diff options
| author | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-05-23 13:24:36 -0400 |
|---|---|---|
| committer | Trond Myklebust <Trond.Myklebust@netapp.com> | 2012-05-23 15:21:13 -0400 |
| commit | 4697bd5e9419348ef9fa9b55cefe4355ad9d3d01 (patch) | |
| tree | 20bf5da80d10ec4df42ae0c3067af39a36f11c28 | |
| parent | 7b38c3682c5cab4f98751d5fe57b78a59020653d (diff) | |
| download | linux-4697bd5e9419348ef9fa9b55cefe4355ad9d3d01.tar.bz2 | |
NFSv4: Fix a race in the net namespace mount notification
Since the struct nfs_client gets added to the global nfs_client_list
before it is initialised, it is possible that rpc_pipefs_event can
end up trying to create idmapper entries on such a thing.
The solution is to have the mount notification wait for the
initialisation of each nfs_client to complete, and then to
skip any entries for which the it failed.
Reported-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
| -rw-r--r-- | fs/nfs/client.c | 16 | ||||
| -rw-r--r-- | fs/nfs/idmap.c | 15 | ||||
| -rw-r--r-- | fs/nfs/internal.h | 1 |
3 files changed, 29 insertions, 3 deletions
diff --git a/fs/nfs/client.c b/fs/nfs/client.c index 25dde0745cfa..d35664287e14 100644 --- a/fs/nfs/client.c +++ b/fs/nfs/client.c @@ -507,6 +507,17 @@ static struct nfs_client *nfs_match_client(const struct nfs_client_initdata *dat return NULL; } +static bool nfs_client_init_is_complete(const struct nfs_client *clp) +{ + return clp->cl_cons_state != NFS_CS_INITING; +} + +int nfs_wait_client_init_complete(const struct nfs_client *clp) +{ + return wait_event_killable(nfs_client_active_wq, + nfs_client_init_is_complete(clp)); +} + /* * Found an existing client. Make sure it's ready before returning. */ @@ -516,8 +527,7 @@ nfs_found_client(const struct nfs_client_initdata *cl_init, { int error; - error = wait_event_killable(nfs_client_active_wq, - clp->cl_cons_state < NFS_CS_INITING); + error = nfs_wait_client_init_complete(clp); if (error < 0) { nfs_put_client(clp); return ERR_PTR(-ERESTARTSYS); @@ -1333,7 +1343,7 @@ static int nfs4_init_client_minor_version(struct nfs_client *clp) * so that the client back channel can find the * nfs_client struct */ - clp->cl_cons_state = NFS_CS_SESSION_INITING; + nfs_mark_client_ready(clp, NFS_CS_SESSION_INITING); } #endif /* CONFIG_NFS_V4_1 */ diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c index 2eaecf9d8db7..861be75eb165 100644 --- a/fs/nfs/idmap.c +++ b/fs/nfs/idmap.c @@ -530,9 +530,24 @@ static struct nfs_client *nfs_get_client_for_event(struct net *net, int event) struct nfs_net *nn = net_generic(net, nfs_net_id); struct dentry *cl_dentry; struct nfs_client *clp; + int err; +restart: spin_lock(&nn->nfs_client_lock); list_for_each_entry(clp, &nn->nfs_client_list, cl_share_link) { + /* Wait for initialisation to finish */ + if (clp->cl_cons_state == NFS_CS_INITING) { + atomic_inc(&clp->cl_count); + spin_unlock(&nn->nfs_client_lock); + err = nfs_wait_client_init_complete(clp); + nfs_put_client(clp); + if (err) + return NULL; + goto restart; + } + /* Skip nfs_clients that failed to initialise */ + if (clp->cl_cons_state < 0) + continue; if (clp->rpc_ops != &nfs_v4_clientops) continue; cl_dentry = clp->cl_idmap->idmap_pipe->dentry; diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h index 5ea571e8d0e9..1848a7275592 100644 --- a/fs/nfs/internal.h +++ b/fs/nfs/internal.h @@ -168,6 +168,7 @@ extern struct nfs_server *nfs_clone_server(struct nfs_server *, struct nfs_fh *, struct nfs_fattr *, rpc_authflavor_t); +extern int nfs_wait_client_init_complete(const struct nfs_client *clp); extern void nfs_mark_client_ready(struct nfs_client *clp, int state); extern struct nfs_client *nfs4_set_ds_client(struct nfs_client* mds_clp, const struct sockaddr *ds_addr, |