[PATCH] NFSD4: return conflict lock without races
Update the NFSv4 server to use the new posix_lock_file_conf() interface.
Remove unnecessary (and race-prone) posix_test_file() calls.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c7b87e9..47ec112 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -2750,37 +2750,31 @@
* Note: locks.c uses the BKL to protect the inode's lock list.
*/
- status = posix_lock_file(filp, &file_lock);
- dprintk("NFSD: nfsd4_lock: posix_lock_file status %d\n",status);
+ /* XXX?: Just to divert the locks_release_private at the start of
+ * locks_copy_lock: */
+ conflock.fl_ops = NULL;
+ conflock.fl_lmops = NULL;
+ status = posix_lock_file_conf(filp, &file_lock, &conflock);
+ dprintk("NFSD: nfsd4_lock: posix_lock_file_conf status %d\n",status);
switch (-status) {
case 0: /* success! */
update_stateid(&lock_stp->st_stateid);
memcpy(&lock->lk_resp_stateid, &lock_stp->st_stateid,
sizeof(stateid_t));
- goto out;
- case (EAGAIN):
- goto conflicting_lock;
+ break;
+ case (EAGAIN): /* conflock holds conflicting lock */
+ status = nfserr_denied;
+ dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
+ nfs4_set_lock_denied(&conflock, &lock->lk_denied);
+ break;
case (EDEADLK):
status = nfserr_deadlock;
- dprintk("NFSD: nfsd4_lock: posix_lock_file() failed! status %d\n",status);
- goto out;
+ break;
default:
- status = nfserrno(status);
- dprintk("NFSD: nfsd4_lock: posix_lock_file() failed! status %d\n",status);
- goto out;
+ dprintk("NFSD: nfsd4_lock: posix_lock_file_conf() failed! status %d\n",status);
+ status = nfserr_resource;
+ break;
}
-
-conflicting_lock:
- dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
- status = nfserr_denied;
- /* XXX There is a race here. Future patch needed to provide
- * an atomic posix_lock_and_test_file
- */
- if (!posix_test_lock(filp, &file_lock, &conflock)) {
- status = nfserr_serverfault;
- goto out;
- }
- nfs4_set_lock_denied(&conflock, &lock->lk_denied);
out:
if (status && lock->lk_is_new && lock_sop)
release_stateowner(lock_sop);