From: Joe Thornber Allow targets to override the 'supports flush' calculation. Set 'flush_supported' if a target needs to receive flushes regardless of whether or not its underlying devices have support. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon --- drivers/md/dm-table.c | 3 +++ include/linux/device-mapper.h | 6 ++++++ 2 files changed, 9 insertions(+) Index: linux/drivers/md/dm-table.c =================================================================== --- linux.orig/drivers/md/dm-table.c +++ linux/drivers/md/dm-table.c @@ -1319,6 +1319,9 @@ static bool dm_table_supports_flush(stru if (!ti->num_flush_requests) continue; + if (ti->flush_supported) + return 1; + if (ti->type->iterate_devices && ti->type->iterate_devices(ti, device_flush_capable, &flush)) return 1; Index: linux/include/linux/device-mapper.h =================================================================== --- linux.orig/include/linux/device-mapper.h +++ linux/include/linux/device-mapper.h @@ -212,6 +212,12 @@ struct dm_target { char *error; /* + * Set if this target needs to receive flushes regardless of + * whether or not its underlying devices have support. + */ + bool flush_supported:1; + + /* * Set if this target needs to receive discards regardless of * whether or not its underlying devices have support. */