NFSv4: fix delegated locking
Arnaud Giersch reports that NFSv4 locking is broken when we hold a
delegation since commit 8e469ebd6dc32cbaf620e134d79f740bf0ebab79 (NFSv4:
Don't allow posix locking against servers that don't support it).
According to Arnaud, the lock succeeds the first time he opens the file
(since we cannot do a delegated open) but then fails after we start using
delegated opens.
The following patch fixes it by ensuring that locking behaviour is
governed by a per-filesystem capability flag that is initially set, but
gets cleared if the server ever returns an OPEN without the
NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set.
Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index fe0cd9e..6380670 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1523,6 +1523,8 @@
nfs_post_op_update_inode(dir, o_res->dir_attr);
} else
nfs_refresh_inode(dir, o_res->dir_attr);
+ if ((o_res->rflags & NFS4_OPEN_RESULT_LOCKTYPE_POSIX) == 0)
+ server->caps &= ~NFS_CAP_POSIX_LOCK;
if(o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
status = _nfs4_proc_open_confirm(data);
if (status != 0)
@@ -1664,7 +1666,7 @@
status = PTR_ERR(state);
if (IS_ERR(state))
goto err_opendata_put;
- if ((opendata->o_res.rflags & NFS4_OPEN_RESULT_LOCKTYPE_POSIX) != 0)
+ if (server->caps & NFS_CAP_POSIX_LOCK)
set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);
nfs4_opendata_put(opendata);
nfs4_put_state_owner(sp);