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);
}
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) {
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);
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
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;
}
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
* at the tail, it doesn't matter what result we get back. This
* is slightly racy because since we were just unlocked, we could
* go to sleep between the call to xfs_ail_min and the call to
- * xfs_log_move_tail, have someone else lock us, commit to us disk,
+ * xfs_log_space_wake, have someone else lock us, commit to us disk,
* move us out of the tail of the AIL, and then we wake up. However,
- * the call to xfs_log_move_tail() doesn't do anything if there's
+ * the call to xfs_log_space_wake() doesn't do anything if there's
* not enough free space to wake people up so we're safe calling it.
*/
min_lip = xfs_ail_min(ailp);
if (min_lip == lip)
- xfs_log_move_tail(ailp->xa_mount, 1);
+ xfs_log_space_wake(ailp->xa_mount, true);
} /* xfs_trans_unlocked_item */
/*
xfs_lsn_t lsn) __releases(ailp->xa_lock)
{
xfs_log_item_t *mlip;
- xfs_lsn_t tail_lsn;
int mlip_changed = 0;
int i;
LIST_HEAD(tmp);
if (!list_empty(&tmp))
xfs_ail_splice(ailp, cur, &tmp, lsn);
+ spin_unlock(&ailp->xa_lock);
- if (!mlip_changed) {
- spin_unlock(&ailp->xa_lock);
- return;
+ if (mlip_changed && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
+ xlog_assign_tail_lsn(ailp->xa_mount);
+ xfs_log_space_wake(ailp->xa_mount, false);
}
-
- /*
- * It is not safe to access mlip after the AIL lock is dropped, so we
- * must get a copy of li_lsn before we do so. This is especially
- * important on 32-bit platforms where accessing and updating 64-bit
- * values like li_lsn is not atomic.
- */
- mlip = xfs_ail_min(ailp);
- tail_lsn = mlip->li_lsn;
- spin_unlock(&ailp->xa_lock);
- xfs_log_move_tail(ailp->xa_mount, tail_lsn);
}
/*
int nr_items) __releases(ailp->xa_lock)
{
xfs_log_item_t *mlip;
- xfs_lsn_t tail_lsn;
int mlip_changed = 0;
int i;
if (mlip == lip)
mlip_changed = 1;
}
+ spin_unlock(&ailp->xa_lock);
- if (!mlip_changed) {
- spin_unlock(&ailp->xa_lock);
- return;
+ if (mlip_changed && !XFS_FORCED_SHUTDOWN(ailp->xa_mount)) {
+ xlog_assign_tail_lsn(ailp->xa_mount);
+ xfs_log_space_wake(ailp->xa_mount, false);
}
-
- /*
- * It is not safe to access mlip after the AIL lock is dropped, so we
- * must get a copy of li_lsn before we do so. This is especially
- * important on 32-bit platforms where accessing and updating 64-bit
- * values like li_lsn is not atomic. It is possible we've emptied the
- * AIL here, so if that is the case, pass an LSN of 0 to the tail move.
- */
- mlip = xfs_ail_min(ailp);
- tail_lsn = mlip ? mlip->li_lsn : 0;
- spin_unlock(&ailp->xa_lock);
- xfs_log_move_tail(ailp->xa_mount, tail_lsn);
}
/*
projects / mirror_ubuntu-artful-kernel.git / commitdiff