From: Greg KH on
2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Trond Myklebust <Trond.Myklebust(a)netapp.com>

commit 0df5dd4aae211edeeeb84f7f84f6d093406d7c22 upstream.

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(a)iut-bm.univ-fcomte.fr>
Signed-off-by: Trond Myklebust <Trond.Myklebust(a)netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
fs/nfs/client.c | 3 ++-
fs/nfs/nfs4proc.c | 4 +++-
include/linux/nfs_fs_sb.h | 1 +
3 files changed, 6 insertions(+), 2 deletions(-)

--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -1293,7 +1293,8 @@ static int nfs4_init_server(struct nfs_s

/* Initialise the client representation from the mount data */
server->flags = data->flags;
- server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR;
+ server->caps |= NFS_CAP_ATOMIC_OPEN|NFS_CAP_CHANGE_ATTR|
+ NFS_CAP_POSIX_LOCK;
server->options = data->options;

/* Get a client record */
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -1520,6 +1520,8 @@ static int _nfs4_proc_open(struct nfs4_o
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)
@@ -1660,7 +1662,7 @@ static int _nfs4_do_open(struct inode *d
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);
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -176,6 +176,7 @@ struct nfs_server {
#define NFS_CAP_ATIME (1U << 11)
#define NFS_CAP_CTIME (1U << 12)
#define NFS_CAP_MTIME (1U << 13)
+#define NFS_CAP_POSIX_LOCK (1U << 14)


/* maximum number of slots to use */


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