From cb64026b6e8af50db598ec7c3f59d504259b00bb Mon Sep 17 00:00:00 2001 From: Dave Chinner Date: Fri, 6 May 2011 02:54:06 +0000 Subject: [PATCH] xfs: always push the AIL to the target The recent conversion of the xfsaild functionality to a work queue introduced a hard-to-hit log space grant hang. One of the problems discovered is a target mismatch between the item pushing loop and the target itself. The push trigger checks for the target increasing (i.e. new target > current) while the push loop only pushes items that have a LSN < current. As a result, we can get the situation where the push target is X, the items at the tail of the AIL have LSN X and they don't get pushed. The push work then completes thinking it is done, and cannot be restarted until the push target increases to >= X + 1. If the push target then never increases (because the tail is not moving), then we never run the push work again and we stall. Fix it by making sure log items with a LSN that matches the target exactly are pushed during the loop. Signed-off-by: Dave Chinner Reviewed-by: Christoph Hellwig Reviewed-by: Alex Elder --- fs/xfs/xfs_trans_ail.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/xfs/xfs_trans_ail.c b/fs/xfs/xfs_trans_ail.c index 226c58bd62e0..9f427c2597bb 100644 --- a/fs/xfs/xfs_trans_ail.c +++ b/fs/xfs/xfs_trans_ail.c @@ -387,7 +387,7 @@ xfs_ail_worker( * lots of contention on the AIL lists. */ lsn = lip->li_lsn; - 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 -- 2.20.1