From: Dong Xu Wang <wdon...@linux.vnet.ibm.com>
We can not use raw to support snapshot_file, but add-cow can do this.
CC: Marcelo Tosatti <mtosa...@redhat.com>
CC: Kevin Wolf <kw...@redhat.com>
CC: Stefan Hajnoczi <stefa...@linux.vnet.ibm.com>
Signed-off-by: Dong Xu Wang <wdon...@linux.vnet.ibm.com>
---
blockdev.c | 53 ++++++++++++++++++++++++++++++++++++++++++----
docs/live-block-ops.txt | 8 ++++++-
2 files changed, 55 insertions(+), 6 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index d78aa51..c820fcb 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -687,12 +687,55 @@ void qmp_blockdev_snapshot_sync(const char *device, const
char *snapshot_file,
return;
}
- ret = bdrv_img_create(snapshot_file, format, bs->filename,
- bs->drv->format_name, NULL, -1, flags);
- if (ret) {
- error_set(errp, QERR_UNDEFINED_ERROR);
- return;
+ if (strcmp(format, "add-cow")) {
+ ret = bdrv_img_create(snapshot_file, format, bs->filename,
+ bs->drv->format_name, NULL, -1, flags);
+ if (ret) {
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
+ }
+ } else {
+ char image_file[1024];
+ char option[1024];
+
+ uint64_t size;
+ BlockDriver *backing_drv = NULL;
+ BlockDriverState *backing_bs = NULL;
+
+ backing_bs = bdrv_new("");
+ backing_drv = bdrv_find_format(bs->drv->format_name);
+ if (!backing_drv) {
+ error_report("Unknown backing file format '%s'",
+ bs->drv->format_name);
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
+ }
+ ret = bdrv_open(backing_bs, bs->filename, flags, backing_drv);
+ if (ret < 0) {
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
+ }
+ bdrv_get_geometry(backing_bs, &size);
+ size *= 512;
+ bdrv_delete(backing_bs);
+
+ sprintf(image_file, "%s.raw", snapshot_file);
+
+ ret = bdrv_img_create(image_file, "raw", NULL,
+ NULL, NULL, size, flags);
+ if (ret) {
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
+ }
+ sprintf(option, "image_file=%s.raw", snapshot_file);
+ ret = bdrv_img_create(snapshot_file, format, bs->filename,
+ bs->drv->format_name, option, -1, flags);
+ if (ret) {
+ error_set(errp, QERR_UNDEFINED_ERROR);
+ return;
+ }
}
+ bs->backing_format[0] = '\0';
bdrv_drain_all();
bdrv_flush(bs);
diff --git a/docs/live-block-ops.txt b/docs/live-block-ops.txt
index a257087..7edbf91 100644
--- a/docs/live-block-ops.txt
+++ b/docs/live-block-ops.txt
@@ -2,7 +2,8 @@ LIVE BLOCK OPERATIONS
=====================
High level description of live block operations. Note these are not
-supported for use with the raw format at the moment.
+supported for use with the raw format at the moment, but we can use
+add-cow as metadata to suport raw format.
Snapshot live merge
===================
@@ -55,4 +56,9 @@ into that image. Example:
(qemu) block_stream ide0-hd0
+Raw is not supported, but we can use add-cow in the 1st step:
+(qemu) snapshot_blkdev ide0-hd0 /new-path/disk.img add-cow
+
+It will create a raw file named disk.img.raw, with the same virtual size of
+ide0-hd0 first, and then create disk.img.
--
1.7.5.4
