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Commit 6fd48b3b authored by Alex Elder's avatar Alex Elder Committed by Sage Weil
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rbd: define rbd_dev_unprobe() 



Define a new function rbd_dev_unprobe() which undoes state changes
that occur from calling rbd_dev_v1_probe() or rbd_dev_v2_probe().
Note that this is a superset of rbd_header_free(), which is now
getting removed (it seems to have been used improperly anyway).

Flesh out rbd_dev_image_release() so it undoes exactly what
rbd_dev_image_probe() does.

This means that:
    - rbd_dev_device_release() gets called when the last device
      reference gets dropped;
    - that undoes everything done by the rbd_dev_device_setup() call
      at the end of rbd_dev_image_probe() (and nothing more), ending
      by calling rbd_dev_image_release(); and
    - rbd_dev_image_release() undoes everything else done by
      rbd_dev_image_probe() (and this includes a call to
      rbd_dev_unprobe().

This means the image and device portions of an rbd device are fairly
cleanly separated now, so error paths should be a little easier to
verify than they used to be.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent 200a6a8b

drivers/block/rbd.c

+38 −40
Original line number Diff line number Diff line
@@ -900,18 +900,6 @@ static void rbd_dev_clear_mapping(struct rbd_device *rbd_dev) 
	rbd_dev->mapping.read_only = true;

}



static void rbd_header_free(struct rbd_image_header *header)

{

	kfree(header->object_prefix);

	header->object_prefix = NULL;

	kfree(header->snap_sizes);

	header->snap_sizes = NULL;

	kfree(header->snap_names);

	header->snap_names = NULL;

	rbd_snap_context_put(header->snapc);

	header->snapc = NULL;

}



static const char *rbd_segment_name(struct rbd_device *rbd_dev, u64 offset)

{

	char *name;
@@ -4588,6 +4576,27 @@ out: 
	return ret;

}



/* Undo whatever state changes are made by v1 or v2 image probe */



static void rbd_dev_unprobe(struct rbd_device *rbd_dev)

{

	struct rbd_image_header	*header;



	rbd_dev_remove_parent(rbd_dev);

	rbd_spec_put(rbd_dev->parent_spec);

	rbd_dev->parent_spec = NULL;

	rbd_dev->parent_overlap = 0;



	/* Free dynamic fields from the header, then zero it out */



	header = &rbd_dev->header;

	rbd_snap_context_put(header->snapc);

	kfree(header->snap_sizes);

	kfree(header->snap_names);

	kfree(header->object_prefix);

	memset(header, 0, sizeof (*header));

}



static int rbd_dev_v1_probe(struct rbd_device *rbd_dev)

{

	int ret;
@@ -4809,10 +4818,19 @@ static int rbd_dev_header_name(struct rbd_device *rbd_dev) 


static void rbd_dev_image_release(struct rbd_device *rbd_dev)

{

	rbd_header_free(&rbd_dev->header);

	rbd_assert(rbd_dev->rbd_client != NULL);

	rbd_spec_put(rbd_dev->parent_spec);

	int ret;



	rbd_remove_all_snaps(rbd_dev);

	rbd_dev_unprobe(rbd_dev);

	ret = rbd_dev_header_watch_sync(rbd_dev, 0);

	if (ret)

		rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);

	kfree(rbd_dev->header_name);

	rbd_dev->header_name = NULL;

	rbd_dev->image_format = 0;

	kfree(rbd_dev->spec->image_id);

	rbd_dev->spec->image_id = NULL;



	rbd_dev_destroy(rbd_dev);

}
@@ -4854,7 +4872,7 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) 


	ret = rbd_dev_snaps_update(rbd_dev);

	if (ret)

		goto err_out_watch;

		goto err_out_probe;



	ret = rbd_dev_spec_update(rbd_dev);

	if (ret)
@@ -4865,15 +4883,13 @@ static int rbd_dev_image_probe(struct rbd_device *rbd_dev) 
		goto err_out_snaps;



	ret = rbd_dev_device_setup(rbd_dev);

	if (ret)

		goto err_out_parent;

	if (!ret)

		return 0;



	return ret;

err_out_parent:

	rbd_dev_remove_parent(rbd_dev);

	rbd_header_free(&rbd_dev->header);

err_out_snaps:

	rbd_remove_all_snaps(rbd_dev);

err_out_probe:

	rbd_dev_unprobe(rbd_dev);

err_out_watch:

	tmp = rbd_dev_header_watch_sync(rbd_dev, 0);

	if (tmp)
@@ -5005,7 +5021,6 @@ static void rbd_dev_remove_parent(struct rbd_device *rbd_dev) 
		struct rbd_device *first = rbd_dev;

		struct rbd_device *second = first->parent;

		struct rbd_device *third;

		int ret;



		/*

		 * Follow to the parent with no grandparent and
@@ -5016,11 +5031,6 @@ static void rbd_dev_remove_parent(struct rbd_device *rbd_dev) 
			second = third;

		}

		rbd_assert(second);

		ret = rbd_dev_header_watch_sync(rbd_dev, 0);

		if (ret)

			rbd_warn(rbd_dev,

				"failed to cancel watch event (%d)\n", ret);

		rbd_remove_all_snaps(second);

		rbd_bus_del_dev(second);

		first->parent = NULL;

		first->parent_overlap = 0;
@@ -5065,19 +5075,7 @@ static ssize_t rbd_remove(struct bus_type *bus, 
	spin_unlock_irq(&rbd_dev->lock);

	if (ret < 0)

		goto done;



	ret = rbd_dev_header_watch_sync(rbd_dev, 0);

	if (ret) {

		rbd_warn(rbd_dev, "failed to cancel watch event (%d)\n", ret);

		clear_bit(RBD_DEV_FLAG_REMOVING, &rbd_dev->flags);

		smp_mb();

		return ret;

	}

	ret = count;



	rbd_dev_remove_parent(rbd_dev);



	rbd_remove_all_snaps(rbd_dev);

	rbd_bus_del_dev(rbd_dev);

	module_put(THIS_MODULE);

done: