From 6f2e64d3e1f661095e274c9d9d47e3f39a6cf1c0 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Fri, 6 Jul 2007 10:53:21 -0400 Subject: NFSv4: Make the NFS state model work with the nosharedcache mount option Consider the case where the user has mounted the remote filesystem server:/foo on the two local directories /bar and /baz using the nosharedcache mount option. The files /bar/file and /baz/file are represented by different inodes in the local namespace, but refer to the same file /foo/file on the server. Consider the case where a process opens both /bar/file and /baz/file, then closes /bar/file: because the nfs4_state is not shared between /bar/file and /baz/file, the kernel will see that the nfs4_state for /bar/file is no longer referenced, so it will send off a CLOSE rpc call. Unless the open_owners differ, then that CLOSE call will invalidate the open state on /baz/file too. Conclusion: we cannot share open state owners between two different non-shared mount instances of the same filesystem. Signed-off-by: Trond Myklebust --- fs/nfs/nfs4state.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) (limited to 'fs/nfs/nfs4state.c') diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c index 523cc2cbb5e1..e9662ba81d86 100644 --- a/fs/nfs/nfs4state.c +++ b/fs/nfs/nfs4state.c @@ -156,8 +156,9 @@ static void nfs_free_unique_id(struct rb_root *root, struct nfs_unique_id *id) } static struct nfs4_state_owner * -nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred) +nfs4_find_state_owner(struct nfs_server *server, struct rpc_cred *cred) { + struct nfs_client *clp = server->nfs_client; struct rb_node **p = &clp->cl_state_owners.rb_node, *parent = NULL; struct nfs4_state_owner *sp, *res = NULL; @@ -166,6 +167,14 @@ nfs4_find_state_owner(struct nfs_client *clp, struct rpc_cred *cred) parent = *p; sp = rb_entry(parent, struct nfs4_state_owner, so_client_node); + if (server < sp->so_server) { + p = &parent->rb_left; + continue; + } + if (server > sp->so_server) { + p = &parent->rb_right; + continue; + } if (cred < sp->so_cred) p = &parent->rb_left; else if (cred > sp->so_cred) @@ -190,6 +199,14 @@ nfs4_insert_state_owner(struct nfs_client *clp, struct nfs4_state_owner *new) parent = *p; sp = rb_entry(parent, struct nfs4_state_owner, so_client_node); + if (new->so_server < sp->so_server) { + p = &parent->rb_left; + continue; + } + if (new->so_server > sp->so_server) { + p = &parent->rb_right; + continue; + } if (new->so_cred < sp->so_cred) p = &parent->rb_left; else if (new->so_cred > sp->so_cred) @@ -260,7 +277,7 @@ struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct struct nfs4_state_owner *sp, *new; spin_lock(&clp->cl_lock); - sp = nfs4_find_state_owner(clp, cred); + sp = nfs4_find_state_owner(server, cred); spin_unlock(&clp->cl_lock); if (sp != NULL) return sp; @@ -268,6 +285,7 @@ struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct if (new == NULL) return NULL; new->so_client = clp; + new->so_server = server; new->so_cred = cred; spin_lock(&clp->cl_lock); sp = nfs4_insert_state_owner(clp, new); -- cgit v1.2.3