diff options
Diffstat (limited to 'blockdev-nbd.c')
| -rw-r--r-- | blockdev-nbd.c | 171 |
1 files changed, 91 insertions, 80 deletions
diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 1a95d89f00..8174023e5c 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -14,7 +14,7 @@ #include "sysemu/block-backend.h" #include "hw/block/block.h" #include "qapi/error.h" -#include "qapi/qapi-commands-block.h" +#include "qapi/qapi-commands-block-export.h" #include "block/nbd.h" #include "io/channel-socket.h" #include "io/net-listener.h" @@ -23,23 +23,52 @@ typedef struct NBDServerData { QIONetListener *listener; QCryptoTLSCreds *tlscreds; char *tlsauthz; + uint32_t max_connections; + uint32_t connections; } NBDServerData; static NBDServerData *nbd_server; +static bool is_qemu_nbd; + +static void nbd_update_server_watch(NBDServerData *s); + +void nbd_server_is_qemu_nbd(bool value) +{ + is_qemu_nbd = value; +} + +bool nbd_server_is_running(void) +{ + return nbd_server || is_qemu_nbd; +} static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) { nbd_client_put(client); + assert(nbd_server->connections > 0); + nbd_server->connections--; + nbd_update_server_watch(nbd_server); } static void nbd_accept(QIONetListener *listener, QIOChannelSocket *cioc, gpointer opaque) { + nbd_server->connections++; + nbd_update_server_watch(nbd_server); + qio_channel_set_name(QIO_CHANNEL(cioc), "nbd-server"); nbd_client_new(cioc, nbd_server->tlscreds, nbd_server->tlsauthz, nbd_blockdev_client_closed); } +static void nbd_update_server_watch(NBDServerData *s) +{ + if (!s->max_connections || s->connections < s->max_connections) { + qio_net_listener_set_client_func(s->listener, nbd_accept, NULL, NULL); + } else { + qio_net_listener_set_client_func(s->listener, NULL, NULL, NULL); + } +} static void nbd_server_free(NBDServerData *server) { @@ -88,7 +117,8 @@ static QCryptoTLSCreds *nbd_get_tls_creds(const char *id, Error **errp) void nbd_server_start(SocketAddress *addr, const char *tls_creds, - const char *tls_authz, Error **errp) + const char *tls_authz, uint32_t max_connections, + Error **errp) { if (nbd_server) { error_setg(errp, "NBD server already running"); @@ -96,6 +126,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, } nbd_server = g_new0(NBDServerData, 1); + nbd_server->max_connections = max_connections; nbd_server->listener = qio_net_listener_new(); qio_net_listener_set_name(nbd_server->listener, @@ -120,10 +151,7 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, nbd_server->tlsauthz = g_strdup(tls_authz); - qio_net_listener_set_client_func(nbd_server->listener, - nbd_accept, - NULL, - NULL); + nbd_update_server_watch(nbd_server); return; @@ -134,117 +162,100 @@ void nbd_server_start(SocketAddress *addr, const char *tls_creds, void nbd_server_start_options(NbdServerOptions *arg, Error **errp) { - nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, errp); + nbd_server_start(arg->addr, arg->tls_creds, arg->tls_authz, + arg->max_connections, errp); } void qmp_nbd_server_start(SocketAddressLegacy *addr, bool has_tls_creds, const char *tls_creds, bool has_tls_authz, const char *tls_authz, + bool has_max_connections, uint32_t max_connections, Error **errp) { SocketAddress *addr_flat = socket_address_flatten(addr); - nbd_server_start(addr_flat, tls_creds, tls_authz, errp); + nbd_server_start(addr_flat, tls_creds, tls_authz, max_connections, errp); qapi_free_SocketAddress(addr_flat); } -void qmp_nbd_server_add(BlockExportNbd *arg, Error **errp) +void qmp_nbd_server_add(NbdServerAddOptions *arg, Error **errp) { - BlockDriverState *bs = NULL; + BlockExport *export; + BlockDriverState *bs; BlockBackend *on_eject_blk; - NBDExport *exp; - int64_t len; - AioContext *aio_context; + BlockExportOptions *export_opts; - if (!nbd_server) { - error_setg(errp, "NBD server not running"); + bs = bdrv_lookup_bs(arg->device, arg->device, errp); + if (!bs) { return; } + /* + * block-export-add would default to the node-name, but we may have to use + * the device name as a default here for compatibility. + */ if (!arg->has_name) { arg->name = arg->device; } - if (strlen(arg->name) > NBD_MAX_STRING_SIZE) { - error_setg(errp, "export name '%s' too long", arg->name); - return; - } - - if (arg->description && strlen(arg->description) > NBD_MAX_STRING_SIZE) { - error_setg(errp, "description '%s' too long", arg->description); - return; + 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)), + .has_writable = arg->has_writable, + .writable = arg->writable, + .u.nbd = { + .has_name = true, + .name = g_strdup(arg->name), + .has_description = arg->has_description, + .description = g_strdup(arg->description), + .has_bitmap = arg->has_bitmap, + .bitmap = g_strdup(arg->bitmap), + }, + }; + + /* + * nbd-server-add doesn't complain when a read-only device should be + * exported as writable, but simply downgrades it. This is an error with + * block-export-add. + */ + if (bdrv_is_read_only(bs)) { + export_opts->has_writable = true; + export_opts->writable = false; } - if (nbd_export_find(arg->name)) { - error_setg(errp, "NBD server already has export named '%s'", arg->name); - return; + export = blk_exp_add(export_opts, errp); + if (!export) { + goto fail; } + /* + * nbd-server-add removes the export when the named BlockBackend used for + * @device goes away. + */ on_eject_blk = blk_by_name(arg->device); - - bs = bdrv_lookup_bs(arg->device, arg->device, errp); - if (!bs) { - return; - } - - aio_context = bdrv_get_aio_context(bs); - aio_context_acquire(aio_context); - len = bdrv_getlength(bs); - if (len < 0) { - error_setg_errno(errp, -len, - "Failed to determine the NBD export's length"); - goto out; - } - - if (!arg->has_writable) { - arg->writable = false; - } - if (bdrv_is_read_only(bs)) { - arg->writable = false; + if (on_eject_blk) { + nbd_export_set_on_eject_blk(export, on_eject_blk); } - exp = nbd_export_new(bs, 0, len, arg->name, arg->description, arg->bitmap, - !arg->writable, !arg->writable, - NULL, false, on_eject_blk, errp); - if (!exp) { - goto out; - } - - /* The list of named exports has a strong reference to this export now and - * our only way of accessing it is through nbd_export_find(), so we can drop - * the strong reference that is @exp. */ - nbd_export_put(exp); - - out: - aio_context_release(aio_context); +fail: + qapi_free_BlockExportOptions(export_opts); } void qmp_nbd_server_remove(const char *name, - bool has_mode, NbdServerRemoveMode mode, + bool has_mode, BlockExportRemoveMode mode, Error **errp) { - NBDExport *exp; - AioContext *aio_context; - - if (!nbd_server) { - error_setg(errp, "NBD server not running"); - return; - } + BlockExport *exp; - exp = nbd_export_find(name); - if (exp == NULL) { - error_setg(errp, "Export '%s' is not found", name); + exp = blk_exp_find(name); + if (exp && exp->drv->type != BLOCK_EXPORT_TYPE_NBD) { + error_setg(errp, "Block export '%s' is not an NBD export", name); return; } - if (!has_mode) { - mode = NBD_SERVER_REMOVE_MODE_SAFE; - } - - aio_context = nbd_export_aio_context(exp); - aio_context_acquire(aio_context); - nbd_export_remove(exp, mode, errp); - aio_context_release(aio_context); + qmp_block_export_del(name, has_mode, mode, errp); } void qmp_nbd_server_stop(Error **errp) @@ -254,7 +265,7 @@ void qmp_nbd_server_stop(Error **errp) return; } - nbd_export_close_all(); + blk_exp_close_all_type(BLOCK_EXPORT_TYPE_NBD); nbd_server_free(nbd_server); nbd_server = NULL; |