This modifies the block operation block-commit so that it will accept node-name arguments for either 'top' or 'base' BDS.
The filename and node-name are mutually exclusive to each other; i.e.: "top" and "top-node-name" are mutually exclusive (enforced) "base" and "base-node-name" are mutually exclusive (enforced) The preferred and recommended method now of using block-commit is to specify the BDS to operate on via their node-name arguments. This also adds an explicit check that base_bs is in the chain of top_bs, because if they are referenced by their unique node-name arguments, the discovery process does not intrinsically verify they are in the same chain. Reviewed-by: Eric Blake <ebl...@redhat.com> Signed-off-by: Jeff Cody <jc...@redhat.com> --- blockdev.c | 54 ++++++++++++++++++++++++++++++++++++++++++++-------- qapi/block-core.json | 37 +++++++++++++++++++++++++---------- qmp-commands.hx | 31 ++++++++++++++++++++++-------- 3 files changed, 96 insertions(+), 26 deletions(-) diff --git a/blockdev.c b/blockdev.c index a9a3b2f..44f0cc4 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1911,12 +1911,15 @@ void qmp_block_stream(const char *device, bool has_base, void qmp_block_commit(const char *device, bool has_base, const char *base, + bool has_base_node_name, const char *base_node_name, bool has_top, const char *top, + bool has_top_node_name, const char *top_node_name, bool has_speed, int64_t speed, Error **errp) { - BlockDriverState *bs; - BlockDriverState *base_bs, *top_bs; + BlockDriverState *bs = NULL; + BlockDriverState *base_bs = NULL; + BlockDriverState *top_bs = NULL; Error *local_err = NULL; /* This will be part of the QMP command, if/when the * BlockdevOnError change for blkmirror makes it in @@ -1930,6 +1933,16 @@ void qmp_block_commit(const char *device, /* drain all i/o before commits */ bdrv_drain_all(); + /* argument combination validation */ + if (has_base && has_base_node_name) { + error_setg(errp, "'base' and 'base-node-name' are mutually exclusive"); + return; + } + if (has_top && has_top_node_name) { + error_setg(errp, "'top' and 'top-node-name' are mutually exclusive"); + return; + } + /* Important Note: * libvirt relies on the DeviceNotFound error class in order to probe for * live commit feature versions; for this to work, we must make sure to @@ -1941,14 +1954,16 @@ void qmp_block_commit(const char *device, return; } - if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, errp)) { - return; - } - /* default top_bs is the active layer */ top_bs = bs; - if (has_top && top) { + if (has_top_node_name) { + top_bs = bdrv_lookup_bs(NULL, top_node_name, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + } else if (has_top && top) { if (strcmp(bs->filename, top) != 0) { top_bs = bdrv_find_backing_image(bs, top); } @@ -1959,7 +1974,13 @@ void qmp_block_commit(const char *device, return; } - if (has_base && base) { + if (has_base_node_name) { + base_bs = bdrv_lookup_bs(NULL, base_node_name, &local_err); + if (local_err) { + error_propagate(errp, local_err); + return; + } + } else if (has_base && base) { base_bs = bdrv_find_backing_image(top_bs, base); } else { base_bs = bdrv_find_base(top_bs); @@ -1976,6 +1997,23 @@ void qmp_block_commit(const char *device, return; } + /* Verify that 'base' is in the same chain as 'top' */ + if (!bdrv_chain_contains(top_bs, base_bs)) { + error_setg(errp, "'base' and 'top' are not in the same chain"); + return; + } + + /* This should technically be caught in commit_start, but + * check here for validation completeness */ + if (!bdrv_chain_contains(bs, top_bs)) { + error_setg(errp, "'%s' and 'top' are not in the same chain", device); + return; + } + + if (bdrv_op_is_blocked(bs, BLOCK_OP_TYPE_COMMIT, errp)) { + return; + } + if (top_bs == bs) { commit_active_start(bs, base_bs, speed, on_error, block_job_cb, bs, &local_err); diff --git a/qapi/block-core.json b/qapi/block-core.json index 6ddce4f..dddaa13 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -685,14 +685,29 @@ # Live commit of data from overlay image nodes into backing nodes - i.e., # writes data between 'top' and 'base' into 'base'. # -# @device: the name of the device +# @device: The name of the device. # -# @base: #optional The file name of the backing image to write data into. -# If not specified, this is the deepest backing image +# For 'base', either @base or @base-node-name may be set but not both. If +# neither is specified, this is the deepest backing image. # -# @top: #optional The file name of the backing image within the image chain, -# which contains the topmost data to be committed down. If -# not specified, this is the active layer. +# @base: #optional The file name of the backing image to write data +# into. +# +# @base-node-name #optional The name of the block driver state node of the +# backing image to write data into. +# (Since 2.1) +# +# For 'top', either @top or @top-node-name must be set but not both. If +# neither is specified, this is the active layer. +# +# @top: #optional The file name of the backing image within the image +# chain, which contains the topmost data to be +# committed down. +# +# @top-node-name: #optional The block driver state node name of the backing +# image within the image chain, which contains the +# topmost data to be committed down. +# (Since 2.1) # # If top == base, that is an error. # If top == active, the job will not be completed by itself, @@ -711,17 +726,19 @@ # # Returns: Nothing on success # If commit or stream is already active on this device, DeviceInUse -# If @device does not exist, DeviceNotFound +# If @device does not exist or cannot be determined, DeviceNotFound # If image commit is not supported by this device, NotSupported -# If @base or @top is invalid, a generic error is returned +# If @base, @top, @base-node-name, @top-node-name invalid, GenericError # If @speed is invalid, InvalidParameter +# If both @base and @base-node-name are specified, GenericError +# If both @top and @top-node-name are specified, GenericError # # Since: 1.3 # ## { 'command': 'block-commit', - 'data': { 'device': 'str', '*base': 'str', '*top': 'str', - '*speed': 'int' } } + 'data': { 'device': 'str', '*base': 'str', '*base-node-name': 'str', + '*top': 'str', '*top-node-name': 'str', '*speed': 'int' } } ## # @drive-backup diff --git a/qmp-commands.hx b/qmp-commands.hx index 4a8e71a..52af928 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -985,7 +985,7 @@ EQMP { .name = "block-commit", - .args_type = "device:B,base:s?,top:s?,speed:o?", + .args_type = "device:B,base:s?,base-node-name:s?,top:s?,top-node-name:s?,speed:o?", .mhandler.cmd_new = qmp_marshal_input_block_commit, }, @@ -998,13 +998,28 @@ data between 'top' and 'base' into 'base'. Arguments: -- "device": The device's ID, must be unique (json-string) -- "base": The file name of the backing image to write data into. - If not specified, this is the deepest backing image - (json-string, optional) -- "top": The file name of the backing image within the image chain, - which contains the topmost data to be committed down. If - not specified, this is the active layer. (json-string, optional) +- "device": The device's ID, must be unique (json-string) + +For 'base', either base or base-node-name may be set but not both. If +neither is specified, this is the deepest backing image + +- "base": The file name of the backing image to write data into. + (json-string, optional) +- "base-node-name": The name of the block driver state node of the + backing image to write data into. + (json-string, optional) (Since 2.1) + +For 'top', either top or top-node-name must be set but not both. If +neither is specified, this is the active layer + +- "top": The file name of the backing image within the image chain, + which contains the topmost data to be committed down. + (json-string, optional) + +- "top-node-name": The block driver state node name of the backing + image within the image chain, which contains the + topmost data to be committed down. + (json-string, optional) (Since 2.1) If top == base, that is an error. If top == active, the job will not be completed by itself, -- 1.9.3