Return-Path: Received: from mail-pa0-f51.google.com ([209.85.220.51]:36582 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750815AbbHSEhB (ORCPT ); Wed, 19 Aug 2015 00:37:01 -0400 Received: by pawq9 with SMTP id q9so51280692paw.3 for ; Tue, 18 Aug 2015 21:37:01 -0700 (PDT) From: Trond Myklebust To: Christoph Hellwig Cc: linux-nfs@vger.kernel.org Subject: [PATCH] NFSv4.1/pnfs: Fix a close/delegreturn hang when return-on-close is set Date: Tue, 18 Aug 2015 23:36:59 -0500 Message-Id: <1439959019-16805-1-git-send-email-trond.myklebust@primarydata.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: The helper pnfs_roc() has already verified that we have no delegations, and no further open files, hence no outstanding I/O and it has marked all the return-on-close lsegs as being invalid. Furthermore, it sets the NFS_LAYOUT_RETURN bit, thus serialising the close/delegreturn with all future layoutget calls on this inode. The checks in pnfs_roc_drain() for valid layout segments are therefore redundant: those cannot exist until another layoutget completes. The other check for whether or not NFS_LAYOUT_RETURN is set, actually causes a hang, since we already know that we hold that flag. To fix, we therefore strip out all the functionality in pnfs_roc_drain() except the retrieval of the barrier state, and then rename the function accordingly. Reported-by: Christoph Hellwig Fixes: 5c4a79fb2b1c ("Don't prevent layoutgets when doing return-on-close") Signed-off-by: Trond Myklebust --- fs/nfs/nfs4proc.c | 12 ++++-------- fs/nfs/pnfs.c | 24 +----------------------- fs/nfs/pnfs.h | 7 +++---- 3 files changed, 8 insertions(+), 35 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index f4e5816a77b0..bda7837dfe6b 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -2737,11 +2737,8 @@ static void nfs4_close_prepare(struct rpc_task *task, void *data) if (calldata->arg.fmode == 0) { task->tk_msg.rpc_proc = &nfs4_procedures[NFSPROC4_CLNT_CLOSE]; - if (calldata->roc && - pnfs_roc_drain(inode, &calldata->roc_barrier, task)) { - nfs_release_seqid(calldata->arg.seqid); - goto out_wait; - } + if (calldata->roc) + pnfs_roc_get_barrier(inode, &calldata->roc_barrier); } calldata->arg.share_access = nfs4_map_atomic_open_share(NFS_SERVER(inode), @@ -5289,9 +5286,8 @@ static void nfs4_delegreturn_prepare(struct rpc_task *task, void *data) d_data = (struct nfs4_delegreturndata *)data; - if (d_data->roc && - pnfs_roc_drain(d_data->inode, &d_data->roc_barrier, task)) - return; + if (d_data->roc) + pnfs_roc_get_barrier(d_data->inode, &d_data->roc_barrier); nfs4_setup_sequence(d_data->res.server, &d_data->args.seq_args, diff --git a/fs/nfs/pnfs.c b/fs/nfs/pnfs.c index 6151f39c8291..6aabbb654021 100644 --- a/fs/nfs/pnfs.c +++ b/fs/nfs/pnfs.c @@ -1141,25 +1141,14 @@ void pnfs_roc_set_barrier(struct inode *ino, u32 barrier) spin_unlock(&ino->i_lock); } -bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task) +void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier) { struct nfs_inode *nfsi = NFS_I(ino); struct pnfs_layout_hdr *lo; - struct pnfs_layout_segment *lseg; nfs4_stateid stateid; u32 current_seqid; - bool layoutreturn = false; spin_lock(&ino->i_lock); - list_for_each_entry(lseg, &nfsi->layout->plh_segs, pls_list) { - if (!test_bit(NFS_LSEG_ROC, &lseg->pls_flags)) - continue; - if (test_bit(NFS_LSEG_VALID, &lseg->pls_flags)) - continue; - rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL); - spin_unlock(&ino->i_lock); - return true; - } lo = nfsi->layout; current_seqid = be32_to_cpu(lo->plh_stateid.seqid); @@ -1168,18 +1157,7 @@ bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task) */ *barrier = current_seqid + atomic_read(&lo->plh_outstanding); stateid = lo->plh_stateid; - if (test_and_clear_bit(NFS_LAYOUT_RETURN_BEFORE_CLOSE, - &lo->plh_flags)) - layoutreturn = pnfs_prepare_layoutreturn(lo); - if (test_bit(NFS_LAYOUT_RETURN, &lo->plh_flags)) - rpc_sleep_on(&NFS_SERVER(ino)->roc_rpcwaitq, task, NULL); - spin_unlock(&ino->i_lock); - if (layoutreturn) { - pnfs_send_layoutreturn(lo, stateid, IOMODE_ANY, false); - return true; - } - return false; } /* diff --git a/fs/nfs/pnfs.h b/fs/nfs/pnfs.h index 738672a0f8da..a3d57a8fac76 100644 --- a/fs/nfs/pnfs.h +++ b/fs/nfs/pnfs.h @@ -267,7 +267,7 @@ int pnfs_mark_matching_lsegs_invalid(struct pnfs_layout_hdr *lo, bool pnfs_roc(struct inode *ino); void pnfs_roc_release(struct inode *ino); void pnfs_roc_set_barrier(struct inode *ino, u32 barrier); -bool pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task); +void pnfs_roc_get_barrier(struct inode *ino, u32 *barrier); void pnfs_set_layoutcommit(struct inode *, struct pnfs_layout_segment *, loff_t); void pnfs_cleanup_layoutcommit(struct nfs4_layoutcommit_data *data); int pnfs_layoutcommit_inode(struct inode *inode, bool sync); @@ -605,10 +605,9 @@ pnfs_roc_set_barrier(struct inode *ino, u32 barrier) { } -static inline bool -pnfs_roc_drain(struct inode *ino, u32 *barrier, struct rpc_task *task) +static inline void +pnfs_roc_get_barrier(struct inode *ino, u32 *barrier) { - return false; } static inline void set_pnfs_layoutdriver(struct nfs_server *s, -- 2.4.3