qcow2: Support BDRV_REQ_MAY_UNMAP

Handling this is similar to what is done to the L2 entry in the case of
compressed clusters.

Signed-off-by: Fam Zheng <famz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Fam Zheng 2016-09-28 15:04:21 +08:00 committed by Kevin Wolf
parent e84a0dd5a7
commit 170f4b2e5c
3 changed files with 9 additions and 6 deletions

View File

@ -1558,7 +1558,7 @@ fail:
* clusters.
*/
static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
uint64_t nb_clusters)
uint64_t nb_clusters, int flags)
{
BDRVQcow2State *s = bs->opaque;
uint64_t *l2_table;
@ -1582,7 +1582,7 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
/* Update L2 entries */
qcow2_cache_entry_mark_dirty(bs, s->l2_table_cache, l2_table);
if (old_offset & QCOW_OFLAG_COMPRESSED) {
if (old_offset & QCOW_OFLAG_COMPRESSED || flags & BDRV_REQ_MAY_UNMAP) {
l2_table[l2_index + i] = cpu_to_be64(QCOW_OFLAG_ZERO);
qcow2_free_any_clusters(bs, old_offset, 1, QCOW2_DISCARD_REQUEST);
} else {
@ -1595,7 +1595,8 @@ static int zero_single_l2(BlockDriverState *bs, uint64_t offset,
return nb_clusters;
}
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors)
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors,
int flags)
{
BDRVQcow2State *s = bs->opaque;
uint64_t nb_clusters;
@ -1612,7 +1613,7 @@ int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors)
s->cache_discards = true;
while (nb_clusters > 0) {
ret = zero_single_l2(bs, offset, nb_clusters);
ret = zero_single_l2(bs, offset, nb_clusters, flags);
if (ret < 0) {
goto fail;
}

View File

@ -1155,6 +1155,7 @@ static int qcow2_open(BlockDriverState *bs, QDict *options, int flags,
/* Initialise locks */
qemu_co_mutex_init(&s->lock);
bs->supported_zero_flags = BDRV_REQ_MAY_UNMAP;
/* Repair image if dirty */
if (!(flags & (BDRV_O_CHECK | BDRV_O_INACTIVE)) && !bs->read_only &&
@ -2477,7 +2478,7 @@ static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, count);
/* Whatever is left can use real zero clusters */
ret = qcow2_zero_clusters(bs, offset, count >> BDRV_SECTOR_BITS);
ret = qcow2_zero_clusters(bs, offset, count >> BDRV_SECTOR_BITS, flags);
qemu_co_mutex_unlock(&s->lock);
return ret;

View File

@ -547,7 +547,8 @@ uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
int nb_sectors, enum qcow2_discard_type type, bool full_discard);
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors,
int flags);
int qcow2_expand_zero_clusters(BlockDriverState *bs,
BlockDriverAmendStatusCB *status_cb,