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Commit c9fdeb28 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
Browse files

NFS: Add basic migration support to state manager thread 



Migration recovery and state recovery must be serialized, so handle
both in the state manager thread.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent ce6cda18

fs/nfs/nfs4_fs.h

+2 −0
Original line number Diff line number Diff line
@@ -29,6 +29,7 @@ enum nfs4_client_state { 
	NFS4CLNT_SERVER_SCOPE_MISMATCH,

	NFS4CLNT_PURGE_STATE,

	NFS4CLNT_BIND_CONN_TO_SESSION,

	NFS4CLNT_MOVED,

};



#define NFS4_RENEW_TIMEOUT		0x01
@@ -421,6 +422,7 @@ extern int nfs4_client_recover_expired_lease(struct nfs_client *clp); 
extern void nfs4_schedule_state_manager(struct nfs_client *);

extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);

extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);

extern int nfs4_schedule_migration_recovery(const struct nfs_server *);

extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);

extern void nfs41_handle_server_scope(struct nfs_client *,

				      struct nfs41_server_scope **);

fs/nfs/nfs4client.c

+1 −0
Original line number Diff line number Diff line
@@ -197,6 +197,7 @@ struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *cl_init) 
	clp->cl_state = 1 << NFS4CLNT_LEASE_EXPIRED;

	clp->cl_minorversion = cl_init->minorversion;

	clp->cl_mvops = nfs_v4_minor_ops[cl_init->minorversion];

	clp->cl_mig_gen = 1;

	return clp;



error:

fs/nfs/nfs4state.c

+158 −3
Original line number Diff line number Diff line
@@ -239,8 +239,6 @@ static void nfs4_end_drain_session(struct nfs_client *clp) 
	}

}



#if defined(CONFIG_NFS_V4_1)



static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)

{

	set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
@@ -270,6 +268,8 @@ static int nfs4_begin_drain_session(struct nfs_client *clp) 
	return nfs4_drain_slot_tbl(&ses->fc_slot_table);

}



#if defined(CONFIG_NFS_V4_1)



static int nfs41_setup_state_renewal(struct nfs_client *clp)

{

	int status;
@@ -1197,6 +1197,42 @@ void nfs4_schedule_lease_recovery(struct nfs_client *clp) 
}

EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);



/**

 * nfs4_schedule_migration_recovery - trigger migration recovery

 *

 * @server: FSID that is migrating

 *

 * Returns zero if recovery has started, otherwise a negative NFS4ERR

 * value is returned.

 */

int nfs4_schedule_migration_recovery(const struct nfs_server *server)

{

	struct nfs_client *clp = server->nfs_client;



	if (server->fh_expire_type != NFS4_FH_PERSISTENT) {

		pr_err("NFS: volatile file handles not supported (server %s)\n",

				clp->cl_hostname);

		return -NFS4ERR_IO;

	}



	if (test_bit(NFS_MIG_FAILED, &server->mig_status))

		return -NFS4ERR_IO;



	dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",

			__func__,

			(unsigned long long)server->fsid.major,

			(unsigned long long)server->fsid.minor,

			clp->cl_hostname);



	set_bit(NFS_MIG_IN_TRANSITION,

			&((struct nfs_server *)server)->mig_status);

	set_bit(NFS4CLNT_MOVED, &clp->cl_state);



	nfs4_schedule_state_manager(clp);

	return 0;

}

EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);



int nfs4_wait_clnt_recover(struct nfs_client *clp)

{

	int res;
@@ -1826,6 +1862,119 @@ static int nfs4_purge_lease(struct nfs_client *clp) 
	return 0;

}



/*

 * Try remote migration of one FSID from a source server to a

 * destination server.  The source server provides a list of

 * potential destinations.

 *

 * Returns zero or a negative NFS4ERR status code.

 */

static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)

{

	struct nfs_client *clp = server->nfs_client;

	struct nfs4_fs_locations *locations = NULL;

	struct inode *inode;

	struct page *page;

	int status, result;



	dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,

			(unsigned long long)server->fsid.major,

			(unsigned long long)server->fsid.minor,

			clp->cl_hostname);



	result = 0;

	page = alloc_page(GFP_KERNEL);

	locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);

	if (page == NULL || locations == NULL) {

		dprintk("<-- %s: no memory\n", __func__);

		goto out;

	}



	inode = server->super->s_root->d_inode;

	result = nfs4_proc_get_locations(inode, locations, page, cred);

	if (result) {

		dprintk("<-- %s: failed to retrieve fs_locations: %d\n",

			__func__, result);

		goto out;

	}



	result = -NFS4ERR_NXIO;

	if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {

		dprintk("<-- %s: No fs_locations data, migration skipped\n",

			__func__);

		goto out;

	}



	nfs4_begin_drain_session(clp);



	status = nfs4_replace_transport(server, locations);

	if (status != 0) {

		dprintk("<-- %s: failed to replace transport: %d\n",

			__func__, status);

		goto out;

	}



	result = 0;

	dprintk("<-- %s: migration succeeded\n", __func__);



out:

	if (page != NULL)

		__free_page(page);

	kfree(locations);

	if (result) {

		pr_err("NFS: migration recovery failed (server %s)\n",

				clp->cl_hostname);

		set_bit(NFS_MIG_FAILED, &server->mig_status);

	}

	return result;

}



/*

 * Returns zero or a negative NFS4ERR status code.

 */

static int nfs4_handle_migration(struct nfs_client *clp)

{

	const struct nfs4_state_maintenance_ops *ops =

				clp->cl_mvops->state_renewal_ops;

	struct nfs_server *server;

	struct rpc_cred *cred;



	dprintk("%s: migration reported on \"%s\"\n", __func__,

			clp->cl_hostname);



	spin_lock(&clp->cl_lock);

	cred = ops->get_state_renewal_cred_locked(clp);

	spin_unlock(&clp->cl_lock);

	if (cred == NULL)

		return -NFS4ERR_NOENT;



	clp->cl_mig_gen++;

restart:

	rcu_read_lock();

	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {

		int status;



		if (server->mig_gen == clp->cl_mig_gen)

			continue;

		server->mig_gen = clp->cl_mig_gen;



		if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,

						&server->mig_status))

			continue;



		rcu_read_unlock();

		status = nfs4_try_migration(server, cred);

		if (status < 0) {

			put_rpccred(cred);

			return status;

		}

		goto restart;

	}

	rcu_read_unlock();

	put_rpccred(cred);

	return 0;

}



/**

 * nfs4_discover_server_trunking - Detect server IP address trunking

 *
@@ -2154,7 +2303,13 @@ static void nfs4_state_manager(struct nfs_client *clp) 
			status = nfs4_check_lease(clp);

			if (status < 0)

				goto out_error;

			continue;

		}



		if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {

			section = "migration";

			status = nfs4_handle_migration(clp);

			if (status < 0)

				goto out_error;

		}



		/* First recover reboot state... */

include/linux/nfs_fs_sb.h

+7 −0
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ struct nfs_client { 
	char			cl_ipaddr[48];

	u32			cl_cb_ident;	/* v4.0 callback identifier */

	const struct nfs4_minor_version_ops *cl_mvops;

	unsigned long		cl_mig_gen;



	/* NFSv4.0 transport blocking */

	struct nfs4_slot_table	*cl_slot_tbl;
@@ -189,6 +190,12 @@ struct nfs_server { 
	struct list_head	state_owners_lru;

	struct list_head	layouts;

	struct list_head	delegations;



	unsigned long		mig_gen;

	unsigned long		mig_status;

#define NFS_MIG_IN_TRANSITION		(1)

#define NFS_MIG_FAILED			(2)



	void (*destroy)(struct nfs_server *);



	atomic_t active; /* Keep trace of any activity to this server */