From 8b1847445159ff6c12e7a24f04dc989ff97e34d4 Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 1 Jun 2016 15:10:01 -0600 Subject: [PATCH] iscsi: Use block size as minimum zero/discard alignment If hardware does not advertise a minimum zero/discard alignment, we still want to guarantee that the block layer will align requests to our blocks, rather than the arbitrary 512-byte BDRV sector size. Signed-off-by: Eric Blake Signed-off-by: Kevin Wolf --- block/iscsi.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/block/iscsi.c b/block/iscsi.c index e7d5f7b0c3..94f9974f10 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1711,6 +1711,8 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) } bs->bl.discard_alignment = sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun); + } else { + bs->bl.discard_alignment = iscsilun->block_size >> BDRV_SECTOR_BITS; } if (iscsilun->bl.max_ws_len < 0xffffffff) { @@ -1720,6 +1722,9 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) if (iscsilun->lbp.lbpws) { bs->bl.write_zeroes_alignment = sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun); + } else { + bs->bl.write_zeroes_alignment = + iscsilun->block_size >> BDRV_SECTOR_BITS; } bs->bl.opt_transfer_length = sector_limits_lun2qemu(iscsilun->bl.opt_xfer_len, iscsilun);