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/drivers/md/dm-table.c b/drivers/md/dm-table.c
index 90267f8..2c876ff 100644
--- a/drivers/md/dm-table.c
+++ b/drivers/md/dm-table.c
@@ -328,12 +328,22 @@
bdev = open_by_devnum(dev, d->dm_dev.mode);
if (IS_ERR(bdev))
return PTR_ERR(bdev);
- r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md));
- if (r)
+
+ r = bd_claim(bdev, _claim_ptr);
+ if (r) {
blkdev_put(bdev, d->dm_dev.mode);
- else
- d->dm_dev.bdev = bdev;
- return r;
+ return r;
+ }
+
+ r = bd_link_disk_holder(bdev, dm_disk(md));
+ if (r) {
+ bd_release(bdev);
+ blkdev_put(bdev, d->dm_dev.mode);
+ return r;
+ }
+
+ d->dm_dev.bdev = bdev;
+ return 0;
}
/*
@@ -344,7 +354,8 @@
if (!d->dm_dev.bdev)
return;
- bd_release_from_disk(d->dm_dev.bdev, dm_disk(md));
+ bd_unlink_disk_holder(d->dm_dev.bdev);
+ bd_release(d->dm_dev.bdev);
blkdev_put(d->dm_dev.bdev, d->dm_dev.mode);
d->dm_dev.bdev = NULL;
}
diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4e957f3..c47644f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -1880,7 +1880,7 @@
rdev->sysfs_state = sysfs_get_dirent_safe(rdev->kobj.sd, "state");
list_add_rcu(&rdev->same_set, &mddev->disks);
- bd_claim_by_disk(rdev->bdev, rdev->bdev->bd_holder, mddev->gendisk);
+ bd_link_disk_holder(rdev->bdev, mddev->gendisk);
/* May as well allow recovery to be retried once */
mddev->recovery_disabled = 0;
@@ -1907,7 +1907,7 @@
MD_BUG();
return;
}
- bd_release_from_disk(rdev->bdev, rdev->mddev->gendisk);
+ bd_unlink_disk_holder(rdev->bdev);
list_del_rcu(&rdev->same_set);
printk(KERN_INFO "md: unbind<%s>\n", bdevname(rdev->bdev,b));
rdev->mddev = NULL;