* [Qemu-devel] [RFC PATCHv2 01/26] block: implement bdrv_snapshot_goto for blkreplay
2017-11-14 8:16 [Qemu-devel] [RFC PATCH v2 00/26] replay additions Pavel Dovgalyuk
@ 2017-11-14 8:16 ` Pavel Dovgalyuk
2017-11-14 8:16 ` [Qemu-devel] [RFC PATCHv2 02/26] blkreplay: create temporary overlay for underlaying devices Pavel Dovgalyuk
1 sibling, 0 replies; 3+ messages in thread
From: Pavel Dovgalyuk @ 2017-11-14 8:16 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, peter.maydell, boost.lists, quintela, jasowang, mst,
zuban32s, maria.klimushenkova, dovgaluk, kraxel, pavel.dovgaluk,
pbonzini, alex.bennee
From: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
This patch enables making snapshots with blkreplay used in
block devices.
This function is required to make bdrv_snapshot_goto without
calling .bdrv_open which is not implemented.
Signed-off-by: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
---
block/blkreplay.c | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 61e44a1..82a88f8 100755
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -127,6 +127,12 @@ static int coroutine_fn blkreplay_co_flush(BlockDriverState *bs)
return ret;
}
+static int blkreplay_snapshot_goto(BlockDriverState *bs,
+ const char *snapshot_id)
+{
+ return bdrv_snapshot_goto(bs->file->bs, snapshot_id);
+}
+
static BlockDriver bdrv_blkreplay = {
.format_name = "blkreplay",
.protocol_name = "blkreplay",
@@ -143,6 +149,8 @@ static BlockDriver bdrv_blkreplay = {
.bdrv_co_pwrite_zeroes = blkreplay_co_pwrite_zeroes,
.bdrv_co_pdiscard = blkreplay_co_pdiscard,
.bdrv_co_flush = blkreplay_co_flush,
+
+ .bdrv_snapshot_goto = blkreplay_snapshot_goto,
};
static void bdrv_blkreplay_init(void)
^ permalink raw reply related [flat|nested] 3+ messages in thread* [Qemu-devel] [RFC PATCHv2 02/26] blkreplay: create temporary overlay for underlaying devices
2017-11-14 8:16 [Qemu-devel] [RFC PATCH v2 00/26] replay additions Pavel Dovgalyuk
2017-11-14 8:16 ` [Qemu-devel] [RFC PATCHv2 01/26] block: implement bdrv_snapshot_goto for blkreplay Pavel Dovgalyuk
@ 2017-11-14 8:16 ` Pavel Dovgalyuk
1 sibling, 0 replies; 3+ messages in thread
From: Pavel Dovgalyuk @ 2017-11-14 8:16 UTC (permalink / raw)
To: qemu-devel
Cc: kwolf, peter.maydell, boost.lists, quintela, jasowang, mst,
zuban32s, maria.klimushenkova, dovgaluk, kraxel, pavel.dovgaluk,
pbonzini, alex.bennee
From: Pavel Dovgalyuk <pavel.dovgaluk@ispras.ru>
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 <pavel.dovgaluk@ispras.ru>
---
block/blkreplay.c | 65 +++++++++++++++++++++++++++++++++++++++++++++++++++++
stubs/replay.c | 1 +
vl.c | 2 +-
3 files changed, 67 insertions(+), 1 deletion(-)
diff --git a/block/blkreplay.c b/block/blkreplay.c
index 82a88f8..c489d50 100755
--- a/block/blkreplay.c
+++ b/block/blkreplay.c
@@ -14,12 +14,69 @@
#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) {
+ 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 +92,14 @@ 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 ec29909..7aa59f0 100644
--- a/vl.c
+++ b/vl.c
@@ -4661,7 +4661,7 @@ 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);
}
^ permalink raw reply related [flat|nested] 3+ messages in thread