diff options
author | Chuck Lever <chuck.lever@oracle.com> | 2022-05-21 19:06:13 -0400 |
---|---|---|
committer | Chuck Lever <chuck.lever@oracle.com> | 2022-05-26 10:50:49 -0400 |
commit | ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b (patch) | |
tree | de2d585897a4956f207e6361d23da1280c39d149 /fs | |
parent | fd5e363eac77ef81542db77ddad0559fa0f9204e (diff) | |
download | linux-ce3c4ad7f4ce5db7b4f08a1e237d8dd94b39180b.tar.bz2 |
NFSD: Fix possible sleep during nfsd4_release_lockowner()
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
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 a280256cbb03..4e0850a10550 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -7557,16 +7557,12 @@ 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; } |