From: Lidong Chen <lidongchen@tencent.com>
BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default,
this maybe cause the qcow2 file size is bigger after migration.
This patch check each cluster, use blk_pwrite_zeroes for each
zero cluster.
Signed-off-by: Lidong Chen <lidongchen@tencent.com>
---
migration/block.c | 34 ++++++++++++++++++++++++++++++++--
1 file changed, 32 insertions(+), 2 deletions(-)
diff --git a/migration/block.c b/migration/block.c
index 7734ff7..1fce9b9 100644
--- a/migration/block.c
+++ b/migration/block.c
@@ -885,6 +885,10 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
int64_t total_sectors = 0;
int nr_sectors;
int ret;
+ int i;
+ int cluster_size;
+ int64_t addr_offset;
+ uint8_t *buf_offset;
do {
addr = qemu_get_be64(f);
@@ -934,8 +938,34 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
} else {
buf = g_malloc(BLOCK_SIZE);
qemu_get_buffer(f, buf, BLOCK_SIZE);
- ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
- nr_sectors * BDRV_SECTOR_SIZE, 0);
+
+ cluster_size = bdrv_get_cluster_size(blk_bs(blk));
+
+ if (cluster_size > 0) {
+ for (i = 0; i < BLOCK_SIZE / cluster_size; i++) {
+ addr_offset = addr * BDRV_SECTOR_SIZE
+ + i * cluster_size;
+ buf_offset = buf + i * cluster_size;
+
+ if (buffer_is_zero(buf_offset, cluster_size)) {
+ ret = blk_pwrite_zeroes(blk, addr_offset,
+ cluster_size,
+ BDRV_REQ_MAY_UNMAP);
+ } else {
+ ret = blk_pwrite(blk, addr_offset,
+ buf_offset, cluster_size, 0);
+ }
+
+ if (ret < 0) {
+ g_free(buf);
+ return ret;
+ }
+ }
+ } else {
+ ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
+ nr_sectors * BDRV_SECTOR_SIZE, 0);
+ }
+
g_free(buf);
}
--
1.8.3.1
On Thu, 04/06 21:15, jemmy858585@gmail.com wrote:
> From: Lidong Chen <lidongchen@tencent.com>
>
> BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default,
> this maybe cause the qcow2 file size is bigger after migration.
> This patch check each cluster, use blk_pwrite_zeroes for each
> zero cluster.
>
> Signed-off-by: Lidong Chen <lidongchen@tencent.com>
> ---
> migration/block.c | 34 ++++++++++++++++++++++++++++++++--
> 1 file changed, 32 insertions(+), 2 deletions(-)
>
> diff --git a/migration/block.c b/migration/block.c
> index 7734ff7..1fce9b9 100644
> --- a/migration/block.c
> +++ b/migration/block.c
> @@ -885,6 +885,10 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
> int64_t total_sectors = 0;
> int nr_sectors;
> int ret;
> + int i;
> + int cluster_size;
> + int64_t addr_offset;
> + uint8_t *buf_offset;
>
> do {
> addr = qemu_get_be64(f);
> @@ -934,8 +938,34 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
> } else {
> buf = g_malloc(BLOCK_SIZE);
> qemu_get_buffer(f, buf, BLOCK_SIZE);
> - ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
> - nr_sectors * BDRV_SECTOR_SIZE, 0);
> +
> + cluster_size = bdrv_get_cluster_size(blk_bs(blk));
> +
> + if (cluster_size > 0) {
> + for (i = 0; i < BLOCK_SIZE / cluster_size; i++) {
Should we check that cluster_size < BLOCK_SIZE and (BLOCK_SIZE % cluster_size ==
0)?
Fam
> + addr_offset = addr * BDRV_SECTOR_SIZE
> + + i * cluster_size;
> + buf_offset = buf + i * cluster_size;
> +
> + if (buffer_is_zero(buf_offset, cluster_size)) {
> + ret = blk_pwrite_zeroes(blk, addr_offset,
> + cluster_size,
> + BDRV_REQ_MAY_UNMAP);
> + } else {
> + ret = blk_pwrite(blk, addr_offset,
> + buf_offset, cluster_size, 0);
> + }
> +
> + if (ret < 0) {
> + g_free(buf);
> + return ret;
> + }
> + }
> + } else {
> + ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
> + nr_sectors * BDRV_SECTOR_SIZE, 0);
> + }
> +
> g_free(buf);
> }
>
> --
> 1.8.3.1
>
On Fri, Apr 7, 2017 at 3:08 PM, Fam Zheng <famz@redhat.com> wrote:
> On Thu, 04/06 21:15, jemmy858585@gmail.com wrote:
>> From: Lidong Chen <lidongchen@tencent.com>
>>
>> BLOCK_SIZE is (1 << 20), qcow2 cluster size is 65536 by default,
>> this maybe cause the qcow2 file size is bigger after migration.
>> This patch check each cluster, use blk_pwrite_zeroes for each
>> zero cluster.
>>
>> Signed-off-by: Lidong Chen <lidongchen@tencent.com>
>> ---
>> migration/block.c | 34 ++++++++++++++++++++++++++++++++--
>> 1 file changed, 32 insertions(+), 2 deletions(-)
>>
>> diff --git a/migration/block.c b/migration/block.c
>> index 7734ff7..1fce9b9 100644
>> --- a/migration/block.c
>> +++ b/migration/block.c
>> @@ -885,6 +885,10 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
>> int64_t total_sectors = 0;
>> int nr_sectors;
>> int ret;
>> + int i;
>> + int cluster_size;
>> + int64_t addr_offset;
>> + uint8_t *buf_offset;
>>
>> do {
>> addr = qemu_get_be64(f);
>> @@ -934,8 +938,34 @@ static int block_load(QEMUFile *f, void *opaque, int version_id)
>> } else {
>> buf = g_malloc(BLOCK_SIZE);
>> qemu_get_buffer(f, buf, BLOCK_SIZE);
>> - ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
>> - nr_sectors * BDRV_SECTOR_SIZE, 0);
>> +
>> + cluster_size = bdrv_get_cluster_size(blk_bs(blk));
>> +
>> + if (cluster_size > 0) {
>> + for (i = 0; i < BLOCK_SIZE / cluster_size; i++) {
>
> Should we check that cluster_size < BLOCK_SIZE and (BLOCK_SIZE % cluster_size ==
> 0)?
I think this is necessary.
Thanks.
>
> Fam
>
>> + addr_offset = addr * BDRV_SECTOR_SIZE
>> + + i * cluster_size;
>> + buf_offset = buf + i * cluster_size;
>> +
>> + if (buffer_is_zero(buf_offset, cluster_size)) {
>> + ret = blk_pwrite_zeroes(blk, addr_offset,
>> + cluster_size,
>> + BDRV_REQ_MAY_UNMAP);
>> + } else {
>> + ret = blk_pwrite(blk, addr_offset,
>> + buf_offset, cluster_size, 0);
>> + }
>> +
>> + if (ret < 0) {
>> + g_free(buf);
>> + return ret;
>> + }
>> + }
>> + } else {
>> + ret = blk_pwrite(blk, addr * BDRV_SECTOR_SIZE, buf,
>> + nr_sectors * BDRV_SECTOR_SIZE, 0);
>> + }
>> +
>> g_free(buf);
>> }
>>
>> --
>> 1.8.3.1
>>
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