{
int open_flags = flags | BDRV_O_CACHE_WB;
+ /* The backing file of a temporary snapshot is read-only */
+ if (flags & BDRV_O_SNAPSHOT) {
+ open_flags &= ~BDRV_O_RDWR;
+ }
+
/*
* Clear flags that are internal to the block layer before opening the
* image.
{
BlockDriver *drv;
const char *drvname;
- bool allow_protocol_prefix = false;
+ bool parse_filename = false;
Error *local_err = NULL;
int ret;
filename = qdict_get_try_str(*options, "filename");
} else if (filename && !qdict_haskey(*options, "filename")) {
qdict_put(*options, "filename", qstring_from_str(filename));
- allow_protocol_prefix = true;
+ parse_filename = true;
} else {
error_setg(errp, "Can't specify 'file' and 'filename' options at the "
"same time");
}
qdict_del(*options, "driver");
} else if (filename) {
- drv = bdrv_find_protocol(filename, allow_protocol_prefix);
+ drv = bdrv_find_protocol(filename, parse_filename);
if (!drv) {
error_setg(errp, "Unknown protocol");
}
}
/* Parse the filename and open it */
- if (drv->bdrv_parse_filename && filename) {
+ if (drv->bdrv_parse_filename && parse_filename) {
drv->bdrv_parse_filename(filename, *options, &local_err);
if (local_err) {
error_propagate(errp, local_err);
return ret;
}
+void bdrv_append_temp_snapshot(BlockDriverState *bs, Error **errp)
+{
+ /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
+ char tmp_filename[PATH_MAX + 1];
+
+ int64_t total_size;
+ BlockDriver *bdrv_qcow2;
+ QEMUOptionParameter *create_options;
+ QDict *snapshot_options;
+ BlockDriverState *bs_snapshot;
+ Error *local_err;
+ int ret;
+
+ /* if snapshot, we create a temporary backing file and open it
+ instead of opening 'filename' directly */
+
+ /* 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");
+ return;
+ }
+ total_size &= BDRV_SECTOR_MASK;
+
+ /* Create the temporary image */
+ ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not get temporary filename");
+ return;
+ }
+
+ bdrv_qcow2 = bdrv_find_format("qcow2");
+ create_options = parse_option_parameters("", bdrv_qcow2->create_options,
+ NULL);
+
+ set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size);
+
+ ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options, &local_err);
+ free_option_parameters(create_options);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret, "Could not create temporary overlay "
+ "'%s': %s", tmp_filename,
+ error_get_pretty(local_err));
+ error_free(local_err);
+ return;
+ }
+
+ /* Prepare a new options QDict for the temporary file */
+ snapshot_options = qdict_new();
+ qdict_put(snapshot_options, "file.driver",
+ qstring_from_str("file"));
+ qdict_put(snapshot_options, "file.filename",
+ qstring_from_str(tmp_filename));
+
+ bs_snapshot = bdrv_new("");
+ bs_snapshot->is_temporary = 1;
+
+ ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options,
+ bs->open_flags & ~BDRV_O_SNAPSHOT, bdrv_qcow2, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ return;
+ }
+
+ bdrv_append(bs_snapshot, bs);
+}
+
/*
* Opens a disk image (raw, qcow2, vmdk, ...)
*
BlockDriver *drv, Error **errp)
{
int ret;
- /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */
- char tmp_filename[PATH_MAX + 1];
BlockDriverState *file = NULL, *bs;
const char *drvname;
Error *local_err = NULL;
}
}
- /* For snapshot=on, create a temporary qcow2 overlay */
- if (flags & BDRV_O_SNAPSHOT) {
- BlockDriverState *bs1;
- int64_t total_size;
- BlockDriver *bdrv_qcow2;
- QEMUOptionParameter *create_options;
- QDict *snapshot_options;
-
- /* if snapshot, we create a temporary backing file and open it
- instead of opening 'filename' directly */
-
- /* Get the required size from the image */
- QINCREF(options);
- bs1 = NULL;
- ret = bdrv_open(&bs1, filename, NULL, options, BDRV_O_NO_BACKING,
- drv, &local_err);
- if (ret < 0) {
- goto fail;
- }
- total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
-
- bdrv_unref(bs1);
-
- /* Create the temporary image */
- ret = get_tmp_filename(tmp_filename, sizeof(tmp_filename));
- if (ret < 0) {
- error_setg_errno(errp, -ret, "Could not get temporary filename");
- goto fail;
- }
-
- bdrv_qcow2 = bdrv_find_format("qcow2");
- create_options = parse_option_parameters("", bdrv_qcow2->create_options,
- NULL);
-
- set_option_parameter_int(create_options, BLOCK_OPT_SIZE, total_size);
-
- ret = bdrv_create(bdrv_qcow2, tmp_filename, create_options, &local_err);
- free_option_parameters(create_options);
- if (ret < 0) {
- error_setg_errno(errp, -ret, "Could not create temporary overlay "
- "'%s': %s", tmp_filename,
- error_get_pretty(local_err));
- error_free(local_err);
- local_err = NULL;
- goto fail;
- }
-
- /* Prepare a new options QDict for the temporary file, where user
- * options refer to the backing file */
- if (filename) {
- qdict_put(options, "file.filename", qstring_from_str(filename));
- }
- if (drv) {
- qdict_put(options, "driver", qstring_from_str(drv->format_name));
- }
-
- snapshot_options = qdict_new();
- qdict_put(snapshot_options, "backing", options);
- qdict_flatten(snapshot_options);
-
- bs->options = snapshot_options;
- options = qdict_clone_shallow(bs->options);
-
- filename = tmp_filename;
- drv = bdrv_qcow2;
- bs->is_temporary = 1;
- }
-
/* Open image file without format layer */
if (flags & BDRV_O_RDWR) {
flags |= BDRV_O_ALLOW_RDWR;
}
}
+ /* For snapshot=on, create a temporary qcow2 overlay. bs points to the
+ * temporary snapshot afterwards. */
+ if (flags & BDRV_O_SNAPSHOT) {
+ bdrv_append_temp_snapshot(bs, &local_err);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ goto close_and_fail;
+ }
+ }
+
+
done:
/* Check if any unknown options were used */
if (options && (qdict_size(options) != 0)) {
projects / lisovros / qemu_apohw.git / blobdiff