| Message ID | 1374054136-28741-12-git-send-email-famz@redhat.com |
|---|---|
| State | New |
| Headers | show |
On 07/17/2013 03:42 AM, Fam Zheng wrote: > Similar to drive-backup, but this command uses a device id as target > instead of creating/opening an image file. > > Signed-off-by: Fam Zheng <famz@redhat.com> > --- > blockdev.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++ > qmp-commands.hx | 22 ++++++++++++++++++ > 3 files changed, 142 insertions(+) > > +++ b/qapi-schema.json > @@ -1665,6 +1665,40 @@ > '*on-target-error': 'BlockdevOnError' } } > > ## > +# @BlockdevBackup > +# > +{ 'type': 'BlockdevBackup', > + 'data': { 'device': 'str', 'target': 'str', > + 'sync': 'MirrorSyncMode', > + '*speed': 'int', > + '*on-source-error': 'BlockdevOnError', > + '*on-target-error': 'BlockdevOnError' } } Seems okay. But what is missing is the addition of this type into the union used for 'transaction' - shouldn't it be possible to mix this with other transaction capabilities?
On Wed, 07/17 06:44, Eric Blake wrote: > On 07/17/2013 03:42 AM, Fam Zheng wrote: > > Similar to drive-backup, but this command uses a device id as target > > instead of creating/opening an image file. > > > > Signed-off-by: Fam Zheng <famz@redhat.com> > > --- > > blockdev.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++ > > qmp-commands.hx | 22 ++++++++++++++++++ > > 3 files changed, 142 insertions(+) > > > > > +++ b/qapi-schema.json > > @@ -1665,6 +1665,40 @@ > > '*on-target-error': 'BlockdevOnError' } } > > > > ## > > +# @BlockdevBackup > > +# > > > +{ 'type': 'BlockdevBackup', > > + 'data': { 'device': 'str', 'target': 'str', > > + 'sync': 'MirrorSyncMode', > > + '*speed': 'int', > > + '*on-source-error': 'BlockdevOnError', > > + '*on-target-error': 'BlockdevOnError' } } > > Seems okay. But what is missing is the addition of this type into the > union used for 'transaction' - shouldn't it be possible to mix this with > other transaction capabilities? > Should be possible, as users may want point-in-time snapshot of multiple disks. If this API looks OK, I will include it into transaction in the next version.
于 2013-7-18 12:41, Fam Zheng 写道: > On Wed, 07/17 06:44, Eric Blake wrote: >> On 07/17/2013 03:42 AM, Fam Zheng wrote: >>> Similar to drive-backup, but this command uses a device id as target >>> instead of creating/opening an image file. >>> >>> Signed-off-by: Fam Zheng <famz@redhat.com> >>> --- >>> blockdev.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ >>> qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++ >>> qmp-commands.hx | 22 ++++++++++++++++++ >>> 3 files changed, 142 insertions(+) >>> >> >>> +++ b/qapi-schema.json >>> @@ -1665,6 +1665,40 @@ >>> '*on-target-error': 'BlockdevOnError' } } >>> >>> ## >>> +# @BlockdevBackup >>> +# >> >>> +{ 'type': 'BlockdevBackup', >>> + 'data': { 'device': 'str', 'target': 'str', >>> + 'sync': 'MirrorSyncMode', >>> + '*speed': 'int', >>> + '*on-source-error': 'BlockdevOnError', >>> + '*on-target-error': 'BlockdevOnError' } } >> >> Seems okay. But what is missing is the addition of this type into the >> union used for 'transaction' - shouldn't it be possible to mix this with >> other transaction capabilities? >> > > Should be possible, as users may want point-in-time snapshot of multiple > disks. If this API looks OK, I will include it into transaction in the > next version. > Instead of add this new API, how about extend Driver-backup API? This patch is basically doing similar things with driver-backup, extension of old API will save trouble to do same things driver-backup already does, such as support qmp_transaction.
On Fri, Jul 19, 2013 at 06:16:55PM +0800, Wenchao Xia wrote: > 于 2013-7-18 12:41, Fam Zheng 写道: > >On Wed, 07/17 06:44, Eric Blake wrote: > >>On 07/17/2013 03:42 AM, Fam Zheng wrote: > >>>Similar to drive-backup, but this command uses a device id as target > >>>instead of creating/opening an image file. > >>> > >>>Signed-off-by: Fam Zheng <famz@redhat.com> > >>>--- > >>> blockdev.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >>> qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++ > >>> qmp-commands.hx | 22 ++++++++++++++++++ > >>> 3 files changed, 142 insertions(+) > >>> > >> > >>>+++ b/qapi-schema.json > >>>@@ -1665,6 +1665,40 @@ > >>> '*on-target-error': 'BlockdevOnError' } } > >>> > >>> ## > >>>+# @BlockdevBackup > >>>+# > >> > >>>+{ 'type': 'BlockdevBackup', > >>>+ 'data': { 'device': 'str', 'target': 'str', > >>>+ 'sync': 'MirrorSyncMode', > >>>+ '*speed': 'int', > >>>+ '*on-source-error': 'BlockdevOnError', > >>>+ '*on-target-error': 'BlockdevOnError' } } > >> > >>Seems okay. But what is missing is the addition of this type into the > >>union used for 'transaction' - shouldn't it be possible to mix this with > >>other transaction capabilities? > >> > > > >Should be possible, as users may want point-in-time snapshot of multiple > >disks. If this API looks OK, I will include it into transaction in the > >next version. > > > Instead of add this new API, how about extend Driver-backup API? This > patch is basically doing similar things with driver-backup, extension > of old API will save trouble to do same things driver-backup already > does, such as support qmp_transaction. The rationale was that drive-* commands should be high-level and can create image files. blockdev-* commands should be low-level and work on an existing -drive. The reason for keeping two separate commands is to avoid adding in parameters that work at different levels (filename vs drive name). In terms of API design I think drive- + blockdev- really is cleaner. Kevin can explain in more detail if I got something wrong. Stefan
diff --git a/blockdev.c b/blockdev.c index bb986a1..a3fa5d1 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1517,7 +1517,78 @@ void qmp_drive_backup(const char *device, const char *target, error_propagate(errp, local_err); return; } + /* Grab a reference so hotplug does not delete the BlockDriverState from + * underneath us. + */ + drive_get_ref(drive_get_by_blockdev(bs)); +} + +void qmp_blockdev_backup(const char *device, const char *target, + enum MirrorSyncMode sync, + bool has_speed, int64_t speed, + bool has_on_source_error, + BlockdevOnError on_source_error, + bool has_on_target_error, + BlockdevOnError on_target_error, + Error **errp) +{ + BlockDriverState *bs; + BlockDriverState *target_bs; + Error *local_err = NULL; + + if (sync != MIRROR_SYNC_MODE_FULL) { + error_setg(errp, "only sync mode 'full' is currently supported"); + return; + } + if (!has_speed) { + speed = 0; + } + if (!has_on_source_error) { + on_source_error = BLOCKDEV_ON_ERROR_REPORT; + } + if (!has_on_target_error) { + on_target_error = BLOCKDEV_ON_ERROR_REPORT; + } + + bs = bdrv_find(device); + if (!bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, device); + return; + } + + if (!bdrv_is_inserted(bs)) { + error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device); + return; + } + + if (bdrv_in_use(bs)) { + error_set(errp, QERR_DEVICE_IN_USE, device); + return; + } + + target_bs = bdrv_find(target); + if (!target_bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, target); + return; + } + + if (!bdrv_is_inserted(target_bs)) { + error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, target); + return; + } + + if (bdrv_in_use(target_bs)) { + error_set(errp, QERR_DEVICE_IN_USE, target); + return; + } + backup_start(bs, target_bs, speed, on_source_error, on_target_error, + block_job_cb, bs, &local_err); + if (local_err != NULL) { + bdrv_delete(target_bs); + error_propagate(errp, local_err); + return; + } /* Grab a reference so hotplug does not delete the BlockDriverState from * underneath us. */ diff --git a/qapi-schema.json b/qapi-schema.json index 7b9fef1..3b7cfcc 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1665,6 +1665,40 @@ '*on-target-error': 'BlockdevOnError' } } ## +# @BlockdevBackup +# +# @device: the name of the device which should be copied. +# +# @target: the name of the backup target device +# +# @sync: what parts of the disk image should be copied to the destination +# (all the disk, only the sectors allocated in the topmost image, or +# only new I/O). +# +# @speed: #optional the maximum speed, in bytes per second +# +# @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). +# +# @on-target-error: #optional the action to take on an error on the target, +# default 'report' (no limitations, since this applies to +# a different block device than @device). +# +# Note that @on-source-error and @on-target-error only affect background I/O. +# If an error occurs during a guest write request, the device's rerror/werror +# actions will be used. +# +# Since: 1.6 +## +{ 'type': 'BlockdevBackup', + 'data': { 'device': 'str', 'target': 'str', + 'sync': 'MirrorSyncMode', + '*speed': 'int', + '*on-source-error': 'BlockdevOnError', + '*on-target-error': 'BlockdevOnError' } } + +## # @Abort # # This action can be used to test transaction failure. @@ -1806,6 +1840,21 @@ { 'command': 'drive-backup', 'data': 'DriveBackup' } ## +# @blockdev-backup +# +# Block device version for drive-backup command. Use existing device as target +# of backup. +# +# For the arguments, see the documentation of BlockdevBackup. +# +# Returns: nothing on success +# If @device or @target is not a valid block device, DeviceNotFound +# +# Since 1.6 +## +{ 'command': 'blockdev-backup', 'data': 'BlockdevBackup' } + +## # @drive-mirror # # Start mirroring a block device's writes to a new destination. diff --git a/qmp-commands.hx b/qmp-commands.hx index e075df4..ecd9f64 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -959,6 +959,28 @@ Example: -> { "execute": "drive-backup", "arguments": { "device": "drive0", "target": "backup.img" } } <- { "return": {} } + +EQMP + + { + .name = "blockdev-backup", + .args_type = "sync:s,device:B,target:B,speed:i?," + "on-source-error:s?,on-target-error:s?", + .mhandler.cmd_new = qmp_marshal_input_blockdev_backup, + }, + +SQMP +blockdev-backup +------------ + +The device version of drive-backup: this command doesn't create new image for +target, instead it uses a existing named device as target. + +Example: +-> { "execute": "blockdev-backup", "arguments": { "device": "drive0", + "target": "drive1" } } +<- { "return": {} } + EQMP {
Similar to drive-backup, but this command uses a device id as target instead of creating/opening an image file. Signed-off-by: Fam Zheng <famz@redhat.com> --- blockdev.c | 71 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ qapi-schema.json | 49 ++++++++++++++++++++++++++++++++++++++ qmp-commands.hx | 22 ++++++++++++++++++ 3 files changed, 142 insertions(+)