From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756896Ab3AYK4n (ORCPT ); Fri, 25 Jan 2013 05:56:43 -0500 Received: from e28smtp07.in.ibm.com ([122.248.162.7]:60823 "EHLO e28smtp07.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756802Ab3AYK4h (ORCPT ); Fri, 25 Jan 2013 05:56:37 -0500 From: Guo Chao To: axboe@kernel.dk Cc: linux-kernel@vger.kernel.org Subject: [PATCH 4/7] loopdev: update block device size in loop_set_status() Date: Fri, 25 Jan 2013 18:56:19 +0800 Message-Id: <1359111382-12654-5-git-send-email-yan@linux.vnet.ibm.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1359111382-12654-1-git-send-email-yan@linux.vnet.ibm.com> References: <1359111382-12654-1-git-send-email-yan@linux.vnet.ibm.com> X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13012510-8878-0000-0000-000005A83864 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Loop device driver sometimes fails to impose the size limit on the device. Keep issuing following two commands: losetup --offset 7517244416 --sizelimit 3224971264 /dev/loop0 backed_file blockdev --getsize64 /dev/loop0 blockdev reports file size instead of sizelimit several out of 100 times. The problems are: - losetup set up the device in two ioctl: LOOP_SET_FD and LOOP_SET_STATUS64. - LOOP_SET_STATUS64 only update size of gendisk. Block device size will be updated lazily when device comes to use. If udev rushes in between the two ioctl, it will bring in a block device whose size is backing file size. If the device is not released after LOOP_SET_STATUS64 ioctl, blockdev will not see the updated size. Update block size in LOOP_SET_STATUS64 ioctl. Reported-by: M. Hindess Signed-off-by: Guo Chao --- drivers/block/loop.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 7f80653..ed85036 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1092,8 +1092,13 @@ loop_set_status(struct loop_device *lo, const struct loop_info64 *info) if (lo->lo_offset != info->lo_offset || lo->lo_sizelimit != info->lo_sizelimit) { + struct block_device *bdev = lo->lo_device; + if (figure_loop_size(lo, info->lo_offset, info->lo_sizelimit)) return -EFBIG; + + bd_set_size(bdev, (loff_t)get_capacity(bdev->bd_disk) << 9); + kobject_uevent(&disk_to_dev(bdev->bd_disk)->kobj, KOBJ_CHANGE); } loop_config_discard(lo); -- 1.7.9.5