[PATCH 05/11] block: take bd_mutex around delete_partitions in del_gendisk

Christoph Hellwig
2021-04-06T06:23:23Z

There is nothing preventing an ioctl from trying do delete partition
concurrenly with del_gendisk, so take open_mutex to serialize against
that.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/genhd.c | 4 ++++
block/partitions/core.c | 2 ++
2 files changed, 6 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index 8303ec67fd7099..e3f3c2321773f9 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -680,7 +680,11 @@ void del_gendisk(struct gendisk *disk)
* disk is marked as dead (GENHD_FL_UP cleared).
*/
down_write(&bdev_lookup_sem);
+
+ mutex_lock(&disk->part0->bd_mutex);
blk_drop_partitions(disk);
+ mutex_unlock(&disk->part0->bd_mutex);
+
fsync_bdev(disk->part0);
__invalidate_device(disk->part0, true);

diff --git a/block/partitions/core.c b/block/partitions/core.c
index 536f7c5bb0b6d2..9fbaec466b516d 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -531,6 +531,8 @@ void blk_drop_partitions(struct gendisk *disk)
struct disk_part_iter piter;
struct block_device *part;

+ lockdep_assert_held(&disk->part0->bd_mutex);
+
disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
while ((part = disk_part_iter_next(&piter)))
delete_partition(part);
--
2.30.1