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Commit | Line | Data |
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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 | ||
72b64b59 | 32 | /* |
3212a80a TT |
33 | * Calculate the block group number and offset into the block/cluster |
34 | * allocation bitmap, given a block number | |
72b64b59 AM |
35 | */ |
36 | void ext4_get_group_no_and_offset(struct super_block *sb, ext4_fsblk_t blocknr, | |
fd2d4291 | 37 | ext4_group_t *blockgrpp, ext4_grpblk_t *offsetp) |
72b64b59 | 38 | { |
8c55e204 | 39 | struct ext4_super_block *es = EXT4_SB(sb)->s_es; |
72b64b59 AM |
40 | ext4_grpblk_t offset; |
41 | ||
8c55e204 | 42 | blocknr = blocknr - le32_to_cpu(es->s_first_data_block); |
3212a80a TT |
43 | offset = do_div(blocknr, EXT4_BLOCKS_PER_GROUP(sb)) >> |
44 | EXT4_SB(sb)->s_cluster_bits; | |
72b64b59 AM |
45 | if (offsetp) |
46 | *offsetp = offset; | |
47 | if (blockgrpp) | |
8c55e204 | 48 | *blockgrpp = blocknr; |
72b64b59 AM |
49 | |
50 | } | |
51 | ||
0bf7e837 JS |
52 | static int ext4_block_in_group(struct super_block *sb, ext4_fsblk_t block, |
53 | ext4_group_t block_group) | |
54 | { | |
55 | ext4_group_t actual_group; | |
7477827f | 56 | ext4_get_group_no_and_offset(sb, block, &actual_group, NULL); |
0bf7e837 JS |
57 | if (actual_group == block_group) |
58 | return 1; | |
59 | return 0; | |
60 | } | |
61 | ||
d5b8f310 TT |
62 | /* Return the number of clusters used for file system metadata; this |
63 | * represents the overhead needed by the file system. | |
64 | */ | |
65 | unsigned ext4_num_overhead_clusters(struct super_block *sb, | |
66 | ext4_group_t block_group, | |
67 | struct ext4_group_desc *gdp) | |
0bf7e837 | 68 | { |
d5b8f310 TT |
69 | unsigned num_clusters; |
70 | int block_cluster = -1, inode_cluster = -1, itbl_cluster = -1, i, c; | |
71 | ext4_fsblk_t start = ext4_group_first_block_no(sb, block_group); | |
72 | ext4_fsblk_t itbl_blk; | |
0bf7e837 | 73 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
0bf7e837 | 74 | |
d5b8f310 TT |
75 | /* This is the number of clusters used by the superblock, |
76 | * block group descriptors, and reserved block group | |
77 | * descriptor blocks */ | |
78 | num_clusters = ext4_num_base_meta_clusters(sb, block_group); | |
79 | ||
80 | /* | |
81 | * For the allocation bitmaps and inode table, we first need | |
82 | * to check to see if the block is in the block group. If it | |
83 | * is, then check to see if the cluster is already accounted | |
84 | * for in the clusters used for the base metadata cluster, or | |
85 | * if we can increment the base metadata cluster to include | |
86 | * that block. Otherwise, we will have to track the cluster | |
87 | * used for the allocation bitmap or inode table explicitly. | |
88 | * Normally all of these blocks are contiguous, so the special | |
89 | * case handling shouldn't be necessary except for *very* | |
90 | * unusual file system layouts. | |
91 | */ | |
92 | if (ext4_block_in_group(sb, ext4_block_bitmap(sb, gdp), block_group)) { | |
93 | block_cluster = EXT4_B2C(sbi, (start - | |
94 | ext4_block_bitmap(sb, gdp))); | |
95 | if (block_cluster < num_clusters) | |
96 | block_cluster = -1; | |
97 | else if (block_cluster == num_clusters) { | |
98 | num_clusters++; | |
99 | block_cluster = -1; | |
100 | } | |
101 | } | |
102 | ||
103 | if (ext4_block_in_group(sb, ext4_inode_bitmap(sb, gdp), block_group)) { | |
104 | inode_cluster = EXT4_B2C(sbi, | |
105 | start - ext4_inode_bitmap(sb, gdp)); | |
106 | if (inode_cluster < num_clusters) | |
107 | inode_cluster = -1; | |
108 | else if (inode_cluster == num_clusters) { | |
109 | num_clusters++; | |
110 | inode_cluster = -1; | |
111 | } | |
112 | } | |
113 | ||
114 | itbl_blk = ext4_inode_table(sb, gdp); | |
115 | for (i = 0; i < sbi->s_itb_per_group; i++) { | |
116 | if (ext4_block_in_group(sb, itbl_blk + i, block_group)) { | |
117 | c = EXT4_B2C(sbi, start - itbl_blk + i); | |
118 | if ((c < num_clusters) || (c == inode_cluster) || | |
119 | (c == block_cluster) || (c == itbl_cluster)) | |
120 | continue; | |
121 | if (c == num_clusters) { | |
122 | num_clusters++; | |
123 | continue; | |
124 | } | |
125 | num_clusters++; | |
126 | itbl_cluster = c; | |
0bf7e837 JS |
127 | } |
128 | } | |
d5b8f310 TT |
129 | |
130 | if (block_cluster != -1) | |
131 | num_clusters++; | |
132 | if (inode_cluster != -1) | |
133 | num_clusters++; | |
134 | ||
135 | return num_clusters; | |
0bf7e837 | 136 | } |
c2ea3fde | 137 | |
d5b8f310 TT |
138 | static unsigned int num_clusters_in_group(struct super_block *sb, |
139 | ext4_group_t block_group) | |
49f7f9af | 140 | { |
d5b8f310 TT |
141 | unsigned int blocks; |
142 | ||
49f7f9af TT |
143 | if (block_group == ext4_get_groups_count(sb) - 1) { |
144 | /* | |
145 | * Even though mke2fs always initializes the first and | |
146 | * last group, just in case some other tool was used, | |
147 | * we need to make sure we calculate the right free | |
148 | * blocks. | |
149 | */ | |
d5b8f310 | 150 | blocks = ext4_blocks_count(EXT4_SB(sb)->s_es) - |
49f7f9af TT |
151 | ext4_group_first_block_no(sb, block_group); |
152 | } else | |
d5b8f310 TT |
153 | blocks = EXT4_BLOCKS_PER_GROUP(sb); |
154 | return EXT4_NUM_B2C(EXT4_SB(sb), blocks); | |
49f7f9af TT |
155 | } |
156 | ||
fd034a84 TT |
157 | /* Initializes an uninitialized block bitmap */ |
158 | void ext4_init_block_bitmap(struct super_block *sb, struct buffer_head *bh, | |
159 | ext4_group_t block_group, | |
160 | struct ext4_group_desc *gdp) | |
717d50e4 | 161 | { |
d5b8f310 | 162 | unsigned int bit, bit_max; |
717d50e4 | 163 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
fd034a84 TT |
164 | ext4_fsblk_t start, tmp; |
165 | int flex_bg = 0; | |
166 | ||
167 | J_ASSERT_BH(bh, buffer_locked(bh)); | |
168 | ||
169 | /* If checksum is bad mark all blocks used to prevent allocation | |
170 | * essentially implementing a per-group read-only flag. */ | |
171 | if (!ext4_group_desc_csum_verify(sbi, block_group, gdp)) { | |
172 | ext4_error(sb, "Checksum bad for group %u", block_group); | |
021b65bb | 173 | ext4_free_group_clusters_set(sb, gdp, 0); |
fd034a84 TT |
174 | ext4_free_inodes_set(sb, gdp, 0); |
175 | ext4_itable_unused_set(sb, gdp, 0); | |
176 | memset(bh->b_data, 0xff, sb->s_blocksize); | |
177 | return; | |
717d50e4 | 178 | } |
fd034a84 | 179 | memset(bh->b_data, 0, sb->s_blocksize); |
717d50e4 | 180 | |
d5b8f310 | 181 | bit_max = ext4_num_base_meta_clusters(sb, block_group); |
fd034a84 TT |
182 | for (bit = 0; bit < bit_max; bit++) |
183 | ext4_set_bit(bit, bh->b_data); | |
d00a6d7b | 184 | |
fd034a84 | 185 | start = ext4_group_first_block_no(sb, block_group); |
717d50e4 | 186 | |
fd034a84 TT |
187 | if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) |
188 | flex_bg = 1; | |
717d50e4 | 189 | |
fd034a84 TT |
190 | /* Set bits for block and inode bitmaps, and inode table */ |
191 | tmp = ext4_block_bitmap(sb, gdp); | |
192 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) | |
d5b8f310 | 193 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
717d50e4 | 194 | |
fd034a84 TT |
195 | tmp = ext4_inode_bitmap(sb, gdp); |
196 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) | |
d5b8f310 | 197 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
0bf7e837 | 198 | |
fd034a84 TT |
199 | tmp = ext4_inode_table(sb, gdp); |
200 | for (; tmp < ext4_inode_table(sb, gdp) + | |
201 | sbi->s_itb_per_group; tmp++) { | |
0bf7e837 | 202 | if (!flex_bg || ext4_block_in_group(sb, tmp, block_group)) |
d5b8f310 | 203 | ext4_set_bit(EXT4_B2C(sbi, tmp - start), bh->b_data); |
717d50e4 | 204 | } |
d5b8f310 | 205 | |
fd034a84 TT |
206 | /* |
207 | * Also if the number of blocks within the group is less than | |
208 | * the blocksize * 8 ( which is the size of bitmap ), set rest | |
209 | * of the block bitmap to 1 | |
210 | */ | |
d5b8f310 | 211 | ext4_mark_bitmap_end(num_clusters_in_group(sb, block_group), |
fd034a84 | 212 | sb->s_blocksize * 8, bh->b_data); |
717d50e4 AD |
213 | } |
214 | ||
fd034a84 TT |
215 | /* Return the number of free blocks in a block group. It is used when |
216 | * the block bitmap is uninitialized, so we can't just count the bits | |
217 | * in the bitmap. */ | |
cff1dfd7 TT |
218 | unsigned ext4_free_clusters_after_init(struct super_block *sb, |
219 | ext4_group_t block_group, | |
220 | struct ext4_group_desc *gdp) | |
fd034a84 | 221 | { |
d5b8f310 TT |
222 | return num_clusters_in_group(sb, block_group) - |
223 | ext4_num_overhead_clusters(sb, block_group, gdp); | |
fd034a84 | 224 | } |
717d50e4 | 225 | |
ac27a0ec DK |
226 | /* |
227 | * The free blocks are managed by bitmaps. A file system contains several | |
228 | * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap | |
229 | * block for inodes, N blocks for the inode table and data blocks. | |
230 | * | |
231 | * The file system contains group descriptors which are located after the | |
232 | * super block. Each descriptor contains the number of the bitmap block and | |
233 | * the free blocks count in the block. The descriptors are loaded in memory | |
e627432c | 234 | * when a file system is mounted (see ext4_fill_super). |
ac27a0ec DK |
235 | */ |
236 | ||
ac27a0ec | 237 | /** |
617ba13b | 238 | * ext4_get_group_desc() -- load group descriptor from disk |
ac27a0ec DK |
239 | * @sb: super block |
240 | * @block_group: given block group | |
241 | * @bh: pointer to the buffer head to store the block | |
242 | * group descriptor | |
243 | */ | |
af5bc92d | 244 | struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb, |
fd2d4291 | 245 | ext4_group_t block_group, |
af5bc92d | 246 | struct buffer_head **bh) |
ac27a0ec | 247 | { |
498e5f24 TT |
248 | unsigned int group_desc; |
249 | unsigned int offset; | |
8df9675f | 250 | ext4_group_t ngroups = ext4_get_groups_count(sb); |
af5bc92d | 251 | struct ext4_group_desc *desc; |
617ba13b | 252 | struct ext4_sb_info *sbi = EXT4_SB(sb); |
ac27a0ec | 253 | |
8df9675f | 254 | if (block_group >= ngroups) { |
12062ddd ES |
255 | ext4_error(sb, "block_group >= groups_count - block_group = %u," |
256 | " groups_count = %u", block_group, ngroups); | |
ac27a0ec DK |
257 | |
258 | return NULL; | |
259 | } | |
ac27a0ec | 260 | |
617ba13b MC |
261 | group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb); |
262 | offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1); | |
ac27a0ec | 263 | if (!sbi->s_group_desc[group_desc]) { |
12062ddd | 264 | ext4_error(sb, "Group descriptor not loaded - " |
498e5f24 | 265 | "block_group = %u, group_desc = %u, desc = %u", |
af5bc92d | 266 | block_group, group_desc, offset); |
ac27a0ec DK |
267 | return NULL; |
268 | } | |
269 | ||
0d1ee42f AR |
270 | desc = (struct ext4_group_desc *)( |
271 | (__u8 *)sbi->s_group_desc[group_desc]->b_data + | |
272 | offset * EXT4_DESC_SIZE(sb)); | |
ac27a0ec DK |
273 | if (bh) |
274 | *bh = sbi->s_group_desc[group_desc]; | |
0d1ee42f | 275 | return desc; |
ac27a0ec DK |
276 | } |
277 | ||
abcb2947 AK |
278 | static int ext4_valid_block_bitmap(struct super_block *sb, |
279 | struct ext4_group_desc *desc, | |
280 | unsigned int block_group, | |
281 | struct buffer_head *bh) | |
282 | { | |
283 | ext4_grpblk_t offset; | |
284 | ext4_grpblk_t next_zero_bit; | |
285 | ext4_fsblk_t bitmap_blk; | |
286 | ext4_fsblk_t group_first_block; | |
287 | ||
288 | if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FLEX_BG)) { | |
289 | /* with FLEX_BG, the inode/block bitmaps and itable | |
290 | * blocks may not be in the group at all | |
291 | * so the bitmap validation will be skipped for those groups | |
292 | * or it has to also read the block group where the bitmaps | |
293 | * are located to verify they are set. | |
294 | */ | |
295 | return 1; | |
296 | } | |
297 | group_first_block = ext4_group_first_block_no(sb, block_group); | |
298 | ||
299 | /* check whether block bitmap block number is set */ | |
300 | bitmap_blk = ext4_block_bitmap(sb, desc); | |
301 | offset = bitmap_blk - group_first_block; | |
302 | if (!ext4_test_bit(offset, bh->b_data)) | |
303 | /* bad block bitmap */ | |
304 | goto err_out; | |
305 | ||
306 | /* check whether the inode bitmap block number is set */ | |
307 | bitmap_blk = ext4_inode_bitmap(sb, desc); | |
308 | offset = bitmap_blk - group_first_block; | |
309 | if (!ext4_test_bit(offset, bh->b_data)) | |
310 | /* bad block bitmap */ | |
311 | goto err_out; | |
312 | ||
313 | /* check whether the inode table block number is set */ | |
314 | bitmap_blk = ext4_inode_table(sb, desc); | |
315 | offset = bitmap_blk - group_first_block; | |
316 | next_zero_bit = ext4_find_next_zero_bit(bh->b_data, | |
317 | offset + EXT4_SB(sb)->s_itb_per_group, | |
318 | offset); | |
319 | if (next_zero_bit >= offset + EXT4_SB(sb)->s_itb_per_group) | |
320 | /* good bitmap for inode tables */ | |
321 | return 1; | |
322 | ||
323 | err_out: | |
12062ddd | 324 | ext4_error(sb, "Invalid block bitmap - block_group = %d, block = %llu", |
abcb2947 AK |
325 | block_group, bitmap_blk); |
326 | return 0; | |
327 | } | |
ac27a0ec | 328 | /** |
574ca174 | 329 | * ext4_read_block_bitmap() |
ac27a0ec DK |
330 | * @sb: super block |
331 | * @block_group: given block group | |
332 | * | |
abcb2947 AK |
333 | * Read the bitmap for a given block_group,and validate the |
334 | * bits for block/inode/inode tables are set in the bitmaps | |
ac27a0ec DK |
335 | * |
336 | * Return buffer_head on success or NULL in case of failure. | |
337 | */ | |
717d50e4 | 338 | struct buffer_head * |
574ca174 | 339 | ext4_read_block_bitmap(struct super_block *sb, ext4_group_t block_group) |
ac27a0ec | 340 | { |
af5bc92d TT |
341 | struct ext4_group_desc *desc; |
342 | struct buffer_head *bh = NULL; | |
7c9e69fa | 343 | ext4_fsblk_t bitmap_blk; |
ac27a0ec | 344 | |
717d50e4 | 345 | desc = ext4_get_group_desc(sb, block_group, NULL); |
ac27a0ec | 346 | if (!desc) |
7c9e69fa AK |
347 | return NULL; |
348 | bitmap_blk = ext4_block_bitmap(sb, desc); | |
abcb2947 AK |
349 | bh = sb_getblk(sb, bitmap_blk); |
350 | if (unlikely(!bh)) { | |
12062ddd | 351 | ext4_error(sb, "Cannot read block bitmap - " |
a9df9a49 | 352 | "block_group = %u, block_bitmap = %llu", |
e29d1cde | 353 | block_group, bitmap_blk); |
abcb2947 AK |
354 | return NULL; |
355 | } | |
2ccb5fb9 AK |
356 | |
357 | if (bitmap_uptodate(bh)) | |
abcb2947 AK |
358 | return bh; |
359 | ||
c806e68f | 360 | lock_buffer(bh); |
2ccb5fb9 AK |
361 | if (bitmap_uptodate(bh)) { |
362 | unlock_buffer(bh); | |
363 | return bh; | |
364 | } | |
955ce5f5 | 365 | ext4_lock_group(sb, block_group); |
717d50e4 | 366 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { |
abcb2947 | 367 | ext4_init_block_bitmap(sb, bh, block_group, desc); |
2ccb5fb9 | 368 | set_bitmap_uptodate(bh); |
abcb2947 | 369 | set_buffer_uptodate(bh); |
955ce5f5 | 370 | ext4_unlock_group(sb, block_group); |
3300beda | 371 | unlock_buffer(bh); |
abcb2947 | 372 | return bh; |
717d50e4 | 373 | } |
955ce5f5 | 374 | ext4_unlock_group(sb, block_group); |
2ccb5fb9 AK |
375 | if (buffer_uptodate(bh)) { |
376 | /* | |
377 | * if not uninit if bh is uptodate, | |
378 | * bitmap is also uptodate | |
379 | */ | |
380 | set_bitmap_uptodate(bh); | |
381 | unlock_buffer(bh); | |
382 | return bh; | |
383 | } | |
384 | /* | |
385 | * submit the buffer_head for read. We can | |
386 | * safely mark the bitmap as uptodate now. | |
387 | * We do it here so the bitmap uptodate bit | |
388 | * get set with buffer lock held. | |
389 | */ | |
0562e0ba | 390 | trace_ext4_read_block_bitmap_load(sb, block_group); |
2ccb5fb9 | 391 | set_bitmap_uptodate(bh); |
abcb2947 AK |
392 | if (bh_submit_read(bh) < 0) { |
393 | put_bh(bh); | |
12062ddd | 394 | ext4_error(sb, "Cannot read block bitmap - " |
a9df9a49 | 395 | "block_group = %u, block_bitmap = %llu", |
e29d1cde | 396 | block_group, bitmap_blk); |
abcb2947 AK |
397 | return NULL; |
398 | } | |
519deca0 AK |
399 | ext4_valid_block_bitmap(sb, desc, block_group, bh); |
400 | /* | |
401 | * file system mounted not to panic on error, | |
402 | * continue with corrupt bitmap | |
403 | */ | |
ac27a0ec DK |
404 | return bh; |
405 | } | |
ac27a0ec | 406 | |
8c3bf8a0 | 407 | /** |
df55c99d | 408 | * ext4_has_free_clusters() |
8c3bf8a0 | 409 | * @sbi: in-core super block structure. |
df55c99d TT |
410 | * @nclusters: number of needed blocks |
411 | * @flags: flags from ext4_mb_new_blocks() | |
8c3bf8a0 | 412 | * |
df55c99d | 413 | * Check if filesystem has nclusters free & available for allocation. |
8c3bf8a0 ES |
414 | * On success return 1, return 0 on failure. |
415 | */ | |
df55c99d TT |
416 | static int ext4_has_free_clusters(struct ext4_sb_info *sbi, |
417 | s64 nclusters, unsigned int flags) | |
a30d542a | 418 | { |
df55c99d | 419 | s64 free_clusters, dirty_clusters, root_clusters; |
57042651 | 420 | struct percpu_counter *fcc = &sbi->s_freeclusters_counter; |
df55c99d | 421 | struct percpu_counter *dcc = &sbi->s_dirtyclusters_counter; |
a30d542a | 422 | |
df55c99d TT |
423 | free_clusters = percpu_counter_read_positive(fcc); |
424 | dirty_clusters = percpu_counter_read_positive(dcc); | |
425 | root_clusters = EXT4_B2C(sbi, ext4_r_blocks_count(sbi->s_es)); | |
a30d542a | 426 | |
df55c99d TT |
427 | if (free_clusters - (nclusters + root_clusters + dirty_clusters) < |
428 | EXT4_FREECLUSTERS_WATERMARK) { | |
429 | free_clusters = EXT4_C2B(sbi, percpu_counter_sum_positive(fcc)); | |
430 | dirty_clusters = percpu_counter_sum_positive(dcc); | |
6bc6e63f | 431 | } |
df55c99d TT |
432 | /* Check whether we have space after accounting for current |
433 | * dirty clusters & root reserved clusters. | |
6bc6e63f | 434 | */ |
df55c99d | 435 | if (free_clusters >= ((root_clusters + nclusters) + dirty_clusters)) |
a996031c | 436 | return 1; |
a30d542a | 437 | |
df55c99d | 438 | /* Hm, nope. Are (enough) root reserved clusters available? */ |
4c9c544e | 439 | if (sbi->s_resuid == current_fsuid() || |
a996031c | 440 | ((sbi->s_resgid != 0) && in_group_p(sbi->s_resgid)) || |
55f020db AH |
441 | capable(CAP_SYS_RESOURCE) || |
442 | (flags & EXT4_MB_USE_ROOT_BLOCKS)) { | |
443 | ||
df55c99d | 444 | if (free_clusters >= (nclusters + dirty_clusters)) |
a996031c ES |
445 | return 1; |
446 | } | |
447 | ||
448 | return 0; | |
a30d542a AK |
449 | } |
450 | ||
e7d5f315 TT |
451 | int ext4_claim_free_clusters(struct ext4_sb_info *sbi, |
452 | s64 nclusters, unsigned int flags) | |
ac27a0ec | 453 | { |
df55c99d | 454 | if (ext4_has_free_clusters(sbi, nclusters, flags)) { |
e7d5f315 | 455 | percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters); |
16eb7295 | 456 | return 0; |
8c3bf8a0 ES |
457 | } else |
458 | return -ENOSPC; | |
a30d542a | 459 | } |
07031431 | 460 | |
ac27a0ec | 461 | /** |
617ba13b | 462 | * ext4_should_retry_alloc() |
ac27a0ec DK |
463 | * @sb: super block |
464 | * @retries number of attemps has been made | |
465 | * | |
617ba13b | 466 | * ext4_should_retry_alloc() is called when ENOSPC is returned, and if |
ac27a0ec | 467 | * it is profitable to retry the operation, this function will wait |
25985edc | 468 | * for the current or committing transaction to complete, and then |
ac27a0ec DK |
469 | * return TRUE. |
470 | * | |
471 | * if the total number of retries exceed three times, return FALSE. | |
472 | */ | |
617ba13b | 473 | int ext4_should_retry_alloc(struct super_block *sb, int *retries) |
ac27a0ec | 474 | { |
df55c99d | 475 | if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) || |
8f64b32e ES |
476 | (*retries)++ > 3 || |
477 | !EXT4_SB(sb)->s_journal) | |
ac27a0ec DK |
478 | return 0; |
479 | ||
480 | jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); | |
481 | ||
dab291af | 482 | return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); |
ac27a0ec DK |
483 | } |
484 | ||
654b4908 | 485 | /* |
d2a17637 | 486 | * ext4_new_meta_blocks() -- allocate block for meta data (indexing) blocks |
654b4908 AK |
487 | * |
488 | * @handle: handle to this transaction | |
489 | * @inode: file inode | |
490 | * @goal: given target block(filesystem wide) | |
7b415bf6 | 491 | * @count: pointer to total number of clusters needed |
654b4908 AK |
492 | * @errp: error code |
493 | * | |
97df5d15 | 494 | * Return 1st allocated block number on success, *count stores total account |
d2a17637 | 495 | * error stores in errp pointer |
654b4908 | 496 | */ |
d2a17637 | 497 | ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode, |
55f020db AH |
498 | ext4_fsblk_t goal, unsigned int flags, |
499 | unsigned long *count, int *errp) | |
654b4908 | 500 | { |
97df5d15 | 501 | struct ext4_allocation_request ar; |
d2a17637 | 502 | ext4_fsblk_t ret; |
97df5d15 TT |
503 | |
504 | memset(&ar, 0, sizeof(ar)); | |
505 | /* Fill with neighbour allocated blocks */ | |
506 | ar.inode = inode; | |
507 | ar.goal = goal; | |
508 | ar.len = count ? *count : 1; | |
55f020db | 509 | ar.flags = flags; |
97df5d15 TT |
510 | |
511 | ret = ext4_mb_new_blocks(handle, &ar, errp); | |
512 | if (count) | |
513 | *count = ar.len; | |
d2a17637 | 514 | /* |
72b8ab9d ES |
515 | * Account for the allocated meta blocks. We will never |
516 | * fail EDQUOT for metdata, but we do account for it. | |
d2a17637 | 517 | */ |
f2321097 TT |
518 | if (!(*errp) && |
519 | ext4_test_inode_state(inode, EXT4_STATE_DELALLOC_RESERVED)) { | |
d2a17637 | 520 | spin_lock(&EXT4_I(inode)->i_block_reservation_lock); |
97df5d15 | 521 | EXT4_I(inode)->i_allocated_meta_blocks += ar.len; |
d2a17637 | 522 | spin_unlock(&EXT4_I(inode)->i_block_reservation_lock); |
7b415bf6 AK |
523 | dquot_alloc_block_nofail(inode, |
524 | EXT4_C2B(EXT4_SB(inode->i_sb), ar.len)); | |
d2a17637 MC |
525 | } |
526 | return ret; | |
654b4908 AK |
527 | } |
528 | ||
ac27a0ec | 529 | /** |
5dee5437 | 530 | * ext4_count_free_clusters() -- count filesystem free clusters |
ac27a0ec DK |
531 | * @sb: superblock |
532 | * | |
5dee5437 | 533 | * Adds up the number of free clusters from each block group. |
ac27a0ec | 534 | */ |
5dee5437 | 535 | ext4_fsblk_t ext4_count_free_clusters(struct super_block *sb) |
ac27a0ec | 536 | { |
617ba13b MC |
537 | ext4_fsblk_t desc_count; |
538 | struct ext4_group_desc *gdp; | |
fd2d4291 | 539 | ext4_group_t i; |
8df9675f | 540 | ext4_group_t ngroups = ext4_get_groups_count(sb); |
617ba13b MC |
541 | #ifdef EXT4FS_DEBUG |
542 | struct ext4_super_block *es; | |
543 | ext4_fsblk_t bitmap_count; | |
498e5f24 | 544 | unsigned int x; |
ac27a0ec DK |
545 | struct buffer_head *bitmap_bh = NULL; |
546 | ||
617ba13b | 547 | es = EXT4_SB(sb)->s_es; |
ac27a0ec DK |
548 | desc_count = 0; |
549 | bitmap_count = 0; | |
550 | gdp = NULL; | |
551 | ||
ac27a0ec | 552 | for (i = 0; i < ngroups; i++) { |
617ba13b | 553 | gdp = ext4_get_group_desc(sb, i, NULL); |
ac27a0ec DK |
554 | if (!gdp) |
555 | continue; | |
021b65bb | 556 | desc_count += ext4_free_group_clusters(sb, gdp); |
ac27a0ec | 557 | brelse(bitmap_bh); |
574ca174 | 558 | bitmap_bh = ext4_read_block_bitmap(sb, i); |
ac27a0ec DK |
559 | if (bitmap_bh == NULL) |
560 | continue; | |
561 | ||
617ba13b | 562 | x = ext4_count_free(bitmap_bh, sb->s_blocksize); |
9fd9784c | 563 | printk(KERN_DEBUG "group %u: stored = %d, counted = %u\n", |
021b65bb | 564 | i, ext4_free_group_clusters(sb, gdp), x); |
ac27a0ec DK |
565 | bitmap_count += x; |
566 | } | |
567 | brelse(bitmap_bh); | |
5dee5437 TT |
568 | printk(KERN_DEBUG "ext4_count_free_clusters: stored = %llu" |
569 | ", computed = %llu, %llu\n", | |
6e58ad69 | 570 | EXT4_B2C(EXT4_SB(sb), ext4_free_blocks_count(es)), |
4776004f | 571 | desc_count, bitmap_count); |
ac27a0ec DK |
572 | return bitmap_count; |
573 | #else | |
574 | desc_count = 0; | |
ac27a0ec | 575 | for (i = 0; i < ngroups; i++) { |
617ba13b | 576 | gdp = ext4_get_group_desc(sb, i, NULL); |
ac27a0ec DK |
577 | if (!gdp) |
578 | continue; | |
021b65bb | 579 | desc_count += ext4_free_group_clusters(sb, gdp); |
ac27a0ec DK |
580 | } |
581 | ||
582 | return desc_count; | |
583 | #endif | |
584 | } | |
585 | ||
fd2d4291 | 586 | static inline int test_root(ext4_group_t a, int b) |
ac27a0ec DK |
587 | { |
588 | int num = b; | |
589 | ||
590 | while (a > num) | |
591 | num *= b; | |
592 | return num == a; | |
593 | } | |
594 | ||
fd2d4291 | 595 | static int ext4_group_sparse(ext4_group_t group) |
ac27a0ec DK |
596 | { |
597 | if (group <= 1) | |
598 | return 1; | |
599 | if (!(group & 1)) | |
600 | return 0; | |
601 | return (test_root(group, 7) || test_root(group, 5) || | |
602 | test_root(group, 3)); | |
603 | } | |
604 | ||
605 | /** | |
617ba13b | 606 | * ext4_bg_has_super - number of blocks used by the superblock in group |
ac27a0ec DK |
607 | * @sb: superblock for filesystem |
608 | * @group: group number to check | |
609 | * | |
610 | * Return the number of blocks used by the superblock (primary or backup) | |
611 | * in this group. Currently this will be only 0 or 1. | |
612 | */ | |
fd2d4291 | 613 | int ext4_bg_has_super(struct super_block *sb, ext4_group_t group) |
ac27a0ec | 614 | { |
617ba13b MC |
615 | if (EXT4_HAS_RO_COMPAT_FEATURE(sb, |
616 | EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) && | |
617 | !ext4_group_sparse(group)) | |
ac27a0ec DK |
618 | return 0; |
619 | return 1; | |
620 | } | |
621 | ||
fd2d4291 AM |
622 | static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb, |
623 | ext4_group_t group) | |
ac27a0ec | 624 | { |
617ba13b | 625 | unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); |
fd2d4291 AM |
626 | ext4_group_t first = metagroup * EXT4_DESC_PER_BLOCK(sb); |
627 | ext4_group_t last = first + EXT4_DESC_PER_BLOCK(sb) - 1; | |
ac27a0ec DK |
628 | |
629 | if (group == first || group == first + 1 || group == last) | |
630 | return 1; | |
631 | return 0; | |
632 | } | |
633 | ||
fd2d4291 AM |
634 | static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, |
635 | ext4_group_t group) | |
ac27a0ec | 636 | { |
8dadb198 TT |
637 | if (!ext4_bg_has_super(sb, group)) |
638 | return 0; | |
639 | ||
640 | if (EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG)) | |
641 | return le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); | |
642 | else | |
643 | return EXT4_SB(sb)->s_gdb_count; | |
ac27a0ec DK |
644 | } |
645 | ||
646 | /** | |
617ba13b | 647 | * ext4_bg_num_gdb - number of blocks used by the group table in group |
ac27a0ec DK |
648 | * @sb: superblock for filesystem |
649 | * @group: group number to check | |
650 | * | |
651 | * Return the number of blocks used by the group descriptor table | |
652 | * (primary or backup) in this group. In the future there may be a | |
653 | * different number of descriptor blocks in each group. | |
654 | */ | |
fd2d4291 | 655 | unsigned long ext4_bg_num_gdb(struct super_block *sb, ext4_group_t group) |
ac27a0ec DK |
656 | { |
657 | unsigned long first_meta_bg = | |
617ba13b MC |
658 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); |
659 | unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); | |
ac27a0ec | 660 | |
617ba13b | 661 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG) || |
ac27a0ec | 662 | metagroup < first_meta_bg) |
af5bc92d | 663 | return ext4_bg_num_gdb_nometa(sb, group); |
ac27a0ec | 664 | |
617ba13b | 665 | return ext4_bg_num_gdb_meta(sb,group); |
ac27a0ec DK |
666 | |
667 | } | |
c2ea3fde | 668 | |
49f7f9af | 669 | /* |
d5b8f310 | 670 | * This function returns the number of file system metadata clusters at |
49f7f9af TT |
671 | * the beginning of a block group, including the reserved gdt blocks. |
672 | */ | |
5f163cc7 | 673 | static unsigned ext4_num_base_meta_clusters(struct super_block *sb, |
d5b8f310 | 674 | ext4_group_t block_group) |
49f7f9af TT |
675 | { |
676 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
d5b8f310 | 677 | unsigned num; |
49f7f9af TT |
678 | |
679 | /* Check for superblock and gdt backups in this group */ | |
680 | num = ext4_bg_has_super(sb, block_group); | |
681 | ||
682 | if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_META_BG) || | |
683 | block_group < le32_to_cpu(sbi->s_es->s_first_meta_bg) * | |
684 | sbi->s_desc_per_block) { | |
685 | if (num) { | |
686 | num += ext4_bg_num_gdb(sb, block_group); | |
687 | num += le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks); | |
688 | } | |
689 | } else { /* For META_BG_BLOCK_GROUPS */ | |
690 | num += ext4_bg_num_gdb(sb, block_group); | |
691 | } | |
d5b8f310 | 692 | return EXT4_NUM_B2C(sbi, num); |
49f7f9af | 693 | } |
f86186b4 ES |
694 | /** |
695 | * ext4_inode_to_goal_block - return a hint for block allocation | |
696 | * @inode: inode for block allocation | |
697 | * | |
698 | * Return the ideal location to start allocating blocks for a | |
699 | * newly created inode. | |
700 | */ | |
701 | ext4_fsblk_t ext4_inode_to_goal_block(struct inode *inode) | |
702 | { | |
703 | struct ext4_inode_info *ei = EXT4_I(inode); | |
704 | ext4_group_t block_group; | |
705 | ext4_grpblk_t colour; | |
706 | int flex_size = ext4_flex_bg_size(EXT4_SB(inode->i_sb)); | |
707 | ext4_fsblk_t bg_start; | |
708 | ext4_fsblk_t last_block; | |
709 | ||
710 | block_group = ei->i_block_group; | |
711 | if (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) { | |
712 | /* | |
713 | * If there are at least EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME | |
714 | * block groups per flexgroup, reserve the first block | |
715 | * group for directories and special files. Regular | |
716 | * files will start at the second block group. This | |
717 | * tends to speed up directory access and improves | |
718 | * fsck times. | |
719 | */ | |
720 | block_group &= ~(flex_size-1); | |
721 | if (S_ISREG(inode->i_mode)) | |
722 | block_group++; | |
723 | } | |
724 | bg_start = ext4_group_first_block_no(inode->i_sb, block_group); | |
725 | last_block = ext4_blocks_count(EXT4_SB(inode->i_sb)->s_es) - 1; | |
726 | ||
727 | /* | |
728 | * If we are doing delayed allocation, we don't need take | |
729 | * colour into account. | |
730 | */ | |
731 | if (test_opt(inode->i_sb, DELALLOC)) | |
732 | return bg_start; | |
733 | ||
734 | if (bg_start + EXT4_BLOCKS_PER_GROUP(inode->i_sb) <= last_block) | |
735 | colour = (current->pid % 16) * | |
736 | (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); | |
737 | else | |
738 | colour = (current->pid % 16) * ((last_block - bg_start) / 16); | |
739 | return bg_start + colour; | |
740 | } | |
741 |