From: Jan Kara <jack@suse.cz>
Date: Wed, 29 Oct 2014 23:35:00 +0000 (+1100)
Subject: mm: Remove false WARN_ON from pagecache_isize_extended()
X-Git-Tag: v3.12.33~18
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=50c36a9ad170f54c46c22a59a94f75ebcb2e51fd;p=thirdparty%2Fkernel%2Fstable.git

mm: Remove false WARN_ON from pagecache_isize_extended()

commit f55fefd1a5a339b1bd08c120b93312d6eb64a9fb upstream.

The WARN_ON checking whether i_mutex is held in
pagecache_isize_extended() was wrong because some filesystems (e.g.
XFS) use different locks for serialization of truncates / writes. So
just remove the check.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---

diff --git a/mm/truncate.c b/mm/truncate.c
index 7dfb7c70fd4b6..827ad8d2b5cd8 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -697,7 +697,6 @@ void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to)
 	struct page *page;
 	pgoff_t index;
 
-	WARN_ON(!mutex_is_locked(&inode->i_mutex));
 	WARN_ON(to > inode->i_size);
 
 	if (from >= to || bsize == PAGE_CACHE_SIZE)