blob: 444ad998f72e77ab663730c6f59e43a7b9ac1e57 [file] [log] [blame]
Alex Tomasc9de5602008-01-29 00:19:52 -05001/*
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
Mingming Cao8f6e39a2008-04-29 22:01:31 -040024#include "mballoc.h"
Alex Tomasc9de5602008-01-29 00:19:52 -050025/*
26 * MUSTDO:
27 * - test ext4_ext_search_left() and ext4_ext_search_right()
28 * - search for metadata in few groups
29 *
30 * TODO v4:
31 * - normalization should take into account whether file is still open
32 * - discard preallocations if no free space left (policy?)
33 * - don't normalize tails
34 * - quota
35 * - reservation for superuser
36 *
37 * TODO v3:
38 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
39 * - track min/max extents in each group for better group selection
40 * - mb_mark_used() may allocate chunk right after splitting buddy
41 * - tree of groups sorted by number of free blocks
42 * - error handling
43 */
44
45/*
46 * The allocation request involve request for multiple number of blocks
47 * near to the goal(block) value specified.
48 *
49 * During initialization phase of the allocator we decide to use the group
50 * preallocation or inode preallocation depending on the size file. The
51 * size of the file could be the resulting file size we would have after
52 * allocation or the current file size which ever is larger. If the size is
53 * less that sbi->s_mb_stream_request we select the group
54 * preallocation. The default value of s_mb_stream_request is 16
55 * blocks. This can also be tuned via
56 * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
57 * of number of blocks.
58 *
59 * The main motivation for having small file use group preallocation is to
60 * ensure that we have small file closer in the disk.
61 *
62 * First stage the allocator looks at the inode prealloc list
63 * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
64 * this particular inode. The inode prealloc space is represented as:
65 *
66 * pa_lstart -> the logical start block for this prealloc space
67 * pa_pstart -> the physical start block for this prealloc space
68 * pa_len -> lenght for this prealloc space
69 * pa_free -> free space available in this prealloc space
70 *
71 * The inode preallocation space is used looking at the _logical_ start
72 * block. If only the logical file block falls within the range of prealloc
73 * space we will consume the particular prealloc space. This make sure that
74 * that the we have contiguous physical blocks representing the file blocks
75 *
76 * The important thing to be noted in case of inode prealloc space is that
77 * we don't modify the values associated to inode prealloc space except
78 * pa_free.
79 *
80 * If we are not able to find blocks in the inode prealloc space and if we
81 * have the group allocation flag set then we look at the locality group
82 * prealloc space. These are per CPU prealloc list repreasented as
83 *
84 * ext4_sb_info.s_locality_groups[smp_processor_id()]
85 *
86 * The reason for having a per cpu locality group is to reduce the contention
87 * between CPUs. It is possible to get scheduled at this point.
88 *
89 * The locality group prealloc space is used looking at whether we have
90 * enough free space (pa_free) withing the prealloc space.
91 *
92 * If we can't allocate blocks via inode prealloc or/and locality group
93 * prealloc then we look at the buddy cache. The buddy cache is represented
94 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
95 * mapped to the buddy and bitmap information regarding different
96 * groups. The buddy information is attached to buddy cache inode so that
97 * we can access them through the page cache. The information regarding
98 * each group is loaded via ext4_mb_load_buddy. The information involve
99 * block bitmap and buddy information. The information are stored in the
100 * inode as:
101 *
102 * { page }
103 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
104 *
105 *
106 * one block each for bitmap and buddy information. So for each group we
107 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
108 * blocksize) blocks. So it can have information regarding groups_per_page
109 * which is blocks_per_page/2
110 *
111 * The buddy cache inode is not stored on disk. The inode is thrown
112 * away when the filesystem is unmounted.
113 *
114 * We look for count number of blocks in the buddy cache. If we were able
115 * to locate that many free blocks we return with additional information
116 * regarding rest of the contiguous physical block available
117 *
118 * Before allocating blocks via buddy cache we normalize the request
119 * blocks. This ensure we ask for more blocks that we needed. The extra
120 * blocks that we get after allocation is added to the respective prealloc
121 * list. In case of inode preallocation we follow a list of heuristics
122 * based on file size. This can be found in ext4_mb_normalize_request. If
123 * we are doing a group prealloc we try to normalize the request to
124 * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
125 * 512 blocks. This can be tuned via
126 * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
127 * terms of number of blocks. If we have mounted the file system with -O
128 * stripe=<value> option the group prealloc request is normalized to the
129 * stripe value (sbi->s_stripe)
130 *
131 * The regular allocator(using the buddy cache) support few tunables.
132 *
133 * /proc/fs/ext4/<partition>/min_to_scan
134 * /proc/fs/ext4/<partition>/max_to_scan
135 * /proc/fs/ext4/<partition>/order2_req
136 *
137 * The regular allocator use buddy scan only if the request len is power of
138 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
139 * value of s_mb_order2_reqs can be tuned via
140 * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
141 * stripe size (sbi->s_stripe), we try to search for contigous block in
142 * stripe size. This should result in better allocation on RAID setup. If
143 * not we search in the specific group using bitmap for best extents. The
144 * tunable min_to_scan and max_to_scan controll the behaviour here.
145 * min_to_scan indicate how long the mballoc __must__ look for a best
146 * extent and max_to_scanindicate how long the mballoc __can__ look for a
147 * best extent in the found extents. Searching for the blocks starts with
148 * the group specified as the goal value in allocation context via
149 * ac_g_ex. Each group is first checked based on the criteria whether it
150 * can used for allocation. ext4_mb_good_group explains how the groups are
151 * checked.
152 *
153 * Both the prealloc space are getting populated as above. So for the first
154 * request we will hit the buddy cache which will result in this prealloc
155 * space getting filled. The prealloc space is then later used for the
156 * subsequent request.
157 */
158
159/*
160 * mballoc operates on the following data:
161 * - on-disk bitmap
162 * - in-core buddy (actually includes buddy and bitmap)
163 * - preallocation descriptors (PAs)
164 *
165 * there are two types of preallocations:
166 * - inode
167 * assiged to specific inode and can be used for this inode only.
168 * it describes part of inode's space preallocated to specific
169 * physical blocks. any block from that preallocated can be used
170 * independent. the descriptor just tracks number of blocks left
171 * unused. so, before taking some block from descriptor, one must
172 * make sure corresponded logical block isn't allocated yet. this
173 * also means that freeing any block within descriptor's range
174 * must discard all preallocated blocks.
175 * - locality group
176 * assigned to specific locality group which does not translate to
177 * permanent set of inodes: inode can join and leave group. space
178 * from this type of preallocation can be used for any inode. thus
179 * it's consumed from the beginning to the end.
180 *
181 * relation between them can be expressed as:
182 * in-core buddy = on-disk bitmap + preallocation descriptors
183 *
184 * this mean blocks mballoc considers used are:
185 * - allocated blocks (persistent)
186 * - preallocated blocks (non-persistent)
187 *
188 * consistency in mballoc world means that at any time a block is either
189 * free or used in ALL structures. notice: "any time" should not be read
190 * literally -- time is discrete and delimited by locks.
191 *
192 * to keep it simple, we don't use block numbers, instead we count number of
193 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
194 *
195 * all operations can be expressed as:
196 * - init buddy: buddy = on-disk + PAs
197 * - new PA: buddy += N; PA = N
198 * - use inode PA: on-disk += N; PA -= N
199 * - discard inode PA buddy -= on-disk - PA; PA = 0
200 * - use locality group PA on-disk += N; PA -= N
201 * - discard locality group PA buddy -= PA; PA = 0
202 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
203 * is used in real operation because we can't know actual used
204 * bits from PA, only from on-disk bitmap
205 *
206 * if we follow this strict logic, then all operations above should be atomic.
207 * given some of them can block, we'd have to use something like semaphores
208 * killing performance on high-end SMP hardware. let's try to relax it using
209 * the following knowledge:
210 * 1) if buddy is referenced, it's already initialized
211 * 2) while block is used in buddy and the buddy is referenced,
212 * nobody can re-allocate that block
213 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
214 * bit set and PA claims same block, it's OK. IOW, one can set bit in
215 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
216 * block
217 *
218 * so, now we're building a concurrency table:
219 * - init buddy vs.
220 * - new PA
221 * blocks for PA are allocated in the buddy, buddy must be referenced
222 * until PA is linked to allocation group to avoid concurrent buddy init
223 * - use inode PA
224 * we need to make sure that either on-disk bitmap or PA has uptodate data
225 * given (3) we care that PA-=N operation doesn't interfere with init
226 * - discard inode PA
227 * the simplest way would be to have buddy initialized by the discard
228 * - use locality group PA
229 * again PA-=N must be serialized with init
230 * - discard locality group PA
231 * the simplest way would be to have buddy initialized by the discard
232 * - new PA vs.
233 * - use inode PA
234 * i_data_sem serializes them
235 * - discard inode PA
236 * discard process must wait until PA isn't used by another process
237 * - use locality group PA
238 * some mutex should serialize them
239 * - discard locality group PA
240 * discard process must wait until PA isn't used by another process
241 * - use inode PA
242 * - use inode PA
243 * i_data_sem or another mutex should serializes them
244 * - discard inode PA
245 * discard process must wait until PA isn't used by another process
246 * - use locality group PA
247 * nothing wrong here -- they're different PAs covering different blocks
248 * - discard locality group PA
249 * discard process must wait until PA isn't used by another process
250 *
251 * now we're ready to make few consequences:
252 * - PA is referenced and while it is no discard is possible
253 * - PA is referenced until block isn't marked in on-disk bitmap
254 * - PA changes only after on-disk bitmap
255 * - discard must not compete with init. either init is done before
256 * any discard or they're serialized somehow
257 * - buddy init as sum of on-disk bitmap and PAs is done atomically
258 *
259 * a special case when we've used PA to emptiness. no need to modify buddy
260 * in this case, but we should care about concurrent init
261 *
262 */
263
264 /*
265 * Logic in few words:
266 *
267 * - allocation:
268 * load group
269 * find blocks
270 * mark bits in on-disk bitmap
271 * release group
272 *
273 * - use preallocation:
274 * find proper PA (per-inode or group)
275 * load group
276 * mark bits in on-disk bitmap
277 * release group
278 * release PA
279 *
280 * - free:
281 * load group
282 * mark bits in on-disk bitmap
283 * release group
284 *
285 * - discard preallocations in group:
286 * mark PAs deleted
287 * move them onto local list
288 * load on-disk bitmap
289 * load group
290 * remove PA from object (inode or locality group)
291 * mark free blocks in-core
292 *
293 * - discard inode's preallocations:
294 */
295
296/*
297 * Locking rules
298 *
299 * Locks:
300 * - bitlock on a group (group)
301 * - object (inode/locality) (object)
302 * - per-pa lock (pa)
303 *
304 * Paths:
305 * - new pa
306 * object
307 * group
308 *
309 * - find and use pa:
310 * pa
311 *
312 * - release consumed pa:
313 * pa
314 * group
315 * object
316 *
317 * - generate in-core bitmap:
318 * group
319 * pa
320 *
321 * - discard all for given object (inode, locality group):
322 * object
323 * pa
324 * group
325 *
326 * - discard all for given group:
327 * group
328 * pa
329 * group
330 * object
331 *
332 */
333
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500334static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
335{
Alex Tomasc9de5602008-01-29 00:19:52 -0500336#if BITS_PER_LONG == 64
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500337 *bit += ((unsigned long) addr & 7UL) << 3;
338 addr = (void *) ((unsigned long) addr & ~7UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500339#elif BITS_PER_LONG == 32
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500340 *bit += ((unsigned long) addr & 3UL) << 3;
341 addr = (void *) ((unsigned long) addr & ~3UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500342#else
343#error "how many bits you are?!"
344#endif
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500345 return addr;
346}
Alex Tomasc9de5602008-01-29 00:19:52 -0500347
348static inline int mb_test_bit(int bit, void *addr)
349{
350 /*
351 * ext4_test_bit on architecture like powerpc
352 * needs unsigned long aligned address
353 */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500354 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500355 return ext4_test_bit(bit, addr);
356}
357
358static inline void mb_set_bit(int bit, void *addr)
359{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500360 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500361 ext4_set_bit(bit, addr);
362}
363
364static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
365{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500366 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500367 ext4_set_bit_atomic(lock, bit, addr);
368}
369
370static inline void mb_clear_bit(int bit, void *addr)
371{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500372 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500373 ext4_clear_bit(bit, addr);
374}
375
376static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
377{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500378 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500379 ext4_clear_bit_atomic(lock, bit, addr);
380}
381
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500382static inline int mb_find_next_zero_bit(void *addr, int max, int start)
383{
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400384 int fix = 0, ret, tmpmax;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500385 addr = mb_correct_addr_and_bit(&fix, addr);
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400386 tmpmax = max + fix;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500387 start += fix;
388
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400389 ret = ext4_find_next_zero_bit(addr, tmpmax, start) - fix;
390 if (ret > max)
391 return max;
392 return ret;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500393}
394
395static inline int mb_find_next_bit(void *addr, int max, int start)
396{
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400397 int fix = 0, ret, tmpmax;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500398 addr = mb_correct_addr_and_bit(&fix, addr);
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400399 tmpmax = max + fix;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500400 start += fix;
401
Aneesh Kumar K.Ve7dfb242008-07-11 19:27:31 -0400402 ret = ext4_find_next_bit(addr, tmpmax, start) - fix;
403 if (ret > max)
404 return max;
405 return ret;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500406}
407
Alex Tomasc9de5602008-01-29 00:19:52 -0500408static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
409{
410 char *bb;
411
Alex Tomasc9de5602008-01-29 00:19:52 -0500412 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
413 BUG_ON(max == NULL);
414
415 if (order > e4b->bd_blkbits + 1) {
416 *max = 0;
417 return NULL;
418 }
419
420 /* at order 0 we see each particular block */
421 *max = 1 << (e4b->bd_blkbits + 3);
422 if (order == 0)
423 return EXT4_MB_BITMAP(e4b);
424
425 bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
426 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
427
428 return bb;
429}
430
431#ifdef DOUBLE_CHECK
432static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
433 int first, int count)
434{
435 int i;
436 struct super_block *sb = e4b->bd_sb;
437
438 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
439 return;
440 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
441 for (i = 0; i < count; i++) {
442 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
443 ext4_fsblk_t blocknr;
444 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
445 blocknr += first + i;
446 blocknr +=
447 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
448
Harvey Harrison46e665e2008-04-17 10:38:59 -0400449 ext4_error(sb, __func__, "double-free of inode"
Alex Tomasc9de5602008-01-29 00:19:52 -0500450 " %lu's block %llu(bit %u in group %lu)\n",
451 inode ? inode->i_ino : 0, blocknr,
452 first + i, e4b->bd_group);
453 }
454 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
455 }
456}
457
458static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
459{
460 int i;
461
462 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
463 return;
464 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
465 for (i = 0; i < count; i++) {
466 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
467 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
468 }
469}
470
471static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
472{
473 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
474 unsigned char *b1, *b2;
475 int i;
476 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
477 b2 = (unsigned char *) bitmap;
478 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
479 if (b1[i] != b2[i]) {
Theodore Ts'o4776004f2008-09-08 23:00:52 -0400480 printk(KERN_ERR "corruption in group %lu "
481 "at byte %u(%u): %x in copy != %x "
482 "on disk/prealloc\n",
483 e4b->bd_group, i, i * 8, b1[i], b2[i]);
Alex Tomasc9de5602008-01-29 00:19:52 -0500484 BUG();
485 }
486 }
487 }
488}
489
490#else
491static inline void mb_free_blocks_double(struct inode *inode,
492 struct ext4_buddy *e4b, int first, int count)
493{
494 return;
495}
496static inline void mb_mark_used_double(struct ext4_buddy *e4b,
497 int first, int count)
498{
499 return;
500}
501static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
502{
503 return;
504}
505#endif
506
507#ifdef AGGRESSIVE_CHECK
508
509#define MB_CHECK_ASSERT(assert) \
510do { \
511 if (!(assert)) { \
512 printk(KERN_EMERG \
513 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
514 function, file, line, # assert); \
515 BUG(); \
516 } \
517} while (0)
518
519static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
520 const char *function, int line)
521{
522 struct super_block *sb = e4b->bd_sb;
523 int order = e4b->bd_blkbits + 1;
524 int max;
525 int max2;
526 int i;
527 int j;
528 int k;
529 int count;
530 struct ext4_group_info *grp;
531 int fragments = 0;
532 int fstart;
533 struct list_head *cur;
534 void *buddy;
535 void *buddy2;
536
Alex Tomasc9de5602008-01-29 00:19:52 -0500537 {
538 static int mb_check_counter;
539 if (mb_check_counter++ % 100 != 0)
540 return 0;
541 }
542
543 while (order > 1) {
544 buddy = mb_find_buddy(e4b, order, &max);
545 MB_CHECK_ASSERT(buddy);
546 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
547 MB_CHECK_ASSERT(buddy2);
548 MB_CHECK_ASSERT(buddy != buddy2);
549 MB_CHECK_ASSERT(max * 2 == max2);
550
551 count = 0;
552 for (i = 0; i < max; i++) {
553
554 if (mb_test_bit(i, buddy)) {
555 /* only single bit in buddy2 may be 1 */
556 if (!mb_test_bit(i << 1, buddy2)) {
557 MB_CHECK_ASSERT(
558 mb_test_bit((i<<1)+1, buddy2));
559 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
560 MB_CHECK_ASSERT(
561 mb_test_bit(i << 1, buddy2));
562 }
563 continue;
564 }
565
566 /* both bits in buddy2 must be 0 */
567 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
568 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
569
570 for (j = 0; j < (1 << order); j++) {
571 k = (i * (1 << order)) + j;
572 MB_CHECK_ASSERT(
573 !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
574 }
575 count++;
576 }
577 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
578 order--;
579 }
580
581 fstart = -1;
582 buddy = mb_find_buddy(e4b, 0, &max);
583 for (i = 0; i < max; i++) {
584 if (!mb_test_bit(i, buddy)) {
585 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
586 if (fstart == -1) {
587 fragments++;
588 fstart = i;
589 }
590 continue;
591 }
592 fstart = -1;
593 /* check used bits only */
594 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
595 buddy2 = mb_find_buddy(e4b, j, &max2);
596 k = i >> j;
597 MB_CHECK_ASSERT(k < max2);
598 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
599 }
600 }
601 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
602 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
603
604 grp = ext4_get_group_info(sb, e4b->bd_group);
605 buddy = mb_find_buddy(e4b, 0, &max);
606 list_for_each(cur, &grp->bb_prealloc_list) {
607 ext4_group_t groupnr;
608 struct ext4_prealloc_space *pa;
Solofo Ramangalahy60bd63d2008-04-29 21:59:59 -0400609 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
610 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &groupnr, &k);
Alex Tomasc9de5602008-01-29 00:19:52 -0500611 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
Solofo Ramangalahy60bd63d2008-04-29 21:59:59 -0400612 for (i = 0; i < pa->pa_len; i++)
Alex Tomasc9de5602008-01-29 00:19:52 -0500613 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
614 }
615 return 0;
616}
617#undef MB_CHECK_ASSERT
618#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
Harvey Harrison46e665e2008-04-17 10:38:59 -0400619 __FILE__, __func__, __LINE__)
Alex Tomasc9de5602008-01-29 00:19:52 -0500620#else
621#define mb_check_buddy(e4b)
622#endif
623
624/* FIXME!! need more doc */
625static void ext4_mb_mark_free_simple(struct super_block *sb,
626 void *buddy, unsigned first, int len,
627 struct ext4_group_info *grp)
628{
629 struct ext4_sb_info *sbi = EXT4_SB(sb);
630 unsigned short min;
631 unsigned short max;
632 unsigned short chunk;
633 unsigned short border;
634
Valerie Clementb73fce62008-02-15 13:48:51 -0500635 BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
Alex Tomasc9de5602008-01-29 00:19:52 -0500636
637 border = 2 << sb->s_blocksize_bits;
638
639 while (len > 0) {
640 /* find how many blocks can be covered since this position */
641 max = ffs(first | border) - 1;
642
643 /* find how many blocks of power 2 we need to mark */
644 min = fls(len) - 1;
645
646 if (max < min)
647 min = max;
648 chunk = 1 << min;
649
650 /* mark multiblock chunks only */
651 grp->bb_counters[min]++;
652 if (min > 0)
653 mb_clear_bit(first >> min,
654 buddy + sbi->s_mb_offsets[min]);
655
656 len -= chunk;
657 first += chunk;
658 }
659}
660
661static void ext4_mb_generate_buddy(struct super_block *sb,
662 void *buddy, void *bitmap, ext4_group_t group)
663{
664 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
665 unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
666 unsigned short i = 0;
667 unsigned short first;
668 unsigned short len;
669 unsigned free = 0;
670 unsigned fragments = 0;
671 unsigned long long period = get_cycles();
672
673 /* initialize buddy from bitmap which is aggregation
674 * of on-disk bitmap and preallocations */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500675 i = mb_find_next_zero_bit(bitmap, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -0500676 grp->bb_first_free = i;
677 while (i < max) {
678 fragments++;
679 first = i;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500680 i = mb_find_next_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500681 len = i - first;
682 free += len;
683 if (len > 1)
684 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
685 else
686 grp->bb_counters[0]++;
687 if (i < max)
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500688 i = mb_find_next_zero_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500689 }
690 grp->bb_fragments = fragments;
691
692 if (free != grp->bb_free) {
Harvey Harrison46e665e2008-04-17 10:38:59 -0400693 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -0500694 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
695 group, free, grp->bb_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -0500696 /*
697 * If we intent to continue, we consider group descritor
698 * corrupt and update bb_free using bitmap value
699 */
Alex Tomasc9de5602008-01-29 00:19:52 -0500700 grp->bb_free = free;
701 }
702
703 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
704
705 period = get_cycles() - period;
706 spin_lock(&EXT4_SB(sb)->s_bal_lock);
707 EXT4_SB(sb)->s_mb_buddies_generated++;
708 EXT4_SB(sb)->s_mb_generation_time += period;
709 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
710}
711
712/* The buddy information is attached the buddy cache inode
713 * for convenience. The information regarding each group
714 * is loaded via ext4_mb_load_buddy. The information involve
715 * block bitmap and buddy information. The information are
716 * stored in the inode as
717 *
718 * { page }
719 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
720 *
721 *
722 * one block each for bitmap and buddy information.
723 * So for each group we take up 2 blocks. A page can
724 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
725 * So it can have information regarding groups_per_page which
726 * is blocks_per_page/2
727 */
728
729static int ext4_mb_init_cache(struct page *page, char *incore)
730{
731 int blocksize;
732 int blocks_per_page;
733 int groups_per_page;
734 int err = 0;
735 int i;
736 ext4_group_t first_group;
737 int first_block;
738 struct super_block *sb;
739 struct buffer_head *bhs;
740 struct buffer_head **bh;
741 struct inode *inode;
742 char *data;
743 char *bitmap;
744
745 mb_debug("init page %lu\n", page->index);
746
747 inode = page->mapping->host;
748 sb = inode->i_sb;
749 blocksize = 1 << inode->i_blkbits;
750 blocks_per_page = PAGE_CACHE_SIZE / blocksize;
751
752 groups_per_page = blocks_per_page >> 1;
753 if (groups_per_page == 0)
754 groups_per_page = 1;
755
756 /* allocate buffer_heads to read bitmaps */
757 if (groups_per_page > 1) {
758 err = -ENOMEM;
759 i = sizeof(struct buffer_head *) * groups_per_page;
760 bh = kzalloc(i, GFP_NOFS);
761 if (bh == NULL)
762 goto out;
763 } else
764 bh = &bhs;
765
766 first_group = page->index * blocks_per_page / 2;
767
768 /* read all groups the page covers into the cache */
769 for (i = 0; i < groups_per_page; i++) {
770 struct ext4_group_desc *desc;
771
772 if (first_group + i >= EXT4_SB(sb)->s_groups_count)
773 break;
774
775 err = -EIO;
776 desc = ext4_get_group_desc(sb, first_group + i, NULL);
777 if (desc == NULL)
778 goto out;
779
780 err = -ENOMEM;
781 bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
782 if (bh[i] == NULL)
783 goto out;
784
Frederic Bohec806e682008-10-10 08:09:18 -0400785 if (buffer_uptodate(bh[i]) &&
786 !(desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)))
Alex Tomasc9de5602008-01-29 00:19:52 -0500787 continue;
788
Frederic Bohec806e682008-10-10 08:09:18 -0400789 lock_buffer(bh[i]);
Eric Sandeenb5f10ee2008-08-02 21:21:08 -0400790 spin_lock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
Alex Tomasc9de5602008-01-29 00:19:52 -0500791 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
792 ext4_init_block_bitmap(sb, bh[i],
793 first_group + i, desc);
794 set_buffer_uptodate(bh[i]);
795 unlock_buffer(bh[i]);
Eric Sandeenb5f10ee2008-08-02 21:21:08 -0400796 spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
Alex Tomasc9de5602008-01-29 00:19:52 -0500797 continue;
798 }
Eric Sandeenb5f10ee2008-08-02 21:21:08 -0400799 spin_unlock(sb_bgl_lock(EXT4_SB(sb), first_group + i));
Alex Tomasc9de5602008-01-29 00:19:52 -0500800 get_bh(bh[i]);
801 bh[i]->b_end_io = end_buffer_read_sync;
802 submit_bh(READ, bh[i]);
803 mb_debug("read bitmap for group %lu\n", first_group + i);
804 }
805
806 /* wait for I/O completion */
807 for (i = 0; i < groups_per_page && bh[i]; i++)
808 wait_on_buffer(bh[i]);
809
810 err = -EIO;
811 for (i = 0; i < groups_per_page && bh[i]; i++)
812 if (!buffer_uptodate(bh[i]))
813 goto out;
814
Mingming Cao31b481d2008-07-11 19:27:31 -0400815 err = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -0500816 first_block = page->index * blocks_per_page;
817 for (i = 0; i < blocks_per_page; i++) {
818 int group;
819 struct ext4_group_info *grinfo;
820
821 group = (first_block + i) >> 1;
822 if (group >= EXT4_SB(sb)->s_groups_count)
823 break;
824
825 /*
826 * data carry information regarding this
827 * particular group in the format specified
828 * above
829 *
830 */
831 data = page_address(page) + (i * blocksize);
832 bitmap = bh[group - first_group]->b_data;
833
834 /*
835 * We place the buddy block and bitmap block
836 * close together
837 */
838 if ((first_block + i) & 1) {
839 /* this is block of buddy */
840 BUG_ON(incore == NULL);
841 mb_debug("put buddy for group %u in page %lu/%x\n",
842 group, page->index, i * blocksize);
843 memset(data, 0xff, blocksize);
844 grinfo = ext4_get_group_info(sb, group);
845 grinfo->bb_fragments = 0;
846 memset(grinfo->bb_counters, 0,
847 sizeof(unsigned short)*(sb->s_blocksize_bits+2));
848 /*
849 * incore got set to the group block bitmap below
850 */
851 ext4_mb_generate_buddy(sb, data, incore, group);
852 incore = NULL;
853 } else {
854 /* this is block of bitmap */
855 BUG_ON(incore != NULL);
856 mb_debug("put bitmap for group %u in page %lu/%x\n",
857 group, page->index, i * blocksize);
858
859 /* see comments in ext4_mb_put_pa() */
860 ext4_lock_group(sb, group);
861 memcpy(data, bitmap, blocksize);
862
863 /* mark all preallocated blks used in in-core bitmap */
864 ext4_mb_generate_from_pa(sb, data, group);
865 ext4_unlock_group(sb, group);
866
867 /* set incore so that the buddy information can be
868 * generated using this
869 */
870 incore = data;
871 }
872 }
873 SetPageUptodate(page);
874
875out:
876 if (bh) {
877 for (i = 0; i < groups_per_page && bh[i]; i++)
878 brelse(bh[i]);
879 if (bh != &bhs)
880 kfree(bh);
881 }
882 return err;
883}
884
Eric Sandeen4ddfef72008-04-29 08:11:12 -0400885static noinline_for_stack int
886ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
887 struct ext4_buddy *e4b)
Alex Tomasc9de5602008-01-29 00:19:52 -0500888{
889 struct ext4_sb_info *sbi = EXT4_SB(sb);
890 struct inode *inode = sbi->s_buddy_cache;
891 int blocks_per_page;
892 int block;
893 int pnum;
894 int poff;
895 struct page *page;
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400896 int ret;
Alex Tomasc9de5602008-01-29 00:19:52 -0500897
898 mb_debug("load group %lu\n", group);
899
900 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
901
902 e4b->bd_blkbits = sb->s_blocksize_bits;
903 e4b->bd_info = ext4_get_group_info(sb, group);
904 e4b->bd_sb = sb;
905 e4b->bd_group = group;
906 e4b->bd_buddy_page = NULL;
907 e4b->bd_bitmap_page = NULL;
908
909 /*
910 * the buddy cache inode stores the block bitmap
911 * and buddy information in consecutive blocks.
912 * So for each group we need two blocks.
913 */
914 block = group * 2;
915 pnum = block / blocks_per_page;
916 poff = block % blocks_per_page;
917
918 /* we could use find_or_create_page(), but it locks page
919 * what we'd like to avoid in fast path ... */
920 page = find_get_page(inode->i_mapping, pnum);
921 if (page == NULL || !PageUptodate(page)) {
922 if (page)
923 page_cache_release(page);
924 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
925 if (page) {
926 BUG_ON(page->mapping != inode->i_mapping);
927 if (!PageUptodate(page)) {
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400928 ret = ext4_mb_init_cache(page, NULL);
929 if (ret) {
930 unlock_page(page);
931 goto err;
932 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500933 mb_cmp_bitmaps(e4b, page_address(page) +
934 (poff * sb->s_blocksize));
935 }
936 unlock_page(page);
937 }
938 }
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400939 if (page == NULL || !PageUptodate(page)) {
940 ret = -EIO;
Alex Tomasc9de5602008-01-29 00:19:52 -0500941 goto err;
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400942 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500943 e4b->bd_bitmap_page = page;
944 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
945 mark_page_accessed(page);
946
947 block++;
948 pnum = block / blocks_per_page;
949 poff = block % blocks_per_page;
950
951 page = find_get_page(inode->i_mapping, pnum);
952 if (page == NULL || !PageUptodate(page)) {
953 if (page)
954 page_cache_release(page);
955 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
956 if (page) {
957 BUG_ON(page->mapping != inode->i_mapping);
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400958 if (!PageUptodate(page)) {
959 ret = ext4_mb_init_cache(page, e4b->bd_bitmap);
960 if (ret) {
961 unlock_page(page);
962 goto err;
963 }
964 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500965 unlock_page(page);
966 }
967 }
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400968 if (page == NULL || !PageUptodate(page)) {
969 ret = -EIO;
Alex Tomasc9de5602008-01-29 00:19:52 -0500970 goto err;
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400971 }
Alex Tomasc9de5602008-01-29 00:19:52 -0500972 e4b->bd_buddy_page = page;
973 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
974 mark_page_accessed(page);
975
976 BUG_ON(e4b->bd_bitmap_page == NULL);
977 BUG_ON(e4b->bd_buddy_page == NULL);
978
979 return 0;
980
981err:
982 if (e4b->bd_bitmap_page)
983 page_cache_release(e4b->bd_bitmap_page);
984 if (e4b->bd_buddy_page)
985 page_cache_release(e4b->bd_buddy_page);
986 e4b->bd_buddy = NULL;
987 e4b->bd_bitmap = NULL;
Shen Fengfdf6c7a2008-07-11 19:27:31 -0400988 return ret;
Alex Tomasc9de5602008-01-29 00:19:52 -0500989}
990
991static void ext4_mb_release_desc(struct ext4_buddy *e4b)
992{
993 if (e4b->bd_bitmap_page)
994 page_cache_release(e4b->bd_bitmap_page);
995 if (e4b->bd_buddy_page)
996 page_cache_release(e4b->bd_buddy_page);
997}
998
999
1000static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1001{
1002 int order = 1;
1003 void *bb;
1004
1005 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
1006 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1007
1008 bb = EXT4_MB_BUDDY(e4b);
1009 while (order <= e4b->bd_blkbits + 1) {
1010 block = block >> 1;
1011 if (!mb_test_bit(block, bb)) {
1012 /* this block is part of buddy of order 'order' */
1013 return order;
1014 }
1015 bb += 1 << (e4b->bd_blkbits - order);
1016 order++;
1017 }
1018 return 0;
1019}
1020
1021static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
1022{
1023 __u32 *addr;
1024
1025 len = cur + len;
1026 while (cur < len) {
1027 if ((cur & 31) == 0 && (len - cur) >= 32) {
1028 /* fast path: clear whole word at once */
1029 addr = bm + (cur >> 3);
1030 *addr = 0;
1031 cur += 32;
1032 continue;
1033 }
1034 mb_clear_bit_atomic(lock, cur, bm);
1035 cur++;
1036 }
1037}
1038
1039static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
1040{
1041 __u32 *addr;
1042
1043 len = cur + len;
1044 while (cur < len) {
1045 if ((cur & 31) == 0 && (len - cur) >= 32) {
1046 /* fast path: set whole word at once */
1047 addr = bm + (cur >> 3);
1048 *addr = 0xffffffff;
1049 cur += 32;
1050 continue;
1051 }
1052 mb_set_bit_atomic(lock, cur, bm);
1053 cur++;
1054 }
1055}
1056
Shen Feng7e5a8cd2008-07-13 21:03:31 -04001057static void mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
Alex Tomasc9de5602008-01-29 00:19:52 -05001058 int first, int count)
1059{
1060 int block = 0;
1061 int max = 0;
1062 int order;
1063 void *buddy;
1064 void *buddy2;
1065 struct super_block *sb = e4b->bd_sb;
1066
1067 BUG_ON(first + count > (sb->s_blocksize << 3));
1068 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
1069 mb_check_buddy(e4b);
1070 mb_free_blocks_double(inode, e4b, first, count);
1071
1072 e4b->bd_info->bb_free += count;
1073 if (first < e4b->bd_info->bb_first_free)
1074 e4b->bd_info->bb_first_free = first;
1075
1076 /* let's maintain fragments counter */
1077 if (first != 0)
1078 block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
1079 if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
1080 max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
1081 if (block && max)
1082 e4b->bd_info->bb_fragments--;
1083 else if (!block && !max)
1084 e4b->bd_info->bb_fragments++;
1085
1086 /* let's maintain buddy itself */
1087 while (count-- > 0) {
1088 block = first++;
1089 order = 0;
1090
1091 if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
1092 ext4_fsblk_t blocknr;
1093 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
1094 blocknr += block;
1095 blocknr +=
1096 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
Shen Feng7e5a8cd2008-07-13 21:03:31 -04001097 ext4_unlock_group(sb, e4b->bd_group);
Harvey Harrison46e665e2008-04-17 10:38:59 -04001098 ext4_error(sb, __func__, "double-free of inode"
Alex Tomasc9de5602008-01-29 00:19:52 -05001099 " %lu's block %llu(bit %u in group %lu)\n",
1100 inode ? inode->i_ino : 0, blocknr, block,
1101 e4b->bd_group);
Shen Feng7e5a8cd2008-07-13 21:03:31 -04001102 ext4_lock_group(sb, e4b->bd_group);
Alex Tomasc9de5602008-01-29 00:19:52 -05001103 }
1104 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
1105 e4b->bd_info->bb_counters[order]++;
1106
1107 /* start of the buddy */
1108 buddy = mb_find_buddy(e4b, order, &max);
1109
1110 do {
1111 block &= ~1UL;
1112 if (mb_test_bit(block, buddy) ||
1113 mb_test_bit(block + 1, buddy))
1114 break;
1115
1116 /* both the buddies are free, try to coalesce them */
1117 buddy2 = mb_find_buddy(e4b, order + 1, &max);
1118
1119 if (!buddy2)
1120 break;
1121
1122 if (order > 0) {
1123 /* for special purposes, we don't set
1124 * free bits in bitmap */
1125 mb_set_bit(block, buddy);
1126 mb_set_bit(block + 1, buddy);
1127 }
1128 e4b->bd_info->bb_counters[order]--;
1129 e4b->bd_info->bb_counters[order]--;
1130
1131 block = block >> 1;
1132 order++;
1133 e4b->bd_info->bb_counters[order]++;
1134
1135 mb_clear_bit(block, buddy2);
1136 buddy = buddy2;
1137 } while (1);
1138 }
1139 mb_check_buddy(e4b);
Alex Tomasc9de5602008-01-29 00:19:52 -05001140}
1141
1142static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
1143 int needed, struct ext4_free_extent *ex)
1144{
1145 int next = block;
1146 int max;
1147 int ord;
1148 void *buddy;
1149
1150 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1151 BUG_ON(ex == NULL);
1152
1153 buddy = mb_find_buddy(e4b, order, &max);
1154 BUG_ON(buddy == NULL);
1155 BUG_ON(block >= max);
1156 if (mb_test_bit(block, buddy)) {
1157 ex->fe_len = 0;
1158 ex->fe_start = 0;
1159 ex->fe_group = 0;
1160 return 0;
1161 }
1162
1163 /* FIXME dorp order completely ? */
1164 if (likely(order == 0)) {
1165 /* find actual order */
1166 order = mb_find_order_for_block(e4b, block);
1167 block = block >> order;
1168 }
1169
1170 ex->fe_len = 1 << order;
1171 ex->fe_start = block << order;
1172 ex->fe_group = e4b->bd_group;
1173
1174 /* calc difference from given start */
1175 next = next - ex->fe_start;
1176 ex->fe_len -= next;
1177 ex->fe_start += next;
1178
1179 while (needed > ex->fe_len &&
1180 (buddy = mb_find_buddy(e4b, order, &max))) {
1181
1182 if (block + 1 >= max)
1183 break;
1184
1185 next = (block + 1) * (1 << order);
1186 if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
1187 break;
1188
1189 ord = mb_find_order_for_block(e4b, next);
1190
1191 order = ord;
1192 block = next >> order;
1193 ex->fe_len += 1 << order;
1194 }
1195
1196 BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
1197 return ex->fe_len;
1198}
1199
1200static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1201{
1202 int ord;
1203 int mlen = 0;
1204 int max = 0;
1205 int cur;
1206 int start = ex->fe_start;
1207 int len = ex->fe_len;
1208 unsigned ret = 0;
1209 int len0 = len;
1210 void *buddy;
1211
1212 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1213 BUG_ON(e4b->bd_group != ex->fe_group);
1214 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1215 mb_check_buddy(e4b);
1216 mb_mark_used_double(e4b, start, len);
1217
1218 e4b->bd_info->bb_free -= len;
1219 if (e4b->bd_info->bb_first_free == start)
1220 e4b->bd_info->bb_first_free += len;
1221
1222 /* let's maintain fragments counter */
1223 if (start != 0)
1224 mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
1225 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1226 max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
1227 if (mlen && max)
1228 e4b->bd_info->bb_fragments++;
1229 else if (!mlen && !max)
1230 e4b->bd_info->bb_fragments--;
1231
1232 /* let's maintain buddy itself */
1233 while (len) {
1234 ord = mb_find_order_for_block(e4b, start);
1235
1236 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1237 /* the whole chunk may be allocated at once! */
1238 mlen = 1 << ord;
1239 buddy = mb_find_buddy(e4b, ord, &max);
1240 BUG_ON((start >> ord) >= max);
1241 mb_set_bit(start >> ord, buddy);
1242 e4b->bd_info->bb_counters[ord]--;
1243 start += mlen;
1244 len -= mlen;
1245 BUG_ON(len < 0);
1246 continue;
1247 }
1248
1249 /* store for history */
1250 if (ret == 0)
1251 ret = len | (ord << 16);
1252
1253 /* we have to split large buddy */
1254 BUG_ON(ord <= 0);
1255 buddy = mb_find_buddy(e4b, ord, &max);
1256 mb_set_bit(start >> ord, buddy);
1257 e4b->bd_info->bb_counters[ord]--;
1258
1259 ord--;
1260 cur = (start >> ord) & ~1U;
1261 buddy = mb_find_buddy(e4b, ord, &max);
1262 mb_clear_bit(cur, buddy);
1263 mb_clear_bit(cur + 1, buddy);
1264 e4b->bd_info->bb_counters[ord]++;
1265 e4b->bd_info->bb_counters[ord]++;
1266 }
1267
1268 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
1269 EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
1270 mb_check_buddy(e4b);
1271
1272 return ret;
1273}
1274
1275/*
1276 * Must be called under group lock!
1277 */
1278static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1279 struct ext4_buddy *e4b)
1280{
1281 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1282 int ret;
1283
1284 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1285 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1286
1287 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1288 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1289 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1290
1291 /* preallocation can change ac_b_ex, thus we store actually
1292 * allocated blocks for history */
1293 ac->ac_f_ex = ac->ac_b_ex;
1294
1295 ac->ac_status = AC_STATUS_FOUND;
1296 ac->ac_tail = ret & 0xffff;
1297 ac->ac_buddy = ret >> 16;
1298
1299 /* XXXXXXX: SUCH A HORRIBLE **CK */
1300 /*FIXME!! Why ? */
1301 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1302 get_page(ac->ac_bitmap_page);
1303 ac->ac_buddy_page = e4b->bd_buddy_page;
1304 get_page(ac->ac_buddy_page);
1305
1306 /* store last allocated for subsequent stream allocation */
1307 if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
1308 spin_lock(&sbi->s_md_lock);
1309 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1310 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1311 spin_unlock(&sbi->s_md_lock);
1312 }
1313}
1314
1315/*
1316 * regular allocator, for general purposes allocation
1317 */
1318
1319static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1320 struct ext4_buddy *e4b,
1321 int finish_group)
1322{
1323 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1324 struct ext4_free_extent *bex = &ac->ac_b_ex;
1325 struct ext4_free_extent *gex = &ac->ac_g_ex;
1326 struct ext4_free_extent ex;
1327 int max;
1328
1329 /*
1330 * We don't want to scan for a whole year
1331 */
1332 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1333 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1334 ac->ac_status = AC_STATUS_BREAK;
1335 return;
1336 }
1337
1338 /*
1339 * Haven't found good chunk so far, let's continue
1340 */
1341 if (bex->fe_len < gex->fe_len)
1342 return;
1343
1344 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1345 && bex->fe_group == e4b->bd_group) {
1346 /* recheck chunk's availability - we don't know
1347 * when it was found (within this lock-unlock
1348 * period or not) */
1349 max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
1350 if (max >= gex->fe_len) {
1351 ext4_mb_use_best_found(ac, e4b);
1352 return;
1353 }
1354 }
1355}
1356
1357/*
1358 * The routine checks whether found extent is good enough. If it is,
1359 * then the extent gets marked used and flag is set to the context
1360 * to stop scanning. Otherwise, the extent is compared with the
1361 * previous found extent and if new one is better, then it's stored
1362 * in the context. Later, the best found extent will be used, if
1363 * mballoc can't find good enough extent.
1364 *
1365 * FIXME: real allocation policy is to be designed yet!
1366 */
1367static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1368 struct ext4_free_extent *ex,
1369 struct ext4_buddy *e4b)
1370{
1371 struct ext4_free_extent *bex = &ac->ac_b_ex;
1372 struct ext4_free_extent *gex = &ac->ac_g_ex;
1373
1374 BUG_ON(ex->fe_len <= 0);
1375 BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1376 BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1377 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1378
1379 ac->ac_found++;
1380
1381 /*
1382 * The special case - take what you catch first
1383 */
1384 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1385 *bex = *ex;
1386 ext4_mb_use_best_found(ac, e4b);
1387 return;
1388 }
1389
1390 /*
1391 * Let's check whether the chuck is good enough
1392 */
1393 if (ex->fe_len == gex->fe_len) {
1394 *bex = *ex;
1395 ext4_mb_use_best_found(ac, e4b);
1396 return;
1397 }
1398
1399 /*
1400 * If this is first found extent, just store it in the context
1401 */
1402 if (bex->fe_len == 0) {
1403 *bex = *ex;
1404 return;
1405 }
1406
1407 /*
1408 * If new found extent is better, store it in the context
1409 */
1410 if (bex->fe_len < gex->fe_len) {
1411 /* if the request isn't satisfied, any found extent
1412 * larger than previous best one is better */
1413 if (ex->fe_len > bex->fe_len)
1414 *bex = *ex;
1415 } else if (ex->fe_len > gex->fe_len) {
1416 /* if the request is satisfied, then we try to find
1417 * an extent that still satisfy the request, but is
1418 * smaller than previous one */
1419 if (ex->fe_len < bex->fe_len)
1420 *bex = *ex;
1421 }
1422
1423 ext4_mb_check_limits(ac, e4b, 0);
1424}
1425
1426static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1427 struct ext4_buddy *e4b)
1428{
1429 struct ext4_free_extent ex = ac->ac_b_ex;
1430 ext4_group_t group = ex.fe_group;
1431 int max;
1432 int err;
1433
1434 BUG_ON(ex.fe_len <= 0);
1435 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1436 if (err)
1437 return err;
1438
1439 ext4_lock_group(ac->ac_sb, group);
1440 max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
1441
1442 if (max > 0) {
1443 ac->ac_b_ex = ex;
1444 ext4_mb_use_best_found(ac, e4b);
1445 }
1446
1447 ext4_unlock_group(ac->ac_sb, group);
1448 ext4_mb_release_desc(e4b);
1449
1450 return 0;
1451}
1452
1453static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1454 struct ext4_buddy *e4b)
1455{
1456 ext4_group_t group = ac->ac_g_ex.fe_group;
1457 int max;
1458 int err;
1459 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1460 struct ext4_super_block *es = sbi->s_es;
1461 struct ext4_free_extent ex;
1462
1463 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1464 return 0;
1465
1466 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1467 if (err)
1468 return err;
1469
1470 ext4_lock_group(ac->ac_sb, group);
1471 max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
1472 ac->ac_g_ex.fe_len, &ex);
1473
1474 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1475 ext4_fsblk_t start;
1476
1477 start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
1478 ex.fe_start + le32_to_cpu(es->s_first_data_block);
1479 /* use do_div to get remainder (would be 64-bit modulo) */
1480 if (do_div(start, sbi->s_stripe) == 0) {
1481 ac->ac_found++;
1482 ac->ac_b_ex = ex;
1483 ext4_mb_use_best_found(ac, e4b);
1484 }
1485 } else if (max >= ac->ac_g_ex.fe_len) {
1486 BUG_ON(ex.fe_len <= 0);
1487 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1488 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1489 ac->ac_found++;
1490 ac->ac_b_ex = ex;
1491 ext4_mb_use_best_found(ac, e4b);
1492 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1493 /* Sometimes, caller may want to merge even small
1494 * number of blocks to an existing extent */
1495 BUG_ON(ex.fe_len <= 0);
1496 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1497 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1498 ac->ac_found++;
1499 ac->ac_b_ex = ex;
1500 ext4_mb_use_best_found(ac, e4b);
1501 }
1502 ext4_unlock_group(ac->ac_sb, group);
1503 ext4_mb_release_desc(e4b);
1504
1505 return 0;
1506}
1507
1508/*
1509 * The routine scans buddy structures (not bitmap!) from given order
1510 * to max order and tries to find big enough chunk to satisfy the req
1511 */
1512static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1513 struct ext4_buddy *e4b)
1514{
1515 struct super_block *sb = ac->ac_sb;
1516 struct ext4_group_info *grp = e4b->bd_info;
1517 void *buddy;
1518 int i;
1519 int k;
1520 int max;
1521
1522 BUG_ON(ac->ac_2order <= 0);
1523 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1524 if (grp->bb_counters[i] == 0)
1525 continue;
1526
1527 buddy = mb_find_buddy(e4b, i, &max);
1528 BUG_ON(buddy == NULL);
1529
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001530 k = mb_find_next_zero_bit(buddy, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -05001531 BUG_ON(k >= max);
1532
1533 ac->ac_found++;
1534
1535 ac->ac_b_ex.fe_len = 1 << i;
1536 ac->ac_b_ex.fe_start = k << i;
1537 ac->ac_b_ex.fe_group = e4b->bd_group;
1538
1539 ext4_mb_use_best_found(ac, e4b);
1540
1541 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1542
1543 if (EXT4_SB(sb)->s_mb_stats)
1544 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1545
1546 break;
1547 }
1548}
1549
1550/*
1551 * The routine scans the group and measures all found extents.
1552 * In order to optimize scanning, caller must pass number of
1553 * free blocks in the group, so the routine can know upper limit.
1554 */
1555static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1556 struct ext4_buddy *e4b)
1557{
1558 struct super_block *sb = ac->ac_sb;
1559 void *bitmap = EXT4_MB_BITMAP(e4b);
1560 struct ext4_free_extent ex;
1561 int i;
1562 int free;
1563
1564 free = e4b->bd_info->bb_free;
1565 BUG_ON(free <= 0);
1566
1567 i = e4b->bd_info->bb_first_free;
1568
1569 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001570 i = mb_find_next_zero_bit(bitmap,
Alex Tomasc9de5602008-01-29 00:19:52 -05001571 EXT4_BLOCKS_PER_GROUP(sb), i);
1572 if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001573 /*
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001574 * IF we have corrupt bitmap, we won't find any
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001575 * free blocks even though group info says we
1576 * we have free blocks
1577 */
Harvey Harrison46e665e2008-04-17 10:38:59 -04001578 ext4_error(sb, __func__, "%d free blocks as per "
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001579 "group info. But bitmap says 0\n",
1580 free);
Alex Tomasc9de5602008-01-29 00:19:52 -05001581 break;
1582 }
1583
1584 mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
1585 BUG_ON(ex.fe_len <= 0);
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001586 if (free < ex.fe_len) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001587 ext4_error(sb, __func__, "%d free blocks as per "
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001588 "group info. But got %d blocks\n",
1589 free, ex.fe_len);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001590 /*
1591 * The number of free blocks differs. This mostly
1592 * indicate that the bitmap is corrupt. So exit
1593 * without claiming the space.
1594 */
1595 break;
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001596 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001597
1598 ext4_mb_measure_extent(ac, &ex, e4b);
1599
1600 i += ex.fe_len;
1601 free -= ex.fe_len;
1602 }
1603
1604 ext4_mb_check_limits(ac, e4b, 1);
1605}
1606
1607/*
1608 * This is a special case for storages like raid5
1609 * we try to find stripe-aligned chunks for stripe-size requests
1610 * XXX should do so at least for multiples of stripe size as well
1611 */
1612static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1613 struct ext4_buddy *e4b)
1614{
1615 struct super_block *sb = ac->ac_sb;
1616 struct ext4_sb_info *sbi = EXT4_SB(sb);
1617 void *bitmap = EXT4_MB_BITMAP(e4b);
1618 struct ext4_free_extent ex;
1619 ext4_fsblk_t first_group_block;
1620 ext4_fsblk_t a;
1621 ext4_grpblk_t i;
1622 int max;
1623
1624 BUG_ON(sbi->s_stripe == 0);
1625
1626 /* find first stripe-aligned block in group */
1627 first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
1628 + le32_to_cpu(sbi->s_es->s_first_data_block);
1629 a = first_group_block + sbi->s_stripe - 1;
1630 do_div(a, sbi->s_stripe);
1631 i = (a * sbi->s_stripe) - first_group_block;
1632
1633 while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
1634 if (!mb_test_bit(i, bitmap)) {
1635 max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
1636 if (max >= sbi->s_stripe) {
1637 ac->ac_found++;
1638 ac->ac_b_ex = ex;
1639 ext4_mb_use_best_found(ac, e4b);
1640 break;
1641 }
1642 }
1643 i += sbi->s_stripe;
1644 }
1645}
1646
1647static int ext4_mb_good_group(struct ext4_allocation_context *ac,
1648 ext4_group_t group, int cr)
1649{
1650 unsigned free, fragments;
1651 unsigned i, bits;
1652 struct ext4_group_desc *desc;
1653 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1654
1655 BUG_ON(cr < 0 || cr >= 4);
1656 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
1657
1658 free = grp->bb_free;
1659 fragments = grp->bb_fragments;
1660 if (free == 0)
1661 return 0;
1662 if (fragments == 0)
1663 return 0;
1664
1665 switch (cr) {
1666 case 0:
1667 BUG_ON(ac->ac_2order == 0);
1668 /* If this group is uninitialized, skip it initially */
1669 desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
1670 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
1671 return 0;
1672
1673 bits = ac->ac_sb->s_blocksize_bits + 1;
1674 for (i = ac->ac_2order; i <= bits; i++)
1675 if (grp->bb_counters[i] > 0)
1676 return 1;
1677 break;
1678 case 1:
1679 if ((free / fragments) >= ac->ac_g_ex.fe_len)
1680 return 1;
1681 break;
1682 case 2:
1683 if (free >= ac->ac_g_ex.fe_len)
1684 return 1;
1685 break;
1686 case 3:
1687 return 1;
1688 default:
1689 BUG();
1690 }
1691
1692 return 0;
1693}
1694
Eric Sandeen4ddfef72008-04-29 08:11:12 -04001695static noinline_for_stack int
1696ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05001697{
1698 ext4_group_t group;
1699 ext4_group_t i;
1700 int cr;
1701 int err = 0;
1702 int bsbits;
1703 struct ext4_sb_info *sbi;
1704 struct super_block *sb;
1705 struct ext4_buddy e4b;
1706 loff_t size, isize;
1707
1708 sb = ac->ac_sb;
1709 sbi = EXT4_SB(sb);
1710 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1711
1712 /* first, try the goal */
1713 err = ext4_mb_find_by_goal(ac, &e4b);
1714 if (err || ac->ac_status == AC_STATUS_FOUND)
1715 goto out;
1716
1717 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
1718 goto out;
1719
1720 /*
1721 * ac->ac2_order is set only if the fe_len is a power of 2
1722 * if ac2_order is set we also set criteria to 0 so that we
1723 * try exact allocation using buddy.
1724 */
1725 i = fls(ac->ac_g_ex.fe_len);
1726 ac->ac_2order = 0;
1727 /*
1728 * We search using buddy data only if the order of the request
1729 * is greater than equal to the sbi_s_mb_order2_reqs
1730 * You can tune it via /proc/fs/ext4/<partition>/order2_req
1731 */
1732 if (i >= sbi->s_mb_order2_reqs) {
1733 /*
1734 * This should tell if fe_len is exactly power of 2
1735 */
1736 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
1737 ac->ac_2order = i - 1;
1738 }
1739
1740 bsbits = ac->ac_sb->s_blocksize_bits;
1741 /* if stream allocation is enabled, use global goal */
1742 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
1743 isize = i_size_read(ac->ac_inode) >> bsbits;
1744 if (size < isize)
1745 size = isize;
1746
1747 if (size < sbi->s_mb_stream_request &&
1748 (ac->ac_flags & EXT4_MB_HINT_DATA)) {
1749 /* TBD: may be hot point */
1750 spin_lock(&sbi->s_md_lock);
1751 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
1752 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
1753 spin_unlock(&sbi->s_md_lock);
1754 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001755 /* Let's just scan groups to find more-less suitable blocks */
1756 cr = ac->ac_2order ? 0 : 1;
1757 /*
1758 * cr == 0 try to get exact allocation,
1759 * cr == 3 try to get anything
1760 */
1761repeat:
1762 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
1763 ac->ac_criteria = cr;
Aneesh Kumar K.Ved8f9c72008-07-11 19:27:31 -04001764 /*
1765 * searching for the right group start
1766 * from the goal value specified
1767 */
1768 group = ac->ac_g_ex.fe_group;
1769
Alex Tomasc9de5602008-01-29 00:19:52 -05001770 for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
1771 struct ext4_group_info *grp;
1772 struct ext4_group_desc *desc;
1773
1774 if (group == EXT4_SB(sb)->s_groups_count)
1775 group = 0;
1776
1777 /* quick check to skip empty groups */
1778 grp = ext4_get_group_info(ac->ac_sb, group);
1779 if (grp->bb_free == 0)
1780 continue;
1781
1782 /*
1783 * if the group is already init we check whether it is
1784 * a good group and if not we don't load the buddy
1785 */
1786 if (EXT4_MB_GRP_NEED_INIT(grp)) {
1787 /*
1788 * we need full data about the group
1789 * to make a good selection
1790 */
1791 err = ext4_mb_load_buddy(sb, group, &e4b);
1792 if (err)
1793 goto out;
1794 ext4_mb_release_desc(&e4b);
1795 }
1796
1797 /*
1798 * If the particular group doesn't satisfy our
1799 * criteria we continue with the next group
1800 */
1801 if (!ext4_mb_good_group(ac, group, cr))
1802 continue;
1803
1804 err = ext4_mb_load_buddy(sb, group, &e4b);
1805 if (err)
1806 goto out;
1807
1808 ext4_lock_group(sb, group);
1809 if (!ext4_mb_good_group(ac, group, cr)) {
1810 /* someone did allocation from this group */
1811 ext4_unlock_group(sb, group);
1812 ext4_mb_release_desc(&e4b);
1813 continue;
1814 }
1815
1816 ac->ac_groups_scanned++;
1817 desc = ext4_get_group_desc(sb, group, NULL);
1818 if (cr == 0 || (desc->bg_flags &
1819 cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
1820 ac->ac_2order != 0))
1821 ext4_mb_simple_scan_group(ac, &e4b);
1822 else if (cr == 1 &&
1823 ac->ac_g_ex.fe_len == sbi->s_stripe)
1824 ext4_mb_scan_aligned(ac, &e4b);
1825 else
1826 ext4_mb_complex_scan_group(ac, &e4b);
1827
1828 ext4_unlock_group(sb, group);
1829 ext4_mb_release_desc(&e4b);
1830
1831 if (ac->ac_status != AC_STATUS_CONTINUE)
1832 break;
1833 }
1834 }
1835
1836 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
1837 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1838 /*
1839 * We've been searching too long. Let's try to allocate
1840 * the best chunk we've found so far
1841 */
1842
1843 ext4_mb_try_best_found(ac, &e4b);
1844 if (ac->ac_status != AC_STATUS_FOUND) {
1845 /*
1846 * Someone more lucky has already allocated it.
1847 * The only thing we can do is just take first
1848 * found block(s)
1849 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
1850 */
1851 ac->ac_b_ex.fe_group = 0;
1852 ac->ac_b_ex.fe_start = 0;
1853 ac->ac_b_ex.fe_len = 0;
1854 ac->ac_status = AC_STATUS_CONTINUE;
1855 ac->ac_flags |= EXT4_MB_HINT_FIRST;
1856 cr = 3;
1857 atomic_inc(&sbi->s_mb_lost_chunks);
1858 goto repeat;
1859 }
1860 }
1861out:
1862 return err;
1863}
1864
1865#ifdef EXT4_MB_HISTORY
1866struct ext4_mb_proc_session {
1867 struct ext4_mb_history *history;
1868 struct super_block *sb;
1869 int start;
1870 int max;
1871};
1872
1873static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
1874 struct ext4_mb_history *hs,
1875 int first)
1876{
1877 if (hs == s->history + s->max)
1878 hs = s->history;
1879 if (!first && hs == s->history + s->start)
1880 return NULL;
1881 while (hs->orig.fe_len == 0) {
1882 hs++;
1883 if (hs == s->history + s->max)
1884 hs = s->history;
1885 if (hs == s->history + s->start)
1886 return NULL;
1887 }
1888 return hs;
1889}
1890
1891static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
1892{
1893 struct ext4_mb_proc_session *s = seq->private;
1894 struct ext4_mb_history *hs;
1895 int l = *pos;
1896
1897 if (l == 0)
1898 return SEQ_START_TOKEN;
1899 hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
1900 if (!hs)
1901 return NULL;
1902 while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
1903 return hs;
1904}
1905
1906static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
1907 loff_t *pos)
1908{
1909 struct ext4_mb_proc_session *s = seq->private;
1910 struct ext4_mb_history *hs = v;
1911
1912 ++*pos;
1913 if (v == SEQ_START_TOKEN)
1914 return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
1915 else
1916 return ext4_mb_history_skip_empty(s, ++hs, 0);
1917}
1918
1919static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
1920{
1921 char buf[25], buf2[25], buf3[25], *fmt;
1922 struct ext4_mb_history *hs = v;
1923
1924 if (v == SEQ_START_TOKEN) {
1925 seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
1926 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
1927 "pid", "inode", "original", "goal", "result", "found",
1928 "grps", "cr", "flags", "merge", "tail", "broken");
1929 return 0;
1930 }
1931
1932 if (hs->op == EXT4_MB_HISTORY_ALLOC) {
1933 fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
1934 "%-5u %-5s %-5u %-6u\n";
1935 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
1936 hs->result.fe_start, hs->result.fe_len,
1937 hs->result.fe_logical);
1938 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
1939 hs->orig.fe_start, hs->orig.fe_len,
1940 hs->orig.fe_logical);
1941 sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group,
1942 hs->goal.fe_start, hs->goal.fe_len,
1943 hs->goal.fe_logical);
1944 seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
1945 hs->found, hs->groups, hs->cr, hs->flags,
1946 hs->merged ? "M" : "", hs->tail,
1947 hs->buddy ? 1 << hs->buddy : 0);
1948 } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
1949 fmt = "%-5u %-8u %-23s %-23s %-23s\n";
1950 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
1951 hs->result.fe_start, hs->result.fe_len,
1952 hs->result.fe_logical);
1953 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
1954 hs->orig.fe_start, hs->orig.fe_len,
1955 hs->orig.fe_logical);
1956 seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
1957 } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
1958 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
1959 hs->result.fe_start, hs->result.fe_len);
1960 seq_printf(seq, "%-5u %-8u %-23s discard\n",
1961 hs->pid, hs->ino, buf2);
1962 } else if (hs->op == EXT4_MB_HISTORY_FREE) {
1963 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
1964 hs->result.fe_start, hs->result.fe_len);
1965 seq_printf(seq, "%-5u %-8u %-23s free\n",
1966 hs->pid, hs->ino, buf2);
1967 }
1968 return 0;
1969}
1970
1971static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
1972{
1973}
1974
1975static struct seq_operations ext4_mb_seq_history_ops = {
1976 .start = ext4_mb_seq_history_start,
1977 .next = ext4_mb_seq_history_next,
1978 .stop = ext4_mb_seq_history_stop,
1979 .show = ext4_mb_seq_history_show,
1980};
1981
1982static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
1983{
1984 struct super_block *sb = PDE(inode)->data;
1985 struct ext4_sb_info *sbi = EXT4_SB(sb);
1986 struct ext4_mb_proc_session *s;
1987 int rc;
1988 int size;
1989
Shen Feng74767c52008-07-11 19:27:31 -04001990 if (unlikely(sbi->s_mb_history == NULL))
1991 return -ENOMEM;
Alex Tomasc9de5602008-01-29 00:19:52 -05001992 s = kmalloc(sizeof(*s), GFP_KERNEL);
1993 if (s == NULL)
1994 return -ENOMEM;
1995 s->sb = sb;
1996 size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
1997 s->history = kmalloc(size, GFP_KERNEL);
1998 if (s->history == NULL) {
1999 kfree(s);
2000 return -ENOMEM;
2001 }
2002
2003 spin_lock(&sbi->s_mb_history_lock);
2004 memcpy(s->history, sbi->s_mb_history, size);
2005 s->max = sbi->s_mb_history_max;
2006 s->start = sbi->s_mb_history_cur % s->max;
2007 spin_unlock(&sbi->s_mb_history_lock);
2008
2009 rc = seq_open(file, &ext4_mb_seq_history_ops);
2010 if (rc == 0) {
2011 struct seq_file *m = (struct seq_file *)file->private_data;
2012 m->private = s;
2013 } else {
2014 kfree(s->history);
2015 kfree(s);
2016 }
2017 return rc;
2018
2019}
2020
2021static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
2022{
2023 struct seq_file *seq = (struct seq_file *)file->private_data;
2024 struct ext4_mb_proc_session *s = seq->private;
2025 kfree(s->history);
2026 kfree(s);
2027 return seq_release(inode, file);
2028}
2029
2030static ssize_t ext4_mb_seq_history_write(struct file *file,
2031 const char __user *buffer,
2032 size_t count, loff_t *ppos)
2033{
2034 struct seq_file *seq = (struct seq_file *)file->private_data;
2035 struct ext4_mb_proc_session *s = seq->private;
2036 struct super_block *sb = s->sb;
2037 char str[32];
2038 int value;
2039
2040 if (count >= sizeof(str)) {
2041 printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
2042 "mb_history", (int)sizeof(str));
2043 return -EOVERFLOW;
2044 }
2045
2046 if (copy_from_user(str, buffer, count))
2047 return -EFAULT;
2048
2049 value = simple_strtol(str, NULL, 0);
2050 if (value < 0)
2051 return -ERANGE;
2052 EXT4_SB(sb)->s_mb_history_filter = value;
2053
2054 return count;
2055}
2056
2057static struct file_operations ext4_mb_seq_history_fops = {
2058 .owner = THIS_MODULE,
2059 .open = ext4_mb_seq_history_open,
2060 .read = seq_read,
2061 .write = ext4_mb_seq_history_write,
2062 .llseek = seq_lseek,
2063 .release = ext4_mb_seq_history_release,
2064};
2065
2066static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2067{
2068 struct super_block *sb = seq->private;
2069 struct ext4_sb_info *sbi = EXT4_SB(sb);
2070 ext4_group_t group;
2071
2072 if (*pos < 0 || *pos >= sbi->s_groups_count)
2073 return NULL;
2074
2075 group = *pos + 1;
2076 return (void *) group;
2077}
2078
2079static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2080{
2081 struct super_block *sb = seq->private;
2082 struct ext4_sb_info *sbi = EXT4_SB(sb);
2083 ext4_group_t group;
2084
2085 ++*pos;
2086 if (*pos < 0 || *pos >= sbi->s_groups_count)
2087 return NULL;
2088 group = *pos + 1;
2089 return (void *) group;;
2090}
2091
2092static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2093{
2094 struct super_block *sb = seq->private;
2095 long group = (long) v;
2096 int i;
2097 int err;
2098 struct ext4_buddy e4b;
2099 struct sg {
2100 struct ext4_group_info info;
2101 unsigned short counters[16];
2102 } sg;
2103
2104 group--;
2105 if (group == 0)
2106 seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
2107 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2108 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2109 "group", "free", "frags", "first",
2110 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2111 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2112
2113 i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2114 sizeof(struct ext4_group_info);
2115 err = ext4_mb_load_buddy(sb, group, &e4b);
2116 if (err) {
2117 seq_printf(seq, "#%-5lu: I/O error\n", group);
2118 return 0;
2119 }
2120 ext4_lock_group(sb, group);
2121 memcpy(&sg, ext4_get_group_info(sb, group), i);
2122 ext4_unlock_group(sb, group);
2123 ext4_mb_release_desc(&e4b);
2124
2125 seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free,
2126 sg.info.bb_fragments, sg.info.bb_first_free);
2127 for (i = 0; i <= 13; i++)
2128 seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
2129 sg.info.bb_counters[i] : 0);
2130 seq_printf(seq, " ]\n");
2131
2132 return 0;
2133}
2134
2135static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2136{
2137}
2138
2139static struct seq_operations ext4_mb_seq_groups_ops = {
2140 .start = ext4_mb_seq_groups_start,
2141 .next = ext4_mb_seq_groups_next,
2142 .stop = ext4_mb_seq_groups_stop,
2143 .show = ext4_mb_seq_groups_show,
2144};
2145
2146static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
2147{
2148 struct super_block *sb = PDE(inode)->data;
2149 int rc;
2150
2151 rc = seq_open(file, &ext4_mb_seq_groups_ops);
2152 if (rc == 0) {
2153 struct seq_file *m = (struct seq_file *)file->private_data;
2154 m->private = sb;
2155 }
2156 return rc;
2157
2158}
2159
2160static struct file_operations ext4_mb_seq_groups_fops = {
2161 .owner = THIS_MODULE,
2162 .open = ext4_mb_seq_groups_open,
2163 .read = seq_read,
2164 .llseek = seq_lseek,
2165 .release = seq_release,
2166};
2167
2168static void ext4_mb_history_release(struct super_block *sb)
2169{
2170 struct ext4_sb_info *sbi = EXT4_SB(sb);
2171
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002172 if (sbi->s_proc != NULL) {
2173 remove_proc_entry("mb_groups", sbi->s_proc);
2174 remove_proc_entry("mb_history", sbi->s_proc);
2175 }
Alex Tomasc9de5602008-01-29 00:19:52 -05002176 kfree(sbi->s_mb_history);
2177}
2178
2179static void ext4_mb_history_init(struct super_block *sb)
2180{
2181 struct ext4_sb_info *sbi = EXT4_SB(sb);
2182 int i;
2183
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002184 if (sbi->s_proc != NULL) {
2185 proc_create_data("mb_history", S_IRUGO, sbi->s_proc,
Denis V. Lunev46fe74f2008-04-29 01:02:08 -07002186 &ext4_mb_seq_history_fops, sb);
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002187 proc_create_data("mb_groups", S_IRUGO, sbi->s_proc,
Denis V. Lunev46fe74f2008-04-29 01:02:08 -07002188 &ext4_mb_seq_groups_fops, sb);
Alex Tomasc9de5602008-01-29 00:19:52 -05002189 }
2190
2191 sbi->s_mb_history_max = 1000;
2192 sbi->s_mb_history_cur = 0;
2193 spin_lock_init(&sbi->s_mb_history_lock);
2194 i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
Shen Feng74767c52008-07-11 19:27:31 -04002195 sbi->s_mb_history = kzalloc(i, GFP_KERNEL);
Alex Tomasc9de5602008-01-29 00:19:52 -05002196 /* if we can't allocate history, then we simple won't use it */
2197}
2198
Eric Sandeen4ddfef72008-04-29 08:11:12 -04002199static noinline_for_stack void
2200ext4_mb_store_history(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05002201{
2202 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2203 struct ext4_mb_history h;
2204
2205 if (unlikely(sbi->s_mb_history == NULL))
2206 return;
2207
2208 if (!(ac->ac_op & sbi->s_mb_history_filter))
2209 return;
2210
2211 h.op = ac->ac_op;
2212 h.pid = current->pid;
2213 h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
2214 h.orig = ac->ac_o_ex;
2215 h.result = ac->ac_b_ex;
2216 h.flags = ac->ac_flags;
2217 h.found = ac->ac_found;
2218 h.groups = ac->ac_groups_scanned;
2219 h.cr = ac->ac_criteria;
2220 h.tail = ac->ac_tail;
2221 h.buddy = ac->ac_buddy;
2222 h.merged = 0;
2223 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
2224 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
2225 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
2226 h.merged = 1;
2227 h.goal = ac->ac_g_ex;
2228 h.result = ac->ac_f_ex;
2229 }
2230
2231 spin_lock(&sbi->s_mb_history_lock);
2232 memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
2233 if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
2234 sbi->s_mb_history_cur = 0;
2235 spin_unlock(&sbi->s_mb_history_lock);
2236}
2237
2238#else
2239#define ext4_mb_history_release(sb)
2240#define ext4_mb_history_init(sb)
2241#endif
2242
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002243
2244/* Create and initialize ext4_group_info data for the given group. */
2245int ext4_mb_add_groupinfo(struct super_block *sb, ext4_group_t group,
2246 struct ext4_group_desc *desc)
2247{
2248 int i, len;
2249 int metalen = 0;
2250 struct ext4_sb_info *sbi = EXT4_SB(sb);
2251 struct ext4_group_info **meta_group_info;
2252
2253 /*
2254 * First check if this group is the first of a reserved block.
2255 * If it's true, we have to allocate a new table of pointers
2256 * to ext4_group_info structures
2257 */
2258 if (group % EXT4_DESC_PER_BLOCK(sb) == 0) {
2259 metalen = sizeof(*meta_group_info) <<
2260 EXT4_DESC_PER_BLOCK_BITS(sb);
2261 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2262 if (meta_group_info == NULL) {
2263 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2264 "buddy group\n");
2265 goto exit_meta_group_info;
2266 }
2267 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)] =
2268 meta_group_info;
2269 }
2270
2271 /*
2272 * calculate needed size. if change bb_counters size,
2273 * don't forget about ext4_mb_generate_buddy()
2274 */
2275 len = offsetof(typeof(**meta_group_info),
2276 bb_counters[sb->s_blocksize_bits + 2]);
2277
2278 meta_group_info =
2279 sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2280 i = group & (EXT4_DESC_PER_BLOCK(sb) - 1);
2281
2282 meta_group_info[i] = kzalloc(len, GFP_KERNEL);
2283 if (meta_group_info[i] == NULL) {
2284 printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
2285 goto exit_group_info;
2286 }
2287 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2288 &(meta_group_info[i]->bb_state));
2289
2290 /*
2291 * initialize bb_free to be able to skip
2292 * empty groups without initialization
2293 */
2294 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2295 meta_group_info[i]->bb_free =
2296 ext4_free_blocks_after_init(sb, group, desc);
2297 } else {
2298 meta_group_info[i]->bb_free =
2299 le16_to_cpu(desc->bg_free_blocks_count);
2300 }
2301
2302 INIT_LIST_HEAD(&meta_group_info[i]->bb_prealloc_list);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002303 meta_group_info[i]->bb_free_root.rb_node = NULL;;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002304
2305#ifdef DOUBLE_CHECK
2306 {
2307 struct buffer_head *bh;
2308 meta_group_info[i]->bb_bitmap =
2309 kmalloc(sb->s_blocksize, GFP_KERNEL);
2310 BUG_ON(meta_group_info[i]->bb_bitmap == NULL);
2311 bh = ext4_read_block_bitmap(sb, group);
2312 BUG_ON(bh == NULL);
2313 memcpy(meta_group_info[i]->bb_bitmap, bh->b_data,
2314 sb->s_blocksize);
2315 put_bh(bh);
2316 }
2317#endif
2318
2319 return 0;
2320
2321exit_group_info:
2322 /* If a meta_group_info table has been allocated, release it now */
2323 if (group % EXT4_DESC_PER_BLOCK(sb) == 0)
2324 kfree(sbi->s_group_info[group >> EXT4_DESC_PER_BLOCK_BITS(sb)]);
2325exit_meta_group_info:
2326 return -ENOMEM;
2327} /* ext4_mb_add_groupinfo */
2328
2329/*
2330 * Add a group to the existing groups.
2331 * This function is used for online resize
2332 */
2333int ext4_mb_add_more_groupinfo(struct super_block *sb, ext4_group_t group,
2334 struct ext4_group_desc *desc)
2335{
2336 struct ext4_sb_info *sbi = EXT4_SB(sb);
2337 struct inode *inode = sbi->s_buddy_cache;
2338 int blocks_per_page;
2339 int block;
2340 int pnum;
2341 struct page *page;
2342 int err;
2343
2344 /* Add group based on group descriptor*/
2345 err = ext4_mb_add_groupinfo(sb, group, desc);
2346 if (err)
2347 return err;
2348
2349 /*
2350 * Cache pages containing dynamic mb_alloc datas (buddy and bitmap
2351 * datas) are set not up to date so that they will be re-initilaized
2352 * during the next call to ext4_mb_load_buddy
2353 */
2354
2355 /* Set buddy page as not up to date */
2356 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
2357 block = group * 2;
2358 pnum = block / blocks_per_page;
2359 page = find_get_page(inode->i_mapping, pnum);
2360 if (page != NULL) {
2361 ClearPageUptodate(page);
2362 page_cache_release(page);
2363 }
2364
2365 /* Set bitmap page as not up to date */
2366 block++;
2367 pnum = block / blocks_per_page;
2368 page = find_get_page(inode->i_mapping, pnum);
2369 if (page != NULL) {
2370 ClearPageUptodate(page);
2371 page_cache_release(page);
2372 }
2373
2374 return 0;
2375}
2376
2377/*
2378 * Update an existing group.
2379 * This function is used for online resize
2380 */
2381void ext4_mb_update_group_info(struct ext4_group_info *grp, ext4_grpblk_t add)
2382{
2383 grp->bb_free += add;
2384}
2385
Alex Tomasc9de5602008-01-29 00:19:52 -05002386static int ext4_mb_init_backend(struct super_block *sb)
2387{
2388 ext4_group_t i;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002389 int metalen;
Alex Tomasc9de5602008-01-29 00:19:52 -05002390 struct ext4_sb_info *sbi = EXT4_SB(sb);
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002391 struct ext4_super_block *es = sbi->s_es;
2392 int num_meta_group_infos;
2393 int num_meta_group_infos_max;
2394 int array_size;
Alex Tomasc9de5602008-01-29 00:19:52 -05002395 struct ext4_group_info **meta_group_info;
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002396 struct ext4_group_desc *desc;
Alex Tomasc9de5602008-01-29 00:19:52 -05002397
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002398 /* This is the number of blocks used by GDT */
2399 num_meta_group_infos = (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) -
2400 1) >> EXT4_DESC_PER_BLOCK_BITS(sb);
2401
2402 /*
2403 * This is the total number of blocks used by GDT including
2404 * the number of reserved blocks for GDT.
2405 * The s_group_info array is allocated with this value
2406 * to allow a clean online resize without a complex
2407 * manipulation of pointer.
2408 * The drawback is the unused memory when no resize
2409 * occurs but it's very low in terms of pages
2410 * (see comments below)
2411 * Need to handle this properly when META_BG resizing is allowed
2412 */
2413 num_meta_group_infos_max = num_meta_group_infos +
2414 le16_to_cpu(es->s_reserved_gdt_blocks);
2415
2416 /*
2417 * array_size is the size of s_group_info array. We round it
2418 * to the next power of two because this approximation is done
2419 * internally by kmalloc so we can have some more memory
2420 * for free here (e.g. may be used for META_BG resize).
2421 */
2422 array_size = 1;
2423 while (array_size < sizeof(*sbi->s_group_info) *
2424 num_meta_group_infos_max)
2425 array_size = array_size << 1;
Alex Tomasc9de5602008-01-29 00:19:52 -05002426 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2427 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2428 * So a two level scheme suffices for now. */
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002429 sbi->s_group_info = kmalloc(array_size, GFP_KERNEL);
Alex Tomasc9de5602008-01-29 00:19:52 -05002430 if (sbi->s_group_info == NULL) {
2431 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
2432 return -ENOMEM;
2433 }
2434 sbi->s_buddy_cache = new_inode(sb);
2435 if (sbi->s_buddy_cache == NULL) {
2436 printk(KERN_ERR "EXT4-fs: can't get new inode\n");
2437 goto err_freesgi;
2438 }
2439 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2440
2441 metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
2442 for (i = 0; i < num_meta_group_infos; i++) {
2443 if ((i + 1) == num_meta_group_infos)
2444 metalen = sizeof(*meta_group_info) *
2445 (sbi->s_groups_count -
2446 (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
2447 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2448 if (meta_group_info == NULL) {
2449 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2450 "buddy group\n");
2451 goto err_freemeta;
2452 }
2453 sbi->s_group_info[i] = meta_group_info;
2454 }
2455
Alex Tomasc9de5602008-01-29 00:19:52 -05002456 for (i = 0; i < sbi->s_groups_count; i++) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002457 desc = ext4_get_group_desc(sb, i, NULL);
2458 if (desc == NULL) {
2459 printk(KERN_ERR
2460 "EXT4-fs: can't read descriptor %lu\n", i);
2461 goto err_freebuddy;
2462 }
Frederic Bohe5f21b0e2008-07-11 19:27:31 -04002463 if (ext4_mb_add_groupinfo(sb, i, desc) != 0)
2464 goto err_freebuddy;
Alex Tomasc9de5602008-01-29 00:19:52 -05002465 }
2466
2467 return 0;
2468
2469err_freebuddy:
Roel Kluinf1fa3342008-04-29 22:01:15 -04002470 while (i-- > 0)
Alex Tomasc9de5602008-01-29 00:19:52 -05002471 kfree(ext4_get_group_info(sb, i));
Alex Tomasc9de5602008-01-29 00:19:52 -05002472 i = num_meta_group_infos;
2473err_freemeta:
Roel Kluinf1fa3342008-04-29 22:01:15 -04002474 while (i-- > 0)
Alex Tomasc9de5602008-01-29 00:19:52 -05002475 kfree(sbi->s_group_info[i]);
2476 iput(sbi->s_buddy_cache);
2477err_freesgi:
2478 kfree(sbi->s_group_info);
2479 return -ENOMEM;
2480}
2481
2482int ext4_mb_init(struct super_block *sb, int needs_recovery)
2483{
2484 struct ext4_sb_info *sbi = EXT4_SB(sb);
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04002485 unsigned i, j;
Alex Tomasc9de5602008-01-29 00:19:52 -05002486 unsigned offset;
2487 unsigned max;
Shen Feng74767c52008-07-11 19:27:31 -04002488 int ret;
Alex Tomasc9de5602008-01-29 00:19:52 -05002489
Alex Tomasc9de5602008-01-29 00:19:52 -05002490 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
2491
2492 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2493 if (sbi->s_mb_offsets == NULL) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002494 return -ENOMEM;
2495 }
2496 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2497 if (sbi->s_mb_maxs == NULL) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002498 kfree(sbi->s_mb_maxs);
2499 return -ENOMEM;
2500 }
2501
2502 /* order 0 is regular bitmap */
2503 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2504 sbi->s_mb_offsets[0] = 0;
2505
2506 i = 1;
2507 offset = 0;
2508 max = sb->s_blocksize << 2;
2509 do {
2510 sbi->s_mb_offsets[i] = offset;
2511 sbi->s_mb_maxs[i] = max;
2512 offset += 1 << (sb->s_blocksize_bits - i);
2513 max = max >> 1;
2514 i++;
2515 } while (i <= sb->s_blocksize_bits + 1);
2516
2517 /* init file for buddy data */
Shen Feng74767c52008-07-11 19:27:31 -04002518 ret = ext4_mb_init_backend(sb);
2519 if (ret != 0) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002520 kfree(sbi->s_mb_offsets);
2521 kfree(sbi->s_mb_maxs);
Shen Feng74767c52008-07-11 19:27:31 -04002522 return ret;
Alex Tomasc9de5602008-01-29 00:19:52 -05002523 }
2524
2525 spin_lock_init(&sbi->s_md_lock);
Alex Tomasc9de5602008-01-29 00:19:52 -05002526 spin_lock_init(&sbi->s_bal_lock);
2527
2528 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2529 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2530 sbi->s_mb_stats = MB_DEFAULT_STATS;
2531 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2532 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2533 sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
2534 sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
2535
Eric Sandeen730c2132008-09-13 15:23:29 -04002536 sbi->s_locality_groups = alloc_percpu(struct ext4_locality_group);
Alex Tomasc9de5602008-01-29 00:19:52 -05002537 if (sbi->s_locality_groups == NULL) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002538 kfree(sbi->s_mb_offsets);
2539 kfree(sbi->s_mb_maxs);
2540 return -ENOMEM;
2541 }
Eric Sandeen730c2132008-09-13 15:23:29 -04002542 for_each_possible_cpu(i) {
Alex Tomasc9de5602008-01-29 00:19:52 -05002543 struct ext4_locality_group *lg;
Eric Sandeen730c2132008-09-13 15:23:29 -04002544 lg = per_cpu_ptr(sbi->s_locality_groups, i);
Alex Tomasc9de5602008-01-29 00:19:52 -05002545 mutex_init(&lg->lg_mutex);
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04002546 for (j = 0; j < PREALLOC_TB_SIZE; j++)
2547 INIT_LIST_HEAD(&lg->lg_prealloc_list[j]);
Alex Tomasc9de5602008-01-29 00:19:52 -05002548 spin_lock_init(&lg->lg_prealloc_lock);
2549 }
2550
2551 ext4_mb_init_per_dev_proc(sb);
2552 ext4_mb_history_init(sb);
2553
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002554 sbi->s_journal->j_commit_callback = release_blocks_on_commit;
2555
Theodore Ts'o4776004f2008-09-08 23:00:52 -04002556 printk(KERN_INFO "EXT4-fs: mballoc enabled\n");
Alex Tomasc9de5602008-01-29 00:19:52 -05002557 return 0;
2558}
2559
2560/* need to called with ext4 group lock (ext4_lock_group) */
2561static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2562{
2563 struct ext4_prealloc_space *pa;
2564 struct list_head *cur, *tmp;
2565 int count = 0;
2566
2567 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2568 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2569 list_del(&pa->pa_group_list);
2570 count++;
Aneesh Kumar K.V688f05a2008-10-13 12:14:14 -04002571 kmem_cache_free(ext4_pspace_cachep, pa);
Alex Tomasc9de5602008-01-29 00:19:52 -05002572 }
2573 if (count)
2574 mb_debug("mballoc: %u PAs left\n", count);
2575
2576}
2577
2578int ext4_mb_release(struct super_block *sb)
2579{
2580 ext4_group_t i;
2581 int num_meta_group_infos;
2582 struct ext4_group_info *grinfo;
2583 struct ext4_sb_info *sbi = EXT4_SB(sb);
2584
Alex Tomasc9de5602008-01-29 00:19:52 -05002585 if (sbi->s_group_info) {
2586 for (i = 0; i < sbi->s_groups_count; i++) {
2587 grinfo = ext4_get_group_info(sb, i);
2588#ifdef DOUBLE_CHECK
2589 kfree(grinfo->bb_bitmap);
2590#endif
2591 ext4_lock_group(sb, i);
2592 ext4_mb_cleanup_pa(grinfo);
2593 ext4_unlock_group(sb, i);
2594 kfree(grinfo);
2595 }
2596 num_meta_group_infos = (sbi->s_groups_count +
2597 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2598 EXT4_DESC_PER_BLOCK_BITS(sb);
2599 for (i = 0; i < num_meta_group_infos; i++)
2600 kfree(sbi->s_group_info[i]);
2601 kfree(sbi->s_group_info);
2602 }
2603 kfree(sbi->s_mb_offsets);
2604 kfree(sbi->s_mb_maxs);
2605 if (sbi->s_buddy_cache)
2606 iput(sbi->s_buddy_cache);
2607 if (sbi->s_mb_stats) {
2608 printk(KERN_INFO
2609 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2610 atomic_read(&sbi->s_bal_allocated),
2611 atomic_read(&sbi->s_bal_reqs),
2612 atomic_read(&sbi->s_bal_success));
2613 printk(KERN_INFO
2614 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2615 "%u 2^N hits, %u breaks, %u lost\n",
2616 atomic_read(&sbi->s_bal_ex_scanned),
2617 atomic_read(&sbi->s_bal_goals),
2618 atomic_read(&sbi->s_bal_2orders),
2619 atomic_read(&sbi->s_bal_breaks),
2620 atomic_read(&sbi->s_mb_lost_chunks));
2621 printk(KERN_INFO
2622 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2623 sbi->s_mb_buddies_generated++,
2624 sbi->s_mb_generation_time);
2625 printk(KERN_INFO
2626 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2627 atomic_read(&sbi->s_mb_preallocated),
2628 atomic_read(&sbi->s_mb_discarded));
2629 }
2630
Eric Sandeen730c2132008-09-13 15:23:29 -04002631 free_percpu(sbi->s_locality_groups);
Alex Tomasc9de5602008-01-29 00:19:52 -05002632 ext4_mb_history_release(sb);
2633 ext4_mb_destroy_per_dev_proc(sb);
2634
2635 return 0;
2636}
2637
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002638/*
2639 * This function is called by the jbd2 layer once the commit has finished,
2640 * so we know we can free the blocks that were released with that commit.
2641 */
2642static void release_blocks_on_commit(journal_t *journal, transaction_t *txn)
Alex Tomasc9de5602008-01-29 00:19:52 -05002643{
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002644 struct super_block *sb = journal->j_private;
Alex Tomasc9de5602008-01-29 00:19:52 -05002645 struct ext4_buddy e4b;
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002646 struct ext4_group_info *db;
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002647 int err, count = 0, count2 = 0;
2648 struct ext4_free_data *entry;
Theodore Ts'o8a0aba72008-10-16 10:06:27 -04002649 ext4_fsblk_t discard_block;
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002650 struct list_head *l, *ltmp;
Alex Tomasc9de5602008-01-29 00:19:52 -05002651
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002652 list_for_each_safe(l, ltmp, &txn->t_private_list) {
2653 entry = list_entry(l, struct ext4_free_data, list);
Alex Tomasc9de5602008-01-29 00:19:52 -05002654
2655 mb_debug("gonna free %u blocks in group %lu (0x%p):",
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002656 entry->count, entry->group, entry);
Alex Tomasc9de5602008-01-29 00:19:52 -05002657
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002658 err = ext4_mb_load_buddy(sb, entry->group, &e4b);
Alex Tomasc9de5602008-01-29 00:19:52 -05002659 /* we expect to find existing buddy because it's pinned */
2660 BUG_ON(err != 0);
2661
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002662 db = e4b.bd_info;
Alex Tomasc9de5602008-01-29 00:19:52 -05002663 /* there are blocks to put in buddy to make them really free */
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002664 count += entry->count;
Alex Tomasc9de5602008-01-29 00:19:52 -05002665 count2++;
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002666 ext4_lock_group(sb, entry->group);
2667 /* Take it out of per group rb tree */
2668 rb_erase(&entry->node, &(db->bb_free_root));
2669 mb_free_blocks(NULL, &e4b, entry->start_blk, entry->count);
2670
2671 if (!db->bb_free_root.rb_node) {
2672 /* No more items in the per group rb tree
2673 * balance refcounts from ext4_mb_free_metadata()
2674 */
2675 page_cache_release(e4b.bd_buddy_page);
2676 page_cache_release(e4b.bd_bitmap_page);
Alex Tomasc9de5602008-01-29 00:19:52 -05002677 }
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002678 ext4_unlock_group(sb, entry->group);
Theodore Ts'o8a0aba72008-10-16 10:06:27 -04002679 discard_block = (ext4_fsblk_t) entry->group * EXT4_BLOCKS_PER_GROUP(sb)
2680 + entry->start_blk
2681 + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
2682 trace_mark(ext4_discard_blocks, "dev %s blk %llu count %u", sb->s_id,
2683 (unsigned long long) discard_block, entry->count);
2684 sb_issue_discard(sb, discard_block, entry->count);
Alex Tomasc9de5602008-01-29 00:19:52 -05002685
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002686 kmem_cache_free(ext4_free_ext_cachep, entry);
Alex Tomasc9de5602008-01-29 00:19:52 -05002687 ext4_mb_release_desc(&e4b);
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04002688 }
Alex Tomasc9de5602008-01-29 00:19:52 -05002689
2690 mb_debug("freed %u blocks in %u structures\n", count, count2);
2691}
2692
Alex Tomasc9de5602008-01-29 00:19:52 -05002693#define EXT4_MB_STATS_NAME "stats"
2694#define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2695#define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2696#define EXT4_MB_ORDER2_REQ "order2_req"
2697#define EXT4_MB_STREAM_REQ "stream_req"
2698#define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2699
Alex Tomasc9de5602008-01-29 00:19:52 -05002700static int ext4_mb_init_per_dev_proc(struct super_block *sb)
2701{
Manish Katiyar0b09923e2008-10-17 14:58:45 -04002702#ifdef CONFIG_PROC_FS
Alex Tomasc9de5602008-01-29 00:19:52 -05002703 mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
2704 struct ext4_sb_info *sbi = EXT4_SB(sb);
2705 struct proc_dir_entry *proc;
Alex Tomasc9de5602008-01-29 00:19:52 -05002706
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002707 if (sbi->s_proc == NULL)
Shen Fengcfbe7e42008-07-13 21:03:31 -04002708 return -EINVAL;
Alex Tomasc9de5602008-01-29 00:19:52 -05002709
Theodore Ts'o5e8814f2008-09-23 18:07:35 -04002710 EXT4_PROC_HANDLER(EXT4_MB_STATS_NAME, mb_stats);
2711 EXT4_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, mb_max_to_scan);
2712 EXT4_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, mb_min_to_scan);
2713 EXT4_PROC_HANDLER(EXT4_MB_ORDER2_REQ, mb_order2_reqs);
2714 EXT4_PROC_HANDLER(EXT4_MB_STREAM_REQ, mb_stream_request);
2715 EXT4_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, mb_group_prealloc);
Alex Tomasc9de5602008-01-29 00:19:52 -05002716 return 0;
2717
2718err_out:
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002719 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_proc);
2720 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_proc);
2721 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_proc);
2722 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_proc);
2723 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_proc);
2724 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_proc);
Alex Tomasc9de5602008-01-29 00:19:52 -05002725 return -ENOMEM;
Manish Katiyar0b09923e2008-10-17 14:58:45 -04002726#else
2727 return 0;
2728#endif
Alex Tomasc9de5602008-01-29 00:19:52 -05002729}
2730
2731static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
2732{
Manish Katiyar0b09923e2008-10-17 14:58:45 -04002733#ifdef CONFIG_PROC_FS
Alex Tomasc9de5602008-01-29 00:19:52 -05002734 struct ext4_sb_info *sbi = EXT4_SB(sb);
Alex Tomasc9de5602008-01-29 00:19:52 -05002735
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002736 if (sbi->s_proc == NULL)
Alex Tomasc9de5602008-01-29 00:19:52 -05002737 return -EINVAL;
2738
Theodore Ts'o9f6200b2008-09-23 09:18:24 -04002739 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_proc);
2740 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_proc);
2741 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_proc);
2742 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_proc);
2743 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_proc);
2744 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_proc);
Manish Katiyar0b09923e2008-10-17 14:58:45 -04002745#endif
Alex Tomasc9de5602008-01-29 00:19:52 -05002746 return 0;
2747}
2748
2749int __init init_ext4_mballoc(void)
2750{
2751 ext4_pspace_cachep =
2752 kmem_cache_create("ext4_prealloc_space",
2753 sizeof(struct ext4_prealloc_space),
2754 0, SLAB_RECLAIM_ACCOUNT, NULL);
2755 if (ext4_pspace_cachep == NULL)
2756 return -ENOMEM;
2757
Eric Sandeen256bdb42008-02-10 01:13:33 -05002758 ext4_ac_cachep =
2759 kmem_cache_create("ext4_alloc_context",
2760 sizeof(struct ext4_allocation_context),
2761 0, SLAB_RECLAIM_ACCOUNT, NULL);
2762 if (ext4_ac_cachep == NULL) {
2763 kmem_cache_destroy(ext4_pspace_cachep);
2764 return -ENOMEM;
2765 }
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002766
2767 ext4_free_ext_cachep =
2768 kmem_cache_create("ext4_free_block_extents",
2769 sizeof(struct ext4_free_data),
2770 0, SLAB_RECLAIM_ACCOUNT, NULL);
2771 if (ext4_free_ext_cachep == NULL) {
2772 kmem_cache_destroy(ext4_pspace_cachep);
2773 kmem_cache_destroy(ext4_ac_cachep);
2774 return -ENOMEM;
2775 }
Alex Tomasc9de5602008-01-29 00:19:52 -05002776 return 0;
2777}
2778
2779void exit_ext4_mballoc(void)
2780{
2781 /* XXX: synchronize_rcu(); */
2782 kmem_cache_destroy(ext4_pspace_cachep);
Eric Sandeen256bdb42008-02-10 01:13:33 -05002783 kmem_cache_destroy(ext4_ac_cachep);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04002784 kmem_cache_destroy(ext4_free_ext_cachep);
Alex Tomasc9de5602008-01-29 00:19:52 -05002785}
2786
2787
2788/*
2789 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
2790 * Returns 0 if success or error code
2791 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04002792static noinline_for_stack int
2793ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04002794 handle_t *handle, unsigned long reserv_blks)
Alex Tomasc9de5602008-01-29 00:19:52 -05002795{
2796 struct buffer_head *bitmap_bh = NULL;
2797 struct ext4_super_block *es;
2798 struct ext4_group_desc *gdp;
2799 struct buffer_head *gdp_bh;
2800 struct ext4_sb_info *sbi;
2801 struct super_block *sb;
2802 ext4_fsblk_t block;
Aneesh Kumar K.V519deca2008-05-15 14:43:20 -04002803 int err, len;
Alex Tomasc9de5602008-01-29 00:19:52 -05002804
2805 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
2806 BUG_ON(ac->ac_b_ex.fe_len <= 0);
2807
2808 sb = ac->ac_sb;
2809 sbi = EXT4_SB(sb);
2810 es = sbi->s_es;
2811
Alex Tomasc9de5602008-01-29 00:19:52 -05002812
2813 err = -EIO;
Theodore Ts'o574ca172008-07-11 19:27:31 -04002814 bitmap_bh = ext4_read_block_bitmap(sb, ac->ac_b_ex.fe_group);
Alex Tomasc9de5602008-01-29 00:19:52 -05002815 if (!bitmap_bh)
2816 goto out_err;
2817
2818 err = ext4_journal_get_write_access(handle, bitmap_bh);
2819 if (err)
2820 goto out_err;
2821
2822 err = -EIO;
2823 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
2824 if (!gdp)
2825 goto out_err;
2826
Aneesh Kumar K.V03cddb82008-06-05 20:59:29 -04002827 ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
2828 gdp->bg_free_blocks_count);
2829
Alex Tomasc9de5602008-01-29 00:19:52 -05002830 err = ext4_journal_get_write_access(handle, gdp_bh);
2831 if (err)
2832 goto out_err;
2833
2834 block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
2835 + ac->ac_b_ex.fe_start
2836 + le32_to_cpu(es->s_first_data_block);
2837
Aneesh Kumar K.V519deca2008-05-15 14:43:20 -04002838 len = ac->ac_b_ex.fe_len;
2839 if (in_range(ext4_block_bitmap(sb, gdp), block, len) ||
2840 in_range(ext4_inode_bitmap(sb, gdp), block, len) ||
2841 in_range(block, ext4_inode_table(sb, gdp),
2842 EXT4_SB(sb)->s_itb_per_group) ||
2843 in_range(block + len - 1, ext4_inode_table(sb, gdp),
2844 EXT4_SB(sb)->s_itb_per_group)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04002845 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05002846 "Allocating block in system zone - block = %llu",
2847 block);
Aneesh Kumar K.V519deca2008-05-15 14:43:20 -04002848 /* File system mounted not to panic on error
2849 * Fix the bitmap and repeat the block allocation
2850 * We leak some of the blocks here.
2851 */
2852 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group),
2853 bitmap_bh->b_data, ac->ac_b_ex.fe_start,
2854 ac->ac_b_ex.fe_len);
2855 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
2856 if (!err)
2857 err = -EAGAIN;
2858 goto out_err;
Alex Tomasc9de5602008-01-29 00:19:52 -05002859 }
2860#ifdef AGGRESSIVE_CHECK
2861 {
2862 int i;
2863 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
2864 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
2865 bitmap_bh->b_data));
2866 }
2867 }
2868#endif
2869 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
2870 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
2871
2872 spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
2873 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2874 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
2875 gdp->bg_free_blocks_count =
2876 cpu_to_le16(ext4_free_blocks_after_init(sb,
2877 ac->ac_b_ex.fe_group,
2878 gdp));
2879 }
Marcin Slusarze8546d02008-04-17 10:38:59 -04002880 le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05002881 gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
2882 spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04002883 percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
Mingming Caod2a17632008-07-14 17:52:37 -04002884 /*
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04002885 * Now reduce the dirty block count also. Should not go negative
Mingming Caod2a17632008-07-14 17:52:37 -04002886 */
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04002887 if (!(ac->ac_flags & EXT4_MB_DELALLOC_RESERVED))
2888 /* release all the reserved blocks if non delalloc */
2889 percpu_counter_sub(&sbi->s_dirtyblocks_counter, reserv_blks);
2890 else
2891 percpu_counter_sub(&sbi->s_dirtyblocks_counter,
2892 ac->ac_b_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05002893
Jose R. Santos772cb7c2008-07-11 19:27:31 -04002894 if (sbi->s_log_groups_per_flex) {
2895 ext4_group_t flex_group = ext4_flex_group(sbi,
2896 ac->ac_b_ex.fe_group);
2897 spin_lock(sb_bgl_lock(sbi, flex_group));
2898 sbi->s_flex_groups[flex_group].free_blocks -= ac->ac_b_ex.fe_len;
2899 spin_unlock(sb_bgl_lock(sbi, flex_group));
2900 }
2901
Alex Tomasc9de5602008-01-29 00:19:52 -05002902 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
2903 if (err)
2904 goto out_err;
2905 err = ext4_journal_dirty_metadata(handle, gdp_bh);
2906
2907out_err:
2908 sb->s_dirt = 1;
Aneesh Kumar K.V42a10ad2008-02-10 01:07:28 -05002909 brelse(bitmap_bh);
Alex Tomasc9de5602008-01-29 00:19:52 -05002910 return err;
2911}
2912
2913/*
2914 * here we normalize request for locality group
2915 * Group request are normalized to s_strip size if we set the same via mount
2916 * option. If not we set it to s_mb_group_prealloc which can be configured via
2917 * /proc/fs/ext4/<partition>/group_prealloc
2918 *
2919 * XXX: should we try to preallocate more than the group has now?
2920 */
2921static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
2922{
2923 struct super_block *sb = ac->ac_sb;
2924 struct ext4_locality_group *lg = ac->ac_lg;
2925
2926 BUG_ON(lg == NULL);
2927 if (EXT4_SB(sb)->s_stripe)
2928 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
2929 else
2930 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
Solofo Ramangalahy60bd63d2008-04-29 21:59:59 -04002931 mb_debug("#%u: goal %u blocks for locality group\n",
Alex Tomasc9de5602008-01-29 00:19:52 -05002932 current->pid, ac->ac_g_ex.fe_len);
2933}
2934
2935/*
2936 * Normalization means making request better in terms of
2937 * size and alignment
2938 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04002939static noinline_for_stack void
2940ext4_mb_normalize_request(struct ext4_allocation_context *ac,
Alex Tomasc9de5602008-01-29 00:19:52 -05002941 struct ext4_allocation_request *ar)
2942{
2943 int bsbits, max;
2944 ext4_lblk_t end;
Alex Tomasc9de5602008-01-29 00:19:52 -05002945 loff_t size, orig_size, start_off;
2946 ext4_lblk_t start, orig_start;
2947 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04002948 struct ext4_prealloc_space *pa;
Alex Tomasc9de5602008-01-29 00:19:52 -05002949
2950 /* do normalize only data requests, metadata requests
2951 do not need preallocation */
2952 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
2953 return;
2954
2955 /* sometime caller may want exact blocks */
2956 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
2957 return;
2958
2959 /* caller may indicate that preallocation isn't
2960 * required (it's a tail, for example) */
2961 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
2962 return;
2963
2964 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
2965 ext4_mb_normalize_group_request(ac);
2966 return ;
2967 }
2968
2969 bsbits = ac->ac_sb->s_blocksize_bits;
2970
2971 /* first, let's learn actual file size
2972 * given current request is allocated */
2973 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
2974 size = size << bsbits;
2975 if (size < i_size_read(ac->ac_inode))
2976 size = i_size_read(ac->ac_inode);
2977
Valerie Clement19304792008-05-13 19:31:14 -04002978 /* max size of free chunks */
2979 max = 2 << bsbits;
Alex Tomasc9de5602008-01-29 00:19:52 -05002980
Valerie Clement19304792008-05-13 19:31:14 -04002981#define NRL_CHECK_SIZE(req, size, max, chunk_size) \
2982 (req <= (size) || max <= (chunk_size))
Alex Tomasc9de5602008-01-29 00:19:52 -05002983
2984 /* first, try to predict filesize */
2985 /* XXX: should this table be tunable? */
2986 start_off = 0;
2987 if (size <= 16 * 1024) {
2988 size = 16 * 1024;
2989 } else if (size <= 32 * 1024) {
2990 size = 32 * 1024;
2991 } else if (size <= 64 * 1024) {
2992 size = 64 * 1024;
2993 } else if (size <= 128 * 1024) {
2994 size = 128 * 1024;
2995 } else if (size <= 256 * 1024) {
2996 size = 256 * 1024;
2997 } else if (size <= 512 * 1024) {
2998 size = 512 * 1024;
2999 } else if (size <= 1024 * 1024) {
3000 size = 1024 * 1024;
Valerie Clement19304792008-05-13 19:31:14 -04003001 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, 2 * 1024)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003002 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
Valerie Clement19304792008-05-13 19:31:14 -04003003 (21 - bsbits)) << 21;
3004 size = 2 * 1024 * 1024;
3005 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, 4 * 1024)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003006 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3007 (22 - bsbits)) << 22;
3008 size = 4 * 1024 * 1024;
3009 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
Valerie Clement19304792008-05-13 19:31:14 -04003010 (8<<20)>>bsbits, max, 8 * 1024)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003011 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3012 (23 - bsbits)) << 23;
3013 size = 8 * 1024 * 1024;
3014 } else {
3015 start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
3016 size = ac->ac_o_ex.fe_len << bsbits;
3017 }
3018 orig_size = size = size >> bsbits;
3019 orig_start = start = start_off >> bsbits;
3020
3021 /* don't cover already allocated blocks in selected range */
3022 if (ar->pleft && start <= ar->lleft) {
3023 size -= ar->lleft + 1 - start;
3024 start = ar->lleft + 1;
3025 }
3026 if (ar->pright && start + size - 1 >= ar->lright)
3027 size -= start + size - ar->lright;
3028
3029 end = start + size;
3030
3031 /* check we don't cross already preallocated blocks */
3032 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003033 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003034 unsigned long pa_end;
3035
Alex Tomasc9de5602008-01-29 00:19:52 -05003036 if (pa->pa_deleted)
3037 continue;
3038 spin_lock(&pa->pa_lock);
3039 if (pa->pa_deleted) {
3040 spin_unlock(&pa->pa_lock);
3041 continue;
3042 }
3043
3044 pa_end = pa->pa_lstart + pa->pa_len;
3045
3046 /* PA must not overlap original request */
3047 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3048 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3049
3050 /* skip PA normalized request doesn't overlap with */
3051 if (pa->pa_lstart >= end) {
3052 spin_unlock(&pa->pa_lock);
3053 continue;
3054 }
3055 if (pa_end <= start) {
3056 spin_unlock(&pa->pa_lock);
3057 continue;
3058 }
3059 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3060
3061 if (pa_end <= ac->ac_o_ex.fe_logical) {
3062 BUG_ON(pa_end < start);
3063 start = pa_end;
3064 }
3065
3066 if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3067 BUG_ON(pa->pa_lstart > end);
3068 end = pa->pa_lstart;
3069 }
3070 spin_unlock(&pa->pa_lock);
3071 }
3072 rcu_read_unlock();
3073 size = end - start;
3074
3075 /* XXX: extra loop to check we really don't overlap preallocations */
3076 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003077 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003078 unsigned long pa_end;
Alex Tomasc9de5602008-01-29 00:19:52 -05003079 spin_lock(&pa->pa_lock);
3080 if (pa->pa_deleted == 0) {
3081 pa_end = pa->pa_lstart + pa->pa_len;
3082 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3083 }
3084 spin_unlock(&pa->pa_lock);
3085 }
3086 rcu_read_unlock();
3087
3088 if (start + size <= ac->ac_o_ex.fe_logical &&
3089 start > ac->ac_o_ex.fe_logical) {
3090 printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
3091 (unsigned long) start, (unsigned long) size,
3092 (unsigned long) ac->ac_o_ex.fe_logical);
3093 }
3094 BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
3095 start > ac->ac_o_ex.fe_logical);
3096 BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3097
3098 /* now prepare goal request */
3099
3100 /* XXX: is it better to align blocks WRT to logical
3101 * placement or satisfy big request as is */
3102 ac->ac_g_ex.fe_logical = start;
3103 ac->ac_g_ex.fe_len = size;
3104
3105 /* define goal start in order to merge */
3106 if (ar->pright && (ar->lright == (start + size))) {
3107 /* merge to the right */
3108 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3109 &ac->ac_f_ex.fe_group,
3110 &ac->ac_f_ex.fe_start);
3111 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3112 }
3113 if (ar->pleft && (ar->lleft + 1 == start)) {
3114 /* merge to the left */
3115 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3116 &ac->ac_f_ex.fe_group,
3117 &ac->ac_f_ex.fe_start);
3118 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3119 }
3120
3121 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
3122 (unsigned) orig_size, (unsigned) start);
3123}
3124
3125static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3126{
3127 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3128
3129 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3130 atomic_inc(&sbi->s_bal_reqs);
3131 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3132 if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
3133 atomic_inc(&sbi->s_bal_success);
3134 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3135 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3136 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3137 atomic_inc(&sbi->s_bal_goals);
3138 if (ac->ac_found > sbi->s_mb_max_to_scan)
3139 atomic_inc(&sbi->s_bal_breaks);
3140 }
3141
3142 ext4_mb_store_history(ac);
3143}
3144
3145/*
3146 * use blocks preallocated to inode
3147 */
3148static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3149 struct ext4_prealloc_space *pa)
3150{
3151 ext4_fsblk_t start;
3152 ext4_fsblk_t end;
3153 int len;
3154
3155 /* found preallocated blocks, use them */
3156 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3157 end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
3158 len = end - start;
3159 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3160 &ac->ac_b_ex.fe_start);
3161 ac->ac_b_ex.fe_len = len;
3162 ac->ac_status = AC_STATUS_FOUND;
3163 ac->ac_pa = pa;
3164
3165 BUG_ON(start < pa->pa_pstart);
3166 BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
3167 BUG_ON(pa->pa_free < len);
3168 pa->pa_free -= len;
3169
Solofo Ramangalahy60bd63d2008-04-29 21:59:59 -04003170 mb_debug("use %llu/%u from inode pa %p\n", start, len, pa);
Alex Tomasc9de5602008-01-29 00:19:52 -05003171}
3172
3173/*
3174 * use blocks preallocated to locality group
3175 */
3176static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3177 struct ext4_prealloc_space *pa)
3178{
Aneesh Kumar K.V03cddb82008-06-05 20:59:29 -04003179 unsigned int len = ac->ac_o_ex.fe_len;
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003180
Alex Tomasc9de5602008-01-29 00:19:52 -05003181 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3182 &ac->ac_b_ex.fe_group,
3183 &ac->ac_b_ex.fe_start);
3184 ac->ac_b_ex.fe_len = len;
3185 ac->ac_status = AC_STATUS_FOUND;
3186 ac->ac_pa = pa;
3187
3188 /* we don't correct pa_pstart or pa_plen here to avoid
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003189 * possible race when the group is being loaded concurrently
Alex Tomasc9de5602008-01-29 00:19:52 -05003190 * instead we correct pa later, after blocks are marked
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003191 * in on-disk bitmap -- see ext4_mb_release_context()
3192 * Other CPUs are prevented from allocating from this pa by lg_mutex
Alex Tomasc9de5602008-01-29 00:19:52 -05003193 */
3194 mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3195}
3196
3197/*
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04003198 * Return the prealloc space that have minimal distance
3199 * from the goal block. @cpa is the prealloc
3200 * space that is having currently known minimal distance
3201 * from the goal block.
3202 */
3203static struct ext4_prealloc_space *
3204ext4_mb_check_group_pa(ext4_fsblk_t goal_block,
3205 struct ext4_prealloc_space *pa,
3206 struct ext4_prealloc_space *cpa)
3207{
3208 ext4_fsblk_t cur_distance, new_distance;
3209
3210 if (cpa == NULL) {
3211 atomic_inc(&pa->pa_count);
3212 return pa;
3213 }
3214 cur_distance = abs(goal_block - cpa->pa_pstart);
3215 new_distance = abs(goal_block - pa->pa_pstart);
3216
3217 if (cur_distance < new_distance)
3218 return cpa;
3219
3220 /* drop the previous reference */
3221 atomic_dec(&cpa->pa_count);
3222 atomic_inc(&pa->pa_count);
3223 return pa;
3224}
3225
3226/*
Alex Tomasc9de5602008-01-29 00:19:52 -05003227 * search goal blocks in preallocated space
3228 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003229static noinline_for_stack int
3230ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003231{
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003232 int order, i;
Alex Tomasc9de5602008-01-29 00:19:52 -05003233 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3234 struct ext4_locality_group *lg;
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04003235 struct ext4_prealloc_space *pa, *cpa = NULL;
3236 ext4_fsblk_t goal_block;
Alex Tomasc9de5602008-01-29 00:19:52 -05003237
3238 /* only data can be preallocated */
3239 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3240 return 0;
3241
3242 /* first, try per-file preallocation */
3243 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003244 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003245
3246 /* all fields in this condition don't change,
3247 * so we can skip locking for them */
3248 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3249 ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
3250 continue;
3251
3252 /* found preallocated blocks, use them */
3253 spin_lock(&pa->pa_lock);
3254 if (pa->pa_deleted == 0 && pa->pa_free) {
3255 atomic_inc(&pa->pa_count);
3256 ext4_mb_use_inode_pa(ac, pa);
3257 spin_unlock(&pa->pa_lock);
3258 ac->ac_criteria = 10;
3259 rcu_read_unlock();
3260 return 1;
3261 }
3262 spin_unlock(&pa->pa_lock);
3263 }
3264 rcu_read_unlock();
3265
3266 /* can we use group allocation? */
3267 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3268 return 0;
3269
3270 /* inode may have no locality group for some reason */
3271 lg = ac->ac_lg;
3272 if (lg == NULL)
3273 return 0;
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003274 order = fls(ac->ac_o_ex.fe_len) - 1;
3275 if (order > PREALLOC_TB_SIZE - 1)
3276 /* The max size of hash table is PREALLOC_TB_SIZE */
3277 order = PREALLOC_TB_SIZE - 1;
Alex Tomasc9de5602008-01-29 00:19:52 -05003278
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04003279 goal_block = ac->ac_g_ex.fe_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb) +
3280 ac->ac_g_ex.fe_start +
3281 le32_to_cpu(EXT4_SB(ac->ac_sb)->s_es->s_first_data_block);
3282 /*
3283 * search for the prealloc space that is having
3284 * minimal distance from the goal block.
3285 */
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003286 for (i = order; i < PREALLOC_TB_SIZE; i++) {
3287 rcu_read_lock();
3288 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[i],
3289 pa_inode_list) {
3290 spin_lock(&pa->pa_lock);
3291 if (pa->pa_deleted == 0 &&
3292 pa->pa_free >= ac->ac_o_ex.fe_len) {
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04003293
3294 cpa = ext4_mb_check_group_pa(goal_block,
3295 pa, cpa);
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003296 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003297 spin_unlock(&pa->pa_lock);
Alex Tomasc9de5602008-01-29 00:19:52 -05003298 }
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003299 rcu_read_unlock();
Alex Tomasc9de5602008-01-29 00:19:52 -05003300 }
Aneesh Kumar K.V5e745b02008-08-18 18:00:57 -04003301 if (cpa) {
3302 ext4_mb_use_group_pa(ac, cpa);
3303 ac->ac_criteria = 20;
3304 return 1;
3305 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003306 return 0;
3307}
3308
3309/*
3310 * the function goes through all preallocation in this group and marks them
3311 * used in in-core bitmap. buddy must be generated from this bitmap
3312 * Need to be called with ext4 group lock (ext4_lock_group)
3313 */
3314static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3315 ext4_group_t group)
3316{
3317 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3318 struct ext4_prealloc_space *pa;
3319 struct list_head *cur;
3320 ext4_group_t groupnr;
3321 ext4_grpblk_t start;
3322 int preallocated = 0;
3323 int count = 0;
3324 int len;
3325
3326 /* all form of preallocation discards first load group,
3327 * so the only competing code is preallocation use.
3328 * we don't need any locking here
3329 * notice we do NOT ignore preallocations with pa_deleted
3330 * otherwise we could leave used blocks available for
3331 * allocation in buddy when concurrent ext4_mb_put_pa()
3332 * is dropping preallocation
3333 */
3334 list_for_each(cur, &grp->bb_prealloc_list) {
3335 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3336 spin_lock(&pa->pa_lock);
3337 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3338 &groupnr, &start);
3339 len = pa->pa_len;
3340 spin_unlock(&pa->pa_lock);
3341 if (unlikely(len == 0))
3342 continue;
3343 BUG_ON(groupnr != group);
3344 mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
3345 bitmap, start, len);
3346 preallocated += len;
3347 count++;
3348 }
3349 mb_debug("prellocated %u for group %lu\n", preallocated, group);
3350}
3351
3352static void ext4_mb_pa_callback(struct rcu_head *head)
3353{
3354 struct ext4_prealloc_space *pa;
3355 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3356 kmem_cache_free(ext4_pspace_cachep, pa);
3357}
3358
3359/*
3360 * drops a reference to preallocated space descriptor
3361 * if this was the last reference and the space is consumed
3362 */
3363static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3364 struct super_block *sb, struct ext4_prealloc_space *pa)
3365{
3366 unsigned long grp;
3367
3368 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
3369 return;
3370
3371 /* in this short window concurrent discard can set pa_deleted */
3372 spin_lock(&pa->pa_lock);
3373 if (pa->pa_deleted == 1) {
3374 spin_unlock(&pa->pa_lock);
3375 return;
3376 }
3377
3378 pa->pa_deleted = 1;
3379 spin_unlock(&pa->pa_lock);
3380
3381 /* -1 is to protect from crossing allocation group */
3382 ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
3383
3384 /*
3385 * possible race:
3386 *
3387 * P1 (buddy init) P2 (regular allocation)
3388 * find block B in PA
3389 * copy on-disk bitmap to buddy
3390 * mark B in on-disk bitmap
3391 * drop PA from group
3392 * mark all PAs in buddy
3393 *
3394 * thus, P1 initializes buddy with B available. to prevent this
3395 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3396 * against that pair
3397 */
3398 ext4_lock_group(sb, grp);
3399 list_del(&pa->pa_group_list);
3400 ext4_unlock_group(sb, grp);
3401
3402 spin_lock(pa->pa_obj_lock);
3403 list_del_rcu(&pa->pa_inode_list);
3404 spin_unlock(pa->pa_obj_lock);
3405
3406 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3407}
3408
3409/*
3410 * creates new preallocated space for given inode
3411 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003412static noinline_for_stack int
3413ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003414{
3415 struct super_block *sb = ac->ac_sb;
3416 struct ext4_prealloc_space *pa;
3417 struct ext4_group_info *grp;
3418 struct ext4_inode_info *ei;
3419
3420 /* preallocate only when found space is larger then requested */
3421 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3422 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3423 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3424
3425 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3426 if (pa == NULL)
3427 return -ENOMEM;
3428
3429 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3430 int winl;
3431 int wins;
3432 int win;
3433 int offs;
3434
3435 /* we can't allocate as much as normalizer wants.
3436 * so, found space must get proper lstart
3437 * to cover original request */
3438 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3439 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3440
3441 /* we're limited by original request in that
3442 * logical block must be covered any way
3443 * winl is window we can move our chunk within */
3444 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3445
3446 /* also, we should cover whole original request */
3447 wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
3448
3449 /* the smallest one defines real window */
3450 win = min(winl, wins);
3451
3452 offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
3453 if (offs && offs < win)
3454 win = offs;
3455
3456 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
3457 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3458 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3459 }
3460
3461 /* preallocation can change ac_b_ex, thus we store actually
3462 * allocated blocks for history */
3463 ac->ac_f_ex = ac->ac_b_ex;
3464
3465 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3466 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3467 pa->pa_len = ac->ac_b_ex.fe_len;
3468 pa->pa_free = pa->pa_len;
3469 atomic_set(&pa->pa_count, 1);
3470 spin_lock_init(&pa->pa_lock);
3471 pa->pa_deleted = 0;
3472 pa->pa_linear = 0;
3473
3474 mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
3475 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3476
3477 ext4_mb_use_inode_pa(ac, pa);
3478 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3479
3480 ei = EXT4_I(ac->ac_inode);
3481 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3482
3483 pa->pa_obj_lock = &ei->i_prealloc_lock;
3484 pa->pa_inode = ac->ac_inode;
3485
3486 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3487 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3488 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3489
3490 spin_lock(pa->pa_obj_lock);
3491 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3492 spin_unlock(pa->pa_obj_lock);
3493
3494 return 0;
3495}
3496
3497/*
3498 * creates new preallocated space for locality group inodes belongs to
3499 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003500static noinline_for_stack int
3501ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003502{
3503 struct super_block *sb = ac->ac_sb;
3504 struct ext4_locality_group *lg;
3505 struct ext4_prealloc_space *pa;
3506 struct ext4_group_info *grp;
3507
3508 /* preallocate only when found space is larger then requested */
3509 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3510 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3511 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3512
3513 BUG_ON(ext4_pspace_cachep == NULL);
3514 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3515 if (pa == NULL)
3516 return -ENOMEM;
3517
3518 /* preallocation can change ac_b_ex, thus we store actually
3519 * allocated blocks for history */
3520 ac->ac_f_ex = ac->ac_b_ex;
3521
3522 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3523 pa->pa_lstart = pa->pa_pstart;
3524 pa->pa_len = ac->ac_b_ex.fe_len;
3525 pa->pa_free = pa->pa_len;
3526 atomic_set(&pa->pa_count, 1);
3527 spin_lock_init(&pa->pa_lock);
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003528 INIT_LIST_HEAD(&pa->pa_inode_list);
Alex Tomasc9de5602008-01-29 00:19:52 -05003529 pa->pa_deleted = 0;
3530 pa->pa_linear = 1;
3531
3532 mb_debug("new group pa %p: %llu/%u for %u\n", pa,
3533 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3534
3535 ext4_mb_use_group_pa(ac, pa);
3536 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3537
3538 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3539 lg = ac->ac_lg;
3540 BUG_ON(lg == NULL);
3541
3542 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3543 pa->pa_inode = NULL;
3544
3545 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3546 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3547 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3548
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04003549 /*
3550 * We will later add the new pa to the right bucket
3551 * after updating the pa_free in ext4_mb_release_context
3552 */
Alex Tomasc9de5602008-01-29 00:19:52 -05003553 return 0;
3554}
3555
3556static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3557{
3558 int err;
3559
3560 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3561 err = ext4_mb_new_group_pa(ac);
3562 else
3563 err = ext4_mb_new_inode_pa(ac);
3564 return err;
3565}
3566
3567/*
3568 * finds all unused blocks in on-disk bitmap, frees them in
3569 * in-core bitmap and buddy.
3570 * @pa must be unlinked from inode and group lists, so that
3571 * nobody else can find/use it.
3572 * the caller MUST hold group/inode locks.
3573 * TODO: optimize the case when there are no in-core structures yet
3574 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003575static noinline_for_stack int
3576ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003577 struct ext4_prealloc_space *pa,
3578 struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003579{
Alex Tomasc9de5602008-01-29 00:19:52 -05003580 struct super_block *sb = e4b->bd_sb;
3581 struct ext4_sb_info *sbi = EXT4_SB(sb);
3582 unsigned long end;
3583 unsigned long next;
3584 ext4_group_t group;
3585 ext4_grpblk_t bit;
3586 sector_t start;
3587 int err = 0;
3588 int free = 0;
3589
3590 BUG_ON(pa->pa_deleted == 0);
3591 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3592 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3593 end = bit + pa->pa_len;
3594
Eric Sandeen256bdb42008-02-10 01:13:33 -05003595 if (ac) {
3596 ac->ac_sb = sb;
3597 ac->ac_inode = pa->pa_inode;
3598 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3599 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003600
3601 while (bit < end) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003602 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003603 if (bit >= end)
3604 break;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003605 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003606 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3607 le32_to_cpu(sbi->s_es->s_first_data_block);
3608 mb_debug(" free preallocated %u/%u in group %u\n",
3609 (unsigned) start, (unsigned) next - bit,
3610 (unsigned) group);
3611 free += next - bit;
3612
Eric Sandeen256bdb42008-02-10 01:13:33 -05003613 if (ac) {
3614 ac->ac_b_ex.fe_group = group;
3615 ac->ac_b_ex.fe_start = bit;
3616 ac->ac_b_ex.fe_len = next - bit;
3617 ac->ac_b_ex.fe_logical = 0;
3618 ext4_mb_store_history(ac);
3619 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003620
3621 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3622 bit = next + 1;
3623 }
3624 if (free != pa->pa_free) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003625 printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n",
Alex Tomasc9de5602008-01-29 00:19:52 -05003626 pa, (unsigned long) pa->pa_lstart,
3627 (unsigned long) pa->pa_pstart,
3628 (unsigned long) pa->pa_len);
Harvey Harrison46e665e2008-04-17 10:38:59 -04003629 ext4_error(sb, __func__, "free %u, pa_free %u\n",
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003630 free, pa->pa_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05003631 /*
3632 * pa is already deleted so we use the value obtained
3633 * from the bitmap and continue.
3634 */
Alex Tomasc9de5602008-01-29 00:19:52 -05003635 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003636 atomic_add(free, &sbi->s_mb_discarded);
3637
3638 return err;
3639}
3640
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003641static noinline_for_stack int
3642ext4_mb_release_group_pa(struct ext4_buddy *e4b,
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003643 struct ext4_prealloc_space *pa,
3644 struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003645{
Alex Tomasc9de5602008-01-29 00:19:52 -05003646 struct super_block *sb = e4b->bd_sb;
3647 ext4_group_t group;
3648 ext4_grpblk_t bit;
3649
Eric Sandeen256bdb42008-02-10 01:13:33 -05003650 if (ac)
3651 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
Alex Tomasc9de5602008-01-29 00:19:52 -05003652
3653 BUG_ON(pa->pa_deleted == 0);
3654 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3655 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3656 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3657 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3658
Eric Sandeen256bdb42008-02-10 01:13:33 -05003659 if (ac) {
3660 ac->ac_sb = sb;
3661 ac->ac_inode = NULL;
3662 ac->ac_b_ex.fe_group = group;
3663 ac->ac_b_ex.fe_start = bit;
3664 ac->ac_b_ex.fe_len = pa->pa_len;
3665 ac->ac_b_ex.fe_logical = 0;
3666 ext4_mb_store_history(ac);
Eric Sandeen256bdb42008-02-10 01:13:33 -05003667 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003668
3669 return 0;
3670}
3671
3672/*
3673 * releases all preallocations in given group
3674 *
3675 * first, we need to decide discard policy:
3676 * - when do we discard
3677 * 1) ENOSPC
3678 * - how many do we discard
3679 * 1) how many requested
3680 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003681static noinline_for_stack int
3682ext4_mb_discard_group_preallocations(struct super_block *sb,
Alex Tomasc9de5602008-01-29 00:19:52 -05003683 ext4_group_t group, int needed)
3684{
3685 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3686 struct buffer_head *bitmap_bh = NULL;
3687 struct ext4_prealloc_space *pa, *tmp;
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003688 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003689 struct list_head list;
3690 struct ext4_buddy e4b;
3691 int err;
3692 int busy = 0;
3693 int free = 0;
3694
3695 mb_debug("discard preallocation for group %lu\n", group);
3696
3697 if (list_empty(&grp->bb_prealloc_list))
3698 return 0;
3699
Theodore Ts'o574ca172008-07-11 19:27:31 -04003700 bitmap_bh = ext4_read_block_bitmap(sb, group);
Alex Tomasc9de5602008-01-29 00:19:52 -05003701 if (bitmap_bh == NULL) {
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04003702 ext4_error(sb, __func__, "Error in reading block "
3703 "bitmap for %lu\n", group);
3704 return 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05003705 }
3706
3707 err = ext4_mb_load_buddy(sb, group, &e4b);
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04003708 if (err) {
3709 ext4_error(sb, __func__, "Error in loading buddy "
3710 "information for %lu\n", group);
3711 put_bh(bitmap_bh);
3712 return 0;
3713 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003714
3715 if (needed == 0)
3716 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
3717
Alex Tomasc9de5602008-01-29 00:19:52 -05003718 INIT_LIST_HEAD(&list);
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003719 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
Alex Tomasc9de5602008-01-29 00:19:52 -05003720repeat:
3721 ext4_lock_group(sb, group);
3722 list_for_each_entry_safe(pa, tmp,
3723 &grp->bb_prealloc_list, pa_group_list) {
3724 spin_lock(&pa->pa_lock);
3725 if (atomic_read(&pa->pa_count)) {
3726 spin_unlock(&pa->pa_lock);
3727 busy = 1;
3728 continue;
3729 }
3730 if (pa->pa_deleted) {
3731 spin_unlock(&pa->pa_lock);
3732 continue;
3733 }
3734
3735 /* seems this one can be freed ... */
3736 pa->pa_deleted = 1;
3737
3738 /* we can trust pa_free ... */
3739 free += pa->pa_free;
3740
3741 spin_unlock(&pa->pa_lock);
3742
3743 list_del(&pa->pa_group_list);
3744 list_add(&pa->u.pa_tmp_list, &list);
3745 }
3746
3747 /* if we still need more blocks and some PAs were used, try again */
3748 if (free < needed && busy) {
3749 busy = 0;
3750 ext4_unlock_group(sb, group);
3751 /*
3752 * Yield the CPU here so that we don't get soft lockup
3753 * in non preempt case.
3754 */
3755 yield();
3756 goto repeat;
3757 }
3758
3759 /* found anything to free? */
3760 if (list_empty(&list)) {
3761 BUG_ON(free != 0);
3762 goto out;
3763 }
3764
3765 /* now free all selected PAs */
3766 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3767
3768 /* remove from object (inode or locality group) */
3769 spin_lock(pa->pa_obj_lock);
3770 list_del_rcu(&pa->pa_inode_list);
3771 spin_unlock(pa->pa_obj_lock);
3772
3773 if (pa->pa_linear)
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003774 ext4_mb_release_group_pa(&e4b, pa, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003775 else
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003776 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003777
3778 list_del(&pa->u.pa_tmp_list);
3779 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3780 }
3781
3782out:
3783 ext4_unlock_group(sb, group);
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003784 if (ac)
3785 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003786 ext4_mb_release_desc(&e4b);
3787 put_bh(bitmap_bh);
3788 return free;
3789}
3790
3791/*
3792 * releases all non-used preallocated blocks for given inode
3793 *
3794 * It's important to discard preallocations under i_data_sem
3795 * We don't want another block to be served from the prealloc
3796 * space when we are discarding the inode prealloc space.
3797 *
3798 * FIXME!! Make sure it is valid at all the call sites
3799 */
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04003800void ext4_discard_preallocations(struct inode *inode)
Alex Tomasc9de5602008-01-29 00:19:52 -05003801{
3802 struct ext4_inode_info *ei = EXT4_I(inode);
3803 struct super_block *sb = inode->i_sb;
3804 struct buffer_head *bitmap_bh = NULL;
3805 struct ext4_prealloc_space *pa, *tmp;
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003806 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003807 ext4_group_t group = 0;
3808 struct list_head list;
3809 struct ext4_buddy e4b;
3810 int err;
3811
Theodore Ts'oc2ea3fd2008-10-10 09:40:52 -04003812 if (!S_ISREG(inode->i_mode)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003813 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3814 return;
3815 }
3816
3817 mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
3818
3819 INIT_LIST_HEAD(&list);
3820
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003821 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
Alex Tomasc9de5602008-01-29 00:19:52 -05003822repeat:
3823 /* first, collect all pa's in the inode */
3824 spin_lock(&ei->i_prealloc_lock);
3825 while (!list_empty(&ei->i_prealloc_list)) {
3826 pa = list_entry(ei->i_prealloc_list.next,
3827 struct ext4_prealloc_space, pa_inode_list);
3828 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
3829 spin_lock(&pa->pa_lock);
3830 if (atomic_read(&pa->pa_count)) {
3831 /* this shouldn't happen often - nobody should
3832 * use preallocation while we're discarding it */
3833 spin_unlock(&pa->pa_lock);
3834 spin_unlock(&ei->i_prealloc_lock);
3835 printk(KERN_ERR "uh-oh! used pa while discarding\n");
3836 WARN_ON(1);
3837 schedule_timeout_uninterruptible(HZ);
3838 goto repeat;
3839
3840 }
3841 if (pa->pa_deleted == 0) {
3842 pa->pa_deleted = 1;
3843 spin_unlock(&pa->pa_lock);
3844 list_del_rcu(&pa->pa_inode_list);
3845 list_add(&pa->u.pa_tmp_list, &list);
3846 continue;
3847 }
3848
3849 /* someone is deleting pa right now */
3850 spin_unlock(&pa->pa_lock);
3851 spin_unlock(&ei->i_prealloc_lock);
3852
3853 /* we have to wait here because pa_deleted
3854 * doesn't mean pa is already unlinked from
3855 * the list. as we might be called from
3856 * ->clear_inode() the inode will get freed
3857 * and concurrent thread which is unlinking
3858 * pa from inode's list may access already
3859 * freed memory, bad-bad-bad */
3860
3861 /* XXX: if this happens too often, we can
3862 * add a flag to force wait only in case
3863 * of ->clear_inode(), but not in case of
3864 * regular truncate */
3865 schedule_timeout_uninterruptible(HZ);
3866 goto repeat;
3867 }
3868 spin_unlock(&ei->i_prealloc_lock);
3869
3870 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3871 BUG_ON(pa->pa_linear != 0);
3872 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
3873
3874 err = ext4_mb_load_buddy(sb, group, &e4b);
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04003875 if (err) {
3876 ext4_error(sb, __func__, "Error in loading buddy "
3877 "information for %lu\n", group);
3878 continue;
3879 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003880
Theodore Ts'o574ca172008-07-11 19:27:31 -04003881 bitmap_bh = ext4_read_block_bitmap(sb, group);
Alex Tomasc9de5602008-01-29 00:19:52 -05003882 if (bitmap_bh == NULL) {
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04003883 ext4_error(sb, __func__, "Error in reading block "
3884 "bitmap for %lu\n", group);
Alex Tomasc9de5602008-01-29 00:19:52 -05003885 ext4_mb_release_desc(&e4b);
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04003886 continue;
Alex Tomasc9de5602008-01-29 00:19:52 -05003887 }
3888
3889 ext4_lock_group(sb, group);
3890 list_del(&pa->pa_group_list);
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003891 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003892 ext4_unlock_group(sb, group);
3893
3894 ext4_mb_release_desc(&e4b);
3895 put_bh(bitmap_bh);
3896
3897 list_del(&pa->u.pa_tmp_list);
3898 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3899 }
Aneesh Kumar K.Vc83617d2008-04-29 22:00:47 -04003900 if (ac)
3901 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003902}
3903
3904/*
3905 * finds all preallocated spaces and return blocks being freed to them
3906 * if preallocated space becomes full (no block is used from the space)
3907 * then the function frees space in buddy
3908 * XXX: at the moment, truncate (which is the only way to free blocks)
3909 * discards all preallocations
3910 */
3911static void ext4_mb_return_to_preallocation(struct inode *inode,
3912 struct ext4_buddy *e4b,
3913 sector_t block, int count)
3914{
3915 BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
3916}
3917#ifdef MB_DEBUG
3918static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
3919{
3920 struct super_block *sb = ac->ac_sb;
3921 ext4_group_t i;
3922
3923 printk(KERN_ERR "EXT4-fs: Can't allocate:"
3924 " Allocation context details:\n");
3925 printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
3926 ac->ac_status, ac->ac_flags);
3927 printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
3928 "best %lu/%lu/%lu@%lu cr %d\n",
3929 (unsigned long)ac->ac_o_ex.fe_group,
3930 (unsigned long)ac->ac_o_ex.fe_start,
3931 (unsigned long)ac->ac_o_ex.fe_len,
3932 (unsigned long)ac->ac_o_ex.fe_logical,
3933 (unsigned long)ac->ac_g_ex.fe_group,
3934 (unsigned long)ac->ac_g_ex.fe_start,
3935 (unsigned long)ac->ac_g_ex.fe_len,
3936 (unsigned long)ac->ac_g_ex.fe_logical,
3937 (unsigned long)ac->ac_b_ex.fe_group,
3938 (unsigned long)ac->ac_b_ex.fe_start,
3939 (unsigned long)ac->ac_b_ex.fe_len,
3940 (unsigned long)ac->ac_b_ex.fe_logical,
3941 (int)ac->ac_criteria);
3942 printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
3943 ac->ac_found);
3944 printk(KERN_ERR "EXT4-fs: groups: \n");
3945 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
3946 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
3947 struct ext4_prealloc_space *pa;
3948 ext4_grpblk_t start;
3949 struct list_head *cur;
3950 ext4_lock_group(sb, i);
3951 list_for_each(cur, &grp->bb_prealloc_list) {
3952 pa = list_entry(cur, struct ext4_prealloc_space,
3953 pa_group_list);
3954 spin_lock(&pa->pa_lock);
3955 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3956 NULL, &start);
3957 spin_unlock(&pa->pa_lock);
3958 printk(KERN_ERR "PA:%lu:%d:%u \n", i,
3959 start, pa->pa_len);
3960 }
Solofo Ramangalahy60bd63d2008-04-29 21:59:59 -04003961 ext4_unlock_group(sb, i);
Alex Tomasc9de5602008-01-29 00:19:52 -05003962
3963 if (grp->bb_free == 0)
3964 continue;
3965 printk(KERN_ERR "%lu: %d/%d \n",
3966 i, grp->bb_free, grp->bb_fragments);
3967 }
3968 printk(KERN_ERR "\n");
3969}
3970#else
3971static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
3972{
3973 return;
3974}
3975#endif
3976
3977/*
3978 * We use locality group preallocation for small size file. The size of the
3979 * file is determined by the current size or the resulting size after
3980 * allocation which ever is larger
3981 *
3982 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
3983 */
3984static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
3985{
3986 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3987 int bsbits = ac->ac_sb->s_blocksize_bits;
3988 loff_t size, isize;
3989
3990 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3991 return;
3992
3993 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
3994 isize = i_size_read(ac->ac_inode) >> bsbits;
3995 size = max(size, isize);
3996
3997 /* don't use group allocation for large files */
3998 if (size >= sbi->s_mb_stream_request)
3999 return;
4000
4001 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4002 return;
4003
4004 BUG_ON(ac->ac_lg != NULL);
4005 /*
4006 * locality group prealloc space are per cpu. The reason for having
4007 * per cpu locality group is to reduce the contention between block
4008 * request from multiple CPUs.
4009 */
Eric Sandeen730c2132008-09-13 15:23:29 -04004010 ac->ac_lg = per_cpu_ptr(sbi->s_locality_groups, raw_smp_processor_id());
Alex Tomasc9de5602008-01-29 00:19:52 -05004011
4012 /* we're going to use group allocation */
4013 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4014
4015 /* serialize all allocations in the group */
4016 mutex_lock(&ac->ac_lg->lg_mutex);
4017}
4018
Eric Sandeen4ddfef72008-04-29 08:11:12 -04004019static noinline_for_stack int
4020ext4_mb_initialize_context(struct ext4_allocation_context *ac,
Alex Tomasc9de5602008-01-29 00:19:52 -05004021 struct ext4_allocation_request *ar)
4022{
4023 struct super_block *sb = ar->inode->i_sb;
4024 struct ext4_sb_info *sbi = EXT4_SB(sb);
4025 struct ext4_super_block *es = sbi->s_es;
4026 ext4_group_t group;
4027 unsigned long len;
4028 unsigned long goal;
4029 ext4_grpblk_t block;
4030
4031 /* we can't allocate > group size */
4032 len = ar->len;
4033
4034 /* just a dirty hack to filter too big requests */
4035 if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
4036 len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
4037
4038 /* start searching from the goal */
4039 goal = ar->goal;
4040 if (goal < le32_to_cpu(es->s_first_data_block) ||
4041 goal >= ext4_blocks_count(es))
4042 goal = le32_to_cpu(es->s_first_data_block);
4043 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4044
4045 /* set up allocation goals */
4046 ac->ac_b_ex.fe_logical = ar->logical;
4047 ac->ac_b_ex.fe_group = 0;
4048 ac->ac_b_ex.fe_start = 0;
4049 ac->ac_b_ex.fe_len = 0;
4050 ac->ac_status = AC_STATUS_CONTINUE;
4051 ac->ac_groups_scanned = 0;
4052 ac->ac_ex_scanned = 0;
4053 ac->ac_found = 0;
4054 ac->ac_sb = sb;
4055 ac->ac_inode = ar->inode;
4056 ac->ac_o_ex.fe_logical = ar->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.fe_logical = ar->logical;
4061 ac->ac_g_ex.fe_group = group;
4062 ac->ac_g_ex.fe_start = block;
4063 ac->ac_g_ex.fe_len = len;
4064 ac->ac_f_ex.fe_len = 0;
4065 ac->ac_flags = ar->flags;
4066 ac->ac_2order = 0;
4067 ac->ac_criteria = 0;
4068 ac->ac_pa = NULL;
4069 ac->ac_bitmap_page = NULL;
4070 ac->ac_buddy_page = NULL;
4071 ac->ac_lg = NULL;
4072
4073 /* we have to define context: we'll we work with a file or
4074 * locality group. this is a policy, actually */
4075 ext4_mb_group_or_file(ac);
4076
4077 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4078 "left: %u/%u, right %u/%u to %swritable\n",
4079 (unsigned) ar->len, (unsigned) ar->logical,
4080 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4081 (unsigned) ar->lleft, (unsigned) ar->pleft,
4082 (unsigned) ar->lright, (unsigned) ar->pright,
4083 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4084 return 0;
4085
4086}
4087
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04004088static noinline_for_stack void
4089ext4_mb_discard_lg_preallocations(struct super_block *sb,
4090 struct ext4_locality_group *lg,
4091 int order, int total_entries)
4092{
4093 ext4_group_t group = 0;
4094 struct ext4_buddy e4b;
4095 struct list_head discard_list;
4096 struct ext4_prealloc_space *pa, *tmp;
4097 struct ext4_allocation_context *ac;
4098
4099 mb_debug("discard locality group preallocation\n");
4100
4101 INIT_LIST_HEAD(&discard_list);
4102 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4103
4104 spin_lock(&lg->lg_prealloc_lock);
4105 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list[order],
4106 pa_inode_list) {
4107 spin_lock(&pa->pa_lock);
4108 if (atomic_read(&pa->pa_count)) {
4109 /*
4110 * This is the pa that we just used
4111 * for block allocation. So don't
4112 * free that
4113 */
4114 spin_unlock(&pa->pa_lock);
4115 continue;
4116 }
4117 if (pa->pa_deleted) {
4118 spin_unlock(&pa->pa_lock);
4119 continue;
4120 }
4121 /* only lg prealloc space */
4122 BUG_ON(!pa->pa_linear);
4123
4124 /* seems this one can be freed ... */
4125 pa->pa_deleted = 1;
4126 spin_unlock(&pa->pa_lock);
4127
4128 list_del_rcu(&pa->pa_inode_list);
4129 list_add(&pa->u.pa_tmp_list, &discard_list);
4130
4131 total_entries--;
4132 if (total_entries <= 5) {
4133 /*
4134 * we want to keep only 5 entries
4135 * allowing it to grow to 8. This
4136 * mak sure we don't call discard
4137 * soon for this list.
4138 */
4139 break;
4140 }
4141 }
4142 spin_unlock(&lg->lg_prealloc_lock);
4143
4144 list_for_each_entry_safe(pa, tmp, &discard_list, u.pa_tmp_list) {
4145
4146 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4147 if (ext4_mb_load_buddy(sb, group, &e4b)) {
4148 ext4_error(sb, __func__, "Error in loading buddy "
4149 "information for %lu\n", group);
4150 continue;
4151 }
4152 ext4_lock_group(sb, group);
4153 list_del(&pa->pa_group_list);
4154 ext4_mb_release_group_pa(&e4b, pa, ac);
4155 ext4_unlock_group(sb, group);
4156
4157 ext4_mb_release_desc(&e4b);
4158 list_del(&pa->u.pa_tmp_list);
4159 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4160 }
4161 if (ac)
4162 kmem_cache_free(ext4_ac_cachep, ac);
4163}
4164
4165/*
4166 * We have incremented pa_count. So it cannot be freed at this
4167 * point. Also we hold lg_mutex. So no parallel allocation is
4168 * possible from this lg. That means pa_free cannot be updated.
4169 *
4170 * A parallel ext4_mb_discard_group_preallocations is possible.
4171 * which can cause the lg_prealloc_list to be updated.
4172 */
4173
4174static void ext4_mb_add_n_trim(struct ext4_allocation_context *ac)
4175{
4176 int order, added = 0, lg_prealloc_count = 1;
4177 struct super_block *sb = ac->ac_sb;
4178 struct ext4_locality_group *lg = ac->ac_lg;
4179 struct ext4_prealloc_space *tmp_pa, *pa = ac->ac_pa;
4180
4181 order = fls(pa->pa_free) - 1;
4182 if (order > PREALLOC_TB_SIZE - 1)
4183 /* The max size of hash table is PREALLOC_TB_SIZE */
4184 order = PREALLOC_TB_SIZE - 1;
4185 /* Add the prealloc space to lg */
4186 rcu_read_lock();
4187 list_for_each_entry_rcu(tmp_pa, &lg->lg_prealloc_list[order],
4188 pa_inode_list) {
4189 spin_lock(&tmp_pa->pa_lock);
4190 if (tmp_pa->pa_deleted) {
4191 spin_unlock(&pa->pa_lock);
4192 continue;
4193 }
4194 if (!added && pa->pa_free < tmp_pa->pa_free) {
4195 /* Add to the tail of the previous entry */
4196 list_add_tail_rcu(&pa->pa_inode_list,
4197 &tmp_pa->pa_inode_list);
4198 added = 1;
4199 /*
4200 * we want to count the total
4201 * number of entries in the list
4202 */
4203 }
4204 spin_unlock(&tmp_pa->pa_lock);
4205 lg_prealloc_count++;
4206 }
4207 if (!added)
4208 list_add_tail_rcu(&pa->pa_inode_list,
4209 &lg->lg_prealloc_list[order]);
4210 rcu_read_unlock();
4211
4212 /* Now trim the list to be not more than 8 elements */
4213 if (lg_prealloc_count > 8) {
4214 ext4_mb_discard_lg_preallocations(sb, lg,
4215 order, lg_prealloc_count);
4216 return;
4217 }
4218 return ;
4219}
4220
Alex Tomasc9de5602008-01-29 00:19:52 -05004221/*
4222 * release all resource we used in allocation
4223 */
4224static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4225{
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04004226 struct ext4_prealloc_space *pa = ac->ac_pa;
4227 if (pa) {
4228 if (pa->pa_linear) {
Alex Tomasc9de5602008-01-29 00:19:52 -05004229 /* see comment in ext4_mb_use_group_pa() */
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04004230 spin_lock(&pa->pa_lock);
4231 pa->pa_pstart += ac->ac_b_ex.fe_len;
4232 pa->pa_lstart += ac->ac_b_ex.fe_len;
4233 pa->pa_free -= ac->ac_b_ex.fe_len;
4234 pa->pa_len -= ac->ac_b_ex.fe_len;
4235 spin_unlock(&pa->pa_lock);
4236 /*
4237 * We want to add the pa to the right bucket.
4238 * Remove it from the list and while adding
4239 * make sure the list to which we are adding
4240 * doesn't grow big.
4241 */
4242 if (likely(pa->pa_free)) {
4243 spin_lock(pa->pa_obj_lock);
4244 list_del_rcu(&pa->pa_inode_list);
4245 spin_unlock(pa->pa_obj_lock);
4246 ext4_mb_add_n_trim(ac);
4247 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004248 }
Aneesh Kumar K.V6be2ded2008-07-23 14:14:05 -04004249 ext4_mb_put_pa(ac, ac->ac_sb, pa);
Alex Tomasc9de5602008-01-29 00:19:52 -05004250 }
4251 if (ac->ac_bitmap_page)
4252 page_cache_release(ac->ac_bitmap_page);
4253 if (ac->ac_buddy_page)
4254 page_cache_release(ac->ac_buddy_page);
4255 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4256 mutex_unlock(&ac->ac_lg->lg_mutex);
4257 ext4_mb_collect_stats(ac);
4258 return 0;
4259}
4260
4261static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4262{
4263 ext4_group_t i;
4264 int ret;
4265 int freed = 0;
4266
4267 for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
4268 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4269 freed += ret;
4270 needed -= ret;
4271 }
4272
4273 return freed;
4274}
4275
4276/*
4277 * Main entry point into mballoc to allocate blocks
4278 * it tries to use preallocation first, then falls back
4279 * to usual allocation
4280 */
4281ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4282 struct ext4_allocation_request *ar, int *errp)
4283{
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04004284 int freed;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004285 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004286 struct ext4_sb_info *sbi;
4287 struct super_block *sb;
4288 ext4_fsblk_t block = 0;
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04004289 unsigned long inquota;
4290 unsigned long reserv_blks = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05004291
4292 sb = ar->inode->i_sb;
4293 sbi = EXT4_SB(sb);
4294
Mingming Caod2a17632008-07-14 17:52:37 -04004295 if (!EXT4_I(ar->inode)->i_delalloc_reserved_flag) {
4296 /*
4297 * With delalloc we already reserved the blocks
4298 */
Aneesh Kumar K.V030ba6b2008-09-08 23:14:50 -04004299 while (ar->len && ext4_claim_free_blocks(sbi, ar->len)) {
4300 /* let others to free the space */
4301 yield();
4302 ar->len = ar->len >> 1;
4303 }
4304 if (!ar->len) {
Aneesh Kumar K.Va30d542a2008-10-09 10:56:23 -04004305 *errp = -ENOSPC;
4306 return 0;
4307 }
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04004308 reserv_blks = ar->len;
Mingming Caod2a17632008-07-14 17:52:37 -04004309 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004310 while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
4311 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4312 ar->len--;
4313 }
4314 if (ar->len == 0) {
4315 *errp = -EDQUOT;
4316 return 0;
4317 }
4318 inquota = ar->len;
4319
Mingming Caod2a17632008-07-14 17:52:37 -04004320 if (EXT4_I(ar->inode)->i_delalloc_reserved_flag)
4321 ar->flags |= EXT4_MB_DELALLOC_RESERVED;
4322
Eric Sandeen256bdb42008-02-10 01:13:33 -05004323 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4324 if (!ac) {
Shen Feng363d4252008-07-11 19:27:31 -04004325 ar->len = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004326 *errp = -ENOMEM;
Shen Feng363d4252008-07-11 19:27:31 -04004327 goto out1;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004328 }
4329
Eric Sandeen256bdb42008-02-10 01:13:33 -05004330 *errp = ext4_mb_initialize_context(ac, ar);
Alex Tomasc9de5602008-01-29 00:19:52 -05004331 if (*errp) {
4332 ar->len = 0;
Shen Feng363d4252008-07-11 19:27:31 -04004333 goto out2;
Alex Tomasc9de5602008-01-29 00:19:52 -05004334 }
4335
Eric Sandeen256bdb42008-02-10 01:13:33 -05004336 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4337 if (!ext4_mb_use_preallocated(ac)) {
Eric Sandeen256bdb42008-02-10 01:13:33 -05004338 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4339 ext4_mb_normalize_request(ac, ar);
Alex Tomasc9de5602008-01-29 00:19:52 -05004340repeat:
4341 /* allocate space in core */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004342 ext4_mb_regular_allocator(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004343
4344 /* as we've just preallocated more space than
4345 * user requested orinally, we store allocated
4346 * space in a special descriptor */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004347 if (ac->ac_status == AC_STATUS_FOUND &&
4348 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4349 ext4_mb_new_preallocation(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004350 }
4351
Eric Sandeen256bdb42008-02-10 01:13:33 -05004352 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
Aneesh Kumar K.V6bc6e632008-10-10 09:39:00 -04004353 *errp = ext4_mb_mark_diskspace_used(ac, handle, reserv_blks);
Aneesh Kumar K.V519deca2008-05-15 14:43:20 -04004354 if (*errp == -EAGAIN) {
4355 ac->ac_b_ex.fe_group = 0;
4356 ac->ac_b_ex.fe_start = 0;
4357 ac->ac_b_ex.fe_len = 0;
4358 ac->ac_status = AC_STATUS_CONTINUE;
4359 goto repeat;
4360 } else if (*errp) {
4361 ac->ac_b_ex.fe_len = 0;
4362 ar->len = 0;
4363 ext4_mb_show_ac(ac);
4364 } else {
4365 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4366 ar->len = ac->ac_b_ex.fe_len;
4367 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004368 } else {
Eric Sandeen256bdb42008-02-10 01:13:33 -05004369 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05004370 if (freed)
4371 goto repeat;
4372 *errp = -ENOSPC;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004373 ac->ac_b_ex.fe_len = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05004374 ar->len = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004375 ext4_mb_show_ac(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004376 }
4377
Eric Sandeen256bdb42008-02-10 01:13:33 -05004378 ext4_mb_release_context(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004379
Shen Feng363d4252008-07-11 19:27:31 -04004380out2:
4381 kmem_cache_free(ext4_ac_cachep, ac);
4382out1:
Alex Tomasc9de5602008-01-29 00:19:52 -05004383 if (ar->len < inquota)
4384 DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
4385
4386 return block;
4387}
Alex Tomasc9de5602008-01-29 00:19:52 -05004388
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004389/*
4390 * We can merge two free data extents only if the physical blocks
4391 * are contiguous, AND the extents were freed by the same transaction,
4392 * AND the blocks are associated with the same group.
4393 */
4394static int can_merge(struct ext4_free_data *entry1,
4395 struct ext4_free_data *entry2)
4396{
4397 if ((entry1->t_tid == entry2->t_tid) &&
4398 (entry1->group == entry2->group) &&
4399 ((entry1->start_blk + entry1->count) == entry2->start_blk))
4400 return 1;
4401 return 0;
4402}
4403
Eric Sandeen4ddfef72008-04-29 08:11:12 -04004404static noinline_for_stack int
4405ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
Alex Tomasc9de5602008-01-29 00:19:52 -05004406 ext4_group_t group, ext4_grpblk_t block, int count)
4407{
4408 struct ext4_group_info *db = e4b->bd_info;
4409 struct super_block *sb = e4b->bd_sb;
4410 struct ext4_sb_info *sbi = EXT4_SB(sb);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004411 struct ext4_free_data *entry, *new_entry;
4412 struct rb_node **n = &db->bb_free_root.rb_node, *node;
4413 struct rb_node *parent = NULL, *new_node;
4414
Alex Tomasc9de5602008-01-29 00:19:52 -05004415
4416 BUG_ON(e4b->bd_bitmap_page == NULL);
4417 BUG_ON(e4b->bd_buddy_page == NULL);
4418
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004419 new_entry = kmem_cache_alloc(ext4_free_ext_cachep, GFP_NOFS);
4420 new_entry->start_blk = block;
4421 new_entry->group = group;
4422 new_entry->count = count;
4423 new_entry->t_tid = handle->h_transaction->t_tid;
4424 new_node = &new_entry->node;
4425
Alex Tomasc9de5602008-01-29 00:19:52 -05004426 ext4_lock_group(sb, group);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004427 if (!*n) {
4428 /* first free block exent. We need to
4429 protect buddy cache from being freed,
4430 * otherwise we'll refresh it from
4431 * on-disk bitmap and lose not-yet-available
4432 * blocks */
4433 page_cache_get(e4b->bd_buddy_page);
4434 page_cache_get(e4b->bd_bitmap_page);
4435 }
4436 while (*n) {
4437 parent = *n;
4438 entry = rb_entry(parent, struct ext4_free_data, node);
4439 if (block < entry->start_blk)
4440 n = &(*n)->rb_left;
4441 else if (block >= (entry->start_blk + entry->count))
4442 n = &(*n)->rb_right;
4443 else {
Aneesh Kumar K.Vae2d9fb2008-11-04 09:10:50 -05004444 ext4_unlock_group(sb, group);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004445 ext4_error(sb, __func__,
4446 "Double free of blocks %d (%d %d)\n",
4447 block, entry->start_blk, entry->count);
4448 return 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05004449 }
4450 }
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004451
4452 rb_link_node(new_node, parent, n);
4453 rb_insert_color(new_node, &db->bb_free_root);
4454
4455 /* Now try to see the extent can be merged to left and right */
4456 node = rb_prev(new_node);
4457 if (node) {
4458 entry = rb_entry(node, struct ext4_free_data, node);
4459 if (can_merge(entry, new_entry)) {
4460 new_entry->start_blk = entry->start_blk;
4461 new_entry->count += entry->count;
4462 rb_erase(node, &(db->bb_free_root));
4463 spin_lock(&sbi->s_md_lock);
4464 list_del(&entry->list);
4465 spin_unlock(&sbi->s_md_lock);
4466 kmem_cache_free(ext4_free_ext_cachep, entry);
4467 }
4468 }
4469
4470 node = rb_next(new_node);
4471 if (node) {
4472 entry = rb_entry(node, struct ext4_free_data, node);
4473 if (can_merge(new_entry, entry)) {
4474 new_entry->count += entry->count;
4475 rb_erase(node, &(db->bb_free_root));
4476 spin_lock(&sbi->s_md_lock);
4477 list_del(&entry->list);
4478 spin_unlock(&sbi->s_md_lock);
4479 kmem_cache_free(ext4_free_ext_cachep, entry);
4480 }
4481 }
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04004482 /* Add the extent to transaction's private list */
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004483 spin_lock(&sbi->s_md_lock);
Theodore Ts'o3e624fc2008-10-16 20:00:24 -04004484 list_add(&new_entry->list, &handle->h_transaction->t_private_list);
Aneesh Kumar K.Vc8940582008-10-16 10:14:27 -04004485 spin_unlock(&sbi->s_md_lock);
Alex Tomasc9de5602008-01-29 00:19:52 -05004486 ext4_unlock_group(sb, group);
4487 return 0;
4488}
4489
4490/*
4491 * Main entry point into mballoc to free blocks
4492 */
4493void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
4494 unsigned long block, unsigned long count,
4495 int metadata, unsigned long *freed)
4496{
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05004497 struct buffer_head *bitmap_bh = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004498 struct super_block *sb = inode->i_sb;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004499 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004500 struct ext4_group_desc *gdp;
4501 struct ext4_super_block *es;
4502 unsigned long overflow;
4503 ext4_grpblk_t bit;
4504 struct buffer_head *gd_bh;
4505 ext4_group_t block_group;
4506 struct ext4_sb_info *sbi;
4507 struct ext4_buddy e4b;
4508 int err = 0;
4509 int ret;
4510
4511 *freed = 0;
4512
Alex Tomasc9de5602008-01-29 00:19:52 -05004513 sbi = EXT4_SB(sb);
4514 es = EXT4_SB(sb)->s_es;
4515 if (block < le32_to_cpu(es->s_first_data_block) ||
4516 block + count < block ||
4517 block + count > ext4_blocks_count(es)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04004518 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05004519 "Freeing blocks not in datazone - "
4520 "block = %lu, count = %lu", block, count);
4521 goto error_return;
4522 }
4523
4524 ext4_debug("freeing block %lu\n", block);
4525
Eric Sandeen256bdb42008-02-10 01:13:33 -05004526 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4527 if (ac) {
4528 ac->ac_op = EXT4_MB_HISTORY_FREE;
4529 ac->ac_inode = inode;
4530 ac->ac_sb = sb;
4531 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004532
4533do_more:
4534 overflow = 0;
4535 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4536
4537 /*
4538 * Check to see if we are freeing blocks across a group
4539 * boundary.
4540 */
4541 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4542 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
4543 count -= overflow;
4544 }
Theodore Ts'o574ca172008-07-11 19:27:31 -04004545 bitmap_bh = ext4_read_block_bitmap(sb, block_group);
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04004546 if (!bitmap_bh) {
4547 err = -EIO;
Alex Tomasc9de5602008-01-29 00:19:52 -05004548 goto error_return;
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04004549 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004550 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04004551 if (!gdp) {
4552 err = -EIO;
Alex Tomasc9de5602008-01-29 00:19:52 -05004553 goto error_return;
Aneesh Kumar K.Vce89f462008-07-23 14:09:29 -04004554 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004555
4556 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4557 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4558 in_range(block, ext4_inode_table(sb, gdp),
4559 EXT4_SB(sb)->s_itb_per_group) ||
4560 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4561 EXT4_SB(sb)->s_itb_per_group)) {
4562
Harvey Harrison46e665e2008-04-17 10:38:59 -04004563 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05004564 "Freeing blocks in system zone - "
4565 "Block = %lu, count = %lu", block, count);
Aneesh Kumar K.V519deca2008-05-15 14:43:20 -04004566 /* err = 0. ext4_std_error should be a no op */
4567 goto error_return;
Alex Tomasc9de5602008-01-29 00:19:52 -05004568 }
4569
4570 BUFFER_TRACE(bitmap_bh, "getting write access");
4571 err = ext4_journal_get_write_access(handle, bitmap_bh);
4572 if (err)
4573 goto error_return;
4574
4575 /*
4576 * We are about to modify some metadata. Call the journal APIs
4577 * to unshare ->b_data if a currently-committing transaction is
4578 * using it
4579 */
4580 BUFFER_TRACE(gd_bh, "get_write_access");
4581 err = ext4_journal_get_write_access(handle, gd_bh);
4582 if (err)
4583 goto error_return;
4584
4585 err = ext4_mb_load_buddy(sb, block_group, &e4b);
4586 if (err)
4587 goto error_return;
4588
4589#ifdef AGGRESSIVE_CHECK
4590 {
4591 int i;
4592 for (i = 0; i < count; i++)
4593 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4594 }
4595#endif
4596 mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
4597 bit, count);
4598
4599 /* We dirtied the bitmap block */
4600 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4601 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
4602
Eric Sandeen256bdb42008-02-10 01:13:33 -05004603 if (ac) {
4604 ac->ac_b_ex.fe_group = block_group;
4605 ac->ac_b_ex.fe_start = bit;
4606 ac->ac_b_ex.fe_len = count;
4607 ext4_mb_store_history(ac);
4608 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004609
4610 if (metadata) {
4611 /* blocks being freed are metadata. these blocks shouldn't
4612 * be used until this transaction is committed */
4613 ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
4614 } else {
4615 ext4_lock_group(sb, block_group);
Shen Feng7e5a8cd2008-07-13 21:03:31 -04004616 mb_free_blocks(inode, &e4b, bit, count);
Alex Tomasc9de5602008-01-29 00:19:52 -05004617 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
4618 ext4_unlock_group(sb, block_group);
Alex Tomasc9de5602008-01-29 00:19:52 -05004619 }
4620
4621 spin_lock(sb_bgl_lock(sbi, block_group));
Marcin Slusarze8546d02008-04-17 10:38:59 -04004622 le16_add_cpu(&gdp->bg_free_blocks_count, count);
Alex Tomasc9de5602008-01-29 00:19:52 -05004623 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
4624 spin_unlock(sb_bgl_lock(sbi, block_group));
4625 percpu_counter_add(&sbi->s_freeblocks_counter, count);
4626
Jose R. Santos772cb7c2008-07-11 19:27:31 -04004627 if (sbi->s_log_groups_per_flex) {
4628 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
4629 spin_lock(sb_bgl_lock(sbi, flex_group));
4630 sbi->s_flex_groups[flex_group].free_blocks += count;
4631 spin_unlock(sb_bgl_lock(sbi, flex_group));
4632 }
4633
Alex Tomasc9de5602008-01-29 00:19:52 -05004634 ext4_mb_release_desc(&e4b);
4635
4636 *freed += count;
4637
4638 /* And the group descriptor block */
4639 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4640 ret = ext4_journal_dirty_metadata(handle, gd_bh);
4641 if (!err)
4642 err = ret;
4643
4644 if (overflow && !err) {
4645 block += count;
4646 count = overflow;
4647 put_bh(bitmap_bh);
4648 goto do_more;
4649 }
4650 sb->s_dirt = 1;
4651error_return:
4652 brelse(bitmap_bh);
4653 ext4_std_error(sb, err);
Eric Sandeen256bdb42008-02-10 01:13:33 -05004654 if (ac)
4655 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004656 return;
4657}