From: Su Yue <suy.fnst@cn.fujitsu.com>
Date: Wed, 30 May 2018 08:48:56 +0000 (+0800)
Subject: btrfs: return error value if create_io_em failed in cow_file_range
X-Git-Tag: v4.19~584^2~22
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=090a127afa8f73e9618d4058d6755f7ec7453dd6;p=platform%2Fkernel%2Flinux-rpi.git

btrfs: return error value if create_io_em failed in cow_file_range

In cow_file_range(), create_io_em() may fail, but its return value is
not recorded.  Then return value may be 0 even it failed which is a
wrong behavior.

Let cow_file_range() return PTR_ERR(em) if create_io_em() failed.

Fixes: 6f9994dbabe5 ("Btrfs: create a helper to create em for IO")
CC: stable@vger.kernel.org # 4.11+
Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 7148aba..f81a48c 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1018,8 +1018,10 @@ static noinline int cow_file_range(struct inode *inode,
 				  ram_size, /* ram_bytes */
 				  BTRFS_COMPRESS_NONE, /* compress_type */
 				  BTRFS_ORDERED_REGULAR /* type */);
-		if (IS_ERR(em))
+		if (IS_ERR(em)) {
+			ret = PTR_ERR(em);
 			goto out_reserve;
+		}
 		free_extent_map(em);
 
 		ret = btrfs_add_ordered_extent(inode, start, ins.objectid,