Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934138Ab1ESSJW (ORCPT ); Thu, 19 May 2011 14:09:22 -0400 Received: from out2.smtp.messagingengine.com ([66.111.4.26]:58798 "EHLO out2.smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934115Ab1ESSJR (ORCPT ); Thu, 19 May 2011 14:09:17 -0400 X-Sasl-enc: ZewZMzQ5vnECOCxExZT4Gt03qx/h5N8S4OvjJAFBs6lT 1305828556 X-Mailbox-Line: From gregkh@clark.kroah.org Thu May 19 11:05:59 2011 Message-Id: <20110519180559.722522150@clark.kroah.org> User-Agent: quilt/0.48-16.4 Date: Thu, 19 May 2011 11:05:25 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: stable-review@kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Tejun Heo , Jens Axboe Subject: [57/71] block: rescan partitions on invalidated devices on -ENOMEDIA too In-Reply-To: <20110519180626.GA16555@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3289 Lines: 104 2.6.38-stable review patch. If anyone has any objections, please let us know. ------------------ From: Tejun Heo commit 02e352287a40bd456eb78df705bf888bc3161d3f upstream. __blkdev_get() doesn't rescan partitions if disk->fops->open() fails, which leads to ghost partition devices lingering after medimum removal is known to both the kernel and userland. The behavior also creates a subtle inconsistency where O_NONBLOCK open, which doesn't fail even if there's no medium, clears the ghots partitions, which is exploited to work around the problem from userland. Fix it by updating __blkdev_get() to issue partition rescan after -ENOMEDIA too. This was reported in the following bz. https://bugzilla.kernel.org/show_bug.cgi?id=13029 Stable: 2.6.38 Signed-off-by: Tejun Heo Reported-by: David Zeuthen Reported-by: Martin Pitt Reported-by: Kay Sievers Tested-by: Kay Sievers Cc: Alan Cox Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/block_dev.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1099,6 +1099,7 @@ static int __blkdev_get(struct block_dev if (!bdev->bd_part) goto out_clear; + ret = 0; if (disk->fops->open) { ret = disk->fops->open(bdev, mode); if (ret == -ERESTARTSYS) { @@ -1114,9 +1115,18 @@ static int __blkdev_get(struct block_dev mutex_unlock(&bdev->bd_mutex); goto restart; } - if (ret) - goto out_clear; } + /* + * If the device is invalidated, rescan partition + * if open succeeded or failed with -ENOMEDIUM. + * The latter is necessary to prevent ghost + * partitions on a removed medium. + */ + if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) + rescan_partitions(disk, bdev); + if (ret) + goto out_clear; + if (!bdev->bd_openers) { bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); bdi = blk_get_backing_dev_info(bdev); @@ -1124,8 +1134,6 @@ static int __blkdev_get(struct block_dev bdi = &default_backing_dev_info; bdev_inode_switch_bdi(bdev->bd_inode, bdi); } - if (bdev->bd_invalidated) - rescan_partitions(disk, bdev); } else { struct block_device *whole; whole = bdget_disk(disk, 0); @@ -1152,13 +1160,14 @@ static int __blkdev_get(struct block_dev put_disk(disk); disk = NULL; if (bdev->bd_contains == bdev) { - if (bdev->bd_disk->fops->open) { + ret = 0; + if (bdev->bd_disk->fops->open) ret = bdev->bd_disk->fops->open(bdev, mode); - if (ret) - goto out_unlock_bdev; - } - if (bdev->bd_invalidated) + /* the same as first opener case, read comment there */ + if (bdev->bd_invalidated && (!ret || ret == -ENOMEDIUM)) rescan_partitions(bdev->bd_disk, bdev); + if (ret) + goto out_unlock_bdev; } } bdev->bd_openers++; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/