allow userspace to modify scsi command filter on per device basis

This patch exports the per-gendisk command filter to user space through
sysfs, so it can be changed by the system administrator.
All users of the old cmd filter have been converted to use the new one.

Original patch from Peter Jones.

Signed-off-by: Adel Gadllah <adel.gadllah@gmail.com>
Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/block/genhd.c b/block/genhd.c
index 43e468ee5993..9074f384b097 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -189,6 +189,7 @@ void add_disk(struct gendisk *disk)
                             disk->minors, NULL, exact_match, exact_lock, disk);
         register_disk(disk);
         blk_register_queue(disk);
+        blk_register_filter(disk);
 
         bdi = &disk->queue->backing_dev_info;
         bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
@@ -200,6 +201,7 @@ EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
 
 void unlink_gendisk(struct gendisk *disk)
 {
+        blk_unregister_filter(disk);
         sysfs_remove_link(&disk->dev.kobj, "bdi");
         bdi_unregister(&disk->queue->backing_dev_info);
         blk_unregister_queue(disk);