Re: [PATCH -next RFC 2/3] block: factor out the setting of GD_NEED_PART_SCAN
From: Jan Kara <jack@suse.cz>
Date: 2023-02-16 13:17:54
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lkml
On Sun 12-02-23 17:26:40, Yu Kuai wrote:
From: Yu Kuai <redacted> 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 <redacted>
I'd rather leave the setting of GD_NEED_PART_SCAN in disk_scan_partitions() to keep it self-contained. On top of that we can set GD_NEED_PART_SCAN in device_add_disk() to ensure initial partition scan but we should probably also make sure flags like GD_SUPPRESS_PART_SCAN or GENHD_FL_NO_PART are not set to avoid unwanted partition scanning. Honza
quoted hunk ↗ jump to hunk
--- 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);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:-- 2.31.1
-- Jan Kara [off-list ref] SUSE Labs, CR