From e6aae1d0368a152924c38775e517f4e83c1d898b Mon Sep 17 00:00:00 2001 From: Eric Blake Date: Wed, 11 May 2022 19:49:23 -0500 Subject: [PATCH 1/2] qemu-nbd: Pass max connections to blockdev layer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Eric Blake RH-MergeRequest: 90: Advertise MULTI_CONN on writeable NBD servers RH-Commit: [1/2] b0e33fd125bf3523b8b9a4dead3c8bb2342bfd4e (ebblake/centos-qemu-kvm) RH-Bugzilla: 1708300 RH-Acked-by: Nir Soffer RH-Acked-by: Kevin Wolf RH-Acked-by: Daniel P. Berrangé The next patch wants to adjust whether the NBD server code advertises MULTI_CONN based on whether it is known if the server limits to exactly one client. For a server started by QMP, this information is obtained through nbd_server_start (which can support more than one export); but for qemu-nbd (which supports exactly one export), it is controlled only by the command-line option -e/--shared. Since we already have a hook function used by qemu-nbd, it's easiest to just alter its signature to fit our needs. Signed-off-by: Eric Blake Message-Id: <20220512004924.417153-2-eblake@redhat.com> Signed-off-by: Kevin Wolf (cherry picked from commit a5fced40212ed73c715ca298a2929dd4d99c9999) Signed-off-by: Eric Blake --- blockdev-nbd.c | 8 ++++---- include/block/nbd.h | 2 +- qemu-nbd.c | 2 +- 3 files changed, 6 insertions(+), 6 deletions(-) diff --git a/blockdev-nbd.c b/blockdev-nbd.c index 9840d25a82..add41a23af 100644 --- a/blockdev-nbd.c +++ b/blockdev-nbd.c @@ -30,18 +30,18 @@ typedef struct NBDServerData { } NBDServerData; static NBDServerData *nbd_server; -static bool is_qemu_nbd; +static int qemu_nbd_connections = -1; /* Non-negative if this is qemu-nbd */ static void nbd_update_server_watch(NBDServerData *s); -void nbd_server_is_qemu_nbd(bool value) +void nbd_server_is_qemu_nbd(int max_connections) { - is_qemu_nbd = value; + qemu_nbd_connections = max_connections; } bool nbd_server_is_running(void) { - return nbd_server || is_qemu_nbd; + return nbd_server || qemu_nbd_connections >= 0; } static void nbd_blockdev_client_closed(NBDClient *client, bool ignored) diff --git a/include/block/nbd.h b/include/block/nbd.h index a98eb665da..c5a29ce1c6 100644 --- a/include/block/nbd.h +++ b/include/block/nbd.h @@ -344,7 +344,7 @@ void nbd_client_new(QIOChannelSocket *sioc, void nbd_client_get(NBDClient *client); void nbd_client_put(NBDClient *client); -void nbd_server_is_qemu_nbd(bool value); +void nbd_server_is_qemu_nbd(int max_connections); bool nbd_server_is_running(void); void nbd_server_start(SocketAddress *addr, const char *tls_creds, const char *tls_authz, uint32_t max_connections, diff --git a/qemu-nbd.c b/qemu-nbd.c index 713e7557a9..8c25ae93df 100644 --- a/qemu-nbd.c +++ b/qemu-nbd.c @@ -1087,7 +1087,7 @@ int main(int argc, char **argv) bs->detect_zeroes = detect_zeroes; - nbd_server_is_qemu_nbd(true); + nbd_server_is_qemu_nbd(shared); export_opts = g_new(BlockExportOptions, 1); *export_opts = (BlockExportOptions) { -- 2.31.1