2 * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved.
3 * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved.
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.
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 #include <linux/writeback.h>
22 #include <linux/list_sort.h>
33 #include "trace_gfs2.h"
36 * gfs2_struct2blk - compute stuff
37 * @sdp: the filesystem
38 * @nstruct: the number of structures
39 * @ssize: the size of the structures
41 * Compute the number of log descriptor blocks needed to hold a certain number
42 * of structures of a certain size.
44 * Returns: the number of blocks needed (minimum is always 1)
47 unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct,
51 unsigned int first, second;
54 first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize;
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);
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
70 * The ail lock _must_ be held when calling this function
74 void gfs2_remove_from_ail(struct gfs2_bufdata *bd)
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);
84 * gfs2_ail1_start_one - Start I/O on a part of the AIL
85 * @sdp: the filesystem
86 * @wbc: The writeback control structure
87 * @ai: The ail structure
91 static int gfs2_ail1_start_one(struct gfs2_sbd *sdp,
92 struct writeback_control *wbc,
94 __releases(&sdp->sd_ail_lock)
95 __acquires(&sdp->sd_ail_lock)
97 struct gfs2_glock *gl = NULL;
98 struct address_space *mapping;
99 struct gfs2_bufdata *bd, *s;
100 struct buffer_head *bh;
102 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) {
105 gfs2_assert(sdp, bd->bd_ail == ai);
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);
114 if (!buffer_dirty(bh))
119 list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list);
120 mapping = bh->b_page->mapping;
123 spin_unlock(&sdp->sd_ail_lock);
124 generic_writepages(mapping, wbc);
125 spin_lock(&sdp->sd_ail_lock);
126 if (wbc->nr_to_write <= 0)
136 * gfs2_ail1_flush - start writeback of some ail1 entries
137 * @sdp: The super block
138 * @wbc: The writeback control structure
140 * Writes back some ail1 entries, according to the limits in the
141 * writeback control structure
144 void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc)
146 struct list_head *head = &sdp->sd_ail1_list;
149 trace_gfs2_ail_flush(sdp, wbc, 1);
150 spin_lock(&sdp->sd_ail_lock);
152 list_for_each_entry_reverse(ai, head, ai_list) {
153 if (wbc->nr_to_write <= 0)
155 if (gfs2_ail1_start_one(sdp, wbc, ai))
158 spin_unlock(&sdp->sd_ail_lock);
159 trace_gfs2_ail_flush(sdp, wbc, 0);
163 * gfs2_ail1_start - start writeback of all ail1 entries
164 * @sdp: The superblock
167 static void gfs2_ail1_start(struct gfs2_sbd *sdp)
169 struct writeback_control wbc = {
170 .sync_mode = WB_SYNC_NONE,
171 .nr_to_write = LONG_MAX,
173 .range_end = LLONG_MAX,
176 return gfs2_ail1_flush(sdp, &wbc);
180 * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced
181 * @sdp: the filesystem
186 static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
188 struct gfs2_bufdata *bd, *s;
189 struct buffer_head *bh;
191 list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list,
194 gfs2_assert(sdp, bd->bd_ail == ai);
197 if (!buffer_uptodate(bh))
198 gfs2_io_error_bh(sdp, bh);
199 list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list);
205 * gfs2_ail1_empty - Try to empty the ail1 lists
206 * @sdp: The superblock
208 * Tries to empty the ail1 lists, starting with the oldest first
211 static int gfs2_ail1_empty(struct gfs2_sbd *sdp)
213 struct gfs2_ail *ai, *s;
216 spin_lock(&sdp->sd_ail_lock);
217 list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) {
218 gfs2_ail1_empty_one(sdp, ai);
219 if (list_empty(&ai->ai_ail1_list))
220 list_move(&ai->ai_list, &sdp->sd_ail2_list);
224 ret = list_empty(&sdp->sd_ail1_list);
225 spin_unlock(&sdp->sd_ail_lock);
230 static void gfs2_ail1_wait(struct gfs2_sbd *sdp)
233 struct gfs2_bufdata *bd;
234 struct buffer_head *bh;
236 spin_lock(&sdp->sd_ail_lock);
237 list_for_each_entry_reverse(ai, &sdp->sd_ail1_list, ai_list) {
238 list_for_each_entry(bd, &ai->ai_ail1_list, bd_ail_st_list) {
240 if (!buffer_locked(bh))
243 spin_unlock(&sdp->sd_ail_lock);
249 spin_unlock(&sdp->sd_ail_lock);
253 * gfs2_ail2_empty_one - Check whether or not a trans in the AIL has been synced
254 * @sdp: the filesystem
259 static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai)
261 struct list_head *head = &ai->ai_ail2_list;
262 struct gfs2_bufdata *bd;
264 while (!list_empty(head)) {
265 bd = list_entry(head->prev, struct gfs2_bufdata,
267 gfs2_assert(sdp, bd->bd_ail == ai);
268 gfs2_remove_from_ail(bd);
272 static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail)
274 struct gfs2_ail *ai, *safe;
275 unsigned int old_tail = sdp->sd_log_tail;
276 int wrap = (new_tail < old_tail);
279 spin_lock(&sdp->sd_ail_lock);
281 list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) {
282 a = (old_tail <= ai->ai_first);
283 b = (ai->ai_first < new_tail);
284 rm = (wrap) ? (a || b) : (a && b);
288 gfs2_ail2_empty_one(sdp, ai);
289 list_del(&ai->ai_list);
290 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list));
291 gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list));
295 spin_unlock(&sdp->sd_ail_lock);
299 * gfs2_log_reserve - Make a log reservation
300 * @sdp: The GFS2 superblock
301 * @blks: The number of blocks to reserve
303 * Note that we never give out the last few blocks of the journal. Thats
304 * due to the fact that there is a small number of header blocks
305 * associated with each log flush. The exact number can't be known until
306 * flush time, so we ensure that we have just enough free blocks at all
307 * times to avoid running out during a log flush.
309 * We no longer flush the log here, instead we wake up logd to do that
310 * for us. To avoid the thundering herd and to ensure that we deal fairly
311 * with queued waiters, we use an exclusive wait. This means that when we
312 * get woken with enough journal space to get our reservation, we need to
313 * wake the next waiter on the list.
318 int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks)
320 unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize);
321 unsigned wanted = blks + reserved_blks;
324 unsigned int free_blocks;
326 if (gfs2_assert_warn(sdp, blks) ||
327 gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks))
330 free_blocks = atomic_read(&sdp->sd_log_blks_free);
331 if (unlikely(free_blocks <= wanted)) {
333 prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait,
334 TASK_UNINTERRUPTIBLE);
335 wake_up(&sdp->sd_logd_waitq);
337 if (atomic_read(&sdp->sd_log_blks_free) <= wanted)
339 free_blocks = atomic_read(&sdp->sd_log_blks_free);
340 } while(free_blocks <= wanted);
341 finish_wait(&sdp->sd_log_waitq, &wait);
343 if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks,
344 free_blocks - blks) != free_blocks)
346 trace_gfs2_log_blocks(sdp, -blks);
349 * If we waited, then so might others, wake them up _after_ we get
350 * our share of the log.
352 if (unlikely(did_wait))
353 wake_up(&sdp->sd_log_waitq);
355 down_read(&sdp->sd_log_flush_lock);
361 * log_distance - Compute distance between two journal blocks
362 * @sdp: The GFS2 superblock
363 * @newer: The most recent journal block of the pair
364 * @older: The older journal block of the pair
366 * Compute the distance (in the journal direction) between two
367 * blocks in the journal
369 * Returns: the distance in blocks
372 static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer,
377 dist = newer - older;
379 dist += sdp->sd_jdesc->jd_blocks;
385 * calc_reserved - Calculate the number of blocks to reserve when
386 * refunding a transaction's unused buffers.
387 * @sdp: The GFS2 superblock
389 * This is complex. We need to reserve room for all our currently used
390 * metadata buffers (e.g. normal file I/O rewriting file time stamps) and
391 * all our journaled data buffers for journaled files (e.g. files in the
392 * meta_fs like rindex, or files for which chattr +j was done.)
393 * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush
394 * will count it as free space (sd_log_blks_free) and corruption will follow.
396 * We can have metadata bufs and jdata bufs in the same journal. So each
397 * type gets its own log header, for which we need to reserve a block.
398 * In fact, each type has the potential for needing more than one header
399 * in cases where we have more buffers than will fit on a journal page.
400 * Metadata journal entries take up half the space of journaled buffer entries.
401 * Thus, metadata entries have buf_limit (502) and journaled buffers have
402 * databuf_limit (251) before they cause a wrap around.
404 * Also, we need to reserve blocks for revoke journal entries and one for an
405 * overall header for the lot.
407 * Returns: the number of blocks reserved
409 static unsigned int calc_reserved(struct gfs2_sbd *sdp)
411 unsigned int reserved = 0;
412 unsigned int mbuf_limit, metabufhdrs_needed;
413 unsigned int dbuf_limit, databufhdrs_needed;
414 unsigned int revokes = 0;
416 mbuf_limit = buf_limit(sdp);
417 metabufhdrs_needed = (sdp->sd_log_commited_buf +
418 (mbuf_limit - 1)) / mbuf_limit;
419 dbuf_limit = databuf_limit(sdp);
420 databufhdrs_needed = (sdp->sd_log_commited_databuf +
421 (dbuf_limit - 1)) / dbuf_limit;
423 if (sdp->sd_log_commited_revoke > 0)
424 revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke,
427 reserved = sdp->sd_log_commited_buf + metabufhdrs_needed +
428 sdp->sd_log_commited_databuf + databufhdrs_needed +
430 /* One for the overall header */
436 static unsigned int current_tail(struct gfs2_sbd *sdp)
441 spin_lock(&sdp->sd_ail_lock);
443 if (list_empty(&sdp->sd_ail1_list)) {
444 tail = sdp->sd_log_head;
446 ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list);
450 spin_unlock(&sdp->sd_ail_lock);
455 static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail)
457 unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail);
459 ail2_empty(sdp, new_tail);
461 atomic_add(dist, &sdp->sd_log_blks_free);
462 trace_gfs2_log_blocks(sdp, dist);
463 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
464 sdp->sd_jdesc->jd_blocks);
466 sdp->sd_log_tail = new_tail;
470 static void log_flush_wait(struct gfs2_sbd *sdp)
474 if (atomic_read(&sdp->sd_log_in_flight)) {
476 prepare_to_wait(&sdp->sd_log_flush_wait, &wait,
477 TASK_UNINTERRUPTIBLE);
478 if (atomic_read(&sdp->sd_log_in_flight))
480 } while(atomic_read(&sdp->sd_log_in_flight));
481 finish_wait(&sdp->sd_log_flush_wait, &wait);
485 static int bd_cmp(void *priv, struct list_head *a, struct list_head *b)
487 struct gfs2_bufdata *bda, *bdb;
489 bda = list_entry(a, struct gfs2_bufdata, bd_list);
490 bdb = list_entry(b, struct gfs2_bufdata, bd_list);
492 if (bda->bd_bh->b_blocknr < bdb->bd_bh->b_blocknr)
494 if (bda->bd_bh->b_blocknr > bdb->bd_bh->b_blocknr)
499 static void gfs2_ordered_write(struct gfs2_sbd *sdp)
501 struct gfs2_bufdata *bd;
502 struct buffer_head *bh;
506 list_sort(NULL, &sdp->sd_log_le_ordered, &bd_cmp);
507 while (!list_empty(&sdp->sd_log_le_ordered)) {
508 bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_list);
509 list_move(&bd->bd_list, &written);
511 if (!buffer_dirty(bh))
514 gfs2_log_unlock(sdp);
516 if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) {
517 bh->b_end_io = end_buffer_write_sync;
518 submit_bh(WRITE_SYNC, bh);
525 list_splice(&written, &sdp->sd_log_le_ordered);
526 gfs2_log_unlock(sdp);
529 static void gfs2_ordered_wait(struct gfs2_sbd *sdp)
531 struct gfs2_bufdata *bd;
532 struct buffer_head *bh;
535 while (!list_empty(&sdp->sd_log_le_ordered)) {
536 bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_list);
538 if (buffer_locked(bh)) {
540 gfs2_log_unlock(sdp);
546 list_del_init(&bd->bd_list);
548 gfs2_log_unlock(sdp);
552 * log_write_header - Get and initialize a journal header buffer
553 * @sdp: The GFS2 superblock
555 * Returns: the initialized log buffer descriptor
558 static void log_write_header(struct gfs2_sbd *sdp, u32 flags)
560 struct gfs2_log_header *lh;
563 int rw = WRITE_FLUSH_FUA | REQ_META;
564 struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO);
565 lh = page_address(page);
568 gfs2_ail1_empty(sdp);
569 tail = current_tail(sdp);
571 lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC);
572 lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH);
573 lh->lh_header.__pad0 = cpu_to_be64(0);
574 lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH);
575 lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid);
576 lh->lh_sequence = cpu_to_be64(sdp->sd_log_sequence++);
577 lh->lh_flags = cpu_to_be32(flags);
578 lh->lh_tail = cpu_to_be32(tail);
579 lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head);
580 hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header));
581 lh->lh_hash = cpu_to_be32(hash);
583 if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) {
584 gfs2_ordered_wait(sdp);
586 rw = WRITE_SYNC | REQ_META | REQ_PRIO;
589 sdp->sd_log_idle = (tail == sdp->sd_log_flush_head);
590 gfs2_log_write_page(sdp, page);
591 gfs2_log_flush_bio(sdp, rw);
594 if (sdp->sd_log_tail != tail)
595 log_pull_tail(sdp, tail);
599 * gfs2_log_flush - flush incore transaction(s)
600 * @sdp: the filesystem
601 * @gl: The glock structure to flush. If NULL, flush the whole incore log
605 void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl)
609 down_write(&sdp->sd_log_flush_lock);
611 /* Log might have been flushed while we waited for the flush lock */
612 if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) {
613 up_write(&sdp->sd_log_flush_lock);
616 trace_gfs2_log_flush(sdp, 1);
618 ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL);
619 INIT_LIST_HEAD(&ai->ai_ail1_list);
620 INIT_LIST_HEAD(&ai->ai_ail2_list);
622 if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) {
623 printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf,
624 sdp->sd_log_commited_buf);
625 gfs2_assert_withdraw(sdp, 0);
627 if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) {
628 printk(KERN_INFO "GFS2: log databuf %u %u\n",
629 sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf);
630 gfs2_assert_withdraw(sdp, 0);
632 gfs2_assert_withdraw(sdp,
633 sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke);
635 sdp->sd_log_flush_head = sdp->sd_log_head;
636 sdp->sd_log_flush_wrapped = 0;
637 ai->ai_first = sdp->sd_log_flush_head;
639 gfs2_ordered_write(sdp);
640 lops_before_commit(sdp);
641 gfs2_log_flush_bio(sdp, WRITE);
643 if (sdp->sd_log_head != sdp->sd_log_flush_head) {
644 log_write_header(sdp, 0);
645 } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){
646 atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */
647 trace_gfs2_log_blocks(sdp, -1);
648 log_write_header(sdp, 0);
650 lops_after_commit(sdp, ai);
653 sdp->sd_log_head = sdp->sd_log_flush_head;
654 sdp->sd_log_blks_reserved = 0;
655 sdp->sd_log_commited_buf = 0;
656 sdp->sd_log_commited_databuf = 0;
657 sdp->sd_log_commited_revoke = 0;
659 spin_lock(&sdp->sd_ail_lock);
660 if (!list_empty(&ai->ai_ail1_list)) {
661 list_add(&ai->ai_list, &sdp->sd_ail1_list);
664 spin_unlock(&sdp->sd_ail_lock);
665 gfs2_log_unlock(sdp);
666 trace_gfs2_log_flush(sdp, 0);
667 up_write(&sdp->sd_log_flush_lock);
672 static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
674 unsigned int reserved;
679 sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm;
680 sdp->sd_log_commited_databuf += tr->tr_num_databuf_new -
681 tr->tr_num_databuf_rm;
682 gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) ||
683 (((int)sdp->sd_log_commited_databuf) >= 0));
684 sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm;
685 reserved = calc_reserved(sdp);
686 gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved);
687 unused = sdp->sd_log_blks_reserved - reserved + tr->tr_reserved;
688 atomic_add(unused, &sdp->sd_log_blks_free);
689 trace_gfs2_log_blocks(sdp, unused);
690 gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <=
691 sdp->sd_jdesc->jd_blocks);
692 sdp->sd_log_blks_reserved = reserved;
694 gfs2_log_unlock(sdp);
698 * gfs2_log_commit - Commit a transaction to the log
699 * @sdp: the filesystem
700 * @tr: the transaction
702 * We wake up gfs2_logd if the number of pinned blocks exceed thresh1
703 * or the total number of used blocks (pinned blocks plus AIL blocks)
704 * is greater than thresh2.
706 * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of
712 void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr)
715 up_read(&sdp->sd_log_flush_lock);
717 if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) ||
718 ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) >
719 atomic_read(&sdp->sd_log_thresh2)))
720 wake_up(&sdp->sd_logd_waitq);
724 * gfs2_log_shutdown - write a shutdown header into a journal
725 * @sdp: the filesystem
729 void gfs2_log_shutdown(struct gfs2_sbd *sdp)
731 down_write(&sdp->sd_log_flush_lock);
733 gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved);
734 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf);
735 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke);
736 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg);
737 gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf);
738 gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list));
740 sdp->sd_log_flush_head = sdp->sd_log_head;
741 sdp->sd_log_flush_wrapped = 0;
743 log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT);
745 gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks);
746 gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail);
747 gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list));
749 sdp->sd_log_head = sdp->sd_log_flush_head;
750 sdp->sd_log_tail = sdp->sd_log_head;
752 up_write(&sdp->sd_log_flush_lock);
757 * gfs2_meta_syncfs - sync all the buffers in a filesystem
758 * @sdp: the filesystem
762 void gfs2_meta_syncfs(struct gfs2_sbd *sdp)
764 gfs2_log_flush(sdp, NULL);
766 gfs2_ail1_start(sdp);
768 if (gfs2_ail1_empty(sdp))
771 gfs2_log_flush(sdp, NULL);
774 static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp)
776 return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1));
779 static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp)
781 unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free);
782 return used_blocks >= atomic_read(&sdp->sd_log_thresh2);
786 * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks
787 * @sdp: Pointer to GFS2 superblock
789 * Also, periodically check to make sure that we're using the most recent
793 int gfs2_logd(void *data)
795 struct gfs2_sbd *sdp = data;
799 while (!kthread_should_stop()) {
801 if (gfs2_jrnl_flush_reqd(sdp) || t == 0) {
802 gfs2_ail1_empty(sdp);
803 gfs2_log_flush(sdp, NULL);
806 if (gfs2_ail_flush_reqd(sdp)) {
807 gfs2_ail1_start(sdp);
809 gfs2_ail1_empty(sdp);
810 gfs2_log_flush(sdp, NULL);
813 if (!gfs2_ail_flush_reqd(sdp))
814 wake_up(&sdp->sd_log_waitq);
816 t = gfs2_tune_get(sdp, gt_logd_secs) * HZ;
821 prepare_to_wait(&sdp->sd_logd_waitq, &wait,
823 if (!gfs2_ail_flush_reqd(sdp) &&
824 !gfs2_jrnl_flush_reqd(sdp) &&
825 !kthread_should_stop())
826 t = schedule_timeout(t);
827 } while(t && !gfs2_ail_flush_reqd(sdp) &&
828 !gfs2_jrnl_flush_reqd(sdp) &&
829 !kthread_should_stop());
830 finish_wait(&sdp->sd_logd_waitq, &wait);