NFSv4: Don't allow posix locking against servers that don't support it

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>

2 files changed, 7 insertions, 1 deletions

diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 865265bdca03..ea2f41b26aea 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -146,6 +146,7 @@ enum {
         NFS_O_RDWR_STATE,               /* OPEN stateid has read/write state */
         NFS_STATE_RECLAIM_REBOOT,       /* OPEN stateid server rebooted */
         NFS_STATE_RECLAIM_NOGRACE,      /* OPEN stateid needs to recover state */
+        NFS_STATE_POSIX_LOCKS,          /* Posix locks are supported */
 };
 
 struct nfs4_state {
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 0b68238ed0c8..be044b58e811 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1658,6 +1658,8 @@ static int _nfs4_do_open(struct inode *dir, struct path *path, fmode_t fmode, in
         status = PTR_ERR(state);
         if (IS_ERR(state))
                 goto err_opendata_put;
+        if ((opendata->o_res.rflags & NFS4_OPEN_RESULT_LOCKTYPE_POSIX) != 0)
+                set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);
         nfs4_opendata_put(opendata);
         nfs4_put_state_owner(sp);
         *res = state;
@@ -4200,8 +4202,11 @@ static int _nfs4_proc_setlk(struct nfs4_state *state, int cmd, struct file_lock
 {
         struct nfs_inode *nfsi = NFS_I(state->inode);
         unsigned char fl_flags = request->fl_flags;
-        int status;
+        int status = -ENOLCK;
 
+        if ((fl_flags & FL_POSIX) &&
+                        !test_bit(NFS_STATE_POSIX_LOCKS, &state->flags))
+                goto out;
         /* Is this a delegated open? */
         status = nfs4_set_lock_state(state, request);
         if (status != 0)