@@ -17,9 +17,6 @@
#include "qemu/ratelimit.h"
#include "bitmap.h"
-#define BLOCK_SIZE (1 << 20)
-#define BDRV_SECTORS_PER_DIRTY_CHUNK (BLOCK_SIZE >> BDRV_SECTOR_BITS)
-
#define SLICE_TIME 100000000ULL /* ns */
typedef struct MirrorBlockJob {
@@ -31,6 +28,7 @@ typedef struct MirrorBlockJob {
bool synced;
bool complete;
int64_t sector_num;
+ int64_t granularity;
int64_t buf_size;
unsigned long *cow_bitmap;
HBitmapIter hbi;
@@ -43,7 +41,7 @@ static int coroutine_fn mirror_iteration(MirrorBlockJob *s,
BlockDriverState *source = s->common.bs;
BlockDriverState *target = s->target;
QEMUIOVector qiov;
- int ret, nb_sectors;
+ int ret, nb_sectors, nb_sectors_chunk;
int64_t end, sector_num, cluster_num;
struct iovec iov;
@@ -58,24 +56,24 @@ static int coroutine_fn mirror_iteration(MirrorBlockJob *s,
* is very large, we need to do COW ourselves. The first time a cluster is
* copied, copy it entirely.
*
- * Because both BDRV_SECTORS_PER_DIRTY_CHUNK and the cluster size are
- * powers of two, the number of sectors to copy cannot exceed one cluster.
+ * Because both the granularity and the cluster size are powers of two, the
+ * number of sectors to copy cannot exceed one cluster.
*/
sector_num = s->sector_num;
- nb_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
- cluster_num = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
+ nb_sectors_chunk = nb_sectors = s->granularity >> BDRV_SECTOR_BITS;
+ cluster_num = sector_num / nb_sectors_chunk;
if (s->cow_bitmap && !test_bit(cluster_num, s->cow_bitmap)) {
bdrv_round_to_clusters(s->target,
- sector_num, BDRV_SECTORS_PER_DIRTY_CHUNK,
+ sector_num, nb_sectors_chunk,
§or_num, &nb_sectors);
- bitmap_set(s->cow_bitmap, sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK,
- nb_sectors / BDRV_SECTORS_PER_DIRTY_CHUNK);
+ bitmap_set(s->cow_bitmap, sector_num / nb_sectors_chunk,
+ nb_sectors / nb_sectors_chunk);
}
end = s->common.len >> BDRV_SECTOR_BITS;
nb_sectors = MIN(nb_sectors, end - sector_num);
trace_mirror_one_iteration(s, sector_num);
- bdrv_reset_dirty(source, sector_num, BDRV_SECTORS_PER_DIRTY_CHUNK);
+ bdrv_reset_dirty(source, sector_num, nb_sectors);
/* Copy the dirty cluster. */
iov.iov_base = s->buf;
@@ -107,7 +105,7 @@ static void coroutine_fn mirror_run(void *opaque)
{
MirrorBlockJob *s = opaque;
BlockDriverState *bs = s->common.bs;
- int64_t sector_num, end;
+ int64_t sector_num, end, nb_sectors_chunk;
int ret = 0;
int n;
@@ -123,13 +121,14 @@ static void coroutine_fn mirror_run(void *opaque)
end = s->common.len >> BDRV_SECTOR_BITS;
s->buf = qemu_blockalign(bs, s->buf_size);
+ nb_sectors_chunk = s->granularity >> BDRV_SECTOR_BITS;
if (s->mode == MIRROR_SYNC_MODE_FULL || s->mode == MIRROR_SYNC_MODE_TOP) {
/* First part, loop on the sectors and initialize the dirty bitmap. */
BlockDriverState *base;
base = s->mode == MIRROR_SYNC_MODE_FULL ? NULL : bs->backing_hd;
for (sector_num = 0; sector_num < end; ) {
- int64_t next = (sector_num | (BDRV_SECTORS_PER_DIRTY_CHUNK - 1)) + 1;
+ int64_t next = (sector_num | (nb_sectors_chunk - 1)) + 1;
ret = bdrv_co_is_allocated_above(bs, base,
sector_num, next - sector_num, &n);
@@ -209,7 +208,7 @@ static void coroutine_fn mirror_run(void *opaque)
s->common.offset = (end - cnt) * BDRV_SECTOR_SIZE;
if (s->common.speed) {
- delay_ns = ratelimit_calculate_delay(&s->limit, BDRV_SECTORS_PER_DIRTY_CHUNK);
+ delay_ns = ratelimit_calculate_delay(&s->limit, nb_sectors_chunk);
} else {
delay_ns = 0;
}
@@ -301,7 +300,7 @@ static BlockJobType mirror_job_type = {
};
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
- int64_t speed, MirrorSyncMode mode,
+ int64_t speed, int64_t granularity, MirrorSyncMode mode,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
BlockDriverCompletionFunc *cb,
@@ -326,19 +325,20 @@ void mirror_start(BlockDriverState *bs, BlockDriverState *target,
* the destination do COW. Instead, we copy sectors around the
* dirty data if needed.
*/
- s->buf_size = BLOCK_SIZE;
+ s->granularity = granularity;
+ s->buf_size = granularity;
bdrv_get_backing_filename(s->target, backing_filename,
sizeof(backing_filename));
if (backing_filename[0] && !s->target->backing_hd) {
bdrv_get_info(s->target, &bdi);
if (s->buf_size < bdi.cluster_size) {
s->buf_size = bdi.cluster_size;
- length = (bdrv_getlength(bs) + BLOCK_SIZE - 1) / BLOCK_SIZE;
+ length = (bdrv_getlength(bs) + granularity - 1) / granularity;
s->cow_bitmap = bitmap_new(length);
}
}
- bdrv_set_dirty_tracking(bs, BDRV_SECTORS_PER_DIRTY_CHUNK);
+ bdrv_set_dirty_tracking(bs, granularity >> BDRV_SECTOR_BITS);
bdrv_set_on_error(s->target, on_target_error, on_target_error);
bdrv_iostatus_enable(s->target);
s->common.co = qemu_coroutine_create(mirror_run);
@@ -311,6 +311,7 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
* @bs: Block device to operate on.
* @target: Block device to write to.
* @speed: The maximum speed, in bytes per second, or 0 for unlimited.
+ * @granularity: The chosen granularity for the dirty bitmap.
* @mode: Whether to collapse all images in the chain to the target.
* @on_source_error: The action to take upon error reading from the source.
* @on_target_error: The action to take upon error writing to the target.
@@ -324,7 +325,7 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
* @bs will be switched to read from @target.
*/
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
- int64_t speed, MirrorSyncMode mode,
+ int64_t speed, int64_t granularity, MirrorSyncMode mode,
BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
BlockDriverCompletionFunc *cb,
@@ -836,6 +836,7 @@ void qmp_drive_mirror(const char *device, const char *target,
enum MirrorSyncMode sync,
bool has_mode, enum NewImageMode mode,
bool has_speed, int64_t speed,
+ bool has_granularity, int64_t granularity,
bool has_on_source_error, BlockdevOnError on_source_error,
bool has_on_target_error, BlockdevOnError on_target_error,
Error **errp)
@@ -858,6 +859,9 @@ void qmp_drive_mirror(const char *device, const char *target,
if (!has_mode) {
mode = NEW_IMAGE_MODE_ABSOLUTE_PATHS;
}
+ if (!has_granularity) {
+ granularity = 65536;
+ }
bs = bdrv_find(device);
if (!bs) {
@@ -936,7 +940,8 @@ void qmp_drive_mirror(const char *device, const char *target,
return;
}
- mirror_start(bs, target_bs, speed, sync, on_source_error, on_target_error,
+ mirror_start(bs, target_bs, speed, granularity, sync,
+ on_source_error, on_target_error,
block_job_cb, bs, &local_err);
if (local_err != NULL) {
bdrv_delete(target_bs);
@@ -717,7 +717,7 @@ void hmp_drive_mirror(Monitor *mon, const QDict *qdict)
qmp_drive_mirror(device, filename, !!format, format,
full ? MIRROR_SYNC_MODE_FULL : MIRROR_SYNC_MODE_TOP,
- true, mode, false, 0,
+ true, mode, false, 0, false, 0,
false, 0, false, 0, &errp);
hmp_handle_error(mon, &errp);
}
@@ -1383,6 +1383,8 @@
# (all the disk, only the sectors allocated in the topmost image, or
# only new I/O).
#
+# @granularity: #optional granularity of the dirty bitmap, default is 64K.
+#
# @on_source_error: #optional the action to take on an error on the source
#
# @on_target_error: #optional the action to take on an error on the target
@@ -1397,7 +1399,8 @@
{ 'command': 'drive-mirror',
'data': { 'device': 'str', 'target': 'str', '*format': 'str',
'sync': 'MirrorSyncMode', '*mode': 'NewImageMode',
- '*speed': 'int', '*on_source_error': 'BlockdevOnError',
+ '*speed': 'int', '*granularity': 'int',
+ '*on_source_error': 'BlockdevOnError',
'*on_target_error': 'BlockdevOnError' } }
##
@@ -839,7 +839,8 @@ EQMP
{
.name = "drive-mirror",
.args_type = "sync:s,device:B,target:s,sync:s?,format:s?,"
- "on_source_error:s?,on_target_error:s?",
+ "on_source_error:s?,on_target_error:s?,"
+ "granularity:i?",
.mhandler.cmd_new = qmp_marshal_input_drive_mirror,
},
@@ -862,6 +863,7 @@ Arguments:
file/device (NewImageMode, optional, default 'absolute-paths')
- "speed": maximum speed of the streaming job, in bytes per second
(json-int)
+- "granularity": granularity of the dirty bitmap (json-int, default 64k)
- "sync": what parts of the disk image should be copied to the destination;
possibilities include "full" for all the disk, "top" for only the sectors
allocated in the topmost image, or "none" to only replicate new I/O
The desired granularity may be very different depending on the kind of operation (e.g. continous replication vs. collapse-to-raw) and whether the VM is expected to perform lots of I/O while mirroring is in progress. Allow the user to customize it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- block/mirror.c | 38 +++++++++++++++++++------------------- block_int.h | 3 ++- blockdev.c | 7 ++++++- hmp.c | 2 +- qapi-schema.json | 5 ++++- qmp-commands.hx | 4 +++- 6 files changed, 35 insertions(+), 24 deletions(-)