From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Anna Schumaker <Anna.Schumaker@Netapp•com>,
Sasha Levin <sashal@kernel•org>,
trond.myklebust@hammerspace•com, anna.schumaker@netapp•com,
chuck.lever@oracle•com, davem@davemloft•net, kuba@kernel•org,
linux-nfs@vger•kernel.org, netdev@vger•kernel.org
Subject: [PATCH AUTOSEL 5.16 13/52] sunrpc: Fix potential race conditions in rpc_sysfs_xprt_state_change()
Date: Thu, 3 Feb 2022 15:29:07 -0500 [thread overview]
Message-ID: <20220203202947.2304-13-sashal@kernel.org> (raw)
In-Reply-To: <20220203202947.2304-1-sashal@kernel.org>
From: Anna Schumaker <Anna.Schumaker@Netapp•com>
[ Upstream commit 1a48db3fef499f615b56093947ec4b0d3d8e3021 ]
We need to use test_and_set_bit() when changing xprt state flags to
avoid potentially getting xps->xps_nactive out of sync.
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp•com>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
net/sunrpc/sysfs.c | 35 +++++++++++++++++++----------------
1 file changed, 19 insertions(+), 16 deletions(-)
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c
index 77e7d011c1ab1..8f309bcdf84fe 100644
--- a/net/sunrpc/sysfs.c
+++ b/net/sunrpc/sysfs.c
@@ -309,25 +309,28 @@ static ssize_t rpc_sysfs_xprt_state_change(struct kobject *kobj,
goto release_tasks;
}
if (offline) {
- set_bit(XPRT_OFFLINE, &xprt->state);
- spin_lock(&xps->xps_lock);
- xps->xps_nactive--;
- spin_unlock(&xps->xps_lock);
+ if (!test_and_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);
+ if (test_and_clear_bit(XPRT_OFFLINE, &xprt->state)) {
+ 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);
+ if (!test_and_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;
--
2.34.1
next prev parent reply other threads:[~2022-02-03 20:30 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20220203202947.2304-1-sashal@kernel.org>
2022-02-03 20:28 ` [PATCH AUTOSEL 5.16 05/52] netfilter: nf_conntrack_netbios_ns: fix helper module alias Sasha Levin
2022-02-03 21:46 ` Jakub Kicinski
2022-02-03 22:23 ` Florian Westphal
2022-02-11 14:41 ` Sasha Levin
2022-02-03 20:29 ` [PATCH AUTOSEL 5.16 11/52] SUNRPC allow for unspecified transport time in rpc_clnt_add_xprt Sasha Levin
2022-02-03 20:29 ` [PATCH AUTOSEL 5.16 12/52] net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change Sasha Levin
2022-02-03 20:29 ` Sasha Levin [this message]
2022-02-03 20:29 ` [PATCH AUTOSEL 5.16 21/52] net: sched: Clarify error message when qdisc kind is unknown Sasha Levin
2022-02-03 20:29 ` [PATCH AUTOSEL 5.16 35/52] net: stmmac: reduce unnecessary wakeups from eee sw timer Sasha Levin
2022-02-03 20:29 ` [PATCH AUTOSEL 5.16 45/52] net: stmmac: dwmac-sun8i: use return val of readl_poll_timeout() Sasha Levin
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