summaryrefslogtreecommitdiffstats
path: root/block/genhd.c
diff options
context:
space:
mode:
authorJan Kara <jack@suse.cz>2017-03-08 17:48:33 +0100
committerJens Axboe <axboe@fb.com>2017-03-08 10:55:17 -0700
commit90f16fddcc2802726142b8386c65ccb89f044613 (patch)
treeda1c8d56ab62dd362dc94fab542ba43a5144f67d /block/genhd.c
parentdf23de55615fa7a190a85f49a950ccecdd9102f3 (diff)
downloadlinux-0-day-90f16fddcc2802726142b8386c65ccb89f044613.tar.gz
block: Make del_gendisk() safer for disks without queues
Commit 165a5e22fafb "block: Move bdi_unregister() to del_gendisk()" added disk->queue dereference to del_gendisk(). Although del_gendisk() is not supposed to be called without disk->queue valid and blk_unregister_queue() warns in that case, this change will make it oops instead. Return to the old more robust behavior of just warning when del_gendisk() gets called for gendisk with disk->queue being NULL. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jan Kara <jack@suse.cz> Tested-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Jens Axboe <axboe@fb.com>
Diffstat (limited to 'block/genhd.c')
-rw-r--r--block/genhd.c16
1 files changed, 10 insertions, 6 deletions
diff --git a/block/genhd.c b/block/genhd.c
index b26a5ea..94f3238 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -681,12 +681,16 @@ void del_gendisk(struct gendisk *disk)
disk->flags &= ~GENHD_FL_UP;
sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
- /*
- * Unregister bdi before releasing device numbers (as they can get
- * reused and we'd get clashes in sysfs).
- */
- bdi_unregister(disk->queue->backing_dev_info);
- blk_unregister_queue(disk);
+ if (disk->queue) {
+ /*
+ * Unregister bdi before releasing device numbers (as they can
+ * get reused and we'd get clashes in sysfs).
+ */
+ bdi_unregister(disk->queue->backing_dev_info);
+ blk_unregister_queue(disk);
+ } else {
+ WARN_ON(1);
+ }
blk_unregister_region(disk_devt(disk), disk->minors);
part_stat_set_all(&disk->part0, 0);