From: Matthew Wilcox (Oracle) <willy@infradead.org>
Date: Mon, 26 Oct 2020 09:12:10 +0000 (+0000)
Subject: cachefiles: Handle readpage error correctly
X-Git-Tag: v4.9.242~36
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0e3c04165f046878d491baf4d470372473c0e22b;p=platform%2Fkernel%2Flinux-amlogic.git

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 7dba96d5fef1..496eeceae040 100644
--- a/fs/cachefiles/rdwr.c
+++ b/fs/cachefiles/rdwr.c
@@ -125,7 +125,7 @@ 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
@@ -142,6 +142,7 @@ 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);