From: Will Drewry <wad@xxxxxxxxxxxx> If a mapped device and table is configured without traversing the dm-ioctl interface (dm-fs-style), then it will not be bound to a name or uuid. This means that it will be inaccessible for userspace management and udev will be unhappy with the lack of a name or uuid. The function added in this change performs the required association to transition to being managed by the ioctl interface. Signed-off-by: Will Drewry <wad@xxxxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> --- v5: resurrection v4: https://patchwork.kernel.org/patch/104860/ --- drivers/md/dm-ioctl.c | 35 +++++++++++++++++++++++++++++++++++ include/linux/device-mapper.h | 6 ++++++ 2 files changed, 41 insertions(+) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 80a439543259..e0efc6844b3a 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1923,6 +1923,41 @@ void dm_interface_exit(void) dm_hash_exit(); } + +/** + * dm_ioctl_export - Permanently export a mapped device via the ioctl interface + * @md: Pointer to mapped_device + * @name: Buffer (size DM_NAME_LEN) for name + * @uuid: Buffer (size DM_UUID_LEN) for uuid or NULL if not desired + */ +int dm_ioctl_export(struct mapped_device *md, const char *name, + const char *uuid) +{ + int r = 0; + struct hash_cell *hc; + + if (!md) + return -ENXIO; + + /* The name and uuid can only be set once. */ + mutex_lock(&dm_hash_cells_mutex); + hc = dm_get_mdptr(md); + mutex_unlock(&dm_hash_cells_mutex); + if (hc) { + DMERR("%s: already exported", dm_device_name(md)); + return -ENXIO; + } + + r = dm_hash_insert(name, uuid, md); + if (r) { + DMERR("%s: could not bind to '%s'", dm_device_name(md), name); + return r; + } + + /* Let udev know we've changed. */ + dm_kobject_uevent(md, KOBJ_CHANGE, dm_get_event_nr(md)); + return r; +} /** * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers * @md: Pointer to mapped_device diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index ec1c61c87d89..87afa0552398 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -381,6 +381,12 @@ void dm_set_mdptr(struct mapped_device *md, void *ptr); void *dm_get_mdptr(struct mapped_device *md); /* + * Export the device via the ioctl interface (uses mdptr). + */ +int dm_ioctl_export(struct mapped_device *md, const char *name, + const char *uuid); + +/* * A device can still be used while suspended, but I/O is deferred. */ int dm_suspend(struct mapped_device *md, unsigned suspend_flags); -- 2.6.3 -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
