[PATCH 5.13 242/351] block: grab a device refcount in disk_uevent

Greg Kroah-Hartman
2021-07-19T17:51:28Z

From: Christoph Hellwig <hch@lst.de>

[ Upstream commit 498dcc13fd6463de29b94e160f40ed04d5477cd8 ]

Sending uevents requires the struct device to be alive. To
ensure that grab the device refcount instead of just an inode
reference.

Fixes: bc359d03c7ec ("block: add a disk_uevent helper")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210701081638.246552-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
block/genhd.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/block/genhd.c b/block/genhd.c
index 9f8cb7beaad1..ad7436bd60c1 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -402,12 +402,12 @@ void disk_uevent(struct gendisk *disk, enum kobject_action action)
xa_for_each(&disk->part_tbl, idx, part) {
if (bdev_is_partition(part) && !bdev_nr_sectors(part))
continue;
- if (!bdgrab(part))
+ if (!kobject_get_unless_zero(&part->bd_device.kobj))
continue;

rcu_read_unlock();
kobject_uevent(bdev_kobj(part), action);
- bdput(part);
+ put_device(&part->bd_device);
rcu_read_lock();
}
rcu_read_unlock();
--
2.30.2