dm target:s introduce iterate devices fn
Add .iterate_devices to 'struct target_type' to allow a function to be
called for all devices in a DM target. Implemented it for all targets
except those in dm-snap.c (origin and snapshot).
(The raid1 version number jumps to 1.12 because we originally reserved
1.1 to 1.11 for 'block_on_error' but ended up using 'handle_errors'
instead.)
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Cc: martin.petersen@oracle.com
diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h
index 236880c..deac3b4 100644
--- a/include/linux/device-mapper.h
+++ b/include/linux/device-mapper.h
@@ -11,6 +11,7 @@
#include <linux/bio.h>
#include <linux/blkdev.h>
+struct dm_dev;
struct dm_target;
struct dm_table;
struct mapped_device;
@@ -81,6 +82,15 @@
typedef int (*dm_merge_fn) (struct dm_target *ti, struct bvec_merge_data *bvm,
struct bio_vec *biovec, int max_size);
+typedef int (*iterate_devices_callout_fn) (struct dm_target *ti,
+ struct dm_dev *dev,
+ sector_t physical_start,
+ void *data);
+
+typedef int (*dm_iterate_devices_fn) (struct dm_target *ti,
+ iterate_devices_callout_fn fn,
+ void *data);
+
/*
* Returns:
* 0: The target can handle the next I/O immediately.
@@ -139,6 +149,7 @@
dm_ioctl_fn ioctl;
dm_merge_fn merge;
dm_busy_fn busy;
+ dm_iterate_devices_fn iterate_devices;
/* For internal device-mapper use. */
struct list_head list;