Introduce functions that can walk through an array of returned
fs_locations information and connect a transport to one of the
destination servers listed therein.
Note that NFS minor version 1 introduces "fs_locations_info" which
extends the locations array sorting criteria available to clients.
This is not supported yet.
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
---
fs/nfs/client.c | 3 +
fs/nfs/internal.h | 3 +
fs/nfs/nfs4_fs.h | 2 +
fs/nfs/nfs4client.c | 78 +++++++++++++++++++++++++++++++++
fs/nfs/nfs4namespace.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 199 insertions(+), 1 deletion(-)
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index dbb65fb..5b7c60a 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -945,7 +945,7 @@ void nfs_server_insert_lists(struct nfs_server *server)
}
EXPORT_SYMBOL_GPL(nfs_server_insert_lists);
-static void nfs_server_remove_lists(struct nfs_server *server)
+void nfs_server_remove_lists(struct nfs_server *server)
{
struct nfs_client *clp = server->nfs_client;
struct nfs_net *nn;
@@ -962,6 +962,7 @@ static void nfs_server_remove_lists(struct nfs_server *server)
synchronize_rcu();
}
+EXPORT_SYMBOL_GPL(nfs_server_remove_lists);
/*
* Allocate and initialise a server record
diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 91e59a3..3de40da 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -153,6 +153,7 @@ struct nfs_client *nfs_get_client(const struct nfs_client_initdata *,
rpc_authflavor_t);
int nfs_probe_fsinfo(struct nfs_server *server, struct nfs_fh *, struct nfs_fattr *);
void nfs_server_insert_lists(struct nfs_server *);
+void nfs_server_remove_lists(struct nfs_server *);
void nfs_init_timeout_values(struct rpc_timeout *, int, unsigned int, unsigned int);
int nfs_init_server_rpcclient(struct nfs_server *, const struct rpc_timeout *t,
rpc_authflavor_t);
@@ -173,6 +174,8 @@ extern struct nfs_server *nfs4_create_server(
struct nfs_subversion *);
extern struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *,
struct nfs_fh *);
+extern int nfs4_update_server(struct nfs_server *server, const char *hostname,
+ struct sockaddr *sap, size_t salen);
extern void nfs_free_server(struct nfs_server *server);
extern struct nfs_server *nfs_clone_server(struct nfs_server *,
struct nfs_fh *,
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index b9c839e..4b83ffc 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -219,6 +219,8 @@ rpc_authflavor_t nfs_find_best_sec(struct nfs4_secinfo_flavors *);
struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *, struct inode *, struct qstr *);
struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
struct nfs_fh *, struct nfs_fattr *);
+int nfs4_replace_transport(struct nfs_server *server,
+ const struct nfs4_fs_locations *locations);
/* nfs4proc.c */
extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
diff --git a/fs/nfs/nfs4client.c b/fs/nfs/nfs4client.c
index 4d208e0..dadd118 100644
--- a/fs/nfs/nfs4client.c
+++ b/fs/nfs/nfs4client.c
@@ -920,3 +920,81 @@ error:
dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
return ERR_PTR(error);
}
+
+/**
+ * nfs4_update_server - Replace transitioned nfs_server's transport
+ *
+ * @server: FSID whose transport will be replaced
+ * @hostname: new end-point's hostname
+ * @sap: new end-point's socket address
+ * @salen: size of "sap"
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+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;
+ struct nfs_fh *mntfh;
+ 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);
+
+ 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;
+ }
+
+ 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;
+ }
+
+ nfs_server_remove_lists(server);
+ error = nfs4_set_client(server, hostname, sap, salen, buf,
+ clp->cl_rpcclient->cl_auth->au_flavor,
+ clp->cl_proto, clnt->cl_timeout,
+ clp->cl_minorversion, clp->cl_net);
+ if (error != 0) {
+ dprintk("<-- %s(): nfs4_set_client returned %d\n",
+ __func__, error);
+ goto out;
+ }
+
+ if (server->nfs_client->cl_hostname == NULL)
+ server->nfs_client->cl_hostname = kstrdup(hostname, GFP_KERNEL);
+
+ mntfh = NFS_FH(server->super->s_root->d_inode);
+ error = nfs4_server_common_setup(server, mntfh);
+ if (error < 0)
+ goto out;
+
+ dprintk("<-- %s() succeeded\n", __func__);
+out:
+ return error;
+}
diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c
index cdb0b41..2459e60 100644
--- a/fs/nfs/nfs4namespace.c
+++ b/fs/nfs/nfs4namespace.c
@@ -387,3 +387,117 @@ struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry,
rpc_shutdown_client(client);
return mnt;
}
+
+/*
+ * Try one location from the fs_locations array.
+ *
+ * Returns zero on success, or a negative errno value.
+ */
+static int nfs4_try_replacing_one_location(struct nfs_server *server,
+ char *page, char *page2,
+ const struct nfs4_fs_location *location)
+{
+ const size_t addr_bufsize = sizeof(struct sockaddr_storage);
+ struct sockaddr *sap;
+ unsigned int s;
+ size_t salen;
+ int error;
+
+ dprintk("--> %s(%llx:%llx)\n", __func__,
+ (unsigned long long)server->fsid.major,
+ (unsigned long long)server->fsid.minor);
+
+ error = -ENOMEM;
+ sap = kmalloc(addr_bufsize, GFP_KERNEL);
+ if (sap == NULL)
+ goto out;
+
+ error = -ENOENT;
+ for (s = 0; s < location->nservers; s++) {
+ const struct nfs4_string *buf = &location->servers[s];
+ char *hostname;
+
+ if (buf->len <= 0 || buf->len > PAGE_SIZE)
+ continue;
+
+ if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len) != NULL)
+ continue;
+
+ salen = nfs_parse_server_name(buf->data, buf->len,
+ sap, addr_bufsize, server);
+ if (salen == 0)
+ continue;
+ rpc_set_port(sap, NFS_PORT);
+
+ error = -ENOMEM;
+ hostname = kstrndup(buf->data, buf->len, GFP_KERNEL);
+ if (hostname == NULL)
+ break;
+
+ error = nfs4_update_server(server, hostname, sap, salen);
+ kfree(hostname);
+ if (error == 0)
+ break;
+ }
+
+ kfree(sap);
+out:
+ dprintk("<-- %s() = %d\n", __func__, error);
+ return error;
+}
+
+/**
+ * nfs4_replace_transport - set up transport to destination server
+ *
+ * @server: export being migrated
+ * @locations: fs_locations array
+ *
+ * Returns zero on success, or a negative errno value.
+ *
+ * The client tries all the entries in the "locations" array, in the
+ * order returned by the server, until one works or the end of the
+ * array is reached.
+ */
+int nfs4_replace_transport(struct nfs_server *server,
+ const struct nfs4_fs_locations *locations)
+{
+ char *page = NULL, *page2 = NULL;
+ int loc, error;
+
+ dprintk("--> %s(%llx:%llx)\n", __func__,
+ (unsigned long long)server->fsid.major,
+ (unsigned long long)server->fsid.minor);
+
+ error = -ENOENT;
+ if (locations == NULL || locations->nlocations <= 0)
+ goto out;
+
+ error = -ENOMEM;
+ page = (char *) __get_free_page(GFP_USER);
+ if (!page)
+ goto out;
+ page2 = (char *) __get_free_page(GFP_USER);
+ if (!page2)
+ goto out;
+
+ for (loc = 0; loc < locations->nlocations; loc++) {
+ const struct nfs4_fs_location *location =
+ &locations->locations[loc];
+
+ if (location == NULL || location->nservers <= 0 ||
+ location->rootpath.ncomponents == 0)
+ continue;
+
+ error = nfs4_try_replacing_one_location(server, page,
+ page2, location);
+ if (error == 0)
+ break;
+ }
+
+out:
+ free_page((unsigned long)page);
+ free_page((unsigned long)page2);
+
+ dprintk("<-- %s() = %d\n", __func__, error);
+ return error;
+}
--
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