From b9684a71fca793213378dd410cd11675d973eaa1 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 27 May 2022 07:58:06 +0200 Subject: block, loop: support partitions without scanning Historically we did distinguish between a flag that surpressed partition scanning, and a combinations of the minors variable and another flag if any partitions were supported. This was generally confusing and doesn't make much sense, but some corner case uses of the loop driver actually do want to support manually added partitions on a device that does not actively scan for partitions. To make things worsee the loop driver also wants to dynamically toggle the scanning for partitions on a live gendisk, which makes the disk->flags updates non-atomic. Introduce a new GD_SUPPRESS_PART_SCAN bit in disk->state that disables just scanning for partitions, and toggle that instead of GENHD_FL_NO_PART in the loop driver. Fixes: 1ebe2e5f9d68 ("block: remove GENHD_FL_EXT_DEVT") Reported-by: Ming Lei Signed-off-by: Christoph Hellwig Reviewed-by: Ming Lei Link: https://lore.kernel.org/r/20220527055806.1972352-1-hch@lst.de Signed-off-by: Jens Axboe --- block/genhd.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'block/genhd.c') diff --git a/block/genhd.c b/block/genhd.c index 36532b931841..27205ae47d59 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -385,6 +385,8 @@ int disk_scan_partitions(struct gendisk *disk, fmode_t mode) if (disk->flags & (GENHD_FL_NO_PART | GENHD_FL_HIDDEN)) return -EINVAL; + if (test_bit(GD_SUPPRESS_PART_SCAN, &disk->state)) + return -EINVAL; if (disk->open_partitions) return -EBUSY; -- cgit v1.2.3