Commit 0df5dd4a authored by Trond Myklebust's avatar Trond Myklebust
Browse files

NFSv4: fix delegated locking 



Arnaud Giersch reports that NFSv4 locking is broken when we hold a
delegation since commit 8e469ebd (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: default avatarArnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
parent 2c61be0a

fs/nfs/client.c

+2 −1
Original line number Diff line number Diff line
@@ -1294,7 +1294,8 @@ static int nfs4_init_server(struct nfs_server *server, 


	/* 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 */

fs/nfs/nfs4proc.c

+3 −1
Original line number Diff line number Diff line
@@ -1523,6 +1523,8 @@ static int _nfs4_proc_open(struct nfs4_opendata *data) 
		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 @@ 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)

	if (server->caps & NFS_CAP_POSIX_LOCK)

		set_bit(NFS_STATE_POSIX_LOCKS, &state->flags);

	nfs4_opendata_put(opendata);

	nfs4_put_state_owner(sp);

include/linux/nfs_fs_sb.h

+1 −0
Original line number Diff line number Diff line
@@ -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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