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1 | /* | |
2 | * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com | |
3 | * Written by Alex Tomas <alex@clusterfs.com> | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License version 2 as | |
7 | * published by the Free Software Foundation. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public Licens | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- | |
17 | */ | |
18 | ||
19 | ||
20 | /* | |
21 | * mballoc.c contains the multiblocks allocation routines | |
22 | */ | |
23 | ||
24 | #include "mballoc.h" | |
25 | #include <linux/debugfs.h> | |
26 | #include <linux/slab.h> | |
27 | #include <trace/events/ext4.h> | |
28 | ||
29 | /* | |
30 | * MUSTDO: | |
31 | * - test ext4_ext_search_left() and ext4_ext_search_right() | |
32 | * - search for metadata in few groups | |
33 | * | |
34 | * TODO v4: | |
35 | * - normalization should take into account whether file is still open | |
36 | * - discard preallocations if no free space left (policy?) | |
37 | * - don't normalize tails | |
38 | * - quota | |
39 | * - reservation for superuser | |
40 | * | |
41 | * TODO v3: | |
42 | * - bitmap read-ahead (proposed by Oleg Drokin aka green) | |
43 | * - track min/max extents in each group for better group selection | |
44 | * - mb_mark_used() may allocate chunk right after splitting buddy | |
45 | * - tree of groups sorted by number of free blocks | |
46 | * - error handling | |
47 | */ | |
48 | ||
49 | /* | |
50 | * The allocation request involve request for multiple number of blocks | |
51 | * near to the goal(block) value specified. | |
52 | * | |
53 | * During initialization phase of the allocator we decide to use the | |
54 | * group preallocation or inode preallocation depending on the size of | |
55 | * the file. The size of the file could be the resulting file size we | |
56 | * would have after allocation, or the current file size, which ever | |
57 | * is larger. If the size is less than sbi->s_mb_stream_request we | |
58 | * select to use the group preallocation. The default value of | |
59 | * s_mb_stream_request is 16 blocks. This can also be tuned via | |
60 | * /sys/fs/ext4/<partition>/mb_stream_req. The value is represented in | |
61 | * terms of number of blocks. | |
62 | * | |
63 | * The main motivation for having small file use group preallocation is to | |
64 | * ensure that we have small files closer together on the disk. | |
65 | * | |
66 | * First stage the allocator looks at the inode prealloc list, | |
67 | * ext4_inode_info->i_prealloc_list, which contains list of prealloc | |
68 | * spaces for this particular inode. The inode prealloc space is | |
69 | * represented as: | |
70 | * | |
71 | * pa_lstart -> the logical start block for this prealloc space | |
72 | * pa_pstart -> the physical start block for this prealloc space | |
73 | * pa_len -> length for this prealloc space (in clusters) | |
74 | * pa_free -> free space available in this prealloc space (in clusters) | |
75 | * | |
76 | * The inode preallocation space is used looking at the _logical_ start | |
77 | * block. If only the logical file block falls within the range of prealloc | |
78 | * space we will consume the particular prealloc space. This makes sure that | |
79 | * we have contiguous physical blocks representing the file blocks | |
80 | * | |
81 | * The important thing to be noted in case of inode prealloc space is that | |
82 | * we don't modify the values associated to inode prealloc space except | |
83 | * pa_free. | |
84 | * | |
85 | * If we are not able to find blocks in the inode prealloc space and if we | |
86 | * have the group allocation flag set then we look at the locality group | |
87 | * prealloc space. These are per CPU prealloc list represented as | |
88 | * | |
89 | * ext4_sb_info.s_locality_groups[smp_processor_id()] | |
90 | * | |
91 | * The reason for having a per cpu locality group is to reduce the contention | |
92 | * between CPUs. It is possible to get scheduled at this point. | |
93 | * | |
94 | * The locality group prealloc space is used looking at whether we have | |
95 | * enough free space (pa_free) within the prealloc space. | |
96 | * | |
97 | * If we can't allocate blocks via inode prealloc or/and locality group | |
98 | * prealloc then we look at the buddy cache. The buddy cache is represented | |
99 | * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets | |
100 | * mapped to the buddy and bitmap information regarding different | |
101 | * groups. The buddy information is attached to buddy cache inode so that | |
102 | * we can access them through the page cache. The information regarding | |
103 | * each group is loaded via ext4_mb_load_buddy. The information involve | |
104 | * block bitmap and buddy information. The information are stored in the | |
105 | * inode as: | |
106 | * | |
107 | * { page } | |
108 | * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... | |
109 | * | |
110 | * | |
111 | * one block each for bitmap and buddy information. So for each group we | |
112 | * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE / | |
113 | * blocksize) blocks. So it can have information regarding groups_per_page | |
114 | * which is blocks_per_page/2 | |
115 | * | |
116 | * The buddy cache inode is not stored on disk. The inode is thrown | |
117 | * away when the filesystem is unmounted. | |
118 | * | |
119 | * We look for count number of blocks in the buddy cache. If we were able | |
120 | * to locate that many free blocks we return with additional information | |
121 | * regarding rest of the contiguous physical block available | |
122 | * | |
123 | * Before allocating blocks via buddy cache we normalize the request | |
124 | * blocks. This ensure we ask for more blocks that we needed. The extra | |
125 | * blocks that we get after allocation is added to the respective prealloc | |
126 | * list. In case of inode preallocation we follow a list of heuristics | |
127 | * based on file size. This can be found in ext4_mb_normalize_request. If | |
128 | * we are doing a group prealloc we try to normalize the request to | |
129 | * sbi->s_mb_group_prealloc. The default value of s_mb_group_prealloc is | |
130 | * dependent on the cluster size; for non-bigalloc file systems, it is | |
131 | * 512 blocks. This can be tuned via | |
132 | * /sys/fs/ext4/<partition>/mb_group_prealloc. The value is represented in | |
133 | * terms of number of blocks. If we have mounted the file system with -O | |
134 | * stripe=<value> option the group prealloc request is normalized to the | |
135 | * the smallest multiple of the stripe value (sbi->s_stripe) which is | |
136 | * greater than the default mb_group_prealloc. | |
137 | * | |
138 | * The regular allocator (using the buddy cache) supports a few tunables. | |
139 | * | |
140 | * /sys/fs/ext4/<partition>/mb_min_to_scan | |
141 | * /sys/fs/ext4/<partition>/mb_max_to_scan | |
142 | * /sys/fs/ext4/<partition>/mb_order2_req | |
143 | * | |
144 | * The regular allocator uses buddy scan only if the request len is power of | |
145 | * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The | |
146 | * value of s_mb_order2_reqs can be tuned via | |
147 | * /sys/fs/ext4/<partition>/mb_order2_req. If the request len is equal to | |
148 | * stripe size (sbi->s_stripe), we try to search for contiguous block in | |
149 | * stripe size. This should result in better allocation on RAID setups. If | |
150 | * not, we search in the specific group using bitmap for best extents. The | |
151 | * tunable min_to_scan and max_to_scan control the behaviour here. | |
152 | * min_to_scan indicate how long the mballoc __must__ look for a best | |
153 | * extent and max_to_scan indicates how long the mballoc __can__ look for a | |
154 | * best extent in the found extents. Searching for the blocks starts with | |
155 | * the group specified as the goal value in allocation context via | |
156 | * ac_g_ex. Each group is first checked based on the criteria whether it | |
157 | * can be used for allocation. ext4_mb_good_group explains how the groups are | |
158 | * checked. | |
159 | * | |
160 | * Both the prealloc space are getting populated as above. So for the first | |
161 | * request we will hit the buddy cache which will result in this prealloc | |
162 | * space getting filled. The prealloc space is then later used for the | |
163 | * subsequent request. | |
164 | */ | |
165 | ||
166 | /* | |
167 | * mballoc operates on the following data: | |
168 | * - on-disk bitmap | |
169 | * - in-core buddy (actually includes buddy and bitmap) | |
170 | * - preallocation descriptors (PAs) | |
171 | * | |
172 | * there are two types of preallocations: | |
173 | * - inode | |
174 | * assiged to specific inode and can be used for this inode only. | |
175 | * it describes part of inode's space preallocated to specific | |
176 | * physical blocks. any block from that preallocated can be used | |
177 | * independent. the descriptor just tracks number of blocks left | |
178 | * unused. so, before taking some block from descriptor, one must | |
179 | * make sure corresponded logical block isn't allocated yet. this | |
180 | * also means that freeing any block within descriptor's range | |
181 | * must discard all preallocated blocks. | |
182 | * - locality group | |
183 | * assigned to specific locality group which does not translate to | |
184 | * permanent set of inodes: inode can join and leave group. space | |
185 | * from this type of preallocation can be used for any inode. thus | |
186 | * it's consumed from the beginning to the end. | |
187 | * | |
188 | * relation between them can be expressed as: | |
189 | * in-core buddy = on-disk bitmap + preallocation descriptors | |
190 | * | |
191 | * this mean blocks mballoc considers used are: | |
192 | * - allocated blocks (persistent) | |
193 | * - preallocated blocks (non-persistent) | |
194 | * | |
195 | * consistency in mballoc world means that at any time a block is either | |
196 | * free or used in ALL structures. notice: "any time" should not be read | |
197 | * literally -- time is discrete and delimited by locks. | |
198 | * | |
199 | * to keep it simple, we don't use block numbers, instead we count number of | |
200 | * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA. | |
201 | * | |
202 | * all operations can be expressed as: | |
203 | * - init buddy: buddy = on-disk + PAs | |
204 | * - new PA: buddy += N; PA = N | |
205 | * - use inode PA: on-disk += N; PA -= N | |
206 | * - discard inode PA buddy -= on-disk - PA; PA = 0 | |
207 | * - use locality group PA on-disk += N; PA -= N | |
208 | * - discard locality group PA buddy -= PA; PA = 0 | |
209 | * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap | |
210 | * is used in real operation because we can't know actual used | |
211 | * bits from PA, only from on-disk bitmap | |
212 | * | |
213 | * if we follow this strict logic, then all operations above should be atomic. | |
214 | * given some of them can block, we'd have to use something like semaphores | |
215 | * killing performance on high-end SMP hardware. let's try to relax it using | |
216 | * the following knowledge: | |
217 | * 1) if buddy is referenced, it's already initialized | |
218 | * 2) while block is used in buddy and the buddy is referenced, | |
219 | * nobody can re-allocate that block | |
220 | * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has | |
221 | * bit set and PA claims same block, it's OK. IOW, one can set bit in | |
222 | * on-disk bitmap if buddy has same bit set or/and PA covers corresponded | |
223 | * block | |
224 | * | |
225 | * so, now we're building a concurrency table: | |
226 | * - init buddy vs. | |
227 | * - new PA | |
228 | * blocks for PA are allocated in the buddy, buddy must be referenced | |
229 | * until PA is linked to allocation group to avoid concurrent buddy init | |
230 | * - use inode PA | |
231 | * we need to make sure that either on-disk bitmap or PA has uptodate data | |
232 | * given (3) we care that PA-=N operation doesn't interfere with init | |
233 | * - discard inode PA | |
234 | * the simplest way would be to have buddy initialized by the discard | |
235 | * - use locality group PA | |
236 | * again PA-=N must be serialized with init | |
237 | * - discard locality group PA | |
238 | * the simplest way would be to have buddy initialized by the discard | |
239 | * - new PA vs. | |
240 | * - use inode PA | |
241 | * i_data_sem serializes them | |
242 | * - discard inode PA | |
243 | * discard process must wait until PA isn't used by another process | |
244 | * - use locality group PA | |
245 | * some mutex should serialize them | |
246 | * - discard locality group PA | |
247 | * discard process must wait until PA isn't used by another process | |
248 | * - use inode PA | |
249 | * - use inode PA | |
250 | * i_data_sem or another mutex should serializes them | |
251 | * - discard inode PA | |
252 | * discard process must wait until PA isn't used by another process | |
253 | * - use locality group PA | |
254 | * nothing wrong here -- they're different PAs covering different blocks | |
255 | * - discard locality group PA | |
256 | * discard process must wait until PA isn't used by another process | |
257 | * | |
258 | * now we're ready to make few consequences: | |
259 | * - PA is referenced and while it is no discard is possible | |
260 | * - PA is referenced until block isn't marked in on-disk bitmap | |
261 | * - PA changes only after on-disk bitmap | |
262 | * - discard must not compete with init. either init is done before | |
263 | * any discard or they're serialized somehow | |
264 | * - buddy init as sum of on-disk bitmap and PAs is done atomically | |
265 | * | |
266 | * a special case when we've used PA to emptiness. no need to modify buddy | |
267 | * in this case, but we should care about concurrent init | |
268 | * | |
269 | */ | |
270 | ||
271 | /* | |
272 | * Logic in few words: | |
273 | * | |
274 | * - allocation: | |
275 | * load group | |
276 | * find blocks | |
277 | * mark bits in on-disk bitmap | |
278 | * release group | |
279 | * | |
280 | * - use preallocation: | |
281 | * find proper PA (per-inode or group) | |
282 | * load group | |
283 | * mark bits in on-disk bitmap | |
284 | * release group | |
285 | * release PA | |
286 | * | |
287 | * - free: | |
288 | * load group | |
289 | * mark bits in on-disk bitmap | |
290 | * release group | |
291 | * | |
292 | * - discard preallocations in group: | |
293 | * mark PAs deleted | |
294 | * move them onto local list | |
295 | * load on-disk bitmap | |
296 | * load group | |
297 | * remove PA from object (inode or locality group) | |
298 | * mark free blocks in-core | |
299 | * | |
300 | * - discard inode's preallocations: | |
301 | */ | |
302 | ||
303 | /* | |
304 | * Locking rules | |
305 | * | |
306 | * Locks: | |
307 | * - bitlock on a group (group) | |
308 | * - object (inode/locality) (object) | |
309 | * - per-pa lock (pa) | |
310 | * | |
311 | * Paths: | |
312 | * - new pa | |
313 | * object | |
314 | * group | |
315 | * | |
316 | * - find and use pa: | |
317 | * pa | |
318 | * | |
319 | * - release consumed pa: | |
320 | * pa | |
321 | * group | |
322 | * object | |
323 | * | |
324 | * - generate in-core bitmap: | |
325 | * group | |
326 | * pa | |
327 | * | |
328 | * - discard all for given object (inode, locality group): | |
329 | * object | |
330 | * pa | |
331 | * group | |
332 | * | |
333 | * - discard all for given group: | |
334 | * group | |
335 | * pa | |
336 | * group | |
337 | * object | |
338 | * | |
339 | */ | |
340 | static struct kmem_cache *ext4_pspace_cachep; | |
341 | static struct kmem_cache *ext4_ac_cachep; | |
342 | static struct kmem_cache *ext4_free_ext_cachep; | |
343 | ||
344 | /* We create slab caches for groupinfo data structures based on the | |
345 | * superblock block size. There will be one per mounted filesystem for | |
346 | * each unique s_blocksize_bits */ | |
347 | #define NR_GRPINFO_CACHES 8 | |
348 | static struct kmem_cache *ext4_groupinfo_caches[NR_GRPINFO_CACHES]; | |
349 | ||
350 | static const char *ext4_groupinfo_slab_names[NR_GRPINFO_CACHES] = { | |
351 | "ext4_groupinfo_1k", "ext4_groupinfo_2k", "ext4_groupinfo_4k", | |
352 | "ext4_groupinfo_8k", "ext4_groupinfo_16k", "ext4_groupinfo_32k", | |
353 | "ext4_groupinfo_64k", "ext4_groupinfo_128k" | |
354 | }; | |
355 | ||
356 | static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, | |
357 | ext4_group_t group); | |
358 | static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, | |
359 | ext4_group_t group); | |
360 | static void release_blocks_on_commit(journal_t *journal, transaction_t *txn); | |
361 | ||
362 | static inline void *mb_correct_addr_and_bit(int *bit, void *addr) | |
363 | { | |
364 | #if BITS_PER_LONG == 64 | |
365 | *bit += ((unsigned long) addr & 7UL) << 3; | |
366 | addr = (void *) ((unsigned long) addr & ~7UL); | |
367 | #elif BITS_PER_LONG == 32 | |
368 | *bit += ((unsigned long) addr & 3UL) << 3; | |
369 | addr = (void *) ((unsigned long) addr & ~3UL); | |
370 | #else | |
371 | #error "how many bits you are?!" | |
372 | #endif | |
373 | return addr; | |
374 | } | |
375 | ||
376 | static inline int mb_test_bit(int bit, void *addr) | |
377 | { | |
378 | /* | |
379 | * ext4_test_bit on architecture like powerpc | |
380 | * needs unsigned long aligned address | |
381 | */ | |
382 | addr = mb_correct_addr_and_bit(&bit, addr); | |
383 | return ext4_test_bit(bit, addr); | |
384 | } | |
385 | ||
386 | static inline void mb_set_bit(int bit, void *addr) | |
387 | { | |
388 | addr = mb_correct_addr_and_bit(&bit, addr); | |
389 | ext4_set_bit(bit, addr); | |
390 | } | |
391 | ||
392 | static inline void mb_clear_bit(int bit, void *addr) | |
393 | { | |
394 | addr = mb_correct_addr_and_bit(&bit, addr); | |
395 | ext4_clear_bit(bit, addr); | |
396 | } | |
397 | ||
398 | static inline int mb_find_next_zero_bit(void *addr, int max, int start) | |
399 | { | |
400 | int fix = 0, ret, tmpmax; | |
401 | addr = mb_correct_addr_and_bit(&fix, addr); | |
402 | tmpmax = max + fix; | |
403 | start += fix; | |
404 | ||
405 | ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix; | |
406 | if (ret > max) | |
407 | return max; | |
408 | return ret; | |
409 | } | |
410 | ||
411 | static inline int mb_find_next_bit(void *addr, int max, int start) | |
412 | { | |
413 | int fix = 0, ret, tmpmax; | |
414 | addr = mb_correct_addr_and_bit(&fix, addr); | |
415 | tmpmax = max + fix; | |
416 | start += fix; | |
417 | ||
418 | ret = ext4_find_next_bit(addr, tmpmax, start) - fix; | |
419 | if (ret > max) | |
420 | return max; | |
421 | return ret; | |
422 | } | |
423 | ||
424 | static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max) | |
425 | { | |
426 | char *bb; | |
427 | ||
428 | BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); | |
429 | BUG_ON(max == NULL); | |
430 | ||
431 | if (order > e4b->bd_blkbits + 1) { | |
432 | *max = 0; | |
433 | return NULL; | |
434 | } | |
435 | ||
436 | /* at order 0 we see each particular block */ | |
437 | if (order == 0) { | |
438 | *max = 1 << (e4b->bd_blkbits + 3); | |
439 | return EXT4_MB_BITMAP(e4b); | |
440 | } | |
441 | ||
442 | bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order]; | |
443 | *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order]; | |
444 | ||
445 | return bb; | |
446 | } | |
447 | ||
448 | #ifdef DOUBLE_CHECK | |
449 | static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b, | |
450 | int first, int count) | |
451 | { | |
452 | int i; | |
453 | struct super_block *sb = e4b->bd_sb; | |
454 | ||
455 | if (unlikely(e4b->bd_info->bb_bitmap == NULL)) | |
456 | return; | |
457 | assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); | |
458 | for (i = 0; i < count; i++) { | |
459 | if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) { | |
460 | ext4_fsblk_t blocknr; | |
461 | ||
462 | blocknr = ext4_group_first_block_no(sb, e4b->bd_group); | |
463 | blocknr += EXT4_C2B(EXT4_SB(sb), first + i); | |
464 | ext4_grp_locked_error(sb, e4b->bd_group, | |
465 | inode ? inode->i_ino : 0, | |
466 | blocknr, | |
467 | "freeing block already freed " | |
468 | "(bit %u)", | |
469 | first + i); | |
470 | } | |
471 | mb_clear_bit(first + i, e4b->bd_info->bb_bitmap); | |
472 | } | |
473 | } | |
474 | ||
475 | static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count) | |
476 | { | |
477 | int i; | |
478 | ||
479 | if (unlikely(e4b->bd_info->bb_bitmap == NULL)) | |
480 | return; | |
481 | assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); | |
482 | for (i = 0; i < count; i++) { | |
483 | BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap)); | |
484 | mb_set_bit(first + i, e4b->bd_info->bb_bitmap); | |
485 | } | |
486 | } | |
487 | ||
488 | static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) | |
489 | { | |
490 | if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) { | |
491 | unsigned char *b1, *b2; | |
492 | int i; | |
493 | b1 = (unsigned char *) e4b->bd_info->bb_bitmap; | |
494 | b2 = (unsigned char *) bitmap; | |
495 | for (i = 0; i < e4b->bd_sb->s_blocksize; i++) { | |
496 | if (b1[i] != b2[i]) { | |
497 | ext4_msg(e4b->bd_sb, KERN_ERR, | |
498 | "corruption in group %u " | |
499 | "at byte %u(%u): %x in copy != %x " | |
500 | "on disk/prealloc", | |
501 | e4b->bd_group, i, i * 8, b1[i], b2[i]); | |
502 | BUG(); | |
503 | } | |
504 | } | |
505 | } | |
506 | } | |
507 | ||
508 | #else | |
509 | static inline void mb_free_blocks_double(struct inode *inode, | |
510 | struct ext4_buddy *e4b, int first, int count) | |
511 | { | |
512 | return; | |
513 | } | |
514 | static inline void mb_mark_used_double(struct ext4_buddy *e4b, | |
515 | int first, int count) | |
516 | { | |
517 | return; | |
518 | } | |
519 | static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap) | |
520 | { | |
521 | return; | |
522 | } | |
523 | #endif | |
524 | ||
525 | #ifdef AGGRESSIVE_CHECK | |
526 | ||
527 | #define MB_CHECK_ASSERT(assert) \ | |
528 | do { \ | |
529 | if (!(assert)) { \ | |
530 | printk(KERN_EMERG \ | |
531 | "Assertion failure in %s() at %s:%d: \"%s\"\n", \ | |
532 | function, file, line, # assert); \ | |
533 | BUG(); \ | |
534 | } \ | |
535 | } while (0) | |
536 | ||
537 | static int __mb_check_buddy(struct ext4_buddy *e4b, char *file, | |
538 | const char *function, int line) | |
539 | { | |
540 | struct super_block *sb = e4b->bd_sb; | |
541 | int order = e4b->bd_blkbits + 1; | |
542 | int max; | |
543 | int max2; | |
544 | int i; | |
545 | int j; | |
546 | int k; | |
547 | int count; | |
548 | struct ext4_group_info *grp; | |
549 | int fragments = 0; | |
550 | int fstart; | |
551 | struct list_head *cur; | |
552 | void *buddy; | |
553 | void *buddy2; | |
554 | ||
555 | { | |
556 | static int mb_check_counter; | |
557 | if (mb_check_counter++ % 100 != 0) | |
558 | return 0; | |
559 | } | |
560 | ||
561 | while (order > 1) { | |
562 | buddy = mb_find_buddy(e4b, order, &max); | |
563 | MB_CHECK_ASSERT(buddy); | |
564 | buddy2 = mb_find_buddy(e4b, order - 1, &max2); | |
565 | MB_CHECK_ASSERT(buddy2); | |
566 | MB_CHECK_ASSERT(buddy != buddy2); | |
567 | MB_CHECK_ASSERT(max * 2 == max2); | |
568 | ||
569 | count = 0; | |
570 | for (i = 0; i < max; i++) { | |
571 | ||
572 | if (mb_test_bit(i, buddy)) { | |
573 | /* only single bit in buddy2 may be 1 */ | |
574 | if (!mb_test_bit(i << 1, buddy2)) { | |
575 | MB_CHECK_ASSERT( | |
576 | mb_test_bit((i<<1)+1, buddy2)); | |
577 | } else if (!mb_test_bit((i << 1) + 1, buddy2)) { | |
578 | MB_CHECK_ASSERT( | |
579 | mb_test_bit(i << 1, buddy2)); | |
580 | } | |
581 | continue; | |
582 | } | |
583 | ||
584 | /* both bits in buddy2 must be 0 */ | |
585 | MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2)); | |
586 | MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2)); | |
587 | ||
588 | for (j = 0; j < (1 << order); j++) { | |
589 | k = (i * (1 << order)) + j; | |
590 | MB_CHECK_ASSERT( | |
591 | !mb_test_bit(k, EXT4_MB_BITMAP(e4b))); | |
592 | } | |
593 | count++; | |
594 | } | |
595 | MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count); | |
596 | order--; | |
597 | } | |
598 | ||
599 | fstart = -1; | |
600 | buddy = mb_find_buddy(e4b, 0, &max); | |
601 | for (i = 0; i < max; i++) { | |
602 | if (!mb_test_bit(i, buddy)) { | |
603 | MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free); | |
604 | if (fstart == -1) { | |
605 | fragments++; | |
606 | fstart = i; | |
607 | } | |
608 | continue; | |
609 | } | |
610 | fstart = -1; | |
611 | /* check used bits only */ | |
612 | for (j = 0; j < e4b->bd_blkbits + 1; j++) { | |
613 | buddy2 = mb_find_buddy(e4b, j, &max2); | |
614 | k = i >> j; | |
615 | MB_CHECK_ASSERT(k < max2); | |
616 | MB_CHECK_ASSERT(mb_test_bit(k, buddy2)); | |
617 | } | |
618 | } | |
619 | MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info)); | |
620 | MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments); | |
621 | ||
622 | grp = ext4_get_group_info(sb, e4b->bd_group); | |
623 | list_for_each(cur, &grp->bb_prealloc_list) { | |
624 | ext4_group_t groupnr; | |
625 | struct ext4_prealloc_space *pa; | |
626 | pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); | |
627 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k); | |
628 | MB_CHECK_ASSERT(groupnr == e4b->bd_group); | |
629 | for (i = 0; i < pa->pa_len; i++) | |
630 | MB_CHECK_ASSERT(mb_test_bit(k + i, buddy)); | |
631 | } | |
632 | return 0; | |
633 | } | |
634 | #undef MB_CHECK_ASSERT | |
635 | #define mb_check_buddy(e4b) __mb_check_buddy(e4b, \ | |
636 | __FILE__, __func__, __LINE__) | |
637 | #else | |
638 | #define mb_check_buddy(e4b) | |
639 | #endif | |
640 | ||
641 | /* | |
642 | * Divide blocks started from @first with length @len into | |
643 | * smaller chunks with power of 2 blocks. | |
644 | * Clear the bits in bitmap which the blocks of the chunk(s) covered, | |
645 | * then increase bb_counters[] for corresponded chunk size. | |
646 | */ | |
647 | static void ext4_mb_mark_free_simple(struct super_block *sb, | |
648 | void *buddy, ext4_grpblk_t first, ext4_grpblk_t len, | |
649 | struct ext4_group_info *grp) | |
650 | { | |
651 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
652 | ext4_grpblk_t min; | |
653 | ext4_grpblk_t max; | |
654 | ext4_grpblk_t chunk; | |
655 | unsigned short border; | |
656 | ||
657 | BUG_ON(len > EXT4_CLUSTERS_PER_GROUP(sb)); | |
658 | ||
659 | border = 2 << sb->s_blocksize_bits; | |
660 | ||
661 | while (len > 0) { | |
662 | /* find how many blocks can be covered since this position */ | |
663 | max = ffs(first | border) - 1; | |
664 | ||
665 | /* find how many blocks of power 2 we need to mark */ | |
666 | min = fls(len) - 1; | |
667 | ||
668 | if (max < min) | |
669 | min = max; | |
670 | chunk = 1 << min; | |
671 | ||
672 | /* mark multiblock chunks only */ | |
673 | grp->bb_counters[min]++; | |
674 | if (min > 0) | |
675 | mb_clear_bit(first >> min, | |
676 | buddy + sbi->s_mb_offsets[min]); | |
677 | ||
678 | len -= chunk; | |
679 | first += chunk; | |
680 | } | |
681 | } | |
682 | ||
683 | /* | |
684 | * Cache the order of the largest free extent we have available in this block | |
685 | * group. | |
686 | */ | |
687 | static void | |
688 | mb_set_largest_free_order(struct super_block *sb, struct ext4_group_info *grp) | |
689 | { | |
690 | int i; | |
691 | int bits; | |
692 | ||
693 | grp->bb_largest_free_order = -1; /* uninit */ | |
694 | ||
695 | bits = sb->s_blocksize_bits + 1; | |
696 | for (i = bits; i >= 0; i--) { | |
697 | if (grp->bb_counters[i] > 0) { | |
698 | grp->bb_largest_free_order = i; | |
699 | break; | |
700 | } | |
701 | } | |
702 | } | |
703 | ||
704 | static noinline_for_stack | |
705 | void ext4_mb_generate_buddy(struct super_block *sb, | |
706 | void *buddy, void *bitmap, ext4_group_t group) | |
707 | { | |
708 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); | |
709 | ext4_grpblk_t max = EXT4_CLUSTERS_PER_GROUP(sb); | |
710 | ext4_grpblk_t i = 0; | |
711 | ext4_grpblk_t first; | |
712 | ext4_grpblk_t len; | |
713 | unsigned free = 0; | |
714 | unsigned fragments = 0; | |
715 | unsigned long long period = get_cycles(); | |
716 | ||
717 | /* initialize buddy from bitmap which is aggregation | |
718 | * of on-disk bitmap and preallocations */ | |
719 | i = mb_find_next_zero_bit(bitmap, max, 0); | |
720 | grp->bb_first_free = i; | |
721 | while (i < max) { | |
722 | fragments++; | |
723 | first = i; | |
724 | i = mb_find_next_bit(bitmap, max, i); | |
725 | len = i - first; | |
726 | free += len; | |
727 | if (len > 1) | |
728 | ext4_mb_mark_free_simple(sb, buddy, first, len, grp); | |
729 | else | |
730 | grp->bb_counters[0]++; | |
731 | if (i < max) | |
732 | i = mb_find_next_zero_bit(bitmap, max, i); | |
733 | } | |
734 | grp->bb_fragments = fragments; | |
735 | ||
736 | if (free != grp->bb_free) { | |
737 | ext4_grp_locked_error(sb, group, 0, 0, | |
738 | "%u clusters in bitmap, %u in gd", | |
739 | free, grp->bb_free); | |
740 | /* | |
741 | * If we intent to continue, we consider group descritor | |
742 | * corrupt and update bb_free using bitmap value | |
743 | */ | |
744 | grp->bb_free = free; | |
745 | } | |
746 | mb_set_largest_free_order(sb, grp); | |
747 | ||
748 | clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state)); | |
749 | ||
750 | period = get_cycles() - period; | |
751 | spin_lock(&EXT4_SB(sb)->s_bal_lock); | |
752 | EXT4_SB(sb)->s_mb_buddies_generated++; | |
753 | EXT4_SB(sb)->s_mb_generation_time += period; | |
754 | spin_unlock(&EXT4_SB(sb)->s_bal_lock); | |
755 | } | |
756 | ||
757 | /* The buddy information is attached the buddy cache inode | |
758 | * for convenience. The information regarding each group | |
759 | * is loaded via ext4_mb_load_buddy. The information involve | |
760 | * block bitmap and buddy information. The information are | |
761 | * stored in the inode as | |
762 | * | |
763 | * { page } | |
764 | * [ group 0 bitmap][ group 0 buddy] [group 1][ group 1]... | |
765 | * | |
766 | * | |
767 | * one block each for bitmap and buddy information. | |
768 | * So for each group we take up 2 blocks. A page can | |
769 | * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks. | |
770 | * So it can have information regarding groups_per_page which | |
771 | * is blocks_per_page/2 | |
772 | * | |
773 | * Locking note: This routine takes the block group lock of all groups | |
774 | * for this page; do not hold this lock when calling this routine! | |
775 | */ | |
776 | ||
777 | static int ext4_mb_init_cache(struct page *page, char *incore) | |
778 | { | |
779 | ext4_group_t ngroups; | |
780 | int blocksize; | |
781 | int blocks_per_page; | |
782 | int groups_per_page; | |
783 | int err = 0; | |
784 | int i; | |
785 | ext4_group_t first_group; | |
786 | int first_block; | |
787 | struct super_block *sb; | |
788 | struct buffer_head *bhs; | |
789 | struct buffer_head **bh; | |
790 | struct inode *inode; | |
791 | char *data; | |
792 | char *bitmap; | |
793 | struct ext4_group_info *grinfo; | |
794 | ||
795 | mb_debug(1, "init page %lu\n", page->index); | |
796 | ||
797 | inode = page->mapping->host; | |
798 | sb = inode->i_sb; | |
799 | ngroups = ext4_get_groups_count(sb); | |
800 | blocksize = 1 << inode->i_blkbits; | |
801 | blocks_per_page = PAGE_CACHE_SIZE / blocksize; | |
802 | ||
803 | groups_per_page = blocks_per_page >> 1; | |
804 | if (groups_per_page == 0) | |
805 | groups_per_page = 1; | |
806 | ||
807 | /* allocate buffer_heads to read bitmaps */ | |
808 | if (groups_per_page > 1) { | |
809 | err = -ENOMEM; | |
810 | i = sizeof(struct buffer_head *) * groups_per_page; | |
811 | bh = kzalloc(i, GFP_NOFS); | |
812 | if (bh == NULL) | |
813 | goto out; | |
814 | } else | |
815 | bh = &bhs; | |
816 | ||
817 | first_group = page->index * blocks_per_page / 2; | |
818 | ||
819 | /* read all groups the page covers into the cache */ | |
820 | for (i = 0; i < groups_per_page; i++) { | |
821 | struct ext4_group_desc *desc; | |
822 | ||
823 | if (first_group + i >= ngroups) | |
824 | break; | |
825 | ||
826 | grinfo = ext4_get_group_info(sb, first_group + i); | |
827 | /* | |
828 | * If page is uptodate then we came here after online resize | |
829 | * which added some new uninitialized group info structs, so | |
830 | * we must skip all initialized uptodate buddies on the page, | |
831 | * which may be currently in use by an allocating task. | |
832 | */ | |
833 | if (PageUptodate(page) && !EXT4_MB_GRP_NEED_INIT(grinfo)) { | |
834 | bh[i] = NULL; | |
835 | continue; | |
836 | } | |
837 | ||
838 | err = -EIO; | |
839 | desc = ext4_get_group_desc(sb, first_group + i, NULL); | |
840 | if (desc == NULL) | |
841 | goto out; | |
842 | ||
843 | err = -ENOMEM; | |
844 | bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc)); | |
845 | if (bh[i] == NULL) | |
846 | goto out; | |
847 | ||
848 | if (bitmap_uptodate(bh[i])) | |
849 | continue; | |
850 | ||
851 | lock_buffer(bh[i]); | |
852 | if (bitmap_uptodate(bh[i])) { | |
853 | unlock_buffer(bh[i]); | |
854 | continue; | |
855 | } | |
856 | ext4_lock_group(sb, first_group + i); | |
857 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { | |
858 | ext4_init_block_bitmap(sb, bh[i], | |
859 | first_group + i, desc); | |
860 | set_bitmap_uptodate(bh[i]); | |
861 | set_buffer_uptodate(bh[i]); | |
862 | ext4_unlock_group(sb, first_group + i); | |
863 | unlock_buffer(bh[i]); | |
864 | continue; | |
865 | } | |
866 | ext4_unlock_group(sb, first_group + i); | |
867 | if (buffer_uptodate(bh[i])) { | |
868 | /* | |
869 | * if not uninit if bh is uptodate, | |
870 | * bitmap is also uptodate | |
871 | */ | |
872 | set_bitmap_uptodate(bh[i]); | |
873 | unlock_buffer(bh[i]); | |
874 | continue; | |
875 | } | |
876 | get_bh(bh[i]); | |
877 | /* | |
878 | * submit the buffer_head for read. We can | |
879 | * safely mark the bitmap as uptodate now. | |
880 | * We do it here so the bitmap uptodate bit | |
881 | * get set with buffer lock held. | |
882 | */ | |
883 | set_bitmap_uptodate(bh[i]); | |
884 | bh[i]->b_end_io = end_buffer_read_sync; | |
885 | submit_bh(READ, bh[i]); | |
886 | mb_debug(1, "read bitmap for group %u\n", first_group + i); | |
887 | } | |
888 | ||
889 | /* wait for I/O completion */ | |
890 | for (i = 0; i < groups_per_page; i++) | |
891 | if (bh[i]) | |
892 | wait_on_buffer(bh[i]); | |
893 | ||
894 | err = -EIO; | |
895 | for (i = 0; i < groups_per_page; i++) | |
896 | if (bh[i] && !buffer_uptodate(bh[i])) | |
897 | goto out; | |
898 | ||
899 | err = 0; | |
900 | first_block = page->index * blocks_per_page; | |
901 | for (i = 0; i < blocks_per_page; i++) { | |
902 | int group; | |
903 | ||
904 | group = (first_block + i) >> 1; | |
905 | if (group >= ngroups) | |
906 | break; | |
907 | ||
908 | if (!bh[group - first_group]) | |
909 | /* skip initialized uptodate buddy */ | |
910 | continue; | |
911 | ||
912 | /* | |
913 | * data carry information regarding this | |
914 | * particular group in the format specified | |
915 | * above | |
916 | * | |
917 | */ | |
918 | data = page_address(page) + (i * blocksize); | |
919 | bitmap = bh[group - first_group]->b_data; | |
920 | ||
921 | /* | |
922 | * We place the buddy block and bitmap block | |
923 | * close together | |
924 | */ | |
925 | if ((first_block + i) & 1) { | |
926 | /* this is block of buddy */ | |
927 | BUG_ON(incore == NULL); | |
928 | mb_debug(1, "put buddy for group %u in page %lu/%x\n", | |
929 | group, page->index, i * blocksize); | |
930 | trace_ext4_mb_buddy_bitmap_load(sb, group); | |
931 | grinfo = ext4_get_group_info(sb, group); | |
932 | grinfo->bb_fragments = 0; | |
933 | memset(grinfo->bb_counters, 0, | |
934 | sizeof(*grinfo->bb_counters) * | |
935 | (sb->s_blocksize_bits+2)); | |
936 | /* | |
937 | * incore got set to the group block bitmap below | |
938 | */ | |
939 | ext4_lock_group(sb, group); | |
940 | /* init the buddy */ | |
941 | memset(data, 0xff, blocksize); | |
942 | ext4_mb_generate_buddy(sb, data, incore, group); | |
943 | ext4_unlock_group(sb, group); | |
944 | incore = NULL; | |
945 | } else { | |
946 | /* this is block of bitmap */ | |
947 | BUG_ON(incore != NULL); | |
948 | mb_debug(1, "put bitmap for group %u in page %lu/%x\n", | |
949 | group, page->index, i * blocksize); | |
950 | trace_ext4_mb_bitmap_load(sb, group); | |
951 | ||
952 | /* see comments in ext4_mb_put_pa() */ | |
953 | ext4_lock_group(sb, group); | |
954 | memcpy(data, bitmap, blocksize); | |
955 | ||
956 | /* mark all preallocated blks used in in-core bitmap */ | |
957 | ext4_mb_generate_from_pa(sb, data, group); | |
958 | ext4_mb_generate_from_freelist(sb, data, group); | |
959 | ext4_unlock_group(sb, group); | |
960 | ||
961 | /* set incore so that the buddy information can be | |
962 | * generated using this | |
963 | */ | |
964 | incore = data; | |
965 | } | |
966 | } | |
967 | SetPageUptodate(page); | |
968 | ||
969 | out: | |
970 | if (bh) { | |
971 | for (i = 0; i < groups_per_page; i++) | |
972 | brelse(bh[i]); | |
973 | if (bh != &bhs) | |
974 | kfree(bh); | |
975 | } | |
976 | return err; | |
977 | } | |
978 | ||
979 | /* | |
980 | * Lock the buddy and bitmap pages. This make sure other parallel init_group | |
981 | * on the same buddy page doesn't happen whild holding the buddy page lock. | |
982 | * Return locked buddy and bitmap pages on e4b struct. If buddy and bitmap | |
983 | * are on the same page e4b->bd_buddy_page is NULL and return value is 0. | |
984 | */ | |
985 | static int ext4_mb_get_buddy_page_lock(struct super_block *sb, | |
986 | ext4_group_t group, struct ext4_buddy *e4b) | |
987 | { | |
988 | struct inode *inode = EXT4_SB(sb)->s_buddy_cache; | |
989 | int block, pnum, poff; | |
990 | int blocks_per_page; | |
991 | struct page *page; | |
992 | ||
993 | e4b->bd_buddy_page = NULL; | |
994 | e4b->bd_bitmap_page = NULL; | |
995 | ||
996 | blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; | |
997 | /* | |
998 | * the buddy cache inode stores the block bitmap | |
999 | * and buddy information in consecutive blocks. | |
1000 | * So for each group we need two blocks. | |
1001 | */ | |
1002 | block = group * 2; | |
1003 | pnum = block / blocks_per_page; | |
1004 | poff = block % blocks_per_page; | |
1005 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); | |
1006 | if (!page) | |
1007 | return -EIO; | |
1008 | BUG_ON(page->mapping != inode->i_mapping); | |
1009 | e4b->bd_bitmap_page = page; | |
1010 | e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); | |
1011 | ||
1012 | if (blocks_per_page >= 2) { | |
1013 | /* buddy and bitmap are on the same page */ | |
1014 | return 0; | |
1015 | } | |
1016 | ||
1017 | block++; | |
1018 | pnum = block / blocks_per_page; | |
1019 | poff = block % blocks_per_page; | |
1020 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); | |
1021 | if (!page) | |
1022 | return -EIO; | |
1023 | BUG_ON(page->mapping != inode->i_mapping); | |
1024 | e4b->bd_buddy_page = page; | |
1025 | return 0; | |
1026 | } | |
1027 | ||
1028 | static void ext4_mb_put_buddy_page_lock(struct ext4_buddy *e4b) | |
1029 | { | |
1030 | if (e4b->bd_bitmap_page) { | |
1031 | unlock_page(e4b->bd_bitmap_page); | |
1032 | page_cache_release(e4b->bd_bitmap_page); | |
1033 | } | |
1034 | if (e4b->bd_buddy_page) { | |
1035 | unlock_page(e4b->bd_buddy_page); | |
1036 | page_cache_release(e4b->bd_buddy_page); | |
1037 | } | |
1038 | } | |
1039 | ||
1040 | /* | |
1041 | * Locking note: This routine calls ext4_mb_init_cache(), which takes the | |
1042 | * block group lock of all groups for this page; do not hold the BG lock when | |
1043 | * calling this routine! | |
1044 | */ | |
1045 | static noinline_for_stack | |
1046 | int ext4_mb_init_group(struct super_block *sb, ext4_group_t group) | |
1047 | { | |
1048 | ||
1049 | struct ext4_group_info *this_grp; | |
1050 | struct ext4_buddy e4b; | |
1051 | struct page *page; | |
1052 | int ret = 0; | |
1053 | ||
1054 | mb_debug(1, "init group %u\n", group); | |
1055 | this_grp = ext4_get_group_info(sb, group); | |
1056 | /* | |
1057 | * This ensures that we don't reinit the buddy cache | |
1058 | * page which map to the group from which we are already | |
1059 | * allocating. If we are looking at the buddy cache we would | |
1060 | * have taken a reference using ext4_mb_load_buddy and that | |
1061 | * would have pinned buddy page to page cache. | |
1062 | */ | |
1063 | ret = ext4_mb_get_buddy_page_lock(sb, group, &e4b); | |
1064 | if (ret || !EXT4_MB_GRP_NEED_INIT(this_grp)) { | |
1065 | /* | |
1066 | * somebody initialized the group | |
1067 | * return without doing anything | |
1068 | */ | |
1069 | goto err; | |
1070 | } | |
1071 | ||
1072 | page = e4b.bd_bitmap_page; | |
1073 | ret = ext4_mb_init_cache(page, NULL); | |
1074 | if (ret) | |
1075 | goto err; | |
1076 | if (!PageUptodate(page)) { | |
1077 | ret = -EIO; | |
1078 | goto err; | |
1079 | } | |
1080 | mark_page_accessed(page); | |
1081 | ||
1082 | if (e4b.bd_buddy_page == NULL) { | |
1083 | /* | |
1084 | * If both the bitmap and buddy are in | |
1085 | * the same page we don't need to force | |
1086 | * init the buddy | |
1087 | */ | |
1088 | ret = 0; | |
1089 | goto err; | |
1090 | } | |
1091 | /* init buddy cache */ | |
1092 | page = e4b.bd_buddy_page; | |
1093 | ret = ext4_mb_init_cache(page, e4b.bd_bitmap); | |
1094 | if (ret) | |
1095 | goto err; | |
1096 | if (!PageUptodate(page)) { | |
1097 | ret = -EIO; | |
1098 | goto err; | |
1099 | } | |
1100 | mark_page_accessed(page); | |
1101 | err: | |
1102 | ext4_mb_put_buddy_page_lock(&e4b); | |
1103 | return ret; | |
1104 | } | |
1105 | ||
1106 | /* | |
1107 | * Locking note: This routine calls ext4_mb_init_cache(), which takes the | |
1108 | * block group lock of all groups for this page; do not hold the BG lock when | |
1109 | * calling this routine! | |
1110 | */ | |
1111 | static noinline_for_stack int | |
1112 | ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group, | |
1113 | struct ext4_buddy *e4b) | |
1114 | { | |
1115 | int blocks_per_page; | |
1116 | int block; | |
1117 | int pnum; | |
1118 | int poff; | |
1119 | struct page *page; | |
1120 | int ret; | |
1121 | struct ext4_group_info *grp; | |
1122 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
1123 | struct inode *inode = sbi->s_buddy_cache; | |
1124 | ||
1125 | mb_debug(1, "load group %u\n", group); | |
1126 | ||
1127 | blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize; | |
1128 | grp = ext4_get_group_info(sb, group); | |
1129 | ||
1130 | e4b->bd_blkbits = sb->s_blocksize_bits; | |
1131 | e4b->bd_info = grp; | |
1132 | e4b->bd_sb = sb; | |
1133 | e4b->bd_group = group; | |
1134 | e4b->bd_buddy_page = NULL; | |
1135 | e4b->bd_bitmap_page = NULL; | |
1136 | ||
1137 | if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { | |
1138 | /* | |
1139 | * we need full data about the group | |
1140 | * to make a good selection | |
1141 | */ | |
1142 | ret = ext4_mb_init_group(sb, group); | |
1143 | if (ret) | |
1144 | return ret; | |
1145 | } | |
1146 | ||
1147 | /* | |
1148 | * the buddy cache inode stores the block bitmap | |
1149 | * and buddy information in consecutive blocks. | |
1150 | * So for each group we need two blocks. | |
1151 | */ | |
1152 | block = group * 2; | |
1153 | pnum = block / blocks_per_page; | |
1154 | poff = block % blocks_per_page; | |
1155 | ||
1156 | /* we could use find_or_create_page(), but it locks page | |
1157 | * what we'd like to avoid in fast path ... */ | |
1158 | page = find_get_page(inode->i_mapping, pnum); | |
1159 | if (page == NULL || !PageUptodate(page)) { | |
1160 | if (page) | |
1161 | /* | |
1162 | * drop the page reference and try | |
1163 | * to get the page with lock. If we | |
1164 | * are not uptodate that implies | |
1165 | * somebody just created the page but | |
1166 | * is yet to initialize the same. So | |
1167 | * wait for it to initialize. | |
1168 | */ | |
1169 | page_cache_release(page); | |
1170 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); | |
1171 | if (page) { | |
1172 | BUG_ON(page->mapping != inode->i_mapping); | |
1173 | if (!PageUptodate(page)) { | |
1174 | ret = ext4_mb_init_cache(page, NULL); | |
1175 | if (ret) { | |
1176 | unlock_page(page); | |
1177 | goto err; | |
1178 | } | |
1179 | mb_cmp_bitmaps(e4b, page_address(page) + | |
1180 | (poff * sb->s_blocksize)); | |
1181 | } | |
1182 | unlock_page(page); | |
1183 | } | |
1184 | } | |
1185 | if (page == NULL || !PageUptodate(page)) { | |
1186 | ret = -EIO; | |
1187 | goto err; | |
1188 | } | |
1189 | e4b->bd_bitmap_page = page; | |
1190 | e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize); | |
1191 | mark_page_accessed(page); | |
1192 | ||
1193 | block++; | |
1194 | pnum = block / blocks_per_page; | |
1195 | poff = block % blocks_per_page; | |
1196 | ||
1197 | page = find_get_page(inode->i_mapping, pnum); | |
1198 | if (page == NULL || !PageUptodate(page)) { | |
1199 | if (page) | |
1200 | page_cache_release(page); | |
1201 | page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS); | |
1202 | if (page) { | |
1203 | BUG_ON(page->mapping != inode->i_mapping); | |
1204 | if (!PageUptodate(page)) { | |
1205 | ret = ext4_mb_init_cache(page, e4b->bd_bitmap); | |
1206 | if (ret) { | |
1207 | unlock_page(page); | |
1208 | goto err; | |
1209 | } | |
1210 | } | |
1211 | unlock_page(page); | |
1212 | } | |
1213 | } | |
1214 | if (page == NULL || !PageUptodate(page)) { | |
1215 | ret = -EIO; | |
1216 | goto err; | |
1217 | } | |
1218 | e4b->bd_buddy_page = page; | |
1219 | e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize); | |
1220 | mark_page_accessed(page); | |
1221 | ||
1222 | BUG_ON(e4b->bd_bitmap_page == NULL); | |
1223 | BUG_ON(e4b->bd_buddy_page == NULL); | |
1224 | ||
1225 | return 0; | |
1226 | ||
1227 | err: | |
1228 | if (page) | |
1229 | page_cache_release(page); | |
1230 | if (e4b->bd_bitmap_page) | |
1231 | page_cache_release(e4b->bd_bitmap_page); | |
1232 | if (e4b->bd_buddy_page) | |
1233 | page_cache_release(e4b->bd_buddy_page); | |
1234 | e4b->bd_buddy = NULL; | |
1235 | e4b->bd_bitmap = NULL; | |
1236 | return ret; | |
1237 | } | |
1238 | ||
1239 | static void ext4_mb_unload_buddy(struct ext4_buddy *e4b) | |
1240 | { | |
1241 | if (e4b->bd_bitmap_page) | |
1242 | page_cache_release(e4b->bd_bitmap_page); | |
1243 | if (e4b->bd_buddy_page) | |
1244 | page_cache_release(e4b->bd_buddy_page); | |
1245 | } | |
1246 | ||
1247 | ||
1248 | static int mb_find_order_for_block(struct ext4_buddy *e4b, int block) | |
1249 | { | |
1250 | int order = 1; | |
1251 | void *bb; | |
1252 | ||
1253 | BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b)); | |
1254 | BUG_ON(block >= (1 << (e4b->bd_blkbits + 3))); | |
1255 | ||
1256 | bb = EXT4_MB_BUDDY(e4b); | |
1257 | while (order <= e4b->bd_blkbits + 1) { | |
1258 | block = block >> 1; | |
1259 | if (!mb_test_bit(block, bb)) { | |
1260 | /* this block is part of buddy of order 'order' */ | |
1261 | return order; | |
1262 | } | |
1263 | bb += 1 << (e4b->bd_blkbits - order); | |
1264 | order++; | |
1265 | } | |
1266 | return 0; | |
1267 | } | |
1268 | ||
1269 | static void mb_clear_bits(void *bm, int cur, int len) | |
1270 | { | |
1271 | __u32 *addr; | |
1272 | ||
1273 | len = cur + len; | |
1274 | while (cur < len) { | |
1275 | if ((cur & 31) == 0 && (len - cur) >= 32) { | |
1276 | /* fast path: clear whole word at once */ | |
1277 | addr = bm + (cur >> 3); | |
1278 | *addr = 0; | |
1279 | cur += 32; | |
1280 | continue; | |
1281 | } | |
1282 | mb_clear_bit(cur, bm); | |
1283 | cur++; | |
1284 | } | |
1285 | } | |
1286 | ||
1287 | void ext4_set_bits(void *bm, int cur, int len) | |
1288 | { | |
1289 | __u32 *addr; | |
1290 | ||
1291 | len = cur + len; | |
1292 | while (cur < len) { | |
1293 | if ((cur & 31) == 0 && (len - cur) >= 32) { | |
1294 | /* fast path: set whole word at once */ | |
1295 | addr = bm + (cur >> 3); | |
1296 | *addr = 0xffffffff; | |
1297 | cur += 32; | |
1298 | continue; | |
1299 | } | |
1300 | mb_set_bit(cur, bm); | |
1301 | cur++; | |
1302 | } | |
1303 | } | |
1304 | ||
1305 | static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b, | |
1306 | int first, int count) | |
1307 | { | |
1308 | int block = 0; | |
1309 | int max = 0; | |
1310 | int order; | |
1311 | void *buddy; | |
1312 | void *buddy2; | |
1313 | struct super_block *sb = e4b->bd_sb; | |
1314 | ||
1315 | BUG_ON(first + count > (sb->s_blocksize << 3)); | |
1316 | assert_spin_locked(ext4_group_lock_ptr(sb, e4b->bd_group)); | |
1317 | mb_check_buddy(e4b); | |
1318 | mb_free_blocks_double(inode, e4b, first, count); | |
1319 | ||
1320 | e4b->bd_info->bb_free += count; | |
1321 | if (first < e4b->bd_info->bb_first_free) | |
1322 | e4b->bd_info->bb_first_free = first; | |
1323 | ||
1324 | /* let's maintain fragments counter */ | |
1325 | if (first != 0) | |
1326 | block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b)); | |
1327 | if (first + count < EXT4_SB(sb)->s_mb_maxs[0]) | |
1328 | max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b)); | |
1329 | if (block && max) | |
1330 | e4b->bd_info->bb_fragments--; | |
1331 | else if (!block && !max) | |
1332 | e4b->bd_info->bb_fragments++; | |
1333 | ||
1334 | /* let's maintain buddy itself */ | |
1335 | while (count-- > 0) { | |
1336 | block = first++; | |
1337 | order = 0; | |
1338 | ||
1339 | if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) { | |
1340 | ext4_fsblk_t blocknr; | |
1341 | ||
1342 | blocknr = ext4_group_first_block_no(sb, e4b->bd_group); | |
1343 | blocknr += EXT4_C2B(EXT4_SB(sb), block); | |
1344 | ext4_grp_locked_error(sb, e4b->bd_group, | |
1345 | inode ? inode->i_ino : 0, | |
1346 | blocknr, | |
1347 | "freeing already freed block " | |
1348 | "(bit %u)", block); | |
1349 | } | |
1350 | mb_clear_bit(block, EXT4_MB_BITMAP(e4b)); | |
1351 | e4b->bd_info->bb_counters[order]++; | |
1352 | ||
1353 | /* start of the buddy */ | |
1354 | buddy = mb_find_buddy(e4b, order, &max); | |
1355 | ||
1356 | do { | |
1357 | block &= ~1UL; | |
1358 | if (mb_test_bit(block, buddy) || | |
1359 | mb_test_bit(block + 1, buddy)) | |
1360 | break; | |
1361 | ||
1362 | /* both the buddies are free, try to coalesce them */ | |
1363 | buddy2 = mb_find_buddy(e4b, order + 1, &max); | |
1364 | ||
1365 | if (!buddy2) | |
1366 | break; | |
1367 | ||
1368 | if (order > 0) { | |
1369 | /* for special purposes, we don't set | |
1370 | * free bits in bitmap */ | |
1371 | mb_set_bit(block, buddy); | |
1372 | mb_set_bit(block + 1, buddy); | |
1373 | } | |
1374 | e4b->bd_info->bb_counters[order]--; | |
1375 | e4b->bd_info->bb_counters[order]--; | |
1376 | ||
1377 | block = block >> 1; | |
1378 | order++; | |
1379 | e4b->bd_info->bb_counters[order]++; | |
1380 | ||
1381 | mb_clear_bit(block, buddy2); | |
1382 | buddy = buddy2; | |
1383 | } while (1); | |
1384 | } | |
1385 | mb_set_largest_free_order(sb, e4b->bd_info); | |
1386 | mb_check_buddy(e4b); | |
1387 | } | |
1388 | ||
1389 | static int mb_find_extent(struct ext4_buddy *e4b, int order, int block, | |
1390 | int needed, struct ext4_free_extent *ex) | |
1391 | { | |
1392 | int next = block; | |
1393 | int max; | |
1394 | int ord; | |
1395 | void *buddy; | |
1396 | ||
1397 | assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); | |
1398 | BUG_ON(ex == NULL); | |
1399 | ||
1400 | buddy = mb_find_buddy(e4b, order, &max); | |
1401 | BUG_ON(buddy == NULL); | |
1402 | BUG_ON(block >= max); | |
1403 | if (mb_test_bit(block, buddy)) { | |
1404 | ex->fe_len = 0; | |
1405 | ex->fe_start = 0; | |
1406 | ex->fe_group = 0; | |
1407 | return 0; | |
1408 | } | |
1409 | ||
1410 | /* FIXME dorp order completely ? */ | |
1411 | if (likely(order == 0)) { | |
1412 | /* find actual order */ | |
1413 | order = mb_find_order_for_block(e4b, block); | |
1414 | block = block >> order; | |
1415 | } | |
1416 | ||
1417 | ex->fe_len = 1 << order; | |
1418 | ex->fe_start = block << order; | |
1419 | ex->fe_group = e4b->bd_group; | |
1420 | ||
1421 | /* calc difference from given start */ | |
1422 | next = next - ex->fe_start; | |
1423 | ex->fe_len -= next; | |
1424 | ex->fe_start += next; | |
1425 | ||
1426 | while (needed > ex->fe_len && | |
1427 | (buddy = mb_find_buddy(e4b, order, &max))) { | |
1428 | ||
1429 | if (block + 1 >= max) | |
1430 | break; | |
1431 | ||
1432 | next = (block + 1) * (1 << order); | |
1433 | if (mb_test_bit(next, EXT4_MB_BITMAP(e4b))) | |
1434 | break; | |
1435 | ||
1436 | ord = mb_find_order_for_block(e4b, next); | |
1437 | ||
1438 | order = ord; | |
1439 | block = next >> order; | |
1440 | ex->fe_len += 1 << order; | |
1441 | } | |
1442 | ||
1443 | BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3))); | |
1444 | return ex->fe_len; | |
1445 | } | |
1446 | ||
1447 | static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex) | |
1448 | { | |
1449 | int ord; | |
1450 | int mlen = 0; | |
1451 | int max = 0; | |
1452 | int cur; | |
1453 | int start = ex->fe_start; | |
1454 | int len = ex->fe_len; | |
1455 | unsigned ret = 0; | |
1456 | int len0 = len; | |
1457 | void *buddy; | |
1458 | ||
1459 | BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3)); | |
1460 | BUG_ON(e4b->bd_group != ex->fe_group); | |
1461 | assert_spin_locked(ext4_group_lock_ptr(e4b->bd_sb, e4b->bd_group)); | |
1462 | mb_check_buddy(e4b); | |
1463 | mb_mark_used_double(e4b, start, len); | |
1464 | ||
1465 | e4b->bd_info->bb_free -= len; | |
1466 | if (e4b->bd_info->bb_first_free == start) | |
1467 | e4b->bd_info->bb_first_free += len; | |
1468 | ||
1469 | /* let's maintain fragments counter */ | |
1470 | if (start != 0) | |
1471 | mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b)); | |
1472 | if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0]) | |
1473 | max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b)); | |
1474 | if (mlen && max) | |
1475 | e4b->bd_info->bb_fragments++; | |
1476 | else if (!mlen && !max) | |
1477 | e4b->bd_info->bb_fragments--; | |
1478 | ||
1479 | /* let's maintain buddy itself */ | |
1480 | while (len) { | |
1481 | ord = mb_find_order_for_block(e4b, start); | |
1482 | ||
1483 | if (((start >> ord) << ord) == start && len >= (1 << ord)) { | |
1484 | /* the whole chunk may be allocated at once! */ | |
1485 | mlen = 1 << ord; | |
1486 | buddy = mb_find_buddy(e4b, ord, &max); | |
1487 | BUG_ON((start >> ord) >= max); | |
1488 | mb_set_bit(start >> ord, buddy); | |
1489 | e4b->bd_info->bb_counters[ord]--; | |
1490 | start += mlen; | |
1491 | len -= mlen; | |
1492 | BUG_ON(len < 0); | |
1493 | continue; | |
1494 | } | |
1495 | ||
1496 | /* store for history */ | |
1497 | if (ret == 0) | |
1498 | ret = len | (ord << 16); | |
1499 | ||
1500 | /* we have to split large buddy */ | |
1501 | BUG_ON(ord <= 0); | |
1502 | buddy = mb_find_buddy(e4b, ord, &max); | |
1503 | mb_set_bit(start >> ord, buddy); | |
1504 | e4b->bd_info->bb_counters[ord]--; | |
1505 | ||
1506 | ord--; | |
1507 | cur = (start >> ord) & ~1U; | |
1508 | buddy = mb_find_buddy(e4b, ord, &max); | |
1509 | mb_clear_bit(cur, buddy); | |
1510 | mb_clear_bit(cur + 1, buddy); | |
1511 | e4b->bd_info->bb_counters[ord]++; | |
1512 | e4b->bd_info->bb_counters[ord]++; | |
1513 | } | |
1514 | mb_set_largest_free_order(e4b->bd_sb, e4b->bd_info); | |
1515 | ||
1516 | ext4_set_bits(EXT4_MB_BITMAP(e4b), ex->fe_start, len0); | |
1517 | mb_check_buddy(e4b); | |
1518 | ||
1519 | return ret; | |
1520 | } | |
1521 | ||
1522 | /* | |
1523 | * Must be called under group lock! | |
1524 | */ | |
1525 | static void ext4_mb_use_best_found(struct ext4_allocation_context *ac, | |
1526 | struct ext4_buddy *e4b) | |
1527 | { | |
1528 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
1529 | int ret; | |
1530 | ||
1531 | BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group); | |
1532 | BUG_ON(ac->ac_status == AC_STATUS_FOUND); | |
1533 | ||
1534 | ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len); | |
1535 | ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical; | |
1536 | ret = mb_mark_used(e4b, &ac->ac_b_ex); | |
1537 | ||
1538 | /* preallocation can change ac_b_ex, thus we store actually | |
1539 | * allocated blocks for history */ | |
1540 | ac->ac_f_ex = ac->ac_b_ex; | |
1541 | ||
1542 | ac->ac_status = AC_STATUS_FOUND; | |
1543 | ac->ac_tail = ret & 0xffff; | |
1544 | ac->ac_buddy = ret >> 16; | |
1545 | ||
1546 | /* | |
1547 | * take the page reference. We want the page to be pinned | |
1548 | * so that we don't get a ext4_mb_init_cache_call for this | |
1549 | * group until we update the bitmap. That would mean we | |
1550 | * double allocate blocks. The reference is dropped | |
1551 | * in ext4_mb_release_context | |
1552 | */ | |
1553 | ac->ac_bitmap_page = e4b->bd_bitmap_page; | |
1554 | get_page(ac->ac_bitmap_page); | |
1555 | ac->ac_buddy_page = e4b->bd_buddy_page; | |
1556 | get_page(ac->ac_buddy_page); | |
1557 | /* store last allocated for subsequent stream allocation */ | |
1558 | if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { | |
1559 | spin_lock(&sbi->s_md_lock); | |
1560 | sbi->s_mb_last_group = ac->ac_f_ex.fe_group; | |
1561 | sbi->s_mb_last_start = ac->ac_f_ex.fe_start; | |
1562 | spin_unlock(&sbi->s_md_lock); | |
1563 | } | |
1564 | } | |
1565 | ||
1566 | /* | |
1567 | * regular allocator, for general purposes allocation | |
1568 | */ | |
1569 | ||
1570 | static void ext4_mb_check_limits(struct ext4_allocation_context *ac, | |
1571 | struct ext4_buddy *e4b, | |
1572 | int finish_group) | |
1573 | { | |
1574 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
1575 | struct ext4_free_extent *bex = &ac->ac_b_ex; | |
1576 | struct ext4_free_extent *gex = &ac->ac_g_ex; | |
1577 | struct ext4_free_extent ex; | |
1578 | int max; | |
1579 | ||
1580 | if (ac->ac_status == AC_STATUS_FOUND) | |
1581 | return; | |
1582 | /* | |
1583 | * We don't want to scan for a whole year | |
1584 | */ | |
1585 | if (ac->ac_found > sbi->s_mb_max_to_scan && | |
1586 | !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { | |
1587 | ac->ac_status = AC_STATUS_BREAK; | |
1588 | return; | |
1589 | } | |
1590 | ||
1591 | /* | |
1592 | * Haven't found good chunk so far, let's continue | |
1593 | */ | |
1594 | if (bex->fe_len < gex->fe_len) | |
1595 | return; | |
1596 | ||
1597 | if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan) | |
1598 | && bex->fe_group == e4b->bd_group) { | |
1599 | /* recheck chunk's availability - we don't know | |
1600 | * when it was found (within this lock-unlock | |
1601 | * period or not) */ | |
1602 | max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex); | |
1603 | if (max >= gex->fe_len) { | |
1604 | ext4_mb_use_best_found(ac, e4b); | |
1605 | return; | |
1606 | } | |
1607 | } | |
1608 | } | |
1609 | ||
1610 | /* | |
1611 | * The routine checks whether found extent is good enough. If it is, | |
1612 | * then the extent gets marked used and flag is set to the context | |
1613 | * to stop scanning. Otherwise, the extent is compared with the | |
1614 | * previous found extent and if new one is better, then it's stored | |
1615 | * in the context. Later, the best found extent will be used, if | |
1616 | * mballoc can't find good enough extent. | |
1617 | * | |
1618 | * FIXME: real allocation policy is to be designed yet! | |
1619 | */ | |
1620 | static void ext4_mb_measure_extent(struct ext4_allocation_context *ac, | |
1621 | struct ext4_free_extent *ex, | |
1622 | struct ext4_buddy *e4b) | |
1623 | { | |
1624 | struct ext4_free_extent *bex = &ac->ac_b_ex; | |
1625 | struct ext4_free_extent *gex = &ac->ac_g_ex; | |
1626 | ||
1627 | BUG_ON(ex->fe_len <= 0); | |
1628 | BUG_ON(ex->fe_len > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); | |
1629 | BUG_ON(ex->fe_start >= EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); | |
1630 | BUG_ON(ac->ac_status != AC_STATUS_CONTINUE); | |
1631 | ||
1632 | ac->ac_found++; | |
1633 | ||
1634 | /* | |
1635 | * The special case - take what you catch first | |
1636 | */ | |
1637 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) { | |
1638 | *bex = *ex; | |
1639 | ext4_mb_use_best_found(ac, e4b); | |
1640 | return; | |
1641 | } | |
1642 | ||
1643 | /* | |
1644 | * Let's check whether the chuck is good enough | |
1645 | */ | |
1646 | if (ex->fe_len == gex->fe_len) { | |
1647 | *bex = *ex; | |
1648 | ext4_mb_use_best_found(ac, e4b); | |
1649 | return; | |
1650 | } | |
1651 | ||
1652 | /* | |
1653 | * If this is first found extent, just store it in the context | |
1654 | */ | |
1655 | if (bex->fe_len == 0) { | |
1656 | *bex = *ex; | |
1657 | return; | |
1658 | } | |
1659 | ||
1660 | /* | |
1661 | * If new found extent is better, store it in the context | |
1662 | */ | |
1663 | if (bex->fe_len < gex->fe_len) { | |
1664 | /* if the request isn't satisfied, any found extent | |
1665 | * larger than previous best one is better */ | |
1666 | if (ex->fe_len > bex->fe_len) | |
1667 | *bex = *ex; | |
1668 | } else if (ex->fe_len > gex->fe_len) { | |
1669 | /* if the request is satisfied, then we try to find | |
1670 | * an extent that still satisfy the request, but is | |
1671 | * smaller than previous one */ | |
1672 | if (ex->fe_len < bex->fe_len) | |
1673 | *bex = *ex; | |
1674 | } | |
1675 | ||
1676 | ext4_mb_check_limits(ac, e4b, 0); | |
1677 | } | |
1678 | ||
1679 | static noinline_for_stack | |
1680 | int ext4_mb_try_best_found(struct ext4_allocation_context *ac, | |
1681 | struct ext4_buddy *e4b) | |
1682 | { | |
1683 | struct ext4_free_extent ex = ac->ac_b_ex; | |
1684 | ext4_group_t group = ex.fe_group; | |
1685 | int max; | |
1686 | int err; | |
1687 | ||
1688 | BUG_ON(ex.fe_len <= 0); | |
1689 | err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); | |
1690 | if (err) | |
1691 | return err; | |
1692 | ||
1693 | ext4_lock_group(ac->ac_sb, group); | |
1694 | max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex); | |
1695 | ||
1696 | if (max > 0) { | |
1697 | ac->ac_b_ex = ex; | |
1698 | ext4_mb_use_best_found(ac, e4b); | |
1699 | } | |
1700 | ||
1701 | ext4_unlock_group(ac->ac_sb, group); | |
1702 | ext4_mb_unload_buddy(e4b); | |
1703 | ||
1704 | return 0; | |
1705 | } | |
1706 | ||
1707 | static noinline_for_stack | |
1708 | int ext4_mb_find_by_goal(struct ext4_allocation_context *ac, | |
1709 | struct ext4_buddy *e4b) | |
1710 | { | |
1711 | ext4_group_t group = ac->ac_g_ex.fe_group; | |
1712 | int max; | |
1713 | int err; | |
1714 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
1715 | struct ext4_free_extent ex; | |
1716 | ||
1717 | if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL)) | |
1718 | return 0; | |
1719 | ||
1720 | err = ext4_mb_load_buddy(ac->ac_sb, group, e4b); | |
1721 | if (err) | |
1722 | return err; | |
1723 | ||
1724 | ext4_lock_group(ac->ac_sb, group); | |
1725 | max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start, | |
1726 | ac->ac_g_ex.fe_len, &ex); | |
1727 | ||
1728 | if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) { | |
1729 | ext4_fsblk_t start; | |
1730 | ||
1731 | start = ext4_group_first_block_no(ac->ac_sb, e4b->bd_group) + | |
1732 | ex.fe_start; | |
1733 | /* use do_div to get remainder (would be 64-bit modulo) */ | |
1734 | if (do_div(start, sbi->s_stripe) == 0) { | |
1735 | ac->ac_found++; | |
1736 | ac->ac_b_ex = ex; | |
1737 | ext4_mb_use_best_found(ac, e4b); | |
1738 | } | |
1739 | } else if (max >= ac->ac_g_ex.fe_len) { | |
1740 | BUG_ON(ex.fe_len <= 0); | |
1741 | BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); | |
1742 | BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); | |
1743 | ac->ac_found++; | |
1744 | ac->ac_b_ex = ex; | |
1745 | ext4_mb_use_best_found(ac, e4b); | |
1746 | } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) { | |
1747 | /* Sometimes, caller may want to merge even small | |
1748 | * number of blocks to an existing extent */ | |
1749 | BUG_ON(ex.fe_len <= 0); | |
1750 | BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group); | |
1751 | BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start); | |
1752 | ac->ac_found++; | |
1753 | ac->ac_b_ex = ex; | |
1754 | ext4_mb_use_best_found(ac, e4b); | |
1755 | } | |
1756 | ext4_unlock_group(ac->ac_sb, group); | |
1757 | ext4_mb_unload_buddy(e4b); | |
1758 | ||
1759 | return 0; | |
1760 | } | |
1761 | ||
1762 | /* | |
1763 | * The routine scans buddy structures (not bitmap!) from given order | |
1764 | * to max order and tries to find big enough chunk to satisfy the req | |
1765 | */ | |
1766 | static noinline_for_stack | |
1767 | void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac, | |
1768 | struct ext4_buddy *e4b) | |
1769 | { | |
1770 | struct super_block *sb = ac->ac_sb; | |
1771 | struct ext4_group_info *grp = e4b->bd_info; | |
1772 | void *buddy; | |
1773 | int i; | |
1774 | int k; | |
1775 | int max; | |
1776 | ||
1777 | BUG_ON(ac->ac_2order <= 0); | |
1778 | for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) { | |
1779 | if (grp->bb_counters[i] == 0) | |
1780 | continue; | |
1781 | ||
1782 | buddy = mb_find_buddy(e4b, i, &max); | |
1783 | BUG_ON(buddy == NULL); | |
1784 | ||
1785 | k = mb_find_next_zero_bit(buddy, max, 0); | |
1786 | BUG_ON(k >= max); | |
1787 | ||
1788 | ac->ac_found++; | |
1789 | ||
1790 | ac->ac_b_ex.fe_len = 1 << i; | |
1791 | ac->ac_b_ex.fe_start = k << i; | |
1792 | ac->ac_b_ex.fe_group = e4b->bd_group; | |
1793 | ||
1794 | ext4_mb_use_best_found(ac, e4b); | |
1795 | ||
1796 | BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len); | |
1797 | ||
1798 | if (EXT4_SB(sb)->s_mb_stats) | |
1799 | atomic_inc(&EXT4_SB(sb)->s_bal_2orders); | |
1800 | ||
1801 | break; | |
1802 | } | |
1803 | } | |
1804 | ||
1805 | /* | |
1806 | * The routine scans the group and measures all found extents. | |
1807 | * In order to optimize scanning, caller must pass number of | |
1808 | * free blocks in the group, so the routine can know upper limit. | |
1809 | */ | |
1810 | static noinline_for_stack | |
1811 | void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac, | |
1812 | struct ext4_buddy *e4b) | |
1813 | { | |
1814 | struct super_block *sb = ac->ac_sb; | |
1815 | void *bitmap = EXT4_MB_BITMAP(e4b); | |
1816 | struct ext4_free_extent ex; | |
1817 | int i; | |
1818 | int free; | |
1819 | ||
1820 | free = e4b->bd_info->bb_free; | |
1821 | BUG_ON(free <= 0); | |
1822 | ||
1823 | i = e4b->bd_info->bb_first_free; | |
1824 | ||
1825 | while (free && ac->ac_status == AC_STATUS_CONTINUE) { | |
1826 | i = mb_find_next_zero_bit(bitmap, | |
1827 | EXT4_CLUSTERS_PER_GROUP(sb), i); | |
1828 | if (i >= EXT4_CLUSTERS_PER_GROUP(sb)) { | |
1829 | /* | |
1830 | * IF we have corrupt bitmap, we won't find any | |
1831 | * free blocks even though group info says we | |
1832 | * we have free blocks | |
1833 | */ | |
1834 | ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, | |
1835 | "%d free clusters as per " | |
1836 | "group info. But bitmap says 0", | |
1837 | free); | |
1838 | break; | |
1839 | } | |
1840 | ||
1841 | mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex); | |
1842 | BUG_ON(ex.fe_len <= 0); | |
1843 | if (free < ex.fe_len) { | |
1844 | ext4_grp_locked_error(sb, e4b->bd_group, 0, 0, | |
1845 | "%d free clusters as per " | |
1846 | "group info. But got %d blocks", | |
1847 | free, ex.fe_len); | |
1848 | /* | |
1849 | * The number of free blocks differs. This mostly | |
1850 | * indicate that the bitmap is corrupt. So exit | |
1851 | * without claiming the space. | |
1852 | */ | |
1853 | break; | |
1854 | } | |
1855 | ||
1856 | ext4_mb_measure_extent(ac, &ex, e4b); | |
1857 | ||
1858 | i += ex.fe_len; | |
1859 | free -= ex.fe_len; | |
1860 | } | |
1861 | ||
1862 | ext4_mb_check_limits(ac, e4b, 1); | |
1863 | } | |
1864 | ||
1865 | /* | |
1866 | * This is a special case for storages like raid5 | |
1867 | * we try to find stripe-aligned chunks for stripe-size-multiple requests | |
1868 | */ | |
1869 | static noinline_for_stack | |
1870 | void ext4_mb_scan_aligned(struct ext4_allocation_context *ac, | |
1871 | struct ext4_buddy *e4b) | |
1872 | { | |
1873 | struct super_block *sb = ac->ac_sb; | |
1874 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
1875 | void *bitmap = EXT4_MB_BITMAP(e4b); | |
1876 | struct ext4_free_extent ex; | |
1877 | ext4_fsblk_t first_group_block; | |
1878 | ext4_fsblk_t a; | |
1879 | ext4_grpblk_t i; | |
1880 | int max; | |
1881 | ||
1882 | BUG_ON(sbi->s_stripe == 0); | |
1883 | ||
1884 | /* find first stripe-aligned block in group */ | |
1885 | first_group_block = ext4_group_first_block_no(sb, e4b->bd_group); | |
1886 | ||
1887 | a = first_group_block + sbi->s_stripe - 1; | |
1888 | do_div(a, sbi->s_stripe); | |
1889 | i = (a * sbi->s_stripe) - first_group_block; | |
1890 | ||
1891 | while (i < EXT4_CLUSTERS_PER_GROUP(sb)) { | |
1892 | if (!mb_test_bit(i, bitmap)) { | |
1893 | max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex); | |
1894 | if (max >= sbi->s_stripe) { | |
1895 | ac->ac_found++; | |
1896 | ac->ac_b_ex = ex; | |
1897 | ext4_mb_use_best_found(ac, e4b); | |
1898 | break; | |
1899 | } | |
1900 | } | |
1901 | i += sbi->s_stripe; | |
1902 | } | |
1903 | } | |
1904 | ||
1905 | /* This is now called BEFORE we load the buddy bitmap. */ | |
1906 | static int ext4_mb_good_group(struct ext4_allocation_context *ac, | |
1907 | ext4_group_t group, int cr) | |
1908 | { | |
1909 | unsigned free, fragments; | |
1910 | int flex_size = ext4_flex_bg_size(EXT4_SB(ac->ac_sb)); | |
1911 | struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group); | |
1912 | ||
1913 | BUG_ON(cr < 0 || cr >= 4); | |
1914 | ||
1915 | /* We only do this if the grp has never been initialized */ | |
1916 | if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { | |
1917 | int ret = ext4_mb_init_group(ac->ac_sb, group); | |
1918 | if (ret) | |
1919 | return 0; | |
1920 | } | |
1921 | ||
1922 | free = grp->bb_free; | |
1923 | fragments = grp->bb_fragments; | |
1924 | if (free == 0) | |
1925 | return 0; | |
1926 | if (fragments == 0) | |
1927 | return 0; | |
1928 | ||
1929 | switch (cr) { | |
1930 | case 0: | |
1931 | BUG_ON(ac->ac_2order == 0); | |
1932 | ||
1933 | if (grp->bb_largest_free_order < ac->ac_2order) | |
1934 | return 0; | |
1935 | ||
1936 | /* Avoid using the first bg of a flexgroup for data files */ | |
1937 | if ((ac->ac_flags & EXT4_MB_HINT_DATA) && | |
1938 | (flex_size >= EXT4_FLEX_SIZE_DIR_ALLOC_SCHEME) && | |
1939 | ((group % flex_size) == 0)) | |
1940 | return 0; | |
1941 | ||
1942 | return 1; | |
1943 | case 1: | |
1944 | if ((free / fragments) >= ac->ac_g_ex.fe_len) | |
1945 | return 1; | |
1946 | break; | |
1947 | case 2: | |
1948 | if (free >= ac->ac_g_ex.fe_len) | |
1949 | return 1; | |
1950 | break; | |
1951 | case 3: | |
1952 | return 1; | |
1953 | default: | |
1954 | BUG(); | |
1955 | } | |
1956 | ||
1957 | return 0; | |
1958 | } | |
1959 | ||
1960 | static noinline_for_stack int | |
1961 | ext4_mb_regular_allocator(struct ext4_allocation_context *ac) | |
1962 | { | |
1963 | ext4_group_t ngroups, group, i; | |
1964 | int cr; | |
1965 | int err = 0; | |
1966 | struct ext4_sb_info *sbi; | |
1967 | struct super_block *sb; | |
1968 | struct ext4_buddy e4b; | |
1969 | ||
1970 | sb = ac->ac_sb; | |
1971 | sbi = EXT4_SB(sb); | |
1972 | ngroups = ext4_get_groups_count(sb); | |
1973 | /* non-extent files are limited to low blocks/groups */ | |
1974 | if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS))) | |
1975 | ngroups = sbi->s_blockfile_groups; | |
1976 | ||
1977 | BUG_ON(ac->ac_status == AC_STATUS_FOUND); | |
1978 | ||
1979 | /* first, try the goal */ | |
1980 | err = ext4_mb_find_by_goal(ac, &e4b); | |
1981 | if (err || ac->ac_status == AC_STATUS_FOUND) | |
1982 | goto out; | |
1983 | ||
1984 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) | |
1985 | goto out; | |
1986 | ||
1987 | /* | |
1988 | * ac->ac2_order is set only if the fe_len is a power of 2 | |
1989 | * if ac2_order is set we also set criteria to 0 so that we | |
1990 | * try exact allocation using buddy. | |
1991 | */ | |
1992 | i = fls(ac->ac_g_ex.fe_len); | |
1993 | ac->ac_2order = 0; | |
1994 | /* | |
1995 | * We search using buddy data only if the order of the request | |
1996 | * is greater than equal to the sbi_s_mb_order2_reqs | |
1997 | * You can tune it via /sys/fs/ext4/<partition>/mb_order2_req | |
1998 | */ | |
1999 | if (i >= sbi->s_mb_order2_reqs) { | |
2000 | /* | |
2001 | * This should tell if fe_len is exactly power of 2 | |
2002 | */ | |
2003 | if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0) | |
2004 | ac->ac_2order = i - 1; | |
2005 | } | |
2006 | ||
2007 | /* if stream allocation is enabled, use global goal */ | |
2008 | if (ac->ac_flags & EXT4_MB_STREAM_ALLOC) { | |
2009 | /* TBD: may be hot point */ | |
2010 | spin_lock(&sbi->s_md_lock); | |
2011 | ac->ac_g_ex.fe_group = sbi->s_mb_last_group; | |
2012 | ac->ac_g_ex.fe_start = sbi->s_mb_last_start; | |
2013 | spin_unlock(&sbi->s_md_lock); | |
2014 | } | |
2015 | ||
2016 | /* Let's just scan groups to find more-less suitable blocks */ | |
2017 | cr = ac->ac_2order ? 0 : 1; | |
2018 | /* | |
2019 | * cr == 0 try to get exact allocation, | |
2020 | * cr == 3 try to get anything | |
2021 | */ | |
2022 | repeat: | |
2023 | for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) { | |
2024 | ac->ac_criteria = cr; | |
2025 | /* | |
2026 | * searching for the right group start | |
2027 | * from the goal value specified | |
2028 | */ | |
2029 | group = ac->ac_g_ex.fe_group; | |
2030 | ||
2031 | for (i = 0; i < ngroups; group++, i++) { | |
2032 | if (group == ngroups) | |
2033 | group = 0; | |
2034 | ||
2035 | /* This now checks without needing the buddy page */ | |
2036 | if (!ext4_mb_good_group(ac, group, cr)) | |
2037 | continue; | |
2038 | ||
2039 | err = ext4_mb_load_buddy(sb, group, &e4b); | |
2040 | if (err) | |
2041 | goto out; | |
2042 | ||
2043 | ext4_lock_group(sb, group); | |
2044 | ||
2045 | /* | |
2046 | * We need to check again after locking the | |
2047 | * block group | |
2048 | */ | |
2049 | if (!ext4_mb_good_group(ac, group, cr)) { | |
2050 | ext4_unlock_group(sb, group); | |
2051 | ext4_mb_unload_buddy(&e4b); | |
2052 | continue; | |
2053 | } | |
2054 | ||
2055 | ac->ac_groups_scanned++; | |
2056 | if (cr == 0) | |
2057 | ext4_mb_simple_scan_group(ac, &e4b); | |
2058 | else if (cr == 1 && sbi->s_stripe && | |
2059 | !(ac->ac_g_ex.fe_len % sbi->s_stripe)) | |
2060 | ext4_mb_scan_aligned(ac, &e4b); | |
2061 | else | |
2062 | ext4_mb_complex_scan_group(ac, &e4b); | |
2063 | ||
2064 | ext4_unlock_group(sb, group); | |
2065 | ext4_mb_unload_buddy(&e4b); | |
2066 | ||
2067 | if (ac->ac_status != AC_STATUS_CONTINUE) | |
2068 | break; | |
2069 | } | |
2070 | } | |
2071 | ||
2072 | if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND && | |
2073 | !(ac->ac_flags & EXT4_MB_HINT_FIRST)) { | |
2074 | /* | |
2075 | * We've been searching too long. Let's try to allocate | |
2076 | * the best chunk we've found so far | |
2077 | */ | |
2078 | ||
2079 | ext4_mb_try_best_found(ac, &e4b); | |
2080 | if (ac->ac_status != AC_STATUS_FOUND) { | |
2081 | /* | |
2082 | * Someone more lucky has already allocated it. | |
2083 | * The only thing we can do is just take first | |
2084 | * found block(s) | |
2085 | printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n"); | |
2086 | */ | |
2087 | ac->ac_b_ex.fe_group = 0; | |
2088 | ac->ac_b_ex.fe_start = 0; | |
2089 | ac->ac_b_ex.fe_len = 0; | |
2090 | ac->ac_status = AC_STATUS_CONTINUE; | |
2091 | ac->ac_flags |= EXT4_MB_HINT_FIRST; | |
2092 | cr = 3; | |
2093 | atomic_inc(&sbi->s_mb_lost_chunks); | |
2094 | goto repeat; | |
2095 | } | |
2096 | } | |
2097 | out: | |
2098 | return err; | |
2099 | } | |
2100 | ||
2101 | static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos) | |
2102 | { | |
2103 | struct super_block *sb = seq->private; | |
2104 | ext4_group_t group; | |
2105 | ||
2106 | if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) | |
2107 | return NULL; | |
2108 | group = *pos + 1; | |
2109 | return (void *) ((unsigned long) group); | |
2110 | } | |
2111 | ||
2112 | static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos) | |
2113 | { | |
2114 | struct super_block *sb = seq->private; | |
2115 | ext4_group_t group; | |
2116 | ||
2117 | ++*pos; | |
2118 | if (*pos < 0 || *pos >= ext4_get_groups_count(sb)) | |
2119 | return NULL; | |
2120 | group = *pos + 1; | |
2121 | return (void *) ((unsigned long) group); | |
2122 | } | |
2123 | ||
2124 | static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v) | |
2125 | { | |
2126 | struct super_block *sb = seq->private; | |
2127 | ext4_group_t group = (ext4_group_t) ((unsigned long) v); | |
2128 | int i; | |
2129 | int err; | |
2130 | struct ext4_buddy e4b; | |
2131 | struct sg { | |
2132 | struct ext4_group_info info; | |
2133 | ext4_grpblk_t counters[16]; | |
2134 | } sg; | |
2135 | ||
2136 | group--; | |
2137 | if (group == 0) | |
2138 | seq_printf(seq, "#%-5s: %-5s %-5s %-5s " | |
2139 | "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s " | |
2140 | "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n", | |
2141 | "group", "free", "frags", "first", | |
2142 | "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6", | |
2143 | "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13"); | |
2144 | ||
2145 | i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) + | |
2146 | sizeof(struct ext4_group_info); | |
2147 | err = ext4_mb_load_buddy(sb, group, &e4b); | |
2148 | if (err) { | |
2149 | seq_printf(seq, "#%-5u: I/O error\n", group); | |
2150 | return 0; | |
2151 | } | |
2152 | ext4_lock_group(sb, group); | |
2153 | memcpy(&sg, ext4_get_group_info(sb, group), i); | |
2154 | ext4_unlock_group(sb, group); | |
2155 | ext4_mb_unload_buddy(&e4b); | |
2156 | ||
2157 | seq_printf(seq, "#%-5u: %-5u %-5u %-5u [", group, sg.info.bb_free, | |
2158 | sg.info.bb_fragments, sg.info.bb_first_free); | |
2159 | for (i = 0; i <= 13; i++) | |
2160 | seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ? | |
2161 | sg.info.bb_counters[i] : 0); | |
2162 | seq_printf(seq, " ]\n"); | |
2163 | ||
2164 | return 0; | |
2165 | } | |
2166 | ||
2167 | static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v) | |
2168 | { | |
2169 | } | |
2170 | ||
2171 | static const struct seq_operations ext4_mb_seq_groups_ops = { | |
2172 | .start = ext4_mb_seq_groups_start, | |
2173 | .next = ext4_mb_seq_groups_next, | |
2174 | .stop = ext4_mb_seq_groups_stop, | |
2175 | .show = ext4_mb_seq_groups_show, | |
2176 | }; | |
2177 | ||
2178 | static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file) | |
2179 | { | |
2180 | struct super_block *sb = PDE(inode)->data; | |
2181 | int rc; | |
2182 | ||
2183 | rc = seq_open(file, &ext4_mb_seq_groups_ops); | |
2184 | if (rc == 0) { | |
2185 | struct seq_file *m = file->private_data; | |
2186 | m->private = sb; | |
2187 | } | |
2188 | return rc; | |
2189 | ||
2190 | } | |
2191 | ||
2192 | static const struct file_operations ext4_mb_seq_groups_fops = { | |
2193 | .owner = THIS_MODULE, | |
2194 | .open = ext4_mb_seq_groups_open, | |
2195 | .read = seq_read, | |
2196 | .llseek = seq_lseek, | |
2197 | .release = seq_release, | |
2198 | }; | |
2199 | ||
2200 | static struct kmem_cache *get_groupinfo_cache(int blocksize_bits) | |
2201 | { | |
2202 | int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; | |
2203 | struct kmem_cache *cachep = ext4_groupinfo_caches[cache_index]; | |
2204 | ||
2205 | BUG_ON(!cachep); | |
2206 | return cachep; | |
2207 | } | |
2208 | ||
2209 | /* Create and initialize ext4_group_info data for the given group. */ | |
2210 | int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group, | |
2211 | struct ext4_group_desc *desc) | |
2212 | { | |
2213 | int i; | |
2214 | int metalen = 0; | |
2215 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
2216 | struct ext4_group_info **meta_group_info; | |
2217 | struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); | |
2218 | ||
2219 | /* | |
2220 | * First check if this group is the first of a reserved block. | |
2221 | * If it's true, we have to allocate a new table of pointers | |
2222 | * to ext4_group_info structures | |
2223 | */ | |
2224 | if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { | |
2225 | metalen = sizeof(*meta_group_info) << | |
2226 | EXT4_DESC_PER_BLOCK_BITS(sb); | |
2227 | meta_group_info = kmalloc(metalen, GFP_KERNEL); | |
2228 | if (meta_group_info == NULL) { | |
2229 | ext4_msg(sb, KERN_ERR, "EXT4-fs: can't allocate mem " | |
2230 | "for a buddy group"); | |
2231 | goto exit_meta_group_info; | |
2232 | } | |
2233 | sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = | |
2234 | meta_group_info; | |
2235 | } | |
2236 | ||
2237 | meta_group_info = | |
2238 | sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]; | |
2239 | i = group & (EXT4_DESC_PER_BLOCK(sb) - 1); | |
2240 | ||
2241 | meta_group_info[i] = kmem_cache_alloc(cachep, GFP_KERNEL); | |
2242 | if (meta_group_info[i] == NULL) { | |
2243 | ext4_msg(sb, KERN_ERR, "EXT4-fs: can't allocate buddy mem"); | |
2244 | goto exit_group_info; | |
2245 | } | |
2246 | memset(meta_group_info[i], 0, kmem_cache_size(cachep)); | |
2247 | set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, | |
2248 | &(meta_group_info[i]->bb_state)); | |
2249 | ||
2250 | /* | |
2251 | * initialize bb_free to be able to skip | |
2252 | * empty groups without initialization | |
2253 | */ | |
2254 | if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { | |
2255 | meta_group_info[i]->bb_free = | |
2256 | ext4_free_clusters_after_init(sb, group, desc); | |
2257 | } else { | |
2258 | meta_group_info[i]->bb_free = | |
2259 | ext4_free_group_clusters(sb, desc); | |
2260 | } | |
2261 | ||
2262 | INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list); | |
2263 | init_rwsem(&meta_group_info[i]->alloc_sem); | |
2264 | meta_group_info[i]->bb_free_root = RB_ROOT; | |
2265 | meta_group_info[i]->bb_largest_free_order = -1; /* uninit */ | |
2266 | ||
2267 | #ifdef DOUBLE_CHECK | |
2268 | { | |
2269 | struct buffer_head *bh; | |
2270 | meta_group_info[i]->bb_bitmap = | |
2271 | kmalloc(sb->s_blocksize, GFP_KERNEL); | |
2272 | BUG_ON(meta_group_info[i]->bb_bitmap == NULL); | |
2273 | bh = ext4_read_block_bitmap(sb, group); | |
2274 | BUG_ON(bh == NULL); | |
2275 | memcpy(meta_group_info[i]->bb_bitmap, bh->b_data, | |
2276 | sb->s_blocksize); | |
2277 | put_bh(bh); | |
2278 | } | |
2279 | #endif | |
2280 | ||
2281 | return 0; | |
2282 | ||
2283 | exit_group_info: | |
2284 | /* If a meta_group_info table has been allocated, release it now */ | |
2285 | if (group % EXT4_DESC_PER_BLOCK(sb) == 0) { | |
2286 | kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]); | |
2287 | sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] = NULL; | |
2288 | } | |
2289 | exit_meta_group_info: | |
2290 | return -ENOMEM; | |
2291 | } /* ext4_mb_add_groupinfo */ | |
2292 | ||
2293 | static int ext4_mb_init_backend(struct super_block *sb) | |
2294 | { | |
2295 | ext4_group_t ngroups = ext4_get_groups_count(sb); | |
2296 | ext4_group_t i; | |
2297 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
2298 | struct ext4_super_block *es = sbi->s_es; | |
2299 | int num_meta_group_infos; | |
2300 | int num_meta_group_infos_max; | |
2301 | int array_size; | |
2302 | struct ext4_group_desc *desc; | |
2303 | struct kmem_cache *cachep; | |
2304 | ||
2305 | /* This is the number of blocks used by GDT */ | |
2306 | num_meta_group_infos = (ngroups + EXT4_DESC_PER_BLOCK(sb) - | |
2307 | 1) >> EXT4_DESC_PER_BLOCK_BITS(sb); | |
2308 | ||
2309 | /* | |
2310 | * This is the total number of blocks used by GDT including | |
2311 | * the number of reserved blocks for GDT. | |
2312 | * The s_group_info array is allocated with this value | |
2313 | * to allow a clean online resize without a complex | |
2314 | * manipulation of pointer. | |
2315 | * The drawback is the unused memory when no resize | |
2316 | * occurs but it's very low in terms of pages | |
2317 | * (see comments below) | |
2318 | * Need to handle this properly when META_BG resizing is allowed | |
2319 | */ | |
2320 | num_meta_group_infos_max = num_meta_group_infos + | |
2321 | le16_to_cpu(es->s_reserved_gdt_blocks); | |
2322 | ||
2323 | /* | |
2324 | * array_size is the size of s_group_info array. We round it | |
2325 | * to the next power of two because this approximation is done | |
2326 | * internally by kmalloc so we can have some more memory | |
2327 | * for free here (e.g. may be used for META_BG resize). | |
2328 | */ | |
2329 | array_size = 1; | |
2330 | while (array_size < sizeof(*sbi->s_group_info) * | |
2331 | num_meta_group_infos_max) | |
2332 | array_size = array_size << 1; | |
2333 | /* An 8TB filesystem with 64-bit pointers requires a 4096 byte | |
2334 | * kmalloc. A 128kb malloc should suffice for a 256TB filesystem. | |
2335 | * So a two level scheme suffices for now. */ | |
2336 | sbi->s_group_info = ext4_kvzalloc(array_size, GFP_KERNEL); | |
2337 | if (sbi->s_group_info == NULL) { | |
2338 | ext4_msg(sb, KERN_ERR, "can't allocate buddy meta group"); | |
2339 | return -ENOMEM; | |
2340 | } | |
2341 | sbi->s_buddy_cache = new_inode(sb); | |
2342 | if (sbi->s_buddy_cache == NULL) { | |
2343 | ext4_msg(sb, KERN_ERR, "can't get new inode"); | |
2344 | goto err_freesgi; | |
2345 | } | |
2346 | /* To avoid potentially colliding with an valid on-disk inode number, | |
2347 | * use EXT4_BAD_INO for the buddy cache inode number. This inode is | |
2348 | * not in the inode hash, so it should never be found by iget(), but | |
2349 | * this will avoid confusion if it ever shows up during debugging. */ | |
2350 | sbi->s_buddy_cache->i_ino = EXT4_BAD_INO; | |
2351 | EXT4_I(sbi->s_buddy_cache)->i_disksize = 0; | |
2352 | for (i = 0; i < ngroups; i++) { | |
2353 | desc = ext4_get_group_desc(sb, i, NULL); | |
2354 | if (desc == NULL) { | |
2355 | ext4_msg(sb, KERN_ERR, "can't read descriptor %u", i); | |
2356 | goto err_freebuddy; | |
2357 | } | |
2358 | if (ext4_mb_add_groupinfo(sb, i, desc) != 0) | |
2359 | goto err_freebuddy; | |
2360 | } | |
2361 | ||
2362 | return 0; | |
2363 | ||
2364 | err_freebuddy: | |
2365 | cachep = get_groupinfo_cache(sb->s_blocksize_bits); | |
2366 | while (i-- > 0) | |
2367 | kmem_cache_free(cachep, ext4_get_group_info(sb, i)); | |
2368 | i = num_meta_group_infos; | |
2369 | while (i-- > 0) | |
2370 | kfree(sbi->s_group_info[i]); | |
2371 | iput(sbi->s_buddy_cache); | |
2372 | err_freesgi: | |
2373 | ext4_kvfree(sbi->s_group_info); | |
2374 | return -ENOMEM; | |
2375 | } | |
2376 | ||
2377 | static void ext4_groupinfo_destroy_slabs(void) | |
2378 | { | |
2379 | int i; | |
2380 | ||
2381 | for (i = 0; i < NR_GRPINFO_CACHES; i++) { | |
2382 | if (ext4_groupinfo_caches[i]) | |
2383 | kmem_cache_destroy(ext4_groupinfo_caches[i]); | |
2384 | ext4_groupinfo_caches[i] = NULL; | |
2385 | } | |
2386 | } | |
2387 | ||
2388 | static int ext4_groupinfo_create_slab(size_t size) | |
2389 | { | |
2390 | static DEFINE_MUTEX(ext4_grpinfo_slab_create_mutex); | |
2391 | int slab_size; | |
2392 | int blocksize_bits = order_base_2(size); | |
2393 | int cache_index = blocksize_bits - EXT4_MIN_BLOCK_LOG_SIZE; | |
2394 | struct kmem_cache *cachep; | |
2395 | ||
2396 | if (cache_index >= NR_GRPINFO_CACHES) | |
2397 | return -EINVAL; | |
2398 | ||
2399 | if (unlikely(cache_index < 0)) | |
2400 | cache_index = 0; | |
2401 | ||
2402 | mutex_lock(&ext4_grpinfo_slab_create_mutex); | |
2403 | if (ext4_groupinfo_caches[cache_index]) { | |
2404 | mutex_unlock(&ext4_grpinfo_slab_create_mutex); | |
2405 | return 0; /* Already created */ | |
2406 | } | |
2407 | ||
2408 | slab_size = offsetof(struct ext4_group_info, | |
2409 | bb_counters[blocksize_bits + 2]); | |
2410 | ||
2411 | cachep = kmem_cache_create(ext4_groupinfo_slab_names[cache_index], | |
2412 | slab_size, 0, SLAB_RECLAIM_ACCOUNT, | |
2413 | NULL); | |
2414 | ||
2415 | ext4_groupinfo_caches[cache_index] = cachep; | |
2416 | ||
2417 | mutex_unlock(&ext4_grpinfo_slab_create_mutex); | |
2418 | if (!cachep) { | |
2419 | printk(KERN_EMERG | |
2420 | "EXT4-fs: no memory for groupinfo slab cache\n"); | |
2421 | return -ENOMEM; | |
2422 | } | |
2423 | ||
2424 | return 0; | |
2425 | } | |
2426 | ||
2427 | int ext4_mb_init(struct super_block *sb, int needs_recovery) | |
2428 | { | |
2429 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
2430 | unsigned i, j; | |
2431 | unsigned offset; | |
2432 | unsigned max; | |
2433 | int ret; | |
2434 | ||
2435 | i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_offsets); | |
2436 | ||
2437 | sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL); | |
2438 | if (sbi->s_mb_offsets == NULL) { | |
2439 | ret = -ENOMEM; | |
2440 | goto out; | |
2441 | } | |
2442 | ||
2443 | i = (sb->s_blocksize_bits + 2) * sizeof(*sbi->s_mb_maxs); | |
2444 | sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL); | |
2445 | if (sbi->s_mb_maxs == NULL) { | |
2446 | ret = -ENOMEM; | |
2447 | goto out; | |
2448 | } | |
2449 | ||
2450 | ret = ext4_groupinfo_create_slab(sb->s_blocksize); | |
2451 | if (ret < 0) | |
2452 | goto out; | |
2453 | ||
2454 | /* order 0 is regular bitmap */ | |
2455 | sbi->s_mb_maxs[0] = sb->s_blocksize << 3; | |
2456 | sbi->s_mb_offsets[0] = 0; | |
2457 | ||
2458 | i = 1; | |
2459 | offset = 0; | |
2460 | max = sb->s_blocksize << 2; | |
2461 | do { | |
2462 | sbi->s_mb_offsets[i] = offset; | |
2463 | sbi->s_mb_maxs[i] = max; | |
2464 | offset += 1 << (sb->s_blocksize_bits - i); | |
2465 | max = max >> 1; | |
2466 | i++; | |
2467 | } while (i <= sb->s_blocksize_bits + 1); | |
2468 | ||
2469 | spin_lock_init(&sbi->s_md_lock); | |
2470 | spin_lock_init(&sbi->s_bal_lock); | |
2471 | ||
2472 | sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN; | |
2473 | sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN; | |
2474 | sbi->s_mb_stats = MB_DEFAULT_STATS; | |
2475 | sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD; | |
2476 | sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS; | |
2477 | /* | |
2478 | * The default group preallocation is 512, which for 4k block | |
2479 | * sizes translates to 2 megabytes. However for bigalloc file | |
2480 | * systems, this is probably too big (i.e, if the cluster size | |
2481 | * is 1 megabyte, then group preallocation size becomes half a | |
2482 | * gigabyte!). As a default, we will keep a two megabyte | |
2483 | * group pralloc size for cluster sizes up to 64k, and after | |
2484 | * that, we will force a minimum group preallocation size of | |
2485 | * 32 clusters. This translates to 8 megs when the cluster | |
2486 | * size is 256k, and 32 megs when the cluster size is 1 meg, | |
2487 | * which seems reasonable as a default. | |
2488 | */ | |
2489 | sbi->s_mb_group_prealloc = max(MB_DEFAULT_GROUP_PREALLOC >> | |
2490 | sbi->s_cluster_bits, 32); | |
2491 | /* | |
2492 | * If there is a s_stripe > 1, then we set the s_mb_group_prealloc | |
2493 | * to the lowest multiple of s_stripe which is bigger than | |
2494 | * the s_mb_group_prealloc as determined above. We want | |
2495 | * the preallocation size to be an exact multiple of the | |
2496 | * RAID stripe size so that preallocations don't fragment | |
2497 | * the stripes. | |
2498 | */ | |
2499 | if (sbi->s_stripe > 1) { | |
2500 | sbi->s_mb_group_prealloc = roundup( | |
2501 | sbi->s_mb_group_prealloc, sbi->s_stripe); | |
2502 | } | |
2503 | ||
2504 | sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group); | |
2505 | if (sbi->s_locality_groups == NULL) { | |
2506 | ret = -ENOMEM; | |
2507 | goto out; | |
2508 | } | |
2509 | for_each_possible_cpu(i) { | |
2510 | struct ext4_locality_group *lg; | |
2511 | lg = per_cpu_ptr(sbi->s_locality_groups, i); | |
2512 | mutex_init(&lg->lg_mutex); | |
2513 | for (j = 0; j < PREALLOC_TB_SIZE; j++) | |
2514 | INIT_LIST_HEAD(&lg->lg_prealloc_list[j]); | |
2515 | spin_lock_init(&lg->lg_prealloc_lock); | |
2516 | } | |
2517 | ||
2518 | /* init file for buddy data */ | |
2519 | ret = ext4_mb_init_backend(sb); | |
2520 | if (ret != 0) { | |
2521 | goto out; | |
2522 | } | |
2523 | ||
2524 | if (sbi->s_proc) | |
2525 | proc_create_data("mb_groups", S_IRUGO, sbi->s_proc, | |
2526 | &ext4_mb_seq_groups_fops, sb); | |
2527 | ||
2528 | if (sbi->s_journal) | |
2529 | sbi->s_journal->j_commit_callback = release_blocks_on_commit; | |
2530 | out: | |
2531 | if (ret) { | |
2532 | kfree(sbi->s_mb_offsets); | |
2533 | kfree(sbi->s_mb_maxs); | |
2534 | } | |
2535 | return ret; | |
2536 | } | |
2537 | ||
2538 | /* need to called with the ext4 group lock held */ | |
2539 | static void ext4_mb_cleanup_pa(struct ext4_group_info *grp) | |
2540 | { | |
2541 | struct ext4_prealloc_space *pa; | |
2542 | struct list_head *cur, *tmp; | |
2543 | int count = 0; | |
2544 | ||
2545 | list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) { | |
2546 | pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); | |
2547 | list_del(&pa->pa_group_list); | |
2548 | count++; | |
2549 | kmem_cache_free(ext4_pspace_cachep, pa); | |
2550 | } | |
2551 | if (count) | |
2552 | mb_debug(1, "mballoc: %u PAs left\n", count); | |
2553 | ||
2554 | } | |
2555 | ||
2556 | int ext4_mb_release(struct super_block *sb) | |
2557 | { | |
2558 | ext4_group_t ngroups = ext4_get_groups_count(sb); | |
2559 | ext4_group_t i; | |
2560 | int num_meta_group_infos; | |
2561 | struct ext4_group_info *grinfo; | |
2562 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
2563 | struct kmem_cache *cachep = get_groupinfo_cache(sb->s_blocksize_bits); | |
2564 | ||
2565 | if (sbi->s_group_info) { | |
2566 | for (i = 0; i < ngroups; i++) { | |
2567 | grinfo = ext4_get_group_info(sb, i); | |
2568 | #ifdef DOUBLE_CHECK | |
2569 | kfree(grinfo->bb_bitmap); | |
2570 | #endif | |
2571 | ext4_lock_group(sb, i); | |
2572 | ext4_mb_cleanup_pa(grinfo); | |
2573 | ext4_unlock_group(sb, i); | |
2574 | kmem_cache_free(cachep, grinfo); | |
2575 | } | |
2576 | num_meta_group_infos = (ngroups + | |
2577 | EXT4_DESC_PER_BLOCK(sb) - 1) >> | |
2578 | EXT4_DESC_PER_BLOCK_BITS(sb); | |
2579 | for (i = 0; i < num_meta_group_infos; i++) | |
2580 | kfree(sbi->s_group_info[i]); | |
2581 | ext4_kvfree(sbi->s_group_info); | |
2582 | } | |
2583 | kfree(sbi->s_mb_offsets); | |
2584 | kfree(sbi->s_mb_maxs); | |
2585 | if (sbi->s_buddy_cache) | |
2586 | iput(sbi->s_buddy_cache); | |
2587 | if (sbi->s_mb_stats) { | |
2588 | ext4_msg(sb, KERN_INFO, | |
2589 | "mballoc: %u blocks %u reqs (%u success)", | |
2590 | atomic_read(&sbi->s_bal_allocated), | |
2591 | atomic_read(&sbi->s_bal_reqs), | |
2592 | atomic_read(&sbi->s_bal_success)); | |
2593 | ext4_msg(sb, KERN_INFO, | |
2594 | "mballoc: %u extents scanned, %u goal hits, " | |
2595 | "%u 2^N hits, %u breaks, %u lost", | |
2596 | atomic_read(&sbi->s_bal_ex_scanned), | |
2597 | atomic_read(&sbi->s_bal_goals), | |
2598 | atomic_read(&sbi->s_bal_2orders), | |
2599 | atomic_read(&sbi->s_bal_breaks), | |
2600 | atomic_read(&sbi->s_mb_lost_chunks)); | |
2601 | ext4_msg(sb, KERN_INFO, | |
2602 | "mballoc: %lu generated and it took %Lu", | |
2603 | sbi->s_mb_buddies_generated, | |
2604 | sbi->s_mb_generation_time); | |
2605 | ext4_msg(sb, KERN_INFO, | |
2606 | "mballoc: %u preallocated, %u discarded", | |
2607 | atomic_read(&sbi->s_mb_preallocated), | |
2608 | atomic_read(&sbi->s_mb_discarded)); | |
2609 | } | |
2610 | ||
2611 | free_percpu(sbi->s_locality_groups); | |
2612 | if (sbi->s_proc) | |
2613 | remove_proc_entry("mb_groups", sbi->s_proc); | |
2614 | ||
2615 | return 0; | |
2616 | } | |
2617 | ||
2618 | static inline int ext4_issue_discard(struct super_block *sb, | |
2619 | ext4_group_t block_group, ext4_grpblk_t cluster, int count) | |
2620 | { | |
2621 | ext4_fsblk_t discard_block; | |
2622 | ||
2623 | discard_block = (EXT4_C2B(EXT4_SB(sb), cluster) + | |
2624 | ext4_group_first_block_no(sb, block_group)); | |
2625 | count = EXT4_C2B(EXT4_SB(sb), count); | |
2626 | trace_ext4_discard_blocks(sb, | |
2627 | (unsigned long long) discard_block, count); | |
2628 | return sb_issue_discard(sb, discard_block, count, GFP_NOFS, 0); | |
2629 | } | |
2630 | ||
2631 | /* | |
2632 | * This function is called by the jbd2 layer once the commit has finished, | |
2633 | * so we know we can free the blocks that were released with that commit. | |
2634 | */ | |
2635 | static void release_blocks_on_commit(journal_t *journal, transaction_t *txn) | |
2636 | { | |
2637 | struct super_block *sb = journal->j_private; | |
2638 | struct ext4_buddy e4b; | |
2639 | struct ext4_group_info *db; | |
2640 | int err, count = 0, count2 = 0; | |
2641 | struct ext4_free_data *entry; | |
2642 | struct list_head *l, *ltmp; | |
2643 | ||
2644 | list_for_each_safe(l, ltmp, &txn->t_private_list) { | |
2645 | entry = list_entry(l, struct ext4_free_data, list); | |
2646 | ||
2647 | mb_debug(1, "gonna free %u blocks in group %u (0x%p):", | |
2648 | entry->count, entry->group, entry); | |
2649 | ||
2650 | if (test_opt(sb, DISCARD)) | |
2651 | ext4_issue_discard(sb, entry->group, | |
2652 | entry->start_cluster, entry->count); | |
2653 | ||
2654 | err = ext4_mb_load_buddy(sb, entry->group, &e4b); | |
2655 | /* we expect to find existing buddy because it's pinned */ | |
2656 | BUG_ON(err != 0); | |
2657 | ||
2658 | db = e4b.bd_info; | |
2659 | /* there are blocks to put in buddy to make them really free */ | |
2660 | count += entry->count; | |
2661 | count2++; | |
2662 | ext4_lock_group(sb, entry->group); | |
2663 | /* Take it out of per group rb tree */ | |
2664 | rb_erase(&entry->node, &(db->bb_free_root)); | |
2665 | mb_free_blocks(NULL, &e4b, entry->start_cluster, entry->count); | |
2666 | ||
2667 | /* | |
2668 | * Clear the trimmed flag for the group so that the next | |
2669 | * ext4_trim_fs can trim it. | |
2670 | * If the volume is mounted with -o discard, online discard | |
2671 | * is supported and the free blocks will be trimmed online. | |
2672 | */ | |
2673 | if (!test_opt(sb, DISCARD)) | |
2674 | EXT4_MB_GRP_CLEAR_TRIMMED(db); | |
2675 | ||
2676 | if (!db->bb_free_root.rb_node) { | |
2677 | /* No more items in the per group rb tree | |
2678 | * balance refcounts from ext4_mb_free_metadata() | |
2679 | */ | |
2680 | page_cache_release(e4b.bd_buddy_page); | |
2681 | page_cache_release(e4b.bd_bitmap_page); | |
2682 | } | |
2683 | ext4_unlock_group(sb, entry->group); | |
2684 | kmem_cache_free(ext4_free_ext_cachep, entry); | |
2685 | ext4_mb_unload_buddy(&e4b); | |
2686 | } | |
2687 | ||
2688 | mb_debug(1, "freed %u blocks in %u structures\n", count, count2); | |
2689 | } | |
2690 | ||
2691 | #ifdef CONFIG_EXT4_DEBUG | |
2692 | u8 mb_enable_debug __read_mostly; | |
2693 | ||
2694 | static struct dentry *debugfs_dir; | |
2695 | static struct dentry *debugfs_debug; | |
2696 | ||
2697 | static void __init ext4_create_debugfs_entry(void) | |
2698 | { | |
2699 | debugfs_dir = debugfs_create_dir("ext4", NULL); | |
2700 | if (debugfs_dir) | |
2701 | debugfs_debug = debugfs_create_u8("mballoc-debug", | |
2702 | S_IRUGO | S_IWUSR, | |
2703 | debugfs_dir, | |
2704 | &mb_enable_debug); | |
2705 | } | |
2706 | ||
2707 | static void ext4_remove_debugfs_entry(void) | |
2708 | { | |
2709 | debugfs_remove(debugfs_debug); | |
2710 | debugfs_remove(debugfs_dir); | |
2711 | } | |
2712 | ||
2713 | #else | |
2714 | ||
2715 | static void __init ext4_create_debugfs_entry(void) | |
2716 | { | |
2717 | } | |
2718 | ||
2719 | static void ext4_remove_debugfs_entry(void) | |
2720 | { | |
2721 | } | |
2722 | ||
2723 | #endif | |
2724 | ||
2725 | int __init ext4_init_mballoc(void) | |
2726 | { | |
2727 | ext4_pspace_cachep = KMEM_CACHE(ext4_prealloc_space, | |
2728 | SLAB_RECLAIM_ACCOUNT); | |
2729 | if (ext4_pspace_cachep == NULL) | |
2730 | return -ENOMEM; | |
2731 | ||
2732 | ext4_ac_cachep = KMEM_CACHE(ext4_allocation_context, | |
2733 | SLAB_RECLAIM_ACCOUNT); | |
2734 | if (ext4_ac_cachep == NULL) { | |
2735 | kmem_cache_destroy(ext4_pspace_cachep); | |
2736 | return -ENOMEM; | |
2737 | } | |
2738 | ||
2739 | ext4_free_ext_cachep = KMEM_CACHE(ext4_free_data, | |
2740 | SLAB_RECLAIM_ACCOUNT); | |
2741 | if (ext4_free_ext_cachep == NULL) { | |
2742 | kmem_cache_destroy(ext4_pspace_cachep); | |
2743 | kmem_cache_destroy(ext4_ac_cachep); | |
2744 | return -ENOMEM; | |
2745 | } | |
2746 | ext4_create_debugfs_entry(); | |
2747 | return 0; | |
2748 | } | |
2749 | ||
2750 | void ext4_exit_mballoc(void) | |
2751 | { | |
2752 | /* | |
2753 | * Wait for completion of call_rcu()'s on ext4_pspace_cachep | |
2754 | * before destroying the slab cache. | |
2755 | */ | |
2756 | rcu_barrier(); | |
2757 | kmem_cache_destroy(ext4_pspace_cachep); | |
2758 | kmem_cache_destroy(ext4_ac_cachep); | |
2759 | kmem_cache_destroy(ext4_free_ext_cachep); | |
2760 | ext4_groupinfo_destroy_slabs(); | |
2761 | ext4_remove_debugfs_entry(); | |
2762 | } | |
2763 | ||
2764 | ||
2765 | /* | |
2766 | * Check quota and mark chosen space (ac->ac_b_ex) non-free in bitmaps | |
2767 | * Returns 0 if success or error code | |
2768 | */ | |
2769 | static noinline_for_stack int | |
2770 | ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac, | |
2771 | handle_t *handle, unsigned int reserv_clstrs) | |
2772 | { | |
2773 | struct buffer_head *bitmap_bh = NULL; | |
2774 | struct ext4_group_desc *gdp; | |
2775 | struct buffer_head *gdp_bh; | |
2776 | struct ext4_sb_info *sbi; | |
2777 | struct super_block *sb; | |
2778 | ext4_fsblk_t block; | |
2779 | int err, len; | |
2780 | ||
2781 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); | |
2782 | BUG_ON(ac->ac_b_ex.fe_len <= 0); | |
2783 | ||
2784 | sb = ac->ac_sb; | |
2785 | sbi = EXT4_SB(sb); | |
2786 | ||
2787 | err = -EIO; | |
2788 | bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group); | |
2789 | if (!bitmap_bh) | |
2790 | goto out_err; | |
2791 | ||
2792 | err = ext4_journal_get_write_access(handle, bitmap_bh); | |
2793 | if (err) | |
2794 | goto out_err; | |
2795 | ||
2796 | err = -EIO; | |
2797 | gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh); | |
2798 | if (!gdp) | |
2799 | goto out_err; | |
2800 | ||
2801 | ext4_debug("using block group %u(%d)\n", ac->ac_b_ex.fe_group, | |
2802 | ext4_free_group_clusters(sb, gdp)); | |
2803 | ||
2804 | err = ext4_journal_get_write_access(handle, gdp_bh); | |
2805 | if (err) | |
2806 | goto out_err; | |
2807 | ||
2808 | block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); | |
2809 | ||
2810 | len = EXT4_C2B(sbi, ac->ac_b_ex.fe_len); | |
2811 | if (!ext4_data_block_valid(sbi, block, len)) { | |
2812 | ext4_error(sb, "Allocating blocks %llu-%llu which overlap " | |
2813 | "fs metadata\n", block, block+len); | |
2814 | /* File system mounted not to panic on error | |
2815 | * Fix the bitmap and repeat the block allocation | |
2816 | * We leak some of the blocks here. | |
2817 | */ | |
2818 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); | |
2819 | ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, | |
2820 | ac->ac_b_ex.fe_len); | |
2821 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); | |
2822 | err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); | |
2823 | if (!err) | |
2824 | err = -EAGAIN; | |
2825 | goto out_err; | |
2826 | } | |
2827 | ||
2828 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); | |
2829 | #ifdef AGGRESSIVE_CHECK | |
2830 | { | |
2831 | int i; | |
2832 | for (i = 0; i < ac->ac_b_ex.fe_len; i++) { | |
2833 | BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i, | |
2834 | bitmap_bh->b_data)); | |
2835 | } | |
2836 | } | |
2837 | #endif | |
2838 | ext4_set_bits(bitmap_bh->b_data, ac->ac_b_ex.fe_start, | |
2839 | ac->ac_b_ex.fe_len); | |
2840 | if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) { | |
2841 | gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT); | |
2842 | ext4_free_group_clusters_set(sb, gdp, | |
2843 | ext4_free_clusters_after_init(sb, | |
2844 | ac->ac_b_ex.fe_group, gdp)); | |
2845 | } | |
2846 | len = ext4_free_group_clusters(sb, gdp) - ac->ac_b_ex.fe_len; | |
2847 | ext4_free_group_clusters_set(sb, gdp, len); | |
2848 | gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp); | |
2849 | ||
2850 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); | |
2851 | percpu_counter_sub(&sbi->s_freeclusters_counter, ac->ac_b_ex.fe_len); | |
2852 | /* | |
2853 | * Now reduce the dirty block count also. Should not go negative | |
2854 | */ | |
2855 | if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED)) | |
2856 | /* release all the reserved blocks if non delalloc */ | |
2857 | percpu_counter_sub(&sbi->s_dirtyclusters_counter, | |
2858 | reserv_clstrs); | |
2859 | ||
2860 | if (sbi->s_log_groups_per_flex) { | |
2861 | ext4_group_t flex_group = ext4_flex_group(sbi, | |
2862 | ac->ac_b_ex.fe_group); | |
2863 | atomic_sub(ac->ac_b_ex.fe_len, | |
2864 | &sbi->s_flex_groups[flex_group].free_clusters); | |
2865 | } | |
2866 | ||
2867 | err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); | |
2868 | if (err) | |
2869 | goto out_err; | |
2870 | err = ext4_handle_dirty_metadata(handle, NULL, gdp_bh); | |
2871 | ||
2872 | out_err: | |
2873 | ext4_mark_super_dirty(sb); | |
2874 | brelse(bitmap_bh); | |
2875 | return err; | |
2876 | } | |
2877 | ||
2878 | /* | |
2879 | * here we normalize request for locality group | |
2880 | * Group request are normalized to s_mb_group_prealloc, which goes to | |
2881 | * s_strip if we set the same via mount option. | |
2882 | * s_mb_group_prealloc can be configured via | |
2883 | * /sys/fs/ext4/<partition>/mb_group_prealloc | |
2884 | * | |
2885 | * XXX: should we try to preallocate more than the group has now? | |
2886 | */ | |
2887 | static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac) | |
2888 | { | |
2889 | struct super_block *sb = ac->ac_sb; | |
2890 | struct ext4_locality_group *lg = ac->ac_lg; | |
2891 | ||
2892 | BUG_ON(lg == NULL); | |
2893 | ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc; | |
2894 | mb_debug(1, "#%u: goal %u blocks for locality group\n", | |
2895 | current->pid, ac->ac_g_ex.fe_len); | |
2896 | } | |
2897 | ||
2898 | /* | |
2899 | * Normalization means making request better in terms of | |
2900 | * size and alignment | |
2901 | */ | |
2902 | static noinline_for_stack void | |
2903 | ext4_mb_normalize_request(struct ext4_allocation_context *ac, | |
2904 | struct ext4_allocation_request *ar) | |
2905 | { | |
2906 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
2907 | int bsbits, max; | |
2908 | ext4_lblk_t end; | |
2909 | loff_t size, orig_size, start_off; | |
2910 | ext4_lblk_t start; | |
2911 | struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); | |
2912 | struct ext4_prealloc_space *pa; | |
2913 | ||
2914 | /* do normalize only data requests, metadata requests | |
2915 | do not need preallocation */ | |
2916 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) | |
2917 | return; | |
2918 | ||
2919 | /* sometime caller may want exact blocks */ | |
2920 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) | |
2921 | return; | |
2922 | ||
2923 | /* caller may indicate that preallocation isn't | |
2924 | * required (it's a tail, for example) */ | |
2925 | if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC) | |
2926 | return; | |
2927 | ||
2928 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) { | |
2929 | ext4_mb_normalize_group_request(ac); | |
2930 | return ; | |
2931 | } | |
2932 | ||
2933 | bsbits = ac->ac_sb->s_blocksize_bits; | |
2934 | ||
2935 | /* first, let's learn actual file size | |
2936 | * given current request is allocated */ | |
2937 | size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); | |
2938 | size = size << bsbits; | |
2939 | if (size < i_size_read(ac->ac_inode)) | |
2940 | size = i_size_read(ac->ac_inode); | |
2941 | orig_size = size; | |
2942 | ||
2943 | /* max size of free chunks */ | |
2944 | max = 2 << bsbits; | |
2945 | ||
2946 | #define NRL_CHECK_SIZE(req, size, max, chunk_size) \ | |
2947 | (req <= (size) || max <= (chunk_size)) | |
2948 | ||
2949 | /* first, try to predict filesize */ | |
2950 | /* XXX: should this table be tunable? */ | |
2951 | start_off = 0; | |
2952 | if (size <= 16 * 1024) { | |
2953 | size = 16 * 1024; | |
2954 | } else if (size <= 32 * 1024) { | |
2955 | size = 32 * 1024; | |
2956 | } else if (size <= 64 * 1024) { | |
2957 | size = 64 * 1024; | |
2958 | } else if (size <= 128 * 1024) { | |
2959 | size = 128 * 1024; | |
2960 | } else if (size <= 256 * 1024) { | |
2961 | size = 256 * 1024; | |
2962 | } else if (size <= 512 * 1024) { | |
2963 | size = 512 * 1024; | |
2964 | } else if (size <= 1024 * 1024) { | |
2965 | size = 1024 * 1024; | |
2966 | } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) { | |
2967 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> | |
2968 | (21 - bsbits)) << 21; | |
2969 | size = 2 * 1024 * 1024; | |
2970 | } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) { | |
2971 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> | |
2972 | (22 - bsbits)) << 22; | |
2973 | size = 4 * 1024 * 1024; | |
2974 | } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len, | |
2975 | (8<<20)>>bsbits, max, 8 * 1024)) { | |
2976 | start_off = ((loff_t)ac->ac_o_ex.fe_logical >> | |
2977 | (23 - bsbits)) << 23; | |
2978 | size = 8 * 1024 * 1024; | |
2979 | } else { | |
2980 | start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits; | |
2981 | size = ac->ac_o_ex.fe_len << bsbits; | |
2982 | } | |
2983 | size = size >> bsbits; | |
2984 | start = start_off >> bsbits; | |
2985 | ||
2986 | /* don't cover already allocated blocks in selected range */ | |
2987 | if (ar->pleft && start <= ar->lleft) { | |
2988 | size -= ar->lleft + 1 - start; | |
2989 | start = ar->lleft + 1; | |
2990 | } | |
2991 | if (ar->pright && start + size - 1 >= ar->lright) | |
2992 | size -= start + size - ar->lright; | |
2993 | ||
2994 | end = start + size; | |
2995 | ||
2996 | /* check we don't cross already preallocated blocks */ | |
2997 | rcu_read_lock(); | |
2998 | list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { | |
2999 | ext4_lblk_t pa_end; | |
3000 | ||
3001 | if (pa->pa_deleted) | |
3002 | continue; | |
3003 | spin_lock(&pa->pa_lock); | |
3004 | if (pa->pa_deleted) { | |
3005 | spin_unlock(&pa->pa_lock); | |
3006 | continue; | |
3007 | } | |
3008 | ||
3009 | pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), | |
3010 | pa->pa_len); | |
3011 | ||
3012 | /* PA must not overlap original request */ | |
3013 | BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end || | |
3014 | ac->ac_o_ex.fe_logical < pa->pa_lstart)); | |
3015 | ||
3016 | /* skip PAs this normalized request doesn't overlap with */ | |
3017 | if (pa->pa_lstart >= end || pa_end <= start) { | |
3018 | spin_unlock(&pa->pa_lock); | |
3019 | continue; | |
3020 | } | |
3021 | BUG_ON(pa->pa_lstart <= start && pa_end >= end); | |
3022 | ||
3023 | /* adjust start or end to be adjacent to this pa */ | |
3024 | if (pa_end <= ac->ac_o_ex.fe_logical) { | |
3025 | BUG_ON(pa_end < start); | |
3026 | start = pa_end; | |
3027 | } else if (pa->pa_lstart > ac->ac_o_ex.fe_logical) { | |
3028 | BUG_ON(pa->pa_lstart > end); | |
3029 | end = pa->pa_lstart; | |
3030 | } | |
3031 | spin_unlock(&pa->pa_lock); | |
3032 | } | |
3033 | rcu_read_unlock(); | |
3034 | size = end - start; | |
3035 | ||
3036 | /* XXX: extra loop to check we really don't overlap preallocations */ | |
3037 | rcu_read_lock(); | |
3038 | list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { | |
3039 | ext4_lblk_t pa_end; | |
3040 | ||
3041 | spin_lock(&pa->pa_lock); | |
3042 | if (pa->pa_deleted == 0) { | |
3043 | pa_end = pa->pa_lstart + EXT4_C2B(EXT4_SB(ac->ac_sb), | |
3044 | pa->pa_len); | |
3045 | BUG_ON(!(start >= pa_end || end <= pa->pa_lstart)); | |
3046 | } | |
3047 | spin_unlock(&pa->pa_lock); | |
3048 | } | |
3049 | rcu_read_unlock(); | |
3050 | ||
3051 | if (start + size <= ac->ac_o_ex.fe_logical && | |
3052 | start > ac->ac_o_ex.fe_logical) { | |
3053 | ext4_msg(ac->ac_sb, KERN_ERR, | |
3054 | "start %lu, size %lu, fe_logical %lu", | |
3055 | (unsigned long) start, (unsigned long) size, | |
3056 | (unsigned long) ac->ac_o_ex.fe_logical); | |
3057 | } | |
3058 | BUG_ON(start + size <= ac->ac_o_ex.fe_logical && | |
3059 | start > ac->ac_o_ex.fe_logical); | |
3060 | BUG_ON(size <= 0 || size > EXT4_CLUSTERS_PER_GROUP(ac->ac_sb)); | |
3061 | ||
3062 | /* now prepare goal request */ | |
3063 | ||
3064 | /* XXX: is it better to align blocks WRT to logical | |
3065 | * placement or satisfy big request as is */ | |
3066 | ac->ac_g_ex.fe_logical = start; | |
3067 | ac->ac_g_ex.fe_len = EXT4_NUM_B2C(sbi, size); | |
3068 | ||
3069 | /* define goal start in order to merge */ | |
3070 | if (ar->pright && (ar->lright == (start + size))) { | |
3071 | /* merge to the right */ | |
3072 | ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size, | |
3073 | &ac->ac_f_ex.fe_group, | |
3074 | &ac->ac_f_ex.fe_start); | |
3075 | ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; | |
3076 | } | |
3077 | if (ar->pleft && (ar->lleft + 1 == start)) { | |
3078 | /* merge to the left */ | |
3079 | ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1, | |
3080 | &ac->ac_f_ex.fe_group, | |
3081 | &ac->ac_f_ex.fe_start); | |
3082 | ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL; | |
3083 | } | |
3084 | ||
3085 | mb_debug(1, "goal: %u(was %u) blocks at %u\n", (unsigned) size, | |
3086 | (unsigned) orig_size, (unsigned) start); | |
3087 | } | |
3088 | ||
3089 | static void ext4_mb_collect_stats(struct ext4_allocation_context *ac) | |
3090 | { | |
3091 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
3092 | ||
3093 | if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) { | |
3094 | atomic_inc(&sbi->s_bal_reqs); | |
3095 | atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated); | |
3096 | if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len) | |
3097 | atomic_inc(&sbi->s_bal_success); | |
3098 | atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned); | |
3099 | if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start && | |
3100 | ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group) | |
3101 | atomic_inc(&sbi->s_bal_goals); | |
3102 | if (ac->ac_found > sbi->s_mb_max_to_scan) | |
3103 | atomic_inc(&sbi->s_bal_breaks); | |
3104 | } | |
3105 | ||
3106 | if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) | |
3107 | trace_ext4_mballoc_alloc(ac); | |
3108 | else | |
3109 | trace_ext4_mballoc_prealloc(ac); | |
3110 | } | |
3111 | ||
3112 | /* | |
3113 | * Called on failure; free up any blocks from the inode PA for this | |
3114 | * context. We don't need this for MB_GROUP_PA because we only change | |
3115 | * pa_free in ext4_mb_release_context(), but on failure, we've already | |
3116 | * zeroed out ac->ac_b_ex.fe_len, so group_pa->pa_free is not changed. | |
3117 | */ | |
3118 | static void ext4_discard_allocated_blocks(struct ext4_allocation_context *ac) | |
3119 | { | |
3120 | struct ext4_prealloc_space *pa = ac->ac_pa; | |
3121 | int len; | |
3122 | ||
3123 | if (pa && pa->pa_type == MB_INODE_PA) { | |
3124 | len = ac->ac_b_ex.fe_len; | |
3125 | pa->pa_free += len; | |
3126 | } | |
3127 | ||
3128 | } | |
3129 | ||
3130 | /* | |
3131 | * use blocks preallocated to inode | |
3132 | */ | |
3133 | static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac, | |
3134 | struct ext4_prealloc_space *pa) | |
3135 | { | |
3136 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
3137 | ext4_fsblk_t start; | |
3138 | ext4_fsblk_t end; | |
3139 | int len; | |
3140 | ||
3141 | /* found preallocated blocks, use them */ | |
3142 | start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart); | |
3143 | end = min(pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len), | |
3144 | start + EXT4_C2B(sbi, ac->ac_o_ex.fe_len)); | |
3145 | len = EXT4_NUM_B2C(sbi, end - start); | |
3146 | ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group, | |
3147 | &ac->ac_b_ex.fe_start); | |
3148 | ac->ac_b_ex.fe_len = len; | |
3149 | ac->ac_status = AC_STATUS_FOUND; | |
3150 | ac->ac_pa = pa; | |
3151 | ||
3152 | BUG_ON(start < pa->pa_pstart); | |
3153 | BUG_ON(end > pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len)); | |
3154 | BUG_ON(pa->pa_free < len); | |
3155 | pa->pa_free -= len; | |
3156 | ||
3157 | mb_debug(1, "use %llu/%u from inode pa %p\n", start, len, pa); | |
3158 | } | |
3159 | ||
3160 | /* | |
3161 | * use blocks preallocated to locality group | |
3162 | */ | |
3163 | static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac, | |
3164 | struct ext4_prealloc_space *pa) | |
3165 | { | |
3166 | unsigned int len = ac->ac_o_ex.fe_len; | |
3167 | ||
3168 | ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart, | |
3169 | &ac->ac_b_ex.fe_group, | |
3170 | &ac->ac_b_ex.fe_start); | |
3171 | ac->ac_b_ex.fe_len = len; | |
3172 | ac->ac_status = AC_STATUS_FOUND; | |
3173 | ac->ac_pa = pa; | |
3174 | ||
3175 | /* we don't correct pa_pstart or pa_plen here to avoid | |
3176 | * possible race when the group is being loaded concurrently | |
3177 | * instead we correct pa later, after blocks are marked | |
3178 | * in on-disk bitmap -- see ext4_mb_release_context() | |
3179 | * Other CPUs are prevented from allocating from this pa by lg_mutex | |
3180 | */ | |
3181 | mb_debug(1, "use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa); | |
3182 | } | |
3183 | ||
3184 | /* | |
3185 | * Return the prealloc space that have minimal distance | |
3186 | * from the goal block. @cpa is the prealloc | |
3187 | * space that is having currently known minimal distance | |
3188 | * from the goal block. | |
3189 | */ | |
3190 | static struct ext4_prealloc_space * | |
3191 | ext4_mb_check_group_pa(ext4_fsblk_t goal_block, | |
3192 | struct ext4_prealloc_space *pa, | |
3193 | struct ext4_prealloc_space *cpa) | |
3194 | { | |
3195 | ext4_fsblk_t cur_distance, new_distance; | |
3196 | ||
3197 | if (cpa == NULL) { | |
3198 | atomic_inc(&pa->pa_count); | |
3199 | return pa; | |
3200 | } | |
3201 | cur_distance = abs(goal_block - cpa->pa_pstart); | |
3202 | new_distance = abs(goal_block - pa->pa_pstart); | |
3203 | ||
3204 | if (cur_distance <= new_distance) | |
3205 | return cpa; | |
3206 | ||
3207 | /* drop the previous reference */ | |
3208 | atomic_dec(&cpa->pa_count); | |
3209 | atomic_inc(&pa->pa_count); | |
3210 | return pa; | |
3211 | } | |
3212 | ||
3213 | /* | |
3214 | * search goal blocks in preallocated space | |
3215 | */ | |
3216 | static noinline_for_stack int | |
3217 | ext4_mb_use_preallocated(struct ext4_allocation_context *ac) | |
3218 | { | |
3219 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
3220 | int order, i; | |
3221 | struct ext4_inode_info *ei = EXT4_I(ac->ac_inode); | |
3222 | struct ext4_locality_group *lg; | |
3223 | struct ext4_prealloc_space *pa, *cpa = NULL; | |
3224 | ext4_fsblk_t goal_block; | |
3225 | ||
3226 | /* only data can be preallocated */ | |
3227 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) | |
3228 | return 0; | |
3229 | ||
3230 | /* first, try per-file preallocation */ | |
3231 | rcu_read_lock(); | |
3232 | list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) { | |
3233 | ||
3234 | /* all fields in this condition don't change, | |
3235 | * so we can skip locking for them */ | |
3236 | if (ac->ac_o_ex.fe_logical < pa->pa_lstart || | |
3237 | ac->ac_o_ex.fe_logical >= (pa->pa_lstart + | |
3238 | EXT4_C2B(sbi, pa->pa_len))) | |
3239 | continue; | |
3240 | ||
3241 | /* non-extent files can't have physical blocks past 2^32 */ | |
3242 | if (!(ext4_test_inode_flag(ac->ac_inode, EXT4_INODE_EXTENTS)) && | |
3243 | (pa->pa_pstart + EXT4_C2B(sbi, pa->pa_len) > | |
3244 | EXT4_MAX_BLOCK_FILE_PHYS)) | |
3245 | continue; | |
3246 | ||
3247 | /* found preallocated blocks, use them */ | |
3248 | spin_lock(&pa->pa_lock); | |
3249 | if (pa->pa_deleted == 0 && pa->pa_free) { | |
3250 | atomic_inc(&pa->pa_count); | |
3251 | ext4_mb_use_inode_pa(ac, pa); | |
3252 | spin_unlock(&pa->pa_lock); | |
3253 | ac->ac_criteria = 10; | |
3254 | rcu_read_unlock(); | |
3255 | return 1; | |
3256 | } | |
3257 | spin_unlock(&pa->pa_lock); | |
3258 | } | |
3259 | rcu_read_unlock(); | |
3260 | ||
3261 | /* can we use group allocation? */ | |
3262 | if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)) | |
3263 | return 0; | |
3264 | ||
3265 | /* inode may have no locality group for some reason */ | |
3266 | lg = ac->ac_lg; | |
3267 | if (lg == NULL) | |
3268 | return 0; | |
3269 | order = fls(ac->ac_o_ex.fe_len) - 1; | |
3270 | if (order > PREALLOC_TB_SIZE - 1) | |
3271 | /* The max size of hash table is PREALLOC_TB_SIZE */ | |
3272 | order = PREALLOC_TB_SIZE - 1; | |
3273 | ||
3274 | goal_block = ext4_grp_offs_to_block(ac->ac_sb, &ac->ac_g_ex); | |
3275 | /* | |
3276 | * search for the prealloc space that is having | |
3277 | * minimal distance from the goal block. | |
3278 | */ | |
3279 | for (i = order; i < PREALLOC_TB_SIZE; i++) { | |
3280 | rcu_read_lock(); | |
3281 | list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i], | |
3282 | pa_inode_list) { | |
3283 | spin_lock(&pa->pa_lock); | |
3284 | if (pa->pa_deleted == 0 && | |
3285 | pa->pa_free >= ac->ac_o_ex.fe_len) { | |
3286 | ||
3287 | cpa = ext4_mb_check_group_pa(goal_block, | |
3288 | pa, cpa); | |
3289 | } | |
3290 | spin_unlock(&pa->pa_lock); | |
3291 | } | |
3292 | rcu_read_unlock(); | |
3293 | } | |
3294 | if (cpa) { | |
3295 | ext4_mb_use_group_pa(ac, cpa); | |
3296 | ac->ac_criteria = 20; | |
3297 | return 1; | |
3298 | } | |
3299 | return 0; | |
3300 | } | |
3301 | ||
3302 | /* | |
3303 | * the function goes through all block freed in the group | |
3304 | * but not yet committed and marks them used in in-core bitmap. | |
3305 | * buddy must be generated from this bitmap | |
3306 | * Need to be called with the ext4 group lock held | |
3307 | */ | |
3308 | static void ext4_mb_generate_from_freelist(struct super_block *sb, void *bitmap, | |
3309 | ext4_group_t group) | |
3310 | { | |
3311 | struct rb_node *n; | |
3312 | struct ext4_group_info *grp; | |
3313 | struct ext4_free_data *entry; | |
3314 | ||
3315 | grp = ext4_get_group_info(sb, group); | |
3316 | n = rb_first(&(grp->bb_free_root)); | |
3317 | ||
3318 | while (n) { | |
3319 | entry = rb_entry(n, struct ext4_free_data, node); | |
3320 | ext4_set_bits(bitmap, entry->start_cluster, entry->count); | |
3321 | n = rb_next(n); | |
3322 | } | |
3323 | return; | |
3324 | } | |
3325 | ||
3326 | /* | |
3327 | * the function goes through all preallocation in this group and marks them | |
3328 | * used in in-core bitmap. buddy must be generated from this bitmap | |
3329 | * Need to be called with ext4 group lock held | |
3330 | */ | |
3331 | static noinline_for_stack | |
3332 | void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap, | |
3333 | ext4_group_t group) | |
3334 | { | |
3335 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); | |
3336 | struct ext4_prealloc_space *pa; | |
3337 | struct list_head *cur; | |
3338 | ext4_group_t groupnr; | |
3339 | ext4_grpblk_t start; | |
3340 | int preallocated = 0; | |
3341 | int count = 0; | |
3342 | int len; | |
3343 | ||
3344 | /* all form of preallocation discards first load group, | |
3345 | * so the only competing code is preallocation use. | |
3346 | * we don't need any locking here | |
3347 | * notice we do NOT ignore preallocations with pa_deleted | |
3348 | * otherwise we could leave used blocks available for | |
3349 | * allocation in buddy when concurrent ext4_mb_put_pa() | |
3350 | * is dropping preallocation | |
3351 | */ | |
3352 | list_for_each(cur, &grp->bb_prealloc_list) { | |
3353 | pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list); | |
3354 | spin_lock(&pa->pa_lock); | |
3355 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, | |
3356 | &groupnr, &start); | |
3357 | len = pa->pa_len; | |
3358 | spin_unlock(&pa->pa_lock); | |
3359 | if (unlikely(len == 0)) | |
3360 | continue; | |
3361 | BUG_ON(groupnr != group); | |
3362 | ext4_set_bits(bitmap, start, len); | |
3363 | preallocated += len; | |
3364 | count++; | |
3365 | } | |
3366 | mb_debug(1, "prellocated %u for group %u\n", preallocated, group); | |
3367 | } | |
3368 | ||
3369 | static void ext4_mb_pa_callback(struct rcu_head *head) | |
3370 | { | |
3371 | struct ext4_prealloc_space *pa; | |
3372 | pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu); | |
3373 | kmem_cache_free(ext4_pspace_cachep, pa); | |
3374 | } | |
3375 | ||
3376 | /* | |
3377 | * drops a reference to preallocated space descriptor | |
3378 | * if this was the last reference and the space is consumed | |
3379 | */ | |
3380 | static void ext4_mb_put_pa(struct ext4_allocation_context *ac, | |
3381 | struct super_block *sb, struct ext4_prealloc_space *pa) | |
3382 | { | |
3383 | ext4_group_t grp; | |
3384 | ext4_fsblk_t grp_blk; | |
3385 | ||
3386 | if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0) | |
3387 | return; | |
3388 | ||
3389 | /* in this short window concurrent discard can set pa_deleted */ | |
3390 | spin_lock(&pa->pa_lock); | |
3391 | if (pa->pa_deleted == 1) { | |
3392 | spin_unlock(&pa->pa_lock); | |
3393 | return; | |
3394 | } | |
3395 | ||
3396 | pa->pa_deleted = 1; | |
3397 | spin_unlock(&pa->pa_lock); | |
3398 | ||
3399 | grp_blk = pa->pa_pstart; | |
3400 | /* | |
3401 | * If doing group-based preallocation, pa_pstart may be in the | |
3402 | * next group when pa is used up | |
3403 | */ | |
3404 | if (pa->pa_type == MB_GROUP_PA) | |
3405 | grp_blk--; | |
3406 | ||
3407 | ext4_get_group_no_and_offset(sb, grp_blk, &grp, NULL); | |
3408 | ||
3409 | /* | |
3410 | * possible race: | |
3411 | * | |
3412 | * P1 (buddy init) P2 (regular allocation) | |
3413 | * find block B in PA | |
3414 | * copy on-disk bitmap to buddy | |
3415 | * mark B in on-disk bitmap | |
3416 | * drop PA from group | |
3417 | * mark all PAs in buddy | |
3418 | * | |
3419 | * thus, P1 initializes buddy with B available. to prevent this | |
3420 | * we make "copy" and "mark all PAs" atomic and serialize "drop PA" | |
3421 | * against that pair | |
3422 | */ | |
3423 | ext4_lock_group(sb, grp); | |
3424 | list_del(&pa->pa_group_list); | |
3425 | ext4_unlock_group(sb, grp); | |
3426 | ||
3427 | spin_lock(pa->pa_obj_lock); | |
3428 | list_del_rcu(&pa->pa_inode_list); | |
3429 | spin_unlock(pa->pa_obj_lock); | |
3430 | ||
3431 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); | |
3432 | } | |
3433 | ||
3434 | /* | |
3435 | * creates new preallocated space for given inode | |
3436 | */ | |
3437 | static noinline_for_stack int | |
3438 | ext4_mb_new_inode_pa(struct ext4_allocation_context *ac) | |
3439 | { | |
3440 | struct super_block *sb = ac->ac_sb; | |
3441 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
3442 | struct ext4_prealloc_space *pa; | |
3443 | struct ext4_group_info *grp; | |
3444 | struct ext4_inode_info *ei; | |
3445 | ||
3446 | /* preallocate only when found space is larger then requested */ | |
3447 | BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); | |
3448 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); | |
3449 | BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); | |
3450 | ||
3451 | pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); | |
3452 | if (pa == NULL) | |
3453 | return -ENOMEM; | |
3454 | ||
3455 | if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) { | |
3456 | int winl; | |
3457 | int wins; | |
3458 | int win; | |
3459 | int offs; | |
3460 | ||
3461 | /* we can't allocate as much as normalizer wants. | |
3462 | * so, found space must get proper lstart | |
3463 | * to cover original request */ | |
3464 | BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical); | |
3465 | BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len); | |
3466 | ||
3467 | /* we're limited by original request in that | |
3468 | * logical block must be covered any way | |
3469 | * winl is window we can move our chunk within */ | |
3470 | winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical; | |
3471 | ||
3472 | /* also, we should cover whole original request */ | |
3473 | wins = EXT4_C2B(sbi, ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len); | |
3474 | ||
3475 | /* the smallest one defines real window */ | |
3476 | win = min(winl, wins); | |
3477 | ||
3478 | offs = ac->ac_o_ex.fe_logical % | |
3479 | EXT4_C2B(sbi, ac->ac_b_ex.fe_len); | |
3480 | if (offs && offs < win) | |
3481 | win = offs; | |
3482 | ||
3483 | ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - | |
3484 | EXT4_B2C(sbi, win); | |
3485 | BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical); | |
3486 | BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len); | |
3487 | } | |
3488 | ||
3489 | /* preallocation can change ac_b_ex, thus we store actually | |
3490 | * allocated blocks for history */ | |
3491 | ac->ac_f_ex = ac->ac_b_ex; | |
3492 | ||
3493 | pa->pa_lstart = ac->ac_b_ex.fe_logical; | |
3494 | pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); | |
3495 | pa->pa_len = ac->ac_b_ex.fe_len; | |
3496 | pa->pa_free = pa->pa_len; | |
3497 | atomic_set(&pa->pa_count, 1); | |
3498 | spin_lock_init(&pa->pa_lock); | |
3499 | INIT_LIST_HEAD(&pa->pa_inode_list); | |
3500 | INIT_LIST_HEAD(&pa->pa_group_list); | |
3501 | pa->pa_deleted = 0; | |
3502 | pa->pa_type = MB_INODE_PA; | |
3503 | ||
3504 | mb_debug(1, "new inode pa %p: %llu/%u for %u\n", pa, | |
3505 | pa->pa_pstart, pa->pa_len, pa->pa_lstart); | |
3506 | trace_ext4_mb_new_inode_pa(ac, pa); | |
3507 | ||
3508 | ext4_mb_use_inode_pa(ac, pa); | |
3509 | atomic_add(pa->pa_free, &sbi->s_mb_preallocated); | |
3510 | ||
3511 | ei = EXT4_I(ac->ac_inode); | |
3512 | grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); | |
3513 | ||
3514 | pa->pa_obj_lock = &ei->i_prealloc_lock; | |
3515 | pa->pa_inode = ac->ac_inode; | |
3516 | ||
3517 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); | |
3518 | list_add(&pa->pa_group_list, &grp->bb_prealloc_list); | |
3519 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); | |
3520 | ||
3521 | spin_lock(pa->pa_obj_lock); | |
3522 | list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list); | |
3523 | spin_unlock(pa->pa_obj_lock); | |
3524 | ||
3525 | return 0; | |
3526 | } | |
3527 | ||
3528 | /* | |
3529 | * creates new preallocated space for locality group inodes belongs to | |
3530 | */ | |
3531 | static noinline_for_stack int | |
3532 | ext4_mb_new_group_pa(struct ext4_allocation_context *ac) | |
3533 | { | |
3534 | struct super_block *sb = ac->ac_sb; | |
3535 | struct ext4_locality_group *lg; | |
3536 | struct ext4_prealloc_space *pa; | |
3537 | struct ext4_group_info *grp; | |
3538 | ||
3539 | /* preallocate only when found space is larger then requested */ | |
3540 | BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len); | |
3541 | BUG_ON(ac->ac_status != AC_STATUS_FOUND); | |
3542 | BUG_ON(!S_ISREG(ac->ac_inode->i_mode)); | |
3543 | ||
3544 | BUG_ON(ext4_pspace_cachep == NULL); | |
3545 | pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS); | |
3546 | if (pa == NULL) | |
3547 | return -ENOMEM; | |
3548 | ||
3549 | /* preallocation can change ac_b_ex, thus we store actually | |
3550 | * allocated blocks for history */ | |
3551 | ac->ac_f_ex = ac->ac_b_ex; | |
3552 | ||
3553 | pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); | |
3554 | pa->pa_lstart = pa->pa_pstart; | |
3555 | pa->pa_len = ac->ac_b_ex.fe_len; | |
3556 | pa->pa_free = pa->pa_len; | |
3557 | atomic_set(&pa->pa_count, 1); | |
3558 | spin_lock_init(&pa->pa_lock); | |
3559 | INIT_LIST_HEAD(&pa->pa_inode_list); | |
3560 | INIT_LIST_HEAD(&pa->pa_group_list); | |
3561 | pa->pa_deleted = 0; | |
3562 | pa->pa_type = MB_GROUP_PA; | |
3563 | ||
3564 | mb_debug(1, "new group pa %p: %llu/%u for %u\n", pa, | |
3565 | pa->pa_pstart, pa->pa_len, pa->pa_lstart); | |
3566 | trace_ext4_mb_new_group_pa(ac, pa); | |
3567 | ||
3568 | ext4_mb_use_group_pa(ac, pa); | |
3569 | atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated); | |
3570 | ||
3571 | grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group); | |
3572 | lg = ac->ac_lg; | |
3573 | BUG_ON(lg == NULL); | |
3574 | ||
3575 | pa->pa_obj_lock = &lg->lg_prealloc_lock; | |
3576 | pa->pa_inode = NULL; | |
3577 | ||
3578 | ext4_lock_group(sb, ac->ac_b_ex.fe_group); | |
3579 | list_add(&pa->pa_group_list, &grp->bb_prealloc_list); | |
3580 | ext4_unlock_group(sb, ac->ac_b_ex.fe_group); | |
3581 | ||
3582 | /* | |
3583 | * We will later add the new pa to the right bucket | |
3584 | * after updating the pa_free in ext4_mb_release_context | |
3585 | */ | |
3586 | return 0; | |
3587 | } | |
3588 | ||
3589 | static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac) | |
3590 | { | |
3591 | int err; | |
3592 | ||
3593 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) | |
3594 | err = ext4_mb_new_group_pa(ac); | |
3595 | else | |
3596 | err = ext4_mb_new_inode_pa(ac); | |
3597 | return err; | |
3598 | } | |
3599 | ||
3600 | /* | |
3601 | * finds all unused blocks in on-disk bitmap, frees them in | |
3602 | * in-core bitmap and buddy. | |
3603 | * @pa must be unlinked from inode and group lists, so that | |
3604 | * nobody else can find/use it. | |
3605 | * the caller MUST hold group/inode locks. | |
3606 | * TODO: optimize the case when there are no in-core structures yet | |
3607 | */ | |
3608 | static noinline_for_stack int | |
3609 | ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh, | |
3610 | struct ext4_prealloc_space *pa) | |
3611 | { | |
3612 | struct super_block *sb = e4b->bd_sb; | |
3613 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
3614 | unsigned int end; | |
3615 | unsigned int next; | |
3616 | ext4_group_t group; | |
3617 | ext4_grpblk_t bit; | |
3618 | unsigned long long grp_blk_start; | |
3619 | int err = 0; | |
3620 | int free = 0; | |
3621 | ||
3622 | BUG_ON(pa->pa_deleted == 0); | |
3623 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); | |
3624 | grp_blk_start = pa->pa_pstart - EXT4_C2B(sbi, bit); | |
3625 | BUG_ON(group != e4b->bd_group && pa->pa_len != 0); | |
3626 | end = bit + pa->pa_len; | |
3627 | ||
3628 | while (bit < end) { | |
3629 | bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit); | |
3630 | if (bit >= end) | |
3631 | break; | |
3632 | next = mb_find_next_bit(bitmap_bh->b_data, end, bit); | |
3633 | mb_debug(1, " free preallocated %u/%u in group %u\n", | |
3634 | (unsigned) ext4_group_first_block_no(sb, group) + bit, | |
3635 | (unsigned) next - bit, (unsigned) group); | |
3636 | free += next - bit; | |
3637 | ||
3638 | trace_ext4_mballoc_discard(sb, NULL, group, bit, next - bit); | |
3639 | trace_ext4_mb_release_inode_pa(pa, (grp_blk_start + | |
3640 | EXT4_C2B(sbi, bit)), | |
3641 | next - bit); | |
3642 | mb_free_blocks(pa->pa_inode, e4b, bit, next - bit); | |
3643 | bit = next + 1; | |
3644 | } | |
3645 | if (free != pa->pa_free) { | |
3646 | ext4_msg(e4b->bd_sb, KERN_CRIT, | |
3647 | "pa %p: logic %lu, phys. %lu, len %lu", | |
3648 | pa, (unsigned long) pa->pa_lstart, | |
3649 | (unsigned long) pa->pa_pstart, | |
3650 | (unsigned long) pa->pa_len); | |
3651 | ext4_grp_locked_error(sb, group, 0, 0, "free %u, pa_free %u", | |
3652 | free, pa->pa_free); | |
3653 | /* | |
3654 | * pa is already deleted so we use the value obtained | |
3655 | * from the bitmap and continue. | |
3656 | */ | |
3657 | } | |
3658 | atomic_add(free, &sbi->s_mb_discarded); | |
3659 | ||
3660 | return err; | |
3661 | } | |
3662 | ||
3663 | static noinline_for_stack int | |
3664 | ext4_mb_release_group_pa(struct ext4_buddy *e4b, | |
3665 | struct ext4_prealloc_space *pa) | |
3666 | { | |
3667 | struct super_block *sb = e4b->bd_sb; | |
3668 | ext4_group_t group; | |
3669 | ext4_grpblk_t bit; | |
3670 | ||
3671 | trace_ext4_mb_release_group_pa(pa); | |
3672 | BUG_ON(pa->pa_deleted == 0); | |
3673 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit); | |
3674 | BUG_ON(group != e4b->bd_group && pa->pa_len != 0); | |
3675 | mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len); | |
3676 | atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded); | |
3677 | trace_ext4_mballoc_discard(sb, NULL, group, bit, pa->pa_len); | |
3678 | ||
3679 | return 0; | |
3680 | } | |
3681 | ||
3682 | /* | |
3683 | * releases all preallocations in given group | |
3684 | * | |
3685 | * first, we need to decide discard policy: | |
3686 | * - when do we discard | |
3687 | * 1) ENOSPC | |
3688 | * - how many do we discard | |
3689 | * 1) how many requested | |
3690 | */ | |
3691 | static noinline_for_stack int | |
3692 | ext4_mb_discard_group_preallocations(struct super_block *sb, | |
3693 | ext4_group_t group, int needed) | |
3694 | { | |
3695 | struct ext4_group_info *grp = ext4_get_group_info(sb, group); | |
3696 | struct buffer_head *bitmap_bh = NULL; | |
3697 | struct ext4_prealloc_space *pa, *tmp; | |
3698 | struct list_head list; | |
3699 | struct ext4_buddy e4b; | |
3700 | int err; | |
3701 | int busy = 0; | |
3702 | int free = 0; | |
3703 | ||
3704 | mb_debug(1, "discard preallocation for group %u\n", group); | |
3705 | ||
3706 | if (list_empty(&grp->bb_prealloc_list)) | |
3707 | return 0; | |
3708 | ||
3709 | bitmap_bh = ext4_read_block_bitmap(sb, group); | |
3710 | if (bitmap_bh == NULL) { | |
3711 | ext4_error(sb, "Error reading block bitmap for %u", group); | |
3712 | return 0; | |
3713 | } | |
3714 | ||
3715 | err = ext4_mb_load_buddy(sb, group, &e4b); | |
3716 | if (err) { | |
3717 | ext4_error(sb, "Error loading buddy information for %u", group); | |
3718 | put_bh(bitmap_bh); | |
3719 | return 0; | |
3720 | } | |
3721 | ||
3722 | if (needed == 0) | |
3723 | needed = EXT4_CLUSTERS_PER_GROUP(sb) + 1; | |
3724 | ||
3725 | INIT_LIST_HEAD(&list); | |
3726 | repeat: | |
3727 | ext4_lock_group(sb, group); | |
3728 | list_for_each_entry_safe(pa, tmp, | |
3729 | &grp->bb_prealloc_list, pa_group_list) { | |
3730 | spin_lock(&pa->pa_lock); | |
3731 | if (atomic_read(&pa->pa_count)) { | |
3732 | spin_unlock(&pa->pa_lock); | |
3733 | busy = 1; | |
3734 | continue; | |
3735 | } | |
3736 | if (pa->pa_deleted) { | |
3737 | spin_unlock(&pa->pa_lock); | |
3738 | continue; | |
3739 | } | |
3740 | ||
3741 | /* seems this one can be freed ... */ | |
3742 | pa->pa_deleted = 1; | |
3743 | ||
3744 | /* we can trust pa_free ... */ | |
3745 | free += pa->pa_free; | |
3746 | ||
3747 | spin_unlock(&pa->pa_lock); | |
3748 | ||
3749 | list_del(&pa->pa_group_list); | |
3750 | list_add(&pa->u.pa_tmp_list, &list); | |
3751 | } | |
3752 | ||
3753 | /* if we still need more blocks and some PAs were used, try again */ | |
3754 | if (free < needed && busy) { | |
3755 | busy = 0; | |
3756 | ext4_unlock_group(sb, group); | |
3757 | /* | |
3758 | * Yield the CPU here so that we don't get soft lockup | |
3759 | * in non preempt case. | |
3760 | */ | |
3761 | yield(); | |
3762 | goto repeat; | |
3763 | } | |
3764 | ||
3765 | /* found anything to free? */ | |
3766 | if (list_empty(&list)) { | |
3767 | BUG_ON(free != 0); | |
3768 | goto out; | |
3769 | } | |
3770 | ||
3771 | /* now free all selected PAs */ | |
3772 | list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { | |
3773 | ||
3774 | /* remove from object (inode or locality group) */ | |
3775 | spin_lock(pa->pa_obj_lock); | |
3776 | list_del_rcu(&pa->pa_inode_list); | |
3777 | spin_unlock(pa->pa_obj_lock); | |
3778 | ||
3779 | if (pa->pa_type == MB_GROUP_PA) | |
3780 | ext4_mb_release_group_pa(&e4b, pa); | |
3781 | else | |
3782 | ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); | |
3783 | ||
3784 | list_del(&pa->u.pa_tmp_list); | |
3785 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); | |
3786 | } | |
3787 | ||
3788 | out: | |
3789 | ext4_unlock_group(sb, group); | |
3790 | ext4_mb_unload_buddy(&e4b); | |
3791 | put_bh(bitmap_bh); | |
3792 | return free; | |
3793 | } | |
3794 | ||
3795 | /* | |
3796 | * releases all non-used preallocated blocks for given inode | |
3797 | * | |
3798 | * It's important to discard preallocations under i_data_sem | |
3799 | * We don't want another block to be served from the prealloc | |
3800 | * space when we are discarding the inode prealloc space. | |
3801 | * | |
3802 | * FIXME!! Make sure it is valid at all the call sites | |
3803 | */ | |
3804 | void ext4_discard_preallocations(struct inode *inode) | |
3805 | { | |
3806 | struct ext4_inode_info *ei = EXT4_I(inode); | |
3807 | struct super_block *sb = inode->i_sb; | |
3808 | struct buffer_head *bitmap_bh = NULL; | |
3809 | struct ext4_prealloc_space *pa, *tmp; | |
3810 | ext4_group_t group = 0; | |
3811 | struct list_head list; | |
3812 | struct ext4_buddy e4b; | |
3813 | int err; | |
3814 | ||
3815 | if (!S_ISREG(inode->i_mode)) { | |
3816 | /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/ | |
3817 | return; | |
3818 | } | |
3819 | ||
3820 | mb_debug(1, "discard preallocation for inode %lu\n", inode->i_ino); | |
3821 | trace_ext4_discard_preallocations(inode); | |
3822 | ||
3823 | INIT_LIST_HEAD(&list); | |
3824 | ||
3825 | repeat: | |
3826 | /* first, collect all pa's in the inode */ | |
3827 | spin_lock(&ei->i_prealloc_lock); | |
3828 | while (!list_empty(&ei->i_prealloc_list)) { | |
3829 | pa = list_entry(ei->i_prealloc_list.next, | |
3830 | struct ext4_prealloc_space, pa_inode_list); | |
3831 | BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock); | |
3832 | spin_lock(&pa->pa_lock); | |
3833 | if (atomic_read(&pa->pa_count)) { | |
3834 | /* this shouldn't happen often - nobody should | |
3835 | * use preallocation while we're discarding it */ | |
3836 | spin_unlock(&pa->pa_lock); | |
3837 | spin_unlock(&ei->i_prealloc_lock); | |
3838 | ext4_msg(sb, KERN_ERR, | |
3839 | "uh-oh! used pa while discarding"); | |
3840 | WARN_ON(1); | |
3841 | schedule_timeout_uninterruptible(HZ); | |
3842 | goto repeat; | |
3843 | ||
3844 | } | |
3845 | if (pa->pa_deleted == 0) { | |
3846 | pa->pa_deleted = 1; | |
3847 | spin_unlock(&pa->pa_lock); | |
3848 | list_del_rcu(&pa->pa_inode_list); | |
3849 | list_add(&pa->u.pa_tmp_list, &list); | |
3850 | continue; | |
3851 | } | |
3852 | ||
3853 | /* someone is deleting pa right now */ | |
3854 | spin_unlock(&pa->pa_lock); | |
3855 | spin_unlock(&ei->i_prealloc_lock); | |
3856 | ||
3857 | /* we have to wait here because pa_deleted | |
3858 | * doesn't mean pa is already unlinked from | |
3859 | * the list. as we might be called from | |
3860 | * ->clear_inode() the inode will get freed | |
3861 | * and concurrent thread which is unlinking | |
3862 | * pa from inode's list may access already | |
3863 | * freed memory, bad-bad-bad */ | |
3864 | ||
3865 | /* XXX: if this happens too often, we can | |
3866 | * add a flag to force wait only in case | |
3867 | * of ->clear_inode(), but not in case of | |
3868 | * regular truncate */ | |
3869 | schedule_timeout_uninterruptible(HZ); | |
3870 | goto repeat; | |
3871 | } | |
3872 | spin_unlock(&ei->i_prealloc_lock); | |
3873 | ||
3874 | list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) { | |
3875 | BUG_ON(pa->pa_type != MB_INODE_PA); | |
3876 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); | |
3877 | ||
3878 | err = ext4_mb_load_buddy(sb, group, &e4b); | |
3879 | if (err) { | |
3880 | ext4_error(sb, "Error loading buddy information for %u", | |
3881 | group); | |
3882 | continue; | |
3883 | } | |
3884 | ||
3885 | bitmap_bh = ext4_read_block_bitmap(sb, group); | |
3886 | if (bitmap_bh == NULL) { | |
3887 | ext4_error(sb, "Error reading block bitmap for %u", | |
3888 | group); | |
3889 | ext4_mb_unload_buddy(&e4b); | |
3890 | continue; | |
3891 | } | |
3892 | ||
3893 | ext4_lock_group(sb, group); | |
3894 | list_del(&pa->pa_group_list); | |
3895 | ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa); | |
3896 | ext4_unlock_group(sb, group); | |
3897 | ||
3898 | ext4_mb_unload_buddy(&e4b); | |
3899 | put_bh(bitmap_bh); | |
3900 | ||
3901 | list_del(&pa->u.pa_tmp_list); | |
3902 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); | |
3903 | } | |
3904 | } | |
3905 | ||
3906 | #ifdef CONFIG_EXT4_DEBUG | |
3907 | static void ext4_mb_show_ac(struct ext4_allocation_context *ac) | |
3908 | { | |
3909 | struct super_block *sb = ac->ac_sb; | |
3910 | ext4_group_t ngroups, i; | |
3911 | ||
3912 | if (!mb_enable_debug || | |
3913 | (EXT4_SB(sb)->s_mount_flags & EXT4_MF_FS_ABORTED)) | |
3914 | return; | |
3915 | ||
3916 | ext4_msg(ac->ac_sb, KERN_ERR, "EXT4-fs: Can't allocate:" | |
3917 | " Allocation context details:"); | |
3918 | ext4_msg(ac->ac_sb, KERN_ERR, "EXT4-fs: status %d flags %d", | |
3919 | ac->ac_status, ac->ac_flags); | |
3920 | ext4_msg(ac->ac_sb, KERN_ERR, "EXT4-fs: orig %lu/%lu/%lu@%lu, " | |
3921 | "goal %lu/%lu/%lu@%lu, " | |
3922 | "best %lu/%lu/%lu@%lu cr %d", | |
3923 | (unsigned long)ac->ac_o_ex.fe_group, | |
3924 | (unsigned long)ac->ac_o_ex.fe_start, | |
3925 | (unsigned long)ac->ac_o_ex.fe_len, | |
3926 | (unsigned long)ac->ac_o_ex.fe_logical, | |
3927 | (unsigned long)ac->ac_g_ex.fe_group, | |
3928 | (unsigned long)ac->ac_g_ex.fe_start, | |
3929 | (unsigned long)ac->ac_g_ex.fe_len, | |
3930 | (unsigned long)ac->ac_g_ex.fe_logical, | |
3931 | (unsigned long)ac->ac_b_ex.fe_group, | |
3932 | (unsigned long)ac->ac_b_ex.fe_start, | |
3933 | (unsigned long)ac->ac_b_ex.fe_len, | |
3934 | (unsigned long)ac->ac_b_ex.fe_logical, | |
3935 | (int)ac->ac_criteria); | |
3936 | ext4_msg(ac->ac_sb, KERN_ERR, "EXT4-fs: %lu scanned, %d found", | |
3937 | ac->ac_ex_scanned, ac->ac_found); | |
3938 | ext4_msg(ac->ac_sb, KERN_ERR, "EXT4-fs: groups: "); | |
3939 | ngroups = ext4_get_groups_count(sb); | |
3940 | for (i = 0; i < ngroups; i++) { | |
3941 | struct ext4_group_info *grp = ext4_get_group_info(sb, i); | |
3942 | struct ext4_prealloc_space *pa; | |
3943 | ext4_grpblk_t start; | |
3944 | struct list_head *cur; | |
3945 | ext4_lock_group(sb, i); | |
3946 | list_for_each(cur, &grp->bb_prealloc_list) { | |
3947 | pa = list_entry(cur, struct ext4_prealloc_space, | |
3948 | pa_group_list); | |
3949 | spin_lock(&pa->pa_lock); | |
3950 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, | |
3951 | NULL, &start); | |
3952 | spin_unlock(&pa->pa_lock); | |
3953 | printk(KERN_ERR "PA:%u:%d:%u \n", i, | |
3954 | start, pa->pa_len); | |
3955 | } | |
3956 | ext4_unlock_group(sb, i); | |
3957 | ||
3958 | if (grp->bb_free == 0) | |
3959 | continue; | |
3960 | printk(KERN_ERR "%u: %d/%d \n", | |
3961 | i, grp->bb_free, grp->bb_fragments); | |
3962 | } | |
3963 | printk(KERN_ERR "\n"); | |
3964 | } | |
3965 | #else | |
3966 | static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac) | |
3967 | { | |
3968 | return; | |
3969 | } | |
3970 | #endif | |
3971 | ||
3972 | /* | |
3973 | * We use locality group preallocation for small size file. The size of the | |
3974 | * file is determined by the current size or the resulting size after | |
3975 | * allocation which ever is larger | |
3976 | * | |
3977 | * One can tune this size via /sys/fs/ext4/<partition>/mb_stream_req | |
3978 | */ | |
3979 | static void ext4_mb_group_or_file(struct ext4_allocation_context *ac) | |
3980 | { | |
3981 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
3982 | int bsbits = ac->ac_sb->s_blocksize_bits; | |
3983 | loff_t size, isize; | |
3984 | ||
3985 | if (!(ac->ac_flags & EXT4_MB_HINT_DATA)) | |
3986 | return; | |
3987 | ||
3988 | if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY)) | |
3989 | return; | |
3990 | ||
3991 | size = ac->ac_o_ex.fe_logical + EXT4_C2B(sbi, ac->ac_o_ex.fe_len); | |
3992 | isize = (i_size_read(ac->ac_inode) + ac->ac_sb->s_blocksize - 1) | |
3993 | >> bsbits; | |
3994 | ||
3995 | if ((size == isize) && | |
3996 | !ext4_fs_is_busy(sbi) && | |
3997 | (atomic_read(&ac->ac_inode->i_writecount) == 0)) { | |
3998 | ac->ac_flags |= EXT4_MB_HINT_NOPREALLOC; | |
3999 | return; | |
4000 | } | |
4001 | ||
4002 | /* don't use group allocation for large files */ | |
4003 | size = max(size, isize); | |
4004 | if (size > sbi->s_mb_stream_request) { | |
4005 | ac->ac_flags |= EXT4_MB_STREAM_ALLOC; | |
4006 | return; | |
4007 | } | |
4008 | ||
4009 | BUG_ON(ac->ac_lg != NULL); | |
4010 | /* | |
4011 | * locality group prealloc space are per cpu. The reason for having | |
4012 | * per cpu locality group is to reduce the contention between block | |
4013 | * request from multiple CPUs. | |
4014 | */ | |
4015 | ac->ac_lg = __this_cpu_ptr(sbi->s_locality_groups); | |
4016 | ||
4017 | /* we're going to use group allocation */ | |
4018 | ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC; | |
4019 | ||
4020 | /* serialize all allocations in the group */ | |
4021 | mutex_lock(&ac->ac_lg->lg_mutex); | |
4022 | } | |
4023 | ||
4024 | static noinline_for_stack int | |
4025 | ext4_mb_initialize_context(struct ext4_allocation_context *ac, | |
4026 | struct ext4_allocation_request *ar) | |
4027 | { | |
4028 | struct super_block *sb = ar->inode->i_sb; | |
4029 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
4030 | struct ext4_super_block *es = sbi->s_es; | |
4031 | ext4_group_t group; | |
4032 | unsigned int len; | |
4033 | ext4_fsblk_t goal; | |
4034 | ext4_grpblk_t block; | |
4035 | ||
4036 | /* we can't allocate > group size */ | |
4037 | len = ar->len; | |
4038 | ||
4039 | /* just a dirty hack to filter too big requests */ | |
4040 | if (len >= EXT4_CLUSTERS_PER_GROUP(sb) - 10) | |
4041 | len = EXT4_CLUSTERS_PER_GROUP(sb) - 10; | |
4042 | ||
4043 | /* start searching from the goal */ | |
4044 | goal = ar->goal; | |
4045 | if (goal < le32_to_cpu(es->s_first_data_block) || | |
4046 | goal >= ext4_blocks_count(es)) | |
4047 | goal = le32_to_cpu(es->s_first_data_block); | |
4048 | ext4_get_group_no_and_offset(sb, goal, &group, &block); | |
4049 | ||
4050 | /* set up allocation goals */ | |
4051 | memset(ac, 0, sizeof(struct ext4_allocation_context)); | |
4052 | ac->ac_b_ex.fe_logical = ar->logical & ~(sbi->s_cluster_ratio - 1); | |
4053 | ac->ac_status = AC_STATUS_CONTINUE; | |
4054 | ac->ac_sb = sb; | |
4055 | ac->ac_inode = ar->inode; | |
4056 | ac->ac_o_ex.fe_logical = ac->ac_b_ex.fe_logical; | |
4057 | ac->ac_o_ex.fe_group = group; | |
4058 | ac->ac_o_ex.fe_start = block; | |
4059 | ac->ac_o_ex.fe_len = len; | |
4060 | ac->ac_g_ex = ac->ac_o_ex; | |
4061 | ac->ac_flags = ar->flags; | |
4062 | ||
4063 | /* we have to define context: we'll we work with a file or | |
4064 | * locality group. this is a policy, actually */ | |
4065 | ext4_mb_group_or_file(ac); | |
4066 | ||
4067 | mb_debug(1, "init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, " | |
4068 | "left: %u/%u, right %u/%u to %swritable\n", | |
4069 | (unsigned) ar->len, (unsigned) ar->logical, | |
4070 | (unsigned) ar->goal, ac->ac_flags, ac->ac_2order, | |
4071 | (unsigned) ar->lleft, (unsigned) ar->pleft, | |
4072 | (unsigned) ar->lright, (unsigned) ar->pright, | |
4073 | atomic_read(&ar->inode->i_writecount) ? "" : "non-"); | |
4074 | return 0; | |
4075 | ||
4076 | } | |
4077 | ||
4078 | static noinline_for_stack void | |
4079 | ext4_mb_discard_lg_preallocations(struct super_block *sb, | |
4080 | struct ext4_locality_group *lg, | |
4081 | int order, int total_entries) | |
4082 | { | |
4083 | ext4_group_t group = 0; | |
4084 | struct ext4_buddy e4b; | |
4085 | struct list_head discard_list; | |
4086 | struct ext4_prealloc_space *pa, *tmp; | |
4087 | ||
4088 | mb_debug(1, "discard locality group preallocation\n"); | |
4089 | ||
4090 | INIT_LIST_HEAD(&discard_list); | |
4091 | ||
4092 | spin_lock(&lg->lg_prealloc_lock); | |
4093 | list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order], | |
4094 | pa_inode_list) { | |
4095 | spin_lock(&pa->pa_lock); | |
4096 | if (atomic_read(&pa->pa_count)) { | |
4097 | /* | |
4098 | * This is the pa that we just used | |
4099 | * for block allocation. So don't | |
4100 | * free that | |
4101 | */ | |
4102 | spin_unlock(&pa->pa_lock); | |
4103 | continue; | |
4104 | } | |
4105 | if (pa->pa_deleted) { | |
4106 | spin_unlock(&pa->pa_lock); | |
4107 | continue; | |
4108 | } | |
4109 | /* only lg prealloc space */ | |
4110 | BUG_ON(pa->pa_type != MB_GROUP_PA); | |
4111 | ||
4112 | /* seems this one can be freed ... */ | |
4113 | pa->pa_deleted = 1; | |
4114 | spin_unlock(&pa->pa_lock); | |
4115 | ||
4116 | list_del_rcu(&pa->pa_inode_list); | |
4117 | list_add(&pa->u.pa_tmp_list, &discard_list); | |
4118 | ||
4119 | total_entries--; | |
4120 | if (total_entries <= 5) { | |
4121 | /* | |
4122 | * we want to keep only 5 entries | |
4123 | * allowing it to grow to 8. This | |
4124 | * mak sure we don't call discard | |
4125 | * soon for this list. | |
4126 | */ | |
4127 | break; | |
4128 | } | |
4129 | } | |
4130 | spin_unlock(&lg->lg_prealloc_lock); | |
4131 | ||
4132 | list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) { | |
4133 | ||
4134 | ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL); | |
4135 | if (ext4_mb_load_buddy(sb, group, &e4b)) { | |
4136 | ext4_error(sb, "Error loading buddy information for %u", | |
4137 | group); | |
4138 | continue; | |
4139 | } | |
4140 | ext4_lock_group(sb, group); | |
4141 | list_del(&pa->pa_group_list); | |
4142 | ext4_mb_release_group_pa(&e4b, pa); | |
4143 | ext4_unlock_group(sb, group); | |
4144 | ||
4145 | ext4_mb_unload_buddy(&e4b); | |
4146 | list_del(&pa->u.pa_tmp_list); | |
4147 | call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback); | |
4148 | } | |
4149 | } | |
4150 | ||
4151 | /* | |
4152 | * We have incremented pa_count. So it cannot be freed at this | |
4153 | * point. Also we hold lg_mutex. So no parallel allocation is | |
4154 | * possible from this lg. That means pa_free cannot be updated. | |
4155 | * | |
4156 | * A parallel ext4_mb_discard_group_preallocations is possible. | |
4157 | * which can cause the lg_prealloc_list to be updated. | |
4158 | */ | |
4159 | ||
4160 | static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac) | |
4161 | { | |
4162 | int order, added = 0, lg_prealloc_count = 1; | |
4163 | struct super_block *sb = ac->ac_sb; | |
4164 | struct ext4_locality_group *lg = ac->ac_lg; | |
4165 | struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa; | |
4166 | ||
4167 | order = fls(pa->pa_free) - 1; | |
4168 | if (order > PREALLOC_TB_SIZE - 1) | |
4169 | /* The max size of hash table is PREALLOC_TB_SIZE */ | |
4170 | order = PREALLOC_TB_SIZE - 1; | |
4171 | /* Add the prealloc space to lg */ | |
4172 | rcu_read_lock(); | |
4173 | list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order], | |
4174 | pa_inode_list) { | |
4175 | spin_lock(&tmp_pa->pa_lock); | |
4176 | if (tmp_pa->pa_deleted) { | |
4177 | spin_unlock(&tmp_pa->pa_lock); | |
4178 | continue; | |
4179 | } | |
4180 | if (!added && pa->pa_free < tmp_pa->pa_free) { | |
4181 | /* Add to the tail of the previous entry */ | |
4182 | list_add_tail_rcu(&pa->pa_inode_list, | |
4183 | &tmp_pa->pa_inode_list); | |
4184 | added = 1; | |
4185 | /* | |
4186 | * we want to count the total | |
4187 | * number of entries in the list | |
4188 | */ | |
4189 | } | |
4190 | spin_unlock(&tmp_pa->pa_lock); | |
4191 | lg_prealloc_count++; | |
4192 | } | |
4193 | if (!added) | |
4194 | list_add_tail_rcu(&pa->pa_inode_list, | |
4195 | &lg->lg_prealloc_list[order]); | |
4196 | rcu_read_unlock(); | |
4197 | ||
4198 | /* Now trim the list to be not more than 8 elements */ | |
4199 | if (lg_prealloc_count > 8) { | |
4200 | ext4_mb_discard_lg_preallocations(sb, lg, | |
4201 | order, lg_prealloc_count); | |
4202 | return; | |
4203 | } | |
4204 | return ; | |
4205 | } | |
4206 | ||
4207 | /* | |
4208 | * release all resource we used in allocation | |
4209 | */ | |
4210 | static int ext4_mb_release_context(struct ext4_allocation_context *ac) | |
4211 | { | |
4212 | struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb); | |
4213 | struct ext4_prealloc_space *pa = ac->ac_pa; | |
4214 | if (pa) { | |
4215 | if (pa->pa_type == MB_GROUP_PA) { | |
4216 | /* see comment in ext4_mb_use_group_pa() */ | |
4217 | spin_lock(&pa->pa_lock); | |
4218 | pa->pa_pstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); | |
4219 | pa->pa_lstart += EXT4_C2B(sbi, ac->ac_b_ex.fe_len); | |
4220 | pa->pa_free -= ac->ac_b_ex.fe_len; | |
4221 | pa->pa_len -= ac->ac_b_ex.fe_len; | |
4222 | spin_unlock(&pa->pa_lock); | |
4223 | } | |
4224 | } | |
4225 | if (pa) { | |
4226 | /* | |
4227 | * We want to add the pa to the right bucket. | |
4228 | * Remove it from the list and while adding | |
4229 | * make sure the list to which we are adding | |
4230 | * doesn't grow big. | |
4231 | */ | |
4232 | if ((pa->pa_type == MB_GROUP_PA) && likely(pa->pa_free)) { | |
4233 | spin_lock(pa->pa_obj_lock); | |
4234 | list_del_rcu(&pa->pa_inode_list); | |
4235 | spin_unlock(pa->pa_obj_lock); | |
4236 | ext4_mb_add_n_trim(ac); | |
4237 | } | |
4238 | ext4_mb_put_pa(ac, ac->ac_sb, pa); | |
4239 | } | |
4240 | if (ac->ac_bitmap_page) | |
4241 | page_cache_release(ac->ac_bitmap_page); | |
4242 | if (ac->ac_buddy_page) | |
4243 | page_cache_release(ac->ac_buddy_page); | |
4244 | if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) | |
4245 | mutex_unlock(&ac->ac_lg->lg_mutex); | |
4246 | ext4_mb_collect_stats(ac); | |
4247 | return 0; | |
4248 | } | |
4249 | ||
4250 | static int ext4_mb_discard_preallocations(struct super_block *sb, int needed) | |
4251 | { | |
4252 | ext4_group_t i, ngroups = ext4_get_groups_count(sb); | |
4253 | int ret; | |
4254 | int freed = 0; | |
4255 | ||
4256 | trace_ext4_mb_discard_preallocations(sb, needed); | |
4257 | for (i = 0; i < ngroups && needed > 0; i++) { | |
4258 | ret = ext4_mb_discard_group_preallocations(sb, i, needed); | |
4259 | freed += ret; | |
4260 | needed -= ret; | |
4261 | } | |
4262 | ||
4263 | return freed; | |
4264 | } | |
4265 | ||
4266 | /* | |
4267 | * Main entry point into mballoc to allocate blocks | |
4268 | * it tries to use preallocation first, then falls back | |
4269 | * to usual allocation | |
4270 | */ | |
4271 | ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle, | |
4272 | struct ext4_allocation_request *ar, int *errp) | |
4273 | { | |
4274 | int freed; | |
4275 | struct ext4_allocation_context *ac = NULL; | |
4276 | struct ext4_sb_info *sbi; | |
4277 | struct super_block *sb; | |
4278 | ext4_fsblk_t block = 0; | |
4279 | unsigned int inquota = 0; | |
4280 | unsigned int reserv_clstrs = 0; | |
4281 | ||
4282 | sb = ar->inode->i_sb; | |
4283 | sbi = EXT4_SB(sb); | |
4284 | ||
4285 | trace_ext4_request_blocks(ar); | |
4286 | ||
4287 | /* | |
4288 | * For delayed allocation, we could skip the ENOSPC and | |
4289 | * EDQUOT check, as blocks and quotas have been already | |
4290 | * reserved when data being copied into pagecache. | |
4291 | */ | |
4292 | if (ext4_test_inode_state(ar->inode, EXT4_STATE_DELALLOC_RESERVED)) | |
4293 | ar->flags |= EXT4_MB_DELALLOC_RESERVED; | |
4294 | else { | |
4295 | /* Without delayed allocation we need to verify | |
4296 | * there is enough free blocks to do block allocation | |
4297 | * and verify allocation doesn't exceed the quota limits. | |
4298 | */ | |
4299 | while (ar->len && | |
4300 | ext4_claim_free_clusters(sbi, ar->len, ar->flags)) { | |
4301 | ||
4302 | /* let others to free the space */ | |
4303 | yield(); | |
4304 | ar->len = ar->len >> 1; | |
4305 | } | |
4306 | if (!ar->len) { | |
4307 | *errp = -ENOSPC; | |
4308 | return 0; | |
4309 | } | |
4310 | reserv_clstrs = ar->len; | |
4311 | if (ar->flags & EXT4_MB_USE_ROOT_BLOCKS) { | |
4312 | dquot_alloc_block_nofail(ar->inode, | |
4313 | EXT4_C2B(sbi, ar->len)); | |
4314 | } else { | |
4315 | while (ar->len && | |
4316 | dquot_alloc_block(ar->inode, | |
4317 | EXT4_C2B(sbi, ar->len))) { | |
4318 | ||
4319 | ar->flags |= EXT4_MB_HINT_NOPREALLOC; | |
4320 | ar->len--; | |
4321 | } | |
4322 | } | |
4323 | inquota = ar->len; | |
4324 | if (ar->len == 0) { | |
4325 | *errp = -EDQUOT; | |
4326 | goto out; | |
4327 | } | |
4328 | } | |
4329 | ||
4330 | ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS); | |
4331 | if (!ac) { | |
4332 | ar->len = 0; | |
4333 | *errp = -ENOMEM; | |
4334 | goto out; | |
4335 | } | |
4336 | ||
4337 | *errp = ext4_mb_initialize_context(ac, ar); | |
4338 | if (*errp) { | |
4339 | ar->len = 0; | |
4340 | goto out; | |
4341 | } | |
4342 | ||
4343 | ac->ac_op = EXT4_MB_HISTORY_PREALLOC; | |
4344 | if (!ext4_mb_use_preallocated(ac)) { | |
4345 | ac->ac_op = EXT4_MB_HISTORY_ALLOC; | |
4346 | ext4_mb_normalize_request(ac, ar); | |
4347 | repeat: | |
4348 | /* allocate space in core */ | |
4349 | *errp = ext4_mb_regular_allocator(ac); | |
4350 | if (*errp) | |
4351 | goto errout; | |
4352 | ||
4353 | /* as we've just preallocated more space than | |
4354 | * user requested orinally, we store allocated | |
4355 | * space in a special descriptor */ | |
4356 | if (ac->ac_status == AC_STATUS_FOUND && | |
4357 | ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len) | |
4358 | ext4_mb_new_preallocation(ac); | |
4359 | } | |
4360 | if (likely(ac->ac_status == AC_STATUS_FOUND)) { | |
4361 | *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_clstrs); | |
4362 | if (*errp == -EAGAIN) { | |
4363 | /* | |
4364 | * drop the reference that we took | |
4365 | * in ext4_mb_use_best_found | |
4366 | */ | |
4367 | ext4_mb_release_context(ac); | |
4368 | ac->ac_b_ex.fe_group = 0; | |
4369 | ac->ac_b_ex.fe_start = 0; | |
4370 | ac->ac_b_ex.fe_len = 0; | |
4371 | ac->ac_status = AC_STATUS_CONTINUE; | |
4372 | goto repeat; | |
4373 | } else if (*errp) | |
4374 | errout: | |
4375 | ext4_discard_allocated_blocks(ac); | |
4376 | else { | |
4377 | block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex); | |
4378 | ar->len = ac->ac_b_ex.fe_len; | |
4379 | } | |
4380 | } else { | |
4381 | freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len); | |
4382 | if (freed) | |
4383 | goto repeat; | |
4384 | *errp = -ENOSPC; | |
4385 | } | |
4386 | ||
4387 | if (*errp) { | |
4388 | ac->ac_b_ex.fe_len = 0; | |
4389 | ar->len = 0; | |
4390 | ext4_mb_show_ac(ac); | |
4391 | } | |
4392 | ext4_mb_release_context(ac); | |
4393 | out: | |
4394 | if (ac) | |
4395 | kmem_cache_free(ext4_ac_cachep, ac); | |
4396 | if (inquota && ar->len < inquota) | |
4397 | dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len)); | |
4398 | if (!ar->len) { | |
4399 | if (!ext4_test_inode_state(ar->inode, | |
4400 | EXT4_STATE_DELALLOC_RESERVED)) | |
4401 | /* release all the reserved blocks if non delalloc */ | |
4402 | percpu_counter_sub(&sbi->s_dirtyclusters_counter, | |
4403 | reserv_clstrs); | |
4404 | } | |
4405 | ||
4406 | trace_ext4_allocate_blocks(ar, (unsigned long long)block); | |
4407 | ||
4408 | return block; | |
4409 | } | |
4410 | ||
4411 | /* | |
4412 | * We can merge two free data extents only if the physical blocks | |
4413 | * are contiguous, AND the extents were freed by the same transaction, | |
4414 | * AND the blocks are associated with the same group. | |
4415 | */ | |
4416 | static int can_merge(struct ext4_free_data *entry1, | |
4417 | struct ext4_free_data *entry2) | |
4418 | { | |
4419 | if ((entry1->t_tid == entry2->t_tid) && | |
4420 | (entry1->group == entry2->group) && | |
4421 | ((entry1->start_cluster + entry1->count) == entry2->start_cluster)) | |
4422 | return 1; | |
4423 | return 0; | |
4424 | } | |
4425 | ||
4426 | static noinline_for_stack int | |
4427 | ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b, | |
4428 | struct ext4_free_data *new_entry) | |
4429 | { | |
4430 | ext4_group_t group = e4b->bd_group; | |
4431 | ext4_grpblk_t cluster; | |
4432 | struct ext4_free_data *entry; | |
4433 | struct ext4_group_info *db = e4b->bd_info; | |
4434 | struct super_block *sb = e4b->bd_sb; | |
4435 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
4436 | struct rb_node **n = &db->bb_free_root.rb_node, *node; | |
4437 | struct rb_node *parent = NULL, *new_node; | |
4438 | ||
4439 | BUG_ON(!ext4_handle_valid(handle)); | |
4440 | BUG_ON(e4b->bd_bitmap_page == NULL); | |
4441 | BUG_ON(e4b->bd_buddy_page == NULL); | |
4442 | ||
4443 | new_node = &new_entry->node; | |
4444 | cluster = new_entry->start_cluster; | |
4445 | ||
4446 | if (!*n) { | |
4447 | /* first free block exent. We need to | |
4448 | protect buddy cache from being freed, | |
4449 | * otherwise we'll refresh it from | |
4450 | * on-disk bitmap and lose not-yet-available | |
4451 | * blocks */ | |
4452 | page_cache_get(e4b->bd_buddy_page); | |
4453 | page_cache_get(e4b->bd_bitmap_page); | |
4454 | } | |
4455 | while (*n) { | |
4456 | parent = *n; | |
4457 | entry = rb_entry(parent, struct ext4_free_data, node); | |
4458 | if (cluster < entry->start_cluster) | |
4459 | n = &(*n)->rb_left; | |
4460 | else if (cluster >= (entry->start_cluster + entry->count)) | |
4461 | n = &(*n)->rb_right; | |
4462 | else { | |
4463 | ext4_grp_locked_error(sb, group, 0, | |
4464 | ext4_group_first_block_no(sb, group) + | |
4465 | EXT4_C2B(sbi, cluster), | |
4466 | "Block already on to-be-freed list"); | |
4467 | return 0; | |
4468 | } | |
4469 | } | |
4470 | ||
4471 | rb_link_node(new_node, parent, n); | |
4472 | rb_insert_color(new_node, &db->bb_free_root); | |
4473 | ||
4474 | /* Now try to see the extent can be merged to left and right */ | |
4475 | node = rb_prev(new_node); | |
4476 | if (node) { | |
4477 | entry = rb_entry(node, struct ext4_free_data, node); | |
4478 | if (can_merge(entry, new_entry)) { | |
4479 | new_entry->start_cluster = entry->start_cluster; | |
4480 | new_entry->count += entry->count; | |
4481 | rb_erase(node, &(db->bb_free_root)); | |
4482 | spin_lock(&sbi->s_md_lock); | |
4483 | list_del(&entry->list); | |
4484 | spin_unlock(&sbi->s_md_lock); | |
4485 | kmem_cache_free(ext4_free_ext_cachep, entry); | |
4486 | } | |
4487 | } | |
4488 | ||
4489 | node = rb_next(new_node); | |
4490 | if (node) { | |
4491 | entry = rb_entry(node, struct ext4_free_data, node); | |
4492 | if (can_merge(new_entry, entry)) { | |
4493 | new_entry->count += entry->count; | |
4494 | rb_erase(node, &(db->bb_free_root)); | |
4495 | spin_lock(&sbi->s_md_lock); | |
4496 | list_del(&entry->list); | |
4497 | spin_unlock(&sbi->s_md_lock); | |
4498 | kmem_cache_free(ext4_free_ext_cachep, entry); | |
4499 | } | |
4500 | } | |
4501 | /* Add the extent to transaction's private list */ | |
4502 | spin_lock(&sbi->s_md_lock); | |
4503 | list_add(&new_entry->list, &handle->h_transaction->t_private_list); | |
4504 | spin_unlock(&sbi->s_md_lock); | |
4505 | return 0; | |
4506 | } | |
4507 | ||
4508 | /** | |
4509 | * ext4_free_blocks() -- Free given blocks and update quota | |
4510 | * @handle: handle for this transaction | |
4511 | * @inode: inode | |
4512 | * @block: start physical block to free | |
4513 | * @count: number of blocks to count | |
4514 | * @flags: flags used by ext4_free_blocks | |
4515 | */ | |
4516 | void ext4_free_blocks(handle_t *handle, struct inode *inode, | |
4517 | struct buffer_head *bh, ext4_fsblk_t block, | |
4518 | unsigned long count, int flags) | |
4519 | { | |
4520 | struct buffer_head *bitmap_bh = NULL; | |
4521 | struct super_block *sb = inode->i_sb; | |
4522 | struct ext4_group_desc *gdp; | |
4523 | unsigned long freed = 0; | |
4524 | unsigned int overflow; | |
4525 | ext4_grpblk_t bit; | |
4526 | struct buffer_head *gd_bh; | |
4527 | ext4_group_t block_group; | |
4528 | struct ext4_sb_info *sbi; | |
4529 | struct ext4_buddy e4b; | |
4530 | unsigned int count_clusters; | |
4531 | int err = 0; | |
4532 | int ret; | |
4533 | ||
4534 | if (bh) { | |
4535 | if (block) | |
4536 | BUG_ON(block != bh->b_blocknr); | |
4537 | else | |
4538 | block = bh->b_blocknr; | |
4539 | } | |
4540 | ||
4541 | sbi = EXT4_SB(sb); | |
4542 | if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) && | |
4543 | !ext4_data_block_valid(sbi, block, count)) { | |
4544 | ext4_error(sb, "Freeing blocks not in datazone - " | |
4545 | "block = %llu, count = %lu", block, count); | |
4546 | goto error_return; | |
4547 | } | |
4548 | ||
4549 | ext4_debug("freeing block %llu\n", block); | |
4550 | trace_ext4_free_blocks(inode, block, count, flags); | |
4551 | ||
4552 | if (flags & EXT4_FREE_BLOCKS_FORGET) { | |
4553 | struct buffer_head *tbh = bh; | |
4554 | int i; | |
4555 | ||
4556 | BUG_ON(bh && (count > 1)); | |
4557 | ||
4558 | for (i = 0; i < count; i++) { | |
4559 | if (!bh) | |
4560 | tbh = sb_find_get_block(inode->i_sb, | |
4561 | block + i); | |
4562 | if (unlikely(!tbh)) | |
4563 | continue; | |
4564 | ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA, | |
4565 | inode, tbh, block + i); | |
4566 | } | |
4567 | } | |
4568 | ||
4569 | /* | |
4570 | * We need to make sure we don't reuse the freed block until | |
4571 | * after the transaction is committed, which we can do by | |
4572 | * treating the block as metadata, below. We make an | |
4573 | * exception if the inode is to be written in writeback mode | |
4574 | * since writeback mode has weak data consistency guarantees. | |
4575 | */ | |
4576 | if (!ext4_should_writeback_data(inode)) | |
4577 | flags |= EXT4_FREE_BLOCKS_METADATA; | |
4578 | ||
4579 | /* | |
4580 | * If the extent to be freed does not begin on a cluster | |
4581 | * boundary, we need to deal with partial clusters at the | |
4582 | * beginning and end of the extent. Normally we will free | |
4583 | * blocks at the beginning or the end unless we are explicitly | |
4584 | * requested to avoid doing so. | |
4585 | */ | |
4586 | overflow = block & (sbi->s_cluster_ratio - 1); | |
4587 | if (overflow) { | |
4588 | if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) { | |
4589 | overflow = sbi->s_cluster_ratio - overflow; | |
4590 | block += overflow; | |
4591 | if (count > overflow) | |
4592 | count -= overflow; | |
4593 | else | |
4594 | return; | |
4595 | } else { | |
4596 | block -= overflow; | |
4597 | count += overflow; | |
4598 | } | |
4599 | } | |
4600 | overflow = count & (sbi->s_cluster_ratio - 1); | |
4601 | if (overflow) { | |
4602 | if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) { | |
4603 | if (count > overflow) | |
4604 | count -= overflow; | |
4605 | else | |
4606 | return; | |
4607 | } else | |
4608 | count += sbi->s_cluster_ratio - overflow; | |
4609 | } | |
4610 | ||
4611 | do_more: | |
4612 | overflow = 0; | |
4613 | ext4_get_group_no_and_offset(sb, block, &block_group, &bit); | |
4614 | ||
4615 | /* | |
4616 | * Check to see if we are freeing blocks across a group | |
4617 | * boundary. | |
4618 | */ | |
4619 | if (EXT4_C2B(sbi, bit) + count > EXT4_BLOCKS_PER_GROUP(sb)) { | |
4620 | overflow = EXT4_C2B(sbi, bit) + count - | |
4621 | EXT4_BLOCKS_PER_GROUP(sb); | |
4622 | count -= overflow; | |
4623 | } | |
4624 | count_clusters = EXT4_B2C(sbi, count); | |
4625 | bitmap_bh = ext4_read_block_bitmap(sb, block_group); | |
4626 | if (!bitmap_bh) { | |
4627 | err = -EIO; | |
4628 | goto error_return; | |
4629 | } | |
4630 | gdp = ext4_get_group_desc(sb, block_group, &gd_bh); | |
4631 | if (!gdp) { | |
4632 | err = -EIO; | |
4633 | goto error_return; | |
4634 | } | |
4635 | ||
4636 | if (in_range(ext4_block_bitmap(sb, gdp), block, count) || | |
4637 | in_range(ext4_inode_bitmap(sb, gdp), block, count) || | |
4638 | in_range(block, ext4_inode_table(sb, gdp), | |
4639 | EXT4_SB(sb)->s_itb_per_group) || | |
4640 | in_range(block + count - 1, ext4_inode_table(sb, gdp), | |
4641 | EXT4_SB(sb)->s_itb_per_group)) { | |
4642 | ||
4643 | ext4_error(sb, "Freeing blocks in system zone - " | |
4644 | "Block = %llu, count = %lu", block, count); | |
4645 | /* err = 0. ext4_std_error should be a no op */ | |
4646 | goto error_return; | |
4647 | } | |
4648 | ||
4649 | BUFFER_TRACE(bitmap_bh, "getting write access"); | |
4650 | err = ext4_journal_get_write_access(handle, bitmap_bh); | |
4651 | if (err) | |
4652 | goto error_return; | |
4653 | ||
4654 | /* | |
4655 | * We are about to modify some metadata. Call the journal APIs | |
4656 | * to unshare ->b_data if a currently-committing transaction is | |
4657 | * using it | |
4658 | */ | |
4659 | BUFFER_TRACE(gd_bh, "get_write_access"); | |
4660 | err = ext4_journal_get_write_access(handle, gd_bh); | |
4661 | if (err) | |
4662 | goto error_return; | |
4663 | #ifdef AGGRESSIVE_CHECK | |
4664 | { | |
4665 | int i; | |
4666 | for (i = 0; i < count_clusters; i++) | |
4667 | BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data)); | |
4668 | } | |
4669 | #endif | |
4670 | trace_ext4_mballoc_free(sb, inode, block_group, bit, count_clusters); | |
4671 | ||
4672 | err = ext4_mb_load_buddy(sb, block_group, &e4b); | |
4673 | if (err) | |
4674 | goto error_return; | |
4675 | ||
4676 | if ((flags & EXT4_FREE_BLOCKS_METADATA) && ext4_handle_valid(handle)) { | |
4677 | struct ext4_free_data *new_entry; | |
4678 | /* | |
4679 | * blocks being freed are metadata. these blocks shouldn't | |
4680 | * be used until this transaction is committed | |
4681 | */ | |
4682 | new_entry = kmem_cache_alloc(ext4_free_ext_cachep, GFP_NOFS); | |
4683 | if (!new_entry) { | |
4684 | err = -ENOMEM; | |
4685 | goto error_return; | |
4686 | } | |
4687 | new_entry->start_cluster = bit; | |
4688 | new_entry->group = block_group; | |
4689 | new_entry->count = count_clusters; | |
4690 | new_entry->t_tid = handle->h_transaction->t_tid; | |
4691 | ||
4692 | ext4_lock_group(sb, block_group); | |
4693 | mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); | |
4694 | ext4_mb_free_metadata(handle, &e4b, new_entry); | |
4695 | } else { | |
4696 | /* need to update group_info->bb_free and bitmap | |
4697 | * with group lock held. generate_buddy look at | |
4698 | * them with group lock_held | |
4699 | */ | |
4700 | ext4_lock_group(sb, block_group); | |
4701 | mb_clear_bits(bitmap_bh->b_data, bit, count_clusters); | |
4702 | mb_free_blocks(inode, &e4b, bit, count_clusters); | |
4703 | } | |
4704 | ||
4705 | ret = ext4_free_group_clusters(sb, gdp) + count_clusters; | |
4706 | ext4_free_group_clusters_set(sb, gdp, ret); | |
4707 | gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); | |
4708 | ext4_unlock_group(sb, block_group); | |
4709 | percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters); | |
4710 | ||
4711 | if (sbi->s_log_groups_per_flex) { | |
4712 | ext4_group_t flex_group = ext4_flex_group(sbi, block_group); | |
4713 | atomic_add(count_clusters, | |
4714 | &sbi->s_flex_groups[flex_group].free_clusters); | |
4715 | } | |
4716 | ||
4717 | ext4_mb_unload_buddy(&e4b); | |
4718 | ||
4719 | freed += count; | |
4720 | ||
4721 | if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE)) | |
4722 | dquot_free_block(inode, EXT4_C2B(sbi, count_clusters)); | |
4723 | ||
4724 | /* We dirtied the bitmap block */ | |
4725 | BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); | |
4726 | err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); | |
4727 | ||
4728 | /* And the group descriptor block */ | |
4729 | BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); | |
4730 | ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); | |
4731 | if (!err) | |
4732 | err = ret; | |
4733 | ||
4734 | if (overflow && !err) { | |
4735 | block += count; | |
4736 | count = overflow; | |
4737 | put_bh(bitmap_bh); | |
4738 | goto do_more; | |
4739 | } | |
4740 | ext4_mark_super_dirty(sb); | |
4741 | error_return: | |
4742 | brelse(bitmap_bh); | |
4743 | ext4_std_error(sb, err); | |
4744 | return; | |
4745 | } | |
4746 | ||
4747 | /** | |
4748 | * ext4_group_add_blocks() -- Add given blocks to an existing group | |
4749 | * @handle: handle to this transaction | |
4750 | * @sb: super block | |
4751 | * @block: start physcial block to add to the block group | |
4752 | * @count: number of blocks to free | |
4753 | * | |
4754 | * This marks the blocks as free in the bitmap and buddy. | |
4755 | */ | |
4756 | int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, | |
4757 | ext4_fsblk_t block, unsigned long count) | |
4758 | { | |
4759 | struct buffer_head *bitmap_bh = NULL; | |
4760 | struct buffer_head *gd_bh; | |
4761 | ext4_group_t block_group; | |
4762 | ext4_grpblk_t bit; | |
4763 | unsigned int i; | |
4764 | struct ext4_group_desc *desc; | |
4765 | struct ext4_sb_info *sbi = EXT4_SB(sb); | |
4766 | struct ext4_buddy e4b; | |
4767 | int err = 0, ret, blk_free_count; | |
4768 | ext4_grpblk_t blocks_freed; | |
4769 | ||
4770 | ext4_debug("Adding block(s) %llu-%llu\n", block, block + count - 1); | |
4771 | ||
4772 | if (count == 0) | |
4773 | return 0; | |
4774 | ||
4775 | ext4_get_group_no_and_offset(sb, block, &block_group, &bit); | |
4776 | /* | |
4777 | * Check to see if we are freeing blocks across a group | |
4778 | * boundary. | |
4779 | */ | |
4780 | if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { | |
4781 | ext4_warning(sb, "too much blocks added to group %u\n", | |
4782 | block_group); | |
4783 | err = -EINVAL; | |
4784 | goto error_return; | |
4785 | } | |
4786 | ||
4787 | bitmap_bh = ext4_read_block_bitmap(sb, block_group); | |
4788 | if (!bitmap_bh) { | |
4789 | err = -EIO; | |
4790 | goto error_return; | |
4791 | } | |
4792 | ||
4793 | desc = ext4_get_group_desc(sb, block_group, &gd_bh); | |
4794 | if (!desc) { | |
4795 | err = -EIO; | |
4796 | goto error_return; | |
4797 | } | |
4798 | ||
4799 | if (in_range(ext4_block_bitmap(sb, desc), block, count) || | |
4800 | in_range(ext4_inode_bitmap(sb, desc), block, count) || | |
4801 | in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) || | |
4802 | in_range(block + count - 1, ext4_inode_table(sb, desc), | |
4803 | sbi->s_itb_per_group)) { | |
4804 | ext4_error(sb, "Adding blocks in system zones - " | |
4805 | "Block = %llu, count = %lu", | |
4806 | block, count); | |
4807 | err = -EINVAL; | |
4808 | goto error_return; | |
4809 | } | |
4810 | ||
4811 | BUFFER_TRACE(bitmap_bh, "getting write access"); | |
4812 | err = ext4_journal_get_write_access(handle, bitmap_bh); | |
4813 | if (err) | |
4814 | goto error_return; | |
4815 | ||
4816 | /* | |
4817 | * We are about to modify some metadata. Call the journal APIs | |
4818 | * to unshare ->b_data if a currently-committing transaction is | |
4819 | * using it | |
4820 | */ | |
4821 | BUFFER_TRACE(gd_bh, "get_write_access"); | |
4822 | err = ext4_journal_get_write_access(handle, gd_bh); | |
4823 | if (err) | |
4824 | goto error_return; | |
4825 | ||
4826 | for (i = 0, blocks_freed = 0; i < count; i++) { | |
4827 | BUFFER_TRACE(bitmap_bh, "clear bit"); | |
4828 | if (!mb_test_bit(bit + i, bitmap_bh->b_data)) { | |
4829 | ext4_error(sb, "bit already cleared for block %llu", | |
4830 | (ext4_fsblk_t)(block + i)); | |
4831 | BUFFER_TRACE(bitmap_bh, "bit already cleared"); | |
4832 | } else { | |
4833 | blocks_freed++; | |
4834 | } | |
4835 | } | |
4836 | ||
4837 | err = ext4_mb_load_buddy(sb, block_group, &e4b); | |
4838 | if (err) | |
4839 | goto error_return; | |
4840 | ||
4841 | /* | |
4842 | * need to update group_info->bb_free and bitmap | |
4843 | * with group lock held. generate_buddy look at | |
4844 | * them with group lock_held | |
4845 | */ | |
4846 | ext4_lock_group(sb, block_group); | |
4847 | mb_clear_bits(bitmap_bh->b_data, bit, count); | |
4848 | mb_free_blocks(NULL, &e4b, bit, count); | |
4849 | blk_free_count = blocks_freed + ext4_free_group_clusters(sb, desc); | |
4850 | ext4_free_group_clusters_set(sb, desc, blk_free_count); | |
4851 | desc->bg_checksum = ext4_group_desc_csum(sbi, block_group, desc); | |
4852 | ext4_unlock_group(sb, block_group); | |
4853 | percpu_counter_add(&sbi->s_freeclusters_counter, | |
4854 | EXT4_B2C(sbi, blocks_freed)); | |
4855 | ||
4856 | if (sbi->s_log_groups_per_flex) { | |
4857 | ext4_group_t flex_group = ext4_flex_group(sbi, block_group); | |
4858 | atomic_add(EXT4_B2C(sbi, blocks_freed), | |
4859 | &sbi->s_flex_groups[flex_group].free_clusters); | |
4860 | } | |
4861 | ||
4862 | ext4_mb_unload_buddy(&e4b); | |
4863 | ||
4864 | /* We dirtied the bitmap block */ | |
4865 | BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); | |
4866 | err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); | |
4867 | ||
4868 | /* And the group descriptor block */ | |
4869 | BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); | |
4870 | ret = ext4_handle_dirty_metadata(handle, NULL, gd_bh); | |
4871 | if (!err) | |
4872 | err = ret; | |
4873 | ||
4874 | error_return: | |
4875 | brelse(bitmap_bh); | |
4876 | ext4_std_error(sb, err); | |
4877 | return err; | |
4878 | } | |
4879 | ||
4880 | /** | |
4881 | * ext4_trim_extent -- function to TRIM one single free extent in the group | |
4882 | * @sb: super block for the file system | |
4883 | * @start: starting block of the free extent in the alloc. group | |
4884 | * @count: number of blocks to TRIM | |
4885 | * @group: alloc. group we are working with | |
4886 | * @e4b: ext4 buddy for the group | |
4887 | * | |
4888 | * Trim "count" blocks starting at "start" in the "group". To assure that no | |
4889 | * one will allocate those blocks, mark it as used in buddy bitmap. This must | |
4890 | * be called with under the group lock. | |
4891 | */ | |
4892 | static void ext4_trim_extent(struct super_block *sb, int start, int count, | |
4893 | ext4_group_t group, struct ext4_buddy *e4b) | |
4894 | { | |
4895 | struct ext4_free_extent ex; | |
4896 | ||
4897 | trace_ext4_trim_extent(sb, group, start, count); | |
4898 | ||
4899 | assert_spin_locked(ext4_group_lock_ptr(sb, group)); | |
4900 | ||
4901 | ex.fe_start = start; | |
4902 | ex.fe_group = group; | |
4903 | ex.fe_len = count; | |
4904 | ||
4905 | /* | |
4906 | * Mark blocks used, so no one can reuse them while | |
4907 | * being trimmed. | |
4908 | */ | |
4909 | mb_mark_used(e4b, &ex); | |
4910 | ext4_unlock_group(sb, group); | |
4911 | ext4_issue_discard(sb, group, start, count); | |
4912 | ext4_lock_group(sb, group); | |
4913 | mb_free_blocks(NULL, e4b, start, ex.fe_len); | |
4914 | } | |
4915 | ||
4916 | /** | |
4917 | * ext4_trim_all_free -- function to trim all free space in alloc. group | |
4918 | * @sb: super block for file system | |
4919 | * @group: group to be trimmed | |
4920 | * @start: first group block to examine | |
4921 | * @max: last group block to examine | |
4922 | * @minblocks: minimum extent block count | |
4923 | * | |
4924 | * ext4_trim_all_free walks through group's buddy bitmap searching for free | |
4925 | * extents. When the free block is found, ext4_trim_extent is called to TRIM | |
4926 | * the extent. | |
4927 | * | |
4928 | * | |
4929 | * ext4_trim_all_free walks through group's block bitmap searching for free | |
4930 | * extents. When the free extent is found, mark it as used in group buddy | |
4931 | * bitmap. Then issue a TRIM command on this extent and free the extent in | |
4932 | * the group buddy bitmap. This is done until whole group is scanned. | |
4933 | */ | |
4934 | static ext4_grpblk_t | |
4935 | ext4_trim_all_free(struct super_block *sb, ext4_group_t group, | |
4936 | ext4_grpblk_t start, ext4_grpblk_t max, | |
4937 | ext4_grpblk_t minblocks) | |
4938 | { | |
4939 | void *bitmap; | |
4940 | ext4_grpblk_t next, count = 0, free_count = 0; | |
4941 | struct ext4_buddy e4b; | |
4942 | int ret; | |
4943 | ||
4944 | trace_ext4_trim_all_free(sb, group, start, max); | |
4945 | ||
4946 | ret = ext4_mb_load_buddy(sb, group, &e4b); | |
4947 | if (ret) { | |
4948 | ext4_error(sb, "Error in loading buddy " | |
4949 | "information for %u", group); | |
4950 | return ret; | |
4951 | } | |
4952 | bitmap = e4b.bd_bitmap; | |
4953 | ||
4954 | ext4_lock_group(sb, group); | |
4955 | if (EXT4_MB_GRP_WAS_TRIMMED(e4b.bd_info) && | |
4956 | minblocks >= atomic_read(&EXT4_SB(sb)->s_last_trim_minblks)) | |
4957 | goto out; | |
4958 | ||
4959 | start = (e4b.bd_info->bb_first_free > start) ? | |
4960 | e4b.bd_info->bb_first_free : start; | |
4961 | ||
4962 | while (start < max) { | |
4963 | start = mb_find_next_zero_bit(bitmap, max, start); | |
4964 | if (start >= max) | |
4965 | break; | |
4966 | next = mb_find_next_bit(bitmap, max, start); | |
4967 | ||
4968 | if ((next - start) >= minblocks) { | |
4969 | ext4_trim_extent(sb, start, | |
4970 | next - start, group, &e4b); | |
4971 | count += next - start; | |
4972 | } | |
4973 | free_count += next - start; | |
4974 | start = next + 1; | |
4975 | ||
4976 | if (fatal_signal_pending(current)) { | |
4977 | count = -ERESTARTSYS; | |
4978 | break; | |
4979 | } | |
4980 | ||
4981 | if (need_resched()) { | |
4982 | ext4_unlock_group(sb, group); | |
4983 | cond_resched(); | |
4984 | ext4_lock_group(sb, group); | |
4985 | } | |
4986 | ||
4987 | if ((e4b.bd_info->bb_free - free_count) < minblocks) | |
4988 | break; | |
4989 | } | |
4990 | ||
4991 | if (!ret) | |
4992 | EXT4_MB_GRP_SET_TRIMMED(e4b.bd_info); | |
4993 | out: | |
4994 | ext4_unlock_group(sb, group); | |
4995 | ext4_mb_unload_buddy(&e4b); | |
4996 | ||
4997 | ext4_debug("trimmed %d blocks in the group %d\n", | |
4998 | count, group); | |
4999 | ||
5000 | return count; | |
5001 | } | |
5002 | ||
5003 | /** | |
5004 | * ext4_trim_fs() -- trim ioctl handle function | |
5005 | * @sb: superblock for filesystem | |
5006 | * @range: fstrim_range structure | |
5007 | * | |
5008 | * start: First Byte to trim | |
5009 | * len: number of Bytes to trim from start | |
5010 | * minlen: minimum extent length in Bytes | |
5011 | * ext4_trim_fs goes through all allocation groups containing Bytes from | |
5012 | * start to start+len. For each such a group ext4_trim_all_free function | |
5013 | * is invoked to trim all free space. | |
5014 | */ | |
5015 | int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range) | |
5016 | { | |
5017 | struct ext4_group_info *grp; | |
5018 | ext4_group_t first_group, last_group; | |
5019 | ext4_group_t group, ngroups = ext4_get_groups_count(sb); | |
5020 | ext4_grpblk_t cnt = 0, first_cluster, last_cluster; | |
5021 | uint64_t start, len, minlen, trimmed = 0; | |
5022 | ext4_fsblk_t first_data_blk = | |
5023 | le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block); | |
5024 | int ret = 0; | |
5025 | ||
5026 | start = range->start >> sb->s_blocksize_bits; | |
5027 | len = range->len >> sb->s_blocksize_bits; | |
5028 | minlen = range->minlen >> sb->s_blocksize_bits; | |
5029 | ||
5030 | if (unlikely(minlen > EXT4_CLUSTERS_PER_GROUP(sb))) | |
5031 | return -EINVAL; | |
5032 | if (start + len <= first_data_blk) | |
5033 | goto out; | |
5034 | if (start < first_data_blk) { | |
5035 | len -= first_data_blk - start; | |
5036 | start = first_data_blk; | |
5037 | } | |
5038 | ||
5039 | /* Determine first and last group to examine based on start and len */ | |
5040 | ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) start, | |
5041 | &first_group, &first_cluster); | |
5042 | ext4_get_group_no_and_offset(sb, (ext4_fsblk_t) (start + len), | |
5043 | &last_group, &last_cluster); | |
5044 | last_group = (last_group > ngroups - 1) ? ngroups - 1 : last_group; | |
5045 | last_cluster = EXT4_CLUSTERS_PER_GROUP(sb); | |
5046 | ||
5047 | if (first_group > last_group) | |
5048 | return -EINVAL; | |
5049 | ||
5050 | for (group = first_group; group <= last_group; group++) { | |
5051 | grp = ext4_get_group_info(sb, group); | |
5052 | /* We only do this if the grp has never been initialized */ | |
5053 | if (unlikely(EXT4_MB_GRP_NEED_INIT(grp))) { | |
5054 | ret = ext4_mb_init_group(sb, group); | |
5055 | if (ret) | |
5056 | break; | |
5057 | } | |
5058 | ||
5059 | /* | |
5060 | * For all the groups except the last one, last block will | |
5061 | * always be EXT4_BLOCKS_PER_GROUP(sb), so we only need to | |
5062 | * change it for the last group in which case start + | |
5063 | * len < EXT4_BLOCKS_PER_GROUP(sb). | |
5064 | */ | |
5065 | if (first_cluster + len < EXT4_CLUSTERS_PER_GROUP(sb)) | |
5066 | last_cluster = first_cluster + len; | |
5067 | len -= last_cluster - first_cluster; | |
5068 | ||
5069 | if (grp->bb_free >= minlen) { | |
5070 | cnt = ext4_trim_all_free(sb, group, first_cluster, | |
5071 | last_cluster, minlen); | |
5072 | if (cnt < 0) { | |
5073 | ret = cnt; | |
5074 | break; | |
5075 | } | |
5076 | } | |
5077 | trimmed += cnt; | |
5078 | first_cluster = 0; | |
5079 | } | |
5080 | range->len = trimmed * sb->s_blocksize; | |
5081 | ||
5082 | if (!ret) | |
5083 | atomic_set(&EXT4_SB(sb)->s_last_trim_minblks, minlen); | |
5084 | ||
5085 | out: | |
5086 | return ret; | |
5087 | } |