From: Olga Kornievskaia <kolga@xxxxxxxxxx>
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: Olga Kornievskaia <kolga@xxxxxxxxxx>
---
include/linux/sunrpc/xprt.h | 1 +
net/sunrpc/sysfs.c | 66 ++++++++++++++++++++++++++++++++++---
net/sunrpc/sysfs.h | 1 +
net/sunrpc/xprtmultipath.c | 6 ++--
4 files changed, 68 insertions(+), 6 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index 692e5946c029..b8ed7fa1b4ca 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -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)
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 816f543d4237..e66888cc4c14 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -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);
@@ -235,6 +246,52 @@ 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);
@@ -305,7 +362,7 @@ 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,
@@ -468,6 +525,7 @@ 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);
}
}
diff --git a/net/sunrpc/sysfs.h b/net/sunrpc/sysfs.h
index ff10451de6fa..6620cebd1037 100644
--- a/net/sunrpc/sysfs.h
+++ b/net/sunrpc/sysfs.h
@@ -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);
diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
index 584349c8cad4..7d40cdf81274 100644
--- a/net/sunrpc/xprtmultipath.c
+++ b/net/sunrpc/xprtmultipath.c
@@ -65,7 +65,8 @@ static void xprt_switch_remove_xprt_locked(struct rpc_xprt_switch *xps,
{
if (unlikely(xprt == NULL))
return;
- xps->xps_nactive--;
+ if (!test_bit(XPRT_OFFLINE, &xprt->state))
+ xps->xps_nactive--;
xps->xps_nxprts--;
if (xps->xps_nxprts == 0)
xps->xps_net = NULL;
@@ -231,7 +232,8 @@ 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
--
2.27.0
