2 * FUSE: Filesystem in Userspace
3 * Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu>
5 * Helper functions to create (simple) standalone programs. With the
6 * aid of these functions it should be possible to create full FUSE
7 * file system by implementing nothing but the request handlers.
9 * This program can be distributed under the terms of the GNU LGPLv2.
10 * See the file COPYING.LIB.
13 #include "qemu/osdep.h"
15 #include "fuse_lowlevel.h"
16 #include "fuse_misc.h"
25 #include <sys/param.h>
28 #define FUSE_HELPER_OPT(t, p) \
30 t, offsetof(struct fuse_cmdline_opts, p), 1 \
32 #define FUSE_HELPER_OPT_VALUE(t, p, v) \
34 t, offsetof(struct fuse_cmdline_opts, p), v \
37 static const struct fuse_opt fuse_helper_opts
[] = {
38 FUSE_HELPER_OPT("-h", show_help
),
39 FUSE_HELPER_OPT("--help", show_help
),
40 FUSE_HELPER_OPT("-V", show_version
),
41 FUSE_HELPER_OPT("--version", show_version
),
42 FUSE_HELPER_OPT("--print-capabilities", print_capabilities
),
43 FUSE_HELPER_OPT("-d", debug
),
44 FUSE_HELPER_OPT("debug", debug
),
45 FUSE_HELPER_OPT("-d", foreground
),
46 FUSE_HELPER_OPT("debug", foreground
),
47 FUSE_OPT_KEY("-d", FUSE_OPT_KEY_KEEP
),
48 FUSE_OPT_KEY("debug", FUSE_OPT_KEY_KEEP
),
49 FUSE_HELPER_OPT("-f", foreground
),
50 FUSE_HELPER_OPT_VALUE("--daemonize", foreground
, 0),
51 FUSE_HELPER_OPT("fsname=", nodefault_subtype
),
52 FUSE_OPT_KEY("fsname=", FUSE_OPT_KEY_KEEP
),
53 FUSE_HELPER_OPT("subtype=", nodefault_subtype
),
54 FUSE_OPT_KEY("subtype=", FUSE_OPT_KEY_KEEP
),
55 FUSE_HELPER_OPT("max_idle_threads=%u", max_idle_threads
),
56 FUSE_HELPER_OPT("--syslog", syslog
),
57 FUSE_HELPER_OPT_VALUE("log_level=debug", log_level
, FUSE_LOG_DEBUG
),
58 FUSE_HELPER_OPT_VALUE("log_level=info", log_level
, FUSE_LOG_INFO
),
59 FUSE_HELPER_OPT_VALUE("log_level=warn", log_level
, FUSE_LOG_WARNING
),
60 FUSE_HELPER_OPT_VALUE("log_level=err", log_level
, FUSE_LOG_ERR
),
64 struct fuse_conn_info_opts
{
66 int no_remote_posix_lock
;
75 int no_auto_inval_data
;
77 int no_readdirplus_auto
;
81 int no_writeback_cache
;
85 unsigned max_readahead
;
86 unsigned max_background
;
87 unsigned congestion_threshold
;
90 int set_max_readahead
;
91 int set_max_background
;
92 int set_congestion_threshold
;
96 #define CONN_OPTION(t, p, v) \
98 t, offsetof(struct fuse_conn_info_opts, p), v \
100 static const struct fuse_opt conn_info_opt_spec
[] = {
101 CONN_OPTION("max_write=%u", max_write
, 0),
102 CONN_OPTION("max_write=", set_max_write
, 1),
103 CONN_OPTION("max_readahead=%u", max_readahead
, 0),
104 CONN_OPTION("max_readahead=", set_max_readahead
, 1),
105 CONN_OPTION("max_background=%u", max_background
, 0),
106 CONN_OPTION("max_background=", set_max_background
, 1),
107 CONN_OPTION("congestion_threshold=%u", congestion_threshold
, 0),
108 CONN_OPTION("congestion_threshold=", set_congestion_threshold
, 1),
109 CONN_OPTION("sync_read", sync_read
, 1),
110 CONN_OPTION("async_read", async_read
, 1),
111 CONN_OPTION("atomic_o_trunc", atomic_o_trunc
, 1),
112 CONN_OPTION("no_remote_lock", no_remote_posix_lock
, 1),
113 CONN_OPTION("no_remote_lock", no_remote_flock
, 1),
114 CONN_OPTION("no_remote_flock", no_remote_flock
, 1),
115 CONN_OPTION("no_remote_posix_lock", no_remote_posix_lock
, 1),
116 CONN_OPTION("splice_write", splice_write
, 1),
117 CONN_OPTION("no_splice_write", no_splice_write
, 1),
118 CONN_OPTION("splice_move", splice_move
, 1),
119 CONN_OPTION("no_splice_move", no_splice_move
, 1),
120 CONN_OPTION("splice_read", splice_read
, 1),
121 CONN_OPTION("no_splice_read", no_splice_read
, 1),
122 CONN_OPTION("auto_inval_data", auto_inval_data
, 1),
123 CONN_OPTION("no_auto_inval_data", no_auto_inval_data
, 1),
124 CONN_OPTION("readdirplus=no", no_readdirplus
, 1),
125 CONN_OPTION("readdirplus=yes", no_readdirplus
, 0),
126 CONN_OPTION("readdirplus=yes", no_readdirplus_auto
, 1),
127 CONN_OPTION("readdirplus=auto", no_readdirplus
, 0),
128 CONN_OPTION("readdirplus=auto", no_readdirplus_auto
, 0),
129 CONN_OPTION("async_dio", async_dio
, 1),
130 CONN_OPTION("no_async_dio", no_async_dio
, 1),
131 CONN_OPTION("writeback_cache", writeback_cache
, 1),
132 CONN_OPTION("no_writeback_cache", no_writeback_cache
, 1),
133 CONN_OPTION("time_gran=%u", time_gran
, 0),
134 CONN_OPTION("time_gran=", set_time_gran
, 1),
139 void fuse_cmdline_help(void)
141 printf(" -h --help print help\n"
142 " -V --version print version\n"
143 " --print-capabilities print vhost-user.json\n"
144 " -d -o debug enable debug output (implies -f)\n"
145 " --syslog log to syslog (default stderr)\n"
146 " -f foreground operation\n"
147 " --daemonize run in background\n"
148 " -o cache=<mode> cache mode. could be one of \"auto, "
151 " -o flock|no_flock enable/disable flock\n"
152 " default: no_flock\n"
153 " -o log_level=<level> log level, default to \"info\"\n"
154 " level could be one of \"debug, "
155 "info, warn, err\"\n"
156 " -o max_idle_threads the maximum number of idle worker "
158 " allowed (default: 10)\n"
159 " -o norace disable racy fallback\n"
161 " -o posix_lock|no_posix_lock\n"
162 " enable/disable remote posix lock\n"
163 " default: posix_lock\n"
164 " -o readdirplus|no_readdirplus\n"
165 " enable/disable readirplus\n"
166 " default: readdirplus except with "
168 " -o timeout=<number> I/O timeout (seconds)\n"
169 " default: depends on cache= option.\n"
170 " -o writeback|no_writeback enable/disable writeback cache\n"
171 " default: no_writeback\n"
172 " -o xattr|no_xattr enable/disable xattr\n"
173 " default: no_xattr\n"
177 static int fuse_helper_opt_proc(void *data
, const char *arg
, int key
,
178 struct fuse_args
*outargs
)
184 case FUSE_OPT_KEY_NONOPT
:
185 fuse_log(FUSE_LOG_ERR
, "fuse: invalid argument `%s'\n", arg
);
189 /* Pass through unknown options */
194 int fuse_parse_cmdline(struct fuse_args
*args
, struct fuse_cmdline_opts
*opts
)
196 memset(opts
, 0, sizeof(struct fuse_cmdline_opts
));
198 opts
->max_idle_threads
= 10;
199 opts
->foreground
= 1;
201 if (fuse_opt_parse(args
, opts
, fuse_helper_opts
, fuse_helper_opt_proc
) ==
210 int fuse_daemonize(int foreground
)
219 fuse_log(FUSE_LOG_ERR
, "fuse_daemonize: pipe: %s\n",
225 * demonize current process by forking it and killing the
226 * parent. This makes current process as a child of 'init'.
230 fuse_log(FUSE_LOG_ERR
, "fuse_daemonize: fork: %s\n",
236 _exit(read(waiter
[0], &completed
,
237 sizeof(completed
) != sizeof(completed
)));
240 if (setsid() == -1) {
241 fuse_log(FUSE_LOG_ERR
, "fuse_daemonize: setsid: %s\n",
248 nullfd
= open("/dev/null", O_RDWR
, 0);
250 rett
= dup2(nullfd
, 0);
254 rett
= dup2(nullfd
, 1);
258 rett
= dup2(nullfd
, 2);
267 /* Propagate completion of daemon initialization */
269 rett
= write(waiter
[1], &completed
, sizeof(completed
));
281 void fuse_apply_conn_info_opts(struct fuse_conn_info_opts
*opts
,
282 struct fuse_conn_info
*conn
)
284 if (opts
->set_max_write
) {
285 conn
->max_write
= opts
->max_write
;
287 if (opts
->set_max_background
) {
288 conn
->max_background
= opts
->max_background
;
290 if (opts
->set_congestion_threshold
) {
291 conn
->congestion_threshold
= opts
->congestion_threshold
;
293 if (opts
->set_time_gran
) {
294 conn
->time_gran
= opts
->time_gran
;
296 if (opts
->set_max_readahead
) {
297 conn
->max_readahead
= opts
->max_readahead
;
300 #define LL_ENABLE(cond, cap) \
303 #define LL_DISABLE(cond, cap) \
307 LL_ENABLE(opts
->splice_read
, FUSE_CAP_SPLICE_READ
);
308 LL_DISABLE(opts
->no_splice_read
, FUSE_CAP_SPLICE_READ
);
310 LL_ENABLE(opts
->splice_write
, FUSE_CAP_SPLICE_WRITE
);
311 LL_DISABLE(opts
->no_splice_write
, FUSE_CAP_SPLICE_WRITE
);
313 LL_ENABLE(opts
->splice_move
, FUSE_CAP_SPLICE_MOVE
);
314 LL_DISABLE(opts
->no_splice_move
, FUSE_CAP_SPLICE_MOVE
);
316 LL_ENABLE(opts
->auto_inval_data
, FUSE_CAP_AUTO_INVAL_DATA
);
317 LL_DISABLE(opts
->no_auto_inval_data
, FUSE_CAP_AUTO_INVAL_DATA
);
319 LL_DISABLE(opts
->no_readdirplus
, FUSE_CAP_READDIRPLUS
);
320 LL_DISABLE(opts
->no_readdirplus_auto
, FUSE_CAP_READDIRPLUS_AUTO
);
322 LL_ENABLE(opts
->async_dio
, FUSE_CAP_ASYNC_DIO
);
323 LL_DISABLE(opts
->no_async_dio
, FUSE_CAP_ASYNC_DIO
);
325 LL_ENABLE(opts
->writeback_cache
, FUSE_CAP_WRITEBACK_CACHE
);
326 LL_DISABLE(opts
->no_writeback_cache
, FUSE_CAP_WRITEBACK_CACHE
);
328 LL_ENABLE(opts
->async_read
, FUSE_CAP_ASYNC_READ
);
329 LL_DISABLE(opts
->sync_read
, FUSE_CAP_ASYNC_READ
);
331 LL_DISABLE(opts
->no_remote_posix_lock
, FUSE_CAP_POSIX_LOCKS
);
332 LL_DISABLE(opts
->no_remote_flock
, FUSE_CAP_FLOCK_LOCKS
);
335 struct fuse_conn_info_opts
*fuse_parse_conn_info_opts(struct fuse_args
*args
)
337 struct fuse_conn_info_opts
*opts
;
339 opts
= calloc(1, sizeof(struct fuse_conn_info_opts
));
341 fuse_log(FUSE_LOG_ERR
, "calloc failed\n");
344 if (fuse_opt_parse(args
, opts
, conn_info_opt_spec
, NULL
) == -1) {