dm: allow targets to return output from messages they are sent

Could be useful for a target to return stats or other information.
If a target does DMEMIT() anything to @result from its .message method
then it must return 1 to the caller.

Signed-off-By: Mike Snitzer <snitzer@redhat.com>
This commit is contained in:
Mike Snitzer 2018-02-28 15:59:59 -05:00
parent da5dadb4f1
commit 1eb5fa849f
11 changed files with 21 additions and 12 deletions

View file

@ -87,7 +87,8 @@ typedef void (*dm_resume_fn) (struct dm_target *ti);
typedef void (*dm_status_fn) (struct dm_target *ti, status_type_t status_type,
unsigned status_flags, char *result, unsigned maxlen);
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv);
typedef int (*dm_message_fn) (struct dm_target *ti, unsigned argc, char **argv,
char *result, unsigned maxlen);
typedef int (*dm_prepare_ioctl_fn) (struct dm_target *ti,
struct block_device **bdev, fmode_t *mode);