diff options
Diffstat (limited to 'fs/gfs2/log.c')
-rw-r--r-- | fs/gfs2/log.c | 157 |
1 files changed, 87 insertions, 70 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c index e5bf4b59d46e..d5959df6deb2 100644 --- a/fs/gfs2/log.c +++ b/fs/gfs2/log.c @@ -168,12 +168,11 @@ static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int fl return list_empty(&ai->ai_ail1_list); } -static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags) +static void gfs2_ail1_start(struct gfs2_sbd *sdp) { struct list_head *head; u64 sync_gen; - struct list_head *first; - struct gfs2_ail *first_ai, *ai, *tmp; + struct gfs2_ail *ai; int done = 0; gfs2_log_lock(sdp); @@ -184,21 +183,9 @@ static void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags) } sync_gen = sdp->sd_ail_sync_gen++; - first = head->prev; - first_ai = list_entry(first, struct gfs2_ail, ai_list); - first_ai->ai_sync_gen = sync_gen; - gfs2_ail1_start_one(sdp, first_ai); /* This may drop log lock */ - - if (flags & DIO_ALL) - first = NULL; - while(!done) { - if (first && (head->prev != first || - gfs2_ail1_empty_one(sdp, first_ai, 0))) - break; - done = 1; - list_for_each_entry_safe_reverse(ai, tmp, head, ai_list) { + list_for_each_entry_reverse(ai, head, ai_list) { if (ai->ai_sync_gen >= sync_gen) continue; ai->ai_sync_gen = sync_gen; @@ -290,58 +277,57 @@ static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) * flush time, so we ensure that we have just enough free blocks at all * times to avoid running out during a log flush. * + * We no longer flush the log here, instead we wake up logd to do that + * for us. To avoid the thundering herd and to ensure that we deal fairly + * with queued waiters, we use an exclusive wait. This means that when we + * get woken with enough journal space to get our reservation, we need to + * wake the next waiter on the list. + * * Returns: errno */ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) { - unsigned int try = 0; unsigned reserved_blks = 6 * (4096 / sdp->sd_vfs->s_blocksize); + unsigned wanted = blks + reserved_blks; + DEFINE_WAIT(wait); + int did_wait = 0; + unsigned int free_blocks; if (gfs2_assert_warn(sdp, blks) || gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) return -EINVAL; - - mutex_lock(&sdp->sd_log_reserve_mutex); - gfs2_log_lock(sdp); - while(atomic_read(&sdp->sd_log_blks_free) <= (blks + reserved_blks)) { - gfs2_log_unlock(sdp); - gfs2_ail1_empty(sdp, 0); - gfs2_log_flush(sdp, NULL); - - if (try++) - gfs2_ail1_start(sdp, 0); - gfs2_log_lock(sdp); +retry: + free_blocks = atomic_read(&sdp->sd_log_blks_free); + if (unlikely(free_blocks <= wanted)) { + do { + prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, + TASK_UNINTERRUPTIBLE); + wake_up(&sdp->sd_logd_waitq); + did_wait = 1; + if (atomic_read(&sdp->sd_log_blks_free) <= wanted) + io_schedule(); + free_blocks = atomic_read(&sdp->sd_log_blks_free); + } while(free_blocks <= wanted); + finish_wait(&sdp->sd_log_waitq, &wait); } - atomic_sub(blks, &sdp->sd_log_blks_free); + if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, + free_blocks - blks) != free_blocks) + goto retry; trace_gfs2_log_blocks(sdp, -blks); - gfs2_log_unlock(sdp); - mutex_unlock(&sdp->sd_log_reserve_mutex); + + /* + * If we waited, then so might others, wake them up _after_ we get + * our share of the log. + */ + if (unlikely(did_wait)) + wake_up(&sdp->sd_log_waitq); down_read(&sdp->sd_log_flush_lock); return 0; } -/** - * gfs2_log_release - Release a given number of log blocks - * @sdp: The GFS2 superblock - * @blks: The number of blocks - * - */ - -void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks) -{ - - gfs2_log_lock(sdp); - atomic_add(blks, &sdp->sd_log_blks_free); - trace_gfs2_log_blocks(sdp, blks); - gfs2_assert_withdraw(sdp, - atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks); - gfs2_log_unlock(sdp); - up_read(&sdp->sd_log_flush_lock); -} - static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) { struct gfs2_journal_extent *je; @@ -559,11 +545,10 @@ static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) ail2_empty(sdp, new_tail); - gfs2_log_lock(sdp); atomic_add(dist, &sdp->sd_log_blks_free); trace_gfs2_log_blocks(sdp, dist); - gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= sdp->sd_jdesc->jd_blocks); - gfs2_log_unlock(sdp); + gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= + sdp->sd_jdesc->jd_blocks); sdp->sd_log_tail = new_tail; } @@ -822,6 +807,13 @@ static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) * @sdp: the filesystem * @tr: the transaction * + * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 + * or the total number of used blocks (pinned blocks plus AIL blocks) + * is greater than thresh2. + * + * At mount time thresh1 is 1/3rd of journal size, thresh2 is 2/3rd of + * journal size. + * * Returns: errno */ @@ -832,10 +824,10 @@ void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) up_read(&sdp->sd_log_flush_lock); - gfs2_log_lock(sdp); - if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) - wake_up_process(sdp->sd_logd_process); - gfs2_log_unlock(sdp); + if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || + ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > + atomic_read(&sdp->sd_log_thresh2))) + wake_up(&sdp->sd_logd_waitq); } /** @@ -882,13 +874,23 @@ void gfs2_meta_syncfs(struct gfs2_sbd *sdp) { gfs2_log_flush(sdp, NULL); for (;;) { - gfs2_ail1_start(sdp, DIO_ALL); + gfs2_ail1_start(sdp); if (gfs2_ail1_empty(sdp, DIO_ALL)) break; msleep(10); } } +static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) +{ + return (atomic_read(&sdp->sd_log_pinned) >= atomic_read(&sdp->sd_log_thresh1)); +} + +static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) +{ + unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); + return used_blocks >= atomic_read(&sdp->sd_log_thresh2); +} /** * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks @@ -901,28 +903,43 @@ void gfs2_meta_syncfs(struct gfs2_sbd *sdp) int gfs2_logd(void *data) { struct gfs2_sbd *sdp = data; - unsigned long t; - int need_flush; + unsigned long t = 1; + DEFINE_WAIT(wait); + unsigned preflush; while (!kthread_should_stop()) { - /* Advance the log tail */ - t = sdp->sd_log_flush_time + - gfs2_tune_get(sdp, gt_log_flush_secs) * HZ; + preflush = atomic_read(&sdp->sd_log_pinned); + if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { + gfs2_ail1_empty(sdp, DIO_ALL); + gfs2_log_flush(sdp, NULL); + gfs2_ail1_empty(sdp, DIO_ALL); + } - gfs2_ail1_empty(sdp, DIO_ALL); - gfs2_log_lock(sdp); - need_flush = sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks); - gfs2_log_unlock(sdp); - if (need_flush || time_after_eq(jiffies, t)) { + if (gfs2_ail_flush_reqd(sdp)) { + gfs2_ail1_start(sdp); + io_schedule(); + gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL); - sdp->sd_log_flush_time = jiffies; + gfs2_ail1_empty(sdp, DIO_ALL); } + wake_up(&sdp->sd_log_waitq); t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; if (freezing(current)) refrigerator(); - schedule_timeout_interruptible(t); + + do { + prepare_to_wait(&sdp->sd_logd_waitq, &wait, + TASK_UNINTERRUPTIBLE); + if (!gfs2_ail_flush_reqd(sdp) && + !gfs2_jrnl_flush_reqd(sdp) && + !kthread_should_stop()) + t = schedule_timeout(t); + } while(t && !gfs2_ail_flush_reqd(sdp) && + !gfs2_jrnl_flush_reqd(sdp) && + !kthread_should_stop()); + finish_wait(&sdp->sd_logd_waitq, &wait); } return 0; |