From f91a9bdc171142174110e9ff1716b611f6fb0039 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 27 Jan 2020 19:01:07 +0100 Subject: [PATCH 036/116] virtiofsd: add --fd=FDNUM fd passing option MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Dr. David Alan Gilbert Message-id: <20200127190227.40942-33-dgilbert@redhat.com> Patchwork-id: 93487 O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 032/112] virtiofsd: add --fd=FDNUM fd passing option Bugzilla: 1694164 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Sergio Lopez Pascual From: Stefan Hajnoczi Although --socket-path=PATH is useful for manual invocations, management tools typically create the UNIX domain socket themselves and pass it to the vhost-user device backend. This way QEMU can be launched immediately with a valid socket. No waiting for the vhost-user device backend is required when fd passing is used. Signed-off-by: Stefan Hajnoczi Reviewed-by: Daniel P. Berrangé Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit cee8e35d4386e34bf79c3ca2aab7f7b1bb48cf8d) Signed-off-by: Miroslav Rezanina --- tools/virtiofsd/fuse_i.h | 1 + tools/virtiofsd/fuse_lowlevel.c | 16 ++++++++++++---- tools/virtiofsd/fuse_virtio.c | 31 +++++++++++++++++++++++++------ 3 files changed, 38 insertions(+), 10 deletions(-) diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h index 1126723..45995f3 100644 --- a/tools/virtiofsd/fuse_i.h +++ b/tools/virtiofsd/fuse_i.h @@ -68,6 +68,7 @@ struct fuse_session { size_t bufsize; int error; char *vu_socket_path; + int vu_listen_fd; int vu_socketfd; struct fv_VuDev *virtio_dev; }; diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 4f4684d..95f4db8 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -2130,6 +2130,7 @@ static const struct fuse_opt fuse_ll_opts[] = { LL_OPTION("--debug", debug, 1), LL_OPTION("allow_root", deny_others, 1), LL_OPTION("--socket-path=%s", vu_socket_path, 0), + LL_OPTION("--fd=%d", vu_listen_fd, 0), FUSE_OPT_END }; @@ -2147,7 +2148,8 @@ void fuse_lowlevel_help(void) */ printf( " -o allow_root allow access by root\n" - " --socket-path=PATH path for the vhost-user socket\n"); + " --socket-path=PATH path for the vhost-user socket\n" + " --fd=FDNUM fd number of vhost-user socket\n"); } void fuse_session_destroy(struct fuse_session *se) @@ -2191,6 +2193,7 @@ struct fuse_session *fuse_session_new(struct fuse_args *args, goto out1; } se->fd = -1; + se->vu_listen_fd = -1; se->conn.max_write = UINT_MAX; se->conn.max_readahead = UINT_MAX; @@ -2212,8 +2215,13 @@ struct fuse_session *fuse_session_new(struct fuse_args *args, goto out4; } - if (!se->vu_socket_path) { - fprintf(stderr, "fuse: missing -o vhost_user_socket option\n"); + if (!se->vu_socket_path && se->vu_listen_fd < 0) { + fuse_log(FUSE_LOG_ERR, "fuse: missing --socket-path or --fd option\n"); + goto out4; + } + if (se->vu_socket_path && se->vu_listen_fd >= 0) { + fuse_log(FUSE_LOG_ERR, + "fuse: --socket-path and --fd cannot be given together\n"); goto out4; } @@ -2253,7 +2261,7 @@ void fuse_session_unmount(struct fuse_session *se) int fuse_lowlevel_is_virtio(struct fuse_session *se) { - return se->vu_socket_path != NULL; + return !!se->virtio_dev; } #ifdef linux diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c index 7e2711b..635f877 100644 --- a/tools/virtiofsd/fuse_virtio.c +++ b/tools/virtiofsd/fuse_virtio.c @@ -638,18 +638,21 @@ int virtio_loop(struct fuse_session *se) return 0; } -int virtio_session_mount(struct fuse_session *se) +static int fv_create_listen_socket(struct fuse_session *se) { struct sockaddr_un un; mode_t old_umask; + /* Nothing to do if fd is already initialized */ + if (se->vu_listen_fd >= 0) { + return 0; + } + if (strlen(se->vu_socket_path) >= sizeof(un.sun_path)) { fuse_log(FUSE_LOG_ERR, "Socket path too long\n"); return -1; } - se->fd = -1; - /* * Create the Unix socket to communicate with qemu * based on QEMU's vhost-user-bridge @@ -682,15 +685,31 @@ int virtio_session_mount(struct fuse_session *se) return -1; } + se->vu_listen_fd = listen_sock; + return 0; +} + +int virtio_session_mount(struct fuse_session *se) +{ + int ret; + + ret = fv_create_listen_socket(se); + if (ret < 0) { + return ret; + } + + se->fd = -1; + fuse_log(FUSE_LOG_INFO, "%s: Waiting for vhost-user socket connection...\n", __func__); - int data_sock = accept(listen_sock, NULL, NULL); + int data_sock = accept(se->vu_listen_fd, NULL, NULL); if (data_sock == -1) { fuse_log(FUSE_LOG_ERR, "vhost socket accept: %m\n"); - close(listen_sock); + close(se->vu_listen_fd); return -1; } - close(listen_sock); + close(se->vu_listen_fd); + se->vu_listen_fd = -1; fuse_log(FUSE_LOG_INFO, "%s: Received vhost-user socket connection\n", __func__); -- 1.8.3.1