From: Will Drewry <wad@xxxxxxxxxxxx> One function is added which allows for a programmatically created mapped device to be inserted into the dm-ioctl hash table. This binds the device to a name and, optional, uuid which is needed by udev and allows for userspace management of the mapped device. Signed-off-by: Will Drewry <wad@xxxxxxxxxxxx> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Signed-off-by: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx> --- v6: none v5: resurrection v4: https://patchwork.kernel.org/patch/104860/ --- drivers/md/dm-ioctl.c | 36 ++++++++++++++++++++++++++++++++++++ include/linux/device-mapper.h | 6 ++++++ 2 files changed, 42 insertions(+) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 4951bf9..f4c610f 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1924,6 +1924,42 @@ void dm_interface_exit(void) } /** + * 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 * @name: Buffer (size DM_NAME_LEN) for name diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index 9f70b21..2efac3b 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -412,6 +412,12 @@ 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); -- 2.9.3 -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
