diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 100 |
1 files changed, 70 insertions, 30 deletions
@@ -629,7 +629,7 @@ BlockDriver *bdrv_find_protocol(const char *filename, } if (!path_has_protocol(filename) || !allow_protocol_prefix) { - return bdrv_find_format("file"); + return &bdrv_file; } p = strchr(filename, ':'); @@ -648,22 +648,49 @@ BlockDriver *bdrv_find_protocol(const char *filename, return NULL; } +/* + * Guess image format by probing its contents. + * This is not a good idea when your image is raw (CVE-2008-2004), but + * we do it anyway for backward compatibility. + * + * @buf contains the image's first @buf_size bytes. + * @buf_size is the buffer size in bytes (generally BLOCK_PROBE_BUF_SIZE, + * but can be smaller if the image file is smaller) + * @filename is its filename. + * + * For all block drivers, call the bdrv_probe() method to get its + * probing score. + * Return the first block driver with the highest probing score. + */ +BlockDriver *bdrv_probe_all(const uint8_t *buf, int buf_size, + const char *filename) +{ + int score_max = 0, score; + BlockDriver *drv = NULL, *d; + + QLIST_FOREACH(d, &bdrv_drivers, list) { + if (d->bdrv_probe) { + score = d->bdrv_probe(buf, buf_size, filename); + if (score > score_max) { + score_max = score; + drv = d; + } + } + } + + return drv; +} + static int find_image_format(BlockDriverState *bs, const char *filename, BlockDriver **pdrv, Error **errp) { - int score, score_max; - BlockDriver *drv1, *drv; - uint8_t buf[2048]; + BlockDriver *drv; + uint8_t buf[BLOCK_PROBE_BUF_SIZE]; int ret = 0; /* Return the raw BlockDriver * to scsi-generic devices or empty drives */ if (bs->sg || !bdrv_is_inserted(bs) || bdrv_getlength(bs) == 0) { - drv = bdrv_find_format("raw"); - if (!drv) { - error_setg(errp, "Could not find raw image format"); - ret = -ENOENT; - } - *pdrv = drv; + *pdrv = &bdrv_raw; return ret; } @@ -675,17 +702,7 @@ static int find_image_format(BlockDriverState *bs, const char *filename, return ret; } - score_max = 0; - drv = NULL; - QLIST_FOREACH(drv1, &bdrv_drivers, list) { - if (drv1->bdrv_probe) { - score = drv1->bdrv_probe(buf, ret, filename); - if (score > score_max) { - score_max = score; - drv = drv1; - } - } - } + drv = bdrv_probe_all(buf, ret, filename); if (!drv) { error_setg(errp, "Could not determine image format: No compatible " "driver found"); @@ -1180,7 +1197,6 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) { char *backing_filename = g_malloc0(PATH_MAX); int ret = 0; - BlockDriver *back_drv = NULL; BlockDriverState *backing_hd; Error *local_err = NULL; @@ -1213,14 +1229,14 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *options, Error **errp) backing_hd = bdrv_new(); - if (bs->backing_format[0] != '\0') { - back_drv = bdrv_find_format(bs->backing_format); + if (bs->backing_format[0] != '\0' && !qdict_haskey(options, "driver")) { + qdict_put(options, "driver", qstring_from_str(bs->backing_format)); } assert(bs->backing_hd == NULL); ret = bdrv_open(&backing_hd, *backing_filename ? backing_filename : NULL, NULL, options, - bdrv_backing_flags(bs->open_flags), back_drv, &local_err); + bdrv_backing_flags(bs->open_flags), NULL, &local_err); if (ret < 0) { bdrv_unref(backing_hd); backing_hd = NULL; @@ -1294,7 +1310,6 @@ int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) /* TODO: extra byte is a hack to ensure MAX_PATH space on Windows. */ char *tmp_filename = g_malloc0(PATH_MAX + 1); int64_t total_size; - BlockDriver *bdrv_qcow2; QemuOpts *opts = NULL; QDict *snapshot_options; BlockDriverState *bs_snapshot; @@ -1319,11 +1334,10 @@ int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) goto out; } - bdrv_qcow2 = bdrv_find_format("qcow2"); - opts = qemu_opts_create(bdrv_qcow2->create_opts, NULL, 0, + opts = qemu_opts_create(bdrv_qcow2.create_opts, NULL, 0, &error_abort); qemu_opt_set_number(opts, BLOCK_OPT_SIZE, total_size); - ret = bdrv_create(bdrv_qcow2, tmp_filename, opts, &local_err); + ret = bdrv_create(&bdrv_qcow2, tmp_filename, opts, &local_err); qemu_opts_del(opts); if (ret < 0) { error_setg_errno(errp, -ret, "Could not create temporary overlay " @@ -1343,7 +1357,7 @@ int bdrv_append_temp_snapshot(BlockDriverState *bs, int flags, Error **errp) bs_snapshot = bdrv_new(); ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, - flags, bdrv_qcow2, &local_err); + flags, &bdrv_qcow2, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto out; @@ -1467,6 +1481,7 @@ int bdrv_open(BlockDriverState **pbs, const char *filename, } /* Image format probing */ + bs->probed = !drv; if (!drv && file) { ret = find_image_format(file, filename, &drv, &local_err); if (ret < 0) { @@ -3801,6 +3816,14 @@ bool bdrv_chain_contains(BlockDriverState *top, BlockDriverState *base) return top != NULL; } +BlockDriverState *bdrv_next_node(BlockDriverState *bs) +{ + if (!bs) { + return QTAILQ_FIRST(&graph_bdrv_states); + } + return QTAILQ_NEXT(bs, node_list); +} + BlockDriverState *bdrv_next(BlockDriverState *bs) { if (!bs) { @@ -3809,6 +3832,11 @@ BlockDriverState *bdrv_next(BlockDriverState *bs) return QTAILQ_NEXT(bs, device_list); } +const char *bdrv_get_node_name(const BlockDriverState *bs) +{ + return bs->node_name; +} + /* TODO check what callers really want: bs->node_name or blk_name() */ const char *bdrv_get_device_name(const BlockDriverState *bs) { @@ -5541,6 +5569,18 @@ void bdrv_img_create(const char *filename, const char *fmt, return; } + if (!drv->create_opts) { + error_setg(errp, "Format driver '%s' does not support image creation", + drv->format_name); + return; + } + + if (!proto_drv->create_opts) { + error_setg(errp, "Protocol driver '%s' does not support image creation", + proto_drv->format_name); + return; + } + create_opts = qemu_opts_append(create_opts, drv->create_opts); create_opts = qemu_opts_append(create_opts, proto_drv->create_opts); |