Adds nfs4_replace_transport() that goes through next replicated server
from the stored replication locations. It replaces the transport.
Signed-off-by: Malahal Naineni <malahal@xxxxxxxxxx>
---
fs/nfs/nfs4_fs.h | 1 +
fs/nfs/nfs4namespace.c | 125 +++++++++++++++++++++++++++++++++++++++++++++
include/linux/nfs_fs_sb.h | 1 +
3 files changed, 127 insertions(+), 0 deletions(-)
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 7ff0177..b2a973b 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -331,6 +331,7 @@ extern void nfs4_close_state(struct nfs4_state *, fmode_t);
extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
extern void nfs4_schedule_lease_recovery(struct nfs_client *);
+int nfs4_replace_transport(struct nfs_server *server);
extern void nfs4_schedule_state_manager(struct nfs_client *);
extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
extern void nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index bb80c49..ee75e27 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -263,3 +263,128 @@ out:
dprintk("%s: done\n", __func__);
return mnt;
}
+
+/*
+ * Returns zero on success, or a negative errno value.
+ */
+static int nfs4_update_server(struct nfs_server *server, const char *hostname,
+ struct sockaddr *sap, size_t salen)
+{
+ struct nfs_client *clp = server->nfs_client;
+ struct rpc_clnt *clnt = server->client;
+ struct xprt_create xargs = {
+ .ident = clp->cl_proto,
+ .net = &init_net,
+ .dstaddr = sap,
+ .addrlen = salen,
+ .servername = hostname,
+ };
+ char buf[INET6_ADDRSTRLEN + 1];
+ struct sockaddr_storage address;
+ struct sockaddr *localaddr = (struct sockaddr *)&address;
+ int error;
+
+ dprintk("--> %s: move FSID %llx:%llx to \"%s\")\n", __func__,
+ (unsigned long long)server->fsid.major,
+ (unsigned long long)server->fsid.minor,
+ hostname);
+
+ /*
+ * rpc_lock_client() deadlocks here. This is because the tasks
+ * that received NFS4ERR_MOVED are waiting for us to wake them
+ * when we are done recovering. But they have bumped
+ * cl_active_tasks for this clnt, so rpc_lock_client() can't make
+ * any progress.
+ */
+#ifdef USE_RPC_LOCK_CLIENT
+ error = rpc_lock_client(clnt, clnt->cl_timeout->to_maxval);
+ if (error != 0) {
+ dprintk("<-- %s(): rpc_lock_client returned %d\n",
+ __func__, error);
+ goto out;
+ }
+#endif /* USE_RPC_LOCK_CLIENT */
+
+ error = rpc_switch_client_transport(clnt, &xargs, clnt->cl_timeout);
+ if (error != 0) {
+ dprintk("<-- %s(): rpc_switch_client_transport returned %d\n",
+ __func__, error);
+ goto out;
+ }
+
+ /*
+ * If we were able to contact the server at @sap, set up a new
+ * nfs_client and move @server to it.
+ */
+ error = rpc_localaddr(clnt, localaddr, sizeof(address));
+ if (error != 0) {
+ dprintk("<-- %s(): rpc_localaddr returned %d\n",
+ __func__, error);
+ goto out;
+ }
+ error = -EAFNOSUPPORT;
+ if (rpc_ntop(localaddr, buf, sizeof(buf)) == 0) {
+ dprintk("<-- %s(): rpc_ntop returned %d\n",
+ __func__, error);
+ goto out;
+ }
+ error = nfs4_clone_client(clp, sap, salen, buf, server);
+ if (error != 0) {
+ dprintk("<-- %s(): nfs4_clone_client returned %d\n",
+ __func__, error);
+ goto out;
+ }
+ if (server->nfs_client->cl_hostname == NULL)
+ server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
+
+ dprintk("<-- %s() succeeded\n", __func__);
+
+out:
+#ifdef USE_RPC_LOCK_CLIENT
+ rpc_unlock_client(clnt);
+#endif /* USE_RPC_LOCK_CLIENT */
+ return error;
+}
+
+int nfs4_replace_transport(struct nfs_server *server)
+{
+ const size_t addr_bufsize = sizeof(struct sockaddr_storage);
+ struct sockaddr *sap;
+ size_t salen;
+ char *hostname;
+ size_t hostnamelen;
+ unsigned int i;
+ int error;
+
+ sap = kmalloc(addr_bufsize, GFP_KERNEL);
+ if (sap == NULL) {
+ error = -ENOMEM;
+ goto out;
+ }
+
+ error = -ENOENT;
+ /* Start after the current entry and search until the current entry */
+ for (i = (server->repli_current + 1) % NFS_MAX_REPLI_SERVERS;
+ i != server->repli_current;
+ i = (i + 1) % NFS_MAX_REPLI_SERVERS) {
+ if (server->repli_servers[i] == NULL)
+ continue;
+ hostname = server->repli_servers[i];
+ hostnamelen = strlen(hostname);
+ salen = nfs_parse_server_name(hostname, hostnamelen, sap,
+ addr_bufsize);
+ if (salen == 0)
+ continue;
+ rpc_set_port(sap, NFS_PORT);
+ error = nfs4_update_server(server, hostname, sap, salen);
+ if (error == 0) {
+ dprintk("%s(): updated with server: %s\n",
+ __func__, hostname);
+ server->repli_current = i;
+ break;
+ }
+ }
+
+out:
+ return error;
+}
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index 4970c58..f5fd4bb 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -160,6 +160,7 @@ struct nfs_server {
struct nfs_fh *rootfh;
#define NFS_MAX_REPLI_SERVERS 2
char *repli_servers[NFS_MAX_REPLI_SERVERS];
+ int repli_current; /* Current serving replica index */
atomic_t active; /* Keep trace of any activity to this server */
--
1.7.8.3
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