Adding a parameter to QMP block-stream command to allow discarding
blocks in the backing chain while blocks are being copied to the
active layer.
Signed-off-by: Andrey Shinkevich <andrey.shinkev...@virtuozzo.com>
---
block/copy-on-read.c | 24 ++++++++++++++++++++++++
block/stream.c | 3 +--
blockdev.c | 8 +++++++-
hmp-commands.hx | 4 ++--
hmp.c | 4 +++-
include/block/block_int.h | 2 +-
qapi/block-core.json | 5 ++++-
7 files changed, 42 insertions(+), 8 deletions(-)
diff --git a/block/copy-on-read.c b/block/copy-on-read.c
index 64dcc42..bf7580e 100644
--- a/block/copy-on-read.c
+++ b/block/copy-on-read.c
@@ -22,11 +22,22 @@
#include "qemu/osdep.h"
#include "block/block_int.h"
+#include "qapi/qmp/qdict.h"
+
+typedef struct BDRVCORState {
+ bool discard;
+} BDRVCORState;
static int cor_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
+ if (qdict_haskey(options, "driver.discard")) {
+ BDRVCORState *s = bs->opaque;
+ s->discard = qdict_get_bool(options, "driver.discard");
+ qdict_del(options, "driver.discard");
+ }
+
bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false,
errp);
if (!bs->file) {
@@ -66,6 +77,11 @@ static void cor_child_perm(BlockDriverState *bs, BdrvChild
*c,
(c->perm & PERM_UNCHANGED);
*nshared = (shared & PERM_PASSTHROUGH) |
(c->shared_perm & PERM_UNCHANGED);
+
+ BDRVCORState *s = bs->opaque;
+ if (s->discard) {
+ *nshared |= BLK_PERM_WRITE;
+ }
}
@@ -134,8 +150,15 @@ static bool
cor_recurse_is_first_non_filter(BlockDriverState *bs,
}
+static int cor_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
+{
+ return bdrv_get_info(bs->file->bs, bdi);
+}
+
+
BlockDriver bdrv_copy_on_read = {
.format_name = "copy-on-read",
+ .instance_size = sizeof(BDRVCORState),
.bdrv_open = cor_open,
.bdrv_child_perm = cor_child_perm,
@@ -148,6 +171,7 @@ BlockDriver bdrv_copy_on_read = {
.bdrv_co_pwrite_zeroes = cor_co_pwrite_zeroes,
.bdrv_co_pdiscard = cor_co_pdiscard,
+ .bdrv_get_info = cor_get_info,
.bdrv_eject = cor_eject,
.bdrv_lock_medium = cor_lock_medium,
diff --git a/block/stream.c b/block/stream.c
index af2eebf..b160eee 100644
--- a/block/stream.c
+++ b/block/stream.c
@@ -465,13 +465,12 @@ static const BlockJobDriver stream_job_driver = {
void stream_start(const char *job_id, BlockDriverState *bs,
BlockDriverState *base, const char *backing_file_str,
- int creation_flags, int64_t speed,
+ int creation_flags, int64_t speed, bool discard,
BlockdevOnError on_error, Error **errp)
{
StreamBlockJob *s;
BlockDriverState *iter;
bool bs_read_only;
- const bool discard = false;
int node_shared_flags = BLK_PERM_CONSISTENT_READ |
BLK_PERM_WRITE_UNCHANGED;
int ret;
diff --git a/blockdev.c b/blockdev.c
index a6f71f9..6a53cb7 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -3138,6 +3138,7 @@ void qmp_block_stream(bool has_job_id, const char
*job_id, const char *device,
bool has_base_node, const char *base_node,
bool has_backing_file, const char *backing_file,
bool has_speed, int64_t speed,
+ bool has_discard, bool discard,
bool has_on_error, BlockdevOnError on_error,
bool has_auto_finalize, bool auto_finalize,
bool has_auto_dismiss, bool auto_dismiss,
@@ -3154,6 +3155,10 @@ void qmp_block_stream(bool has_job_id, const char
*job_id, const char *device,
on_error = BLOCKDEV_ON_ERROR_REPORT;
}
+ if (!has_discard) {
+ discard = false;
+ }
+
bs = bdrv_lookup_bs(device, device, errp);
if (!bs) {
return;
@@ -3218,7 +3223,8 @@ void qmp_block_stream(bool has_job_id, const char
*job_id, const char *device,
}
stream_start(has_job_id ? job_id : NULL, bs, base_bs, base_name,
- job_flags, has_speed ? speed : 0, on_error, &local_err);
+ job_flags, has_speed ? speed : 0,
+ discard, on_error, &local_err);
if (local_err) {
error_propagate(errp, local_err);
goto out;
diff --git a/hmp-commands.hx b/hmp-commands.hx
index ba71558..12806db 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -95,8 +95,8 @@ ETEXI
{
.name = "block_stream",
- .args_type = "device:B,speed:o?,base:s?",
- .params = "device [speed [base]]",
+ .args_type = "device:B,speed:o?,base:s?,discard:-d",
+ .params = "device [speed [base]] [-d]",
.help = "copy data from a backing file into a block device",
.cmd = hmp_block_stream,
},
diff --git a/hmp.c b/hmp.c
index 80aa5ab..353a164 100644
--- a/hmp.c
+++ b/hmp.c
@@ -1923,9 +1923,11 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict)
const char *device = qdict_get_str(qdict, "device");
const char *base = qdict_get_try_str(qdict, "base");
int64_t speed = qdict_get_try_int(qdict, "speed", 0);
+ bool discard = qdict_get_try_bool(qdict, "discard", false);
qmp_block_stream(true, device, device, base != NULL, base, false, NULL,
- false, NULL, qdict_haskey(qdict, "speed"), speed, true,
+ false, NULL, qdict_haskey(qdict, "speed"), speed,
+ true, discard, true,
BLOCKDEV_ON_ERROR_REPORT, false, false, false, false,
&error);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index f605622..2660336 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -970,7 +970,7 @@ int is_windows_drive(const char *filename);
*/
void stream_start(const char *job_id, BlockDriverState *bs,
BlockDriverState *base, const char *backing_file_str,
- int creation_flags, int64_t speed,
+ int creation_flags, int64_t speed, bool discard,
BlockdevOnError on_error, Error **errp);
/**
diff --git a/qapi/block-core.json b/qapi/block-core.json
index 762000f..5005c57 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -2337,6 +2337,9 @@
#
# @speed: the maximum speed, in bytes per second
#
+# @discard: true to delete blocks duplicated in old backing files.
+# (default: false). Since 4.0.
+#
# @on-error: the action to take on an error (default report).
# 'stop' and 'enospc' can only be used if the block device
# supports io-status (see BlockInfo). Since 1.3.
@@ -2369,7 +2372,7 @@
{ 'command': 'block-stream',
'data': { '*job-id': 'str', 'device': 'str', '*base': 'str',
'*base-node': 'str', '*backing-file': 'str', '*speed': 'int',
- '*on-error': 'BlockdevOnError',
+ '*discard': 'bool', '*on-error': 'BlockdevOnError',
'*auto-finalize': 'bool', '*auto-dismiss': 'bool' } }
##
--
1.8.3.1
