return ret;
}
-int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
+/**
+ * Helper function for bdrv_create_file_fallback(): Resize @blk to at
+ * least the given @minimum_size.
+ *
+ * On success, return @blk's actual length.
+ * Otherwise, return -errno.
+ */
+static int64_t create_file_fallback_truncate(BlockBackend *blk,
+ int64_t minimum_size, Error **errp)
{
- BlockDriver *drv;
Error *local_err = NULL;
+ int64_t size;
+ int ret;
+
+ ret = blk_truncate(blk, minimum_size, false, PREALLOC_MODE_OFF, &local_err);
+ if (ret < 0 && ret != -ENOTSUP) {
+ error_propagate(errp, local_err);
+ return ret;
+ }
+
+ size = blk_getlength(blk);
+ if (size < 0) {
+ error_free(local_err);
+ error_setg_errno(errp, -size,
+ "Failed to inquire the new image file's length");
+ return size;
+ }
+
+ if (size < minimum_size) {
+ /* Need to grow the image, but we failed to do that */
+ error_propagate(errp, local_err);
+ return -ENOTSUP;
+ }
+
+ error_free(local_err);
+ local_err = NULL;
+
+ return size;
+}
+
+/**
+ * Helper function for bdrv_create_file_fallback(): Zero the first
+ * sector to remove any potentially pre-existing image header.
+ */
+static int create_file_fallback_zero_first_sector(BlockBackend *blk,
+ int64_t current_size,
+ Error **errp)
+{
+ int64_t bytes_to_clear;
int ret;
+ bytes_to_clear = MIN(current_size, BDRV_SECTOR_SIZE);
+ if (bytes_to_clear) {
+ ret = blk_pwrite_zeroes(blk, 0, bytes_to_clear, BDRV_REQ_MAY_UNMAP);
+ if (ret < 0) {
+ error_setg_errno(errp, -ret,
+ "Failed to clear the new image's first sector");
+ return ret;
+ }
+ }
+
+ return 0;
+}
+
+static int bdrv_create_file_fallback(const char *filename, BlockDriver *drv,
+ QemuOpts *opts, Error **errp)
+{
+ BlockBackend *blk;
+ QDict *options;
+ int64_t size = 0;
+ char *buf = NULL;
+ PreallocMode prealloc;
+ Error *local_err = NULL;
+ int ret;
+
+ size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0);
+ buf = qemu_opt_get_del(opts, BLOCK_OPT_PREALLOC);
+ prealloc = qapi_enum_parse(&PreallocMode_lookup, buf,
+ PREALLOC_MODE_OFF, &local_err);
+ g_free(buf);
+ if (local_err) {
+ error_propagate(errp, local_err);
+ return -EINVAL;
+ }
+
+ if (prealloc != PREALLOC_MODE_OFF) {
+ error_setg(errp, "Unsupported preallocation mode '%s'",
+ PreallocMode_str(prealloc));
+ return -ENOTSUP;
+ }
+
+ options = qdict_new();
+ qdict_put_str(options, "driver", drv->format_name);
+
+ blk = blk_new_open(filename, NULL, options,
+ BDRV_O_RDWR | BDRV_O_RESIZE, errp);
+ if (!blk) {
+ error_prepend(errp, "Protocol driver '%s' does not support image "
+ "creation, and opening the image failed: ",
+ drv->format_name);
+ return -EINVAL;
+ }
+
+ size = create_file_fallback_truncate(blk, size, errp);
+ if (size < 0) {
+ ret = size;
+ goto out;
+ }
+
+ ret = create_file_fallback_zero_first_sector(blk, size, errp);
+ if (ret < 0) {
+ goto out;
+ }
+
+ ret = 0;
+out:
+ blk_unref(blk);
+ return ret;
+}
+
+int bdrv_create_file(const char *filename, QemuOpts *opts, Error **errp)
+{
+ BlockDriver *drv;
+
drv = bdrv_find_protocol(filename, true, errp);
if (drv == NULL) {
return -ENOENT;
}
- ret = bdrv_create(drv, filename, opts, &local_err);
- error_propagate(errp, local_err);
- return ret;
+ if (drv->bdrv_co_create_opts) {
+ return bdrv_create(drv, filename, opts, errp);
+ } else {
+ return bdrv_create_file_fallback(filename, drv, opts, errp);
+ }
}
/**
},
};
+static QemuOptsList fallback_create_opts = {
+ .name = "fallback-create-opts",
+ .head = QTAILQ_HEAD_INITIALIZER(fallback_create_opts.head),
+ .desc = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = QEMU_OPT_SIZE,
+ .help = "Virtual disk size"
+ },
+ {
+ .name = BLOCK_OPT_PREALLOC,
+ .type = QEMU_OPT_STRING,
+ .help = "Preallocation mode (allowed values: off)"
+ },
+ { /* end of list */ }
+ }
+};
+
/*
* Common part for opening disk images and files
*
{ 0, NULL }
};
- char *result = g_strdup("");
+ GString *result = g_string_sized_new(30);
struct perm_name *p;
for (p = permissions; p->name; p++) {
if (perm & p->perm) {
- char *old = result;
- result = g_strdup_printf("%s%s%s", old, *old ? ", " : "", p->name);
- g_free(old);
+ if (result->len > 0) {
+ g_string_append(result, ", ");
+ }
+ g_string_append(result, p->name);
}
}
- return result;
+ return g_string_free(result, FALSE);
}
/*
if (bdrv_get_aio_context(child_bs) != ctx) {
ret = bdrv_try_set_aio_context(child_bs, ctx, &local_err);
if (ret < 0 && child_role->can_set_aio_ctx) {
- GSList *ignore = g_slist_prepend(NULL, child);;
+ GSList *ignore = g_slist_prepend(NULL, child);
ctx = bdrv_get_aio_context(child_bs);
if (child_role->can_set_aio_ctx(child, ctx, &ignore, NULL)) {
error_free(local_err);
ret = 0;
g_slist_free(ignore);
- ignore = g_slist_prepend(NULL, child);;
+ ignore = g_slist_prepend(NULL, child);
child_role->set_aio_ctx(child, ctx, &ignore);
}
g_slist_free(ignore);
static void bdrv_detach_child(BdrvChild *child)
{
- if (child->next.le_prev) {
- QLIST_REMOVE(child, next);
- child->next.le_prev = NULL;
- }
+ QLIST_SAFE_REMOVE(child, next);
bdrv_replace_child(child, NULL);
}
}
}
+
+ if (ret == 0) {
+ QTAILQ_FOREACH_REVERSE(bs_entry, bs_queue, entry) {
+ BlockDriverState *bs = bs_entry->state.bs;
+
+ if (bs->drv->bdrv_reopen_commit_post)
+ bs->drv->bdrv_reopen_commit_post(&bs_entry->state);
+ }
+ }
cleanup:
QTAILQ_FOREACH_SAFE(bs_entry, bs_queue, entry, next) {
if (ret) {
*shared = cumulative_shared_perms;
}
+static bool bdrv_reopen_can_attach(BlockDriverState *parent,
+ BdrvChild *child,
+ BlockDriverState *new_child,
+ Error **errp)
+{
+ AioContext *parent_ctx = bdrv_get_aio_context(parent);
+ AioContext *child_ctx = bdrv_get_aio_context(new_child);
+ GSList *ignore;
+ bool ret;
+
+ ignore = g_slist_prepend(NULL, child);
+ ret = bdrv_can_set_aio_context(new_child, parent_ctx, &ignore, NULL);
+ g_slist_free(ignore);
+ if (ret) {
+ return ret;
+ }
+
+ ignore = g_slist_prepend(NULL, child);
+ ret = bdrv_can_set_aio_context(parent, child_ctx, &ignore, errp);
+ g_slist_free(ignore);
+ return ret;
+}
+
/*
* Take a BDRVReopenState and check if the value of 'backing' in the
* reopen_state->options QDict is valid or not.
}
/*
- * TODO: before removing the x- prefix from x-blockdev-reopen we
- * should move the new backing file into the right AioContext
- * instead of returning an error.
+ * Check AioContext compatibility so that the bdrv_set_backing_hd() call in
+ * bdrv_reopen_commit() won't fail.
*/
if (new_backing_bs) {
- if (bdrv_get_aio_context(new_backing_bs) != bdrv_get_aio_context(bs)) {
- error_setg(errp, "Cannot use a new backing file "
- "with a different AioContext");
+ if (!bdrv_reopen_can_attach(bs, bs->backing, new_backing_bs, errp)) {
return -EINVAL;
}
}
}
/* Put this QMP function here so it can access the static graph_bdrv_states. */
-BlockDeviceInfoList *bdrv_named_nodes_list(Error **errp)
+BlockDeviceInfoList *bdrv_named_nodes_list(bool flat,
+ Error **errp)
{
BlockDeviceInfoList *list, *entry;
BlockDriverState *bs;
list = NULL;
QTAILQ_FOREACH(bs, &graph_bdrv_states, node_list) {
- BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, errp);
+ BlockDeviceInfo *info = bdrv_block_device_info(NULL, bs, flat, errp);
if (!info) {
qapi_free_BlockDeviceInfoList(list);
return NULL;
return;
}
- if (!proto_drv->create_opts) {
- error_setg(errp, "Protocol driver '%s' does not support image creation",
- proto_drv->format_name);
- return;
- }
-
/* Create parameter list */
create_opts = qemu_opts_append(create_opts, drv->create_opts);
- create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
+ if (proto_drv->create_opts) {
+ create_opts = qemu_opts_append(create_opts, proto_drv->create_opts);
+ } else {
+ create_opts = qemu_opts_append(create_opts, &fallback_create_opts);
+ }
opts = qemu_opts_create(create_opts, NULL, 0, &error_abort);
return bs->drv->bdrv_amend_options(bs, opts, status_cb, cb_opaque, errp);
}
-/* This function will be called by the bdrv_recurse_is_first_non_filter method
- * of block filter and by bdrv_is_first_non_filter.
- * It is used to test if the given bs is the candidate or recurse more in the
- * node graph.
+/*
+ * This function checks whether the given @to_replace is allowed to be
+ * replaced by a node that always shows the same data as @bs. This is
+ * used for example to verify whether the mirror job can replace
+ * @to_replace by the target mirrored from @bs.
+ * To be replaceable, @bs and @to_replace may either be guaranteed to
+ * always show the same data (because they are only connected through
+ * filters), or some driver may allow replacing one of its children
+ * because it can guarantee that this child's data is not visible at
+ * all (for example, for dissenting quorum children that have no other
+ * parents).
*/
-bool bdrv_recurse_is_first_non_filter(BlockDriverState *bs,
- BlockDriverState *candidate)
+bool bdrv_recurse_can_replace(BlockDriverState *bs,
+ BlockDriverState *to_replace)
{
- /* return false if basic checks fails */
if (!bs || !bs->drv) {
return false;
}
- /* the code reached a non block filter driver -> check if the bs is
- * the same as the candidate. It's the recursion termination condition.
- */
- if (!bs->drv->is_filter) {
- return bs == candidate;
+ if (bs == to_replace) {
+ return true;
}
- /* Down this path the driver is a block filter driver */
- /* If the block filter recursion method is defined use it to recurse down
- * the node graph.
- */
- if (bs->drv->bdrv_recurse_is_first_non_filter) {
- return bs->drv->bdrv_recurse_is_first_non_filter(bs, candidate);
+ /* See what the driver can do */
+ if (bs->drv->bdrv_recurse_can_replace) {
+ return bs->drv->bdrv_recurse_can_replace(bs, to_replace);
}
- /* the driver is a block filter but don't allow to recurse -> return false
- */
- return false;
-}
-
-/* This function checks if the candidate is the first non filter bs down it's
- * bs chain. Since we don't have pointers to parents it explore all bs chains
- * from the top. Some filters can choose not to pass down the recursion.
- */
-bool bdrv_is_first_non_filter(BlockDriverState *candidate)
-{
- BlockDriverState *bs;
- BdrvNextIterator it;
-
- /* walk down the bs forest recursively */
- for (bs = bdrv_first(&it); bs; bs = bdrv_next(&it)) {
- bool perm;
-
- /* try to recurse in this top level bs */
- perm = bdrv_recurse_is_first_non_filter(bs, candidate);
-
- /* candidate is the first non filter */
- if (perm) {
- bdrv_next_cleanup(&it);
- return true;
- }
+ /* For filters without an own implementation, we can recurse on our own */
+ if (bs->drv->is_filter) {
+ BdrvChild *child = bs->file ?: bs->backing;
+ return bdrv_recurse_can_replace(child->bs, to_replace);
}
+ /* Safe default */
return false;
}
+/*
+ * Check whether the given @node_name can be replaced by a node that
+ * has the same data as @parent_bs. If so, return @node_name's BDS;
+ * NULL otherwise.
+ *
+ * @node_name must be a (recursive) *child of @parent_bs (or this
+ * function will return NULL).
+ *
+ * The result (whether the node can be replaced or not) is only valid
+ * for as long as no graph or permission changes occur.
+ */
BlockDriverState *check_to_replace_node(BlockDriverState *parent_bs,
const char *node_name, Error **errp)
{
* Another benefit is that this tests exclude backing files which are
* blocked by the backing blockers.
*/
- if (!bdrv_recurse_is_first_non_filter(parent_bs, to_replace_bs)) {
- error_setg(errp, "Only top most non filter can be replaced");
+ if (!bdrv_recurse_can_replace(parent_bs, to_replace_bs)) {
+ error_setg(errp, "Cannot replace '%s' by a node mirrored from '%s', "
+ "because it cannot be guaranteed that doing so would not "
+ "lead to an abrupt change of visible data",
+ node_name, parent_bs->node_name);
to_replace_bs = NULL;
goto out;
}
child->bs->exact_filename);
pstrcpy(bs->filename, sizeof(bs->filename), child->bs->filename);
+ qobject_unref(bs->full_open_options);
bs->full_open_options = qobject_ref(child->bs->full_open_options);
return;
projects / thirdparty / qemu.git / blobdiff