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1da177e4 LT |
1 | /* |
2 | * linux/fs/ext2/inode.c | |
3 | * | |
4 | * Copyright (C) 1992, 1993, 1994, 1995 | |
5 | * Remy Card (card@masi.ibp.fr) | |
6 | * Laboratoire MASI - Institut Blaise Pascal | |
7 | * Universite Pierre et Marie Curie (Paris VI) | |
8 | * | |
9 | * from | |
10 | * | |
11 | * linux/fs/minix/inode.c | |
12 | * | |
13 | * Copyright (C) 1991, 1992 Linus Torvalds | |
14 | * | |
15 | * Goal-directed block allocation by Stephen Tweedie | |
16 | * (sct@dcs.ed.ac.uk), 1993, 1998 | |
17 | * Big-endian to little-endian byte-swapping/bitmaps by | |
18 | * David S. Miller (davem@caip.rutgers.edu), 1995 | |
19 | * 64-bit file support on 64-bit platforms by Jakub Jelinek | |
20 | * (jj@sunsite.ms.mff.cuni.cz) | |
21 | * | |
22 | * Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000 | |
23 | */ | |
24 | ||
25 | #include <linux/smp_lock.h> | |
26 | #include <linux/time.h> | |
27 | #include <linux/highuid.h> | |
28 | #include <linux/pagemap.h> | |
29 | #include <linux/quotaops.h> | |
30 | #include <linux/module.h> | |
31 | #include <linux/writeback.h> | |
32 | #include <linux/buffer_head.h> | |
33 | #include <linux/mpage.h> | |
34 | #include "ext2.h" | |
35 | #include "acl.h" | |
6d79125b | 36 | #include "xip.h" |
1da177e4 LT |
37 | |
38 | MODULE_AUTHOR("Remy Card and others"); | |
39 | MODULE_DESCRIPTION("Second Extended Filesystem"); | |
40 | MODULE_LICENSE("GPL"); | |
41 | ||
42 | static int ext2_update_inode(struct inode * inode, int do_sync); | |
43 | ||
44 | /* | |
45 | * Test whether an inode is a fast symlink. | |
46 | */ | |
47 | static inline int ext2_inode_is_fast_symlink(struct inode *inode) | |
48 | { | |
49 | int ea_blocks = EXT2_I(inode)->i_file_acl ? | |
50 | (inode->i_sb->s_blocksize >> 9) : 0; | |
51 | ||
52 | return (S_ISLNK(inode->i_mode) && | |
53 | inode->i_blocks - ea_blocks == 0); | |
54 | } | |
55 | ||
56 | /* | |
57 | * Called at the last iput() if i_nlink is zero. | |
58 | */ | |
59 | void ext2_delete_inode (struct inode * inode) | |
60 | { | |
fef26658 MF |
61 | truncate_inode_pages(&inode->i_data, 0); |
62 | ||
1da177e4 LT |
63 | if (is_bad_inode(inode)) |
64 | goto no_delete; | |
65 | EXT2_I(inode)->i_dtime = get_seconds(); | |
66 | mark_inode_dirty(inode); | |
67 | ext2_update_inode(inode, inode_needs_sync(inode)); | |
68 | ||
69 | inode->i_size = 0; | |
70 | if (inode->i_blocks) | |
71 | ext2_truncate (inode); | |
72 | ext2_free_inode (inode); | |
73 | ||
74 | return; | |
75 | no_delete: | |
76 | clear_inode(inode); /* We must guarantee clearing of inode... */ | |
77 | } | |
78 | ||
1da177e4 LT |
79 | typedef struct { |
80 | __le32 *p; | |
81 | __le32 key; | |
82 | struct buffer_head *bh; | |
83 | } Indirect; | |
84 | ||
85 | static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) | |
86 | { | |
87 | p->key = *(p->p = v); | |
88 | p->bh = bh; | |
89 | } | |
90 | ||
91 | static inline int verify_chain(Indirect *from, Indirect *to) | |
92 | { | |
93 | while (from <= to && from->key == *from->p) | |
94 | from++; | |
95 | return (from > to); | |
96 | } | |
97 | ||
98 | /** | |
99 | * ext2_block_to_path - parse the block number into array of offsets | |
100 | * @inode: inode in question (we are only interested in its superblock) | |
101 | * @i_block: block number to be parsed | |
102 | * @offsets: array to store the offsets in | |
103 | * @boundary: set this non-zero if the referred-to block is likely to be | |
104 | * followed (on disk) by an indirect block. | |
105 | * To store the locations of file's data ext2 uses a data structure common | |
106 | * for UNIX filesystems - tree of pointers anchored in the inode, with | |
107 | * data blocks at leaves and indirect blocks in intermediate nodes. | |
108 | * This function translates the block number into path in that tree - | |
109 | * return value is the path length and @offsets[n] is the offset of | |
110 | * pointer to (n+1)th node in the nth one. If @block is out of range | |
111 | * (negative or too large) warning is printed and zero returned. | |
112 | * | |
113 | * Note: function doesn't find node addresses, so no IO is needed. All | |
114 | * we need to know is the capacity of indirect blocks (taken from the | |
115 | * inode->i_sb). | |
116 | */ | |
117 | ||
118 | /* | |
119 | * Portability note: the last comparison (check that we fit into triple | |
120 | * indirect block) is spelled differently, because otherwise on an | |
121 | * architecture with 32-bit longs and 8Kb pages we might get into trouble | |
122 | * if our filesystem had 8Kb blocks. We might use long long, but that would | |
123 | * kill us on x86. Oh, well, at least the sign propagation does not matter - | |
124 | * i_block would have to be negative in the very beginning, so we would not | |
125 | * get there at all. | |
126 | */ | |
127 | ||
128 | static int ext2_block_to_path(struct inode *inode, | |
129 | long i_block, int offsets[4], int *boundary) | |
130 | { | |
131 | int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb); | |
132 | int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb); | |
133 | const long direct_blocks = EXT2_NDIR_BLOCKS, | |
134 | indirect_blocks = ptrs, | |
135 | double_blocks = (1 << (ptrs_bits * 2)); | |
136 | int n = 0; | |
137 | int final = 0; | |
138 | ||
139 | if (i_block < 0) { | |
140 | ext2_warning (inode->i_sb, "ext2_block_to_path", "block < 0"); | |
141 | } else if (i_block < direct_blocks) { | |
142 | offsets[n++] = i_block; | |
143 | final = direct_blocks; | |
144 | } else if ( (i_block -= direct_blocks) < indirect_blocks) { | |
145 | offsets[n++] = EXT2_IND_BLOCK; | |
146 | offsets[n++] = i_block; | |
147 | final = ptrs; | |
148 | } else if ((i_block -= indirect_blocks) < double_blocks) { | |
149 | offsets[n++] = EXT2_DIND_BLOCK; | |
150 | offsets[n++] = i_block >> ptrs_bits; | |
151 | offsets[n++] = i_block & (ptrs - 1); | |
152 | final = ptrs; | |
153 | } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) { | |
154 | offsets[n++] = EXT2_TIND_BLOCK; | |
155 | offsets[n++] = i_block >> (ptrs_bits * 2); | |
156 | offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1); | |
157 | offsets[n++] = i_block & (ptrs - 1); | |
158 | final = ptrs; | |
159 | } else { | |
160 | ext2_warning (inode->i_sb, "ext2_block_to_path", "block > big"); | |
161 | } | |
162 | if (boundary) | |
a686cd89 MB |
163 | *boundary = final - 1 - (i_block & (ptrs - 1)); |
164 | ||
1da177e4 LT |
165 | return n; |
166 | } | |
167 | ||
168 | /** | |
169 | * ext2_get_branch - read the chain of indirect blocks leading to data | |
170 | * @inode: inode in question | |
171 | * @depth: depth of the chain (1 - direct pointer, etc.) | |
172 | * @offsets: offsets of pointers in inode/indirect blocks | |
173 | * @chain: place to store the result | |
174 | * @err: here we store the error value | |
175 | * | |
176 | * Function fills the array of triples <key, p, bh> and returns %NULL | |
177 | * if everything went OK or the pointer to the last filled triple | |
178 | * (incomplete one) otherwise. Upon the return chain[i].key contains | |
179 | * the number of (i+1)-th block in the chain (as it is stored in memory, | |
180 | * i.e. little-endian 32-bit), chain[i].p contains the address of that | |
181 | * number (it points into struct inode for i==0 and into the bh->b_data | |
182 | * for i>0) and chain[i].bh points to the buffer_head of i-th indirect | |
183 | * block for i>0 and NULL for i==0. In other words, it holds the block | |
184 | * numbers of the chain, addresses they were taken from (and where we can | |
185 | * verify that chain did not change) and buffer_heads hosting these | |
186 | * numbers. | |
187 | * | |
188 | * Function stops when it stumbles upon zero pointer (absent block) | |
189 | * (pointer to last triple returned, *@err == 0) | |
190 | * or when it gets an IO error reading an indirect block | |
191 | * (ditto, *@err == -EIO) | |
192 | * or when it notices that chain had been changed while it was reading | |
193 | * (ditto, *@err == -EAGAIN) | |
194 | * or when it reads all @depth-1 indirect blocks successfully and finds | |
195 | * the whole chain, all way to the data (returns %NULL, *err == 0). | |
196 | */ | |
197 | static Indirect *ext2_get_branch(struct inode *inode, | |
198 | int depth, | |
199 | int *offsets, | |
200 | Indirect chain[4], | |
201 | int *err) | |
202 | { | |
203 | struct super_block *sb = inode->i_sb; | |
204 | Indirect *p = chain; | |
205 | struct buffer_head *bh; | |
206 | ||
207 | *err = 0; | |
208 | /* i_data is not going away, no lock needed */ | |
209 | add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets); | |
210 | if (!p->key) | |
211 | goto no_block; | |
212 | while (--depth) { | |
213 | bh = sb_bread(sb, le32_to_cpu(p->key)); | |
214 | if (!bh) | |
215 | goto failure; | |
216 | read_lock(&EXT2_I(inode)->i_meta_lock); | |
217 | if (!verify_chain(chain, p)) | |
218 | goto changed; | |
219 | add_chain(++p, bh, (__le32*)bh->b_data + *++offsets); | |
220 | read_unlock(&EXT2_I(inode)->i_meta_lock); | |
221 | if (!p->key) | |
222 | goto no_block; | |
223 | } | |
224 | return NULL; | |
225 | ||
226 | changed: | |
227 | read_unlock(&EXT2_I(inode)->i_meta_lock); | |
228 | brelse(bh); | |
229 | *err = -EAGAIN; | |
230 | goto no_block; | |
231 | failure: | |
232 | *err = -EIO; | |
233 | no_block: | |
234 | return p; | |
235 | } | |
236 | ||
237 | /** | |
238 | * ext2_find_near - find a place for allocation with sufficient locality | |
239 | * @inode: owner | |
240 | * @ind: descriptor of indirect block. | |
241 | * | |
242 | * This function returns the prefered place for block allocation. | |
243 | * It is used when heuristic for sequential allocation fails. | |
244 | * Rules are: | |
245 | * + if there is a block to the left of our position - allocate near it. | |
246 | * + if pointer will live in indirect block - allocate near that block. | |
247 | * + if pointer will live in inode - allocate in the same cylinder group. | |
248 | * | |
249 | * In the latter case we colour the starting block by the callers PID to | |
250 | * prevent it from clashing with concurrent allocations for a different inode | |
251 | * in the same block group. The PID is used here so that functionally related | |
252 | * files will be close-by on-disk. | |
253 | * | |
254 | * Caller must make sure that @ind is valid and will stay that way. | |
255 | */ | |
256 | ||
257 | static unsigned long ext2_find_near(struct inode *inode, Indirect *ind) | |
258 | { | |
259 | struct ext2_inode_info *ei = EXT2_I(inode); | |
260 | __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data; | |
261 | __le32 *p; | |
262 | unsigned long bg_start; | |
263 | unsigned long colour; | |
264 | ||
265 | /* Try to find previous block */ | |
266 | for (p = ind->p - 1; p >= start; p--) | |
267 | if (*p) | |
268 | return le32_to_cpu(*p); | |
269 | ||
270 | /* No such thing, so let's try location of indirect block */ | |
271 | if (ind->bh) | |
272 | return ind->bh->b_blocknr; | |
273 | ||
274 | /* | |
275 | * It is going to be refered from inode itself? OK, just put it into | |
276 | * the same cylinder group then. | |
277 | */ | |
278 | bg_start = (ei->i_block_group * EXT2_BLOCKS_PER_GROUP(inode->i_sb)) + | |
279 | le32_to_cpu(EXT2_SB(inode->i_sb)->s_es->s_first_data_block); | |
280 | colour = (current->pid % 16) * | |
281 | (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
282 | return bg_start + colour; | |
283 | } | |
284 | ||
285 | /** | |
286 | * ext2_find_goal - find a prefered place for allocation. | |
287 | * @inode: owner | |
288 | * @block: block we want | |
289 | * @chain: chain of indirect blocks | |
290 | * @partial: pointer to the last triple within a chain | |
1da177e4 | 291 | * |
a686cd89 | 292 | * Returns preferred place for a block (the goal). |
1da177e4 LT |
293 | */ |
294 | ||
295 | static inline int ext2_find_goal(struct inode *inode, | |
296 | long block, | |
297 | Indirect chain[4], | |
a686cd89 | 298 | Indirect *partial) |
1da177e4 | 299 | { |
a686cd89 MB |
300 | struct ext2_block_alloc_info *block_i; |
301 | ||
302 | block_i = EXT2_I(inode)->i_block_alloc_info; | |
303 | ||
304 | /* | |
305 | * try the heuristic for sequential allocation, | |
306 | * failing that at least try to get decent locality. | |
307 | */ | |
308 | if (block_i && (block == block_i->last_alloc_logical_block + 1) | |
309 | && (block_i->last_alloc_physical_block != 0)) { | |
310 | return block_i->last_alloc_physical_block + 1; | |
311 | } | |
312 | ||
313 | return ext2_find_near(inode, partial); | |
314 | } | |
315 | ||
316 | /** | |
317 | * ext2_blks_to_allocate: Look up the block map and count the number | |
318 | * of direct blocks need to be allocated for the given branch. | |
319 | * | |
320 | * @branch: chain of indirect blocks | |
321 | * @k: number of blocks need for indirect blocks | |
322 | * @blks: number of data blocks to be mapped. | |
323 | * @blocks_to_boundary: the offset in the indirect block | |
324 | * | |
325 | * return the total number of blocks to be allocate, including the | |
326 | * direct and indirect blocks. | |
327 | */ | |
328 | static int | |
329 | ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks, | |
330 | int blocks_to_boundary) | |
331 | { | |
332 | unsigned long count = 0; | |
333 | ||
334 | /* | |
335 | * Simple case, [t,d]Indirect block(s) has not allocated yet | |
336 | * then it's clear blocks on that path have not allocated | |
337 | */ | |
338 | if (k > 0) { | |
339 | /* right now don't hanel cross boundary allocation */ | |
340 | if (blks < blocks_to_boundary + 1) | |
341 | count += blks; | |
342 | else | |
343 | count += blocks_to_boundary + 1; | |
344 | return count; | |
1da177e4 | 345 | } |
a686cd89 MB |
346 | |
347 | count++; | |
348 | while (count < blks && count <= blocks_to_boundary | |
349 | && le32_to_cpu(*(branch[0].p + count)) == 0) { | |
350 | count++; | |
351 | } | |
352 | return count; | |
353 | } | |
354 | ||
355 | /** | |
356 | * ext2_alloc_blocks: multiple allocate blocks needed for a branch | |
357 | * @indirect_blks: the number of blocks need to allocate for indirect | |
358 | * blocks | |
359 | * | |
360 | * @new_blocks: on return it will store the new block numbers for | |
361 | * the indirect blocks(if needed) and the first direct block, | |
362 | * @blks: on return it will store the total number of allocated | |
363 | * direct blocks | |
364 | */ | |
365 | static int ext2_alloc_blocks(struct inode *inode, | |
366 | ext2_fsblk_t goal, int indirect_blks, int blks, | |
367 | ext2_fsblk_t new_blocks[4], int *err) | |
368 | { | |
369 | int target, i; | |
370 | unsigned long count = 0; | |
371 | int index = 0; | |
372 | ext2_fsblk_t current_block = 0; | |
373 | int ret = 0; | |
374 | ||
375 | /* | |
376 | * Here we try to allocate the requested multiple blocks at once, | |
377 | * on a best-effort basis. | |
378 | * To build a branch, we should allocate blocks for | |
379 | * the indirect blocks(if not allocated yet), and at least | |
380 | * the first direct block of this branch. That's the | |
381 | * minimum number of blocks need to allocate(required) | |
382 | */ | |
383 | target = blks + indirect_blks; | |
384 | ||
385 | while (1) { | |
386 | count = target; | |
387 | /* allocating blocks for indirect blocks and direct blocks */ | |
388 | current_block = ext2_new_blocks(inode,goal,&count,err); | |
389 | if (*err) | |
390 | goto failed_out; | |
391 | ||
392 | target -= count; | |
393 | /* allocate blocks for indirect blocks */ | |
394 | while (index < indirect_blks && count) { | |
395 | new_blocks[index++] = current_block++; | |
396 | count--; | |
397 | } | |
398 | ||
399 | if (count > 0) | |
400 | break; | |
401 | } | |
402 | ||
403 | /* save the new block number for the first direct block */ | |
404 | new_blocks[index] = current_block; | |
405 | ||
406 | /* total number of blocks allocated for direct blocks */ | |
407 | ret = count; | |
408 | *err = 0; | |
409 | return ret; | |
410 | failed_out: | |
411 | for (i = 0; i <index; i++) | |
412 | ext2_free_blocks(inode, new_blocks[i], 1); | |
413 | return ret; | |
1da177e4 LT |
414 | } |
415 | ||
416 | /** | |
417 | * ext2_alloc_branch - allocate and set up a chain of blocks. | |
418 | * @inode: owner | |
419 | * @num: depth of the chain (number of blocks to allocate) | |
420 | * @offsets: offsets (in the blocks) to store the pointers to next. | |
421 | * @branch: place to store the chain in. | |
422 | * | |
423 | * This function allocates @num blocks, zeroes out all but the last one, | |
424 | * links them into chain and (if we are synchronous) writes them to disk. | |
425 | * In other words, it prepares a branch that can be spliced onto the | |
426 | * inode. It stores the information about that chain in the branch[], in | |
427 | * the same format as ext2_get_branch() would do. We are calling it after | |
428 | * we had read the existing part of chain and partial points to the last | |
429 | * triple of that (one with zero ->key). Upon the exit we have the same | |
430 | * picture as after the successful ext2_get_block(), excpet that in one | |
431 | * place chain is disconnected - *branch->p is still zero (we did not | |
432 | * set the last link), but branch->key contains the number that should | |
433 | * be placed into *branch->p to fill that gap. | |
434 | * | |
435 | * If allocation fails we free all blocks we've allocated (and forget | |
436 | * their buffer_heads) and return the error value the from failed | |
437 | * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain | |
438 | * as described above and return 0. | |
439 | */ | |
440 | ||
441 | static int ext2_alloc_branch(struct inode *inode, | |
a686cd89 MB |
442 | int indirect_blks, int *blks, ext2_fsblk_t goal, |
443 | int *offsets, Indirect *branch) | |
1da177e4 LT |
444 | { |
445 | int blocksize = inode->i_sb->s_blocksize; | |
a686cd89 MB |
446 | int i, n = 0; |
447 | int err = 0; | |
448 | struct buffer_head *bh; | |
449 | int num; | |
450 | ext2_fsblk_t new_blocks[4]; | |
451 | ext2_fsblk_t current_block; | |
452 | ||
453 | num = ext2_alloc_blocks(inode, goal, indirect_blks, | |
454 | *blks, new_blocks, &err); | |
455 | if (err) | |
456 | return err; | |
457 | ||
458 | branch[0].key = cpu_to_le32(new_blocks[0]); | |
459 | /* | |
460 | * metadata blocks and data blocks are allocated. | |
461 | */ | |
462 | for (n = 1; n <= indirect_blks; n++) { | |
1da177e4 | 463 | /* |
a686cd89 MB |
464 | * Get buffer_head for parent block, zero it out |
465 | * and set the pointer to new one, then send | |
466 | * parent to disk. | |
1da177e4 | 467 | */ |
a686cd89 MB |
468 | bh = sb_getblk(inode->i_sb, new_blocks[n-1]); |
469 | branch[n].bh = bh; | |
1da177e4 LT |
470 | lock_buffer(bh); |
471 | memset(bh->b_data, 0, blocksize); | |
1da177e4 | 472 | branch[n].p = (__le32 *) bh->b_data + offsets[n]; |
a686cd89 | 473 | branch[n].key = cpu_to_le32(new_blocks[n]); |
1da177e4 | 474 | *branch[n].p = branch[n].key; |
a686cd89 MB |
475 | if ( n == indirect_blks) { |
476 | current_block = new_blocks[n]; | |
477 | /* | |
478 | * End of chain, update the last new metablock of | |
479 | * the chain to point to the new allocated | |
480 | * data blocks numbers | |
481 | */ | |
482 | for (i=1; i < num; i++) | |
483 | *(branch[n].p + i) = cpu_to_le32(++current_block); | |
484 | } | |
1da177e4 LT |
485 | set_buffer_uptodate(bh); |
486 | unlock_buffer(bh); | |
487 | mark_buffer_dirty_inode(bh, inode); | |
488 | /* We used to sync bh here if IS_SYNC(inode). | |
489 | * But we now rely upon generic_osync_inode() | |
490 | * and b_inode_buffers. But not for directories. | |
491 | */ | |
492 | if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode)) | |
493 | sync_dirty_buffer(bh); | |
1da177e4 | 494 | } |
a686cd89 | 495 | *blks = num; |
1da177e4 LT |
496 | return err; |
497 | } | |
498 | ||
499 | /** | |
a686cd89 MB |
500 | * ext2_splice_branch - splice the allocated branch onto inode. |
501 | * @inode: owner | |
502 | * @block: (logical) number of block we are adding | |
503 | * @chain: chain of indirect blocks (with a missing link - see | |
504 | * ext2_alloc_branch) | |
505 | * @where: location of missing link | |
506 | * @num: number of indirect blocks we are adding | |
507 | * @blks: number of direct blocks we are adding | |
1da177e4 | 508 | * |
a686cd89 MB |
509 | * This function fills the missing link and does all housekeeping needed in |
510 | * inode (->i_blocks, etc.). In case of success we end up with the full | |
511 | * chain to new block and return 0. | |
1da177e4 | 512 | */ |
a686cd89 MB |
513 | static void ext2_splice_branch(struct inode *inode, |
514 | long block, Indirect *where, int num, int blks) | |
1da177e4 | 515 | { |
1da177e4 | 516 | int i; |
a686cd89 MB |
517 | struct ext2_block_alloc_info *block_i; |
518 | ext2_fsblk_t current_block; | |
1da177e4 | 519 | |
a686cd89 | 520 | block_i = EXT2_I(inode)->i_block_alloc_info; |
1da177e4 | 521 | |
a686cd89 | 522 | /* XXX LOCKING probably should have i_meta_lock ?*/ |
1da177e4 LT |
523 | /* That's it */ |
524 | ||
525 | *where->p = where->key; | |
1da177e4 | 526 | |
a686cd89 MB |
527 | /* |
528 | * Update the host buffer_head or inode to point to more just allocated | |
529 | * direct blocks blocks | |
530 | */ | |
531 | if (num == 0 && blks > 1) { | |
532 | current_block = le32_to_cpu(where->key) + 1; | |
533 | for (i = 1; i < blks; i++) | |
534 | *(where->p + i ) = cpu_to_le32(current_block++); | |
535 | } | |
1da177e4 | 536 | |
a686cd89 MB |
537 | /* |
538 | * update the most recently allocated logical & physical block | |
539 | * in i_block_alloc_info, to assist find the proper goal block for next | |
540 | * allocation | |
541 | */ | |
542 | if (block_i) { | |
543 | block_i->last_alloc_logical_block = block + blks - 1; | |
544 | block_i->last_alloc_physical_block = | |
545 | le32_to_cpu(where[num].key) + blks - 1; | |
546 | } | |
1da177e4 | 547 | |
a686cd89 | 548 | /* We are done with atomic stuff, now do the rest of housekeeping */ |
1da177e4 LT |
549 | |
550 | /* had we spliced it onto indirect block? */ | |
551 | if (where->bh) | |
552 | mark_buffer_dirty_inode(where->bh, inode); | |
553 | ||
a686cd89 | 554 | inode->i_ctime = CURRENT_TIME_SEC; |
1da177e4 | 555 | mark_inode_dirty(inode); |
1da177e4 LT |
556 | } |
557 | ||
558 | /* | |
559 | * Allocation strategy is simple: if we have to allocate something, we will | |
560 | * have to go the whole way to leaf. So let's do it before attaching anything | |
561 | * to tree, set linkage between the newborn blocks, write them if sync is | |
562 | * required, recheck the path, free and repeat if check fails, otherwise | |
563 | * set the last missing link (that will protect us from any truncate-generated | |
564 | * removals - all blocks on the path are immune now) and possibly force the | |
565 | * write on the parent block. | |
566 | * That has a nice additional property: no special recovery from the failed | |
567 | * allocations is needed - we simply release blocks and do not touch anything | |
568 | * reachable from inode. | |
a686cd89 MB |
569 | * |
570 | * `handle' can be NULL if create == 0. | |
571 | * | |
a686cd89 MB |
572 | * return > 0, # of blocks mapped or allocated. |
573 | * return = 0, if plain lookup failed. | |
574 | * return < 0, error case. | |
1da177e4 | 575 | */ |
a686cd89 MB |
576 | static int ext2_get_blocks(struct inode *inode, |
577 | sector_t iblock, unsigned long maxblocks, | |
578 | struct buffer_head *bh_result, | |
579 | int create) | |
1da177e4 LT |
580 | { |
581 | int err = -EIO; | |
582 | int offsets[4]; | |
583 | Indirect chain[4]; | |
584 | Indirect *partial; | |
a686cd89 MB |
585 | ext2_fsblk_t goal; |
586 | int indirect_blks; | |
587 | int blocks_to_boundary = 0; | |
588 | int depth; | |
589 | struct ext2_inode_info *ei = EXT2_I(inode); | |
590 | int count = 0; | |
591 | ext2_fsblk_t first_block = 0; | |
1da177e4 | 592 | |
a686cd89 | 593 | depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary); |
1da177e4 | 594 | |
a686cd89 MB |
595 | if (depth == 0) |
596 | return (err); | |
1da177e4 LT |
597 | reread: |
598 | partial = ext2_get_branch(inode, depth, offsets, chain, &err); | |
599 | ||
600 | /* Simplest case - block found, no allocation needed */ | |
601 | if (!partial) { | |
a686cd89 MB |
602 | first_block = le32_to_cpu(chain[depth - 1].key); |
603 | clear_buffer_new(bh_result); /* What's this do? */ | |
604 | count++; | |
605 | /*map more blocks*/ | |
606 | while (count < maxblocks && count <= blocks_to_boundary) { | |
607 | ext2_fsblk_t blk; | |
608 | ||
609 | if (!verify_chain(chain, partial)) { | |
610 | /* | |
611 | * Indirect block might be removed by | |
612 | * truncate while we were reading it. | |
613 | * Handling of that case: forget what we've | |
614 | * got now, go to reread. | |
615 | */ | |
616 | count = 0; | |
617 | goto changed; | |
618 | } | |
619 | blk = le32_to_cpu(*(chain[depth-1].p + count)); | |
620 | if (blk == first_block + count) | |
621 | count++; | |
622 | else | |
623 | break; | |
624 | } | |
625 | goto got_it; | |
1da177e4 LT |
626 | } |
627 | ||
628 | /* Next simple case - plain lookup or failed read of indirect block */ | |
a686cd89 MB |
629 | if (!create || err == -EIO) |
630 | goto cleanup; | |
631 | ||
632 | mutex_lock(&ei->truncate_mutex); | |
1da177e4 LT |
633 | |
634 | /* | |
a686cd89 MB |
635 | * Okay, we need to do block allocation. Lazily initialize the block |
636 | * allocation info here if necessary | |
637 | */ | |
638 | if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info)) | |
639 | ext2_init_block_alloc_info(inode); | |
1da177e4 | 640 | |
a686cd89 | 641 | goal = ext2_find_goal(inode, iblock, chain, partial); |
1da177e4 | 642 | |
a686cd89 MB |
643 | /* the number of blocks need to allocate for [d,t]indirect blocks */ |
644 | indirect_blks = (chain + depth) - partial - 1; | |
645 | /* | |
646 | * Next look up the indirect map to count the totoal number of | |
647 | * direct blocks to allocate for this branch. | |
648 | */ | |
649 | count = ext2_blks_to_allocate(partial, indirect_blks, | |
650 | maxblocks, blocks_to_boundary); | |
651 | /* | |
652 | * XXX ???? Block out ext2_truncate while we alter the tree | |
653 | */ | |
654 | err = ext2_alloc_branch(inode, indirect_blks, &count, goal, | |
655 | offsets + (partial - chain), partial); | |
656 | ||
657 | if (err) { | |
658 | mutex_unlock(&ei->truncate_mutex); | |
1da177e4 | 659 | goto cleanup; |
a686cd89 | 660 | } |
1da177e4 | 661 | |
6d79125b CO |
662 | if (ext2_use_xip(inode->i_sb)) { |
663 | /* | |
664 | * we need to clear the block | |
665 | */ | |
666 | err = ext2_clear_xip_target (inode, | |
667 | le32_to_cpu(chain[depth-1].key)); | |
a686cd89 MB |
668 | if (err) { |
669 | mutex_unlock(&ei->truncate_mutex); | |
6d79125b | 670 | goto cleanup; |
a686cd89 | 671 | } |
6d79125b CO |
672 | } |
673 | ||
a686cd89 MB |
674 | ext2_splice_branch(inode, iblock, partial, indirect_blks, count); |
675 | mutex_unlock(&ei->truncate_mutex); | |
1da177e4 | 676 | set_buffer_new(bh_result); |
a686cd89 MB |
677 | got_it: |
678 | map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key)); | |
679 | if (count > blocks_to_boundary) | |
680 | set_buffer_boundary(bh_result); | |
681 | err = count; | |
682 | /* Clean up and exit */ | |
683 | partial = chain + depth - 1; /* the whole chain */ | |
684 | cleanup: | |
685 | while (partial > chain) { | |
686 | brelse(partial->bh); | |
687 | partial--; | |
688 | } | |
689 | return err; | |
1da177e4 LT |
690 | changed: |
691 | while (partial > chain) { | |
692 | brelse(partial->bh); | |
693 | partial--; | |
694 | } | |
695 | goto reread; | |
696 | } | |
697 | ||
a686cd89 MB |
698 | int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create) |
699 | { | |
700 | unsigned max_blocks = bh_result->b_size >> inode->i_blkbits; | |
701 | int ret = ext2_get_blocks(inode, iblock, max_blocks, | |
702 | bh_result, create); | |
703 | if (ret > 0) { | |
704 | bh_result->b_size = (ret << inode->i_blkbits); | |
705 | ret = 0; | |
706 | } | |
707 | return ret; | |
708 | ||
709 | } | |
710 | ||
1da177e4 LT |
711 | static int ext2_writepage(struct page *page, struct writeback_control *wbc) |
712 | { | |
713 | return block_write_full_page(page, ext2_get_block, wbc); | |
714 | } | |
715 | ||
716 | static int ext2_readpage(struct file *file, struct page *page) | |
717 | { | |
718 | return mpage_readpage(page, ext2_get_block); | |
719 | } | |
720 | ||
721 | static int | |
722 | ext2_readpages(struct file *file, struct address_space *mapping, | |
723 | struct list_head *pages, unsigned nr_pages) | |
724 | { | |
725 | return mpage_readpages(mapping, pages, nr_pages, ext2_get_block); | |
726 | } | |
727 | ||
f34fb6ec NP |
728 | int __ext2_write_begin(struct file *file, struct address_space *mapping, |
729 | loff_t pos, unsigned len, unsigned flags, | |
730 | struct page **pagep, void **fsdata) | |
1da177e4 | 731 | { |
f34fb6ec NP |
732 | return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata, |
733 | ext2_get_block); | |
1da177e4 LT |
734 | } |
735 | ||
736 | static int | |
f34fb6ec NP |
737 | ext2_write_begin(struct file *file, struct address_space *mapping, |
738 | loff_t pos, unsigned len, unsigned flags, | |
739 | struct page **pagep, void **fsdata) | |
1da177e4 | 740 | { |
f34fb6ec NP |
741 | *pagep = NULL; |
742 | return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata); | |
1da177e4 LT |
743 | } |
744 | ||
03158cd7 NP |
745 | static int |
746 | ext2_nobh_write_begin(struct file *file, struct address_space *mapping, | |
747 | loff_t pos, unsigned len, unsigned flags, | |
748 | struct page **pagep, void **fsdata) | |
749 | { | |
750 | /* | |
751 | * Dir-in-pagecache still uses ext2_write_begin. Would have to rework | |
752 | * directory handling code to pass around offsets rather than struct | |
753 | * pages in order to make this work easily. | |
754 | */ | |
755 | return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata, | |
756 | ext2_get_block); | |
757 | } | |
758 | ||
1da177e4 LT |
759 | static int ext2_nobh_writepage(struct page *page, |
760 | struct writeback_control *wbc) | |
761 | { | |
762 | return nobh_writepage(page, ext2_get_block, wbc); | |
763 | } | |
764 | ||
765 | static sector_t ext2_bmap(struct address_space *mapping, sector_t block) | |
766 | { | |
767 | return generic_block_bmap(mapping,block,ext2_get_block); | |
768 | } | |
769 | ||
1da177e4 LT |
770 | static ssize_t |
771 | ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov, | |
772 | loff_t offset, unsigned long nr_segs) | |
773 | { | |
774 | struct file *file = iocb->ki_filp; | |
775 | struct inode *inode = file->f_mapping->host; | |
776 | ||
777 | return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov, | |
1d8fa7a2 | 778 | offset, nr_segs, ext2_get_block, NULL); |
1da177e4 LT |
779 | } |
780 | ||
781 | static int | |
782 | ext2_writepages(struct address_space *mapping, struct writeback_control *wbc) | |
783 | { | |
784 | return mpage_writepages(mapping, wbc, ext2_get_block); | |
785 | } | |
786 | ||
f5e54d6e | 787 | const struct address_space_operations ext2_aops = { |
1da177e4 LT |
788 | .readpage = ext2_readpage, |
789 | .readpages = ext2_readpages, | |
790 | .writepage = ext2_writepage, | |
791 | .sync_page = block_sync_page, | |
f34fb6ec NP |
792 | .write_begin = ext2_write_begin, |
793 | .write_end = generic_write_end, | |
1da177e4 LT |
794 | .bmap = ext2_bmap, |
795 | .direct_IO = ext2_direct_IO, | |
796 | .writepages = ext2_writepages, | |
e965f963 | 797 | .migratepage = buffer_migrate_page, |
1da177e4 LT |
798 | }; |
799 | ||
f5e54d6e | 800 | const struct address_space_operations ext2_aops_xip = { |
6d79125b CO |
801 | .bmap = ext2_bmap, |
802 | .get_xip_page = ext2_get_xip_page, | |
803 | }; | |
804 | ||
f5e54d6e | 805 | const struct address_space_operations ext2_nobh_aops = { |
1da177e4 LT |
806 | .readpage = ext2_readpage, |
807 | .readpages = ext2_readpages, | |
808 | .writepage = ext2_nobh_writepage, | |
809 | .sync_page = block_sync_page, | |
03158cd7 NP |
810 | .write_begin = ext2_nobh_write_begin, |
811 | .write_end = nobh_write_end, | |
1da177e4 LT |
812 | .bmap = ext2_bmap, |
813 | .direct_IO = ext2_direct_IO, | |
814 | .writepages = ext2_writepages, | |
e965f963 | 815 | .migratepage = buffer_migrate_page, |
1da177e4 LT |
816 | }; |
817 | ||
818 | /* | |
819 | * Probably it should be a library function... search for first non-zero word | |
820 | * or memcmp with zero_page, whatever is better for particular architecture. | |
821 | * Linus? | |
822 | */ | |
823 | static inline int all_zeroes(__le32 *p, __le32 *q) | |
824 | { | |
825 | while (p < q) | |
826 | if (*p++) | |
827 | return 0; | |
828 | return 1; | |
829 | } | |
830 | ||
831 | /** | |
832 | * ext2_find_shared - find the indirect blocks for partial truncation. | |
833 | * @inode: inode in question | |
834 | * @depth: depth of the affected branch | |
835 | * @offsets: offsets of pointers in that branch (see ext2_block_to_path) | |
836 | * @chain: place to store the pointers to partial indirect blocks | |
837 | * @top: place to the (detached) top of branch | |
838 | * | |
839 | * This is a helper function used by ext2_truncate(). | |
840 | * | |
841 | * When we do truncate() we may have to clean the ends of several indirect | |
842 | * blocks but leave the blocks themselves alive. Block is partially | |
843 | * truncated if some data below the new i_size is refered from it (and | |
844 | * it is on the path to the first completely truncated data block, indeed). | |
845 | * We have to free the top of that path along with everything to the right | |
846 | * of the path. Since no allocation past the truncation point is possible | |
847 | * until ext2_truncate() finishes, we may safely do the latter, but top | |
848 | * of branch may require special attention - pageout below the truncation | |
849 | * point might try to populate it. | |
850 | * | |
851 | * We atomically detach the top of branch from the tree, store the block | |
852 | * number of its root in *@top, pointers to buffer_heads of partially | |
853 | * truncated blocks - in @chain[].bh and pointers to their last elements | |
854 | * that should not be removed - in @chain[].p. Return value is the pointer | |
855 | * to last filled element of @chain. | |
856 | * | |
857 | * The work left to caller to do the actual freeing of subtrees: | |
858 | * a) free the subtree starting from *@top | |
859 | * b) free the subtrees whose roots are stored in | |
860 | * (@chain[i].p+1 .. end of @chain[i].bh->b_data) | |
861 | * c) free the subtrees growing from the inode past the @chain[0].p | |
862 | * (no partially truncated stuff there). | |
863 | */ | |
864 | ||
865 | static Indirect *ext2_find_shared(struct inode *inode, | |
866 | int depth, | |
867 | int offsets[4], | |
868 | Indirect chain[4], | |
869 | __le32 *top) | |
870 | { | |
871 | Indirect *partial, *p; | |
872 | int k, err; | |
873 | ||
874 | *top = 0; | |
875 | for (k = depth; k > 1 && !offsets[k-1]; k--) | |
876 | ; | |
877 | partial = ext2_get_branch(inode, k, offsets, chain, &err); | |
878 | if (!partial) | |
879 | partial = chain + k-1; | |
880 | /* | |
881 | * If the branch acquired continuation since we've looked at it - | |
882 | * fine, it should all survive and (new) top doesn't belong to us. | |
883 | */ | |
884 | write_lock(&EXT2_I(inode)->i_meta_lock); | |
885 | if (!partial->key && *partial->p) { | |
886 | write_unlock(&EXT2_I(inode)->i_meta_lock); | |
887 | goto no_top; | |
888 | } | |
889 | for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--) | |
890 | ; | |
891 | /* | |
892 | * OK, we've found the last block that must survive. The rest of our | |
893 | * branch should be detached before unlocking. However, if that rest | |
894 | * of branch is all ours and does not grow immediately from the inode | |
895 | * it's easier to cheat and just decrement partial->p. | |
896 | */ | |
897 | if (p == chain + k - 1 && p > chain) { | |
898 | p->p--; | |
899 | } else { | |
900 | *top = *p->p; | |
901 | *p->p = 0; | |
902 | } | |
903 | write_unlock(&EXT2_I(inode)->i_meta_lock); | |
904 | ||
905 | while(partial > p) | |
906 | { | |
907 | brelse(partial->bh); | |
908 | partial--; | |
909 | } | |
910 | no_top: | |
911 | return partial; | |
912 | } | |
913 | ||
914 | /** | |
915 | * ext2_free_data - free a list of data blocks | |
916 | * @inode: inode we are dealing with | |
917 | * @p: array of block numbers | |
918 | * @q: points immediately past the end of array | |
919 | * | |
920 | * We are freeing all blocks refered from that array (numbers are | |
921 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
922 | * appropriately. | |
923 | */ | |
924 | static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q) | |
925 | { | |
926 | unsigned long block_to_free = 0, count = 0; | |
927 | unsigned long nr; | |
928 | ||
929 | for ( ; p < q ; p++) { | |
930 | nr = le32_to_cpu(*p); | |
931 | if (nr) { | |
932 | *p = 0; | |
933 | /* accumulate blocks to free if they're contiguous */ | |
934 | if (count == 0) | |
935 | goto free_this; | |
936 | else if (block_to_free == nr - count) | |
937 | count++; | |
938 | else { | |
939 | mark_inode_dirty(inode); | |
940 | ext2_free_blocks (inode, block_to_free, count); | |
941 | free_this: | |
942 | block_to_free = nr; | |
943 | count = 1; | |
944 | } | |
945 | } | |
946 | } | |
947 | if (count > 0) { | |
948 | mark_inode_dirty(inode); | |
949 | ext2_free_blocks (inode, block_to_free, count); | |
950 | } | |
951 | } | |
952 | ||
953 | /** | |
954 | * ext2_free_branches - free an array of branches | |
955 | * @inode: inode we are dealing with | |
956 | * @p: array of block numbers | |
957 | * @q: pointer immediately past the end of array | |
958 | * @depth: depth of the branches to free | |
959 | * | |
960 | * We are freeing all blocks refered from these branches (numbers are | |
961 | * stored as little-endian 32-bit) and updating @inode->i_blocks | |
962 | * appropriately. | |
963 | */ | |
964 | static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth) | |
965 | { | |
966 | struct buffer_head * bh; | |
967 | unsigned long nr; | |
968 | ||
969 | if (depth--) { | |
970 | int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); | |
971 | for ( ; p < q ; p++) { | |
972 | nr = le32_to_cpu(*p); | |
973 | if (!nr) | |
974 | continue; | |
975 | *p = 0; | |
976 | bh = sb_bread(inode->i_sb, nr); | |
977 | /* | |
978 | * A read failure? Report error and clear slot | |
979 | * (should be rare). | |
980 | */ | |
981 | if (!bh) { | |
982 | ext2_error(inode->i_sb, "ext2_free_branches", | |
983 | "Read failure, inode=%ld, block=%ld", | |
984 | inode->i_ino, nr); | |
985 | continue; | |
986 | } | |
987 | ext2_free_branches(inode, | |
988 | (__le32*)bh->b_data, | |
989 | (__le32*)bh->b_data + addr_per_block, | |
990 | depth); | |
991 | bforget(bh); | |
992 | ext2_free_blocks(inode, nr, 1); | |
993 | mark_inode_dirty(inode); | |
994 | } | |
995 | } else | |
996 | ext2_free_data(inode, p, q); | |
997 | } | |
998 | ||
a686cd89 | 999 | void ext2_truncate(struct inode *inode) |
1da177e4 LT |
1000 | { |
1001 | __le32 *i_data = EXT2_I(inode)->i_data; | |
a686cd89 | 1002 | struct ext2_inode_info *ei = EXT2_I(inode); |
1da177e4 LT |
1003 | int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb); |
1004 | int offsets[4]; | |
1005 | Indirect chain[4]; | |
1006 | Indirect *partial; | |
1007 | __le32 nr = 0; | |
1008 | int n; | |
1009 | long iblock; | |
1010 | unsigned blocksize; | |
1011 | ||
1012 | if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) || | |
1013 | S_ISLNK(inode->i_mode))) | |
1014 | return; | |
1015 | if (ext2_inode_is_fast_symlink(inode)) | |
1016 | return; | |
1017 | if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) | |
1018 | return; | |
1019 | ||
1da177e4 LT |
1020 | blocksize = inode->i_sb->s_blocksize; |
1021 | iblock = (inode->i_size + blocksize-1) | |
1022 | >> EXT2_BLOCK_SIZE_BITS(inode->i_sb); | |
1023 | ||
6d79125b CO |
1024 | if (mapping_is_xip(inode->i_mapping)) |
1025 | xip_truncate_page(inode->i_mapping, inode->i_size); | |
1026 | else if (test_opt(inode->i_sb, NOBH)) | |
03158cd7 NP |
1027 | nobh_truncate_page(inode->i_mapping, |
1028 | inode->i_size, ext2_get_block); | |
1da177e4 LT |
1029 | else |
1030 | block_truncate_page(inode->i_mapping, | |
1031 | inode->i_size, ext2_get_block); | |
1032 | ||
1033 | n = ext2_block_to_path(inode, iblock, offsets, NULL); | |
1034 | if (n == 0) | |
1035 | return; | |
1036 | ||
a686cd89 MB |
1037 | /* |
1038 | * From here we block out all ext2_get_block() callers who want to | |
1039 | * modify the block allocation tree. | |
1040 | */ | |
1041 | mutex_lock(&ei->truncate_mutex); | |
1042 | ||
1da177e4 LT |
1043 | if (n == 1) { |
1044 | ext2_free_data(inode, i_data+offsets[0], | |
1045 | i_data + EXT2_NDIR_BLOCKS); | |
1046 | goto do_indirects; | |
1047 | } | |
1048 | ||
1049 | partial = ext2_find_shared(inode, n, offsets, chain, &nr); | |
1050 | /* Kill the top of shared branch (already detached) */ | |
1051 | if (nr) { | |
1052 | if (partial == chain) | |
1053 | mark_inode_dirty(inode); | |
1054 | else | |
1055 | mark_buffer_dirty_inode(partial->bh, inode); | |
1056 | ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial); | |
1057 | } | |
1058 | /* Clear the ends of indirect blocks on the shared branch */ | |
1059 | while (partial > chain) { | |
1060 | ext2_free_branches(inode, | |
1061 | partial->p + 1, | |
1062 | (__le32*)partial->bh->b_data+addr_per_block, | |
1063 | (chain+n-1) - partial); | |
1064 | mark_buffer_dirty_inode(partial->bh, inode); | |
1065 | brelse (partial->bh); | |
1066 | partial--; | |
1067 | } | |
1068 | do_indirects: | |
1069 | /* Kill the remaining (whole) subtrees */ | |
1070 | switch (offsets[0]) { | |
1071 | default: | |
1072 | nr = i_data[EXT2_IND_BLOCK]; | |
1073 | if (nr) { | |
1074 | i_data[EXT2_IND_BLOCK] = 0; | |
1075 | mark_inode_dirty(inode); | |
1076 | ext2_free_branches(inode, &nr, &nr+1, 1); | |
1077 | } | |
1078 | case EXT2_IND_BLOCK: | |
1079 | nr = i_data[EXT2_DIND_BLOCK]; | |
1080 | if (nr) { | |
1081 | i_data[EXT2_DIND_BLOCK] = 0; | |
1082 | mark_inode_dirty(inode); | |
1083 | ext2_free_branches(inode, &nr, &nr+1, 2); | |
1084 | } | |
1085 | case EXT2_DIND_BLOCK: | |
1086 | nr = i_data[EXT2_TIND_BLOCK]; | |
1087 | if (nr) { | |
1088 | i_data[EXT2_TIND_BLOCK] = 0; | |
1089 | mark_inode_dirty(inode); | |
1090 | ext2_free_branches(inode, &nr, &nr+1, 3); | |
1091 | } | |
1092 | case EXT2_TIND_BLOCK: | |
1093 | ; | |
1094 | } | |
a686cd89 MB |
1095 | |
1096 | ext2_discard_reservation(inode); | |
1097 | ||
1098 | mutex_unlock(&ei->truncate_mutex); | |
1da177e4 LT |
1099 | inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC; |
1100 | if (inode_needs_sync(inode)) { | |
1101 | sync_mapping_buffers(inode->i_mapping); | |
1102 | ext2_sync_inode (inode); | |
1103 | } else { | |
1104 | mark_inode_dirty(inode); | |
1105 | } | |
1106 | } | |
1107 | ||
1108 | static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino, | |
1109 | struct buffer_head **p) | |
1110 | { | |
1111 | struct buffer_head * bh; | |
1112 | unsigned long block_group; | |
1113 | unsigned long block; | |
1114 | unsigned long offset; | |
1115 | struct ext2_group_desc * gdp; | |
1116 | ||
1117 | *p = NULL; | |
1118 | if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) || | |
1119 | ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count)) | |
1120 | goto Einval; | |
1121 | ||
1122 | block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb); | |
ef2fb679 | 1123 | gdp = ext2_get_group_desc(sb, block_group, NULL); |
1da177e4 LT |
1124 | if (!gdp) |
1125 | goto Egdp; | |
1126 | /* | |
1127 | * Figure out the offset within the block group inode table | |
1128 | */ | |
1129 | offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb); | |
1130 | block = le32_to_cpu(gdp->bg_inode_table) + | |
1131 | (offset >> EXT2_BLOCK_SIZE_BITS(sb)); | |
1132 | if (!(bh = sb_bread(sb, block))) | |
1133 | goto Eio; | |
1134 | ||
1135 | *p = bh; | |
1136 | offset &= (EXT2_BLOCK_SIZE(sb) - 1); | |
1137 | return (struct ext2_inode *) (bh->b_data + offset); | |
1138 | ||
1139 | Einval: | |
1140 | ext2_error(sb, "ext2_get_inode", "bad inode number: %lu", | |
1141 | (unsigned long) ino); | |
1142 | return ERR_PTR(-EINVAL); | |
1143 | Eio: | |
1144 | ext2_error(sb, "ext2_get_inode", | |
1145 | "unable to read inode block - inode=%lu, block=%lu", | |
1146 | (unsigned long) ino, block); | |
1147 | Egdp: | |
1148 | return ERR_PTR(-EIO); | |
1149 | } | |
1150 | ||
1151 | void ext2_set_inode_flags(struct inode *inode) | |
1152 | { | |
1153 | unsigned int flags = EXT2_I(inode)->i_flags; | |
1154 | ||
1155 | inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC); | |
1156 | if (flags & EXT2_SYNC_FL) | |
1157 | inode->i_flags |= S_SYNC; | |
1158 | if (flags & EXT2_APPEND_FL) | |
1159 | inode->i_flags |= S_APPEND; | |
1160 | if (flags & EXT2_IMMUTABLE_FL) | |
1161 | inode->i_flags |= S_IMMUTABLE; | |
1162 | if (flags & EXT2_NOATIME_FL) | |
1163 | inode->i_flags |= S_NOATIME; | |
1164 | if (flags & EXT2_DIRSYNC_FL) | |
1165 | inode->i_flags |= S_DIRSYNC; | |
1166 | } | |
1167 | ||
4f99ed67 JK |
1168 | /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */ |
1169 | void ext2_get_inode_flags(struct ext2_inode_info *ei) | |
1170 | { | |
1171 | unsigned int flags = ei->vfs_inode.i_flags; | |
1172 | ||
1173 | ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL| | |
1174 | EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL); | |
1175 | if (flags & S_SYNC) | |
1176 | ei->i_flags |= EXT2_SYNC_FL; | |
1177 | if (flags & S_APPEND) | |
1178 | ei->i_flags |= EXT2_APPEND_FL; | |
1179 | if (flags & S_IMMUTABLE) | |
1180 | ei->i_flags |= EXT2_IMMUTABLE_FL; | |
1181 | if (flags & S_NOATIME) | |
1182 | ei->i_flags |= EXT2_NOATIME_FL; | |
1183 | if (flags & S_DIRSYNC) | |
1184 | ei->i_flags |= EXT2_DIRSYNC_FL; | |
1185 | } | |
1186 | ||
1da177e4 LT |
1187 | void ext2_read_inode (struct inode * inode) |
1188 | { | |
1189 | struct ext2_inode_info *ei = EXT2_I(inode); | |
1190 | ino_t ino = inode->i_ino; | |
1191 | struct buffer_head * bh; | |
1192 | struct ext2_inode * raw_inode = ext2_get_inode(inode->i_sb, ino, &bh); | |
1193 | int n; | |
1194 | ||
1195 | #ifdef CONFIG_EXT2_FS_POSIX_ACL | |
1196 | ei->i_acl = EXT2_ACL_NOT_CACHED; | |
1197 | ei->i_default_acl = EXT2_ACL_NOT_CACHED; | |
1198 | #endif | |
a686cd89 MB |
1199 | ei->i_block_alloc_info = NULL; |
1200 | ||
1da177e4 LT |
1201 | if (IS_ERR(raw_inode)) |
1202 | goto bad_inode; | |
1203 | ||
1204 | inode->i_mode = le16_to_cpu(raw_inode->i_mode); | |
1205 | inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low); | |
1206 | inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low); | |
1207 | if (!(test_opt (inode->i_sb, NO_UID32))) { | |
1208 | inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16; | |
1209 | inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16; | |
1210 | } | |
1211 | inode->i_nlink = le16_to_cpu(raw_inode->i_links_count); | |
1212 | inode->i_size = le32_to_cpu(raw_inode->i_size); | |
4d7bf11d MR |
1213 | inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime); |
1214 | inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime); | |
1215 | inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime); | |
1da177e4 LT |
1216 | inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0; |
1217 | ei->i_dtime = le32_to_cpu(raw_inode->i_dtime); | |
1218 | /* We now have enough fields to check if the inode was active or not. | |
1219 | * This is needed because nfsd might try to access dead inodes | |
1220 | * the test is that same one that e2fsck uses | |
1221 | * NeilBrown 1999oct15 | |
1222 | */ | |
1223 | if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) { | |
1224 | /* this inode is deleted */ | |
1225 | brelse (bh); | |
1226 | goto bad_inode; | |
1227 | } | |
1da177e4 LT |
1228 | inode->i_blocks = le32_to_cpu(raw_inode->i_blocks); |
1229 | ei->i_flags = le32_to_cpu(raw_inode->i_flags); | |
1230 | ei->i_faddr = le32_to_cpu(raw_inode->i_faddr); | |
1231 | ei->i_frag_no = raw_inode->i_frag; | |
1232 | ei->i_frag_size = raw_inode->i_fsize; | |
1233 | ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl); | |
1234 | ei->i_dir_acl = 0; | |
1235 | if (S_ISREG(inode->i_mode)) | |
1236 | inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32; | |
1237 | else | |
1238 | ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl); | |
1239 | ei->i_dtime = 0; | |
1240 | inode->i_generation = le32_to_cpu(raw_inode->i_generation); | |
1241 | ei->i_state = 0; | |
1da177e4 LT |
1242 | ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb); |
1243 | ei->i_dir_start_lookup = 0; | |
1244 | ||
1245 | /* | |
1246 | * NOTE! The in-memory inode i_data array is in little-endian order | |
1247 | * even on big-endian machines: we do NOT byteswap the block numbers! | |
1248 | */ | |
1249 | for (n = 0; n < EXT2_N_BLOCKS; n++) | |
1250 | ei->i_data[n] = raw_inode->i_block[n]; | |
1251 | ||
1252 | if (S_ISREG(inode->i_mode)) { | |
1253 | inode->i_op = &ext2_file_inode_operations; | |
6d79125b CO |
1254 | if (ext2_use_xip(inode->i_sb)) { |
1255 | inode->i_mapping->a_ops = &ext2_aops_xip; | |
1256 | inode->i_fop = &ext2_xip_file_operations; | |
1257 | } else if (test_opt(inode->i_sb, NOBH)) { | |
1da177e4 | 1258 | inode->i_mapping->a_ops = &ext2_nobh_aops; |
6d79125b CO |
1259 | inode->i_fop = &ext2_file_operations; |
1260 | } else { | |
1da177e4 | 1261 | inode->i_mapping->a_ops = &ext2_aops; |
6d79125b CO |
1262 | inode->i_fop = &ext2_file_operations; |
1263 | } | |
1da177e4 LT |
1264 | } else if (S_ISDIR(inode->i_mode)) { |
1265 | inode->i_op = &ext2_dir_inode_operations; | |
1266 | inode->i_fop = &ext2_dir_operations; | |
1267 | if (test_opt(inode->i_sb, NOBH)) | |
1268 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
1269 | else | |
1270 | inode->i_mapping->a_ops = &ext2_aops; | |
1271 | } else if (S_ISLNK(inode->i_mode)) { | |
1272 | if (ext2_inode_is_fast_symlink(inode)) | |
1273 | inode->i_op = &ext2_fast_symlink_inode_operations; | |
1274 | else { | |
1275 | inode->i_op = &ext2_symlink_inode_operations; | |
1276 | if (test_opt(inode->i_sb, NOBH)) | |
1277 | inode->i_mapping->a_ops = &ext2_nobh_aops; | |
1278 | else | |
1279 | inode->i_mapping->a_ops = &ext2_aops; | |
1280 | } | |
1281 | } else { | |
1282 | inode->i_op = &ext2_special_inode_operations; | |
1283 | if (raw_inode->i_block[0]) | |
1284 | init_special_inode(inode, inode->i_mode, | |
1285 | old_decode_dev(le32_to_cpu(raw_inode->i_block[0]))); | |
1286 | else | |
1287 | init_special_inode(inode, inode->i_mode, | |
1288 | new_decode_dev(le32_to_cpu(raw_inode->i_block[1]))); | |
1289 | } | |
1290 | brelse (bh); | |
1291 | ext2_set_inode_flags(inode); | |
1292 | return; | |
1293 | ||
1294 | bad_inode: | |
1295 | make_bad_inode(inode); | |
1296 | return; | |
1297 | } | |
1298 | ||
1299 | static int ext2_update_inode(struct inode * inode, int do_sync) | |
1300 | { | |
1301 | struct ext2_inode_info *ei = EXT2_I(inode); | |
1302 | struct super_block *sb = inode->i_sb; | |
1303 | ino_t ino = inode->i_ino; | |
1304 | uid_t uid = inode->i_uid; | |
1305 | gid_t gid = inode->i_gid; | |
1306 | struct buffer_head * bh; | |
1307 | struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh); | |
1308 | int n; | |
1309 | int err = 0; | |
1310 | ||
1311 | if (IS_ERR(raw_inode)) | |
1312 | return -EIO; | |
1313 | ||
1314 | /* For fields not not tracking in the in-memory inode, | |
1315 | * initialise them to zero for new inodes. */ | |
1316 | if (ei->i_state & EXT2_STATE_NEW) | |
1317 | memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size); | |
1318 | ||
4f99ed67 | 1319 | ext2_get_inode_flags(ei); |
1da177e4 LT |
1320 | raw_inode->i_mode = cpu_to_le16(inode->i_mode); |
1321 | if (!(test_opt(sb, NO_UID32))) { | |
1322 | raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid)); | |
1323 | raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid)); | |
1324 | /* | |
1325 | * Fix up interoperability with old kernels. Otherwise, old inodes get | |
1326 | * re-used with the upper 16 bits of the uid/gid intact | |
1327 | */ | |
1328 | if (!ei->i_dtime) { | |
1329 | raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid)); | |
1330 | raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid)); | |
1331 | } else { | |
1332 | raw_inode->i_uid_high = 0; | |
1333 | raw_inode->i_gid_high = 0; | |
1334 | } | |
1335 | } else { | |
1336 | raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid)); | |
1337 | raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid)); | |
1338 | raw_inode->i_uid_high = 0; | |
1339 | raw_inode->i_gid_high = 0; | |
1340 | } | |
1341 | raw_inode->i_links_count = cpu_to_le16(inode->i_nlink); | |
1342 | raw_inode->i_size = cpu_to_le32(inode->i_size); | |
1343 | raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec); | |
1344 | raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec); | |
1345 | raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec); | |
1346 | ||
1347 | raw_inode->i_blocks = cpu_to_le32(inode->i_blocks); | |
1348 | raw_inode->i_dtime = cpu_to_le32(ei->i_dtime); | |
1349 | raw_inode->i_flags = cpu_to_le32(ei->i_flags); | |
1350 | raw_inode->i_faddr = cpu_to_le32(ei->i_faddr); | |
1351 | raw_inode->i_frag = ei->i_frag_no; | |
1352 | raw_inode->i_fsize = ei->i_frag_size; | |
1353 | raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl); | |
1354 | if (!S_ISREG(inode->i_mode)) | |
1355 | raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl); | |
1356 | else { | |
1357 | raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32); | |
1358 | if (inode->i_size > 0x7fffffffULL) { | |
1359 | if (!EXT2_HAS_RO_COMPAT_FEATURE(sb, | |
1360 | EXT2_FEATURE_RO_COMPAT_LARGE_FILE) || | |
1361 | EXT2_SB(sb)->s_es->s_rev_level == | |
1362 | cpu_to_le32(EXT2_GOOD_OLD_REV)) { | |
1363 | /* If this is the first large file | |
1364 | * created, add a flag to the superblock. | |
1365 | */ | |
1366 | lock_kernel(); | |
1367 | ext2_update_dynamic_rev(sb); | |
1368 | EXT2_SET_RO_COMPAT_FEATURE(sb, | |
1369 | EXT2_FEATURE_RO_COMPAT_LARGE_FILE); | |
1370 | unlock_kernel(); | |
1371 | ext2_write_super(sb); | |
1372 | } | |
1373 | } | |
1374 | } | |
1375 | ||
1376 | raw_inode->i_generation = cpu_to_le32(inode->i_generation); | |
1377 | if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) { | |
1378 | if (old_valid_dev(inode->i_rdev)) { | |
1379 | raw_inode->i_block[0] = | |
1380 | cpu_to_le32(old_encode_dev(inode->i_rdev)); | |
1381 | raw_inode->i_block[1] = 0; | |
1382 | } else { | |
1383 | raw_inode->i_block[0] = 0; | |
1384 | raw_inode->i_block[1] = | |
1385 | cpu_to_le32(new_encode_dev(inode->i_rdev)); | |
1386 | raw_inode->i_block[2] = 0; | |
1387 | } | |
1388 | } else for (n = 0; n < EXT2_N_BLOCKS; n++) | |
1389 | raw_inode->i_block[n] = ei->i_data[n]; | |
1390 | mark_buffer_dirty(bh); | |
1391 | if (do_sync) { | |
1392 | sync_dirty_buffer(bh); | |
1393 | if (buffer_req(bh) && !buffer_uptodate(bh)) { | |
1394 | printk ("IO error syncing ext2 inode [%s:%08lx]\n", | |
1395 | sb->s_id, (unsigned long) ino); | |
1396 | err = -EIO; | |
1397 | } | |
1398 | } | |
1399 | ei->i_state &= ~EXT2_STATE_NEW; | |
1400 | brelse (bh); | |
1401 | return err; | |
1402 | } | |
1403 | ||
1404 | int ext2_write_inode(struct inode *inode, int wait) | |
1405 | { | |
1406 | return ext2_update_inode(inode, wait); | |
1407 | } | |
1408 | ||
1409 | int ext2_sync_inode(struct inode *inode) | |
1410 | { | |
1411 | struct writeback_control wbc = { | |
1412 | .sync_mode = WB_SYNC_ALL, | |
1413 | .nr_to_write = 0, /* sys_fsync did this */ | |
1414 | }; | |
1415 | return sync_inode(inode, &wbc); | |
1416 | } | |
1417 | ||
1418 | int ext2_setattr(struct dentry *dentry, struct iattr *iattr) | |
1419 | { | |
1420 | struct inode *inode = dentry->d_inode; | |
1421 | int error; | |
1422 | ||
1423 | error = inode_change_ok(inode, iattr); | |
1424 | if (error) | |
1425 | return error; | |
1426 | if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) || | |
1427 | (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) { | |
1428 | error = DQUOT_TRANSFER(inode, iattr) ? -EDQUOT : 0; | |
1429 | if (error) | |
1430 | return error; | |
1431 | } | |
1432 | error = inode_setattr(inode, iattr); | |
1433 | if (!error && (iattr->ia_valid & ATTR_MODE)) | |
1434 | error = ext2_acl_chmod(inode); | |
1435 | return error; | |
1436 | } |