From cf081fca4e3cc02a309659b571ab0c5b225ea4cf Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 1 Jun 2016 15:10:02 -0600 Subject: block: Track write zero limits in bytes Another step towards removing sector-based interfaces: convert the maximum write and minimum alignment values from sectors to bytes. Rename the variables to let the compiler check that all users are converted to the new semantics. The maximum remains an int as long as BDRV_REQUEST_MAX_SECTORS is constrained by INT_MAX (this means that we can't even support a 2G write_zeroes, but just under it) - changing operation lengths to unsigned or to 64-bits is a much bigger audit, and debatable if we even want to do it (since at the core, a 32-bit platform will still have ssize_t as its underlying limit on write()). Meanwhile, alignment is changed to 'uint32_t', since it makes no sense to have an alignment larger than the maximum write, and less painful to use an unsigned type with well-defined behavior in bit operations than to have to worry about what happens if a driver mistakenly supplies a negative alignment. Add an assert that no one was trying to use sectors to get a write zeroes larger than 2G, and therefore that a later conversion to bytes won't be impacted by keeping the limit at 32 bits. Signed-off-by: Eric Blake Signed-off-by: Kevin Wolf --- block/iscsi.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) (limited to 'block/iscsi.c') diff --git a/block/iscsi.c b/block/iscsi.c index 94f9974f10..52ea9d7a70 100644 --- a/block/iscsi.c +++ b/block/iscsi.c @@ -1715,16 +1715,15 @@ static void iscsi_refresh_limits(BlockDriverState *bs, Error **errp) bs->bl.discard_alignment = iscsilun->block_size >> BDRV_SECTOR_BITS; } - if (iscsilun->bl.max_ws_len < 0xffffffff) { - bs->bl.max_write_zeroes = - sector_limits_lun2qemu(iscsilun->bl.max_ws_len, iscsilun); + if (iscsilun->bl.max_ws_len < 0xffffffff / iscsilun->block_size) { + bs->bl.max_pwrite_zeroes = + iscsilun->bl.max_ws_len * iscsilun->block_size; } if (iscsilun->lbp.lbpws) { - bs->bl.write_zeroes_alignment = - sector_limits_lun2qemu(iscsilun->bl.opt_unmap_gran, iscsilun); + bs->bl.pwrite_zeroes_alignment = + iscsilun->bl.opt_unmap_gran * iscsilun->block_size; } else { - bs->bl.write_zeroes_alignment = - iscsilun->block_size >> BDRV_SECTOR_BITS; + bs->bl.pwrite_zeroes_alignment = iscsilun->block_size; } bs->bl.opt_transfer_length = sector_limits_lun2qemu(iscsilun->bl.opt_xfer_len, iscsilun); -- cgit v1.2.3