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 08:20:58 +0200 |
commit | 2ec65dc6635d1976bd1dbf2640ff7f810b2f6dd1 (patch) | |
tree | f94d31a592cc196a74951380c65bf2e2dcac8e41 | |
parent | bb4720010810d13fd2544363e2398b22fbfe0105 (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>
-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 6720c82ac351..2adbf471d107 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -6351,16 +6351,12 @@ 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; } |