NFS refactor nfs_find_client and reference client across callback processing
Fixes a bug where the nfs_client could be freed during callback processing.
Refactor nfs_find_client to use minorversion specific means to locate the
correct nfs_client structure.
In the NFS layer, V4.0 clients are found using the callback_ident field in the
CB_COMPOUND header. V4.1 clients are found using the sessionID in the
CB_SEQUENCE operation which is also compared against the sessionID associated
with the back channel thread after a successful CREATE_SESSION.
Each of these methods finds the one an only nfs_client associated
with the incoming callback request - so nfs_find_client_next is not needed.
In the RPC layer, the pg_authenticate call needs to find the nfs_client. For
the v4.0 callback service, the callback identifier has not been decoded so a
search by address, version, and minorversion is used. The sessionid for the
sessions based callback service has (usually) not been set for the
pg_authenticate on a CB_NULL call which can be sent prior to the return
of a CREATE_SESSION call, so the sessionid associated with the back channel
thread is not used to find the client in pg_authenticate for CB_NULL calls.
Pass the referenced nfs_client to each CB_COMPOUND operation being proceesed
via the new cb_process_state structure. The reference is held across
cb_compound processing.
Use the new cb_process_state struct to move the NFS4ERR_RETRY_UNCACHED_REP
processing from process_op into nfs4_callback_sequence where it belongs.
Signed-off-by: Andy Adamson <andros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index bc3a862..11eb993 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -410,70 +410,28 @@
return 0;
}
-/*
- * Find a client by IP address and protocol version
- * - returns NULL if no such client
- */
-struct nfs_client *nfs_find_client(const struct sockaddr *addr, u32 nfsversion)
+/* Common match routine for v4.0 and v4.1 callback services */
+bool
+nfs4_cb_match_client(const struct sockaddr *addr, struct nfs_client *clp,
+ u32 minorversion)
{
- struct nfs_client *clp;
+ struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
- spin_lock(&nfs_client_lock);
- list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
- struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
+ /* Don't match clients that failed to initialise */
+ if (!(clp->cl_cons_state == NFS_CS_READY ||
+ clp->cl_cons_state == NFS_CS_SESSION_INITING))
+ return false;
- /* Don't match clients that failed to initialise properly */
- if (!(clp->cl_cons_state == NFS_CS_READY ||
- clp->cl_cons_state == NFS_CS_SESSION_INITING))
- continue;
+ /* Match the version and minorversion */
+ if (clp->rpc_ops->version != 4 ||
+ clp->cl_minorversion != minorversion)
+ return false;
- /* Different NFS versions cannot share the same nfs_client */
- if (clp->rpc_ops->version != nfsversion)
- continue;
+ /* Match only the IP address, not the port number */
+ if (!nfs_sockaddr_match_ipaddr(addr, clap))
+ return false;
- /* Match only the IP address, not the port number */
- if (!nfs_sockaddr_match_ipaddr(addr, clap))
- continue;
-
- atomic_inc(&clp->cl_count);
- spin_unlock(&nfs_client_lock);
- return clp;
- }
- spin_unlock(&nfs_client_lock);
- return NULL;
-}
-
-/*
- * Find a client by IP address and protocol version
- * - returns NULL if no such client
- */
-struct nfs_client *nfs_find_client_next(struct nfs_client *clp)
-{
- struct sockaddr *sap = (struct sockaddr *)&clp->cl_addr;
- u32 nfsvers = clp->rpc_ops->version;
-
- spin_lock(&nfs_client_lock);
- list_for_each_entry_continue(clp, &nfs_client_list, cl_share_link) {
- struct sockaddr *clap = (struct sockaddr *)&clp->cl_addr;
-
- /* Don't match clients that failed to initialise properly */
- if (clp->cl_cons_state != NFS_CS_READY)
- continue;
-
- /* Different NFS versions cannot share the same nfs_client */
- if (clp->rpc_ops->version != nfsvers)
- continue;
-
- /* Match only the IP address, not the port number */
- if (!nfs_sockaddr_match_ipaddr(sap, clap))
- continue;
-
- atomic_inc(&clp->cl_count);
- spin_unlock(&nfs_client_lock);
- return clp;
- }
- spin_unlock(&nfs_client_lock);
- return NULL;
+ return true;
}
/*
@@ -1172,6 +1130,101 @@
#ifdef CONFIG_NFS_V4
/*
+ * NFSv4.0 callback thread helper
+ *
+ * Find a client by IP address, protocol version, and minorversion
+ *
+ * Called from the pg_authenticate method. The callback identifier
+ * is not used as it has not been decoded.
+ *
+ * Returns NULL if no such client
+ */
+struct nfs_client *
+nfs4_find_client_no_ident(const struct sockaddr *addr)
+{
+ struct nfs_client *clp;
+
+ spin_lock(&nfs_client_lock);
+ list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+ if (nfs4_cb_match_client(addr, clp, 0) == false)
+ continue;
+ atomic_inc(&clp->cl_count);
+ spin_unlock(&nfs_client_lock);
+ return clp;
+ }
+ spin_unlock(&nfs_client_lock);
+ return NULL;
+}
+
+/*
+ * NFSv4.0 callback thread helper
+ *
+ * Find a client by callback identifier
+ */
+struct nfs_client *
+nfs4_find_client_ident(int cb_ident)
+{
+ struct nfs_client *clp;
+
+ spin_lock(&nfs_client_lock);
+ clp = idr_find(&cb_ident_idr, cb_ident);
+ if (clp)
+ atomic_inc(&clp->cl_count);
+ spin_unlock(&nfs_client_lock);
+ return clp;
+}
+
+#if defined(CONFIG_NFS_V4_1)
+/*
+ * NFSv4.1 callback thread helper
+ * For CB_COMPOUND calls, find a client by IP address, protocol version,
+ * minorversion, and sessionID
+ *
+ * CREATE_SESSION triggers a CB_NULL ping from servers. The callback service
+ * sessionid can only be set after the CREATE_SESSION return, so a CB_NULL
+ * can arrive before the callback sessionid is set. For CB_NULL calls,
+ * find a client by IP address protocol version, and minorversion.
+ *
+ * Returns NULL if no such client
+ */
+struct nfs_client *
+nfs4_find_client_sessionid(const struct sockaddr *addr,
+ struct nfs4_sessionid *sid, int is_cb_compound)
+{
+ struct nfs_client *clp;
+
+ spin_lock(&nfs_client_lock);
+ list_for_each_entry(clp, &nfs_client_list, cl_share_link) {
+ if (nfs4_cb_match_client(addr, clp, 1) == false)
+ continue;
+
+ if (!nfs4_has_session(clp))
+ continue;
+
+ /* Match sessionid unless cb_null call*/
+ if (is_cb_compound && (memcmp(clp->cl_session->sess_id.data,
+ sid->data, NFS4_MAX_SESSIONID_LEN) != 0))
+ continue;
+
+ atomic_inc(&clp->cl_count);
+ spin_unlock(&nfs_client_lock);
+ return clp;
+ }
+ spin_unlock(&nfs_client_lock);
+ return NULL;
+}
+
+#else /* CONFIG_NFS_V4_1 */
+
+struct nfs_client *
+nfs4_find_client_sessionid(const struct sockaddr *addr,
+ struct nfs4_sessionid *sid, int is_cb_compound)
+{
+ return NULL;
+}
+#endif /* CONFIG_NFS_V4_1 */
+
+/*
* Initialize the NFS4 callback service
*/
static int nfs4_init_callback(struct nfs_client *clp)