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@xxxxxxxxxxxxx>
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
Cc: Stanislav Kinsbursky <skinsbursky@xxxxxxxxxxxxx>
---
fs/nfs/client.c | 16 +++++++++++++---
fs/nfs/idmap.c | 15 +++++++++++++++
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 78970a1..e6070ea 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -504,6 +504,17 @@ 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));
+}
+
/*
* Look up a client by IP address and protocol version
* - creates a new record if one doesn't yet exist
@@ -564,8 +575,7 @@ found_client:
if (new)
nfs_free_client(new);
- 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);
@@ -1317,7 +1327,7 @@ 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 3e8edbe..6ca949b 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 00b66de..a23daa9 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -167,6 +167,7 @@ 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,
--
1.7.7.6
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