02d31e35f0cab822246967fad74cbc063fea8cd0
[safe/jmp/linux-2.6] / fs / gfs2 / log.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2005 Red Hat, Inc.  All rights reserved.
4  *
5  * This copyrighted material is made available to anyone wishing to use,
6  * modify, copy, or redistribute it subject to the terms and conditions
7  * of the GNU General Public License v.2.
8  */
9
10 #include <linux/sched.h>
11 #include <linux/slab.h>
12 #include <linux/spinlock.h>
13 #include <linux/completion.h>
14 #include <linux/buffer_head.h>
15 #include <linux/gfs2_ondisk.h>
16 #include <linux/crc32.h>
17 #include <asm/semaphore.h>
18
19 #include "gfs2.h"
20 #include "lm_interface.h"
21 #include "incore.h"
22 #include "bmap.h"
23 #include "glock.h"
24 #include "log.h"
25 #include "lops.h"
26 #include "meta_io.h"
27 #include "util.h"
28 #include "dir.h"
29
30 #define PULL 1
31
32 /**
33  * gfs2_struct2blk - compute stuff
34  * @sdp: the filesystem
35  * @nstruct: the number of structures
36  * @ssize: the size of the structures
37  *
38  * Compute the number of log descriptor blocks needed to hold a certain number
39  * of structures of a certain size.
40  *
41  * Returns: the number of blocks needed (minimum is always 1)
42  */
43
44 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
45                              unsigned int ssize)
46 {
47         unsigned int blks;
48         unsigned int first, second;
49
50         blks = 1;
51         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) /
52                 ssize;
53
54         if (nstruct > first) {
55                 second = (sdp->sd_sb.sb_bsize -
56                           sizeof(struct gfs2_meta_header)) / ssize;
57                 blks += DIV_ROUND_UP(nstruct - first, second);
58         }
59
60         return blks;
61 }
62
63 void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags)
64 {
65         struct list_head *head = &sdp->sd_ail1_list;
66         uint64_t sync_gen;
67         struct list_head *first, *tmp;
68         struct gfs2_ail *first_ai, *ai;
69
70         gfs2_log_lock(sdp);
71         if (list_empty(head)) {
72                 gfs2_log_unlock(sdp);
73                 return;
74         }
75         sync_gen = sdp->sd_ail_sync_gen++;
76
77         first = head->prev;
78         first_ai = list_entry(first, struct gfs2_ail, ai_list);
79         first_ai->ai_sync_gen = sync_gen;
80         gfs2_ail1_start_one(sdp, first_ai);
81
82         if (flags & DIO_ALL)
83                 first = NULL;
84
85         for (;;) {
86                 if (first && (head->prev != first ||
87                               gfs2_ail1_empty_one(sdp, first_ai, 0)))
88                         break;
89
90                 for (tmp = head->prev; tmp != head; tmp = tmp->prev) {
91                         ai = list_entry(tmp, struct gfs2_ail, ai_list);
92                         if (ai->ai_sync_gen >= sync_gen)
93                                 continue;
94                         ai->ai_sync_gen = sync_gen;
95                         gfs2_ail1_start_one(sdp, ai);
96                         break;
97                 }
98
99                 if (tmp == head)
100                         break;
101         }
102
103         gfs2_log_unlock(sdp);
104 }
105
106 int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
107 {
108         struct gfs2_ail *ai, *s;
109         int ret;
110
111         gfs2_log_lock(sdp);
112
113         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
114                 if (gfs2_ail1_empty_one(sdp, ai, flags))
115                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
116                 else if (!(flags & DIO_ALL))
117                         break;
118         }
119
120         ret = list_empty(&sdp->sd_ail1_list);
121
122         gfs2_log_unlock(sdp);
123
124         return ret;
125 }
126
127 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
128 {
129         struct gfs2_ail *ai, *safe;
130         unsigned int old_tail = sdp->sd_log_tail;
131         int wrap = (new_tail < old_tail);
132         int a, b, rm;
133
134         gfs2_log_lock(sdp);
135
136         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
137                 a = (old_tail <= ai->ai_first);
138                 b = (ai->ai_first < new_tail);
139                 rm = (wrap) ? (a || b) : (a && b);
140                 if (!rm)
141                         continue;
142
143                 gfs2_ail2_empty_one(sdp, ai);
144                 list_del(&ai->ai_list);
145                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
146                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
147                 kfree(ai);
148         }
149
150         gfs2_log_unlock(sdp);
151 }
152
153 /**
154  * gfs2_log_reserve - Make a log reservation
155  * @sdp: The GFS2 superblock
156  * @blks: The number of blocks to reserve
157  *
158  * Returns: errno
159  */
160
161 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
162 {
163         unsigned int try = 0;
164
165         if (gfs2_assert_warn(sdp, blks) ||
166             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
167                 return -EINVAL;
168
169         mutex_lock(&sdp->sd_log_reserve_mutex);
170         gfs2_log_lock(sdp);
171         while(sdp->sd_log_blks_free <= blks) {
172                 gfs2_log_unlock(sdp);
173                 gfs2_ail1_empty(sdp, 0);
174                 gfs2_log_flush(sdp, NULL);
175
176                 if (try++)
177                         gfs2_ail1_start(sdp, 0);
178                 gfs2_log_lock(sdp);
179         }
180         sdp->sd_log_blks_free -= blks;
181         /* printk(KERN_INFO "reserved %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
182         gfs2_log_unlock(sdp);
183         mutex_unlock(&sdp->sd_log_reserve_mutex);
184
185         down_read(&sdp->sd_log_flush_lock);
186
187         return 0;
188 }
189
190 /**
191  * gfs2_log_release - Release a given number of log blocks
192  * @sdp: The GFS2 superblock
193  * @blks: The number of blocks
194  *
195  */
196
197 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
198 {
199
200         gfs2_log_lock(sdp);
201         sdp->sd_log_blks_free += blks;
202         /* printk(KERN_INFO "released %u blocks (%u left)\n", blks, sdp->sd_log_blks_free); */
203         gfs2_assert_withdraw(sdp,
204                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
205         gfs2_log_unlock(sdp);
206         up_read(&sdp->sd_log_flush_lock);
207 }
208
209 static uint64_t log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
210 {
211         int new = 0;
212         uint64_t dbn;
213         int error;
214         int bdy;
215
216         error = gfs2_block_map(sdp->sd_jdesc->jd_inode, lbn, &new, &dbn, &bdy);
217         gfs2_assert_withdraw(sdp, !error && dbn);
218
219         return dbn;
220 }
221
222 /**
223  * log_distance - Compute distance between two journal blocks
224  * @sdp: The GFS2 superblock
225  * @newer: The most recent journal block of the pair
226  * @older: The older journal block of the pair
227  *
228  *   Compute the distance (in the journal direction) between two
229  *   blocks in the journal
230  *
231  * Returns: the distance in blocks
232  */
233
234 static inline unsigned int log_distance(struct gfs2_sbd *sdp,
235                                         unsigned int newer,
236                                         unsigned int older)
237 {
238         int dist;
239
240         dist = newer - older;
241         if (dist < 0)
242                 dist += sdp->sd_jdesc->jd_blocks;
243
244         return dist;
245 }
246
247 static unsigned int current_tail(struct gfs2_sbd *sdp)
248 {
249         struct gfs2_ail *ai;
250         unsigned int tail;
251
252         gfs2_log_lock(sdp);
253
254         if (list_empty(&sdp->sd_ail1_list))
255                 tail = sdp->sd_log_head;
256         else {
257                 ai = list_entry(sdp->sd_ail1_list.prev,
258                                 struct gfs2_ail, ai_list);
259                 tail = ai->ai_first;
260         }
261
262         gfs2_log_unlock(sdp);
263
264         return tail;
265 }
266
267 static inline void log_incr_head(struct gfs2_sbd *sdp)
268 {
269         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
270                 gfs2_assert_withdraw(sdp,
271                                 sdp->sd_log_flush_head == sdp->sd_log_head);
272
273         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
274                 sdp->sd_log_flush_head = 0;
275                 sdp->sd_log_flush_wrapped = 1;
276         }
277 }
278
279 /**
280  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
281  * @sdp: The GFS2 superblock
282  *
283  * Returns: the buffer_head
284  */
285
286 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
287 {
288         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
289         struct gfs2_log_buf *lb;
290         struct buffer_head *bh;
291
292         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
293         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
294
295         bh = lb->lb_bh = sb_getblk(sdp->sd_vfs, blkno);
296         lock_buffer(bh);
297         memset(bh->b_data, 0, bh->b_size);
298         set_buffer_uptodate(bh);
299         clear_buffer_dirty(bh);
300         unlock_buffer(bh);
301
302         log_incr_head(sdp);
303
304         return bh;
305 }
306
307 /**
308  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
309  * @sdp: the filesystem
310  * @data: the data the buffer_head should point to
311  *
312  * Returns: the log buffer descriptor
313  */
314
315 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
316                                       struct buffer_head *real)
317 {
318         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
319         struct gfs2_log_buf *lb;
320         struct buffer_head *bh;
321
322         lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_NOFS | __GFP_NOFAIL);
323         list_add(&lb->lb_list, &sdp->sd_log_flush_list);
324         lb->lb_real = real;
325
326         bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
327         atomic_set(&bh->b_count, 1);
328         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate);
329         set_bh_page(bh, real->b_page, bh_offset(real));
330         bh->b_blocknr = blkno;
331         bh->b_size = sdp->sd_sb.sb_bsize;
332         bh->b_bdev = sdp->sd_vfs->s_bdev;
333
334         log_incr_head(sdp);
335
336         return bh;
337 }
338
339 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull)
340 {
341         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
342
343         ail2_empty(sdp, new_tail);
344
345         gfs2_log_lock(sdp);
346         sdp->sd_log_blks_free += dist - ((pull) ? 1 : 0);
347         /* printk(KERN_INFO "pull tail refunding %u blocks (%u left) pull=%d\n", dist - ((pull) ? 1 : 0), sdp->sd_log_blks_free, pull); */
348         gfs2_assert_withdraw(sdp,
349                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks);
350         gfs2_log_unlock(sdp);
351
352         sdp->sd_log_tail = new_tail;
353 }
354
355 /**
356  * log_write_header - Get and initialize a journal header buffer
357  * @sdp: The GFS2 superblock
358  *
359  * Returns: the initialized log buffer descriptor
360  */
361
362 static void log_write_header(struct gfs2_sbd *sdp, uint32_t flags, int pull)
363 {
364         uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head);
365         struct buffer_head *bh;
366         struct gfs2_log_header *lh;
367         unsigned int tail;
368         uint32_t hash;
369
370         /* printk(KERN_INFO "log write header start (flags=%08x, pull=%d)\n", flags, pull); */
371
372         bh = sb_getblk(sdp->sd_vfs, blkno);
373         lock_buffer(bh);
374         memset(bh->b_data, 0, bh->b_size);
375         set_buffer_uptodate(bh);
376         clear_buffer_dirty(bh);
377         unlock_buffer(bh);
378
379         gfs2_ail1_empty(sdp, 0);
380         tail = current_tail(sdp);
381
382         lh = (struct gfs2_log_header *)bh->b_data;
383         memset(lh, 0, sizeof(struct gfs2_log_header));
384         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
385         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
386         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
387         lh->lh_sequence = be64_to_cpu(sdp->sd_log_sequence++);
388         lh->lh_flags = be32_to_cpu(flags);
389         lh->lh_tail = be32_to_cpu(tail);
390         lh->lh_blkno = be32_to_cpu(sdp->sd_log_flush_head);
391         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
392         lh->lh_hash = cpu_to_be32(hash);
393
394         set_buffer_dirty(bh);
395         if (sync_dirty_buffer(bh))
396                 gfs2_io_error_bh(sdp, bh);
397         brelse(bh);
398
399         if (sdp->sd_log_tail != tail)
400                 log_pull_tail(sdp, tail, pull);
401         else
402                 gfs2_assert_withdraw(sdp, !pull);
403
404         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
405         log_incr_head(sdp);
406
407         /* printk(KERN_INFO "log write header out\n"); */
408 }
409
410 static void log_flush_commit(struct gfs2_sbd *sdp)
411 {
412         struct list_head *head = &sdp->sd_log_flush_list;
413         struct gfs2_log_buf *lb;
414         struct buffer_head *bh;
415 #if 0
416         unsigned int d;
417
418         d = log_distance(sdp, sdp->sd_log_flush_head, sdp->sd_log_head);
419
420         gfs2_assert_withdraw(sdp, d + 1 == sdp->sd_log_blks_reserved);
421 #endif
422
423         while (!list_empty(head)) {
424                 lb = list_entry(head->next, struct gfs2_log_buf, lb_list);
425                 list_del(&lb->lb_list);
426                 bh = lb->lb_bh;
427
428                 wait_on_buffer(bh);
429                 if (!buffer_uptodate(bh))
430                         gfs2_io_error_bh(sdp, bh);
431                 if (lb->lb_real) {
432                         while (atomic_read(&bh->b_count) != 1)  /* Grrrr... */
433                                 schedule();
434                         free_buffer_head(bh);
435                 } else
436                         brelse(bh);
437                 kfree(lb);
438         }
439
440         log_write_header(sdp, 0, 0);
441 }
442
443 /**
444  * gfs2_log_flush - flush incore transaction(s)
445  * @sdp: the filesystem
446  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
447  *
448  */
449
450 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
451 {
452         struct gfs2_ail *ai;
453
454         down_write(&sdp->sd_log_flush_lock);
455
456         if (gl) {
457                 gfs2_log_lock(sdp);
458                 if (list_empty(&gl->gl_le.le_list)) {
459                         gfs2_log_unlock(sdp);
460                         up_write(&sdp->sd_log_flush_lock);
461                         return;
462                 }
463                 gfs2_log_unlock(sdp);
464         }
465
466         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
467         INIT_LIST_HEAD(&ai->ai_ail1_list);
468         INIT_LIST_HEAD(&ai->ai_ail2_list);
469
470         gfs2_assert_withdraw(sdp,
471                         sdp->sd_log_num_buf == sdp->sd_log_commited_buf);
472         gfs2_assert_withdraw(sdp,
473                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
474
475         sdp->sd_log_flush_head = sdp->sd_log_head;
476         sdp->sd_log_flush_wrapped = 0;
477         ai->ai_first = sdp->sd_log_flush_head;
478
479         lops_before_commit(sdp);
480         if (!list_empty(&sdp->sd_log_flush_list))
481                 log_flush_commit(sdp);
482         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle)
483                 log_write_header(sdp, 0, PULL);
484         lops_after_commit(sdp, ai);
485         sdp->sd_log_head = sdp->sd_log_flush_head;
486
487         /* printk(KERN_INFO "sd_log_num_hdrs %u\n", sdp->sd_log_num_hdrs); */
488         sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs;
489
490         sdp->sd_log_blks_reserved =
491                 sdp->sd_log_commited_buf =
492                 sdp->sd_log_num_hdrs = 
493                 sdp->sd_log_commited_revoke = 0;
494
495         gfs2_log_lock(sdp);
496         if (!list_empty(&ai->ai_ail1_list)) {
497                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
498                 ai = NULL;
499         }
500         gfs2_log_unlock(sdp);
501
502         sdp->sd_vfs->s_dirt = 0;
503         up_write(&sdp->sd_log_flush_lock);
504
505         kfree(ai);
506 }
507
508 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
509 {
510         unsigned int reserved = 1;
511         unsigned int old;
512
513         gfs2_log_lock(sdp);
514
515         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
516         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0);
517         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
518         gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0);
519
520         if (sdp->sd_log_commited_buf)
521                 reserved += sdp->sd_log_commited_buf;
522         if (sdp->sd_log_commited_revoke)
523                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
524                                             sizeof(uint64_t));
525
526         old = sdp->sd_log_blks_free;
527         sdp->sd_log_blks_free += tr->tr_reserved -
528                                  (reserved - sdp->sd_log_blks_reserved);
529
530         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free >= old);
531         gfs2_assert_withdraw(sdp,
532                              sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks +
533                              sdp->sd_log_num_hdrs);
534
535         sdp->sd_log_blks_reserved = reserved;
536
537         gfs2_log_unlock(sdp);
538 }
539
540 /**
541  * gfs2_log_commit - Commit a transaction to the log
542  * @sdp: the filesystem
543  * @tr: the transaction
544  *
545  * Returns: errno
546  */
547
548 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
549 {
550         log_refund(sdp, tr);
551         lops_incore_commit(sdp, tr);
552
553         sdp->sd_vfs->s_dirt = 1;
554         up_read(&sdp->sd_log_flush_lock);
555
556         gfs2_log_lock(sdp);
557         if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) {
558                 gfs2_log_unlock(sdp);
559                 gfs2_log_flush(sdp, NULL);
560         } else
561                 gfs2_log_unlock(sdp);
562 }
563
564 /**
565  * gfs2_log_shutdown - write a shutdown header into a journal
566  * @sdp: the filesystem
567  *
568  */
569
570 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
571 {
572         down_write(&sdp->sd_log_flush_lock);
573
574         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
575         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl);
576         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
577         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_jdata);
578         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
579         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
580         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
581         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_hdrs);
582         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
583
584         sdp->sd_log_flush_head = sdp->sd_log_head;
585         sdp->sd_log_flush_wrapped = 0;
586
587         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT, 0);
588
589         /* printk(KERN_INFO "sd_log_blks_free %u, sd_jdesc->jd_blocks %u\n", sdp->sd_log_blks_free, sdp->sd_jdesc->jd_blocks); */
590         gfs2_assert_warn(sdp, sdp->sd_log_blks_free == sdp->sd_jdesc->jd_blocks);
591         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
592         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
593
594         sdp->sd_log_head = sdp->sd_log_flush_head;
595         sdp->sd_log_tail = sdp->sd_log_head;
596
597         up_write(&sdp->sd_log_flush_lock);
598 }
599