There is quite a bit of code on del_gendisk() which relates to
unregistering the disk, using register_disk() as an counter.
Move all this code into a helper instead of re-writing our own,
which we'll need later to handle errors on add_disk().
I note that register_disk() links the bdi at the end, but since
del_gendisk() deals with this before queue de-registration we'll
take a hint that's the right order that this should be done, and
we shouldn't instead strictly unwind register_disk() exactly.
We'll instead keep whatever lessons have been learned from
del_gendisk().
Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx>
---
block/genhd.c | 41 ++++++++++++++++++++++++-----------------
1 file changed, 24 insertions(+), 17 deletions(-)
diff --git a/block/genhd.c b/block/genhd.c
index b4d75a15fd31..ed2a0eaa4e7b 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -762,6 +762,28 @@ static void disk_invalidate(struct gendisk *disk)
up_write(&disk->lookup_sem);
}
+static void unregister_disk(struct gendisk *disk)
+{
+ /*
+ * Remove gendisk pointer from idr so that it cannot be looked up
+ * while RCU period before freeing gendisk is running to prevent
+ * use-after-free issues. Note that the device number stays
+ * "in-use" until we really free the gendisk.
+ */
+ blk_invalidate_devt(disk_devt(disk));
+
+ kobject_put(disk->part0.holder_dir);
+ kobject_put(disk->slave_dir);
+
+ part_stat_set_all(&disk->part0, 0);
+ disk->part0.stamp = 0;
+ if (!sysfs_deprecated)
+ sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
+
+ pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
+ device_del(disk_to_dev(disk));
+}
+
static void register_disk(struct device *parent, struct gendisk *disk,
const struct attribute_group **groups)
{
@@ -972,25 +994,10 @@ void del_gendisk(struct gendisk *disk)
WARN_ON(1);
}
+ unregister_disk(disk);
+
if (!(disk->flags & GENHD_FL_HIDDEN))
blk_unregister_region(disk_devt(disk), disk->minors);
- /*
- * Remove gendisk pointer from idr so that it cannot be looked up
- * while RCU period before freeing gendisk is running to prevent
- * use-after-free issues. Note that the device number stays
- * "in-use" until we really free the gendisk.
- */
- blk_invalidate_devt(disk_devt(disk));
-
- kobject_put(disk->part0.holder_dir);
- kobject_put(disk->slave_dir);
-
- part_stat_set_all(&disk->part0, 0);
- disk->part0.stamp = 0;
- if (!sysfs_deprecated)
- sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
- pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
- device_del(disk_to_dev(disk));
}
EXPORT_SYMBOL(del_gendisk);
--
2.25.1
