From 12d3ba821da9f8a039240a8a1bc01e27a12f9c22 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Beno=C3=AEt=20Canet?= Date: Thu, 23 Jan 2014 21:31:35 +0100 Subject: [PATCH] qmp: Allow to change password on named block driver states. Signed-off-by: Benoit Canet Reviewed-by: Fam Zheng There was two candidate ways to implement named node manipulation: 1) { 'command': 'block_passwd', 'data': {'*device': 'str', '*node-name': 'str', 'password': 'str'} } 2) { 'command': 'block_passwd', 'data': {'device': 'str', '*device-is-node': 'bool', 'password': 'str'} } Luiz proposed 1 and says 2 was an abuse of the QMP interface and proposed to rewrite the QMP block interface for 2.0. Luiz does not like in 1 the fact that 2 fields are optional but one of them must be specified leading to an abuse of the QMP semantic. Kevin argumented that 2 what a clear abuse of the device field and would not be practical when reading fast some log file because the user would read "device" and think that a device is manipulated when it's in fact a node name. Documentation of 1 make it pretty clear what to do for the user. Kevin argued that all bs are node including devices ones so 2 does not make sense. Kevin also argued that rewriting the QMP block interface would not make disapear the current one. Kevin pushed the argument that making the QAPI generator compatible with the semantic of the operation would need a rewrite that no one has done yet. A vote has been done on the list to elect the version to use and 1 won. For reference the complete thread is: "[Qemu-devel] [PATCH V4 4/7] qmp: Allow to change password on names block driver states." Signed-off-by: Benoit Canet Signed-off-by: Kevin Wolf --- block.c | 32 ++++++++++++++++++++++++++++++++ blockdev.c | 13 +++++++++---- hmp.c | 2 +- include/block/block.h | 3 +++ qapi-schema.json | 9 +++++++-- qmp-commands.hx | 3 ++- 6 files changed, 54 insertions(+), 8 deletions(-) diff --git a/block.c b/block.c index 5f6308df67..064df90917 100644 --- a/block.c +++ b/block.c @@ -3309,6 +3309,38 @@ BlockDeviceInfoList *bdrv_named_nodes_list(void) return list; } +BlockDriverState *bdrv_lookup_bs(const char *device, + const char *node_name, + Error **errp) +{ + BlockDriverState *bs = NULL; + + if ((!device && !node_name) || (device && node_name)) { + error_setg(errp, "Use either device or node-name but not both"); + return NULL; + } + + if (device) { + bs = bdrv_find(device); + + if (!bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, device); + return NULL; + } + + return bs; + } + + bs = bdrv_find_node(node_name); + + if (!bs) { + error_set(errp, QERR_DEVICE_NOT_FOUND, node_name); + return NULL; + } + + return bs; +} + BlockDriverState *bdrv_next(BlockDriverState *bs) { if (!bs) { diff --git a/blockdev.c b/blockdev.c index 0bfe38027b..2f4065e2cd 100644 --- a/blockdev.c +++ b/blockdev.c @@ -1481,14 +1481,19 @@ void qmp_eject(const char *device, bool has_force, bool force, Error **errp) eject_device(bs, force, errp); } -void qmp_block_passwd(const char *device, const char *password, Error **errp) +void qmp_block_passwd(bool has_device, const char *device, + bool has_node_name, const char *node_name, + const char *password, Error **errp) { + Error *local_err = NULL; BlockDriverState *bs; int err; - bs = bdrv_find(device); - if (!bs) { - error_set(errp, QERR_DEVICE_NOT_FOUND, device); + bs = bdrv_lookup_bs(has_device ? device : NULL, + has_node_name ? node_name : NULL, + &local_err); + if (error_is_set(&local_err)) { + error_propagate(errp, local_err); return; } diff --git a/hmp.c b/hmp.c index 468f97d176..5804a5a2ad 100644 --- a/hmp.c +++ b/hmp.c @@ -871,7 +871,7 @@ void hmp_block_passwd(Monitor *mon, const QDict *qdict) const char *password = qdict_get_str(qdict, "password"); Error *errp = NULL; - qmp_block_passwd(device, password, &errp); + qmp_block_passwd(true, device, false, NULL, password, &errp); hmp_handle_error(mon, &errp); } diff --git a/include/block/block.h b/include/block/block.h index 13654ede8b..b4a77e6cff 100644 --- a/include/block/block.h +++ b/include/block/block.h @@ -380,6 +380,9 @@ const char *bdrv_get_format_name(BlockDriverState *bs); BlockDriverState *bdrv_find(const char *name); BlockDriverState *bdrv_find_node(const char *node_name); BlockDeviceInfoList *bdrv_named_nodes_list(void); +BlockDriverState *bdrv_lookup_bs(const char *device, + const char *node_name, + Error **errp); BlockDriverState *bdrv_next(BlockDriverState *bs); void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque); diff --git a/qapi-schema.json b/qapi-schema.json index b619f019ee..3f48ae9be4 100644 --- a/qapi-schema.json +++ b/qapi-schema.json @@ -1678,7 +1678,11 @@ # determine which ones are encrypted, set the passwords with this command, and # then start the guest with the @cont command. # -# @device: the name of the device to set the password on +# Either @device or @node-name must be set but not both. +# +# @device: #optional the name of the block backend device to set the password on +# +# @node-name: #optional graph node name to set the password on (Since 2.0) # # @password: the password to use for the device # @@ -1692,7 +1696,8 @@ # # Since: 0.14.0 ## -{ 'command': 'block_passwd', 'data': {'device': 'str', 'password': 'str'} } +{ 'command': 'block_passwd', 'data': {'*device': 'str', + '*node-name': 'str', 'password': 'str'} } ## # @balloon: diff --git a/qmp-commands.hx b/qmp-commands.hx index 11b44c51b7..5492eb061b 100644 --- a/qmp-commands.hx +++ b/qmp-commands.hx @@ -1503,7 +1503,7 @@ EQMP { .name = "block_passwd", - .args_type = "device:B,password:s", + .args_type = "device:s?,node-name:s?,password:s", .mhandler.cmd_new = qmp_marshal_input_block_passwd, }, @@ -1516,6 +1516,7 @@ Set the password of encrypted block devices. Arguments: - "device": device name (json-string) +- "node-name": name in the block driver state graph (json-string) - "password": password (json-string) Example: