Messages in this thread | | | Date | Sun, 12 Feb 2023 12:36:52 +0100 | Subject | Re: [PATCH -next RFC 2/3] block: factor out the setting of GD_NEED_PART_SCAN | From | Hannes Reinecke <> |
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On 2/12/23 10:26, Yu Kuai wrote: > From: Yu Kuai <yukuai3@huawei.com> > > In order to prevent scan partition for a device that is opened > exclusively by someone else, new conditions will be added to > disk_scan_partitions() in the next patch. Hence if device is opened > exclusively between bdev_add() and disk_scan_partitions(), the first > partition scan will fail unexpected. This patch factor out the setting > of GD_NEED_PART_SCAN to prevent the problem. > > Signed-off-by: Yu Kuai <yukuai3@huawei.com> > --- > block/genhd.c | 2 +- > block/ioctl.c | 1 + > 2 files changed, 2 insertions(+), 1 deletion(-) > > diff --git a/block/genhd.c b/block/genhd.c > index 075d8da284f5..c0d1220bd798 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -367,7 +367,6 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) > if (disk->open_partitions) > return -EBUSY; > > - set_bit(GD_NEED_PART_SCAN, &disk->state); > bdev = blkdev_get_by_dev(disk_devt(disk), mode, NULL); > if (IS_ERR(bdev)) > return PTR_ERR(bdev); > @@ -493,6 +492,7 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, > if (ret) > goto out_unregister_bdi; > > + set_bit(GD_NEED_PART_SCAN, &disk->state); > bdev_add(disk->part0, ddev->devt); > if (get_capacity(disk)) > disk_scan_partitions(disk, FMODE_READ); Usual caveat: What happens if the flag is already set here? Wouldn't that imply that another scan is underway? And wouldn't it be better to use 'test_and_set()'?
> diff --git a/block/ioctl.c b/block/ioctl.c > index 6dd49d877584..0eefcdb936a0 100644 > --- a/block/ioctl.c > +++ b/block/ioctl.c > @@ -528,6 +528,7 @@ static int blkdev_common_ioctl(struct block_device *bdev, fmode_t mode, > return -EACCES; > if (bdev_is_partition(bdev)) > return -EINVAL; > + set_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); > return disk_scan_partitions(bdev->bd_disk, mode & ~FMODE_EXCL); > case BLKTRACESTART: > case BLKTRACESTOP: Similar here.
Cheers,
Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@suse.de +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
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