Commit 5b7eb784 authored by Olga Kornievskaia's avatar Olga Kornievskaia Committed by Trond Myklebust
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SUNRPC: take a xprt offline using sysfs 



Using sysfs's xprt_state attribute, mark a particular transport offline.
It will not be picked during the round-robin selection. It's not allowed
to take the main (1st created transport associated with the rpc_client)
offline. Also bring a transport back online via sysfs by writing "online"
and that would allow for this transport to be picked during the round-
robin selection.

Signed-off-by: default avatarOlga Kornievskaia <kolga@netapp.com>
Signed-off-by: default avatarTrond Myklebust <trond.myklebust@hammerspace.com>
parent c1830a63

include/linux/sunrpc/xprt.h

+1 −0
Original line number Diff line number Diff line
@@ -427,6 +427,7 @@ void xprt_release_write(struct rpc_xprt *, struct rpc_task *); 
#define XPRT_BOUND		(4)

#define XPRT_BINDING		(5)

#define XPRT_CLOSING		(6)

#define XPRT_OFFLINE		(7)

#define XPRT_CONGESTED		(9)

#define XPRT_CWND_WAIT		(10)

#define XPRT_WRITE_SPACE	(11)

net/sunrpc/sysfs.c

+62 −4
Original line number Diff line number Diff line
@@ -68,6 +68,15 @@ rpc_sysfs_xprt_kobj_get_xprt(struct kobject *kobj) 
	return xprt_get(x->xprt);

}



static inline struct rpc_xprt_switch *

rpc_sysfs_xprt_kobj_get_xprt_switch(struct kobject *kobj)

{

	struct rpc_sysfs_xprt *x = container_of(kobj,

		struct rpc_sysfs_xprt, kobject);



	return xprt_switch_get(x->xprt_switch);

}



static inline struct rpc_xprt_switch *

rpc_sysfs_xprt_switch_kobj_get_xprt(struct kobject *kobj)

{
@@ -122,7 +131,7 @@ static ssize_t rpc_sysfs_xprt_state_show(struct kobject *kobj, 
	struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);

	ssize_t ret;

	int locked, connected, connecting, close_wait, bound, binding,

	    closing, congested, cwnd_wait, write_space;

	    closing, congested, cwnd_wait, write_space, offline;



	if (!xprt)

		return 0;
@@ -140,8 +149,9 @@ static ssize_t rpc_sysfs_xprt_state_show(struct kobject *kobj, 
		congested = test_bit(XPRT_CONGESTED, &xprt->state);

		cwnd_wait = test_bit(XPRT_CWND_WAIT, &xprt->state);

		write_space = test_bit(XPRT_WRITE_SPACE, &xprt->state);

		offline = test_bit(XPRT_OFFLINE, &xprt->state);



		ret = sprintf(buf, "state=%s %s %s %s %s %s %s %s %s %s\n",

		ret = sprintf(buf, "state=%s %s %s %s %s %s %s %s %s %s %s\n",

			      locked ? "LOCKED" : "",

			      connected ? "CONNECTED" : "",

			      connecting ? "CONNECTING" : "",
@@ -151,7 +161,8 @@ static ssize_t rpc_sysfs_xprt_state_show(struct kobject *kobj, 
			      closing ? "CLOSING" : "",

			      congested ? "CONGESTED" : "",

			      cwnd_wait ? "CWND_WAIT" : "",

			      write_space ? "WRITE_SPACE" : "");

			      write_space ? "WRITE_SPACE" : "",

			      offline ? "OFFLINE" : "");

	}



	xprt_put(xprt);
@@ -233,6 +244,52 @@ static ssize_t rpc_sysfs_xprt_dstaddr_store(struct kobject *kobj, 
	goto out;

}



static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,

					   struct kobj_attribute *attr,

					   const char *buf, size_t count)

{

	struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);

	int offline = 0, online = 0;

	struct rpc_xprt_switch *xps = rpc_sysfs_xprt_kobj_get_xprt_switch(kobj);



	if (!xprt)

		return 0;



	if (!strncmp(buf, "offline", 7))

		offline = 1;

	else if (!strncmp(buf, "online", 6))

		online = 1;

	else

		return -EINVAL;



	if (wait_on_bit_lock(&xprt->state, XPRT_LOCKED, TASK_KILLABLE)) {

		count = -EINTR;

		goto out_put;

	}

	if (xprt->main) {

		count = -EINVAL;

		goto release_tasks;

	}

	if (offline) {

		set_bit(XPRT_OFFLINE, &xprt->state);

		spin_lock(&xps->xps_lock);

		xps->xps_nactive--;

		spin_unlock(&xps->xps_lock);

	} else if (online) {

		clear_bit(XPRT_OFFLINE, &xprt->state);

		spin_lock(&xps->xps_lock);

		xps->xps_nactive++;

		spin_unlock(&xps->xps_lock);

	}



release_tasks:

	xprt_release_write(xprt, NULL);

out_put:

	xprt_put(xprt);

	xprt_switch_put(xps);

	return count;

}



int rpc_sysfs_init(void)

{

	rpc_sunrpc_kset = kset_create_and_add("sunrpc", NULL, kernel_kobj);
@@ -303,7 +360,7 @@ static struct kobj_attribute rpc_sysfs_xprt_info = __ATTR(xprt_info, 
	0444, rpc_sysfs_xprt_info_show, NULL);



static struct kobj_attribute rpc_sysfs_xprt_change_state = __ATTR(xprt_state,

	0644, rpc_sysfs_xprt_state_show, NULL);

	0644, rpc_sysfs_xprt_state_show, rpc_sysfs_xprt_state_change);



static struct attribute *rpc_sysfs_xprt_attrs[] = {

	&rpc_sysfs_xprt_dstaddr.attr,
@@ -466,6 +523,7 @@ void rpc_sysfs_xprt_setup(struct rpc_xprt_switch *xprt_switch, 
	if (rpc_xprt) {

		xprt->xprt_sysfs = rpc_xprt;

		rpc_xprt->xprt = xprt;

		rpc_xprt->xprt_switch = xprt_switch;

		kobject_uevent(&rpc_xprt->kobject, KOBJ_ADD);

	}

}

net/sunrpc/sysfs.h

+1 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ struct rpc_sysfs_xprt_switch { 
struct rpc_sysfs_xprt {

	struct kobject kobject;

	struct rpc_xprt *xprt;

	struct rpc_xprt_switch *xprt_switch;

};



int rpc_sysfs_init(void);

net/sunrpc/xprtmultipath.c

+4 −2
Original line number Diff line number Diff line
@@ -65,6 +65,7 @@ static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps, 
{

	if (unlikely(xprt == NULL))

		return;

	if (!test_bit(XPRT_OFFLINE, &xprt->state))

		xps->xps_nactive--;

	xps->xps_nxprts--;

	if (xps->xps_nxprts == 0)
@@ -230,7 +231,8 @@ void xprt_iter_default_rewind(struct rpc_xprt_iter *xpi) 
static

bool xprt_is_active(const struct rpc_xprt *xprt)

{

	return kref_read(&xprt->kref) != 0;

	return (kref_read(&xprt->kref) != 0 &&

		!test_bit(XPRT_OFFLINE, &xprt->state));

}



static