From 86cfb0418537460baf0de0b5e9253784be27a6f9 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 19 Dec 2016 11:48:23 +1100 Subject: [PATCH] NFS: Don't disconnect open-owner on NFS4ERR_BAD_SEQID When an NFS4ERR_BAD_SEQID is received the open-owner is removed from the ->state_owners rbtree so that it will no longer be used. If any stateids attached to this open-owner are still in use, and if a request using one gets an NFS4ERR_BAD_STATEID reply, this can for bad. The state is marked as needing recovery and the nfs4_state_manager() is scheduled to clean up. nfs4_state_manager() finds states to be recovered by walking the state_owners rbtree. As the open-owner is not in the rbtree, the bad state is not found so nfs4_state_manager() completes having done nothing. The request is then retried, with a predicatable result (indefinite retries). If the stateid is for a delegation, this open_owner will be used to open files when the delegation is returned. For that to work, a new open-owner needs to be presented to the server. This patch changes NFS4ERR_BAD_SEQID handling to leave the open-owner in the rbtree but updates the 'create_time' so it looks like a new open-owner. With this the indefinite retries no longer happen. Signed-off-by: NeilBrown Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 27 ++++++++++++--------------- 1 file changed, 12 insertions(+), 15 deletions(-) diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index cf869802ff23..1d152f4470cd 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -494,21 +494,18 @@ nfs4_alloc_state_owner(struct nfs_server *server, } static void -nfs4_drop_state_owner(struct nfs4_state_owner *sp) +nfs4_reset_state_owner(struct nfs4_state_owner *sp) { - 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); - if (!RB_EMPTY_NODE(rb_node)) { - rb_erase(rb_node, &server->state_owners); - RB_CLEAR_NODE(rb_node); - } - spin_unlock(&clp->cl_lock); - } + /* This state_owner is no longer usable, but must + * remain in place so that state recovery can find it + * and the opens associated with it. + * It may also be used for new 'open' request to + * return a delegation to the server. + * So update the 'create_time' so that it looks like + * a new state_owner. This will cause the server to + * request an OPEN_CONFIRM to start a new sequence. + */ + sp->so_seqid.create_time = ktime_get(); } static void nfs4_free_state_owner(struct nfs4_state_owner *sp) @@ -1113,7 +1110,7 @@ void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid) sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid); if (status == -NFS4ERR_BAD_SEQID) - nfs4_drop_state_owner(sp); + nfs4_reset_state_owner(sp); if (!nfs4_has_session(sp->so_server->nfs_client)) nfs_increment_seqid(status, seqid); }