From: Valerie Clement Subject: [PATCH RESEND] ext4: Fix kernel BUG at fs/ext4/mballoc.c:910! Date: Thu, 14 Feb 2008 17:35:09 +0100 Message-ID: <1203006909.8970.20.camel@ext1.frec.bull.fr> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: Andreas Dilger , Aneesh Kumar , Mingming Cao To: linux-ext4 Return-path: Received: from ecfrec.frec.bull.fr ([129.183.4.8]:52297 "EHLO ecfrec.frec.bull.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760290AbYBNQ3l (ORCPT ); Thu, 14 Feb 2008 11:29:41 -0500 Sender: linux-ext4-owner@vger.kernel.org List-ID: Fix kernel BUG at fs/ext4/mballoc.c:910! From: Valerie Clement With the flex_bg feature enabled, a large file creation oopses the kernel. The BUG_ON is: BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); As the allocation of the bitmaps and the inode table can be done outside the block group with flex_bg, this allows to allocate up to EXT4_BLOCKS_PER_GROUP blocks in a group. Depending on the group size and the block size, extents might be larger than BLOCKS_PER_GROUP(); use EXT_INIT_MAX_LEN instead of BLOCKS_PER_GROUP(). This patch fixes the oops. Signed-off-by: Valerie Clement --- fs/ext4/mballoc.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index b0f84b4..ccc33e9 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -34,6 +34,7 @@ #include #include #include +#include #include "group.h" /* @@ -907,7 +908,9 @@ static void ext4_mb_mark_free_simple(struct super_block *sb, unsigned short chunk; unsigned short border; - BUG_ON(len >= EXT4_BLOCKS_PER_GROUP(sb)); + BUG_ON(len > EXT4_HAS_INCOMPAT_FEATURE(sb, + EXT4_FEATURE_INCOMPAT_FLEX_BG) ? EXT_INIT_MAX_LEN : + EXT4_BLOCKS_PER_GROUP(sb)); border = 2 << sb->s_blocksize_bits;