blob: ef97f19c2f9d7a51d68ccb281ca982e79a53e823 [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
24#include <linux/time.h>
25#include <linux/fs.h>
26#include <linux/namei.h>
27#include <linux/ext4_jbd2.h>
28#include <linux/ext4_fs.h>
29#include <linux/quotaops.h>
30#include <linux/buffer_head.h>
31#include <linux/module.h>
32#include <linux/swap.h>
33#include <linux/proc_fs.h>
34#include <linux/pagemap.h>
35#include <linux/seq_file.h>
36#include <linux/version.h>
37#include "group.h"
38
39/*
40 * MUSTDO:
41 * - test ext4_ext_search_left() and ext4_ext_search_right()
42 * - search for metadata in few groups
43 *
44 * TODO v4:
45 * - normalization should take into account whether file is still open
46 * - discard preallocations if no free space left (policy?)
47 * - don't normalize tails
48 * - quota
49 * - reservation for superuser
50 *
51 * TODO v3:
52 * - bitmap read-ahead (proposed by Oleg Drokin aka green)
53 * - track min/max extents in each group for better group selection
54 * - mb_mark_used() may allocate chunk right after splitting buddy
55 * - tree of groups sorted by number of free blocks
56 * - error handling
57 */
58
59/*
60 * The allocation request involve request for multiple number of blocks
61 * near to the goal(block) value specified.
62 *
63 * During initialization phase of the allocator we decide to use the group
64 * preallocation or inode preallocation depending on the size file. The
65 * size of the file could be the resulting file size we would have after
66 * allocation or the current file size which ever is larger. If the size is
67 * less that sbi->s_mb_stream_request we select the group
68 * preallocation. The default value of s_mb_stream_request is 16
69 * blocks. This can also be tuned via
70 * /proc/fs/ext4/<partition>/stream_req. The value is represented in terms
71 * of number of blocks.
72 *
73 * The main motivation for having small file use group preallocation is to
74 * ensure that we have small file closer in the disk.
75 *
76 * First stage the allocator looks at the inode prealloc list
77 * ext4_inode_info->i_prealloc_list contain list of prealloc spaces for
78 * this particular inode. The inode prealloc space is represented as:
79 *
80 * pa_lstart -> the logical start block for this prealloc space
81 * pa_pstart -> the physical start block for this prealloc space
82 * pa_len -> lenght for this prealloc space
83 * pa_free -> free space available in this prealloc space
84 *
85 * The inode preallocation space is used looking at the _logical_ start
86 * block. If only the logical file block falls within the range of prealloc
87 * space we will consume the particular prealloc space. This make sure that
88 * that the we have contiguous physical blocks representing the file blocks
89 *
90 * The important thing to be noted in case of inode prealloc space is that
91 * we don't modify the values associated to inode prealloc space except
92 * pa_free.
93 *
94 * If we are not able to find blocks in the inode prealloc space and if we
95 * have the group allocation flag set then we look at the locality group
96 * prealloc space. These are per CPU prealloc list repreasented as
97 *
98 * ext4_sb_info.s_locality_groups[smp_processor_id()]
99 *
100 * The reason for having a per cpu locality group is to reduce the contention
101 * between CPUs. It is possible to get scheduled at this point.
102 *
103 * The locality group prealloc space is used looking at whether we have
104 * enough free space (pa_free) withing the prealloc space.
105 *
106 * If we can't allocate blocks via inode prealloc or/and locality group
107 * prealloc then we look at the buddy cache. The buddy cache is represented
108 * by ext4_sb_info.s_buddy_cache (struct inode) whose file offset gets
109 * mapped to the buddy and bitmap information regarding different
110 * groups. The buddy information is attached to buddy cache inode so that
111 * we can access them through the page cache. The information regarding
112 * each group is loaded via ext4_mb_load_buddy. The information involve
113 * block bitmap and buddy information. The information are stored in the
114 * inode as:
115 *
116 * { page }
117 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
118 *
119 *
120 * one block each for bitmap and buddy information. So for each group we
121 * take up 2 blocks. A page can contain blocks_per_page (PAGE_CACHE_SIZE /
122 * blocksize) blocks. So it can have information regarding groups_per_page
123 * which is blocks_per_page/2
124 *
125 * The buddy cache inode is not stored on disk. The inode is thrown
126 * away when the filesystem is unmounted.
127 *
128 * We look for count number of blocks in the buddy cache. If we were able
129 * to locate that many free blocks we return with additional information
130 * regarding rest of the contiguous physical block available
131 *
132 * Before allocating blocks via buddy cache we normalize the request
133 * blocks. This ensure we ask for more blocks that we needed. The extra
134 * blocks that we get after allocation is added to the respective prealloc
135 * list. In case of inode preallocation we follow a list of heuristics
136 * based on file size. This can be found in ext4_mb_normalize_request. If
137 * we are doing a group prealloc we try to normalize the request to
138 * sbi->s_mb_group_prealloc. Default value of s_mb_group_prealloc is set to
139 * 512 blocks. This can be tuned via
140 * /proc/fs/ext4/<partition/group_prealloc. The value is represented in
141 * terms of number of blocks. If we have mounted the file system with -O
142 * stripe=<value> option the group prealloc request is normalized to the
143 * stripe value (sbi->s_stripe)
144 *
145 * The regular allocator(using the buddy cache) support few tunables.
146 *
147 * /proc/fs/ext4/<partition>/min_to_scan
148 * /proc/fs/ext4/<partition>/max_to_scan
149 * /proc/fs/ext4/<partition>/order2_req
150 *
151 * The regular allocator use buddy scan only if the request len is power of
152 * 2 blocks and the order of allocation is >= sbi->s_mb_order2_reqs. The
153 * value of s_mb_order2_reqs can be tuned via
154 * /proc/fs/ext4/<partition>/order2_req. If the request len is equal to
155 * stripe size (sbi->s_stripe), we try to search for contigous block in
156 * stripe size. This should result in better allocation on RAID setup. If
157 * not we search in the specific group using bitmap for best extents. The
158 * tunable min_to_scan and max_to_scan controll the behaviour here.
159 * min_to_scan indicate how long the mballoc __must__ look for a best
160 * extent and max_to_scanindicate how long the mballoc __can__ look for a
161 * best extent in the found extents. Searching for the blocks starts with
162 * the group specified as the goal value in allocation context via
163 * ac_g_ex. Each group is first checked based on the criteria whether it
164 * can used for allocation. ext4_mb_good_group explains how the groups are
165 * checked.
166 *
167 * Both the prealloc space are getting populated as above. So for the first
168 * request we will hit the buddy cache which will result in this prealloc
169 * space getting filled. The prealloc space is then later used for the
170 * subsequent request.
171 */
172
173/*
174 * mballoc operates on the following data:
175 * - on-disk bitmap
176 * - in-core buddy (actually includes buddy and bitmap)
177 * - preallocation descriptors (PAs)
178 *
179 * there are two types of preallocations:
180 * - inode
181 * assiged to specific inode and can be used for this inode only.
182 * it describes part of inode's space preallocated to specific
183 * physical blocks. any block from that preallocated can be used
184 * independent. the descriptor just tracks number of blocks left
185 * unused. so, before taking some block from descriptor, one must
186 * make sure corresponded logical block isn't allocated yet. this
187 * also means that freeing any block within descriptor's range
188 * must discard all preallocated blocks.
189 * - locality group
190 * assigned to specific locality group which does not translate to
191 * permanent set of inodes: inode can join and leave group. space
192 * from this type of preallocation can be used for any inode. thus
193 * it's consumed from the beginning to the end.
194 *
195 * relation between them can be expressed as:
196 * in-core buddy = on-disk bitmap + preallocation descriptors
197 *
198 * this mean blocks mballoc considers used are:
199 * - allocated blocks (persistent)
200 * - preallocated blocks (non-persistent)
201 *
202 * consistency in mballoc world means that at any time a block is either
203 * free or used in ALL structures. notice: "any time" should not be read
204 * literally -- time is discrete and delimited by locks.
205 *
206 * to keep it simple, we don't use block numbers, instead we count number of
207 * blocks: how many blocks marked used/free in on-disk bitmap, buddy and PA.
208 *
209 * all operations can be expressed as:
210 * - init buddy: buddy = on-disk + PAs
211 * - new PA: buddy += N; PA = N
212 * - use inode PA: on-disk += N; PA -= N
213 * - discard inode PA buddy -= on-disk - PA; PA = 0
214 * - use locality group PA on-disk += N; PA -= N
215 * - discard locality group PA buddy -= PA; PA = 0
216 * note: 'buddy -= on-disk - PA' is used to show that on-disk bitmap
217 * is used in real operation because we can't know actual used
218 * bits from PA, only from on-disk bitmap
219 *
220 * if we follow this strict logic, then all operations above should be atomic.
221 * given some of them can block, we'd have to use something like semaphores
222 * killing performance on high-end SMP hardware. let's try to relax it using
223 * the following knowledge:
224 * 1) if buddy is referenced, it's already initialized
225 * 2) while block is used in buddy and the buddy is referenced,
226 * nobody can re-allocate that block
227 * 3) we work on bitmaps and '+' actually means 'set bits'. if on-disk has
228 * bit set and PA claims same block, it's OK. IOW, one can set bit in
229 * on-disk bitmap if buddy has same bit set or/and PA covers corresponded
230 * block
231 *
232 * so, now we're building a concurrency table:
233 * - init buddy vs.
234 * - new PA
235 * blocks for PA are allocated in the buddy, buddy must be referenced
236 * until PA is linked to allocation group to avoid concurrent buddy init
237 * - use inode PA
238 * we need to make sure that either on-disk bitmap or PA has uptodate data
239 * given (3) we care that PA-=N operation doesn't interfere with init
240 * - discard inode PA
241 * the simplest way would be to have buddy initialized by the discard
242 * - use locality group PA
243 * again PA-=N must be serialized with init
244 * - discard locality group PA
245 * the simplest way would be to have buddy initialized by the discard
246 * - new PA vs.
247 * - use inode PA
248 * i_data_sem serializes them
249 * - discard inode PA
250 * discard process must wait until PA isn't used by another process
251 * - use locality group PA
252 * some mutex should serialize them
253 * - discard locality group PA
254 * discard process must wait until PA isn't used by another process
255 * - use inode PA
256 * - use inode PA
257 * i_data_sem or another mutex should serializes them
258 * - discard inode PA
259 * discard process must wait until PA isn't used by another process
260 * - use locality group PA
261 * nothing wrong here -- they're different PAs covering different blocks
262 * - discard locality group PA
263 * discard process must wait until PA isn't used by another process
264 *
265 * now we're ready to make few consequences:
266 * - PA is referenced and while it is no discard is possible
267 * - PA is referenced until block isn't marked in on-disk bitmap
268 * - PA changes only after on-disk bitmap
269 * - discard must not compete with init. either init is done before
270 * any discard or they're serialized somehow
271 * - buddy init as sum of on-disk bitmap and PAs is done atomically
272 *
273 * a special case when we've used PA to emptiness. no need to modify buddy
274 * in this case, but we should care about concurrent init
275 *
276 */
277
278 /*
279 * Logic in few words:
280 *
281 * - allocation:
282 * load group
283 * find blocks
284 * mark bits in on-disk bitmap
285 * release group
286 *
287 * - use preallocation:
288 * find proper PA (per-inode or group)
289 * load group
290 * mark bits in on-disk bitmap
291 * release group
292 * release PA
293 *
294 * - free:
295 * load group
296 * mark bits in on-disk bitmap
297 * release group
298 *
299 * - discard preallocations in group:
300 * mark PAs deleted
301 * move them onto local list
302 * load on-disk bitmap
303 * load group
304 * remove PA from object (inode or locality group)
305 * mark free blocks in-core
306 *
307 * - discard inode's preallocations:
308 */
309
310/*
311 * Locking rules
312 *
313 * Locks:
314 * - bitlock on a group (group)
315 * - object (inode/locality) (object)
316 * - per-pa lock (pa)
317 *
318 * Paths:
319 * - new pa
320 * object
321 * group
322 *
323 * - find and use pa:
324 * pa
325 *
326 * - release consumed pa:
327 * pa
328 * group
329 * object
330 *
331 * - generate in-core bitmap:
332 * group
333 * pa
334 *
335 * - discard all for given object (inode, locality group):
336 * object
337 * pa
338 * group
339 *
340 * - discard all for given group:
341 * group
342 * pa
343 * group
344 * object
345 *
346 */
347
348/*
349 * with AGGRESSIVE_CHECK allocator runs consistency checks over
350 * structures. these checks slow things down a lot
351 */
352#define AGGRESSIVE_CHECK__
353
354/*
355 * with DOUBLE_CHECK defined mballoc creates persistent in-core
356 * bitmaps, maintains and uses them to check for double allocations
357 */
358#define DOUBLE_CHECK__
359
360/*
361 */
362#define MB_DEBUG__
363#ifdef MB_DEBUG
364#define mb_debug(fmt, a...) printk(fmt, ##a)
365#else
366#define mb_debug(fmt, a...)
367#endif
368
369/*
370 * with EXT4_MB_HISTORY mballoc stores last N allocations in memory
371 * and you can monitor it in /proc/fs/ext4/<dev>/mb_history
372 */
373#define EXT4_MB_HISTORY
374#define EXT4_MB_HISTORY_ALLOC 1 /* allocation */
375#define EXT4_MB_HISTORY_PREALLOC 2 /* preallocated blocks used */
376#define EXT4_MB_HISTORY_DISCARD 4 /* preallocation discarded */
377#define EXT4_MB_HISTORY_FREE 8 /* free */
378
379#define EXT4_MB_HISTORY_DEFAULT (EXT4_MB_HISTORY_ALLOC | \
380 EXT4_MB_HISTORY_PREALLOC)
381
382/*
383 * How long mballoc can look for a best extent (in found extents)
384 */
385#define MB_DEFAULT_MAX_TO_SCAN 200
386
387/*
388 * How long mballoc must look for a best extent
389 */
390#define MB_DEFAULT_MIN_TO_SCAN 10
391
392/*
393 * How many groups mballoc will scan looking for the best chunk
394 */
395#define MB_DEFAULT_MAX_GROUPS_TO_SCAN 5
396
397/*
398 * with 'ext4_mb_stats' allocator will collect stats that will be
399 * shown at umount. The collecting costs though!
400 */
401#define MB_DEFAULT_STATS 1
402
403/*
404 * files smaller than MB_DEFAULT_STREAM_THRESHOLD are served
405 * by the stream allocator, which purpose is to pack requests
406 * as close each to other as possible to produce smooth I/O traffic
407 * We use locality group prealloc space for stream request.
408 * We can tune the same via /proc/fs/ext4/<parition>/stream_req
409 */
410#define MB_DEFAULT_STREAM_THRESHOLD 16 /* 64K */
411
412/*
413 * for which requests use 2^N search using buddies
414 */
415#define MB_DEFAULT_ORDER2_REQS 2
416
417/*
418 * default group prealloc size 512 blocks
419 */
420#define MB_DEFAULT_GROUP_PREALLOC 512
421
422static struct kmem_cache *ext4_pspace_cachep;
Eric Sandeen256bdb42008-02-10 01:13:33 -0500423static struct kmem_cache *ext4_ac_cachep;
Alex Tomasc9de5602008-01-29 00:19:52 -0500424
425#ifdef EXT4_BB_MAX_BLOCKS
426#undef EXT4_BB_MAX_BLOCKS
427#endif
428#define EXT4_BB_MAX_BLOCKS 30
429
430struct ext4_free_metadata {
431 ext4_group_t group;
432 unsigned short num;
433 ext4_grpblk_t blocks[EXT4_BB_MAX_BLOCKS];
434 struct list_head list;
435};
436
437struct ext4_group_info {
438 unsigned long bb_state;
439 unsigned long bb_tid;
440 struct ext4_free_metadata *bb_md_cur;
441 unsigned short bb_first_free;
442 unsigned short bb_free;
443 unsigned short bb_fragments;
444 struct list_head bb_prealloc_list;
445#ifdef DOUBLE_CHECK
446 void *bb_bitmap;
447#endif
448 unsigned short bb_counters[];
449};
450
451#define EXT4_GROUP_INFO_NEED_INIT_BIT 0
452#define EXT4_GROUP_INFO_LOCKED_BIT 1
453
454#define EXT4_MB_GRP_NEED_INIT(grp) \
455 (test_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &((grp)->bb_state)))
456
457
458struct ext4_prealloc_space {
459 struct list_head pa_inode_list;
460 struct list_head pa_group_list;
461 union {
462 struct list_head pa_tmp_list;
463 struct rcu_head pa_rcu;
464 } u;
465 spinlock_t pa_lock;
466 atomic_t pa_count;
467 unsigned pa_deleted;
468 ext4_fsblk_t pa_pstart; /* phys. block */
469 ext4_lblk_t pa_lstart; /* log. block */
470 unsigned short pa_len; /* len of preallocated chunk */
471 unsigned short pa_free; /* how many blocks are free */
472 unsigned short pa_linear; /* consumed in one direction
473 * strictly, for grp prealloc */
474 spinlock_t *pa_obj_lock;
475 struct inode *pa_inode; /* hack, for history only */
476};
477
478
479struct ext4_free_extent {
480 ext4_lblk_t fe_logical;
481 ext4_grpblk_t fe_start;
482 ext4_group_t fe_group;
483 int fe_len;
484};
485
486/*
487 * Locality group:
488 * we try to group all related changes together
489 * so that writeback can flush/allocate them together as well
490 */
491struct ext4_locality_group {
492 /* for allocator */
493 struct mutex lg_mutex; /* to serialize allocates */
494 struct list_head lg_prealloc_list;/* list of preallocations */
495 spinlock_t lg_prealloc_lock;
496};
497
498struct ext4_allocation_context {
499 struct inode *ac_inode;
500 struct super_block *ac_sb;
501
502 /* original request */
503 struct ext4_free_extent ac_o_ex;
504
505 /* goal request (after normalization) */
506 struct ext4_free_extent ac_g_ex;
507
508 /* the best found extent */
509 struct ext4_free_extent ac_b_ex;
510
511 /* copy of the bext found extent taken before preallocation efforts */
512 struct ext4_free_extent ac_f_ex;
513
514 /* number of iterations done. we have to track to limit searching */
515 unsigned long ac_ex_scanned;
516 __u16 ac_groups_scanned;
517 __u16 ac_found;
518 __u16 ac_tail;
519 __u16 ac_buddy;
520 __u16 ac_flags; /* allocation hints */
521 __u8 ac_status;
522 __u8 ac_criteria;
523 __u8 ac_repeats;
524 __u8 ac_2order; /* if request is to allocate 2^N blocks and
525 * N > 0, the field stores N, otherwise 0 */
526 __u8 ac_op; /* operation, for history only */
527 struct page *ac_bitmap_page;
528 struct page *ac_buddy_page;
529 struct ext4_prealloc_space *ac_pa;
530 struct ext4_locality_group *ac_lg;
531};
532
533#define AC_STATUS_CONTINUE 1
534#define AC_STATUS_FOUND 2
535#define AC_STATUS_BREAK 3
536
537struct ext4_mb_history {
538 struct ext4_free_extent orig; /* orig allocation */
539 struct ext4_free_extent goal; /* goal allocation */
540 struct ext4_free_extent result; /* result allocation */
541 unsigned pid;
542 unsigned ino;
543 __u16 found; /* how many extents have been found */
544 __u16 groups; /* how many groups have been scanned */
545 __u16 tail; /* what tail broke some buddy */
546 __u16 buddy; /* buddy the tail ^^^ broke */
547 __u16 flags;
548 __u8 cr:3; /* which phase the result extent was found at */
549 __u8 op:4;
550 __u8 merged:1;
551};
552
553struct ext4_buddy {
554 struct page *bd_buddy_page;
555 void *bd_buddy;
556 struct page *bd_bitmap_page;
557 void *bd_bitmap;
558 struct ext4_group_info *bd_info;
559 struct super_block *bd_sb;
560 __u16 bd_blkbits;
561 ext4_group_t bd_group;
562};
563#define EXT4_MB_BITMAP(e4b) ((e4b)->bd_bitmap)
564#define EXT4_MB_BUDDY(e4b) ((e4b)->bd_buddy)
565
566#ifndef EXT4_MB_HISTORY
567static inline void ext4_mb_store_history(struct ext4_allocation_context *ac)
568{
569 return;
570}
571#else
572static void ext4_mb_store_history(struct ext4_allocation_context *ac);
573#endif
574
575#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1)
576
577static struct proc_dir_entry *proc_root_ext4;
578struct buffer_head *read_block_bitmap(struct super_block *, ext4_group_t);
579ext4_fsblk_t ext4_new_blocks_old(handle_t *handle, struct inode *inode,
580 ext4_fsblk_t goal, unsigned long *count, int *errp);
581
582static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
583 ext4_group_t group);
584static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *);
585static void ext4_mb_free_committed_blocks(struct super_block *);
586static void ext4_mb_return_to_preallocation(struct inode *inode,
587 struct ext4_buddy *e4b, sector_t block,
588 int count);
589static void ext4_mb_put_pa(struct ext4_allocation_context *,
590 struct super_block *, struct ext4_prealloc_space *pa);
591static int ext4_mb_init_per_dev_proc(struct super_block *sb);
592static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
593
594
595static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
596{
597 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
598
599 bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
600}
601
602static inline void ext4_unlock_group(struct super_block *sb,
603 ext4_group_t group)
604{
605 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
606
607 bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
608}
609
610static inline int ext4_is_group_locked(struct super_block *sb,
611 ext4_group_t group)
612{
613 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
614
615 return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
616 &(grinfo->bb_state));
617}
618
619static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
620 struct ext4_free_extent *fex)
621{
622 ext4_fsblk_t block;
623
624 block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
625 + fex->fe_start
626 + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
627 return block;
628}
629
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500630static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
631{
Alex Tomasc9de5602008-01-29 00:19:52 -0500632#if BITS_PER_LONG == 64
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500633 *bit += ((unsigned long) addr & 7UL) << 3;
634 addr = (void *) ((unsigned long) addr & ~7UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500635#elif BITS_PER_LONG == 32
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500636 *bit += ((unsigned long) addr & 3UL) << 3;
637 addr = (void *) ((unsigned long) addr & ~3UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500638#else
639#error "how many bits you are?!"
640#endif
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500641 return addr;
642}
Alex Tomasc9de5602008-01-29 00:19:52 -0500643
644static inline int mb_test_bit(int bit, void *addr)
645{
646 /*
647 * ext4_test_bit on architecture like powerpc
648 * needs unsigned long aligned address
649 */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500650 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500651 return ext4_test_bit(bit, addr);
652}
653
654static inline void mb_set_bit(int bit, void *addr)
655{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500656 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500657 ext4_set_bit(bit, addr);
658}
659
660static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
661{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500662 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500663 ext4_set_bit_atomic(lock, bit, addr);
664}
665
666static inline void mb_clear_bit(int bit, void *addr)
667{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500668 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500669 ext4_clear_bit(bit, addr);
670}
671
672static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
673{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500674 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500675 ext4_clear_bit_atomic(lock, bit, addr);
676}
677
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500678static inline int mb_find_next_zero_bit(void *addr, int max, int start)
679{
680 int fix = 0;
681 addr = mb_correct_addr_and_bit(&fix, addr);
682 max += fix;
683 start += fix;
684
685 return ext4_find_next_zero_bit(addr, max, start) - fix;
686}
687
688static inline int mb_find_next_bit(void *addr, int max, int start)
689{
690 int fix = 0;
691 addr = mb_correct_addr_and_bit(&fix, addr);
692 max += fix;
693 start += fix;
694
695 return ext4_find_next_bit(addr, max, start) - fix;
696}
697
Alex Tomasc9de5602008-01-29 00:19:52 -0500698static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
699{
700 char *bb;
701
Alex Tomasc9de5602008-01-29 00:19:52 -0500702 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
703 BUG_ON(max == NULL);
704
705 if (order > e4b->bd_blkbits + 1) {
706 *max = 0;
707 return NULL;
708 }
709
710 /* at order 0 we see each particular block */
711 *max = 1 << (e4b->bd_blkbits + 3);
712 if (order == 0)
713 return EXT4_MB_BITMAP(e4b);
714
715 bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
716 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
717
718 return bb;
719}
720
721#ifdef DOUBLE_CHECK
722static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
723 int first, int count)
724{
725 int i;
726 struct super_block *sb = e4b->bd_sb;
727
728 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
729 return;
730 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
731 for (i = 0; i < count; i++) {
732 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
733 ext4_fsblk_t blocknr;
734 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
735 blocknr += first + i;
736 blocknr +=
737 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
738
739 ext4_error(sb, __FUNCTION__, "double-free of inode"
740 " %lu's block %llu(bit %u in group %lu)\n",
741 inode ? inode->i_ino : 0, blocknr,
742 first + i, e4b->bd_group);
743 }
744 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
745 }
746}
747
748static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
749{
750 int i;
751
752 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
753 return;
754 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
755 for (i = 0; i < count; i++) {
756 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
757 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
758 }
759}
760
761static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
762{
763 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
764 unsigned char *b1, *b2;
765 int i;
766 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
767 b2 = (unsigned char *) bitmap;
768 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
769 if (b1[i] != b2[i]) {
770 printk("corruption in group %lu at byte %u(%u):"
771 " %x in copy != %x on disk/prealloc\n",
772 e4b->bd_group, i, i * 8, b1[i], b2[i]);
773 BUG();
774 }
775 }
776 }
777}
778
779#else
780static inline void mb_free_blocks_double(struct inode *inode,
781 struct ext4_buddy *e4b, int first, int count)
782{
783 return;
784}
785static inline void mb_mark_used_double(struct ext4_buddy *e4b,
786 int first, int count)
787{
788 return;
789}
790static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
791{
792 return;
793}
794#endif
795
796#ifdef AGGRESSIVE_CHECK
797
798#define MB_CHECK_ASSERT(assert) \
799do { \
800 if (!(assert)) { \
801 printk(KERN_EMERG \
802 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
803 function, file, line, # assert); \
804 BUG(); \
805 } \
806} while (0)
807
808static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
809 const char *function, int line)
810{
811 struct super_block *sb = e4b->bd_sb;
812 int order = e4b->bd_blkbits + 1;
813 int max;
814 int max2;
815 int i;
816 int j;
817 int k;
818 int count;
819 struct ext4_group_info *grp;
820 int fragments = 0;
821 int fstart;
822 struct list_head *cur;
823 void *buddy;
824 void *buddy2;
825
826 if (!test_opt(sb, MBALLOC))
827 return 0;
828
829 {
830 static int mb_check_counter;
831 if (mb_check_counter++ % 100 != 0)
832 return 0;
833 }
834
835 while (order > 1) {
836 buddy = mb_find_buddy(e4b, order, &max);
837 MB_CHECK_ASSERT(buddy);
838 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
839 MB_CHECK_ASSERT(buddy2);
840 MB_CHECK_ASSERT(buddy != buddy2);
841 MB_CHECK_ASSERT(max * 2 == max2);
842
843 count = 0;
844 for (i = 0; i < max; i++) {
845
846 if (mb_test_bit(i, buddy)) {
847 /* only single bit in buddy2 may be 1 */
848 if (!mb_test_bit(i << 1, buddy2)) {
849 MB_CHECK_ASSERT(
850 mb_test_bit((i<<1)+1, buddy2));
851 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
852 MB_CHECK_ASSERT(
853 mb_test_bit(i << 1, buddy2));
854 }
855 continue;
856 }
857
858 /* both bits in buddy2 must be 0 */
859 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
860 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
861
862 for (j = 0; j < (1 << order); j++) {
863 k = (i * (1 << order)) + j;
864 MB_CHECK_ASSERT(
865 !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
866 }
867 count++;
868 }
869 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
870 order--;
871 }
872
873 fstart = -1;
874 buddy = mb_find_buddy(e4b, 0, &max);
875 for (i = 0; i < max; i++) {
876 if (!mb_test_bit(i, buddy)) {
877 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
878 if (fstart == -1) {
879 fragments++;
880 fstart = i;
881 }
882 continue;
883 }
884 fstart = -1;
885 /* check used bits only */
886 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
887 buddy2 = mb_find_buddy(e4b, j, &max2);
888 k = i >> j;
889 MB_CHECK_ASSERT(k < max2);
890 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
891 }
892 }
893 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
894 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
895
896 grp = ext4_get_group_info(sb, e4b->bd_group);
897 buddy = mb_find_buddy(e4b, 0, &max);
898 list_for_each(cur, &grp->bb_prealloc_list) {
899 ext4_group_t groupnr;
900 struct ext4_prealloc_space *pa;
901 pa = list_entry(cur, struct ext4_prealloc_space, group_list);
902 ext4_get_group_no_and_offset(sb, pa->pstart, &groupnr, &k);
903 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
904 for (i = 0; i < pa->len; i++)
905 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
906 }
907 return 0;
908}
909#undef MB_CHECK_ASSERT
910#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
911 __FILE__, __FUNCTION__, __LINE__)
912#else
913#define mb_check_buddy(e4b)
914#endif
915
916/* FIXME!! need more doc */
917static void ext4_mb_mark_free_simple(struct super_block *sb,
918 void *buddy, unsigned first, int len,
919 struct ext4_group_info *grp)
920{
921 struct ext4_sb_info *sbi = EXT4_SB(sb);
922 unsigned short min;
923 unsigned short max;
924 unsigned short chunk;
925 unsigned short border;
926
Valerie Clementb73fce62008-02-15 13:48:51 -0500927 BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
Alex Tomasc9de5602008-01-29 00:19:52 -0500928
929 border = 2 << sb->s_blocksize_bits;
930
931 while (len > 0) {
932 /* find how many blocks can be covered since this position */
933 max = ffs(first | border) - 1;
934
935 /* find how many blocks of power 2 we need to mark */
936 min = fls(len) - 1;
937
938 if (max < min)
939 min = max;
940 chunk = 1 << min;
941
942 /* mark multiblock chunks only */
943 grp->bb_counters[min]++;
944 if (min > 0)
945 mb_clear_bit(first >> min,
946 buddy + sbi->s_mb_offsets[min]);
947
948 len -= chunk;
949 first += chunk;
950 }
951}
952
953static void ext4_mb_generate_buddy(struct super_block *sb,
954 void *buddy, void *bitmap, ext4_group_t group)
955{
956 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
957 unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
958 unsigned short i = 0;
959 unsigned short first;
960 unsigned short len;
961 unsigned free = 0;
962 unsigned fragments = 0;
963 unsigned long long period = get_cycles();
964
965 /* initialize buddy from bitmap which is aggregation
966 * of on-disk bitmap and preallocations */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500967 i = mb_find_next_zero_bit(bitmap, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -0500968 grp->bb_first_free = i;
969 while (i < max) {
970 fragments++;
971 first = i;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500972 i = mb_find_next_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500973 len = i - first;
974 free += len;
975 if (len > 1)
976 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
977 else
978 grp->bb_counters[0]++;
979 if (i < max)
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500980 i = mb_find_next_zero_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500981 }
982 grp->bb_fragments = fragments;
983
984 if (free != grp->bb_free) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -0500985 ext4_error(sb, __FUNCTION__,
Alex Tomasc9de5602008-01-29 00:19:52 -0500986 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
987 group, free, grp->bb_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -0500988 /*
989 * If we intent to continue, we consider group descritor
990 * corrupt and update bb_free using bitmap value
991 */
Alex Tomasc9de5602008-01-29 00:19:52 -0500992 grp->bb_free = free;
993 }
994
995 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
996
997 period = get_cycles() - period;
998 spin_lock(&EXT4_SB(sb)->s_bal_lock);
999 EXT4_SB(sb)->s_mb_buddies_generated++;
1000 EXT4_SB(sb)->s_mb_generation_time += period;
1001 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
1002}
1003
1004/* The buddy information is attached the buddy cache inode
1005 * for convenience. The information regarding each group
1006 * is loaded via ext4_mb_load_buddy. The information involve
1007 * block bitmap and buddy information. The information are
1008 * stored in the inode as
1009 *
1010 * { page }
1011 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
1012 *
1013 *
1014 * one block each for bitmap and buddy information.
1015 * So for each group we take up 2 blocks. A page can
1016 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
1017 * So it can have information regarding groups_per_page which
1018 * is blocks_per_page/2
1019 */
1020
1021static int ext4_mb_init_cache(struct page *page, char *incore)
1022{
1023 int blocksize;
1024 int blocks_per_page;
1025 int groups_per_page;
1026 int err = 0;
1027 int i;
1028 ext4_group_t first_group;
1029 int first_block;
1030 struct super_block *sb;
1031 struct buffer_head *bhs;
1032 struct buffer_head **bh;
1033 struct inode *inode;
1034 char *data;
1035 char *bitmap;
1036
1037 mb_debug("init page %lu\n", page->index);
1038
1039 inode = page->mapping->host;
1040 sb = inode->i_sb;
1041 blocksize = 1 << inode->i_blkbits;
1042 blocks_per_page = PAGE_CACHE_SIZE / blocksize;
1043
1044 groups_per_page = blocks_per_page >> 1;
1045 if (groups_per_page == 0)
1046 groups_per_page = 1;
1047
1048 /* allocate buffer_heads to read bitmaps */
1049 if (groups_per_page > 1) {
1050 err = -ENOMEM;
1051 i = sizeof(struct buffer_head *) * groups_per_page;
1052 bh = kzalloc(i, GFP_NOFS);
1053 if (bh == NULL)
1054 goto out;
1055 } else
1056 bh = &bhs;
1057
1058 first_group = page->index * blocks_per_page / 2;
1059
1060 /* read all groups the page covers into the cache */
1061 for (i = 0; i < groups_per_page; i++) {
1062 struct ext4_group_desc *desc;
1063
1064 if (first_group + i >= EXT4_SB(sb)->s_groups_count)
1065 break;
1066
1067 err = -EIO;
1068 desc = ext4_get_group_desc(sb, first_group + i, NULL);
1069 if (desc == NULL)
1070 goto out;
1071
1072 err = -ENOMEM;
1073 bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
1074 if (bh[i] == NULL)
1075 goto out;
1076
1077 if (bh_uptodate_or_lock(bh[i]))
1078 continue;
1079
1080 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1081 ext4_init_block_bitmap(sb, bh[i],
1082 first_group + i, desc);
1083 set_buffer_uptodate(bh[i]);
1084 unlock_buffer(bh[i]);
1085 continue;
1086 }
1087 get_bh(bh[i]);
1088 bh[i]->b_end_io = end_buffer_read_sync;
1089 submit_bh(READ, bh[i]);
1090 mb_debug("read bitmap for group %lu\n", first_group + i);
1091 }
1092
1093 /* wait for I/O completion */
1094 for (i = 0; i < groups_per_page && bh[i]; i++)
1095 wait_on_buffer(bh[i]);
1096
1097 err = -EIO;
1098 for (i = 0; i < groups_per_page && bh[i]; i++)
1099 if (!buffer_uptodate(bh[i]))
1100 goto out;
1101
1102 first_block = page->index * blocks_per_page;
1103 for (i = 0; i < blocks_per_page; i++) {
1104 int group;
1105 struct ext4_group_info *grinfo;
1106
1107 group = (first_block + i) >> 1;
1108 if (group >= EXT4_SB(sb)->s_groups_count)
1109 break;
1110
1111 /*
1112 * data carry information regarding this
1113 * particular group in the format specified
1114 * above
1115 *
1116 */
1117 data = page_address(page) + (i * blocksize);
1118 bitmap = bh[group - first_group]->b_data;
1119
1120 /*
1121 * We place the buddy block and bitmap block
1122 * close together
1123 */
1124 if ((first_block + i) & 1) {
1125 /* this is block of buddy */
1126 BUG_ON(incore == NULL);
1127 mb_debug("put buddy for group %u in page %lu/%x\n",
1128 group, page->index, i * blocksize);
1129 memset(data, 0xff, blocksize);
1130 grinfo = ext4_get_group_info(sb, group);
1131 grinfo->bb_fragments = 0;
1132 memset(grinfo->bb_counters, 0,
1133 sizeof(unsigned short)*(sb->s_blocksize_bits+2));
1134 /*
1135 * incore got set to the group block bitmap below
1136 */
1137 ext4_mb_generate_buddy(sb, data, incore, group);
1138 incore = NULL;
1139 } else {
1140 /* this is block of bitmap */
1141 BUG_ON(incore != NULL);
1142 mb_debug("put bitmap for group %u in page %lu/%x\n",
1143 group, page->index, i * blocksize);
1144
1145 /* see comments in ext4_mb_put_pa() */
1146 ext4_lock_group(sb, group);
1147 memcpy(data, bitmap, blocksize);
1148
1149 /* mark all preallocated blks used in in-core bitmap */
1150 ext4_mb_generate_from_pa(sb, data, group);
1151 ext4_unlock_group(sb, group);
1152
1153 /* set incore so that the buddy information can be
1154 * generated using this
1155 */
1156 incore = data;
1157 }
1158 }
1159 SetPageUptodate(page);
1160
1161out:
1162 if (bh) {
1163 for (i = 0; i < groups_per_page && bh[i]; i++)
1164 brelse(bh[i]);
1165 if (bh != &bhs)
1166 kfree(bh);
1167 }
1168 return err;
1169}
1170
1171static int ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1172 struct ext4_buddy *e4b)
1173{
1174 struct ext4_sb_info *sbi = EXT4_SB(sb);
1175 struct inode *inode = sbi->s_buddy_cache;
1176 int blocks_per_page;
1177 int block;
1178 int pnum;
1179 int poff;
1180 struct page *page;
1181
1182 mb_debug("load group %lu\n", group);
1183
1184 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
1185
1186 e4b->bd_blkbits = sb->s_blocksize_bits;
1187 e4b->bd_info = ext4_get_group_info(sb, group);
1188 e4b->bd_sb = sb;
1189 e4b->bd_group = group;
1190 e4b->bd_buddy_page = NULL;
1191 e4b->bd_bitmap_page = NULL;
1192
1193 /*
1194 * the buddy cache inode stores the block bitmap
1195 * and buddy information in consecutive blocks.
1196 * So for each group we need two blocks.
1197 */
1198 block = group * 2;
1199 pnum = block / blocks_per_page;
1200 poff = block % blocks_per_page;
1201
1202 /* we could use find_or_create_page(), but it locks page
1203 * what we'd like to avoid in fast path ... */
1204 page = find_get_page(inode->i_mapping, pnum);
1205 if (page == NULL || !PageUptodate(page)) {
1206 if (page)
1207 page_cache_release(page);
1208 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1209 if (page) {
1210 BUG_ON(page->mapping != inode->i_mapping);
1211 if (!PageUptodate(page)) {
1212 ext4_mb_init_cache(page, NULL);
1213 mb_cmp_bitmaps(e4b, page_address(page) +
1214 (poff * sb->s_blocksize));
1215 }
1216 unlock_page(page);
1217 }
1218 }
1219 if (page == NULL || !PageUptodate(page))
1220 goto err;
1221 e4b->bd_bitmap_page = page;
1222 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1223 mark_page_accessed(page);
1224
1225 block++;
1226 pnum = block / blocks_per_page;
1227 poff = block % blocks_per_page;
1228
1229 page = find_get_page(inode->i_mapping, pnum);
1230 if (page == NULL || !PageUptodate(page)) {
1231 if (page)
1232 page_cache_release(page);
1233 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1234 if (page) {
1235 BUG_ON(page->mapping != inode->i_mapping);
1236 if (!PageUptodate(page))
1237 ext4_mb_init_cache(page, e4b->bd_bitmap);
1238
1239 unlock_page(page);
1240 }
1241 }
1242 if (page == NULL || !PageUptodate(page))
1243 goto err;
1244 e4b->bd_buddy_page = page;
1245 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1246 mark_page_accessed(page);
1247
1248 BUG_ON(e4b->bd_bitmap_page == NULL);
1249 BUG_ON(e4b->bd_buddy_page == NULL);
1250
1251 return 0;
1252
1253err:
1254 if (e4b->bd_bitmap_page)
1255 page_cache_release(e4b->bd_bitmap_page);
1256 if (e4b->bd_buddy_page)
1257 page_cache_release(e4b->bd_buddy_page);
1258 e4b->bd_buddy = NULL;
1259 e4b->bd_bitmap = NULL;
1260 return -EIO;
1261}
1262
1263static void ext4_mb_release_desc(struct ext4_buddy *e4b)
1264{
1265 if (e4b->bd_bitmap_page)
1266 page_cache_release(e4b->bd_bitmap_page);
1267 if (e4b->bd_buddy_page)
1268 page_cache_release(e4b->bd_buddy_page);
1269}
1270
1271
1272static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1273{
1274 int order = 1;
1275 void *bb;
1276
1277 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
1278 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1279
1280 bb = EXT4_MB_BUDDY(e4b);
1281 while (order <= e4b->bd_blkbits + 1) {
1282 block = block >> 1;
1283 if (!mb_test_bit(block, bb)) {
1284 /* this block is part of buddy of order 'order' */
1285 return order;
1286 }
1287 bb += 1 << (e4b->bd_blkbits - order);
1288 order++;
1289 }
1290 return 0;
1291}
1292
1293static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
1294{
1295 __u32 *addr;
1296
1297 len = cur + len;
1298 while (cur < len) {
1299 if ((cur & 31) == 0 && (len - cur) >= 32) {
1300 /* fast path: clear whole word at once */
1301 addr = bm + (cur >> 3);
1302 *addr = 0;
1303 cur += 32;
1304 continue;
1305 }
1306 mb_clear_bit_atomic(lock, cur, bm);
1307 cur++;
1308 }
1309}
1310
1311static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
1312{
1313 __u32 *addr;
1314
1315 len = cur + len;
1316 while (cur < len) {
1317 if ((cur & 31) == 0 && (len - cur) >= 32) {
1318 /* fast path: set whole word at once */
1319 addr = bm + (cur >> 3);
1320 *addr = 0xffffffff;
1321 cur += 32;
1322 continue;
1323 }
1324 mb_set_bit_atomic(lock, cur, bm);
1325 cur++;
1326 }
1327}
1328
1329static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1330 int first, int count)
1331{
1332 int block = 0;
1333 int max = 0;
1334 int order;
1335 void *buddy;
1336 void *buddy2;
1337 struct super_block *sb = e4b->bd_sb;
1338
1339 BUG_ON(first + count > (sb->s_blocksize << 3));
1340 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
1341 mb_check_buddy(e4b);
1342 mb_free_blocks_double(inode, e4b, first, count);
1343
1344 e4b->bd_info->bb_free += count;
1345 if (first < e4b->bd_info->bb_first_free)
1346 e4b->bd_info->bb_first_free = first;
1347
1348 /* let's maintain fragments counter */
1349 if (first != 0)
1350 block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
1351 if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
1352 max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
1353 if (block && max)
1354 e4b->bd_info->bb_fragments--;
1355 else if (!block && !max)
1356 e4b->bd_info->bb_fragments++;
1357
1358 /* let's maintain buddy itself */
1359 while (count-- > 0) {
1360 block = first++;
1361 order = 0;
1362
1363 if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
1364 ext4_fsblk_t blocknr;
1365 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
1366 blocknr += block;
1367 blocknr +=
1368 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1369
1370 ext4_error(sb, __FUNCTION__, "double-free of inode"
1371 " %lu's block %llu(bit %u in group %lu)\n",
1372 inode ? inode->i_ino : 0, blocknr, block,
1373 e4b->bd_group);
1374 }
1375 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
1376 e4b->bd_info->bb_counters[order]++;
1377
1378 /* start of the buddy */
1379 buddy = mb_find_buddy(e4b, order, &max);
1380
1381 do {
1382 block &= ~1UL;
1383 if (mb_test_bit(block, buddy) ||
1384 mb_test_bit(block + 1, buddy))
1385 break;
1386
1387 /* both the buddies are free, try to coalesce them */
1388 buddy2 = mb_find_buddy(e4b, order + 1, &max);
1389
1390 if (!buddy2)
1391 break;
1392
1393 if (order > 0) {
1394 /* for special purposes, we don't set
1395 * free bits in bitmap */
1396 mb_set_bit(block, buddy);
1397 mb_set_bit(block + 1, buddy);
1398 }
1399 e4b->bd_info->bb_counters[order]--;
1400 e4b->bd_info->bb_counters[order]--;
1401
1402 block = block >> 1;
1403 order++;
1404 e4b->bd_info->bb_counters[order]++;
1405
1406 mb_clear_bit(block, buddy2);
1407 buddy = buddy2;
1408 } while (1);
1409 }
1410 mb_check_buddy(e4b);
1411
1412 return 0;
1413}
1414
1415static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
1416 int needed, struct ext4_free_extent *ex)
1417{
1418 int next = block;
1419 int max;
1420 int ord;
1421 void *buddy;
1422
1423 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1424 BUG_ON(ex == NULL);
1425
1426 buddy = mb_find_buddy(e4b, order, &max);
1427 BUG_ON(buddy == NULL);
1428 BUG_ON(block >= max);
1429 if (mb_test_bit(block, buddy)) {
1430 ex->fe_len = 0;
1431 ex->fe_start = 0;
1432 ex->fe_group = 0;
1433 return 0;
1434 }
1435
1436 /* FIXME dorp order completely ? */
1437 if (likely(order == 0)) {
1438 /* find actual order */
1439 order = mb_find_order_for_block(e4b, block);
1440 block = block >> order;
1441 }
1442
1443 ex->fe_len = 1 << order;
1444 ex->fe_start = block << order;
1445 ex->fe_group = e4b->bd_group;
1446
1447 /* calc difference from given start */
1448 next = next - ex->fe_start;
1449 ex->fe_len -= next;
1450 ex->fe_start += next;
1451
1452 while (needed > ex->fe_len &&
1453 (buddy = mb_find_buddy(e4b, order, &max))) {
1454
1455 if (block + 1 >= max)
1456 break;
1457
1458 next = (block + 1) * (1 << order);
1459 if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
1460 break;
1461
1462 ord = mb_find_order_for_block(e4b, next);
1463
1464 order = ord;
1465 block = next >> order;
1466 ex->fe_len += 1 << order;
1467 }
1468
1469 BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
1470 return ex->fe_len;
1471}
1472
1473static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1474{
1475 int ord;
1476 int mlen = 0;
1477 int max = 0;
1478 int cur;
1479 int start = ex->fe_start;
1480 int len = ex->fe_len;
1481 unsigned ret = 0;
1482 int len0 = len;
1483 void *buddy;
1484
1485 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1486 BUG_ON(e4b->bd_group != ex->fe_group);
1487 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1488 mb_check_buddy(e4b);
1489 mb_mark_used_double(e4b, start, len);
1490
1491 e4b->bd_info->bb_free -= len;
1492 if (e4b->bd_info->bb_first_free == start)
1493 e4b->bd_info->bb_first_free += len;
1494
1495 /* let's maintain fragments counter */
1496 if (start != 0)
1497 mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
1498 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1499 max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
1500 if (mlen && max)
1501 e4b->bd_info->bb_fragments++;
1502 else if (!mlen && !max)
1503 e4b->bd_info->bb_fragments--;
1504
1505 /* let's maintain buddy itself */
1506 while (len) {
1507 ord = mb_find_order_for_block(e4b, start);
1508
1509 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1510 /* the whole chunk may be allocated at once! */
1511 mlen = 1 << ord;
1512 buddy = mb_find_buddy(e4b, ord, &max);
1513 BUG_ON((start >> ord) >= max);
1514 mb_set_bit(start >> ord, buddy);
1515 e4b->bd_info->bb_counters[ord]--;
1516 start += mlen;
1517 len -= mlen;
1518 BUG_ON(len < 0);
1519 continue;
1520 }
1521
1522 /* store for history */
1523 if (ret == 0)
1524 ret = len | (ord << 16);
1525
1526 /* we have to split large buddy */
1527 BUG_ON(ord <= 0);
1528 buddy = mb_find_buddy(e4b, ord, &max);
1529 mb_set_bit(start >> ord, buddy);
1530 e4b->bd_info->bb_counters[ord]--;
1531
1532 ord--;
1533 cur = (start >> ord) & ~1U;
1534 buddy = mb_find_buddy(e4b, ord, &max);
1535 mb_clear_bit(cur, buddy);
1536 mb_clear_bit(cur + 1, buddy);
1537 e4b->bd_info->bb_counters[ord]++;
1538 e4b->bd_info->bb_counters[ord]++;
1539 }
1540
1541 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
1542 EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
1543 mb_check_buddy(e4b);
1544
1545 return ret;
1546}
1547
1548/*
1549 * Must be called under group lock!
1550 */
1551static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1552 struct ext4_buddy *e4b)
1553{
1554 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1555 int ret;
1556
1557 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1558 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1559
1560 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1561 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1562 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1563
1564 /* preallocation can change ac_b_ex, thus we store actually
1565 * allocated blocks for history */
1566 ac->ac_f_ex = ac->ac_b_ex;
1567
1568 ac->ac_status = AC_STATUS_FOUND;
1569 ac->ac_tail = ret & 0xffff;
1570 ac->ac_buddy = ret >> 16;
1571
1572 /* XXXXXXX: SUCH A HORRIBLE **CK */
1573 /*FIXME!! Why ? */
1574 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1575 get_page(ac->ac_bitmap_page);
1576 ac->ac_buddy_page = e4b->bd_buddy_page;
1577 get_page(ac->ac_buddy_page);
1578
1579 /* store last allocated for subsequent stream allocation */
1580 if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
1581 spin_lock(&sbi->s_md_lock);
1582 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1583 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1584 spin_unlock(&sbi->s_md_lock);
1585 }
1586}
1587
1588/*
1589 * regular allocator, for general purposes allocation
1590 */
1591
1592static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1593 struct ext4_buddy *e4b,
1594 int finish_group)
1595{
1596 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1597 struct ext4_free_extent *bex = &ac->ac_b_ex;
1598 struct ext4_free_extent *gex = &ac->ac_g_ex;
1599 struct ext4_free_extent ex;
1600 int max;
1601
1602 /*
1603 * We don't want to scan for a whole year
1604 */
1605 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1606 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1607 ac->ac_status = AC_STATUS_BREAK;
1608 return;
1609 }
1610
1611 /*
1612 * Haven't found good chunk so far, let's continue
1613 */
1614 if (bex->fe_len < gex->fe_len)
1615 return;
1616
1617 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1618 && bex->fe_group == e4b->bd_group) {
1619 /* recheck chunk's availability - we don't know
1620 * when it was found (within this lock-unlock
1621 * period or not) */
1622 max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
1623 if (max >= gex->fe_len) {
1624 ext4_mb_use_best_found(ac, e4b);
1625 return;
1626 }
1627 }
1628}
1629
1630/*
1631 * The routine checks whether found extent is good enough. If it is,
1632 * then the extent gets marked used and flag is set to the context
1633 * to stop scanning. Otherwise, the extent is compared with the
1634 * previous found extent and if new one is better, then it's stored
1635 * in the context. Later, the best found extent will be used, if
1636 * mballoc can't find good enough extent.
1637 *
1638 * FIXME: real allocation policy is to be designed yet!
1639 */
1640static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1641 struct ext4_free_extent *ex,
1642 struct ext4_buddy *e4b)
1643{
1644 struct ext4_free_extent *bex = &ac->ac_b_ex;
1645 struct ext4_free_extent *gex = &ac->ac_g_ex;
1646
1647 BUG_ON(ex->fe_len <= 0);
1648 BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1649 BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1650 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1651
1652 ac->ac_found++;
1653
1654 /*
1655 * The special case - take what you catch first
1656 */
1657 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1658 *bex = *ex;
1659 ext4_mb_use_best_found(ac, e4b);
1660 return;
1661 }
1662
1663 /*
1664 * Let's check whether the chuck is good enough
1665 */
1666 if (ex->fe_len == gex->fe_len) {
1667 *bex = *ex;
1668 ext4_mb_use_best_found(ac, e4b);
1669 return;
1670 }
1671
1672 /*
1673 * If this is first found extent, just store it in the context
1674 */
1675 if (bex->fe_len == 0) {
1676 *bex = *ex;
1677 return;
1678 }
1679
1680 /*
1681 * If new found extent is better, store it in the context
1682 */
1683 if (bex->fe_len < gex->fe_len) {
1684 /* if the request isn't satisfied, any found extent
1685 * larger than previous best one is better */
1686 if (ex->fe_len > bex->fe_len)
1687 *bex = *ex;
1688 } else if (ex->fe_len > gex->fe_len) {
1689 /* if the request is satisfied, then we try to find
1690 * an extent that still satisfy the request, but is
1691 * smaller than previous one */
1692 if (ex->fe_len < bex->fe_len)
1693 *bex = *ex;
1694 }
1695
1696 ext4_mb_check_limits(ac, e4b, 0);
1697}
1698
1699static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1700 struct ext4_buddy *e4b)
1701{
1702 struct ext4_free_extent ex = ac->ac_b_ex;
1703 ext4_group_t group = ex.fe_group;
1704 int max;
1705 int err;
1706
1707 BUG_ON(ex.fe_len <= 0);
1708 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1709 if (err)
1710 return err;
1711
1712 ext4_lock_group(ac->ac_sb, group);
1713 max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
1714
1715 if (max > 0) {
1716 ac->ac_b_ex = ex;
1717 ext4_mb_use_best_found(ac, e4b);
1718 }
1719
1720 ext4_unlock_group(ac->ac_sb, group);
1721 ext4_mb_release_desc(e4b);
1722
1723 return 0;
1724}
1725
1726static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1727 struct ext4_buddy *e4b)
1728{
1729 ext4_group_t group = ac->ac_g_ex.fe_group;
1730 int max;
1731 int err;
1732 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1733 struct ext4_super_block *es = sbi->s_es;
1734 struct ext4_free_extent ex;
1735
1736 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1737 return 0;
1738
1739 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1740 if (err)
1741 return err;
1742
1743 ext4_lock_group(ac->ac_sb, group);
1744 max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
1745 ac->ac_g_ex.fe_len, &ex);
1746
1747 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1748 ext4_fsblk_t start;
1749
1750 start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
1751 ex.fe_start + le32_to_cpu(es->s_first_data_block);
1752 /* use do_div to get remainder (would be 64-bit modulo) */
1753 if (do_div(start, sbi->s_stripe) == 0) {
1754 ac->ac_found++;
1755 ac->ac_b_ex = ex;
1756 ext4_mb_use_best_found(ac, e4b);
1757 }
1758 } else if (max >= ac->ac_g_ex.fe_len) {
1759 BUG_ON(ex.fe_len <= 0);
1760 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1761 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1762 ac->ac_found++;
1763 ac->ac_b_ex = ex;
1764 ext4_mb_use_best_found(ac, e4b);
1765 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1766 /* Sometimes, caller may want to merge even small
1767 * number of blocks to an existing extent */
1768 BUG_ON(ex.fe_len <= 0);
1769 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1770 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1771 ac->ac_found++;
1772 ac->ac_b_ex = ex;
1773 ext4_mb_use_best_found(ac, e4b);
1774 }
1775 ext4_unlock_group(ac->ac_sb, group);
1776 ext4_mb_release_desc(e4b);
1777
1778 return 0;
1779}
1780
1781/*
1782 * The routine scans buddy structures (not bitmap!) from given order
1783 * to max order and tries to find big enough chunk to satisfy the req
1784 */
1785static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1786 struct ext4_buddy *e4b)
1787{
1788 struct super_block *sb = ac->ac_sb;
1789 struct ext4_group_info *grp = e4b->bd_info;
1790 void *buddy;
1791 int i;
1792 int k;
1793 int max;
1794
1795 BUG_ON(ac->ac_2order <= 0);
1796 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1797 if (grp->bb_counters[i] == 0)
1798 continue;
1799
1800 buddy = mb_find_buddy(e4b, i, &max);
1801 BUG_ON(buddy == NULL);
1802
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001803 k = mb_find_next_zero_bit(buddy, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -05001804 BUG_ON(k >= max);
1805
1806 ac->ac_found++;
1807
1808 ac->ac_b_ex.fe_len = 1 << i;
1809 ac->ac_b_ex.fe_start = k << i;
1810 ac->ac_b_ex.fe_group = e4b->bd_group;
1811
1812 ext4_mb_use_best_found(ac, e4b);
1813
1814 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1815
1816 if (EXT4_SB(sb)->s_mb_stats)
1817 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1818
1819 break;
1820 }
1821}
1822
1823/*
1824 * The routine scans the group and measures all found extents.
1825 * In order to optimize scanning, caller must pass number of
1826 * free blocks in the group, so the routine can know upper limit.
1827 */
1828static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1829 struct ext4_buddy *e4b)
1830{
1831 struct super_block *sb = ac->ac_sb;
1832 void *bitmap = EXT4_MB_BITMAP(e4b);
1833 struct ext4_free_extent ex;
1834 int i;
1835 int free;
1836
1837 free = e4b->bd_info->bb_free;
1838 BUG_ON(free <= 0);
1839
1840 i = e4b->bd_info->bb_first_free;
1841
1842 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001843 i = mb_find_next_zero_bit(bitmap,
Alex Tomasc9de5602008-01-29 00:19:52 -05001844 EXT4_BLOCKS_PER_GROUP(sb), i);
1845 if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001846 /*
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001847 * IF we have corrupt bitmap, we won't find any
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001848 * free blocks even though group info says we
1849 * we have free blocks
1850 */
1851 ext4_error(sb, __FUNCTION__, "%d free blocks as per "
1852 "group info. But bitmap says 0\n",
1853 free);
Alex Tomasc9de5602008-01-29 00:19:52 -05001854 break;
1855 }
1856
1857 mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
1858 BUG_ON(ex.fe_len <= 0);
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001859 if (free < ex.fe_len) {
1860 ext4_error(sb, __FUNCTION__, "%d free blocks as per "
1861 "group info. But got %d blocks\n",
1862 free, ex.fe_len);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001863 /*
1864 * The number of free blocks differs. This mostly
1865 * indicate that the bitmap is corrupt. So exit
1866 * without claiming the space.
1867 */
1868 break;
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001869 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001870
1871 ext4_mb_measure_extent(ac, &ex, e4b);
1872
1873 i += ex.fe_len;
1874 free -= ex.fe_len;
1875 }
1876
1877 ext4_mb_check_limits(ac, e4b, 1);
1878}
1879
1880/*
1881 * This is a special case for storages like raid5
1882 * we try to find stripe-aligned chunks for stripe-size requests
1883 * XXX should do so at least for multiples of stripe size as well
1884 */
1885static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1886 struct ext4_buddy *e4b)
1887{
1888 struct super_block *sb = ac->ac_sb;
1889 struct ext4_sb_info *sbi = EXT4_SB(sb);
1890 void *bitmap = EXT4_MB_BITMAP(e4b);
1891 struct ext4_free_extent ex;
1892 ext4_fsblk_t first_group_block;
1893 ext4_fsblk_t a;
1894 ext4_grpblk_t i;
1895 int max;
1896
1897 BUG_ON(sbi->s_stripe == 0);
1898
1899 /* find first stripe-aligned block in group */
1900 first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
1901 + le32_to_cpu(sbi->s_es->s_first_data_block);
1902 a = first_group_block + sbi->s_stripe - 1;
1903 do_div(a, sbi->s_stripe);
1904 i = (a * sbi->s_stripe) - first_group_block;
1905
1906 while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
1907 if (!mb_test_bit(i, bitmap)) {
1908 max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
1909 if (max >= sbi->s_stripe) {
1910 ac->ac_found++;
1911 ac->ac_b_ex = ex;
1912 ext4_mb_use_best_found(ac, e4b);
1913 break;
1914 }
1915 }
1916 i += sbi->s_stripe;
1917 }
1918}
1919
1920static int ext4_mb_good_group(struct ext4_allocation_context *ac,
1921 ext4_group_t group, int cr)
1922{
1923 unsigned free, fragments;
1924 unsigned i, bits;
1925 struct ext4_group_desc *desc;
1926 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1927
1928 BUG_ON(cr < 0 || cr >= 4);
1929 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
1930
1931 free = grp->bb_free;
1932 fragments = grp->bb_fragments;
1933 if (free == 0)
1934 return 0;
1935 if (fragments == 0)
1936 return 0;
1937
1938 switch (cr) {
1939 case 0:
1940 BUG_ON(ac->ac_2order == 0);
1941 /* If this group is uninitialized, skip it initially */
1942 desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
1943 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
1944 return 0;
1945
1946 bits = ac->ac_sb->s_blocksize_bits + 1;
1947 for (i = ac->ac_2order; i <= bits; i++)
1948 if (grp->bb_counters[i] > 0)
1949 return 1;
1950 break;
1951 case 1:
1952 if ((free / fragments) >= ac->ac_g_ex.fe_len)
1953 return 1;
1954 break;
1955 case 2:
1956 if (free >= ac->ac_g_ex.fe_len)
1957 return 1;
1958 break;
1959 case 3:
1960 return 1;
1961 default:
1962 BUG();
1963 }
1964
1965 return 0;
1966}
1967
1968static int ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
1969{
1970 ext4_group_t group;
1971 ext4_group_t i;
1972 int cr;
1973 int err = 0;
1974 int bsbits;
1975 struct ext4_sb_info *sbi;
1976 struct super_block *sb;
1977 struct ext4_buddy e4b;
1978 loff_t size, isize;
1979
1980 sb = ac->ac_sb;
1981 sbi = EXT4_SB(sb);
1982 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1983
1984 /* first, try the goal */
1985 err = ext4_mb_find_by_goal(ac, &e4b);
1986 if (err || ac->ac_status == AC_STATUS_FOUND)
1987 goto out;
1988
1989 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
1990 goto out;
1991
1992 /*
1993 * ac->ac2_order is set only if the fe_len is a power of 2
1994 * if ac2_order is set we also set criteria to 0 so that we
1995 * try exact allocation using buddy.
1996 */
1997 i = fls(ac->ac_g_ex.fe_len);
1998 ac->ac_2order = 0;
1999 /*
2000 * We search using buddy data only if the order of the request
2001 * is greater than equal to the sbi_s_mb_order2_reqs
2002 * You can tune it via /proc/fs/ext4/<partition>/order2_req
2003 */
2004 if (i >= sbi->s_mb_order2_reqs) {
2005 /*
2006 * This should tell if fe_len is exactly power of 2
2007 */
2008 if ((ac->ac_g_ex.fe_len & (~(1 << (i - 1)))) == 0)
2009 ac->ac_2order = i - 1;
2010 }
2011
2012 bsbits = ac->ac_sb->s_blocksize_bits;
2013 /* if stream allocation is enabled, use global goal */
2014 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
2015 isize = i_size_read(ac->ac_inode) >> bsbits;
2016 if (size < isize)
2017 size = isize;
2018
2019 if (size < sbi->s_mb_stream_request &&
2020 (ac->ac_flags & EXT4_MB_HINT_DATA)) {
2021 /* TBD: may be hot point */
2022 spin_lock(&sbi->s_md_lock);
2023 ac->ac_g_ex.fe_group = sbi->s_mb_last_group;
2024 ac->ac_g_ex.fe_start = sbi->s_mb_last_start;
2025 spin_unlock(&sbi->s_md_lock);
2026 }
2027
2028 /* searching for the right group start from the goal value specified */
2029 group = ac->ac_g_ex.fe_group;
2030
2031 /* Let's just scan groups to find more-less suitable blocks */
2032 cr = ac->ac_2order ? 0 : 1;
2033 /*
2034 * cr == 0 try to get exact allocation,
2035 * cr == 3 try to get anything
2036 */
2037repeat:
2038 for (; cr < 4 && ac->ac_status == AC_STATUS_CONTINUE; cr++) {
2039 ac->ac_criteria = cr;
2040 for (i = 0; i < EXT4_SB(sb)->s_groups_count; group++, i++) {
2041 struct ext4_group_info *grp;
2042 struct ext4_group_desc *desc;
2043
2044 if (group == EXT4_SB(sb)->s_groups_count)
2045 group = 0;
2046
2047 /* quick check to skip empty groups */
2048 grp = ext4_get_group_info(ac->ac_sb, group);
2049 if (grp->bb_free == 0)
2050 continue;
2051
2052 /*
2053 * if the group is already init we check whether it is
2054 * a good group and if not we don't load the buddy
2055 */
2056 if (EXT4_MB_GRP_NEED_INIT(grp)) {
2057 /*
2058 * we need full data about the group
2059 * to make a good selection
2060 */
2061 err = ext4_mb_load_buddy(sb, group, &e4b);
2062 if (err)
2063 goto out;
2064 ext4_mb_release_desc(&e4b);
2065 }
2066
2067 /*
2068 * If the particular group doesn't satisfy our
2069 * criteria we continue with the next group
2070 */
2071 if (!ext4_mb_good_group(ac, group, cr))
2072 continue;
2073
2074 err = ext4_mb_load_buddy(sb, group, &e4b);
2075 if (err)
2076 goto out;
2077
2078 ext4_lock_group(sb, group);
2079 if (!ext4_mb_good_group(ac, group, cr)) {
2080 /* someone did allocation from this group */
2081 ext4_unlock_group(sb, group);
2082 ext4_mb_release_desc(&e4b);
2083 continue;
2084 }
2085
2086 ac->ac_groups_scanned++;
2087 desc = ext4_get_group_desc(sb, group, NULL);
2088 if (cr == 0 || (desc->bg_flags &
2089 cpu_to_le16(EXT4_BG_BLOCK_UNINIT) &&
2090 ac->ac_2order != 0))
2091 ext4_mb_simple_scan_group(ac, &e4b);
2092 else if (cr == 1 &&
2093 ac->ac_g_ex.fe_len == sbi->s_stripe)
2094 ext4_mb_scan_aligned(ac, &e4b);
2095 else
2096 ext4_mb_complex_scan_group(ac, &e4b);
2097
2098 ext4_unlock_group(sb, group);
2099 ext4_mb_release_desc(&e4b);
2100
2101 if (ac->ac_status != AC_STATUS_CONTINUE)
2102 break;
2103 }
2104 }
2105
2106 if (ac->ac_b_ex.fe_len > 0 && ac->ac_status != AC_STATUS_FOUND &&
2107 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
2108 /*
2109 * We've been searching too long. Let's try to allocate
2110 * the best chunk we've found so far
2111 */
2112
2113 ext4_mb_try_best_found(ac, &e4b);
2114 if (ac->ac_status != AC_STATUS_FOUND) {
2115 /*
2116 * Someone more lucky has already allocated it.
2117 * The only thing we can do is just take first
2118 * found block(s)
2119 printk(KERN_DEBUG "EXT4-fs: someone won our chunk\n");
2120 */
2121 ac->ac_b_ex.fe_group = 0;
2122 ac->ac_b_ex.fe_start = 0;
2123 ac->ac_b_ex.fe_len = 0;
2124 ac->ac_status = AC_STATUS_CONTINUE;
2125 ac->ac_flags |= EXT4_MB_HINT_FIRST;
2126 cr = 3;
2127 atomic_inc(&sbi->s_mb_lost_chunks);
2128 goto repeat;
2129 }
2130 }
2131out:
2132 return err;
2133}
2134
2135#ifdef EXT4_MB_HISTORY
2136struct ext4_mb_proc_session {
2137 struct ext4_mb_history *history;
2138 struct super_block *sb;
2139 int start;
2140 int max;
2141};
2142
2143static void *ext4_mb_history_skip_empty(struct ext4_mb_proc_session *s,
2144 struct ext4_mb_history *hs,
2145 int first)
2146{
2147 if (hs == s->history + s->max)
2148 hs = s->history;
2149 if (!first && hs == s->history + s->start)
2150 return NULL;
2151 while (hs->orig.fe_len == 0) {
2152 hs++;
2153 if (hs == s->history + s->max)
2154 hs = s->history;
2155 if (hs == s->history + s->start)
2156 return NULL;
2157 }
2158 return hs;
2159}
2160
2161static void *ext4_mb_seq_history_start(struct seq_file *seq, loff_t *pos)
2162{
2163 struct ext4_mb_proc_session *s = seq->private;
2164 struct ext4_mb_history *hs;
2165 int l = *pos;
2166
2167 if (l == 0)
2168 return SEQ_START_TOKEN;
2169 hs = ext4_mb_history_skip_empty(s, s->history + s->start, 1);
2170 if (!hs)
2171 return NULL;
2172 while (--l && (hs = ext4_mb_history_skip_empty(s, ++hs, 0)) != NULL);
2173 return hs;
2174}
2175
2176static void *ext4_mb_seq_history_next(struct seq_file *seq, void *v,
2177 loff_t *pos)
2178{
2179 struct ext4_mb_proc_session *s = seq->private;
2180 struct ext4_mb_history *hs = v;
2181
2182 ++*pos;
2183 if (v == SEQ_START_TOKEN)
2184 return ext4_mb_history_skip_empty(s, s->history + s->start, 1);
2185 else
2186 return ext4_mb_history_skip_empty(s, ++hs, 0);
2187}
2188
2189static int ext4_mb_seq_history_show(struct seq_file *seq, void *v)
2190{
2191 char buf[25], buf2[25], buf3[25], *fmt;
2192 struct ext4_mb_history *hs = v;
2193
2194 if (v == SEQ_START_TOKEN) {
2195 seq_printf(seq, "%-5s %-8s %-23s %-23s %-23s %-5s "
2196 "%-5s %-2s %-5s %-5s %-5s %-6s\n",
2197 "pid", "inode", "original", "goal", "result", "found",
2198 "grps", "cr", "flags", "merge", "tail", "broken");
2199 return 0;
2200 }
2201
2202 if (hs->op == EXT4_MB_HISTORY_ALLOC) {
2203 fmt = "%-5u %-8u %-23s %-23s %-23s %-5u %-5u %-2u "
2204 "%-5u %-5s %-5u %-6u\n";
2205 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
2206 hs->result.fe_start, hs->result.fe_len,
2207 hs->result.fe_logical);
2208 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
2209 hs->orig.fe_start, hs->orig.fe_len,
2210 hs->orig.fe_logical);
2211 sprintf(buf3, "%lu/%d/%u@%u", hs->goal.fe_group,
2212 hs->goal.fe_start, hs->goal.fe_len,
2213 hs->goal.fe_logical);
2214 seq_printf(seq, fmt, hs->pid, hs->ino, buf, buf3, buf2,
2215 hs->found, hs->groups, hs->cr, hs->flags,
2216 hs->merged ? "M" : "", hs->tail,
2217 hs->buddy ? 1 << hs->buddy : 0);
2218 } else if (hs->op == EXT4_MB_HISTORY_PREALLOC) {
2219 fmt = "%-5u %-8u %-23s %-23s %-23s\n";
2220 sprintf(buf2, "%lu/%d/%u@%u", hs->result.fe_group,
2221 hs->result.fe_start, hs->result.fe_len,
2222 hs->result.fe_logical);
2223 sprintf(buf, "%lu/%d/%u@%u", hs->orig.fe_group,
2224 hs->orig.fe_start, hs->orig.fe_len,
2225 hs->orig.fe_logical);
2226 seq_printf(seq, fmt, hs->pid, hs->ino, buf, "", buf2);
2227 } else if (hs->op == EXT4_MB_HISTORY_DISCARD) {
2228 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
2229 hs->result.fe_start, hs->result.fe_len);
2230 seq_printf(seq, "%-5u %-8u %-23s discard\n",
2231 hs->pid, hs->ino, buf2);
2232 } else if (hs->op == EXT4_MB_HISTORY_FREE) {
2233 sprintf(buf2, "%lu/%d/%u", hs->result.fe_group,
2234 hs->result.fe_start, hs->result.fe_len);
2235 seq_printf(seq, "%-5u %-8u %-23s free\n",
2236 hs->pid, hs->ino, buf2);
2237 }
2238 return 0;
2239}
2240
2241static void ext4_mb_seq_history_stop(struct seq_file *seq, void *v)
2242{
2243}
2244
2245static struct seq_operations ext4_mb_seq_history_ops = {
2246 .start = ext4_mb_seq_history_start,
2247 .next = ext4_mb_seq_history_next,
2248 .stop = ext4_mb_seq_history_stop,
2249 .show = ext4_mb_seq_history_show,
2250};
2251
2252static int ext4_mb_seq_history_open(struct inode *inode, struct file *file)
2253{
2254 struct super_block *sb = PDE(inode)->data;
2255 struct ext4_sb_info *sbi = EXT4_SB(sb);
2256 struct ext4_mb_proc_session *s;
2257 int rc;
2258 int size;
2259
2260 s = kmalloc(sizeof(*s), GFP_KERNEL);
2261 if (s == NULL)
2262 return -ENOMEM;
2263 s->sb = sb;
2264 size = sizeof(struct ext4_mb_history) * sbi->s_mb_history_max;
2265 s->history = kmalloc(size, GFP_KERNEL);
2266 if (s->history == NULL) {
2267 kfree(s);
2268 return -ENOMEM;
2269 }
2270
2271 spin_lock(&sbi->s_mb_history_lock);
2272 memcpy(s->history, sbi->s_mb_history, size);
2273 s->max = sbi->s_mb_history_max;
2274 s->start = sbi->s_mb_history_cur % s->max;
2275 spin_unlock(&sbi->s_mb_history_lock);
2276
2277 rc = seq_open(file, &ext4_mb_seq_history_ops);
2278 if (rc == 0) {
2279 struct seq_file *m = (struct seq_file *)file->private_data;
2280 m->private = s;
2281 } else {
2282 kfree(s->history);
2283 kfree(s);
2284 }
2285 return rc;
2286
2287}
2288
2289static int ext4_mb_seq_history_release(struct inode *inode, struct file *file)
2290{
2291 struct seq_file *seq = (struct seq_file *)file->private_data;
2292 struct ext4_mb_proc_session *s = seq->private;
2293 kfree(s->history);
2294 kfree(s);
2295 return seq_release(inode, file);
2296}
2297
2298static ssize_t ext4_mb_seq_history_write(struct file *file,
2299 const char __user *buffer,
2300 size_t count, loff_t *ppos)
2301{
2302 struct seq_file *seq = (struct seq_file *)file->private_data;
2303 struct ext4_mb_proc_session *s = seq->private;
2304 struct super_block *sb = s->sb;
2305 char str[32];
2306 int value;
2307
2308 if (count >= sizeof(str)) {
2309 printk(KERN_ERR "EXT4-fs: %s string too long, max %u bytes\n",
2310 "mb_history", (int)sizeof(str));
2311 return -EOVERFLOW;
2312 }
2313
2314 if (copy_from_user(str, buffer, count))
2315 return -EFAULT;
2316
2317 value = simple_strtol(str, NULL, 0);
2318 if (value < 0)
2319 return -ERANGE;
2320 EXT4_SB(sb)->s_mb_history_filter = value;
2321
2322 return count;
2323}
2324
2325static struct file_operations ext4_mb_seq_history_fops = {
2326 .owner = THIS_MODULE,
2327 .open = ext4_mb_seq_history_open,
2328 .read = seq_read,
2329 .write = ext4_mb_seq_history_write,
2330 .llseek = seq_lseek,
2331 .release = ext4_mb_seq_history_release,
2332};
2333
2334static void *ext4_mb_seq_groups_start(struct seq_file *seq, loff_t *pos)
2335{
2336 struct super_block *sb = seq->private;
2337 struct ext4_sb_info *sbi = EXT4_SB(sb);
2338 ext4_group_t group;
2339
2340 if (*pos < 0 || *pos >= sbi->s_groups_count)
2341 return NULL;
2342
2343 group = *pos + 1;
2344 return (void *) group;
2345}
2346
2347static void *ext4_mb_seq_groups_next(struct seq_file *seq, void *v, loff_t *pos)
2348{
2349 struct super_block *sb = seq->private;
2350 struct ext4_sb_info *sbi = EXT4_SB(sb);
2351 ext4_group_t group;
2352
2353 ++*pos;
2354 if (*pos < 0 || *pos >= sbi->s_groups_count)
2355 return NULL;
2356 group = *pos + 1;
2357 return (void *) group;;
2358}
2359
2360static int ext4_mb_seq_groups_show(struct seq_file *seq, void *v)
2361{
2362 struct super_block *sb = seq->private;
2363 long group = (long) v;
2364 int i;
2365 int err;
2366 struct ext4_buddy e4b;
2367 struct sg {
2368 struct ext4_group_info info;
2369 unsigned short counters[16];
2370 } sg;
2371
2372 group--;
2373 if (group == 0)
2374 seq_printf(seq, "#%-5s: %-5s %-5s %-5s "
2375 "[ %-5s %-5s %-5s %-5s %-5s %-5s %-5s "
2376 "%-5s %-5s %-5s %-5s %-5s %-5s %-5s ]\n",
2377 "group", "free", "frags", "first",
2378 "2^0", "2^1", "2^2", "2^3", "2^4", "2^5", "2^6",
2379 "2^7", "2^8", "2^9", "2^10", "2^11", "2^12", "2^13");
2380
2381 i = (sb->s_blocksize_bits + 2) * sizeof(sg.info.bb_counters[0]) +
2382 sizeof(struct ext4_group_info);
2383 err = ext4_mb_load_buddy(sb, group, &e4b);
2384 if (err) {
2385 seq_printf(seq, "#%-5lu: I/O error\n", group);
2386 return 0;
2387 }
2388 ext4_lock_group(sb, group);
2389 memcpy(&sg, ext4_get_group_info(sb, group), i);
2390 ext4_unlock_group(sb, group);
2391 ext4_mb_release_desc(&e4b);
2392
2393 seq_printf(seq, "#%-5lu: %-5u %-5u %-5u [", group, sg.info.bb_free,
2394 sg.info.bb_fragments, sg.info.bb_first_free);
2395 for (i = 0; i <= 13; i++)
2396 seq_printf(seq, " %-5u", i <= sb->s_blocksize_bits + 1 ?
2397 sg.info.bb_counters[i] : 0);
2398 seq_printf(seq, " ]\n");
2399
2400 return 0;
2401}
2402
2403static void ext4_mb_seq_groups_stop(struct seq_file *seq, void *v)
2404{
2405}
2406
2407static struct seq_operations ext4_mb_seq_groups_ops = {
2408 .start = ext4_mb_seq_groups_start,
2409 .next = ext4_mb_seq_groups_next,
2410 .stop = ext4_mb_seq_groups_stop,
2411 .show = ext4_mb_seq_groups_show,
2412};
2413
2414static int ext4_mb_seq_groups_open(struct inode *inode, struct file *file)
2415{
2416 struct super_block *sb = PDE(inode)->data;
2417 int rc;
2418
2419 rc = seq_open(file, &ext4_mb_seq_groups_ops);
2420 if (rc == 0) {
2421 struct seq_file *m = (struct seq_file *)file->private_data;
2422 m->private = sb;
2423 }
2424 return rc;
2425
2426}
2427
2428static struct file_operations ext4_mb_seq_groups_fops = {
2429 .owner = THIS_MODULE,
2430 .open = ext4_mb_seq_groups_open,
2431 .read = seq_read,
2432 .llseek = seq_lseek,
2433 .release = seq_release,
2434};
2435
2436static void ext4_mb_history_release(struct super_block *sb)
2437{
2438 struct ext4_sb_info *sbi = EXT4_SB(sb);
2439
2440 remove_proc_entry("mb_groups", sbi->s_mb_proc);
2441 remove_proc_entry("mb_history", sbi->s_mb_proc);
2442
2443 kfree(sbi->s_mb_history);
2444}
2445
2446static void ext4_mb_history_init(struct super_block *sb)
2447{
2448 struct ext4_sb_info *sbi = EXT4_SB(sb);
2449 int i;
2450
2451 if (sbi->s_mb_proc != NULL) {
2452 struct proc_dir_entry *p;
2453 p = create_proc_entry("mb_history", S_IRUGO, sbi->s_mb_proc);
2454 if (p) {
2455 p->proc_fops = &ext4_mb_seq_history_fops;
2456 p->data = sb;
2457 }
2458 p = create_proc_entry("mb_groups", S_IRUGO, sbi->s_mb_proc);
2459 if (p) {
2460 p->proc_fops = &ext4_mb_seq_groups_fops;
2461 p->data = sb;
2462 }
2463 }
2464
2465 sbi->s_mb_history_max = 1000;
2466 sbi->s_mb_history_cur = 0;
2467 spin_lock_init(&sbi->s_mb_history_lock);
2468 i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
2469 sbi->s_mb_history = kmalloc(i, GFP_KERNEL);
2470 if (likely(sbi->s_mb_history != NULL))
2471 memset(sbi->s_mb_history, 0, i);
2472 /* if we can't allocate history, then we simple won't use it */
2473}
2474
2475static void ext4_mb_store_history(struct ext4_allocation_context *ac)
2476{
2477 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2478 struct ext4_mb_history h;
2479
2480 if (unlikely(sbi->s_mb_history == NULL))
2481 return;
2482
2483 if (!(ac->ac_op & sbi->s_mb_history_filter))
2484 return;
2485
2486 h.op = ac->ac_op;
2487 h.pid = current->pid;
2488 h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
2489 h.orig = ac->ac_o_ex;
2490 h.result = ac->ac_b_ex;
2491 h.flags = ac->ac_flags;
2492 h.found = ac->ac_found;
2493 h.groups = ac->ac_groups_scanned;
2494 h.cr = ac->ac_criteria;
2495 h.tail = ac->ac_tail;
2496 h.buddy = ac->ac_buddy;
2497 h.merged = 0;
2498 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
2499 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
2500 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
2501 h.merged = 1;
2502 h.goal = ac->ac_g_ex;
2503 h.result = ac->ac_f_ex;
2504 }
2505
2506 spin_lock(&sbi->s_mb_history_lock);
2507 memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
2508 if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
2509 sbi->s_mb_history_cur = 0;
2510 spin_unlock(&sbi->s_mb_history_lock);
2511}
2512
2513#else
2514#define ext4_mb_history_release(sb)
2515#define ext4_mb_history_init(sb)
2516#endif
2517
2518static int ext4_mb_init_backend(struct super_block *sb)
2519{
2520 ext4_group_t i;
2521 int j, len, metalen;
2522 struct ext4_sb_info *sbi = EXT4_SB(sb);
2523 int num_meta_group_infos =
2524 (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2525 EXT4_DESC_PER_BLOCK_BITS(sb);
2526 struct ext4_group_info **meta_group_info;
2527
2528 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2529 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2530 * So a two level scheme suffices for now. */
2531 sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
2532 num_meta_group_infos, GFP_KERNEL);
2533 if (sbi->s_group_info == NULL) {
2534 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
2535 return -ENOMEM;
2536 }
2537 sbi->s_buddy_cache = new_inode(sb);
2538 if (sbi->s_buddy_cache == NULL) {
2539 printk(KERN_ERR "EXT4-fs: can't get new inode\n");
2540 goto err_freesgi;
2541 }
2542 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2543
2544 metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
2545 for (i = 0; i < num_meta_group_infos; i++) {
2546 if ((i + 1) == num_meta_group_infos)
2547 metalen = sizeof(*meta_group_info) *
2548 (sbi->s_groups_count -
2549 (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
2550 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2551 if (meta_group_info == NULL) {
2552 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2553 "buddy group\n");
2554 goto err_freemeta;
2555 }
2556 sbi->s_group_info[i] = meta_group_info;
2557 }
2558
2559 /*
2560 * calculate needed size. if change bb_counters size,
2561 * don't forget about ext4_mb_generate_buddy()
2562 */
2563 len = sizeof(struct ext4_group_info);
2564 len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
2565 for (i = 0; i < sbi->s_groups_count; i++) {
2566 struct ext4_group_desc *desc;
2567
2568 meta_group_info =
2569 sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2570 j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
2571
2572 meta_group_info[j] = kzalloc(len, GFP_KERNEL);
2573 if (meta_group_info[j] == NULL) {
2574 printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
2575 i--;
2576 goto err_freebuddy;
2577 }
2578 desc = ext4_get_group_desc(sb, i, NULL);
2579 if (desc == NULL) {
2580 printk(KERN_ERR
2581 "EXT4-fs: can't read descriptor %lu\n", i);
2582 goto err_freebuddy;
2583 }
2584 memset(meta_group_info[j], 0, len);
2585 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2586 &(meta_group_info[j]->bb_state));
2587
2588 /*
2589 * initialize bb_free to be able to skip
2590 * empty groups without initialization
2591 */
2592 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2593 meta_group_info[j]->bb_free =
2594 ext4_free_blocks_after_init(sb, i, desc);
2595 } else {
2596 meta_group_info[j]->bb_free =
2597 le16_to_cpu(desc->bg_free_blocks_count);
2598 }
2599
2600 INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
2601
2602#ifdef DOUBLE_CHECK
2603 {
2604 struct buffer_head *bh;
2605 meta_group_info[j]->bb_bitmap =
2606 kmalloc(sb->s_blocksize, GFP_KERNEL);
2607 BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
2608 bh = read_block_bitmap(sb, i);
2609 BUG_ON(bh == NULL);
2610 memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
2611 sb->s_blocksize);
2612 put_bh(bh);
2613 }
2614#endif
2615
2616 }
2617
2618 return 0;
2619
2620err_freebuddy:
2621 while (i >= 0) {
2622 kfree(ext4_get_group_info(sb, i));
2623 i--;
2624 }
2625 i = num_meta_group_infos;
2626err_freemeta:
2627 while (--i >= 0)
2628 kfree(sbi->s_group_info[i]);
2629 iput(sbi->s_buddy_cache);
2630err_freesgi:
2631 kfree(sbi->s_group_info);
2632 return -ENOMEM;
2633}
2634
2635int ext4_mb_init(struct super_block *sb, int needs_recovery)
2636{
2637 struct ext4_sb_info *sbi = EXT4_SB(sb);
2638 unsigned i;
2639 unsigned offset;
2640 unsigned max;
2641
2642 if (!test_opt(sb, MBALLOC))
2643 return 0;
2644
2645 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
2646
2647 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2648 if (sbi->s_mb_offsets == NULL) {
2649 clear_opt(sbi->s_mount_opt, MBALLOC);
2650 return -ENOMEM;
2651 }
2652 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2653 if (sbi->s_mb_maxs == NULL) {
2654 clear_opt(sbi->s_mount_opt, MBALLOC);
2655 kfree(sbi->s_mb_maxs);
2656 return -ENOMEM;
2657 }
2658
2659 /* order 0 is regular bitmap */
2660 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2661 sbi->s_mb_offsets[0] = 0;
2662
2663 i = 1;
2664 offset = 0;
2665 max = sb->s_blocksize << 2;
2666 do {
2667 sbi->s_mb_offsets[i] = offset;
2668 sbi->s_mb_maxs[i] = max;
2669 offset += 1 << (sb->s_blocksize_bits - i);
2670 max = max >> 1;
2671 i++;
2672 } while (i <= sb->s_blocksize_bits + 1);
2673
2674 /* init file for buddy data */
2675 i = ext4_mb_init_backend(sb);
2676 if (i) {
2677 clear_opt(sbi->s_mount_opt, MBALLOC);
2678 kfree(sbi->s_mb_offsets);
2679 kfree(sbi->s_mb_maxs);
2680 return i;
2681 }
2682
2683 spin_lock_init(&sbi->s_md_lock);
2684 INIT_LIST_HEAD(&sbi->s_active_transaction);
2685 INIT_LIST_HEAD(&sbi->s_closed_transaction);
2686 INIT_LIST_HEAD(&sbi->s_committed_transaction);
2687 spin_lock_init(&sbi->s_bal_lock);
2688
2689 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2690 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2691 sbi->s_mb_stats = MB_DEFAULT_STATS;
2692 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2693 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2694 sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
2695 sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
2696
2697 i = sizeof(struct ext4_locality_group) * NR_CPUS;
2698 sbi->s_locality_groups = kmalloc(i, GFP_KERNEL);
2699 if (sbi->s_locality_groups == NULL) {
2700 clear_opt(sbi->s_mount_opt, MBALLOC);
2701 kfree(sbi->s_mb_offsets);
2702 kfree(sbi->s_mb_maxs);
2703 return -ENOMEM;
2704 }
2705 for (i = 0; i < NR_CPUS; i++) {
2706 struct ext4_locality_group *lg;
2707 lg = &sbi->s_locality_groups[i];
2708 mutex_init(&lg->lg_mutex);
2709 INIT_LIST_HEAD(&lg->lg_prealloc_list);
2710 spin_lock_init(&lg->lg_prealloc_lock);
2711 }
2712
2713 ext4_mb_init_per_dev_proc(sb);
2714 ext4_mb_history_init(sb);
2715
2716 printk("EXT4-fs: mballoc enabled\n");
2717 return 0;
2718}
2719
2720/* need to called with ext4 group lock (ext4_lock_group) */
2721static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2722{
2723 struct ext4_prealloc_space *pa;
2724 struct list_head *cur, *tmp;
2725 int count = 0;
2726
2727 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2728 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2729 list_del(&pa->pa_group_list);
2730 count++;
2731 kfree(pa);
2732 }
2733 if (count)
2734 mb_debug("mballoc: %u PAs left\n", count);
2735
2736}
2737
2738int ext4_mb_release(struct super_block *sb)
2739{
2740 ext4_group_t i;
2741 int num_meta_group_infos;
2742 struct ext4_group_info *grinfo;
2743 struct ext4_sb_info *sbi = EXT4_SB(sb);
2744
2745 if (!test_opt(sb, MBALLOC))
2746 return 0;
2747
2748 /* release freed, non-committed blocks */
2749 spin_lock(&sbi->s_md_lock);
2750 list_splice_init(&sbi->s_closed_transaction,
2751 &sbi->s_committed_transaction);
2752 list_splice_init(&sbi->s_active_transaction,
2753 &sbi->s_committed_transaction);
2754 spin_unlock(&sbi->s_md_lock);
2755 ext4_mb_free_committed_blocks(sb);
2756
2757 if (sbi->s_group_info) {
2758 for (i = 0; i < sbi->s_groups_count; i++) {
2759 grinfo = ext4_get_group_info(sb, i);
2760#ifdef DOUBLE_CHECK
2761 kfree(grinfo->bb_bitmap);
2762#endif
2763 ext4_lock_group(sb, i);
2764 ext4_mb_cleanup_pa(grinfo);
2765 ext4_unlock_group(sb, i);
2766 kfree(grinfo);
2767 }
2768 num_meta_group_infos = (sbi->s_groups_count +
2769 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2770 EXT4_DESC_PER_BLOCK_BITS(sb);
2771 for (i = 0; i < num_meta_group_infos; i++)
2772 kfree(sbi->s_group_info[i]);
2773 kfree(sbi->s_group_info);
2774 }
2775 kfree(sbi->s_mb_offsets);
2776 kfree(sbi->s_mb_maxs);
2777 if (sbi->s_buddy_cache)
2778 iput(sbi->s_buddy_cache);
2779 if (sbi->s_mb_stats) {
2780 printk(KERN_INFO
2781 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2782 atomic_read(&sbi->s_bal_allocated),
2783 atomic_read(&sbi->s_bal_reqs),
2784 atomic_read(&sbi->s_bal_success));
2785 printk(KERN_INFO
2786 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2787 "%u 2^N hits, %u breaks, %u lost\n",
2788 atomic_read(&sbi->s_bal_ex_scanned),
2789 atomic_read(&sbi->s_bal_goals),
2790 atomic_read(&sbi->s_bal_2orders),
2791 atomic_read(&sbi->s_bal_breaks),
2792 atomic_read(&sbi->s_mb_lost_chunks));
2793 printk(KERN_INFO
2794 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2795 sbi->s_mb_buddies_generated++,
2796 sbi->s_mb_generation_time);
2797 printk(KERN_INFO
2798 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2799 atomic_read(&sbi->s_mb_preallocated),
2800 atomic_read(&sbi->s_mb_discarded));
2801 }
2802
2803 kfree(sbi->s_locality_groups);
2804
2805 ext4_mb_history_release(sb);
2806 ext4_mb_destroy_per_dev_proc(sb);
2807
2808 return 0;
2809}
2810
2811static void ext4_mb_free_committed_blocks(struct super_block *sb)
2812{
2813 struct ext4_sb_info *sbi = EXT4_SB(sb);
2814 int err;
2815 int i;
2816 int count = 0;
2817 int count2 = 0;
2818 struct ext4_free_metadata *md;
2819 struct ext4_buddy e4b;
2820
2821 if (list_empty(&sbi->s_committed_transaction))
2822 return;
2823
2824 /* there is committed blocks to be freed yet */
2825 do {
2826 /* get next array of blocks */
2827 md = NULL;
2828 spin_lock(&sbi->s_md_lock);
2829 if (!list_empty(&sbi->s_committed_transaction)) {
2830 md = list_entry(sbi->s_committed_transaction.next,
2831 struct ext4_free_metadata, list);
2832 list_del(&md->list);
2833 }
2834 spin_unlock(&sbi->s_md_lock);
2835
2836 if (md == NULL)
2837 break;
2838
2839 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2840 md->num, md->group, md);
2841
2842 err = ext4_mb_load_buddy(sb, md->group, &e4b);
2843 /* we expect to find existing buddy because it's pinned */
2844 BUG_ON(err != 0);
2845
2846 /* there are blocks to put in buddy to make them really free */
2847 count += md->num;
2848 count2++;
2849 ext4_lock_group(sb, md->group);
2850 for (i = 0; i < md->num; i++) {
2851 mb_debug(" %u", md->blocks[i]);
2852 err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
2853 BUG_ON(err != 0);
2854 }
2855 mb_debug("\n");
2856 ext4_unlock_group(sb, md->group);
2857
2858 /* balance refcounts from ext4_mb_free_metadata() */
2859 page_cache_release(e4b.bd_buddy_page);
2860 page_cache_release(e4b.bd_bitmap_page);
2861
2862 kfree(md);
2863 ext4_mb_release_desc(&e4b);
2864
2865 } while (md);
2866
2867 mb_debug("freed %u blocks in %u structures\n", count, count2);
2868}
2869
2870#define EXT4_ROOT "ext4"
2871#define EXT4_MB_STATS_NAME "stats"
2872#define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2873#define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2874#define EXT4_MB_ORDER2_REQ "order2_req"
2875#define EXT4_MB_STREAM_REQ "stream_req"
2876#define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2877
2878
2879
2880#define MB_PROC_VALUE_READ(name) \
2881static int ext4_mb_read_##name(char *page, char **start, \
2882 off_t off, int count, int *eof, void *data) \
2883{ \
2884 struct ext4_sb_info *sbi = data; \
2885 int len; \
2886 *eof = 1; \
2887 if (off != 0) \
2888 return 0; \
2889 len = sprintf(page, "%ld\n", sbi->s_mb_##name); \
2890 *start = page; \
2891 return len; \
2892}
2893
2894#define MB_PROC_VALUE_WRITE(name) \
2895static int ext4_mb_write_##name(struct file *file, \
2896 const char __user *buf, unsigned long cnt, void *data) \
2897{ \
2898 struct ext4_sb_info *sbi = data; \
2899 char str[32]; \
2900 long value; \
2901 if (cnt >= sizeof(str)) \
2902 return -EINVAL; \
2903 if (copy_from_user(str, buf, cnt)) \
2904 return -EFAULT; \
2905 value = simple_strtol(str, NULL, 0); \
2906 if (value <= 0) \
2907 return -ERANGE; \
2908 sbi->s_mb_##name = value; \
2909 return cnt; \
2910}
2911
2912MB_PROC_VALUE_READ(stats);
2913MB_PROC_VALUE_WRITE(stats);
2914MB_PROC_VALUE_READ(max_to_scan);
2915MB_PROC_VALUE_WRITE(max_to_scan);
2916MB_PROC_VALUE_READ(min_to_scan);
2917MB_PROC_VALUE_WRITE(min_to_scan);
2918MB_PROC_VALUE_READ(order2_reqs);
2919MB_PROC_VALUE_WRITE(order2_reqs);
2920MB_PROC_VALUE_READ(stream_request);
2921MB_PROC_VALUE_WRITE(stream_request);
2922MB_PROC_VALUE_READ(group_prealloc);
2923MB_PROC_VALUE_WRITE(group_prealloc);
2924
2925#define MB_PROC_HANDLER(name, var) \
2926do { \
2927 proc = create_proc_entry(name, mode, sbi->s_mb_proc); \
2928 if (proc == NULL) { \
2929 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2930 goto err_out; \
2931 } \
2932 proc->data = sbi; \
2933 proc->read_proc = ext4_mb_read_##var ; \
2934 proc->write_proc = ext4_mb_write_##var; \
2935} while (0)
2936
2937static int ext4_mb_init_per_dev_proc(struct super_block *sb)
2938{
2939 mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
2940 struct ext4_sb_info *sbi = EXT4_SB(sb);
2941 struct proc_dir_entry *proc;
2942 char devname[64];
2943
2944 snprintf(devname, sizeof(devname) - 1, "%s",
2945 bdevname(sb->s_bdev, devname));
2946 sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
2947
2948 MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
2949 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
2950 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan);
2951 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs);
2952 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request);
2953 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc);
2954
2955 return 0;
2956
2957err_out:
2958 printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);
2959 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2960 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2961 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2962 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2963 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2964 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2965 remove_proc_entry(devname, proc_root_ext4);
2966 sbi->s_mb_proc = NULL;
2967
2968 return -ENOMEM;
2969}
2970
2971static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
2972{
2973 struct ext4_sb_info *sbi = EXT4_SB(sb);
2974 char devname[64];
2975
2976 if (sbi->s_mb_proc == NULL)
2977 return -EINVAL;
2978
2979 snprintf(devname, sizeof(devname) - 1, "%s",
2980 bdevname(sb->s_bdev, devname));
2981 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2982 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2983 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2984 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2985 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2986 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2987 remove_proc_entry(devname, proc_root_ext4);
2988
2989 return 0;
2990}
2991
2992int __init init_ext4_mballoc(void)
2993{
2994 ext4_pspace_cachep =
2995 kmem_cache_create("ext4_prealloc_space",
2996 sizeof(struct ext4_prealloc_space),
2997 0, SLAB_RECLAIM_ACCOUNT, NULL);
2998 if (ext4_pspace_cachep == NULL)
2999 return -ENOMEM;
3000
Eric Sandeen256bdb42008-02-10 01:13:33 -05003001 ext4_ac_cachep =
3002 kmem_cache_create("ext4_alloc_context",
3003 sizeof(struct ext4_allocation_context),
3004 0, SLAB_RECLAIM_ACCOUNT, NULL);
3005 if (ext4_ac_cachep == NULL) {
3006 kmem_cache_destroy(ext4_pspace_cachep);
3007 return -ENOMEM;
3008 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003009#ifdef CONFIG_PROC_FS
3010 proc_root_ext4 = proc_mkdir(EXT4_ROOT, proc_root_fs);
3011 if (proc_root_ext4 == NULL)
3012 printk(KERN_ERR "EXT4-fs: Unable to create %s\n", EXT4_ROOT);
3013#endif
Alex Tomasc9de5602008-01-29 00:19:52 -05003014 return 0;
3015}
3016
3017void exit_ext4_mballoc(void)
3018{
3019 /* XXX: synchronize_rcu(); */
3020 kmem_cache_destroy(ext4_pspace_cachep);
Eric Sandeen256bdb42008-02-10 01:13:33 -05003021 kmem_cache_destroy(ext4_ac_cachep);
Alex Tomasc9de5602008-01-29 00:19:52 -05003022#ifdef CONFIG_PROC_FS
3023 remove_proc_entry(EXT4_ROOT, proc_root_fs);
3024#endif
3025}
3026
3027
3028/*
3029 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
3030 * Returns 0 if success or error code
3031 */
3032static int ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
3033 handle_t *handle)
3034{
3035 struct buffer_head *bitmap_bh = NULL;
3036 struct ext4_super_block *es;
3037 struct ext4_group_desc *gdp;
3038 struct buffer_head *gdp_bh;
3039 struct ext4_sb_info *sbi;
3040 struct super_block *sb;
3041 ext4_fsblk_t block;
3042 int err;
3043
3044 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3045 BUG_ON(ac->ac_b_ex.fe_len <= 0);
3046
3047 sb = ac->ac_sb;
3048 sbi = EXT4_SB(sb);
3049 es = sbi->s_es;
3050
3051 ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
3052 gdp->bg_free_blocks_count);
3053
3054 err = -EIO;
3055 bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group);
3056 if (!bitmap_bh)
3057 goto out_err;
3058
3059 err = ext4_journal_get_write_access(handle, bitmap_bh);
3060 if (err)
3061 goto out_err;
3062
3063 err = -EIO;
3064 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
3065 if (!gdp)
3066 goto out_err;
3067
3068 err = ext4_journal_get_write_access(handle, gdp_bh);
3069 if (err)
3070 goto out_err;
3071
3072 block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
3073 + ac->ac_b_ex.fe_start
3074 + le32_to_cpu(es->s_first_data_block);
3075
3076 if (block == ext4_block_bitmap(sb, gdp) ||
3077 block == ext4_inode_bitmap(sb, gdp) ||
3078 in_range(block, ext4_inode_table(sb, gdp),
3079 EXT4_SB(sb)->s_itb_per_group)) {
3080
3081 ext4_error(sb, __FUNCTION__,
3082 "Allocating block in system zone - block = %llu",
3083 block);
3084 }
3085#ifdef AGGRESSIVE_CHECK
3086 {
3087 int i;
3088 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3089 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3090 bitmap_bh->b_data));
3091 }
3092 }
3093#endif
3094 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
3095 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
3096
3097 spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
3098 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
3099 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3100 gdp->bg_free_blocks_count =
3101 cpu_to_le16(ext4_free_blocks_after_init(sb,
3102 ac->ac_b_ex.fe_group,
3103 gdp));
3104 }
3105 gdp->bg_free_blocks_count =
3106 cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count)
3107 - ac->ac_b_ex.fe_len);
3108 gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
3109 spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
3110 percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
3111
3112 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
3113 if (err)
3114 goto out_err;
3115 err = ext4_journal_dirty_metadata(handle, gdp_bh);
3116
3117out_err:
3118 sb->s_dirt = 1;
Aneesh Kumar K.V42a10ad2008-02-10 01:07:28 -05003119 brelse(bitmap_bh);
Alex Tomasc9de5602008-01-29 00:19:52 -05003120 return err;
3121}
3122
3123/*
3124 * here we normalize request for locality group
3125 * Group request are normalized to s_strip size if we set the same via mount
3126 * option. If not we set it to s_mb_group_prealloc which can be configured via
3127 * /proc/fs/ext4/<partition>/group_prealloc
3128 *
3129 * XXX: should we try to preallocate more than the group has now?
3130 */
3131static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3132{
3133 struct super_block *sb = ac->ac_sb;
3134 struct ext4_locality_group *lg = ac->ac_lg;
3135
3136 BUG_ON(lg == NULL);
3137 if (EXT4_SB(sb)->s_stripe)
3138 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
3139 else
3140 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3141 mb_debug("#%u: goal %lu blocks for locality group\n",
3142 current->pid, ac->ac_g_ex.fe_len);
3143}
3144
3145/*
3146 * Normalization means making request better in terms of
3147 * size and alignment
3148 */
3149static void ext4_mb_normalize_request(struct ext4_allocation_context *ac,
3150 struct ext4_allocation_request *ar)
3151{
3152 int bsbits, max;
3153 ext4_lblk_t end;
3154 struct list_head *cur;
3155 loff_t size, orig_size, start_off;
3156 ext4_lblk_t start, orig_start;
3157 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3158
3159 /* do normalize only data requests, metadata requests
3160 do not need preallocation */
3161 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3162 return;
3163
3164 /* sometime caller may want exact blocks */
3165 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3166 return;
3167
3168 /* caller may indicate that preallocation isn't
3169 * required (it's a tail, for example) */
3170 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3171 return;
3172
3173 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3174 ext4_mb_normalize_group_request(ac);
3175 return ;
3176 }
3177
3178 bsbits = ac->ac_sb->s_blocksize_bits;
3179
3180 /* first, let's learn actual file size
3181 * given current request is allocated */
3182 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
3183 size = size << bsbits;
3184 if (size < i_size_read(ac->ac_inode))
3185 size = i_size_read(ac->ac_inode);
3186
3187 /* max available blocks in a free group */
3188 max = EXT4_BLOCKS_PER_GROUP(ac->ac_sb) - 1 - 1 -
3189 EXT4_SB(ac->ac_sb)->s_itb_per_group;
3190
3191#define NRL_CHECK_SIZE(req, size, max,bits) \
3192 (req <= (size) || max <= ((size) >> bits))
3193
3194 /* first, try to predict filesize */
3195 /* XXX: should this table be tunable? */
3196 start_off = 0;
3197 if (size <= 16 * 1024) {
3198 size = 16 * 1024;
3199 } else if (size <= 32 * 1024) {
3200 size = 32 * 1024;
3201 } else if (size <= 64 * 1024) {
3202 size = 64 * 1024;
3203 } else if (size <= 128 * 1024) {
3204 size = 128 * 1024;
3205 } else if (size <= 256 * 1024) {
3206 size = 256 * 1024;
3207 } else if (size <= 512 * 1024) {
3208 size = 512 * 1024;
3209 } else if (size <= 1024 * 1024) {
3210 size = 1024 * 1024;
3211 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, bsbits)) {
3212 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3213 (20 - bsbits)) << 20;
3214 size = 1024 * 1024;
3215 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, bsbits)) {
3216 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3217 (22 - bsbits)) << 22;
3218 size = 4 * 1024 * 1024;
3219 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3220 (8<<20)>>bsbits, max, bsbits)) {
3221 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3222 (23 - bsbits)) << 23;
3223 size = 8 * 1024 * 1024;
3224 } else {
3225 start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
3226 size = ac->ac_o_ex.fe_len << bsbits;
3227 }
3228 orig_size = size = size >> bsbits;
3229 orig_start = start = start_off >> bsbits;
3230
3231 /* don't cover already allocated blocks in selected range */
3232 if (ar->pleft && start <= ar->lleft) {
3233 size -= ar->lleft + 1 - start;
3234 start = ar->lleft + 1;
3235 }
3236 if (ar->pright && start + size - 1 >= ar->lright)
3237 size -= start + size - ar->lright;
3238
3239 end = start + size;
3240
3241 /* check we don't cross already preallocated blocks */
3242 rcu_read_lock();
3243 list_for_each_rcu(cur, &ei->i_prealloc_list) {
3244 struct ext4_prealloc_space *pa;
3245 unsigned long pa_end;
3246
3247 pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
3248
3249 if (pa->pa_deleted)
3250 continue;
3251 spin_lock(&pa->pa_lock);
3252 if (pa->pa_deleted) {
3253 spin_unlock(&pa->pa_lock);
3254 continue;
3255 }
3256
3257 pa_end = pa->pa_lstart + pa->pa_len;
3258
3259 /* PA must not overlap original request */
3260 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3261 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3262
3263 /* skip PA normalized request doesn't overlap with */
3264 if (pa->pa_lstart >= end) {
3265 spin_unlock(&pa->pa_lock);
3266 continue;
3267 }
3268 if (pa_end <= start) {
3269 spin_unlock(&pa->pa_lock);
3270 continue;
3271 }
3272 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3273
3274 if (pa_end <= ac->ac_o_ex.fe_logical) {
3275 BUG_ON(pa_end < start);
3276 start = pa_end;
3277 }
3278
3279 if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3280 BUG_ON(pa->pa_lstart > end);
3281 end = pa->pa_lstart;
3282 }
3283 spin_unlock(&pa->pa_lock);
3284 }
3285 rcu_read_unlock();
3286 size = end - start;
3287
3288 /* XXX: extra loop to check we really don't overlap preallocations */
3289 rcu_read_lock();
3290 list_for_each_rcu(cur, &ei->i_prealloc_list) {
3291 struct ext4_prealloc_space *pa;
3292 unsigned long pa_end;
3293 pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
3294 spin_lock(&pa->pa_lock);
3295 if (pa->pa_deleted == 0) {
3296 pa_end = pa->pa_lstart + pa->pa_len;
3297 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3298 }
3299 spin_unlock(&pa->pa_lock);
3300 }
3301 rcu_read_unlock();
3302
3303 if (start + size <= ac->ac_o_ex.fe_logical &&
3304 start > ac->ac_o_ex.fe_logical) {
3305 printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
3306 (unsigned long) start, (unsigned long) size,
3307 (unsigned long) ac->ac_o_ex.fe_logical);
3308 }
3309 BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
3310 start > ac->ac_o_ex.fe_logical);
3311 BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3312
3313 /* now prepare goal request */
3314
3315 /* XXX: is it better to align blocks WRT to logical
3316 * placement or satisfy big request as is */
3317 ac->ac_g_ex.fe_logical = start;
3318 ac->ac_g_ex.fe_len = size;
3319
3320 /* define goal start in order to merge */
3321 if (ar->pright && (ar->lright == (start + size))) {
3322 /* merge to the right */
3323 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3324 &ac->ac_f_ex.fe_group,
3325 &ac->ac_f_ex.fe_start);
3326 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3327 }
3328 if (ar->pleft && (ar->lleft + 1 == start)) {
3329 /* merge to the left */
3330 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3331 &ac->ac_f_ex.fe_group,
3332 &ac->ac_f_ex.fe_start);
3333 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3334 }
3335
3336 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
3337 (unsigned) orig_size, (unsigned) start);
3338}
3339
3340static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3341{
3342 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3343
3344 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3345 atomic_inc(&sbi->s_bal_reqs);
3346 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3347 if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
3348 atomic_inc(&sbi->s_bal_success);
3349 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3350 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3351 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3352 atomic_inc(&sbi->s_bal_goals);
3353 if (ac->ac_found > sbi->s_mb_max_to_scan)
3354 atomic_inc(&sbi->s_bal_breaks);
3355 }
3356
3357 ext4_mb_store_history(ac);
3358}
3359
3360/*
3361 * use blocks preallocated to inode
3362 */
3363static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3364 struct ext4_prealloc_space *pa)
3365{
3366 ext4_fsblk_t start;
3367 ext4_fsblk_t end;
3368 int len;
3369
3370 /* found preallocated blocks, use them */
3371 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3372 end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
3373 len = end - start;
3374 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3375 &ac->ac_b_ex.fe_start);
3376 ac->ac_b_ex.fe_len = len;
3377 ac->ac_status = AC_STATUS_FOUND;
3378 ac->ac_pa = pa;
3379
3380 BUG_ON(start < pa->pa_pstart);
3381 BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
3382 BUG_ON(pa->pa_free < len);
3383 pa->pa_free -= len;
3384
3385 mb_debug("use %llu/%lu from inode pa %p\n", start, len, pa);
3386}
3387
3388/*
3389 * use blocks preallocated to locality group
3390 */
3391static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3392 struct ext4_prealloc_space *pa)
3393{
3394 unsigned len = ac->ac_o_ex.fe_len;
3395
3396 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3397 &ac->ac_b_ex.fe_group,
3398 &ac->ac_b_ex.fe_start);
3399 ac->ac_b_ex.fe_len = len;
3400 ac->ac_status = AC_STATUS_FOUND;
3401 ac->ac_pa = pa;
3402
3403 /* we don't correct pa_pstart or pa_plen here to avoid
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003404 * possible race when the group is being loaded concurrently
Alex Tomasc9de5602008-01-29 00:19:52 -05003405 * instead we correct pa later, after blocks are marked
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003406 * in on-disk bitmap -- see ext4_mb_release_context()
3407 * Other CPUs are prevented from allocating from this pa by lg_mutex
Alex Tomasc9de5602008-01-29 00:19:52 -05003408 */
3409 mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3410}
3411
3412/*
3413 * search goal blocks in preallocated space
3414 */
3415static int ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
3416{
3417 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3418 struct ext4_locality_group *lg;
3419 struct ext4_prealloc_space *pa;
3420 struct list_head *cur;
3421
3422 /* only data can be preallocated */
3423 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3424 return 0;
3425
3426 /* first, try per-file preallocation */
3427 rcu_read_lock();
3428 list_for_each_rcu(cur, &ei->i_prealloc_list) {
3429 pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
3430
3431 /* all fields in this condition don't change,
3432 * so we can skip locking for them */
3433 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3434 ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
3435 continue;
3436
3437 /* found preallocated blocks, use them */
3438 spin_lock(&pa->pa_lock);
3439 if (pa->pa_deleted == 0 && pa->pa_free) {
3440 atomic_inc(&pa->pa_count);
3441 ext4_mb_use_inode_pa(ac, pa);
3442 spin_unlock(&pa->pa_lock);
3443 ac->ac_criteria = 10;
3444 rcu_read_unlock();
3445 return 1;
3446 }
3447 spin_unlock(&pa->pa_lock);
3448 }
3449 rcu_read_unlock();
3450
3451 /* can we use group allocation? */
3452 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3453 return 0;
3454
3455 /* inode may have no locality group for some reason */
3456 lg = ac->ac_lg;
3457 if (lg == NULL)
3458 return 0;
3459
3460 rcu_read_lock();
3461 list_for_each_rcu(cur, &lg->lg_prealloc_list) {
3462 pa = list_entry(cur, struct ext4_prealloc_space, pa_inode_list);
3463 spin_lock(&pa->pa_lock);
3464 if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) {
3465 atomic_inc(&pa->pa_count);
3466 ext4_mb_use_group_pa(ac, pa);
3467 spin_unlock(&pa->pa_lock);
3468 ac->ac_criteria = 20;
3469 rcu_read_unlock();
3470 return 1;
3471 }
3472 spin_unlock(&pa->pa_lock);
3473 }
3474 rcu_read_unlock();
3475
3476 return 0;
3477}
3478
3479/*
3480 * the function goes through all preallocation in this group and marks them
3481 * used in in-core bitmap. buddy must be generated from this bitmap
3482 * Need to be called with ext4 group lock (ext4_lock_group)
3483 */
3484static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3485 ext4_group_t group)
3486{
3487 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3488 struct ext4_prealloc_space *pa;
3489 struct list_head *cur;
3490 ext4_group_t groupnr;
3491 ext4_grpblk_t start;
3492 int preallocated = 0;
3493 int count = 0;
3494 int len;
3495
3496 /* all form of preallocation discards first load group,
3497 * so the only competing code is preallocation use.
3498 * we don't need any locking here
3499 * notice we do NOT ignore preallocations with pa_deleted
3500 * otherwise we could leave used blocks available for
3501 * allocation in buddy when concurrent ext4_mb_put_pa()
3502 * is dropping preallocation
3503 */
3504 list_for_each(cur, &grp->bb_prealloc_list) {
3505 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3506 spin_lock(&pa->pa_lock);
3507 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3508 &groupnr, &start);
3509 len = pa->pa_len;
3510 spin_unlock(&pa->pa_lock);
3511 if (unlikely(len == 0))
3512 continue;
3513 BUG_ON(groupnr != group);
3514 mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
3515 bitmap, start, len);
3516 preallocated += len;
3517 count++;
3518 }
3519 mb_debug("prellocated %u for group %lu\n", preallocated, group);
3520}
3521
3522static void ext4_mb_pa_callback(struct rcu_head *head)
3523{
3524 struct ext4_prealloc_space *pa;
3525 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3526 kmem_cache_free(ext4_pspace_cachep, pa);
3527}
3528
3529/*
3530 * drops a reference to preallocated space descriptor
3531 * if this was the last reference and the space is consumed
3532 */
3533static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3534 struct super_block *sb, struct ext4_prealloc_space *pa)
3535{
3536 unsigned long grp;
3537
3538 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
3539 return;
3540
3541 /* in this short window concurrent discard can set pa_deleted */
3542 spin_lock(&pa->pa_lock);
3543 if (pa->pa_deleted == 1) {
3544 spin_unlock(&pa->pa_lock);
3545 return;
3546 }
3547
3548 pa->pa_deleted = 1;
3549 spin_unlock(&pa->pa_lock);
3550
3551 /* -1 is to protect from crossing allocation group */
3552 ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
3553
3554 /*
3555 * possible race:
3556 *
3557 * P1 (buddy init) P2 (regular allocation)
3558 * find block B in PA
3559 * copy on-disk bitmap to buddy
3560 * mark B in on-disk bitmap
3561 * drop PA from group
3562 * mark all PAs in buddy
3563 *
3564 * thus, P1 initializes buddy with B available. to prevent this
3565 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3566 * against that pair
3567 */
3568 ext4_lock_group(sb, grp);
3569 list_del(&pa->pa_group_list);
3570 ext4_unlock_group(sb, grp);
3571
3572 spin_lock(pa->pa_obj_lock);
3573 list_del_rcu(&pa->pa_inode_list);
3574 spin_unlock(pa->pa_obj_lock);
3575
3576 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3577}
3578
3579/*
3580 * creates new preallocated space for given inode
3581 */
3582static int ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
3583{
3584 struct super_block *sb = ac->ac_sb;
3585 struct ext4_prealloc_space *pa;
3586 struct ext4_group_info *grp;
3587 struct ext4_inode_info *ei;
3588
3589 /* preallocate only when found space is larger then requested */
3590 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3591 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3592 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3593
3594 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3595 if (pa == NULL)
3596 return -ENOMEM;
3597
3598 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3599 int winl;
3600 int wins;
3601 int win;
3602 int offs;
3603
3604 /* we can't allocate as much as normalizer wants.
3605 * so, found space must get proper lstart
3606 * to cover original request */
3607 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3608 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3609
3610 /* we're limited by original request in that
3611 * logical block must be covered any way
3612 * winl is window we can move our chunk within */
3613 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3614
3615 /* also, we should cover whole original request */
3616 wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
3617
3618 /* the smallest one defines real window */
3619 win = min(winl, wins);
3620
3621 offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
3622 if (offs && offs < win)
3623 win = offs;
3624
3625 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
3626 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3627 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3628 }
3629
3630 /* preallocation can change ac_b_ex, thus we store actually
3631 * allocated blocks for history */
3632 ac->ac_f_ex = ac->ac_b_ex;
3633
3634 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3635 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3636 pa->pa_len = ac->ac_b_ex.fe_len;
3637 pa->pa_free = pa->pa_len;
3638 atomic_set(&pa->pa_count, 1);
3639 spin_lock_init(&pa->pa_lock);
3640 pa->pa_deleted = 0;
3641 pa->pa_linear = 0;
3642
3643 mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
3644 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3645
3646 ext4_mb_use_inode_pa(ac, pa);
3647 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3648
3649 ei = EXT4_I(ac->ac_inode);
3650 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3651
3652 pa->pa_obj_lock = &ei->i_prealloc_lock;
3653 pa->pa_inode = ac->ac_inode;
3654
3655 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3656 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3657 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3658
3659 spin_lock(pa->pa_obj_lock);
3660 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3661 spin_unlock(pa->pa_obj_lock);
3662
3663 return 0;
3664}
3665
3666/*
3667 * creates new preallocated space for locality group inodes belongs to
3668 */
3669static int ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
3670{
3671 struct super_block *sb = ac->ac_sb;
3672 struct ext4_locality_group *lg;
3673 struct ext4_prealloc_space *pa;
3674 struct ext4_group_info *grp;
3675
3676 /* preallocate only when found space is larger then requested */
3677 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3678 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3679 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3680
3681 BUG_ON(ext4_pspace_cachep == NULL);
3682 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3683 if (pa == NULL)
3684 return -ENOMEM;
3685
3686 /* preallocation can change ac_b_ex, thus we store actually
3687 * allocated blocks for history */
3688 ac->ac_f_ex = ac->ac_b_ex;
3689
3690 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3691 pa->pa_lstart = pa->pa_pstart;
3692 pa->pa_len = ac->ac_b_ex.fe_len;
3693 pa->pa_free = pa->pa_len;
3694 atomic_set(&pa->pa_count, 1);
3695 spin_lock_init(&pa->pa_lock);
3696 pa->pa_deleted = 0;
3697 pa->pa_linear = 1;
3698
3699 mb_debug("new group pa %p: %llu/%u for %u\n", pa,
3700 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3701
3702 ext4_mb_use_group_pa(ac, pa);
3703 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3704
3705 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3706 lg = ac->ac_lg;
3707 BUG_ON(lg == NULL);
3708
3709 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3710 pa->pa_inode = NULL;
3711
3712 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3713 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3714 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3715
3716 spin_lock(pa->pa_obj_lock);
3717 list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list);
3718 spin_unlock(pa->pa_obj_lock);
3719
3720 return 0;
3721}
3722
3723static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3724{
3725 int err;
3726
3727 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3728 err = ext4_mb_new_group_pa(ac);
3729 else
3730 err = ext4_mb_new_inode_pa(ac);
3731 return err;
3732}
3733
3734/*
3735 * finds all unused blocks in on-disk bitmap, frees them in
3736 * in-core bitmap and buddy.
3737 * @pa must be unlinked from inode and group lists, so that
3738 * nobody else can find/use it.
3739 * the caller MUST hold group/inode locks.
3740 * TODO: optimize the case when there are no in-core structures yet
3741 */
3742static int ext4_mb_release_inode_pa(struct ext4_buddy *e4b,
3743 struct buffer_head *bitmap_bh,
3744 struct ext4_prealloc_space *pa)
3745{
Eric Sandeen256bdb42008-02-10 01:13:33 -05003746 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003747 struct super_block *sb = e4b->bd_sb;
3748 struct ext4_sb_info *sbi = EXT4_SB(sb);
3749 unsigned long end;
3750 unsigned long next;
3751 ext4_group_t group;
3752 ext4_grpblk_t bit;
3753 sector_t start;
3754 int err = 0;
3755 int free = 0;
3756
3757 BUG_ON(pa->pa_deleted == 0);
3758 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3759 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3760 end = bit + pa->pa_len;
3761
Eric Sandeen256bdb42008-02-10 01:13:33 -05003762 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3763
3764 if (ac) {
3765 ac->ac_sb = sb;
3766 ac->ac_inode = pa->pa_inode;
3767 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3768 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003769
3770 while (bit < end) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003771 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003772 if (bit >= end)
3773 break;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003774 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003775 if (next > end)
3776 next = end;
3777 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3778 le32_to_cpu(sbi->s_es->s_first_data_block);
3779 mb_debug(" free preallocated %u/%u in group %u\n",
3780 (unsigned) start, (unsigned) next - bit,
3781 (unsigned) group);
3782 free += next - bit;
3783
Eric Sandeen256bdb42008-02-10 01:13:33 -05003784 if (ac) {
3785 ac->ac_b_ex.fe_group = group;
3786 ac->ac_b_ex.fe_start = bit;
3787 ac->ac_b_ex.fe_len = next - bit;
3788 ac->ac_b_ex.fe_logical = 0;
3789 ext4_mb_store_history(ac);
3790 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003791
3792 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3793 bit = next + 1;
3794 }
3795 if (free != pa->pa_free) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003796 printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n",
Alex Tomasc9de5602008-01-29 00:19:52 -05003797 pa, (unsigned long) pa->pa_lstart,
3798 (unsigned long) pa->pa_pstart,
3799 (unsigned long) pa->pa_len);
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003800 ext4_error(sb, __FUNCTION__, "free %u, pa_free %u\n",
3801 free, pa->pa_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05003802 /*
3803 * pa is already deleted so we use the value obtained
3804 * from the bitmap and continue.
3805 */
Alex Tomasc9de5602008-01-29 00:19:52 -05003806 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003807 atomic_add(free, &sbi->s_mb_discarded);
Eric Sandeen256bdb42008-02-10 01:13:33 -05003808 if (ac)
3809 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003810
3811 return err;
3812}
3813
3814static int ext4_mb_release_group_pa(struct ext4_buddy *e4b,
3815 struct ext4_prealloc_space *pa)
3816{
Eric Sandeen256bdb42008-02-10 01:13:33 -05003817 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003818 struct super_block *sb = e4b->bd_sb;
3819 ext4_group_t group;
3820 ext4_grpblk_t bit;
3821
Eric Sandeen256bdb42008-02-10 01:13:33 -05003822 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3823
3824 if (ac)
3825 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
Alex Tomasc9de5602008-01-29 00:19:52 -05003826
3827 BUG_ON(pa->pa_deleted == 0);
3828 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3829 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3830 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3831 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3832
Eric Sandeen256bdb42008-02-10 01:13:33 -05003833 if (ac) {
3834 ac->ac_sb = sb;
3835 ac->ac_inode = NULL;
3836 ac->ac_b_ex.fe_group = group;
3837 ac->ac_b_ex.fe_start = bit;
3838 ac->ac_b_ex.fe_len = pa->pa_len;
3839 ac->ac_b_ex.fe_logical = 0;
3840 ext4_mb_store_history(ac);
3841 kmem_cache_free(ext4_ac_cachep, ac);
3842 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003843
3844 return 0;
3845}
3846
3847/*
3848 * releases all preallocations in given group
3849 *
3850 * first, we need to decide discard policy:
3851 * - when do we discard
3852 * 1) ENOSPC
3853 * - how many do we discard
3854 * 1) how many requested
3855 */
3856static int ext4_mb_discard_group_preallocations(struct super_block *sb,
3857 ext4_group_t group, int needed)
3858{
3859 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3860 struct buffer_head *bitmap_bh = NULL;
3861 struct ext4_prealloc_space *pa, *tmp;
3862 struct list_head list;
3863 struct ext4_buddy e4b;
3864 int err;
3865 int busy = 0;
3866 int free = 0;
3867
3868 mb_debug("discard preallocation for group %lu\n", group);
3869
3870 if (list_empty(&grp->bb_prealloc_list))
3871 return 0;
3872
3873 bitmap_bh = read_block_bitmap(sb, group);
3874 if (bitmap_bh == NULL) {
3875 /* error handling here */
3876 ext4_mb_release_desc(&e4b);
3877 BUG_ON(bitmap_bh == NULL);
3878 }
3879
3880 err = ext4_mb_load_buddy(sb, group, &e4b);
3881 BUG_ON(err != 0); /* error handling here */
3882
3883 if (needed == 0)
3884 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
3885
3886 grp = ext4_get_group_info(sb, group);
3887 INIT_LIST_HEAD(&list);
3888
3889repeat:
3890 ext4_lock_group(sb, group);
3891 list_for_each_entry_safe(pa, tmp,
3892 &grp->bb_prealloc_list, pa_group_list) {
3893 spin_lock(&pa->pa_lock);
3894 if (atomic_read(&pa->pa_count)) {
3895 spin_unlock(&pa->pa_lock);
3896 busy = 1;
3897 continue;
3898 }
3899 if (pa->pa_deleted) {
3900 spin_unlock(&pa->pa_lock);
3901 continue;
3902 }
3903
3904 /* seems this one can be freed ... */
3905 pa->pa_deleted = 1;
3906
3907 /* we can trust pa_free ... */
3908 free += pa->pa_free;
3909
3910 spin_unlock(&pa->pa_lock);
3911
3912 list_del(&pa->pa_group_list);
3913 list_add(&pa->u.pa_tmp_list, &list);
3914 }
3915
3916 /* if we still need more blocks and some PAs were used, try again */
3917 if (free < needed && busy) {
3918 busy = 0;
3919 ext4_unlock_group(sb, group);
3920 /*
3921 * Yield the CPU here so that we don't get soft lockup
3922 * in non preempt case.
3923 */
3924 yield();
3925 goto repeat;
3926 }
3927
3928 /* found anything to free? */
3929 if (list_empty(&list)) {
3930 BUG_ON(free != 0);
3931 goto out;
3932 }
3933
3934 /* now free all selected PAs */
3935 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3936
3937 /* remove from object (inode or locality group) */
3938 spin_lock(pa->pa_obj_lock);
3939 list_del_rcu(&pa->pa_inode_list);
3940 spin_unlock(pa->pa_obj_lock);
3941
3942 if (pa->pa_linear)
3943 ext4_mb_release_group_pa(&e4b, pa);
3944 else
3945 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
3946
3947 list_del(&pa->u.pa_tmp_list);
3948 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3949 }
3950
3951out:
3952 ext4_unlock_group(sb, group);
3953 ext4_mb_release_desc(&e4b);
3954 put_bh(bitmap_bh);
3955 return free;
3956}
3957
3958/*
3959 * releases all non-used preallocated blocks for given inode
3960 *
3961 * It's important to discard preallocations under i_data_sem
3962 * We don't want another block to be served from the prealloc
3963 * space when we are discarding the inode prealloc space.
3964 *
3965 * FIXME!! Make sure it is valid at all the call sites
3966 */
3967void ext4_mb_discard_inode_preallocations(struct inode *inode)
3968{
3969 struct ext4_inode_info *ei = EXT4_I(inode);
3970 struct super_block *sb = inode->i_sb;
3971 struct buffer_head *bitmap_bh = NULL;
3972 struct ext4_prealloc_space *pa, *tmp;
3973 ext4_group_t group = 0;
3974 struct list_head list;
3975 struct ext4_buddy e4b;
3976 int err;
3977
3978 if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
3979 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3980 return;
3981 }
3982
3983 mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
3984
3985 INIT_LIST_HEAD(&list);
3986
3987repeat:
3988 /* first, collect all pa's in the inode */
3989 spin_lock(&ei->i_prealloc_lock);
3990 while (!list_empty(&ei->i_prealloc_list)) {
3991 pa = list_entry(ei->i_prealloc_list.next,
3992 struct ext4_prealloc_space, pa_inode_list);
3993 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
3994 spin_lock(&pa->pa_lock);
3995 if (atomic_read(&pa->pa_count)) {
3996 /* this shouldn't happen often - nobody should
3997 * use preallocation while we're discarding it */
3998 spin_unlock(&pa->pa_lock);
3999 spin_unlock(&ei->i_prealloc_lock);
4000 printk(KERN_ERR "uh-oh! used pa while discarding\n");
4001 WARN_ON(1);
4002 schedule_timeout_uninterruptible(HZ);
4003 goto repeat;
4004
4005 }
4006 if (pa->pa_deleted == 0) {
4007 pa->pa_deleted = 1;
4008 spin_unlock(&pa->pa_lock);
4009 list_del_rcu(&pa->pa_inode_list);
4010 list_add(&pa->u.pa_tmp_list, &list);
4011 continue;
4012 }
4013
4014 /* someone is deleting pa right now */
4015 spin_unlock(&pa->pa_lock);
4016 spin_unlock(&ei->i_prealloc_lock);
4017
4018 /* we have to wait here because pa_deleted
4019 * doesn't mean pa is already unlinked from
4020 * the list. as we might be called from
4021 * ->clear_inode() the inode will get freed
4022 * and concurrent thread which is unlinking
4023 * pa from inode's list may access already
4024 * freed memory, bad-bad-bad */
4025
4026 /* XXX: if this happens too often, we can
4027 * add a flag to force wait only in case
4028 * of ->clear_inode(), but not in case of
4029 * regular truncate */
4030 schedule_timeout_uninterruptible(HZ);
4031 goto repeat;
4032 }
4033 spin_unlock(&ei->i_prealloc_lock);
4034
4035 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4036 BUG_ON(pa->pa_linear != 0);
4037 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4038
4039 err = ext4_mb_load_buddy(sb, group, &e4b);
4040 BUG_ON(err != 0); /* error handling here */
4041
4042 bitmap_bh = read_block_bitmap(sb, group);
4043 if (bitmap_bh == NULL) {
4044 /* error handling here */
4045 ext4_mb_release_desc(&e4b);
4046 BUG_ON(bitmap_bh == NULL);
4047 }
4048
4049 ext4_lock_group(sb, group);
4050 list_del(&pa->pa_group_list);
4051 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4052 ext4_unlock_group(sb, group);
4053
4054 ext4_mb_release_desc(&e4b);
4055 put_bh(bitmap_bh);
4056
4057 list_del(&pa->u.pa_tmp_list);
4058 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4059 }
4060}
4061
4062/*
4063 * finds all preallocated spaces and return blocks being freed to them
4064 * if preallocated space becomes full (no block is used from the space)
4065 * then the function frees space in buddy
4066 * XXX: at the moment, truncate (which is the only way to free blocks)
4067 * discards all preallocations
4068 */
4069static void ext4_mb_return_to_preallocation(struct inode *inode,
4070 struct ext4_buddy *e4b,
4071 sector_t block, int count)
4072{
4073 BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
4074}
4075#ifdef MB_DEBUG
4076static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4077{
4078 struct super_block *sb = ac->ac_sb;
4079 ext4_group_t i;
4080
4081 printk(KERN_ERR "EXT4-fs: Can't allocate:"
4082 " Allocation context details:\n");
4083 printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
4084 ac->ac_status, ac->ac_flags);
4085 printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
4086 "best %lu/%lu/%lu@%lu cr %d\n",
4087 (unsigned long)ac->ac_o_ex.fe_group,
4088 (unsigned long)ac->ac_o_ex.fe_start,
4089 (unsigned long)ac->ac_o_ex.fe_len,
4090 (unsigned long)ac->ac_o_ex.fe_logical,
4091 (unsigned long)ac->ac_g_ex.fe_group,
4092 (unsigned long)ac->ac_g_ex.fe_start,
4093 (unsigned long)ac->ac_g_ex.fe_len,
4094 (unsigned long)ac->ac_g_ex.fe_logical,
4095 (unsigned long)ac->ac_b_ex.fe_group,
4096 (unsigned long)ac->ac_b_ex.fe_start,
4097 (unsigned long)ac->ac_b_ex.fe_len,
4098 (unsigned long)ac->ac_b_ex.fe_logical,
4099 (int)ac->ac_criteria);
4100 printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
4101 ac->ac_found);
4102 printk(KERN_ERR "EXT4-fs: groups: \n");
4103 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
4104 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4105 struct ext4_prealloc_space *pa;
4106 ext4_grpblk_t start;
4107 struct list_head *cur;
4108 ext4_lock_group(sb, i);
4109 list_for_each(cur, &grp->bb_prealloc_list) {
4110 pa = list_entry(cur, struct ext4_prealloc_space,
4111 pa_group_list);
4112 spin_lock(&pa->pa_lock);
4113 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4114 NULL, &start);
4115 spin_unlock(&pa->pa_lock);
4116 printk(KERN_ERR "PA:%lu:%d:%u \n", i,
4117 start, pa->pa_len);
4118 }
4119 ext4_lock_group(sb, i);
4120
4121 if (grp->bb_free == 0)
4122 continue;
4123 printk(KERN_ERR "%lu: %d/%d \n",
4124 i, grp->bb_free, grp->bb_fragments);
4125 }
4126 printk(KERN_ERR "\n");
4127}
4128#else
4129static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4130{
4131 return;
4132}
4133#endif
4134
4135/*
4136 * We use locality group preallocation for small size file. The size of the
4137 * file is determined by the current size or the resulting size after
4138 * allocation which ever is larger
4139 *
4140 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
4141 */
4142static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4143{
4144 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4145 int bsbits = ac->ac_sb->s_blocksize_bits;
4146 loff_t size, isize;
4147
4148 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4149 return;
4150
4151 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
4152 isize = i_size_read(ac->ac_inode) >> bsbits;
4153 size = max(size, isize);
4154
4155 /* don't use group allocation for large files */
4156 if (size >= sbi->s_mb_stream_request)
4157 return;
4158
4159 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4160 return;
4161
4162 BUG_ON(ac->ac_lg != NULL);
4163 /*
4164 * locality group prealloc space are per cpu. The reason for having
4165 * per cpu locality group is to reduce the contention between block
4166 * request from multiple CPUs.
4167 */
4168 ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
4169 put_cpu();
4170
4171 /* we're going to use group allocation */
4172 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4173
4174 /* serialize all allocations in the group */
4175 mutex_lock(&ac->ac_lg->lg_mutex);
4176}
4177
4178static int ext4_mb_initialize_context(struct ext4_allocation_context *ac,
4179 struct ext4_allocation_request *ar)
4180{
4181 struct super_block *sb = ar->inode->i_sb;
4182 struct ext4_sb_info *sbi = EXT4_SB(sb);
4183 struct ext4_super_block *es = sbi->s_es;
4184 ext4_group_t group;
4185 unsigned long len;
4186 unsigned long goal;
4187 ext4_grpblk_t block;
4188
4189 /* we can't allocate > group size */
4190 len = ar->len;
4191
4192 /* just a dirty hack to filter too big requests */
4193 if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
4194 len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
4195
4196 /* start searching from the goal */
4197 goal = ar->goal;
4198 if (goal < le32_to_cpu(es->s_first_data_block) ||
4199 goal >= ext4_blocks_count(es))
4200 goal = le32_to_cpu(es->s_first_data_block);
4201 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4202
4203 /* set up allocation goals */
4204 ac->ac_b_ex.fe_logical = ar->logical;
4205 ac->ac_b_ex.fe_group = 0;
4206 ac->ac_b_ex.fe_start = 0;
4207 ac->ac_b_ex.fe_len = 0;
4208 ac->ac_status = AC_STATUS_CONTINUE;
4209 ac->ac_groups_scanned = 0;
4210 ac->ac_ex_scanned = 0;
4211 ac->ac_found = 0;
4212 ac->ac_sb = sb;
4213 ac->ac_inode = ar->inode;
4214 ac->ac_o_ex.fe_logical = ar->logical;
4215 ac->ac_o_ex.fe_group = group;
4216 ac->ac_o_ex.fe_start = block;
4217 ac->ac_o_ex.fe_len = len;
4218 ac->ac_g_ex.fe_logical = ar->logical;
4219 ac->ac_g_ex.fe_group = group;
4220 ac->ac_g_ex.fe_start = block;
4221 ac->ac_g_ex.fe_len = len;
4222 ac->ac_f_ex.fe_len = 0;
4223 ac->ac_flags = ar->flags;
4224 ac->ac_2order = 0;
4225 ac->ac_criteria = 0;
4226 ac->ac_pa = NULL;
4227 ac->ac_bitmap_page = NULL;
4228 ac->ac_buddy_page = NULL;
4229 ac->ac_lg = NULL;
4230
4231 /* we have to define context: we'll we work with a file or
4232 * locality group. this is a policy, actually */
4233 ext4_mb_group_or_file(ac);
4234
4235 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4236 "left: %u/%u, right %u/%u to %swritable\n",
4237 (unsigned) ar->len, (unsigned) ar->logical,
4238 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4239 (unsigned) ar->lleft, (unsigned) ar->pleft,
4240 (unsigned) ar->lright, (unsigned) ar->pright,
4241 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4242 return 0;
4243
4244}
4245
4246/*
4247 * release all resource we used in allocation
4248 */
4249static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4250{
4251 if (ac->ac_pa) {
4252 if (ac->ac_pa->pa_linear) {
4253 /* see comment in ext4_mb_use_group_pa() */
4254 spin_lock(&ac->ac_pa->pa_lock);
4255 ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len;
4256 ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len;
4257 ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len;
4258 ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len;
4259 spin_unlock(&ac->ac_pa->pa_lock);
4260 }
4261 ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa);
4262 }
4263 if (ac->ac_bitmap_page)
4264 page_cache_release(ac->ac_bitmap_page);
4265 if (ac->ac_buddy_page)
4266 page_cache_release(ac->ac_buddy_page);
4267 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4268 mutex_unlock(&ac->ac_lg->lg_mutex);
4269 ext4_mb_collect_stats(ac);
4270 return 0;
4271}
4272
4273static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4274{
4275 ext4_group_t i;
4276 int ret;
4277 int freed = 0;
4278
4279 for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
4280 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4281 freed += ret;
4282 needed -= ret;
4283 }
4284
4285 return freed;
4286}
4287
4288/*
4289 * Main entry point into mballoc to allocate blocks
4290 * it tries to use preallocation first, then falls back
4291 * to usual allocation
4292 */
4293ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4294 struct ext4_allocation_request *ar, int *errp)
4295{
Eric Sandeen256bdb42008-02-10 01:13:33 -05004296 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004297 struct ext4_sb_info *sbi;
4298 struct super_block *sb;
4299 ext4_fsblk_t block = 0;
4300 int freed;
4301 int inquota;
4302
4303 sb = ar->inode->i_sb;
4304 sbi = EXT4_SB(sb);
4305
4306 if (!test_opt(sb, MBALLOC)) {
4307 block = ext4_new_blocks_old(handle, ar->inode, ar->goal,
4308 &(ar->len), errp);
4309 return block;
4310 }
4311
4312 while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
4313 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4314 ar->len--;
4315 }
4316 if (ar->len == 0) {
4317 *errp = -EDQUOT;
4318 return 0;
4319 }
4320 inquota = ar->len;
4321
Eric Sandeen256bdb42008-02-10 01:13:33 -05004322 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4323 if (!ac) {
4324 *errp = -ENOMEM;
4325 return 0;
4326 }
4327
Alex Tomasc9de5602008-01-29 00:19:52 -05004328 ext4_mb_poll_new_transaction(sb, handle);
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;
4333 goto out;
4334 }
4335
Eric Sandeen256bdb42008-02-10 01:13:33 -05004336 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4337 if (!ext4_mb_use_preallocated(ac)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05004338
Eric Sandeen256bdb42008-02-10 01:13:33 -05004339 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4340 ext4_mb_normalize_request(ac, ar);
Alex Tomasc9de5602008-01-29 00:19:52 -05004341
4342repeat:
4343 /* allocate space in core */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004344 ext4_mb_regular_allocator(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004345
4346 /* as we've just preallocated more space than
4347 * user requested orinally, we store allocated
4348 * space in a special descriptor */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004349 if (ac->ac_status == AC_STATUS_FOUND &&
4350 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4351 ext4_mb_new_preallocation(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004352 }
4353
Eric Sandeen256bdb42008-02-10 01:13:33 -05004354 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4355 ext4_mb_mark_diskspace_used(ac, handle);
Alex Tomasc9de5602008-01-29 00:19:52 -05004356 *errp = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004357 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4358 ar->len = ac->ac_b_ex.fe_len;
Alex Tomasc9de5602008-01-29 00:19:52 -05004359 } else {
Eric Sandeen256bdb42008-02-10 01:13:33 -05004360 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05004361 if (freed)
4362 goto repeat;
4363 *errp = -ENOSPC;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004364 ac->ac_b_ex.fe_len = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05004365 ar->len = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004366 ext4_mb_show_ac(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004367 }
4368
Eric Sandeen256bdb42008-02-10 01:13:33 -05004369 ext4_mb_release_context(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004370
4371out:
4372 if (ar->len < inquota)
4373 DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
4374
Eric Sandeen256bdb42008-02-10 01:13:33 -05004375 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004376 return block;
4377}
4378static void ext4_mb_poll_new_transaction(struct super_block *sb,
4379 handle_t *handle)
4380{
4381 struct ext4_sb_info *sbi = EXT4_SB(sb);
4382
4383 if (sbi->s_last_transaction == handle->h_transaction->t_tid)
4384 return;
4385
4386 /* new transaction! time to close last one and free blocks for
4387 * committed transaction. we know that only transaction can be
4388 * active, so previos transaction can be being logged and we
4389 * know that transaction before previous is known to be already
4390 * logged. this means that now we may free blocks freed in all
4391 * transactions before previous one. hope I'm clear enough ... */
4392
4393 spin_lock(&sbi->s_md_lock);
4394 if (sbi->s_last_transaction != handle->h_transaction->t_tid) {
4395 mb_debug("new transaction %lu, old %lu\n",
4396 (unsigned long) handle->h_transaction->t_tid,
4397 (unsigned long) sbi->s_last_transaction);
4398 list_splice_init(&sbi->s_closed_transaction,
4399 &sbi->s_committed_transaction);
4400 list_splice_init(&sbi->s_active_transaction,
4401 &sbi->s_closed_transaction);
4402 sbi->s_last_transaction = handle->h_transaction->t_tid;
4403 }
4404 spin_unlock(&sbi->s_md_lock);
4405
4406 ext4_mb_free_committed_blocks(sb);
4407}
4408
4409static int ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
4410 ext4_group_t group, ext4_grpblk_t block, int count)
4411{
4412 struct ext4_group_info *db = e4b->bd_info;
4413 struct super_block *sb = e4b->bd_sb;
4414 struct ext4_sb_info *sbi = EXT4_SB(sb);
4415 struct ext4_free_metadata *md;
4416 int i;
4417
4418 BUG_ON(e4b->bd_bitmap_page == NULL);
4419 BUG_ON(e4b->bd_buddy_page == NULL);
4420
4421 ext4_lock_group(sb, group);
4422 for (i = 0; i < count; i++) {
4423 md = db->bb_md_cur;
4424 if (md && db->bb_tid != handle->h_transaction->t_tid) {
4425 db->bb_md_cur = NULL;
4426 md = NULL;
4427 }
4428
4429 if (md == NULL) {
4430 ext4_unlock_group(sb, group);
4431 md = kmalloc(sizeof(*md), GFP_NOFS);
4432 if (md == NULL)
4433 return -ENOMEM;
4434 md->num = 0;
4435 md->group = group;
4436
4437 ext4_lock_group(sb, group);
4438 if (db->bb_md_cur == NULL) {
4439 spin_lock(&sbi->s_md_lock);
4440 list_add(&md->list, &sbi->s_active_transaction);
4441 spin_unlock(&sbi->s_md_lock);
4442 /* protect buddy cache from being freed,
4443 * otherwise we'll refresh it from
4444 * on-disk bitmap and lose not-yet-available
4445 * blocks */
4446 page_cache_get(e4b->bd_buddy_page);
4447 page_cache_get(e4b->bd_bitmap_page);
4448 db->bb_md_cur = md;
4449 db->bb_tid = handle->h_transaction->t_tid;
4450 mb_debug("new md 0x%p for group %lu\n",
4451 md, md->group);
4452 } else {
4453 kfree(md);
4454 md = db->bb_md_cur;
4455 }
4456 }
4457
4458 BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS);
4459 md->blocks[md->num] = block + i;
4460 md->num++;
4461 if (md->num == EXT4_BB_MAX_BLOCKS) {
4462 /* no more space, put full container on a sb's list */
4463 db->bb_md_cur = NULL;
4464 }
4465 }
4466 ext4_unlock_group(sb, group);
4467 return 0;
4468}
4469
4470/*
4471 * Main entry point into mballoc to free blocks
4472 */
4473void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
4474 unsigned long block, unsigned long count,
4475 int metadata, unsigned long *freed)
4476{
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05004477 struct buffer_head *bitmap_bh = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004478 struct super_block *sb = inode->i_sb;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004479 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004480 struct ext4_group_desc *gdp;
4481 struct ext4_super_block *es;
4482 unsigned long overflow;
4483 ext4_grpblk_t bit;
4484 struct buffer_head *gd_bh;
4485 ext4_group_t block_group;
4486 struct ext4_sb_info *sbi;
4487 struct ext4_buddy e4b;
4488 int err = 0;
4489 int ret;
4490
4491 *freed = 0;
4492
4493 ext4_mb_poll_new_transaction(sb, handle);
4494
4495 sbi = EXT4_SB(sb);
4496 es = EXT4_SB(sb)->s_es;
4497 if (block < le32_to_cpu(es->s_first_data_block) ||
4498 block + count < block ||
4499 block + count > ext4_blocks_count(es)) {
4500 ext4_error(sb, __FUNCTION__,
4501 "Freeing blocks not in datazone - "
4502 "block = %lu, count = %lu", block, count);
4503 goto error_return;
4504 }
4505
4506 ext4_debug("freeing block %lu\n", block);
4507
Eric Sandeen256bdb42008-02-10 01:13:33 -05004508 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4509 if (ac) {
4510 ac->ac_op = EXT4_MB_HISTORY_FREE;
4511 ac->ac_inode = inode;
4512 ac->ac_sb = sb;
4513 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004514
4515do_more:
4516 overflow = 0;
4517 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4518
4519 /*
4520 * Check to see if we are freeing blocks across a group
4521 * boundary.
4522 */
4523 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4524 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
4525 count -= overflow;
4526 }
4527 bitmap_bh = read_block_bitmap(sb, block_group);
4528 if (!bitmap_bh)
4529 goto error_return;
4530 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4531 if (!gdp)
4532 goto error_return;
4533
4534 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4535 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4536 in_range(block, ext4_inode_table(sb, gdp),
4537 EXT4_SB(sb)->s_itb_per_group) ||
4538 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4539 EXT4_SB(sb)->s_itb_per_group)) {
4540
4541 ext4_error(sb, __FUNCTION__,
4542 "Freeing blocks in system zone - "
4543 "Block = %lu, count = %lu", block, count);
4544 }
4545
4546 BUFFER_TRACE(bitmap_bh, "getting write access");
4547 err = ext4_journal_get_write_access(handle, bitmap_bh);
4548 if (err)
4549 goto error_return;
4550
4551 /*
4552 * We are about to modify some metadata. Call the journal APIs
4553 * to unshare ->b_data if a currently-committing transaction is
4554 * using it
4555 */
4556 BUFFER_TRACE(gd_bh, "get_write_access");
4557 err = ext4_journal_get_write_access(handle, gd_bh);
4558 if (err)
4559 goto error_return;
4560
4561 err = ext4_mb_load_buddy(sb, block_group, &e4b);
4562 if (err)
4563 goto error_return;
4564
4565#ifdef AGGRESSIVE_CHECK
4566 {
4567 int i;
4568 for (i = 0; i < count; i++)
4569 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4570 }
4571#endif
4572 mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
4573 bit, count);
4574
4575 /* We dirtied the bitmap block */
4576 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4577 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
4578
Eric Sandeen256bdb42008-02-10 01:13:33 -05004579 if (ac) {
4580 ac->ac_b_ex.fe_group = block_group;
4581 ac->ac_b_ex.fe_start = bit;
4582 ac->ac_b_ex.fe_len = count;
4583 ext4_mb_store_history(ac);
4584 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004585
4586 if (metadata) {
4587 /* blocks being freed are metadata. these blocks shouldn't
4588 * be used until this transaction is committed */
4589 ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
4590 } else {
4591 ext4_lock_group(sb, block_group);
4592 err = mb_free_blocks(inode, &e4b, bit, count);
4593 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
4594 ext4_unlock_group(sb, block_group);
4595 BUG_ON(err != 0);
4596 }
4597
4598 spin_lock(sb_bgl_lock(sbi, block_group));
4599 gdp->bg_free_blocks_count =
4600 cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) + count);
4601 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
4602 spin_unlock(sb_bgl_lock(sbi, block_group));
4603 percpu_counter_add(&sbi->s_freeblocks_counter, count);
4604
4605 ext4_mb_release_desc(&e4b);
4606
4607 *freed += count;
4608
4609 /* And the group descriptor block */
4610 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4611 ret = ext4_journal_dirty_metadata(handle, gd_bh);
4612 if (!err)
4613 err = ret;
4614
4615 if (overflow && !err) {
4616 block += count;
4617 count = overflow;
4618 put_bh(bitmap_bh);
4619 goto do_more;
4620 }
4621 sb->s_dirt = 1;
4622error_return:
4623 brelse(bitmap_bh);
4624 ext4_std_error(sb, err);
Eric Sandeen256bdb42008-02-10 01:13:33 -05004625 if (ac)
4626 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004627 return;
4628}