ocfs2: don't use MLF* in the file system
[linux-2.6.git] / 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 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg);
50 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe);
51 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl);
52 static int ocfs2_block_group_fill(struct ocfs2_journal_handle *handle,
53                                   struct inode *alloc_inode,
54                                   struct buffer_head *bg_bh,
55                                   u64 group_blkno,
56                                   u16 my_chain,
57                                   struct ocfs2_chain_list *cl);
58 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
59                                    struct inode *alloc_inode,
60                                    struct buffer_head *bh);
61
62 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
63                                        struct ocfs2_alloc_context *ac);
64
65 static int ocfs2_cluster_group_search(struct inode *inode,
66                                       struct buffer_head *group_bh,
67                                       u32 bits_wanted, u32 min_bits,
68                                       u16 *bit_off, u16 *bits_found);
69 static int ocfs2_block_group_search(struct inode *inode,
70                                     struct buffer_head *group_bh,
71                                     u32 bits_wanted, u32 min_bits,
72                                     u16 *bit_off, u16 *bits_found);
73 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
74                               u32 bits_wanted,
75                               u32 min_bits,
76                               u16 *bit_off,
77                               unsigned int *num_bits,
78                               u64 *bg_blkno);
79 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
80                                      struct ocfs2_alloc_context *ac,
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 int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
89                                              struct buffer_head *bg_bh,
90                                              unsigned int bits_wanted,
91                                              u16 *bit_off,
92                                              u16 *bits_found);
93 static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
94                                              struct inode *alloc_inode,
95                                              struct ocfs2_group_desc *bg,
96                                              struct buffer_head *group_bh,
97                                              unsigned int bit_off,
98                                              unsigned int num_bits);
99 static inline int ocfs2_block_group_clear_bits(struct ocfs2_journal_handle *handle,
100                                                struct inode *alloc_inode,
101                                                struct ocfs2_group_desc *bg,
102                                                struct buffer_head *group_bh,
103                                                unsigned int bit_off,
104                                                unsigned int num_bits);
105
106 static int ocfs2_relink_block_group(struct ocfs2_journal_handle *handle,
107                                     struct inode *alloc_inode,
108                                     struct buffer_head *fe_bh,
109                                     struct buffer_head *bg_bh,
110                                     struct buffer_head *prev_bg_bh,
111                                     u16 chain);
112 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
113                                                      u32 wanted);
114 static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
115                                     struct inode *alloc_inode,
116                                     struct buffer_head *alloc_bh,
117                                     unsigned int start_bit,
118                                     u64 bg_blkno,
119                                     unsigned int count);
120 static inline u64 ocfs2_which_suballoc_group(u64 block,
121                                              unsigned int bit);
122 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
123                                                    u64 bg_blkno,
124                                                    u16 bg_bit_off);
125 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
126                                             u32 cluster);
127 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
128                                                 u64 data_blkno,
129                                                 u64 *bg_blkno,
130                                                 u16 *bg_bit_off);
131
132 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
133 {
134         if (ac->ac_inode)
135                 iput(ac->ac_inode);
136         if (ac->ac_bh)
137                 brelse(ac->ac_bh);
138         kfree(ac);
139 }
140
141 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
142 {
143         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
144 }
145
146 static int ocfs2_block_group_fill(struct ocfs2_journal_handle *handle,
147                                   struct inode *alloc_inode,
148                                   struct buffer_head *bg_bh,
149                                   u64 group_blkno,
150                                   u16 my_chain,
151                                   struct ocfs2_chain_list *cl)
152 {
153         int status = 0;
154         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
155         struct super_block * sb = alloc_inode->i_sb;
156
157         mlog_entry_void();
158
159         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
160                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
161                             "b_blocknr (%llu)",
162                             (unsigned long long)group_blkno,
163                             (unsigned long long) bg_bh->b_blocknr);
164                 status = -EIO;
165                 goto bail;
166         }
167
168         status = ocfs2_journal_access(handle,
169                                       alloc_inode,
170                                       bg_bh,
171                                       OCFS2_JOURNAL_ACCESS_CREATE);
172         if (status < 0) {
173                 mlog_errno(status);
174                 goto bail;
175         }
176
177         memset(bg, 0, sb->s_blocksize);
178         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
179         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
180         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
181         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
182         bg->bg_chain = cpu_to_le16(my_chain);
183         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
184         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
185         bg->bg_blkno = cpu_to_le64(group_blkno);
186         /* set the 1st bit in the bitmap to account for the descriptor block */
187         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
188         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
189
190         status = ocfs2_journal_dirty(handle, bg_bh);
191         if (status < 0)
192                 mlog_errno(status);
193
194         /* There is no need to zero out or otherwise initialize the
195          * other blocks in a group - All valid FS metadata in a block
196          * group stores the superblock fs_generation value at
197          * allocation time. */
198
199 bail:
200         mlog_exit(status);
201         return status;
202 }
203
204 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
205 {
206         u16 curr, best;
207
208         best = curr = 0;
209         while (curr < le16_to_cpu(cl->cl_count)) {
210                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
211                     le32_to_cpu(cl->cl_recs[curr].c_total))
212                         best = curr;
213                 curr++;
214         }
215         return best;
216 }
217
218 /*
219  * We expect the block group allocator to already be locked.
220  */
221 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
222                                    struct inode *alloc_inode,
223                                    struct buffer_head *bh)
224 {
225         int status, credits;
226         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
227         struct ocfs2_chain_list *cl;
228         struct ocfs2_alloc_context *ac = NULL;
229         struct ocfs2_journal_handle *handle = NULL;
230         u32 bit_off, num_bits;
231         u16 alloc_rec;
232         u64 bg_blkno;
233         struct buffer_head *bg_bh = NULL;
234         struct ocfs2_group_desc *bg;
235
236         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
237
238         mlog_entry_void();
239
240         handle = ocfs2_alloc_handle(osb);
241         if (!handle) {
242                 status = -ENOMEM;
243                 mlog_errno(status);
244                 goto bail;
245         }
246
247         cl = &fe->id2.i_chain;
248         status = ocfs2_reserve_clusters(osb,
249                                         handle,
250                                         le16_to_cpu(cl->cl_cpg),
251                                         &ac);
252         if (status < 0) {
253                 if (status != -ENOSPC)
254                         mlog_errno(status);
255                 goto bail;
256         }
257
258         credits = ocfs2_calc_group_alloc_credits(osb->sb,
259                                                  le16_to_cpu(cl->cl_cpg));
260         handle = ocfs2_start_trans(osb, handle, credits);
261         if (IS_ERR(handle)) {
262                 status = PTR_ERR(handle);
263                 handle = NULL;
264                 mlog_errno(status);
265                 goto bail;
266         }
267
268         status = ocfs2_claim_clusters(osb,
269                                       handle,
270                                       ac,
271                                       le16_to_cpu(cl->cl_cpg),
272                                       &bit_off,
273                                       &num_bits);
274         if (status < 0) {
275                 if (status != -ENOSPC)
276                         mlog_errno(status);
277                 goto bail;
278         }
279
280         alloc_rec = ocfs2_find_smallest_chain(cl);
281
282         /* setup the group */
283         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
284         mlog(0, "new descriptor, record %u, at block %llu\n",
285              alloc_rec, (unsigned long long)bg_blkno);
286
287         bg_bh = sb_getblk(osb->sb, bg_blkno);
288         if (!bg_bh) {
289                 status = -EIO;
290                 mlog_errno(status);
291                 goto bail;
292         }
293         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
294
295         status = ocfs2_block_group_fill(handle,
296                                         alloc_inode,
297                                         bg_bh,
298                                         bg_blkno,
299                                         alloc_rec,
300                                         cl);
301         if (status < 0) {
302                 mlog_errno(status);
303                 goto bail;
304         }
305
306         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
307
308         status = ocfs2_journal_access(handle, alloc_inode,
309                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
310         if (status < 0) {
311                 mlog_errno(status);
312                 goto bail;
313         }
314
315         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
316                      le16_to_cpu(bg->bg_free_bits_count));
317         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
318         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
319         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
320                 le16_add_cpu(&cl->cl_next_free_rec, 1);
321
322         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
323                                         le16_to_cpu(bg->bg_free_bits_count));
324         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
325         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
326
327         status = ocfs2_journal_dirty(handle, bh);
328         if (status < 0) {
329                 mlog_errno(status);
330                 goto bail;
331         }
332
333         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
334         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
335         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
336                                              le32_to_cpu(fe->i_clusters)));
337         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
338         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
339         alloc_inode->i_blocks =
340                 ocfs2_align_bytes_to_sectors(i_size_read(alloc_inode));
341
342         status = 0;
343 bail:
344         if (handle)
345                 ocfs2_commit_trans(handle);
346
347         if (ac)
348                 ocfs2_free_alloc_context(ac);
349
350         if (bg_bh)
351                 brelse(bg_bh);
352
353         mlog_exit(status);
354         return status;
355 }
356
357 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
358                                        struct ocfs2_alloc_context *ac)
359 {
360         int status;
361         u32 bits_wanted = ac->ac_bits_wanted;
362         struct inode *alloc_inode = ac->ac_inode;
363         struct buffer_head *bh = NULL;
364         struct ocfs2_journal_handle *handle = ac->ac_handle;
365         struct ocfs2_dinode *fe;
366         u32 free_bits;
367
368         mlog_entry_void();
369
370         BUG_ON(handle->flags & OCFS2_HANDLE_STARTED);
371
372         ocfs2_handle_add_inode(handle, alloc_inode);
373         status = ocfs2_meta_lock(alloc_inode, handle, &bh, 1);
374         if (status < 0) {
375                 mlog_errno(status);
376                 goto bail;
377         }
378
379         fe = (struct ocfs2_dinode *) bh->b_data;
380         if (!OCFS2_IS_VALID_DINODE(fe)) {
381                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
382                 status = -EIO;
383                 goto bail;
384         }
385         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
386                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
387                             (unsigned long long)le64_to_cpu(fe->i_blkno));
388                 status = -EIO;
389                 goto bail;
390         }
391
392         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
393                 le32_to_cpu(fe->id1.bitmap1.i_used);
394
395         if (bits_wanted > free_bits) {
396                 /* cluster bitmap never grows */
397                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
398                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
399                              bits_wanted, free_bits);
400                         status = -ENOSPC;
401                         goto bail;
402                 }
403
404                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
405                 if (status < 0) {
406                         if (status != -ENOSPC)
407                                 mlog_errno(status);
408                         goto bail;
409                 }
410                 atomic_inc(&osb->alloc_stats.bg_extends);
411
412                 /* You should never ask for this much metadata */
413                 BUG_ON(bits_wanted >
414                        (le32_to_cpu(fe->id1.bitmap1.i_total)
415                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
416         }
417
418         get_bh(bh);
419         ac->ac_bh = bh;
420 bail:
421         if (bh)
422                 brelse(bh);
423
424         mlog_exit(status);
425         return status;
426 }
427
428 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
429                                struct ocfs2_journal_handle *handle,
430                                struct ocfs2_dinode *fe,
431                                struct ocfs2_alloc_context **ac)
432 {
433         int status;
434         struct inode *alloc_inode = NULL;
435
436         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
437         if (!(*ac)) {
438                 status = -ENOMEM;
439                 mlog_errno(status);
440                 goto bail;
441         }
442
443         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
444         (*ac)->ac_handle = handle;
445         (*ac)->ac_which = OCFS2_AC_USE_META;
446
447 #ifndef OCFS2_USE_ALL_METADATA_SUBALLOCATORS
448         alloc_inode = ocfs2_get_system_file_inode(osb,
449                                                   EXTENT_ALLOC_SYSTEM_INODE,
450                                                   0);
451 #else
452         alloc_inode = ocfs2_get_system_file_inode(osb,
453                                                   EXTENT_ALLOC_SYSTEM_INODE,
454                                                   osb->slot_num);
455 #endif
456         if (!alloc_inode) {
457                 status = -ENOMEM;
458                 mlog_errno(status);
459                 goto bail;
460         }
461
462         (*ac)->ac_inode = igrab(alloc_inode);
463         (*ac)->ac_group_search = ocfs2_block_group_search;
464
465         status = ocfs2_reserve_suballoc_bits(osb, (*ac));
466         if (status < 0) {
467                 if (status != -ENOSPC)
468                         mlog_errno(status);
469                 goto bail;
470         }
471
472         status = 0;
473 bail:
474         if ((status < 0) && *ac) {
475                 ocfs2_free_alloc_context(*ac);
476                 *ac = NULL;
477         }
478
479         if (alloc_inode)
480                 iput(alloc_inode);
481
482         mlog_exit(status);
483         return status;
484 }
485
486 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
487                             struct ocfs2_journal_handle *handle,
488                             struct ocfs2_alloc_context **ac)
489 {
490         int status;
491         struct inode *alloc_inode = NULL;
492
493         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
494         if (!(*ac)) {
495                 status = -ENOMEM;
496                 mlog_errno(status);
497                 goto bail;
498         }
499
500         (*ac)->ac_bits_wanted = 1;
501         (*ac)->ac_handle = handle;
502         (*ac)->ac_which = OCFS2_AC_USE_INODE;
503
504         alloc_inode = ocfs2_get_system_file_inode(osb,
505                                                   INODE_ALLOC_SYSTEM_INODE,
506                                                   osb->slot_num);
507         if (!alloc_inode) {
508                 status = -ENOMEM;
509                 mlog_errno(status);
510                 goto bail;
511         }
512
513         (*ac)->ac_inode = igrab(alloc_inode);
514         (*ac)->ac_group_search = ocfs2_block_group_search;
515
516         status = ocfs2_reserve_suballoc_bits(osb, *ac);
517         if (status < 0) {
518                 if (status != -ENOSPC)
519                         mlog_errno(status);
520                 goto bail;
521         }
522
523         status = 0;
524 bail:
525         if ((status < 0) && *ac) {
526                 ocfs2_free_alloc_context(*ac);
527                 *ac = NULL;
528         }
529
530         if (alloc_inode)
531                 iput(alloc_inode);
532
533         mlog_exit(status);
534         return status;
535 }
536
537 /* local alloc code has to do the same thing, so rather than do this
538  * twice.. */
539 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
540                                       struct ocfs2_alloc_context *ac)
541 {
542         int status;
543
544         ac->ac_inode = ocfs2_get_system_file_inode(osb,
545                                                    GLOBAL_BITMAP_SYSTEM_INODE,
546                                                    OCFS2_INVALID_SLOT);
547         if (!ac->ac_inode) {
548                 status = -EINVAL;
549                 mlog(ML_ERROR, "Could not get bitmap inode!\n");
550                 goto bail;
551         }
552         ac->ac_which = OCFS2_AC_USE_MAIN;
553         ac->ac_group_search = ocfs2_cluster_group_search;
554
555         status = ocfs2_reserve_suballoc_bits(osb, ac);
556         if (status < 0 && status != -ENOSPC)
557                 mlog_errno(status);
558 bail:
559         return status;
560 }
561
562 /* Callers don't need to care which bitmap (local alloc or main) to
563  * use so we figure it out for them, but unfortunately this clutters
564  * things a bit. */
565 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
566                            struct ocfs2_journal_handle *handle,
567                            u32 bits_wanted,
568                            struct ocfs2_alloc_context **ac)
569 {
570         int status;
571
572         mlog_entry_void();
573
574         BUG_ON(!handle);
575
576         *ac = kcalloc(1, sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
577         if (!(*ac)) {
578                 status = -ENOMEM;
579                 mlog_errno(status);
580                 goto bail;
581         }
582
583         (*ac)->ac_bits_wanted = bits_wanted;
584         (*ac)->ac_handle = handle;
585
586         status = -ENOSPC;
587         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
588                 status = ocfs2_reserve_local_alloc_bits(osb,
589                                                         handle,
590                                                         bits_wanted,
591                                                         *ac);
592                 if ((status < 0) && (status != -ENOSPC)) {
593                         mlog_errno(status);
594                         goto bail;
595                 } else if (status == -ENOSPC) {
596                         /* reserve_local_bits will return enospc with
597                          * the local alloc inode still locked, so we
598                          * can change this safely here. */
599                         mlog(0, "Disabling local alloc\n");
600                         /* We set to OCFS2_LA_DISABLED so that umount
601                          * can clean up what's left of the local
602                          * allocation */
603                         osb->local_alloc_state = OCFS2_LA_DISABLED;
604                 }
605         }
606
607         if (status == -ENOSPC) {
608                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
609                 if (status < 0) {
610                         if (status != -ENOSPC)
611                                 mlog_errno(status);
612                         goto bail;
613                 }
614         }
615
616         status = 0;
617 bail:
618         if ((status < 0) && *ac) {
619                 ocfs2_free_alloc_context(*ac);
620                 *ac = NULL;
621         }
622
623         mlog_exit(status);
624         return status;
625 }
626
627 /*
628  * More or less lifted from ext3. I'll leave their description below:
629  *
630  * "For ext3 allocations, we must not reuse any blocks which are
631  * allocated in the bitmap buffer's "last committed data" copy.  This
632  * prevents deletes from freeing up the page for reuse until we have
633  * committed the delete transaction.
634  *
635  * If we didn't do this, then deleting something and reallocating it as
636  * data would allow the old block to be overwritten before the
637  * transaction committed (because we force data to disk before commit).
638  * This would lead to corruption if we crashed between overwriting the
639  * data and committing the delete.
640  *
641  * @@@ We may want to make this allocation behaviour conditional on
642  * data-writes at some point, and disable it for metadata allocations or
643  * sync-data inodes."
644  *
645  * Note: OCFS2 already does this differently for metadata vs data
646  * allocations, as those bitmaps are seperate and undo access is never
647  * called on a metadata group descriptor.
648  */
649 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
650                                          int nr)
651 {
652         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
653
654         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
655                 return 0;
656         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
657                 return 1;
658
659         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
660         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
661 }
662
663 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
664                                              struct buffer_head *bg_bh,
665                                              unsigned int bits_wanted,
666                                              u16 *bit_off,
667                                              u16 *bits_found)
668 {
669         void *bitmap;
670         u16 best_offset, best_size;
671         int offset, start, found, status = 0;
672         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
673
674         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
675                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
676                 return -EIO;
677         }
678
679         found = start = best_offset = best_size = 0;
680         bitmap = bg->bg_bitmap;
681
682         while((offset = ocfs2_find_next_zero_bit(bitmap,
683                                                  le16_to_cpu(bg->bg_bits),
684                                                  start)) != -1) {
685                 if (offset == le16_to_cpu(bg->bg_bits))
686                         break;
687
688                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
689                         /* We found a zero, but we can't use it as it
690                          * hasn't been put to disk yet! */
691                         found = 0;
692                         start = offset + 1;
693                 } else if (offset == start) {
694                         /* we found a zero */
695                         found++;
696                         /* move start to the next bit to test */
697                         start++;
698                 } else {
699                         /* got a zero after some ones */
700                         found = 1;
701                         start = offset + 1;
702                 }
703                 if (found > best_size) {
704                         best_size = found;
705                         best_offset = start - found;
706                 }
707                 /* we got everything we needed */
708                 if (found == bits_wanted) {
709                         /* mlog(0, "Found it all!\n"); */
710                         break;
711                 }
712         }
713
714         /* XXX: I think the first clause is equivalent to the second
715          *      - jlbec */
716         if (found == bits_wanted) {
717                 *bit_off = start - found;
718                 *bits_found = found;
719         } else if (best_size) {
720                 *bit_off = best_offset;
721                 *bits_found = best_size;
722         } else {
723                 status = -ENOSPC;
724                 /* No error log here -- see the comment above
725                  * ocfs2_test_bg_bit_allocatable */
726         }
727
728         return status;
729 }
730
731 static inline int ocfs2_block_group_set_bits(struct ocfs2_journal_handle *handle,
732                                              struct inode *alloc_inode,
733                                              struct ocfs2_group_desc *bg,
734                                              struct buffer_head *group_bh,
735                                              unsigned int bit_off,
736                                              unsigned int num_bits)
737 {
738         int status;
739         void *bitmap = bg->bg_bitmap;
740         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
741
742         mlog_entry_void();
743
744         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
745                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
746                 status = -EIO;
747                 goto bail;
748         }
749         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
750
751         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
752              num_bits);
753
754         if (ocfs2_is_cluster_bitmap(alloc_inode))
755                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
756
757         status = ocfs2_journal_access(handle,
758                                       alloc_inode,
759                                       group_bh,
760                                       journal_type);
761         if (status < 0) {
762                 mlog_errno(status);
763                 goto bail;
764         }
765
766         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
767
768         while(num_bits--)
769                 ocfs2_set_bit(bit_off++, bitmap);
770
771         status = ocfs2_journal_dirty(handle,
772                                      group_bh);
773         if (status < 0) {
774                 mlog_errno(status);
775                 goto bail;
776         }
777
778 bail:
779         mlog_exit(status);
780         return status;
781 }
782
783 /* find the one with the most empty bits */
784 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
785 {
786         u16 curr, best;
787
788         BUG_ON(!cl->cl_next_free_rec);
789
790         best = curr = 0;
791         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
792                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
793                     le32_to_cpu(cl->cl_recs[best].c_free))
794                         best = curr;
795                 curr++;
796         }
797
798         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
799         return best;
800 }
801
802 static int ocfs2_relink_block_group(struct ocfs2_journal_handle *handle,
803                                     struct inode *alloc_inode,
804                                     struct buffer_head *fe_bh,
805                                     struct buffer_head *bg_bh,
806                                     struct buffer_head *prev_bg_bh,
807                                     u16 chain)
808 {
809         int status;
810         /* there is a really tiny chance the journal calls could fail,
811          * but we wouldn't want inconsistent blocks in *any* case. */
812         u64 fe_ptr, bg_ptr, prev_bg_ptr;
813         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
814         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
815         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
816
817         if (!OCFS2_IS_VALID_DINODE(fe)) {
818                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
819                 status = -EIO;
820                 goto out;
821         }
822         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
823                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
824                 status = -EIO;
825                 goto out;
826         }
827         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
828                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
829                 status = -EIO;
830                 goto out;
831         }
832
833         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
834              (unsigned long long)fe->i_blkno, chain,
835              (unsigned long long)bg->bg_blkno,
836              (unsigned long long)prev_bg->bg_blkno);
837
838         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
839         bg_ptr = le64_to_cpu(bg->bg_next_group);
840         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
841
842         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
843                                       OCFS2_JOURNAL_ACCESS_WRITE);
844         if (status < 0) {
845                 mlog_errno(status);
846                 goto out_rollback;
847         }
848
849         prev_bg->bg_next_group = bg->bg_next_group;
850
851         status = ocfs2_journal_dirty(handle, prev_bg_bh);
852         if (status < 0) {
853                 mlog_errno(status);
854                 goto out_rollback;
855         }
856
857         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
858                                       OCFS2_JOURNAL_ACCESS_WRITE);
859         if (status < 0) {
860                 mlog_errno(status);
861                 goto out_rollback;
862         }
863
864         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
865
866         status = ocfs2_journal_dirty(handle, bg_bh);
867         if (status < 0) {
868                 mlog_errno(status);
869                 goto out_rollback;
870         }
871
872         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
873                                       OCFS2_JOURNAL_ACCESS_WRITE);
874         if (status < 0) {
875                 mlog_errno(status);
876                 goto out_rollback;
877         }
878
879         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
880
881         status = ocfs2_journal_dirty(handle, fe_bh);
882         if (status < 0) {
883                 mlog_errno(status);
884                 goto out_rollback;
885         }
886
887         status = 0;
888 out_rollback:
889         if (status < 0) {
890                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
891                 bg->bg_next_group = cpu_to_le64(bg_ptr);
892                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
893         }
894 out:
895         mlog_exit(status);
896         return status;
897 }
898
899 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
900                                                      u32 wanted)
901 {
902         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
903 }
904
905 /* return 0 on success, -ENOSPC to keep searching and any other < 0
906  * value on error. */
907 static int ocfs2_cluster_group_search(struct inode *inode,
908                                       struct buffer_head *group_bh,
909                                       u32 bits_wanted, u32 min_bits,
910                                       u16 *bit_off, u16 *bits_found)
911 {
912         int search = -ENOSPC;
913         int ret;
914         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
915         u16 tmp_off, tmp_found;
916
917         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
918
919         if (bg->bg_free_bits_count) {
920                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
921                                                         group_bh, bits_wanted,
922                                                         &tmp_off, &tmp_found);
923                 if (ret)
924                         return ret;
925
926                 /* ocfs2_block_group_find_clear_bits() might
927                  * return success, but we still want to return
928                  * -ENOSPC unless it found the minimum number
929                  * of bits. */
930                 if (min_bits <= tmp_found) {
931                         *bit_off = tmp_off;
932                         *bits_found = tmp_found;
933                         search = 0; /* success */
934                 }
935         }
936
937         return search;
938 }
939
940 static int ocfs2_block_group_search(struct inode *inode,
941                                     struct buffer_head *group_bh,
942                                     u32 bits_wanted, u32 min_bits,
943                                     u16 *bit_off, u16 *bits_found)
944 {
945         int ret = -ENOSPC;
946         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
947
948         BUG_ON(min_bits != 1);
949         BUG_ON(ocfs2_is_cluster_bitmap(inode));
950
951         if (bg->bg_free_bits_count)
952                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
953                                                         group_bh, bits_wanted,
954                                                         bit_off, bits_found);
955
956         return ret;
957 }
958
959 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
960                               u32 bits_wanted,
961                               u32 min_bits,
962                               u16 *bit_off,
963                               unsigned int *num_bits,
964                               u64 *bg_blkno)
965 {
966         int status;
967         u16 chain, tmp_bits;
968         u32 tmp_used;
969         u64 next_group;
970         struct ocfs2_journal_handle *handle = ac->ac_handle;
971         struct inode *alloc_inode = ac->ac_inode;
972         struct buffer_head *group_bh = NULL;
973         struct buffer_head *prev_group_bh = NULL;
974         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
975         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
976         struct ocfs2_group_desc *bg;
977
978         chain = ac->ac_chain;
979         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
980              bits_wanted, chain,
981              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
982
983         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
984                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
985                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
986         if (status < 0) {
987                 mlog_errno(status);
988                 goto bail;
989         }
990         bg = (struct ocfs2_group_desc *) group_bh->b_data;
991         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
992                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
993                 status = -EIO;
994                 goto bail;
995         }
996
997         status = -ENOSPC;
998         /* for now, the chain search is a bit simplistic. We just use
999          * the 1st group with any empty bits. */
1000         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1001                                              bits_wanted, min_bits, bit_off,
1002                                              &tmp_bits)) == -ENOSPC) {
1003                 if (!bg->bg_next_group)
1004                         break;
1005
1006                 if (prev_group_bh) {
1007                         brelse(prev_group_bh);
1008                         prev_group_bh = NULL;
1009                 }
1010                 next_group = le64_to_cpu(bg->bg_next_group);
1011                 prev_group_bh = group_bh;
1012                 group_bh = NULL;
1013                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1014                                           next_group, &group_bh,
1015                                           OCFS2_BH_CACHED, alloc_inode);
1016                 if (status < 0) {
1017                         mlog_errno(status);
1018                         goto bail;
1019                 }
1020                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1021                 if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1022                         OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1023                         status = -EIO;
1024                         goto bail;
1025                 }
1026         }
1027         if (status < 0) {
1028                 if (status != -ENOSPC)
1029                         mlog_errno(status);
1030                 goto bail;
1031         }
1032
1033         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1034              tmp_bits, (unsigned long long)bg->bg_blkno);
1035
1036         *num_bits = tmp_bits;
1037
1038         BUG_ON(*num_bits == 0);
1039
1040         /*
1041          * Keep track of previous block descriptor read. When
1042          * we find a target, if we have read more than X
1043          * number of descriptors, and the target is reasonably
1044          * empty, relink him to top of his chain.
1045          *
1046          * We've read 0 extra blocks and only send one more to
1047          * the transaction, yet the next guy to search has a
1048          * much easier time.
1049          *
1050          * Do this *after* figuring out how many bits we're taking out
1051          * of our target group.
1052          */
1053         if (ac->ac_allow_chain_relink &&
1054             (prev_group_bh) &&
1055             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1056                 status = ocfs2_relink_block_group(handle, alloc_inode,
1057                                                   ac->ac_bh, group_bh,
1058                                                   prev_group_bh, chain);
1059                 if (status < 0) {
1060                         mlog_errno(status);
1061                         goto bail;
1062                 }
1063         }
1064
1065         /* Ok, claim our bits now: set the info on dinode, chainlist
1066          * and then the group */
1067         status = ocfs2_journal_access(handle,
1068                                       alloc_inode,
1069                                       ac->ac_bh,
1070                                       OCFS2_JOURNAL_ACCESS_WRITE);
1071         if (status < 0) {
1072                 mlog_errno(status);
1073                 goto bail;
1074         }
1075
1076         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1077         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1078         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1079
1080         status = ocfs2_journal_dirty(handle,
1081                                      ac->ac_bh);
1082         if (status < 0) {
1083                 mlog_errno(status);
1084                 goto bail;
1085         }
1086
1087         status = ocfs2_block_group_set_bits(handle,
1088                                             alloc_inode,
1089                                             bg,
1090                                             group_bh,
1091                                             *bit_off,
1092                                             *num_bits);
1093         if (status < 0) {
1094                 mlog_errno(status);
1095                 goto bail;
1096         }
1097
1098         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1099              (unsigned long long)fe->i_blkno);
1100
1101         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1102 bail:
1103         if (group_bh)
1104                 brelse(group_bh);
1105         if (prev_group_bh)
1106                 brelse(prev_group_bh);
1107
1108         mlog_exit(status);
1109         return status;
1110 }
1111
1112 /* will give out up to bits_wanted contiguous bits. */
1113 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1114                                      struct ocfs2_alloc_context *ac,
1115                                      u32 bits_wanted,
1116                                      u32 min_bits,
1117                                      u16 *bit_off,
1118                                      unsigned int *num_bits,
1119                                      u64 *bg_blkno)
1120 {
1121         int status;
1122         u16 victim, i;
1123         struct ocfs2_chain_list *cl;
1124         struct ocfs2_dinode *fe;
1125
1126         mlog_entry_void();
1127
1128         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1129         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1130         BUG_ON(!ac->ac_bh);
1131
1132         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1133         if (!OCFS2_IS_VALID_DINODE(fe)) {
1134                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1135                 status = -EIO;
1136                 goto bail;
1137         }
1138         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1139             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1140                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1141                             "bits but only %u total.",
1142                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1143                             le32_to_cpu(fe->id1.bitmap1.i_used),
1144                             le32_to_cpu(fe->id1.bitmap1.i_total));
1145                 status = -EIO;
1146                 goto bail;
1147         }
1148
1149         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1150
1151         victim = ocfs2_find_victim_chain(cl);
1152         ac->ac_chain = victim;
1153         ac->ac_allow_chain_relink = 1;
1154
1155         status = ocfs2_search_chain(ac, bits_wanted, min_bits, bit_off,
1156                                     num_bits, bg_blkno);
1157         if (!status)
1158                 goto bail;
1159         if (status < 0 && status != -ENOSPC) {
1160                 mlog_errno(status);
1161                 goto bail;
1162         }
1163
1164         mlog(0, "Search of victim chain %u came up with nothing, "
1165              "trying all chains now.\n", victim);
1166
1167         /* If we didn't pick a good victim, then just default to
1168          * searching each chain in order. Don't allow chain relinking
1169          * because we only calculate enough journal credits for one
1170          * relink per alloc. */
1171         ac->ac_allow_chain_relink = 0;
1172         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1173                 if (i == victim)
1174                         continue;
1175                 if (!cl->cl_recs[i].c_free)
1176                         continue;
1177
1178                 ac->ac_chain = i;
1179                 status = ocfs2_search_chain(ac, bits_wanted, min_bits,
1180                                             bit_off, num_bits,
1181                                             bg_blkno);
1182                 if (!status)
1183                         break;
1184                 if (status < 0 && status != -ENOSPC) {
1185                         mlog_errno(status);
1186                         goto bail;
1187                 }
1188         }
1189 bail:
1190
1191         mlog_exit(status);
1192         return status;
1193 }
1194
1195 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1196                          struct ocfs2_journal_handle *handle,
1197                          struct ocfs2_alloc_context *ac,
1198                          u32 bits_wanted,
1199                          u16 *suballoc_bit_start,
1200                          unsigned int *num_bits,
1201                          u64 *blkno_start)
1202 {
1203         int status;
1204         u64 bg_blkno;
1205
1206         BUG_ON(!ac);
1207         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1208         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1209         BUG_ON(ac->ac_handle != handle);
1210
1211         status = ocfs2_claim_suballoc_bits(osb,
1212                                            ac,
1213                                            bits_wanted,
1214                                            1,
1215                                            suballoc_bit_start,
1216                                            num_bits,
1217                                            &bg_blkno);
1218         if (status < 0) {
1219                 mlog_errno(status);
1220                 goto bail;
1221         }
1222         atomic_inc(&osb->alloc_stats.bg_allocs);
1223
1224         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1225         ac->ac_bits_given += (*num_bits);
1226         status = 0;
1227 bail:
1228         mlog_exit(status);
1229         return status;
1230 }
1231
1232 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1233                           struct ocfs2_journal_handle *handle,
1234                           struct ocfs2_alloc_context *ac,
1235                           u16 *suballoc_bit,
1236                           u64 *fe_blkno)
1237 {
1238         int status;
1239         unsigned int num_bits;
1240         u64 bg_blkno;
1241
1242         mlog_entry_void();
1243
1244         BUG_ON(!ac);
1245         BUG_ON(ac->ac_bits_given != 0);
1246         BUG_ON(ac->ac_bits_wanted != 1);
1247         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1248         BUG_ON(ac->ac_handle != handle);
1249
1250         status = ocfs2_claim_suballoc_bits(osb,
1251                                            ac,
1252                                            1,
1253                                            1,
1254                                            suballoc_bit,
1255                                            &num_bits,
1256                                            &bg_blkno);
1257         if (status < 0) {
1258                 mlog_errno(status);
1259                 goto bail;
1260         }
1261         atomic_inc(&osb->alloc_stats.bg_allocs);
1262
1263         BUG_ON(num_bits != 1);
1264
1265         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1266         ac->ac_bits_given++;
1267         status = 0;
1268 bail:
1269         mlog_exit(status);
1270         return status;
1271 }
1272
1273 /* translate a group desc. blkno and it's bitmap offset into
1274  * disk cluster offset. */
1275 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1276                                                    u64 bg_blkno,
1277                                                    u16 bg_bit_off)
1278 {
1279         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1280         u32 cluster = 0;
1281
1282         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1283
1284         if (bg_blkno != osb->first_cluster_group_blkno)
1285                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1286         cluster += (u32) bg_bit_off;
1287         return cluster;
1288 }
1289
1290 /* given a cluster offset, calculate which block group it belongs to
1291  * and return that block offset. */
1292 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1293                                             u32 cluster)
1294 {
1295         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1296         u32 group_no;
1297
1298         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1299
1300         group_no = cluster / osb->bitmap_cpg;
1301         if (!group_no)
1302                 return osb->first_cluster_group_blkno;
1303         return ocfs2_clusters_to_blocks(inode->i_sb,
1304                                         group_no * osb->bitmap_cpg);
1305 }
1306
1307 /* given the block number of a cluster start, calculate which cluster
1308  * group and descriptor bitmap offset that corresponds to. */
1309 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1310                                                 u64 data_blkno,
1311                                                 u64 *bg_blkno,
1312                                                 u16 *bg_bit_off)
1313 {
1314         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1315         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1316
1317         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1318
1319         *bg_blkno = ocfs2_which_cluster_group(inode,
1320                                               data_cluster);
1321
1322         if (*bg_blkno == osb->first_cluster_group_blkno)
1323                 *bg_bit_off = (u16) data_cluster;
1324         else
1325                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1326                                                              data_blkno - *bg_blkno);
1327 }
1328
1329 /*
1330  * min_bits - minimum contiguous chunk from this total allocation we
1331  * can handle. set to what we asked for originally for a full
1332  * contig. allocation, set to '1' to indicate we can deal with extents
1333  * of any size.
1334  */
1335 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1336                          struct ocfs2_journal_handle *handle,
1337                          struct ocfs2_alloc_context *ac,
1338                          u32 min_clusters,
1339                          u32 *cluster_start,
1340                          u32 *num_clusters)
1341 {
1342         int status;
1343         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1344         u64 bg_blkno;
1345         u16 bg_bit_off;
1346
1347         mlog_entry_void();
1348
1349         BUG_ON(!ac);
1350         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1351
1352         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1353                && ac->ac_which != OCFS2_AC_USE_MAIN);
1354         BUG_ON(ac->ac_handle != handle);
1355
1356         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1357                 status = ocfs2_claim_local_alloc_bits(osb,
1358                                                       handle,
1359                                                       ac,
1360                                                       bits_wanted,
1361                                                       cluster_start,
1362                                                       num_clusters);
1363                 if (!status)
1364                         atomic_inc(&osb->alloc_stats.local_data);
1365         } else {
1366                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1367                         /* The only paths asking for contiguousness
1368                          * should know about this already. */
1369                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1370                                        "group bitmap size!");
1371                         status = -ENOSPC;
1372                         goto bail;
1373                 }
1374                 /* clamp the current request down to a realistic size. */
1375                 if (bits_wanted > (osb->bitmap_cpg - 1))
1376                         bits_wanted = osb->bitmap_cpg - 1;
1377
1378                 status = ocfs2_claim_suballoc_bits(osb,
1379                                                    ac,
1380                                                    bits_wanted,
1381                                                    min_clusters,
1382                                                    &bg_bit_off,
1383                                                    num_clusters,
1384                                                    &bg_blkno);
1385                 if (!status) {
1386                         *cluster_start =
1387                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1388                                                                  bg_blkno,
1389                                                                  bg_bit_off);
1390                         atomic_inc(&osb->alloc_stats.bitmap_data);
1391                 }
1392         }
1393         if (status < 0) {
1394                 if (status != -ENOSPC)
1395                         mlog_errno(status);
1396                 goto bail;
1397         }
1398
1399         ac->ac_bits_given += *num_clusters;
1400
1401 bail:
1402         mlog_exit(status);
1403         return status;
1404 }
1405
1406 static inline int ocfs2_block_group_clear_bits(struct ocfs2_journal_handle *handle,
1407                                                struct inode *alloc_inode,
1408                                                struct ocfs2_group_desc *bg,
1409                                                struct buffer_head *group_bh,
1410                                                unsigned int bit_off,
1411                                                unsigned int num_bits)
1412 {
1413         int status;
1414         unsigned int tmp;
1415         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1416         struct ocfs2_group_desc *undo_bg = NULL;
1417
1418         mlog_entry_void();
1419
1420         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1421                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1422                 status = -EIO;
1423                 goto bail;
1424         }
1425
1426         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1427
1428         if (ocfs2_is_cluster_bitmap(alloc_inode))
1429                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1430
1431         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1432                                       journal_type);
1433         if (status < 0) {
1434                 mlog_errno(status);
1435                 goto bail;
1436         }
1437
1438         if (ocfs2_is_cluster_bitmap(alloc_inode))
1439                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1440
1441         tmp = num_bits;
1442         while(tmp--) {
1443                 ocfs2_clear_bit((bit_off + tmp),
1444                                 (unsigned long *) bg->bg_bitmap);
1445                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1446                         ocfs2_set_bit(bit_off + tmp,
1447                                       (unsigned long *) undo_bg->bg_bitmap);
1448         }
1449         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1450
1451         status = ocfs2_journal_dirty(handle, group_bh);
1452         if (status < 0)
1453                 mlog_errno(status);
1454 bail:
1455         return status;
1456 }
1457
1458 /*
1459  * expects the suballoc inode to already be locked.
1460  */
1461 static int ocfs2_free_suballoc_bits(struct ocfs2_journal_handle *handle,
1462                                     struct inode *alloc_inode,
1463                                     struct buffer_head *alloc_bh,
1464                                     unsigned int start_bit,
1465                                     u64 bg_blkno,
1466                                     unsigned int count)
1467 {
1468         int status = 0;
1469         u32 tmp_used;
1470         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1471         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1472         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1473         struct buffer_head *group_bh = NULL;
1474         struct ocfs2_group_desc *group;
1475
1476         mlog_entry_void();
1477
1478         if (!OCFS2_IS_VALID_DINODE(fe)) {
1479                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1480                 status = -EIO;
1481                 goto bail;
1482         }
1483         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1484
1485         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1486              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1487              (unsigned long long)bg_blkno, start_bit);
1488
1489         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1490                                   alloc_inode);
1491         if (status < 0) {
1492                 mlog_errno(status);
1493                 goto bail;
1494         }
1495
1496         group = (struct ocfs2_group_desc *) group_bh->b_data;
1497         if (!OCFS2_IS_VALID_GROUP_DESC(group)) {
1498                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, group);
1499                 status = -EIO;
1500                 goto bail;
1501         }
1502         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1503
1504         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1505                                               group, group_bh,
1506                                               start_bit, count);
1507         if (status < 0) {
1508                 mlog_errno(status);
1509                 goto bail;
1510         }
1511
1512         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1513                                       OCFS2_JOURNAL_ACCESS_WRITE);
1514         if (status < 0) {
1515                 mlog_errno(status);
1516                 goto bail;
1517         }
1518
1519         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1520                      count);
1521         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1522         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1523
1524         status = ocfs2_journal_dirty(handle, alloc_bh);
1525         if (status < 0) {
1526                 mlog_errno(status);
1527                 goto bail;
1528         }
1529
1530 bail:
1531         if (group_bh)
1532                 brelse(group_bh);
1533
1534         mlog_exit(status);
1535         return status;
1536 }
1537
1538 static inline u64 ocfs2_which_suballoc_group(u64 block, unsigned int bit)
1539 {
1540         u64 group = block - (u64) bit;
1541
1542         return group;
1543 }
1544
1545 int ocfs2_free_dinode(struct ocfs2_journal_handle *handle,
1546                       struct inode *inode_alloc_inode,
1547                       struct buffer_head *inode_alloc_bh,
1548                       struct ocfs2_dinode *di)
1549 {
1550         u64 blk = le64_to_cpu(di->i_blkno);
1551         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1552         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1553
1554         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1555                                         inode_alloc_bh, bit, bg_blkno, 1);
1556 }
1557
1558 int ocfs2_free_extent_block(struct ocfs2_journal_handle *handle,
1559                             struct inode *eb_alloc_inode,
1560                             struct buffer_head *eb_alloc_bh,
1561                             struct ocfs2_extent_block *eb)
1562 {
1563         u64 blk = le64_to_cpu(eb->h_blkno);
1564         u16 bit = le16_to_cpu(eb->h_suballoc_bit);
1565         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1566
1567         return ocfs2_free_suballoc_bits(handle, eb_alloc_inode, eb_alloc_bh,
1568                                         bit, bg_blkno, 1);
1569 }
1570
1571 int ocfs2_free_clusters(struct ocfs2_journal_handle *handle,
1572                        struct inode *bitmap_inode,
1573                        struct buffer_head *bitmap_bh,
1574                        u64 start_blk,
1575                        unsigned int num_clusters)
1576 {
1577         int status;
1578         u16 bg_start_bit;
1579         u64 bg_blkno;
1580         struct ocfs2_dinode *fe;
1581
1582         /* You can't ever have a contiguous set of clusters
1583          * bigger than a block group bitmap so we never have to worry
1584          * about looping on them. */
1585
1586         mlog_entry_void();
1587
1588         /* This is expensive. We can safely remove once this stuff has
1589          * gotten tested really well. */
1590         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1591
1592         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1593
1594         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1595                                      &bg_start_bit);
1596
1597         mlog(0, "want to free %u clusters starting at block %llu\n",
1598              num_clusters, (unsigned long long)start_blk);
1599         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1600              (unsigned long long)bg_blkno, bg_start_bit);
1601
1602         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1603                                           bg_start_bit, bg_blkno,
1604                                           num_clusters);
1605         if (status < 0)
1606                 mlog_errno(status);
1607
1608         mlog_exit(status);
1609         return status;
1610 }
1611
1612 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1613 {
1614         printk("Block Group:\n");
1615         printk("bg_signature:       %s\n", bg->bg_signature);
1616         printk("bg_size:            %u\n", bg->bg_size);
1617         printk("bg_bits:            %u\n", bg->bg_bits);
1618         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1619         printk("bg_chain:           %u\n", bg->bg_chain);
1620         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1621         printk("bg_next_group:      %llu\n",
1622                (unsigned long long)bg->bg_next_group);
1623         printk("bg_parent_dinode:   %llu\n",
1624                (unsigned long long)bg->bg_parent_dinode);
1625         printk("bg_blkno:           %llu\n",
1626                (unsigned long long)bg->bg_blkno);
1627 }
1628
1629 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1630 {
1631         int i;
1632
1633         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1634         printk("i_signature:                  %s\n", fe->i_signature);
1635         printk("i_size:                       %llu\n",
1636                (unsigned long long)fe->i_size);
1637         printk("i_clusters:                   %u\n", fe->i_clusters);
1638         printk("i_generation:                 %u\n",
1639                le32_to_cpu(fe->i_generation));
1640         printk("id1.bitmap1.i_used:           %u\n",
1641                le32_to_cpu(fe->id1.bitmap1.i_used));
1642         printk("id1.bitmap1.i_total:          %u\n",
1643                le32_to_cpu(fe->id1.bitmap1.i_total));
1644         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1645         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1646         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1647         printk("id2.i_chain.cl_next_free_rec: %u\n",
1648                fe->id2.i_chain.cl_next_free_rec);
1649         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1650                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1651                        fe->id2.i_chain.cl_recs[i].c_free);
1652                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1653                        fe->id2.i_chain.cl_recs[i].c_total);
1654                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1655                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1656         }
1657 }