block: Introduce bdrv_co_writev_flags()

This function will allow drivers to implement BDRV_REQ_FUA natively
instead of sending a separate flush after the write.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Kevin Wolf 2016-03-10 13:39:55 +01:00
parent c83f9fba2a
commit 93f5e6d88a
2 changed files with 13 additions and 1 deletions

View File

@ -1154,13 +1154,20 @@ static int coroutine_fn bdrv_aligned_pwritev(BlockDriverState *bs,
} else if (flags & BDRV_REQ_ZERO_WRITE) {
bdrv_debug_event(bs, BLKDBG_PWRITEV_ZERO);
ret = bdrv_co_do_write_zeroes(bs, sector_num, nb_sectors, flags);
} else if (drv->bdrv_co_writev_flags) {
bdrv_debug_event(bs, BLKDBG_PWRITEV);
ret = drv->bdrv_co_writev_flags(bs, sector_num, nb_sectors, qiov,
flags);
} else {
assert(drv->supported_write_flags == 0);
bdrv_debug_event(bs, BLKDBG_PWRITEV);
ret = drv->bdrv_co_writev(bs, sector_num, nb_sectors, qiov);
}
bdrv_debug_event(bs, BLKDBG_PWRITEV_DONE);
if (ret == 0 && (flags & BDRV_REQ_FUA)) {
if (ret == 0 && (flags & BDRV_REQ_FUA) &&
!(drv->supported_write_flags & BDRV_REQ_FUA))
{
ret = bdrv_co_flush(bs);
}

View File

@ -155,6 +155,11 @@ struct BlockDriver {
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn (*bdrv_co_writev)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov);
int coroutine_fn (*bdrv_co_writev_flags)(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, QEMUIOVector *qiov, int flags);
int supported_write_flags;
/*
* Efficiently zero a region of the disk image. Typically an image format
* would use a compact metadata representation to implement this. This