From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: [PATCH] ext4: Trim allocation requests to group size Date: Tue, 10 Jan 2017 10:32:01 +0100 Message-ID: <20170110093201.1403-1-jack@suse.cz> Cc: , "Kirill A. Shutemov" , Jan Kara To: Ted Tso Return-path: Received: from mx2.suse.de ([195.135.220.15]:38899 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1765267AbdAJJcK (ORCPT ); Tue, 10 Jan 2017 04:32:10 -0500 Sender: linux-ext4-owner@vger.kernel.org List-ID: If filesystem groups are artifically small (using parameter -g to mkfs.ext4), ext4_mb_normalize_request() can result in a request that is larger than a block group. Trim the request size to not confuse allocation code. Reported-by: "Kirill A. Shutemov" Signed-off-by: Jan Kara --- fs/ext4/mballoc.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c index 7ae43c59bc79..2e9fc7a61048 100644 --- a/fs/ext4/mballoc.c +++ b/fs/ext4/mballoc.c @@ -3123,6 +3123,13 @@ ext4_mb_normalize_request(struct ext4_allocation_context *ac, if (ar->pright && start + size - 1 >= ar->lright) size -= start + size - ar->lright; + /* + * Trim allocation request for filesystems with artificially small + * groups. + */ + if (size > EXT4_BLOCKS_PER_GROUP(ac->ac_sb)) + size = EXT4_BLOCKS_PER_GROUP(ac->ac_sb); + end = start + size; /* check we don't cross already preallocated blocks */ -- 2.10.2