From: Jan Kara <jack@suse.cz>
Date: Mon, 10 Jan 2011 17:30:39 +0000 (-0500)
Subject: ext4: fix trimming of a single group
X-Git-Tag: v2.6.37.1~143
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=3d597eb5d470de0073e9e7feaa7413918699579b;p=karo-tx-linux.git

ext4: fix trimming of a single group

commit ca6e909f9bebe709bc65a3ee605ce32969db0452 upstream.

When ext4_trim_fs() is called to trim a part of a single group, the
logic will wrongly set last block of the interval to 'len' instead
of 'first_block + len'. Thus a shorter interval is possibly trimmed.
Fix it.

CC: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 5b4d4e3a4d58..4c4766c0d52c 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4851,7 +4851,7 @@ int ext4_trim_fs(struct super_block *sb, struct fstrim_range *range)
 		if (len >= EXT4_BLOCKS_PER_GROUP(sb))
 			len -= (EXT4_BLOCKS_PER_GROUP(sb) - first_block);
 		else
-			last_block = len;
+			last_block = first_block + len;
 
 		if (e4b.bd_info->bb_free >= minlen) {
 			cnt = ext4_trim_all_free(sb, &e4b, first_block,