From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: ext4fs error "ext4_mb_generate_buddy:741:group 16, 8160 clusters in bitmap, 4064 in gd" (with repro) Date: Thu, 09 Aug 2012 12:00:09 +0200 Message-ID: <50238A29.3060808@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Transfer-Encoding: 7bit To: tytso@mit.edu, "Linux Kernel Mailinlinux-ext4@vger.kernel.orgg List" , linux-ext4@vger.kernel.org Return-path: Received: from mx1.redhat.com ([209.132.183.28]:32265 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757479Ab2HIKAQ (ORCPT ); Thu, 9 Aug 2012 06:00:16 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: Here is how to reproduce it. It happens during fstrim. I found other occurrences of the error in the mailing list, but they were not related to trim so they may be something different. modprobe scsi_debug dev_size_mb=256 lbpws=1 dd if=/dev/zero of=/dev/sdb bs=1M fdisk /dev/sdb >> create a new partition accepting all defaults fdisk -lu /dev/sdb|tail -1 >> should show: /dev/sdb1 57 524285 262114+ 83 Linux mkfs.ext4 /dev/sdb1 mkdir test mount /dev/sdb1 test fstrim ./test Here is the output in dmesg: [140934.644166] EXT4-fs (sdb1): mounted filesystem with ordered data mode. Opts: (null) [140941.562060] EXT4-fs error (device sdb1): ext4_mb_generate_buddy:741: group 16, 8160 clusters in bitmap, 4064 in gd [140941.603066] EXT4-fs error (device sdb1): ext4_mb_generate_buddy:741: group 25, 8192 clusters in bitmap, 7934 in gd [140941.613060] EXT4-fs error (device sdb1): ext4_mb_generate_buddy:741: group 27, 8192 clusters in bitmap, 7934 in gd [140941.634074] EXT4-fs error (device sdb1): ext4_mb_generate_buddy:741: group 31, 8192 clusters in bitmap, 8159 in gd Hope this helps, Paolo