From 96a1f7dba6e464155c0d1dc69c6c2efa96b644ac Mon Sep 17 00:00:00 2001 From: Mike Anderson Date: Fri, 19 Oct 2007 22:47:59 +0100 Subject: [PATCH] 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: Mike Anderson Signed-off-by: Alasdair G Kergon --- drivers/md/dm-ioctl.c | 32 ++++++++++++++++++++++++++++++++ include/linux/device-mapper.h | 1 + 2 files changed, 33 insertions(+) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 6af95f9b7b..138200bf5e 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -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; +} diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 499f5373e2..8b3c7cdc59 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -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); -- 2.39.5