From mboxrd@z Thu Jan 1 00:00:00 1970 From: liubo Subject: Re: [PATCH] Btrfs: skip looking for delalloc if we don't have ->fill_delalloc Date: Tue, 02 Aug 2011 09:32:29 +0800 Message-ID: <4E3753AD.4010606@cn.fujitsu.com> References: <1312215076-10329-1-git-send-email-josef@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Cc: linux-btrfs@vger.kernel.org To: Josef Bacik Return-path: In-Reply-To: <1312215076-10329-1-git-send-email-josef@redhat.com> List-ID: On 08/02/2011 12:11 AM, Josef Bacik wrote: > We always look for delalloc bytes in our io_tree so we can fill in delalloc. > This is fine in most cases, but if we're writing out the btree_inode this is > just a superfluous tree search on the io_tree, and if we have a lot of metadata > dirty this could be an expensive check. So instead check to see if our io_tree > has a ->fill_delalloc op, and if not don't even bother doing the lookup. > Thanks, > > Signed-off-by: Josef Bacik > --- With the patch, mkfs.btrfs /dev/sda15 mount /dev/sda15 /mnt/btrfs dd if=/dev/zero of=/mnt/btrfs/tmp bs=1G then it comes the following bug: Btrfs loaded device fsid 91d23288-d352-4346-979f-d6f93cac04a3 devid 1 transid 7 /dev/sda15 ------------[ cut here ]------------ kernel BUG at fs/btrfs/inode.c:1583! ... Call Trace: [] worker_loop+0x138/0x510 [btrfs] [] ? btrfs_queue_worker+0x2d0/0x2d0 [btrfs] [] ? btrfs_queue_worker+0x2d0/0x2d0 [btrfs] [] kthread+0x96/0xa0 [] kernel_thread_helper+0x4/0x10 [] ? kthread_worker_fn+0x1a0/0x1a0 [] ? gs_change+0xb/0xb Code: e0 48 83 c4 28 5b 41 5c 41 5d 41 5e 41 5f c9 c3 48 8b 7d b8 48 8d 4d c8 41 b8 50 00 00 00 4c 89 fa 4c 89 e6 e8 19 cf 01 00 eb bd <0f> 0b eb fe 48 89 df e8 1b 48 b6 e0 eb 9d 66 0f 1f 84 00 00 00 RIP [] btrfs_writepage_fixup_worker+0x139/0x150 [btrfs] RSP ---[ end trace 5089b598ce74fcfc ]--- thanks, liubo