diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /fs/ext2/balloc.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'fs/ext2/balloc.c')
-rw-r--r-- | fs/ext2/balloc.c | 699 |
1 files changed, 699 insertions, 0 deletions
diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c new file mode 100644 index 000000000000..6591abef64d0 --- /dev/null +++ b/fs/ext2/balloc.c | |||
@@ -0,0 +1,699 @@ | |||
1 | /* | ||
2 | * linux/fs/ext2/balloc.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 | * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993 | ||
10 | * Big-endian to little-endian byte-swapping/bitmaps by | ||
11 | * David S. Miller (davem@caip.rutgers.edu), 1995 | ||
12 | */ | ||
13 | |||
14 | #include <linux/config.h> | ||
15 | #include "ext2.h" | ||
16 | #include <linux/quotaops.h> | ||
17 | #include <linux/sched.h> | ||
18 | #include <linux/buffer_head.h> | ||
19 | |||
20 | /* | ||
21 | * balloc.c contains the blocks allocation and deallocation routines | ||
22 | */ | ||
23 | |||
24 | /* | ||
25 | * The free blocks are managed by bitmaps. A file system contains several | ||
26 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap | ||
27 | * block for inodes, N blocks for the inode table and data blocks. | ||
28 | * | ||
29 | * The file system contains group descriptors which are located after the | ||
30 | * super block. Each descriptor contains the number of the bitmap block and | ||
31 | * the free blocks count in the block. The descriptors are loaded in memory | ||
32 | * when a file system is mounted (see ext2_read_super). | ||
33 | */ | ||
34 | |||
35 | |||
36 | #define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) | ||
37 | |||
38 | struct ext2_group_desc * ext2_get_group_desc(struct super_block * sb, | ||
39 | unsigned int block_group, | ||
40 | struct buffer_head ** bh) | ||
41 | { | ||
42 | unsigned long group_desc; | ||
43 | unsigned long offset; | ||
44 | struct ext2_group_desc * desc; | ||
45 | struct ext2_sb_info *sbi = EXT2_SB(sb); | ||
46 | |||
47 | if (block_group >= sbi->s_groups_count) { | ||
48 | ext2_error (sb, "ext2_get_group_desc", | ||
49 | "block_group >= groups_count - " | ||
50 | "block_group = %d, groups_count = %lu", | ||
51 | block_group, sbi->s_groups_count); | ||
52 | |||
53 | return NULL; | ||
54 | } | ||
55 | |||
56 | group_desc = block_group >> EXT2_DESC_PER_BLOCK_BITS(sb); | ||
57 | offset = block_group & (EXT2_DESC_PER_BLOCK(sb) - 1); | ||
58 | if (!sbi->s_group_desc[group_desc]) { | ||
59 | ext2_error (sb, "ext2_get_group_desc", | ||
60 | "Group descriptor not loaded - " | ||
61 | "block_group = %d, group_desc = %lu, desc = %lu", | ||
62 | block_group, group_desc, offset); | ||
63 | return NULL; | ||
64 | } | ||
65 | |||
66 | desc = (struct ext2_group_desc *) sbi->s_group_desc[group_desc]->b_data; | ||
67 | if (bh) | ||
68 | *bh = sbi->s_group_desc[group_desc]; | ||
69 | return desc + offset; | ||
70 | } | ||
71 | |||
72 | /* | ||
73 | * Read the bitmap for a given block_group, reading into the specified | ||
74 | * slot in the superblock's bitmap cache. | ||
75 | * | ||
76 | * Return buffer_head on success or NULL in case of failure. | ||
77 | */ | ||
78 | static struct buffer_head * | ||
79 | read_block_bitmap(struct super_block *sb, unsigned int block_group) | ||
80 | { | ||
81 | struct ext2_group_desc * desc; | ||
82 | struct buffer_head * bh = NULL; | ||
83 | |||
84 | desc = ext2_get_group_desc (sb, block_group, NULL); | ||
85 | if (!desc) | ||
86 | goto error_out; | ||
87 | bh = sb_bread(sb, le32_to_cpu(desc->bg_block_bitmap)); | ||
88 | if (!bh) | ||
89 | ext2_error (sb, "read_block_bitmap", | ||
90 | "Cannot read block bitmap - " | ||
91 | "block_group = %d, block_bitmap = %u", | ||
92 | block_group, le32_to_cpu(desc->bg_block_bitmap)); | ||
93 | error_out: | ||
94 | return bh; | ||
95 | } | ||
96 | |||
97 | /* | ||
98 | * Set sb->s_dirt here because the superblock was "logically" altered. We | ||
99 | * need to recalculate its free blocks count and flush it out. | ||
100 | */ | ||
101 | static int reserve_blocks(struct super_block *sb, int count) | ||
102 | { | ||
103 | struct ext2_sb_info *sbi = EXT2_SB(sb); | ||
104 | struct ext2_super_block *es = sbi->s_es; | ||
105 | unsigned free_blocks; | ||
106 | unsigned root_blocks; | ||
107 | |||
108 | free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); | ||
109 | root_blocks = le32_to_cpu(es->s_r_blocks_count); | ||
110 | |||
111 | if (free_blocks < count) | ||
112 | count = free_blocks; | ||
113 | |||
114 | if (free_blocks < root_blocks + count && !capable(CAP_SYS_RESOURCE) && | ||
115 | sbi->s_resuid != current->fsuid && | ||
116 | (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { | ||
117 | /* | ||
118 | * We are too close to reserve and we are not privileged. | ||
119 | * Can we allocate anything at all? | ||
120 | */ | ||
121 | if (free_blocks > root_blocks) | ||
122 | count = free_blocks - root_blocks; | ||
123 | else | ||
124 | return 0; | ||
125 | } | ||
126 | |||
127 | percpu_counter_mod(&sbi->s_freeblocks_counter, -count); | ||
128 | sb->s_dirt = 1; | ||
129 | return count; | ||
130 | } | ||
131 | |||
132 | static void release_blocks(struct super_block *sb, int count) | ||
133 | { | ||
134 | if (count) { | ||
135 | struct ext2_sb_info *sbi = EXT2_SB(sb); | ||
136 | |||
137 | percpu_counter_mod(&sbi->s_freeblocks_counter, count); | ||
138 | sb->s_dirt = 1; | ||
139 | } | ||
140 | } | ||
141 | |||
142 | static int group_reserve_blocks(struct ext2_sb_info *sbi, int group_no, | ||
143 | struct ext2_group_desc *desc, struct buffer_head *bh, int count) | ||
144 | { | ||
145 | unsigned free_blocks; | ||
146 | |||
147 | if (!desc->bg_free_blocks_count) | ||
148 | return 0; | ||
149 | |||
150 | spin_lock(sb_bgl_lock(sbi, group_no)); | ||
151 | free_blocks = le16_to_cpu(desc->bg_free_blocks_count); | ||
152 | if (free_blocks < count) | ||
153 | count = free_blocks; | ||
154 | desc->bg_free_blocks_count = cpu_to_le16(free_blocks - count); | ||
155 | spin_unlock(sb_bgl_lock(sbi, group_no)); | ||
156 | mark_buffer_dirty(bh); | ||
157 | return count; | ||
158 | } | ||
159 | |||
160 | static void group_release_blocks(struct super_block *sb, int group_no, | ||
161 | struct ext2_group_desc *desc, struct buffer_head *bh, int count) | ||
162 | { | ||
163 | if (count) { | ||
164 | struct ext2_sb_info *sbi = EXT2_SB(sb); | ||
165 | unsigned free_blocks; | ||
166 | |||
167 | spin_lock(sb_bgl_lock(sbi, group_no)); | ||
168 | free_blocks = le16_to_cpu(desc->bg_free_blocks_count); | ||
169 | desc->bg_free_blocks_count = cpu_to_le16(free_blocks + count); | ||
170 | spin_unlock(sb_bgl_lock(sbi, group_no)); | ||
171 | sb->s_dirt = 1; | ||
172 | mark_buffer_dirty(bh); | ||
173 | } | ||
174 | } | ||
175 | |||
176 | /* Free given blocks, update quota and i_blocks field */ | ||
177 | void ext2_free_blocks (struct inode * inode, unsigned long block, | ||
178 | unsigned long count) | ||
179 | { | ||
180 | struct buffer_head *bitmap_bh = NULL; | ||
181 | struct buffer_head * bh2; | ||
182 | unsigned long block_group; | ||
183 | unsigned long bit; | ||
184 | unsigned long i; | ||
185 | unsigned long overflow; | ||
186 | struct super_block * sb = inode->i_sb; | ||
187 | struct ext2_sb_info * sbi = EXT2_SB(sb); | ||
188 | struct ext2_group_desc * desc; | ||
189 | struct ext2_super_block * es = sbi->s_es; | ||
190 | unsigned freed = 0, group_freed; | ||
191 | |||
192 | if (block < le32_to_cpu(es->s_first_data_block) || | ||
193 | block + count < block || | ||
194 | block + count > le32_to_cpu(es->s_blocks_count)) { | ||
195 | ext2_error (sb, "ext2_free_blocks", | ||
196 | "Freeing blocks not in datazone - " | ||
197 | "block = %lu, count = %lu", block, count); | ||
198 | goto error_return; | ||
199 | } | ||
200 | |||
201 | ext2_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); | ||
202 | |||
203 | do_more: | ||
204 | overflow = 0; | ||
205 | block_group = (block - le32_to_cpu(es->s_first_data_block)) / | ||
206 | EXT2_BLOCKS_PER_GROUP(sb); | ||
207 | bit = (block - le32_to_cpu(es->s_first_data_block)) % | ||
208 | EXT2_BLOCKS_PER_GROUP(sb); | ||
209 | /* | ||
210 | * Check to see if we are freeing blocks across a group | ||
211 | * boundary. | ||
212 | */ | ||
213 | if (bit + count > EXT2_BLOCKS_PER_GROUP(sb)) { | ||
214 | overflow = bit + count - EXT2_BLOCKS_PER_GROUP(sb); | ||
215 | count -= overflow; | ||
216 | } | ||
217 | brelse(bitmap_bh); | ||
218 | bitmap_bh = read_block_bitmap(sb, block_group); | ||
219 | if (!bitmap_bh) | ||
220 | goto error_return; | ||
221 | |||
222 | desc = ext2_get_group_desc (sb, block_group, &bh2); | ||
223 | if (!desc) | ||
224 | goto error_return; | ||
225 | |||
226 | if (in_range (le32_to_cpu(desc->bg_block_bitmap), block, count) || | ||
227 | in_range (le32_to_cpu(desc->bg_inode_bitmap), block, count) || | ||
228 | in_range (block, le32_to_cpu(desc->bg_inode_table), | ||
229 | sbi->s_itb_per_group) || | ||
230 | in_range (block + count - 1, le32_to_cpu(desc->bg_inode_table), | ||
231 | sbi->s_itb_per_group)) | ||
232 | ext2_error (sb, "ext2_free_blocks", | ||
233 | "Freeing blocks in system zones - " | ||
234 | "Block = %lu, count = %lu", | ||
235 | block, count); | ||
236 | |||
237 | for (i = 0, group_freed = 0; i < count; i++) { | ||
238 | if (!ext2_clear_bit_atomic(sb_bgl_lock(sbi, block_group), | ||
239 | bit + i, bitmap_bh->b_data)) { | ||
240 | ext2_error(sb, __FUNCTION__, | ||
241 | "bit already cleared for block %lu", block + i); | ||
242 | } else { | ||
243 | group_freed++; | ||
244 | } | ||
245 | } | ||
246 | |||
247 | mark_buffer_dirty(bitmap_bh); | ||
248 | if (sb->s_flags & MS_SYNCHRONOUS) | ||
249 | sync_dirty_buffer(bitmap_bh); | ||
250 | |||
251 | group_release_blocks(sb, block_group, desc, bh2, group_freed); | ||
252 | freed += group_freed; | ||
253 | |||
254 | if (overflow) { | ||
255 | block += count; | ||
256 | count = overflow; | ||
257 | goto do_more; | ||
258 | } | ||
259 | error_return: | ||
260 | brelse(bitmap_bh); | ||
261 | release_blocks(sb, freed); | ||
262 | DQUOT_FREE_BLOCK(inode, freed); | ||
263 | } | ||
264 | |||
265 | static int grab_block(spinlock_t *lock, char *map, unsigned size, int goal) | ||
266 | { | ||
267 | int k; | ||
268 | char *p, *r; | ||
269 | |||
270 | if (!ext2_test_bit(goal, map)) | ||
271 | goto got_it; | ||
272 | |||
273 | repeat: | ||
274 | if (goal) { | ||
275 | /* | ||
276 | * The goal was occupied; search forward for a free | ||
277 | * block within the next XX blocks. | ||
278 | * | ||
279 | * end_goal is more or less random, but it has to be | ||
280 | * less than EXT2_BLOCKS_PER_GROUP. Aligning up to the | ||
281 | * next 64-bit boundary is simple.. | ||
282 | */ | ||
283 | k = (goal + 63) & ~63; | ||
284 | goal = ext2_find_next_zero_bit(map, k, goal); | ||
285 | if (goal < k) | ||
286 | goto got_it; | ||
287 | /* | ||
288 | * Search in the remainder of the current group. | ||
289 | */ | ||
290 | } | ||
291 | |||
292 | p = map + (goal >> 3); | ||
293 | r = memscan(p, 0, (size - goal + 7) >> 3); | ||
294 | k = (r - map) << 3; | ||
295 | if (k < size) { | ||
296 | /* | ||
297 | * We have succeeded in finding a free byte in the block | ||
298 | * bitmap. Now search backwards to find the start of this | ||
299 | * group of free blocks - won't take more than 7 iterations. | ||
300 | */ | ||
301 | for (goal = k; goal && !ext2_test_bit (goal - 1, map); goal--) | ||
302 | ; | ||
303 | goto got_it; | ||
304 | } | ||
305 | |||
306 | k = ext2_find_next_zero_bit ((u32 *)map, size, goal); | ||
307 | if (k < size) { | ||
308 | goal = k; | ||
309 | goto got_it; | ||
310 | } | ||
311 | return -1; | ||
312 | got_it: | ||
313 | if (ext2_set_bit_atomic(lock, goal, (void *) map)) | ||
314 | goto repeat; | ||
315 | return goal; | ||
316 | } | ||
317 | |||
318 | /* | ||
319 | * ext2_new_block uses a goal block to assist allocation. If the goal is | ||
320 | * free, or there is a free block within 32 blocks of the goal, that block | ||
321 | * is allocated. Otherwise a forward search is made for a free block; within | ||
322 | * each block group the search first looks for an entire free byte in the block | ||
323 | * bitmap, and then for any free bit if that fails. | ||
324 | * This function also updates quota and i_blocks field. | ||
325 | */ | ||
326 | int ext2_new_block(struct inode *inode, unsigned long goal, | ||
327 | u32 *prealloc_count, u32 *prealloc_block, int *err) | ||
328 | { | ||
329 | struct buffer_head *bitmap_bh = NULL; | ||
330 | struct buffer_head *gdp_bh; /* bh2 */ | ||
331 | struct ext2_group_desc *desc; | ||
332 | int group_no; /* i */ | ||
333 | int ret_block; /* j */ | ||
334 | int group_idx; /* k */ | ||
335 | int target_block; /* tmp */ | ||
336 | int block = 0; | ||
337 | struct super_block *sb = inode->i_sb; | ||
338 | struct ext2_sb_info *sbi = EXT2_SB(sb); | ||
339 | struct ext2_super_block *es = sbi->s_es; | ||
340 | unsigned group_size = EXT2_BLOCKS_PER_GROUP(sb); | ||
341 | unsigned prealloc_goal = es->s_prealloc_blocks; | ||
342 | unsigned group_alloc = 0, es_alloc, dq_alloc; | ||
343 | int nr_scanned_groups; | ||
344 | |||
345 | if (!prealloc_goal--) | ||
346 | prealloc_goal = EXT2_DEFAULT_PREALLOC_BLOCKS - 1; | ||
347 | if (!prealloc_count || *prealloc_count) | ||
348 | prealloc_goal = 0; | ||
349 | |||
350 | if (DQUOT_ALLOC_BLOCK(inode, 1)) { | ||
351 | *err = -EDQUOT; | ||
352 | goto out; | ||
353 | } | ||
354 | |||
355 | while (prealloc_goal && DQUOT_PREALLOC_BLOCK(inode, prealloc_goal)) | ||
356 | prealloc_goal--; | ||
357 | |||
358 | dq_alloc = prealloc_goal + 1; | ||
359 | es_alloc = reserve_blocks(sb, dq_alloc); | ||
360 | if (!es_alloc) { | ||
361 | *err = -ENOSPC; | ||
362 | goto out_dquot; | ||
363 | } | ||
364 | |||
365 | ext2_debug ("goal=%lu.\n", goal); | ||
366 | |||
367 | if (goal < le32_to_cpu(es->s_first_data_block) || | ||
368 | goal >= le32_to_cpu(es->s_blocks_count)) | ||
369 | goal = le32_to_cpu(es->s_first_data_block); | ||
370 | group_no = (goal - le32_to_cpu(es->s_first_data_block)) / group_size; | ||
371 | desc = ext2_get_group_desc (sb, group_no, &gdp_bh); | ||
372 | if (!desc) { | ||
373 | /* | ||
374 | * gdp_bh may still be uninitialised. But group_release_blocks | ||
375 | * will not touch it because group_alloc is zero. | ||
376 | */ | ||
377 | goto io_error; | ||
378 | } | ||
379 | |||
380 | group_alloc = group_reserve_blocks(sbi, group_no, desc, | ||
381 | gdp_bh, es_alloc); | ||
382 | if (group_alloc) { | ||
383 | ret_block = ((goal - le32_to_cpu(es->s_first_data_block)) % | ||
384 | group_size); | ||
385 | brelse(bitmap_bh); | ||
386 | bitmap_bh = read_block_bitmap(sb, group_no); | ||
387 | if (!bitmap_bh) | ||
388 | goto io_error; | ||
389 | |||
390 | ext2_debug("goal is at %d:%d.\n", group_no, ret_block); | ||
391 | |||
392 | ret_block = grab_block(sb_bgl_lock(sbi, group_no), | ||
393 | bitmap_bh->b_data, group_size, ret_block); | ||
394 | if (ret_block >= 0) | ||
395 | goto got_block; | ||
396 | group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); | ||
397 | group_alloc = 0; | ||
398 | } | ||
399 | |||
400 | ext2_debug ("Bit not found in block group %d.\n", group_no); | ||
401 | |||
402 | /* | ||
403 | * Now search the rest of the groups. We assume that | ||
404 | * i and desc correctly point to the last group visited. | ||
405 | */ | ||
406 | nr_scanned_groups = 0; | ||
407 | retry: | ||
408 | for (group_idx = 0; !group_alloc && | ||
409 | group_idx < sbi->s_groups_count; group_idx++) { | ||
410 | group_no++; | ||
411 | if (group_no >= sbi->s_groups_count) | ||
412 | group_no = 0; | ||
413 | desc = ext2_get_group_desc(sb, group_no, &gdp_bh); | ||
414 | if (!desc) | ||
415 | goto io_error; | ||
416 | group_alloc = group_reserve_blocks(sbi, group_no, desc, | ||
417 | gdp_bh, es_alloc); | ||
418 | } | ||
419 | if (!group_alloc) { | ||
420 | *err = -ENOSPC; | ||
421 | goto out_release; | ||
422 | } | ||
423 | brelse(bitmap_bh); | ||
424 | bitmap_bh = read_block_bitmap(sb, group_no); | ||
425 | if (!bitmap_bh) | ||
426 | goto io_error; | ||
427 | |||
428 | ret_block = grab_block(sb_bgl_lock(sbi, group_no), bitmap_bh->b_data, | ||
429 | group_size, 0); | ||
430 | if (ret_block < 0) { | ||
431 | /* | ||
432 | * If a free block counter is corrupted we can loop inifintely. | ||
433 | * Detect that here. | ||
434 | */ | ||
435 | nr_scanned_groups++; | ||
436 | if (nr_scanned_groups > 2 * sbi->s_groups_count) { | ||
437 | ext2_error(sb, "ext2_new_block", | ||
438 | "corrupted free blocks counters"); | ||
439 | goto io_error; | ||
440 | } | ||
441 | /* | ||
442 | * Someone else grabbed the last free block in this blockgroup | ||
443 | * before us. Retry the scan. | ||
444 | */ | ||
445 | group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); | ||
446 | group_alloc = 0; | ||
447 | goto retry; | ||
448 | } | ||
449 | |||
450 | got_block: | ||
451 | ext2_debug("using block group %d(%d)\n", | ||
452 | group_no, desc->bg_free_blocks_count); | ||
453 | |||
454 | target_block = ret_block + group_no * group_size + | ||
455 | le32_to_cpu(es->s_first_data_block); | ||
456 | |||
457 | if (target_block == le32_to_cpu(desc->bg_block_bitmap) || | ||
458 | target_block == le32_to_cpu(desc->bg_inode_bitmap) || | ||
459 | in_range(target_block, le32_to_cpu(desc->bg_inode_table), | ||
460 | sbi->s_itb_per_group)) | ||
461 | ext2_error (sb, "ext2_new_block", | ||
462 | "Allocating block in system zone - " | ||
463 | "block = %u", target_block); | ||
464 | |||
465 | if (target_block >= le32_to_cpu(es->s_blocks_count)) { | ||
466 | ext2_error (sb, "ext2_new_block", | ||
467 | "block(%d) >= blocks count(%d) - " | ||
468 | "block_group = %d, es == %p ", ret_block, | ||
469 | le32_to_cpu(es->s_blocks_count), group_no, es); | ||
470 | goto io_error; | ||
471 | } | ||
472 | block = target_block; | ||
473 | |||
474 | /* OK, we _had_ allocated something */ | ||
475 | ext2_debug("found bit %d\n", ret_block); | ||
476 | |||
477 | dq_alloc--; | ||
478 | es_alloc--; | ||
479 | group_alloc--; | ||
480 | |||
481 | /* | ||
482 | * Do block preallocation now if required. | ||
483 | */ | ||
484 | write_lock(&EXT2_I(inode)->i_meta_lock); | ||
485 | if (group_alloc && !*prealloc_count) { | ||
486 | unsigned n; | ||
487 | |||
488 | for (n = 0; n < group_alloc && ++ret_block < group_size; n++) { | ||
489 | if (ext2_set_bit_atomic(sb_bgl_lock(sbi, group_no), | ||
490 | ret_block, | ||
491 | (void*) bitmap_bh->b_data)) | ||
492 | break; | ||
493 | } | ||
494 | *prealloc_block = block + 1; | ||
495 | *prealloc_count = n; | ||
496 | es_alloc -= n; | ||
497 | dq_alloc -= n; | ||
498 | group_alloc -= n; | ||
499 | } | ||
500 | write_unlock(&EXT2_I(inode)->i_meta_lock); | ||
501 | |||
502 | mark_buffer_dirty(bitmap_bh); | ||
503 | if (sb->s_flags & MS_SYNCHRONOUS) | ||
504 | sync_dirty_buffer(bitmap_bh); | ||
505 | |||
506 | ext2_debug ("allocating block %d. ", block); | ||
507 | |||
508 | *err = 0; | ||
509 | out_release: | ||
510 | group_release_blocks(sb, group_no, desc, gdp_bh, group_alloc); | ||
511 | release_blocks(sb, es_alloc); | ||
512 | out_dquot: | ||
513 | DQUOT_FREE_BLOCK(inode, dq_alloc); | ||
514 | out: | ||
515 | brelse(bitmap_bh); | ||
516 | return block; | ||
517 | |||
518 | io_error: | ||
519 | *err = -EIO; | ||
520 | goto out_release; | ||
521 | } | ||
522 | |||
523 | unsigned long ext2_count_free_blocks (struct super_block * sb) | ||
524 | { | ||
525 | struct ext2_group_desc * desc; | ||
526 | unsigned long desc_count = 0; | ||
527 | int i; | ||
528 | #ifdef EXT2FS_DEBUG | ||
529 | unsigned long bitmap_count, x; | ||
530 | struct ext2_super_block *es; | ||
531 | |||
532 | lock_super (sb); | ||
533 | es = EXT2_SB(sb)->s_es; | ||
534 | desc_count = 0; | ||
535 | bitmap_count = 0; | ||
536 | desc = NULL; | ||
537 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { | ||
538 | struct buffer_head *bitmap_bh; | ||
539 | desc = ext2_get_group_desc (sb, i, NULL); | ||
540 | if (!desc) | ||
541 | continue; | ||
542 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); | ||
543 | bitmap_bh = read_block_bitmap(sb, i); | ||
544 | if (!bitmap_bh) | ||
545 | continue; | ||
546 | |||
547 | x = ext2_count_free(bitmap_bh, sb->s_blocksize); | ||
548 | printk ("group %d: stored = %d, counted = %lu\n", | ||
549 | i, le16_to_cpu(desc->bg_free_blocks_count), x); | ||
550 | bitmap_count += x; | ||
551 | brelse(bitmap_bh); | ||
552 | } | ||
553 | printk("ext2_count_free_blocks: stored = %lu, computed = %lu, %lu\n", | ||
554 | (long)le32_to_cpu(es->s_free_blocks_count), | ||
555 | desc_count, bitmap_count); | ||
556 | unlock_super (sb); | ||
557 | return bitmap_count; | ||
558 | #else | ||
559 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { | ||
560 | desc = ext2_get_group_desc (sb, i, NULL); | ||
561 | if (!desc) | ||
562 | continue; | ||
563 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); | ||
564 | } | ||
565 | return desc_count; | ||
566 | #endif | ||
567 | } | ||
568 | |||
569 | static inline int | ||
570 | block_in_use(unsigned long block, struct super_block *sb, unsigned char *map) | ||
571 | { | ||
572 | return ext2_test_bit ((block - | ||
573 | le32_to_cpu(EXT2_SB(sb)->s_es->s_first_data_block)) % | ||
574 | EXT2_BLOCKS_PER_GROUP(sb), map); | ||
575 | } | ||
576 | |||
577 | static inline int test_root(int a, int b) | ||
578 | { | ||
579 | int num = b; | ||
580 | |||
581 | while (a > num) | ||
582 | num *= b; | ||
583 | return num == a; | ||
584 | } | ||
585 | |||
586 | static int ext2_group_sparse(int group) | ||
587 | { | ||
588 | if (group <= 1) | ||
589 | return 1; | ||
590 | return (test_root(group, 3) || test_root(group, 5) || | ||
591 | test_root(group, 7)); | ||
592 | } | ||
593 | |||
594 | /** | ||
595 | * ext2_bg_has_super - number of blocks used by the superblock in group | ||
596 | * @sb: superblock for filesystem | ||
597 | * @group: group number to check | ||
598 | * | ||
599 | * Return the number of blocks used by the superblock (primary or backup) | ||
600 | * in this group. Currently this will be only 0 or 1. | ||
601 | */ | ||
602 | int ext2_bg_has_super(struct super_block *sb, int group) | ||
603 | { | ||
604 | if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& | ||
605 | !ext2_group_sparse(group)) | ||
606 | return 0; | ||
607 | return 1; | ||
608 | } | ||
609 | |||
610 | /** | ||
611 | * ext2_bg_num_gdb - number of blocks used by the group table in group | ||
612 | * @sb: superblock for filesystem | ||
613 | * @group: group number to check | ||
614 | * | ||
615 | * Return the number of blocks used by the group descriptor table | ||
616 | * (primary or backup) in this group. In the future there may be a | ||
617 | * different number of descriptor blocks in each group. | ||
618 | */ | ||
619 | unsigned long ext2_bg_num_gdb(struct super_block *sb, int group) | ||
620 | { | ||
621 | if (EXT2_HAS_RO_COMPAT_FEATURE(sb,EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER)&& | ||
622 | !ext2_group_sparse(group)) | ||
623 | return 0; | ||
624 | return EXT2_SB(sb)->s_gdb_count; | ||
625 | } | ||
626 | |||
627 | #ifdef CONFIG_EXT2_CHECK | ||
628 | /* Called at mount-time, super-block is locked */ | ||
629 | void ext2_check_blocks_bitmap (struct super_block * sb) | ||
630 | { | ||
631 | struct buffer_head *bitmap_bh = NULL; | ||
632 | struct ext2_super_block * es; | ||
633 | unsigned long desc_count, bitmap_count, x, j; | ||
634 | unsigned long desc_blocks; | ||
635 | struct ext2_group_desc * desc; | ||
636 | int i; | ||
637 | |||
638 | es = EXT2_SB(sb)->s_es; | ||
639 | desc_count = 0; | ||
640 | bitmap_count = 0; | ||
641 | desc = NULL; | ||
642 | for (i = 0; i < EXT2_SB(sb)->s_groups_count; i++) { | ||
643 | desc = ext2_get_group_desc (sb, i, NULL); | ||
644 | if (!desc) | ||
645 | continue; | ||
646 | desc_count += le16_to_cpu(desc->bg_free_blocks_count); | ||
647 | brelse(bitmap_bh); | ||
648 | bitmap_bh = read_block_bitmap(sb, i); | ||
649 | if (!bitmap_bh) | ||
650 | continue; | ||
651 | |||
652 | if (ext2_bg_has_super(sb, i) && | ||
653 | !ext2_test_bit(0, bitmap_bh->b_data)) | ||
654 | ext2_error(sb, __FUNCTION__, | ||
655 | "Superblock in group %d is marked free", i); | ||
656 | |||
657 | desc_blocks = ext2_bg_num_gdb(sb, i); | ||
658 | for (j = 0; j < desc_blocks; j++) | ||
659 | if (!ext2_test_bit(j + 1, bitmap_bh->b_data)) | ||
660 | ext2_error(sb, __FUNCTION__, | ||
661 | "Descriptor block #%ld in group " | ||
662 | "%d is marked free", j, i); | ||
663 | |||
664 | if (!block_in_use(le32_to_cpu(desc->bg_block_bitmap), | ||
665 | sb, bitmap_bh->b_data)) | ||
666 | ext2_error(sb, "ext2_check_blocks_bitmap", | ||
667 | "Block bitmap for group %d is marked free", | ||
668 | i); | ||
669 | |||
670 | if (!block_in_use(le32_to_cpu(desc->bg_inode_bitmap), | ||
671 | sb, bitmap_bh->b_data)) | ||
672 | ext2_error(sb, "ext2_check_blocks_bitmap", | ||
673 | "Inode bitmap for group %d is marked free", | ||
674 | i); | ||
675 | |||
676 | for (j = 0; j < EXT2_SB(sb)->s_itb_per_group; j++) | ||
677 | if (!block_in_use(le32_to_cpu(desc->bg_inode_table) + j, | ||
678 | sb, bitmap_bh->b_data)) | ||
679 | ext2_error (sb, "ext2_check_blocks_bitmap", | ||
680 | "Block #%ld of the inode table in " | ||
681 | "group %d is marked free", j, i); | ||
682 | |||
683 | x = ext2_count_free(bitmap_bh, sb->s_blocksize); | ||
684 | if (le16_to_cpu(desc->bg_free_blocks_count) != x) | ||
685 | ext2_error (sb, "ext2_check_blocks_bitmap", | ||
686 | "Wrong free blocks count for group %d, " | ||
687 | "stored = %d, counted = %lu", i, | ||
688 | le16_to_cpu(desc->bg_free_blocks_count), x); | ||
689 | bitmap_count += x; | ||
690 | } | ||
691 | if (le32_to_cpu(es->s_free_blocks_count) != bitmap_count) | ||
692 | ext2_error (sb, "ext2_check_blocks_bitmap", | ||
693 | "Wrong free blocks count in super block, " | ||
694 | "stored = %lu, counted = %lu", | ||
695 | (unsigned long)le32_to_cpu(es->s_free_blocks_count), | ||
696 | bitmap_count); | ||
697 | brelse(bitmap_bh); | ||
698 | } | ||
699 | #endif | ||