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| author | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2021-11-15 17:54:25 +0100 |
|---|---|---|
| committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2022-01-13 15:36:58 +0100 |
| commit | 1a48db3fef499f615b56093947ec4b0d3d8e3021 (patch) | |
| tree | 9e3a4329e9b28aaea39c1e1523dcd43b68f4e29f /net | |
| parent | net/sunrpc: fix reference count leaks in rpc_sysfs_xprt_state_change (diff) | |
| download | linux-1a48db3fef499f615b56093947ec4b0d3d8e3021.tar.xz linux-1a48db3fef499f615b56093947ec4b0d3d8e3021.zip | |
sunrpc: Fix potential race conditions in rpc_sysfs_xprt_state_change()
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>
Diffstat (limited to 'net')
| -rw-r--r-- | net/sunrpc/sysfs.c | 35 |
1 files changed, 19 insertions, 16 deletions
diff --git a/net/sunrpc/sysfs.c b/net/sunrpc/sysfs.c index 49fd0339dc59..b64a0286b182 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; |