qemu-img should use QMP commands whenever possible in order to ensure
feature completeness of both online and offline image operations. As
qemu-img itself has no access to QMP (since this would basically require
just everything being linked into qemu-img), imitate QMP's
implementation of block-commit by using commit_active_start() and then
waiting for the block job to finish.
This new implementation does not empty the snapshot image, as opposed to
the old implementation using bdrv_commit(). However, as QMP's
block-commit apparently never did this and as qcow2 (which is probably
qemu's standard image format) does not even implement the required
function (bdrv_make_empty()), it does not seem necessary.
Signed-off-by: Max Reitz <mre...@redhat.com>
---
block/Makefile.objs | 2 +-
qemu-img.c | 86 +++++++++++++++++++++++++++++++++++++++++------------
2 files changed, 68 insertions(+), 20 deletions(-)
diff --git a/block/Makefile.objs b/block/Makefile.objs
index fd88c03..2c37e80 100644
--- a/block/Makefile.objs
+++ b/block/Makefile.objs
@@ -9,6 +9,7 @@ block-obj-y += snapshot.o qapi.o
block-obj-$(CONFIG_WIN32) += raw-win32.o win32-aio.o
block-obj-$(CONFIG_POSIX) += raw-posix.o
block-obj-$(CONFIG_LINUX_AIO) += linux-aio.o
+block-obj-y += mirror.o
ifeq ($(CONFIG_POSIX),y)
block-obj-y += nbd.o nbd-client.o sheepdog.o
@@ -22,7 +23,6 @@ endif
common-obj-y += stream.o
common-obj-y += commit.o
-common-obj-y += mirror.o
common-obj-y += backup.o
iscsi.o-cflags := $(LIBISCSI_CFLAGS)
diff --git a/qemu-img.c b/qemu-img.c
index 8455994..9fe6384 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -30,6 +30,7 @@
#include "qemu/osdep.h"
#include "sysemu/sysemu.h"
#include "block/block_int.h"
+#include "block/blockjob.h"
#include "block/qapi.h"
#include <getopt.h>
@@ -682,12 +683,49 @@ fail:
return ret;
}
+struct CommonBlockJobCBInfo {
+ Error **errp;
+ bool done;
+};
+
+static void common_block_job_cb(void *opaque, int ret)
+{
+ struct CommonBlockJobCBInfo *cbi = opaque;
+
+ if (ret < 0) {
+ error_setg_errno(cbi->errp, -ret, "Block job failed");
+ }
+
+ cbi->done = true;
+}
+
+static void run_block_job(BlockJob *job, struct CommonBlockJobCBInfo *cbi)
+{
+ BlockJobInfo *info;
+
+ do {
+ qemu_aio_wait();
+
+ info = block_job_query(job);
+
+ if (!info->busy && info->offset < info->len) {
+ block_job_resume(job);
+ }
+ } while (info->offset < info->len);
+
+ block_job_complete_sync(job, cbi->errp);
+}
+
+/* Same as in block.c */
+#define COMMIT_BUF_SECTORS 2048
+
static int img_commit(int argc, char **argv)
{
int c, ret, flags;
const char *filename, *fmt, *cache;
- BlockDriverState *bs;
+ BlockDriverState *bs, *base_bs;
bool quiet = false;
+ Error *local_err = NULL;
fmt = NULL;
cache = BDRV_DEFAULT_CACHE;
@@ -728,29 +766,39 @@ static int img_commit(int argc, char **argv)
if (!bs) {
return 1;
}
- ret = bdrv_commit(bs);
- switch(ret) {
- case 0:
- qprintf(quiet, "Image committed.\n");
- break;
- case -ENOENT:
- error_report("No disk inserted");
- break;
- case -EACCES:
- error_report("Image is read-only");
- break;
- case -ENOTSUP:
- error_report("Image is already committed");
- break;
- default:
- error_report("Error while committing image");
- break;
+
+ /* This is different from QMP, which by default uses the deepest file in
the
+ * backing chain (i.e., the very base); however, the traditional behavior
of
+ * qemu-img commit is using the immediate backing file. */
+ base_bs = bs->backing_hd;
+ if (!base_bs) {
+ error_set(&local_err, QERR_BASE_NOT_FOUND, "NULL");
+ goto done;
}
+ struct CommonBlockJobCBInfo cbi = {
+ .errp = &local_err,
+ };
+
+ commit_active_start(bs, base_bs, 0, COMMIT_BUF_SECTORS << BDRV_SECTOR_BITS,
+ BLOCKDEV_ON_ERROR_REPORT, common_block_job_cb, &cbi,
+ &local_err);
+ if (local_err) {
+ goto done;
+ }
+
+ run_block_job(bs->job, &cbi);
+
+done:
bdrv_unref(bs);
- if (ret) {
+
+ if (local_err) {
+ qerror_report_err(local_err);
+ error_free(local_err);
return 1;
}
+
+ qprintf(quiet, "Image committed.\n");
return 0;
}
--
1.9.2
