@@ -14,12 +14,76 @@
#include "block/block_int.h"
#include "sysemu/replay.h"
#include "qapi/error.h"
+#include "qapi/qmp/qstring.h"
typedef struct Request {
Coroutine *co;
QEMUBH *bh;
} Request;
+static BlockDriverState *blkreplay_append_snapshot(BlockDriverState *bs,
+ Error **errp)
+{
+ int ret;
+ BlockDriverState *bs_snapshot;
+ int64_t total_size;
+ QemuOpts *opts = NULL;
+ char tmp_filename[PATH_MAX + 1];
+ QDict *snapshot_options = qdict_new();
+
+ /* Prepare options QDict for the overlay file */
+ qdict_put(snapshot_options, "file.driver",
+ qstring_from_str("file"));
+ qdict_put(snapshot_options, "driver",
+ qstring_from_str("qcow2"));
+
+ /* Create temporary file */
+ ret = get_tmp_filename(tmp_filename, PATH_MAX + 1);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not get temporary filename");
+ goto out;
+ }
+ qdict_put(snapshot_options, "file.filename",
+ qstring_from_str(tmp_filename));
+
+ /* Get the required size from the image */
+ total_size = bdrv_getlength(bs);
+ if (total_size < 0) {
+ error_setg_errno(errp, -total_size, "Could not get image size");
+ goto out;
+ }
+
+ opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, &error_abort);
+ qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size, &error_abort);
+ ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, errp);
+ qemu_opts_del(opts);
+ if (ret < 0) {
+ error_prepend(errp, "Could not create temporary overlay '%s': ",
+ tmp_filename);
+ goto out;
+ }
+
+ bs_snapshot = bdrv_open(NULL, NULL, snapshot_options,
+ BDRV_O_RDWR | BDRV_O_TEMPORARY, errp);
+ snapshot_options = NULL;
+ if (!bs_snapshot) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ /* bdrv_append() consumes a strong reference to bs_snapshot (i.e. it will
+ * call bdrv_unref() on it), so in order to be able to return one, we have
+ * to increase bs_snapshot's refcount here */
+ bdrv_ref(bs_snapshot);
+ bdrv_append(bs_snapshot, bs);
+
+ return bs_snapshot;
+
+out:
+ QDECREF(snapshot_options);
+ return NULL;
+}
+
static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
@@ -35,6 +99,14 @@ static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
goto fail;
}
+ /* Add temporary snapshot to preserve the image */
+ if (!replay_snapshot
+ && !blkreplay_append_snapshot(bs->file->bs, &local_err)) {
+ ret = -EINVAL;
+ error_propagate(errp, local_err);
+ goto fail;
+ }
+
ret = 0;
fail:
if (ret < 0) {
@@ -45,6 +117,10 @@ fail:
static void blkreplay_close(BlockDriverState *bs)
{
+ if (!replay_snapshot) {
+ /* Unref created snapshot file */
+ bdrv_unref(bs->file->bs);
+ }
}
static int64_t blkreplay_getlength(BlockDriverState *bs)
@@ -3,6 +3,7 @@
#include "sysemu/sysemu.h"
ReplayMode replay_mode;
+char *replay_snapshot;
int64_t replay_save_clock(unsigned int kind, int64_t clock)
{
@@ -4479,7 +4479,7 @@ int main(int argc, char **argv, char **envp)
}
/* open the virtual block devices */
- if (snapshot || replay_mode != REPLAY_MODE_NONE) {
+ if (snapshot) {
qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot,
NULL, NULL);
}
This patch allows using '-snapshot' behavior in record/replay mode. blkreplay layer creates temporary overlays on top of underlaying disk images. It is needed, because creating an overlay over blkreplay breaks the determinism. Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru> --- block/blkreplay.c | 76 +++++++++++++++++++++++++++++++++++++++++++++++++++++ stubs/replay.c | 1 + vl.c | 2 + 3 files changed, 78 insertions(+), 1 deletion(-)