diff mbox series

[v2,4/6] block/nbd: define new max_write_zero_fast limit

Message ID 20200401150112.9557-5-vsementsov@virtuozzo.com (mailing list archive)
State New, archived
Headers show
Series nbd: reduce max_block restrictions | expand

Commit Message

Vladimir Sementsov-Ogievskiy April 1, 2020, 3:01 p.m. UTC 
The NBD spec was recently updated to clarify that max_block doesn't
relate to NBD_CMD_WRITE_ZEROES with NBD_CMD_FLAG_FAST_ZERO (which
mirrors Qemu flag BDRV_REQ_NO_FALLBACK).

bs->bl.max_write_zero_fast is zero by default which means using
max_pwrite_zeroes. Update nbd driver to allow larger requests with
BDRV_REQ_NO_FALLBACK.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 block/nbd.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/block/nbd.c b/block/nbd.c
index 4ac23c8f62..b0584cf68d 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -1956,6 +1956,7 @@  static void nbd_refresh_limits(BlockDriverState *bs, Error **errp)
 
     bs->bl.request_alignment = min;
     bs->bl.max_pdiscard = QEMU_ALIGN_DOWN(INT_MAX, min);
+    bs->bl.max_pwrite_zeroes_fast = bs->bl.max_pdiscard;
     bs->bl.max_pwrite_zeroes = max;
     bs->bl.max_transfer = max;