[Devel] [PATCH] ploop: Add lockout on discard requests

[Kirill Tkhai]

In case of ext4 sends discard, it prohibits to reuse
the discarded block in its internals. But in case of
direct using of the device, there is no such protection.
This patch implements it.

Signed-off-by: Kirill Tkhai <ktkhai at virtuozzo.com>
---
 drivers/block/ploop/dev.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/block/ploop/dev.c b/drivers/block/ploop/dev.c
index 36df41450c4d..fa87bfdd84bb 100644
--- a/drivers/block/ploop/dev.c
+++ b/drivers/block/ploop/dev.c
@@ -2459,7 +2459,8 @@ ploop_entry_request(struct ploop_request * preq)
 			if (delta == top_delta) {
 				/* Block exists in top delta. Good. */
 				if (plo->maintenance_type == PLOOP_MNTN_GROW ||
-				    plo->maintenance_type == PLOOP_MNTN_RELOC) {
+				    plo->maintenance_type == PLOOP_MNTN_RELOC ||
+				    preq->req_rw & REQ_DISCARD) {
 					spin_lock_irq(&plo->lock);
 					ploop_add_lockout(preq, 0);
 					spin_unlock_irq(&plo->lock);