Signed-off-by: Federico Simoncelli<fsimo...@redhat.com>
---
blockdev.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
hmp-commands.hx | 7 ++++---
qmp-commands.hx | 4 ++--
3 files changed, 58 insertions(+), 7 deletions(-)
diff --git a/blockdev.c b/blockdev.c
index 0827bf7..bd46808 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -550,8 +550,53 @@ void do_commit(Monitor *mon, const QDict *qdict)
}
}
+static int check_snapshot_file(const char *filename, const char *oldfilename,
+ int flags, BlockDriver *drv)
+{
+ BlockDriverState *bs;
+ char bak_filename[1024], *abs_filename;
+ int ret = 0;
+
+ bs = bdrv_new("");
+ if (!bs) {
+ return -1;
+ }
+
+ ret = bdrv_open(bs, filename, flags, drv);
+ if (ret) {
+ qerror_report(QERR_OPEN_FILE_FAILED, filename);
+ goto err0;
+ }
+
+ if (bs->backing_file) {
+ path_combine(bak_filename, sizeof(bak_filename),
+ filename, bs->backing_file);
+
+ abs_filename = realpath(bak_filename, NULL);
+ if (!abs_filename) {
+ ret = -1;
+ goto err1;
+ }
+
+ if (strcmp(abs_filename, oldfilename)) {
+ qerror_report(QERR_OPEN_FILE_FAILED, filename);
+ ret = -1;
+ }
+
+ free(abs_filename);
+ }
+
+err1:
+ bdrv_close(bs);
+
+err0:
+ bdrv_delete(bs);
+ return ret;
+}
+
int do_snapshot_blkdev(Monitor *mon, const QDict *qdict, QObject **ret_data)
{
+ const int nocreate = qdict_get_try_bool(qdict, "nocreate", 0);
const char *device = qdict_get_str(qdict, "device");
const char *filename = qdict_get_try_str(qdict, "snapshot-file");
const char *format = qdict_get_try_str(qdict, "format");
@@ -597,8 +642,13 @@ int do_snapshot_blkdev(Monitor *mon, const QDict *qdict,
QObject **ret_data)
goto out;
}
- ret = bdrv_img_create(filename, format, bs->filename,
- bs->drv->format_name, NULL, -1, flags);
+ if (nocreate) {
+ ret = check_snapshot_file(filename, bs->filename, flags, drv);
+ } else {
+ ret = bdrv_img_create(filename, format, bs->filename,
+ bs->drv->format_name, NULL, -1, flags);
+ }
+
if (ret) {
goto out;
}
diff --git a/hmp-commands.hx b/hmp-commands.hx
index 9e1cca8..eb9fcd4 100644
--- a/hmp-commands.hx
+++ b/hmp-commands.hx
@@ -840,11 +840,12 @@ ETEXI
{
.name = "snapshot_blkdev",
- .args_type = "device:B,snapshot-file:s?,format:s?",
- .params = "device [new-image-file] [format]",
+ .args_type = "nocreate:-n,device:B,snapshot-file:s?,format:s?",
+ .params = "[-n] device [new-image-file] [format]",
.help = "initiates a live snapshot\n\t\t\t"
"of device. If a new image file is specified,
the\n\t\t\t"
- "new image file will become the new root image.\n\t\t\t"
+ "new image file will be created (unless -n is\n\t\t\t"
+ "specified) and will become the new root image.\n\t\t\t"
"If format is specified, the snapshot file will\n\t\t\t"
"be created in that format. Otherwise the\n\t\t\t"
"snapshot will be internal! (currently unsupported)",
diff --git a/qmp-commands.hx b/qmp-commands.hx
index d83bce5..7af36d8 100644
--- a/qmp-commands.hx
+++ b/qmp-commands.hx
@@ -695,8 +695,8 @@ EQMP
{
.name = "blockdev-snapshot-sync",
- .args_type = "device:B,snapshot-file:s?,format:s?",
- .params = "device [new-image-file] [format]",
+ .args_type = "nocreate:-n,device:B,snapshot-file:s?,format:s?",
+ .params = "[-n] device [new-image-file] [format]",
.user_print = monitor_user_noop,
.mhandler.cmd_new = do_snapshot_blkdev,
},