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author | Rick Macklem <rmacklem@FreeBSD.org> | 2021-10-13 00:21:01 +0000 |
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committer | Rick Macklem <rmacklem@FreeBSD.org> | 2021-10-19 03:46:00 +0000 |
commit | 75d71cf8df8c83b2b2bc3a16ef66a540a2ebac70 (patch) | |
tree | 66dcda1223e08f682f9a96260ab450283db13759 | |
parent | 16f3a89d08b2deffccace6f605a9e9883cfbd4e2 (diff) | |
download | src-75d71cf8df8c83b2b2bc3a16ef66a540a2ebac70.tar.gz src-75d71cf8df8c83b2b2bc3a16ef66a540a2ebac70.zip |
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)
-rw-r--r-- | sys/fs/nfsclient/nfs_clstate.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/sys/fs/nfsclient/nfs_clstate.c b/sys/fs/nfsclient/nfs_clstate.c index 92688fcfbe28..5f35e4e708e9 100644 --- a/sys/fs/nfsclient/nfs_clstate.c +++ b/sys/fs/nfsclient/nfs_clstate.c @@ -4480,6 +4480,8 @@ nfscl_removedeleg(vnode_t vp, NFSPROC_T *p, nfsv4stateid_t *stp) int igotlock = 0, triedrecall = 0, needsrecall, retcnt = 0, islept; nmp = VFSTONFS(vnode_mount(vp)); + if (NFSHASPNFS(nmp)) + return (retcnt); np = VTONFS(vp); NFSLOCKCLSTATE(); /* @@ -4579,6 +4581,8 @@ nfscl_renamedeleg(vnode_t fvp, nfsv4stateid_t *fstp, int *gotfdp, vnode_t tvp, nmp = VFSTONFS(vnode_mount(fvp)); *gotfdp = 0; *gottdp = 0; + if (NFSHASPNFS(nmp)) + return (retcnt); NFSLOCKCLSTATE(); /* * Loop around waiting for: |