From d53be9ce55a38e430b88985f637f696bf99cbf0b Mon Sep 17 00:00:00 2001 From: Kevin Wolf Date: Thu, 24 Sep 2020 17:27:04 +0200 Subject: block/export: Add 'id' option to block-export-add We'll need an id to identify block exports in monitor commands. This adds one. Note that this is different from the 'name' option in the NBD server, which is the externally visible export name. While block export ids need to be unique in the whole process, export names must be unique only for the same server. Different export types or (potentially in the future) multiple NBD servers can have the same export name externally, but still need different block export ids internally. Signed-off-by: Kevin Wolf Reviewed-by: Max Reitz Message-Id: <20200924152717.287415-19-kwolf@redhat.com> Acked-by: Stefan Hajnoczi Signed-off-by: Kevin Wolf --- block/export/export.c | 26 ++++++++++++++++++++++++++ blockdev-nbd.c | 1 + include/block/export.h | 3 +++ qapi/block-export.json | 5 +++++ qemu-nbd.c | 1 + storage-daemon/qemu-storage-daemon.c | 2 +- tests/qemu-iotests/223.out | 4 ++-- 7 files changed, 39 insertions(+), 3 deletions(-) diff --git a/block/export/export.c b/block/export/export.c index e94a68c..7a4a784 100644 --- a/block/export/export.c +++ b/block/export/export.c @@ -19,6 +19,7 @@ #include "block/nbd.h" #include "qapi/error.h" #include "qapi/qapi-commands-block-export.h" +#include "qemu/id.h" static const BlockExportDriver *blk_exp_drivers[] = { &blk_exp_nbd, @@ -28,6 +29,19 @@ static const BlockExportDriver *blk_exp_drivers[] = { static QLIST_HEAD(, BlockExport) block_exports = QLIST_HEAD_INITIALIZER(block_exports); +static BlockExport *blk_exp_find(const char *id) +{ + BlockExport *exp; + + QLIST_FOREACH(exp, &block_exports, next) { + if (strcmp(id, exp->id) == 0) { + return exp; + } + } + + return NULL; +} + static const BlockExportDriver *blk_exp_find_driver(BlockExportType type) { int i; @@ -46,6 +60,15 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) BlockExport *exp; int ret; + if (!id_wellformed(export->id)) { + error_setg(errp, "Invalid block export id"); + return NULL; + } + if (blk_exp_find(export->id)) { + error_setg(errp, "Block export id '%s' is already in use", export->id); + return NULL; + } + drv = blk_exp_find_driver(export->type); if (!drv) { error_setg(errp, "No driver found for the requested export type"); @@ -57,10 +80,12 @@ BlockExport *blk_exp_add(BlockExportOptions *export, Error **errp) *exp = (BlockExport) { .drv = drv, .refcount = 1, + .id = g_strdup(export->id), }; ret = drv->create(exp, export, errp); if (ret < 0) { + g_free(exp->id); g_free(exp); return NULL; } @@ -87,6 +112,7 @@ static void blk_exp_delete_bh(void *opaque) assert(exp->refcount == 0); QLIST_REMOVE(exp, next); exp->drv->delete(exp); + g_free(exp->id); g_free(exp); aio_context_release(aio_context); diff --git a/blockdev-nbd.c b/blockdev-nbd.c index f927264..814554d 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -269,6 +269,7 @@ void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, + .id = g_strdup(arg->name), .node_name = g_strdup(bdrv_get_node_name(bs)), .u.nbd = { .has_name = true, diff --git a/include/block/export.h b/include/block/export.h index 6fffcb5..cdc6e16 100644 --- a/include/block/export.h +++ b/include/block/export.h @@ -50,6 +50,9 @@ typedef struct BlockExportDriver { struct BlockExport { const BlockExportDriver *drv; + /* Unique identifier for the export */ + char *id; + /* * Reference count for this block export. This includes strong references * both from the owner (qemu-nbd or the monitor) and clients connected to diff --git a/qapi/block-export.json b/qapi/block-export.json index 1091c97..658bdf0 100644 --- a/qapi/block-export.json +++ b/qapi/block-export.json @@ -105,6 +105,8 @@ # # Export a block node to QEMU's embedded NBD server. # +# The export name will be used as the id for the resulting block export. +# # Returns: error if the server is not running, or export with the same name # already exists. # @@ -182,6 +184,8 @@ # Describes a block export, i.e. how single node should be exported on an # external interface. # +# @id: A unique identifier for the block export (across all export types) +# # @node-name: The node name of the block node to be exported (since: 5.2) # # @writethrough: If true, caches are flushed after every write request to the @@ -192,6 +196,7 @@ ## { 'union': 'BlockExportOptions', 'base': { 'type': 'BlockExportType', + 'id': 'str', 'node-name': 'str', '*writethrough': 'bool' }, 'discriminator': 'type', diff --git a/qemu-nbd.c b/qemu-nbd.c index cfa5b78..66cb8f9 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1064,6 +1064,7 @@ int main(int argc, char **argv) export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { .type = BLOCK_EXPORT_TYPE_NBD, + .id = g_strdup("qemu-nbd-export"), .node_name = g_strdup(bdrv_get_node_name(bs)), .has_writethrough = true, .writethrough = writethrough, diff --git a/storage-daemon/qemu-storage-daemon.c b/storage-daemon/qemu-storage-daemon.c index 0fcab6e..e6157ff 100644 --- a/storage-daemon/qemu-storage-daemon.c +++ b/storage-daemon/qemu-storage-daemon.c @@ -92,7 +92,7 @@ static void help(void) " --chardev configure a character device backend\n" " (see the qemu(1) man page for possible options)\n" "\n" -" --export [type=]nbd,device=[,name=]\n" +" --export [type=]nbd,device=,id=,[,name=]\n" " [,writable=on|off][,bitmap=]\n" " export the specified block node over NBD\n" " (requires --nbd-server)\n" diff --git a/tests/qemu-iotests/223.out b/tests/qemu-iotests/223.out index e1eaaed..31ce9e6 100644 --- a/tests/qemu-iotests/223.out +++ b/tests/qemu-iotests/223.out @@ -45,7 +45,7 @@ exports available: 0 {"execute":"nbd-server-add", "arguments":{"device":"nosuch"}} {"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}} {"execute":"nbd-server-add", "arguments":{"device":"n"}} -{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}} +{"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b2"}} {"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b3"}} @@ -126,7 +126,7 @@ exports available: 0 {"execute":"nbd-server-add", "arguments":{"device":"nosuch"}} {"error": {"class": "GenericError", "desc": "Cannot find device=nosuch nor node_name=nosuch"}} {"execute":"nbd-server-add", "arguments":{"device":"n"}} -{"error": {"class": "GenericError", "desc": "NBD server already has export named 'n'"}} +{"error": {"class": "GenericError", "desc": "Block export id 'n' is already in use"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b2"}} {"error": {"class": "GenericError", "desc": "Enabled bitmap 'b2' incompatible with readonly export"}} {"execute":"nbd-server-add", "arguments":{"device":"n", "name":"n2", "bitmap":"b3"}} -- cgit v1.1