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1 | /* |
2 | * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. |
3 | * Copyright (C) 2004-2006 Red Hat, Inc. All rights reserved. |
4 | * |
5 | * This copyrighted material is made available to anyone wishing to use, |
6 | * modify, copy, or redistribute it subject to the terms and conditions |
7 | * of the GNU General Public License version 2. |
8 | */ |
9 | |
10 | #include <linux/slab.h> |
11 | #include <linux/spinlock.h> |
12 | #include <linux/completion.h> |
13 | #include <linux/buffer_head.h> |
14 | #include <linux/gfs2_ondisk.h> |
15 | #include <linux/crc32.h> |
16 | |
17 | #include "gfs2.h" |
18 | #include "incore.h" |
19 | #include "bmap.h" |
20 | #include "glock.h" |
21 | #include "inode.h" |
22 | #include "meta_io.h" |
23 | #include "quota.h" |
24 | #include "rgrp.h" |
25 | #include "trans.h" |
26 | #include "dir.h" |
27 | #include "util.h" |
28 | #include "trace_gfs2.h" |
29 | |
30 | /* This doesn't need to be that large as max 64 bit pointers in a 4k |
31 | * block is 512, so __u16 is fine for that. It saves stack space to |
32 | * keep it small. |
33 | */ |
34 | struct metapath { |
35 | struct buffer_head *mp_bh[GFS2_MAX_META_HEIGHT]; |
36 | __u16 mp_list[GFS2_MAX_META_HEIGHT]; |
37 | }; |
38 | |
39 | typedef int (*block_call_t) (struct gfs2_inode *ip, struct buffer_head *dibh, |
40 | struct buffer_head *bh, __be64 *top, |
41 | __be64 *bottom, unsigned int height, |
42 | void *data); |
43 | |
44 | struct strip_mine { |
45 | int sm_first; |
46 | unsigned int sm_height; |
47 | }; |
48 | |
49 | /** |
50 | * gfs2_unstuffer_page - unstuff a stuffed inode into a block cached by a page |
51 | * @ip: the inode |
52 | * @dibh: the dinode buffer |
53 | * @block: the block number that was allocated |
54 | * @private: any locked page held by the caller process |
55 | * |
56 | * Returns: errno |
57 | */ |
58 | |
59 | static int gfs2_unstuffer_page(struct gfs2_inode *ip, struct buffer_head *dibh, |
60 | u64 block, struct page *page) |
61 | { |
62 | struct inode *inode = &ip->i_inode; |
63 | struct buffer_head *bh; |
64 | int release = 0; |
65 | |
66 | if (!page || page->index) { |
67 | page = grab_cache_page(inode->i_mapping, 0); |
68 | if (!page) |
69 | return -ENOMEM; |
70 | release = 1; |
71 | } |
72 | |
73 | if (!PageUptodate(page)) { |
74 | void *kaddr = kmap(page); |
75 | |
76 | memcpy(kaddr, dibh->b_data + sizeof(struct gfs2_dinode), |
77 | ip->i_disksize); |
78 | memset(kaddr + ip->i_disksize, 0, |
79 | PAGE_CACHE_SIZE - ip->i_disksize); |
80 | kunmap(page); |
81 | |
82 | SetPageUptodate(page); |
83 | } |
84 | |
85 | if (!page_has_buffers(page)) |
86 | create_empty_buffers(page, 1 << inode->i_blkbits, |
87 | (1 << BH_Uptodate)); |
88 | |
89 | bh = page_buffers(page); |
90 | |
91 | if (!buffer_mapped(bh)) |
92 | map_bh(bh, inode->i_sb, block); |
93 | |
94 | set_buffer_uptodate(bh); |
95 | if (!gfs2_is_jdata(ip)) |
96 | mark_buffer_dirty(bh); |
97 | if (!gfs2_is_writeback(ip)) |
98 | gfs2_trans_add_bh(ip->i_gl, bh, 0); |
99 | |
100 | if (release) { |
101 | unlock_page(page); |
102 | page_cache_release(page); |
103 | } |
104 | |
105 | return 0; |
106 | } |
107 | |
108 | /** |
109 | * gfs2_unstuff_dinode - Unstuff a dinode when the data has grown too big |
110 | * @ip: The GFS2 inode to unstuff |
111 | * @unstuffer: the routine that handles unstuffing a non-zero length file |
112 | * @private: private data for the unstuffer |
113 | * |
114 | * This routine unstuffs a dinode and returns it to a "normal" state such |
115 | * that the height can be grown in the traditional way. |
116 | * |
117 | * Returns: errno |
118 | */ |
119 | |
120 | int gfs2_unstuff_dinode(struct gfs2_inode *ip, struct page *page) |
121 | { |
122 | struct buffer_head *bh, *dibh; |
123 | struct gfs2_dinode *di; |
124 | u64 block = 0; |
125 | int isdir = gfs2_is_dir(ip); |
126 | int error; |
127 | |
128 | down_write(&ip->i_rw_mutex); |
129 | |
130 | error = gfs2_meta_inode_buffer(ip, &dibh); |
131 | if (error) |
132 | goto out; |
133 | |
134 | if (ip->i_disksize) { |
135 | /* Get a free block, fill it with the stuffed data, |
136 | and write it out to disk */ |
137 | |
138 | unsigned int n = 1; |
139 | error = gfs2_alloc_block(ip, &block, &n); |
140 | if (error) |
141 | goto out_brelse; |
142 | if (isdir) { |
143 | gfs2_trans_add_unrevoke(GFS2_SB(&ip->i_inode), block, 1); |
144 | error = gfs2_dir_get_new_buffer(ip, block, &bh); |
145 | if (error) |
146 | goto out_brelse; |
147 | gfs2_buffer_copy_tail(bh, sizeof(struct gfs2_meta_header), |
148 | dibh, sizeof(struct gfs2_dinode)); |
149 | brelse(bh); |
150 | } else { |
151 | error = gfs2_unstuffer_page(ip, dibh, block, page); |
152 | if (error) |
153 | goto out_brelse; |
154 | } |
155 | } |
156 | |
157 | /* Set up the pointer to the new block */ |
158 | |
159 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
160 | di = (struct gfs2_dinode *)dibh->b_data; |
161 | gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); |
162 | |
163 | if (ip->i_disksize) { |
164 | *(__be64 *)(di + 1) = cpu_to_be64(block); |
165 | gfs2_add_inode_blocks(&ip->i_inode, 1); |
166 | di->di_blocks = cpu_to_be64(gfs2_get_inode_blocks(&ip->i_inode)); |
167 | } |
168 | |
169 | ip->i_height = 1; |
170 | di->di_height = cpu_to_be16(1); |
171 | |
172 | out_brelse: |
173 | brelse(dibh); |
174 | out: |
175 | up_write(&ip->i_rw_mutex); |
176 | return error; |
177 | } |
178 | |
179 | |
180 | /** |
181 | * find_metapath - Find path through the metadata tree |
182 | * @sdp: The superblock |
183 | * @mp: The metapath to return the result in |
184 | * @block: The disk block to look up |
185 | * @height: The pre-calculated height of the metadata tree |
186 | * |
187 | * This routine returns a struct metapath structure that defines a path |
188 | * through the metadata of inode "ip" to get to block "block". |
189 | * |
190 | * Example: |
191 | * Given: "ip" is a height 3 file, "offset" is 101342453, and this is a |
192 | * filesystem with a blocksize of 4096. |
193 | * |
194 | * find_metapath() would return a struct metapath structure set to: |
195 | * mp_offset = 101342453, mp_height = 3, mp_list[0] = 0, mp_list[1] = 48, |
196 | * and mp_list[2] = 165. |
197 | * |
198 | * That means that in order to get to the block containing the byte at |
199 | * offset 101342453, we would load the indirect block pointed to by pointer |
200 | * 0 in the dinode. We would then load the indirect block pointed to by |
201 | * pointer 48 in that indirect block. We would then load the data block |
202 | * pointed to by pointer 165 in that indirect block. |
203 | * |
204 | * ---------------------------------------- |
205 | * | Dinode | | |
206 | * | | 4| |
207 | * | |0 1 2 3 4 5 9| |
208 | * | | 6| |
209 | * ---------------------------------------- |
210 | * | |
211 | * | |
212 | * V |
213 | * ---------------------------------------- |
214 | * | Indirect Block | |
215 | * | 5| |
216 | * | 4 4 4 4 4 5 5 1| |
217 | * |0 5 6 7 8 9 0 1 2| |
218 | * ---------------------------------------- |
219 | * | |
220 | * | |
221 | * V |
222 | * ---------------------------------------- |
223 | * | Indirect Block | |
224 | * | 1 1 1 1 1 5| |
225 | * | 6 6 6 6 6 1| |
226 | * |0 3 4 5 6 7 2| |
227 | * ---------------------------------------- |
228 | * | |
229 | * | |
230 | * V |
231 | * ---------------------------------------- |
232 | * | Data block containing offset | |
233 | * | 101342453 | |
234 | * | | |
235 | * | | |
236 | * ---------------------------------------- |
237 | * |
238 | */ |
239 | |
240 | static void find_metapath(const struct gfs2_sbd *sdp, u64 block, |
241 | struct metapath *mp, unsigned int height) |
242 | { |
243 | unsigned int i; |
244 | |
245 | for (i = height; i--;) |
246 | mp->mp_list[i] = do_div(block, sdp->sd_inptrs); |
247 | |
248 | } |
249 | |
250 | static inline unsigned int metapath_branch_start(const struct metapath *mp) |
251 | { |
252 | if (mp->mp_list[0] == 0) |
253 | return 2; |
254 | return 1; |
255 | } |
256 | |
257 | /** |
258 | * metapointer - Return pointer to start of metadata in a buffer |
259 | * @height: The metadata height (0 = dinode) |
260 | * @mp: The metapath |
261 | * |
262 | * Return a pointer to the block number of the next height of the metadata |
263 | * tree given a buffer containing the pointer to the current height of the |
264 | * metadata tree. |
265 | */ |
266 | |
267 | static inline __be64 *metapointer(unsigned int height, const struct metapath *mp) |
268 | { |
269 | struct buffer_head *bh = mp->mp_bh[height]; |
270 | unsigned int head_size = (height > 0) ? |
271 | sizeof(struct gfs2_meta_header) : sizeof(struct gfs2_dinode); |
272 | return ((__be64 *)(bh->b_data + head_size)) + mp->mp_list[height]; |
273 | } |
274 | |
275 | /** |
276 | * lookup_metapath - Walk the metadata tree to a specific point |
277 | * @ip: The inode |
278 | * @mp: The metapath |
279 | * |
280 | * Assumes that the inode's buffer has already been looked up and |
281 | * hooked onto mp->mp_bh[0] and that the metapath has been initialised |
282 | * by find_metapath(). |
283 | * |
284 | * If this function encounters part of the tree which has not been |
285 | * allocated, it returns the current height of the tree at the point |
286 | * at which it found the unallocated block. Blocks which are found are |
287 | * added to the mp->mp_bh[] list. |
288 | * |
289 | * Returns: error or height of metadata tree |
290 | */ |
291 | |
292 | static int lookup_metapath(struct gfs2_inode *ip, struct metapath *mp) |
293 | { |
294 | unsigned int end_of_metadata = ip->i_height - 1; |
295 | unsigned int x; |
296 | __be64 *ptr; |
297 | u64 dblock; |
298 | int ret; |
299 | |
300 | for (x = 0; x < end_of_metadata; x++) { |
301 | ptr = metapointer(x, mp); |
302 | dblock = be64_to_cpu(*ptr); |
303 | if (!dblock) |
304 | return x + 1; |
305 | |
306 | ret = gfs2_meta_indirect_buffer(ip, x+1, dblock, 0, &mp->mp_bh[x+1]); |
307 | if (ret) |
308 | return ret; |
309 | } |
310 | |
311 | return ip->i_height; |
312 | } |
313 | |
314 | static inline void release_metapath(struct metapath *mp) |
315 | { |
316 | int i; |
317 | |
318 | for (i = 0; i < GFS2_MAX_META_HEIGHT; i++) { |
319 | if (mp->mp_bh[i] == NULL) |
320 | break; |
321 | brelse(mp->mp_bh[i]); |
322 | } |
323 | } |
324 | |
325 | /** |
326 | * gfs2_extent_length - Returns length of an extent of blocks |
327 | * @start: Start of the buffer |
328 | * @len: Length of the buffer in bytes |
329 | * @ptr: Current position in the buffer |
330 | * @limit: Max extent length to return (0 = unlimited) |
331 | * @eob: Set to 1 if we hit "end of block" |
332 | * |
333 | * If the first block is zero (unallocated) it will return the number of |
334 | * unallocated blocks in the extent, otherwise it will return the number |
335 | * of contiguous blocks in the extent. |
336 | * |
337 | * Returns: The length of the extent (minimum of one block) |
338 | */ |
339 | |
340 | static inline unsigned int gfs2_extent_length(void *start, unsigned int len, __be64 *ptr, unsigned limit, int *eob) |
341 | { |
342 | const __be64 *end = (start + len); |
343 | const __be64 *first = ptr; |
344 | u64 d = be64_to_cpu(*ptr); |
345 | |
346 | *eob = 0; |
347 | do { |
348 | ptr++; |
349 | if (ptr >= end) |
350 | break; |
351 | if (limit && --limit == 0) |
352 | break; |
353 | if (d) |
354 | d++; |
355 | } while(be64_to_cpu(*ptr) == d); |
356 | if (ptr >= end) |
357 | *eob = 1; |
358 | return (ptr - first); |
359 | } |
360 | |
361 | static inline void bmap_lock(struct gfs2_inode *ip, int create) |
362 | { |
363 | if (create) |
364 | down_write(&ip->i_rw_mutex); |
365 | else |
366 | down_read(&ip->i_rw_mutex); |
367 | } |
368 | |
369 | static inline void bmap_unlock(struct gfs2_inode *ip, int create) |
370 | { |
371 | if (create) |
372 | up_write(&ip->i_rw_mutex); |
373 | else |
374 | up_read(&ip->i_rw_mutex); |
375 | } |
376 | |
377 | static inline __be64 *gfs2_indirect_init(struct metapath *mp, |
378 | struct gfs2_glock *gl, unsigned int i, |
379 | unsigned offset, u64 bn) |
380 | { |
381 | __be64 *ptr = (__be64 *)(mp->mp_bh[i - 1]->b_data + |
382 | ((i > 1) ? sizeof(struct gfs2_meta_header) : |
383 | sizeof(struct gfs2_dinode))); |
384 | BUG_ON(i < 1); |
385 | BUG_ON(mp->mp_bh[i] != NULL); |
386 | mp->mp_bh[i] = gfs2_meta_new(gl, bn); |
387 | gfs2_trans_add_bh(gl, mp->mp_bh[i], 1); |
388 | gfs2_metatype_set(mp->mp_bh[i], GFS2_METATYPE_IN, GFS2_FORMAT_IN); |
389 | gfs2_buffer_clear_tail(mp->mp_bh[i], sizeof(struct gfs2_meta_header)); |
390 | ptr += offset; |
391 | *ptr = cpu_to_be64(bn); |
392 | return ptr; |
393 | } |
394 | |
395 | enum alloc_state { |
396 | ALLOC_DATA = 0, |
397 | ALLOC_GROW_DEPTH = 1, |
398 | ALLOC_GROW_HEIGHT = 2, |
399 | /* ALLOC_UNSTUFF = 3, TBD and rather complicated */ |
400 | }; |
401 | |
402 | /** |
403 | * gfs2_bmap_alloc - Build a metadata tree of the requested height |
404 | * @inode: The GFS2 inode |
405 | * @lblock: The logical starting block of the extent |
406 | * @bh_map: This is used to return the mapping details |
407 | * @mp: The metapath |
408 | * @sheight: The starting height (i.e. whats already mapped) |
409 | * @height: The height to build to |
410 | * @maxlen: The max number of data blocks to alloc |
411 | * |
412 | * In this routine we may have to alloc: |
413 | * i) Indirect blocks to grow the metadata tree height |
414 | * ii) Indirect blocks to fill in lower part of the metadata tree |
415 | * iii) Data blocks |
416 | * |
417 | * The function is in two parts. The first part works out the total |
418 | * number of blocks which we need. The second part does the actual |
419 | * allocation asking for an extent at a time (if enough contiguous free |
420 | * blocks are available, there will only be one request per bmap call) |
421 | * and uses the state machine to initialise the blocks in order. |
422 | * |
423 | * Returns: errno on error |
424 | */ |
425 | |
426 | static int gfs2_bmap_alloc(struct inode *inode, const sector_t lblock, |
427 | struct buffer_head *bh_map, struct metapath *mp, |
428 | const unsigned int sheight, |
429 | const unsigned int height, |
430 | const unsigned int maxlen) |
431 | { |
432 | struct gfs2_inode *ip = GFS2_I(inode); |
433 | struct gfs2_sbd *sdp = GFS2_SB(inode); |
434 | struct buffer_head *dibh = mp->mp_bh[0]; |
435 | u64 bn, dblock = 0; |
436 | unsigned n, i, blks, alloced = 0, iblks = 0, branch_start = 0; |
437 | unsigned dblks = 0; |
438 | unsigned ptrs_per_blk; |
439 | const unsigned end_of_metadata = height - 1; |
440 | int eob = 0; |
441 | enum alloc_state state; |
442 | __be64 *ptr; |
443 | __be64 zero_bn = 0; |
444 | |
445 | BUG_ON(sheight < 1); |
446 | BUG_ON(dibh == NULL); |
447 | |
448 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
449 | |
450 | if (height == sheight) { |
451 | struct buffer_head *bh; |
452 | /* Bottom indirect block exists, find unalloced extent size */ |
453 | ptr = metapointer(end_of_metadata, mp); |
454 | bh = mp->mp_bh[end_of_metadata]; |
455 | dblks = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, |
456 | &eob); |
457 | BUG_ON(dblks < 1); |
458 | state = ALLOC_DATA; |
459 | } else { |
460 | /* Need to allocate indirect blocks */ |
461 | ptrs_per_blk = height > 1 ? sdp->sd_inptrs : sdp->sd_diptrs; |
462 | dblks = min(maxlen, ptrs_per_blk - mp->mp_list[end_of_metadata]); |
463 | if (height == ip->i_height) { |
464 | /* Writing into existing tree, extend tree down */ |
465 | iblks = height - sheight; |
466 | state = ALLOC_GROW_DEPTH; |
467 | } else { |
468 | /* Building up tree height */ |
469 | state = ALLOC_GROW_HEIGHT; |
470 | iblks = height - ip->i_height; |
471 | branch_start = metapath_branch_start(mp); |
472 | iblks += (height - branch_start); |
473 | } |
474 | } |
475 | |
476 | /* start of the second part of the function (state machine) */ |
477 | |
478 | blks = dblks + iblks; |
479 | i = sheight; |
480 | do { |
481 | int error; |
482 | n = blks - alloced; |
483 | error = gfs2_alloc_block(ip, &bn, &n); |
484 | if (error) |
485 | return error; |
486 | alloced += n; |
487 | if (state != ALLOC_DATA || gfs2_is_jdata(ip)) |
488 | gfs2_trans_add_unrevoke(sdp, bn, n); |
489 | switch (state) { |
490 | /* Growing height of tree */ |
491 | case ALLOC_GROW_HEIGHT: |
492 | if (i == 1) { |
493 | ptr = (__be64 *)(dibh->b_data + |
494 | sizeof(struct gfs2_dinode)); |
495 | zero_bn = *ptr; |
496 | } |
497 | for (; i - 1 < height - ip->i_height && n > 0; i++, n--) |
498 | gfs2_indirect_init(mp, ip->i_gl, i, 0, bn++); |
499 | if (i - 1 == height - ip->i_height) { |
500 | i--; |
501 | gfs2_buffer_copy_tail(mp->mp_bh[i], |
502 | sizeof(struct gfs2_meta_header), |
503 | dibh, sizeof(struct gfs2_dinode)); |
504 | gfs2_buffer_clear_tail(dibh, |
505 | sizeof(struct gfs2_dinode) + |
506 | sizeof(__be64)); |
507 | ptr = (__be64 *)(mp->mp_bh[i]->b_data + |
508 | sizeof(struct gfs2_meta_header)); |
509 | *ptr = zero_bn; |
510 | state = ALLOC_GROW_DEPTH; |
511 | for(i = branch_start; i < height; i++) { |
512 | if (mp->mp_bh[i] == NULL) |
513 | break; |
514 | brelse(mp->mp_bh[i]); |
515 | mp->mp_bh[i] = NULL; |
516 | } |
517 | i = branch_start; |
518 | } |
519 | if (n == 0) |
520 | break; |
521 | /* Branching from existing tree */ |
522 | case ALLOC_GROW_DEPTH: |
523 | if (i > 1 && i < height) |
524 | gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[i-1], 1); |
525 | for (; i < height && n > 0; i++, n--) |
526 | gfs2_indirect_init(mp, ip->i_gl, i, |
527 | mp->mp_list[i-1], bn++); |
528 | if (i == height) |
529 | state = ALLOC_DATA; |
530 | if (n == 0) |
531 | break; |
532 | /* Tree complete, adding data blocks */ |
533 | case ALLOC_DATA: |
534 | BUG_ON(n > dblks); |
535 | BUG_ON(mp->mp_bh[end_of_metadata] == NULL); |
536 | gfs2_trans_add_bh(ip->i_gl, mp->mp_bh[end_of_metadata], 1); |
537 | dblks = n; |
538 | ptr = metapointer(end_of_metadata, mp); |
539 | dblock = bn; |
540 | while (n-- > 0) |
541 | *ptr++ = cpu_to_be64(bn++); |
542 | break; |
543 | } |
544 | } while (state != ALLOC_DATA); |
545 | |
546 | ip->i_height = height; |
547 | gfs2_add_inode_blocks(&ip->i_inode, alloced); |
548 | gfs2_dinode_out(ip, mp->mp_bh[0]->b_data); |
549 | map_bh(bh_map, inode->i_sb, dblock); |
550 | bh_map->b_size = dblks << inode->i_blkbits; |
551 | set_buffer_new(bh_map); |
552 | return 0; |
553 | } |
554 | |
555 | /** |
556 | * gfs2_block_map - Map a block from an inode to a disk block |
557 | * @inode: The inode |
558 | * @lblock: The logical block number |
559 | * @bh_map: The bh to be mapped |
560 | * @create: True if its ok to alloc blocks to satify the request |
561 | * |
562 | * Sets buffer_mapped() if successful, sets buffer_boundary() if a |
563 | * read of metadata will be required before the next block can be |
564 | * mapped. Sets buffer_new() if new blocks were allocated. |
565 | * |
566 | * Returns: errno |
567 | */ |
568 | |
569 | int gfs2_block_map(struct inode *inode, sector_t lblock, |
570 | struct buffer_head *bh_map, int create) |
571 | { |
572 | struct gfs2_inode *ip = GFS2_I(inode); |
573 | struct gfs2_sbd *sdp = GFS2_SB(inode); |
574 | unsigned int bsize = sdp->sd_sb.sb_bsize; |
575 | const unsigned int maxlen = bh_map->b_size >> inode->i_blkbits; |
576 | const u64 *arr = sdp->sd_heightsize; |
577 | __be64 *ptr; |
578 | u64 size; |
579 | struct metapath mp; |
580 | int ret; |
581 | int eob; |
582 | unsigned int len; |
583 | struct buffer_head *bh; |
584 | u8 height; |
585 | |
586 | BUG_ON(maxlen == 0); |
587 | |
588 | memset(mp.mp_bh, 0, sizeof(mp.mp_bh)); |
589 | bmap_lock(ip, create); |
590 | clear_buffer_mapped(bh_map); |
591 | clear_buffer_new(bh_map); |
592 | clear_buffer_boundary(bh_map); |
593 | trace_gfs2_bmap(ip, bh_map, lblock, create, 1); |
594 | if (gfs2_is_dir(ip)) { |
595 | bsize = sdp->sd_jbsize; |
596 | arr = sdp->sd_jheightsize; |
597 | } |
598 | |
599 | ret = gfs2_meta_inode_buffer(ip, &mp.mp_bh[0]); |
600 | if (ret) |
601 | goto out; |
602 | |
603 | height = ip->i_height; |
604 | size = (lblock + 1) * bsize; |
605 | while (size > arr[height]) |
606 | height++; |
607 | find_metapath(sdp, lblock, &mp, height); |
608 | ret = 1; |
609 | if (height > ip->i_height || gfs2_is_stuffed(ip)) |
610 | goto do_alloc; |
611 | ret = lookup_metapath(ip, &mp); |
612 | if (ret < 0) |
613 | goto out; |
614 | if (ret != ip->i_height) |
615 | goto do_alloc; |
616 | ptr = metapointer(ip->i_height - 1, &mp); |
617 | if (*ptr == 0) |
618 | goto do_alloc; |
619 | map_bh(bh_map, inode->i_sb, be64_to_cpu(*ptr)); |
620 | bh = mp.mp_bh[ip->i_height - 1]; |
621 | len = gfs2_extent_length(bh->b_data, bh->b_size, ptr, maxlen, &eob); |
622 | bh_map->b_size = (len << inode->i_blkbits); |
623 | if (eob) |
624 | set_buffer_boundary(bh_map); |
625 | ret = 0; |
626 | out: |
627 | release_metapath(&mp); |
628 | trace_gfs2_bmap(ip, bh_map, lblock, create, ret); |
629 | bmap_unlock(ip, create); |
630 | return ret; |
631 | |
632 | do_alloc: |
633 | /* All allocations are done here, firstly check create flag */ |
634 | if (!create) { |
635 | BUG_ON(gfs2_is_stuffed(ip)); |
636 | ret = 0; |
637 | goto out; |
638 | } |
639 | |
640 | /* At this point ret is the tree depth of already allocated blocks */ |
641 | ret = gfs2_bmap_alloc(inode, lblock, bh_map, &mp, ret, height, maxlen); |
642 | goto out; |
643 | } |
644 | |
645 | /* |
646 | * Deprecated: do not use in new code |
647 | */ |
648 | int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsigned *extlen) |
649 | { |
650 | struct buffer_head bh = { .b_state = 0, .b_blocknr = 0 }; |
651 | int ret; |
652 | int create = *new; |
653 | |
654 | BUG_ON(!extlen); |
655 | BUG_ON(!dblock); |
656 | BUG_ON(!new); |
657 | |
658 | bh.b_size = 1 << (inode->i_blkbits + (create ? 0 : 5)); |
659 | ret = gfs2_block_map(inode, lblock, &bh, create); |
660 | *extlen = bh.b_size >> inode->i_blkbits; |
661 | *dblock = bh.b_blocknr; |
662 | if (buffer_new(&bh)) |
663 | *new = 1; |
664 | else |
665 | *new = 0; |
666 | return ret; |
667 | } |
668 | |
669 | /** |
670 | * recursive_scan - recursively scan through the end of a file |
671 | * @ip: the inode |
672 | * @dibh: the dinode buffer |
673 | * @mp: the path through the metadata to the point to start |
674 | * @height: the height the recursion is at |
675 | * @block: the indirect block to look at |
676 | * @first: 1 if this is the first block |
677 | * @bc: the call to make for each piece of metadata |
678 | * @data: data opaque to this function to pass to @bc |
679 | * |
680 | * When this is first called @height and @block should be zero and |
681 | * @first should be 1. |
682 | * |
683 | * Returns: errno |
684 | */ |
685 | |
686 | static int recursive_scan(struct gfs2_inode *ip, struct buffer_head *dibh, |
687 | struct metapath *mp, unsigned int height, |
688 | u64 block, int first, block_call_t bc, |
689 | void *data) |
690 | { |
691 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
692 | struct buffer_head *bh = NULL; |
693 | __be64 *top, *bottom; |
694 | u64 bn; |
695 | int error; |
696 | int mh_size = sizeof(struct gfs2_meta_header); |
697 | |
698 | if (!height) { |
699 | error = gfs2_meta_inode_buffer(ip, &bh); |
700 | if (error) |
701 | return error; |
702 | dibh = bh; |
703 | |
704 | top = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + mp->mp_list[0]; |
705 | bottom = (__be64 *)(bh->b_data + sizeof(struct gfs2_dinode)) + sdp->sd_diptrs; |
706 | } else { |
707 | error = gfs2_meta_indirect_buffer(ip, height, block, 0, &bh); |
708 | if (error) |
709 | return error; |
710 | |
711 | top = (__be64 *)(bh->b_data + mh_size) + |
712 | (first ? mp->mp_list[height] : 0); |
713 | |
714 | bottom = (__be64 *)(bh->b_data + mh_size) + sdp->sd_inptrs; |
715 | } |
716 | |
717 | error = bc(ip, dibh, bh, top, bottom, height, data); |
718 | if (error) |
719 | goto out; |
720 | |
721 | if (height < ip->i_height - 1) |
722 | for (; top < bottom; top++, first = 0) { |
723 | if (!*top) |
724 | continue; |
725 | |
726 | bn = be64_to_cpu(*top); |
727 | |
728 | error = recursive_scan(ip, dibh, mp, height + 1, bn, |
729 | first, bc, data); |
730 | if (error) |
731 | break; |
732 | } |
733 | |
734 | out: |
735 | brelse(bh); |
736 | return error; |
737 | } |
738 | |
739 | /** |
740 | * do_strip - Look for a layer a particular layer of the file and strip it off |
741 | * @ip: the inode |
742 | * @dibh: the dinode buffer |
743 | * @bh: A buffer of pointers |
744 | * @top: The first pointer in the buffer |
745 | * @bottom: One more than the last pointer |
746 | * @height: the height this buffer is at |
747 | * @data: a pointer to a struct strip_mine |
748 | * |
749 | * Returns: errno |
750 | */ |
751 | |
752 | static int do_strip(struct gfs2_inode *ip, struct buffer_head *dibh, |
753 | struct buffer_head *bh, __be64 *top, __be64 *bottom, |
754 | unsigned int height, void *data) |
755 | { |
756 | struct strip_mine *sm = data; |
757 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
758 | struct gfs2_rgrp_list rlist; |
759 | u64 bn, bstart; |
760 | u32 blen; |
761 | __be64 *p; |
762 | unsigned int rg_blocks = 0; |
763 | int metadata; |
764 | unsigned int revokes = 0; |
765 | int x; |
766 | int error; |
767 | |
768 | if (!*top) |
769 | sm->sm_first = 0; |
770 | |
771 | if (height != sm->sm_height) |
772 | return 0; |
773 | |
774 | if (sm->sm_first) { |
775 | top++; |
776 | sm->sm_first = 0; |
777 | } |
778 | |
779 | metadata = (height != ip->i_height - 1); |
780 | if (metadata) |
781 | revokes = (height) ? sdp->sd_inptrs : sdp->sd_diptrs; |
782 | |
783 | error = gfs2_rindex_hold(sdp, &ip->i_alloc->al_ri_gh); |
784 | if (error) |
785 | return error; |
786 | |
787 | memset(&rlist, 0, sizeof(struct gfs2_rgrp_list)); |
788 | bstart = 0; |
789 | blen = 0; |
790 | |
791 | for (p = top; p < bottom; p++) { |
792 | if (!*p) |
793 | continue; |
794 | |
795 | bn = be64_to_cpu(*p); |
796 | |
797 | if (bstart + blen == bn) |
798 | blen++; |
799 | else { |
800 | if (bstart) |
801 | gfs2_rlist_add(sdp, &rlist, bstart); |
802 | |
803 | bstart = bn; |
804 | blen = 1; |
805 | } |
806 | } |
807 | |
808 | if (bstart) |
809 | gfs2_rlist_add(sdp, &rlist, bstart); |
810 | else |
811 | goto out; /* Nothing to do */ |
812 | |
813 | gfs2_rlist_alloc(&rlist, LM_ST_EXCLUSIVE); |
814 | |
815 | for (x = 0; x < rlist.rl_rgrps; x++) { |
816 | struct gfs2_rgrpd *rgd; |
817 | rgd = rlist.rl_ghs[x].gh_gl->gl_object; |
818 | rg_blocks += rgd->rd_length; |
819 | } |
820 | |
821 | error = gfs2_glock_nq_m(rlist.rl_rgrps, rlist.rl_ghs); |
822 | if (error) |
823 | goto out_rlist; |
824 | |
825 | error = gfs2_trans_begin(sdp, rg_blocks + RES_DINODE + |
826 | RES_INDIRECT + RES_STATFS + RES_QUOTA, |
827 | revokes); |
828 | if (error) |
829 | goto out_rg_gunlock; |
830 | |
831 | down_write(&ip->i_rw_mutex); |
832 | |
833 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
834 | gfs2_trans_add_bh(ip->i_gl, bh, 1); |
835 | |
836 | bstart = 0; |
837 | blen = 0; |
838 | |
839 | for (p = top; p < bottom; p++) { |
840 | if (!*p) |
841 | continue; |
842 | |
843 | bn = be64_to_cpu(*p); |
844 | |
845 | if (bstart + blen == bn) |
846 | blen++; |
847 | else { |
848 | if (bstart) { |
849 | if (metadata) |
850 | gfs2_free_meta(ip, bstart, blen); |
851 | else |
852 | gfs2_free_data(ip, bstart, blen); |
853 | } |
854 | |
855 | bstart = bn; |
856 | blen = 1; |
857 | } |
858 | |
859 | *p = 0; |
860 | gfs2_add_inode_blocks(&ip->i_inode, -1); |
861 | } |
862 | if (bstart) { |
863 | if (metadata) |
864 | gfs2_free_meta(ip, bstart, blen); |
865 | else |
866 | gfs2_free_data(ip, bstart, blen); |
867 | } |
868 | |
869 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
870 | |
871 | gfs2_dinode_out(ip, dibh->b_data); |
872 | |
873 | up_write(&ip->i_rw_mutex); |
874 | |
875 | gfs2_trans_end(sdp); |
876 | |
877 | out_rg_gunlock: |
878 | gfs2_glock_dq_m(rlist.rl_rgrps, rlist.rl_ghs); |
879 | out_rlist: |
880 | gfs2_rlist_free(&rlist); |
881 | out: |
882 | gfs2_glock_dq_uninit(&ip->i_alloc->al_ri_gh); |
883 | return error; |
884 | } |
885 | |
886 | /** |
887 | * do_grow - Make a file look bigger than it is |
888 | * @ip: the inode |
889 | * @size: the size to set the file to |
890 | * |
891 | * Called with an exclusive lock on @ip. |
892 | * |
893 | * Returns: errno |
894 | */ |
895 | |
896 | static int do_grow(struct gfs2_inode *ip, u64 size) |
897 | { |
898 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
899 | struct gfs2_alloc *al; |
900 | struct buffer_head *dibh; |
901 | int error; |
902 | |
903 | al = gfs2_alloc_get(ip); |
904 | if (!al) |
905 | return -ENOMEM; |
906 | |
907 | error = gfs2_quota_lock_check(ip); |
908 | if (error) |
909 | goto out; |
910 | |
911 | al->al_requested = sdp->sd_max_height + RES_DATA; |
912 | |
913 | error = gfs2_inplace_reserve(ip); |
914 | if (error) |
915 | goto out_gunlock_q; |
916 | |
917 | error = gfs2_trans_begin(sdp, |
918 | sdp->sd_max_height + al->al_rgd->rd_length + |
919 | RES_JDATA + RES_DINODE + RES_STATFS + RES_QUOTA, 0); |
920 | if (error) |
921 | goto out_ipres; |
922 | |
923 | error = gfs2_meta_inode_buffer(ip, &dibh); |
924 | if (error) |
925 | goto out_end_trans; |
926 | |
927 | if (size > sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) { |
928 | if (gfs2_is_stuffed(ip)) { |
929 | error = gfs2_unstuff_dinode(ip, NULL); |
930 | if (error) |
931 | goto out_brelse; |
932 | } |
933 | } |
934 | |
935 | ip->i_disksize = size; |
936 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
937 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
938 | gfs2_dinode_out(ip, dibh->b_data); |
939 | |
940 | out_brelse: |
941 | brelse(dibh); |
942 | out_end_trans: |
943 | gfs2_trans_end(sdp); |
944 | out_ipres: |
945 | gfs2_inplace_release(ip); |
946 | out_gunlock_q: |
947 | gfs2_quota_unlock(ip); |
948 | out: |
949 | gfs2_alloc_put(ip); |
950 | return error; |
951 | } |
952 | |
953 | |
954 | /** |
955 | * gfs2_block_truncate_page - Deal with zeroing out data for truncate |
956 | * |
957 | * This is partly borrowed from ext3. |
958 | */ |
959 | static int gfs2_block_truncate_page(struct address_space *mapping) |
960 | { |
961 | struct inode *inode = mapping->host; |
962 | struct gfs2_inode *ip = GFS2_I(inode); |
963 | loff_t from = inode->i_size; |
964 | unsigned long index = from >> PAGE_CACHE_SHIFT; |
965 | unsigned offset = from & (PAGE_CACHE_SIZE-1); |
966 | unsigned blocksize, iblock, length, pos; |
967 | struct buffer_head *bh; |
968 | struct page *page; |
969 | int err; |
970 | |
971 | page = grab_cache_page(mapping, index); |
972 | if (!page) |
973 | return 0; |
974 | |
975 | blocksize = inode->i_sb->s_blocksize; |
976 | length = blocksize - (offset & (blocksize - 1)); |
977 | iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); |
978 | |
979 | if (!page_has_buffers(page)) |
980 | create_empty_buffers(page, blocksize, 0); |
981 | |
982 | /* Find the buffer that contains "offset" */ |
983 | bh = page_buffers(page); |
984 | pos = blocksize; |
985 | while (offset >= pos) { |
986 | bh = bh->b_this_page; |
987 | iblock++; |
988 | pos += blocksize; |
989 | } |
990 | |
991 | err = 0; |
992 | |
993 | if (!buffer_mapped(bh)) { |
994 | gfs2_block_map(inode, iblock, bh, 0); |
995 | /* unmapped? It's a hole - nothing to do */ |
996 | if (!buffer_mapped(bh)) |
997 | goto unlock; |
998 | } |
999 | |
1000 | /* Ok, it's mapped. Make sure it's up-to-date */ |
1001 | if (PageUptodate(page)) |
1002 | set_buffer_uptodate(bh); |
1003 | |
1004 | if (!buffer_uptodate(bh)) { |
1005 | err = -EIO; |
1006 | ll_rw_block(READ, 1, &bh); |
1007 | wait_on_buffer(bh); |
1008 | /* Uhhuh. Read error. Complain and punt. */ |
1009 | if (!buffer_uptodate(bh)) |
1010 | goto unlock; |
1011 | err = 0; |
1012 | } |
1013 | |
1014 | if (!gfs2_is_writeback(ip)) |
1015 | gfs2_trans_add_bh(ip->i_gl, bh, 0); |
1016 | |
1017 | zero_user(page, offset, length); |
1018 | mark_buffer_dirty(bh); |
1019 | unlock: |
1020 | unlock_page(page); |
1021 | page_cache_release(page); |
1022 | return err; |
1023 | } |
1024 | |
1025 | static int trunc_start(struct gfs2_inode *ip, u64 size) |
1026 | { |
1027 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
1028 | struct buffer_head *dibh; |
1029 | int journaled = gfs2_is_jdata(ip); |
1030 | int error; |
1031 | |
1032 | error = gfs2_trans_begin(sdp, |
1033 | RES_DINODE + (journaled ? RES_JDATA : 0), 0); |
1034 | if (error) |
1035 | return error; |
1036 | |
1037 | error = gfs2_meta_inode_buffer(ip, &dibh); |
1038 | if (error) |
1039 | goto out; |
1040 | |
1041 | if (gfs2_is_stuffed(ip)) { |
1042 | ip->i_disksize = size; |
1043 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
1044 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
1045 | gfs2_dinode_out(ip, dibh->b_data); |
1046 | gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + size); |
1047 | error = 1; |
1048 | |
1049 | } else { |
1050 | if (size & (u64)(sdp->sd_sb.sb_bsize - 1)) |
1051 | error = gfs2_block_truncate_page(ip->i_inode.i_mapping); |
1052 | |
1053 | if (!error) { |
1054 | ip->i_disksize = size; |
1055 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
1056 | ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; |
1057 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
1058 | gfs2_dinode_out(ip, dibh->b_data); |
1059 | } |
1060 | } |
1061 | |
1062 | brelse(dibh); |
1063 | |
1064 | out: |
1065 | gfs2_trans_end(sdp); |
1066 | return error; |
1067 | } |
1068 | |
1069 | static int trunc_dealloc(struct gfs2_inode *ip, u64 size) |
1070 | { |
1071 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
1072 | unsigned int height = ip->i_height; |
1073 | u64 lblock; |
1074 | struct metapath mp; |
1075 | int error; |
1076 | |
1077 | if (!size) |
1078 | lblock = 0; |
1079 | else |
1080 | lblock = (size - 1) >> sdp->sd_sb.sb_bsize_shift; |
1081 | |
1082 | find_metapath(sdp, lblock, &mp, ip->i_height); |
1083 | if (!gfs2_alloc_get(ip)) |
1084 | return -ENOMEM; |
1085 | |
1086 | error = gfs2_quota_hold(ip, NO_QUOTA_CHANGE, NO_QUOTA_CHANGE); |
1087 | if (error) |
1088 | goto out; |
1089 | |
1090 | while (height--) { |
1091 | struct strip_mine sm; |
1092 | sm.sm_first = !!size; |
1093 | sm.sm_height = height; |
1094 | |
1095 | error = recursive_scan(ip, NULL, &mp, 0, 0, 1, do_strip, &sm); |
1096 | if (error) |
1097 | break; |
1098 | } |
1099 | |
1100 | gfs2_quota_unhold(ip); |
1101 | |
1102 | out: |
1103 | gfs2_alloc_put(ip); |
1104 | return error; |
1105 | } |
1106 | |
1107 | static int trunc_end(struct gfs2_inode *ip) |
1108 | { |
1109 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
1110 | struct buffer_head *dibh; |
1111 | int error; |
1112 | |
1113 | error = gfs2_trans_begin(sdp, RES_DINODE, 0); |
1114 | if (error) |
1115 | return error; |
1116 | |
1117 | down_write(&ip->i_rw_mutex); |
1118 | |
1119 | error = gfs2_meta_inode_buffer(ip, &dibh); |
1120 | if (error) |
1121 | goto out; |
1122 | |
1123 | if (!ip->i_disksize) { |
1124 | ip->i_height = 0; |
1125 | ip->i_goal = ip->i_no_addr; |
1126 | gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode)); |
1127 | } |
1128 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
1129 | ip->i_diskflags &= ~GFS2_DIF_TRUNC_IN_PROG; |
1130 | |
1131 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
1132 | gfs2_dinode_out(ip, dibh->b_data); |
1133 | brelse(dibh); |
1134 | |
1135 | out: |
1136 | up_write(&ip->i_rw_mutex); |
1137 | gfs2_trans_end(sdp); |
1138 | return error; |
1139 | } |
1140 | |
1141 | /** |
1142 | * do_shrink - make a file smaller |
1143 | * @ip: the inode |
1144 | * @size: the size to make the file |
1145 | * @truncator: function to truncate the last partial block |
1146 | * |
1147 | * Called with an exclusive lock on @ip. |
1148 | * |
1149 | * Returns: errno |
1150 | */ |
1151 | |
1152 | static int do_shrink(struct gfs2_inode *ip, u64 size) |
1153 | { |
1154 | int error; |
1155 | |
1156 | error = trunc_start(ip, size); |
1157 | if (error < 0) |
1158 | return error; |
1159 | if (error > 0) |
1160 | return 0; |
1161 | |
1162 | error = trunc_dealloc(ip, size); |
1163 | if (!error) |
1164 | error = trunc_end(ip); |
1165 | |
1166 | return error; |
1167 | } |
1168 | |
1169 | static int do_touch(struct gfs2_inode *ip, u64 size) |
1170 | { |
1171 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
1172 | struct buffer_head *dibh; |
1173 | int error; |
1174 | |
1175 | error = gfs2_trans_begin(sdp, RES_DINODE, 0); |
1176 | if (error) |
1177 | return error; |
1178 | |
1179 | down_write(&ip->i_rw_mutex); |
1180 | |
1181 | error = gfs2_meta_inode_buffer(ip, &dibh); |
1182 | if (error) |
1183 | goto do_touch_out; |
1184 | |
1185 | ip->i_inode.i_mtime = ip->i_inode.i_ctime = CURRENT_TIME; |
1186 | gfs2_trans_add_bh(ip->i_gl, dibh, 1); |
1187 | gfs2_dinode_out(ip, dibh->b_data); |
1188 | brelse(dibh); |
1189 | |
1190 | do_touch_out: |
1191 | up_write(&ip->i_rw_mutex); |
1192 | gfs2_trans_end(sdp); |
1193 | return error; |
1194 | } |
1195 | |
1196 | /** |
1197 | * gfs2_truncatei - make a file a given size |
1198 | * @ip: the inode |
1199 | * @size: the size to make the file |
1200 | * @truncator: function to truncate the last partial block |
1201 | * |
1202 | * The file size can grow, shrink, or stay the same size. |
1203 | * |
1204 | * Returns: errno |
1205 | */ |
1206 | |
1207 | int gfs2_truncatei(struct gfs2_inode *ip, u64 size) |
1208 | { |
1209 | int error; |
1210 | |
1211 | if (gfs2_assert_warn(GFS2_SB(&ip->i_inode), S_ISREG(ip->i_inode.i_mode))) |
1212 | return -EINVAL; |
1213 | |
1214 | if (size > ip->i_disksize) |
1215 | error = do_grow(ip, size); |
1216 | else if (size < ip->i_disksize) |
1217 | error = do_shrink(ip, size); |
1218 | else |
1219 | /* update time stamps */ |
1220 | error = do_touch(ip, size); |
1221 | |
1222 | return error; |
1223 | } |
1224 | |
1225 | int gfs2_truncatei_resume(struct gfs2_inode *ip) |
1226 | { |
1227 | int error; |
1228 | error = trunc_dealloc(ip, ip->i_disksize); |
1229 | if (!error) |
1230 | error = trunc_end(ip); |
1231 | return error; |
1232 | } |
1233 | |
1234 | int gfs2_file_dealloc(struct gfs2_inode *ip) |
1235 | { |
1236 | return trunc_dealloc(ip, 0); |
1237 | } |
1238 | |
1239 | /** |
1240 | * gfs2_write_alloc_required - figure out if a write will require an allocation |
1241 | * @ip: the file being written to |
1242 | * @offset: the offset to write to |
1243 | * @len: the number of bytes being written |
1244 | * @alloc_required: set to 1 if an alloc is required, 0 otherwise |
1245 | * |
1246 | * Returns: errno |
1247 | */ |
1248 | |
1249 | int gfs2_write_alloc_required(struct gfs2_inode *ip, u64 offset, |
1250 | unsigned int len, int *alloc_required) |
1251 | { |
1252 | struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); |
1253 | struct buffer_head bh; |
1254 | unsigned int shift; |
1255 | u64 lblock, lblock_stop, size; |
1256 | u64 end_of_file; |
1257 | |
1258 | *alloc_required = 0; |
1259 | |
1260 | if (!len) |
1261 | return 0; |
1262 | |
1263 | if (gfs2_is_stuffed(ip)) { |
1264 | if (offset + len > |
1265 | sdp->sd_sb.sb_bsize - sizeof(struct gfs2_dinode)) |
1266 | *alloc_required = 1; |
1267 | return 0; |
1268 | } |
1269 | |
1270 | *alloc_required = 1; |
1271 | shift = sdp->sd_sb.sb_bsize_shift; |
1272 | BUG_ON(gfs2_is_dir(ip)); |
1273 | end_of_file = (ip->i_disksize + sdp->sd_sb.sb_bsize - 1) >> shift; |
1274 | lblock = offset >> shift; |
1275 | lblock_stop = (offset + len + sdp->sd_sb.sb_bsize - 1) >> shift; |
1276 | if (lblock_stop > end_of_file) |
1277 | return 0; |
1278 | |
1279 | size = (lblock_stop - lblock) << shift; |
1280 | do { |
1281 | bh.b_state = 0; |
1282 | bh.b_size = size; |
1283 | gfs2_block_map(&ip->i_inode, lblock, &bh, 0); |
1284 | if (!buffer_mapped(&bh)) |
1285 | return 0; |
1286 | size -= bh.b_size; |
1287 | lblock += (bh.b_size >> ip->i_inode.i_blkbits); |
1288 | } while(size > 0); |
1289 | |
1290 | *alloc_required = 0; |
1291 | return 0; |
1292 | } |
1293 | |
1294 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
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jz-3.3
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jz-3.6-rc2-pwm
jz-3.9
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jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9