[PATCH] dm/md dependency tree in sysfs: bd_claim_by_kobject

Adding bd_claim_by_kobject() function which takes kobject as additional
signature of holder device and creates sysfs symlinks between holder device
and claimed device.  bd_release_from_kobject() is a counterpart of
bd_claim_by_kobject.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9d9674946956..680d913350e7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -410,6 +410,9 @@ struct block_device {
         struct list_head        bd_inodes;
         void *                  bd_holder;
         int                     bd_holders;
+#ifdef CONFIG_SYSFS
+        struct list_head        bd_holder_list;
+#endif
         struct block_device *   bd_contains;
         unsigned                bd_block_size;
         struct hd_struct *      bd_part;
@@ -1399,6 +1402,13 @@ extern int blkdev_get(struct block_device *, mode_t, unsigned);
 extern int blkdev_put(struct block_device *);
 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 *);
+#else
+#define bd_claim_by_disk(bdev, holder, disk)    bd_claim(bdev, holder)
+#define bd_release_from_disk(bdev, disk)        bd_release(bdev)
+#endif
 
 /* fs/char_dev.c */
 extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *);