block: simplify holder symlink handling
Code to manage symlinks in /sys/block/*/{holders|slaves} are overly
complex with multiple holder considerations, redundant extra
references to all involved kobjects, unused generic kobject holder
support and unnecessary mixup with bd_claim/release functionalities.
Strip it down to what's necessary (single gendisk holder) and make it
use a separate interface. This is a step for cleaning up
bd_claim/release. This patch makes dm-table slightly more complex but
it will be simplified again with further changes.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Brown <neilb@suse.de>
Acked-by: Mike Snitzer <snitzer@redhat.com>
Cc: dm-devel@redhat.com
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 334d68a..66b7f2c 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -663,7 +663,7 @@
void * bd_holder;
int bd_holders;
#ifdef CONFIG_SYSFS
- struct list_head bd_holder_list;
+ struct gendisk * bd_holder_disk; /* for sysfs slave linkng */
#endif
struct block_device * bd_contains;
unsigned bd_block_size;
@@ -2042,11 +2042,17 @@
extern int bd_claim(struct block_device *, void *);
extern void bd_release(struct block_device *);
#ifdef CONFIG_SYSFS
-extern int bd_claim_by_disk(struct block_device *, void *, struct gendisk *);
-extern void bd_release_from_disk(struct block_device *, struct gendisk *);
+extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk);
+extern void bd_unlink_disk_holder(struct block_device *bdev);
#else
-#define bd_claim_by_disk(bdev, holder, disk) bd_claim(bdev, holder)
-#define bd_release_from_disk(bdev, disk) bd_release(bdev)
+static inline int bd_link_disk_holder(struct block_device *bdev,
+ struct gendisk *disk)
+{
+ return 0;
+}
+static inline void bd_unlink_disk_holder(struct block_device *bdev)
+{
+}
#endif
#endif
