From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Date: Mon, 27 Jan 2020 19:00:56 +0000
Subject: [PATCH] virtiofsd: Open vhost connection instead of mounting
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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 <dgilbert@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
(cherry picked from commit d14bf584dd965821e80d14c16d9292a464b1ab85)
---
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 26b1a7da88..82d6ac7115 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 17e8718283..5df124e64b 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 <assert.h>
#include <errno.h>
@@ -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 0000000000..cbef6ffdda
--- /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 <dgilbert@redhat.com>
+ *
+ * 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 <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <unistd.h>
+
+/* 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 0000000000..8f2edb69ca
--- /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 <dgilbert@redhat.com>
+ *
+ * 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