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Commit ef50a3e3 authored by Lars Ellenberg's avatar Lars Ellenberg Committed by Philipp Reisner
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drbd: implicitly create unconfigured devices on sync-after dependencies 



If pacemaker (for example) decided to initialize minor devices not in
the exact sync-after dependency order, the configuration partially
failed with an error "The sync-after minor number is invalid". (Bugz. #322)

We can avoid that by implicitly creating unconfigured minor devices,
if others depend on them.

Signed-off-by: default avatarPhilipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: default avatarLars Ellenberg <lars.ellenberg@linbit.com>
parent 3f3a9b84

drivers/block/drbd/drbd_nl.c

+41 −35
Original line number Diff line number Diff line
@@ -413,6 +413,39 @@ int drbd_set_role(struct drbd_conf *mdev, enum drbd_role new_role, int force) 
	return r;

}



static struct drbd_conf *ensure_mdev(int minor, int create)

{

	struct drbd_conf *mdev;



	if (minor >= minor_count)

		return NULL;



	mdev = minor_to_mdev(minor);



	if (!mdev && create) {

		struct gendisk *disk = NULL;

		mdev = drbd_new_device(minor);



		spin_lock_irq(&drbd_pp_lock);

		if (minor_table[minor] == NULL) {

			minor_table[minor] = mdev;

			disk = mdev->vdisk;

			mdev = NULL;

		} /* else: we lost the race */

		spin_unlock_irq(&drbd_pp_lock);



		if (disk) /* we won the race above */

			/* in case we ever add a drbd_delete_device(),

			 * don't forget the del_gendisk! */

			add_disk(disk);

		else /* we lost the race above */

			drbd_free_mdev(mdev);



		mdev = minor_to_mdev(minor);

	}



	return mdev;

}



static int drbd_nl_primary(struct drbd_conf *mdev, struct drbd_nl_cfg_req *nlp,

			   struct drbd_nl_cfg_reply *reply)
@@ -1713,6 +1746,12 @@ static int drbd_nl_syncer_conf(struct drbd_conf *mdev, struct drbd_nl_cfg_req *n 
	}

#undef AL_MAX



	/* to avoid spurious errors when configuring minors before configuring

	 * the minors they depend on: if necessary, first create the minor we

	 * depend on */

	if (sc.after >= 0)

		ensure_mdev(sc.after, 1);



	/* most sanity checks done, try to assign the new sync-after

	 * dependency.  need to hold the global lock in there,

	 * to avoid a race in the dependency loop check. */
@@ -2080,40 +2119,6 @@ out: 
	return 0;

}



static struct drbd_conf *ensure_mdev(struct drbd_nl_cfg_req *nlp)

{

	struct drbd_conf *mdev;



	if (nlp->drbd_minor >= minor_count)

		return NULL;



	mdev = minor_to_mdev(nlp->drbd_minor);



	if (!mdev && (nlp->flags & DRBD_NL_CREATE_DEVICE)) {

		struct gendisk *disk = NULL;

		mdev = drbd_new_device(nlp->drbd_minor);



		spin_lock_irq(&drbd_pp_lock);

		if (minor_table[nlp->drbd_minor] == NULL) {

			minor_table[nlp->drbd_minor] = mdev;

			disk = mdev->vdisk;

			mdev = NULL;

		} /* else: we lost the race */

		spin_unlock_irq(&drbd_pp_lock);



		if (disk) /* we won the race above */

			/* in case we ever add a drbd_delete_device(),

			 * don't forget the del_gendisk! */

			add_disk(disk);

		else /* we lost the race above */

			drbd_free_mdev(mdev);



		mdev = minor_to_mdev(nlp->drbd_minor);

	}



	return mdev;

}



struct cn_handler_struct {

	int (*function)(struct drbd_conf *,

			 struct drbd_nl_cfg_req *,
@@ -2174,7 +2179,8 @@ static void drbd_connector_callback(struct cn_msg *req, struct netlink_skb_parms 
		goto fail;

	}



	mdev = ensure_mdev(nlp);

	mdev = ensure_mdev(nlp->drbd_minor,

			(nlp->flags & DRBD_NL_CREATE_DEVICE));

	if (!mdev) {

		retcode = ERR_MINOR_INVALID;

		goto fail;