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[Qemu-devel] [PATCH v7 03/22] blkreplay: create temporary overlay for un
From: |
Pavel Dovgalyuk |
Subject: |
[Qemu-devel] [PATCH v7 03/22] blkreplay: create temporary overlay for underlaying devices |
Date: |
Tue, 27 Feb 2018 12:51:52 +0300 |
User-agent: |
StGit/0.17.1-dirty |
From: Pavel Dovgalyuk <address@hidden>
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.
This patch creates similar temporary overlay (when it is needed)
under the blkreplay driver. Therefore all block operations are controlled
by blkreplay.
Signed-off-by: Pavel Dovgalyuk <address@hidden>
---
block/blkreplay.c | 67 +++++++++++++++++++++++++++++++++++++++++++++++++++++
stubs/replay.c | 1 +
vl.c | 2 +-
3 files changed, 69 insertions(+), 1 deletion(-)
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 4c58bd2..2b68ac3 100755
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -14,12 +14,71 @@
#include "block/block_int.h"
#include "sysemu/replay.h"
#include "qapi/error.h"
+#include "qapi/qmp/qstring.h"
+#include "qapi/qmp/qdict.h"
+#include "qemu/option.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) {
+ goto out;
+ }
+
+ bdrv_append(bs_snapshot, bs, errp);
+
+ return bs_snapshot;
+
+out:
+ QDECREF(snapshot_options);
+ return NULL;
+}
+
static int blkreplay_open(BlockDriverState *bs, QDict *options, int flags,
Error **errp)
{
@@ -35,6 +94,14 @@ 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:
return ret;
diff --git a/stubs/replay.c b/stubs/replay.c
index 9c8aa48..9991ee5 100644
--- a/stubs/replay.c
+++ b/stubs/replay.c
@@ -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)
{
diff --git a/vl.c b/vl.c
index 9e7235d..d260a06 100644
--- a/vl.c
+++ b/vl.c
@@ -4523,7 +4523,7 @@ int main(int argc, char **argv, char **envp)
qapi_free_BlockdevOptions(bdo->bdo);
g_free(bdo);
}
- if (snapshot || replay_mode != REPLAY_MODE_NONE) {
+ if (snapshot) {
qemu_opts_foreach(qemu_find_opts("drive"), drive_enable_snapshot,
NULL, NULL);
}
- [Qemu-devel] [ PATCH v7 00/22] replay additions, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 01/22] cpu-exec: fix exception_index handling, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 02/22] block: implement bdrv_snapshot_goto for blkreplay, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 03/22] blkreplay: create temporary overlay for underlaying devices,
Pavel Dovgalyuk <=
- [Qemu-devel] [PATCH v7 04/22] replay: disable default snapshot for record/replay, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 05/22] replay: fix processing async events, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 06/22] replay: fixed replay_enable_events, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 07/22] replay: fix save/load vm for non-empty queue, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 08/22] replay: added replay log format description, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 09/22] replay: save prior value of the host clock, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 11/22] replay/replay-internal.c: track holding of replay_lock, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 10/22] replay/replay.c: bump REPLAY_VERSION again, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 12/22] replay: make locking visible outside replay code, Pavel Dovgalyuk, 2018/02/27
- [Qemu-devel] [PATCH v7 13/22] replay: push replay_mutex_lock up the call tree, Pavel Dovgalyuk, 2018/02/27