Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6
[linux-2.6] / fs / ocfs2 / suballoc.c
1 /* -*- mode: c; c-basic-offset: 8; -*-
2  * vim: noexpandtab sw=8 ts=8 sts=0:
3  *
4  * suballoc.c
5  *
6  * metadata alloc and free
7  * Inspired by ext3 block groups.
8  *
9  * Copyright (C) 2002, 2004 Oracle.  All rights reserved.
10  *
11  * This program is free software; you can redistribute it and/or
12  * modify it under the terms of the GNU General Public
13  * License as published by the Free Software Foundation; either
14  * version 2 of the License, or (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19  * General Public License for more details.
20  *
21  * You should have received a copy of the GNU General Public
22  * License along with this program; if not, write to the
23  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
24  * Boston, MA 021110-1307, USA.
25  */
26
27 #include <linux/fs.h>
28 #include <linux/types.h>
29 #include <linux/slab.h>
30 #include <linux/highmem.h>
31
32 #define MLOG_MASK_PREFIX ML_DISK_ALLOC
33 #include <cluster/masklog.h>
34
35 #include "ocfs2.h"
36
37 #include "alloc.h"
38 #include "dlmglue.h"
39 #include "inode.h"
40 #include "journal.h"
41 #include "localalloc.h"
42 #include "suballoc.h"
43 #include "super.h"
44 #include "sysfile.h"
45 #include "uptodate.h"
46
47 #include "buffer_head_io.h"
48
49 #define NOT_ALLOC_NEW_GROUP             0
50 #define ALLOC_NEW_GROUP                 1
51
52 #define OCFS2_MAX_INODES_TO_STEAL       1024
53
54 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
55 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
56 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
57 static int ocfs2_block_group_fill(handle_t *handle,
58                                   struct inode *alloc_inode,
59                                   struct buffer_head *bg_bh,
60                                   u64 group_blkno,
61                                   u16 my_chain,
62                                   struct ocfs2_chain_list *cl);
63 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
64                                    struct inode *alloc_inode,
65                                    struct buffer_head *bh,
66                                    u64 max_block);
67
68 static int ocfs2_cluster_group_search(struct inode *inode,
69                                       struct buffer_head *group_bh,
70                                       u32 bits_wanted, u32 min_bits,
71                                       u64 max_block,
72                                       u16 *bit_off, u16 *bits_found);
73 static int ocfs2_block_group_search(struct inode *inode,
74                                     struct buffer_head *group_bh,
75                                     u32 bits_wanted, u32 min_bits,
76                                     u64 max_block,
77                                     u16 *bit_off, u16 *bits_found);
78 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
79                                      struct ocfs2_alloc_context *ac,
80                                      handle_t *handle,
81                                      u32 bits_wanted,
82                                      u32 min_bits,
83                                      u16 *bit_off,
84                                      unsigned int *num_bits,
85                                      u64 *bg_blkno);
86 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
87                                          int nr);
88 static inline int ocfs2_block_group_set_bits(handle_t *handle,
89                                              struct inode *alloc_inode,
90                                              struct ocfs2_group_desc *bg,
91                                              struct buffer_head *group_bh,
92                                              unsigned int bit_off,
93                                              unsigned int num_bits);
94 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
95                                                struct inode *alloc_inode,
96                                                struct ocfs2_group_desc *bg,
97                                                struct buffer_head *group_bh,
98                                                unsigned int bit_off,
99                                                unsigned int num_bits);
100
101 static int ocfs2_relink_block_group(handle_t *handle,
102                                     struct inode *alloc_inode,
103                                     struct buffer_head *fe_bh,
104                                     struct buffer_head *bg_bh,
105                                     struct buffer_head *prev_bg_bh,
106                                     u16 chain);
107 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
108                                                      u32 wanted);
109 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
110                                                    u64 bg_blkno,
111                                                    u16 bg_bit_off);
112 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
113                                                 u64 data_blkno,
114                                                 u64 *bg_blkno,
115                                                 u16 *bg_bit_off);
116 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
117                                              u32 bits_wanted, u64 max_block,
118                                              struct ocfs2_alloc_context **ac);
119
120 void ocfs2_free_ac_resource(struct ocfs2_alloc_context *ac)
121 {
122         struct inode *inode = ac->ac_inode;
123
124         if (inode) {
125                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
126                         ocfs2_inode_unlock(inode, 1);
127
128                 mutex_unlock(&inode->i_mutex);
129
130                 iput(inode);
131                 ac->ac_inode = NULL;
132         }
133         brelse(ac->ac_bh);
134         ac->ac_bh = NULL;
135 }
136
137 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
138 {
139         ocfs2_free_ac_resource(ac);
140         kfree(ac);
141 }
142
143 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
144 {
145         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
146 }
147
148 /* somewhat more expensive than our other checks, so use sparingly. */
149 int ocfs2_check_group_descriptor(struct super_block *sb,
150                                  struct ocfs2_dinode *di,
151                                  struct ocfs2_group_desc *gd)
152 {
153         unsigned int max_bits;
154
155         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
156                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
157                 return -EIO;
158         }
159
160         if (di->i_blkno != gd->bg_parent_dinode) {
161                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
162                             "pointer (%llu, expected %llu)",
163                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
164                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
165                             (unsigned long long)le64_to_cpu(di->i_blkno));
166                 return -EIO;
167         }
168
169         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
170         if (le16_to_cpu(gd->bg_bits) > max_bits) {
171                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
172                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
173                             le16_to_cpu(gd->bg_bits));
174                 return -EIO;
175         }
176
177         if (le16_to_cpu(gd->bg_chain) >=
178             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
179                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
180                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
181                             le16_to_cpu(gd->bg_chain));
182                 return -EIO;
183         }
184
185         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
186                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
187                             "claims that %u are free",
188                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
189                             le16_to_cpu(gd->bg_bits),
190                             le16_to_cpu(gd->bg_free_bits_count));
191                 return -EIO;
192         }
193
194         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
195                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
196                             "max bitmap bits of %u",
197                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
198                             le16_to_cpu(gd->bg_bits),
199                             8 * le16_to_cpu(gd->bg_size));
200                 return -EIO;
201         }
202
203         return 0;
204 }
205
206 static int ocfs2_block_group_fill(handle_t *handle,
207                                   struct inode *alloc_inode,
208                                   struct buffer_head *bg_bh,
209                                   u64 group_blkno,
210                                   u16 my_chain,
211                                   struct ocfs2_chain_list *cl)
212 {
213         int status = 0;
214         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
215         struct super_block * sb = alloc_inode->i_sb;
216
217         mlog_entry_void();
218
219         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
220                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
221                             "b_blocknr (%llu)",
222                             (unsigned long long)group_blkno,
223                             (unsigned long long) bg_bh->b_blocknr);
224                 status = -EIO;
225                 goto bail;
226         }
227
228         status = ocfs2_journal_access(handle,
229                                       alloc_inode,
230                                       bg_bh,
231                                       OCFS2_JOURNAL_ACCESS_CREATE);
232         if (status < 0) {
233                 mlog_errno(status);
234                 goto bail;
235         }
236
237         memset(bg, 0, sb->s_blocksize);
238         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
239         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
240         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
241         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
242         bg->bg_chain = cpu_to_le16(my_chain);
243         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
244         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
245         bg->bg_blkno = cpu_to_le64(group_blkno);
246         /* set the 1st bit in the bitmap to account for the descriptor block */
247         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
248         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
249
250         status = ocfs2_journal_dirty(handle, bg_bh);
251         if (status < 0)
252                 mlog_errno(status);
253
254         /* There is no need to zero out or otherwise initialize the
255          * other blocks in a group - All valid FS metadata in a block
256          * group stores the superblock fs_generation value at
257          * allocation time. */
258
259 bail:
260         mlog_exit(status);
261         return status;
262 }
263
264 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
265 {
266         u16 curr, best;
267
268         best = curr = 0;
269         while (curr < le16_to_cpu(cl->cl_count)) {
270                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
271                     le32_to_cpu(cl->cl_recs[curr].c_total))
272                         best = curr;
273                 curr++;
274         }
275         return best;
276 }
277
278 /*
279  * We expect the block group allocator to already be locked.
280  */
281 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
282                                    struct inode *alloc_inode,
283                                    struct buffer_head *bh,
284                                    u64 max_block)
285 {
286         int status, credits;
287         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
288         struct ocfs2_chain_list *cl;
289         struct ocfs2_alloc_context *ac = NULL;
290         handle_t *handle = NULL;
291         u32 bit_off, num_bits;
292         u16 alloc_rec;
293         u64 bg_blkno;
294         struct buffer_head *bg_bh = NULL;
295         struct ocfs2_group_desc *bg;
296
297         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
298
299         mlog_entry_void();
300
301         cl = &fe->id2.i_chain;
302         status = ocfs2_reserve_clusters_with_limit(osb,
303                                                    le16_to_cpu(cl->cl_cpg),
304                                                    max_block, &ac);
305         if (status < 0) {
306                 if (status != -ENOSPC)
307                         mlog_errno(status);
308                 goto bail;
309         }
310
311         credits = ocfs2_calc_group_alloc_credits(osb->sb,
312                                                  le16_to_cpu(cl->cl_cpg));
313         handle = ocfs2_start_trans(osb, credits);
314         if (IS_ERR(handle)) {
315                 status = PTR_ERR(handle);
316                 handle = NULL;
317                 mlog_errno(status);
318                 goto bail;
319         }
320
321         status = ocfs2_claim_clusters(osb,
322                                       handle,
323                                       ac,
324                                       le16_to_cpu(cl->cl_cpg),
325                                       &bit_off,
326                                       &num_bits);
327         if (status < 0) {
328                 if (status != -ENOSPC)
329                         mlog_errno(status);
330                 goto bail;
331         }
332
333         alloc_rec = ocfs2_find_smallest_chain(cl);
334
335         /* setup the group */
336         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
337         mlog(0, "new descriptor, record %u, at block %llu\n",
338              alloc_rec, (unsigned long long)bg_blkno);
339
340         bg_bh = sb_getblk(osb->sb, bg_blkno);
341         if (!bg_bh) {
342                 status = -EIO;
343                 mlog_errno(status);
344                 goto bail;
345         }
346         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
347
348         status = ocfs2_block_group_fill(handle,
349                                         alloc_inode,
350                                         bg_bh,
351                                         bg_blkno,
352                                         alloc_rec,
353                                         cl);
354         if (status < 0) {
355                 mlog_errno(status);
356                 goto bail;
357         }
358
359         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
360
361         status = ocfs2_journal_access(handle, alloc_inode,
362                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
363         if (status < 0) {
364                 mlog_errno(status);
365                 goto bail;
366         }
367
368         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
369                      le16_to_cpu(bg->bg_free_bits_count));
370         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
371         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
372         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
373                 le16_add_cpu(&cl->cl_next_free_rec, 1);
374
375         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
376                                         le16_to_cpu(bg->bg_free_bits_count));
377         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
378         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
379
380         status = ocfs2_journal_dirty(handle, bh);
381         if (status < 0) {
382                 mlog_errno(status);
383                 goto bail;
384         }
385
386         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
387         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
388         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
389                                              le32_to_cpu(fe->i_clusters)));
390         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
391         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
392         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
393
394         status = 0;
395 bail:
396         if (handle)
397                 ocfs2_commit_trans(osb, handle);
398
399         if (ac)
400                 ocfs2_free_alloc_context(ac);
401
402         brelse(bg_bh);
403
404         mlog_exit(status);
405         return status;
406 }
407
408 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
409                                        struct ocfs2_alloc_context *ac,
410                                        int type,
411                                        u32 slot,
412                                        int alloc_new_group)
413 {
414         int status;
415         u32 bits_wanted = ac->ac_bits_wanted;
416         struct inode *alloc_inode;
417         struct buffer_head *bh = NULL;
418         struct ocfs2_dinode *fe;
419         u32 free_bits;
420
421         mlog_entry_void();
422
423         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
424         if (!alloc_inode) {
425                 mlog_errno(-EINVAL);
426                 return -EINVAL;
427         }
428
429         mutex_lock(&alloc_inode->i_mutex);
430
431         status = ocfs2_inode_lock(alloc_inode, &bh, 1);
432         if (status < 0) {
433                 mutex_unlock(&alloc_inode->i_mutex);
434                 iput(alloc_inode);
435
436                 mlog_errno(status);
437                 return status;
438         }
439
440         ac->ac_inode = alloc_inode;
441         ac->ac_alloc_slot = slot;
442
443         fe = (struct ocfs2_dinode *) bh->b_data;
444         if (!OCFS2_IS_VALID_DINODE(fe)) {
445                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
446                 status = -EIO;
447                 goto bail;
448         }
449         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
450                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
451                             (unsigned long long)le64_to_cpu(fe->i_blkno));
452                 status = -EIO;
453                 goto bail;
454         }
455
456         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
457                 le32_to_cpu(fe->id1.bitmap1.i_used);
458
459         if (bits_wanted > free_bits) {
460                 /* cluster bitmap never grows */
461                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
462                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
463                              bits_wanted, free_bits);
464                         status = -ENOSPC;
465                         goto bail;
466                 }
467
468                 if (alloc_new_group != ALLOC_NEW_GROUP) {
469                         mlog(0, "Alloc File %u Full: wanted=%u, free_bits=%u, "
470                              "and we don't alloc a new group for it.\n",
471                              slot, bits_wanted, free_bits);
472                         status = -ENOSPC;
473                         goto bail;
474                 }
475
476                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh,
477                                                  ac->ac_max_block);
478                 if (status < 0) {
479                         if (status != -ENOSPC)
480                                 mlog_errno(status);
481                         goto bail;
482                 }
483                 atomic_inc(&osb->alloc_stats.bg_extends);
484
485                 /* You should never ask for this much metadata */
486                 BUG_ON(bits_wanted >
487                        (le32_to_cpu(fe->id1.bitmap1.i_total)
488                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
489         }
490
491         get_bh(bh);
492         ac->ac_bh = bh;
493 bail:
494         brelse(bh);
495
496         mlog_exit(status);
497         return status;
498 }
499
500 int ocfs2_reserve_new_metadata_blocks(struct ocfs2_super *osb,
501                                       int blocks,
502                                       struct ocfs2_alloc_context **ac)
503 {
504         int status;
505         u32 slot;
506
507         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
508         if (!(*ac)) {
509                 status = -ENOMEM;
510                 mlog_errno(status);
511                 goto bail;
512         }
513
514         (*ac)->ac_bits_wanted = blocks;
515         (*ac)->ac_which = OCFS2_AC_USE_META;
516         slot = osb->slot_num;
517         (*ac)->ac_group_search = ocfs2_block_group_search;
518
519         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
520                                              EXTENT_ALLOC_SYSTEM_INODE,
521                                              slot, ALLOC_NEW_GROUP);
522         if (status < 0) {
523                 if (status != -ENOSPC)
524                         mlog_errno(status);
525                 goto bail;
526         }
527
528         status = 0;
529 bail:
530         if ((status < 0) && *ac) {
531                 ocfs2_free_alloc_context(*ac);
532                 *ac = NULL;
533         }
534
535         mlog_exit(status);
536         return status;
537 }
538
539 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
540                                struct ocfs2_extent_list *root_el,
541                                struct ocfs2_alloc_context **ac)
542 {
543         return ocfs2_reserve_new_metadata_blocks(osb,
544                                         ocfs2_extend_meta_needed(root_el),
545                                         ac);
546 }
547
548 static int ocfs2_steal_inode_from_other_nodes(struct ocfs2_super *osb,
549                                               struct ocfs2_alloc_context *ac)
550 {
551         int i, status = -ENOSPC;
552         s16 slot = ocfs2_get_inode_steal_slot(osb);
553
554         /* Start to steal inodes from the first slot after ours. */
555         if (slot == OCFS2_INVALID_SLOT)
556                 slot = osb->slot_num + 1;
557
558         for (i = 0; i < osb->max_slots; i++, slot++) {
559                 if (slot == osb->max_slots)
560                         slot = 0;
561
562                 if (slot == osb->slot_num)
563                         continue;
564
565                 status = ocfs2_reserve_suballoc_bits(osb, ac,
566                                                      INODE_ALLOC_SYSTEM_INODE,
567                                                      slot, NOT_ALLOC_NEW_GROUP);
568                 if (status >= 0) {
569                         ocfs2_set_inode_steal_slot(osb, slot);
570                         break;
571                 }
572
573                 ocfs2_free_ac_resource(ac);
574         }
575
576         return status;
577 }
578
579 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
580                             struct ocfs2_alloc_context **ac)
581 {
582         int status;
583         s16 slot = ocfs2_get_inode_steal_slot(osb);
584
585         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
586         if (!(*ac)) {
587                 status = -ENOMEM;
588                 mlog_errno(status);
589                 goto bail;
590         }
591
592         (*ac)->ac_bits_wanted = 1;
593         (*ac)->ac_which = OCFS2_AC_USE_INODE;
594
595         (*ac)->ac_group_search = ocfs2_block_group_search;
596
597         /*
598          * stat(2) can't handle i_ino > 32bits, so we tell the
599          * lower levels not to allocate us a block group past that
600          * limit.  The 'inode64' mount option avoids this behavior.
601          */
602         if (!(osb->s_mount_opt & OCFS2_MOUNT_INODE64))
603                 (*ac)->ac_max_block = (u32)~0U;
604
605         /*
606          * slot is set when we successfully steal inode from other nodes.
607          * It is reset in 3 places:
608          * 1. when we flush the truncate log
609          * 2. when we complete local alloc recovery.
610          * 3. when we successfully allocate from our own slot.
611          * After it is set, we will go on stealing inodes until we find the
612          * need to check our slots to see whether there is some space for us.
613          */
614         if (slot != OCFS2_INVALID_SLOT &&
615             atomic_read(&osb->s_num_inodes_stolen) < OCFS2_MAX_INODES_TO_STEAL)
616                 goto inode_steal;
617
618         atomic_set(&osb->s_num_inodes_stolen, 0);
619         status = ocfs2_reserve_suballoc_bits(osb, *ac,
620                                              INODE_ALLOC_SYSTEM_INODE,
621                                              osb->slot_num, ALLOC_NEW_GROUP);
622         if (status >= 0) {
623                 status = 0;
624
625                 /*
626                  * Some inodes must be freed by us, so try to allocate
627                  * from our own next time.
628                  */
629                 if (slot != OCFS2_INVALID_SLOT)
630                         ocfs2_init_inode_steal_slot(osb);
631                 goto bail;
632         } else if (status < 0 && status != -ENOSPC) {
633                 mlog_errno(status);
634                 goto bail;
635         }
636
637         ocfs2_free_ac_resource(*ac);
638
639 inode_steal:
640         status = ocfs2_steal_inode_from_other_nodes(osb, *ac);
641         atomic_inc(&osb->s_num_inodes_stolen);
642         if (status < 0) {
643                 if (status != -ENOSPC)
644                         mlog_errno(status);
645                 goto bail;
646         }
647
648         status = 0;
649 bail:
650         if ((status < 0) && *ac) {
651                 ocfs2_free_alloc_context(*ac);
652                 *ac = NULL;
653         }
654
655         mlog_exit(status);
656         return status;
657 }
658
659 /* local alloc code has to do the same thing, so rather than do this
660  * twice.. */
661 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
662                                       struct ocfs2_alloc_context *ac)
663 {
664         int status;
665
666         ac->ac_which = OCFS2_AC_USE_MAIN;
667         ac->ac_group_search = ocfs2_cluster_group_search;
668
669         status = ocfs2_reserve_suballoc_bits(osb, ac,
670                                              GLOBAL_BITMAP_SYSTEM_INODE,
671                                              OCFS2_INVALID_SLOT,
672                                              ALLOC_NEW_GROUP);
673         if (status < 0 && status != -ENOSPC) {
674                 mlog_errno(status);
675                 goto bail;
676         }
677
678 bail:
679         return status;
680 }
681
682 /* Callers don't need to care which bitmap (local alloc or main) to
683  * use so we figure it out for them, but unfortunately this clutters
684  * things a bit. */
685 static int ocfs2_reserve_clusters_with_limit(struct ocfs2_super *osb,
686                                              u32 bits_wanted, u64 max_block,
687                                              struct ocfs2_alloc_context **ac)
688 {
689         int status;
690
691         mlog_entry_void();
692
693         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
694         if (!(*ac)) {
695                 status = -ENOMEM;
696                 mlog_errno(status);
697                 goto bail;
698         }
699
700         (*ac)->ac_bits_wanted = bits_wanted;
701         (*ac)->ac_max_block = max_block;
702
703         status = -ENOSPC;
704         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
705                 status = ocfs2_reserve_local_alloc_bits(osb,
706                                                         bits_wanted,
707                                                         *ac);
708                 if (status == -EFBIG) {
709                         /* The local alloc window is outside ac_max_block.
710                          * use the main bitmap. */
711                         status = -ENOSPC;
712                 } else if ((status < 0) && (status != -ENOSPC)) {
713                         mlog_errno(status);
714                         goto bail;
715                 }
716         }
717
718         if (status == -ENOSPC) {
719                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
720                 if (status < 0) {
721                         if (status != -ENOSPC)
722                                 mlog_errno(status);
723                         goto bail;
724                 }
725         }
726
727         status = 0;
728 bail:
729         if ((status < 0) && *ac) {
730                 ocfs2_free_alloc_context(*ac);
731                 *ac = NULL;
732         }
733
734         mlog_exit(status);
735         return status;
736 }
737
738 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
739                            u32 bits_wanted,
740                            struct ocfs2_alloc_context **ac)
741 {
742         return ocfs2_reserve_clusters_with_limit(osb, bits_wanted, 0, ac);
743 }
744
745 /*
746  * More or less lifted from ext3. I'll leave their description below:
747  *
748  * "For ext3 allocations, we must not reuse any blocks which are
749  * allocated in the bitmap buffer's "last committed data" copy.  This
750  * prevents deletes from freeing up the page for reuse until we have
751  * committed the delete transaction.
752  *
753  * If we didn't do this, then deleting something and reallocating it as
754  * data would allow the old block to be overwritten before the
755  * transaction committed (because we force data to disk before commit).
756  * This would lead to corruption if we crashed between overwriting the
757  * data and committing the delete.
758  *
759  * @@@ We may want to make this allocation behaviour conditional on
760  * data-writes at some point, and disable it for metadata allocations or
761  * sync-data inodes."
762  *
763  * Note: OCFS2 already does this differently for metadata vs data
764  * allocations, as those bitmaps are separate and undo access is never
765  * called on a metadata group descriptor.
766  */
767 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
768                                          int nr)
769 {
770         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
771
772         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
773                 return 0;
774         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
775                 return 1;
776
777         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
778         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
779 }
780
781 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
782                                              struct buffer_head *bg_bh,
783                                              unsigned int bits_wanted,
784                                              unsigned int total_bits,
785                                              u16 *bit_off,
786                                              u16 *bits_found)
787 {
788         void *bitmap;
789         u16 best_offset, best_size;
790         int offset, start, found, status = 0;
791         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
792
793         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
794                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
795                 return -EIO;
796         }
797
798         found = start = best_offset = best_size = 0;
799         bitmap = bg->bg_bitmap;
800
801         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
802                 if (offset == total_bits)
803                         break;
804
805                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
806                         /* We found a zero, but we can't use it as it
807                          * hasn't been put to disk yet! */
808                         found = 0;
809                         start = offset + 1;
810                 } else if (offset == start) {
811                         /* we found a zero */
812                         found++;
813                         /* move start to the next bit to test */
814                         start++;
815                 } else {
816                         /* got a zero after some ones */
817                         found = 1;
818                         start = offset + 1;
819                 }
820                 if (found > best_size) {
821                         best_size = found;
822                         best_offset = start - found;
823                 }
824                 /* we got everything we needed */
825                 if (found == bits_wanted) {
826                         /* mlog(0, "Found it all!\n"); */
827                         break;
828                 }
829         }
830
831         /* XXX: I think the first clause is equivalent to the second
832          *      - jlbec */
833         if (found == bits_wanted) {
834                 *bit_off = start - found;
835                 *bits_found = found;
836         } else if (best_size) {
837                 *bit_off = best_offset;
838                 *bits_found = best_size;
839         } else {
840                 status = -ENOSPC;
841                 /* No error log here -- see the comment above
842                  * ocfs2_test_bg_bit_allocatable */
843         }
844
845         return status;
846 }
847
848 static inline int ocfs2_block_group_set_bits(handle_t *handle,
849                                              struct inode *alloc_inode,
850                                              struct ocfs2_group_desc *bg,
851                                              struct buffer_head *group_bh,
852                                              unsigned int bit_off,
853                                              unsigned int num_bits)
854 {
855         int status;
856         void *bitmap = bg->bg_bitmap;
857         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
858
859         mlog_entry_void();
860
861         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
862                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
863                 status = -EIO;
864                 goto bail;
865         }
866         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
867
868         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
869              num_bits);
870
871         if (ocfs2_is_cluster_bitmap(alloc_inode))
872                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
873
874         status = ocfs2_journal_access(handle,
875                                       alloc_inode,
876                                       group_bh,
877                                       journal_type);
878         if (status < 0) {
879                 mlog_errno(status);
880                 goto bail;
881         }
882
883         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
884
885         while(num_bits--)
886                 ocfs2_set_bit(bit_off++, bitmap);
887
888         status = ocfs2_journal_dirty(handle,
889                                      group_bh);
890         if (status < 0) {
891                 mlog_errno(status);
892                 goto bail;
893         }
894
895 bail:
896         mlog_exit(status);
897         return status;
898 }
899
900 /* find the one with the most empty bits */
901 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
902 {
903         u16 curr, best;
904
905         BUG_ON(!cl->cl_next_free_rec);
906
907         best = curr = 0;
908         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
909                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
910                     le32_to_cpu(cl->cl_recs[best].c_free))
911                         best = curr;
912                 curr++;
913         }
914
915         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
916         return best;
917 }
918
919 static int ocfs2_relink_block_group(handle_t *handle,
920                                     struct inode *alloc_inode,
921                                     struct buffer_head *fe_bh,
922                                     struct buffer_head *bg_bh,
923                                     struct buffer_head *prev_bg_bh,
924                                     u16 chain)
925 {
926         int status;
927         /* there is a really tiny chance the journal calls could fail,
928          * but we wouldn't want inconsistent blocks in *any* case. */
929         u64 fe_ptr, bg_ptr, prev_bg_ptr;
930         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
931         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
932         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
933
934         if (!OCFS2_IS_VALID_DINODE(fe)) {
935                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
936                 status = -EIO;
937                 goto out;
938         }
939         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
940                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
941                 status = -EIO;
942                 goto out;
943         }
944         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
945                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
946                 status = -EIO;
947                 goto out;
948         }
949
950         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
951              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
952              (unsigned long long)le64_to_cpu(bg->bg_blkno),
953              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
954
955         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
956         bg_ptr = le64_to_cpu(bg->bg_next_group);
957         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
958
959         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
960                                       OCFS2_JOURNAL_ACCESS_WRITE);
961         if (status < 0) {
962                 mlog_errno(status);
963                 goto out_rollback;
964         }
965
966         prev_bg->bg_next_group = bg->bg_next_group;
967
968         status = ocfs2_journal_dirty(handle, prev_bg_bh);
969         if (status < 0) {
970                 mlog_errno(status);
971                 goto out_rollback;
972         }
973
974         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
975                                       OCFS2_JOURNAL_ACCESS_WRITE);
976         if (status < 0) {
977                 mlog_errno(status);
978                 goto out_rollback;
979         }
980
981         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
982
983         status = ocfs2_journal_dirty(handle, bg_bh);
984         if (status < 0) {
985                 mlog_errno(status);
986                 goto out_rollback;
987         }
988
989         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
990                                       OCFS2_JOURNAL_ACCESS_WRITE);
991         if (status < 0) {
992                 mlog_errno(status);
993                 goto out_rollback;
994         }
995
996         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
997
998         status = ocfs2_journal_dirty(handle, fe_bh);
999         if (status < 0) {
1000                 mlog_errno(status);
1001                 goto out_rollback;
1002         }
1003
1004         status = 0;
1005 out_rollback:
1006         if (status < 0) {
1007                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
1008                 bg->bg_next_group = cpu_to_le64(bg_ptr);
1009                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
1010         }
1011 out:
1012         mlog_exit(status);
1013         return status;
1014 }
1015
1016 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
1017                                                      u32 wanted)
1018 {
1019         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
1020 }
1021
1022 /* return 0 on success, -ENOSPC to keep searching and any other < 0
1023  * value on error. */
1024 static int ocfs2_cluster_group_search(struct inode *inode,
1025                                       struct buffer_head *group_bh,
1026                                       u32 bits_wanted, u32 min_bits,
1027                                       u64 max_block,
1028                                       u16 *bit_off, u16 *bits_found)
1029 {
1030         int search = -ENOSPC;
1031         int ret;
1032         u64 blkoff;
1033         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
1034         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1035         u16 tmp_off, tmp_found;
1036         unsigned int max_bits, gd_cluster_off;
1037
1038         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1039
1040         if (gd->bg_free_bits_count) {
1041                 max_bits = le16_to_cpu(gd->bg_bits);
1042
1043                 /* Tail groups in cluster bitmaps which aren't cpg
1044                  * aligned are prone to partial extention by a failed
1045                  * fs resize. If the file system resize never got to
1046                  * update the dinode cluster count, then we don't want
1047                  * to trust any clusters past it, regardless of what
1048                  * the group descriptor says. */
1049                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
1050                                                           le64_to_cpu(gd->bg_blkno));
1051                 if ((gd_cluster_off + max_bits) >
1052                     OCFS2_I(inode)->ip_clusters) {
1053                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
1054                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
1055                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
1056                              le16_to_cpu(gd->bg_bits),
1057                              OCFS2_I(inode)->ip_clusters, max_bits);
1058                 }
1059
1060                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1061                                                         group_bh, bits_wanted,
1062                                                         max_bits,
1063                                                         &tmp_off, &tmp_found);
1064                 if (ret)
1065                         return ret;
1066
1067                 if (max_block) {
1068                         blkoff = ocfs2_clusters_to_blocks(inode->i_sb,
1069                                                           gd_cluster_off +
1070                                                           tmp_off + tmp_found);
1071                         mlog(0, "Checking %llu against %llu\n",
1072                              (unsigned long long)blkoff,
1073                              (unsigned long long)max_block);
1074                         if (blkoff > max_block)
1075                                 return -ENOSPC;
1076                 }
1077
1078                 /* ocfs2_block_group_find_clear_bits() might
1079                  * return success, but we still want to return
1080                  * -ENOSPC unless it found the minimum number
1081                  * of bits. */
1082                 if (min_bits <= tmp_found) {
1083                         *bit_off = tmp_off;
1084                         *bits_found = tmp_found;
1085                         search = 0; /* success */
1086                 } else if (tmp_found) {
1087                         /*
1088                          * Don't show bits which we'll be returning
1089                          * for allocation to the local alloc bitmap.
1090                          */
1091                         ocfs2_local_alloc_seen_free_bits(osb, tmp_found);
1092                 }
1093         }
1094
1095         return search;
1096 }
1097
1098 static int ocfs2_block_group_search(struct inode *inode,
1099                                     struct buffer_head *group_bh,
1100                                     u32 bits_wanted, u32 min_bits,
1101                                     u64 max_block,
1102                                     u16 *bit_off, u16 *bits_found)
1103 {
1104         int ret = -ENOSPC;
1105         u64 blkoff;
1106         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
1107
1108         BUG_ON(min_bits != 1);
1109         BUG_ON(ocfs2_is_cluster_bitmap(inode));
1110
1111         if (bg->bg_free_bits_count) {
1112                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
1113                                                         group_bh, bits_wanted,
1114                                                         le16_to_cpu(bg->bg_bits),
1115                                                         bit_off, bits_found);
1116                 if (!ret && max_block) {
1117                         blkoff = le64_to_cpu(bg->bg_blkno) + *bit_off +
1118                                 *bits_found;
1119                         mlog(0, "Checking %llu against %llu\n",
1120                              (unsigned long long)blkoff,
1121                              (unsigned long long)max_block);
1122                         if (blkoff > max_block)
1123                                 ret = -ENOSPC;
1124                 }
1125         }
1126
1127         return ret;
1128 }
1129
1130 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
1131                                        handle_t *handle,
1132                                        struct buffer_head *di_bh,
1133                                        u32 num_bits,
1134                                        u16 chain)
1135 {
1136         int ret;
1137         u32 tmp_used;
1138         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
1139         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
1140
1141         ret = ocfs2_journal_access(handle, inode, di_bh,
1142                                    OCFS2_JOURNAL_ACCESS_WRITE);
1143         if (ret < 0) {
1144                 mlog_errno(ret);
1145                 goto out;
1146         }
1147
1148         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1149         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1150         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1151
1152         ret = ocfs2_journal_dirty(handle, di_bh);
1153         if (ret < 0)
1154                 mlog_errno(ret);
1155
1156 out:
1157         return ret;
1158 }
1159
1160 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1161                                   handle_t *handle,
1162                                   u32 bits_wanted,
1163                                   u32 min_bits,
1164                                   u16 *bit_off,
1165                                   unsigned int *num_bits,
1166                                   u64 gd_blkno,
1167                                   u16 *bits_left)
1168 {
1169         int ret;
1170         u16 found;
1171         struct buffer_head *group_bh = NULL;
1172         struct ocfs2_group_desc *gd;
1173         struct inode *alloc_inode = ac->ac_inode;
1174
1175         ret = ocfs2_read_block(alloc_inode, gd_blkno, &group_bh);
1176         if (ret < 0) {
1177                 mlog_errno(ret);
1178                 return ret;
1179         }
1180
1181         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1182         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1183                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1184                 ret = -EIO;
1185                 goto out;
1186         }
1187
1188         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1189                                   ac->ac_max_block, bit_off, &found);
1190         if (ret < 0) {
1191                 if (ret != -ENOSPC)
1192                         mlog_errno(ret);
1193                 goto out;
1194         }
1195
1196         *num_bits = found;
1197
1198         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1199                                                *num_bits,
1200                                                le16_to_cpu(gd->bg_chain));
1201         if (ret < 0) {
1202                 mlog_errno(ret);
1203                 goto out;
1204         }
1205
1206         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1207                                          *bit_off, *num_bits);
1208         if (ret < 0)
1209                 mlog_errno(ret);
1210
1211         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1212
1213 out:
1214         brelse(group_bh);
1215
1216         return ret;
1217 }
1218
1219 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1220                               handle_t *handle,
1221                               u32 bits_wanted,
1222                               u32 min_bits,
1223                               u16 *bit_off,
1224                               unsigned int *num_bits,
1225                               u64 *bg_blkno,
1226                               u16 *bits_left)
1227 {
1228         int status;
1229         u16 chain, tmp_bits;
1230         u32 tmp_used;
1231         u64 next_group;
1232         struct inode *alloc_inode = ac->ac_inode;
1233         struct buffer_head *group_bh = NULL;
1234         struct buffer_head *prev_group_bh = NULL;
1235         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1236         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1237         struct ocfs2_group_desc *bg;
1238
1239         chain = ac->ac_chain;
1240         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1241              bits_wanted, chain,
1242              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1243
1244         status = ocfs2_read_block(alloc_inode,
1245                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1246                                   &group_bh);
1247         if (status < 0) {
1248                 mlog_errno(status);
1249                 goto bail;
1250         }
1251         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1252         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1253         if (status) {
1254                 mlog_errno(status);
1255                 goto bail;
1256         }
1257
1258         status = -ENOSPC;
1259         /* for now, the chain search is a bit simplistic. We just use
1260          * the 1st group with any empty bits. */
1261         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1262                                              bits_wanted, min_bits,
1263                                              ac->ac_max_block, bit_off,
1264                                              &tmp_bits)) == -ENOSPC) {
1265                 if (!bg->bg_next_group)
1266                         break;
1267
1268                 brelse(prev_group_bh);
1269                 prev_group_bh = NULL;
1270
1271                 next_group = le64_to_cpu(bg->bg_next_group);
1272                 prev_group_bh = group_bh;
1273                 group_bh = NULL;
1274                 status = ocfs2_read_block(alloc_inode,
1275                                           next_group, &group_bh);
1276                 if (status < 0) {
1277                         mlog_errno(status);
1278                         goto bail;
1279                 }
1280                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1281                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1282                 if (status) {
1283                         mlog_errno(status);
1284                         goto bail;
1285                 }
1286         }
1287         if (status < 0) {
1288                 if (status != -ENOSPC)
1289                         mlog_errno(status);
1290                 goto bail;
1291         }
1292
1293         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1294              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1295
1296         *num_bits = tmp_bits;
1297
1298         BUG_ON(*num_bits == 0);
1299
1300         /*
1301          * Keep track of previous block descriptor read. When
1302          * we find a target, if we have read more than X
1303          * number of descriptors, and the target is reasonably
1304          * empty, relink him to top of his chain.
1305          *
1306          * We've read 0 extra blocks and only send one more to
1307          * the transaction, yet the next guy to search has a
1308          * much easier time.
1309          *
1310          * Do this *after* figuring out how many bits we're taking out
1311          * of our target group.
1312          */
1313         if (ac->ac_allow_chain_relink &&
1314             (prev_group_bh) &&
1315             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1316                 status = ocfs2_relink_block_group(handle, alloc_inode,
1317                                                   ac->ac_bh, group_bh,
1318                                                   prev_group_bh, chain);
1319                 if (status < 0) {
1320                         mlog_errno(status);
1321                         goto bail;
1322                 }
1323         }
1324
1325         /* Ok, claim our bits now: set the info on dinode, chainlist
1326          * and then the group */
1327         status = ocfs2_journal_access(handle,
1328                                       alloc_inode,
1329                                       ac->ac_bh,
1330                                       OCFS2_JOURNAL_ACCESS_WRITE);
1331         if (status < 0) {
1332                 mlog_errno(status);
1333                 goto bail;
1334         }
1335
1336         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1337         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1338         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1339
1340         status = ocfs2_journal_dirty(handle,
1341                                      ac->ac_bh);
1342         if (status < 0) {
1343                 mlog_errno(status);
1344                 goto bail;
1345         }
1346
1347         status = ocfs2_block_group_set_bits(handle,
1348                                             alloc_inode,
1349                                             bg,
1350                                             group_bh,
1351                                             *bit_off,
1352                                             *num_bits);
1353         if (status < 0) {
1354                 mlog_errno(status);
1355                 goto bail;
1356         }
1357
1358         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1359              (unsigned long long)le64_to_cpu(fe->i_blkno));
1360
1361         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1362         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1363 bail:
1364         brelse(group_bh);
1365         brelse(prev_group_bh);
1366
1367         mlog_exit(status);
1368         return status;
1369 }
1370
1371 /* will give out up to bits_wanted contiguous bits. */
1372 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1373                                      struct ocfs2_alloc_context *ac,
1374                                      handle_t *handle,
1375                                      u32 bits_wanted,
1376                                      u32 min_bits,
1377                                      u16 *bit_off,
1378                                      unsigned int *num_bits,
1379                                      u64 *bg_blkno)
1380 {
1381         int status;
1382         u16 victim, i;
1383         u16 bits_left = 0;
1384         u64 hint_blkno = ac->ac_last_group;
1385         struct ocfs2_chain_list *cl;
1386         struct ocfs2_dinode *fe;
1387
1388         mlog_entry_void();
1389
1390         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1391         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1392         BUG_ON(!ac->ac_bh);
1393
1394         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1395         if (!OCFS2_IS_VALID_DINODE(fe)) {
1396                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1397                 status = -EIO;
1398                 goto bail;
1399         }
1400         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1401             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1402                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1403                             "bits but only %u total.",
1404                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1405                             le32_to_cpu(fe->id1.bitmap1.i_used),
1406                             le32_to_cpu(fe->id1.bitmap1.i_total));
1407                 status = -EIO;
1408                 goto bail;
1409         }
1410
1411         if (hint_blkno) {
1412                 /* Attempt to short-circuit the usual search mechanism
1413                  * by jumping straight to the most recently used
1414                  * allocation group. This helps us mantain some
1415                  * contiguousness across allocations. */
1416                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1417                                                 min_bits, bit_off, num_bits,
1418                                                 hint_blkno, &bits_left);
1419                 if (!status) {
1420                         /* Be careful to update *bg_blkno here as the
1421                          * caller is expecting it to be filled in, and
1422                          * ocfs2_search_one_group() won't do that for
1423                          * us. */
1424                         *bg_blkno = hint_blkno;
1425                         goto set_hint;
1426                 }
1427                 if (status < 0 && status != -ENOSPC) {
1428                         mlog_errno(status);
1429                         goto bail;
1430                 }
1431         }
1432
1433         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1434
1435         victim = ocfs2_find_victim_chain(cl);
1436         ac->ac_chain = victim;
1437         ac->ac_allow_chain_relink = 1;
1438
1439         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1440                                     num_bits, bg_blkno, &bits_left);
1441         if (!status)
1442                 goto set_hint;
1443         if (status < 0 && status != -ENOSPC) {
1444                 mlog_errno(status);
1445                 goto bail;
1446         }
1447
1448         mlog(0, "Search of victim chain %u came up with nothing, "
1449              "trying all chains now.\n", victim);
1450
1451         /* If we didn't pick a good victim, then just default to
1452          * searching each chain in order. Don't allow chain relinking
1453          * because we only calculate enough journal credits for one
1454          * relink per alloc. */
1455         ac->ac_allow_chain_relink = 0;
1456         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1457                 if (i == victim)
1458                         continue;
1459                 if (!cl->cl_recs[i].c_free)
1460                         continue;
1461
1462                 ac->ac_chain = i;
1463                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1464                                             bit_off, num_bits, bg_blkno,
1465                                             &bits_left);
1466                 if (!status)
1467                         break;
1468                 if (status < 0 && status != -ENOSPC) {
1469                         mlog_errno(status);
1470                         goto bail;
1471                 }
1472         }
1473
1474 set_hint:
1475         if (status != -ENOSPC) {
1476                 /* If the next search of this group is not likely to
1477                  * yield a suitable extent, then we reset the last
1478                  * group hint so as to not waste a disk read */
1479                 if (bits_left < min_bits)
1480                         ac->ac_last_group = 0;
1481                 else
1482                         ac->ac_last_group = *bg_blkno;
1483         }
1484
1485 bail:
1486         mlog_exit(status);
1487         return status;
1488 }
1489
1490 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1491                          handle_t *handle,
1492                          struct ocfs2_alloc_context *ac,
1493                          u32 bits_wanted,
1494                          u16 *suballoc_bit_start,
1495                          unsigned int *num_bits,
1496                          u64 *blkno_start)
1497 {
1498         int status;
1499         u64 bg_blkno;
1500
1501         BUG_ON(!ac);
1502         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1503         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1504
1505         status = ocfs2_claim_suballoc_bits(osb,
1506                                            ac,
1507                                            handle,
1508                                            bits_wanted,
1509                                            1,
1510                                            suballoc_bit_start,
1511                                            num_bits,
1512                                            &bg_blkno);
1513         if (status < 0) {
1514                 mlog_errno(status);
1515                 goto bail;
1516         }
1517         atomic_inc(&osb->alloc_stats.bg_allocs);
1518
1519         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1520         ac->ac_bits_given += (*num_bits);
1521         status = 0;
1522 bail:
1523         mlog_exit(status);
1524         return status;
1525 }
1526
1527 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1528                           handle_t *handle,
1529                           struct ocfs2_alloc_context *ac,
1530                           u16 *suballoc_bit,
1531                           u64 *fe_blkno)
1532 {
1533         int status;
1534         unsigned int num_bits;
1535         u64 bg_blkno;
1536
1537         mlog_entry_void();
1538
1539         BUG_ON(!ac);
1540         BUG_ON(ac->ac_bits_given != 0);
1541         BUG_ON(ac->ac_bits_wanted != 1);
1542         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1543
1544         status = ocfs2_claim_suballoc_bits(osb,
1545                                            ac,
1546                                            handle,
1547                                            1,
1548                                            1,
1549                                            suballoc_bit,
1550                                            &num_bits,
1551                                            &bg_blkno);
1552         if (status < 0) {
1553                 mlog_errno(status);
1554                 goto bail;
1555         }
1556         atomic_inc(&osb->alloc_stats.bg_allocs);
1557
1558         BUG_ON(num_bits != 1);
1559
1560         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1561         ac->ac_bits_given++;
1562         status = 0;
1563 bail:
1564         mlog_exit(status);
1565         return status;
1566 }
1567
1568 /* translate a group desc. blkno and it's bitmap offset into
1569  * disk cluster offset. */
1570 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1571                                                    u64 bg_blkno,
1572                                                    u16 bg_bit_off)
1573 {
1574         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1575         u32 cluster = 0;
1576
1577         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1578
1579         if (bg_blkno != osb->first_cluster_group_blkno)
1580                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1581         cluster += (u32) bg_bit_off;
1582         return cluster;
1583 }
1584
1585 /* given a cluster offset, calculate which block group it belongs to
1586  * and return that block offset. */
1587 u64 ocfs2_which_cluster_group(struct inode *inode, u32 cluster)
1588 {
1589         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1590         u32 group_no;
1591
1592         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1593
1594         group_no = cluster / osb->bitmap_cpg;
1595         if (!group_no)
1596                 return osb->first_cluster_group_blkno;
1597         return ocfs2_clusters_to_blocks(inode->i_sb,
1598                                         group_no * osb->bitmap_cpg);
1599 }
1600
1601 /* given the block number of a cluster start, calculate which cluster
1602  * group and descriptor bitmap offset that corresponds to. */
1603 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1604                                                 u64 data_blkno,
1605                                                 u64 *bg_blkno,
1606                                                 u16 *bg_bit_off)
1607 {
1608         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1609         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1610
1611         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1612
1613         *bg_blkno = ocfs2_which_cluster_group(inode,
1614                                               data_cluster);
1615
1616         if (*bg_blkno == osb->first_cluster_group_blkno)
1617                 *bg_bit_off = (u16) data_cluster;
1618         else
1619                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1620                                                              data_blkno - *bg_blkno);
1621 }
1622
1623 /*
1624  * min_bits - minimum contiguous chunk from this total allocation we
1625  * can handle. set to what we asked for originally for a full
1626  * contig. allocation, set to '1' to indicate we can deal with extents
1627  * of any size.
1628  */
1629 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1630                            handle_t *handle,
1631                            struct ocfs2_alloc_context *ac,
1632                            u32 min_clusters,
1633                            u32 max_clusters,
1634                            u32 *cluster_start,
1635                            u32 *num_clusters)
1636 {
1637         int status;
1638         unsigned int bits_wanted = max_clusters;
1639         u64 bg_blkno = 0;
1640         u16 bg_bit_off;
1641
1642         mlog_entry_void();
1643
1644         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1645
1646         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1647                && ac->ac_which != OCFS2_AC_USE_MAIN);
1648
1649         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1650                 status = ocfs2_claim_local_alloc_bits(osb,
1651                                                       handle,
1652                                                       ac,
1653                                                       bits_wanted,
1654                                                       cluster_start,
1655                                                       num_clusters);
1656                 if (!status)
1657                         atomic_inc(&osb->alloc_stats.local_data);
1658         } else {
1659                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1660                         /* The only paths asking for contiguousness
1661                          * should know about this already. */
1662                         mlog(ML_ERROR, "minimum allocation requested %u exceeds "
1663                              "group bitmap size %u!\n", min_clusters,
1664                              osb->bitmap_cpg);
1665                         status = -ENOSPC;
1666                         goto bail;
1667                 }
1668                 /* clamp the current request down to a realistic size. */
1669                 if (bits_wanted > (osb->bitmap_cpg - 1))
1670                         bits_wanted = osb->bitmap_cpg - 1;
1671
1672                 status = ocfs2_claim_suballoc_bits(osb,
1673                                                    ac,
1674                                                    handle,
1675                                                    bits_wanted,
1676                                                    min_clusters,
1677                                                    &bg_bit_off,
1678                                                    num_clusters,
1679                                                    &bg_blkno);
1680                 if (!status) {
1681                         *cluster_start =
1682                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1683                                                                  bg_blkno,
1684                                                                  bg_bit_off);
1685                         atomic_inc(&osb->alloc_stats.bitmap_data);
1686                 }
1687         }
1688         if (status < 0) {
1689                 if (status != -ENOSPC)
1690                         mlog_errno(status);
1691                 goto bail;
1692         }
1693
1694         ac->ac_bits_given += *num_clusters;
1695
1696 bail:
1697         mlog_exit(status);
1698         return status;
1699 }
1700
1701 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1702                          handle_t *handle,
1703                          struct ocfs2_alloc_context *ac,
1704                          u32 min_clusters,
1705                          u32 *cluster_start,
1706                          u32 *num_clusters)
1707 {
1708         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1709
1710         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1711                                       bits_wanted, cluster_start, num_clusters);
1712 }
1713
1714 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1715                                                struct inode *alloc_inode,
1716                                                struct ocfs2_group_desc *bg,
1717                                                struct buffer_head *group_bh,
1718                                                unsigned int bit_off,
1719                                                unsigned int num_bits)
1720 {
1721         int status;
1722         unsigned int tmp;
1723         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1724         struct ocfs2_group_desc *undo_bg = NULL;
1725
1726         mlog_entry_void();
1727
1728         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1729                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1730                 status = -EIO;
1731                 goto bail;
1732         }
1733
1734         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1735
1736         if (ocfs2_is_cluster_bitmap(alloc_inode))
1737                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1738
1739         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1740                                       journal_type);
1741         if (status < 0) {
1742                 mlog_errno(status);
1743                 goto bail;
1744         }
1745
1746         if (ocfs2_is_cluster_bitmap(alloc_inode))
1747                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1748
1749         tmp = num_bits;
1750         while(tmp--) {
1751                 ocfs2_clear_bit((bit_off + tmp),
1752                                 (unsigned long *) bg->bg_bitmap);
1753                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1754                         ocfs2_set_bit(bit_off + tmp,
1755                                       (unsigned long *) undo_bg->bg_bitmap);
1756         }
1757         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1758
1759         status = ocfs2_journal_dirty(handle, group_bh);
1760         if (status < 0)
1761                 mlog_errno(status);
1762 bail:
1763         return status;
1764 }
1765
1766 /*
1767  * expects the suballoc inode to already be locked.
1768  */
1769 int ocfs2_free_suballoc_bits(handle_t *handle,
1770                              struct inode *alloc_inode,
1771                              struct buffer_head *alloc_bh,
1772                              unsigned int start_bit,
1773                              u64 bg_blkno,
1774                              unsigned int count)
1775 {
1776         int status = 0;
1777         u32 tmp_used;
1778         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1779         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1780         struct buffer_head *group_bh = NULL;
1781         struct ocfs2_group_desc *group;
1782
1783         mlog_entry_void();
1784
1785         if (!OCFS2_IS_VALID_DINODE(fe)) {
1786                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1787                 status = -EIO;
1788                 goto bail;
1789         }
1790         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1791
1792         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1793              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1794              (unsigned long long)bg_blkno, start_bit);
1795
1796         status = ocfs2_read_block(alloc_inode, bg_blkno, &group_bh);
1797         if (status < 0) {
1798                 mlog_errno(status);
1799                 goto bail;
1800         }
1801
1802         group = (struct ocfs2_group_desc *) group_bh->b_data;
1803         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1804         if (status) {
1805                 mlog_errno(status);
1806                 goto bail;
1807         }
1808         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1809
1810         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1811                                               group, group_bh,
1812                                               start_bit, count);
1813         if (status < 0) {
1814                 mlog_errno(status);
1815                 goto bail;
1816         }
1817
1818         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1819                                       OCFS2_JOURNAL_ACCESS_WRITE);
1820         if (status < 0) {
1821                 mlog_errno(status);
1822                 goto bail;
1823         }
1824
1825         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1826                      count);
1827         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1828         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1829
1830         status = ocfs2_journal_dirty(handle, alloc_bh);
1831         if (status < 0) {
1832                 mlog_errno(status);
1833                 goto bail;
1834         }
1835
1836 bail:
1837         brelse(group_bh);
1838
1839         mlog_exit(status);
1840         return status;
1841 }
1842
1843 int ocfs2_free_dinode(handle_t *handle,
1844                       struct inode *inode_alloc_inode,
1845                       struct buffer_head *inode_alloc_bh,
1846                       struct ocfs2_dinode *di)
1847 {
1848         u64 blk = le64_to_cpu(di->i_blkno);
1849         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1850         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1851
1852         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1853                                         inode_alloc_bh, bit, bg_blkno, 1);
1854 }
1855
1856 int ocfs2_free_clusters(handle_t *handle,
1857                        struct inode *bitmap_inode,
1858                        struct buffer_head *bitmap_bh,
1859                        u64 start_blk,
1860                        unsigned int num_clusters)
1861 {
1862         int status;
1863         u16 bg_start_bit;
1864         u64 bg_blkno;
1865         struct ocfs2_dinode *fe;
1866
1867         /* You can't ever have a contiguous set of clusters
1868          * bigger than a block group bitmap so we never have to worry
1869          * about looping on them. */
1870
1871         mlog_entry_void();
1872
1873         /* This is expensive. We can safely remove once this stuff has
1874          * gotten tested really well. */
1875         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1876
1877         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1878
1879         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1880                                      &bg_start_bit);
1881
1882         mlog(0, "want to free %u clusters starting at block %llu\n",
1883              num_clusters, (unsigned long long)start_blk);
1884         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1885              (unsigned long long)bg_blkno, bg_start_bit);
1886
1887         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1888                                           bg_start_bit, bg_blkno,
1889                                           num_clusters);
1890         if (status < 0) {
1891                 mlog_errno(status);
1892                 goto out;
1893         }
1894
1895         ocfs2_local_alloc_seen_free_bits(OCFS2_SB(bitmap_inode->i_sb),
1896                                          num_clusters);
1897
1898 out:
1899         mlog_exit(status);
1900         return status;
1901 }
1902
1903 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1904 {
1905         printk("Block Group:\n");
1906         printk("bg_signature:       %s\n", bg->bg_signature);
1907         printk("bg_size:            %u\n", bg->bg_size);
1908         printk("bg_bits:            %u\n", bg->bg_bits);
1909         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1910         printk("bg_chain:           %u\n", bg->bg_chain);
1911         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1912         printk("bg_next_group:      %llu\n",
1913                (unsigned long long)bg->bg_next_group);
1914         printk("bg_parent_dinode:   %llu\n",
1915                (unsigned long long)bg->bg_parent_dinode);
1916         printk("bg_blkno:           %llu\n",
1917                (unsigned long long)bg->bg_blkno);
1918 }
1919
1920 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1921 {
1922         int i;
1923
1924         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1925         printk("i_signature:                  %s\n", fe->i_signature);
1926         printk("i_size:                       %llu\n",
1927                (unsigned long long)fe->i_size);
1928         printk("i_clusters:                   %u\n", fe->i_clusters);
1929         printk("i_generation:                 %u\n",
1930                le32_to_cpu(fe->i_generation));
1931         printk("id1.bitmap1.i_used:           %u\n",
1932                le32_to_cpu(fe->id1.bitmap1.i_used));
1933         printk("id1.bitmap1.i_total:          %u\n",
1934                le32_to_cpu(fe->id1.bitmap1.i_total));
1935         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1936         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1937         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1938         printk("id2.i_chain.cl_next_free_rec: %u\n",
1939                fe->id2.i_chain.cl_next_free_rec);
1940         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1941                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1942                        fe->id2.i_chain.cl_recs[i].c_free);
1943                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1944                        fe->id2.i_chain.cl_recs[i].c_total);
1945                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1946                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1947         }
1948 }
1949
1950 /*
1951  * For a given allocation, determine which allocators will need to be
1952  * accessed, and lock them, reserving the appropriate number of bits.
1953  *
1954  * Sparse file systems call this from ocfs2_write_begin_nolock()
1955  * and ocfs2_allocate_unwritten_extents().
1956  *
1957  * File systems which don't support holes call this from
1958  * ocfs2_extend_allocation().
1959  */
1960 int ocfs2_lock_allocators(struct inode *inode,
1961                           struct ocfs2_extent_tree *et,
1962                           u32 clusters_to_add, u32 extents_to_split,
1963                           struct ocfs2_alloc_context **data_ac,
1964                           struct ocfs2_alloc_context **meta_ac)
1965 {
1966         int ret = 0, num_free_extents;
1967         unsigned int max_recs_needed = clusters_to_add + 2 * extents_to_split;
1968         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1969
1970         *meta_ac = NULL;
1971         if (data_ac)
1972                 *data_ac = NULL;
1973
1974         BUG_ON(clusters_to_add != 0 && data_ac == NULL);
1975
1976         num_free_extents = ocfs2_num_free_extents(osb, inode, et);
1977         if (num_free_extents < 0) {
1978                 ret = num_free_extents;
1979                 mlog_errno(ret);
1980                 goto out;
1981         }
1982
1983         /*
1984          * Sparse allocation file systems need to be more conservative
1985          * with reserving room for expansion - the actual allocation
1986          * happens while we've got a journal handle open so re-taking
1987          * a cluster lock (because we ran out of room for another
1988          * extent) will violate ordering rules.
1989          *
1990          * Most of the time we'll only be seeing this 1 cluster at a time
1991          * anyway.
1992          *
1993          * Always lock for any unwritten extents - we might want to
1994          * add blocks during a split.
1995          */
1996         if (!num_free_extents ||
1997             (ocfs2_sparse_alloc(osb) && num_free_extents < max_recs_needed)) {
1998                 ret = ocfs2_reserve_new_metadata(osb, et->et_root_el, meta_ac);
1999                 if (ret < 0) {
2000                         if (ret != -ENOSPC)
2001                                 mlog_errno(ret);
2002                         goto out;
2003                 }
2004         }
2005
2006         if (clusters_to_add == 0)
2007                 goto out;
2008
2009         ret = ocfs2_reserve_clusters(osb, clusters_to_add, data_ac);
2010         if (ret < 0) {
2011                 if (ret != -ENOSPC)
2012                         mlog_errno(ret);
2013                 goto out;
2014         }
2015
2016 out:
2017         if (ret) {
2018                 if (*meta_ac) {
2019                         ocfs2_free_alloc_context(*meta_ac);
2020                         *meta_ac = NULL;
2021                 }
2022
2023                 /*
2024                  * We cannot have an error and a non null *data_ac.
2025                  */
2026         }
2027
2028         return ret;
2029 }