Commit 8e507243 authored by Fam Zheng's avatar Fam Zheng Committed by Michael Tokarev
Browse files

vmdk: fix comment for vmdk_co_write_zeroes 



The comment was truncated. Add the missing parts, especially explain why
we need zero_dry_run.

Signed-off-by: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarMichael Tokarev <mjt@tls.msk.ru>
parent 437de2ad

block/vmdk.c

+6 −2
Original line number Diff line number Diff line
@@ -1201,7 +1201,9 @@ static coroutine_fn int vmdk_co_read(BlockDriverState *bs, int64_t sector_num, 
 * vmdk_write:

 * @zeroed:       buf is ignored (data is zero), use zeroed_grain GTE feature

 *                if possible, otherwise return -ENOTSUP.

 * @zero_dry_run: used for zeroed == true only, don't update L2 table, just

 * @zero_dry_run: used for zeroed == true only, don't update L2 table, just try

 *                with each cluster. By dry run we can find if the zero write

 *                is possible without modifying image data.

 *

 * Returns: error code with 0 for success.

 */
@@ -1328,6 +1330,8 @@ static int coroutine_fn vmdk_co_write_zeroes(BlockDriverState *bs, 
    int ret;

    BDRVVmdkState *s = bs->opaque;

    qemu_co_mutex_lock(&s->lock);

    /* write zeroes could fail if sectors not aligned to cluster, test it with

     * dry_run == true before really updating image */

    ret = vmdk_write(bs, sector_num, NULL, nb_sectors, true, true);

    if (!ret) {

        ret = vmdk_write(bs, sector_num, NULL, nb_sectors, true, false);