From 95b72eb0bdef6476b7e73061f0382adf46c5495a Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 20 Apr 2012 19:24:51 -0400 Subject: NFSv4: Ensure we do not reuse open owner names The NFSv4 spec is ambiguous about whether or not it is permissible to reuse open owner names, so play it safe. This patch adds a timestamp to the state_owner structure, and combines that with the IDA based uniquifier. Fixes a regression whereby the Linux server returns NFS4ERR_BAD_SEQID. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 1 + 1 file changed, 1 insertion(+) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 0f43414eb25a..3b07f094f3a9 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -393,6 +393,7 @@ nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp) static void nfs4_init_seqid_counter(struct nfs_seqid_counter *sc) { + sc->create_time = ktime_get(); sc->flags = 0; sc->counter = 0; spin_lock_init(&sc->lock); -- cgit v1.2.3 From c77365c963cf8703ecf1004cd3b298068a3e1b76 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 21 Apr 2012 12:31:05 -0400 Subject: NFSv4: Ensure that we don't drop a state owner more than once Retest the RB_EMPTY_NODE() condition under the spin lock to ensure that we don't call rb_erase() more than once on the same state owner. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 3b07f094f3a9..b300fb840b21 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -435,13 +435,17 @@ nfs4_alloc_state_owner(struct nfs_server *server, static void nfs4_drop_state_owner(struct nfs4_state_owner *sp) { - if (!RB_EMPTY_NODE(&sp->so_server_node)) { + struct rb_node *rb_node = &sp->so_server_node; + + if (!RB_EMPTY_NODE(rb_node)) { struct nfs_server *server = sp->so_server; struct nfs_client *clp = server->nfs_client; spin_lock(&clp->cl_lock); - rb_erase(&sp->so_server_node, &server->state_owners); - RB_CLEAR_NODE(&sp->so_server_node); + if (!RB_EMPTY_NODE(rb_node)) { + rb_erase(rb_node, &server->state_owners); + RB_CLEAR_NODE(rb_node); + } spin_unlock(&clp->cl_lock); } } -- cgit v1.2.3 From 7bf97bc27308cfdc7a8dadd40ae50f7c4cb09b01 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sat, 21 Apr 2012 12:36:19 -0400 Subject: NFSv4: Keep dropped state owners on the LRU list for a while To ensure that we don't reuse their identifiers. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 20 +++++++++++--------- 1 file changed, 11 insertions(+), 9 deletions(-) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index b300fb840b21..7f0fcfc1fe9d 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -521,6 +521,14 @@ out: /** * nfs4_put_state_owner - Release a nfs4_state_owner * @sp: state owner data to release + * + * Note that we keep released state owners on an LRU + * list. + * This caches valid state owners so that they can be + * reused, to avoid the OPEN_CONFIRM on minor version 0. + * It also pins the uniquifier of dropped state owners for + * a while, to ensure that those state owner names are + * never reused. */ void nfs4_put_state_owner(struct nfs4_state_owner *sp) { @@ -530,15 +538,9 @@ void nfs4_put_state_owner(struct nfs4_state_owner *sp) if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock)) return; - if (!RB_EMPTY_NODE(&sp->so_server_node)) { - sp->so_expires = jiffies; - list_add_tail(&sp->so_lru, &server->state_owners_lru); - spin_unlock(&clp->cl_lock); - } else { - nfs4_remove_state_owner_locked(sp); - spin_unlock(&clp->cl_lock); - nfs4_free_state_owner(sp); - } + sp->so_expires = jiffies; + list_add_tail(&sp->so_lru, &server->state_owners_lru); + spin_unlock(&clp->cl_lock); } /** -- cgit v1.2.3