git: 00595201ad4d - stable/13 - nfscl: Fix another deadlock related to the NFSv4 clientID lock
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Date: Wed, 20 Oct 2021 01:43:50 UTC
The branch stable/13 has been updated by rmacklem: URL: https://cgit.FreeBSD.org/src/commit/?id=00595201ad4de48a1537d43c77445873df6028db commit 00595201ad4de48a1537d43c77445873df6028db Author: Rick Macklem <rmacklem@FreeBSD.org> AuthorDate: 2021-10-13 00:21:01 +0000 Commit: Rick Macklem <rmacklem@FreeBSD.org> CommitDate: 2021-10-20 01:40:27 +0000 nfscl: Fix another deadlock related to the NFSv4 clientID lock Without this patch, it is possible to hang the NFSv4 client, when a rename/remove is being done on a file where the client holds a delegation, if pNFS is being used. For a delegation to be returned, dirty data blocks must be flushed to the NFSv4 server. When pNFS is in use, a shared lock on the clientID must be acquired while doing a write to the DS(s). However, if rename/remove is doing the delegation return an exclusive lock will be acquired on the clientID, preventing the write to the DS(s) from acquiring a shared lock on the clientID. This patch stops rename/remove from doing a delegation return if pNFS is enabled. Since doing delegation return in the same compound as rename/remove is only an optimization, not doing so should not cause problems. This problem was detected during a recent NFSv4 interoperability testing event held by the IETF working group. (cherry picked from commit b82168e657d378ff86ea18c4f03b98aac9ee9bb3) --- sys/fs/nfsclient/nfs_clstate.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c index 5aebd68dd9e1..276e94002d34 100644 --- a/sys/fs/nfsclient/nfs_clstate.c +++ b/sys/fs/nfsclient/nfs_clstate.c @@ -4609,6 +4609,8 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp) int igotlock = 0, triedrecall = 0, needsrecall, retcnt = 0, islept; nmp = VFSTONFS(vp->v_mount); + if (NFSHASPNFS(nmp)) + return (retcnt); NFSLOCKMNT(nmp); if ((nmp->nm_privflag & NFSMNTP_DELEGISSUED) == 0) { NFSUNLOCKMNT(nmp); @@ -4714,6 +4716,8 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp, nmp = VFSTONFS(fvp->v_mount); *gotfdp = 0; *gottdp = 0; + if (NFSHASPNFS(nmp)) + return (retcnt); NFSLOCKCLSTATE(); /* * Loop around waiting for: