block: Set default request_alignment during bdrv_refresh_limits()

We want to eventually stick request_alignment alongside other
BlockLimits, but first, we must ensure it is populated at the
same time as all other limits, rather than being a special case
that is set only when a block is first opened.

Now that all drivers have been updated to supply an override
of request_alignment during their .bdrv_refresh_limits(), as
needed, the block layer itself can defer setting the default
alignment until part of the overall bdrv_refresh_limits().

Signed-off-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-06-23 16:37:18 -06:00 committed by Kevin Wolf
parent a65064816d
commit 79ba8c986a
2 changed files with 3 additions and 1 deletions

View File

@ -937,7 +937,6 @@ static int bdrv_open_common(BlockDriverState *bs, BdrvChild *file,
goto fail_opts;
}
bs->request_alignment = drv->bdrv_co_preadv ? 1 : 512;
bs->read_only = !(bs->open_flags & BDRV_O_RDWR);
if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv, bs->read_only)) {

View File

@ -78,6 +78,9 @@ void bdrv_refresh_limits(BlockDriverState *bs, Error **errp)
return;
}
/* Default alignment based on whether driver has byte interface */
bs->request_alignment = drv->bdrv_co_preadv ? 1 : 512;
/* Take some limits from the children as a default */
if (bs->file) {
bdrv_refresh_limits(bs->file->bs, &local_err);