | |
2773 | } else { | |
2774 | inode->i_size |= | |
2775 | ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; | |
2776 | } | |
2777 | ei->i_disksize = inode->i_size; | |
2778 | inode->i_generation = le32_to_cpu(raw_inode->i_generation); | |
2779 | ei->i_block_group = iloc.block_group; | |
2780 | /* | |
2781 | * NOTE! The in-memory inode i_data array is in little-endian order | |
2782 | * even on big-endian machines: we do NOT byteswap the block numbers! | |
2783 | */ | |
2784 | for (block = 0; block < EXT3_N_BLOCKS; block++) | |
2785 | ei->i_data[block] = raw_inode->i_block[block]; | |
2786 | INIT_LIST_HEAD(&ei->i_orphan); | |
2787 | ||
2788 | if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 && | |
2789 | EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) { | |
2790 | /* | |
2791 | * When mke2fs creates big inodes it does not zero out | |
2792 | * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE, | |
2793 | * so ignore those first few inodes. | |
2794 | */ | |
2795 | ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize); | |
2796 | if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize > | |
e4a10a36 KK |
2797 | EXT3_INODE_SIZE(inode->i_sb)) { |
2798 | brelse (bh); | |
473043dc | 2799 | ret = -EIO; |
1da177e4 | 2800 | goto bad_inode; |
e4a10a36 | 2801 | } |
1da177e4 LT |
2802 | if (ei->i_extra_isize == 0) { |
2803 | /* The extra space is currently unused. Use it. */ | |
2804 | ei->i_extra_isize = sizeof(struct ext3_inode) - | |
2805 | EXT3_GOOD_OLD_INODE_SIZE; | |
2806 | } else { | |
2807 | __le32 *magic = (void *)raw_inode + | |
2808 | EXT3_GOOD_OLD_INODE_SIZE + | |
2809 | ei->i_extra_isize; | |
2810 | if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC)) | |
2811 | ei->i_state |= EXT3_STATE_XATTR; | |
2812 | } | |
2813 | } else | |
2814 | ei->i_extra_isize = 0; | |
2815 | ||
2816 | if (S_ISREG(inode->i_mode)) { | |
2817 | inode->i_op = &ext3_file_inode_operations; | |
2818 | inode->i_fop = &ext3_file_operations; | |
2819 | ext3_set_aops(inode); | |
2820 | } else if (S_ISDIR(inode->i_mode)) { | |
2821 | inode->i_op = &ext3_dir_inode_operations; | |
2822 | inode->i_fop = &ext3_dir_operations; | |
2823 | } else if (S_ISLNK(inode->i_mode)) { | |
b5ed3112 | 2824 | if (ext3_inode_is_fast_symlink(inode)) { |
1da177e4 | 2825 | inode->i_op = &ext3_fast_symlink_inode_operations; |
b5ed3112 DG |
2826 | nd_terminate_link(ei->i_data, inode->i_size, |
2827 | sizeof(ei->i_data) - 1); | |
2828 | } else { | |
1da177e4 LT |
2829 | inode->i_op = &ext3_symlink_inode_operations; |
2830 | ext3_set_aops(inode); | |
2831 | } | |
2832 | } else { | |
2833 | inode->i_op = &ext3_special_inode_operations; | |
2834 | if (raw_inode->i_block[0]) | |
2835 | init_special_inode(inode, inode->i_mode, | |
2836 | old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); | |
ae6ddcc5 | 2837 | else |
1da177e4 LT |
2838 | init_special_inode(inode, inode->i_mode, |
2839 | new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); | |
2840 | } | |
2841 | brelse (iloc.bh); | |
2842 | ext3_set_inode_flags(inode); | |
473043dc DH |
2843 | unlock_new_inode(inode); |
2844 | return inode; | |
1da177e4 LT |
2845 | |
2846 | bad_inode: | |
473043dc DH |
2847 | iget_failed(inode); |
2848 | return ERR_PTR(ret); | |
1da177e4 LT |
2849 | } |
2850 | ||
2851 | /* | |
2852 | * Post the struct inode info into an on-disk inode location in the | |
2853 | * buffer-cache. This gobbles the caller's reference to the | |
2854 | * buffer_head in the inode location struct. | |
2855 | * | |
2856 | * The caller must have write access to iloc->bh. | |
2857 | */ | |
ae6ddcc5 MC |
2858 | static int ext3_do_update_inode(handle_t *handle, |
2859 | struct inode *inode, | |
1da177e4 LT |
2860 | struct ext3_iloc *iloc) |
2861 | { | |
2862 | struct ext3_inode *raw_inode = ext3_raw_inode(iloc); | |
2863 | struct ext3_inode_info *ei = EXT3_I(inode); | |
2864 | struct buffer_head *bh = iloc->bh; | |
2865 | int err = 0, rc, block; | |
2866 | ||
2867 | /* For fields not not tracking in the in-memory inode, | |
2868 | * initialise them to zero for new inodes. */ | |
2869 | if (ei->i_state & EXT3_STATE_NEW) | |
2870 | memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size); | |
2871 | ||
28be5abb | 2872 | ext3_get_inode_flags(ei); |
1da177e4 LT |
2873 | raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
2874 | if(!(test_opt(inode->i_sb, NO_UID32))) { | |
2875 | raw_inode->i_uid_low = cpu_to_le16(low_16_bits(inode->i_uid)); | |
2876 | raw_inode->i_gid_low = cpu_to_le16(low_16_bits(inode->i_gid)); | |
2877 | /* | |
2878 | * Fix up interoperability with old kernels. Otherwise, old inodes get | |
2879 | * re-used with the upper 16 bits of the uid/gid intact | |
2880 | */ | |
2881 | if(!ei->i_dtime) { | |
2882 | raw_inode->i_uid_high = | |
2883 | cpu_to_le16(high_16_bits(inode->i_uid)); | |
2884 | raw_inode->i_gid_high = | |
2885 | cpu_to_le16(high_16_bits(inode->i_gid)); | |
2886 | } else { | |
2887 | raw_inode->i_uid_high = 0; | |
2888 | raw_inode->i_gid_high = 0; | |
2889 | } | |
2890 | } else { | |
2891 | raw_inode->i_uid_low = | |
2892 | cpu_to_le16(fs_high2lowuid(inode->i_uid)); | |
2893 | raw_inode->i_gid_low = | |
2894 | cpu_to_le16(fs_high2lowgid(inode->i_gid)); | |
2895 | raw_inode->i_uid_high = 0; | |
2896 | raw_inode->i_gid_high = 0; | |
2897 | } | |
2898 | raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); | |
2899 | raw_inode->i_size = cpu_to_le32(ei->i_disksize); | |
2900 | raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); | |
2901 | raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); | |
2902 | raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); | |
2903 | raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); | |
2904 | raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); | |
2905 | raw_inode->i_flags = cpu_to_le32(ei->i_flags); | |
2906 | #ifdef EXT3_FRAGMENTS | |
2907 | raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); | |
2908 | raw_inode->i_frag = ei->i_frag_no; | |
2909 | raw_inode->i_fsize = ei->i_frag_size; | |
2910 | #endif | |
2911 | raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); | |
2912 | if (!S_ISREG(inode->i_mode)) { | |
2913 | raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); | |
2914 | } else { | |
2915 | raw_inode->i_size_high = | |
2916 | cpu_to_le32(ei->i_disksize >> 32); | |
2917 | if (ei->i_disksize > 0x7fffffffULL) { | |
2918 | struct super_block *sb = inode->i_sb; | |
2919 | if (!EXT3_HAS_RO_COMPAT_FEATURE(sb, | |
2920 | EXT3_FEATURE_RO_COMPAT_LARGE_FILE) || | |
2921 | EXT3_SB(sb)->s_es->s_rev_level == | |
2922 | cpu_to_le32(EXT3_GOOD_OLD_REV)) { | |
2923 | /* If this is the first large file | |
2924 | * created, add a flag to the superblock. | |
2925 | */ | |
2926 | err = ext3_journal_get_write_access(handle, | |
2927 | EXT3_SB(sb)->s_sbh); | |
2928 | if (err) | |
2929 | goto out_brelse; | |
2930 | ext3_update_dynamic_rev(sb); | |
2931 | EXT3_SET_RO_COMPAT_FEATURE(sb, | |
2932 | EXT3_FEATURE_RO_COMPAT_LARGE_FILE); | |
2933 | sb->s_dirt = 1; | |
2934 | handle->h_sync = 1; | |
2935 | err = ext3_journal_dirty_metadata(handle, | |
2936 | EXT3_SB(sb)->s_sbh); | |
2937 | } | |
2938 | } | |
2939 | } | |
2940 | raw_inode->i_generation = cpu_to_le32(inode->i_generation); | |
2941 | if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { | |
2942 | if (old_valid_dev(inode->i_rdev)) { | |
2943 | raw_inode->i_block[0] = | |
2944 | cpu_to_le32(old_encode_dev(inode->i_rdev)); | |
2945 | raw_inode->i_block[1] = 0; | |
2946 | } else { | |
2947 | raw_inode->i_block[0] = 0; | |
2948 | raw_inode->i_block[1] = | |
2949 | cpu_to_le32(new_encode_dev(inode->i_rdev)); | |
2950 | raw_inode->i_block[2] = 0; | |
2951 | } | |
2952 | } else for (block = 0; block < EXT3_N_BLOCKS; block++) | |
2953 | raw_inode->i_block[block] = ei->i_data[block]; | |
2954 | ||
ff87b37d | 2955 | if (ei->i_extra_isize) |
1da177e4 LT |
2956 | raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize); |
2957 | ||
2958 | BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); | |
2959 | rc = ext3_journal_dirty_metadata(handle, bh); | |
2960 | if (!err) | |
2961 | err = rc; | |
2962 | ei->i_state &= ~EXT3_STATE_NEW; | |
2963 | ||
2964 | out_brelse: | |
2965 | brelse (bh); | |
2966 | ext3_std_error(inode->i_sb, err); | |
2967 | return err; | |
2968 | } | |
2969 | ||
2970 | /* | |
2971 | * ext3_write_inode() | |
2972 | * | |
2973 | * We are called from a few places: | |
2974 | * | |
2975 | * - Within generic_file_write() for O_SYNC files. | |
2976 | * Here, there will be no transaction running. We wait for any running | |
2977 | * trasnaction to commit. | |
2978 | * | |
2979 | * - Within sys_sync(), kupdate and such. | |
2980 | * We wait on commit, if tol to. | |
2981 | * | |
2982 | * - Within prune_icache() (PF_MEMALLOC == true) | |
2983 | * Here we simply return. We can't afford to block kswapd on the | |
2984 | * journal commit. | |
2985 | * | |
2986 | * In all cases it is actually safe for us to return without doing anything, | |
2987 | * because the inode has been copied into a raw inode buffer in | |
2988 | * ext3_mark_inode_dirty(). This is a correctness thing for O_SYNC and for | |
2989 | * knfsd. | |
2990 | * | |
2991 | * Note that we are absolutely dependent upon all inode dirtiers doing the | |
2992 | * right thing: they *must* call mark_inode_dirty() after dirtying info in | |
2993 | * which we are interested. | |
2994 | * | |
2995 | * It would be a bug for them to not do this. The code: | |
2996 | * | |
2997 | * mark_inode_dirty(inode) | |
2998 | * stuff(); | |
2999 | * inode->i_size = expr; | |
3000 | * | |
3001 | * is in error because a kswapd-driven write_inode() could occur while | |
3002 | * `stuff()' is running, and the new i_size will be lost. Plus the inode | |
3003 | * will no longer be on the superblock's dirty inode list. | |
3004 | */ | |
3005 | int ext3_write_inode(struct inode *inode, int wait) | |
3006 | { | |
3007 | if (current->flags & PF_MEMALLOC) | |
3008 | return 0; | |
3009 | ||
3010 | if (ext3_journal_current_handle()) { | |
9ad163ae | 3011 | jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n"); |
1da177e4 LT |
3012 | dump_stack(); |
3013 | return -EIO; | |
3014 | } | |
3015 | ||
3016 | if (!wait) | |
3017 | return 0; | |
3018 | ||
3019 | return ext3_force_commit(inode->i_sb); | |
3020 | } | |
3021 | ||
3022 | /* | |
3023 | * ext3_setattr() | |
3024 | * | |
3025 | * Called from notify_change. | |
3026 | * | |
3027 | * We want to trap VFS attempts to truncate the file as soon as | |
3028 | * possible. In particular, we want to make sure that when the VFS | |
3029 | * shrinks i_size, we put the inode on the orphan list and modify | |
3030 | * i_disksize immediately, so that during the subsequent flushing of | |
3031 | * dirty pages and freeing of disk blocks, we can guarantee that any | |
3032 | * commit will leave the blocks being flushed in an unused state on | |
3033 | * disk. (On recovery, the inode will get truncated and the blocks will | |
3034 | * be freed, so we have a strong guarantee that no future commit will | |
ae6ddcc5 | 3035 | * leave these blocks visible to the user.) |
1da177e4 LT |
3036 | * |
3037 | * Called with inode->sem down. | |
3038 | */ | |
3039 | int ext3_setattr(struct dentry *dentry, struct iattr *attr) | |
3040 | { | |
3041 | struct inode *inode = dentry->d_inode; | |
3042 | int error, rc = 0; | |
3043 | const unsigned int ia_valid = attr->ia_valid; | |
3044 | ||
3045 | error = inode_change_ok(inode, attr); | |
3046 | if (error) | |
3047 | return error; | |
3048 | ||
3049 | if ((ia_valid & ATTR_UID && attr->ia_uid != inode->i_uid) || | |
3050 | (ia_valid & ATTR_GID && attr->ia_gid != inode->i_gid)) { | |
3051 | handle_t *handle; | |
3052 | ||
3053 | /* (user+group)*(old+new) structure, inode write (sb, | |
3054 | * inode block, ? - but truncate inode update has it) */ | |
1f54587b JK |
3055 | handle = ext3_journal_start(inode, 2*(EXT3_QUOTA_INIT_BLOCKS(inode->i_sb)+ |
3056 | EXT3_QUOTA_DEL_BLOCKS(inode->i_sb))+3); | |
1da177e4 LT |
3057 | if (IS_ERR(handle)) { |
3058 | error = PTR_ERR(handle); | |
3059 | goto err_out; | |
3060 | } | |
3061 | error = DQUOT_TRANSFER(inode, attr) ? -EDQUOT : 0; | |
3062 | if (error) { | |
3063 | ext3_journal_stop(handle); | |
3064 | return error; | |
3065 | } | |
3066 | /* Update corresponding info in inode so that everything is in | |
3067 | * one transaction */ | |
3068 | if (attr->ia_valid & ATTR_UID) | |
3069 | inode->i_uid = attr->ia_uid; | |
3070 | if (attr->ia_valid & ATTR_GID) | |
3071 | inode->i_gid = attr->ia_gid; | |
3072 | error = ext3_mark_inode_dirty(handle, inode); | |
3073 | ext3_journal_stop(handle); | |
3074 | } | |
3075 | ||
3076 | if (S_ISREG(inode->i_mode) && | |
3077 | attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) { | |
3078 | handle_t *handle; | |
3079 | ||
3080 | handle = ext3_journal_start(inode, 3); | |
3081 | if (IS_ERR(handle)) { | |
3082 | error = PTR_ERR(handle); | |
3083 | goto err_out; | |
3084 | } | |
3085 | ||
3086 | error = ext3_orphan_add(handle, inode); | |
3087 | EXT3_I(inode)->i_disksize = attr->ia_size; | |
3088 | rc = ext3_mark_inode_dirty(handle, inode); | |
3089 | if (!error) | |
3090 | error = rc; | |
3091 | ext3_journal_stop(handle); | |
3092 | } | |
3093 | ||
3094 | rc = inode_setattr(inode, attr); | |
3095 | ||
3096 | /* If inode_setattr's call to ext3_truncate failed to get a | |
3097 | * transaction handle at all, we need to clean up the in-core | |
3098 | * orphan list manually. */ | |
3099 | if (inode->i_nlink) | |
3100 | ext3_orphan_del(NULL, inode); | |
3101 | ||
3102 | if (!rc && (ia_valid & ATTR_MODE)) | |
3103 | rc = ext3_acl_chmod(inode); | |
3104 | ||
3105 | err_out: | |
3106 | ext3_std_error(inode->i_sb, error); | |
3107 | if (!error) | |
3108 | error = rc; | |
3109 | return error; | |
3110 | } | |
3111 | ||
3112 | ||
3113 | /* | |
d6859bfc | 3114 | * How many blocks doth make a writepage()? |
1da177e4 LT |
3115 | * |
3116 | * With N blocks per page, it may be: | |
3117 | * N data blocks | |
3118 | * 2 indirect block | |
3119 | * 2 dindirect | |
3120 | * 1 tindirect | |
3121 | * N+5 bitmap blocks (from the above) | |
3122 | * N+5 group descriptor summary blocks | |
3123 | * 1 inode block | |
3124 | * 1 superblock. | |
3125 | * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files | |
3126 | * | |
3127 | * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS | |
3128 | * | |
3129 | * With ordered or writeback data it's the same, less the N data blocks. | |
3130 | * | |
3131 | * If the inode's direct blocks can hold an integral number of pages then a | |
3132 | * page cannot straddle two indirect blocks, and we can only touch one indirect | |
3133 | * and dindirect block, and the "5" above becomes "3". | |
3134 | * | |
3135 | * This still overestimates under most circumstances. If we were to pass the | |
3136 | * start and end offsets in here as well we could do block_to_path() on each | |
3137 | * block and work out the exact number of indirects which are touched. Pah. | |
3138 | */ | |
3139 | ||
3140 | static int ext3_writepage_trans_blocks(struct inode *inode) | |
3141 | { | |
3142 | int bpp = ext3_journal_blocks_per_page(inode); | |
3143 | int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3; | |
3144 | int ret; | |
3145 | ||
3146 | if (ext3_should_journal_data(inode)) | |
3147 | ret = 3 * (bpp + indirects) + 2; | |
3148 | else | |
3149 | ret = 2 * (bpp + indirects) + 2; | |
3150 | ||
3151 | #ifdef CONFIG_QUOTA | |
3152 | /* We know that structure was already allocated during DQUOT_INIT so | |
3153 | * we will be updating only the data blocks + inodes */ | |
1f54587b | 3154 | ret += 2*EXT3_QUOTA_TRANS_BLOCKS(inode->i_sb); |
1da177e4 LT |
3155 | #endif |
3156 | ||
3157 | return ret; | |
3158 | } | |
3159 | ||
3160 | /* | |
3161 | * The caller must have previously called ext3_reserve_inode_write(). | |
3162 | * Give this, we know that the caller already has write access to iloc->bh. | |
3163 | */ | |
3164 | int ext3_mark_iloc_dirty(handle_t *handle, | |
3165 | struct inode *inode, struct ext3_iloc *iloc) | |
3166 | { | |
3167 | int err = 0; | |
3168 | ||
3169 | /* the do_update_inode consumes one bh->b_count */ | |
3170 | get_bh(iloc->bh); | |
3171 | ||
3172 | /* ext3_do_update_inode() does journal_dirty_metadata */ | |
3173 | err = ext3_do_update_inode(handle, inode, iloc); | |
3174 | put_bh(iloc->bh); | |
3175 | return err; | |
3176 | } | |
3177 | ||
ae6ddcc5 | 3178 | /* |
1da177e4 | 3179 | * On success, We end up with an outstanding reference count against |
ae6ddcc5 | 3180 | * iloc->bh. This _must_ be cleaned up later. |
1da177e4 LT |
3181 | */ |
3182 | ||
3183 | int | |
ae6ddcc5 | 3184 | ext3_reserve_inode_write(handle_t *handle, struct inode *inode, |
1da177e4 LT |
3185 | struct ext3_iloc *iloc) |
3186 | { | |
3187 | int err = 0; | |
3188 | if (handle) { | |
3189 | err = ext3_get_inode_loc(inode, iloc); | |
3190 | if (!err) { | |
3191 | BUFFER_TRACE(iloc->bh, "get_write_access"); | |
3192 | err = ext3_journal_get_write_access(handle, iloc->bh); | |
3193 | if (err) { | |
3194 | brelse(iloc->bh); | |
3195 | iloc->bh = NULL; | |
3196 | } | |
3197 | } | |
3198 | } | |
3199 | ext3_std_error(inode->i_sb, err); | |
3200 | return err; | |
3201 | } | |
3202 | ||
3203 | /* | |
d6859bfc AM |
3204 | * What we do here is to mark the in-core inode as clean with respect to inode |
3205 | * dirtiness (it may still be data-dirty). | |
1da177e4 LT |
3206 | * This means that the in-core inode may be reaped by prune_icache |
3207 | * without having to perform any I/O. This is a very good thing, | |
3208 | * because *any* task may call prune_icache - even ones which | |
3209 | * have a transaction open against a different journal. | |
3210 | * | |
3211 | * Is this cheating? Not really. Sure, we haven't written the | |
3212 | * inode out, but prune_icache isn't a user-visible syncing function. | |
3213 | * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync) | |
3214 | * we start and wait on commits. | |
3215 | * | |
3216 | * Is this efficient/effective? Well, we're being nice to the system | |
3217 | * by cleaning up our inodes proactively so they can be reaped | |
3218 | * without I/O. But we are potentially leaving up to five seconds' | |
3219 | * worth of inodes floating about which prune_icache wants us to | |
3220 | * write out. One way to fix that would be to get prune_icache() | |
3221 | * to do a write_super() to free up some memory. It has the desired | |
3222 | * effect. | |
3223 | */ | |
3224 | int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode) | |
3225 | { | |
3226 | struct ext3_iloc iloc; | |
3227 | int err; | |
3228 | ||
3229 | might_sleep(); | |
3230 | err = ext3_reserve_inode_write(handle, inode, &iloc); | |
3231 | if (!err) | |
3232 | err = ext3_mark_iloc_dirty(handle, inode, &iloc); | |
3233 | return err; | |
3234 | } | |
3235 | ||
3236 | /* | |
d6859bfc | 3237 | * ext3_dirty_inode() is called from __mark_inode_dirty() |
1da177e4 LT |
3238 | * |
3239 | * We're really interested in the case where a file is being extended. | |
3240 | * i_size has been changed by generic_commit_write() and we thus need | |
3241 | * to include the updated inode in the current transaction. | |
3242 | * | |
3243 | * Also, DQUOT_ALLOC_SPACE() will always dirty the inode when blocks | |
3244 | * are allocated to the file. | |
3245 | * | |
3246 | * If the inode is marked synchronous, we don't honour that here - doing | |
3247 | * so would cause a commit on atime updates, which we don't bother doing. | |
3248 | * We handle synchronous inodes at the highest possible level. | |
3249 | */ | |
3250 | void ext3_dirty_inode(struct inode *inode) | |
3251 | { | |
3252 | handle_t *current_handle = ext3_journal_current_handle(); | |
3253 | handle_t *handle; | |
3254 | ||
3255 | handle = ext3_journal_start(inode, 2); | |
3256 | if (IS_ERR(handle)) | |
3257 | goto out; | |
3258 | if (current_handle && | |
3259 | current_handle->h_transaction != handle->h_transaction) { | |
3260 | /* This task has a transaction open against a different fs */ | |
3261 | printk(KERN_EMERG "%s: transactions do not match!\n", | |
e05b6b52 | 3262 | __func__); |
1da177e4 LT |
3263 | } else { |
3264 | jbd_debug(5, "marking dirty. outer handle=%p\n", | |
3265 | current_handle); | |
3266 | ext3_mark_inode_dirty(handle, inode); | |
3267 | } | |
3268 | ext3_journal_stop(handle); | |
3269 | out: | |
3270 | return; | |
3271 | } | |
3272 | ||
d6859bfc | 3273 | #if 0 |
ae6ddcc5 | 3274 | /* |
1da177e4 LT |
3275 | * Bind an inode's backing buffer_head into this transaction, to prevent |
3276 | * it from being flushed to disk early. Unlike | |
3277 | * ext3_reserve_inode_write, this leaves behind no bh reference and | |
3278 | * returns no iloc structure, so the caller needs to repeat the iloc | |
3279 | * lookup to mark the inode dirty later. | |
3280 | */ | |
d6859bfc | 3281 | static int ext3_pin_inode(handle_t *handle, struct inode *inode) |
1da177e4 LT |
3282 | { |
3283 | struct ext3_iloc iloc; | |
3284 | ||
3285 | int err = 0; | |
3286 | if (handle) { | |
3287 | err = ext3_get_inode_loc(inode, &iloc); | |
3288 | if (!err) { | |
3289 | BUFFER_TRACE(iloc.bh, "get_write_access"); | |
3290 | err = journal_get_write_access(handle, iloc.bh); | |
3291 | if (!err) | |
ae6ddcc5 | 3292 | err = ext3_journal_dirty_metadata(handle, |
1da177e4 LT |
3293 | iloc.bh); |
3294 | brelse(iloc.bh); | |
3295 | } | |
3296 | } | |
3297 | ext3_std_error(inode->i_sb, err); | |
3298 | return err; | |
3299 | } | |
3300 | #endif | |
3301 | ||
3302 | int ext3_change_inode_journal_flag(struct inode *inode, int val) | |
3303 | { | |
3304 | journal_t *journal; | |
3305 | handle_t *handle; | |
3306 | int err; | |
3307 | ||
3308 | /* | |
3309 | * We have to be very careful here: changing a data block's | |
3310 | * journaling status dynamically is dangerous. If we write a | |
3311 | * data block to the journal, change the status and then delete | |
3312 | * that block, we risk forgetting to revoke the old log record | |
3313 | * from the journal and so a subsequent replay can corrupt data. | |
3314 | * So, first we make sure that the journal is empty and that | |
3315 | * nobody is changing anything. | |
3316 | */ | |
3317 | ||
3318 | journal = EXT3_JOURNAL(inode); | |
e3a68e30 | 3319 | if (is_journal_aborted(journal)) |
1da177e4 LT |
3320 | return -EROFS; |
3321 | ||
3322 | journal_lock_updates(journal); | |
3323 | journal_flush(journal); | |
3324 | ||
3325 | /* | |
3326 | * OK, there are no updates running now, and all cached data is | |
3327 | * synced to disk. We are now in a completely consistent state | |
3328 | * which doesn't have anything in the journal, and we know that | |
3329 | * no filesystem updates are running, so it is safe to modify | |
3330 | * the inode's in-core data-journaling state flag now. | |
3331 | */ | |
3332 | ||
3333 | if (val) | |
3334 | EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL; | |
3335 | else | |
3336 | EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL; | |
3337 | ext3_set_aops(inode); | |
3338 | ||
3339 | journal_unlock_updates(journal); | |
3340 | ||
3341 | /* Finally we can mark the inode as dirty. */ | |
3342 | ||
3343 | handle = ext3_journal_start(inode, 1); | |
3344 | if (IS_ERR(handle)) | |
3345 | return PTR_ERR(handle); | |
3346 | ||
3347 | err = ext3_mark_inode_dirty(handle, inode); | |
3348 | handle->h_sync = 1; | |
3349 | ext3_journal_stop(handle); | |
3350 | ext3_std_error(inode->i_sb, err); | |
3351 | ||
3352 | return err; | |
3353 | } |