Commit 170f4b2e authored by Fam Zheng's avatar Fam Zheng Committed by Kevin Wolf
Browse files

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: default avatarFam Zheng <famz@redhat.com>
Signed-off-by: default avatarKevin Wolf <kwolf@redhat.com>
parent e84a0dd5

block/qcow2-cluster.c

+5 −4
Original line number Diff line number Diff line
@@ -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;

        }

block/qcow2.c

+2 −1
Original line number Diff line number Diff line
@@ -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;

block/qcow2.h

+2 −1
Original line number Diff line number Diff line
@@ -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,