From a370182fed893c65c4d5a6ec96ce70535e861c62 Mon Sep 17 00:00:00 2001 From: Paul Dagnelie Date: Fri, 21 Jun 2019 09:40:56 -0700 Subject: [PATCH] Add SCSI_PASSTHROUGH to zvols to enable UNMAP support When exporting ZVOLs as SCSI LUNs, by default Windows will not issue them UNMAP commands. This reduces storage efficiency in many cases. We add the SCSI_PASSTHROUGH flag to the zvol's device queue, which lets the SCSI target logic know that it can handle SCSI commands. Reviewed-by: Brian Behlendorf Reviewed-by: George Melikov Reviewed-by: John Gallagher Signed-off-by: Paul Dagnelie Closes #8933 --- module/zfs/zvol.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/module/zfs/zvol.c b/module/zfs/zvol.c index 9aeadb22b6..f74eb28aec 100644 --- a/module/zfs/zvol.c +++ b/module/zfs/zvol.c @@ -1876,6 +1876,10 @@ zvol_create_minor_impl(const char *name) #ifdef QUEUE_FLAG_ADD_RANDOM blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, zv->zv_queue); #endif + /* This flag was introduced in kernel version 4.12. */ +#ifdef QUEUE_FLAG_SCSI_PASSTHROUGH + blk_queue_flag_set(QUEUE_FLAG_SCSI_PASSTHROUGH, zv->zv_queue); +#endif if (spa_writeable(dmu_objset_spa(os))) { if (zil_replay_disable)