diff options
| -rw-r--r-- | fs/xfs/xfs_trans_ail.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index d7eebbf7136..5fc2380092c 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -487,15 +487,19 @@ out_done: 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 (XFS_LSN_CMP(ailp->xa_target, target) == 0) { - 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) { /* |