diff options
author | Chuck Lever <chuck.lever@oracle.com> | 2022-05-21 19:06:13 -0400 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-06 08:19:46 +0200 |
commit | fea1d0940301378206955264a01778700fc9c16f (patch) | |
tree | 4e4ee1017fe88630e9cdbac601e22b6cb9cc801a /fs | |
parent | 0b6f6940a2bd40a3a0796e93c28689033437948b (diff) |
NFSD: Fix possible sleep during nfsd4_release_lockowner()
commit ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b upstream.
nfsd4_release_lockowner() holds clp->cl_lock when it calls
check_for_locks(). However, check_for_locks() calls nfsd_file_get()
/ nfsd_file_put() to access the backing inode's flc_posix list, and
nfsd_file_put() can sleep if the inode was recently removed.
Let's instead rely on the stateowner's reference count to gate
whether the release is permitted. This should be a reliable
indication of locks-in-use since file lock operations and
->lm_get_owner take appropriate references, which are released
appropriately when file locks are removed.
Reported-by: Dai Ngo <dai.ngo@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/nfsd/nfs4state.c | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index d9381ca0ac47..b13649c63653 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6342,16 +6342,12 @@ nfsd4_release_lockowner(struct svc_rqst *rqstp, if (sop->so_is_open_owner || !same_owner_str(sop, owner)) continue; - /* see if there are still any locks associated with it */ - lo = lockowner(sop); - list_for_each_entry(stp, &sop->so_stateids, st_perstateowner) { - if (check_for_locks(stp->st_stid.sc_file, lo)) { - status = nfserr_locks_held; - spin_unlock(&clp->cl_lock); - return status; - } + if (atomic_read(&sop->so_count) != 1) { + spin_unlock(&clp->cl_lock); + return nfserr_locks_held; } + lo = lockowner(sop); nfs4_get_stateowner(sop); break; } |