Commit 96a1f7db authored by Mike Anderson's avatar Mike Anderson Committed by Alasdair G Kergon
Browse files

dm: export name and uuid 



This patch adds a function to obtain a copy of a mapped device's name and uuid.

Signed-off-by: default avatarMike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent aa5617c5

drivers/md/dm-ioctl.c

+32 −0
Original line number Diff line number Diff line
@@ -1515,3 +1515,35 @@ void dm_interface_exit(void) 


	dm_hash_exit();

}



/**

 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers

 * @md: Pointer to mapped_device

 * @name: Buffer (size DM_NAME_LEN) for name

 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined

 */

int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)

{

	int r = 0;

	struct hash_cell *hc;



	if (!md)

		return -ENXIO;



	dm_get(md);

	down_read(&_hash_lock);

	hc = dm_get_mdptr(md);

	if (!hc || hc->md != md) {

		r = -ENXIO;

		goto out;

	}



	strcpy(name, hc->name);

	strcpy(uuid, hc->uuid ? : "");



out:

	up_read(&_hash_lock);

	dm_put(md);



	return r;

}

include/linux/device-mapper.h

+1 −0
Original line number Diff line number Diff line
@@ -188,6 +188,7 @@ int dm_wait_event(struct mapped_device *md, int event_nr); 
 * Info functions.

 */

const char *dm_device_name(struct mapped_device *md);

int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid);

struct gendisk *dm_disk(struct mapped_device *md);

int dm_suspended(struct mapped_device *md);

int dm_noflush_suspending(struct dm_target *ti);