New function nfs4_update_server() moves an nfs_server to a different
nfs_client.  This is done as part of migration recovery.

Though it may be appealing to think of them as the same thing,
migration recovery is not the same as following a referral.

For a referral, the client has not descended into the file system
yet: it has no nfs_server, no super block, no inodes or open state.
It is enough to simply instantiate the nfs_server and super block,
and perform a referral mount.

For a migration, however, we have all of those things already, and
they have to be moved to a different nfs_client.  No local namespace
changes are needed here.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever 2013-10-17 14:12:28 -04:00 коммит произвёл Trond Myklebust
Родитель 40b00b6b17
Коммит 32e62b7c3e
3 изменённых файлов: 113 добавлений и 1 удалений

Просмотреть файл

@ -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

Просмотреть файл

@ -154,6 +154,7 @@ 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);
@ -174,6 +175,8 @@ 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 *,

Просмотреть файл

@ -1092,3 +1092,111 @@ error:
dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
return ERR_PTR(error);
}
/*
* Grab the destination's particulars, including lease expiry time.
*
* Returns zero if probe succeeded and retrieved FSID matches the FSID
* we have cached.
*/
static int nfs_probe_destination(struct nfs_server *server)
{
struct inode *inode = server->super->s_root->d_inode;
struct nfs_fattr *fattr;
int error;
fattr = nfs_alloc_fattr();
if (fattr == NULL)
return -ENOMEM;
/* Sanity: the probe won't work if the destination server
* does not recognize the migrated FH. */
error = nfs_probe_fsinfo(server, NFS_FH(inode), fattr);
nfs_free_fattr(fattr);
return error;
}
/**
* nfs4_update_server - Move an nfs_server to a different nfs_client
*
* @server: represents FSID to be moved
* @hostname: new end-point's hostname
* @sap: new end-point's socket address
* @salen: size of "sap"
*
* The nfs_server must be quiescent before this function is invoked.
* Either its session is drained (NFSv4.1+), or its transport is
* plugged and drained (NFSv4.0).
*
* 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;
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);
nfs_put_client(clp);
if (error != 0) {
nfs_server_insert_lists(server);
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);
nfs_server_insert_lists(server);
error = nfs_probe_destination(server);
if (error < 0)
goto out;
dprintk("<-- %s() succeeded\n", __func__);
out:
return error;
}