Re: [PATCH 12/13] example/service: create a sample systemd service for a high-level fuse server

Bernd Schubert
2026-04-26T21:04:37Z

On 4/23/26 01:22, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
>
> Create a simple high-level fuse server that can be run as a systemd
> service.
>
> Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
> ---
> example/single_file.h | 38 ++++++
> example/meson.build | 6 +
> example/service_hl.c | 224 +++++++++++++++++++++++++++++++++++
> example/service_hl.socket.in | 15 ++
> example/service_hl@.service | 102 ++++++++++++++++
> example/service_ll.c | 1
> example/single_file.c | 271 +++++++++++++++++++++++++++++++++++++++---
> 7 files changed, 640 insertions(+), 17 deletions(-)
> create mode 100644 example/service_hl.c
> create mode 100644 example/service_hl.socket.in
> create mode 100644 example/service_hl@.service
>
>
> diff --git a/example/single_file.h b/example/single_file.h
> index d8a91adbf875ef..86edb51afb3384 100644
> --- a/example/single_file.h
> +++ b/example/single_file.h
> @@ -124,6 +124,7 @@ ssize_t single_file_pread(char *buf, size_t count, off_t pos);
>
> /* low-level fuse operation handlers */
>
> +#ifdef USE_SINGLE_FILE_LL_API
> bool is_single_file_child(fuse_ino_t parent, const char *name);
> bool is_single_file_ino(fuse_ino_t ino);
>
> @@ -149,5 +150,42 @@ void single_file_ll_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
>
> int reply_buf_limited(fuse_req_t req, const char *buf, size_t bufsize,
> off_t off, size_t maxsize);
> +#endif
> +
> +/* high-level fuse operation handlers */
> +
> +#ifdef USE_SINGLE_FILE_HL_API
> +bool is_single_open_file_path(const struct fuse_file_info *fi, const char *name);
> +
> +int single_file_hl_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
> + off_t offset, struct fuse_file_info *fi,
> + enum fuse_readdir_flags flags);
> +
> +int single_file_hl_statfs(const char *path, struct statvfs *buf);
> +
> +int single_file_hl_statx(const char *path, int statx_flags, int statx_mask,
> + struct statx *stx, struct fuse_file_info *fi);
> +
> +int single_file_hl_getattr(const char *path, struct stat *stbuf,
> + struct fuse_file_info *fi);
> +int single_file_hl_chmod(const char *path, mode_t mode,
> + struct fuse_file_info *fi);
> +int single_file_hl_utimens(const char *path, const struct timespec ctv[2],
> + struct fuse_file_info *fi);
> +int single_file_hl_chown(const char *path, uid_t owner, gid_t group,
> + struct fuse_file_info *fi);
> +int single_file_hl_truncate(const char *path, off_t len,
> + struct fuse_file_info *fi);
> +
> +int single_file_hl_opendir(const char *path, struct fuse_file_info *fi);
> +int single_file_hl_open(const char *path, struct fuse_file_info *fi);
> +
> +int single_file_hl_fsync(const char *path, int datasync,
> + struct fuse_file_info *fi);
> +#endif
> +
> +#if !defined(USE_SINGLE_FILE_LL_API) && !defined(USE_SINGLE_FILE_HL_API)
> +# warning USE_SINGLE_FILE_[HL]L_API not defined!
> +#endif
>
> #endif /* FUSE_SINGLE_FILE_H_ */
> diff --git a/example/meson.build b/example/meson.build
> index e948f6ba74fdfa..19a383f7cd2c74 100644
> --- a/example/meson.build
> +++ b/example/meson.build
> @@ -19,6 +19,12 @@ if platform.endswith('linux')
> configure_file(input: 'service_ll.socket.in',
> output: 'service_ll.socket',
> configuration: private_cfg)
> +
> + single_file_examples += [ 'service_hl' ]
> + configure_file(input: 'service_hl.socket.in',
> + output: 'service_hl.socket',
> + configuration: private_cfg)
> +
> endif
>
> threaded_examples = [ 'notify_inval_inode',
> diff --git a/example/service_hl.c b/example/service_hl.c
> new file mode 100644
> index 00000000000000..9c4f3ae7a6cf3c
> --- /dev/null
> +++ b/example/service_hl.c
> @@ -0,0 +1,224 @@
> +/*
> + * FUSE: Filesystem in Userspace
> + * Copyright (C) 2026 Oracle.
> + *
> + * This program can be distributed under the terms of the GNU GPLv2.
> + * See the file GPL2.txt.
> + */
> +
> +/** @file
> + *
> + * minimal example filesystem using high-level API and systemd service api
> + *
> + * Compile with:
> + *
> + * gcc -Wall single_file.c service_hl.c `pkg-config fuse3 --cflags --libs` -o service_hl
> + *
> + * Note: If the pkg-config command fails due to the absence of the fuse3.pc
> + * file, you should configure the path to the fuse3.pc file in the
> + * PKG_CONFIG_PATH variable.
> + *
> + * Change the ExecStart line in service_hl@.service:
> + *
> + * ExecStart=/path/to/service_hl
> + *
> + * to point to the actual path of the service_hl binary.
> + *
> + * Finally, install the service_hl@.service and service_hl.socket files to the
> + * systemd service directory, usually /run/systemd/system.
> + *
> + * ## Source code ##
> + * \include service_hl.c
> + * \include service_hl.socket
> + * \include service_hl@.service
> + * \include single_file.c
> + * \include single_file.h
> + */
> +
> +#define FUSE_USE_VERSION FUSE_MAKE_VERSION(3, 19)
> +
> +#ifndef _GNU_SOURCE
> +#define _GNU_SOURCE
> +#endif
> +
> +#include <fuse.h>
> +#include <fuse_service.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +#include <errno.h>
> +#include <fcntl.h>
> +#include <unistd.h>
> +#include <assert.h>
> +#include <pthread.h>
> +#include <stddef.h>
> +#include <sys/ioctl.h>
> +#include <sys/stat.h>
> +#include <linux/fs.h>
> +#include <linux/stat.h>
> +#define USE_SINGLE_FILE_HL_API
> +#include "single_file.h"
> +
> +struct service_hl {
> + char *device;
> + struct fuse_service *service;
> +
> + /* really booleans */
> + int debug;
> +};
> +
> +static struct service_hl hl = { };
> +
> +static void *service_hl_init(struct fuse_conn_info *conn,
> + struct fuse_config *cfg)
> +{
> + (void) conn;
> + cfg->kernel_cache = 1;
> +
> + return NULL;
> +}
> +
> +static int service_hl_read(const char *path, char *buf, size_t count,
> + off_t pos, struct fuse_file_info *fi)
> +{
> + if (!is_single_open_file_path(fi, path))
> + return -EIO;
> +
> + if (hl.debug)
> + fprintf(stderr, "%s: pos 0x%llx count 0x%llx\n",
> + __func__,
> + (unsigned long long)pos,
> + (unsigned long long)count);
> +
> + if (!single_file.allow_dio && fi->direct_io)
> + return -ENOSYS;
> +
> + single_file_check_read(pos, &count);
> +
> + if (!count)
> + return 0;
> +
> + return single_file_pread(buf, count, pos);
> +}
> +
> +static int service_hl_write(const char *path, const char *buf, size_t count,
> + off_t pos, struct fuse_file_info *fi)
> +{
> + int ret;
> +
> + if (!is_single_open_file_path(fi, path))
> + return -EIO;
> +
> + if (hl.debug)
> + fprintf(stderr, "%s: pos 0x%llx count 0x%llx\n",
> + __func__,
> + (unsigned long long)pos,
> + (unsigned long long)count);
> +
> + if (!single_file.allow_dio && fi->direct_io)
> + return -ENOSYS;
> +
> + ret = single_file_check_write(pos, &count);
> + if (ret < 0)
> + return ret;
> +
> + if (!count)
> + return 0;
> +
> + return single_file_pwrite(buf, count, pos);
> +}
> +
> +static const struct fuse_operations service_hl_oper = {
> + .getattr = single_file_hl_getattr,
> + .readdir = single_file_hl_readdir,
> + .open = single_file_hl_open,
> + .opendir = single_file_hl_opendir,
> + .statfs = single_file_hl_statfs,
> + .chmod = single_file_hl_chmod,
> + .utimens = single_file_hl_utimens,
> + .fsync = single_file_hl_fsync,
> + .chown = single_file_hl_chown,
> + .truncate = single_file_hl_truncate,
> + .statx = single_file_hl_statx,
> +
> + .init = service_hl_init,
> + .read = service_hl_read,
> + .write = service_hl_write,
> +};
> +
> +#define SERVICE_HL_OPT(t, p, v) { t, offsetof(struct service_hl, p), v }
> +
> +static struct fuse_opt service_hl_opts[] = {
> + SERVICE_HL_OPT("debug", debug, 1),
> + SINGLE_FILE_OPT_KEYS,
> + FUSE_OPT_END
> +};
> +
> +static int service_hl_opt_proc(void *data, const char *arg, int key,
> + struct fuse_args *outargs)
> +{
> + int ret = single_file_opt_proc(data, arg, key, outargs);
> +
> + if (ret < 1)
> + return ret;
> +
> + switch (key) {
> + case FUSE_OPT_KEY_NONOPT:
> + if (!hl.device) {
> + hl.device = strdup(arg);
> + return 0;
> + }
> + return 1;
> + default:
> + break;
> + }
> +
> + return 1;
> +}
> +
> +int main(int argc, char *argv[])
> +{
> + struct fuse_args args = FUSE_ARGS_INIT(argc, argv);
> + int ret = 1;
> +
> + if (fuse_service_accept(&hl.service))
> + goto err_args;
> +
> + if (!fuse_service_accepted(hl.service))
> + goto err_args;
> +
> + if (fuse_service_append_args(hl.service, &args))
> + goto err_service;
> +
> + if (fuse_opt_parse(&args, &hl, service_hl_opts, service_hl_opt_proc))
> + goto err_service;
> +
> + if (!hl.device) {
> + printf("usage: %s [options] <device> <mountpoint>\n", argv[0]);
> + printf(" %s --help\n", argv[0]);
> + goto err_service;
> + }
> +
> + if (single_file_service_open(hl.service, hl.device))
> + goto err_service;
> +
> + if (fuse_service_finish_file_requests(hl.service))
> + goto err_singlefile;
> +
> + if (single_file_configure(hl.device, NULL))
> + goto err_singlefile;
> +
> + fuse_service_expect_mount_format(hl.service, S_IFDIR);
> +
> + ret = fuse_service_main(hl.service, &args, &service_hl_oper, NULL);
> +
> +err_singlefile:
> + single_file_close();
> +err_service:
> + free(hl.device);
> + fuse_service_send_goodbye(hl.service, ret);
> + fuse_service_destroy(&hl.service);
> +err_args:
> + fuse_opt_free_args(&args);
> + return fuse_service_exit(ret);
> +}
> diff --git a/example/service_hl.socket.in b/example/service_hl.socket.in
> new file mode 100644
> index 00000000000000..46035d6c315b8d
> --- /dev/null
> +++ b/example/service_hl.socket.in
> @@ -0,0 +1,15 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (C) 2026 Oracle. All Rights Reserved.
> +# Author: Darrick J. Wong <djwong@kernel.org>
> +[Unit]
> +Description=Socket for service_hl Service
> +
> +[Socket]
> +ListenSequentialPacket=@FUSE_SERVICE_SOCKET_DIR_RAW@/service_hl
> +Accept=yes
> +SocketMode=@FUSE_SERVICE_SOCKET_PERMS@
> +RemoveOnStop=yes
> +
> +[Install]
> +WantedBy=sockets.target
> diff --git a/example/service_hl@.service b/example/service_hl@.service
> new file mode 100644
> index 00000000000000..883b9c649cbc90
> --- /dev/null
> +++ b/example/service_hl@.service
> @@ -0,0 +1,102 @@
> +# SPDX-License-Identifier: GPL-2.0-or-later
> +#
> +# Copyright (C) 2026 Oracle. All Rights Reserved.
> +# Author: Darrick J. Wong <djwong@kernel.org>
> +[Unit]
> +Description=service_hl Sample Fuse Service
> +
> +# Don't leave failed units behind, systemd does not clean them up!
> +CollectMode=inactive-or-failed
> +
> +[Service]
> +Type=exec
> +ExecStart=/path/to/service_hl
> +
> +# Try to capture core dumps
> +LimitCORE=infinity
> +
> +SyslogIdentifier=%N
> +
> +# No realtime CPU scheduling
> +RestrictRealtime=true
> +
> +# Don't let us see anything in the regular system, and don't run as root
> +DynamicUser=true
> +ProtectSystem=strict
> +ProtectHome=true
> +PrivateTmp=true
> +PrivateDevices=true
> +PrivateUsers=true
> +
> +# No network access
> +PrivateNetwork=true
> +ProtectHostname=true
> +RestrictAddressFamilies=none
> +IPAddressDeny=any
> +
> +# Don't let the program mess with the kernel configuration at all
> +ProtectKernelLogs=true
> +ProtectKernelModules=true
> +ProtectKernelTunables=true
> +ProtectControlGroups=true
> +ProtectProc=invisible
> +RestrictNamespaces=true
> +RestrictFileSystems=
> +
> +# Hide everything in /proc, even /proc/mounts
> +ProcSubset=pid
> +
> +# Only allow the default personality Linux
> +LockPersonality=true
> +
> +# No writable memory pages
> +MemoryDenyWriteExecute=true
> +
> +# Don't let our mounts leak out to the host
> +PrivateMounts=true
> +
> +# Restrict system calls to the native arch and only enough to get things going
> +SystemCallArchitectures=native
> +SystemCallFilter=@system-service
> +SystemCallFilter=~@privileged
> +SystemCallFilter=~@resources
> +
> +SystemCallFilter=~@clock
> +SystemCallFilter=~@cpu-emulation
> +SystemCallFilter=~@debug
> +SystemCallFilter=~@module
> +SystemCallFilter=~@reboot
> +SystemCallFilter=~@swap
> +
> +SystemCallFilter=~@mount
> +
> +# libfuse io_uring wants to pin cores and memory
> +SystemCallFilter=mbind
> +SystemCallFilter=sched_setaffinity
> +
> +# Leave a breadcrumb if we get whacked by the system call filter
> +SystemCallErrorNumber=EL3RST
> +
> +# Log to the kernel dmesg, just like an in-kernel filesystem driver
> +StandardOutput=append:/dev/ttyprintk
> +StandardError=append:/dev/ttyprintk
> +
> +# Run with no capabilities at all
> +CapabilityBoundingSet=
> +AmbientCapabilities=
> +NoNewPrivileges=true
> +
> +# We don't create files
> +UMask=7777
> +
> +# No access to hardware /dev files at all
> +ProtectClock=true
> +DevicePolicy=closed
> +
> +# Don't mess with set[ug]id anything.
> +RestrictSUIDSGID=true
> +
> +# Don't let OOM kills of processes in this containment group kill the whole
> +# service, because we don't want filesystem drivers to go down.
> +OOMPolicy=continue
> +OOMScoreAdjust=-1000
> diff --git a/example/service_ll.c b/example/service_ll.c
> index 704b0a89972501..8958a221e09a66 100644
> --- a/example/service_ll.c
> +++ b/example/service_ll.c
> @@ -51,6 +51,7 @@
> #include <unistd.h>
> #include <assert.h>
> #include <pthread.h>
> +#define USE_SINGLE_FILE_LL_API
> #include "single_file.h"
>
> struct service_ll {
> diff --git a/example/single_file.c b/example/single_file.c
> index 5ed1fb5a318a37..187cc397d26117 100644
> --- a/example/single_file.c
> +++ b/example/single_file.c
> @@ -23,7 +23,10 @@
> #define FUSE_USE_VERSION (FUSE_MAKE_VERSION(3, 19))
>
> #include "fuse_lowlevel.h"
> +#include "fuse.h"
> #include "fuse_service.h"
> +#define USE_SINGLE_FILE_LL_API
> +#define USE_SINGLE_FILE_HL_API
> #include "single_file.h"
>
> #define min(x, y) ((x) < (y) ? (x) : (y))
> @@ -56,6 +59,23 @@ struct single_file single_file = {
> .lock = PTHREAD_MUTEX_INITIALIZER,
> };
>
> +static fuse_ino_t single_file_path_to_ino(const char *path)
> +{
> + if (strcmp(path, "/") == 0)
> + return FUSE_ROOT_ID;
> + if (strcmp(path + 1, single_file_name) == 0)
> + return SINGLE_FILE_INO;
> + return 0;
> +}
> +
> +static fuse_ino_t single_open_file_path_to_ino(const struct fuse_file_info *fi,
> + const char *path)
> +{
> + if (fi)
> + return fi->fh;
> + return single_file_path_to_ino(path);
> +}
> +
> static void dirbuf_add(fuse_req_t req, struct dirbuf *b, const char *name,
> fuse_ino_t ino)
> {
> @@ -91,6 +111,13 @@ bool is_single_file_ino(fuse_ino_t ino)
> return ino == SINGLE_FILE_INO;
> }
>
> +bool is_single_open_file_path(const struct fuse_file_info *fi, const char *name)
> +{
> + if (fi)
> + return is_single_file_ino(fi->fh);
> + return name[0] == '/' && strcmp(name + 1, single_file_name) == 0;
> +}
> +
> void single_file_ll_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
> off_t off, struct fuse_file_info *fi)
> {
> @@ -117,6 +144,37 @@ void single_file_ll_readdir(fuse_req_t req, fuse_ino_t ino, size_t size,
> free(b.p);
> }
>
> +int single_file_hl_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
> + off_t offset, struct fuse_file_info *fi,
> + enum fuse_readdir_flags flags)
> +{
> + struct stat stbuf;
> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> +
> + memset(&stbuf, 0, sizeof(stbuf));
> +
> + (void) offset;
> + (void) flags;
> +
> + switch (ino) {
> + case FUSE_ROOT_ID:
> + break;
> + case SINGLE_FILE_INO:
> + return -ENOTDIR;
> + default:
> + return -ENOENT;
> + }
> +
> + stbuf.st_ino = FUSE_ROOT_ID;
> + filler(buf, ".", &stbuf, 0, FUSE_FILL_DIR_DEFAULTS);
> + filler(buf, "..", &stbuf, 0, FUSE_FILL_DIR_DEFAULTS);
> +
> + stbuf.st_ino = SINGLE_FILE_INO;
> + filler(buf, single_file_name, &stbuf, 0, FUSE_FILL_DIR_DEFAULTS);
> +
> + return 0;
> +}
> +
> static bool sf_stat(fuse_ino_t ino, struct single_file_stat *llstat)
> {
> struct fuse_entry_param *entry = &llstat->entry;
> @@ -235,40 +293,74 @@ void single_file_ll_statx(fuse_req_t req, fuse_ino_t ino, int flags, int mask,
> else
> fuse_reply_statx(req, 0, &stx, 0.0);
> }
> +
> +int single_file_hl_statx(const char *path, int statx_flags, int statx_mask,
> + struct statx *stx, struct fuse_file_info *fi)
> +{

bschubert2@imesrv6 build>ninja
[55/102] Compiling C object example/service_ll.p/single_file.c.o
../example/single_file.c:297:48: warning: unused parameter 'statx_flags'
[-Wunused-parameter]
297 | int single_file_hl_statx(const char *path, int statx_flags, int
statx_mask,
| ^
1 warning generated.
[56/102] Compiling C object example/service_hl.p/single_file.c.o
../example/single_file.c:297:48: warning: unused parameter 'statx_flags'
[-Wunused-parameter]
297 | int single_file_hl_statx(const char *path, int statx_flags, int
statx_mask,
| ^
1 warning generated.
[102/102] Linking target example/passthrough_hp

And CI tests run with -Werror - fails here.

> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> + bool filled;
> +
> + if (!ino)
> + return -ENOENT;
> +
> + pthread_mutex_lock(&single_file.lock);
> + filled = sf_statx(ino, statx_mask, stx);
> + pthread_mutex_unlock(&single_file.lock);
> +
> + return filled ? 0 : -ENOENT;
> +}
> #else
> void single_file_ll_statx(fuse_req_t req, fuse_ino_t ino, int flags, int mask,
> struct fuse_file_info *fi)
> {
> fuse_reply_err(req, ENOSYS);
> }
> +
> +int single_file_hl_statx(const char *path, int statx_flags, int statx_mask,
> + struct statx *stx, struct fuse_file_info *fi)
> +{
> + return -ENOSYS;
> +}
> #endif /* STATX_BASIC_STATS */
>
> +static void single_file_statfs(struct statvfs *buf)
> +{
> + pthread_mutex_lock(&single_file.lock);
> + buf->f_bsize = single_file.blocksize;
> + buf->f_frsize = 0;
> +
> + buf->f_blocks = single_file.blocks;
> + buf->f_bfree = 0;
> + buf->f_bavail = 0;
> + buf->f_files = 1;
> + buf->f_ffree = 0;
> + buf->f_favail = 0;
> + buf->f_fsid = 0x50C00L;
> + buf->f_flag = 0;
> + if (single_file.ro)
> + buf->f_flag |= ST_RDONLY;
> + buf->f_namemax = 255;
> + pthread_mutex_unlock(&single_file.lock);
> +}
> +
> void single_file_ll_statfs(fuse_req_t req, fuse_ino_t ino)
> {
> struct statvfs buf;
>
> (void)ino;
>
> - pthread_mutex_lock(&single_file.lock);
> - buf.f_bsize = single_file.blocksize;
> - buf.f_frsize = 0;
> -
> - buf.f_blocks = single_file.blocks;
> - buf.f_bfree = 0;
> - buf.f_bavail = 0;
> - buf.f_files = 1;
> - buf.f_ffree = 0;
> - buf.f_favail = 0;
> - buf.f_fsid = 0x50C00L;
> - buf.f_flag = 0;
> - if (single_file.ro)
> - buf.f_flag |= ST_RDONLY;
> - buf.f_namemax = 255;
> - pthread_mutex_unlock(&single_file.lock);
> -
> + single_file_statfs(&buf);
> fuse_reply_statfs(req, &buf);
> }
>
> +int single_file_hl_statfs(const char *path, struct statvfs *buf)
> +{
> + (void)path;
> +
> + single_file_statfs(buf);
> + return 0;
> +}
> +
> void single_file_ll_getattr(fuse_req_t req, fuse_ino_t ino,
> struct fuse_file_info *fi)
> {
> @@ -288,6 +380,28 @@ void single_file_ll_getattr(fuse_req_t req, fuse_ino_t ino,
> llstat.entry.attr_timeout);
> }
>
> +int single_file_hl_getattr(const char *path, struct stat *stbuf,
> + struct fuse_file_info *fi)
> +{
> + struct single_file_stat llstat;
> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> + bool filled;
> +
> + if (!ino)
> + return -ENOENT;
> +
> + memset(&llstat, 0, sizeof(llstat));
> + pthread_mutex_lock(&single_file.lock);
> + filled = sf_stat(ino, &llstat);
> + pthread_mutex_unlock(&single_file.lock);
> +
> + if (!filled)
> + return -ENOENT;
> +
> + memcpy(stbuf, &llstat.entry.attr, sizeof(*stbuf));
> + return 0;
> +}
> +
> static void get_now(struct timespec *now)
> {
> #ifdef CLOCK_REALTIME
> @@ -342,6 +456,81 @@ void single_file_ll_setattr(fuse_req_t req, fuse_ino_t ino, struct stat *attr,
> fuse_reply_err(req, EPERM);
> }
>
> +int single_file_hl_chmod(const char *path, mode_t mode,
> + struct fuse_file_info *fi)
> +{
> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> +
> + if (!ino)
> + return -ENOENT;
> + if (ino != SINGLE_FILE_INO)
> + return -EPERM;
> + if (single_file.ro)
> + return -EPERM;
> +
> + pthread_mutex_lock(&single_file.lock);
> + single_file.mode = (single_file.mode & S_IFMT) | (mode & ~S_IFMT);
> + pthread_mutex_unlock(&single_file.lock);
> +
> + return 0;
> +}
> +
> +static void set_time(const struct timespec *ctv, struct timespec *tv)
> +{
> + switch (ctv->tv_nsec) {
> + case UTIME_OMIT:
> + return;
> + case UTIME_NOW:
> + get_now(tv);
> + break;
> + default:
> + memcpy(tv, ctv, sizeof(*tv));
> + break;
> + }
> +}
> +
> +int single_file_hl_utimens(const char *path, const struct timespec ctv[2],
> + struct fuse_file_info *fi)
> +{
> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> +
> + if (!ino)
> + return -ENOENT;
> + if (ino != SINGLE_FILE_INO)
> + return -EPERM;
> + if (single_file.ro)
> + return -EPERM;
> +
> + pthread_mutex_lock(&single_file.lock);
> + set_time(&ctv[0], &single_file.atime);
> + set_time(&ctv[1], &single_file.mtime);
> + get_now(&single_file.ctime);
> + pthread_mutex_unlock(&single_file.lock);
> +
> + return 0;
> +}
> +
> +int single_file_hl_chown(const char *path, uid_t owner, gid_t group,
> + struct fuse_file_info *fi)
> +{
> + (void)path;
> + (void)owner;
> + (void)group;
> + (void)fi;
> +
> + return -EPERM;
> +}
> +
> +int single_file_hl_truncate(const char *path, off_t len,
> + struct fuse_file_info *fi)
> +{
> + (void)path;
> + (void)len;
> + (void)fi;
> +
> + return -EPERM;
> +}
> +
> void single_file_ll_lookup(fuse_req_t req, fuse_ino_t parent, const char *name)
> {
> struct single_file_stat llstat;
> @@ -373,6 +562,34 @@ void single_file_ll_open(fuse_req_t req, fuse_ino_t ino,
> fuse_reply_open(req, fi);
> }
>
> +int single_file_hl_opendir(const char *path, struct fuse_file_info *fi)
> +{
> + fuse_ino_t ino = single_file_path_to_ino(path);
> +
> + if (!ino)
> + return -ENOENT;
> + if (ino == SINGLE_FILE_INO)
> + return -ENOTDIR;
> +
> + fi->fh = ino;
> + return 0;
> +}
> +
> +int single_file_hl_open(const char *path, struct fuse_file_info *fi)
> +{
> + fuse_ino_t ino = single_file_path_to_ino(path);
> +
> + if (!ino)
> + return -ENOENT;
> + if (ino != SINGLE_FILE_INO)
> + return -EISDIR;
> + if (single_file.ro && (fi->flags & O_ACCMODE) != O_RDONLY)
> + return -EROFS;
> +
> + fi->fh = ino;
> + return 0;
> +}
> +
> void single_file_ll_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
> struct fuse_file_info *fi)
> {
> @@ -390,6 +607,26 @@ void single_file_ll_fsync(fuse_req_t req, fuse_ino_t ino, int datasync,
> fuse_reply_err(req, ret);
> }
>
> +int single_file_hl_fsync(const char *path, int datasync,
> + struct fuse_file_info *fi)
> +{
> + fuse_ino_t ino = single_open_file_path_to_ino(fi, path);
> +
> + (void)datasync;
> +
> + if (!ino)
> + return -ENOENT;
> +
> + if (ino == SINGLE_FILE_INO) {
> + int ret = fsync(single_file.backing_fd);
> +
> + if (ret)
> + return -errno;
> + }
> +
> + return 0;
> +}
> +
> unsigned long long parse_num_blocks(const char *arg, int log_block_size)
> {
> char *p;
>
>