Commit | Line | Data |
---|---|---|
ac27a0ec | 1 | /* |
617ba13b | 2 | * linux/fs/ext4/balloc.c |
ac27a0ec DK |
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/time.h> | |
15 | #include <linux/capability.h> | |
16 | #include <linux/fs.h> | |
dab291af | 17 | #include <linux/jbd2.h> |
ac27a0ec DK |
18 | #include <linux/quotaops.h> |
19 | #include <linux/buffer_head.h> | |
3dcf5451 CH |
20 | #include "ext4.h" |
21 | #include "ext4_jbd2.h" | |
e21675d4 | 22 | #include "mballoc.h" |
3dcf5451 | 23 | |
0562e0ba JZ |
24 | #include <trace/events/ext4.h> |
25 | ||
5f163cc7 ES |
26 | static unsigned ext4_num_base_meta_clusters(struct super_block *sb, |
27 | ext4_group_t block_group); | |
ac27a0ec DK |
28 | /* |
29 | * balloc.c contains the blocks allocation and deallocation routines | |
30 | */ | |
31 | ||
bd86298e LC |
32 | /* |
33 | * Calculate block group number for a given block number | |
34 | */ | |
35 | ext4_group_t ext4_get_group_number(struct super_block *sb, | |
36 | ext4_fsblk_t block) | |
37 | { | |
38 | ext4_group_t group; | |
39 | ||
40 | if (test_opt2(sb, STD_GROUP_SIZE)) | |
960fd856 TT |
41 | group = (block - |
42 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) >> | |
bd86298e LC |
43 | (EXT4_BLOCK_SIZE_BITS(sb) + EXT4_CLUSTER_BITS(sb) + 3); |
44 | else | |
45 | ext4_get_group_no_and_offset(sb, block, &group, NULL); | |
46 | return group; | |
47 | } | |
48 | ||
72b64b59 | 49 | /* |
3212a80a TT |
50 | * Calculate the block group number and offset into the block/cluster |
51 | * allocation bitmap, given a block number | |
72b64b59 AM |
52 | */ |
53 | void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, | |
fd2d4291 | 54 | ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp) |
72b64b59 | 55 | { |
8c55e204 | 56 | struct ext4_super_block *es = EXT4_SB(sb)->s_es; |
72b64b59 AM |
57 | ext4_grpblk_t offset; |
58 | ||
8c55e204 | 59 | blocknr = blocknr - le32_to_cpu(es->s_first_data_block); |
3212a80a TT |
60 | offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >> |
61 | EXT4_SB(sb)->s_cluster_bits; | |
72b64b59 AM |
62 | if (offsetp) |
63 | *offsetp = offset; | |
64 | if (blockgrpp) | |
8c55e204 | 65 | *blockgrpp = blocknr; |
72b64b59 AM |
66 | |
67 | } | |
68 | ||
68911009 LC |
69 | /* |
70 | * Check whether the 'block' lives within the 'block_group'. Returns 1 if so | |
71 | * and 0 otherwise. | |
72 | */ | |
73 | static inline int ext4_block_in_group(struct super_block *sb, | |
74 | ext4_fsblk_t block, | |
75 | ext4_group_t block_group) | |
0bf7e837 JS |
76 | { |
77 | ext4_group_t actual_group; | |
68911009 | 78 | |
bd86298e | 79 | actual_group = ext4_get_group_number(sb, block); |
68911009 | 80 | return (actual_group == block_group) ? 1 : 0; |
0bf7e837 JS |
81 | } |
82 | ||
d5b8f310 TT |
83 | /* Return the number of clusters used for file system metadata; this |
84 | * represents the overhead needed by the file system. | |
85 | */ | |
86 | unsigned ext4_num_overhead_clusters(struct super_block *sb, | |
87 | ext4_group_t block_group, | |
88 | struct ext4_group_desc *gdp) | |
0bf7e837 | 89 | { |
d5b8f310 TT |
90 | unsigned num_clusters; |
91 | int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c; | |
92 | ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group); | |
93 | ext4_fsblk_t itbl_blk; | |
0bf7e837 | 94 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
0bf7e837 | 95 | |
d5b8f310 TT |
96 | /* This is the number of clusters used by the superblock, |
97 | * block group descriptors, and reserved block group | |
98 | * descriptor blocks */ | |
99 | num_clusters = ext4_num_base_meta_clusters(sb, block_group); | |
100 | ||
101 | /* | |
102 | * For the allocation bitmaps and inode table, we first need | |
103 | * to check to see if the block is in the block group. If it | |
104 | * is, then check to see if the cluster is already accounted | |
105 | * for in the clusters used for the base metadata cluster, or | |
106 | * if we can increment the base metadata cluster to include | |
107 | * that block. Otherwise, we will have to track the cluster | |
108 | * used for the allocation bitmap or inode table explicitly. | |
109 | * Normally all of these blocks are contiguous, so the special | |
110 | * case handling shouldn't be necessary except for *very* | |
111 | * unusual file system layouts. | |
112 | */ | |
113 | if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) { | |
b0dd6b70 TT |
114 | block_cluster = EXT4_B2C(sbi, |
115 | ext4_block_bitmap(sb, gdp) - start); | |
d5b8f310 TT |
116 | if (block_cluster < num_clusters) |
117 | block_cluster = -1; | |
118 | else if (block_cluster == num_clusters) { | |
119 | num_clusters++; | |
120 | block_cluster = -1; | |
121 | } | |
122 | } | |
123 | ||
124 | if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) { | |
125 | inode_cluster = EXT4_B2C(sbi, | |
b0dd6b70 | 126 | ext4_inode_bitmap(sb, gdp) - start); |
d5b8f310 TT |
127 | if (inode_cluster < num_clusters) |
128 | inode_cluster = -1; | |
129 | else if (inode_cluster == num_clusters) { | |
130 | num_clusters++; | |
131 | inode_cluster = -1; | |
132 | } | |
133 | } | |
134 | ||
135 | itbl_blk = ext4_inode_table(sb, gdp); | |
136 | for (i = 0; i < sbi->s_itb_per_group; i++) { | |
137 | if (ext4_block_in_group(sb, itbl_blk + i, block_group)) { | |
b0dd6b70 | 138 | c = EXT4_B2C(sbi, itbl_blk + i - start); |
d5b8f310 TT |
139 | if ((c < num_clusters) || (c == inode_cluster) || |
140 | (c == block_cluster) || (c == itbl_cluster)) | |
141 | continue; | |
142 | if (c == num_clusters) { | |
143 | num_clusters++; | |
144 | continue; | |
145 | } | |
146 | num_clusters++; | |
147 | itbl_cluster = c; | |
0bf7e837 JS |
148 | } |
149 | } | |
d5b8f310 TT |
150 | |
151 | if (block_cluster != -1) | |
152 | num_clusters++; | |
153 | if (inode_cluster != -1) | |
154 | num_clusters++; | |
155 | ||
156 | return num_clusters; | |
0bf7e837 | 157 | } |
c2ea3fde | 158 | |
d5b8f310 TT |
159 | static unsigned int num_clusters_in_group(struct super_block *sb, |
160 | ext4_group_t block_group) | |
49f7f9af | 161 | { |
d5b8f310 TT |
162 | unsigned int blocks; |
163 | ||
49f7f9af TT |
164 | if (block_group == ext4_get_groups_count(sb) - 1) { |
165 | /* | |
166 | * Even though mke2fs always initializes the first and | |
167 | * last group, just in case some other tool was used, | |
168 | * we need to make sure we calculate the right free | |
169 | * blocks. | |
170 | */ | |
d5b8f310 | 171 | blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) - |
49f7f9af TT |
172 | ext4_group_first_block_no(sb, block_group); |
173 | } else | |
d5b8f310 TT |
174 | blocks = EXT4_BLOCKS_PER_GROUP(sb); |
175 | return EXT4_NUM_B2C(EXT4_SB(sb), blocks); | |
49f7f9af TT |
176 | } |
177 | ||
fd034a84 TT |
178 | /* Initializes an uninitialized block bitmap */ |
179 | void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, | |
180 | ext4_group_t block_group, | |
181 | struct ext4_group_desc *gdp) | |
717d50e4 | 182 | { |
d5b8f310 | 183 | unsigned int bit, bit_max; |
717d50e4 | 184 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
fd034a84 TT |
185 | ext4_fsblk_t start, tmp; |
186 | int flex_bg = 0; | |
187 | ||
188 | J_ASSERT_BH(bh, buffer_locked(bh)); | |
189 | ||
190 | /* If checksum is bad mark all blocks used to prevent allocation | |
191 | * essentially implementing a per-group read-only flag. */ | |
feb0ab32 | 192 | if (!ext4_group_desc_csum_verify(sb, block_group, gdp)) { |
fd034a84 | 193 | ext4_error(sb, "Checksum bad for group %u", block_group); |
021b65bb | 194 | ext4_free_group_clusters_set(sb, gdp, 0); |
fd034a84 TT |
195 | ext4_free_inodes_set(sb, gdp, 0); |
196 | ext4_itable_unused_set(sb, gdp, 0); | |
197 | memset(bh->b_data, 0xff, sb->s_blocksize); | |
79f1ba49 | 198 | ext4_block_bitmap_csum_set(sb, block_group, gdp, bh); |
fd034a84 | 199 | return; |
717d50e4 | 200 | } |
fd034a84 | 201 | memset(bh->b_data, 0, sb->s_blocksize); |
717d50e4 | 202 | |
d5b8f310 | 203 | bit_max = ext4_num_base_meta_clusters(sb, block_group); |
fd034a84 TT |
204 | for (bit = 0; bit < bit_max; bit++) |
205 | ext4_set_bit(bit, bh->b_data); | |
d00a6d7b | 206 | |
fd034a84 | 207 | start = ext4_group_first_block_no(sb, block_group); |
717d50e4 | 208 | |
fd034a84 TT |
209 | if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) |
210 | flex_bg = 1; | |
717d50e4 | 211 | |
fd034a84 TT |
212 | /* Set bits for block and inode bitmaps, and inode table */ |
213 | tmp = ext4_block_bitmap(sb, gdp); | |
214 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) | |
d5b8f310 | 215 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
717d50e4 | 216 | |
fd034a84 TT |
217 | tmp = ext4_inode_bitmap(sb, gdp); |
218 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) | |
d5b8f310 | 219 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
0bf7e837 | 220 | |
fd034a84 TT |
221 | tmp = ext4_inode_table(sb, gdp); |
222 | for (; tmp < ext4_inode_table(sb, gdp) + | |
223 | sbi->s_itb_per_group; tmp++) { | |
0bf7e837 | 224 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) |
d5b8f310 | 225 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
717d50e4 | 226 | } |
d5b8f310 | 227 | |
fd034a84 TT |
228 | /* |
229 | * Also if the number of blocks within the group is less than | |
230 | * the blocksize * 8 ( which is the size of bitmap ), set rest | |
231 | * of the block bitmap to 1 | |
232 | */ | |
d5b8f310 | 233 | ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group), |
fd034a84 | 234 | sb->s_blocksize * 8, bh->b_data); |
79f1ba49 | 235 | ext4_block_bitmap_csum_set(sb, block_group, gdp, bh); |
feb0ab32 | 236 | ext4_group_desc_csum_set(sb, block_group, gdp); |
717d50e4 AD |
237 | } |
238 | ||
fd034a84 TT |
239 | /* Return the number of free blocks in a block group. It is used when |
240 | * the block bitmap is uninitialized, so we can't just count the bits | |
241 | * in the bitmap. */ | |
cff1dfd7 TT |
242 | unsigned ext4_free_clusters_after_init(struct super_block *sb, |
243 | ext4_group_t block_group, | |
244 | struct ext4_group_desc *gdp) | |
fd034a84 | 245 | { |
d5b8f310 TT |
246 | return num_clusters_in_group(sb, block_group) - |
247 | ext4_num_overhead_clusters(sb, block_group, gdp); | |
fd034a84 | 248 | } |
717d50e4 | 249 | |
ac27a0ec DK |
250 | /* |
251 | * The free blocks are managed by bitmaps. A file system contains several | |
252 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap | |
253 | * block for inodes, N blocks for the inode table and data blocks. | |
254 | * | |
255 | * The file system contains group descriptors which are located after the | |
256 | * super block. Each descriptor contains the number of the bitmap block and | |
257 | * the free blocks count in the block. The descriptors are loaded in memory | |
e627432c | 258 | * when a file system is mounted (see ext4_fill_super). |
ac27a0ec DK |
259 | */ |
260 | ||
ac27a0ec | 261 | /** |
617ba13b | 262 | * ext4_get_group_desc() -- load group descriptor from disk |
ac27a0ec DK |
263 | * @sb: super block |
264 | * @block_group: given block group | |
265 | * @bh: pointer to the buffer head to store the block | |
266 | * group descriptor | |
267 | */ | |
af5bc92d | 268 | struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb, |
fd2d4291 | 269 | ext4_group_t block_group, |
af5bc92d | 270 | struct buffer_head **bh) |
ac27a0ec | 271 | { |
498e5f24 TT |
272 | unsigned int group_desc; |
273 | unsigned int offset; | |
8df9675f | 274 | ext4_group_t ngroups = ext4_get_groups_count(sb); |
af5bc92d | 275 | struct ext4_group_desc *desc; |
617ba13b | 276 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
ac27a0ec | 277 | |
8df9675f | 278 | if (block_group >= ngroups) { |
12062ddd ES |
279 | ext4_error(sb, "block_group >= groups_count - block_group = %u," |
280 | " groups_count = %u", block_group, ngroups); | |
ac27a0ec DK |
281 | |
282 | return NULL; | |
283 | } | |
ac27a0ec | 284 | |
617ba13b MC |
285 | group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb); |
286 | offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1); | |
ac27a0ec | 287 | if (!sbi->s_group_desc[group_desc]) { |
12062ddd | 288 | ext4_error(sb, "Group descriptor not loaded - " |
498e5f24 | 289 | "block_group = %u, group_desc = %u, desc = %u", |
af5bc92d | 290 | block_group, group_desc, offset); |
ac27a0ec DK |
291 | return NULL; |
292 | } | |
293 | ||
0d1ee42f AR |
294 | desc = (struct ext4_group_desc *)( |
295 | (__u8 *)sbi->s_group_desc[group_desc]->b_data + | |
296 | offset * EXT4_DESC_SIZE(sb)); | |
ac27a0ec DK |
297 | if (bh) |
298 | *bh = sbi->s_group_desc[group_desc]; | |
0d1ee42f | 299 | return desc; |
ac27a0ec DK |
300 | } |
301 | ||
7a4c5de2 TT |
302 | /* |
303 | * Return the block number which was discovered to be invalid, or 0 if | |
304 | * the block bitmap is valid. | |
305 | */ | |
306 | static ext4_fsblk_t ext4_valid_block_bitmap(struct super_block *sb, | |
307 | struct ext4_group_desc *desc, | |
dbde0abe | 308 | ext4_group_t block_group, |
7a4c5de2 | 309 | struct buffer_head *bh) |
abcb2947 AK |
310 | { |
311 | ext4_grpblk_t offset; | |
312 | ext4_grpblk_t next_zero_bit; | |
7a4c5de2 | 313 | ext4_fsblk_t blk; |
abcb2947 AK |
314 | ext4_fsblk_t group_first_block; |
315 | ||
316 | if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) { | |
317 | /* with FLEX_BG, the inode/block bitmaps and itable | |
318 | * blocks may not be in the group at all | |
319 | * so the bitmap validation will be skipped for those groups | |
320 | * or it has to also read the block group where the bitmaps | |
321 | * are located to verify they are set. | |
322 | */ | |
7a4c5de2 | 323 | return 0; |
abcb2947 AK |
324 | } |
325 | group_first_block = ext4_group_first_block_no(sb, block_group); | |
326 | ||
327 | /* check whether block bitmap block number is set */ | |
7a4c5de2 TT |
328 | blk = ext4_block_bitmap(sb, desc); |
329 | offset = blk - group_first_block; | |
abcb2947 AK |
330 | if (!ext4_test_bit(offset, bh->b_data)) |
331 | /* bad block bitmap */ | |
7a4c5de2 | 332 | return blk; |
abcb2947 AK |
333 | |
334 | /* check whether the inode bitmap block number is set */ | |
7a4c5de2 TT |
335 | blk = ext4_inode_bitmap(sb, desc); |
336 | offset = blk - group_first_block; | |
abcb2947 AK |
337 | if (!ext4_test_bit(offset, bh->b_data)) |
338 | /* bad block bitmap */ | |
7a4c5de2 | 339 | return blk; |
abcb2947 AK |
340 | |
341 | /* check whether the inode table block number is set */ | |
7a4c5de2 TT |
342 | blk = ext4_inode_table(sb, desc); |
343 | offset = blk - group_first_block; | |
abcb2947 AK |
344 | next_zero_bit = ext4_find_next_zero_bit(bh->b_data, |
345 | offset + EXT4_SB(sb)->s_itb_per_group, | |
346 | offset); | |
7a4c5de2 TT |
347 | if (next_zero_bit < offset + EXT4_SB(sb)->s_itb_per_group) |
348 | /* bad bitmap for inode tables */ | |
349 | return blk; | |
abcb2947 AK |
350 | return 0; |
351 | } | |
fa77dcfa DW |
352 | |
353 | void ext4_validate_block_bitmap(struct super_block *sb, | |
354 | struct ext4_group_desc *desc, | |
dbde0abe | 355 | ext4_group_t block_group, |
fa77dcfa DW |
356 | struct buffer_head *bh) |
357 | { | |
7a4c5de2 TT |
358 | ext4_fsblk_t blk; |
359 | ||
fa77dcfa DW |
360 | if (buffer_verified(bh)) |
361 | return; | |
362 | ||
363 | ext4_lock_group(sb, block_group); | |
7a4c5de2 TT |
364 | blk = ext4_valid_block_bitmap(sb, desc, block_group, bh); |
365 | if (unlikely(blk != 0)) { | |
366 | ext4_unlock_group(sb, block_group); | |
367 | ext4_error(sb, "bg %u: block %llu: invalid block bitmap", | |
368 | block_group, blk); | |
369 | return; | |
370 | } | |
371 | if (unlikely(!ext4_block_bitmap_csum_verify(sb, block_group, | |
79f1ba49 | 372 | desc, bh))) { |
7a4c5de2 TT |
373 | ext4_unlock_group(sb, block_group); |
374 | ext4_error(sb, "bg %u: bad block bitmap checksum", block_group); | |
375 | return; | |
376 | } | |
377 | set_buffer_verified(bh); | |
fa77dcfa DW |
378 | ext4_unlock_group(sb, block_group); |
379 | } | |
380 | ||
ac27a0ec | 381 | /** |
15b49132 | 382 | * ext4_read_block_bitmap_nowait() |
ac27a0ec DK |
383 | * @sb: super block |
384 | * @block_group: given block group | |
385 | * | |
abcb2947 AK |
386 | * Read the bitmap for a given block_group,and validate the |
387 | * bits for block/inode/inode tables are set in the bitmaps | |
ac27a0ec DK |
388 | * |
389 | * Return buffer_head on success or NULL in case of failure. | |
390 | */ | |
717d50e4 | 391 | struct buffer_head * |
813e5727 | 392 | ext4_read_block_bitmap_nowait(struct super_block *sb, ext4_group_t block_group) |
ac27a0ec | 393 | { |
af5bc92d | 394 | struct ext4_group_desc *desc; |
813e5727 | 395 | struct buffer_head *bh; |
7c9e69fa | 396 | ext4_fsblk_t bitmap_blk; |
ac27a0ec | 397 | |
717d50e4 | 398 | desc = ext4_get_group_desc(sb, block_group, NULL); |
ac27a0ec | 399 | if (!desc) |
7c9e69fa AK |
400 | return NULL; |
401 | bitmap_blk = ext4_block_bitmap(sb, desc); | |
abcb2947 AK |
402 | bh = sb_getblk(sb, bitmap_blk); |
403 | if (unlikely(!bh)) { | |
813e5727 TT |
404 | ext4_error(sb, "Cannot get buffer for block bitmap - " |
405 | "block_group = %u, block_bitmap = %llu", | |
406 | block_group, bitmap_blk); | |
abcb2947 AK |
407 | return NULL; |
408 | } | |
2ccb5fb9 AK |
409 | |
410 | if (bitmap_uptodate(bh)) | |
fa77dcfa | 411 | goto verify; |
abcb2947 | 412 | |
c806e68f | 413 | lock_buffer(bh); |
2ccb5fb9 AK |
414 | if (bitmap_uptodate(bh)) { |
415 | unlock_buffer(bh); | |
fa77dcfa | 416 | goto verify; |
2ccb5fb9 | 417 | } |
955ce5f5 | 418 | ext4_lock_group(sb, block_group); |
717d50e4 | 419 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
abcb2947 | 420 | ext4_init_block_bitmap(sb, bh, block_group, desc); |
2ccb5fb9 | 421 | set_bitmap_uptodate(bh); |
abcb2947 | 422 | set_buffer_uptodate(bh); |
955ce5f5 | 423 | ext4_unlock_group(sb, block_group); |
3300beda | 424 | unlock_buffer(bh); |
abcb2947 | 425 | return bh; |
717d50e4 | 426 | } |
955ce5f5 | 427 | ext4_unlock_group(sb, block_group); |
2ccb5fb9 AK |
428 | if (buffer_uptodate(bh)) { |
429 | /* | |
430 | * if not uninit if bh is uptodate, | |
431 | * bitmap is also uptodate | |
432 | */ | |
433 | set_bitmap_uptodate(bh); | |
434 | unlock_buffer(bh); | |
fa77dcfa | 435 | goto verify; |
2ccb5fb9 AK |
436 | } |
437 | /* | |
813e5727 | 438 | * submit the buffer_head for reading |
2ccb5fb9 | 439 | */ |
813e5727 | 440 | set_buffer_new(bh); |
0562e0ba | 441 | trace_ext4_read_block_bitmap_load(sb, block_group); |
813e5727 TT |
442 | bh->b_end_io = ext4_end_bitmap_read; |
443 | get_bh(bh); | |
9f203507 | 444 | submit_bh(READ | REQ_META | REQ_PRIO, bh); |
813e5727 | 445 | return bh; |
fa77dcfa DW |
446 | verify: |
447 | ext4_validate_block_bitmap(sb, desc, block_group, bh); | |
48d9eb97 DW |
448 | if (buffer_verified(bh)) |
449 | return bh; | |
450 | put_bh(bh); | |
451 | return NULL; | |
813e5727 TT |
452 | } |
453 | ||
454 | /* Returns 0 on success, 1 on error */ | |
455 | int ext4_wait_block_bitmap(struct super_block *sb, ext4_group_t block_group, | |
456 | struct buffer_head *bh) | |
457 | { | |
458 | struct ext4_group_desc *desc; | |
459 | ||
460 | if (!buffer_new(bh)) | |
461 | return 0; | |
462 | desc = ext4_get_group_desc(sb, block_group, NULL); | |
463 | if (!desc) | |
464 | return 1; | |
465 | wait_on_buffer(bh); | |
466 | if (!buffer_uptodate(bh)) { | |
12062ddd | 467 | ext4_error(sb, "Cannot read block bitmap - " |
813e5727 | 468 | "block_group = %u, block_bitmap = %llu", |
d4dc462f | 469 | block_group, (unsigned long long) bh->b_blocknr); |
813e5727 | 470 | return 1; |
abcb2947 | 471 | } |
813e5727 TT |
472 | clear_buffer_new(bh); |
473 | /* Panic or remount fs read-only if block bitmap is invalid */ | |
fa77dcfa | 474 | ext4_validate_block_bitmap(sb, desc, block_group, bh); |
48d9eb97 DW |
475 | /* ...but check for error just in case errors=continue. */ |
476 | return !buffer_verified(bh); | |
813e5727 TT |
477 | } |
478 | ||
479 | struct buffer_head * | |
480 | ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group) | |
481 | { | |
482 | struct buffer_head *bh; | |
483 | ||
484 | bh = ext4_read_block_bitmap_nowait(sb, block_group); | |
15b49132 EG |
485 | if (!bh) |
486 | return NULL; | |
813e5727 TT |
487 | if (ext4_wait_block_bitmap(sb, block_group, bh)) { |
488 | put_bh(bh); | |
489 | return NULL; | |
490 | } | |
ac27a0ec DK |
491 | return bh; |
492 | } | |
ac27a0ec | 493 | |
8c3bf8a0 | 494 | /** |
df55c99d | 495 | * ext4_has_free_clusters() |
8c3bf8a0 | 496 | * @sbi: in-core super block structure. |
df55c99d TT |
497 | * @nclusters: number of needed blocks |
498 | * @flags: flags from ext4_mb_new_blocks() | |
8c3bf8a0 | 499 | * |
df55c99d | 500 | * Check if filesystem has nclusters free & available for allocation. |
8c3bf8a0 ES |
501 | * On success return 1, return 0 on failure. |
502 | */ | |
df55c99d TT |
503 | static int ext4_has_free_clusters(struct ext4_sb_info *sbi, |
504 | s64 nclusters, unsigned int flags) | |
a30d542a | 505 | { |
27dd4385 | 506 | s64 free_clusters, dirty_clusters, rsv, resv_clusters; |
57042651 | 507 | struct percpu_counter *fcc = &sbi->s_freeclusters_counter; |
df55c99d | 508 | struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter; |
a30d542a | 509 | |
df55c99d TT |
510 | free_clusters = percpu_counter_read_positive(fcc); |
511 | dirty_clusters = percpu_counter_read_positive(dcc); | |
27dd4385 | 512 | resv_clusters = atomic64_read(&sbi->s_resv_clusters); |
304e220f LC |
513 | |
514 | /* | |
515 | * r_blocks_count should always be multiple of the cluster ratio so | |
516 | * we are safe to do a plane bit shift only. | |
517 | */ | |
27dd4385 LC |
518 | rsv = (ext4_r_blocks_count(sbi->s_es) >> sbi->s_cluster_bits) + |
519 | resv_clusters; | |
a30d542a | 520 | |
27dd4385 | 521 | if (free_clusters - (nclusters + rsv + dirty_clusters) < |
df55c99d | 522 | EXT4_FREECLUSTERS_WATERMARK) { |
304e220f | 523 | free_clusters = percpu_counter_sum_positive(fcc); |
df55c99d | 524 | dirty_clusters = percpu_counter_sum_positive(dcc); |
6bc6e63f | 525 | } |
df55c99d TT |
526 | /* Check whether we have space after accounting for current |
527 | * dirty clusters & root reserved clusters. | |
6bc6e63f | 528 | */ |
27dd4385 | 529 | if (free_clusters >= (rsv + nclusters + dirty_clusters)) |
a996031c | 530 | return 1; |
a30d542a | 531 | |
df55c99d | 532 | /* Hm, nope. Are (enough) root reserved clusters available? */ |
08cefc7a EB |
533 | if (uid_eq(sbi->s_resuid, current_fsuid()) || |
534 | (!gid_eq(sbi->s_resgid, GLOBAL_ROOT_GID) && in_group_p(sbi->s_resgid)) || | |
55f020db | 535 | capable(CAP_SYS_RESOURCE) || |
27dd4385 | 536 | (flags & EXT4_MB_USE_ROOT_BLOCKS)) { |
55f020db | 537 | |
27dd4385 LC |
538 | if (free_clusters >= (nclusters + dirty_clusters + |
539 | resv_clusters)) | |
540 | return 1; | |
541 | } | |
542 | /* No free blocks. Let's see if we can dip into reserved pool */ | |
543 | if (flags & EXT4_MB_USE_RESERVED) { | |
df55c99d | 544 | if (free_clusters >= (nclusters + dirty_clusters)) |
a996031c ES |
545 | return 1; |
546 | } | |
547 | ||
548 | return 0; | |
a30d542a AK |
549 | } |
550 | ||
e7d5f315 TT |
551 | int ext4_claim_free_clusters(struct ext4_sb_info *sbi, |
552 | s64 nclusters, unsigned int flags) | |
ac27a0ec | 553 | { |
df55c99d | 554 | if (ext4_has_free_clusters(sbi, nclusters, flags)) { |
e7d5f315 | 555 | percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters); |
16eb7295 | 556 | return 0; |
8c3bf8a0 ES |
557 | } else |
558 | return -ENOSPC; | |
a30d542a | 559 | } |
07031431 | 560 | |
ac27a0ec | 561 | /** |
617ba13b | 562 | * ext4_should_retry_alloc() |
ac27a0ec DK |
563 | * @sb: super block |
564 | * @retries number of attemps has been made | |
565 | * | |
617ba13b | 566 | * ext4_should_retry_alloc() is called when ENOSPC is returned, and if |
ac27a0ec | 567 | * it is profitable to retry the operation, this function will wait |
25985edc | 568 | * for the current or committing transaction to complete, and then |
ac27a0ec DK |
569 | * return TRUE. |
570 | * | |
571 | * if the total number of retries exceed three times, return FALSE. | |
572 | */ | |
617ba13b | 573 | int ext4_should_retry_alloc(struct super_block *sb, int *retries) |
ac27a0ec | 574 | { |
df55c99d | 575 | if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) || |
8f64b32e ES |
576 | (*retries)++ > 3 || |
577 | !EXT4_SB(sb)->s_journal) | |
ac27a0ec DK |
578 | return 0; |
579 | ||
580 | jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); | |
581 | ||
dab291af | 582 | return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); |
ac27a0ec DK |
583 | } |
584 | ||
654b4908 | 585 | /* |
d2a17637 | 586 | * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks |
654b4908 AK |
587 | * |
588 | * @handle: handle to this transaction | |
589 | * @inode: file inode | |
590 | * @goal: given target block(filesystem wide) | |
7b415bf6 | 591 | * @count: pointer to total number of clusters needed |
654b4908 AK |
592 | * @errp: error code |
593 | * | |
97df5d15 | 594 | * Return 1st allocated block number on success, *count stores total account |
d2a17637 | 595 | * error stores in errp pointer |
654b4908 | 596 | */ |
d2a17637 | 597 | ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode, |
55f020db AH |
598 | ext4_fsblk_t goal, unsigned int flags, |
599 | unsigned long *count, int *errp) | |
654b4908 | 600 | { |
97df5d15 | 601 | struct ext4_allocation_request ar; |
d2a17637 | 602 | ext4_fsblk_t ret; |
97df5d15 TT |
603 | |
604 | memset(&ar, 0, sizeof(ar)); | |
605 | /* Fill with neighbour allocated blocks */ | |
606 | ar.inode = inode; | |
607 | ar.goal = goal; | |
608 | ar.len = count ? *count : 1; | |
55f020db | 609 | ar.flags = flags; |
97df5d15 TT |
610 | |
611 | ret = ext4_mb_new_blocks(handle, &ar, errp); | |
612 | if (count) | |
613 | *count = ar.len; | |
d2a17637 | 614 | /* |
72b8ab9d ES |
615 | * Account for the allocated meta blocks. We will never |
616 | * fail EDQUOT for metdata, but we do account for it. | |
d2a17637 | 617 | */ |
f2321097 TT |
618 | if (!(*errp) && |
619 | ext4_test_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED)) { | |
d2a17637 | 620 | spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
97df5d15 | 621 | EXT4_I(inode)->i_allocated_meta_blocks += ar.len; |
d2a17637 | 622 | spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
7b415bf6 AK |
623 | dquot_alloc_block_nofail(inode, |
624 | EXT4_C2B(EXT4_SB(inode->i_sb), ar.len)); | |
d2a17637 MC |
625 | } |
626 | return ret; | |
654b4908 AK |
627 | } |
628 | ||
ac27a0ec | 629 | /** |
5dee5437 | 630 | * ext4_count_free_clusters() -- count filesystem free clusters |
ac27a0ec DK |
631 | * @sb: superblock |
632 | * | |
5dee5437 | 633 | * Adds up the number of free clusters from each block group. |
ac27a0ec | 634 | */ |
5dee5437 | 635 | ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb) |
ac27a0ec | 636 | { |
617ba13b MC |
637 | ext4_fsblk_t desc_count; |
638 | struct ext4_group_desc *gdp; | |
fd2d4291 | 639 | ext4_group_t i; |
8df9675f | 640 | ext4_group_t ngroups = ext4_get_groups_count(sb); |
617ba13b MC |
641 | #ifdef EXT4FS_DEBUG |
642 | struct ext4_super_block *es; | |
643 | ext4_fsblk_t bitmap_count; | |
498e5f24 | 644 | unsigned int x; |
ac27a0ec DK |
645 | struct buffer_head *bitmap_bh = NULL; |
646 | ||
617ba13b | 647 | es = EXT4_SB(sb)->s_es; |
ac27a0ec DK |
648 | desc_count = 0; |
649 | bitmap_count = 0; | |
650 | gdp = NULL; | |
651 | ||
ac27a0ec | 652 | for (i = 0; i < ngroups; i++) { |
617ba13b | 653 | gdp = ext4_get_group_desc(sb, i, NULL); |
ac27a0ec DK |
654 | if (!gdp) |
655 | continue; | |
021b65bb | 656 | desc_count += ext4_free_group_clusters(sb, gdp); |
ac27a0ec | 657 | brelse(bitmap_bh); |
574ca174 | 658 | bitmap_bh = ext4_read_block_bitmap(sb, i); |
ac27a0ec DK |
659 | if (bitmap_bh == NULL) |
660 | continue; | |
661 | ||
f6fb99ca TT |
662 | x = ext4_count_free(bitmap_bh->b_data, |
663 | EXT4_BLOCKS_PER_GROUP(sb) / 8); | |
9fd9784c | 664 | printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n", |
021b65bb | 665 | i, ext4_free_group_clusters(sb, gdp), x); |
ac27a0ec DK |
666 | bitmap_count += x; |
667 | } | |
668 | brelse(bitmap_bh); | |
5dee5437 TT |
669 | printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu" |
670 | ", computed = %llu, %llu\n", | |
810da240 | 671 | EXT4_NUM_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)), |
4776004f | 672 | desc_count, bitmap_count); |
ac27a0ec DK |
673 | return bitmap_count; |
674 | #else | |
675 | desc_count = 0; | |
ac27a0ec | 676 | for (i = 0; i < ngroups; i++) { |
617ba13b | 677 | gdp = ext4_get_group_desc(sb, i, NULL); |
ac27a0ec DK |
678 | if (!gdp) |
679 | continue; | |
021b65bb | 680 | desc_count += ext4_free_group_clusters(sb, gdp); |
ac27a0ec DK |
681 | } |
682 | ||
683 | return desc_count; | |
684 | #endif | |
685 | } | |
686 | ||
fd2d4291 | 687 | static inline int test_root(ext4_group_t a, int b) |
ac27a0ec | 688 | { |
f4afb4f4 TT |
689 | while (1) { |
690 | if (a < b) | |
691 | return 0; | |
692 | if (a == b) | |
693 | return 1; | |
694 | if ((a % b) != 0) | |
695 | return 0; | |
696 | a = a / b; | |
697 | } | |
ac27a0ec DK |
698 | } |
699 | ||
fd2d4291 | 700 | static int ext4_group_sparse(ext4_group_t group) |
ac27a0ec DK |
701 | { |
702 | if (group <= 1) | |
703 | return 1; | |
704 | if (!(group & 1)) | |
705 | return 0; | |
706 | return (test_root(group, 7) || test_root(group, 5) || | |
707 | test_root(group, 3)); | |
708 | } | |
709 | ||
710 | /** | |
617ba13b | 711 | * ext4_bg_has_super - number of blocks used by the superblock in group |
ac27a0ec DK |
712 | * @sb: superblock for filesystem |
713 | * @group: group number to check | |
714 | * | |
715 | * Return the number of blocks used by the superblock (primary or backup) | |
716 | * in this group. Currently this will be only 0 or 1. | |
717 | */ | |
fd2d4291 | 718 | int ext4_bg_has_super(struct super_block *sb, ext4_group_t group) |
ac27a0ec | 719 | { |
617ba13b MC |
720 | if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
721 | EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) && | |
722 | !ext4_group_sparse(group)) | |
ac27a0ec DK |
723 | return 0; |
724 | return 1; | |
725 | } | |
726 | ||
fd2d4291 AM |
727 | static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb, |
728 | ext4_group_t group) | |
ac27a0ec | 729 | { |
617ba13b | 730 | unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); |
fd2d4291 AM |
731 | ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb); |
732 | ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1; | |
ac27a0ec DK |
733 | |
734 | if (group == first || group == first + 1 || group == last) | |
735 | return 1; | |
736 | return 0; | |
737 | } | |
738 | ||
fd2d4291 AM |
739 | static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, |
740 | ext4_group_t group) | |
ac27a0ec | 741 | { |
8dadb198 TT |
742 | if (!ext4_bg_has_super(sb, group)) |
743 | return 0; | |
744 | ||
745 | if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG)) | |
746 | return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); | |
747 | else | |
748 | return EXT4_SB(sb)->s_gdb_count; | |
ac27a0ec DK |
749 | } |
750 | ||
751 | /** | |
617ba13b | 752 | * ext4_bg_num_gdb - number of blocks used by the group table in group |
ac27a0ec DK |
753 | * @sb: superblock for filesystem |
754 | * @group: group number to check | |
755 | * | |
756 | * Return the number of blocks used by the group descriptor table | |
757 | * (primary or backup) in this group. In the future there may be a | |
758 | * different number of descriptor blocks in each group. | |
759 | */ | |
fd2d4291 | 760 | unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group) |
ac27a0ec DK |
761 | { |
762 | unsigned long first_meta_bg = | |
617ba13b MC |
763 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); |
764 | unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); | |
ac27a0ec | 765 | |
617ba13b | 766 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG) || |
ac27a0ec | 767 | metagroup < first_meta_bg) |
af5bc92d | 768 | return ext4_bg_num_gdb_nometa(sb, group); |
ac27a0ec | 769 | |
617ba13b | 770 | return ext4_bg_num_gdb_meta(sb,group); |
ac27a0ec DK |
771 | |
772 | } | |
c2ea3fde | 773 | |
49f7f9af | 774 | /* |
d5b8f310 | 775 | * This function returns the number of file system metadata clusters at |
49f7f9af TT |
776 | * the beginning of a block group, including the reserved gdt blocks. |
777 | */ | |
5f163cc7 | 778 | static unsigned ext4_num_base_meta_clusters(struct super_block *sb, |
d5b8f310 | 779 | ext4_group_t block_group) |
49f7f9af TT |
780 | { |
781 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
d5b8f310 | 782 | unsigned num; |
49f7f9af TT |
783 | |
784 | /* Check for superblock and gdt backups in this group */ | |
785 | num = ext4_bg_has_super(sb, block_group); | |
786 | ||
787 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) || | |
788 | block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) * | |
789 | sbi->s_desc_per_block) { | |
790 | if (num) { | |
791 | num += ext4_bg_num_gdb(sb, block_group); | |
792 | num += le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks); | |
793 | } | |
794 | } else { /* For META_BG_BLOCK_GROUPS */ | |
795 | num += ext4_bg_num_gdb(sb, block_group); | |
796 | } | |
d5b8f310 | 797 | return EXT4_NUM_B2C(sbi, num); |
49f7f9af | 798 | } |
f86186b4 ES |
799 | /** |
800 | * ext4_inode_to_goal_block - return a hint for block allocation | |
801 | * @inode: inode for block allocation | |
802 | * | |
803 | * Return the ideal location to start allocating blocks for a | |
804 | * newly created inode. | |
805 | */ | |
806 | ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode) | |
807 | { | |
808 | struct ext4_inode_info *ei = EXT4_I(inode); | |
809 | ext4_group_t block_group; | |
810 | ext4_grpblk_t colour; | |
811 | int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb)); | |
812 | ext4_fsblk_t bg_start; | |
813 | ext4_fsblk_t last_block; | |
814 | ||
815 | block_group = ei->i_block_group; | |
816 | if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) { | |
817 | /* | |
818 | * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME | |
819 | * block groups per flexgroup, reserve the first block | |
820 | * group for directories and special files. Regular | |
821 | * files will start at the second block group. This | |
822 | * tends to speed up directory access and improves | |
823 | * fsck times. | |
824 | */ | |
825 | block_group &= ~(flex_size-1); | |
826 | if (S_ISREG(inode->i_mode)) | |
827 | block_group++; | |
828 | } | |
829 | bg_start = ext4_group_first_block_no(inode->i_sb, block_group); | |
830 | last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; | |
831 | ||
832 | /* | |
833 | * If we are doing delayed allocation, we don't need take | |
834 | * colour into account. | |
835 | */ | |
836 | if (test_opt(inode->i_sb, DELALLOC)) | |
837 | return bg_start; | |
838 | ||
839 | if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) | |
840 | colour = (current->pid % 16) * | |
841 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
842 | else | |
843 | colour = (current->pid % 16) * ((last_block - bg_start) / 16); | |
844 | return bg_start + colour; | |
845 | } | |
846 |