Unfortunately, this conversion required an additional change.
In the old QMP command, the 'snapshot-file' argument is specified as
optional. The idea is to take the snapshot internally if 'snapshot-file'
is not passed. However, internal snapshots are not supported yet so
the command returns a MissingParamater error if 'snapshot-file' is not
passed. Which makes the argument actually required and will cause
compatibility breakage if we change that in the future.
To fix this the QAPI converted blockdev_snapshot_sync command makes the
'snapshot-file' argument required. Again, in practice it's actually required,
so this is not incompatible.
If we do implement internal snapshots someday, we'll need a new argument
for it.
Note that this discussion doesn't affect HMP.
Signed-off-by: Luiz Capitulino <lcapitul...@redhat.com>
---
blockdev.c | 49 +++++++++++++++++--------------------------------
blockdev.h | 2 --
hmp-commands.hx | 2 +-
hmp.c | 19 +++++++++++++++++++
hmp.h | 1 +
qapi-schema.json | 29 +++++++++++++++++++++++++++++
qmp-commands.hx | 6 ++----
7 files changed, 69 insertions(+), 39 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index 5270404..c832782 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -601,28 +601,20 @@ void do_commit(Monitor *mon, const QDict *qdict)
}
}
-int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
+void qmp_blockdev_snapshot_sync(const char *device, const char *snapshot_file,
+ bool has_format, const char *format,
+ Error **errp)
{
- const char *device = qdict_get_str(qdict, "device");
- const char *filename = qdict_get_try_str(qdict, "snapshot-file");
- const char *format = qdict_get_try_str(qdict, "format");
BlockDriverState *bs;
BlockDriver *drv, *old_drv, *proto_drv;
int ret = 0;
int flags;
char old_filename[1024];
- if (!filename) {
- qerror_report(QERR_MISSING_PARAMETER, "snapshot-file");
- ret = -1;
- goto out;
- }
-
bs = bdrv_find(device);
if (!bs) {
- qerror_report(QERR_DEVICE_NOT_FOUND, device);
- ret = -1;
- goto out;
+ error_set(errp, QERR_DEVICE_NOT_FOUND, device);
+ return;
}
pstrcpy(old_filename, sizeof(old_filename), bs->filename);
@@ -630,35 +622,34 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict,
QObject **ret_data)
old_drv = bs->drv;
flags = bs->open_flags;
- if (!format) {
+ if (!has_format) {
format = "qcow2";
}
drv = bdrv_find_format(format);
if (!drv) {
- qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
- ret = -1;
- goto out;
+ error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
+ return;
}
- proto_drv = bdrv_find_protocol(filename);
+ proto_drv = bdrv_find_protocol(snapshot_file);
if (!proto_drv) {
- qerror_report(QERR_INVALID_BLOCK_FORMAT, format);
- ret = -1;
- goto out;
+ error_set(errp, QERR_INVALID_BLOCK_FORMAT, format);
+ return;
}
- ret = bdrv_img_create(filename, format, bs->filename,
+ ret = bdrv_img_create(snapshot_file, format, bs->filename,
bs->drv->format_name, NULL, -1, flags);
if (ret) {
- goto out;
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
}
bdrv_drain_all();
bdrv_flush(bs);
bdrv_close(bs);
- ret = bdrv_open(bs, filename, flags, drv);
+ ret = bdrv_open(bs, snapshot_file, flags, drv);
/*
* If reopening the image file we just created fails, fall back
* and try to re-open the original image. If that fails too, we
@@ -667,17 +658,11 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict,
QObject **ret_data)
if (ret != 0) {
ret = bdrv_open(bs, old_filename, flags, old_drv);
if (ret != 0) {
- qerror_report(QERR_OPEN_FILE_FAILED, old_filename);
+ error_set(errp, QERR_OPEN_FILE_FAILED, old_filename);
} else {
- qerror_report(QERR_OPEN_FILE_FAILED, filename);
+ error_set(errp, QERR_OPEN_FILE_FAILED, snapshot_file);
}
}
-out:
- if (ret) {
- ret = -1;
- }
-
- return ret;
}
static int eject_device(Monitor *mon, BlockDriverState *bs, int force)
diff --git a/blockdev.h b/blockdev.h
index b69a549..f1b6396 100644
--- a/blockdev.h
+++ b/blockdev.h
@@ -64,6 +64,4 @@ int do_change_block(Monitor *mon, const char *device,
int do_drive_del(Monitor *mon, const QDict *qdict, QObject **ret_data);
int do_block_set_io_throttle(Monitor *mon,
const QDict *qdict, QObject **ret_data);
-int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data);
-
#endif
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 734a364..131b21c 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -840,7 +840,7 @@ ETEXI
"If format is specified, the snapshot file will\n\t\t\t"
"be created in that format. Otherwise the\n\t\t\t"
"snapshot will be internal! (currently unsupported)",
- .mhandler.cmd_new = do_snapshot_blkdev,
+ .mhandler.cmd = hmp_snapshot_blkdev,
},
STEXI
diff --git a/hmp.c b/hmp.c
index db199b2..934e931 100644
--- a/hmp.c
+++ b/hmp.c
@@ -643,3 +643,22 @@ void hmp_block_resize(Monitor *mon, const QDict *qdict)
qmp_block_resize(device, size, &errp);
hmp_handle_error(mon, &errp);
}
+
+void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict)
+{
+ const char *device = qdict_get_str(qdict, "device");
+ const char *filename = qdict_get_try_str(qdict, "snapshot-file");
+ const char *format = qdict_get_try_str(qdict, "format");
+ Error *errp = NULL;
+
+ if (!filename) {
+ /* In the future, if 'snapshot-file' is not specified, the snapshot
+ will be taken internally. Today it's actually required. */
+ error_set(&errp, QERR_MISSING_PARAMETER, "snapshot-file");
+ hmp_handle_error(mon, &errp);
+ return;
+ }
+
+ qmp_blockdev_snapshot_sync(device, filename, !!format, format, &errp);
+ hmp_handle_error(mon, &errp);
+}
diff --git a/hmp.h b/hmp.h
index c236fd2..e4227d3 100644
--- a/hmp.h
+++ b/hmp.h
@@ -45,5 +45,6 @@ void hmp_set_link(Monitor *mon, const QDict *qdict);
void hmp_block_passwd(Monitor *mon, const QDict *qdict);
void hmp_balloon(Monitor *mon, const QDict *qdict);
void hmp_block_resize(Monitor *mon, const QDict *qdict);
+void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict);
#endif
diff --git a/qapi-schema.json b/qapi-schema.json
index f33fe00..0ed39f3 100644
--- a/qapi-schema.json
+++ b/qapi-schema.json
@@ -1070,3 +1070,32 @@
# Since: 0.14.0
##
{ 'command': 'block_resize', 'data': { 'device': 'str', 'size': 'int' }}
+
+##
+# @blockdev-snapshot-sync
+#
+# Generates a synchronous snapshot of a block device.
+#
+# @device: the name of the device to generate the snapshot from.
+#
+# @snapshot-file: the target of the new image. If the file exists, or if it
+# is a device, the snapshot will be created in the existing
+# file/device. If does not exist, a new file will be created.
+#
+# @format: #optional the format of the snapshot image, default is 'qcow2'.
+#
+# Returns: nothing on success
+# If @device is not a valid block device, DeviceNotFound
+# If @snapshot-file can't be opened, OpenFileFailed
+# If @format is invalid, InvalidBlockFormat
+#
+# Notes: One of the last steps taken by this command is to close the current
+# image being used by @device and open the @snapshot-file one. If that
+# fails, the command will try to reopen the original image file. If
+# that also fails OpenFileFailed will be returned and the guest may get
+# unexpected errors.
+#
+# Since 0.14.0
+##
+{ 'command': 'blockdev-snapshot-sync',
+ 'data': { 'device': 'str', 'snapshot-file': 'str', '*format': 'str' } }
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 721b157..9d68206 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -665,10 +665,8 @@ EQMP
{
.name = "blockdev-snapshot-sync",
- .args_type = "device:B,snapshot-file:s?,format:s?",
- .params = "device [new-image-file] [format]",
- .user_print = monitor_user_noop,
- .mhandler.cmd_new = do_snapshot_blkdev,
+ .args_type = "device:B,snapshot-file:s,format:s?",
+ .mhandler.cmd_new = qmp_marshal_input_blockdev_snapshot_sync,
},
SQMP
--
1.7.8.dirty
