This makes sense when the next commit starts using the extra buffer space
to perform many I/O operations asynchronously.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
block/mirror.c | 6 +++---
block_int.h | 5 +++--
blockdev.c | 9 ++++++++-
hmp.c | 2 +-
qapi-schema.json | 5 ++++-
qmp-commands.hx | 4 +++-
tests/qemu-iotests/041 | 31 +++++++++++++++++++++++++++++++
7 files changed, 53 insertions(+), 9 deletions(-)
diff --git a/block/mirror.c b/block/mirror.c
index f02ffb3..ed56b86 100644
--- a/block/mirror.c
+++ b/block/mirror.c
@@ -408,8 +408,8 @@ static BlockJobType mirror_job_type = {
};
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
- int64_t speed, int64_t granularity, MirrorSyncMode mode,
- BlockdevOnError on_source_error,
+ int64_t speed, int64_t granularity, int64_t buf_size,
+ MirrorSyncMode mode, BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
BlockDriverCompletionFunc *cb,
void *opaque, Error **errp)
@@ -447,7 +447,7 @@ void mirror_start(BlockDriverState *bs, BlockDriverState
*target,
s->target = target;
s->mode = mode;
s->granularity = granularity;
- s->buf_size = granularity;
+ s->buf_size = MAX(buf_size, granularity);
bdrv_set_dirty_tracking(bs, granularity);
bdrv_set_enable_write_cache(s->target, true);
diff --git a/block_int.h b/block_int.h
index 8d038c8..8f54b41 100644
--- a/block_int.h
+++ b/block_int.h
@@ -339,6 +339,7 @@ void commit_start(BlockDriverState *bs, BlockDriverState
*base,
* @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.
+ * @buf_size: The amount of data that can be in flight at one time.
* @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.
@@ -352,8 +353,8 @@ void commit_start(BlockDriverState *bs, BlockDriverState
*base,
* @bs will be switched to read from @target.
*/
void mirror_start(BlockDriverState *bs, BlockDriverState *target,
- int64_t speed, int64_t granularity, MirrorSyncMode mode,
- BlockdevOnError on_source_error,
+ int64_t speed, int64_t granularity, int64_t buf_size,
+ MirrorSyncMode mode, BlockdevOnError on_source_error,
BlockdevOnError on_target_error,
BlockDriverCompletionFunc *cb,
void *opaque, Error **errp);
diff --git a/blockdev.c b/blockdev.c
index d554c03..dff6c3d 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1187,12 +1187,15 @@ void qmp_block_commit(const char *device,
drive_get_ref(drive_get_by_blockdev(bs));
}
+#define DEFAULT_MIRROR_BUF_SIZE (10 << 20)
+
void qmp_drive_mirror(const char *device, const char *target,
bool has_format, const char *format,
enum MirrorSyncMode sync,
bool has_mode, enum NewImageMode mode,
bool has_speed, int64_t speed,
bool has_granularity, uint32_t granularity,
+ bool has_buf_size, int64_t buf_size,
bool has_on_source_error, BlockdevOnError
on_source_error,
bool has_on_target_error, BlockdevOnError
on_target_error,
Error **errp)
@@ -1221,6 +1224,10 @@ void qmp_drive_mirror(const char *device, const char
*target,
if (!has_granularity) {
granularity = 0;
}
+ if (!has_buf_size) {
+ buf_size = DEFAULT_MIRROR_BUF_SIZE;
+ }
+
if (granularity != 0 && (granularity < 512 || granularity > 1048576 * 64))
{
error_set(errp, QERR_INVALID_PARAMETER, device);
return;
@@ -1310,7 +1317,7 @@ void qmp_drive_mirror(const char *device, const char
*target,
return;
}
- mirror_start(bs, target_bs, speed, granularity, sync,
+ mirror_start(bs, target_bs, speed, granularity, buf_size, sync,
on_source_error, on_target_error,
block_job_cb, bs, &local_err);
if (local_err != NULL) {
diff --git a/hmp.c b/hmp.c
index e6d2930..428c563 100644
--- a/hmp.c
+++ b/hmp.c
@@ -795,7 +795,7 @@ 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, false, 0,
+ true, mode, false, 0, false, 0, false, 0,
false, 0, false, 0, &errp);
hmp_handle_error(mon, &errp);
}
diff --git a/qapi-schema.json b/qapi-schema.json
index 465984e..fb38106 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1641,6 +1641,9 @@
# are smaller than that, else the cluster size. Must be a
# power of 2 between 512 and 64M.
#
+# @buf-size: #optional maximum amount of data in flight from source to
+# target.
+#
# @on-source-error: #optional the action to take on an error on the source,
# default 'report'. 'stop' and 'enospc' can only be used
# if the block device supports io-status (see BlockInfo).
@@ -1658,7 +1661,7 @@
'data': { 'device': 'str', 'target': 'str', '*format': 'str',
'sync': 'MirrorSyncMode', '*mode': 'NewImageMode',
'*speed': 'int', '*granularity': 'uint32',
- '*on-source-error': 'BlockdevOnError',
+ '*buf-size': 'int', '*on-source-error': 'BlockdevOnError',
'*on-target-error': 'BlockdevOnError' } }
##
diff --git a/qmp-commands.hx b/qmp-commands.hx
index d8faad0..97c52c9 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -939,7 +939,7 @@ EQMP
.name = "drive-mirror",
.args_type = "sync:s,device:B,target:s,speed:i?,mode:s?,format:s?,"
"on-source-error:s?,on-target-error:s?,"
- "granularity:i?",
+ "buf-size:i?,granularity:i?",
.mhandler.cmd_new = qmp_marshal_input_drive_mirror,
},
@@ -964,6 +964,8 @@ Arguments:
- "speed": maximum speed of the streaming job, in bytes per second
(json-int)
- "granularity": granularity of the dirty bitmap (json-int, optional)
+- "buf_size": maximum amount of data in flight from source to target
+ (json-int, default 10M)
- "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
diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041
index d0e9a7f..05ff0f8 100755
--- a/tests/qemu-iotests/041
+++ b/tests/qemu-iotests/041
@@ -207,6 +207,37 @@ class TestSingleDrive(ImageMirroringTestCase):
self.assertTrue(self.compare_images(test_img, target_img),
'target image does not match source after mirroring')
+ def test_small_buffer(self):
+ self.assert_no_active_mirrors()
+
+ # A small buffer is rounded up automatically
+ result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
+ buf_size=4096, target=target_img)
+ self.assert_qmp(result, 'return', {})
+
+ self.complete_and_wait()
+ result = self.vm.qmp('query-block')
+ self.assert_qmp(result, 'return[0]/inserted/file', target_img)
+ self.vm.shutdown()
+ self.assertTrue(self.compare_images(test_img, target_img),
+ 'target image does not match source after mirroring')
+
+ def test_small_buffer2(self):
+ self.assert_no_active_mirrors()
+
+ qemu_img('create', '-f', iotests.imgfmt, '-o',
'cluster_size=%d,size=%d'
+ % (TestSingleDrive.image_len,
TestSingleDrive.image_len), target_img)
+ result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
+ buf_size=65536, mode='existing',
target=target_img)
+ self.assert_qmp(result, 'return', {})
+
+ self.complete_and_wait()
+ result = self.vm.qmp('query-block')
+ self.assert_qmp(result, 'return[0]/inserted/file', target_img)
+ self.vm.shutdown()
+ self.assertTrue(self.compare_images(test_img, target_img),
+ 'target image does not match source after mirroring')
+
def test_large_cluster(self):
self.assert_no_active_mirrors()
--
1.8.0.1
