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-rw-r--r--block.c8
-rw-r--r--block/commit.c9
-rw-r--r--blockdev.c8
-rw-r--r--include/block/block.h3
-rw-r--r--include/block/block_int.h3
-rw-r--r--qapi/block-core.json20
-rw-r--r--qmp-commands.hx19
7 files changed, 59 insertions, 11 deletions
diff --git a/block.c b/block.c
index f45e63c88b..f80e2b2b58 100644
--- a/block.c
+++ b/block.c
@@ -2555,12 +2555,15 @@ typedef struct BlkIntermediateStates {
*
* base <- active
*
+ * If backing_file_str is non-NULL, it will be used when modifying top's
+ * overlay image metadata.
+ *
* Error conditions:
* if active == top, that is considered an error
*
*/
int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
- BlockDriverState *base)
+ BlockDriverState *base, const char *backing_file_str)
{
BlockDriverState *intermediate;
BlockDriverState *base_bs = NULL;
@@ -2612,7 +2615,8 @@ int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
}
/* success - we can delete the intermediate states, and link top->base */
- ret = bdrv_change_backing_file(new_top_bs, base_bs->filename,
+ backing_file_str = backing_file_str ? backing_file_str : base_bs->filename;
+ ret = bdrv_change_backing_file(new_top_bs, backing_file_str,
base_bs->drv ? base_bs->drv->format_name : "");
if (ret) {
goto exit;
diff --git a/block/commit.c b/block/commit.c
index 5c09f4444e..91517d3512 100644
--- a/block/commit.c
+++ b/block/commit.c
@@ -37,6 +37,7 @@ typedef struct CommitBlockJob {
BlockdevOnError on_error;
int base_flags;
int orig_overlay_flags;
+ char *backing_file_str;
} CommitBlockJob;
static int coroutine_fn commit_populate(BlockDriverState *bs,
@@ -141,7 +142,7 @@ wait:
if (!block_job_is_cancelled(&s->common) && sector_num == end) {
/* success */
- ret = bdrv_drop_intermediate(active, top, base);
+ ret = bdrv_drop_intermediate(active, top, base, s->backing_file_str);
}
exit_free_buf:
@@ -158,7 +159,7 @@ exit_restore_reopen:
if (overlay_bs && s->orig_overlay_flags != bdrv_get_flags(overlay_bs)) {
bdrv_reopen(overlay_bs, s->orig_overlay_flags, NULL);
}
-
+ g_free(s->backing_file_str);
block_job_completed(&s->common, ret);
}
@@ -182,7 +183,7 @@ static const BlockJobDriver commit_job_driver = {
void commit_start(BlockDriverState *bs, BlockDriverState *base,
BlockDriverState *top, int64_t speed,
BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
- void *opaque, Error **errp)
+ void *opaque, const char *backing_file_str, Error **errp)
{
CommitBlockJob *s;
BlockReopenQueue *reopen_queue = NULL;
@@ -244,6 +245,8 @@ void commit_start(BlockDriverState *bs, BlockDriverState *base,
s->base_flags = orig_base_flags;
s->orig_overlay_flags = orig_overlay_flags;
+ s->backing_file_str = g_strdup(backing_file_str);
+
s->on_error = on_error;
s->common.co = qemu_coroutine_create(commit_run);
diff --git a/blockdev.c b/blockdev.c
index 57373d3661..48315e86c0 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -1915,6 +1915,7 @@ 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_top, const char *top,
+ bool has_backing_file, const char *backing_file,
bool has_speed, int64_t speed,
Error **errp)
{
@@ -1980,11 +1981,16 @@ void qmp_block_commit(const char *device,
}
if (top_bs == bs) {
+ if (has_backing_file) {
+ error_setg(errp, "'backing-file' specified,"
+ " but 'top' is the active layer");
+ return;
+ }
commit_active_start(bs, base_bs, speed, on_error, block_job_cb,
bs, &local_err);
} else {
commit_start(bs, base_bs, top_bs, speed, on_error, block_job_cb, bs,
- &local_err);
+ has_backing_file ? backing_file : NULL, &local_err);
}
if (local_err != NULL) {
error_propagate(errp, local_err);
diff --git a/include/block/block.h b/include/block/block.h
index 29c9e50ddb..baecc26dfc 100644
--- a/include/block/block.h
+++ b/include/block/block.h
@@ -285,7 +285,8 @@ int bdrv_change_backing_file(BlockDriverState *bs,
const char *backing_file, const char *backing_fmt);
void bdrv_register(BlockDriver *bdrv);
int bdrv_drop_intermediate(BlockDriverState *active, BlockDriverState *top,
- BlockDriverState *base);
+ BlockDriverState *base,
+ const char *backing_file_str);
BlockDriverState *bdrv_find_overlay(BlockDriverState *active,
BlockDriverState *bs);
BlockDriverState *bdrv_find_base(BlockDriverState *bs);
diff --git a/include/block/block_int.h b/include/block/block_int.h
index eaf6e313d5..8f8e65e763 100644
--- a/include/block/block_int.h
+++ b/include/block/block_int.h
@@ -463,13 +463,14 @@ void stream_start(BlockDriverState *bs, BlockDriverState *base,
* @on_error: The action to take upon error.
* @cb: Completion function for the job.
* @opaque: Opaque pointer value passed to @cb.
+ * @backing_file_str: String to use as the backing file in @top's overlay
* @errp: Error object.
*
*/
void commit_start(BlockDriverState *bs, BlockDriverState *base,
BlockDriverState *top, int64_t speed,
BlockdevOnError on_error, BlockDriverCompletionFunc *cb,
- void *opaque, Error **errp);
+ void *opaque, const char *backing_file_str, Error **errp);
/**
* commit_active_start:
* @bs: Active block device to be committed.
diff --git a/qapi/block-core.json b/qapi/block-core.json
index aa1252778c..5b4d75fa81 100644
--- a/qapi/block-core.json
+++ b/qapi/block-core.json
@@ -720,6 +720,23 @@
# which contains the topmost data to be committed down. If
# not specified, this is the active layer.
#
+# @backing-file: #optional The backing file string to write into the overlay
+# image of 'top'. If 'top' is the active layer,
+# specifying a backing file string is an error. This
+# filename is not validated.
+#
+# If a pathname string is such that it cannot be
+# resolved by QEMU, that means that subsequent QMP or
+# HMP commands must use node-names for the image in
+# question, as filename lookup methods will fail.
+#
+# If not specified, QEMU will automatically determine
+# the backing file string to use, or error out if
+# there is no obvious choice. Care should be taken
+# when specifying the string, to specify a valid
+# filename or protocol.
+# (Since 2.1)
+#
# If top == base, that is an error.
# If top == active, the job will not be completed by itself,
# user needs to complete the job with the block-job-complete
@@ -732,7 +749,6 @@
# size of the smaller top, you can safely truncate it
# yourself once the commit operation successfully completes.
#
-#
# @speed: #optional the maximum speed, in bytes per second
#
# Returns: Nothing on success
@@ -747,7 +763,7 @@
##
{ 'command': 'block-commit',
'data': { 'device': 'str', '*base': 'str', '*top': 'str',
- '*speed': 'int' } }
+ '*backing-file': 'str', '*speed': 'int' } }
##
# @drive-backup
diff --git a/qmp-commands.hx b/qmp-commands.hx
index 8534948e3f..a3f932cb46 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?,top:s?,backing-file:s?,speed:o?",
.mhandler.cmd_new = qmp_marshal_input_block_commit,
},
@@ -1006,6 +1006,23 @@ Arguments:
which contains the topmost data to be committed down. If
not specified, this is the active layer. (json-string, optional)
+- backing-file: The backing file string to write into the overlay
+ image of 'top'. If 'top' is the active layer,
+ specifying a backing file string is an error. This
+ filename is not validated.
+
+ If a pathname string is such that it cannot be
+ resolved by QEMU, that means that subsequent QMP or
+ HMP commands must use node-names for the image in
+ question, as filename lookup methods will fail.
+
+ If not specified, QEMU will automatically determine
+ the backing file string to use, or error out if
+ there is no obvious choice. Care should be taken
+ when specifying the string, to specify a valid
+ filename or protocol.
+ (json-string, optional) (Since 2.1)
+
If top == base, that is an error.
If top == active, the job will not be completed by itself,
user needs to complete the job with the block-job-complete