block: unify flags for struct bio and struct request
[linux-3.10.git] / fs / gfs2 / log.c
1 /*
2  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
3  * Copyright (C) 2004-2007 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 version 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 <linux/delay.h>
18 #include <linux/kthread.h>
19 #include <linux/freezer.h>
20 #include <linux/bio.h>
21
22 #include "gfs2.h"
23 #include "incore.h"
24 #include "bmap.h"
25 #include "glock.h"
26 #include "log.h"
27 #include "lops.h"
28 #include "meta_io.h"
29 #include "util.h"
30 #include "dir.h"
31 #include "trace_gfs2.h"
32
33 #define PULL 1
34
35 /**
36  * gfs2_struct2blk - compute stuff
37  * @sdp: the filesystem
38  * @nstruct: the number of structures
39  * @ssize: the size of the structures
40  *
41  * Compute the number of log descriptor blocks needed to hold a certain number
42  * of structures of a certain size.
43  *
44  * Returns: the number of blocks needed (minimum is always 1)
45  */
46
47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
48                              unsigned int ssize)
49 {
50         unsigned int blks;
51         unsigned int first, second;
52
53         blks = 1;
54         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
55
56         if (nstruct > first) {
57                 second = (sdp->sd_sb.sb_bsize -
58                           sizeof(struct gfs2_meta_header)) / ssize;
59                 blks += DIV_ROUND_UP(nstruct - first, second);
60         }
61
62         return blks;
63 }
64
65 /**
66  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
67  * @mapping: The associated mapping (maybe NULL)
68  * @bd: The gfs2_bufdata to remove
69  *
70  * The log lock _must_ be held when calling this function
71  *
72  */
73
74 void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
75 {
76         bd->bd_ail = NULL;
77         list_del_init(&bd->bd_ail_st_list);
78         list_del_init(&bd->bd_ail_gl_list);
79         atomic_dec(&bd->bd_gl->gl_ail_count);
80         brelse(bd->bd_bh);
81 }
82
83 /**
84  * gfs2_ail1_start_one - Start I/O on a part of the AIL
85  * @sdp: the filesystem
86  * @tr: the part of the AIL
87  *
88  */
89
90 static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
91 __releases(&sdp->sd_log_lock)
92 __acquires(&sdp->sd_log_lock)
93 {
94         struct gfs2_bufdata *bd, *s;
95         struct buffer_head *bh;
96         int retry;
97
98         do {
99                 retry = 0;
100
101                 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
102                                                  bd_ail_st_list) {
103                         bh = bd->bd_bh;
104
105                         gfs2_assert(sdp, bd->bd_ail == ai);
106
107                         if (!buffer_busy(bh)) {
108                                 if (!buffer_uptodate(bh))
109                                         gfs2_io_error_bh(sdp, bh);
110                                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
111                                 continue;
112                         }
113
114                         if (!buffer_dirty(bh))
115                                 continue;
116
117                         list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
118
119                         get_bh(bh);
120                         gfs2_log_unlock(sdp);
121                         lock_buffer(bh);
122                         if (test_clear_buffer_dirty(bh)) {
123                                 bh->b_end_io = end_buffer_write_sync;
124                                 submit_bh(WRITE_SYNC_PLUG, bh);
125                         } else {
126                                 unlock_buffer(bh);
127                                 brelse(bh);
128                         }
129                         gfs2_log_lock(sdp);
130
131                         retry = 1;
132                         break;
133                 }
134         } while (retry);
135 }
136
137 /**
138  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
139  * @sdp: the filesystem
140  * @ai: the AIL entry
141  *
142  */
143
144 static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags)
145 {
146         struct gfs2_bufdata *bd, *s;
147         struct buffer_head *bh;
148
149         list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
150                                          bd_ail_st_list) {
151                 bh = bd->bd_bh;
152
153                 gfs2_assert(sdp, bd->bd_ail == ai);
154
155                 if (buffer_busy(bh)) {
156                         if (flags & DIO_ALL)
157                                 continue;
158                         else
159                                 break;
160                 }
161
162                 if (!buffer_uptodate(bh))
163                         gfs2_io_error_bh(sdp, bh);
164
165                 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
166         }
167
168         return list_empty(&ai->ai_ail1_list);
169 }
170
171 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
172 {
173         struct list_head *head;
174         u64 sync_gen;
175         struct gfs2_ail *ai;
176         int done = 0;
177
178         gfs2_log_lock(sdp);
179         head = &sdp->sd_ail1_list;
180         if (list_empty(head)) {
181                 gfs2_log_unlock(sdp);
182                 return;
183         }
184         sync_gen = sdp->sd_ail_sync_gen++;
185
186         while(!done) {
187                 done = 1;
188                 list_for_each_entry_reverse(ai, head, ai_list) {
189                         if (ai->ai_sync_gen >= sync_gen)
190                                 continue;
191                         ai->ai_sync_gen = sync_gen;
192                         gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */
193                         done = 0;
194                         break;
195                 }
196         }
197
198         gfs2_log_unlock(sdp);
199 }
200
201 static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags)
202 {
203         struct gfs2_ail *ai, *s;
204         int ret;
205
206         gfs2_log_lock(sdp);
207
208         list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
209                 if (gfs2_ail1_empty_one(sdp, ai, flags))
210                         list_move(&ai->ai_list, &sdp->sd_ail2_list);
211                 else if (!(flags & DIO_ALL))
212                         break;
213         }
214
215         ret = list_empty(&sdp->sd_ail1_list);
216
217         gfs2_log_unlock(sdp);
218
219         return ret;
220 }
221
222
223 /**
224  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
225  * @sdp: the filesystem
226  * @ai: the AIL entry
227  *
228  */
229
230 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
231 {
232         struct list_head *head = &ai->ai_ail2_list;
233         struct gfs2_bufdata *bd;
234
235         while (!list_empty(head)) {
236                 bd = list_entry(head->prev, struct gfs2_bufdata,
237                                 bd_ail_st_list);
238                 gfs2_assert(sdp, bd->bd_ail == ai);
239                 gfs2_remove_from_ail(bd);
240         }
241 }
242
243 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
244 {
245         struct gfs2_ail *ai, *safe;
246         unsigned int old_tail = sdp->sd_log_tail;
247         int wrap = (new_tail < old_tail);
248         int a, b, rm;
249
250         gfs2_log_lock(sdp);
251
252         list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
253                 a = (old_tail <= ai->ai_first);
254                 b = (ai->ai_first < new_tail);
255                 rm = (wrap) ? (a || b) : (a && b);
256                 if (!rm)
257                         continue;
258
259                 gfs2_ail2_empty_one(sdp, ai);
260                 list_del(&ai->ai_list);
261                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
262                 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
263                 kfree(ai);
264         }
265
266         gfs2_log_unlock(sdp);
267 }
268
269 /**
270  * gfs2_log_reserve - Make a log reservation
271  * @sdp: The GFS2 superblock
272  * @blks: The number of blocks to reserve
273  *
274  * Note that we never give out the last few blocks of the journal. Thats
275  * due to the fact that there is a small number of header blocks
276  * associated with each log flush. The exact number can't be known until
277  * flush time, so we ensure that we have just enough free blocks at all
278  * times to avoid running out during a log flush.
279  *
280  * We no longer flush the log here, instead we wake up logd to do that
281  * for us. To avoid the thundering herd and to ensure that we deal fairly
282  * with queued waiters, we use an exclusive wait. This means that when we
283  * get woken with enough journal space to get our reservation, we need to
284  * wake the next waiter on the list.
285  *
286  * Returns: errno
287  */
288
289 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
290 {
291         unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
292         unsigned wanted = blks + reserved_blks;
293         DEFINE_WAIT(wait);
294         int did_wait = 0;
295         unsigned int free_blocks;
296
297         if (gfs2_assert_warn(sdp, blks) ||
298             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
299                 return -EINVAL;
300 retry:
301         free_blocks = atomic_read(&sdp->sd_log_blks_free);
302         if (unlikely(free_blocks <= wanted)) {
303                 do {
304                         prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
305                                         TASK_UNINTERRUPTIBLE);
306                         wake_up(&sdp->sd_logd_waitq);
307                         did_wait = 1;
308                         if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
309                                 io_schedule();
310                         free_blocks = atomic_read(&sdp->sd_log_blks_free);
311                 } while(free_blocks <= wanted);
312                 finish_wait(&sdp->sd_log_waitq, &wait);
313         }
314         if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
315                                 free_blocks - blks) != free_blocks)
316                 goto retry;
317         trace_gfs2_log_blocks(sdp, -blks);
318
319         /*
320          * If we waited, then so might others, wake them up _after_ we get
321          * our share of the log.
322          */
323         if (unlikely(did_wait))
324                 wake_up(&sdp->sd_log_waitq);
325
326         down_read(&sdp->sd_log_flush_lock);
327
328         return 0;
329 }
330
331 static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn)
332 {
333         struct gfs2_journal_extent *je;
334
335         list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) {
336                 if (lbn >= je->lblock && lbn < je->lblock + je->blocks)
337                         return je->dblock + lbn - je->lblock;
338         }
339
340         return -1;
341 }
342
343 /**
344  * log_distance - Compute distance between two journal blocks
345  * @sdp: The GFS2 superblock
346  * @newer: The most recent journal block of the pair
347  * @older: The older journal block of the pair
348  *
349  *   Compute the distance (in the journal direction) between two
350  *   blocks in the journal
351  *
352  * Returns: the distance in blocks
353  */
354
355 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
356                                         unsigned int older)
357 {
358         int dist;
359
360         dist = newer - older;
361         if (dist < 0)
362                 dist += sdp->sd_jdesc->jd_blocks;
363
364         return dist;
365 }
366
367 /**
368  * calc_reserved - Calculate the number of blocks to reserve when
369  *                 refunding a transaction's unused buffers.
370  * @sdp: The GFS2 superblock
371  *
372  * This is complex.  We need to reserve room for all our currently used
373  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 
374  * all our journaled data buffers for journaled files (e.g. files in the 
375  * meta_fs like rindex, or files for which chattr +j was done.)
376  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
377  * will count it as free space (sd_log_blks_free) and corruption will follow.
378  *
379  * We can have metadata bufs and jdata bufs in the same journal.  So each
380  * type gets its own log header, for which we need to reserve a block.
381  * In fact, each type has the potential for needing more than one header 
382  * in cases where we have more buffers than will fit on a journal page.
383  * Metadata journal entries take up half the space of journaled buffer entries.
384  * Thus, metadata entries have buf_limit (502) and journaled buffers have
385  * databuf_limit (251) before they cause a wrap around.
386  *
387  * Also, we need to reserve blocks for revoke journal entries and one for an
388  * overall header for the lot.
389  *
390  * Returns: the number of blocks reserved
391  */
392 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
393 {
394         unsigned int reserved = 0;
395         unsigned int mbuf_limit, metabufhdrs_needed;
396         unsigned int dbuf_limit, databufhdrs_needed;
397         unsigned int revokes = 0;
398
399         mbuf_limit = buf_limit(sdp);
400         metabufhdrs_needed = (sdp->sd_log_commited_buf +
401                               (mbuf_limit - 1)) / mbuf_limit;
402         dbuf_limit = databuf_limit(sdp);
403         databufhdrs_needed = (sdp->sd_log_commited_databuf +
404                               (dbuf_limit - 1)) / dbuf_limit;
405
406         if (sdp->sd_log_commited_revoke > 0)
407                 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
408                                           sizeof(u64));
409
410         reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
411                 sdp->sd_log_commited_databuf + databufhdrs_needed +
412                 revokes;
413         /* One for the overall header */
414         if (reserved)
415                 reserved++;
416         return reserved;
417 }
418
419 static unsigned int current_tail(struct gfs2_sbd *sdp)
420 {
421         struct gfs2_ail *ai;
422         unsigned int tail;
423
424         gfs2_log_lock(sdp);
425
426         if (list_empty(&sdp->sd_ail1_list)) {
427                 tail = sdp->sd_log_head;
428         } else {
429                 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
430                 tail = ai->ai_first;
431         }
432
433         gfs2_log_unlock(sdp);
434
435         return tail;
436 }
437
438 void gfs2_log_incr_head(struct gfs2_sbd *sdp)
439 {
440         if (sdp->sd_log_flush_head == sdp->sd_log_tail)
441                 BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head);
442
443         if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) {
444                 sdp->sd_log_flush_head = 0;
445                 sdp->sd_log_flush_wrapped = 1;
446         }
447 }
448
449 /**
450  * gfs2_log_write_endio - End of I/O for a log buffer
451  * @bh: The buffer head
452  * @uptodate: I/O Status
453  *
454  */
455
456 static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate)
457 {
458         struct gfs2_sbd *sdp = bh->b_private;
459         bh->b_private = NULL;
460
461         end_buffer_write_sync(bh, uptodate);
462         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
463                 wake_up(&sdp->sd_log_flush_wait);
464 }
465
466 /**
467  * gfs2_log_get_buf - Get and initialize a buffer to use for log control data
468  * @sdp: The GFS2 superblock
469  *
470  * Returns: the buffer_head
471  */
472
473 struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp)
474 {
475         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
476         struct buffer_head *bh;
477
478         bh = sb_getblk(sdp->sd_vfs, blkno);
479         lock_buffer(bh);
480         memset(bh->b_data, 0, bh->b_size);
481         set_buffer_uptodate(bh);
482         clear_buffer_dirty(bh);
483         gfs2_log_incr_head(sdp);
484         atomic_inc(&sdp->sd_log_in_flight);
485         bh->b_private = sdp;
486         bh->b_end_io = gfs2_log_write_endio;
487
488         return bh;
489 }
490
491 /**
492  * gfs2_fake_write_endio - 
493  * @bh: The buffer head
494  * @uptodate: The I/O Status
495  *
496  */
497
498 static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate)
499 {
500         struct buffer_head *real_bh = bh->b_private;
501         struct gfs2_bufdata *bd = real_bh->b_private;
502         struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd;
503
504         end_buffer_write_sync(bh, uptodate);
505         free_buffer_head(bh);
506         unlock_buffer(real_bh);
507         brelse(real_bh);
508         if (atomic_dec_and_test(&sdp->sd_log_in_flight))
509                 wake_up(&sdp->sd_log_flush_wait);
510 }
511
512 /**
513  * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log
514  * @sdp: the filesystem
515  * @data: the data the buffer_head should point to
516  *
517  * Returns: the log buffer descriptor
518  */
519
520 struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp,
521                                       struct buffer_head *real)
522 {
523         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
524         struct buffer_head *bh;
525
526         bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL);
527         atomic_set(&bh->b_count, 1);
528         bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock);
529         set_bh_page(bh, real->b_page, bh_offset(real));
530         bh->b_blocknr = blkno;
531         bh->b_size = sdp->sd_sb.sb_bsize;
532         bh->b_bdev = sdp->sd_vfs->s_bdev;
533         bh->b_private = real;
534         bh->b_end_io = gfs2_fake_write_endio;
535
536         gfs2_log_incr_head(sdp);
537         atomic_inc(&sdp->sd_log_in_flight);
538
539         return bh;
540 }
541
542 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
543 {
544         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
545
546         ail2_empty(sdp, new_tail);
547
548         atomic_add(dist, &sdp->sd_log_blks_free);
549         trace_gfs2_log_blocks(sdp, dist);
550         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
551                              sdp->sd_jdesc->jd_blocks);
552
553         sdp->sd_log_tail = new_tail;
554 }
555
556 /**
557  * log_write_header - Get and initialize a journal header buffer
558  * @sdp: The GFS2 superblock
559  *
560  * Returns: the initialized log buffer descriptor
561  */
562
563 static void log_write_header(struct gfs2_sbd *sdp, u32 flags, int pull)
564 {
565         u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head);
566         struct buffer_head *bh;
567         struct gfs2_log_header *lh;
568         unsigned int tail;
569         u32 hash;
570
571         bh = sb_getblk(sdp->sd_vfs, blkno);
572         lock_buffer(bh);
573         memset(bh->b_data, 0, bh->b_size);
574         set_buffer_uptodate(bh);
575         clear_buffer_dirty(bh);
576
577         gfs2_ail1_empty(sdp, 0);
578         tail = current_tail(sdp);
579
580         lh = (struct gfs2_log_header *)bh->b_data;
581         memset(lh, 0, sizeof(struct gfs2_log_header));
582         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
583         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
584         lh->lh_header.__pad0 = cpu_to_be64(0);
585         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
586         lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
587         lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
588         lh->lh_flags = cpu_to_be32(flags);
589         lh->lh_tail = cpu_to_be32(tail);
590         lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
591         hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header));
592         lh->lh_hash = cpu_to_be32(hash);
593
594         bh->b_end_io = end_buffer_write_sync;
595         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags))
596                 goto skip_barrier;
597         get_bh(bh);
598         submit_bh(WRITE_BARRIER | REQ_META, bh);
599         wait_on_buffer(bh);
600         if (buffer_eopnotsupp(bh)) {
601                 clear_buffer_eopnotsupp(bh);
602                 set_buffer_uptodate(bh);
603                 fs_info(sdp, "barrier sync failed - disabling barriers\n");
604                 set_bit(SDF_NOBARRIERS, &sdp->sd_flags);
605                 lock_buffer(bh);
606 skip_barrier:
607                 get_bh(bh);
608                 submit_bh(WRITE_SYNC | REQ_META, bh);
609                 wait_on_buffer(bh);
610         }
611         if (!buffer_uptodate(bh))
612                 gfs2_io_error_bh(sdp, bh);
613         brelse(bh);
614
615         if (sdp->sd_log_tail != tail)
616                 log_pull_tail(sdp, tail);
617         else
618                 gfs2_assert_withdraw(sdp, !pull);
619
620         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
621         gfs2_log_incr_head(sdp);
622 }
623
624 static void log_flush_commit(struct gfs2_sbd *sdp)
625 {
626         DEFINE_WAIT(wait);
627
628         if (atomic_read(&sdp->sd_log_in_flight)) {
629                 do {
630                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
631                                         TASK_UNINTERRUPTIBLE);
632                         if (atomic_read(&sdp->sd_log_in_flight))
633                                 io_schedule();
634                 } while(atomic_read(&sdp->sd_log_in_flight));
635                 finish_wait(&sdp->sd_log_flush_wait, &wait);
636         }
637
638         log_write_header(sdp, 0, 0);
639 }
640
641 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
642 {
643         struct gfs2_bufdata *bd;
644         struct buffer_head *bh;
645         LIST_HEAD(written);
646
647         gfs2_log_lock(sdp);
648         while (!list_empty(&sdp->sd_log_le_ordered)) {
649                 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list);
650                 list_move(&bd->bd_le.le_list, &written);
651                 bh = bd->bd_bh;
652                 if (!buffer_dirty(bh))
653                         continue;
654                 get_bh(bh);
655                 gfs2_log_unlock(sdp);
656                 lock_buffer(bh);
657                 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
658                         bh->b_end_io = end_buffer_write_sync;
659                         submit_bh(WRITE_SYNC_PLUG, bh);
660                 } else {
661                         unlock_buffer(bh);
662                         brelse(bh);
663                 }
664                 gfs2_log_lock(sdp);
665         }
666         list_splice(&written, &sdp->sd_log_le_ordered);
667         gfs2_log_unlock(sdp);
668 }
669
670 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
671 {
672         struct gfs2_bufdata *bd;
673         struct buffer_head *bh;
674
675         gfs2_log_lock(sdp);
676         while (!list_empty(&sdp->sd_log_le_ordered)) {
677                 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list);
678                 bh = bd->bd_bh;
679                 if (buffer_locked(bh)) {
680                         get_bh(bh);
681                         gfs2_log_unlock(sdp);
682                         wait_on_buffer(bh);
683                         brelse(bh);
684                         gfs2_log_lock(sdp);
685                         continue;
686                 }
687                 list_del_init(&bd->bd_le.le_list);
688         }
689         gfs2_log_unlock(sdp);
690 }
691
692 /**
693  * gfs2_log_flush - flush incore transaction(s)
694  * @sdp: the filesystem
695  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
696  *
697  */
698
699 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
700 {
701         struct gfs2_ail *ai;
702
703         down_write(&sdp->sd_log_flush_lock);
704
705         /* Log might have been flushed while we waited for the flush lock */
706         if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
707                 up_write(&sdp->sd_log_flush_lock);
708                 return;
709         }
710         trace_gfs2_log_flush(sdp, 1);
711
712         ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
713         INIT_LIST_HEAD(&ai->ai_ail1_list);
714         INIT_LIST_HEAD(&ai->ai_ail2_list);
715
716         if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
717                 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
718                        sdp->sd_log_commited_buf);
719                 gfs2_assert_withdraw(sdp, 0);
720         }
721         if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
722                 printk(KERN_INFO "GFS2: log databuf %u %u\n",
723                        sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
724                 gfs2_assert_withdraw(sdp, 0);
725         }
726         gfs2_assert_withdraw(sdp,
727                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
728
729         sdp->sd_log_flush_head = sdp->sd_log_head;
730         sdp->sd_log_flush_wrapped = 0;
731         ai->ai_first = sdp->sd_log_flush_head;
732
733         gfs2_ordered_write(sdp);
734         lops_before_commit(sdp);
735         gfs2_ordered_wait(sdp);
736
737         if (sdp->sd_log_head != sdp->sd_log_flush_head)
738                 log_flush_commit(sdp);
739         else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
740                 gfs2_log_lock(sdp);
741                 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
742                 trace_gfs2_log_blocks(sdp, -1);
743                 gfs2_log_unlock(sdp);
744                 log_write_header(sdp, 0, PULL);
745         }
746         lops_after_commit(sdp, ai);
747
748         gfs2_log_lock(sdp);
749         sdp->sd_log_head = sdp->sd_log_flush_head;
750         sdp->sd_log_blks_reserved = 0;
751         sdp->sd_log_commited_buf = 0;
752         sdp->sd_log_commited_databuf = 0;
753         sdp->sd_log_commited_revoke = 0;
754
755         if (!list_empty(&ai->ai_ail1_list)) {
756                 list_add(&ai->ai_list, &sdp->sd_ail1_list);
757                 ai = NULL;
758         }
759         gfs2_log_unlock(sdp);
760         trace_gfs2_log_flush(sdp, 0);
761         up_write(&sdp->sd_log_flush_lock);
762
763         kfree(ai);
764 }
765
766 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
767 {
768         unsigned int reserved;
769         unsigned int unused;
770
771         gfs2_log_lock(sdp);
772
773         sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
774         sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
775                 tr->tr_num_databuf_rm;
776         gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
777                              (((int)sdp->sd_log_commited_databuf) >= 0));
778         sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
779         reserved = calc_reserved(sdp);
780         gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
781         unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
782         atomic_add(unused, &sdp->sd_log_blks_free);
783         trace_gfs2_log_blocks(sdp, unused);
784         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
785                              sdp->sd_jdesc->jd_blocks);
786         sdp->sd_log_blks_reserved = reserved;
787
788         gfs2_log_unlock(sdp);
789 }
790
791 static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
792 {
793         struct list_head *head = &tr->tr_list_buf;
794         struct gfs2_bufdata *bd;
795
796         gfs2_log_lock(sdp);
797         while (!list_empty(head)) {
798                 bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr);
799                 list_del_init(&bd->bd_list_tr);
800                 tr->tr_num_buf--;
801         }
802         gfs2_log_unlock(sdp);
803         gfs2_assert_warn(sdp, !tr->tr_num_buf);
804 }
805
806 /**
807  * gfs2_log_commit - Commit a transaction to the log
808  * @sdp: the filesystem
809  * @tr: the transaction
810  *
811  * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
812  * or the total number of used blocks (pinned blocks plus AIL blocks)
813  * is greater than thresh2.
814  *
815  * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
816  * journal size.
817  *
818  * Returns: errno
819  */
820
821 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
822 {
823         log_refund(sdp, tr);
824         buf_lo_incore_commit(sdp, tr);
825
826         up_read(&sdp->sd_log_flush_lock);
827
828         if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
829             ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
830             atomic_read(&sdp->sd_log_thresh2)))
831                 wake_up(&sdp->sd_logd_waitq);
832 }
833
834 /**
835  * gfs2_log_shutdown - write a shutdown header into a journal
836  * @sdp: the filesystem
837  *
838  */
839
840 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
841 {
842         down_write(&sdp->sd_log_flush_lock);
843
844         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
845         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
846         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
847         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
848         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
849         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
850
851         sdp->sd_log_flush_head = sdp->sd_log_head;
852         sdp->sd_log_flush_wrapped = 0;
853
854         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT,
855                          (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL);
856
857         gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
858         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
859         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
860
861         sdp->sd_log_head = sdp->sd_log_flush_head;
862         sdp->sd_log_tail = sdp->sd_log_head;
863
864         up_write(&sdp->sd_log_flush_lock);
865 }
866
867
868 /**
869  * gfs2_meta_syncfs - sync all the buffers in a filesystem
870  * @sdp: the filesystem
871  *
872  */
873
874 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
875 {
876         gfs2_log_flush(sdp, NULL);
877         for (;;) {
878                 gfs2_ail1_start(sdp);
879                 if (gfs2_ail1_empty(sdp, DIO_ALL))
880                         break;
881                 msleep(10);
882         }
883 }
884
885 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
886 {
887         return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
888 }
889
890 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
891 {
892         unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
893         return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
894 }
895
896 /**
897  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
898  * @sdp: Pointer to GFS2 superblock
899  *
900  * Also, periodically check to make sure that we're using the most recent
901  * journal index.
902  */
903
904 int gfs2_logd(void *data)
905 {
906         struct gfs2_sbd *sdp = data;
907         unsigned long t = 1;
908         DEFINE_WAIT(wait);
909         unsigned preflush;
910
911         while (!kthread_should_stop()) {
912
913                 preflush = atomic_read(&sdp->sd_log_pinned);
914                 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
915                         gfs2_ail1_empty(sdp, DIO_ALL);
916                         gfs2_log_flush(sdp, NULL);
917                         gfs2_ail1_empty(sdp, DIO_ALL);
918                 }
919
920                 if (gfs2_ail_flush_reqd(sdp)) {
921                         gfs2_ail1_start(sdp);
922                         io_schedule();
923                         gfs2_ail1_empty(sdp, 0);
924                         gfs2_log_flush(sdp, NULL);
925                         gfs2_ail1_empty(sdp, DIO_ALL);
926                 }
927
928                 wake_up(&sdp->sd_log_waitq);
929                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
930                 if (freezing(current))
931                         refrigerator();
932
933                 do {
934                         prepare_to_wait(&sdp->sd_logd_waitq, &wait,
935                                         TASK_UNINTERRUPTIBLE);
936                         if (!gfs2_ail_flush_reqd(sdp) &&
937                             !gfs2_jrnl_flush_reqd(sdp) &&
938                             !kthread_should_stop())
939                                 t = schedule_timeout(t);
940                 } while(t && !gfs2_ail_flush_reqd(sdp) &&
941                         !gfs2_jrnl_flush_reqd(sdp) &&
942                         !kthread_should_stop());
943                 finish_wait(&sdp->sd_logd_waitq, &wait);
944         }
945
946         return 0;
947 }
948