From: Yang Erkun <yangerkun@xxxxxxxxxx>
rcu_read_lock/rcu_read_unlock has already protect any ptr we will
reference when we call e_show. No need get cache ref. Besides, exp_put
may drop the last ref for cache_head, and the .put like
expkey_put/svc_export_put will call dput, which may sleep, and this will
break rcu protection.
Fixes: ae74136b4bb6 ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Signed-off-by: Yang Erkun <yangerkun@xxxxxxxxxx>
---
fs/nfsd/export.c | 8 +-------
1 file changed, 1 insertion(+), 7 deletions(-)
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index 56002d9ef66b..1c795dc5a74b 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1427,15 +1427,9 @@ static int e_show(struct seq_file *m, void *p)
return 0;
}
- if (!cache_get_rcu(&exp->h))
+ if (cache_check(cd, &exp->h, NULL))
return 0;
- if (cache_check(cd, &exp->h, NULL)) {
- cache_put(&exp->h, cd);
- return 0;
- }
-
- exp_put(exp);
return svc_export_show(m, cd, cp);
}
--
2.39.2
