From: Trond Myklebust Date: Wed, 8 Aug 2012 20:03:13 +0000 (-0400) Subject: NFSv4.1: Remove a bogus BUG_ON() in nfs4_layoutreturn_done X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=47fbf7976e0b7d9dcdd799e2a1baba19064d9631;p=openwrt%2Fstaging%2Fblogic.git NFSv4.1: Remove a bogus BUG_ON() in nfs4_layoutreturn_done Ever since commit 0a57cdac3f (NFSv4.1 send layoutreturn to fence disconnected data server) we've been sending layoutreturn calls while there is potentially still outstanding I/O to the data servers. The reason we do this is to avoid races between replayed writes to the MDS and the original writes to the DS. When this happens, the BUG_ON() in nfs4_layoutreturn_done can be triggered because it assumes that we would never call layoutreturn without knowing that all I/O to the DS is finished. The fix is to remove the BUG_ON() now that the assumptions behind the test are obsolete. Reported-by: Boaz Harrosh Reported-by: Tigran Mkrtchyan Signed-off-by: Trond Myklebust Cc: stable@vger.kernel.org [>=3.5] --- diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index f94f6b3928fc..c77d296bdaa6 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6359,12 +6359,8 @@ static void nfs4_layoutreturn_done(struct rpc_task *task, void *calldata) return; } spin_lock(&lo->plh_inode->i_lock); - if (task->tk_status == 0) { - if (lrp->res.lrs_present) { - pnfs_set_layout_stateid(lo, &lrp->res.stateid, true); - } else - BUG_ON(!list_empty(&lo->plh_segs)); - } + if (task->tk_status == 0 && lrp->res.lrs_present) + pnfs_set_layout_stateid(lo, &lrp->res.stateid, true); lo->plh_block_lgets--; spin_unlock(&lo->plh_inode->i_lock); dprintk("<-- %s\n", __func__);