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authorChristian Brauner <brauner@kernel.org>2023-10-17 21:48:20 +0300
committerChristian Brauner <brauner@kernel.org>2023-10-28 14:29:22 +0300
commit51b4cb4f3e2265cf8303ffd9a4f239ee3805d3ca (patch)
tree73c4f79d3eaf2efc959e69e9c57389cae0208d3b /block
parentc30b9787a48118d2ed0283b6c8f2abee873a1d19 (diff)
downloadlinux-51b4cb4f3e2265cf8303ffd9a4f239ee3805d3ca.tar.xz
block: WARN_ON_ONCE() when we remove active partitions
The logic for disk->open_partitions is: blkdev_get_by_*() -> bdev_is_partition() -> blkdev_get_part() -> blkdev_get_whole() // bdev_whole->bd_openers++ -> if (part->bd_openers == 0) disk->open_partitions++ part->bd_openers In other words, when we first claim/open a partition we increment disk->open_partitions and only when all part->bd_openers are closed will disk->open_partitions be zero. That should mean that disk->open_partitions is always > 0 as long as there's anyone that has an open partition. So the check for disk->open_partitions should mean that we can never remove an active partition that has a holder and holder ops set. Assert that in the code. The main disk isn't removed so that check doesn't work for disk->part0 which is what we want. After all we only care about partition not about the main disk. Link: https://lore.kernel.org/r/20231017184823.1383356-3-hch@lst.de Reviewed-by: Ming Lei <ming.lei@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'block')
-rw-r--r--block/partitions/core.c30
1 files changed, 17 insertions, 13 deletions
diff --git a/block/partitions/core.c b/block/partitions/core.c
index b0585536b407..f47ffcfdfcec 100644
--- a/block/partitions/core.c
+++ b/block/partitions/core.c
@@ -274,17 +274,6 @@ void drop_partition(struct block_device *part)
put_device(&part->bd_device);
}
-static void delete_partition(struct block_device *part)
-{
- /*
- * Remove the block device from the inode hash, so that it cannot be
- * looked up any more even when openers still hold references.
- */
- remove_inode_hash(part->bd_inode);
- bdev_mark_dead(part, false);
- drop_partition(part);
-}
-
static ssize_t whole_disk_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@@ -674,8 +663,23 @@ rescan:
sync_blockdev(disk->part0);
invalidate_bdev(disk->part0);
- xa_for_each_start(&disk->part_tbl, idx, part, 1)
- delete_partition(part);
+ xa_for_each_start(&disk->part_tbl, idx, part, 1) {
+ /*
+ * Remove the block device from the inode hash, so that
+ * it cannot be looked up any more even when openers
+ * still hold references.
+ */
+ remove_inode_hash(part->bd_inode);
+
+ /*
+ * If @disk->open_partitions isn't elevated but there's
+ * still an active holder of that block device things
+ * are broken.
+ */
+ WARN_ON_ONCE(atomic_read(&part->bd_openers));
+ invalidate_bdev(part);
+ drop_partition(part);
+ }
clear_bit(GD_NEED_PART_SCAN, &disk->state);
/*