/*
* Opens a file using a protocol (file, host_device, nbd, ...)
*
- * options is a QDict of options to pass to the block drivers, or NULL for an
- * empty set of options. The reference to the QDict belongs to the block layer
- * after the call (even on failure), so if the caller intends to reuse the
- * dictionary, it needs to use QINCREF() before calling bdrv_file_open.
+ * options is an indirect pointer to a QDict of options to pass to the block
+ * drivers, or pointer to NULL for an empty set of options. If this function
+ * takes ownership of the QDict reference, it will set *options to NULL;
+ * otherwise, it will contain unused/unrecognized options after this function
+ * returns. Then, the caller is responsible for freeing it. If it intends to
+ * reuse the QDict, QINCREF() should be called beforehand.
*/
-int bdrv_file_open(BlockDriverState **pbs, const char *filename,
- const char *reference, QDict *options, int flags,
- Error **errp)
+static int bdrv_file_open(BlockDriverState *bs, const char *filename,
+ QDict **options, int flags, Error **errp)
{
- BlockDriverState *bs = NULL;
BlockDriver *drv;
const char *drvname;
bool allow_protocol_prefix = false;
Error *local_err = NULL;
int ret;
- /* NULL means an empty set of options */
- if (options == NULL) {
- options = qdict_new();
- }
-
- if (reference) {
- if (filename || qdict_size(options)) {
- error_setg(errp, "Cannot reference an existing block device with "
- "additional options or a new filename");
- return -EINVAL;
- }
- QDECREF(options);
-
- bs = bdrv_lookup_bs(reference, reference, errp);
- if (!bs) {
- return -ENODEV;
- }
- bdrv_ref(bs);
- *pbs = bs;
- return 0;
- }
-
- bs = bdrv_new("");
- bs->options = options;
- options = qdict_clone_shallow(options);
-
/* Fetch the file name from the options QDict if necessary */
if (!filename) {
- filename = qdict_get_try_str(options, "filename");
- } else if (filename && !qdict_haskey(options, "filename")) {
- qdict_put(options, "filename", qstring_from_str(filename));
+ 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;
} else {
error_setg(errp, "Can't specify 'file' and 'filename' options at the "
}
/* Find the right block driver */
- drvname = qdict_get_try_str(options, "driver");
+ drvname = qdict_get_try_str(*options, "driver");
if (drvname) {
drv = bdrv_find_format(drvname);
if (!drv) {
error_setg(errp, "Unknown driver '%s'", drvname);
}
- qdict_del(options, "driver");
+ qdict_del(*options, "driver");
} else if (filename) {
drv = bdrv_find_protocol(filename, allow_protocol_prefix);
if (!drv) {
/* Parse the filename and open it */
if (drv->bdrv_parse_filename && filename) {
- drv->bdrv_parse_filename(filename, options, &local_err);
+ drv->bdrv_parse_filename(filename, *options, &local_err);
if (local_err) {
error_propagate(errp, local_err);
ret = -EINVAL;
goto fail;
}
- qdict_del(options, "filename");
+ qdict_del(*options, "filename");
}
if (!drv->bdrv_file_open) {
- ret = bdrv_open(bs, filename, options, flags, drv, &local_err);
- options = NULL;
+ ret = bdrv_open(&bs, filename, NULL, *options, flags, drv, &local_err);
+ *options = NULL;
} else {
- ret = bdrv_open_common(bs, NULL, options, flags, drv, &local_err);
+ ret = bdrv_open_common(bs, NULL, *options, flags, drv, &local_err);
}
if (ret < 0) {
error_propagate(errp, local_err);
goto fail;
}
- /* Check if any unknown options were used */
- if (options && (qdict_size(options) != 0)) {
- const QDictEntry *entry = qdict_first(options);
- error_setg(errp, "Block protocol '%s' doesn't support the option '%s'",
- drv->format_name, entry->key);
- ret = -EINVAL;
- goto fail;
- }
- QDECREF(options);
-
bs->growable = 1;
- *pbs = bs;
return 0;
fail:
- QDECREF(options);
- if (!bs->drv) {
- QDECREF(bs->options);
- }
- bdrv_unref(bs);
return ret;
}
sizeof(backing_filename));
}
- bs->backing_hd = bdrv_new("");
-
if (bs->backing_format[0] != '\0') {
back_drv = bdrv_find_format(bs->backing_format);
}
back_flags = bs->open_flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT |
BDRV_O_COPY_ON_READ);
- ret = bdrv_open(bs->backing_hd,
- *backing_filename ? backing_filename : NULL, options,
+ assert(bs->backing_hd == NULL);
+ ret = bdrv_open(&bs->backing_hd,
+ *backing_filename ? backing_filename : NULL, NULL, options,
back_flags, back_drv, &local_err);
if (ret < 0) {
- bdrv_unref(bs->backing_hd);
bs->backing_hd = NULL;
bs->open_flags |= BDRV_O_NO_BACKING;
error_setg(errp, "Could not open backing file: %s",
* Opens a disk image whose options are given as BlockdevRef in another block
* device's options.
*
- * If force_raw is true, bdrv_file_open() will be used, thereby preventing any
- * image format auto-detection. If it is false and a filename is given,
- * bdrv_open() will be used for auto-detection.
- *
* If allow_none is true, no image will be opened if filename is false and no
* BlockdevRef is given. *pbs will remain unchanged and 0 will be returned.
*
* BlockdevRef.
*
* The BlockdevRef will be removed from the options QDict.
+ *
+ * To conform with the behavior of bdrv_open(), *pbs has to be NULL.
*/
int bdrv_open_image(BlockDriverState **pbs, const char *filename,
QDict *options, const char *bdref_key, int flags,
- bool force_raw, bool allow_none, Error **errp)
+ bool allow_none, Error **errp)
{
QDict *image_options;
int ret;
char *bdref_key_dot;
const char *reference;
+ assert(pbs);
+ assert(*pbs == NULL);
+
bdref_key_dot = g_strdup_printf("%s.", bdref_key);
qdict_extract_subqdict(options, &image_options, bdref_key_dot);
g_free(bdref_key_dot);
goto done;
}
- if (filename && !force_raw) {
- /* If a filename is given and the block driver should be detected
- automatically (instead of using none), use bdrv_open() in order to do
- that auto-detection. */
- BlockDriverState *bs;
-
- if (reference) {
- error_setg(errp, "Cannot reference an existing block device while "
- "giving a filename");
- ret = -EINVAL;
- goto done;
- }
-
- bs = bdrv_new("");
- ret = bdrv_open(bs, filename, image_options, flags, NULL, errp);
- if (ret < 0) {
- bdrv_unref(bs);
- } else {
- *pbs = bs;
- }
- } else {
- ret = bdrv_file_open(pbs, filename, reference, image_options, flags,
- errp);
- }
+ ret = bdrv_open(pbs, filename, reference, image_options, flags, NULL, errp);
done:
qdict_del(options, bdref_key);
* empty set of options. The reference to the QDict belongs to the block layer
* after the call (even on failure), so if the caller intends to reuse the
* dictionary, it needs to use QINCREF() before calling bdrv_open.
+ *
+ * If *pbs is NULL, a new BDS will be created with a pointer to it stored there.
+ * If it is not NULL, the referenced BDS will be reused.
+ *
+ * The reference parameter may be used to specify an existing block device which
+ * should be opened. If specified, neither options nor a filename may be given,
+ * nor can an existing BDS be reused (that is, *pbs has to be NULL).
*/
-int bdrv_open(BlockDriverState *bs, const char *filename, QDict *options,
- int flags, BlockDriver *drv, Error **errp)
+int bdrv_open(BlockDriverState **pbs, const char *filename,
+ const char *reference, QDict *options, int flags,
+ 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;
+ BlockDriverState *file = NULL, *bs;
const char *drvname;
Error *local_err = NULL;
+ assert(pbs);
+
+ if (reference) {
+ bool options_non_empty = options ? qdict_size(options) : false;
+ QDECREF(options);
+
+ if (*pbs) {
+ error_setg(errp, "Cannot reuse an existing BDS when referencing "
+ "another block device");
+ return -EINVAL;
+ }
+
+ if (filename || options_non_empty) {
+ error_setg(errp, "Cannot reference an existing block device with "
+ "additional options or a new filename");
+ return -EINVAL;
+ }
+
+ bs = bdrv_lookup_bs(reference, reference, errp);
+ if (!bs) {
+ return -ENODEV;
+ }
+ bdrv_ref(bs);
+ *pbs = bs;
+ return 0;
+ }
+
+ if (*pbs) {
+ bs = *pbs;
+ } else {
+ bs = bdrv_new("");
+ }
+
/* NULL means an empty set of options */
if (options == NULL) {
options = qdict_new();
bs->options = options;
options = qdict_clone_shallow(options);
+ if (flags & BDRV_O_PROTOCOL) {
+ assert(!drv);
+ ret = bdrv_file_open(bs, filename, &options, flags & ~BDRV_O_PROTOCOL,
+ &local_err);
+ if (!ret) {
+ goto done;
+ } else if (bs->drv) {
+ goto close_and_fail;
+ } else {
+ goto fail;
+ }
+ }
+
/* For snapshot=on, create a temporary qcow2 overlay */
if (flags & BDRV_O_SNAPSHOT) {
BlockDriverState *bs1;
instead of opening 'filename' directly */
/* Get the required size from the image */
- bs1 = bdrv_new("");
QINCREF(options);
- ret = bdrv_open(bs1, filename, options, BDRV_O_NO_BACKING,
+ bs1 = NULL;
+ ret = bdrv_open(&bs1, filename, NULL, options, BDRV_O_NO_BACKING,
drv, &local_err);
if (ret < 0) {
- bdrv_unref(bs1);
goto fail;
}
total_size = bdrv_getlength(bs1) & BDRV_SECTOR_MASK;
flags |= BDRV_O_ALLOW_RDWR;
}
+ assert(file == NULL);
ret = bdrv_open_image(&file, filename, options, "file",
- bdrv_open_flags(bs, flags | BDRV_O_UNMAP), true, true,
- &local_err);
+ bdrv_open_flags(bs, flags | BDRV_O_UNMAP) |
+ BDRV_O_PROTOCOL, true, &local_err);
if (ret < 0) {
goto fail;
}
}
}
+done:
/* Check if any unknown options were used */
- if (qdict_size(options) != 0) {
+ if (options && (qdict_size(options) != 0)) {
const QDictEntry *entry = qdict_first(options);
- error_setg(errp, "Block format '%s' used by device '%s' doesn't "
- "support the option '%s'", drv->format_name, bs->device_name,
- entry->key);
+ if (flags & BDRV_O_PROTOCOL) {
+ error_setg(errp, "Block protocol '%s' doesn't support the option "
+ "'%s'", drv->format_name, entry->key);
+ } else {
+ error_setg(errp, "Block format '%s' used by device '%s' doesn't "
+ "support the option '%s'", drv->format_name,
+ bs->device_name, entry->key);
+ }
ret = -EINVAL;
goto close_and_fail;
bdrv_dev_change_media_cb(bs, true);
}
+ *pbs = bs;
return 0;
unlink_and_fail:
QDECREF(bs->options);
QDECREF(options);
bs->options = NULL;
+ if (!*pbs) {
+ /* If *pbs is NULL, a new BDS has been created in this function and
+ needs to be freed now. Otherwise, it does not need to be closed,
+ since it has not really been opened yet. */
+ bdrv_unref(bs);
+ }
if (local_err) {
error_propagate(errp, local_err);
}
return ret;
close_and_fail:
- bdrv_close(bs);
+ /* See fail path, but now the BDS has to be always closed */
+ if (*pbs) {
+ bdrv_close(bs);
+ } else {
+ bdrv_unref(bs);
+ }
QDECREF(options);
if (local_err) {
error_propagate(errp, local_err);
back_flags =
flags & ~(BDRV_O_RDWR | BDRV_O_SNAPSHOT | BDRV_O_NO_BACKING);
- bs = bdrv_new("");
-
- ret = bdrv_open(bs, backing_file->value.s, NULL, back_flags,
+ bs = NULL;
+ ret = bdrv_open(&bs, backing_file->value.s, NULL, NULL, back_flags,
backing_drv, &local_err);
if (ret < 0) {
error_setg_errno(errp, -ret, "Could not open '%s': %s",
error_get_pretty(local_err));
error_free(local_err);
local_err = NULL;
- bdrv_unref(bs);
goto out;
}
bdrv_get_geometry(bs, &size);
projects / qemu.git / blobdiff