fscache: Detect multiple relinquishment of a cookie

Report if an fscache cookie is relinquished multiple times by the netfs.

Signed-off-by: David <dhowells@redhat.com>

diff --git a/fs/fscache/cookie.c b/fs/fscache/cookie.c
index d705125665f07ae485f53eff67db2fef9606092f..98d22f495cd8f73a3b2ccf76a0f4801e7ffaa973 100644 (file)
--- a/fs/fscache/cookie.c
+++ b/fs/fscache/cookie.c
@@ -602,7 +602,8 @@ void __fscache_relinquish_cookie(struct fscache_cookie *cookie, bool retire)
               atomic_read(&cookie->n_active), retire);
 
        /* No further netfs-accessing operations on this cookie permitted */
-       set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags);
+       if (test_and_set_bit(FSCACHE_COOKIE_RELINQUISHED, &cookie->flags))
+               BUG();
 
        __fscache_disable_cookie(cookie, retire);