rcu_read_lock/rcu_read_unlock has already provide protection for the
pointer we will reference when we call e_show. Therefore, there is no
need to obtain a cache reference to help protect cache_head.
Additionally, the .put such as expkey_put/svc_export_put will invoke
dput, which can sleep and break rcu. Stop get cache reference to fix
them all.
Fixes: ae74136b4bb6 ("SUNRPC: Allow cache lookups to use RCU protection rather than the r/w spinlock")
Suggested-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Yang Erkun <yangerkun@xxxxxxxxxx>
---
fs/nfsd/export.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/fs/nfsd/export.c b/fs/nfsd/export.c
index aa4712362b3b..c6168bccfb6c 100644
--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -1425,13 +1425,9 @@ static int e_show(struct seq_file *m, void *p)
return 0;
}
- if (!cache_get_rcu(&exp->h))
+ if (cache_check_rcu(cd, &exp->h, NULL))
return 0;
- if (cache_check(cd, &exp->h, NULL))
- return 0;
-
- exp_put(exp);
return svc_export_show(m, cd, cp);
}
--
2.46.1
