[PATCH v3 05/11] qapi: add x-blockdev-replace command

Add a command that can replace bs in following BdrvChild structures: - qdev blk root child - block-export blk root child - any child BlockDriverState selected by child-name Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov(a)virtuozzo.com&gt; --- qapi/block-core.json | 62 ++++++++++++++++++++++++++++++++++++++++ blockdev.c | 65 ++++++++++++++++++++++++++++++++++++++++++ stubs/blk-by-qdev-id.c | 9 ++++++ stubs/meson.build | 1 + 4 files changed, 137 insertions(+) create mode 100644 stubs/blk-by-qdev-id.c diff --git a/qapi/block-core.json b/qapi/block-core.json index 9a5a3641d0..f760dc21f5 100644 --- a/qapi/block-core.json +++ b/qapi/block-core.json @@ -5574,3 +5574,65 @@ { 'command': 'blockdev-snapshot-delete-internal-sync', 'data': { 'device': 'str', '*id': 'str', '*name': 'str'}, 'returns': 'SnapshotInfo' } + +## +# @BlockParentType: +# +# Since 7.0 +## +{ 'enum': 'BlockParentType', + 'data': ['qdev', 'driver', 'export'] } + +## +# @BdrvChildRefQdev: +# +# Since 7.0 +## +{ 'struct': 'BdrvChildRefQdev', + 'data': { 'qdev-id': 'str' } } + +## +# @BdrvChildRefExport: +# +# Since 7.0 +## +{ 'struct': 'BdrvChildRefExport', + 'data': { 'export-id': 'str' } } + +## +# @BdrvChildRefDriver: +# +# Since 7.0 +## +{ 'struct': 'BdrvChildRefDriver', + 'data': { 'node-name': 'str', 'child': 'str' } } + +## +# @BlockdevReplace: +# +# Since 7.0 +## +{ 'union': 'BlockdevReplace', + 'base': { + 'parent-type': 'BlockParentType', + 'new-child': 'str' + }, + 'discriminator': 'parent-type', + 'data': { + 'qdev': 'BdrvChildRefQdev', + 'export': 'BdrvChildRefExport', + 'driver': 'BdrvChildRefDriver' + } } + +## +# @x-blockdev-replace: +# +# Replace a block-node associated with device (selected by +# @qdev-id) or with block-export (selected by @export-id) or +# any child of block-node (selected by @node-name and @child) +# with @new-child block-node. +# +# Since 7.0 +## +{ 'command': 'x-blockdev-replace', 'boxed': true, + 'data': 'BlockdevReplace' } diff --git a/blockdev.c b/blockdev.c index d20963be2a..9fd1783be2 100644 --- a/blockdev.c +++ b/blockdev.c @@ -2229,6 +2229,71 @@ static void blockdev_add_abort(BlkActionState *common) bdrv_unref(s->bs); } +static int blockdev_replace(BlockdevReplace *repl, Transaction *tran, + Error **errp) +{ + BdrvChild *child = NULL; + BlockDriverState *new_child_bs; + + if (repl->parent_type == BLOCK_PARENT_TYPE_DRIVER) { + BlockDriverState *parent_bs; + + parent_bs = bdrv_find_node(repl->u.driver.node_name); + if (!parent_bs) { + error_setg(errp, "Block driver node with node-name '%s' not " + "found", repl->u.driver.node_name); + return -EINVAL; + } + + child = bdrv_find_child(parent_bs, repl->u.driver.child); + if (!child) { + error_setg(errp, "Block driver node '%s' doesn't have child " + "named '%s'", repl->u.driver.node_name, + repl->u.driver.child); + return -EINVAL; + } + } else { + /* Other types are similar, they work through blk */ + BlockBackend *blk; + bool is_qdev = repl->parent_type == BLOCK_PARENT_TYPE_QDEV; + const char *id = + is_qdev ? repl->u.qdev.qdev_id : repl->u.export.export_id; + + assert(is_qdev || repl->parent_type == BLOCK_PARENT_TYPE_EXPORT); + + blk = is_qdev ? blk_by_qdev_id(id, errp) : blk_by_export_id(id, errp); + if (!blk) { + return -EINVAL; + } + + child = blk_root(blk); + if (!child) { + error_setg(errp, "%s '%s' is empty, nothing to replace", + is_qdev ? "Device" : "Export", id); + return -EINVAL; + } + } + + assert(child); + assert(child->bs); + + new_child_bs = bdrv_find_node(repl->new_child); + if (!new_child_bs) { + error_setg(errp, "Node '%s' not found", repl->new_child); + return -EINVAL; + } + + return bdrv_replace_child_bs(child, new_child_bs, tran, errp); +} + +void qmp_x_blockdev_replace(BlockdevReplace *repl, Error **errp) +{ + Transaction *tran = tran_new(); + int ret = blockdev_replace(repl, tran, errp); + + tran_finalize(tran, ret); +} + static const BlkActionOps actions[] = { [TRANSACTION_ACTION_KIND_BLOCKDEV_SNAPSHOT] = { .instance_size = sizeof(ExternalSnapshotState), diff --git a/stubs/blk-by-qdev-id.c b/stubs/blk-by-qdev-id.c new file mode 100644 index 0000000000..0e751ce4f7 --- /dev/null +++ b/stubs/blk-by-qdev-id.c @@ -0,0 +1,9 @@ +#include "qemu/osdep.h" +#include "qapi/error.h" +#include "sysemu/block-backend.h" + +BlockBackend *blk_by_qdev_id(const char *id, Error **errp) +{ + error_setg(errp, "blk '%s' not found", id); + return NULL; +} diff --git a/stubs/meson.build b/stubs/meson.build index d359cbe1ad..90358823fc 100644 --- a/stubs/meson.build +++ b/stubs/meson.build @@ -1,6 +1,7 @@ stub_ss.add(files('bdrv-next-monitor-owned.c')) stub_ss.add(files('blk-commit-all.c')) stub_ss.add(files('blk-exp-close-all.c')) +stub_ss.add(files('blk-by-qdev-id.c')) stub_ss.add(files('blockdev-close-all-bdrv-states.c')) stub_ss.add(files('change-state-handler.c')) stub_ss.add(files('cmos.c')) -- 2.31.1