NFSv4: Fix a race in NFSv4.1 server trunking discovery
We do not want to allow a race with another NFS mount to cause
nfs41_walk_client_list() to establish a lease on our nfs_client before
we're done checking for trunking.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index f9f4845..1987415 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -433,7 +433,7 @@
static bool nfs_client_init_is_complete(const struct nfs_client *clp)
{
- return clp->cl_cons_state != NFS_CS_INITING;
+ return clp->cl_cons_state <= NFS_CS_READY;
}
int nfs_wait_client_init_complete(const struct nfs_client *clp)
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 8646af9..86d6214 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -621,6 +621,9 @@
spin_lock(&nn->nfs_client_lock);
list_for_each_entry(pos, &nn->nfs_client_list, cl_share_link) {
+ if (pos == new)
+ goto found;
+
if (pos->rpc_ops != new->rpc_ops)
continue;
@@ -639,10 +642,6 @@
prev = pos;
status = nfs_wait_client_init_complete(pos);
- if (pos->cl_cons_state == NFS_CS_SESSION_INITING) {
- nfs4_schedule_lease_recovery(pos);
- status = nfs4_wait_clnt_recover(pos);
- }
spin_lock(&nn->nfs_client_lock);
if (status < 0)
break;
@@ -668,7 +667,7 @@
*/
if (!nfs4_match_client_owner_id(pos, new))
continue;
-
+found:
atomic_inc(&pos->cl_count);
*result = pos;
status = 0;
diff --git a/fs/nfs/nfs4state.c b/fs/nfs/nfs4state.c
index 5ad908e..d8b43f0 100644
--- a/fs/nfs/nfs4state.c
+++ b/fs/nfs/nfs4state.c
@@ -346,9 +346,19 @@
status = nfs4_proc_exchange_id(clp, cred);
if (status != NFS4_OK)
return status;
- set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
- return nfs41_walk_client_list(clp, result, cred);
+ status = nfs41_walk_client_list(clp, result, cred);
+ if (status < 0)
+ return status;
+ if (clp != *result)
+ return 0;
+
+ set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
+ nfs4_schedule_state_manager(clp);
+ status = nfs_wait_client_init_complete(clp);
+ if (status < 0)
+ nfs_put_client(clp);
+ return status;
}
#endif /* CONFIG_NFS_V4_1 */