From 6f081693e7b2ba63422b735684b05a850a6351ba Mon Sep 17 00:00:00 2001
From: Olga Kornievskaia <kolga@netapp.com>
Date: Wed, 23 Jun 2021 23:28:53 -0400
Subject: [PATCH] sunrpc: remove an offlined xprt using sysfs
Once a transport has been put offline, this transport can be also
removed from the list of transports. Any tasks that have been stuck
on this transport would find the next available active transport
and be re-tried. This transport would be removed from the xprt_switch
list and freed.
Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
---
include/linux/sunrpc/xprt.h | 1 +
net/sunrpc/clnt.c | 24 ++++++++++++++++++++++++
net/sunrpc/sysfs.c | 26 ++++++++++++++++++++++----
3 files changed, 47 insertions(+), 4 deletions(-)
diff --git a/include/linux/sunrpc/xprt.h b/include/linux/sunrpc/xprt.h
index b8ed7fa1b4cae..c8c39f22d3b16 100644
--- a/include/linux/sunrpc/xprt.h
+++ b/include/linux/sunrpc/xprt.h
@@ -428,6 +428,7 @@ void xprt_release_write(struct rpc_xprt *, struct rpc_task *);
#define XPRT_BINDING (5)
#define XPRT_CLOSING (6)
#define XPRT_OFFLINE (7)
+#define XPRT_REMOVE (8)
#define XPRT_CONGESTED (9)
#define XPRT_CWND_WAIT (10)
#define XPRT_WRITE_SPACE (11)
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 408618765aa54..8b4de70e8ead4 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2106,6 +2106,30 @@ call_connect_status(struct rpc_task *task)
case -ENOTCONN:
case -EAGAIN:
case -ETIMEDOUT:
+ if (!(task->tk_flags & RPC_TASK_NO_ROUND_ROBIN) &&
+ (task->tk_flags & RPC_TASK_MOVEABLE) &&
+ test_bit(XPRT_REMOVE, &xprt->state)) {
+ struct rpc_xprt *saved = task->tk_xprt;
+ struct rpc_xprt_switch *xps;
+
+ rcu_read_lock();
+ xps = xprt_switch_get(rcu_dereference(clnt->cl_xpi.xpi_xpswitch));
+ rcu_read_unlock();
+ if (xps->xps_nxprts > 1) {
+ long value;
+
+ xprt_release(task);
+ value = atomic_long_dec_return(&xprt->queuelen);
+ if (value == 0)
+ rpc_xprt_switch_remove_xprt(xps, saved);
+ xprt_put(saved);
+ task->tk_xprt = NULL;
+ task->tk_action = call_start;
+ }
+ xprt_switch_put(xps);
+ if (!task->tk_xprt)
+ return;
+ }
goto out_retry;
case -ENOBUFS:
rpc_delay(task, HZ >> 2);
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index b576c7f068294..64da3bfd28e6c 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -133,7 +133,7 @@ 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, offline;
+ closing, congested, cwnd_wait, write_space, offline, remove;
if (!xprt)
return 0;
@@ -152,8 +152,9 @@ static ssize_t rpc_sysfs_xprt_state_show(struct kobject *kobj,
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);
+ remove = test_bit(XPRT_REMOVE, &xprt->state);
- ret = sprintf(buf, "state=%s %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 %s\n",
locked ? "LOCKED" : "",
connected ? "CONNECTED" : "",
connecting ? "CONNECTING" : "",
@@ -164,7 +165,8 @@ static ssize_t rpc_sysfs_xprt_state_show(struct kobject *kobj,
congested ? "CONGESTED" : "",
cwnd_wait ? "CWND_WAIT" : "",
write_space ? "WRITE_SPACE" : "",
- offline ? "OFFLINE" : "");
+ offline ? "OFFLINE" : "",
+ remove ? "REMOVE" : "");
}
xprt_put(xprt);
@@ -251,7 +253,7 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
const char *buf, size_t count)
{
struct rpc_xprt *xprt = rpc_sysfs_xprt_kobj_get_xprt(kobj);
- int offline = 0, online = 0;
+ int offline = 0, online = 0, remove = 0;
struct rpc_xprt_switch *xps = rpc_sysfs_xprt_kobj_get_xprt_switch(kobj);
if (!xprt)
@@ -261,6 +263,8 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
offline = 1;
else if (!strncmp(buf, "online", 6))
online = 1;
+ else if (!strncmp(buf, "remove", 6))
+ remove = 1;
else
return -EINVAL;
@@ -282,6 +286,20 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
spin_lock(&xps->xps_lock);
xps->xps_nactive++;
spin_unlock(&xps->xps_lock);
+ } else if (remove) {
+ if (test_bit(XPRT_OFFLINE, &xprt->state)) {
+ set_bit(XPRT_REMOVE, &xprt->state);
+ xprt_force_disconnect(xprt);
+ if (test_bit(XPRT_CONNECTED, &xprt->state)) {
+ if (!xprt->sending.qlen &&
+ !xprt->pending.qlen &&
+ !xprt->backlog.qlen &&
+ !atomic_long_read(&xprt->queuelen))
+ rpc_xprt_switch_remove_xprt(xps, xprt);
+ }
+ } else {
+ count = -EINVAL;
+ }
}
release_tasks: