From a96042f05eaf494fbe26a9cbd940f5f815f782f9 Mon Sep 17 00:00:00 2001 From: "Dr. David Alan Gilbert" Date: Mon, 27 Jan 2020 19:00:56 +0100 Subject: [PATCH 025/116] virtiofsd: Open vhost connection instead of mounting MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Dr. David Alan Gilbert Message-id: <20200127190227.40942-22-dgilbert@redhat.com> Patchwork-id: 93476 O-Subject: [RHEL-AV-8.2 qemu-kvm PATCH 021/112] virtiofsd: Open vhost connection instead of mounting Bugzilla: 1694164 RH-Acked-by: Philippe Mathieu-Daudé RH-Acked-by: Stefan Hajnoczi RH-Acked-by: Sergio Lopez Pascual From: "Dr. David Alan Gilbert" When run with vhost-user options we conect to the QEMU instead via a socket. Start this off by creating the socket. Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Daniel P. Berrangé Reviewed-by: Misono Tomohiro Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit d14bf584dd965821e80d14c16d9292a464b1ab85) Signed-off-by: Miroslav Rezanina --- tools/virtiofsd/fuse_i.h | 7 ++-- tools/virtiofsd/fuse_lowlevel.c | 55 ++++------------------------ tools/virtiofsd/fuse_virtio.c | 79 +++++++++++++++++++++++++++++++++++++++++ tools/virtiofsd/fuse_virtio.h | 23 ++++++++++++ 4 files changed, 114 insertions(+), 50 deletions(-) create mode 100644 tools/virtiofsd/fuse_virtio.c create mode 100644 tools/virtiofsd/fuse_virtio.h diff --git a/tools/virtiofsd/fuse_i.h b/tools/virtiofsd/fuse_i.h index 26b1a7d..82d6ac7 100644 --- a/tools/virtiofsd/fuse_i.h +++ b/tools/virtiofsd/fuse_i.h @@ -6,9 +6,10 @@ * See the file COPYING.LIB */ -#define FUSE_USE_VERSION 31 - +#ifndef FUSE_I_H +#define FUSE_I_H +#define FUSE_USE_VERSION 31 #include "fuse.h" #include "fuse_lowlevel.h" @@ -101,3 +102,5 @@ void fuse_session_process_buf_int(struct fuse_session *se, /* room needed in buffer to accommodate header */ #define FUSE_BUFFER_HEADER_SIZE 0x1000 + +#endif diff --git a/tools/virtiofsd/fuse_lowlevel.c b/tools/virtiofsd/fuse_lowlevel.c index 17e8718..5df124e 100644 --- a/tools/virtiofsd/fuse_lowlevel.c +++ b/tools/virtiofsd/fuse_lowlevel.c @@ -14,6 +14,7 @@ #include "standard-headers/linux/fuse.h" #include "fuse_misc.h" #include "fuse_opt.h" +#include "fuse_virtio.h" #include #include @@ -2202,6 +2203,11 @@ 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"); + goto out4; + } + se->bufsize = FUSE_MAX_MAX_PAGES * getpagesize() + FUSE_BUFFER_HEADER_SIZE; list_init_req(&se->list); @@ -2224,54 +2230,7 @@ out1: int fuse_session_mount(struct fuse_session *se) { - int fd; - - /* - * Make sure file descriptors 0, 1 and 2 are open, otherwise chaos - * would ensue. - */ - do { - fd = open("/dev/null", O_RDWR); - if (fd > 2) { - close(fd); - } - } while (fd >= 0 && fd <= 2); - - /* - * To allow FUSE daemons to run without privileges, the caller may open - * /dev/fuse before launching the file system and pass on the file - * descriptor by specifying /dev/fd/N as the mount point. Note that the - * parent process takes care of performing the mount in this case. - */ - fd = fuse_mnt_parse_fuse_fd(mountpoint); - if (fd != -1) { - if (fcntl(fd, F_GETFD) == -1) { - fuse_log(FUSE_LOG_ERR, "fuse: Invalid file descriptor /dev/fd/%u\n", - fd); - return -1; - } - se->fd = fd; - return 0; - } - - /* Open channel */ - fd = fuse_kern_mount(mountpoint, se->mo); - if (fd == -1) { - return -1; - } - se->fd = fd; - - /* Save mountpoint */ - se->mountpoint = strdup(mountpoint); - if (se->mountpoint == NULL) { - goto error_out; - } - - return 0; - -error_out: - fuse_kern_unmount(mountpoint, fd); - return -1; + return virtio_session_mount(se); } int fuse_session_fd(struct fuse_session *se) diff --git a/tools/virtiofsd/fuse_virtio.c b/tools/virtiofsd/fuse_virtio.c new file mode 100644 index 0000000..cbef6ff --- /dev/null +++ b/tools/virtiofsd/fuse_virtio.c @@ -0,0 +1,79 @@ +/* + * virtio-fs glue for FUSE + * Copyright (C) 2018 Red Hat, Inc. and/or its affiliates + * + * Authors: + * Dave Gilbert + * + * Implements the glue between libfuse and libvhost-user + * + * This program can be distributed under the terms of the GNU LGPLv2. + * See the file COPYING.LIB + */ + +#include "fuse_i.h" +#include "standard-headers/linux/fuse.h" +#include "fuse_misc.h" +#include "fuse_opt.h" +#include "fuse_virtio.h" + +#include +#include +#include +#include +#include +#include +#include + +/* From spec */ +struct virtio_fs_config { + char tag[36]; + uint32_t num_queues; +}; + +int virtio_session_mount(struct fuse_session *se) +{ + struct sockaddr_un un; + mode_t old_umask; + + 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 + */ + unlink(se->vu_socket_path); + strcpy(un.sun_path, se->vu_socket_path); + size_t addr_len = sizeof(un); + + int listen_sock = socket(AF_UNIX, SOCK_STREAM, 0); + if (listen_sock == -1) { + fuse_log(FUSE_LOG_ERR, "vhost socket creation: %m\n"); + return -1; + } + un.sun_family = AF_UNIX; + + /* + * Unfortunately bind doesn't let you set the mask on the socket, + * so set umask to 077 and restore it later. + */ + old_umask = umask(0077); + if (bind(listen_sock, (struct sockaddr *)&un, addr_len) == -1) { + fuse_log(FUSE_LOG_ERR, "vhost socket bind: %m\n"); + umask(old_umask); + return -1; + } + umask(old_umask); + + if (listen(listen_sock, 1) == -1) { + fuse_log(FUSE_LOG_ERR, "vhost socket listen: %m\n"); + return -1; + } + + return -1; +} diff --git a/tools/virtiofsd/fuse_virtio.h b/tools/virtiofsd/fuse_virtio.h new file mode 100644 index 0000000..8f2edb6 --- /dev/null +++ b/tools/virtiofsd/fuse_virtio.h @@ -0,0 +1,23 @@ +/* + * virtio-fs glue for FUSE + * Copyright (C) 2018 Red Hat, Inc. and/or its affiliates + * + * Authors: + * Dave Gilbert + * + * Implements the glue between libfuse and libvhost-user + * + * This program can be distributed under the terms of the GNU LGPLv2. + * See the file COPYING.LIB + */ + +#ifndef FUSE_VIRTIO_H +#define FUSE_VIRTIO_H + +#include "fuse_i.h" + +struct fuse_session; + +int virtio_session_mount(struct fuse_session *se); + +#endif -- 1.8.3.1