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Commit 3420a8c4 authored by Chuck Lever's avatar Chuck Lever Committed by J. Bruce Fields
Browse files

NSM: Add nsm_lookup() function 



Introduce a new API to fs/lockd/mon.c that allows nlm_host_rebooted()
to lookup up nsm_handles via the contents of an nlm_reboot struct.

The new function is equivalent to calling nsm_find() with @create set
to zero, but it takes a struct nlm_reboot instead of separate
arguments.

Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Signed-off-by: default avatarJ. Bruce Fields <bfields@citi.umich.edu>
parent 576df463

fs/lockd/mon.c

+64 −0
Original line number Diff line number Diff line
@@ -201,6 +201,29 @@ void nsm_unmonitor(const struct nlm_host *host) 
	}

}



static struct nsm_handle *nsm_lookup_hostname(const char *hostname,

					      const size_t len)

{

	struct nsm_handle *nsm;



	list_for_each_entry(nsm, &nsm_handles, sm_link)

		if (strlen(nsm->sm_name) == len &&

		    memcmp(nsm->sm_name, hostname, len) == 0)

			return nsm;

	return NULL;

}



static struct nsm_handle *nsm_lookup_priv(const struct nsm_private *priv)

{

	struct nsm_handle *nsm;



	list_for_each_entry(nsm, &nsm_handles, sm_link)

		if (memcmp(nsm->sm_priv.data, priv->data,

					sizeof(priv->data)) == 0)

			return nsm;

	return NULL;

}



/*

 * Construct a unique cookie to match this nsm_handle to this monitored

 * host.  It is passed to the local rpc.statd via NSMPROC_MON, and
@@ -297,6 +320,47 @@ struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen, 
	return nsm;

}



/**

 * nsm_reboot_lookup - match NLMPROC_SM_NOTIFY arguments to an nsm_handle

 * @info: pointer to NLMPROC_SM_NOTIFY arguments

 *

 * Returns a matching nsm_handle if found in the nsm cache; the returned

 * nsm_handle's reference count is bumped and sm_monitored is cleared.

 * Otherwise returns NULL if some error occurred.

 */

struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info)

{

	struct nsm_handle *cached;



	spin_lock(&nsm_lock);



	if (nsm_use_hostnames && info->mon != NULL)

		cached = nsm_lookup_hostname(info->mon, info->len);

	else

		cached = nsm_lookup_priv(&info->priv);



	if (unlikely(cached == NULL)) {

		spin_unlock(&nsm_lock);

		dprintk("lockd: never saw rebooted peer '%.*s' before\n",

				info->len, info->mon);

		return cached;

	}



	atomic_inc(&cached->sm_count);

	spin_unlock(&nsm_lock);



	/*

	 * During subsequent lock activity, force a fresh

	 * notification to be set up for this host.

	 */

	cached->sm_monitored = 0;



	dprintk("lockd: host %s (%s) rebooted, cnt %d\n",

			cached->sm_name, cached->sm_addrbuf,

			atomic_read(&cached->sm_count));

	return cached;

}



/**

 * nsm_release - Release an NSM handle

 * @nsm: pointer to handle to be released

include/linux/lockd/lockd.h

+1 −0
Original line number Diff line number Diff line
@@ -251,6 +251,7 @@ struct nsm_handle *nsm_find(const struct sockaddr *sap, const size_t salen, 
					const char *hostname,

					const size_t hostname_len,

					const int create);

struct nsm_handle *nsm_reboot_lookup(const struct nlm_reboot *info);

void		  nsm_release(struct nsm_handle *nsm);



/*