2.6.32-longterm review patch. If anyone has any objections, please let us know.
------------------ too From: Tejun Heo <[email protected]> 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 <[email protected]> Reported-by: David Zeuthen <[email protected]> Reported-by: Martin Pitt <[email protected]> Reported-by: Kay Sievers <[email protected]> Tested-by: Kay Sievers <[email protected]> Cc: Alan Cox <[email protected]> Signed-off-by: Jens Axboe <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- fs/block_dev.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1203,6 +1203,7 @@ 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) { @@ -1218,9 +1219,18 @@ 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); @@ -1228,8 +1238,6 @@ static int __blkdev_get(struct block_dev bdi = &default_backing_dev_info; bdev->bd_inode->i_data.backing_dev_info = bdi; } - if (bdev->bd_invalidated) - rescan_partitions(disk, bdev); } else { struct block_device *whole; whole = bdget_disk(disk, 0); @@ -1256,13 +1264,14 @@ 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++; _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
