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Commit 32e62b7c authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: Add nfs4_update_server 



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: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 40b00b6b

fs/nfs/client.c

+2 −1
Original line number Diff line number Diff line
@@ -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

fs/nfs/internal.h

+3 −0
Original line number Diff line number Diff line
@@ -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 *,

fs/nfs/nfs4client.c

+108 −0
Original line number Diff line number Diff line
@@ -1092,3 +1092,111 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data, 
	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;

}