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qcow2: Convert to bdrv_co_pwrite_zeroes()

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Another step on our continuing quest to switch to byte-based
interfaces.

Signed-off-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This commit is contained in:
Eric Blake 2016-06-01 15:10:06 -06:00 committed by Kevin Wolf
parent 94d047a35b
commit 5544b59f8e
2 changed files with 21 additions and 20 deletions
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37
block/qcow2.c
View File

@ -2421,38 +2421,39 @@ static bool is_zero_sectors(BlockDriverState *bs, int64_t start,
return res >= 0 && (res & BDRV_BLOCK_ZERO) && nr == count;
}
static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs,
int64_t sector_num, int nb_sectors, BdrvRequestFlags flags)
static coroutine_fn int qcow2_co_pwrite_zeroes(BlockDriverState *bs,
int64_t offset, int count, BdrvRequestFlags flags)
{
int ret;
BDRVQcow2State *s = bs->opaque;
uint32_t head = sector_num % s->cluster_sectors;
uint32_t tail = (sector_num + nb_sectors) % s->cluster_sectors;
uint32_t head = offset % s->cluster_size;
uint32_t tail = (offset + count) % s->cluster_size;
trace_qcow2_write_zeroes_start_req(qemu_coroutine_self(), sector_num,
nb_sectors);
trace_qcow2_pwrite_zeroes_start_req(qemu_coroutine_self(), offset, count);
if (head || tail) {
int64_t cl_start = sector_num - head;
int64_t cl_start = (offset - head) >> BDRV_SECTOR_BITS;
uint64_t off;
int nr;
assert(cl_start + s->cluster_sectors >= sector_num + nb_sectors);
assert(head + count <= s->cluster_size);
/* check whether remainder of cluster already reads as zero */
if (!(is_zero_sectors(bs, cl_start, head) &&
is_zero_sectors(bs, sector_num + nb_sectors,
-tail & (s->cluster_sectors - 1)))) {
if (!(is_zero_sectors(bs, cl_start,
DIV_ROUND_UP(head, BDRV_SECTOR_SIZE)) &&
is_zero_sectors(bs, (offset + count) >> BDRV_SECTOR_BITS,
DIV_ROUND_UP(-tail & (s->cluster_size - 1),
BDRV_SECTOR_SIZE)))) {
return -ENOTSUP;
}
qemu_co_mutex_lock(&s->lock);
/* We can have new write after previous check */
sector_num = cl_start;
nb_sectors = nr = s->cluster_sectors;
ret = qcow2_get_cluster_offset(bs, cl_start << BDRV_SECTOR_BITS,
&nr, &off);
offset = cl_start << BDRV_SECTOR_BITS;
count = s->cluster_size;
nr = s->cluster_sectors;
ret = qcow2_get_cluster_offset(bs, offset, &nr, &off);
if (ret != QCOW2_CLUSTER_UNALLOCATED && ret != QCOW2_CLUSTER_ZERO) {
qemu_co_mutex_unlock(&s->lock);
return -ENOTSUP;
@ -2461,10 +2462,10 @@ static coroutine_fn int qcow2_co_write_zeroes(BlockDriverState *bs,
qemu_co_mutex_lock(&s->lock);
}
trace_qcow2_write_zeroes(qemu_coroutine_self(), sector_num, nb_sectors);
trace_qcow2_pwrite_zeroes(qemu_coroutine_self(), offset, count);
/* Whatever is left can use real zero clusters */
ret = qcow2_zero_clusters(bs, sector_num << BDRV_SECTOR_BITS, nb_sectors);
ret = qcow2_zero_clusters(bs, offset, count >> BDRV_SECTOR_BITS);
qemu_co_mutex_unlock(&s->lock);
return ret;
@ -3371,7 +3372,7 @@ BlockDriver bdrv_qcow2 = {
.bdrv_co_writev = qcow2_co_writev,
.bdrv_co_flush_to_os = qcow2_co_flush_to_os,
.bdrv_co_write_zeroes = qcow2_co_write_zeroes,
.bdrv_co_pwrite_zeroes = qcow2_co_pwrite_zeroes,
.bdrv_co_discard = qcow2_co_discard,
.bdrv_truncate = qcow2_truncate,
.bdrv_write_compressed = qcow2_write_compressed,

4
trace-events
View File

@ -611,8 +611,8 @@ qcow2_writev_done_req(void *co, int ret) "co %p ret %d"
qcow2_writev_start_part(void *co) "co %p"
qcow2_writev_done_part(void *co, int cur_nr_sectors) "co %p cur_nr_sectors %d"
qcow2_writev_data(void *co, uint64_t offset) "co %p offset %" PRIx64
qcow2_write_zeroes_start_req(void *co, int64_t sector, int nb_sectors) "co %p sector %" PRIx64 " nb_sectors %d"
qcow2_write_zeroes(void *co, int64_t sector, int nb_sectors) "co %p sector %" PRIx64 " nb_sectors %d"
qcow2_pwrite_zeroes_start_req(void *co, int64_t offset, int count) "co %p offset %" PRIx64 " count %d"
qcow2_pwrite_zeroes(void *co, int64_t offset, int count) "co %p offset %" PRIx64 " count %d"
# block/qcow2-cluster.c
qcow2_alloc_clusters_offset(void *co, uint64_t offset, int num) "co %p offset %" PRIx64 " num %d"