diff options
Diffstat (limited to 'block.c')
| -rw-r--r-- | block.c | 138 |
1 files changed, 44 insertions, 94 deletions
@@ -64,10 +64,12 @@ static QTAILQ_HEAD(, BlockDriverState) all_bdrv_states = static QLIST_HEAD(, BlockDriver) bdrv_drivers = QLIST_HEAD_INITIALIZER(bdrv_drivers); -static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, - BlockDriverState *parent, - const BdrvChildRole *child_role, Error **errp); +static BlockDriverState *bdrv_open_inherit(const char *filename, + const char *reference, + QDict *options, int flags, + BlockDriverState *parent, + const BdrvChildRole *child_role, + Error **errp); /* If non-zero, use only whitelisted block drivers */ static int use_bdrv_whitelist; @@ -1336,14 +1338,13 @@ int bdrv_open_backing_file(BlockDriverState *bs, QDict *parent_options, qdict_put(options, "driver", qstring_from_str(bs->backing_format)); } - backing_hd = NULL; - ret = bdrv_open_inherit(&backing_hd, - *backing_filename ? backing_filename : NULL, - reference, options, 0, bs, &child_backing, - errp); - if (ret < 0) { + backing_hd = bdrv_open_inherit(*backing_filename ? backing_filename : NULL, + reference, options, 0, bs, &child_backing, + errp); + if (!backing_hd) { bs->open_flags |= BDRV_O_NO_BACKING; error_prepend(errp, "Could not open backing file: "); + ret = -EINVAL; goto free_exit; } @@ -1383,7 +1384,6 @@ BdrvChild *bdrv_open_child(const char *filename, BdrvChild *c = NULL; BlockDriverState *bs; QDict *image_options; - int ret; char *bdref_key_dot; const char *reference; @@ -1403,10 +1403,9 @@ BdrvChild *bdrv_open_child(const char *filename, goto done; } - bs = NULL; - ret = bdrv_open_inherit(&bs, filename, reference, image_options, 0, - parent, child_role, errp); - if (ret < 0) { + bs = bdrv_open_inherit(filename, reference, image_options, 0, + parent, child_role, errp); + if (!bs) { goto done; } @@ -1427,7 +1426,6 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, int64_t total_size; QemuOpts *opts = NULL; BlockDriverState *bs_snapshot; - Error *local_err = NULL; int ret; /* if snapshot, we create a temporary backing file and open it @@ -1466,12 +1464,10 @@ static BlockDriverState *bdrv_append_temp_snapshot(BlockDriverState *bs, qdict_put(snapshot_options, "driver", qstring_from_str("qcow2")); - bs_snapshot = NULL; - ret = bdrv_open(&bs_snapshot, NULL, NULL, snapshot_options, - flags, &local_err); + bs_snapshot = bdrv_open(NULL, NULL, snapshot_options, flags, errp); snapshot_options = NULL; - if (ret < 0) { - error_propagate(errp, local_err); + if (!bs_snapshot) { + ret = -EINVAL; goto out; } @@ -1505,10 +1501,12 @@ out: * 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). */ -static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, - BlockDriverState *parent, - const BdrvChildRole *child_role, Error **errp) +static BlockDriverState *bdrv_open_inherit(const char *filename, + const char *reference, + QDict *options, int flags, + BlockDriverState *parent, + const BdrvChildRole *child_role, + Error **errp) { int ret; BdrvChild *file = NULL; @@ -1520,7 +1518,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, QDict *snapshot_options = NULL; int snapshot_flags = 0; - assert(pbs); assert(!child_role || !flags); assert(!child_role == !parent); @@ -1528,33 +1525,22 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, 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; + return NULL; } bs = bdrv_lookup_bs(reference, reference, errp); if (!bs) { - return -ENODEV; + return NULL; } bdrv_ref(bs); - *pbs = bs; - return 0; + return bs; } - if (*pbs) { - bs = *pbs; - } else { - bs = bdrv_new(); - } + bs = bdrv_new(); /* NULL means an empty set of options */ if (options == NULL) { @@ -1564,7 +1550,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, /* json: syntax counts as explicit options, as if in the QDict */ parse_json_protocol(options, &filename, &local_err); if (local_err) { - ret = -EINVAL; goto fail; } @@ -1591,7 +1576,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, drv = bdrv_find_format(drvname); if (!drv) { error_setg(errp, "Unknown driver: '%s'", drvname); - ret = -EINVAL; goto fail; } } @@ -1621,7 +1605,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, file = bdrv_open_child(filename, options, "file", bs, &child_file, true, &local_err); if (local_err) { - ret = -EINVAL; goto fail; } } @@ -1648,7 +1631,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, qdict_put(options, "driver", qstring_from_str(drv->format_name)); } else if (!drv) { error_setg(errp, "Must specify either driver or file"); - ret = -EINVAL; goto fail; } @@ -1691,7 +1673,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, drv->format_name, entry->key); } - ret = -EINVAL; goto close_and_fail; } @@ -1702,7 +1683,6 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, && !runstate_check(RUN_STATE_PAUSED)) { /* HACK */ error_setg(errp, "Guest must be stopped for opening of encrypted image"); - ret = -EBUSY; goto close_and_fail; } @@ -1716,36 +1696,17 @@ static int bdrv_open_inherit(BlockDriverState **pbs, const char *filename, snapshot_options, &local_err); snapshot_options = NULL; if (local_err) { - ret = -EINVAL; goto close_and_fail; } - if (!*pbs) { - /* We are not going to return bs but the overlay on top of it - * (snapshot_bs); thus, we have to drop the strong reference to bs - * (which we obtained by calling bdrv_new()). bs will not be - * deleted, though, because the overlay still has a reference to it. - */ - bdrv_unref(bs); - bs = snapshot_bs; - } else { - /* We are not going to return snapshot_bs, so we have to drop the - * strong reference to it (which was returned by - * bdrv_append_temp_snapshot()). snapshot_bs will not be deleted, - * though, because bdrv_append_temp_snapshot() made all parental - * references to bs (*pbs) point to snapshot_bs. - * In fact, if *pbs was not NULL, we are not going to return any new - * BDS. But we do not need to decrement bs's refcount here as is - * done above, because with a non-NULL *pbs this function never even - * had a strong reference to bs. */ - bdrv_unref(snapshot_bs); - } - } - - if (!*pbs) { - *pbs = bs; + /* We are not going to return bs but the overlay on top of it + * (snapshot_bs); thus, we have to drop the strong reference to bs + * (which we obtained by calling bdrv_new()). bs will not be deleted, + * though, because the overlay still has a reference to it. */ + bdrv_unref(bs); + bs = snapshot_bs; } - return 0; + return bs; fail: if (file != NULL) { @@ -1756,36 +1717,26 @@ 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); - } + bdrv_unref(bs); if (local_err) { error_propagate(errp, local_err); } - return ret; + return NULL; close_and_fail: - /* See fail path, but now the BDS has to be always closed */ - if (*pbs) { - bdrv_close(bs); - } else { - bdrv_unref(bs); - } + bdrv_unref(bs); QDECREF(snapshot_options); QDECREF(options); if (local_err) { error_propagate(errp, local_err); } - return ret; + return NULL; } -int bdrv_open(BlockDriverState **pbs, const char *filename, - const char *reference, QDict *options, int flags, Error **errp) +BlockDriverState *bdrv_open(const char *filename, const char *reference, + QDict *options, int flags, Error **errp) { - return bdrv_open_inherit(pbs, filename, reference, options, flags, NULL, + return bdrv_open_inherit(filename, reference, options, flags, NULL, NULL, errp); } @@ -3572,11 +3523,10 @@ void bdrv_img_create(const char *filename, const char *fmt, qstring_from_str(backing_fmt)); } - bs = NULL; - ret = bdrv_open(&bs, full_backing, NULL, backing_options, - back_flags, &local_err); + bs = bdrv_open(full_backing, NULL, backing_options, back_flags, + &local_err); g_free(full_backing); - if (ret < 0) { + if (!bs) { goto out; } size = bdrv_getlength(bs); |