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Diffstat (limited to 'fs/xfs/xfs_log.c')
-rw-r--r--fs/xfs/xfs_log.c74
1 files changed, 31 insertions, 43 deletions
diff --git a/fs/xfs/xfs_log.c b/fs/xfs/xfs_log.c
index e2cc3568c29..372642d3987 100644
--- a/fs/xfs/xfs_log.c
+++ b/fs/xfs/xfs_log.c
@@ -760,37 +760,35 @@ xfs_log_item_init(
INIT_LIST_HEAD(&item->li_cil);
}
+/*
+ * Wake up processes waiting for log space after we have moved the log tail.
+ *
+ * If opportunistic is set wake up one waiter even if we do not have enough
+ * free space by our strict accounting.
+ */
void
-xfs_log_move_tail(xfs_mount_t *mp,
- xfs_lsn_t tail_lsn)
+xfs_log_space_wake(
+ struct xfs_mount *mp,
+ bool opportunistic)
{
- xlog_ticket_t *tic;
- xlog_t *log = mp->m_log;
- int need_bytes, free_bytes;
+ struct xlog_ticket *tic;
+ struct log *log = mp->m_log;
+ int need_bytes, free_bytes;
if (XLOG_FORCED_SHUTDOWN(log))
return;
- if (tail_lsn == 0)
- tail_lsn = atomic64_read(&log->l_last_sync_lsn);
-
- /* tail_lsn == 1 implies that we weren't passed a valid value. */
- if (tail_lsn != 1)
- atomic64_set(&log->l_tail_lsn, tail_lsn);
-
if (!list_empty_careful(&log->l_writeq)) {
-#ifdef DEBUG
- if (log->l_flags & XLOG_ACTIVE_RECOVERY)
- panic("Recovery problem");
-#endif
+ ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
+
spin_lock(&log->l_grant_write_lock);
free_bytes = xlog_space_left(log, &log->l_grant_write_head);
list_for_each_entry(tic, &log->l_writeq, t_queue) {
ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
- if (free_bytes < tic->t_unit_res && tail_lsn != 1)
+ if (free_bytes < tic->t_unit_res && !opportunistic)
break;
- tail_lsn = 0;
+ opportunistic = false;
free_bytes -= tic->t_unit_res;
trace_xfs_log_regrant_write_wake_up(log, tic);
wake_up(&tic->t_wait);
@@ -799,10 +797,8 @@ xfs_log_move_tail(xfs_mount_t *mp,
}
if (!list_empty_careful(&log->l_reserveq)) {
-#ifdef DEBUG
- if (log->l_flags & XLOG_ACTIVE_RECOVERY)
- panic("Recovery problem");
-#endif
+ ASSERT(!(log->l_flags & XLOG_ACTIVE_RECOVERY));
+
spin_lock(&log->l_grant_reserve_lock);
free_bytes = xlog_space_left(log, &log->l_grant_reserve_head);
list_for_each_entry(tic, &log->l_reserveq, t_queue) {
@@ -810,9 +806,9 @@ xfs_log_move_tail(xfs_mount_t *mp,
need_bytes = tic->t_unit_res*tic->t_cnt;
else
need_bytes = tic->t_unit_res;
- if (free_bytes < need_bytes && tail_lsn != 1)
+ if (free_bytes < need_bytes && !opportunistic)
break;
- tail_lsn = 0;
+ opportunistic = false;
free_bytes -= need_bytes;
trace_xfs_log_grant_wake_up(log, tic);
wake_up(&tic->t_wait);
@@ -867,21 +863,7 @@ xfs_log_need_covered(xfs_mount_t *mp)
return needed;
}
-/******************************************************************************
- *
- * local routines
- *
- ******************************************************************************
- */
-
-/* xfs_trans_tail_ail returns 0 when there is nothing in the list.
- * The log manager must keep track of the last LR which was committed
- * to disk. The lsn of this LR will become the new tail_lsn whenever
- * xfs_trans_tail_ail returns 0. If we don't do this, we run into
- * the situation where stuff could be written into the log but nothing
- * was ever in the AIL when asked. Eventually, we panic since the
- * tail hits the head.
- *
+/*
* We may be holding the log iclog lock upon entering this routine.
*/
xfs_lsn_t
@@ -891,10 +873,17 @@ xlog_assign_tail_lsn(
xfs_lsn_t tail_lsn;
struct log *log = mp->m_log;
+ /*
+ * To make sure we always have a valid LSN for the log tail we keep
+ * track of the last LSN which was committed in log->l_last_sync_lsn,
+ * and use that when the AIL was empty and xfs_ail_min_lsn returns 0.
+ *
+ * If the AIL has been emptied we also need to wake any process
+ * waiting for this condition.
+ */
tail_lsn = xfs_ail_min_lsn(mp->m_ail);
if (!tail_lsn)
tail_lsn = atomic64_read(&log->l_last_sync_lsn);
-
atomic64_set(&log->l_tail_lsn, tail_lsn);
return tail_lsn;
}
@@ -2759,9 +2748,8 @@ xlog_ungrant_log_space(xlog_t *log,
trace_xfs_log_ungrant_exit(log, ticket);
- xfs_log_move_tail(log->l_mp, 1);
-} /* xlog_ungrant_log_space */
-
+ xfs_log_space_wake(log->l_mp, true);
+}
/*
* Flush iclog to disk if this is the last reference to the given iclog and