ocfs2: convert to new aops
[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 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(handle_t *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_cluster_group_search(struct inode *inode,
63                                       struct buffer_head *group_bh,
64                                       u32 bits_wanted, u32 min_bits,
65                                       u16 *bit_off, u16 *bits_found);
66 static int ocfs2_block_group_search(struct inode *inode,
67                                     struct buffer_head *group_bh,
68                                     u32 bits_wanted, u32 min_bits,
69                                     u16 *bit_off, u16 *bits_found);
70 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
71                                      struct ocfs2_alloc_context *ac,
72                                      handle_t *handle,
73                                      u32 bits_wanted,
74                                      u32 min_bits,
75                                      u16 *bit_off,
76                                      unsigned int *num_bits,
77                                      u64 *bg_blkno);
78 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
79                                          int nr);
80 static inline int ocfs2_block_group_set_bits(handle_t *handle,
81                                              struct inode *alloc_inode,
82                                              struct ocfs2_group_desc *bg,
83                                              struct buffer_head *group_bh,
84                                              unsigned int bit_off,
85                                              unsigned int num_bits);
86 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
87                                                struct inode *alloc_inode,
88                                                struct ocfs2_group_desc *bg,
89                                                struct buffer_head *group_bh,
90                                                unsigned int bit_off,
91                                                unsigned int num_bits);
92
93 static int ocfs2_relink_block_group(handle_t *handle,
94                                     struct inode *alloc_inode,
95                                     struct buffer_head *fe_bh,
96                                     struct buffer_head *bg_bh,
97                                     struct buffer_head *prev_bg_bh,
98                                     u16 chain);
99 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
100                                                      u32 wanted);
101 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
102                                                    u64 bg_blkno,
103                                                    u16 bg_bit_off);
104 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
105                                             u32 cluster);
106 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
107                                                 u64 data_blkno,
108                                                 u64 *bg_blkno,
109                                                 u16 *bg_bit_off);
110
111 void ocfs2_free_alloc_context(struct ocfs2_alloc_context *ac)
112 {
113         struct inode *inode = ac->ac_inode;
114
115         if (inode) {
116                 if (ac->ac_which != OCFS2_AC_USE_LOCAL)
117                         ocfs2_meta_unlock(inode, 1);
118
119                 mutex_unlock(&inode->i_mutex);
120
121                 iput(inode);
122         }
123         if (ac->ac_bh)
124                 brelse(ac->ac_bh);
125         kfree(ac);
126 }
127
128 static u32 ocfs2_bits_per_group(struct ocfs2_chain_list *cl)
129 {
130         return (u32)le16_to_cpu(cl->cl_cpg) * (u32)le16_to_cpu(cl->cl_bpc);
131 }
132
133 /* somewhat more expensive than our other checks, so use sparingly. */
134 static int ocfs2_check_group_descriptor(struct super_block *sb,
135                                         struct ocfs2_dinode *di,
136                                         struct ocfs2_group_desc *gd)
137 {
138         unsigned int max_bits;
139
140         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
141                 OCFS2_RO_ON_INVALID_GROUP_DESC(sb, gd);
142                 return -EIO;
143         }
144
145         if (di->i_blkno != gd->bg_parent_dinode) {
146                 ocfs2_error(sb, "Group descriptor # %llu has bad parent "
147                             "pointer (%llu, expected %llu)",
148                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
149                             (unsigned long long)le64_to_cpu(gd->bg_parent_dinode),
150                             (unsigned long long)le64_to_cpu(di->i_blkno));
151                 return -EIO;
152         }
153
154         max_bits = le16_to_cpu(di->id2.i_chain.cl_cpg) * le16_to_cpu(di->id2.i_chain.cl_bpc);
155         if (le16_to_cpu(gd->bg_bits) > max_bits) {
156                 ocfs2_error(sb, "Group descriptor # %llu has bit count of %u",
157                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
158                             le16_to_cpu(gd->bg_bits));
159                 return -EIO;
160         }
161
162         if (le16_to_cpu(gd->bg_chain) >=
163             le16_to_cpu(di->id2.i_chain.cl_next_free_rec)) {
164                 ocfs2_error(sb, "Group descriptor # %llu has bad chain %u",
165                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
166                             le16_to_cpu(gd->bg_chain));
167                 return -EIO;
168         }
169
170         if (le16_to_cpu(gd->bg_free_bits_count) > le16_to_cpu(gd->bg_bits)) {
171                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
172                             "claims that %u are free",
173                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
174                             le16_to_cpu(gd->bg_bits),
175                             le16_to_cpu(gd->bg_free_bits_count));
176                 return -EIO;
177         }
178
179         if (le16_to_cpu(gd->bg_bits) > (8 * le16_to_cpu(gd->bg_size))) {
180                 ocfs2_error(sb, "Group descriptor # %llu has bit count %u but "
181                             "max bitmap bits of %u",
182                             (unsigned long long)le64_to_cpu(gd->bg_blkno),
183                             le16_to_cpu(gd->bg_bits),
184                             8 * le16_to_cpu(gd->bg_size));
185                 return -EIO;
186         }
187
188         return 0;
189 }
190
191 static int ocfs2_block_group_fill(handle_t *handle,
192                                   struct inode *alloc_inode,
193                                   struct buffer_head *bg_bh,
194                                   u64 group_blkno,
195                                   u16 my_chain,
196                                   struct ocfs2_chain_list *cl)
197 {
198         int status = 0;
199         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
200         struct super_block * sb = alloc_inode->i_sb;
201
202         mlog_entry_void();
203
204         if (((unsigned long long) bg_bh->b_blocknr) != group_blkno) {
205                 ocfs2_error(alloc_inode->i_sb, "group block (%llu) != "
206                             "b_blocknr (%llu)",
207                             (unsigned long long)group_blkno,
208                             (unsigned long long) bg_bh->b_blocknr);
209                 status = -EIO;
210                 goto bail;
211         }
212
213         status = ocfs2_journal_access(handle,
214                                       alloc_inode,
215                                       bg_bh,
216                                       OCFS2_JOURNAL_ACCESS_CREATE);
217         if (status < 0) {
218                 mlog_errno(status);
219                 goto bail;
220         }
221
222         memset(bg, 0, sb->s_blocksize);
223         strcpy(bg->bg_signature, OCFS2_GROUP_DESC_SIGNATURE);
224         bg->bg_generation = cpu_to_le32(OCFS2_SB(sb)->fs_generation);
225         bg->bg_size = cpu_to_le16(ocfs2_group_bitmap_size(sb));
226         bg->bg_bits = cpu_to_le16(ocfs2_bits_per_group(cl));
227         bg->bg_chain = cpu_to_le16(my_chain);
228         bg->bg_next_group = cl->cl_recs[my_chain].c_blkno;
229         bg->bg_parent_dinode = cpu_to_le64(OCFS2_I(alloc_inode)->ip_blkno);
230         bg->bg_blkno = cpu_to_le64(group_blkno);
231         /* set the 1st bit in the bitmap to account for the descriptor block */
232         ocfs2_set_bit(0, (unsigned long *)bg->bg_bitmap);
233         bg->bg_free_bits_count = cpu_to_le16(le16_to_cpu(bg->bg_bits) - 1);
234
235         status = ocfs2_journal_dirty(handle, bg_bh);
236         if (status < 0)
237                 mlog_errno(status);
238
239         /* There is no need to zero out or otherwise initialize the
240          * other blocks in a group - All valid FS metadata in a block
241          * group stores the superblock fs_generation value at
242          * allocation time. */
243
244 bail:
245         mlog_exit(status);
246         return status;
247 }
248
249 static inline u16 ocfs2_find_smallest_chain(struct ocfs2_chain_list *cl)
250 {
251         u16 curr, best;
252
253         best = curr = 0;
254         while (curr < le16_to_cpu(cl->cl_count)) {
255                 if (le32_to_cpu(cl->cl_recs[best].c_total) >
256                     le32_to_cpu(cl->cl_recs[curr].c_total))
257                         best = curr;
258                 curr++;
259         }
260         return best;
261 }
262
263 /*
264  * We expect the block group allocator to already be locked.
265  */
266 static int ocfs2_block_group_alloc(struct ocfs2_super *osb,
267                                    struct inode *alloc_inode,
268                                    struct buffer_head *bh)
269 {
270         int status, credits;
271         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) bh->b_data;
272         struct ocfs2_chain_list *cl;
273         struct ocfs2_alloc_context *ac = NULL;
274         handle_t *handle = NULL;
275         u32 bit_off, num_bits;
276         u16 alloc_rec;
277         u64 bg_blkno;
278         struct buffer_head *bg_bh = NULL;
279         struct ocfs2_group_desc *bg;
280
281         BUG_ON(ocfs2_is_cluster_bitmap(alloc_inode));
282
283         mlog_entry_void();
284
285         cl = &fe->id2.i_chain;
286         status = ocfs2_reserve_clusters(osb,
287                                         le16_to_cpu(cl->cl_cpg),
288                                         &ac);
289         if (status < 0) {
290                 if (status != -ENOSPC)
291                         mlog_errno(status);
292                 goto bail;
293         }
294
295         credits = ocfs2_calc_group_alloc_credits(osb->sb,
296                                                  le16_to_cpu(cl->cl_cpg));
297         handle = ocfs2_start_trans(osb, credits);
298         if (IS_ERR(handle)) {
299                 status = PTR_ERR(handle);
300                 handle = NULL;
301                 mlog_errno(status);
302                 goto bail;
303         }
304
305         status = ocfs2_claim_clusters(osb,
306                                       handle,
307                                       ac,
308                                       le16_to_cpu(cl->cl_cpg),
309                                       &bit_off,
310                                       &num_bits);
311         if (status < 0) {
312                 if (status != -ENOSPC)
313                         mlog_errno(status);
314                 goto bail;
315         }
316
317         alloc_rec = ocfs2_find_smallest_chain(cl);
318
319         /* setup the group */
320         bg_blkno = ocfs2_clusters_to_blocks(osb->sb, bit_off);
321         mlog(0, "new descriptor, record %u, at block %llu\n",
322              alloc_rec, (unsigned long long)bg_blkno);
323
324         bg_bh = sb_getblk(osb->sb, bg_blkno);
325         if (!bg_bh) {
326                 status = -EIO;
327                 mlog_errno(status);
328                 goto bail;
329         }
330         ocfs2_set_new_buffer_uptodate(alloc_inode, bg_bh);
331
332         status = ocfs2_block_group_fill(handle,
333                                         alloc_inode,
334                                         bg_bh,
335                                         bg_blkno,
336                                         alloc_rec,
337                                         cl);
338         if (status < 0) {
339                 mlog_errno(status);
340                 goto bail;
341         }
342
343         bg = (struct ocfs2_group_desc *) bg_bh->b_data;
344
345         status = ocfs2_journal_access(handle, alloc_inode,
346                                       bh, OCFS2_JOURNAL_ACCESS_WRITE);
347         if (status < 0) {
348                 mlog_errno(status);
349                 goto bail;
350         }
351
352         le32_add_cpu(&cl->cl_recs[alloc_rec].c_free,
353                      le16_to_cpu(bg->bg_free_bits_count));
354         le32_add_cpu(&cl->cl_recs[alloc_rec].c_total, le16_to_cpu(bg->bg_bits));
355         cl->cl_recs[alloc_rec].c_blkno  = cpu_to_le64(bg_blkno);
356         if (le16_to_cpu(cl->cl_next_free_rec) < le16_to_cpu(cl->cl_count))
357                 le16_add_cpu(&cl->cl_next_free_rec, 1);
358
359         le32_add_cpu(&fe->id1.bitmap1.i_used, le16_to_cpu(bg->bg_bits) -
360                                         le16_to_cpu(bg->bg_free_bits_count));
361         le32_add_cpu(&fe->id1.bitmap1.i_total, le16_to_cpu(bg->bg_bits));
362         le32_add_cpu(&fe->i_clusters, le16_to_cpu(cl->cl_cpg));
363
364         status = ocfs2_journal_dirty(handle, bh);
365         if (status < 0) {
366                 mlog_errno(status);
367                 goto bail;
368         }
369
370         spin_lock(&OCFS2_I(alloc_inode)->ip_lock);
371         OCFS2_I(alloc_inode)->ip_clusters = le32_to_cpu(fe->i_clusters);
372         fe->i_size = cpu_to_le64(ocfs2_clusters_to_bytes(alloc_inode->i_sb,
373                                              le32_to_cpu(fe->i_clusters)));
374         spin_unlock(&OCFS2_I(alloc_inode)->ip_lock);
375         i_size_write(alloc_inode, le64_to_cpu(fe->i_size));
376         alloc_inode->i_blocks = ocfs2_inode_sector_count(alloc_inode);
377
378         status = 0;
379 bail:
380         if (handle)
381                 ocfs2_commit_trans(osb, handle);
382
383         if (ac)
384                 ocfs2_free_alloc_context(ac);
385
386         if (bg_bh)
387                 brelse(bg_bh);
388
389         mlog_exit(status);
390         return status;
391 }
392
393 static int ocfs2_reserve_suballoc_bits(struct ocfs2_super *osb,
394                                        struct ocfs2_alloc_context *ac,
395                                        int type,
396                                        u32 slot)
397 {
398         int status;
399         u32 bits_wanted = ac->ac_bits_wanted;
400         struct inode *alloc_inode;
401         struct buffer_head *bh = NULL;
402         struct ocfs2_dinode *fe;
403         u32 free_bits;
404
405         mlog_entry_void();
406
407         alloc_inode = ocfs2_get_system_file_inode(osb, type, slot);
408         if (!alloc_inode) {
409                 mlog_errno(-EINVAL);
410                 return -EINVAL;
411         }
412
413         mutex_lock(&alloc_inode->i_mutex);
414
415         status = ocfs2_meta_lock(alloc_inode, &bh, 1);
416         if (status < 0) {
417                 mutex_unlock(&alloc_inode->i_mutex);
418                 iput(alloc_inode);
419
420                 mlog_errno(status);
421                 return status;
422         }
423
424         ac->ac_inode = alloc_inode;
425
426         fe = (struct ocfs2_dinode *) bh->b_data;
427         if (!OCFS2_IS_VALID_DINODE(fe)) {
428                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
429                 status = -EIO;
430                 goto bail;
431         }
432         if (!(fe->i_flags & cpu_to_le32(OCFS2_CHAIN_FL))) {
433                 ocfs2_error(alloc_inode->i_sb, "Invalid chain allocator %llu",
434                             (unsigned long long)le64_to_cpu(fe->i_blkno));
435                 status = -EIO;
436                 goto bail;
437         }
438
439         free_bits = le32_to_cpu(fe->id1.bitmap1.i_total) -
440                 le32_to_cpu(fe->id1.bitmap1.i_used);
441
442         if (bits_wanted > free_bits) {
443                 /* cluster bitmap never grows */
444                 if (ocfs2_is_cluster_bitmap(alloc_inode)) {
445                         mlog(0, "Disk Full: wanted=%u, free_bits=%u\n",
446                              bits_wanted, free_bits);
447                         status = -ENOSPC;
448                         goto bail;
449                 }
450
451                 status = ocfs2_block_group_alloc(osb, alloc_inode, bh);
452                 if (status < 0) {
453                         if (status != -ENOSPC)
454                                 mlog_errno(status);
455                         goto bail;
456                 }
457                 atomic_inc(&osb->alloc_stats.bg_extends);
458
459                 /* You should never ask for this much metadata */
460                 BUG_ON(bits_wanted >
461                        (le32_to_cpu(fe->id1.bitmap1.i_total)
462                         - le32_to_cpu(fe->id1.bitmap1.i_used)));
463         }
464
465         get_bh(bh);
466         ac->ac_bh = bh;
467 bail:
468         if (bh)
469                 brelse(bh);
470
471         mlog_exit(status);
472         return status;
473 }
474
475 int ocfs2_reserve_new_metadata(struct ocfs2_super *osb,
476                                struct ocfs2_dinode *fe,
477                                struct ocfs2_alloc_context **ac)
478 {
479         int status;
480         u32 slot;
481
482         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
483         if (!(*ac)) {
484                 status = -ENOMEM;
485                 mlog_errno(status);
486                 goto bail;
487         }
488
489         (*ac)->ac_bits_wanted = ocfs2_extend_meta_needed(fe);
490         (*ac)->ac_which = OCFS2_AC_USE_META;
491         slot = osb->slot_num;
492         (*ac)->ac_group_search = ocfs2_block_group_search;
493
494         status = ocfs2_reserve_suballoc_bits(osb, (*ac),
495                                              EXTENT_ALLOC_SYSTEM_INODE, slot);
496         if (status < 0) {
497                 if (status != -ENOSPC)
498                         mlog_errno(status);
499                 goto bail;
500         }
501
502         status = 0;
503 bail:
504         if ((status < 0) && *ac) {
505                 ocfs2_free_alloc_context(*ac);
506                 *ac = NULL;
507         }
508
509         mlog_exit(status);
510         return status;
511 }
512
513 int ocfs2_reserve_new_inode(struct ocfs2_super *osb,
514                             struct ocfs2_alloc_context **ac)
515 {
516         int status;
517
518         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
519         if (!(*ac)) {
520                 status = -ENOMEM;
521                 mlog_errno(status);
522                 goto bail;
523         }
524
525         (*ac)->ac_bits_wanted = 1;
526         (*ac)->ac_which = OCFS2_AC_USE_INODE;
527
528         (*ac)->ac_group_search = ocfs2_block_group_search;
529
530         status = ocfs2_reserve_suballoc_bits(osb, *ac,
531                                              INODE_ALLOC_SYSTEM_INODE,
532                                              osb->slot_num);
533         if (status < 0) {
534                 if (status != -ENOSPC)
535                         mlog_errno(status);
536                 goto bail;
537         }
538
539         status = 0;
540 bail:
541         if ((status < 0) && *ac) {
542                 ocfs2_free_alloc_context(*ac);
543                 *ac = NULL;
544         }
545
546         mlog_exit(status);
547         return status;
548 }
549
550 /* local alloc code has to do the same thing, so rather than do this
551  * twice.. */
552 int ocfs2_reserve_cluster_bitmap_bits(struct ocfs2_super *osb,
553                                       struct ocfs2_alloc_context *ac)
554 {
555         int status;
556
557         ac->ac_which = OCFS2_AC_USE_MAIN;
558         ac->ac_group_search = ocfs2_cluster_group_search;
559
560         status = ocfs2_reserve_suballoc_bits(osb, ac,
561                                              GLOBAL_BITMAP_SYSTEM_INODE,
562                                              OCFS2_INVALID_SLOT);
563         if (status < 0 && status != -ENOSPC) {
564                 mlog_errno(status);
565                 goto bail;
566         }
567
568 bail:
569         return status;
570 }
571
572 /* Callers don't need to care which bitmap (local alloc or main) to
573  * use so we figure it out for them, but unfortunately this clutters
574  * things a bit. */
575 int ocfs2_reserve_clusters(struct ocfs2_super *osb,
576                            u32 bits_wanted,
577                            struct ocfs2_alloc_context **ac)
578 {
579         int status;
580
581         mlog_entry_void();
582
583         *ac = kzalloc(sizeof(struct ocfs2_alloc_context), GFP_KERNEL);
584         if (!(*ac)) {
585                 status = -ENOMEM;
586                 mlog_errno(status);
587                 goto bail;
588         }
589
590         (*ac)->ac_bits_wanted = bits_wanted;
591
592         status = -ENOSPC;
593         if (ocfs2_alloc_should_use_local(osb, bits_wanted)) {
594                 status = ocfs2_reserve_local_alloc_bits(osb,
595                                                         bits_wanted,
596                                                         *ac);
597                 if ((status < 0) && (status != -ENOSPC)) {
598                         mlog_errno(status);
599                         goto bail;
600                 } else if (status == -ENOSPC) {
601                         /* reserve_local_bits will return enospc with
602                          * the local alloc inode still locked, so we
603                          * can change this safely here. */
604                         mlog(0, "Disabling local alloc\n");
605                         /* We set to OCFS2_LA_DISABLED so that umount
606                          * can clean up what's left of the local
607                          * allocation */
608                         osb->local_alloc_state = OCFS2_LA_DISABLED;
609                 }
610         }
611
612         if (status == -ENOSPC) {
613                 status = ocfs2_reserve_cluster_bitmap_bits(osb, *ac);
614                 if (status < 0) {
615                         if (status != -ENOSPC)
616                                 mlog_errno(status);
617                         goto bail;
618                 }
619         }
620
621         status = 0;
622 bail:
623         if ((status < 0) && *ac) {
624                 ocfs2_free_alloc_context(*ac);
625                 *ac = NULL;
626         }
627
628         mlog_exit(status);
629         return status;
630 }
631
632 /*
633  * More or less lifted from ext3. I'll leave their description below:
634  *
635  * "For ext3 allocations, we must not reuse any blocks which are
636  * allocated in the bitmap buffer's "last committed data" copy.  This
637  * prevents deletes from freeing up the page for reuse until we have
638  * committed the delete transaction.
639  *
640  * If we didn't do this, then deleting something and reallocating it as
641  * data would allow the old block to be overwritten before the
642  * transaction committed (because we force data to disk before commit).
643  * This would lead to corruption if we crashed between overwriting the
644  * data and committing the delete.
645  *
646  * @@@ We may want to make this allocation behaviour conditional on
647  * data-writes at some point, and disable it for metadata allocations or
648  * sync-data inodes."
649  *
650  * Note: OCFS2 already does this differently for metadata vs data
651  * allocations, as those bitmaps are seperate and undo access is never
652  * called on a metadata group descriptor.
653  */
654 static int ocfs2_test_bg_bit_allocatable(struct buffer_head *bg_bh,
655                                          int nr)
656 {
657         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
658
659         if (ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap))
660                 return 0;
661         if (!buffer_jbd(bg_bh) || !bh2jh(bg_bh)->b_committed_data)
662                 return 1;
663
664         bg = (struct ocfs2_group_desc *) bh2jh(bg_bh)->b_committed_data;
665         return !ocfs2_test_bit(nr, (unsigned long *)bg->bg_bitmap);
666 }
667
668 static int ocfs2_block_group_find_clear_bits(struct ocfs2_super *osb,
669                                              struct buffer_head *bg_bh,
670                                              unsigned int bits_wanted,
671                                              unsigned int total_bits,
672                                              u16 *bit_off,
673                                              u16 *bits_found)
674 {
675         void *bitmap;
676         u16 best_offset, best_size;
677         int offset, start, found, status = 0;
678         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
679
680         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
681                 OCFS2_RO_ON_INVALID_GROUP_DESC(osb->sb, bg);
682                 return -EIO;
683         }
684
685         found = start = best_offset = best_size = 0;
686         bitmap = bg->bg_bitmap;
687
688         while((offset = ocfs2_find_next_zero_bit(bitmap, total_bits, start)) != -1) {
689                 if (offset == total_bits)
690                         break;
691
692                 if (!ocfs2_test_bg_bit_allocatable(bg_bh, offset)) {
693                         /* We found a zero, but we can't use it as it
694                          * hasn't been put to disk yet! */
695                         found = 0;
696                         start = offset + 1;
697                 } else if (offset == start) {
698                         /* we found a zero */
699                         found++;
700                         /* move start to the next bit to test */
701                         start++;
702                 } else {
703                         /* got a zero after some ones */
704                         found = 1;
705                         start = offset + 1;
706                 }
707                 if (found > best_size) {
708                         best_size = found;
709                         best_offset = start - found;
710                 }
711                 /* we got everything we needed */
712                 if (found == bits_wanted) {
713                         /* mlog(0, "Found it all!\n"); */
714                         break;
715                 }
716         }
717
718         /* XXX: I think the first clause is equivalent to the second
719          *      - jlbec */
720         if (found == bits_wanted) {
721                 *bit_off = start - found;
722                 *bits_found = found;
723         } else if (best_size) {
724                 *bit_off = best_offset;
725                 *bits_found = best_size;
726         } else {
727                 status = -ENOSPC;
728                 /* No error log here -- see the comment above
729                  * ocfs2_test_bg_bit_allocatable */
730         }
731
732         return status;
733 }
734
735 static inline int ocfs2_block_group_set_bits(handle_t *handle,
736                                              struct inode *alloc_inode,
737                                              struct ocfs2_group_desc *bg,
738                                              struct buffer_head *group_bh,
739                                              unsigned int bit_off,
740                                              unsigned int num_bits)
741 {
742         int status;
743         void *bitmap = bg->bg_bitmap;
744         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
745
746         mlog_entry_void();
747
748         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
749                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
750                 status = -EIO;
751                 goto bail;
752         }
753         BUG_ON(le16_to_cpu(bg->bg_free_bits_count) < num_bits);
754
755         mlog(0, "block_group_set_bits: off = %u, num = %u\n", bit_off,
756              num_bits);
757
758         if (ocfs2_is_cluster_bitmap(alloc_inode))
759                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
760
761         status = ocfs2_journal_access(handle,
762                                       alloc_inode,
763                                       group_bh,
764                                       journal_type);
765         if (status < 0) {
766                 mlog_errno(status);
767                 goto bail;
768         }
769
770         le16_add_cpu(&bg->bg_free_bits_count, -num_bits);
771
772         while(num_bits--)
773                 ocfs2_set_bit(bit_off++, bitmap);
774
775         status = ocfs2_journal_dirty(handle,
776                                      group_bh);
777         if (status < 0) {
778                 mlog_errno(status);
779                 goto bail;
780         }
781
782 bail:
783         mlog_exit(status);
784         return status;
785 }
786
787 /* find the one with the most empty bits */
788 static inline u16 ocfs2_find_victim_chain(struct ocfs2_chain_list *cl)
789 {
790         u16 curr, best;
791
792         BUG_ON(!cl->cl_next_free_rec);
793
794         best = curr = 0;
795         while (curr < le16_to_cpu(cl->cl_next_free_rec)) {
796                 if (le32_to_cpu(cl->cl_recs[curr].c_free) >
797                     le32_to_cpu(cl->cl_recs[best].c_free))
798                         best = curr;
799                 curr++;
800         }
801
802         BUG_ON(best >= le16_to_cpu(cl->cl_next_free_rec));
803         return best;
804 }
805
806 static int ocfs2_relink_block_group(handle_t *handle,
807                                     struct inode *alloc_inode,
808                                     struct buffer_head *fe_bh,
809                                     struct buffer_head *bg_bh,
810                                     struct buffer_head *prev_bg_bh,
811                                     u16 chain)
812 {
813         int status;
814         /* there is a really tiny chance the journal calls could fail,
815          * but we wouldn't want inconsistent blocks in *any* case. */
816         u64 fe_ptr, bg_ptr, prev_bg_ptr;
817         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) fe_bh->b_data;
818         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) bg_bh->b_data;
819         struct ocfs2_group_desc *prev_bg = (struct ocfs2_group_desc *) prev_bg_bh->b_data;
820
821         if (!OCFS2_IS_VALID_DINODE(fe)) {
822                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
823                 status = -EIO;
824                 goto out;
825         }
826         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
827                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
828                 status = -EIO;
829                 goto out;
830         }
831         if (!OCFS2_IS_VALID_GROUP_DESC(prev_bg)) {
832                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, prev_bg);
833                 status = -EIO;
834                 goto out;
835         }
836
837         mlog(0, "Suballoc %llu, chain %u, move group %llu to top, prev = %llu\n",
838              (unsigned long long)le64_to_cpu(fe->i_blkno), chain,
839              (unsigned long long)le64_to_cpu(bg->bg_blkno),
840              (unsigned long long)le64_to_cpu(prev_bg->bg_blkno));
841
842         fe_ptr = le64_to_cpu(fe->id2.i_chain.cl_recs[chain].c_blkno);
843         bg_ptr = le64_to_cpu(bg->bg_next_group);
844         prev_bg_ptr = le64_to_cpu(prev_bg->bg_next_group);
845
846         status = ocfs2_journal_access(handle, alloc_inode, prev_bg_bh,
847                                       OCFS2_JOURNAL_ACCESS_WRITE);
848         if (status < 0) {
849                 mlog_errno(status);
850                 goto out_rollback;
851         }
852
853         prev_bg->bg_next_group = bg->bg_next_group;
854
855         status = ocfs2_journal_dirty(handle, prev_bg_bh);
856         if (status < 0) {
857                 mlog_errno(status);
858                 goto out_rollback;
859         }
860
861         status = ocfs2_journal_access(handle, alloc_inode, bg_bh,
862                                       OCFS2_JOURNAL_ACCESS_WRITE);
863         if (status < 0) {
864                 mlog_errno(status);
865                 goto out_rollback;
866         }
867
868         bg->bg_next_group = fe->id2.i_chain.cl_recs[chain].c_blkno;
869
870         status = ocfs2_journal_dirty(handle, bg_bh);
871         if (status < 0) {
872                 mlog_errno(status);
873                 goto out_rollback;
874         }
875
876         status = ocfs2_journal_access(handle, alloc_inode, fe_bh,
877                                       OCFS2_JOURNAL_ACCESS_WRITE);
878         if (status < 0) {
879                 mlog_errno(status);
880                 goto out_rollback;
881         }
882
883         fe->id2.i_chain.cl_recs[chain].c_blkno = bg->bg_blkno;
884
885         status = ocfs2_journal_dirty(handle, fe_bh);
886         if (status < 0) {
887                 mlog_errno(status);
888                 goto out_rollback;
889         }
890
891         status = 0;
892 out_rollback:
893         if (status < 0) {
894                 fe->id2.i_chain.cl_recs[chain].c_blkno = cpu_to_le64(fe_ptr);
895                 bg->bg_next_group = cpu_to_le64(bg_ptr);
896                 prev_bg->bg_next_group = cpu_to_le64(prev_bg_ptr);
897         }
898 out:
899         mlog_exit(status);
900         return status;
901 }
902
903 static inline int ocfs2_block_group_reasonably_empty(struct ocfs2_group_desc *bg,
904                                                      u32 wanted)
905 {
906         return le16_to_cpu(bg->bg_free_bits_count) > wanted;
907 }
908
909 /* return 0 on success, -ENOSPC to keep searching and any other < 0
910  * value on error. */
911 static int ocfs2_cluster_group_search(struct inode *inode,
912                                       struct buffer_head *group_bh,
913                                       u32 bits_wanted, u32 min_bits,
914                                       u16 *bit_off, u16 *bits_found)
915 {
916         int search = -ENOSPC;
917         int ret;
918         struct ocfs2_group_desc *gd = (struct ocfs2_group_desc *) group_bh->b_data;
919         u16 tmp_off, tmp_found;
920         unsigned int max_bits, gd_cluster_off;
921
922         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
923
924         if (gd->bg_free_bits_count) {
925                 max_bits = le16_to_cpu(gd->bg_bits);
926
927                 /* Tail groups in cluster bitmaps which aren't cpg
928                  * aligned are prone to partial extention by a failed
929                  * fs resize. If the file system resize never got to
930                  * update the dinode cluster count, then we don't want
931                  * to trust any clusters past it, regardless of what
932                  * the group descriptor says. */
933                 gd_cluster_off = ocfs2_blocks_to_clusters(inode->i_sb,
934                                                           le64_to_cpu(gd->bg_blkno));
935                 if ((gd_cluster_off + max_bits) >
936                     OCFS2_I(inode)->ip_clusters) {
937                         max_bits = OCFS2_I(inode)->ip_clusters - gd_cluster_off;
938                         mlog(0, "Desc %llu, bg_bits %u, clusters %u, use %u\n",
939                              (unsigned long long)le64_to_cpu(gd->bg_blkno),
940                              le16_to_cpu(gd->bg_bits),
941                              OCFS2_I(inode)->ip_clusters, max_bits);
942                 }
943
944                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
945                                                         group_bh, bits_wanted,
946                                                         max_bits,
947                                                         &tmp_off, &tmp_found);
948                 if (ret)
949                         return ret;
950
951                 /* ocfs2_block_group_find_clear_bits() might
952                  * return success, but we still want to return
953                  * -ENOSPC unless it found the minimum number
954                  * of bits. */
955                 if (min_bits <= tmp_found) {
956                         *bit_off = tmp_off;
957                         *bits_found = tmp_found;
958                         search = 0; /* success */
959                 }
960         }
961
962         return search;
963 }
964
965 static int ocfs2_block_group_search(struct inode *inode,
966                                     struct buffer_head *group_bh,
967                                     u32 bits_wanted, u32 min_bits,
968                                     u16 *bit_off, u16 *bits_found)
969 {
970         int ret = -ENOSPC;
971         struct ocfs2_group_desc *bg = (struct ocfs2_group_desc *) group_bh->b_data;
972
973         BUG_ON(min_bits != 1);
974         BUG_ON(ocfs2_is_cluster_bitmap(inode));
975
976         if (bg->bg_free_bits_count)
977                 ret = ocfs2_block_group_find_clear_bits(OCFS2_SB(inode->i_sb),
978                                                         group_bh, bits_wanted,
979                                                         le16_to_cpu(bg->bg_bits),
980                                                         bit_off, bits_found);
981
982         return ret;
983 }
984
985 static int ocfs2_alloc_dinode_update_counts(struct inode *inode,
986                                        handle_t *handle,
987                                        struct buffer_head *di_bh,
988                                        u32 num_bits,
989                                        u16 chain)
990 {
991         int ret;
992         u32 tmp_used;
993         struct ocfs2_dinode *di = (struct ocfs2_dinode *) di_bh->b_data;
994         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &di->id2.i_chain;
995
996         ret = ocfs2_journal_access(handle, inode, di_bh,
997                                    OCFS2_JOURNAL_ACCESS_WRITE);
998         if (ret < 0) {
999                 mlog_errno(ret);
1000                 goto out;
1001         }
1002
1003         tmp_used = le32_to_cpu(di->id1.bitmap1.i_used);
1004         di->id1.bitmap1.i_used = cpu_to_le32(num_bits + tmp_used);
1005         le32_add_cpu(&cl->cl_recs[chain].c_free, -num_bits);
1006
1007         ret = ocfs2_journal_dirty(handle, di_bh);
1008         if (ret < 0)
1009                 mlog_errno(ret);
1010
1011 out:
1012         return ret;
1013 }
1014
1015 static int ocfs2_search_one_group(struct ocfs2_alloc_context *ac,
1016                                   handle_t *handle,
1017                                   u32 bits_wanted,
1018                                   u32 min_bits,
1019                                   u16 *bit_off,
1020                                   unsigned int *num_bits,
1021                                   u64 gd_blkno,
1022                                   u16 *bits_left)
1023 {
1024         int ret;
1025         u16 found;
1026         struct buffer_head *group_bh = NULL;
1027         struct ocfs2_group_desc *gd;
1028         struct inode *alloc_inode = ac->ac_inode;
1029
1030         ret = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb), gd_blkno,
1031                                &group_bh, OCFS2_BH_CACHED, alloc_inode);
1032         if (ret < 0) {
1033                 mlog_errno(ret);
1034                 return ret;
1035         }
1036
1037         gd = (struct ocfs2_group_desc *) group_bh->b_data;
1038         if (!OCFS2_IS_VALID_GROUP_DESC(gd)) {
1039                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, gd);
1040                 ret = -EIO;
1041                 goto out;
1042         }
1043
1044         ret = ac->ac_group_search(alloc_inode, group_bh, bits_wanted, min_bits,
1045                                   bit_off, &found);
1046         if (ret < 0) {
1047                 if (ret != -ENOSPC)
1048                         mlog_errno(ret);
1049                 goto out;
1050         }
1051
1052         *num_bits = found;
1053
1054         ret = ocfs2_alloc_dinode_update_counts(alloc_inode, handle, ac->ac_bh,
1055                                                *num_bits,
1056                                                le16_to_cpu(gd->bg_chain));
1057         if (ret < 0) {
1058                 mlog_errno(ret);
1059                 goto out;
1060         }
1061
1062         ret = ocfs2_block_group_set_bits(handle, alloc_inode, gd, group_bh,
1063                                          *bit_off, *num_bits);
1064         if (ret < 0)
1065                 mlog_errno(ret);
1066
1067         *bits_left = le16_to_cpu(gd->bg_free_bits_count);
1068
1069 out:
1070         brelse(group_bh);
1071
1072         return ret;
1073 }
1074
1075 static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
1076                               handle_t *handle,
1077                               u32 bits_wanted,
1078                               u32 min_bits,
1079                               u16 *bit_off,
1080                               unsigned int *num_bits,
1081                               u64 *bg_blkno,
1082                               u16 *bits_left)
1083 {
1084         int status;
1085         u16 chain, tmp_bits;
1086         u32 tmp_used;
1087         u64 next_group;
1088         struct inode *alloc_inode = ac->ac_inode;
1089         struct buffer_head *group_bh = NULL;
1090         struct buffer_head *prev_group_bh = NULL;
1091         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1092         struct ocfs2_chain_list *cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1093         struct ocfs2_group_desc *bg;
1094
1095         chain = ac->ac_chain;
1096         mlog(0, "trying to alloc %u bits from chain %u, inode %llu\n",
1097              bits_wanted, chain,
1098              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno);
1099
1100         status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1101                                   le64_to_cpu(cl->cl_recs[chain].c_blkno),
1102                                   &group_bh, OCFS2_BH_CACHED, alloc_inode);
1103         if (status < 0) {
1104                 mlog_errno(status);
1105                 goto bail;
1106         }
1107         bg = (struct ocfs2_group_desc *) group_bh->b_data;
1108         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1109         if (status) {
1110                 mlog_errno(status);
1111                 goto bail;
1112         }
1113
1114         status = -ENOSPC;
1115         /* for now, the chain search is a bit simplistic. We just use
1116          * the 1st group with any empty bits. */
1117         while ((status = ac->ac_group_search(alloc_inode, group_bh,
1118                                              bits_wanted, min_bits, bit_off,
1119                                              &tmp_bits)) == -ENOSPC) {
1120                 if (!bg->bg_next_group)
1121                         break;
1122
1123                 if (prev_group_bh) {
1124                         brelse(prev_group_bh);
1125                         prev_group_bh = NULL;
1126                 }
1127                 next_group = le64_to_cpu(bg->bg_next_group);
1128                 prev_group_bh = group_bh;
1129                 group_bh = NULL;
1130                 status = ocfs2_read_block(OCFS2_SB(alloc_inode->i_sb),
1131                                           next_group, &group_bh,
1132                                           OCFS2_BH_CACHED, alloc_inode);
1133                 if (status < 0) {
1134                         mlog_errno(status);
1135                         goto bail;
1136                 }
1137                 bg = (struct ocfs2_group_desc *) group_bh->b_data;
1138                 status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, bg);
1139                 if (status) {
1140                         mlog_errno(status);
1141                         goto bail;
1142                 }
1143         }
1144         if (status < 0) {
1145                 if (status != -ENOSPC)
1146                         mlog_errno(status);
1147                 goto bail;
1148         }
1149
1150         mlog(0, "alloc succeeds: we give %u bits from block group %llu\n",
1151              tmp_bits, (unsigned long long)le64_to_cpu(bg->bg_blkno));
1152
1153         *num_bits = tmp_bits;
1154
1155         BUG_ON(*num_bits == 0);
1156
1157         /*
1158          * Keep track of previous block descriptor read. When
1159          * we find a target, if we have read more than X
1160          * number of descriptors, and the target is reasonably
1161          * empty, relink him to top of his chain.
1162          *
1163          * We've read 0 extra blocks and only send one more to
1164          * the transaction, yet the next guy to search has a
1165          * much easier time.
1166          *
1167          * Do this *after* figuring out how many bits we're taking out
1168          * of our target group.
1169          */
1170         if (ac->ac_allow_chain_relink &&
1171             (prev_group_bh) &&
1172             (ocfs2_block_group_reasonably_empty(bg, *num_bits))) {
1173                 status = ocfs2_relink_block_group(handle, alloc_inode,
1174                                                   ac->ac_bh, group_bh,
1175                                                   prev_group_bh, chain);
1176                 if (status < 0) {
1177                         mlog_errno(status);
1178                         goto bail;
1179                 }
1180         }
1181
1182         /* Ok, claim our bits now: set the info on dinode, chainlist
1183          * and then the group */
1184         status = ocfs2_journal_access(handle,
1185                                       alloc_inode,
1186                                       ac->ac_bh,
1187                                       OCFS2_JOURNAL_ACCESS_WRITE);
1188         if (status < 0) {
1189                 mlog_errno(status);
1190                 goto bail;
1191         }
1192
1193         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1194         fe->id1.bitmap1.i_used = cpu_to_le32(*num_bits + tmp_used);
1195         le32_add_cpu(&cl->cl_recs[chain].c_free, -(*num_bits));
1196
1197         status = ocfs2_journal_dirty(handle,
1198                                      ac->ac_bh);
1199         if (status < 0) {
1200                 mlog_errno(status);
1201                 goto bail;
1202         }
1203
1204         status = ocfs2_block_group_set_bits(handle,
1205                                             alloc_inode,
1206                                             bg,
1207                                             group_bh,
1208                                             *bit_off,
1209                                             *num_bits);
1210         if (status < 0) {
1211                 mlog_errno(status);
1212                 goto bail;
1213         }
1214
1215         mlog(0, "Allocated %u bits from suballocator %llu\n", *num_bits,
1216              (unsigned long long)le64_to_cpu(fe->i_blkno));
1217
1218         *bg_blkno = le64_to_cpu(bg->bg_blkno);
1219         *bits_left = le16_to_cpu(bg->bg_free_bits_count);
1220 bail:
1221         if (group_bh)
1222                 brelse(group_bh);
1223         if (prev_group_bh)
1224                 brelse(prev_group_bh);
1225
1226         mlog_exit(status);
1227         return status;
1228 }
1229
1230 /* will give out up to bits_wanted contiguous bits. */
1231 static int ocfs2_claim_suballoc_bits(struct ocfs2_super *osb,
1232                                      struct ocfs2_alloc_context *ac,
1233                                      handle_t *handle,
1234                                      u32 bits_wanted,
1235                                      u32 min_bits,
1236                                      u16 *bit_off,
1237                                      unsigned int *num_bits,
1238                                      u64 *bg_blkno)
1239 {
1240         int status;
1241         u16 victim, i;
1242         u16 bits_left = 0;
1243         u64 hint_blkno = ac->ac_last_group;
1244         struct ocfs2_chain_list *cl;
1245         struct ocfs2_dinode *fe;
1246
1247         mlog_entry_void();
1248
1249         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1250         BUG_ON(bits_wanted > (ac->ac_bits_wanted - ac->ac_bits_given));
1251         BUG_ON(!ac->ac_bh);
1252
1253         fe = (struct ocfs2_dinode *) ac->ac_bh->b_data;
1254         if (!OCFS2_IS_VALID_DINODE(fe)) {
1255                 OCFS2_RO_ON_INVALID_DINODE(osb->sb, fe);
1256                 status = -EIO;
1257                 goto bail;
1258         }
1259         if (le32_to_cpu(fe->id1.bitmap1.i_used) >=
1260             le32_to_cpu(fe->id1.bitmap1.i_total)) {
1261                 ocfs2_error(osb->sb, "Chain allocator dinode %llu has %u used "
1262                             "bits but only %u total.",
1263                             (unsigned long long)le64_to_cpu(fe->i_blkno),
1264                             le32_to_cpu(fe->id1.bitmap1.i_used),
1265                             le32_to_cpu(fe->id1.bitmap1.i_total));
1266                 status = -EIO;
1267                 goto bail;
1268         }
1269
1270         if (hint_blkno) {
1271                 /* Attempt to short-circuit the usual search mechanism
1272                  * by jumping straight to the most recently used
1273                  * allocation group. This helps us mantain some
1274                  * contiguousness across allocations. */
1275                 status = ocfs2_search_one_group(ac, handle, bits_wanted,
1276                                                 min_bits, bit_off, num_bits,
1277                                                 hint_blkno, &bits_left);
1278                 if (!status) {
1279                         /* Be careful to update *bg_blkno here as the
1280                          * caller is expecting it to be filled in, and
1281                          * ocfs2_search_one_group() won't do that for
1282                          * us. */
1283                         *bg_blkno = hint_blkno;
1284                         goto set_hint;
1285                 }
1286                 if (status < 0 && status != -ENOSPC) {
1287                         mlog_errno(status);
1288                         goto bail;
1289                 }
1290         }
1291
1292         cl = (struct ocfs2_chain_list *) &fe->id2.i_chain;
1293
1294         victim = ocfs2_find_victim_chain(cl);
1295         ac->ac_chain = victim;
1296         ac->ac_allow_chain_relink = 1;
1297
1298         status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits, bit_off,
1299                                     num_bits, bg_blkno, &bits_left);
1300         if (!status)
1301                 goto set_hint;
1302         if (status < 0 && status != -ENOSPC) {
1303                 mlog_errno(status);
1304                 goto bail;
1305         }
1306
1307         mlog(0, "Search of victim chain %u came up with nothing, "
1308              "trying all chains now.\n", victim);
1309
1310         /* If we didn't pick a good victim, then just default to
1311          * searching each chain in order. Don't allow chain relinking
1312          * because we only calculate enough journal credits for one
1313          * relink per alloc. */
1314         ac->ac_allow_chain_relink = 0;
1315         for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
1316                 if (i == victim)
1317                         continue;
1318                 if (!cl->cl_recs[i].c_free)
1319                         continue;
1320
1321                 ac->ac_chain = i;
1322                 status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
1323                                             bit_off, num_bits, bg_blkno,
1324                                             &bits_left);
1325                 if (!status)
1326                         break;
1327                 if (status < 0 && status != -ENOSPC) {
1328                         mlog_errno(status);
1329                         goto bail;
1330                 }
1331         }
1332
1333 set_hint:
1334         if (status != -ENOSPC) {
1335                 /* If the next search of this group is not likely to
1336                  * yield a suitable extent, then we reset the last
1337                  * group hint so as to not waste a disk read */
1338                 if (bits_left < min_bits)
1339                         ac->ac_last_group = 0;
1340                 else
1341                         ac->ac_last_group = *bg_blkno;
1342         }
1343
1344 bail:
1345         mlog_exit(status);
1346         return status;
1347 }
1348
1349 int ocfs2_claim_metadata(struct ocfs2_super *osb,
1350                          handle_t *handle,
1351                          struct ocfs2_alloc_context *ac,
1352                          u32 bits_wanted,
1353                          u16 *suballoc_bit_start,
1354                          unsigned int *num_bits,
1355                          u64 *blkno_start)
1356 {
1357         int status;
1358         u64 bg_blkno;
1359
1360         BUG_ON(!ac);
1361         BUG_ON(ac->ac_bits_wanted < (ac->ac_bits_given + bits_wanted));
1362         BUG_ON(ac->ac_which != OCFS2_AC_USE_META);
1363
1364         status = ocfs2_claim_suballoc_bits(osb,
1365                                            ac,
1366                                            handle,
1367                                            bits_wanted,
1368                                            1,
1369                                            suballoc_bit_start,
1370                                            num_bits,
1371                                            &bg_blkno);
1372         if (status < 0) {
1373                 mlog_errno(status);
1374                 goto bail;
1375         }
1376         atomic_inc(&osb->alloc_stats.bg_allocs);
1377
1378         *blkno_start = bg_blkno + (u64) *suballoc_bit_start;
1379         ac->ac_bits_given += (*num_bits);
1380         status = 0;
1381 bail:
1382         mlog_exit(status);
1383         return status;
1384 }
1385
1386 int ocfs2_claim_new_inode(struct ocfs2_super *osb,
1387                           handle_t *handle,
1388                           struct ocfs2_alloc_context *ac,
1389                           u16 *suballoc_bit,
1390                           u64 *fe_blkno)
1391 {
1392         int status;
1393         unsigned int num_bits;
1394         u64 bg_blkno;
1395
1396         mlog_entry_void();
1397
1398         BUG_ON(!ac);
1399         BUG_ON(ac->ac_bits_given != 0);
1400         BUG_ON(ac->ac_bits_wanted != 1);
1401         BUG_ON(ac->ac_which != OCFS2_AC_USE_INODE);
1402
1403         status = ocfs2_claim_suballoc_bits(osb,
1404                                            ac,
1405                                            handle,
1406                                            1,
1407                                            1,
1408                                            suballoc_bit,
1409                                            &num_bits,
1410                                            &bg_blkno);
1411         if (status < 0) {
1412                 mlog_errno(status);
1413                 goto bail;
1414         }
1415         atomic_inc(&osb->alloc_stats.bg_allocs);
1416
1417         BUG_ON(num_bits != 1);
1418
1419         *fe_blkno = bg_blkno + (u64) (*suballoc_bit);
1420         ac->ac_bits_given++;
1421         status = 0;
1422 bail:
1423         mlog_exit(status);
1424         return status;
1425 }
1426
1427 /* translate a group desc. blkno and it's bitmap offset into
1428  * disk cluster offset. */
1429 static inline u32 ocfs2_desc_bitmap_to_cluster_off(struct inode *inode,
1430                                                    u64 bg_blkno,
1431                                                    u16 bg_bit_off)
1432 {
1433         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1434         u32 cluster = 0;
1435
1436         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1437
1438         if (bg_blkno != osb->first_cluster_group_blkno)
1439                 cluster = ocfs2_blocks_to_clusters(inode->i_sb, bg_blkno);
1440         cluster += (u32) bg_bit_off;
1441         return cluster;
1442 }
1443
1444 /* given a cluster offset, calculate which block group it belongs to
1445  * and return that block offset. */
1446 static inline u64 ocfs2_which_cluster_group(struct inode *inode,
1447                                             u32 cluster)
1448 {
1449         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1450         u32 group_no;
1451
1452         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1453
1454         group_no = cluster / osb->bitmap_cpg;
1455         if (!group_no)
1456                 return osb->first_cluster_group_blkno;
1457         return ocfs2_clusters_to_blocks(inode->i_sb,
1458                                         group_no * osb->bitmap_cpg);
1459 }
1460
1461 /* given the block number of a cluster start, calculate which cluster
1462  * group and descriptor bitmap offset that corresponds to. */
1463 static inline void ocfs2_block_to_cluster_group(struct inode *inode,
1464                                                 u64 data_blkno,
1465                                                 u64 *bg_blkno,
1466                                                 u16 *bg_bit_off)
1467 {
1468         struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
1469         u32 data_cluster = ocfs2_blocks_to_clusters(osb->sb, data_blkno);
1470
1471         BUG_ON(!ocfs2_is_cluster_bitmap(inode));
1472
1473         *bg_blkno = ocfs2_which_cluster_group(inode,
1474                                               data_cluster);
1475
1476         if (*bg_blkno == osb->first_cluster_group_blkno)
1477                 *bg_bit_off = (u16) data_cluster;
1478         else
1479                 *bg_bit_off = (u16) ocfs2_blocks_to_clusters(osb->sb,
1480                                                              data_blkno - *bg_blkno);
1481 }
1482
1483 /*
1484  * min_bits - minimum contiguous chunk from this total allocation we
1485  * can handle. set to what we asked for originally for a full
1486  * contig. allocation, set to '1' to indicate we can deal with extents
1487  * of any size.
1488  */
1489 int __ocfs2_claim_clusters(struct ocfs2_super *osb,
1490                            handle_t *handle,
1491                            struct ocfs2_alloc_context *ac,
1492                            u32 min_clusters,
1493                            u32 max_clusters,
1494                            u32 *cluster_start,
1495                            u32 *num_clusters)
1496 {
1497         int status;
1498         unsigned int bits_wanted = max_clusters;
1499         u64 bg_blkno = 0;
1500         u16 bg_bit_off;
1501
1502         mlog_entry_void();
1503
1504         BUG_ON(ac->ac_bits_given >= ac->ac_bits_wanted);
1505
1506         BUG_ON(ac->ac_which != OCFS2_AC_USE_LOCAL
1507                && ac->ac_which != OCFS2_AC_USE_MAIN);
1508
1509         if (ac->ac_which == OCFS2_AC_USE_LOCAL) {
1510                 status = ocfs2_claim_local_alloc_bits(osb,
1511                                                       handle,
1512                                                       ac,
1513                                                       bits_wanted,
1514                                                       cluster_start,
1515                                                       num_clusters);
1516                 if (!status)
1517                         atomic_inc(&osb->alloc_stats.local_data);
1518         } else {
1519                 if (min_clusters > (osb->bitmap_cpg - 1)) {
1520                         /* The only paths asking for contiguousness
1521                          * should know about this already. */
1522                         mlog(ML_ERROR, "minimum allocation requested exceeds "
1523                                        "group bitmap size!");
1524                         status = -ENOSPC;
1525                         goto bail;
1526                 }
1527                 /* clamp the current request down to a realistic size. */
1528                 if (bits_wanted > (osb->bitmap_cpg - 1))
1529                         bits_wanted = osb->bitmap_cpg - 1;
1530
1531                 status = ocfs2_claim_suballoc_bits(osb,
1532                                                    ac,
1533                                                    handle,
1534                                                    bits_wanted,
1535                                                    min_clusters,
1536                                                    &bg_bit_off,
1537                                                    num_clusters,
1538                                                    &bg_blkno);
1539                 if (!status) {
1540                         *cluster_start =
1541                                 ocfs2_desc_bitmap_to_cluster_off(ac->ac_inode,
1542                                                                  bg_blkno,
1543                                                                  bg_bit_off);
1544                         atomic_inc(&osb->alloc_stats.bitmap_data);
1545                 }
1546         }
1547         if (status < 0) {
1548                 if (status != -ENOSPC)
1549                         mlog_errno(status);
1550                 goto bail;
1551         }
1552
1553         ac->ac_bits_given += *num_clusters;
1554
1555 bail:
1556         mlog_exit(status);
1557         return status;
1558 }
1559
1560 int ocfs2_claim_clusters(struct ocfs2_super *osb,
1561                          handle_t *handle,
1562                          struct ocfs2_alloc_context *ac,
1563                          u32 min_clusters,
1564                          u32 *cluster_start,
1565                          u32 *num_clusters)
1566 {
1567         unsigned int bits_wanted = ac->ac_bits_wanted - ac->ac_bits_given;
1568
1569         return __ocfs2_claim_clusters(osb, handle, ac, min_clusters,
1570                                       bits_wanted, cluster_start, num_clusters);
1571 }
1572
1573 static inline int ocfs2_block_group_clear_bits(handle_t *handle,
1574                                                struct inode *alloc_inode,
1575                                                struct ocfs2_group_desc *bg,
1576                                                struct buffer_head *group_bh,
1577                                                unsigned int bit_off,
1578                                                unsigned int num_bits)
1579 {
1580         int status;
1581         unsigned int tmp;
1582         int journal_type = OCFS2_JOURNAL_ACCESS_WRITE;
1583         struct ocfs2_group_desc *undo_bg = NULL;
1584
1585         mlog_entry_void();
1586
1587         if (!OCFS2_IS_VALID_GROUP_DESC(bg)) {
1588                 OCFS2_RO_ON_INVALID_GROUP_DESC(alloc_inode->i_sb, bg);
1589                 status = -EIO;
1590                 goto bail;
1591         }
1592
1593         mlog(0, "off = %u, num = %u\n", bit_off, num_bits);
1594
1595         if (ocfs2_is_cluster_bitmap(alloc_inode))
1596                 journal_type = OCFS2_JOURNAL_ACCESS_UNDO;
1597
1598         status = ocfs2_journal_access(handle, alloc_inode, group_bh,
1599                                       journal_type);
1600         if (status < 0) {
1601                 mlog_errno(status);
1602                 goto bail;
1603         }
1604
1605         if (ocfs2_is_cluster_bitmap(alloc_inode))
1606                 undo_bg = (struct ocfs2_group_desc *) bh2jh(group_bh)->b_committed_data;
1607
1608         tmp = num_bits;
1609         while(tmp--) {
1610                 ocfs2_clear_bit((bit_off + tmp),
1611                                 (unsigned long *) bg->bg_bitmap);
1612                 if (ocfs2_is_cluster_bitmap(alloc_inode))
1613                         ocfs2_set_bit(bit_off + tmp,
1614                                       (unsigned long *) undo_bg->bg_bitmap);
1615         }
1616         le16_add_cpu(&bg->bg_free_bits_count, num_bits);
1617
1618         status = ocfs2_journal_dirty(handle, group_bh);
1619         if (status < 0)
1620                 mlog_errno(status);
1621 bail:
1622         return status;
1623 }
1624
1625 /*
1626  * expects the suballoc inode to already be locked.
1627  */
1628 int ocfs2_free_suballoc_bits(handle_t *handle,
1629                              struct inode *alloc_inode,
1630                              struct buffer_head *alloc_bh,
1631                              unsigned int start_bit,
1632                              u64 bg_blkno,
1633                              unsigned int count)
1634 {
1635         int status = 0;
1636         u32 tmp_used;
1637         struct ocfs2_super *osb = OCFS2_SB(alloc_inode->i_sb);
1638         struct ocfs2_dinode *fe = (struct ocfs2_dinode *) alloc_bh->b_data;
1639         struct ocfs2_chain_list *cl = &fe->id2.i_chain;
1640         struct buffer_head *group_bh = NULL;
1641         struct ocfs2_group_desc *group;
1642
1643         mlog_entry_void();
1644
1645         if (!OCFS2_IS_VALID_DINODE(fe)) {
1646                 OCFS2_RO_ON_INVALID_DINODE(alloc_inode->i_sb, fe);
1647                 status = -EIO;
1648                 goto bail;
1649         }
1650         BUG_ON((count + start_bit) > ocfs2_bits_per_group(cl));
1651
1652         mlog(0, "%llu: freeing %u bits from group %llu, starting at %u\n",
1653              (unsigned long long)OCFS2_I(alloc_inode)->ip_blkno, count,
1654              (unsigned long long)bg_blkno, start_bit);
1655
1656         status = ocfs2_read_block(osb, bg_blkno, &group_bh, OCFS2_BH_CACHED,
1657                                   alloc_inode);
1658         if (status < 0) {
1659                 mlog_errno(status);
1660                 goto bail;
1661         }
1662
1663         group = (struct ocfs2_group_desc *) group_bh->b_data;
1664         status = ocfs2_check_group_descriptor(alloc_inode->i_sb, fe, group);
1665         if (status) {
1666                 mlog_errno(status);
1667                 goto bail;
1668         }
1669         BUG_ON((count + start_bit) > le16_to_cpu(group->bg_bits));
1670
1671         status = ocfs2_block_group_clear_bits(handle, alloc_inode,
1672                                               group, group_bh,
1673                                               start_bit, count);
1674         if (status < 0) {
1675                 mlog_errno(status);
1676                 goto bail;
1677         }
1678
1679         status = ocfs2_journal_access(handle, alloc_inode, alloc_bh,
1680                                       OCFS2_JOURNAL_ACCESS_WRITE);
1681         if (status < 0) {
1682                 mlog_errno(status);
1683                 goto bail;
1684         }
1685
1686         le32_add_cpu(&cl->cl_recs[le16_to_cpu(group->bg_chain)].c_free,
1687                      count);
1688         tmp_used = le32_to_cpu(fe->id1.bitmap1.i_used);
1689         fe->id1.bitmap1.i_used = cpu_to_le32(tmp_used - count);
1690
1691         status = ocfs2_journal_dirty(handle, alloc_bh);
1692         if (status < 0) {
1693                 mlog_errno(status);
1694                 goto bail;
1695         }
1696
1697 bail:
1698         if (group_bh)
1699                 brelse(group_bh);
1700
1701         mlog_exit(status);
1702         return status;
1703 }
1704
1705 int ocfs2_free_dinode(handle_t *handle,
1706                       struct inode *inode_alloc_inode,
1707                       struct buffer_head *inode_alloc_bh,
1708                       struct ocfs2_dinode *di)
1709 {
1710         u64 blk = le64_to_cpu(di->i_blkno);
1711         u16 bit = le16_to_cpu(di->i_suballoc_bit);
1712         u64 bg_blkno = ocfs2_which_suballoc_group(blk, bit);
1713
1714         return ocfs2_free_suballoc_bits(handle, inode_alloc_inode,
1715                                         inode_alloc_bh, bit, bg_blkno, 1);
1716 }
1717
1718 int ocfs2_free_clusters(handle_t *handle,
1719                        struct inode *bitmap_inode,
1720                        struct buffer_head *bitmap_bh,
1721                        u64 start_blk,
1722                        unsigned int num_clusters)
1723 {
1724         int status;
1725         u16 bg_start_bit;
1726         u64 bg_blkno;
1727         struct ocfs2_dinode *fe;
1728
1729         /* You can't ever have a contiguous set of clusters
1730          * bigger than a block group bitmap so we never have to worry
1731          * about looping on them. */
1732
1733         mlog_entry_void();
1734
1735         /* This is expensive. We can safely remove once this stuff has
1736          * gotten tested really well. */
1737         BUG_ON(start_blk != ocfs2_clusters_to_blocks(bitmap_inode->i_sb, ocfs2_blocks_to_clusters(bitmap_inode->i_sb, start_blk)));
1738
1739         fe = (struct ocfs2_dinode *) bitmap_bh->b_data;
1740
1741         ocfs2_block_to_cluster_group(bitmap_inode, start_blk, &bg_blkno,
1742                                      &bg_start_bit);
1743
1744         mlog(0, "want to free %u clusters starting at block %llu\n",
1745              num_clusters, (unsigned long long)start_blk);
1746         mlog(0, "bg_blkno = %llu, bg_start_bit = %u\n",
1747              (unsigned long long)bg_blkno, bg_start_bit);
1748
1749         status = ocfs2_free_suballoc_bits(handle, bitmap_inode, bitmap_bh,
1750                                           bg_start_bit, bg_blkno,
1751                                           num_clusters);
1752         if (status < 0)
1753                 mlog_errno(status);
1754
1755         mlog_exit(status);
1756         return status;
1757 }
1758
1759 static inline void ocfs2_debug_bg(struct ocfs2_group_desc *bg)
1760 {
1761         printk("Block Group:\n");
1762         printk("bg_signature:       %s\n", bg->bg_signature);
1763         printk("bg_size:            %u\n", bg->bg_size);
1764         printk("bg_bits:            %u\n", bg->bg_bits);
1765         printk("bg_free_bits_count: %u\n", bg->bg_free_bits_count);
1766         printk("bg_chain:           %u\n", bg->bg_chain);
1767         printk("bg_generation:      %u\n", le32_to_cpu(bg->bg_generation));
1768         printk("bg_next_group:      %llu\n",
1769                (unsigned long long)bg->bg_next_group);
1770         printk("bg_parent_dinode:   %llu\n",
1771                (unsigned long long)bg->bg_parent_dinode);
1772         printk("bg_blkno:           %llu\n",
1773                (unsigned long long)bg->bg_blkno);
1774 }
1775
1776 static inline void ocfs2_debug_suballoc_inode(struct ocfs2_dinode *fe)
1777 {
1778         int i;
1779
1780         printk("Suballoc Inode %llu:\n", (unsigned long long)fe->i_blkno);
1781         printk("i_signature:                  %s\n", fe->i_signature);
1782         printk("i_size:                       %llu\n",
1783                (unsigned long long)fe->i_size);
1784         printk("i_clusters:                   %u\n", fe->i_clusters);
1785         printk("i_generation:                 %u\n",
1786                le32_to_cpu(fe->i_generation));
1787         printk("id1.bitmap1.i_used:           %u\n",
1788                le32_to_cpu(fe->id1.bitmap1.i_used));
1789         printk("id1.bitmap1.i_total:          %u\n",
1790                le32_to_cpu(fe->id1.bitmap1.i_total));
1791         printk("id2.i_chain.cl_cpg:           %u\n", fe->id2.i_chain.cl_cpg);
1792         printk("id2.i_chain.cl_bpc:           %u\n", fe->id2.i_chain.cl_bpc);
1793         printk("id2.i_chain.cl_count:         %u\n", fe->id2.i_chain.cl_count);
1794         printk("id2.i_chain.cl_next_free_rec: %u\n",
1795                fe->id2.i_chain.cl_next_free_rec);
1796         for(i = 0; i < fe->id2.i_chain.cl_next_free_rec; i++) {
1797                 printk("fe->id2.i_chain.cl_recs[%d].c_free:  %u\n", i,
1798                        fe->id2.i_chain.cl_recs[i].c_free);
1799                 printk("fe->id2.i_chain.cl_recs[%d].c_total: %u\n", i,
1800                        fe->id2.i_chain.cl_recs[i].c_total);
1801                 printk("fe->id2.i_chain.cl_recs[%d].c_blkno: %llu\n", i,
1802                        (unsigned long long)fe->id2.i_chain.cl_recs[i].c_blkno);
1803         }
1804 }