cachefiles: Handle readpage error correctly

commit 9480b4e75b7108ee68ecf5bc6b4bd68e8031c521 upstream.

If ->readpage returns an error, it has already unlocked the page.

Fixes: 5e929b33c393 ("CacheFiles: Handle truncate unlocking the page we're reading")
Cc: stable@vger.kernel.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c
index ad057ed2b30b07ac8d179e8677f41aaca61f62c4..bd5fe8d00d0093d1664e13e0d6770905965fadf7 100644 (file)
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -121,7 +121,7 @@ static int cachefiles_read_reissue(struct cachefiles_object *object,
                _debug("reissue read");
                ret = bmapping->a_ops->readpage(NULL, backpage);
                if (ret < 0)
-                       goto unlock_discard;
+                       goto discard;
        }
 
        /* but the page may have been read before the monitor was installed, so
@@ -138,6 +138,7 @@ static int cachefiles_read_reissue(struct cachefiles_object *object,
 
 unlock_discard:
        unlock_page(backpage);
+discard:
        spin_lock_irq(&object->work_lock);
        list_del(&monitor->op_link);
        spin_unlock_irq(&object->work_lock);