[PATCH] lockd: Fix host reference leak in nlmclnt_recovery()

[Wentao Liang]

In nlmclnt_recovery(), nlm_get_host(host) is called to take a reference
on the host before spawning the reclaimer thread via kthread_run(). If
kthread_run() fails, the reference is never released, and
host->h_reclaiming remains incremented, preventing subsequent reclaim
attempts.

Fix this by releasing the host reference with nlmclnt_release_host(host)
and resetting host->h_reclaiming to 0 on kthread_run() error.

Fixes: df94f000c46c ("lockd: convert reclaimer thread to kthread interface")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Wentao Liang <vulab@xxxxxxxxxxx>
---
 fs/lockd/clntlock.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/lockd/clntlock.c b/fs/lockd/clntlock.c
index 8fa30c42c92a..aba37847356c 100644
--- a/fs/lockd/clntlock.c
+++ b/fs/lockd/clntlock.c
@@ -216,10 +216,13 @@ nlmclnt_recovery(struct nlm_host *host)
 	if (!host->h_reclaiming++) {
 		nlm_get_host(host);
 		task = kthread_run(reclaimer, host, "%s-reclaim", host->h_name);
-		if (IS_ERR(task))
+		if (IS_ERR(task)) {
 			printk(KERN_ERR "lockd: unable to spawn reclaimer "
 				"thread. Locks for %s won't be reclaimed! "
 				"(%ld)\n", host->h_name, PTR_ERR(task));
+			host->h_reclaiming = 0;
+			nlmclnt_release_host(host);
+		}
 	}
 }
 
-- 
2.34.1