diff options
Diffstat (limited to 'fs/xfs/xfs_trans_ail.c')
-rw-r--r-- | fs/xfs/xfs_trans_ail.c | 47 |
1 files changed, 26 insertions, 21 deletions
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index acdb92f..5fc2380 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -346,20 +346,23 @@ xfs_ail_delete( */ STATIC void xfs_ail_worker( - struct work_struct *work) + struct work_struct *work) { - struct xfs_ail *ailp = container_of(to_delayed_work(work), + struct xfs_ail *ailp = container_of(to_delayed_work(work), struct xfs_ail, xa_work); - long tout; - xfs_lsn_t target = ailp->xa_target; - xfs_lsn_t lsn; - xfs_log_item_t *lip; - int flush_log, count, stuck; - xfs_mount_t *mp = ailp->xa_mount; + xfs_mount_t *mp = ailp->xa_mount; struct xfs_ail_cursor *cur = &ailp->xa_cursors; - int push_xfsbufd = 0; + xfs_log_item_t *lip; + xfs_lsn_t lsn; + xfs_lsn_t target; + long tout = 10; + int flush_log = 0; + int stuck = 0; + int count = 0; + int push_xfsbufd = 0; spin_lock(&ailp->xa_lock); + target = ailp->xa_target; xfs_trans_ail_cursor_init(ailp, cur); lip = xfs_trans_ail_cursor_first(ailp, cur, ailp->xa_last_pushed_lsn); if (!lip || XFS_FORCED_SHUTDOWN(mp)) { @@ -368,8 +371,7 @@ xfs_ail_worker( */ xfs_trans_ail_cursor_done(ailp, cur); spin_unlock(&ailp->xa_lock); - ailp->xa_last_pushed_lsn = 0; - return; + goto out_done; } XFS_STATS_INC(xs_push_ail); @@ -386,8 +388,7 @@ xfs_ail_worker( * lots of contention on the AIL lists. */ lsn = lip->li_lsn; - flush_log = stuck = count = 0; - while ((XFS_LSN_CMP(lip->li_lsn, target) < 0)) { + while ((XFS_LSN_CMP(lip->li_lsn, target) <= 0)) { int lock_result; /* * If we can lock the item without sleeping, unlock the AIL @@ -480,21 +481,25 @@ xfs_ail_worker( } /* assume we have more work to do in a short while */ - tout = 10; +out_done: if (!count) { /* We're past our target or empty, so idle */ ailp->xa_last_pushed_lsn = 0; /* - * Check for an updated push target before clearing the - * XFS_AIL_PUSHING_BIT. If the target changed, we've got more - * work to do. Wait a bit longer before starting that work. + * We clear the XFS_AIL_PUSHING_BIT first before checking + * whether the target has changed. If the target has changed, + * this pushes the requeue race directly onto the result of the + * atomic test/set bit, so we are guaranteed that either the + * the pusher that changed the target or ourselves will requeue + * the work (but not both). */ + clear_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags); smp_rmb(); - if (ailp->xa_target == target) { - clear_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags); + if (XFS_LSN_CMP(ailp->xa_target, target) == 0 || + test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags)) return; - } + tout = 50; } else if (XFS_LSN_CMP(lsn, target) >= 0) { /* @@ -553,7 +558,7 @@ xfs_ail_push( * the XFS_AIL_PUSHING_BIT. */ smp_wmb(); - ailp->xa_target = threshold_lsn; + xfs_trans_ail_copy_lsn(ailp, &ailp->xa_target, &threshold_lsn); if (!test_and_set_bit(XFS_AIL_PUSHING_BIT, &ailp->xa_flags)) queue_delayed_work(xfs_syncd_wq, &ailp->xa_work, 0); } |