Line data Source code
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 <linux/fiemap.h>
35 : #include <linux/namei.h>
36 : #include "ext2.h"
37 : #include "acl.h"
38 : #include "xip.h"
39 :
40 : MODULE_AUTHOR("Remy Card and others");
41 : MODULE_DESCRIPTION("Second Extended Filesystem");
42 : MODULE_LICENSE("GPL");
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 90 : int ea_blocks = EXT2_I(inode)->i_file_acl ?
50 10 : (inode->i_sb->s_blocksize >> 9) : 0;
51 :
52 70 : 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 : {
61 2 : truncate_inode_pages(&inode->i_data, 0);
62 1 :
63 4 : if (is_bad_inode(inode))
64 2 : goto no_delete;
65 4 : EXT2_I(inode)->i_dtime = get_seconds();
66 2 : mark_inode_dirty(inode);
67 4 : ext2_write_inode(inode, inode_needs_sync(inode));
68 :
69 1 : inode->i_size = 0;
70 2 : if (inode->i_blocks)
71 6 : ext2_truncate (inode);
72 4 : ext2_free_inode (inode);
73 :
74 1 : return;
75 1 : no_delete:
76 1 : clear_inode(inode); /* We must guarantee clearing of inode... */
77 1 : }
78 :
79 : typedef struct {
80 : __le32 *p;
81 : __le32 key;
82 : struct buffer_head *bh;
83 2 : } Indirect;
84 :
85 : static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
86 : {
87 40 : p->key = *(p->p = v);
88 10 : p->bh = bh;
89 10 : }
90 :
91 : static inline int verify_chain(Indirect *from, Indirect *to)
92 : {
93 25 : while (from <= to && from->key == *from->p)
94 10 : from++;
95 15 : 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 10 : int ptrs = EXT2_ADDR_PER_BLOCK(inode->i_sb);
132 20 : int ptrs_bits = EXT2_ADDR_PER_BLOCK_BITS(inode->i_sb);
133 10 : const long direct_blocks = EXT2_NDIR_BLOCKS,
134 10 : indirect_blocks = ptrs,
135 10 : double_blocks = (1 << (ptrs_bits * 2));
136 10 : int n = 0;
137 10 : int final = 0;
138 5 :
139 15 : if (i_block < 0) {
140 15 : ext2_msg(inode->i_sb, KERN_WARNING,
141 5 : "warning: %s: block < 0", __func__);
142 15 : } else if (i_block < direct_blocks) {
143 20 : offsets[n++] = i_block;
144 10 : final = direct_blocks;
145 20 : } else if ( (i_block -= direct_blocks) < indirect_blocks) {
146 20 : offsets[n++] = EXT2_IND_BLOCK;
147 20 : offsets[n++] = i_block;
148 10 : final = ptrs;
149 15 : } else if ((i_block -= indirect_blocks) < double_blocks) {
150 15 : offsets[n++] = EXT2_DIND_BLOCK;
151 15 : offsets[n++] = i_block >> ptrs_bits;
152 15 : offsets[n++] = i_block & (ptrs - 1);
153 5 : final = ptrs;
154 15 : } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
155 15 : offsets[n++] = EXT2_TIND_BLOCK;
156 15 : offsets[n++] = i_block >> (ptrs_bits * 2);
157 15 : offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
158 15 : offsets[n++] = i_block & (ptrs - 1);
159 5 : final = ptrs;
160 : } else {
161 10 : ext2_msg(inode->i_sb, KERN_WARNING,
162 : "warning: %s: block is too big", __func__);
163 : }
164 30 : if (boundary)
165 15 : *boundary = final - 1 - (i_block & (ptrs - 1));
166 :
167 15 : return n;
168 : }
169 :
170 : /**
171 : * ext2_get_branch - read the chain of indirect blocks leading to data
172 : * @inode: inode in question
173 : * @depth: depth of the chain (1 - direct pointer, etc.)
174 : * @offsets: offsets of pointers in inode/indirect blocks
175 : * @chain: place to store the result
176 : * @err: here we store the error value
177 : *
178 : * Function fills the array of triples <key, p, bh> and returns %NULL
179 : * if everything went OK or the pointer to the last filled triple
180 : * (incomplete one) otherwise. Upon the return chain[i].key contains
181 : * the number of (i+1)-th block in the chain (as it is stored in memory,
182 : * i.e. little-endian 32-bit), chain[i].p contains the address of that
183 : * number (it points into struct inode for i==0 and into the bh->b_data
184 : * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
185 : * block for i>0 and NULL for i==0. In other words, it holds the block
186 : * numbers of the chain, addresses they were taken from (and where we can
187 : * verify that chain did not change) and buffer_heads hosting these
188 : * numbers.
189 : *
190 : * Function stops when it stumbles upon zero pointer (absent block)
191 : * (pointer to last triple returned, *@err == 0)
192 : * or when it gets an IO error reading an indirect block
193 : * (ditto, *@err == -EIO)
194 : * or when it notices that chain had been changed while it was reading
195 : * (ditto, *@err == -EAGAIN)
196 : * or when it reads all @depth-1 indirect blocks successfully and finds
197 : * the whole chain, all way to the data (returns %NULL, *err == 0).
198 : */
199 : static Indirect *ext2_get_branch(struct inode *inode,
200 : int depth,
201 : int *offsets,
202 5 : Indirect chain[4],
203 5 : int *err)
204 5 : {
205 10 : struct super_block *sb = inode->i_sb;
206 10 : Indirect *p = chain;
207 5 : struct buffer_head *bh;
208 5 :
209 10 : *err = 0;
210 : /* i_data is not going away, no lock needed */
211 20 : add_chain (chain, NULL, EXT2_I(inode)->i_data + *offsets);
212 10 : if (!p->key)
213 5 : goto no_block;
214 20 : while (--depth) {
215 20 : bh = sb_bread(sb, le32_to_cpu(p->key));
216 15 : if (!bh)
217 5 : goto failure;
218 15 : read_lock(&EXT2_I(inode)->i_meta_lock);
219 20 : if (!verify_chain(chain, p))
220 5 : goto changed;
221 20 : add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
222 20 : read_unlock(&EXT2_I(inode)->i_meta_lock);
223 10 : if (!p->key)
224 5 : goto no_block;
225 : }
226 5 : return NULL;
227 5 :
228 5 : changed:
229 20 : read_unlock(&EXT2_I(inode)->i_meta_lock);
230 10 : brelse(bh);
231 5 : *err = -EAGAIN;
232 5 : goto no_block;
233 5 : failure:
234 5 : *err = -EIO;
235 5 : no_block:
236 20 : return p;
237 : }
238 :
239 : /**
240 : * ext2_find_near - find a place for allocation with sufficient locality
241 : * @inode: owner
242 : * @ind: descriptor of indirect block.
243 : *
244 : * This function returns the preferred place for block allocation.
245 : * It is used when heuristic for sequential allocation fails.
246 : * Rules are:
247 : * + if there is a block to the left of our position - allocate near it.
248 : * + if pointer will live in indirect block - allocate near that block.
249 : * + if pointer will live in inode - allocate in the same cylinder group.
250 : *
251 : * In the latter case we colour the starting block by the callers PID to
252 : * prevent it from clashing with concurrent allocations for a different inode
253 : * in the same block group. The PID is used here so that functionally related
254 : * files will be close-by on-disk.
255 : *
256 : * Caller must make sure that @ind is valid and will stay that way.
257 : */
258 :
259 : static ext2_fsblk_t ext2_find_near(struct inode *inode, Indirect *ind)
260 : {
261 0 : struct ext2_inode_info *ei = EXT2_I(inode);
262 0 : __le32 *start = ind->bh ? (__le32 *) ind->bh->b_data : ei->i_data;
263 0 : __le32 *p;
264 0 : ext2_fsblk_t bg_start;
265 0 : ext2_fsblk_t colour;
266 0 :
267 0 : /* Try to find previous block */
268 0 : for (p = ind->p - 1; p >= start; p--)
269 0 : if (*p)
270 0 : return le32_to_cpu(*p);
271 :
272 : /* No such thing, so let's try location of indirect block */
273 0 : if (ind->bh)
274 0 : return ind->bh->b_blocknr;
275 :
276 : /*
277 : * It is going to be refered from inode itself? OK, just put it into
278 : * the same cylinder group then.
279 : */
280 0 : bg_start = ext2_group_first_block_no(inode->i_sb, ei->i_block_group);
281 0 : colour = (current->pid % 16) *
282 : (EXT2_BLOCKS_PER_GROUP(inode->i_sb) / 16);
283 0 : return bg_start + colour;
284 : }
285 :
286 : /**
287 : * ext2_find_goal - find a preferred place for allocation.
288 : * @inode: owner
289 : * @block: block we want
290 : * @partial: pointer to the last triple within a chain
291 : *
292 : * Returns preferred place for a block (the goal).
293 : */
294 :
295 : static inline ext2_fsblk_t ext2_find_goal(struct inode *inode, long block,
296 : Indirect *partial)
297 0 : {
298 0 : struct ext2_block_alloc_info *block_i;
299 0 :
300 0 : block_i = EXT2_I(inode)->i_block_alloc_info;
301 :
302 : /*
303 : * try the heuristic for sequential allocation,
304 : * failing that at least try to get decent locality.
305 : */
306 0 : if (block_i && (block == block_i->last_alloc_logical_block + 1)
307 : && (block_i->last_alloc_physical_block != 0)) {
308 0 : return block_i->last_alloc_physical_block + 1;
309 : }
310 :
311 0 : return ext2_find_near(inode, partial);
312 : }
313 :
314 : /**
315 : * ext2_blks_to_allocate: Look up the block map and count the number
316 : * of direct blocks need to be allocated for the given branch.
317 : *
318 : * @branch: chain of indirect blocks
319 : * @k: number of blocks need for indirect blocks
320 : * @blks: number of data blocks to be mapped.
321 : * @blocks_to_boundary: the offset in the indirect block
322 : *
323 : * return the total number of blocks to be allocate, including the
324 : * direct and indirect blocks.
325 : */
326 : static int
327 : ext2_blks_to_allocate(Indirect * branch, int k, unsigned long blks,
328 : int blocks_to_boundary)
329 0 : {
330 0 : unsigned long count = 0;
331 :
332 : /*
333 : * Simple case, [t,d]Indirect block(s) has not allocated yet
334 : * then it's clear blocks on that path have not allocated
335 : */
336 0 : if (k > 0) {
337 : /* right now don't hanel cross boundary allocation */
338 0 : if (blks < blocks_to_boundary + 1)
339 0 : count += blks;
340 : else
341 0 : count += blocks_to_boundary + 1;
342 0 : return count;
343 : }
344 :
345 0 : count++;
346 0 : while (count < blks && count <= blocks_to_boundary
347 0 : && le32_to_cpu(*(branch[0].p + count)) == 0) {
348 0 : count++;
349 0 : }
350 0 : return count;
351 : }
352 :
353 : /**
354 : * ext2_alloc_blocks: multiple allocate blocks needed for a branch
355 : * @indirect_blks: the number of blocks need to allocate for indirect
356 : * blocks
357 : *
358 : * @new_blocks: on return it will store the new block numbers for
359 : * the indirect blocks(if needed) and the first direct block,
360 : * @blks: on return it will store the total number of allocated
361 : * direct blocks
362 : */
363 : static int ext2_alloc_blocks(struct inode *inode,
364 : ext2_fsblk_t goal, int indirect_blks, int blks,
365 : ext2_fsblk_t new_blocks[4], int *err)
366 0 : {
367 0 : int target, i;
368 0 : unsigned long count = 0;
369 0 : int index = 0;
370 0 : ext2_fsblk_t current_block = 0;
371 0 : int ret = 0;
372 0 :
373 0 : /*
374 : * Here we try to allocate the requested multiple blocks at once,
375 : * on a best-effort basis.
376 : * To build a branch, we should allocate blocks for
377 : * the indirect blocks(if not allocated yet), and at least
378 : * the first direct block of this branch. That's the
379 : * minimum number of blocks need to allocate(required)
380 : */
381 0 : target = blks + indirect_blks;
382 0 :
383 : while (1) {
384 0 : count = target;
385 : /* allocating blocks for indirect blocks and direct blocks */
386 0 : current_block = ext2_new_blocks(inode,goal,&count,err);
387 0 : if (*err)
388 0 : goto failed_out;
389 :
390 0 : target -= count;
391 : /* allocate blocks for indirect blocks */
392 0 : while (index < indirect_blks && count) {
393 0 : new_blocks[index++] = current_block++;
394 0 : count--;
395 0 : }
396 :
397 0 : if (count > 0)
398 0 : break;
399 0 : }
400 0 :
401 : /* save the new block number for the first direct block */
402 0 : new_blocks[index] = current_block;
403 :
404 : /* total number of blocks allocated for direct blocks */
405 0 : ret = count;
406 0 : *err = 0;
407 0 : return ret;
408 0 : failed_out:
409 0 : for (i = 0; i <index; i++)
410 0 : ext2_free_blocks(inode, new_blocks[i], 1);
411 0 : return ret;
412 : }
413 :
414 : /**
415 : * ext2_alloc_branch - allocate and set up a chain of blocks.
416 : * @inode: owner
417 : * @num: depth of the chain (number of blocks to allocate)
418 : * @offsets: offsets (in the blocks) to store the pointers to next.
419 : * @branch: place to store the chain in.
420 : *
421 : * This function allocates @num blocks, zeroes out all but the last one,
422 : * links them into chain and (if we are synchronous) writes them to disk.
423 : * In other words, it prepares a branch that can be spliced onto the
424 : * inode. It stores the information about that chain in the branch[], in
425 : * the same format as ext2_get_branch() would do. We are calling it after
426 : * we had read the existing part of chain and partial points to the last
427 : * triple of that (one with zero ->key). Upon the exit we have the same
428 : * picture as after the successful ext2_get_block(), excpet that in one
429 : * place chain is disconnected - *branch->p is still zero (we did not
430 : * set the last link), but branch->key contains the number that should
431 : * be placed into *branch->p to fill that gap.
432 : *
433 : * If allocation fails we free all blocks we've allocated (and forget
434 : * their buffer_heads) and return the error value the from failed
435 : * ext2_alloc_block() (normally -ENOSPC). Otherwise we set the chain
436 : * as described above and return 0.
437 : */
438 :
439 : static int ext2_alloc_branch(struct inode *inode,
440 : int indirect_blks, int *blks, ext2_fsblk_t goal,
441 : int *offsets, Indirect *branch)
442 0 : {
443 0 : int blocksize = inode->i_sb->s_blocksize;
444 0 : int i, n = 0;
445 0 : int err = 0;
446 0 : struct buffer_head *bh;
447 0 : int num;
448 0 : ext2_fsblk_t new_blocks[4];
449 0 : ext2_fsblk_t current_block;
450 :
451 0 : num = ext2_alloc_blocks(inode, goal, indirect_blks,
452 : *blks, new_blocks, &err);
453 0 : if (err)
454 0 : return err;
455 :
456 0 : branch[0].key = cpu_to_le32(new_blocks[0]);
457 : /*
458 : * metadata blocks and data blocks are allocated.
459 : */
460 0 : for (n = 1; n <= indirect_blks; n++) {
461 0 : /*
462 0 : * Get buffer_head for parent block, zero it out
463 : * and set the pointer to new one, then send
464 : * parent to disk.
465 : */
466 0 : bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
467 0 : branch[n].bh = bh;
468 0 : lock_buffer(bh);
469 0 : memset(bh->b_data, 0, blocksize);
470 0 : branch[n].p = (__le32 *) bh->b_data + offsets[n];
471 0 : branch[n].key = cpu_to_le32(new_blocks[n]);
472 0 : *branch[n].p = branch[n].key;
473 0 : if ( n == indirect_blks) {
474 0 : current_block = new_blocks[n];
475 : /*
476 : * End of chain, update the last new metablock of
477 : * the chain to point to the new allocated
478 : * data blocks numbers
479 : */
480 0 : for (i=1; i < num; i++)
481 0 : *(branch[n].p + i) = cpu_to_le32(++current_block);
482 0 : }
483 0 : set_buffer_uptodate(bh);
484 0 : unlock_buffer(bh);
485 0 : mark_buffer_dirty_inode(bh, inode);
486 : /* We used to sync bh here if IS_SYNC(inode).
487 : * But we now rely upon generic_write_sync()
488 : * and b_inode_buffers. But not for directories.
489 : */
490 0 : if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
491 0 : sync_dirty_buffer(bh);
492 : }
493 0 : *blks = num;
494 0 : return err;
495 : }
496 :
497 : /**
498 : * ext2_splice_branch - splice the allocated branch onto inode.
499 : * @inode: owner
500 : * @block: (logical) number of block we are adding
501 : * @where: location of missing link
502 : * @num: number of indirect blocks we are adding
503 : * @blks: number of direct blocks we are adding
504 : *
505 : * This function fills the missing link and does all housekeeping needed in
506 : * inode (->i_blocks, etc.). In case of success we end up with the full
507 : * chain to new block and return 0.
508 : */
509 : static void ext2_splice_branch(struct inode *inode,
510 : long block, Indirect *where, int num, int blks)
511 : {
512 0 : int i;
513 0 : struct ext2_block_alloc_info *block_i;
514 0 : ext2_fsblk_t current_block;
515 0 :
516 0 : block_i = EXT2_I(inode)->i_block_alloc_info;
517 0 :
518 0 : /* XXX LOCKING probably should have i_meta_lock ?*/
519 : /* That's it */
520 :
521 0 : *where->p = where->key;
522 :
523 : /*
524 : * Update the host buffer_head or inode to point to more just allocated
525 : * direct blocks blocks
526 : */
527 0 : if (num == 0 && blks > 1) {
528 0 : current_block = le32_to_cpu(where->key) + 1;
529 0 : for (i = 1; i < blks; i++)
530 0 : *(where->p + i ) = cpu_to_le32(current_block++);
531 0 : }
532 :
533 : /*
534 : * update the most recently allocated logical & physical block
535 : * in i_block_alloc_info, to assist find the proper goal block for next
536 : * allocation
537 : */
538 0 : if (block_i) {
539 0 : block_i->last_alloc_logical_block = block + blks - 1;
540 0 : block_i->last_alloc_physical_block =
541 : le32_to_cpu(where[num].key) + blks - 1;
542 : }
543 :
544 : /* We are done with atomic stuff, now do the rest of housekeeping */
545 :
546 : /* had we spliced it onto indirect block? */
547 0 : if (where->bh)
548 0 : mark_buffer_dirty_inode(where->bh, inode);
549 :
550 0 : inode->i_ctime = CURRENT_TIME_SEC;
551 0 : mark_inode_dirty(inode);
552 0 : }
553 :
554 : /*
555 : * Allocation strategy is simple: if we have to allocate something, we will
556 : * have to go the whole way to leaf. So let's do it before attaching anything
557 : * to tree, set linkage between the newborn blocks, write them if sync is
558 : * required, recheck the path, free and repeat if check fails, otherwise
559 : * set the last missing link (that will protect us from any truncate-generated
560 : * removals - all blocks on the path are immune now) and possibly force the
561 : * write on the parent block.
562 : * That has a nice additional property: no special recovery from the failed
563 : * allocations is needed - we simply release blocks and do not touch anything
564 : * reachable from inode.
565 : *
566 : * `handle' can be NULL if create == 0.
567 : *
568 : * return > 0, # of blocks mapped or allocated.
569 : * return = 0, if plain lookup failed.
570 : * return < 0, error case.
571 : */
572 : static int ext2_get_blocks(struct inode *inode,
573 : sector_t iblock, unsigned long maxblocks,
574 : struct buffer_head *bh_result,
575 0 : int create)
576 0 : {
577 0 : int err = -EIO;
578 0 : int offsets[4];
579 0 : Indirect chain[4];
580 0 : Indirect *partial;
581 0 : ext2_fsblk_t goal;
582 0 : int indirect_blks;
583 0 : int blocks_to_boundary = 0;
584 0 : int depth;
585 0 : struct ext2_inode_info *ei = EXT2_I(inode);
586 0 : int count = 0;
587 0 : ext2_fsblk_t first_block = 0;
588 0 :
589 0 : depth = ext2_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
590 :
591 0 : if (depth == 0)
592 0 : return (err);
593 :
594 0 : partial = ext2_get_branch(inode, depth, offsets, chain, &err);
595 : /* Simplest case - block found, no allocation needed */
596 0 : if (!partial) {
597 0 : first_block = le32_to_cpu(chain[depth - 1].key);
598 0 : clear_buffer_new(bh_result); /* What's this do? */
599 0 : count++;
600 : /*map more blocks*/
601 0 : while (count < maxblocks && count <= blocks_to_boundary) {
602 0 : ext2_fsblk_t blk;
603 0 :
604 0 : if (!verify_chain(chain, chain + depth - 1)) {
605 : /*
606 : * Indirect block might be removed by
607 0 : * truncate while we were reading it.
608 : * Handling of that case: forget what we've
609 : * got now, go to reread.
610 : */
611 0 : err = -EAGAIN;
612 0 : count = 0;
613 0 : break;
614 : }
615 0 : blk = le32_to_cpu(*(chain[depth-1].p + count));
616 0 : if (blk == first_block + count)
617 0 : count++;
618 : else
619 0 : break;
620 : }
621 0 : if (err != -EAGAIN)
622 0 : goto got_it;
623 : }
624 :
625 : /* Next simple case - plain lookup or failed read of indirect block */
626 0 : if (!create || err == -EIO)
627 0 : goto cleanup;
628 :
629 0 : mutex_lock(&ei->truncate_mutex);
630 : /*
631 : * If the indirect block is missing while we are reading
632 : * the chain(ext3_get_branch() returns -EAGAIN err), or
633 : * if the chain has been changed after we grab the semaphore,
634 : * (either because another process truncated this branch, or
635 : * another get_block allocated this branch) re-grab the chain to see if
636 : * the request block has been allocated or not.
637 : *
638 : * Since we already block the truncate/other get_block
639 : * at this point, we will have the current copy of the chain when we
640 : * splice the branch into the tree.
641 : */
642 0 : if (err == -EAGAIN || !verify_chain(chain, partial)) {
643 0 : while (partial > chain) {
644 0 : brelse(partial->bh);
645 0 : partial--;
646 : }
647 0 : partial = ext2_get_branch(inode, depth, offsets, chain, &err);
648 0 : if (!partial) {
649 0 : count++;
650 0 : mutex_unlock(&ei->truncate_mutex);
651 0 : if (err)
652 0 : goto cleanup;
653 0 : clear_buffer_new(bh_result);
654 0 : goto got_it;
655 : }
656 : }
657 :
658 : /*
659 : * Okay, we need to do block allocation. Lazily initialize the block
660 : * allocation info here if necessary
661 : */
662 0 : if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
663 0 : ext2_init_block_alloc_info(inode);
664 :
665 0 : goal = ext2_find_goal(inode, iblock, partial);
666 :
667 : /* the number of blocks need to allocate for [d,t]indirect blocks */
668 0 : indirect_blks = (chain + depth) - partial - 1;
669 : /*
670 : * Next look up the indirect map to count the totoal number of
671 : * direct blocks to allocate for this branch.
672 : */
673 0 : count = ext2_blks_to_allocate(partial, indirect_blks,
674 : maxblocks, blocks_to_boundary);
675 : /*
676 : * XXX ???? Block out ext2_truncate while we alter the tree
677 : */
678 0 : err = ext2_alloc_branch(inode, indirect_blks, &count, goal,
679 : offsets + (partial - chain), partial);
680 :
681 0 : if (err) {
682 0 : mutex_unlock(&ei->truncate_mutex);
683 0 : goto cleanup;
684 : }
685 :
686 : if (ext2_use_xip(inode->i_sb)) {
687 : /*
688 : * we need to clear the block
689 : */
690 : err = ext2_clear_xip_target (inode,
691 : le32_to_cpu(chain[depth-1].key));
692 : if (err) {
693 : mutex_unlock(&ei->truncate_mutex);
694 : goto cleanup;
695 : }
696 : }
697 :
698 0 : ext2_splice_branch(inode, iblock, partial, indirect_blks, count);
699 0 : mutex_unlock(&ei->truncate_mutex);
700 0 : set_buffer_new(bh_result);
701 : got_it:
702 0 : map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
703 0 : if (count > blocks_to_boundary)
704 0 : set_buffer_boundary(bh_result);
705 0 : err = count;
706 : /* Clean up and exit */
707 0 : partial = chain + depth - 1; /* the whole chain */
708 0 : cleanup:
709 0 : while (partial > chain) {
710 0 : brelse(partial->bh);
711 0 : partial--;
712 : }
713 0 : return err;
714 : }
715 :
716 : int ext2_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
717 : {
718 0 : unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
719 0 : int ret = ext2_get_blocks(inode, iblock, max_blocks,
720 0 : bh_result, create);
721 0 : if (ret > 0) {
722 0 : bh_result->b_size = (ret << inode->i_blkbits);
723 0 : ret = 0;
724 : }
725 0 : return ret;
726 :
727 : }
728 :
729 : int ext2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
730 : u64 start, u64 len)
731 : {
732 12 : return generic_block_fiemap(inode, fieinfo, start, len,
733 : ext2_get_block);
734 : }
735 :
736 : static int ext2_writepage(struct page *page, struct writeback_control *wbc)
737 : {
738 3 : return block_write_full_page(page, ext2_get_block, wbc);
739 : }
740 :
741 : static int ext2_readpage(struct file *file, struct page *page)
742 : {
743 3 : return mpage_readpage(page, ext2_get_block);
744 : }
745 :
746 : static int
747 : ext2_readpages(struct file *file, struct address_space *mapping,
748 : struct list_head *pages, unsigned nr_pages)
749 : {
750 3 : return mpage_readpages(mapping, pages, nr_pages, ext2_get_block);
751 : }
752 :
753 : int __ext2_write_begin(struct file *file, struct address_space *mapping,
754 : loff_t pos, unsigned len, unsigned flags,
755 : struct page **pagep, void **fsdata)
756 : {
757 159 : return block_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
758 : ext2_get_block);
759 : }
760 :
761 : static int
762 : ext2_write_begin(struct file *file, struct address_space *mapping,
763 : loff_t pos, unsigned len, unsigned flags,
764 : struct page **pagep, void **fsdata)
765 : {
766 2 : *pagep = NULL;
767 3 : return __ext2_write_begin(file, mapping, pos, len, flags, pagep,fsdata);
768 : }
769 :
770 : static int
771 : ext2_nobh_write_begin(struct file *file, struct address_space *mapping,
772 : loff_t pos, unsigned len, unsigned flags,
773 : struct page **pagep, void **fsdata)
774 : {
775 0 : /*
776 : * Dir-in-pagecache still uses ext2_write_begin. Would have to rework
777 : * directory handling code to pass around offsets rather than struct
778 : * pages in order to make this work easily.
779 : */
780 0 : return nobh_write_begin(file, mapping, pos, len, flags, pagep, fsdata,
781 : ext2_get_block);
782 : }
783 :
784 : static int ext2_nobh_writepage(struct page *page,
785 : struct writeback_control *wbc)
786 0 : {
787 0 : return nobh_writepage(page, ext2_get_block, wbc);
788 : }
789 :
790 : static sector_t ext2_bmap(struct address_space *mapping, sector_t block)
791 : {
792 3 : return generic_block_bmap(mapping,block,ext2_get_block);
793 : }
794 :
795 : static ssize_t
796 : ext2_direct_IO(int rw, struct kiocb *iocb, const struct iovec *iov,
797 : loff_t offset, unsigned long nr_segs)
798 : {
799 2 : struct file *file = iocb->ki_filp;
800 2 : struct inode *inode = file->f_mapping->host;
801 1 :
802 3 : return blockdev_direct_IO(rw, iocb, inode, inode->i_sb->s_bdev, iov,
803 : offset, nr_segs, ext2_get_block, NULL);
804 : }
805 :
806 : static int
807 : ext2_writepages(struct address_space *mapping, struct writeback_control *wbc)
808 : {
809 3 : return mpage_writepages(mapping, wbc, ext2_get_block);
810 : }
811 :
812 1 : const struct address_space_operations ext2_aops = {
813 : .readpage = ext2_readpage,
814 : .readpages = ext2_readpages,
815 : .writepage = ext2_writepage,
816 : .sync_page = block_sync_page,
817 : .write_begin = ext2_write_begin,
818 : .write_end = generic_write_end,
819 : .bmap = ext2_bmap,
820 : .direct_IO = ext2_direct_IO,
821 : .writepages = ext2_writepages,
822 : .migratepage = buffer_migrate_page,
823 : .is_partially_uptodate = block_is_partially_uptodate,
824 : .error_remove_page = generic_error_remove_page,
825 : };
826 :
827 1 : const struct address_space_operations ext2_aops_xip = {
828 : .bmap = ext2_bmap,
829 : .get_xip_mem = ext2_get_xip_mem,
830 : };
831 :
832 1 : const struct address_space_operations ext2_nobh_aops = {
833 : .readpage = ext2_readpage,
834 : .readpages = ext2_readpages,
835 : .writepage = ext2_nobh_writepage,
836 : .sync_page = block_sync_page,
837 : .write_begin = ext2_nobh_write_begin,
838 : .write_end = nobh_write_end,
839 : .bmap = ext2_bmap,
840 : .direct_IO = ext2_direct_IO,
841 : .writepages = ext2_writepages,
842 : .migratepage = buffer_migrate_page,
843 : .error_remove_page = generic_error_remove_page,
844 : };
845 :
846 : /*
847 : * Probably it should be a library function... search for first non-zero word
848 : * or memcmp with zero_page, whatever is better for particular architecture.
849 : * Linus?
850 : */
851 : static inline int all_zeroes(__le32 *p, __le32 *q)
852 : {
853 20 : while (p < q)
854 25 : if (*p++)
855 10 : return 0;
856 5 : return 1;
857 : }
858 :
859 5 : /**
860 : * ext2_find_shared - find the indirect blocks for partial truncation.
861 : * @inode: inode in question
862 : * @depth: depth of the affected branch
863 : * @offsets: offsets of pointers in that branch (see ext2_block_to_path)
864 : * @chain: place to store the pointers to partial indirect blocks
865 : * @top: place to the (detached) top of branch
866 : *
867 : * This is a helper function used by ext2_truncate().
868 : *
869 : * When we do truncate() we may have to clean the ends of several indirect
870 : * blocks but leave the blocks themselves alive. Block is partially
871 : * truncated if some data below the new i_size is refered from it (and
872 : * it is on the path to the first completely truncated data block, indeed).
873 : * We have to free the top of that path along with everything to the right
874 : * of the path. Since no allocation past the truncation point is possible
875 : * until ext2_truncate() finishes, we may safely do the latter, but top
876 : * of branch may require special attention - pageout below the truncation
877 : * point might try to populate it.
878 : *
879 : * We atomically detach the top of branch from the tree, store the block
880 : * number of its root in *@top, pointers to buffer_heads of partially
881 : * truncated blocks - in @chain[].bh and pointers to their last elements
882 : * that should not be removed - in @chain[].p. Return value is the pointer
883 : * to last filled element of @chain.
884 : *
885 : * The work left to caller to do the actual freeing of subtrees:
886 : * a) free the subtree starting from *@top
887 : * b) free the subtrees whose roots are stored in
888 : * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
889 : * c) free the subtrees growing from the inode past the @chain[0].p
890 : * (no partially truncated stuff there).
891 : */
892 :
893 : static Indirect *ext2_find_shared(struct inode *inode,
894 : int depth,
895 : int offsets[4],
896 5 : Indirect chain[4],
897 5 : __le32 *top)
898 5 : {
899 5 : Indirect *partial, *p;
900 5 : int k, err;
901 5 :
902 10 : *top = 0;
903 40 : for (k = depth; k > 1 && !offsets[k-1]; k--)
904 10 : ;
905 35 : partial = ext2_get_branch(inode, k, offsets, chain, &err);
906 10 : if (!partial)
907 5 : partial = chain + k-1;
908 : /*
909 : * If the branch acquired continuation since we've looked at it -
910 : * fine, it should all survive and (new) top doesn't belong to us.
911 : */
912 15 : write_lock(&EXT2_I(inode)->i_meta_lock);
913 20 : if (!partial->key && *partial->p) {
914 20 : write_unlock(&EXT2_I(inode)->i_meta_lock);
915 5 : goto no_top;
916 : }
917 50 : for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
918 10 : ;
919 5 : /*
920 : * OK, we've found the last block that must survive. The rest of our
921 : * branch should be detached before unlocking. However, if that rest
922 5 : * of branch is all ours and does not grow immediately from the inode
923 : * it's easier to cheat and just decrement partial->p.
924 : */
925 40 : if (p == chain + k - 1 && p > chain) {
926 10 : p->p--;
927 5 : } else {
928 10 : *top = *p->p;
929 10 : *p->p = 0;
930 : }
931 30 : write_unlock(&EXT2_I(inode)->i_meta_lock);
932 :
933 15 : while(partial > p)
934 5 : {
935 15 : brelse(partial->bh);
936 5 : partial--;
937 : }
938 5 : no_top:
939 10 : return partial;
940 5 : }
941 :
942 : /**
943 : * ext2_free_data - free a list of data blocks
944 : * @inode: inode we are dealing with
945 : * @p: array of block numbers
946 : * @q: points immediately past the end of array
947 : *
948 : * We are freeing all blocks refered from that array (numbers are
949 : * stored as little-endian 32-bit) and updating @inode->i_blocks
950 : * appropriately.
951 : */
952 : static inline void ext2_free_data(struct inode *inode, __le32 *p, __le32 *q)
953 : {
954 105 : unsigned long block_to_free = 0, count = 0;
955 35 : unsigned long nr;
956 35 :
957 175 : for ( ; p < q ; p++) {
958 140 : nr = le32_to_cpu(*p);
959 105 : if (nr) {
960 35 : *p = 0;
961 : /* accumulate blocks to free if they're contiguous */
962 70 : if (count == 0)
963 35 : goto free_this;
964 70 : else if (block_to_free == nr - count)
965 35 : count++;
966 : else {
967 70 : mark_inode_dirty(inode);
968 70 : ext2_free_blocks (inode, block_to_free, count);
969 : free_this:
970 105 : block_to_free = nr;
971 70 : count = 1;
972 : }
973 : }
974 : }
975 70 : if (count > 0) {
976 70 : mark_inode_dirty(inode);
977 70 : ext2_free_blocks (inode, block_to_free, count);
978 : }
979 70 : }
980 :
981 : /**
982 : * ext2_free_branches - free an array of branches
983 : * @inode: inode we are dealing with
984 : * @p: array of block numbers
985 : * @q: pointer immediately past the end of array
986 : * @depth: depth of the branches to free
987 : *
988 : * We are freeing all blocks refered from these branches (numbers are
989 : * stored as little-endian 32-bit) and updating @inode->i_blocks
990 : * appropriately.
991 : */
992 : static void ext2_free_branches(struct inode *inode, __le32 *p, __le32 *q, int depth)
993 : {
994 30 : struct buffer_head * bh;
995 30 : unsigned long nr;
996 30 :
997 150 : if (depth--) {
998 30 : int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
999 180 : for ( ; p < q ; p++) {
1000 150 : nr = le32_to_cpu(*p);
1001 90 : if (!nr)
1002 30 : continue;
1003 30 : *p = 0;
1004 60 : bh = sb_bread(inode->i_sb, nr);
1005 : /*
1006 : * A read failure? Report error and clear slot
1007 : * (should be rare).
1008 : */
1009 60 : if (!bh) {
1010 90 : ext2_error(inode->i_sb, "ext2_free_branches",
1011 : "Read failure, inode=%ld, block=%ld",
1012 : inode->i_ino, nr);
1013 30 : continue;
1014 : }
1015 60 : ext2_free_branches(inode,
1016 : (__le32*)bh->b_data,
1017 : (__le32*)bh->b_data + addr_per_block,
1018 : depth);
1019 60 : bforget(bh);
1020 60 : ext2_free_blocks(inode, nr, 1);
1021 60 : mark_inode_dirty(inode);
1022 : }
1023 30 : } else
1024 90 : ext2_free_data(inode, p, q);
1025 60 : }
1026 :
1027 : void ext2_truncate(struct inode *inode)
1028 : {
1029 20 : __le32 *i_data = EXT2_I(inode)->i_data;
1030 20 : struct ext2_inode_info *ei = EXT2_I(inode);
1031 10 : int addr_per_block = EXT2_ADDR_PER_BLOCK(inode->i_sb);
1032 5 : int offsets[4];
1033 5 : Indirect chain[4];
1034 5 : Indirect *partial;
1035 10 : __le32 nr = 0;
1036 5 : int n;
1037 5 : long iblock;
1038 5 : unsigned blocksize;
1039 5 :
1040 50 : if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1041 5 : S_ISLNK(inode->i_mode)))
1042 10 : return;
1043 25 : if (ext2_inode_is_fast_symlink(inode))
1044 10 : return;
1045 15 : if (IS_APPEND(inode) || IS_IMMUTABLE(inode))
1046 10 : return;
1047 :
1048 10 : blocksize = inode->i_sb->s_blocksize;
1049 10 : iblock = (inode->i_size + blocksize-1)
1050 : >> EXT2_BLOCK_SIZE_BITS(inode->i_sb);
1051 :
1052 : if (mapping_is_xip(inode->i_mapping))
1053 : xip_truncate_page(inode->i_mapping, inode->i_size);
1054 20 : else if (test_opt(inode->i_sb, NOBH))
1055 5 : nobh_truncate_page(inode->i_mapping,
1056 : inode->i_size, ext2_get_block);
1057 : else
1058 5 : block_truncate_page(inode->i_mapping,
1059 : inode->i_size, ext2_get_block);
1060 :
1061 20 : n = ext2_block_to_path(inode, iblock, offsets, NULL);
1062 10 : if (n == 0)
1063 5 : return;
1064 :
1065 : /*
1066 : * From here we block out all ext2_get_block() callers who want to
1067 : * modify the block allocation tree.
1068 : */
1069 5 : mutex_lock(&ei->truncate_mutex);
1070 :
1071 10 : if (n == 1) {
1072 15 : ext2_free_data(inode, i_data+offsets[0],
1073 : i_data + EXT2_NDIR_BLOCKS);
1074 5 : goto do_indirects;
1075 : }
1076 :
1077 15 : partial = ext2_find_shared(inode, n, offsets, chain, &nr);
1078 : /* Kill the top of shared branch (already detached) */
1079 10 : if (nr) {
1080 10 : if (partial == chain)
1081 10 : mark_inode_dirty(inode);
1082 : else
1083 5 : mark_buffer_dirty_inode(partial->bh, inode);
1084 30 : ext2_free_branches(inode, &nr, &nr+1, (chain+n-1) - partial);
1085 : }
1086 : /* Clear the ends of indirect blocks on the shared branch */
1087 20 : while (partial > chain) {
1088 20 : ext2_free_branches(inode,
1089 5 : partial->p + 1,
1090 : (__le32*)partial->bh->b_data+addr_per_block,
1091 : (chain+n-1) - partial);
1092 5 : mark_buffer_dirty_inode(partial->bh, inode);
1093 10 : brelse (partial->bh);
1094 10 : partial--;
1095 : }
1096 5 : do_indirects:
1097 : /* Kill the remaining (whole) subtrees */
1098 : switch (offsets[0]) {
1099 10 : default:
1100 20 : nr = i_data[EXT2_IND_BLOCK];
1101 20 : if (nr) {
1102 10 : i_data[EXT2_IND_BLOCK] = 0;
1103 20 : mark_inode_dirty(inode);
1104 15 : ext2_free_branches(inode, &nr, &nr+1, 1);
1105 : }
1106 30 : case EXT2_IND_BLOCK:
1107 15 : nr = i_data[EXT2_DIND_BLOCK];
1108 30 : if (nr) {
1109 30 : i_data[EXT2_DIND_BLOCK] = 0;
1110 30 : mark_inode_dirty(inode);
1111 15 : ext2_free_branches(inode, &nr, &nr+1, 2);
1112 : }
1113 30 : case EXT2_DIND_BLOCK:
1114 20 : nr = i_data[EXT2_TIND_BLOCK];
1115 40 : if (nr) {
1116 40 : i_data[EXT2_TIND_BLOCK] = 0;
1117 40 : mark_inode_dirty(inode);
1118 15 : ext2_free_branches(inode, &nr, &nr+1, 3);
1119 : }
1120 30 : case EXT2_TIND_BLOCK:
1121 : ;
1122 : }
1123 25 :
1124 125 : ext2_discard_reservation(inode);
1125 :
1126 5 : mutex_unlock(&ei->truncate_mutex);
1127 30 : inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
1128 15 : if (inode_needs_sync(inode)) {
1129 5 : sync_mapping_buffers(inode->i_mapping);
1130 10 : ext2_sync_inode (inode);
1131 : } else {
1132 10 : mark_inode_dirty(inode);
1133 10 : }
1134 : }
1135 :
1136 : static struct ext2_inode *ext2_get_inode(struct super_block *sb, ino_t ino,
1137 : struct buffer_head **p)
1138 7 : {
1139 7 : struct buffer_head * bh;
1140 7 : unsigned long block_group;
1141 7 : unsigned long block;
1142 7 : unsigned long offset;
1143 7 : struct ext2_group_desc * gdp;
1144 7 :
1145 14 : *p = NULL;
1146 112 : if ((ino != EXT2_ROOT_INO && ino < EXT2_FIRST_INO(sb)) ||
1147 7 : ino > le32_to_cpu(EXT2_SB(sb)->s_es->s_inodes_count))
1148 21 : goto Einval;
1149 14 :
1150 21 : block_group = (ino - 1) / EXT2_INODES_PER_GROUP(sb);
1151 28 : gdp = ext2_get_group_desc(sb, block_group, NULL);
1152 14 : if (!gdp)
1153 7 : goto Egdp;
1154 : /*
1155 : * Figure out the offset within the block group inode table
1156 : */
1157 42 : offset = ((ino - 1) % EXT2_INODES_PER_GROUP(sb)) * EXT2_INODE_SIZE(sb);
1158 21 : block = le32_to_cpu(gdp->bg_inode_table) +
1159 : (offset >> EXT2_BLOCK_SIZE_BITS(sb));
1160 28 : if (!(bh = sb_bread(sb, block)))
1161 7 : goto Eio;
1162 :
1163 7 : *p = bh;
1164 7 : offset &= (EXT2_BLOCK_SIZE(sb) - 1);
1165 7 : return (struct ext2_inode *) (bh->b_data + offset);
1166 14 :
1167 : Einval:
1168 42 : ext2_error(sb, "ext2_get_inode", "bad inode number: %lu",
1169 : (unsigned long) ino);
1170 21 : return ERR_PTR(-EINVAL);
1171 7 : Eio:
1172 21 : ext2_error(sb, "ext2_get_inode",
1173 : "unable to read inode block - inode=%lu, block=%lu",
1174 : (unsigned long) ino, block);
1175 7 : Egdp:
1176 35 : return ERR_PTR(-EIO);
1177 : }
1178 :
1179 : void ext2_set_inode_flags(struct inode *inode)
1180 : {
1181 100 : unsigned int flags = EXT2_I(inode)->i_flags;
1182 25 :
1183 25 : inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
1184 50 : if (flags & EXT2_SYNC_FL)
1185 25 : inode->i_flags |= S_SYNC;
1186 50 : if (flags & EXT2_APPEND_FL)
1187 25 : inode->i_flags |= S_APPEND;
1188 50 : if (flags & EXT2_IMMUTABLE_FL)
1189 25 : inode->i_flags |= S_IMMUTABLE;
1190 50 : if (flags & EXT2_NOATIME_FL)
1191 25 : inode->i_flags |= S_NOATIME;
1192 50 : if (flags & EXT2_DIRSYNC_FL)
1193 25 : inode->i_flags |= S_DIRSYNC;
1194 25 : }
1195 :
1196 : /* Propagate flags from i_flags to EXT2_I(inode)->i_flags */
1197 : void ext2_get_inode_flags(struct ext2_inode_info *ei)
1198 : {
1199 16 : unsigned int flags = ei->vfs_inode.i_flags;
1200 :
1201 8 : ei->i_flags &= ~(EXT2_SYNC_FL|EXT2_APPEND_FL|
1202 : EXT2_IMMUTABLE_FL|EXT2_NOATIME_FL|EXT2_DIRSYNC_FL);
1203 16 : if (flags & S_SYNC)
1204 8 : ei->i_flags |= EXT2_SYNC_FL;
1205 16 : if (flags & S_APPEND)
1206 8 : ei->i_flags |= EXT2_APPEND_FL;
1207 16 : if (flags & S_IMMUTABLE)
1208 8 : ei->i_flags |= EXT2_IMMUTABLE_FL;
1209 16 : if (flags & S_NOATIME)
1210 8 : ei->i_flags |= EXT2_NOATIME_FL;
1211 16 : if (flags & S_DIRSYNC)
1212 8 : ei->i_flags |= EXT2_DIRSYNC_FL;
1213 8 : }
1214 :
1215 : struct inode *ext2_iget (struct super_block *sb, unsigned long ino)
1216 : {
1217 5 : struct ext2_inode_info *ei;
1218 5 : struct buffer_head * bh;
1219 5 : struct ext2_inode *raw_inode;
1220 5 : struct inode *inode;
1221 10 : long ret = -EIO;
1222 5 : int n;
1223 5 :
1224 10 : inode = iget_locked(sb, ino);
1225 15 : if (!inode)
1226 20 : return ERR_PTR(-ENOMEM);
1227 15 : if (!(inode->i_state & I_NEW))
1228 10 : return inode;
1229 5 :
1230 15 : ei = EXT2_I(inode);
1231 10 : ei->i_block_alloc_info = NULL;
1232 5 :
1233 25 : raw_inode = ext2_get_inode(inode->i_sb, ino, &bh);
1234 25 : if (IS_ERR(raw_inode)) {
1235 15 : ret = PTR_ERR(raw_inode);
1236 5 : goto bad_inode;
1237 : }
1238 :
1239 5 : inode->i_mode = le16_to_cpu(raw_inode->i_mode);
1240 10 : inode->i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
1241 10 : inode->i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
1242 20 : if (!(test_opt (inode->i_sb, NO_UID32))) {
1243 5 : inode->i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
1244 5 : inode->i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
1245 : }
1246 10 : inode->i_nlink = le16_to_cpu(raw_inode->i_links_count);
1247 10 : inode->i_size = le32_to_cpu(raw_inode->i_size);
1248 10 : inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
1249 10 : inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
1250 10 : inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
1251 25 : inode->i_atime.tv_nsec = inode->i_mtime.tv_nsec = inode->i_ctime.tv_nsec = 0;
1252 5 : ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
1253 : /* We now have enough fields to check if the inode was active or not.
1254 : * This is needed because nfsd might try to access dead inodes
1255 : * the test is that same one that e2fsck uses
1256 : * NeilBrown 1999oct15
1257 : */
1258 35 : if (inode->i_nlink == 0 && (inode->i_mode == 0 || ei->i_dtime)) {
1259 : /* this inode is deleted */
1260 10 : brelse (bh);
1261 5 : ret = -ESTALE;
1262 5 : goto bad_inode;
1263 : }
1264 10 : inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
1265 5 : ei->i_flags = le32_to_cpu(raw_inode->i_flags);
1266 5 : ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
1267 5 : ei->i_frag_no = raw_inode->i_frag;
1268 5 : ei->i_frag_size = raw_inode->i_fsize;
1269 5 : ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
1270 5 : ei->i_dir_acl = 0;
1271 15 : if (S_ISREG(inode->i_mode))
1272 15 : inode->i_size |= ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
1273 : else
1274 5 : ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
1275 5 : ei->i_dtime = 0;
1276 5 : inode->i_generation = le32_to_cpu(raw_inode->i_generation);
1277 5 : ei->i_state = 0;
1278 15 : ei->i_block_group = (ino - 1) / EXT2_INODES_PER_GROUP(inode->i_sb);
1279 5 : ei->i_dir_start_lookup = 0;
1280 :
1281 : /*
1282 : * NOTE! The in-memory inode i_data array is in little-endian order
1283 : * even on big-endian machines: we do NOT byteswap the block numbers!
1284 : */
1285 25 : for (n = 0; n < EXT2_N_BLOCKS; n++)
1286 15 : ei->i_data[n] = raw_inode->i_block[n];
1287 5 :
1288 15 : if (S_ISREG(inode->i_mode)) {
1289 5 : inode->i_op = &ext2_file_inode_operations;
1290 : if (ext2_use_xip(inode->i_sb)) {
1291 : inode->i_mapping->a_ops = &ext2_aops_xip;
1292 : inode->i_fop = &ext2_xip_file_operations;
1293 20 : } else if (test_opt(inode->i_sb, NOBH)) {
1294 5 : inode->i_mapping->a_ops = &ext2_nobh_aops;
1295 5 : inode->i_fop = &ext2_file_operations;
1296 : } else {
1297 5 : inode->i_mapping->a_ops = &ext2_aops;
1298 5 : inode->i_fop = &ext2_file_operations;
1299 : }
1300 15 : } else if (S_ISDIR(inode->i_mode)) {
1301 5 : inode->i_op = &ext2_dir_inode_operations;
1302 5 : inode->i_fop = &ext2_dir_operations;
1303 20 : if (test_opt(inode->i_sb, NOBH))
1304 5 : inode->i_mapping->a_ops = &ext2_nobh_aops;
1305 : else
1306 5 : inode->i_mapping->a_ops = &ext2_aops;
1307 15 : } else if (S_ISLNK(inode->i_mode)) {
1308 20 : if (ext2_inode_is_fast_symlink(inode)) {
1309 5 : inode->i_op = &ext2_fast_symlink_inode_operations;
1310 15 : nd_terminate_link(ei->i_data, inode->i_size,
1311 : sizeof(ei->i_data) - 1);
1312 : } else {
1313 5 : inode->i_op = &ext2_symlink_inode_operations;
1314 20 : if (test_opt(inode->i_sb, NOBH))
1315 5 : inode->i_mapping->a_ops = &ext2_nobh_aops;
1316 : else
1317 5 : inode->i_mapping->a_ops = &ext2_aops;
1318 : }
1319 : } else {
1320 5 : inode->i_op = &ext2_special_inode_operations;
1321 10 : if (raw_inode->i_block[0])
1322 20 : init_special_inode(inode, inode->i_mode,
1323 : old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
1324 : else
1325 20 : init_special_inode(inode, inode->i_mode,
1326 : new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
1327 : }
1328 60 : brelse (bh);
1329 10 : ext2_set_inode_flags(inode);
1330 5 : unlock_new_inode(inode);
1331 5 : return inode;
1332 10 :
1333 : bad_inode:
1334 10 : iget_failed(inode);
1335 25 : return ERR_PTR(ret);
1336 : }
1337 :
1338 : int ext2_write_inode(struct inode *inode, int do_sync)
1339 : {
1340 8 : struct ext2_inode_info *ei = EXT2_I(inode);
1341 4 : struct super_block *sb = inode->i_sb;
1342 4 : ino_t ino = inode->i_ino;
1343 4 : uid_t uid = inode->i_uid;
1344 4 : gid_t gid = inode->i_gid;
1345 2 : struct buffer_head * bh;
1346 12 : struct ext2_inode * raw_inode = ext2_get_inode(sb, ino, &bh);
1347 2 : int n;
1348 4 : int err = 0;
1349 2 :
1350 10 : if (IS_ERR(raw_inode))
1351 4 : return -EIO;
1352 2 :
1353 2 : /* For fields not not tracking in the in-memory inode,
1354 2 : * initialise them to zero for new inodes. */
1355 8 : if (ei->i_state & EXT2_STATE_NEW)
1356 10 : memset(raw_inode, 0, EXT2_SB(sb)->s_inode_size);
1357 2 :
1358 10 : ext2_get_inode_flags(ei);
1359 4 : raw_inode->i_mode = cpu_to_le16(inode->i_mode);
1360 10 : if (!(test_opt(sb, NO_UID32))) {
1361 2 : raw_inode->i_uid_low = cpu_to_le16(low_16_bits(uid));
1362 2 : raw_inode->i_gid_low = cpu_to_le16(low_16_bits(gid));
1363 : /*
1364 : * Fix up interoperability with old kernels. Otherwise, old inodes get
1365 : * re-used with the upper 16 bits of the uid/gid intact
1366 : */
1367 4 : if (!ei->i_dtime) {
1368 2 : raw_inode->i_uid_high = cpu_to_le16(high_16_bits(uid));
1369 2 : raw_inode->i_gid_high = cpu_to_le16(high_16_bits(gid));
1370 : } else {
1371 2 : raw_inode->i_uid_high = 0;
1372 2 : raw_inode->i_gid_high = 0;
1373 : }
1374 : } else {
1375 12 : raw_inode->i_uid_low = cpu_to_le16(fs_high2lowuid(uid));
1376 12 : raw_inode->i_gid_low = cpu_to_le16(fs_high2lowgid(gid));
1377 2 : raw_inode->i_uid_high = 0;
1378 2 : raw_inode->i_gid_high = 0;
1379 : }
1380 4 : raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
1381 4 : raw_inode->i_size = cpu_to_le32(inode->i_size);
1382 2 : raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
1383 2 : raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
1384 2 : raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
1385 :
1386 4 : raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
1387 2 : raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
1388 2 : raw_inode->i_flags = cpu_to_le32(ei->i_flags);
1389 2 : raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
1390 2 : raw_inode->i_frag = ei->i_frag_no;
1391 2 : raw_inode->i_fsize = ei->i_frag_size;
1392 2 : raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
1393 6 : if (!S_ISREG(inode->i_mode))
1394 2 : raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
1395 : else {
1396 2 : raw_inode->i_size_high = cpu_to_le32(inode->i_size >> 32);
1397 6 : if (inode->i_size > 0x7fffffffULL) {
1398 18 : if (!EXT2_HAS_RO_COMPAT_FEATURE(sb,
1399 2 : EXT2_FEATURE_RO_COMPAT_LARGE_FILE) ||
1400 : EXT2_SB(sb)->s_es->s_rev_level ==
1401 : cpu_to_le32(EXT2_GOOD_OLD_REV)) {
1402 : /* If this is the first large file
1403 : * created, add a flag to the superblock.
1404 : */
1405 4 : lock_kernel();
1406 12 : ext2_update_dynamic_rev(sb);
1407 6 : EXT2_SET_RO_COMPAT_FEATURE(sb,
1408 : EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
1409 2 : unlock_kernel();
1410 6 : ext2_write_super(sb);
1411 : }
1412 : }
1413 : }
1414 :
1415 6 : raw_inode->i_generation = cpu_to_le32(inode->i_generation);
1416 36 : if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
1417 16 : if (old_valid_dev(inode->i_rdev)) {
1418 6 : raw_inode->i_block[0] =
1419 : cpu_to_le32(old_encode_dev(inode->i_rdev));
1420 2 : raw_inode->i_block[1] = 0;
1421 : } else {
1422 2 : raw_inode->i_block[0] = 0;
1423 4 : raw_inode->i_block[1] =
1424 : cpu_to_le32(new_encode_dev(inode->i_rdev));
1425 2 : raw_inode->i_block[2] = 0;
1426 : }
1427 18 : } else for (n = 0; n < EXT2_N_BLOCKS; n++)
1428 6 : raw_inode->i_block[n] = ei->i_data[n];
1429 8 : mark_buffer_dirty(bh);
1430 12 : if (do_sync) {
1431 6 : sync_dirty_buffer(bh);
1432 24 : if (buffer_req(bh) && !buffer_uptodate(bh)) {
1433 2 : printk ("IO error syncing ext2 inode [%s:%08lx]\n",
1434 : sb->s_id, (unsigned long) ino);
1435 2 : err = -EIO;
1436 : }
1437 : }
1438 20 : ei->i_state &= ~EXT2_STATE_NEW;
1439 20 : brelse (bh);
1440 2 : return err;
1441 : }
1442 :
1443 : int ext2_sync_inode(struct inode *inode)
1444 : {
1445 3961 : struct writeback_control wbc = {
1446 233 : .sync_mode = WB_SYNC_ALL,
1447 : .nr_to_write = 0, /* sys_fsync did this */
1448 : };
1449 466 : return sync_inode(inode, &wbc);
1450 : }
1451 :
1452 : int ext2_setattr(struct dentry *dentry, struct iattr *iattr)
1453 : {
1454 8 : struct inode *inode = dentry->d_inode;
1455 4 : int error;
1456 4 :
1457 4 : error = inode_change_ok(inode, iattr);
1458 8 : if (error)
1459 4 : return error;
1460 32 : if ((iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid) ||
1461 : (iattr->ia_valid & ATTR_GID && iattr->ia_gid != inode->i_gid)) {
1462 32 : error = vfs_dq_transfer(inode, iattr) ? -EDQUOT : 0;
1463 8 : if (error)
1464 4 : return error;
1465 : }
1466 8 : error = inode_setattr(inode, iattr);
1467 40 : if (!error && (iattr->ia_valid & ATTR_MODE))
1468 16 : error = ext2_acl_chmod(inode);
1469 12 : return error;
1470 : }
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