blob: 0b46fc0ca196f98d86597561820ca161daa46ae3 [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);
Alex Tomasc9de5602008-01-29 00:19:52 -0500579
580static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
581 ext4_group_t group);
582static void ext4_mb_poll_new_transaction(struct super_block *, handle_t *);
583static void ext4_mb_free_committed_blocks(struct super_block *);
584static void ext4_mb_return_to_preallocation(struct inode *inode,
585 struct ext4_buddy *e4b, sector_t block,
586 int count);
587static void ext4_mb_put_pa(struct ext4_allocation_context *,
588 struct super_block *, struct ext4_prealloc_space *pa);
589static int ext4_mb_init_per_dev_proc(struct super_block *sb);
590static int ext4_mb_destroy_per_dev_proc(struct super_block *sb);
591
592
593static inline void ext4_lock_group(struct super_block *sb, ext4_group_t group)
594{
595 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
596
597 bit_spin_lock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
598}
599
600static inline void ext4_unlock_group(struct super_block *sb,
601 ext4_group_t group)
602{
603 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
604
605 bit_spin_unlock(EXT4_GROUP_INFO_LOCKED_BIT, &(grinfo->bb_state));
606}
607
608static inline int ext4_is_group_locked(struct super_block *sb,
609 ext4_group_t group)
610{
611 struct ext4_group_info *grinfo = ext4_get_group_info(sb, group);
612
613 return bit_spin_is_locked(EXT4_GROUP_INFO_LOCKED_BIT,
614 &(grinfo->bb_state));
615}
616
617static ext4_fsblk_t ext4_grp_offs_to_block(struct super_block *sb,
618 struct ext4_free_extent *fex)
619{
620 ext4_fsblk_t block;
621
622 block = (ext4_fsblk_t) fex->fe_group * EXT4_BLOCKS_PER_GROUP(sb)
623 + fex->fe_start
624 + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
625 return block;
626}
627
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500628static inline void *mb_correct_addr_and_bit(int *bit, void *addr)
629{
Alex Tomasc9de5602008-01-29 00:19:52 -0500630#if BITS_PER_LONG == 64
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500631 *bit += ((unsigned long) addr & 7UL) << 3;
632 addr = (void *) ((unsigned long) addr & ~7UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500633#elif BITS_PER_LONG == 32
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500634 *bit += ((unsigned long) addr & 3UL) << 3;
635 addr = (void *) ((unsigned long) addr & ~3UL);
Alex Tomasc9de5602008-01-29 00:19:52 -0500636#else
637#error "how many bits you are?!"
638#endif
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500639 return addr;
640}
Alex Tomasc9de5602008-01-29 00:19:52 -0500641
642static inline int mb_test_bit(int bit, void *addr)
643{
644 /*
645 * ext4_test_bit on architecture like powerpc
646 * needs unsigned long aligned address
647 */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500648 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500649 return ext4_test_bit(bit, addr);
650}
651
652static inline void mb_set_bit(int bit, void *addr)
653{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500654 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500655 ext4_set_bit(bit, addr);
656}
657
658static inline void mb_set_bit_atomic(spinlock_t *lock, int bit, void *addr)
659{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500660 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500661 ext4_set_bit_atomic(lock, bit, addr);
662}
663
664static inline void mb_clear_bit(int bit, void *addr)
665{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500666 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500667 ext4_clear_bit(bit, addr);
668}
669
670static inline void mb_clear_bit_atomic(spinlock_t *lock, int bit, void *addr)
671{
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500672 addr = mb_correct_addr_and_bit(&bit, addr);
Alex Tomasc9de5602008-01-29 00:19:52 -0500673 ext4_clear_bit_atomic(lock, bit, addr);
674}
675
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500676static inline int mb_find_next_zero_bit(void *addr, int max, int start)
677{
678 int fix = 0;
679 addr = mb_correct_addr_and_bit(&fix, addr);
680 max += fix;
681 start += fix;
682
683 return ext4_find_next_zero_bit(addr, max, start) - fix;
684}
685
686static inline int mb_find_next_bit(void *addr, int max, int start)
687{
688 int fix = 0;
689 addr = mb_correct_addr_and_bit(&fix, addr);
690 max += fix;
691 start += fix;
692
693 return ext4_find_next_bit(addr, max, start) - fix;
694}
695
Alex Tomasc9de5602008-01-29 00:19:52 -0500696static void *mb_find_buddy(struct ext4_buddy *e4b, int order, int *max)
697{
698 char *bb;
699
Alex Tomasc9de5602008-01-29 00:19:52 -0500700 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
701 BUG_ON(max == NULL);
702
703 if (order > e4b->bd_blkbits + 1) {
704 *max = 0;
705 return NULL;
706 }
707
708 /* at order 0 we see each particular block */
709 *max = 1 << (e4b->bd_blkbits + 3);
710 if (order == 0)
711 return EXT4_MB_BITMAP(e4b);
712
713 bb = EXT4_MB_BUDDY(e4b) + EXT4_SB(e4b->bd_sb)->s_mb_offsets[order];
714 *max = EXT4_SB(e4b->bd_sb)->s_mb_maxs[order];
715
716 return bb;
717}
718
719#ifdef DOUBLE_CHECK
720static void mb_free_blocks_double(struct inode *inode, struct ext4_buddy *e4b,
721 int first, int count)
722{
723 int i;
724 struct super_block *sb = e4b->bd_sb;
725
726 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
727 return;
728 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
729 for (i = 0; i < count; i++) {
730 if (!mb_test_bit(first + i, e4b->bd_info->bb_bitmap)) {
731 ext4_fsblk_t blocknr;
732 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
733 blocknr += first + i;
734 blocknr +=
735 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
736
Harvey Harrison46e665e2008-04-17 10:38:59 -0400737 ext4_error(sb, __func__, "double-free of inode"
Alex Tomasc9de5602008-01-29 00:19:52 -0500738 " %lu's block %llu(bit %u in group %lu)\n",
739 inode ? inode->i_ino : 0, blocknr,
740 first + i, e4b->bd_group);
741 }
742 mb_clear_bit(first + i, e4b->bd_info->bb_bitmap);
743 }
744}
745
746static void mb_mark_used_double(struct ext4_buddy *e4b, int first, int count)
747{
748 int i;
749
750 if (unlikely(e4b->bd_info->bb_bitmap == NULL))
751 return;
752 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
753 for (i = 0; i < count; i++) {
754 BUG_ON(mb_test_bit(first + i, e4b->bd_info->bb_bitmap));
755 mb_set_bit(first + i, e4b->bd_info->bb_bitmap);
756 }
757}
758
759static void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
760{
761 if (memcmp(e4b->bd_info->bb_bitmap, bitmap, e4b->bd_sb->s_blocksize)) {
762 unsigned char *b1, *b2;
763 int i;
764 b1 = (unsigned char *) e4b->bd_info->bb_bitmap;
765 b2 = (unsigned char *) bitmap;
766 for (i = 0; i < e4b->bd_sb->s_blocksize; i++) {
767 if (b1[i] != b2[i]) {
768 printk("corruption in group %lu at byte %u(%u):"
769 " %x in copy != %x on disk/prealloc\n",
770 e4b->bd_group, i, i * 8, b1[i], b2[i]);
771 BUG();
772 }
773 }
774 }
775}
776
777#else
778static inline void mb_free_blocks_double(struct inode *inode,
779 struct ext4_buddy *e4b, int first, int count)
780{
781 return;
782}
783static inline void mb_mark_used_double(struct ext4_buddy *e4b,
784 int first, int count)
785{
786 return;
787}
788static inline void mb_cmp_bitmaps(struct ext4_buddy *e4b, void *bitmap)
789{
790 return;
791}
792#endif
793
794#ifdef AGGRESSIVE_CHECK
795
796#define MB_CHECK_ASSERT(assert) \
797do { \
798 if (!(assert)) { \
799 printk(KERN_EMERG \
800 "Assertion failure in %s() at %s:%d: \"%s\"\n", \
801 function, file, line, # assert); \
802 BUG(); \
803 } \
804} while (0)
805
806static int __mb_check_buddy(struct ext4_buddy *e4b, char *file,
807 const char *function, int line)
808{
809 struct super_block *sb = e4b->bd_sb;
810 int order = e4b->bd_blkbits + 1;
811 int max;
812 int max2;
813 int i;
814 int j;
815 int k;
816 int count;
817 struct ext4_group_info *grp;
818 int fragments = 0;
819 int fstart;
820 struct list_head *cur;
821 void *buddy;
822 void *buddy2;
823
824 if (!test_opt(sb, MBALLOC))
825 return 0;
826
827 {
828 static int mb_check_counter;
829 if (mb_check_counter++ % 100 != 0)
830 return 0;
831 }
832
833 while (order > 1) {
834 buddy = mb_find_buddy(e4b, order, &max);
835 MB_CHECK_ASSERT(buddy);
836 buddy2 = mb_find_buddy(e4b, order - 1, &max2);
837 MB_CHECK_ASSERT(buddy2);
838 MB_CHECK_ASSERT(buddy != buddy2);
839 MB_CHECK_ASSERT(max * 2 == max2);
840
841 count = 0;
842 for (i = 0; i < max; i++) {
843
844 if (mb_test_bit(i, buddy)) {
845 /* only single bit in buddy2 may be 1 */
846 if (!mb_test_bit(i << 1, buddy2)) {
847 MB_CHECK_ASSERT(
848 mb_test_bit((i<<1)+1, buddy2));
849 } else if (!mb_test_bit((i << 1) + 1, buddy2)) {
850 MB_CHECK_ASSERT(
851 mb_test_bit(i << 1, buddy2));
852 }
853 continue;
854 }
855
856 /* both bits in buddy2 must be 0 */
857 MB_CHECK_ASSERT(mb_test_bit(i << 1, buddy2));
858 MB_CHECK_ASSERT(mb_test_bit((i << 1) + 1, buddy2));
859
860 for (j = 0; j < (1 << order); j++) {
861 k = (i * (1 << order)) + j;
862 MB_CHECK_ASSERT(
863 !mb_test_bit(k, EXT4_MB_BITMAP(e4b)));
864 }
865 count++;
866 }
867 MB_CHECK_ASSERT(e4b->bd_info->bb_counters[order] == count);
868 order--;
869 }
870
871 fstart = -1;
872 buddy = mb_find_buddy(e4b, 0, &max);
873 for (i = 0; i < max; i++) {
874 if (!mb_test_bit(i, buddy)) {
875 MB_CHECK_ASSERT(i >= e4b->bd_info->bb_first_free);
876 if (fstart == -1) {
877 fragments++;
878 fstart = i;
879 }
880 continue;
881 }
882 fstart = -1;
883 /* check used bits only */
884 for (j = 0; j < e4b->bd_blkbits + 1; j++) {
885 buddy2 = mb_find_buddy(e4b, j, &max2);
886 k = i >> j;
887 MB_CHECK_ASSERT(k < max2);
888 MB_CHECK_ASSERT(mb_test_bit(k, buddy2));
889 }
890 }
891 MB_CHECK_ASSERT(!EXT4_MB_GRP_NEED_INIT(e4b->bd_info));
892 MB_CHECK_ASSERT(e4b->bd_info->bb_fragments == fragments);
893
894 grp = ext4_get_group_info(sb, e4b->bd_group);
895 buddy = mb_find_buddy(e4b, 0, &max);
896 list_for_each(cur, &grp->bb_prealloc_list) {
897 ext4_group_t groupnr;
898 struct ext4_prealloc_space *pa;
899 pa = list_entry(cur, struct ext4_prealloc_space, group_list);
900 ext4_get_group_no_and_offset(sb, pa->pstart, &groupnr, &k);
901 MB_CHECK_ASSERT(groupnr == e4b->bd_group);
902 for (i = 0; i < pa->len; i++)
903 MB_CHECK_ASSERT(mb_test_bit(k + i, buddy));
904 }
905 return 0;
906}
907#undef MB_CHECK_ASSERT
908#define mb_check_buddy(e4b) __mb_check_buddy(e4b, \
Harvey Harrison46e665e2008-04-17 10:38:59 -0400909 __FILE__, __func__, __LINE__)
Alex Tomasc9de5602008-01-29 00:19:52 -0500910#else
911#define mb_check_buddy(e4b)
912#endif
913
914/* FIXME!! need more doc */
915static void ext4_mb_mark_free_simple(struct super_block *sb,
916 void *buddy, unsigned first, int len,
917 struct ext4_group_info *grp)
918{
919 struct ext4_sb_info *sbi = EXT4_SB(sb);
920 unsigned short min;
921 unsigned short max;
922 unsigned short chunk;
923 unsigned short border;
924
Valerie Clementb73fce62008-02-15 13:48:51 -0500925 BUG_ON(len > EXT4_BLOCKS_PER_GROUP(sb));
Alex Tomasc9de5602008-01-29 00:19:52 -0500926
927 border = 2 << sb->s_blocksize_bits;
928
929 while (len > 0) {
930 /* find how many blocks can be covered since this position */
931 max = ffs(first | border) - 1;
932
933 /* find how many blocks of power 2 we need to mark */
934 min = fls(len) - 1;
935
936 if (max < min)
937 min = max;
938 chunk = 1 << min;
939
940 /* mark multiblock chunks only */
941 grp->bb_counters[min]++;
942 if (min > 0)
943 mb_clear_bit(first >> min,
944 buddy + sbi->s_mb_offsets[min]);
945
946 len -= chunk;
947 first += chunk;
948 }
949}
950
951static void ext4_mb_generate_buddy(struct super_block *sb,
952 void *buddy, void *bitmap, ext4_group_t group)
953{
954 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
955 unsigned short max = EXT4_BLOCKS_PER_GROUP(sb);
956 unsigned short i = 0;
957 unsigned short first;
958 unsigned short len;
959 unsigned free = 0;
960 unsigned fragments = 0;
961 unsigned long long period = get_cycles();
962
963 /* initialize buddy from bitmap which is aggregation
964 * of on-disk bitmap and preallocations */
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500965 i = mb_find_next_zero_bit(bitmap, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -0500966 grp->bb_first_free = i;
967 while (i < max) {
968 fragments++;
969 first = i;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500970 i = mb_find_next_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500971 len = i - first;
972 free += len;
973 if (len > 1)
974 ext4_mb_mark_free_simple(sb, buddy, first, len, grp);
975 else
976 grp->bb_counters[0]++;
977 if (i < max)
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -0500978 i = mb_find_next_zero_bit(bitmap, max, i);
Alex Tomasc9de5602008-01-29 00:19:52 -0500979 }
980 grp->bb_fragments = fragments;
981
982 if (free != grp->bb_free) {
Harvey Harrison46e665e2008-04-17 10:38:59 -0400983 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -0500984 "EXT4-fs: group %lu: %u blocks in bitmap, %u in gd\n",
985 group, free, grp->bb_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -0500986 /*
987 * If we intent to continue, we consider group descritor
988 * corrupt and update bb_free using bitmap value
989 */
Alex Tomasc9de5602008-01-29 00:19:52 -0500990 grp->bb_free = free;
991 }
992
993 clear_bit(EXT4_GROUP_INFO_NEED_INIT_BIT, &(grp->bb_state));
994
995 period = get_cycles() - period;
996 spin_lock(&EXT4_SB(sb)->s_bal_lock);
997 EXT4_SB(sb)->s_mb_buddies_generated++;
998 EXT4_SB(sb)->s_mb_generation_time += period;
999 spin_unlock(&EXT4_SB(sb)->s_bal_lock);
1000}
1001
1002/* The buddy information is attached the buddy cache inode
1003 * for convenience. The information regarding each group
1004 * is loaded via ext4_mb_load_buddy. The information involve
1005 * block bitmap and buddy information. The information are
1006 * stored in the inode as
1007 *
1008 * { page }
1009 * [ group 0 buddy][ group 0 bitmap] [group 1][ group 1]...
1010 *
1011 *
1012 * one block each for bitmap and buddy information.
1013 * So for each group we take up 2 blocks. A page can
1014 * contain blocks_per_page (PAGE_CACHE_SIZE / blocksize) blocks.
1015 * So it can have information regarding groups_per_page which
1016 * is blocks_per_page/2
1017 */
1018
1019static int ext4_mb_init_cache(struct page *page, char *incore)
1020{
1021 int blocksize;
1022 int blocks_per_page;
1023 int groups_per_page;
1024 int err = 0;
1025 int i;
1026 ext4_group_t first_group;
1027 int first_block;
1028 struct super_block *sb;
1029 struct buffer_head *bhs;
1030 struct buffer_head **bh;
1031 struct inode *inode;
1032 char *data;
1033 char *bitmap;
1034
1035 mb_debug("init page %lu\n", page->index);
1036
1037 inode = page->mapping->host;
1038 sb = inode->i_sb;
1039 blocksize = 1 << inode->i_blkbits;
1040 blocks_per_page = PAGE_CACHE_SIZE / blocksize;
1041
1042 groups_per_page = blocks_per_page >> 1;
1043 if (groups_per_page == 0)
1044 groups_per_page = 1;
1045
1046 /* allocate buffer_heads to read bitmaps */
1047 if (groups_per_page > 1) {
1048 err = -ENOMEM;
1049 i = sizeof(struct buffer_head *) * groups_per_page;
1050 bh = kzalloc(i, GFP_NOFS);
1051 if (bh == NULL)
1052 goto out;
1053 } else
1054 bh = &bhs;
1055
1056 first_group = page->index * blocks_per_page / 2;
1057
1058 /* read all groups the page covers into the cache */
1059 for (i = 0; i < groups_per_page; i++) {
1060 struct ext4_group_desc *desc;
1061
1062 if (first_group + i >= EXT4_SB(sb)->s_groups_count)
1063 break;
1064
1065 err = -EIO;
1066 desc = ext4_get_group_desc(sb, first_group + i, NULL);
1067 if (desc == NULL)
1068 goto out;
1069
1070 err = -ENOMEM;
1071 bh[i] = sb_getblk(sb, ext4_block_bitmap(sb, desc));
1072 if (bh[i] == NULL)
1073 goto out;
1074
1075 if (bh_uptodate_or_lock(bh[i]))
1076 continue;
1077
1078 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
1079 ext4_init_block_bitmap(sb, bh[i],
1080 first_group + i, desc);
1081 set_buffer_uptodate(bh[i]);
1082 unlock_buffer(bh[i]);
1083 continue;
1084 }
1085 get_bh(bh[i]);
1086 bh[i]->b_end_io = end_buffer_read_sync;
1087 submit_bh(READ, bh[i]);
1088 mb_debug("read bitmap for group %lu\n", first_group + i);
1089 }
1090
1091 /* wait for I/O completion */
1092 for (i = 0; i < groups_per_page && bh[i]; i++)
1093 wait_on_buffer(bh[i]);
1094
1095 err = -EIO;
1096 for (i = 0; i < groups_per_page && bh[i]; i++)
1097 if (!buffer_uptodate(bh[i]))
1098 goto out;
1099
1100 first_block = page->index * blocks_per_page;
1101 for (i = 0; i < blocks_per_page; i++) {
1102 int group;
1103 struct ext4_group_info *grinfo;
1104
1105 group = (first_block + i) >> 1;
1106 if (group >= EXT4_SB(sb)->s_groups_count)
1107 break;
1108
1109 /*
1110 * data carry information regarding this
1111 * particular group in the format specified
1112 * above
1113 *
1114 */
1115 data = page_address(page) + (i * blocksize);
1116 bitmap = bh[group - first_group]->b_data;
1117
1118 /*
1119 * We place the buddy block and bitmap block
1120 * close together
1121 */
1122 if ((first_block + i) & 1) {
1123 /* this is block of buddy */
1124 BUG_ON(incore == NULL);
1125 mb_debug("put buddy for group %u in page %lu/%x\n",
1126 group, page->index, i * blocksize);
1127 memset(data, 0xff, blocksize);
1128 grinfo = ext4_get_group_info(sb, group);
1129 grinfo->bb_fragments = 0;
1130 memset(grinfo->bb_counters, 0,
1131 sizeof(unsigned short)*(sb->s_blocksize_bits+2));
1132 /*
1133 * incore got set to the group block bitmap below
1134 */
1135 ext4_mb_generate_buddy(sb, data, incore, group);
1136 incore = NULL;
1137 } else {
1138 /* this is block of bitmap */
1139 BUG_ON(incore != NULL);
1140 mb_debug("put bitmap for group %u in page %lu/%x\n",
1141 group, page->index, i * blocksize);
1142
1143 /* see comments in ext4_mb_put_pa() */
1144 ext4_lock_group(sb, group);
1145 memcpy(data, bitmap, blocksize);
1146
1147 /* mark all preallocated blks used in in-core bitmap */
1148 ext4_mb_generate_from_pa(sb, data, group);
1149 ext4_unlock_group(sb, group);
1150
1151 /* set incore so that the buddy information can be
1152 * generated using this
1153 */
1154 incore = data;
1155 }
1156 }
1157 SetPageUptodate(page);
1158
1159out:
1160 if (bh) {
1161 for (i = 0; i < groups_per_page && bh[i]; i++)
1162 brelse(bh[i]);
1163 if (bh != &bhs)
1164 kfree(bh);
1165 }
1166 return err;
1167}
1168
Eric Sandeen4ddfef72008-04-29 08:11:12 -04001169static noinline_for_stack int
1170ext4_mb_load_buddy(struct super_block *sb, ext4_group_t group,
1171 struct ext4_buddy *e4b)
Alex Tomasc9de5602008-01-29 00:19:52 -05001172{
1173 struct ext4_sb_info *sbi = EXT4_SB(sb);
1174 struct inode *inode = sbi->s_buddy_cache;
1175 int blocks_per_page;
1176 int block;
1177 int pnum;
1178 int poff;
1179 struct page *page;
1180
1181 mb_debug("load group %lu\n", group);
1182
1183 blocks_per_page = PAGE_CACHE_SIZE / sb->s_blocksize;
1184
1185 e4b->bd_blkbits = sb->s_blocksize_bits;
1186 e4b->bd_info = ext4_get_group_info(sb, group);
1187 e4b->bd_sb = sb;
1188 e4b->bd_group = group;
1189 e4b->bd_buddy_page = NULL;
1190 e4b->bd_bitmap_page = NULL;
1191
1192 /*
1193 * the buddy cache inode stores the block bitmap
1194 * and buddy information in consecutive blocks.
1195 * So for each group we need two blocks.
1196 */
1197 block = group * 2;
1198 pnum = block / blocks_per_page;
1199 poff = block % blocks_per_page;
1200
1201 /* we could use find_or_create_page(), but it locks page
1202 * what we'd like to avoid in fast path ... */
1203 page = find_get_page(inode->i_mapping, pnum);
1204 if (page == NULL || !PageUptodate(page)) {
1205 if (page)
1206 page_cache_release(page);
1207 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1208 if (page) {
1209 BUG_ON(page->mapping != inode->i_mapping);
1210 if (!PageUptodate(page)) {
1211 ext4_mb_init_cache(page, NULL);
1212 mb_cmp_bitmaps(e4b, page_address(page) +
1213 (poff * sb->s_blocksize));
1214 }
1215 unlock_page(page);
1216 }
1217 }
1218 if (page == NULL || !PageUptodate(page))
1219 goto err;
1220 e4b->bd_bitmap_page = page;
1221 e4b->bd_bitmap = page_address(page) + (poff * sb->s_blocksize);
1222 mark_page_accessed(page);
1223
1224 block++;
1225 pnum = block / blocks_per_page;
1226 poff = block % blocks_per_page;
1227
1228 page = find_get_page(inode->i_mapping, pnum);
1229 if (page == NULL || !PageUptodate(page)) {
1230 if (page)
1231 page_cache_release(page);
1232 page = find_or_create_page(inode->i_mapping, pnum, GFP_NOFS);
1233 if (page) {
1234 BUG_ON(page->mapping != inode->i_mapping);
1235 if (!PageUptodate(page))
1236 ext4_mb_init_cache(page, e4b->bd_bitmap);
1237
1238 unlock_page(page);
1239 }
1240 }
1241 if (page == NULL || !PageUptodate(page))
1242 goto err;
1243 e4b->bd_buddy_page = page;
1244 e4b->bd_buddy = page_address(page) + (poff * sb->s_blocksize);
1245 mark_page_accessed(page);
1246
1247 BUG_ON(e4b->bd_bitmap_page == NULL);
1248 BUG_ON(e4b->bd_buddy_page == NULL);
1249
1250 return 0;
1251
1252err:
1253 if (e4b->bd_bitmap_page)
1254 page_cache_release(e4b->bd_bitmap_page);
1255 if (e4b->bd_buddy_page)
1256 page_cache_release(e4b->bd_buddy_page);
1257 e4b->bd_buddy = NULL;
1258 e4b->bd_bitmap = NULL;
1259 return -EIO;
1260}
1261
1262static void ext4_mb_release_desc(struct ext4_buddy *e4b)
1263{
1264 if (e4b->bd_bitmap_page)
1265 page_cache_release(e4b->bd_bitmap_page);
1266 if (e4b->bd_buddy_page)
1267 page_cache_release(e4b->bd_buddy_page);
1268}
1269
1270
1271static int mb_find_order_for_block(struct ext4_buddy *e4b, int block)
1272{
1273 int order = 1;
1274 void *bb;
1275
1276 BUG_ON(EXT4_MB_BITMAP(e4b) == EXT4_MB_BUDDY(e4b));
1277 BUG_ON(block >= (1 << (e4b->bd_blkbits + 3)));
1278
1279 bb = EXT4_MB_BUDDY(e4b);
1280 while (order <= e4b->bd_blkbits + 1) {
1281 block = block >> 1;
1282 if (!mb_test_bit(block, bb)) {
1283 /* this block is part of buddy of order 'order' */
1284 return order;
1285 }
1286 bb += 1 << (e4b->bd_blkbits - order);
1287 order++;
1288 }
1289 return 0;
1290}
1291
1292static void mb_clear_bits(spinlock_t *lock, void *bm, int cur, int len)
1293{
1294 __u32 *addr;
1295
1296 len = cur + len;
1297 while (cur < len) {
1298 if ((cur & 31) == 0 && (len - cur) >= 32) {
1299 /* fast path: clear whole word at once */
1300 addr = bm + (cur >> 3);
1301 *addr = 0;
1302 cur += 32;
1303 continue;
1304 }
1305 mb_clear_bit_atomic(lock, cur, bm);
1306 cur++;
1307 }
1308}
1309
1310static void mb_set_bits(spinlock_t *lock, void *bm, int cur, int len)
1311{
1312 __u32 *addr;
1313
1314 len = cur + len;
1315 while (cur < len) {
1316 if ((cur & 31) == 0 && (len - cur) >= 32) {
1317 /* fast path: set whole word at once */
1318 addr = bm + (cur >> 3);
1319 *addr = 0xffffffff;
1320 cur += 32;
1321 continue;
1322 }
1323 mb_set_bit_atomic(lock, cur, bm);
1324 cur++;
1325 }
1326}
1327
1328static int mb_free_blocks(struct inode *inode, struct ext4_buddy *e4b,
1329 int first, int count)
1330{
1331 int block = 0;
1332 int max = 0;
1333 int order;
1334 void *buddy;
1335 void *buddy2;
1336 struct super_block *sb = e4b->bd_sb;
1337
1338 BUG_ON(first + count > (sb->s_blocksize << 3));
1339 BUG_ON(!ext4_is_group_locked(sb, e4b->bd_group));
1340 mb_check_buddy(e4b);
1341 mb_free_blocks_double(inode, e4b, first, count);
1342
1343 e4b->bd_info->bb_free += count;
1344 if (first < e4b->bd_info->bb_first_free)
1345 e4b->bd_info->bb_first_free = first;
1346
1347 /* let's maintain fragments counter */
1348 if (first != 0)
1349 block = !mb_test_bit(first - 1, EXT4_MB_BITMAP(e4b));
1350 if (first + count < EXT4_SB(sb)->s_mb_maxs[0])
1351 max = !mb_test_bit(first + count, EXT4_MB_BITMAP(e4b));
1352 if (block && max)
1353 e4b->bd_info->bb_fragments--;
1354 else if (!block && !max)
1355 e4b->bd_info->bb_fragments++;
1356
1357 /* let's maintain buddy itself */
1358 while (count-- > 0) {
1359 block = first++;
1360 order = 0;
1361
1362 if (!mb_test_bit(block, EXT4_MB_BITMAP(e4b))) {
1363 ext4_fsblk_t blocknr;
1364 blocknr = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb);
1365 blocknr += block;
1366 blocknr +=
1367 le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block);
1368
Harvey Harrison46e665e2008-04-17 10:38:59 -04001369 ext4_error(sb, __func__, "double-free of inode"
Alex Tomasc9de5602008-01-29 00:19:52 -05001370 " %lu's block %llu(bit %u in group %lu)\n",
1371 inode ? inode->i_ino : 0, blocknr, block,
1372 e4b->bd_group);
1373 }
1374 mb_clear_bit(block, EXT4_MB_BITMAP(e4b));
1375 e4b->bd_info->bb_counters[order]++;
1376
1377 /* start of the buddy */
1378 buddy = mb_find_buddy(e4b, order, &max);
1379
1380 do {
1381 block &= ~1UL;
1382 if (mb_test_bit(block, buddy) ||
1383 mb_test_bit(block + 1, buddy))
1384 break;
1385
1386 /* both the buddies are free, try to coalesce them */
1387 buddy2 = mb_find_buddy(e4b, order + 1, &max);
1388
1389 if (!buddy2)
1390 break;
1391
1392 if (order > 0) {
1393 /* for special purposes, we don't set
1394 * free bits in bitmap */
1395 mb_set_bit(block, buddy);
1396 mb_set_bit(block + 1, buddy);
1397 }
1398 e4b->bd_info->bb_counters[order]--;
1399 e4b->bd_info->bb_counters[order]--;
1400
1401 block = block >> 1;
1402 order++;
1403 e4b->bd_info->bb_counters[order]++;
1404
1405 mb_clear_bit(block, buddy2);
1406 buddy = buddy2;
1407 } while (1);
1408 }
1409 mb_check_buddy(e4b);
1410
1411 return 0;
1412}
1413
1414static int mb_find_extent(struct ext4_buddy *e4b, int order, int block,
1415 int needed, struct ext4_free_extent *ex)
1416{
1417 int next = block;
1418 int max;
1419 int ord;
1420 void *buddy;
1421
1422 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1423 BUG_ON(ex == NULL);
1424
1425 buddy = mb_find_buddy(e4b, order, &max);
1426 BUG_ON(buddy == NULL);
1427 BUG_ON(block >= max);
1428 if (mb_test_bit(block, buddy)) {
1429 ex->fe_len = 0;
1430 ex->fe_start = 0;
1431 ex->fe_group = 0;
1432 return 0;
1433 }
1434
1435 /* FIXME dorp order completely ? */
1436 if (likely(order == 0)) {
1437 /* find actual order */
1438 order = mb_find_order_for_block(e4b, block);
1439 block = block >> order;
1440 }
1441
1442 ex->fe_len = 1 << order;
1443 ex->fe_start = block << order;
1444 ex->fe_group = e4b->bd_group;
1445
1446 /* calc difference from given start */
1447 next = next - ex->fe_start;
1448 ex->fe_len -= next;
1449 ex->fe_start += next;
1450
1451 while (needed > ex->fe_len &&
1452 (buddy = mb_find_buddy(e4b, order, &max))) {
1453
1454 if (block + 1 >= max)
1455 break;
1456
1457 next = (block + 1) * (1 << order);
1458 if (mb_test_bit(next, EXT4_MB_BITMAP(e4b)))
1459 break;
1460
1461 ord = mb_find_order_for_block(e4b, next);
1462
1463 order = ord;
1464 block = next >> order;
1465 ex->fe_len += 1 << order;
1466 }
1467
1468 BUG_ON(ex->fe_start + ex->fe_len > (1 << (e4b->bd_blkbits + 3)));
1469 return ex->fe_len;
1470}
1471
1472static int mb_mark_used(struct ext4_buddy *e4b, struct ext4_free_extent *ex)
1473{
1474 int ord;
1475 int mlen = 0;
1476 int max = 0;
1477 int cur;
1478 int start = ex->fe_start;
1479 int len = ex->fe_len;
1480 unsigned ret = 0;
1481 int len0 = len;
1482 void *buddy;
1483
1484 BUG_ON(start + len > (e4b->bd_sb->s_blocksize << 3));
1485 BUG_ON(e4b->bd_group != ex->fe_group);
1486 BUG_ON(!ext4_is_group_locked(e4b->bd_sb, e4b->bd_group));
1487 mb_check_buddy(e4b);
1488 mb_mark_used_double(e4b, start, len);
1489
1490 e4b->bd_info->bb_free -= len;
1491 if (e4b->bd_info->bb_first_free == start)
1492 e4b->bd_info->bb_first_free += len;
1493
1494 /* let's maintain fragments counter */
1495 if (start != 0)
1496 mlen = !mb_test_bit(start - 1, EXT4_MB_BITMAP(e4b));
1497 if (start + len < EXT4_SB(e4b->bd_sb)->s_mb_maxs[0])
1498 max = !mb_test_bit(start + len, EXT4_MB_BITMAP(e4b));
1499 if (mlen && max)
1500 e4b->bd_info->bb_fragments++;
1501 else if (!mlen && !max)
1502 e4b->bd_info->bb_fragments--;
1503
1504 /* let's maintain buddy itself */
1505 while (len) {
1506 ord = mb_find_order_for_block(e4b, start);
1507
1508 if (((start >> ord) << ord) == start && len >= (1 << ord)) {
1509 /* the whole chunk may be allocated at once! */
1510 mlen = 1 << ord;
1511 buddy = mb_find_buddy(e4b, ord, &max);
1512 BUG_ON((start >> ord) >= max);
1513 mb_set_bit(start >> ord, buddy);
1514 e4b->bd_info->bb_counters[ord]--;
1515 start += mlen;
1516 len -= mlen;
1517 BUG_ON(len < 0);
1518 continue;
1519 }
1520
1521 /* store for history */
1522 if (ret == 0)
1523 ret = len | (ord << 16);
1524
1525 /* we have to split large buddy */
1526 BUG_ON(ord <= 0);
1527 buddy = mb_find_buddy(e4b, ord, &max);
1528 mb_set_bit(start >> ord, buddy);
1529 e4b->bd_info->bb_counters[ord]--;
1530
1531 ord--;
1532 cur = (start >> ord) & ~1U;
1533 buddy = mb_find_buddy(e4b, ord, &max);
1534 mb_clear_bit(cur, buddy);
1535 mb_clear_bit(cur + 1, buddy);
1536 e4b->bd_info->bb_counters[ord]++;
1537 e4b->bd_info->bb_counters[ord]++;
1538 }
1539
1540 mb_set_bits(sb_bgl_lock(EXT4_SB(e4b->bd_sb), ex->fe_group),
1541 EXT4_MB_BITMAP(e4b), ex->fe_start, len0);
1542 mb_check_buddy(e4b);
1543
1544 return ret;
1545}
1546
1547/*
1548 * Must be called under group lock!
1549 */
1550static void ext4_mb_use_best_found(struct ext4_allocation_context *ac,
1551 struct ext4_buddy *e4b)
1552{
1553 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1554 int ret;
1555
1556 BUG_ON(ac->ac_b_ex.fe_group != e4b->bd_group);
1557 BUG_ON(ac->ac_status == AC_STATUS_FOUND);
1558
1559 ac->ac_b_ex.fe_len = min(ac->ac_b_ex.fe_len, ac->ac_g_ex.fe_len);
1560 ac->ac_b_ex.fe_logical = ac->ac_g_ex.fe_logical;
1561 ret = mb_mark_used(e4b, &ac->ac_b_ex);
1562
1563 /* preallocation can change ac_b_ex, thus we store actually
1564 * allocated blocks for history */
1565 ac->ac_f_ex = ac->ac_b_ex;
1566
1567 ac->ac_status = AC_STATUS_FOUND;
1568 ac->ac_tail = ret & 0xffff;
1569 ac->ac_buddy = ret >> 16;
1570
1571 /* XXXXXXX: SUCH A HORRIBLE **CK */
1572 /*FIXME!! Why ? */
1573 ac->ac_bitmap_page = e4b->bd_bitmap_page;
1574 get_page(ac->ac_bitmap_page);
1575 ac->ac_buddy_page = e4b->bd_buddy_page;
1576 get_page(ac->ac_buddy_page);
1577
1578 /* store last allocated for subsequent stream allocation */
1579 if ((ac->ac_flags & EXT4_MB_HINT_DATA)) {
1580 spin_lock(&sbi->s_md_lock);
1581 sbi->s_mb_last_group = ac->ac_f_ex.fe_group;
1582 sbi->s_mb_last_start = ac->ac_f_ex.fe_start;
1583 spin_unlock(&sbi->s_md_lock);
1584 }
1585}
1586
1587/*
1588 * regular allocator, for general purposes allocation
1589 */
1590
1591static void ext4_mb_check_limits(struct ext4_allocation_context *ac,
1592 struct ext4_buddy *e4b,
1593 int finish_group)
1594{
1595 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1596 struct ext4_free_extent *bex = &ac->ac_b_ex;
1597 struct ext4_free_extent *gex = &ac->ac_g_ex;
1598 struct ext4_free_extent ex;
1599 int max;
1600
1601 /*
1602 * We don't want to scan for a whole year
1603 */
1604 if (ac->ac_found > sbi->s_mb_max_to_scan &&
1605 !(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1606 ac->ac_status = AC_STATUS_BREAK;
1607 return;
1608 }
1609
1610 /*
1611 * Haven't found good chunk so far, let's continue
1612 */
1613 if (bex->fe_len < gex->fe_len)
1614 return;
1615
1616 if ((finish_group || ac->ac_found > sbi->s_mb_min_to_scan)
1617 && bex->fe_group == e4b->bd_group) {
1618 /* recheck chunk's availability - we don't know
1619 * when it was found (within this lock-unlock
1620 * period or not) */
1621 max = mb_find_extent(e4b, 0, bex->fe_start, gex->fe_len, &ex);
1622 if (max >= gex->fe_len) {
1623 ext4_mb_use_best_found(ac, e4b);
1624 return;
1625 }
1626 }
1627}
1628
1629/*
1630 * The routine checks whether found extent is good enough. If it is,
1631 * then the extent gets marked used and flag is set to the context
1632 * to stop scanning. Otherwise, the extent is compared with the
1633 * previous found extent and if new one is better, then it's stored
1634 * in the context. Later, the best found extent will be used, if
1635 * mballoc can't find good enough extent.
1636 *
1637 * FIXME: real allocation policy is to be designed yet!
1638 */
1639static void ext4_mb_measure_extent(struct ext4_allocation_context *ac,
1640 struct ext4_free_extent *ex,
1641 struct ext4_buddy *e4b)
1642{
1643 struct ext4_free_extent *bex = &ac->ac_b_ex;
1644 struct ext4_free_extent *gex = &ac->ac_g_ex;
1645
1646 BUG_ON(ex->fe_len <= 0);
1647 BUG_ON(ex->fe_len >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1648 BUG_ON(ex->fe_start >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
1649 BUG_ON(ac->ac_status != AC_STATUS_CONTINUE);
1650
1651 ac->ac_found++;
1652
1653 /*
1654 * The special case - take what you catch first
1655 */
1656 if (unlikely(ac->ac_flags & EXT4_MB_HINT_FIRST)) {
1657 *bex = *ex;
1658 ext4_mb_use_best_found(ac, e4b);
1659 return;
1660 }
1661
1662 /*
1663 * Let's check whether the chuck is good enough
1664 */
1665 if (ex->fe_len == gex->fe_len) {
1666 *bex = *ex;
1667 ext4_mb_use_best_found(ac, e4b);
1668 return;
1669 }
1670
1671 /*
1672 * If this is first found extent, just store it in the context
1673 */
1674 if (bex->fe_len == 0) {
1675 *bex = *ex;
1676 return;
1677 }
1678
1679 /*
1680 * If new found extent is better, store it in the context
1681 */
1682 if (bex->fe_len < gex->fe_len) {
1683 /* if the request isn't satisfied, any found extent
1684 * larger than previous best one is better */
1685 if (ex->fe_len > bex->fe_len)
1686 *bex = *ex;
1687 } else if (ex->fe_len > gex->fe_len) {
1688 /* if the request is satisfied, then we try to find
1689 * an extent that still satisfy the request, but is
1690 * smaller than previous one */
1691 if (ex->fe_len < bex->fe_len)
1692 *bex = *ex;
1693 }
1694
1695 ext4_mb_check_limits(ac, e4b, 0);
1696}
1697
1698static int ext4_mb_try_best_found(struct ext4_allocation_context *ac,
1699 struct ext4_buddy *e4b)
1700{
1701 struct ext4_free_extent ex = ac->ac_b_ex;
1702 ext4_group_t group = ex.fe_group;
1703 int max;
1704 int err;
1705
1706 BUG_ON(ex.fe_len <= 0);
1707 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1708 if (err)
1709 return err;
1710
1711 ext4_lock_group(ac->ac_sb, group);
1712 max = mb_find_extent(e4b, 0, ex.fe_start, ex.fe_len, &ex);
1713
1714 if (max > 0) {
1715 ac->ac_b_ex = ex;
1716 ext4_mb_use_best_found(ac, e4b);
1717 }
1718
1719 ext4_unlock_group(ac->ac_sb, group);
1720 ext4_mb_release_desc(e4b);
1721
1722 return 0;
1723}
1724
1725static int ext4_mb_find_by_goal(struct ext4_allocation_context *ac,
1726 struct ext4_buddy *e4b)
1727{
1728 ext4_group_t group = ac->ac_g_ex.fe_group;
1729 int max;
1730 int err;
1731 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
1732 struct ext4_super_block *es = sbi->s_es;
1733 struct ext4_free_extent ex;
1734
1735 if (!(ac->ac_flags & EXT4_MB_HINT_TRY_GOAL))
1736 return 0;
1737
1738 err = ext4_mb_load_buddy(ac->ac_sb, group, e4b);
1739 if (err)
1740 return err;
1741
1742 ext4_lock_group(ac->ac_sb, group);
1743 max = mb_find_extent(e4b, 0, ac->ac_g_ex.fe_start,
1744 ac->ac_g_ex.fe_len, &ex);
1745
1746 if (max >= ac->ac_g_ex.fe_len && ac->ac_g_ex.fe_len == sbi->s_stripe) {
1747 ext4_fsblk_t start;
1748
1749 start = (e4b->bd_group * EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) +
1750 ex.fe_start + le32_to_cpu(es->s_first_data_block);
1751 /* use do_div to get remainder (would be 64-bit modulo) */
1752 if (do_div(start, sbi->s_stripe) == 0) {
1753 ac->ac_found++;
1754 ac->ac_b_ex = ex;
1755 ext4_mb_use_best_found(ac, e4b);
1756 }
1757 } else if (max >= ac->ac_g_ex.fe_len) {
1758 BUG_ON(ex.fe_len <= 0);
1759 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1760 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1761 ac->ac_found++;
1762 ac->ac_b_ex = ex;
1763 ext4_mb_use_best_found(ac, e4b);
1764 } else if (max > 0 && (ac->ac_flags & EXT4_MB_HINT_MERGE)) {
1765 /* Sometimes, caller may want to merge even small
1766 * number of blocks to an existing extent */
1767 BUG_ON(ex.fe_len <= 0);
1768 BUG_ON(ex.fe_group != ac->ac_g_ex.fe_group);
1769 BUG_ON(ex.fe_start != ac->ac_g_ex.fe_start);
1770 ac->ac_found++;
1771 ac->ac_b_ex = ex;
1772 ext4_mb_use_best_found(ac, e4b);
1773 }
1774 ext4_unlock_group(ac->ac_sb, group);
1775 ext4_mb_release_desc(e4b);
1776
1777 return 0;
1778}
1779
1780/*
1781 * The routine scans buddy structures (not bitmap!) from given order
1782 * to max order and tries to find big enough chunk to satisfy the req
1783 */
1784static void ext4_mb_simple_scan_group(struct ext4_allocation_context *ac,
1785 struct ext4_buddy *e4b)
1786{
1787 struct super_block *sb = ac->ac_sb;
1788 struct ext4_group_info *grp = e4b->bd_info;
1789 void *buddy;
1790 int i;
1791 int k;
1792 int max;
1793
1794 BUG_ON(ac->ac_2order <= 0);
1795 for (i = ac->ac_2order; i <= sb->s_blocksize_bits + 1; i++) {
1796 if (grp->bb_counters[i] == 0)
1797 continue;
1798
1799 buddy = mb_find_buddy(e4b, i, &max);
1800 BUG_ON(buddy == NULL);
1801
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001802 k = mb_find_next_zero_bit(buddy, max, 0);
Alex Tomasc9de5602008-01-29 00:19:52 -05001803 BUG_ON(k >= max);
1804
1805 ac->ac_found++;
1806
1807 ac->ac_b_ex.fe_len = 1 << i;
1808 ac->ac_b_ex.fe_start = k << i;
1809 ac->ac_b_ex.fe_group = e4b->bd_group;
1810
1811 ext4_mb_use_best_found(ac, e4b);
1812
1813 BUG_ON(ac->ac_b_ex.fe_len != ac->ac_g_ex.fe_len);
1814
1815 if (EXT4_SB(sb)->s_mb_stats)
1816 atomic_inc(&EXT4_SB(sb)->s_bal_2orders);
1817
1818 break;
1819 }
1820}
1821
1822/*
1823 * The routine scans the group and measures all found extents.
1824 * In order to optimize scanning, caller must pass number of
1825 * free blocks in the group, so the routine can know upper limit.
1826 */
1827static void ext4_mb_complex_scan_group(struct ext4_allocation_context *ac,
1828 struct ext4_buddy *e4b)
1829{
1830 struct super_block *sb = ac->ac_sb;
1831 void *bitmap = EXT4_MB_BITMAP(e4b);
1832 struct ext4_free_extent ex;
1833 int i;
1834 int free;
1835
1836 free = e4b->bd_info->bb_free;
1837 BUG_ON(free <= 0);
1838
1839 i = e4b->bd_info->bb_first_free;
1840
1841 while (free && ac->ac_status == AC_STATUS_CONTINUE) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05001842 i = mb_find_next_zero_bit(bitmap,
Alex Tomasc9de5602008-01-29 00:19:52 -05001843 EXT4_BLOCKS_PER_GROUP(sb), i);
1844 if (i >= EXT4_BLOCKS_PER_GROUP(sb)) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001845 /*
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001846 * IF we have corrupt bitmap, we won't find any
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001847 * free blocks even though group info says we
1848 * we have free blocks
1849 */
Harvey Harrison46e665e2008-04-17 10:38:59 -04001850 ext4_error(sb, __func__, "%d free blocks as per "
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001851 "group info. But bitmap says 0\n",
1852 free);
Alex Tomasc9de5602008-01-29 00:19:52 -05001853 break;
1854 }
1855
1856 mb_find_extent(e4b, 0, i, ac->ac_g_ex.fe_len, &ex);
1857 BUG_ON(ex.fe_len <= 0);
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001858 if (free < ex.fe_len) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04001859 ext4_error(sb, __func__, "%d free blocks as per "
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001860 "group info. But got %d blocks\n",
1861 free, ex.fe_len);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05001862 /*
1863 * The number of free blocks differs. This mostly
1864 * indicate that the bitmap is corrupt. So exit
1865 * without claiming the space.
1866 */
1867 break;
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05001868 }
Alex Tomasc9de5602008-01-29 00:19:52 -05001869
1870 ext4_mb_measure_extent(ac, &ex, e4b);
1871
1872 i += ex.fe_len;
1873 free -= ex.fe_len;
1874 }
1875
1876 ext4_mb_check_limits(ac, e4b, 1);
1877}
1878
1879/*
1880 * This is a special case for storages like raid5
1881 * we try to find stripe-aligned chunks for stripe-size requests
1882 * XXX should do so at least for multiples of stripe size as well
1883 */
1884static void ext4_mb_scan_aligned(struct ext4_allocation_context *ac,
1885 struct ext4_buddy *e4b)
1886{
1887 struct super_block *sb = ac->ac_sb;
1888 struct ext4_sb_info *sbi = EXT4_SB(sb);
1889 void *bitmap = EXT4_MB_BITMAP(e4b);
1890 struct ext4_free_extent ex;
1891 ext4_fsblk_t first_group_block;
1892 ext4_fsblk_t a;
1893 ext4_grpblk_t i;
1894 int max;
1895
1896 BUG_ON(sbi->s_stripe == 0);
1897
1898 /* find first stripe-aligned block in group */
1899 first_group_block = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb)
1900 + le32_to_cpu(sbi->s_es->s_first_data_block);
1901 a = first_group_block + sbi->s_stripe - 1;
1902 do_div(a, sbi->s_stripe);
1903 i = (a * sbi->s_stripe) - first_group_block;
1904
1905 while (i < EXT4_BLOCKS_PER_GROUP(sb)) {
1906 if (!mb_test_bit(i, bitmap)) {
1907 max = mb_find_extent(e4b, 0, i, sbi->s_stripe, &ex);
1908 if (max >= sbi->s_stripe) {
1909 ac->ac_found++;
1910 ac->ac_b_ex = ex;
1911 ext4_mb_use_best_found(ac, e4b);
1912 break;
1913 }
1914 }
1915 i += sbi->s_stripe;
1916 }
1917}
1918
1919static int ext4_mb_good_group(struct ext4_allocation_context *ac,
1920 ext4_group_t group, int cr)
1921{
1922 unsigned free, fragments;
1923 unsigned i, bits;
1924 struct ext4_group_desc *desc;
1925 struct ext4_group_info *grp = ext4_get_group_info(ac->ac_sb, group);
1926
1927 BUG_ON(cr < 0 || cr >= 4);
1928 BUG_ON(EXT4_MB_GRP_NEED_INIT(grp));
1929
1930 free = grp->bb_free;
1931 fragments = grp->bb_fragments;
1932 if (free == 0)
1933 return 0;
1934 if (fragments == 0)
1935 return 0;
1936
1937 switch (cr) {
1938 case 0:
1939 BUG_ON(ac->ac_2order == 0);
1940 /* If this group is uninitialized, skip it initially */
1941 desc = ext4_get_group_desc(ac->ac_sb, group, NULL);
1942 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))
1943 return 0;
1944
1945 bits = ac->ac_sb->s_blocksize_bits + 1;
1946 for (i = ac->ac_2order; i <= bits; i++)
1947 if (grp->bb_counters[i] > 0)
1948 return 1;
1949 break;
1950 case 1:
1951 if ((free / fragments) >= ac->ac_g_ex.fe_len)
1952 return 1;
1953 break;
1954 case 2:
1955 if (free >= ac->ac_g_ex.fe_len)
1956 return 1;
1957 break;
1958 case 3:
1959 return 1;
1960 default:
1961 BUG();
1962 }
1963
1964 return 0;
1965}
1966
Eric Sandeen4ddfef72008-04-29 08:11:12 -04001967static noinline_for_stack int
1968ext4_mb_regular_allocator(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05001969{
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) {
Denis V. Lunev46fe74f2008-04-29 01:02:08 -07002452 proc_create_data("mb_history", S_IRUGO, sbi->s_mb_proc,
2453 &ext4_mb_seq_history_fops, sb);
2454 proc_create_data("mb_groups", S_IRUGO, sbi->s_mb_proc,
2455 &ext4_mb_seq_groups_fops, sb);
Alex Tomasc9de5602008-01-29 00:19:52 -05002456 }
2457
2458 sbi->s_mb_history_max = 1000;
2459 sbi->s_mb_history_cur = 0;
2460 spin_lock_init(&sbi->s_mb_history_lock);
2461 i = sbi->s_mb_history_max * sizeof(struct ext4_mb_history);
2462 sbi->s_mb_history = kmalloc(i, GFP_KERNEL);
2463 if (likely(sbi->s_mb_history != NULL))
2464 memset(sbi->s_mb_history, 0, i);
2465 /* if we can't allocate history, then we simple won't use it */
2466}
2467
Eric Sandeen4ddfef72008-04-29 08:11:12 -04002468static noinline_for_stack void
2469ext4_mb_store_history(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05002470{
2471 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
2472 struct ext4_mb_history h;
2473
2474 if (unlikely(sbi->s_mb_history == NULL))
2475 return;
2476
2477 if (!(ac->ac_op & sbi->s_mb_history_filter))
2478 return;
2479
2480 h.op = ac->ac_op;
2481 h.pid = current->pid;
2482 h.ino = ac->ac_inode ? ac->ac_inode->i_ino : 0;
2483 h.orig = ac->ac_o_ex;
2484 h.result = ac->ac_b_ex;
2485 h.flags = ac->ac_flags;
2486 h.found = ac->ac_found;
2487 h.groups = ac->ac_groups_scanned;
2488 h.cr = ac->ac_criteria;
2489 h.tail = ac->ac_tail;
2490 h.buddy = ac->ac_buddy;
2491 h.merged = 0;
2492 if (ac->ac_op == EXT4_MB_HISTORY_ALLOC) {
2493 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
2494 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
2495 h.merged = 1;
2496 h.goal = ac->ac_g_ex;
2497 h.result = ac->ac_f_ex;
2498 }
2499
2500 spin_lock(&sbi->s_mb_history_lock);
2501 memcpy(sbi->s_mb_history + sbi->s_mb_history_cur, &h, sizeof(h));
2502 if (++sbi->s_mb_history_cur >= sbi->s_mb_history_max)
2503 sbi->s_mb_history_cur = 0;
2504 spin_unlock(&sbi->s_mb_history_lock);
2505}
2506
2507#else
2508#define ext4_mb_history_release(sb)
2509#define ext4_mb_history_init(sb)
2510#endif
2511
2512static int ext4_mb_init_backend(struct super_block *sb)
2513{
2514 ext4_group_t i;
2515 int j, len, metalen;
2516 struct ext4_sb_info *sbi = EXT4_SB(sb);
2517 int num_meta_group_infos =
2518 (sbi->s_groups_count + EXT4_DESC_PER_BLOCK(sb) - 1) >>
2519 EXT4_DESC_PER_BLOCK_BITS(sb);
2520 struct ext4_group_info **meta_group_info;
2521
2522 /* An 8TB filesystem with 64-bit pointers requires a 4096 byte
2523 * kmalloc. A 128kb malloc should suffice for a 256TB filesystem.
2524 * So a two level scheme suffices for now. */
2525 sbi->s_group_info = kmalloc(sizeof(*sbi->s_group_info) *
2526 num_meta_group_infos, GFP_KERNEL);
2527 if (sbi->s_group_info == NULL) {
2528 printk(KERN_ERR "EXT4-fs: can't allocate buddy meta group\n");
2529 return -ENOMEM;
2530 }
2531 sbi->s_buddy_cache = new_inode(sb);
2532 if (sbi->s_buddy_cache == NULL) {
2533 printk(KERN_ERR "EXT4-fs: can't get new inode\n");
2534 goto err_freesgi;
2535 }
2536 EXT4_I(sbi->s_buddy_cache)->i_disksize = 0;
2537
2538 metalen = sizeof(*meta_group_info) << EXT4_DESC_PER_BLOCK_BITS(sb);
2539 for (i = 0; i < num_meta_group_infos; i++) {
2540 if ((i + 1) == num_meta_group_infos)
2541 metalen = sizeof(*meta_group_info) *
2542 (sbi->s_groups_count -
2543 (i << EXT4_DESC_PER_BLOCK_BITS(sb)));
2544 meta_group_info = kmalloc(metalen, GFP_KERNEL);
2545 if (meta_group_info == NULL) {
2546 printk(KERN_ERR "EXT4-fs: can't allocate mem for a "
2547 "buddy group\n");
2548 goto err_freemeta;
2549 }
2550 sbi->s_group_info[i] = meta_group_info;
2551 }
2552
2553 /*
2554 * calculate needed size. if change bb_counters size,
2555 * don't forget about ext4_mb_generate_buddy()
2556 */
2557 len = sizeof(struct ext4_group_info);
2558 len += sizeof(unsigned short) * (sb->s_blocksize_bits + 2);
2559 for (i = 0; i < sbi->s_groups_count; i++) {
2560 struct ext4_group_desc *desc;
2561
2562 meta_group_info =
2563 sbi->s_group_info[i >> EXT4_DESC_PER_BLOCK_BITS(sb)];
2564 j = i & (EXT4_DESC_PER_BLOCK(sb) - 1);
2565
2566 meta_group_info[j] = kzalloc(len, GFP_KERNEL);
2567 if (meta_group_info[j] == NULL) {
2568 printk(KERN_ERR "EXT4-fs: can't allocate buddy mem\n");
2569 i--;
2570 goto err_freebuddy;
2571 }
2572 desc = ext4_get_group_desc(sb, i, NULL);
2573 if (desc == NULL) {
2574 printk(KERN_ERR
2575 "EXT4-fs: can't read descriptor %lu\n", i);
2576 goto err_freebuddy;
2577 }
2578 memset(meta_group_info[j], 0, len);
2579 set_bit(EXT4_GROUP_INFO_NEED_INIT_BIT,
2580 &(meta_group_info[j]->bb_state));
2581
2582 /*
2583 * initialize bb_free to be able to skip
2584 * empty groups without initialization
2585 */
2586 if (desc->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
2587 meta_group_info[j]->bb_free =
2588 ext4_free_blocks_after_init(sb, i, desc);
2589 } else {
2590 meta_group_info[j]->bb_free =
2591 le16_to_cpu(desc->bg_free_blocks_count);
2592 }
2593
2594 INIT_LIST_HEAD(&meta_group_info[j]->bb_prealloc_list);
2595
2596#ifdef DOUBLE_CHECK
2597 {
2598 struct buffer_head *bh;
2599 meta_group_info[j]->bb_bitmap =
2600 kmalloc(sb->s_blocksize, GFP_KERNEL);
2601 BUG_ON(meta_group_info[j]->bb_bitmap == NULL);
2602 bh = read_block_bitmap(sb, i);
2603 BUG_ON(bh == NULL);
2604 memcpy(meta_group_info[j]->bb_bitmap, bh->b_data,
2605 sb->s_blocksize);
2606 put_bh(bh);
2607 }
2608#endif
2609
2610 }
2611
2612 return 0;
2613
2614err_freebuddy:
2615 while (i >= 0) {
2616 kfree(ext4_get_group_info(sb, i));
2617 i--;
2618 }
2619 i = num_meta_group_infos;
2620err_freemeta:
2621 while (--i >= 0)
2622 kfree(sbi->s_group_info[i]);
2623 iput(sbi->s_buddy_cache);
2624err_freesgi:
2625 kfree(sbi->s_group_info);
2626 return -ENOMEM;
2627}
2628
2629int ext4_mb_init(struct super_block *sb, int needs_recovery)
2630{
2631 struct ext4_sb_info *sbi = EXT4_SB(sb);
2632 unsigned i;
2633 unsigned offset;
2634 unsigned max;
2635
2636 if (!test_opt(sb, MBALLOC))
2637 return 0;
2638
2639 i = (sb->s_blocksize_bits + 2) * sizeof(unsigned short);
2640
2641 sbi->s_mb_offsets = kmalloc(i, GFP_KERNEL);
2642 if (sbi->s_mb_offsets == NULL) {
2643 clear_opt(sbi->s_mount_opt, MBALLOC);
2644 return -ENOMEM;
2645 }
2646 sbi->s_mb_maxs = kmalloc(i, GFP_KERNEL);
2647 if (sbi->s_mb_maxs == NULL) {
2648 clear_opt(sbi->s_mount_opt, MBALLOC);
2649 kfree(sbi->s_mb_maxs);
2650 return -ENOMEM;
2651 }
2652
2653 /* order 0 is regular bitmap */
2654 sbi->s_mb_maxs[0] = sb->s_blocksize << 3;
2655 sbi->s_mb_offsets[0] = 0;
2656
2657 i = 1;
2658 offset = 0;
2659 max = sb->s_blocksize << 2;
2660 do {
2661 sbi->s_mb_offsets[i] = offset;
2662 sbi->s_mb_maxs[i] = max;
2663 offset += 1 << (sb->s_blocksize_bits - i);
2664 max = max >> 1;
2665 i++;
2666 } while (i <= sb->s_blocksize_bits + 1);
2667
2668 /* init file for buddy data */
2669 i = ext4_mb_init_backend(sb);
2670 if (i) {
2671 clear_opt(sbi->s_mount_opt, MBALLOC);
2672 kfree(sbi->s_mb_offsets);
2673 kfree(sbi->s_mb_maxs);
2674 return i;
2675 }
2676
2677 spin_lock_init(&sbi->s_md_lock);
2678 INIT_LIST_HEAD(&sbi->s_active_transaction);
2679 INIT_LIST_HEAD(&sbi->s_closed_transaction);
2680 INIT_LIST_HEAD(&sbi->s_committed_transaction);
2681 spin_lock_init(&sbi->s_bal_lock);
2682
2683 sbi->s_mb_max_to_scan = MB_DEFAULT_MAX_TO_SCAN;
2684 sbi->s_mb_min_to_scan = MB_DEFAULT_MIN_TO_SCAN;
2685 sbi->s_mb_stats = MB_DEFAULT_STATS;
2686 sbi->s_mb_stream_request = MB_DEFAULT_STREAM_THRESHOLD;
2687 sbi->s_mb_order2_reqs = MB_DEFAULT_ORDER2_REQS;
2688 sbi->s_mb_history_filter = EXT4_MB_HISTORY_DEFAULT;
2689 sbi->s_mb_group_prealloc = MB_DEFAULT_GROUP_PREALLOC;
2690
2691 i = sizeof(struct ext4_locality_group) * NR_CPUS;
2692 sbi->s_locality_groups = kmalloc(i, GFP_KERNEL);
2693 if (sbi->s_locality_groups == NULL) {
2694 clear_opt(sbi->s_mount_opt, MBALLOC);
2695 kfree(sbi->s_mb_offsets);
2696 kfree(sbi->s_mb_maxs);
2697 return -ENOMEM;
2698 }
2699 for (i = 0; i < NR_CPUS; i++) {
2700 struct ext4_locality_group *lg;
2701 lg = &sbi->s_locality_groups[i];
2702 mutex_init(&lg->lg_mutex);
2703 INIT_LIST_HEAD(&lg->lg_prealloc_list);
2704 spin_lock_init(&lg->lg_prealloc_lock);
2705 }
2706
2707 ext4_mb_init_per_dev_proc(sb);
2708 ext4_mb_history_init(sb);
2709
2710 printk("EXT4-fs: mballoc enabled\n");
2711 return 0;
2712}
2713
2714/* need to called with ext4 group lock (ext4_lock_group) */
2715static void ext4_mb_cleanup_pa(struct ext4_group_info *grp)
2716{
2717 struct ext4_prealloc_space *pa;
2718 struct list_head *cur, *tmp;
2719 int count = 0;
2720
2721 list_for_each_safe(cur, tmp, &grp->bb_prealloc_list) {
2722 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
2723 list_del(&pa->pa_group_list);
2724 count++;
2725 kfree(pa);
2726 }
2727 if (count)
2728 mb_debug("mballoc: %u PAs left\n", count);
2729
2730}
2731
2732int ext4_mb_release(struct super_block *sb)
2733{
2734 ext4_group_t i;
2735 int num_meta_group_infos;
2736 struct ext4_group_info *grinfo;
2737 struct ext4_sb_info *sbi = EXT4_SB(sb);
2738
2739 if (!test_opt(sb, MBALLOC))
2740 return 0;
2741
2742 /* release freed, non-committed blocks */
2743 spin_lock(&sbi->s_md_lock);
2744 list_splice_init(&sbi->s_closed_transaction,
2745 &sbi->s_committed_transaction);
2746 list_splice_init(&sbi->s_active_transaction,
2747 &sbi->s_committed_transaction);
2748 spin_unlock(&sbi->s_md_lock);
2749 ext4_mb_free_committed_blocks(sb);
2750
2751 if (sbi->s_group_info) {
2752 for (i = 0; i < sbi->s_groups_count; i++) {
2753 grinfo = ext4_get_group_info(sb, i);
2754#ifdef DOUBLE_CHECK
2755 kfree(grinfo->bb_bitmap);
2756#endif
2757 ext4_lock_group(sb, i);
2758 ext4_mb_cleanup_pa(grinfo);
2759 ext4_unlock_group(sb, i);
2760 kfree(grinfo);
2761 }
2762 num_meta_group_infos = (sbi->s_groups_count +
2763 EXT4_DESC_PER_BLOCK(sb) - 1) >>
2764 EXT4_DESC_PER_BLOCK_BITS(sb);
2765 for (i = 0; i < num_meta_group_infos; i++)
2766 kfree(sbi->s_group_info[i]);
2767 kfree(sbi->s_group_info);
2768 }
2769 kfree(sbi->s_mb_offsets);
2770 kfree(sbi->s_mb_maxs);
2771 if (sbi->s_buddy_cache)
2772 iput(sbi->s_buddy_cache);
2773 if (sbi->s_mb_stats) {
2774 printk(KERN_INFO
2775 "EXT4-fs: mballoc: %u blocks %u reqs (%u success)\n",
2776 atomic_read(&sbi->s_bal_allocated),
2777 atomic_read(&sbi->s_bal_reqs),
2778 atomic_read(&sbi->s_bal_success));
2779 printk(KERN_INFO
2780 "EXT4-fs: mballoc: %u extents scanned, %u goal hits, "
2781 "%u 2^N hits, %u breaks, %u lost\n",
2782 atomic_read(&sbi->s_bal_ex_scanned),
2783 atomic_read(&sbi->s_bal_goals),
2784 atomic_read(&sbi->s_bal_2orders),
2785 atomic_read(&sbi->s_bal_breaks),
2786 atomic_read(&sbi->s_mb_lost_chunks));
2787 printk(KERN_INFO
2788 "EXT4-fs: mballoc: %lu generated and it took %Lu\n",
2789 sbi->s_mb_buddies_generated++,
2790 sbi->s_mb_generation_time);
2791 printk(KERN_INFO
2792 "EXT4-fs: mballoc: %u preallocated, %u discarded\n",
2793 atomic_read(&sbi->s_mb_preallocated),
2794 atomic_read(&sbi->s_mb_discarded));
2795 }
2796
2797 kfree(sbi->s_locality_groups);
2798
2799 ext4_mb_history_release(sb);
2800 ext4_mb_destroy_per_dev_proc(sb);
2801
2802 return 0;
2803}
2804
Eric Sandeen4ddfef72008-04-29 08:11:12 -04002805static noinline_for_stack void
2806ext4_mb_free_committed_blocks(struct super_block *sb)
Alex Tomasc9de5602008-01-29 00:19:52 -05002807{
2808 struct ext4_sb_info *sbi = EXT4_SB(sb);
2809 int err;
2810 int i;
2811 int count = 0;
2812 int count2 = 0;
2813 struct ext4_free_metadata *md;
2814 struct ext4_buddy e4b;
2815
2816 if (list_empty(&sbi->s_committed_transaction))
2817 return;
2818
2819 /* there is committed blocks to be freed yet */
2820 do {
2821 /* get next array of blocks */
2822 md = NULL;
2823 spin_lock(&sbi->s_md_lock);
2824 if (!list_empty(&sbi->s_committed_transaction)) {
2825 md = list_entry(sbi->s_committed_transaction.next,
2826 struct ext4_free_metadata, list);
2827 list_del(&md->list);
2828 }
2829 spin_unlock(&sbi->s_md_lock);
2830
2831 if (md == NULL)
2832 break;
2833
2834 mb_debug("gonna free %u blocks in group %lu (0x%p):",
2835 md->num, md->group, md);
2836
2837 err = ext4_mb_load_buddy(sb, md->group, &e4b);
2838 /* we expect to find existing buddy because it's pinned */
2839 BUG_ON(err != 0);
2840
2841 /* there are blocks to put in buddy to make them really free */
2842 count += md->num;
2843 count2++;
2844 ext4_lock_group(sb, md->group);
2845 for (i = 0; i < md->num; i++) {
2846 mb_debug(" %u", md->blocks[i]);
2847 err = mb_free_blocks(NULL, &e4b, md->blocks[i], 1);
2848 BUG_ON(err != 0);
2849 }
2850 mb_debug("\n");
2851 ext4_unlock_group(sb, md->group);
2852
2853 /* balance refcounts from ext4_mb_free_metadata() */
2854 page_cache_release(e4b.bd_buddy_page);
2855 page_cache_release(e4b.bd_bitmap_page);
2856
2857 kfree(md);
2858 ext4_mb_release_desc(&e4b);
2859
2860 } while (md);
2861
2862 mb_debug("freed %u blocks in %u structures\n", count, count2);
2863}
2864
Alex Tomasc9de5602008-01-29 00:19:52 -05002865#define EXT4_MB_STATS_NAME "stats"
2866#define EXT4_MB_MAX_TO_SCAN_NAME "max_to_scan"
2867#define EXT4_MB_MIN_TO_SCAN_NAME "min_to_scan"
2868#define EXT4_MB_ORDER2_REQ "order2_req"
2869#define EXT4_MB_STREAM_REQ "stream_req"
2870#define EXT4_MB_GROUP_PREALLOC "group_prealloc"
2871
2872
2873
2874#define MB_PROC_VALUE_READ(name) \
2875static int ext4_mb_read_##name(char *page, char **start, \
2876 off_t off, int count, int *eof, void *data) \
2877{ \
2878 struct ext4_sb_info *sbi = data; \
2879 int len; \
2880 *eof = 1; \
2881 if (off != 0) \
2882 return 0; \
2883 len = sprintf(page, "%ld\n", sbi->s_mb_##name); \
2884 *start = page; \
2885 return len; \
2886}
2887
2888#define MB_PROC_VALUE_WRITE(name) \
2889static int ext4_mb_write_##name(struct file *file, \
2890 const char __user *buf, unsigned long cnt, void *data) \
2891{ \
2892 struct ext4_sb_info *sbi = data; \
2893 char str[32]; \
2894 long value; \
2895 if (cnt >= sizeof(str)) \
2896 return -EINVAL; \
2897 if (copy_from_user(str, buf, cnt)) \
2898 return -EFAULT; \
2899 value = simple_strtol(str, NULL, 0); \
2900 if (value <= 0) \
2901 return -ERANGE; \
2902 sbi->s_mb_##name = value; \
2903 return cnt; \
2904}
2905
2906MB_PROC_VALUE_READ(stats);
2907MB_PROC_VALUE_WRITE(stats);
2908MB_PROC_VALUE_READ(max_to_scan);
2909MB_PROC_VALUE_WRITE(max_to_scan);
2910MB_PROC_VALUE_READ(min_to_scan);
2911MB_PROC_VALUE_WRITE(min_to_scan);
2912MB_PROC_VALUE_READ(order2_reqs);
2913MB_PROC_VALUE_WRITE(order2_reqs);
2914MB_PROC_VALUE_READ(stream_request);
2915MB_PROC_VALUE_WRITE(stream_request);
2916MB_PROC_VALUE_READ(group_prealloc);
2917MB_PROC_VALUE_WRITE(group_prealloc);
2918
2919#define MB_PROC_HANDLER(name, var) \
2920do { \
2921 proc = create_proc_entry(name, mode, sbi->s_mb_proc); \
2922 if (proc == NULL) { \
2923 printk(KERN_ERR "EXT4-fs: can't to create %s\n", name); \
2924 goto err_out; \
2925 } \
2926 proc->data = sbi; \
2927 proc->read_proc = ext4_mb_read_##var ; \
2928 proc->write_proc = ext4_mb_write_##var; \
2929} while (0)
2930
2931static int ext4_mb_init_per_dev_proc(struct super_block *sb)
2932{
2933 mode_t mode = S_IFREG | S_IRUGO | S_IWUSR;
2934 struct ext4_sb_info *sbi = EXT4_SB(sb);
2935 struct proc_dir_entry *proc;
2936 char devname[64];
2937
2938 snprintf(devname, sizeof(devname) - 1, "%s",
2939 bdevname(sb->s_bdev, devname));
2940 sbi->s_mb_proc = proc_mkdir(devname, proc_root_ext4);
2941
2942 MB_PROC_HANDLER(EXT4_MB_STATS_NAME, stats);
2943 MB_PROC_HANDLER(EXT4_MB_MAX_TO_SCAN_NAME, max_to_scan);
2944 MB_PROC_HANDLER(EXT4_MB_MIN_TO_SCAN_NAME, min_to_scan);
2945 MB_PROC_HANDLER(EXT4_MB_ORDER2_REQ, order2_reqs);
2946 MB_PROC_HANDLER(EXT4_MB_STREAM_REQ, stream_request);
2947 MB_PROC_HANDLER(EXT4_MB_GROUP_PREALLOC, group_prealloc);
2948
2949 return 0;
2950
2951err_out:
2952 printk(KERN_ERR "EXT4-fs: Unable to create %s\n", devname);
2953 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2954 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2955 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2956 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2957 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2958 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2959 remove_proc_entry(devname, proc_root_ext4);
2960 sbi->s_mb_proc = NULL;
2961
2962 return -ENOMEM;
2963}
2964
2965static int ext4_mb_destroy_per_dev_proc(struct super_block *sb)
2966{
2967 struct ext4_sb_info *sbi = EXT4_SB(sb);
2968 char devname[64];
2969
2970 if (sbi->s_mb_proc == NULL)
2971 return -EINVAL;
2972
2973 snprintf(devname, sizeof(devname) - 1, "%s",
2974 bdevname(sb->s_bdev, devname));
2975 remove_proc_entry(EXT4_MB_GROUP_PREALLOC, sbi->s_mb_proc);
2976 remove_proc_entry(EXT4_MB_STREAM_REQ, sbi->s_mb_proc);
2977 remove_proc_entry(EXT4_MB_ORDER2_REQ, sbi->s_mb_proc);
2978 remove_proc_entry(EXT4_MB_MIN_TO_SCAN_NAME, sbi->s_mb_proc);
2979 remove_proc_entry(EXT4_MB_MAX_TO_SCAN_NAME, sbi->s_mb_proc);
2980 remove_proc_entry(EXT4_MB_STATS_NAME, sbi->s_mb_proc);
2981 remove_proc_entry(devname, proc_root_ext4);
2982
2983 return 0;
2984}
2985
2986int __init init_ext4_mballoc(void)
2987{
2988 ext4_pspace_cachep =
2989 kmem_cache_create("ext4_prealloc_space",
2990 sizeof(struct ext4_prealloc_space),
2991 0, SLAB_RECLAIM_ACCOUNT, NULL);
2992 if (ext4_pspace_cachep == NULL)
2993 return -ENOMEM;
2994
Eric Sandeen256bdb42008-02-10 01:13:33 -05002995 ext4_ac_cachep =
2996 kmem_cache_create("ext4_alloc_context",
2997 sizeof(struct ext4_allocation_context),
2998 0, SLAB_RECLAIM_ACCOUNT, NULL);
2999 if (ext4_ac_cachep == NULL) {
3000 kmem_cache_destroy(ext4_pspace_cachep);
3001 return -ENOMEM;
3002 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003003#ifdef CONFIG_PROC_FS
Alexey Dobriyan36a5aeb2008-04-29 01:01:42 -07003004 proc_root_ext4 = proc_mkdir("fs/ext4", NULL);
Alex Tomasc9de5602008-01-29 00:19:52 -05003005 if (proc_root_ext4 == NULL)
Alexey Dobriyan36a5aeb2008-04-29 01:01:42 -07003006 printk(KERN_ERR "EXT4-fs: Unable to create fs/ext4\n");
Alex Tomasc9de5602008-01-29 00:19:52 -05003007#endif
Alex Tomasc9de5602008-01-29 00:19:52 -05003008 return 0;
3009}
3010
3011void exit_ext4_mballoc(void)
3012{
3013 /* XXX: synchronize_rcu(); */
3014 kmem_cache_destroy(ext4_pspace_cachep);
Eric Sandeen256bdb42008-02-10 01:13:33 -05003015 kmem_cache_destroy(ext4_ac_cachep);
Alex Tomasc9de5602008-01-29 00:19:52 -05003016#ifdef CONFIG_PROC_FS
Alexey Dobriyan36a5aeb2008-04-29 01:01:42 -07003017 remove_proc_entry("fs/ext4", NULL);
Alex Tomasc9de5602008-01-29 00:19:52 -05003018#endif
3019}
3020
3021
3022/*
3023 * Check quota and mark choosed space (ac->ac_b_ex) non-free in bitmaps
3024 * Returns 0 if success or error code
3025 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003026static noinline_for_stack int
3027ext4_mb_mark_diskspace_used(struct ext4_allocation_context *ac,
Alex Tomasc9de5602008-01-29 00:19:52 -05003028 handle_t *handle)
3029{
3030 struct buffer_head *bitmap_bh = NULL;
3031 struct ext4_super_block *es;
3032 struct ext4_group_desc *gdp;
3033 struct buffer_head *gdp_bh;
3034 struct ext4_sb_info *sbi;
3035 struct super_block *sb;
3036 ext4_fsblk_t block;
3037 int err;
3038
3039 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3040 BUG_ON(ac->ac_b_ex.fe_len <= 0);
3041
3042 sb = ac->ac_sb;
3043 sbi = EXT4_SB(sb);
3044 es = sbi->s_es;
3045
3046 ext4_debug("using block group %lu(%d)\n", ac->ac_b_ex.fe_group,
3047 gdp->bg_free_blocks_count);
3048
3049 err = -EIO;
3050 bitmap_bh = read_block_bitmap(sb, ac->ac_b_ex.fe_group);
3051 if (!bitmap_bh)
3052 goto out_err;
3053
3054 err = ext4_journal_get_write_access(handle, bitmap_bh);
3055 if (err)
3056 goto out_err;
3057
3058 err = -EIO;
3059 gdp = ext4_get_group_desc(sb, ac->ac_b_ex.fe_group, &gdp_bh);
3060 if (!gdp)
3061 goto out_err;
3062
3063 err = ext4_journal_get_write_access(handle, gdp_bh);
3064 if (err)
3065 goto out_err;
3066
3067 block = ac->ac_b_ex.fe_group * EXT4_BLOCKS_PER_GROUP(sb)
3068 + ac->ac_b_ex.fe_start
3069 + le32_to_cpu(es->s_first_data_block);
3070
3071 if (block == ext4_block_bitmap(sb, gdp) ||
3072 block == ext4_inode_bitmap(sb, gdp) ||
3073 in_range(block, ext4_inode_table(sb, gdp),
3074 EXT4_SB(sb)->s_itb_per_group)) {
3075
Harvey Harrison46e665e2008-04-17 10:38:59 -04003076 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05003077 "Allocating block in system zone - block = %llu",
3078 block);
3079 }
3080#ifdef AGGRESSIVE_CHECK
3081 {
3082 int i;
3083 for (i = 0; i < ac->ac_b_ex.fe_len; i++) {
3084 BUG_ON(mb_test_bit(ac->ac_b_ex.fe_start + i,
3085 bitmap_bh->b_data));
3086 }
3087 }
3088#endif
3089 mb_set_bits(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group), bitmap_bh->b_data,
3090 ac->ac_b_ex.fe_start, ac->ac_b_ex.fe_len);
3091
3092 spin_lock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
3093 if (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT)) {
3094 gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
3095 gdp->bg_free_blocks_count =
3096 cpu_to_le16(ext4_free_blocks_after_init(sb,
3097 ac->ac_b_ex.fe_group,
3098 gdp));
3099 }
Marcin Slusarze8546d02008-04-17 10:38:59 -04003100 le16_add_cpu(&gdp->bg_free_blocks_count, -ac->ac_b_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05003101 gdp->bg_checksum = ext4_group_desc_csum(sbi, ac->ac_b_ex.fe_group, gdp);
3102 spin_unlock(sb_bgl_lock(sbi, ac->ac_b_ex.fe_group));
3103 percpu_counter_sub(&sbi->s_freeblocks_counter, ac->ac_b_ex.fe_len);
3104
3105 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
3106 if (err)
3107 goto out_err;
3108 err = ext4_journal_dirty_metadata(handle, gdp_bh);
3109
3110out_err:
3111 sb->s_dirt = 1;
Aneesh Kumar K.V42a10ad2008-02-10 01:07:28 -05003112 brelse(bitmap_bh);
Alex Tomasc9de5602008-01-29 00:19:52 -05003113 return err;
3114}
3115
3116/*
3117 * here we normalize request for locality group
3118 * Group request are normalized to s_strip size if we set the same via mount
3119 * option. If not we set it to s_mb_group_prealloc which can be configured via
3120 * /proc/fs/ext4/<partition>/group_prealloc
3121 *
3122 * XXX: should we try to preallocate more than the group has now?
3123 */
3124static void ext4_mb_normalize_group_request(struct ext4_allocation_context *ac)
3125{
3126 struct super_block *sb = ac->ac_sb;
3127 struct ext4_locality_group *lg = ac->ac_lg;
3128
3129 BUG_ON(lg == NULL);
3130 if (EXT4_SB(sb)->s_stripe)
3131 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_stripe;
3132 else
3133 ac->ac_g_ex.fe_len = EXT4_SB(sb)->s_mb_group_prealloc;
3134 mb_debug("#%u: goal %lu blocks for locality group\n",
3135 current->pid, ac->ac_g_ex.fe_len);
3136}
3137
3138/*
3139 * Normalization means making request better in terms of
3140 * size and alignment
3141 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003142static noinline_for_stack void
3143ext4_mb_normalize_request(struct ext4_allocation_context *ac,
Alex Tomasc9de5602008-01-29 00:19:52 -05003144 struct ext4_allocation_request *ar)
3145{
3146 int bsbits, max;
3147 ext4_lblk_t end;
Alex Tomasc9de5602008-01-29 00:19:52 -05003148 loff_t size, orig_size, start_off;
3149 ext4_lblk_t start, orig_start;
3150 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003151 struct ext4_prealloc_space *pa;
Alex Tomasc9de5602008-01-29 00:19:52 -05003152
3153 /* do normalize only data requests, metadata requests
3154 do not need preallocation */
3155 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3156 return;
3157
3158 /* sometime caller may want exact blocks */
3159 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
3160 return;
3161
3162 /* caller may indicate that preallocation isn't
3163 * required (it's a tail, for example) */
3164 if (ac->ac_flags & EXT4_MB_HINT_NOPREALLOC)
3165 return;
3166
3167 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC) {
3168 ext4_mb_normalize_group_request(ac);
3169 return ;
3170 }
3171
3172 bsbits = ac->ac_sb->s_blocksize_bits;
3173
3174 /* first, let's learn actual file size
3175 * given current request is allocated */
3176 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
3177 size = size << bsbits;
3178 if (size < i_size_read(ac->ac_inode))
3179 size = i_size_read(ac->ac_inode);
3180
3181 /* max available blocks in a free group */
3182 max = EXT4_BLOCKS_PER_GROUP(ac->ac_sb) - 1 - 1 -
3183 EXT4_SB(ac->ac_sb)->s_itb_per_group;
3184
3185#define NRL_CHECK_SIZE(req, size, max,bits) \
3186 (req <= (size) || max <= ((size) >> bits))
3187
3188 /* first, try to predict filesize */
3189 /* XXX: should this table be tunable? */
3190 start_off = 0;
3191 if (size <= 16 * 1024) {
3192 size = 16 * 1024;
3193 } else if (size <= 32 * 1024) {
3194 size = 32 * 1024;
3195 } else if (size <= 64 * 1024) {
3196 size = 64 * 1024;
3197 } else if (size <= 128 * 1024) {
3198 size = 128 * 1024;
3199 } else if (size <= 256 * 1024) {
3200 size = 256 * 1024;
3201 } else if (size <= 512 * 1024) {
3202 size = 512 * 1024;
3203 } else if (size <= 1024 * 1024) {
3204 size = 1024 * 1024;
3205 } else if (NRL_CHECK_SIZE(size, 4 * 1024 * 1024, max, bsbits)) {
3206 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3207 (20 - bsbits)) << 20;
3208 size = 1024 * 1024;
3209 } else if (NRL_CHECK_SIZE(size, 8 * 1024 * 1024, max, bsbits)) {
3210 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3211 (22 - bsbits)) << 22;
3212 size = 4 * 1024 * 1024;
3213 } else if (NRL_CHECK_SIZE(ac->ac_o_ex.fe_len,
3214 (8<<20)>>bsbits, max, bsbits)) {
3215 start_off = ((loff_t)ac->ac_o_ex.fe_logical >>
3216 (23 - bsbits)) << 23;
3217 size = 8 * 1024 * 1024;
3218 } else {
3219 start_off = (loff_t)ac->ac_o_ex.fe_logical << bsbits;
3220 size = ac->ac_o_ex.fe_len << bsbits;
3221 }
3222 orig_size = size = size >> bsbits;
3223 orig_start = start = start_off >> bsbits;
3224
3225 /* don't cover already allocated blocks in selected range */
3226 if (ar->pleft && start <= ar->lleft) {
3227 size -= ar->lleft + 1 - start;
3228 start = ar->lleft + 1;
3229 }
3230 if (ar->pright && start + size - 1 >= ar->lright)
3231 size -= start + size - ar->lright;
3232
3233 end = start + size;
3234
3235 /* check we don't cross already preallocated blocks */
3236 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003237 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003238 unsigned long pa_end;
3239
Alex Tomasc9de5602008-01-29 00:19:52 -05003240 if (pa->pa_deleted)
3241 continue;
3242 spin_lock(&pa->pa_lock);
3243 if (pa->pa_deleted) {
3244 spin_unlock(&pa->pa_lock);
3245 continue;
3246 }
3247
3248 pa_end = pa->pa_lstart + pa->pa_len;
3249
3250 /* PA must not overlap original request */
3251 BUG_ON(!(ac->ac_o_ex.fe_logical >= pa_end ||
3252 ac->ac_o_ex.fe_logical < pa->pa_lstart));
3253
3254 /* skip PA normalized request doesn't overlap with */
3255 if (pa->pa_lstart >= end) {
3256 spin_unlock(&pa->pa_lock);
3257 continue;
3258 }
3259 if (pa_end <= start) {
3260 spin_unlock(&pa->pa_lock);
3261 continue;
3262 }
3263 BUG_ON(pa->pa_lstart <= start && pa_end >= end);
3264
3265 if (pa_end <= ac->ac_o_ex.fe_logical) {
3266 BUG_ON(pa_end < start);
3267 start = pa_end;
3268 }
3269
3270 if (pa->pa_lstart > ac->ac_o_ex.fe_logical) {
3271 BUG_ON(pa->pa_lstart > end);
3272 end = pa->pa_lstart;
3273 }
3274 spin_unlock(&pa->pa_lock);
3275 }
3276 rcu_read_unlock();
3277 size = end - start;
3278
3279 /* XXX: extra loop to check we really don't overlap preallocations */
3280 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003281 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003282 unsigned long pa_end;
Alex Tomasc9de5602008-01-29 00:19:52 -05003283 spin_lock(&pa->pa_lock);
3284 if (pa->pa_deleted == 0) {
3285 pa_end = pa->pa_lstart + pa->pa_len;
3286 BUG_ON(!(start >= pa_end || end <= pa->pa_lstart));
3287 }
3288 spin_unlock(&pa->pa_lock);
3289 }
3290 rcu_read_unlock();
3291
3292 if (start + size <= ac->ac_o_ex.fe_logical &&
3293 start > ac->ac_o_ex.fe_logical) {
3294 printk(KERN_ERR "start %lu, size %lu, fe_logical %lu\n",
3295 (unsigned long) start, (unsigned long) size,
3296 (unsigned long) ac->ac_o_ex.fe_logical);
3297 }
3298 BUG_ON(start + size <= ac->ac_o_ex.fe_logical &&
3299 start > ac->ac_o_ex.fe_logical);
3300 BUG_ON(size <= 0 || size >= EXT4_BLOCKS_PER_GROUP(ac->ac_sb));
3301
3302 /* now prepare goal request */
3303
3304 /* XXX: is it better to align blocks WRT to logical
3305 * placement or satisfy big request as is */
3306 ac->ac_g_ex.fe_logical = start;
3307 ac->ac_g_ex.fe_len = size;
3308
3309 /* define goal start in order to merge */
3310 if (ar->pright && (ar->lright == (start + size))) {
3311 /* merge to the right */
3312 ext4_get_group_no_and_offset(ac->ac_sb, ar->pright - size,
3313 &ac->ac_f_ex.fe_group,
3314 &ac->ac_f_ex.fe_start);
3315 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3316 }
3317 if (ar->pleft && (ar->lleft + 1 == start)) {
3318 /* merge to the left */
3319 ext4_get_group_no_and_offset(ac->ac_sb, ar->pleft + 1,
3320 &ac->ac_f_ex.fe_group,
3321 &ac->ac_f_ex.fe_start);
3322 ac->ac_flags |= EXT4_MB_HINT_TRY_GOAL;
3323 }
3324
3325 mb_debug("goal: %u(was %u) blocks at %u\n", (unsigned) size,
3326 (unsigned) orig_size, (unsigned) start);
3327}
3328
3329static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
3330{
3331 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
3332
3333 if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
3334 atomic_inc(&sbi->s_bal_reqs);
3335 atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
3336 if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
3337 atomic_inc(&sbi->s_bal_success);
3338 atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
3339 if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&
3340 ac->ac_g_ex.fe_group == ac->ac_b_ex.fe_group)
3341 atomic_inc(&sbi->s_bal_goals);
3342 if (ac->ac_found > sbi->s_mb_max_to_scan)
3343 atomic_inc(&sbi->s_bal_breaks);
3344 }
3345
3346 ext4_mb_store_history(ac);
3347}
3348
3349/*
3350 * use blocks preallocated to inode
3351 */
3352static void ext4_mb_use_inode_pa(struct ext4_allocation_context *ac,
3353 struct ext4_prealloc_space *pa)
3354{
3355 ext4_fsblk_t start;
3356 ext4_fsblk_t end;
3357 int len;
3358
3359 /* found preallocated blocks, use them */
3360 start = pa->pa_pstart + (ac->ac_o_ex.fe_logical - pa->pa_lstart);
3361 end = min(pa->pa_pstart + pa->pa_len, start + ac->ac_o_ex.fe_len);
3362 len = end - start;
3363 ext4_get_group_no_and_offset(ac->ac_sb, start, &ac->ac_b_ex.fe_group,
3364 &ac->ac_b_ex.fe_start);
3365 ac->ac_b_ex.fe_len = len;
3366 ac->ac_status = AC_STATUS_FOUND;
3367 ac->ac_pa = pa;
3368
3369 BUG_ON(start < pa->pa_pstart);
3370 BUG_ON(start + len > pa->pa_pstart + pa->pa_len);
3371 BUG_ON(pa->pa_free < len);
3372 pa->pa_free -= len;
3373
3374 mb_debug("use %llu/%lu from inode pa %p\n", start, len, pa);
3375}
3376
3377/*
3378 * use blocks preallocated to locality group
3379 */
3380static void ext4_mb_use_group_pa(struct ext4_allocation_context *ac,
3381 struct ext4_prealloc_space *pa)
3382{
3383 unsigned len = ac->ac_o_ex.fe_len;
3384
3385 ext4_get_group_no_and_offset(ac->ac_sb, pa->pa_pstart,
3386 &ac->ac_b_ex.fe_group,
3387 &ac->ac_b_ex.fe_start);
3388 ac->ac_b_ex.fe_len = len;
3389 ac->ac_status = AC_STATUS_FOUND;
3390 ac->ac_pa = pa;
3391
3392 /* we don't correct pa_pstart or pa_plen here to avoid
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003393 * possible race when the group is being loaded concurrently
Alex Tomasc9de5602008-01-29 00:19:52 -05003394 * instead we correct pa later, after blocks are marked
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003395 * in on-disk bitmap -- see ext4_mb_release_context()
3396 * Other CPUs are prevented from allocating from this pa by lg_mutex
Alex Tomasc9de5602008-01-29 00:19:52 -05003397 */
3398 mb_debug("use %u/%u from group pa %p\n", pa->pa_lstart-len, len, pa);
3399}
3400
3401/*
3402 * search goal blocks in preallocated space
3403 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003404static noinline_for_stack int
3405ext4_mb_use_preallocated(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003406{
3407 struct ext4_inode_info *ei = EXT4_I(ac->ac_inode);
3408 struct ext4_locality_group *lg;
3409 struct ext4_prealloc_space *pa;
Alex Tomasc9de5602008-01-29 00:19:52 -05003410
3411 /* only data can be preallocated */
3412 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
3413 return 0;
3414
3415 /* first, try per-file preallocation */
3416 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003417 list_for_each_entry_rcu(pa, &ei->i_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003418
3419 /* all fields in this condition don't change,
3420 * so we can skip locking for them */
3421 if (ac->ac_o_ex.fe_logical < pa->pa_lstart ||
3422 ac->ac_o_ex.fe_logical >= pa->pa_lstart + pa->pa_len)
3423 continue;
3424
3425 /* found preallocated blocks, use them */
3426 spin_lock(&pa->pa_lock);
3427 if (pa->pa_deleted == 0 && pa->pa_free) {
3428 atomic_inc(&pa->pa_count);
3429 ext4_mb_use_inode_pa(ac, pa);
3430 spin_unlock(&pa->pa_lock);
3431 ac->ac_criteria = 10;
3432 rcu_read_unlock();
3433 return 1;
3434 }
3435 spin_unlock(&pa->pa_lock);
3436 }
3437 rcu_read_unlock();
3438
3439 /* can we use group allocation? */
3440 if (!(ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC))
3441 return 0;
3442
3443 /* inode may have no locality group for some reason */
3444 lg = ac->ac_lg;
3445 if (lg == NULL)
3446 return 0;
3447
3448 rcu_read_lock();
Aneesh Kumar K.V9a0762c2008-04-17 10:38:59 -04003449 list_for_each_entry_rcu(pa, &lg->lg_prealloc_list, pa_inode_list) {
Alex Tomasc9de5602008-01-29 00:19:52 -05003450 spin_lock(&pa->pa_lock);
3451 if (pa->pa_deleted == 0 && pa->pa_free >= ac->ac_o_ex.fe_len) {
3452 atomic_inc(&pa->pa_count);
3453 ext4_mb_use_group_pa(ac, pa);
3454 spin_unlock(&pa->pa_lock);
3455 ac->ac_criteria = 20;
3456 rcu_read_unlock();
3457 return 1;
3458 }
3459 spin_unlock(&pa->pa_lock);
3460 }
3461 rcu_read_unlock();
3462
3463 return 0;
3464}
3465
3466/*
3467 * the function goes through all preallocation in this group and marks them
3468 * used in in-core bitmap. buddy must be generated from this bitmap
3469 * Need to be called with ext4 group lock (ext4_lock_group)
3470 */
3471static void ext4_mb_generate_from_pa(struct super_block *sb, void *bitmap,
3472 ext4_group_t group)
3473{
3474 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3475 struct ext4_prealloc_space *pa;
3476 struct list_head *cur;
3477 ext4_group_t groupnr;
3478 ext4_grpblk_t start;
3479 int preallocated = 0;
3480 int count = 0;
3481 int len;
3482
3483 /* all form of preallocation discards first load group,
3484 * so the only competing code is preallocation use.
3485 * we don't need any locking here
3486 * notice we do NOT ignore preallocations with pa_deleted
3487 * otherwise we could leave used blocks available for
3488 * allocation in buddy when concurrent ext4_mb_put_pa()
3489 * is dropping preallocation
3490 */
3491 list_for_each(cur, &grp->bb_prealloc_list) {
3492 pa = list_entry(cur, struct ext4_prealloc_space, pa_group_list);
3493 spin_lock(&pa->pa_lock);
3494 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
3495 &groupnr, &start);
3496 len = pa->pa_len;
3497 spin_unlock(&pa->pa_lock);
3498 if (unlikely(len == 0))
3499 continue;
3500 BUG_ON(groupnr != group);
3501 mb_set_bits(sb_bgl_lock(EXT4_SB(sb), group),
3502 bitmap, start, len);
3503 preallocated += len;
3504 count++;
3505 }
3506 mb_debug("prellocated %u for group %lu\n", preallocated, group);
3507}
3508
3509static void ext4_mb_pa_callback(struct rcu_head *head)
3510{
3511 struct ext4_prealloc_space *pa;
3512 pa = container_of(head, struct ext4_prealloc_space, u.pa_rcu);
3513 kmem_cache_free(ext4_pspace_cachep, pa);
3514}
3515
3516/*
3517 * drops a reference to preallocated space descriptor
3518 * if this was the last reference and the space is consumed
3519 */
3520static void ext4_mb_put_pa(struct ext4_allocation_context *ac,
3521 struct super_block *sb, struct ext4_prealloc_space *pa)
3522{
3523 unsigned long grp;
3524
3525 if (!atomic_dec_and_test(&pa->pa_count) || pa->pa_free != 0)
3526 return;
3527
3528 /* in this short window concurrent discard can set pa_deleted */
3529 spin_lock(&pa->pa_lock);
3530 if (pa->pa_deleted == 1) {
3531 spin_unlock(&pa->pa_lock);
3532 return;
3533 }
3534
3535 pa->pa_deleted = 1;
3536 spin_unlock(&pa->pa_lock);
3537
3538 /* -1 is to protect from crossing allocation group */
3539 ext4_get_group_no_and_offset(sb, pa->pa_pstart - 1, &grp, NULL);
3540
3541 /*
3542 * possible race:
3543 *
3544 * P1 (buddy init) P2 (regular allocation)
3545 * find block B in PA
3546 * copy on-disk bitmap to buddy
3547 * mark B in on-disk bitmap
3548 * drop PA from group
3549 * mark all PAs in buddy
3550 *
3551 * thus, P1 initializes buddy with B available. to prevent this
3552 * we make "copy" and "mark all PAs" atomic and serialize "drop PA"
3553 * against that pair
3554 */
3555 ext4_lock_group(sb, grp);
3556 list_del(&pa->pa_group_list);
3557 ext4_unlock_group(sb, grp);
3558
3559 spin_lock(pa->pa_obj_lock);
3560 list_del_rcu(&pa->pa_inode_list);
3561 spin_unlock(pa->pa_obj_lock);
3562
3563 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3564}
3565
3566/*
3567 * creates new preallocated space for given inode
3568 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003569static noinline_for_stack int
3570ext4_mb_new_inode_pa(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003571{
3572 struct super_block *sb = ac->ac_sb;
3573 struct ext4_prealloc_space *pa;
3574 struct ext4_group_info *grp;
3575 struct ext4_inode_info *ei;
3576
3577 /* preallocate only when found space is larger then requested */
3578 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3579 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3580 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3581
3582 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3583 if (pa == NULL)
3584 return -ENOMEM;
3585
3586 if (ac->ac_b_ex.fe_len < ac->ac_g_ex.fe_len) {
3587 int winl;
3588 int wins;
3589 int win;
3590 int offs;
3591
3592 /* we can't allocate as much as normalizer wants.
3593 * so, found space must get proper lstart
3594 * to cover original request */
3595 BUG_ON(ac->ac_g_ex.fe_logical > ac->ac_o_ex.fe_logical);
3596 BUG_ON(ac->ac_g_ex.fe_len < ac->ac_o_ex.fe_len);
3597
3598 /* we're limited by original request in that
3599 * logical block must be covered any way
3600 * winl is window we can move our chunk within */
3601 winl = ac->ac_o_ex.fe_logical - ac->ac_g_ex.fe_logical;
3602
3603 /* also, we should cover whole original request */
3604 wins = ac->ac_b_ex.fe_len - ac->ac_o_ex.fe_len;
3605
3606 /* the smallest one defines real window */
3607 win = min(winl, wins);
3608
3609 offs = ac->ac_o_ex.fe_logical % ac->ac_b_ex.fe_len;
3610 if (offs && offs < win)
3611 win = offs;
3612
3613 ac->ac_b_ex.fe_logical = ac->ac_o_ex.fe_logical - win;
3614 BUG_ON(ac->ac_o_ex.fe_logical < ac->ac_b_ex.fe_logical);
3615 BUG_ON(ac->ac_o_ex.fe_len > ac->ac_b_ex.fe_len);
3616 }
3617
3618 /* preallocation can change ac_b_ex, thus we store actually
3619 * allocated blocks for history */
3620 ac->ac_f_ex = ac->ac_b_ex;
3621
3622 pa->pa_lstart = ac->ac_b_ex.fe_logical;
3623 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3624 pa->pa_len = ac->ac_b_ex.fe_len;
3625 pa->pa_free = pa->pa_len;
3626 atomic_set(&pa->pa_count, 1);
3627 spin_lock_init(&pa->pa_lock);
3628 pa->pa_deleted = 0;
3629 pa->pa_linear = 0;
3630
3631 mb_debug("new inode pa %p: %llu/%u for %u\n", pa,
3632 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3633
3634 ext4_mb_use_inode_pa(ac, pa);
3635 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3636
3637 ei = EXT4_I(ac->ac_inode);
3638 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3639
3640 pa->pa_obj_lock = &ei->i_prealloc_lock;
3641 pa->pa_inode = ac->ac_inode;
3642
3643 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3644 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3645 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3646
3647 spin_lock(pa->pa_obj_lock);
3648 list_add_rcu(&pa->pa_inode_list, &ei->i_prealloc_list);
3649 spin_unlock(pa->pa_obj_lock);
3650
3651 return 0;
3652}
3653
3654/*
3655 * creates new preallocated space for locality group inodes belongs to
3656 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003657static noinline_for_stack int
3658ext4_mb_new_group_pa(struct ext4_allocation_context *ac)
Alex Tomasc9de5602008-01-29 00:19:52 -05003659{
3660 struct super_block *sb = ac->ac_sb;
3661 struct ext4_locality_group *lg;
3662 struct ext4_prealloc_space *pa;
3663 struct ext4_group_info *grp;
3664
3665 /* preallocate only when found space is larger then requested */
3666 BUG_ON(ac->ac_o_ex.fe_len >= ac->ac_b_ex.fe_len);
3667 BUG_ON(ac->ac_status != AC_STATUS_FOUND);
3668 BUG_ON(!S_ISREG(ac->ac_inode->i_mode));
3669
3670 BUG_ON(ext4_pspace_cachep == NULL);
3671 pa = kmem_cache_alloc(ext4_pspace_cachep, GFP_NOFS);
3672 if (pa == NULL)
3673 return -ENOMEM;
3674
3675 /* preallocation can change ac_b_ex, thus we store actually
3676 * allocated blocks for history */
3677 ac->ac_f_ex = ac->ac_b_ex;
3678
3679 pa->pa_pstart = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
3680 pa->pa_lstart = pa->pa_pstart;
3681 pa->pa_len = ac->ac_b_ex.fe_len;
3682 pa->pa_free = pa->pa_len;
3683 atomic_set(&pa->pa_count, 1);
3684 spin_lock_init(&pa->pa_lock);
3685 pa->pa_deleted = 0;
3686 pa->pa_linear = 1;
3687
3688 mb_debug("new group pa %p: %llu/%u for %u\n", pa,
3689 pa->pa_pstart, pa->pa_len, pa->pa_lstart);
3690
3691 ext4_mb_use_group_pa(ac, pa);
3692 atomic_add(pa->pa_free, &EXT4_SB(sb)->s_mb_preallocated);
3693
3694 grp = ext4_get_group_info(sb, ac->ac_b_ex.fe_group);
3695 lg = ac->ac_lg;
3696 BUG_ON(lg == NULL);
3697
3698 pa->pa_obj_lock = &lg->lg_prealloc_lock;
3699 pa->pa_inode = NULL;
3700
3701 ext4_lock_group(sb, ac->ac_b_ex.fe_group);
3702 list_add(&pa->pa_group_list, &grp->bb_prealloc_list);
3703 ext4_unlock_group(sb, ac->ac_b_ex.fe_group);
3704
3705 spin_lock(pa->pa_obj_lock);
3706 list_add_tail_rcu(&pa->pa_inode_list, &lg->lg_prealloc_list);
3707 spin_unlock(pa->pa_obj_lock);
3708
3709 return 0;
3710}
3711
3712static int ext4_mb_new_preallocation(struct ext4_allocation_context *ac)
3713{
3714 int err;
3715
3716 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
3717 err = ext4_mb_new_group_pa(ac);
3718 else
3719 err = ext4_mb_new_inode_pa(ac);
3720 return err;
3721}
3722
3723/*
3724 * finds all unused blocks in on-disk bitmap, frees them in
3725 * in-core bitmap and buddy.
3726 * @pa must be unlinked from inode and group lists, so that
3727 * nobody else can find/use it.
3728 * the caller MUST hold group/inode locks.
3729 * TODO: optimize the case when there are no in-core structures yet
3730 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003731static noinline_for_stack int
3732ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
Alex Tomasc9de5602008-01-29 00:19:52 -05003733 struct ext4_prealloc_space *pa)
3734{
Eric Sandeen256bdb42008-02-10 01:13:33 -05003735 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003736 struct super_block *sb = e4b->bd_sb;
3737 struct ext4_sb_info *sbi = EXT4_SB(sb);
3738 unsigned long end;
3739 unsigned long next;
3740 ext4_group_t group;
3741 ext4_grpblk_t bit;
3742 sector_t start;
3743 int err = 0;
3744 int free = 0;
3745
3746 BUG_ON(pa->pa_deleted == 0);
3747 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3748 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3749 end = bit + pa->pa_len;
3750
Eric Sandeen256bdb42008-02-10 01:13:33 -05003751 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3752
3753 if (ac) {
3754 ac->ac_sb = sb;
3755 ac->ac_inode = pa->pa_inode;
3756 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
3757 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003758
3759 while (bit < end) {
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003760 bit = mb_find_next_zero_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003761 if (bit >= end)
3762 break;
Aneesh Kumar K.Vffad0a42008-02-23 01:38:34 -05003763 next = mb_find_next_bit(bitmap_bh->b_data, end, bit);
Alex Tomasc9de5602008-01-29 00:19:52 -05003764 if (next > end)
3765 next = end;
3766 start = group * EXT4_BLOCKS_PER_GROUP(sb) + bit +
3767 le32_to_cpu(sbi->s_es->s_first_data_block);
3768 mb_debug(" free preallocated %u/%u in group %u\n",
3769 (unsigned) start, (unsigned) next - bit,
3770 (unsigned) group);
3771 free += next - bit;
3772
Eric Sandeen256bdb42008-02-10 01:13:33 -05003773 if (ac) {
3774 ac->ac_b_ex.fe_group = group;
3775 ac->ac_b_ex.fe_start = bit;
3776 ac->ac_b_ex.fe_len = next - bit;
3777 ac->ac_b_ex.fe_logical = 0;
3778 ext4_mb_store_history(ac);
3779 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003780
3781 mb_free_blocks(pa->pa_inode, e4b, bit, next - bit);
3782 bit = next + 1;
3783 }
3784 if (free != pa->pa_free) {
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003785 printk(KERN_CRIT "pa %p: logic %lu, phys. %lu, len %lu\n",
Alex Tomasc9de5602008-01-29 00:19:52 -05003786 pa, (unsigned long) pa->pa_lstart,
3787 (unsigned long) pa->pa_pstart,
3788 (unsigned long) pa->pa_len);
Harvey Harrison46e665e2008-04-17 10:38:59 -04003789 ext4_error(sb, __func__, "free %u, pa_free %u\n",
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05003790 free, pa->pa_free);
Aneesh Kumar K.Ve56eb652008-02-15 13:48:21 -05003791 /*
3792 * pa is already deleted so we use the value obtained
3793 * from the bitmap and continue.
3794 */
Alex Tomasc9de5602008-01-29 00:19:52 -05003795 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003796 atomic_add(free, &sbi->s_mb_discarded);
Eric Sandeen256bdb42008-02-10 01:13:33 -05003797 if (ac)
3798 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05003799
3800 return err;
3801}
3802
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003803static noinline_for_stack int
3804ext4_mb_release_group_pa(struct ext4_buddy *e4b,
Alex Tomasc9de5602008-01-29 00:19:52 -05003805 struct ext4_prealloc_space *pa)
3806{
Eric Sandeen256bdb42008-02-10 01:13:33 -05003807 struct ext4_allocation_context *ac;
Alex Tomasc9de5602008-01-29 00:19:52 -05003808 struct super_block *sb = e4b->bd_sb;
3809 ext4_group_t group;
3810 ext4_grpblk_t bit;
3811
Eric Sandeen256bdb42008-02-10 01:13:33 -05003812 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
3813
3814 if (ac)
3815 ac->ac_op = EXT4_MB_HISTORY_DISCARD;
Alex Tomasc9de5602008-01-29 00:19:52 -05003816
3817 BUG_ON(pa->pa_deleted == 0);
3818 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, &bit);
3819 BUG_ON(group != e4b->bd_group && pa->pa_len != 0);
3820 mb_free_blocks(pa->pa_inode, e4b, bit, pa->pa_len);
3821 atomic_add(pa->pa_len, &EXT4_SB(sb)->s_mb_discarded);
3822
Eric Sandeen256bdb42008-02-10 01:13:33 -05003823 if (ac) {
3824 ac->ac_sb = sb;
3825 ac->ac_inode = NULL;
3826 ac->ac_b_ex.fe_group = group;
3827 ac->ac_b_ex.fe_start = bit;
3828 ac->ac_b_ex.fe_len = pa->pa_len;
3829 ac->ac_b_ex.fe_logical = 0;
3830 ext4_mb_store_history(ac);
3831 kmem_cache_free(ext4_ac_cachep, ac);
3832 }
Alex Tomasc9de5602008-01-29 00:19:52 -05003833
3834 return 0;
3835}
3836
3837/*
3838 * releases all preallocations in given group
3839 *
3840 * first, we need to decide discard policy:
3841 * - when do we discard
3842 * 1) ENOSPC
3843 * - how many do we discard
3844 * 1) how many requested
3845 */
Eric Sandeen4ddfef72008-04-29 08:11:12 -04003846static noinline_for_stack int
3847ext4_mb_discard_group_preallocations(struct super_block *sb,
Alex Tomasc9de5602008-01-29 00:19:52 -05003848 ext4_group_t group, int needed)
3849{
3850 struct ext4_group_info *grp = ext4_get_group_info(sb, group);
3851 struct buffer_head *bitmap_bh = NULL;
3852 struct ext4_prealloc_space *pa, *tmp;
3853 struct list_head list;
3854 struct ext4_buddy e4b;
3855 int err;
3856 int busy = 0;
3857 int free = 0;
3858
3859 mb_debug("discard preallocation for group %lu\n", group);
3860
3861 if (list_empty(&grp->bb_prealloc_list))
3862 return 0;
3863
3864 bitmap_bh = read_block_bitmap(sb, group);
3865 if (bitmap_bh == NULL) {
3866 /* error handling here */
3867 ext4_mb_release_desc(&e4b);
3868 BUG_ON(bitmap_bh == NULL);
3869 }
3870
3871 err = ext4_mb_load_buddy(sb, group, &e4b);
3872 BUG_ON(err != 0); /* error handling here */
3873
3874 if (needed == 0)
3875 needed = EXT4_BLOCKS_PER_GROUP(sb) + 1;
3876
3877 grp = ext4_get_group_info(sb, group);
3878 INIT_LIST_HEAD(&list);
3879
3880repeat:
3881 ext4_lock_group(sb, group);
3882 list_for_each_entry_safe(pa, tmp,
3883 &grp->bb_prealloc_list, pa_group_list) {
3884 spin_lock(&pa->pa_lock);
3885 if (atomic_read(&pa->pa_count)) {
3886 spin_unlock(&pa->pa_lock);
3887 busy = 1;
3888 continue;
3889 }
3890 if (pa->pa_deleted) {
3891 spin_unlock(&pa->pa_lock);
3892 continue;
3893 }
3894
3895 /* seems this one can be freed ... */
3896 pa->pa_deleted = 1;
3897
3898 /* we can trust pa_free ... */
3899 free += pa->pa_free;
3900
3901 spin_unlock(&pa->pa_lock);
3902
3903 list_del(&pa->pa_group_list);
3904 list_add(&pa->u.pa_tmp_list, &list);
3905 }
3906
3907 /* if we still need more blocks and some PAs were used, try again */
3908 if (free < needed && busy) {
3909 busy = 0;
3910 ext4_unlock_group(sb, group);
3911 /*
3912 * Yield the CPU here so that we don't get soft lockup
3913 * in non preempt case.
3914 */
3915 yield();
3916 goto repeat;
3917 }
3918
3919 /* found anything to free? */
3920 if (list_empty(&list)) {
3921 BUG_ON(free != 0);
3922 goto out;
3923 }
3924
3925 /* now free all selected PAs */
3926 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
3927
3928 /* remove from object (inode or locality group) */
3929 spin_lock(pa->pa_obj_lock);
3930 list_del_rcu(&pa->pa_inode_list);
3931 spin_unlock(pa->pa_obj_lock);
3932
3933 if (pa->pa_linear)
3934 ext4_mb_release_group_pa(&e4b, pa);
3935 else
3936 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
3937
3938 list_del(&pa->u.pa_tmp_list);
3939 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
3940 }
3941
3942out:
3943 ext4_unlock_group(sb, group);
3944 ext4_mb_release_desc(&e4b);
3945 put_bh(bitmap_bh);
3946 return free;
3947}
3948
3949/*
3950 * releases all non-used preallocated blocks for given inode
3951 *
3952 * It's important to discard preallocations under i_data_sem
3953 * We don't want another block to be served from the prealloc
3954 * space when we are discarding the inode prealloc space.
3955 *
3956 * FIXME!! Make sure it is valid at all the call sites
3957 */
3958void ext4_mb_discard_inode_preallocations(struct inode *inode)
3959{
3960 struct ext4_inode_info *ei = EXT4_I(inode);
3961 struct super_block *sb = inode->i_sb;
3962 struct buffer_head *bitmap_bh = NULL;
3963 struct ext4_prealloc_space *pa, *tmp;
3964 ext4_group_t group = 0;
3965 struct list_head list;
3966 struct ext4_buddy e4b;
3967 int err;
3968
3969 if (!test_opt(sb, MBALLOC) || !S_ISREG(inode->i_mode)) {
3970 /*BUG_ON(!list_empty(&ei->i_prealloc_list));*/
3971 return;
3972 }
3973
3974 mb_debug("discard preallocation for inode %lu\n", inode->i_ino);
3975
3976 INIT_LIST_HEAD(&list);
3977
3978repeat:
3979 /* first, collect all pa's in the inode */
3980 spin_lock(&ei->i_prealloc_lock);
3981 while (!list_empty(&ei->i_prealloc_list)) {
3982 pa = list_entry(ei->i_prealloc_list.next,
3983 struct ext4_prealloc_space, pa_inode_list);
3984 BUG_ON(pa->pa_obj_lock != &ei->i_prealloc_lock);
3985 spin_lock(&pa->pa_lock);
3986 if (atomic_read(&pa->pa_count)) {
3987 /* this shouldn't happen often - nobody should
3988 * use preallocation while we're discarding it */
3989 spin_unlock(&pa->pa_lock);
3990 spin_unlock(&ei->i_prealloc_lock);
3991 printk(KERN_ERR "uh-oh! used pa while discarding\n");
3992 WARN_ON(1);
3993 schedule_timeout_uninterruptible(HZ);
3994 goto repeat;
3995
3996 }
3997 if (pa->pa_deleted == 0) {
3998 pa->pa_deleted = 1;
3999 spin_unlock(&pa->pa_lock);
4000 list_del_rcu(&pa->pa_inode_list);
4001 list_add(&pa->u.pa_tmp_list, &list);
4002 continue;
4003 }
4004
4005 /* someone is deleting pa right now */
4006 spin_unlock(&pa->pa_lock);
4007 spin_unlock(&ei->i_prealloc_lock);
4008
4009 /* we have to wait here because pa_deleted
4010 * doesn't mean pa is already unlinked from
4011 * the list. as we might be called from
4012 * ->clear_inode() the inode will get freed
4013 * and concurrent thread which is unlinking
4014 * pa from inode's list may access already
4015 * freed memory, bad-bad-bad */
4016
4017 /* XXX: if this happens too often, we can
4018 * add a flag to force wait only in case
4019 * of ->clear_inode(), but not in case of
4020 * regular truncate */
4021 schedule_timeout_uninterruptible(HZ);
4022 goto repeat;
4023 }
4024 spin_unlock(&ei->i_prealloc_lock);
4025
4026 list_for_each_entry_safe(pa, tmp, &list, u.pa_tmp_list) {
4027 BUG_ON(pa->pa_linear != 0);
4028 ext4_get_group_no_and_offset(sb, pa->pa_pstart, &group, NULL);
4029
4030 err = ext4_mb_load_buddy(sb, group, &e4b);
4031 BUG_ON(err != 0); /* error handling here */
4032
4033 bitmap_bh = read_block_bitmap(sb, group);
4034 if (bitmap_bh == NULL) {
4035 /* error handling here */
4036 ext4_mb_release_desc(&e4b);
4037 BUG_ON(bitmap_bh == NULL);
4038 }
4039
4040 ext4_lock_group(sb, group);
4041 list_del(&pa->pa_group_list);
4042 ext4_mb_release_inode_pa(&e4b, bitmap_bh, pa);
4043 ext4_unlock_group(sb, group);
4044
4045 ext4_mb_release_desc(&e4b);
4046 put_bh(bitmap_bh);
4047
4048 list_del(&pa->u.pa_tmp_list);
4049 call_rcu(&(pa)->u.pa_rcu, ext4_mb_pa_callback);
4050 }
4051}
4052
4053/*
4054 * finds all preallocated spaces and return blocks being freed to them
4055 * if preallocated space becomes full (no block is used from the space)
4056 * then the function frees space in buddy
4057 * XXX: at the moment, truncate (which is the only way to free blocks)
4058 * discards all preallocations
4059 */
4060static void ext4_mb_return_to_preallocation(struct inode *inode,
4061 struct ext4_buddy *e4b,
4062 sector_t block, int count)
4063{
4064 BUG_ON(!list_empty(&EXT4_I(inode)->i_prealloc_list));
4065}
4066#ifdef MB_DEBUG
4067static void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4068{
4069 struct super_block *sb = ac->ac_sb;
4070 ext4_group_t i;
4071
4072 printk(KERN_ERR "EXT4-fs: Can't allocate:"
4073 " Allocation context details:\n");
4074 printk(KERN_ERR "EXT4-fs: status %d flags %d\n",
4075 ac->ac_status, ac->ac_flags);
4076 printk(KERN_ERR "EXT4-fs: orig %lu/%lu/%lu@%lu, goal %lu/%lu/%lu@%lu, "
4077 "best %lu/%lu/%lu@%lu cr %d\n",
4078 (unsigned long)ac->ac_o_ex.fe_group,
4079 (unsigned long)ac->ac_o_ex.fe_start,
4080 (unsigned long)ac->ac_o_ex.fe_len,
4081 (unsigned long)ac->ac_o_ex.fe_logical,
4082 (unsigned long)ac->ac_g_ex.fe_group,
4083 (unsigned long)ac->ac_g_ex.fe_start,
4084 (unsigned long)ac->ac_g_ex.fe_len,
4085 (unsigned long)ac->ac_g_ex.fe_logical,
4086 (unsigned long)ac->ac_b_ex.fe_group,
4087 (unsigned long)ac->ac_b_ex.fe_start,
4088 (unsigned long)ac->ac_b_ex.fe_len,
4089 (unsigned long)ac->ac_b_ex.fe_logical,
4090 (int)ac->ac_criteria);
4091 printk(KERN_ERR "EXT4-fs: %lu scanned, %d found\n", ac->ac_ex_scanned,
4092 ac->ac_found);
4093 printk(KERN_ERR "EXT4-fs: groups: \n");
4094 for (i = 0; i < EXT4_SB(sb)->s_groups_count; i++) {
4095 struct ext4_group_info *grp = ext4_get_group_info(sb, i);
4096 struct ext4_prealloc_space *pa;
4097 ext4_grpblk_t start;
4098 struct list_head *cur;
4099 ext4_lock_group(sb, i);
4100 list_for_each(cur, &grp->bb_prealloc_list) {
4101 pa = list_entry(cur, struct ext4_prealloc_space,
4102 pa_group_list);
4103 spin_lock(&pa->pa_lock);
4104 ext4_get_group_no_and_offset(sb, pa->pa_pstart,
4105 NULL, &start);
4106 spin_unlock(&pa->pa_lock);
4107 printk(KERN_ERR "PA:%lu:%d:%u \n", i,
4108 start, pa->pa_len);
4109 }
4110 ext4_lock_group(sb, i);
4111
4112 if (grp->bb_free == 0)
4113 continue;
4114 printk(KERN_ERR "%lu: %d/%d \n",
4115 i, grp->bb_free, grp->bb_fragments);
4116 }
4117 printk(KERN_ERR "\n");
4118}
4119#else
4120static inline void ext4_mb_show_ac(struct ext4_allocation_context *ac)
4121{
4122 return;
4123}
4124#endif
4125
4126/*
4127 * We use locality group preallocation for small size file. The size of the
4128 * file is determined by the current size or the resulting size after
4129 * allocation which ever is larger
4130 *
4131 * One can tune this size via /proc/fs/ext4/<partition>/stream_req
4132 */
4133static void ext4_mb_group_or_file(struct ext4_allocation_context *ac)
4134{
4135 struct ext4_sb_info *sbi = EXT4_SB(ac->ac_sb);
4136 int bsbits = ac->ac_sb->s_blocksize_bits;
4137 loff_t size, isize;
4138
4139 if (!(ac->ac_flags & EXT4_MB_HINT_DATA))
4140 return;
4141
4142 size = ac->ac_o_ex.fe_logical + ac->ac_o_ex.fe_len;
4143 isize = i_size_read(ac->ac_inode) >> bsbits;
4144 size = max(size, isize);
4145
4146 /* don't use group allocation for large files */
4147 if (size >= sbi->s_mb_stream_request)
4148 return;
4149
4150 if (unlikely(ac->ac_flags & EXT4_MB_HINT_GOAL_ONLY))
4151 return;
4152
4153 BUG_ON(ac->ac_lg != NULL);
4154 /*
4155 * locality group prealloc space are per cpu. The reason for having
4156 * per cpu locality group is to reduce the contention between block
4157 * request from multiple CPUs.
4158 */
4159 ac->ac_lg = &sbi->s_locality_groups[get_cpu()];
4160 put_cpu();
4161
4162 /* we're going to use group allocation */
4163 ac->ac_flags |= EXT4_MB_HINT_GROUP_ALLOC;
4164
4165 /* serialize all allocations in the group */
4166 mutex_lock(&ac->ac_lg->lg_mutex);
4167}
4168
Eric Sandeen4ddfef72008-04-29 08:11:12 -04004169static noinline_for_stack int
4170ext4_mb_initialize_context(struct ext4_allocation_context *ac,
Alex Tomasc9de5602008-01-29 00:19:52 -05004171 struct ext4_allocation_request *ar)
4172{
4173 struct super_block *sb = ar->inode->i_sb;
4174 struct ext4_sb_info *sbi = EXT4_SB(sb);
4175 struct ext4_super_block *es = sbi->s_es;
4176 ext4_group_t group;
4177 unsigned long len;
4178 unsigned long goal;
4179 ext4_grpblk_t block;
4180
4181 /* we can't allocate > group size */
4182 len = ar->len;
4183
4184 /* just a dirty hack to filter too big requests */
4185 if (len >= EXT4_BLOCKS_PER_GROUP(sb) - 10)
4186 len = EXT4_BLOCKS_PER_GROUP(sb) - 10;
4187
4188 /* start searching from the goal */
4189 goal = ar->goal;
4190 if (goal < le32_to_cpu(es->s_first_data_block) ||
4191 goal >= ext4_blocks_count(es))
4192 goal = le32_to_cpu(es->s_first_data_block);
4193 ext4_get_group_no_and_offset(sb, goal, &group, &block);
4194
4195 /* set up allocation goals */
4196 ac->ac_b_ex.fe_logical = ar->logical;
4197 ac->ac_b_ex.fe_group = 0;
4198 ac->ac_b_ex.fe_start = 0;
4199 ac->ac_b_ex.fe_len = 0;
4200 ac->ac_status = AC_STATUS_CONTINUE;
4201 ac->ac_groups_scanned = 0;
4202 ac->ac_ex_scanned = 0;
4203 ac->ac_found = 0;
4204 ac->ac_sb = sb;
4205 ac->ac_inode = ar->inode;
4206 ac->ac_o_ex.fe_logical = ar->logical;
4207 ac->ac_o_ex.fe_group = group;
4208 ac->ac_o_ex.fe_start = block;
4209 ac->ac_o_ex.fe_len = len;
4210 ac->ac_g_ex.fe_logical = ar->logical;
4211 ac->ac_g_ex.fe_group = group;
4212 ac->ac_g_ex.fe_start = block;
4213 ac->ac_g_ex.fe_len = len;
4214 ac->ac_f_ex.fe_len = 0;
4215 ac->ac_flags = ar->flags;
4216 ac->ac_2order = 0;
4217 ac->ac_criteria = 0;
4218 ac->ac_pa = NULL;
4219 ac->ac_bitmap_page = NULL;
4220 ac->ac_buddy_page = NULL;
4221 ac->ac_lg = NULL;
4222
4223 /* we have to define context: we'll we work with a file or
4224 * locality group. this is a policy, actually */
4225 ext4_mb_group_or_file(ac);
4226
4227 mb_debug("init ac: %u blocks @ %u, goal %u, flags %x, 2^%d, "
4228 "left: %u/%u, right %u/%u to %swritable\n",
4229 (unsigned) ar->len, (unsigned) ar->logical,
4230 (unsigned) ar->goal, ac->ac_flags, ac->ac_2order,
4231 (unsigned) ar->lleft, (unsigned) ar->pleft,
4232 (unsigned) ar->lright, (unsigned) ar->pright,
4233 atomic_read(&ar->inode->i_writecount) ? "" : "non-");
4234 return 0;
4235
4236}
4237
4238/*
4239 * release all resource we used in allocation
4240 */
4241static int ext4_mb_release_context(struct ext4_allocation_context *ac)
4242{
4243 if (ac->ac_pa) {
4244 if (ac->ac_pa->pa_linear) {
4245 /* see comment in ext4_mb_use_group_pa() */
4246 spin_lock(&ac->ac_pa->pa_lock);
4247 ac->ac_pa->pa_pstart += ac->ac_b_ex.fe_len;
4248 ac->ac_pa->pa_lstart += ac->ac_b_ex.fe_len;
4249 ac->ac_pa->pa_free -= ac->ac_b_ex.fe_len;
4250 ac->ac_pa->pa_len -= ac->ac_b_ex.fe_len;
4251 spin_unlock(&ac->ac_pa->pa_lock);
4252 }
4253 ext4_mb_put_pa(ac, ac->ac_sb, ac->ac_pa);
4254 }
4255 if (ac->ac_bitmap_page)
4256 page_cache_release(ac->ac_bitmap_page);
4257 if (ac->ac_buddy_page)
4258 page_cache_release(ac->ac_buddy_page);
4259 if (ac->ac_flags & EXT4_MB_HINT_GROUP_ALLOC)
4260 mutex_unlock(&ac->ac_lg->lg_mutex);
4261 ext4_mb_collect_stats(ac);
4262 return 0;
4263}
4264
4265static int ext4_mb_discard_preallocations(struct super_block *sb, int needed)
4266{
4267 ext4_group_t i;
4268 int ret;
4269 int freed = 0;
4270
4271 for (i = 0; i < EXT4_SB(sb)->s_groups_count && needed > 0; i++) {
4272 ret = ext4_mb_discard_group_preallocations(sb, i, needed);
4273 freed += ret;
4274 needed -= ret;
4275 }
4276
4277 return freed;
4278}
4279
4280/*
4281 * Main entry point into mballoc to allocate blocks
4282 * it tries to use preallocation first, then falls back
4283 * to usual allocation
4284 */
4285ext4_fsblk_t ext4_mb_new_blocks(handle_t *handle,
4286 struct ext4_allocation_request *ar, int *errp)
4287{
Eric Sandeen256bdb42008-02-10 01:13:33 -05004288 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004289 struct ext4_sb_info *sbi;
4290 struct super_block *sb;
4291 ext4_fsblk_t block = 0;
4292 int freed;
4293 int inquota;
4294
4295 sb = ar->inode->i_sb;
4296 sbi = EXT4_SB(sb);
4297
4298 if (!test_opt(sb, MBALLOC)) {
4299 block = ext4_new_blocks_old(handle, ar->inode, ar->goal,
4300 &(ar->len), errp);
4301 return block;
4302 }
4303
4304 while (ar->len && DQUOT_ALLOC_BLOCK(ar->inode, ar->len)) {
4305 ar->flags |= EXT4_MB_HINT_NOPREALLOC;
4306 ar->len--;
4307 }
4308 if (ar->len == 0) {
4309 *errp = -EDQUOT;
4310 return 0;
4311 }
4312 inquota = ar->len;
4313
Eric Sandeen256bdb42008-02-10 01:13:33 -05004314 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4315 if (!ac) {
4316 *errp = -ENOMEM;
4317 return 0;
4318 }
4319
Alex Tomasc9de5602008-01-29 00:19:52 -05004320 ext4_mb_poll_new_transaction(sb, handle);
4321
Eric Sandeen256bdb42008-02-10 01:13:33 -05004322 *errp = ext4_mb_initialize_context(ac, ar);
Alex Tomasc9de5602008-01-29 00:19:52 -05004323 if (*errp) {
4324 ar->len = 0;
4325 goto out;
4326 }
4327
Eric Sandeen256bdb42008-02-10 01:13:33 -05004328 ac->ac_op = EXT4_MB_HISTORY_PREALLOC;
4329 if (!ext4_mb_use_preallocated(ac)) {
Alex Tomasc9de5602008-01-29 00:19:52 -05004330
Eric Sandeen256bdb42008-02-10 01:13:33 -05004331 ac->ac_op = EXT4_MB_HISTORY_ALLOC;
4332 ext4_mb_normalize_request(ac, ar);
Alex Tomasc9de5602008-01-29 00:19:52 -05004333
4334repeat:
4335 /* allocate space in core */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004336 ext4_mb_regular_allocator(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004337
4338 /* as we've just preallocated more space than
4339 * user requested orinally, we store allocated
4340 * space in a special descriptor */
Eric Sandeen256bdb42008-02-10 01:13:33 -05004341 if (ac->ac_status == AC_STATUS_FOUND &&
4342 ac->ac_o_ex.fe_len < ac->ac_b_ex.fe_len)
4343 ext4_mb_new_preallocation(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004344 }
4345
Eric Sandeen256bdb42008-02-10 01:13:33 -05004346 if (likely(ac->ac_status == AC_STATUS_FOUND)) {
4347 ext4_mb_mark_diskspace_used(ac, handle);
Alex Tomasc9de5602008-01-29 00:19:52 -05004348 *errp = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004349 block = ext4_grp_offs_to_block(sb, &ac->ac_b_ex);
4350 ar->len = ac->ac_b_ex.fe_len;
Alex Tomasc9de5602008-01-29 00:19:52 -05004351 } else {
Eric Sandeen256bdb42008-02-10 01:13:33 -05004352 freed = ext4_mb_discard_preallocations(sb, ac->ac_o_ex.fe_len);
Alex Tomasc9de5602008-01-29 00:19:52 -05004353 if (freed)
4354 goto repeat;
4355 *errp = -ENOSPC;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004356 ac->ac_b_ex.fe_len = 0;
Alex Tomasc9de5602008-01-29 00:19:52 -05004357 ar->len = 0;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004358 ext4_mb_show_ac(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004359 }
4360
Eric Sandeen256bdb42008-02-10 01:13:33 -05004361 ext4_mb_release_context(ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004362
4363out:
4364 if (ar->len < inquota)
4365 DQUOT_FREE_BLOCK(ar->inode, inquota - ar->len);
4366
Eric Sandeen256bdb42008-02-10 01:13:33 -05004367 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004368 return block;
4369}
4370static void ext4_mb_poll_new_transaction(struct super_block *sb,
4371 handle_t *handle)
4372{
4373 struct ext4_sb_info *sbi = EXT4_SB(sb);
4374
4375 if (sbi->s_last_transaction == handle->h_transaction->t_tid)
4376 return;
4377
4378 /* new transaction! time to close last one and free blocks for
4379 * committed transaction. we know that only transaction can be
4380 * active, so previos transaction can be being logged and we
4381 * know that transaction before previous is known to be already
4382 * logged. this means that now we may free blocks freed in all
4383 * transactions before previous one. hope I'm clear enough ... */
4384
4385 spin_lock(&sbi->s_md_lock);
4386 if (sbi->s_last_transaction != handle->h_transaction->t_tid) {
4387 mb_debug("new transaction %lu, old %lu\n",
4388 (unsigned long) handle->h_transaction->t_tid,
4389 (unsigned long) sbi->s_last_transaction);
4390 list_splice_init(&sbi->s_closed_transaction,
4391 &sbi->s_committed_transaction);
4392 list_splice_init(&sbi->s_active_transaction,
4393 &sbi->s_closed_transaction);
4394 sbi->s_last_transaction = handle->h_transaction->t_tid;
4395 }
4396 spin_unlock(&sbi->s_md_lock);
4397
4398 ext4_mb_free_committed_blocks(sb);
4399}
4400
Eric Sandeen4ddfef72008-04-29 08:11:12 -04004401static noinline_for_stack int
4402ext4_mb_free_metadata(handle_t *handle, struct ext4_buddy *e4b,
Alex Tomasc9de5602008-01-29 00:19:52 -05004403 ext4_group_t group, ext4_grpblk_t block, int count)
4404{
4405 struct ext4_group_info *db = e4b->bd_info;
4406 struct super_block *sb = e4b->bd_sb;
4407 struct ext4_sb_info *sbi = EXT4_SB(sb);
4408 struct ext4_free_metadata *md;
4409 int i;
4410
4411 BUG_ON(e4b->bd_bitmap_page == NULL);
4412 BUG_ON(e4b->bd_buddy_page == NULL);
4413
4414 ext4_lock_group(sb, group);
4415 for (i = 0; i < count; i++) {
4416 md = db->bb_md_cur;
4417 if (md && db->bb_tid != handle->h_transaction->t_tid) {
4418 db->bb_md_cur = NULL;
4419 md = NULL;
4420 }
4421
4422 if (md == NULL) {
4423 ext4_unlock_group(sb, group);
4424 md = kmalloc(sizeof(*md), GFP_NOFS);
4425 if (md == NULL)
4426 return -ENOMEM;
4427 md->num = 0;
4428 md->group = group;
4429
4430 ext4_lock_group(sb, group);
4431 if (db->bb_md_cur == NULL) {
4432 spin_lock(&sbi->s_md_lock);
4433 list_add(&md->list, &sbi->s_active_transaction);
4434 spin_unlock(&sbi->s_md_lock);
4435 /* protect buddy cache from being freed,
4436 * otherwise we'll refresh it from
4437 * on-disk bitmap and lose not-yet-available
4438 * blocks */
4439 page_cache_get(e4b->bd_buddy_page);
4440 page_cache_get(e4b->bd_bitmap_page);
4441 db->bb_md_cur = md;
4442 db->bb_tid = handle->h_transaction->t_tid;
4443 mb_debug("new md 0x%p for group %lu\n",
4444 md, md->group);
4445 } else {
4446 kfree(md);
4447 md = db->bb_md_cur;
4448 }
4449 }
4450
4451 BUG_ON(md->num >= EXT4_BB_MAX_BLOCKS);
4452 md->blocks[md->num] = block + i;
4453 md->num++;
4454 if (md->num == EXT4_BB_MAX_BLOCKS) {
4455 /* no more space, put full container on a sb's list */
4456 db->bb_md_cur = NULL;
4457 }
4458 }
4459 ext4_unlock_group(sb, group);
4460 return 0;
4461}
4462
4463/*
4464 * Main entry point into mballoc to free blocks
4465 */
4466void ext4_mb_free_blocks(handle_t *handle, struct inode *inode,
4467 unsigned long block, unsigned long count,
4468 int metadata, unsigned long *freed)
4469{
Aneesh Kumar K.V26346ff2008-02-10 01:10:04 -05004470 struct buffer_head *bitmap_bh = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004471 struct super_block *sb = inode->i_sb;
Eric Sandeen256bdb42008-02-10 01:13:33 -05004472 struct ext4_allocation_context *ac = NULL;
Alex Tomasc9de5602008-01-29 00:19:52 -05004473 struct ext4_group_desc *gdp;
4474 struct ext4_super_block *es;
4475 unsigned long overflow;
4476 ext4_grpblk_t bit;
4477 struct buffer_head *gd_bh;
4478 ext4_group_t block_group;
4479 struct ext4_sb_info *sbi;
4480 struct ext4_buddy e4b;
4481 int err = 0;
4482 int ret;
4483
4484 *freed = 0;
4485
4486 ext4_mb_poll_new_transaction(sb, handle);
4487
4488 sbi = EXT4_SB(sb);
4489 es = EXT4_SB(sb)->s_es;
4490 if (block < le32_to_cpu(es->s_first_data_block) ||
4491 block + count < block ||
4492 block + count > ext4_blocks_count(es)) {
Harvey Harrison46e665e2008-04-17 10:38:59 -04004493 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05004494 "Freeing blocks not in datazone - "
4495 "block = %lu, count = %lu", block, count);
4496 goto error_return;
4497 }
4498
4499 ext4_debug("freeing block %lu\n", block);
4500
Eric Sandeen256bdb42008-02-10 01:13:33 -05004501 ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
4502 if (ac) {
4503 ac->ac_op = EXT4_MB_HISTORY_FREE;
4504 ac->ac_inode = inode;
4505 ac->ac_sb = sb;
4506 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004507
4508do_more:
4509 overflow = 0;
4510 ext4_get_group_no_and_offset(sb, block, &block_group, &bit);
4511
4512 /*
4513 * Check to see if we are freeing blocks across a group
4514 * boundary.
4515 */
4516 if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) {
4517 overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb);
4518 count -= overflow;
4519 }
4520 bitmap_bh = read_block_bitmap(sb, block_group);
4521 if (!bitmap_bh)
4522 goto error_return;
4523 gdp = ext4_get_group_desc(sb, block_group, &gd_bh);
4524 if (!gdp)
4525 goto error_return;
4526
4527 if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
4528 in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
4529 in_range(block, ext4_inode_table(sb, gdp),
4530 EXT4_SB(sb)->s_itb_per_group) ||
4531 in_range(block + count - 1, ext4_inode_table(sb, gdp),
4532 EXT4_SB(sb)->s_itb_per_group)) {
4533
Harvey Harrison46e665e2008-04-17 10:38:59 -04004534 ext4_error(sb, __func__,
Alex Tomasc9de5602008-01-29 00:19:52 -05004535 "Freeing blocks in system zone - "
4536 "Block = %lu, count = %lu", block, count);
4537 }
4538
4539 BUFFER_TRACE(bitmap_bh, "getting write access");
4540 err = ext4_journal_get_write_access(handle, bitmap_bh);
4541 if (err)
4542 goto error_return;
4543
4544 /*
4545 * We are about to modify some metadata. Call the journal APIs
4546 * to unshare ->b_data if a currently-committing transaction is
4547 * using it
4548 */
4549 BUFFER_TRACE(gd_bh, "get_write_access");
4550 err = ext4_journal_get_write_access(handle, gd_bh);
4551 if (err)
4552 goto error_return;
4553
4554 err = ext4_mb_load_buddy(sb, block_group, &e4b);
4555 if (err)
4556 goto error_return;
4557
4558#ifdef AGGRESSIVE_CHECK
4559 {
4560 int i;
4561 for (i = 0; i < count; i++)
4562 BUG_ON(!mb_test_bit(bit + i, bitmap_bh->b_data));
4563 }
4564#endif
4565 mb_clear_bits(sb_bgl_lock(sbi, block_group), bitmap_bh->b_data,
4566 bit, count);
4567
4568 /* We dirtied the bitmap block */
4569 BUFFER_TRACE(bitmap_bh, "dirtied bitmap block");
4570 err = ext4_journal_dirty_metadata(handle, bitmap_bh);
4571
Eric Sandeen256bdb42008-02-10 01:13:33 -05004572 if (ac) {
4573 ac->ac_b_ex.fe_group = block_group;
4574 ac->ac_b_ex.fe_start = bit;
4575 ac->ac_b_ex.fe_len = count;
4576 ext4_mb_store_history(ac);
4577 }
Alex Tomasc9de5602008-01-29 00:19:52 -05004578
4579 if (metadata) {
4580 /* blocks being freed are metadata. these blocks shouldn't
4581 * be used until this transaction is committed */
4582 ext4_mb_free_metadata(handle, &e4b, block_group, bit, count);
4583 } else {
4584 ext4_lock_group(sb, block_group);
4585 err = mb_free_blocks(inode, &e4b, bit, count);
4586 ext4_mb_return_to_preallocation(inode, &e4b, block, count);
4587 ext4_unlock_group(sb, block_group);
4588 BUG_ON(err != 0);
4589 }
4590
4591 spin_lock(sb_bgl_lock(sbi, block_group));
Marcin Slusarze8546d02008-04-17 10:38:59 -04004592 le16_add_cpu(&gdp->bg_free_blocks_count, count);
Alex Tomasc9de5602008-01-29 00:19:52 -05004593 gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp);
4594 spin_unlock(sb_bgl_lock(sbi, block_group));
4595 percpu_counter_add(&sbi->s_freeblocks_counter, count);
4596
4597 ext4_mb_release_desc(&e4b);
4598
4599 *freed += count;
4600
4601 /* And the group descriptor block */
4602 BUFFER_TRACE(gd_bh, "dirtied group descriptor block");
4603 ret = ext4_journal_dirty_metadata(handle, gd_bh);
4604 if (!err)
4605 err = ret;
4606
4607 if (overflow && !err) {
4608 block += count;
4609 count = overflow;
4610 put_bh(bitmap_bh);
4611 goto do_more;
4612 }
4613 sb->s_dirt = 1;
4614error_return:
4615 brelse(bitmap_bh);
4616 ext4_std_error(sb, err);
Eric Sandeen256bdb42008-02-10 01:13:33 -05004617 if (ac)
4618 kmem_cache_free(ext4_ac_cachep, ac);
Alex Tomasc9de5602008-01-29 00:19:52 -05004619 return;
4620}