From 4b028cbe7540b302d48f7d9e59a8cb860209d9fa Mon Sep 17 00:00:00 2001 From: Peter Krempa Date: Tue, 5 Dec 2023 18:14:41 +0100 Subject: commit: Allow users to request only format driver names in backing file format Introduce a new flag 'backing-mask-protocol' for the block-commit 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: <2cb46e37093ce793ea1604abc8bbb90f4c8e434b.1701796348.git.pkrempa@redhat.com> Reviewed-by: Kevin Wolf Signed-off-by: Kevin Wolf --- block/commit.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) (limited to 'block') diff --git a/block/commit.c b/block/commit.c index 1dd7a65..7c3fdcb 100644 --- a/block/commit.c +++ b/block/commit.c @@ -42,6 +42,7 @@ typedef struct CommitBlockJob { bool base_read_only; bool chain_frozen; char *backing_file_str; + bool backing_mask_protocol; } CommitBlockJob; static int commit_prepare(Job *job) @@ -61,7 +62,8 @@ static int commit_prepare(Job *job) /* FIXME: bdrv_drop_intermediate treats total failures and partial failures * identically. Further work is needed to disambiguate these cases. */ return bdrv_drop_intermediate(s->commit_top_bs, s->base_bs, - s->backing_file_str); + s->backing_file_str, + s->backing_mask_protocol); } static void commit_abort(Job *job) @@ -254,6 +256,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, BlockDriverState *base, BlockDriverState *top, int creation_flags, int64_t speed, BlockdevOnError on_error, const char *backing_file_str, + bool backing_mask_protocol, const char *filter_node_name, Error **errp) { CommitBlockJob *s; @@ -408,6 +411,7 @@ void commit_start(const char *job_id, BlockDriverState *bs, blk_set_disable_request_queuing(s->top, true); s->backing_file_str = g_strdup(backing_file_str); + s->backing_mask_protocol = backing_mask_protocol; s->on_error = on_error; trace_commit_start(bs, base, top, s); -- cgit v1.1