Merge tag 'gpio-v5.5-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux...
[linux-2.6-microblaze.git] / fs / gfs2 / log.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) Sistina Software, Inc.  1997-2003 All rights reserved.
4  * Copyright (C) 2004-2007 Red Hat, Inc.  All rights reserved.
5  */
6
7 #include <linux/sched.h>
8 #include <linux/slab.h>
9 #include <linux/spinlock.h>
10 #include <linux/completion.h>
11 #include <linux/buffer_head.h>
12 #include <linux/gfs2_ondisk.h>
13 #include <linux/crc32.h>
14 #include <linux/crc32c.h>
15 #include <linux/delay.h>
16 #include <linux/kthread.h>
17 #include <linux/freezer.h>
18 #include <linux/bio.h>
19 #include <linux/blkdev.h>
20 #include <linux/writeback.h>
21 #include <linux/list_sort.h>
22
23 #include "gfs2.h"
24 #include "incore.h"
25 #include "bmap.h"
26 #include "glock.h"
27 #include "log.h"
28 #include "lops.h"
29 #include "meta_io.h"
30 #include "util.h"
31 #include "dir.h"
32 #include "trace_gfs2.h"
33
34 /**
35  * gfs2_struct2blk - compute stuff
36  * @sdp: the filesystem
37  * @nstruct: the number of structures
38  * @ssize: the size of the structures
39  *
40  * Compute the number of log descriptor blocks needed to hold a certain number
41  * of structures of a certain size.
42  *
43  * Returns: the number of blocks needed (minimum is always 1)
44  */
45
46 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
47                              unsigned int ssize)
48 {
49         unsigned int blks;
50         unsigned int first, second;
51
52         blks = 1;
53         first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
54
55         if (nstruct > first) {
56                 second = (sdp->sd_sb.sb_bsize -
57                           sizeof(struct gfs2_meta_header)) / ssize;
58                 blks += DIV_ROUND_UP(nstruct - first, second);
59         }
60
61         return blks;
62 }
63
64 /**
65  * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters
66  * @mapping: The associated mapping (maybe NULL)
67  * @bd: The gfs2_bufdata to remove
68  *
69  * The ail lock _must_ be held when calling this function
70  *
71  */
72
73 static void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
74 {
75         bd->bd_tr = NULL;
76         list_del_init(&bd->bd_ail_st_list);
77         list_del_init(&bd->bd_ail_gl_list);
78         atomic_dec(&bd->bd_gl->gl_ail_count);
79         brelse(bd->bd_bh);
80 }
81
82 /**
83  * gfs2_ail1_start_one - Start I/O on a part of the AIL
84  * @sdp: the filesystem
85  * @wbc: The writeback control structure
86  * @ai: The ail structure
87  *
88  */
89
90 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
91                                struct writeback_control *wbc,
92                                struct gfs2_trans *tr,
93                                bool *withdraw)
94 __releases(&sdp->sd_ail_lock)
95 __acquires(&sdp->sd_ail_lock)
96 {
97         struct gfs2_glock *gl = NULL;
98         struct address_space *mapping;
99         struct gfs2_bufdata *bd, *s;
100         struct buffer_head *bh;
101
102         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) {
103                 bh = bd->bd_bh;
104
105                 gfs2_assert(sdp, bd->bd_tr == tr);
106
107                 if (!buffer_busy(bh)) {
108                         if (!buffer_uptodate(bh) &&
109                             !test_and_set_bit(SDF_AIL1_IO_ERROR,
110                                               &sdp->sd_flags)) {
111                                 gfs2_io_error_bh(sdp, bh);
112                                 *withdraw = true;
113                         }
114                         list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
115                         continue;
116                 }
117
118                 if (!buffer_dirty(bh))
119                         continue;
120                 if (gl == bd->bd_gl)
121                         continue;
122                 gl = bd->bd_gl;
123                 list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list);
124                 mapping = bh->b_page->mapping;
125                 if (!mapping)
126                         continue;
127                 spin_unlock(&sdp->sd_ail_lock);
128                 generic_writepages(mapping, wbc);
129                 spin_lock(&sdp->sd_ail_lock);
130                 if (wbc->nr_to_write <= 0)
131                         break;
132                 return 1;
133         }
134
135         return 0;
136 }
137
138
139 /**
140  * gfs2_ail1_flush - start writeback of some ail1 entries 
141  * @sdp: The super block
142  * @wbc: The writeback control structure
143  *
144  * Writes back some ail1 entries, according to the limits in the
145  * writeback control structure
146  */
147
148 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
149 {
150         struct list_head *head = &sdp->sd_ail1_list;
151         struct gfs2_trans *tr;
152         struct blk_plug plug;
153         bool withdraw = false;
154
155         trace_gfs2_ail_flush(sdp, wbc, 1);
156         blk_start_plug(&plug);
157         spin_lock(&sdp->sd_ail_lock);
158 restart:
159         list_for_each_entry_reverse(tr, head, tr_list) {
160                 if (wbc->nr_to_write <= 0)
161                         break;
162                 if (gfs2_ail1_start_one(sdp, wbc, tr, &withdraw))
163                         goto restart;
164         }
165         spin_unlock(&sdp->sd_ail_lock);
166         blk_finish_plug(&plug);
167         if (withdraw)
168                 gfs2_lm_withdraw(sdp, NULL);
169         trace_gfs2_ail_flush(sdp, wbc, 0);
170 }
171
172 /**
173  * gfs2_ail1_start - start writeback of all ail1 entries
174  * @sdp: The superblock
175  */
176
177 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
178 {
179         struct writeback_control wbc = {
180                 .sync_mode = WB_SYNC_NONE,
181                 .nr_to_write = LONG_MAX,
182                 .range_start = 0,
183                 .range_end = LLONG_MAX,
184         };
185
186         return gfs2_ail1_flush(sdp, &wbc);
187 }
188
189 /**
190  * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
191  * @sdp: the filesystem
192  * @ai: the AIL entry
193  *
194  */
195
196 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr,
197                                 bool *withdraw)
198 {
199         struct gfs2_bufdata *bd, *s;
200         struct buffer_head *bh;
201
202         list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list,
203                                          bd_ail_st_list) {
204                 bh = bd->bd_bh;
205                 gfs2_assert(sdp, bd->bd_tr == tr);
206                 if (buffer_busy(bh))
207                         continue;
208                 if (!buffer_uptodate(bh) &&
209                     !test_and_set_bit(SDF_AIL1_IO_ERROR, &sdp->sd_flags)) {
210                         gfs2_io_error_bh(sdp, bh);
211                         *withdraw = true;
212                 }
213                 list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list);
214         }
215 }
216
217 /**
218  * gfs2_ail1_empty - Try to empty the ail1 lists
219  * @sdp: The superblock
220  *
221  * Tries to empty the ail1 lists, starting with the oldest first
222  */
223
224 static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
225 {
226         struct gfs2_trans *tr, *s;
227         int oldest_tr = 1;
228         int ret;
229         bool withdraw = false;
230
231         spin_lock(&sdp->sd_ail_lock);
232         list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) {
233                 gfs2_ail1_empty_one(sdp, tr, &withdraw);
234                 if (list_empty(&tr->tr_ail1_list) && oldest_tr)
235                         list_move(&tr->tr_list, &sdp->sd_ail2_list);
236                 else
237                         oldest_tr = 0;
238         }
239         ret = list_empty(&sdp->sd_ail1_list);
240         spin_unlock(&sdp->sd_ail_lock);
241
242         if (withdraw)
243                 gfs2_lm_withdraw(sdp, "fatal: I/O error(s)\n");
244
245         return ret;
246 }
247
248 static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
249 {
250         struct gfs2_trans *tr;
251         struct gfs2_bufdata *bd;
252         struct buffer_head *bh;
253
254         spin_lock(&sdp->sd_ail_lock);
255         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
256                 list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) {
257                         bh = bd->bd_bh;
258                         if (!buffer_locked(bh))
259                                 continue;
260                         get_bh(bh);
261                         spin_unlock(&sdp->sd_ail_lock);
262                         wait_on_buffer(bh);
263                         brelse(bh);
264                         return;
265                 }
266         }
267         spin_unlock(&sdp->sd_ail_lock);
268 }
269
270 /**
271  * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
272  * @sdp: the filesystem
273  * @ai: the AIL entry
274  *
275  */
276
277 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
278 {
279         struct list_head *head = &tr->tr_ail2_list;
280         struct gfs2_bufdata *bd;
281
282         while (!list_empty(head)) {
283                 bd = list_entry(head->prev, struct gfs2_bufdata,
284                                 bd_ail_st_list);
285                 gfs2_assert(sdp, bd->bd_tr == tr);
286                 gfs2_remove_from_ail(bd);
287         }
288 }
289
290 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
291 {
292         struct gfs2_trans *tr, *safe;
293         unsigned int old_tail = sdp->sd_log_tail;
294         int wrap = (new_tail < old_tail);
295         int a, b, rm;
296
297         spin_lock(&sdp->sd_ail_lock);
298
299         list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) {
300                 a = (old_tail <= tr->tr_first);
301                 b = (tr->tr_first < new_tail);
302                 rm = (wrap) ? (a || b) : (a && b);
303                 if (!rm)
304                         continue;
305
306                 gfs2_ail2_empty_one(sdp, tr);
307                 list_del(&tr->tr_list);
308                 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list));
309                 gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list));
310                 kfree(tr);
311         }
312
313         spin_unlock(&sdp->sd_ail_lock);
314 }
315
316 /**
317  * gfs2_log_release - Release a given number of log blocks
318  * @sdp: The GFS2 superblock
319  * @blks: The number of blocks
320  *
321  */
322
323 void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks)
324 {
325
326         atomic_add(blks, &sdp->sd_log_blks_free);
327         trace_gfs2_log_blocks(sdp, blks);
328         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
329                                   sdp->sd_jdesc->jd_blocks);
330         up_read(&sdp->sd_log_flush_lock);
331 }
332
333 /**
334  * gfs2_log_reserve - Make a log reservation
335  * @sdp: The GFS2 superblock
336  * @blks: The number of blocks to reserve
337  *
338  * Note that we never give out the last few blocks of the journal. Thats
339  * due to the fact that there is a small number of header blocks
340  * associated with each log flush. The exact number can't be known until
341  * flush time, so we ensure that we have just enough free blocks at all
342  * times to avoid running out during a log flush.
343  *
344  * We no longer flush the log here, instead we wake up logd to do that
345  * for us. To avoid the thundering herd and to ensure that we deal fairly
346  * with queued waiters, we use an exclusive wait. This means that when we
347  * get woken with enough journal space to get our reservation, we need to
348  * wake the next waiter on the list.
349  *
350  * Returns: errno
351  */
352
353 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
354 {
355         int ret = 0;
356         unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize);
357         unsigned wanted = blks + reserved_blks;
358         DEFINE_WAIT(wait);
359         int did_wait = 0;
360         unsigned int free_blocks;
361
362         if (gfs2_assert_warn(sdp, blks) ||
363             gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
364                 return -EINVAL;
365         atomic_add(blks, &sdp->sd_log_blks_needed);
366 retry:
367         free_blocks = atomic_read(&sdp->sd_log_blks_free);
368         if (unlikely(free_blocks <= wanted)) {
369                 do {
370                         prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
371                                         TASK_UNINTERRUPTIBLE);
372                         wake_up(&sdp->sd_logd_waitq);
373                         did_wait = 1;
374                         if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
375                                 io_schedule();
376                         free_blocks = atomic_read(&sdp->sd_log_blks_free);
377                 } while(free_blocks <= wanted);
378                 finish_wait(&sdp->sd_log_waitq, &wait);
379         }
380         atomic_inc(&sdp->sd_reserving_log);
381         if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
382                                 free_blocks - blks) != free_blocks) {
383                 if (atomic_dec_and_test(&sdp->sd_reserving_log))
384                         wake_up(&sdp->sd_reserving_log_wait);
385                 goto retry;
386         }
387         atomic_sub(blks, &sdp->sd_log_blks_needed);
388         trace_gfs2_log_blocks(sdp, -blks);
389
390         /*
391          * If we waited, then so might others, wake them up _after_ we get
392          * our share of the log.
393          */
394         if (unlikely(did_wait))
395                 wake_up(&sdp->sd_log_waitq);
396
397         down_read(&sdp->sd_log_flush_lock);
398         if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) {
399                 gfs2_log_release(sdp, blks);
400                 ret = -EROFS;
401         }
402         if (atomic_dec_and_test(&sdp->sd_reserving_log))
403                 wake_up(&sdp->sd_reserving_log_wait);
404         return ret;
405 }
406
407 /**
408  * log_distance - Compute distance between two journal blocks
409  * @sdp: The GFS2 superblock
410  * @newer: The most recent journal block of the pair
411  * @older: The older journal block of the pair
412  *
413  *   Compute the distance (in the journal direction) between two
414  *   blocks in the journal
415  *
416  * Returns: the distance in blocks
417  */
418
419 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
420                                         unsigned int older)
421 {
422         int dist;
423
424         dist = newer - older;
425         if (dist < 0)
426                 dist += sdp->sd_jdesc->jd_blocks;
427
428         return dist;
429 }
430
431 /**
432  * calc_reserved - Calculate the number of blocks to reserve when
433  *                 refunding a transaction's unused buffers.
434  * @sdp: The GFS2 superblock
435  *
436  * This is complex.  We need to reserve room for all our currently used
437  * metadata buffers (e.g. normal file I/O rewriting file time stamps) and 
438  * all our journaled data buffers for journaled files (e.g. files in the 
439  * meta_fs like rindex, or files for which chattr +j was done.)
440  * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
441  * will count it as free space (sd_log_blks_free) and corruption will follow.
442  *
443  * We can have metadata bufs and jdata bufs in the same journal.  So each
444  * type gets its own log header, for which we need to reserve a block.
445  * In fact, each type has the potential for needing more than one header 
446  * in cases where we have more buffers than will fit on a journal page.
447  * Metadata journal entries take up half the space of journaled buffer entries.
448  * Thus, metadata entries have buf_limit (502) and journaled buffers have
449  * databuf_limit (251) before they cause a wrap around.
450  *
451  * Also, we need to reserve blocks for revoke journal entries and one for an
452  * overall header for the lot.
453  *
454  * Returns: the number of blocks reserved
455  */
456 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
457 {
458         unsigned int reserved = 0;
459         unsigned int mbuf;
460         unsigned int dbuf;
461         struct gfs2_trans *tr = sdp->sd_log_tr;
462
463         if (tr) {
464                 mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm;
465                 dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm;
466                 reserved = mbuf + dbuf;
467                 /* Account for header blocks */
468                 reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp));
469                 reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp));
470         }
471
472         if (sdp->sd_log_commited_revoke > 0)
473                 reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
474                                           sizeof(u64));
475         /* One for the overall header */
476         if (reserved)
477                 reserved++;
478         return reserved;
479 }
480
481 static unsigned int current_tail(struct gfs2_sbd *sdp)
482 {
483         struct gfs2_trans *tr;
484         unsigned int tail;
485
486         spin_lock(&sdp->sd_ail_lock);
487
488         if (list_empty(&sdp->sd_ail1_list)) {
489                 tail = sdp->sd_log_head;
490         } else {
491                 tr = list_entry(sdp->sd_ail1_list.prev, struct gfs2_trans,
492                                 tr_list);
493                 tail = tr->tr_first;
494         }
495
496         spin_unlock(&sdp->sd_ail_lock);
497
498         return tail;
499 }
500
501 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
502 {
503         unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
504
505         ail2_empty(sdp, new_tail);
506
507         atomic_add(dist, &sdp->sd_log_blks_free);
508         trace_gfs2_log_blocks(sdp, dist);
509         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
510                              sdp->sd_jdesc->jd_blocks);
511
512         sdp->sd_log_tail = new_tail;
513 }
514
515
516 static void log_flush_wait(struct gfs2_sbd *sdp)
517 {
518         DEFINE_WAIT(wait);
519
520         if (atomic_read(&sdp->sd_log_in_flight)) {
521                 do {
522                         prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
523                                         TASK_UNINTERRUPTIBLE);
524                         if (atomic_read(&sdp->sd_log_in_flight))
525                                 io_schedule();
526                 } while(atomic_read(&sdp->sd_log_in_flight));
527                 finish_wait(&sdp->sd_log_flush_wait, &wait);
528         }
529 }
530
531 static int ip_cmp(void *priv, struct list_head *a, struct list_head *b)
532 {
533         struct gfs2_inode *ipa, *ipb;
534
535         ipa = list_entry(a, struct gfs2_inode, i_ordered);
536         ipb = list_entry(b, struct gfs2_inode, i_ordered);
537
538         if (ipa->i_no_addr < ipb->i_no_addr)
539                 return -1;
540         if (ipa->i_no_addr > ipb->i_no_addr)
541                 return 1;
542         return 0;
543 }
544
545 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
546 {
547         struct gfs2_inode *ip;
548         LIST_HEAD(written);
549
550         spin_lock(&sdp->sd_ordered_lock);
551         list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp);
552         while (!list_empty(&sdp->sd_log_ordered)) {
553                 ip = list_entry(sdp->sd_log_ordered.next, struct gfs2_inode, i_ordered);
554                 if (ip->i_inode.i_mapping->nrpages == 0) {
555                         test_and_clear_bit(GIF_ORDERED, &ip->i_flags);
556                         list_del(&ip->i_ordered);
557                         continue;
558                 }
559                 list_move(&ip->i_ordered, &written);
560                 spin_unlock(&sdp->sd_ordered_lock);
561                 filemap_fdatawrite(ip->i_inode.i_mapping);
562                 spin_lock(&sdp->sd_ordered_lock);
563         }
564         list_splice(&written, &sdp->sd_log_ordered);
565         spin_unlock(&sdp->sd_ordered_lock);
566 }
567
568 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
569 {
570         struct gfs2_inode *ip;
571
572         spin_lock(&sdp->sd_ordered_lock);
573         while (!list_empty(&sdp->sd_log_ordered)) {
574                 ip = list_entry(sdp->sd_log_ordered.next, struct gfs2_inode, i_ordered);
575                 list_del(&ip->i_ordered);
576                 WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags));
577                 if (ip->i_inode.i_mapping->nrpages == 0)
578                         continue;
579                 spin_unlock(&sdp->sd_ordered_lock);
580                 filemap_fdatawait(ip->i_inode.i_mapping);
581                 spin_lock(&sdp->sd_ordered_lock);
582         }
583         spin_unlock(&sdp->sd_ordered_lock);
584 }
585
586 void gfs2_ordered_del_inode(struct gfs2_inode *ip)
587 {
588         struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode);
589
590         spin_lock(&sdp->sd_ordered_lock);
591         if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags))
592                 list_del(&ip->i_ordered);
593         spin_unlock(&sdp->sd_ordered_lock);
594 }
595
596 void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd)
597 {
598         struct buffer_head *bh = bd->bd_bh;
599         struct gfs2_glock *gl = bd->bd_gl;
600
601         bh->b_private = NULL;
602         bd->bd_blkno = bh->b_blocknr;
603         gfs2_remove_from_ail(bd); /* drops ref on bh */
604         bd->bd_bh = NULL;
605         sdp->sd_log_num_revoke++;
606         if (atomic_inc_return(&gl->gl_revokes) == 1)
607                 gfs2_glock_hold(gl);
608         set_bit(GLF_LFLUSH, &gl->gl_flags);
609         list_add(&bd->bd_list, &sdp->sd_log_revokes);
610 }
611
612 void gfs2_write_revokes(struct gfs2_sbd *sdp)
613 {
614         struct gfs2_trans *tr;
615         struct gfs2_bufdata *bd, *tmp;
616         int have_revokes = 0;
617         int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64);
618
619         gfs2_ail1_empty(sdp);
620         spin_lock(&sdp->sd_ail_lock);
621         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
622                 list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) {
623                         if (list_empty(&bd->bd_list)) {
624                                 have_revokes = 1;
625                                 goto done;
626                         }
627                 }
628         }
629 done:
630         spin_unlock(&sdp->sd_ail_lock);
631         if (have_revokes == 0)
632                 return;
633         while (sdp->sd_log_num_revoke > max_revokes)
634                 max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64);
635         max_revokes -= sdp->sd_log_num_revoke;
636         if (!sdp->sd_log_num_revoke) {
637                 atomic_dec(&sdp->sd_log_blks_free);
638                 /* If no blocks have been reserved, we need to also
639                  * reserve a block for the header */
640                 if (!sdp->sd_log_blks_reserved)
641                         atomic_dec(&sdp->sd_log_blks_free);
642         }
643         gfs2_log_lock(sdp);
644         spin_lock(&sdp->sd_ail_lock);
645         list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) {
646                 list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) {
647                         if (max_revokes == 0)
648                                 goto out_of_blocks;
649                         if (!list_empty(&bd->bd_list))
650                                 continue;
651                         gfs2_add_revoke(sdp, bd);
652                         max_revokes--;
653                 }
654         }
655 out_of_blocks:
656         spin_unlock(&sdp->sd_ail_lock);
657         gfs2_log_unlock(sdp);
658
659         if (!sdp->sd_log_num_revoke) {
660                 atomic_inc(&sdp->sd_log_blks_free);
661                 if (!sdp->sd_log_blks_reserved)
662                         atomic_inc(&sdp->sd_log_blks_free);
663         }
664 }
665
666 /**
667  * gfs2_write_log_header - Write a journal log header buffer at lblock
668  * @sdp: The GFS2 superblock
669  * @jd: journal descriptor of the journal to which we are writing
670  * @seq: sequence number
671  * @tail: tail of the log
672  * @lblock: value for lh_blkno (block number relative to start of journal)
673  * @flags: log header flags GFS2_LOG_HEAD_*
674  * @op_flags: flags to pass to the bio
675  *
676  * Returns: the initialized log buffer descriptor
677  */
678
679 void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd,
680                            u64 seq, u32 tail, u32 lblock, u32 flags,
681                            int op_flags)
682 {
683         struct gfs2_log_header *lh;
684         u32 hash, crc;
685         struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
686         struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local;
687         struct timespec64 tv;
688         struct super_block *sb = sdp->sd_vfs;
689         u64 dblock;
690
691         lh = page_address(page);
692         clear_page(lh);
693
694         lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
695         lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
696         lh->lh_header.__pad0 = cpu_to_be64(0);
697         lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
698         lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
699         lh->lh_sequence = cpu_to_be64(seq);
700         lh->lh_flags = cpu_to_be32(flags);
701         lh->lh_tail = cpu_to_be32(tail);
702         lh->lh_blkno = cpu_to_be32(lblock);
703         hash = ~crc32(~0, lh, LH_V1_SIZE);
704         lh->lh_hash = cpu_to_be32(hash);
705
706         ktime_get_coarse_real_ts64(&tv);
707         lh->lh_nsec = cpu_to_be32(tv.tv_nsec);
708         lh->lh_sec = cpu_to_be64(tv.tv_sec);
709         if (!list_empty(&jd->extent_list))
710                 dblock = gfs2_log_bmap(sdp);
711         else {
712                 int ret = gfs2_lblk_to_dblk(jd->jd_inode, lblock, &dblock);
713                 if (gfs2_assert_withdraw(sdp, ret == 0))
714                         return;
715         }
716         lh->lh_addr = cpu_to_be64(dblock);
717         lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr);
718
719         /* We may only write local statfs, quota, etc., when writing to our
720            own journal. The values are left 0 when recovering a journal
721            different from our own. */
722         if (!(flags & GFS2_LOG_HEAD_RECOVERY)) {
723                 lh->lh_statfs_addr =
724                         cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr);
725                 lh->lh_quota_addr =
726                         cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr);
727
728                 spin_lock(&sdp->sd_statfs_spin);
729                 lh->lh_local_total = cpu_to_be64(l_sc->sc_total);
730                 lh->lh_local_free = cpu_to_be64(l_sc->sc_free);
731                 lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes);
732                 spin_unlock(&sdp->sd_statfs_spin);
733         }
734
735         BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE);
736
737         crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4,
738                      sb->s_blocksize - LH_V1_SIZE - 4);
739         lh->lh_crc = cpu_to_be32(crc);
740
741         gfs2_log_write(sdp, page, sb->s_blocksize, 0, dblock);
742         gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE | op_flags);
743         log_flush_wait(sdp);
744 }
745
746 /**
747  * log_write_header - Get and initialize a journal header buffer
748  * @sdp: The GFS2 superblock
749  * @flags: The log header flags, including log header origin
750  *
751  * Returns: the initialized log buffer descriptor
752  */
753
754 static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
755 {
756         unsigned int tail;
757         int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC;
758         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
759
760         gfs2_assert_withdraw(sdp, (state != SFS_FROZEN));
761         tail = current_tail(sdp);
762
763         if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
764                 gfs2_ordered_wait(sdp);
765                 log_flush_wait(sdp);
766                 op_flags = REQ_SYNC | REQ_META | REQ_PRIO;
767         }
768         sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
769         gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail,
770                               sdp->sd_log_flush_head, flags, op_flags);
771
772         if (sdp->sd_log_tail != tail)
773                 log_pull_tail(sdp, tail);
774 }
775
776 /**
777  * gfs2_log_flush - flush incore transaction(s)
778  * @sdp: the filesystem
779  * @gl: The glock structure to flush.  If NULL, flush the whole incore log
780  * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags
781  *
782  */
783
784 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags)
785 {
786         struct gfs2_trans *tr;
787         enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state);
788
789         down_write(&sdp->sd_log_flush_lock);
790
791         /* Log might have been flushed while we waited for the flush lock */
792         if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
793                 up_write(&sdp->sd_log_flush_lock);
794                 return;
795         }
796         trace_gfs2_log_flush(sdp, 1, flags);
797
798         if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN)
799                 clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags);
800
801         sdp->sd_log_flush_head = sdp->sd_log_head;
802         tr = sdp->sd_log_tr;
803         if (tr) {
804                 sdp->sd_log_tr = NULL;
805                 INIT_LIST_HEAD(&tr->tr_ail1_list);
806                 INIT_LIST_HEAD(&tr->tr_ail2_list);
807                 tr->tr_first = sdp->sd_log_flush_head;
808                 if (unlikely (state == SFS_FROZEN))
809                         gfs2_assert_withdraw(sdp, !tr->tr_num_buf_new && !tr->tr_num_databuf_new);
810         }
811
812         if (unlikely(state == SFS_FROZEN))
813                 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
814         gfs2_assert_withdraw(sdp,
815                         sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
816
817         gfs2_ordered_write(sdp);
818         lops_before_commit(sdp, tr);
819         gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE);
820
821         if (sdp->sd_log_head != sdp->sd_log_flush_head) {
822                 log_flush_wait(sdp);
823                 log_write_header(sdp, flags);
824         } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
825                 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
826                 trace_gfs2_log_blocks(sdp, -1);
827                 log_write_header(sdp, flags);
828         }
829         lops_after_commit(sdp, tr);
830
831         gfs2_log_lock(sdp);
832         sdp->sd_log_head = sdp->sd_log_flush_head;
833         sdp->sd_log_blks_reserved = 0;
834         sdp->sd_log_commited_revoke = 0;
835
836         spin_lock(&sdp->sd_ail_lock);
837         if (tr && !list_empty(&tr->tr_ail1_list)) {
838                 list_add(&tr->tr_list, &sdp->sd_ail1_list);
839                 tr = NULL;
840         }
841         spin_unlock(&sdp->sd_ail_lock);
842         gfs2_log_unlock(sdp);
843
844         if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) {
845                 if (!sdp->sd_log_idle) {
846                         for (;;) {
847                                 gfs2_ail1_start(sdp);
848                                 gfs2_ail1_wait(sdp);
849                                 if (gfs2_ail1_empty(sdp))
850                                         break;
851                         }
852                         atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
853                         trace_gfs2_log_blocks(sdp, -1);
854                         log_write_header(sdp, flags);
855                         sdp->sd_log_head = sdp->sd_log_flush_head;
856                 }
857                 if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN |
858                              GFS2_LOG_HEAD_FLUSH_FREEZE))
859                         gfs2_log_shutdown(sdp);
860                 if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE)
861                         atomic_set(&sdp->sd_freeze_state, SFS_FROZEN);
862         }
863
864         trace_gfs2_log_flush(sdp, 0, flags);
865         up_write(&sdp->sd_log_flush_lock);
866
867         kfree(tr);
868 }
869
870 /**
871  * gfs2_merge_trans - Merge a new transaction into a cached transaction
872  * @old: Original transaction to be expanded
873  * @new: New transaction to be merged
874  */
875
876 static void gfs2_merge_trans(struct gfs2_trans *old, struct gfs2_trans *new)
877 {
878         WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags));
879
880         old->tr_num_buf_new     += new->tr_num_buf_new;
881         old->tr_num_databuf_new += new->tr_num_databuf_new;
882         old->tr_num_buf_rm      += new->tr_num_buf_rm;
883         old->tr_num_databuf_rm  += new->tr_num_databuf_rm;
884         old->tr_num_revoke      += new->tr_num_revoke;
885
886         list_splice_tail_init(&new->tr_databuf, &old->tr_databuf);
887         list_splice_tail_init(&new->tr_buf, &old->tr_buf);
888 }
889
890 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
891 {
892         unsigned int reserved;
893         unsigned int unused;
894         unsigned int maxres;
895
896         gfs2_log_lock(sdp);
897
898         if (sdp->sd_log_tr) {
899                 gfs2_merge_trans(sdp->sd_log_tr, tr);
900         } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) {
901                 gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags));
902                 sdp->sd_log_tr = tr;
903                 set_bit(TR_ATTACHED, &tr->tr_flags);
904         }
905
906         sdp->sd_log_commited_revoke += tr->tr_num_revoke;
907         reserved = calc_reserved(sdp);
908         maxres = sdp->sd_log_blks_reserved + tr->tr_reserved;
909         gfs2_assert_withdraw(sdp, maxres >= reserved);
910         unused = maxres - reserved;
911         atomic_add(unused, &sdp->sd_log_blks_free);
912         trace_gfs2_log_blocks(sdp, unused);
913         gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
914                              sdp->sd_jdesc->jd_blocks);
915         sdp->sd_log_blks_reserved = reserved;
916
917         gfs2_log_unlock(sdp);
918 }
919
920 /**
921  * gfs2_log_commit - Commit a transaction to the log
922  * @sdp: the filesystem
923  * @tr: the transaction
924  *
925  * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
926  * or the total number of used blocks (pinned blocks plus AIL blocks)
927  * is greater than thresh2.
928  *
929  * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
930  * journal size.
931  *
932  * Returns: errno
933  */
934
935 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
936 {
937         log_refund(sdp, tr);
938
939         if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
940             ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
941             atomic_read(&sdp->sd_log_thresh2)))
942                 wake_up(&sdp->sd_logd_waitq);
943 }
944
945 /**
946  * gfs2_log_shutdown - write a shutdown header into a journal
947  * @sdp: the filesystem
948  *
949  */
950
951 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
952 {
953         gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
954         gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
955         gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
956
957         sdp->sd_log_flush_head = sdp->sd_log_head;
958
959         log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN);
960
961         gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
962         gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
963
964         sdp->sd_log_head = sdp->sd_log_flush_head;
965         sdp->sd_log_tail = sdp->sd_log_head;
966 }
967
968 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
969 {
970         return (atomic_read(&sdp->sd_log_pinned) +
971                 atomic_read(&sdp->sd_log_blks_needed) >=
972                 atomic_read(&sdp->sd_log_thresh1));
973 }
974
975 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
976 {
977         unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
978
979         if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags))
980                 return 1;
981
982         return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >=
983                 atomic_read(&sdp->sd_log_thresh2);
984 }
985
986 /**
987  * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
988  * @sdp: Pointer to GFS2 superblock
989  *
990  * Also, periodically check to make sure that we're using the most recent
991  * journal index.
992  */
993
994 int gfs2_logd(void *data)
995 {
996         struct gfs2_sbd *sdp = data;
997         unsigned long t = 1;
998         DEFINE_WAIT(wait);
999         bool did_flush;
1000
1001         while (!kthread_should_stop()) {
1002
1003                 /* Check for errors writing to the journal */
1004                 if (sdp->sd_log_error) {
1005                         gfs2_lm_withdraw(sdp,
1006                                          "GFS2: fsid=%s: error %d: "
1007                                          "withdrawing the file system to "
1008                                          "prevent further damage.\n",
1009                                          sdp->sd_fsname, sdp->sd_log_error);
1010                 }
1011
1012                 did_flush = false;
1013                 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
1014                         gfs2_ail1_empty(sdp);
1015                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1016                                        GFS2_LFC_LOGD_JFLUSH_REQD);
1017                         did_flush = true;
1018                 }
1019
1020                 if (gfs2_ail_flush_reqd(sdp)) {
1021                         gfs2_ail1_start(sdp);
1022                         gfs2_ail1_wait(sdp);
1023                         gfs2_ail1_empty(sdp);
1024                         gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL |
1025                                        GFS2_LFC_LOGD_AIL_FLUSH_REQD);
1026                         did_flush = true;
1027                 }
1028
1029                 if (!gfs2_ail_flush_reqd(sdp) || did_flush)
1030                         wake_up(&sdp->sd_log_waitq);
1031
1032                 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
1033
1034                 try_to_freeze();
1035
1036                 do {
1037                         prepare_to_wait(&sdp->sd_logd_waitq, &wait,
1038                                         TASK_INTERRUPTIBLE);
1039                         if (!gfs2_ail_flush_reqd(sdp) &&
1040                             !gfs2_jrnl_flush_reqd(sdp) &&
1041                             !kthread_should_stop())
1042                                 t = schedule_timeout(t);
1043                 } while(t && !gfs2_ail_flush_reqd(sdp) &&
1044                         !gfs2_jrnl_flush_reqd(sdp) &&
1045                         !kthread_should_stop());
1046                 finish_wait(&sdp->sd_logd_waitq, &wait);
1047         }
1048
1049         return 0;
1050 }
1051