From 72098a3aba7a7fccd7d1287c2ff88c1dac9b807d Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Tue, 5 Dec 2023 18:14:42 +0100 Subject: [PATCH] stream: Allow users to request only format driver names in backing file format Introduce a new flag 'backing-mask-protocol' for the block-stream QMP command which instructs the internals to use 'raw' instead of the protocol driver in case when a image is used without a dummy 'raw' wrapper. The flag is designed such that it can be always asserted by management tools even when there isn't any update to backing files. The flag will be used by libvirt so that the backing images still reference the proper format even when libvirt will stop using the dummy raw driver (raw driver with no other config). Libvirt needs this so that the images stay compatible with older libvirt versions which didn't expect that a protocol driver name can appear in the backing file format field. Signed-off-by: Peter Krempa Reviewed-by: Vladimir Sementsov-Ogievskiy Message-ID: Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/monitor/block-hmp-cmds.c | 2 +- block/stream.c | 10 +++++++++- blockdev.c | 7 +++++++ include/block/block_int-global-state.h | 3 +++ qapi/block-core.json | 9 ++++++++- 5 files changed, 28 insertions(+), 3 deletions(-) diff --git a/block/monitor/block-hmp-cmds.c b/block/monitor/block-hmp-cmds.c index bdbb5cb141..d954bec6f1 100644 --- a/block/monitor/block-hmp-cmds.c +++ b/block/monitor/block-hmp-cmds.c @@ -496,7 +496,7 @@ void hmp_block_stream(Monitor *mon, const QDict *qdict) const char *base = qdict_get_try_str(qdict, "base"); int64_t speed = qdict_get_try_int(qdict, "speed", 0); - qmp_block_stream(device, device, base, NULL, NULL, NULL, + qmp_block_stream(device, device, base, NULL, NULL, false, false, NULL, qdict_haskey(qdict, "speed"), speed, true, BLOCKDEV_ON_ERROR_REPORT, NULL, false, false, false, false, &error); diff --git a/block/stream.c b/block/stream.c index 048c2d282f..7031eef12b 100644 --- a/block/stream.c +++ b/block/stream.c @@ -39,6 +39,7 @@ typedef struct StreamBlockJob { BlockDriverState *target_bs; BlockdevOnError on_error; char *backing_file_str; + bool backing_mask_protocol; bool bs_read_only; } StreamBlockJob; @@ -95,7 +96,12 @@ static int stream_prepare(Job *job) if (unfiltered_base) { base_id = s->backing_file_str ?: unfiltered_base->filename; if (unfiltered_base->drv) { - base_fmt = unfiltered_base->drv->format_name; + if (s->backing_mask_protocol && + unfiltered_base->drv->protocol_name) { + base_fmt = "raw"; + } else { + base_fmt = unfiltered_base->drv->format_name; + } } } @@ -247,6 +253,7 @@ static const BlockJobDriver stream_job_driver = { void stream_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, const char *backing_file_str, + bool backing_mask_protocol, BlockDriverState *bottom, int creation_flags, int64_t speed, BlockdevOnError on_error, @@ -398,6 +405,7 @@ void stream_start(const char *job_id, BlockDriverState *bs, s->base_overlay = base_overlay; s->above_base = above_base; s->backing_file_str = g_strdup(backing_file_str); + s->backing_mask_protocol = backing_mask_protocol; s->cor_filter_bs = cor_filter_bs; s->target_bs = bs; s->bs_read_only = bs_read_only; diff --git a/blockdev.c b/blockdev.c index 292c8af3f9..f8bb0932f8 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2278,6 +2278,8 @@ void qmp_block_stream(const char *job_id, const char *device, const char *base, const char *base_node, const char *backing_file, + bool has_backing_mask_protocol, + bool backing_mask_protocol, const char *bottom, bool has_speed, int64_t speed, bool has_on_error, BlockdevOnError on_error, @@ -2313,6 +2315,10 @@ void qmp_block_stream(const char *job_id, const char *device, return; } + if (!has_backing_mask_protocol) { + backing_mask_protocol = false; + } + if (!has_on_error) { on_error = BLOCKDEV_ON_ERROR_REPORT; } @@ -2400,6 +2406,7 @@ void qmp_block_stream(const char *job_id, const char *device, } stream_start(job_id, bs, base_bs, backing_file, + backing_mask_protocol, bottom_bs, job_flags, has_speed ? speed : 0, on_error, filter_node_name, &local_err); if (local_err) { diff --git a/include/block/block_int-global-state.h b/include/block/block_int-global-state.h index 2162269df6..d2201e27f4 100644 --- a/include/block/block_int-global-state.h +++ b/include/block/block_int-global-state.h @@ -46,6 +46,8 @@ * flatten the whole backing file chain onto @bs. * @backing_file_str: The file name that will be written to @bs as the * the new backing file if the job completes. Ignored if @base is %NULL. + * @backing_mask_protocol: Replace potential protocol name with 'raw' in + * 'backing file format' header * @creation_flags: Flags that control the behavior of the Job lifetime. * See @BlockJobCreateFlags * @speed: The maximum speed, in bytes per second, or 0 for unlimited. @@ -64,6 +66,7 @@ */ void stream_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, const char *backing_file_str, + bool backing_mask_protocol, BlockDriverState *bottom, int creation_flags, int64_t speed, BlockdevOnError on_error, diff --git a/qapi/block-core.json b/qapi/block-core.json index 726145ec8a..04982bff96 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -2826,6 +2826,11 @@ # Care should be taken when specifying the string, to specify a # valid filename or protocol. (Since 2.1) # +# @backing-mask-protocol: If true, replace any protocol mentioned in the +# 'backing file format' with 'raw', rather than storing the protocol +# name as the backing format. Can be used even when no image header +# will be updated (default false; since 9.0). +# # @speed: the maximum speed, in bytes per second # # @on-error: the action to take on an error (default report). 'stop' @@ -2864,7 +2869,9 @@ ## { 'command': 'block-stream', 'data': { '*job-id': 'str', 'device': 'str', '*base': 'str', - '*base-node': 'str', '*backing-file': 'str', '*bottom': 'str', + '*base-node': 'str', '*backing-file': 'str', + '*backing-mask-protocol': 'bool', + '*bottom': 'str', '*speed': 'int', '*on-error': 'BlockdevOnError', '*filter-node-name': 'str', '*auto-finalize': 'bool', '*auto-dismiss': 'bool' },