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 <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-06-01 15:10:01 -06:00 committed by Kevin Wolf
parent ebb718a5c7
commit 8b18474451
1 changed files with 5 additions and 0 deletions

View File

@ -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);