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13#include "qemu/osdep.h"
14#include "fuse_i.h"
15#include "fuse_lowlevel.h"
16#include "fuse_misc.h"
17#include "fuse_opt.h"
18
19#include <errno.h>
20#include <limits.h>
21#include <stddef.h>
22#include <stdio.h>
23#include <stdlib.h>
24#include <string.h>
25#include <sys/param.h>
26#include <sys/time.h>
27#include <sys/resource.h>
28#include <unistd.h>
29
30#define FUSE_HELPER_OPT(t, p) \
31 { \
32 t, offsetof(struct fuse_cmdline_opts, p), 1 \
33 }
34#define FUSE_HELPER_OPT_VALUE(t, p, v) \
35 { \
36 t, offsetof(struct fuse_cmdline_opts, p), v \
37 }
38
39static const struct fuse_opt fuse_helper_opts[] = {
40 FUSE_HELPER_OPT("-h", show_help),
41 FUSE_HELPER_OPT("--help", show_help),
42 FUSE_HELPER_OPT("-V", show_version),
43 FUSE_HELPER_OPT("--version", show_version),
44 FUSE_HELPER_OPT("--print-capabilities", print_capabilities),
45 FUSE_HELPER_OPT("-d", debug),
46 FUSE_HELPER_OPT("debug", debug),
47 FUSE_HELPER_OPT("-d", foreground),
48 FUSE_HELPER_OPT("debug", foreground),
49 FUSE_OPT_KEY("-d", FUSE_OPT_KEY_KEEP),
50 FUSE_OPT_KEY("debug", FUSE_OPT_KEY_KEEP),
51 FUSE_HELPER_OPT("-f", foreground),
52 FUSE_HELPER_OPT_VALUE("--daemonize", foreground, 0),
53 FUSE_HELPER_OPT("fsname=", nodefault_subtype),
54 FUSE_OPT_KEY("fsname=", FUSE_OPT_KEY_KEEP),
55 FUSE_HELPER_OPT("subtype=", nodefault_subtype),
56 FUSE_OPT_KEY("subtype=", FUSE_OPT_KEY_KEEP),
57 FUSE_HELPER_OPT("max_idle_threads=%u", max_idle_threads),
58 FUSE_HELPER_OPT("--rlimit-nofile=%lu", rlimit_nofile),
59 FUSE_HELPER_OPT("--syslog", syslog),
60 FUSE_HELPER_OPT_VALUE("log_level=debug", log_level, FUSE_LOG_DEBUG),
61 FUSE_HELPER_OPT_VALUE("log_level=info", log_level, FUSE_LOG_INFO),
62 FUSE_HELPER_OPT_VALUE("log_level=warn", log_level, FUSE_LOG_WARNING),
63 FUSE_HELPER_OPT_VALUE("log_level=err", log_level, FUSE_LOG_ERR),
64 FUSE_OPT_END
65};
66
67struct fuse_conn_info_opts {
68 int atomic_o_trunc;
69 int no_remote_posix_lock;
70 int no_remote_flock;
71 int splice_write;
72 int splice_move;
73 int splice_read;
74 int no_splice_write;
75 int no_splice_move;
76 int no_splice_read;
77 int auto_inval_data;
78 int no_auto_inval_data;
79 int no_readdirplus;
80 int no_readdirplus_auto;
81 int async_dio;
82 int no_async_dio;
83 int writeback_cache;
84 int no_writeback_cache;
85 int async_read;
86 int sync_read;
87 unsigned max_write;
88 unsigned max_readahead;
89 unsigned max_background;
90 unsigned congestion_threshold;
91 unsigned time_gran;
92 int set_max_write;
93 int set_max_readahead;
94 int set_max_background;
95 int set_congestion_threshold;
96 int set_time_gran;
97};
98
99#define CONN_OPTION(t, p, v) \
100 { \
101 t, offsetof(struct fuse_conn_info_opts, p), v \
102 }
103static const struct fuse_opt conn_info_opt_spec[] = {
104 CONN_OPTION("max_write=%u", max_write, 0),
105 CONN_OPTION("max_write=", set_max_write, 1),
106 CONN_OPTION("max_readahead=%u", max_readahead, 0),
107 CONN_OPTION("max_readahead=", set_max_readahead, 1),
108 CONN_OPTION("max_background=%u", max_background, 0),
109 CONN_OPTION("max_background=", set_max_background, 1),
110 CONN_OPTION("congestion_threshold=%u", congestion_threshold, 0),
111 CONN_OPTION("congestion_threshold=", set_congestion_threshold, 1),
112 CONN_OPTION("sync_read", sync_read, 1),
113 CONN_OPTION("async_read", async_read, 1),
114 CONN_OPTION("atomic_o_trunc", atomic_o_trunc, 1),
115 CONN_OPTION("no_remote_lock", no_remote_posix_lock, 1),
116 CONN_OPTION("no_remote_lock", no_remote_flock, 1),
117 CONN_OPTION("no_remote_flock", no_remote_flock, 1),
118 CONN_OPTION("no_remote_posix_lock", no_remote_posix_lock, 1),
119 CONN_OPTION("splice_write", splice_write, 1),
120 CONN_OPTION("no_splice_write", no_splice_write, 1),
121 CONN_OPTION("splice_move", splice_move, 1),
122 CONN_OPTION("no_splice_move", no_splice_move, 1),
123 CONN_OPTION("splice_read", splice_read, 1),
124 CONN_OPTION("no_splice_read", no_splice_read, 1),
125 CONN_OPTION("auto_inval_data", auto_inval_data, 1),
126 CONN_OPTION("no_auto_inval_data", no_auto_inval_data, 1),
127 CONN_OPTION("readdirplus=no", no_readdirplus, 1),
128 CONN_OPTION("readdirplus=yes", no_readdirplus, 0),
129 CONN_OPTION("readdirplus=yes", no_readdirplus_auto, 1),
130 CONN_OPTION("readdirplus=auto", no_readdirplus, 0),
131 CONN_OPTION("readdirplus=auto", no_readdirplus_auto, 0),
132 CONN_OPTION("async_dio", async_dio, 1),
133 CONN_OPTION("no_async_dio", no_async_dio, 1),
134 CONN_OPTION("writeback_cache", writeback_cache, 1),
135 CONN_OPTION("no_writeback_cache", no_writeback_cache, 1),
136 CONN_OPTION("time_gran=%u", time_gran, 0),
137 CONN_OPTION("time_gran=", set_time_gran, 1),
138 FUSE_OPT_END
139};
140
141
142void fuse_cmdline_help(void)
143{
144 printf(" -h --help print help\n"
145 " -V --version print version\n"
146 " --print-capabilities print vhost-user.json\n"
147 " -d -o debug enable debug output (implies -f)\n"
148 " --syslog log to syslog (default stderr)\n"
149 " -f foreground operation\n"
150 " --daemonize run in background\n"
151 " -o cache=<mode> cache mode. could be one of \"auto, "
152 "always, none\"\n"
153 " default: auto\n"
154 " -o flock|no_flock enable/disable flock\n"
155 " default: no_flock\n"
156 " -o log_level=<level> log level, default to \"info\"\n"
157 " level could be one of \"debug, "
158 "info, warn, err\"\n"
159 " -o max_idle_threads the maximum number of idle worker "
160 "threads\n"
161 " allowed (default: 10)\n"
162 " -o posix_lock|no_posix_lock\n"
163 " enable/disable remote posix lock\n"
164 " default: no_posix_lock\n"
165 " -o readdirplus|no_readdirplus\n"
166 " enable/disable readirplus\n"
167 " default: readdirplus except with "
168 "cache=none\n"
169 " -o sandbox=namespace|chroot\n"
170 " sandboxing mode:\n"
171 " - namespace: mount, pid, and net\n"
172 " namespaces with pivot_root(2)\n"
173 " into shared directory\n"
174 " - chroot: chroot(2) into shared\n"
175 " directory (use in containers)\n"
176 " default: namespace\n"
177 " -o timeout=<number> I/O timeout (seconds)\n"
178 " default: depends on cache= option.\n"
179 " -o writeback|no_writeback enable/disable writeback cache\n"
180 " default: no_writeback\n"
181 " -o xattr|no_xattr enable/disable xattr\n"
182 " default: no_xattr\n"
183 " -o modcaps=CAPLIST Modify the list of capabilities\n"
184 " e.g. -o modcaps=+sys_admin:-chown\n"
185 " --rlimit-nofile=<num> set maximum number of file descriptors\n"
186 " (0 leaves rlimit unchanged)\n"
187 " default: min(1000000, fs.file-max - 16384)\n"
188 " if the current rlimit is lower\n"
189 " -o allow_direct_io|no_allow_direct_io\n"
190 " retain/discard O_DIRECT flags passed down\n"
191 " to virtiofsd from guest applications.\n"
192 " default: no_allow_direct_io\n"
193 " -o announce_submounts Announce sub-mount points to the guest\n"
194 );
195}
196
197static int fuse_helper_opt_proc(void *data, const char *arg, int key,
198 struct fuse_args *outargs)
199{
200 (void)data;
201 (void)outargs;
202
203 switch (key) {
204 case FUSE_OPT_KEY_NONOPT:
205 fuse_log(FUSE_LOG_ERR, "fuse: invalid argument `%s'\n", arg);
206 return -1;
207
208 default:
209
210 return 1;
211 }
212}
213
214static unsigned long get_default_rlimit_nofile(void)
215{
216 g_autofree gchar *file_max_str = NULL;
217 const rlim_t reserved_fds = 16384;
218 rlim_t max_fds = 1000000;
219 rlim_t file_max;
220 struct rlimit rlim;
221
222
223
224
225
226
227 if (!g_file_get_contents("/proc/sys/fs/file-max", &file_max_str,
228 NULL, NULL)) {
229 fuse_log(FUSE_LOG_ERR, "can't read /proc/sys/fs/file-max\n");
230 exit(1);
231 }
232 file_max = g_ascii_strtoull(file_max_str, NULL, 10);
233 if (file_max < 2 * reserved_fds) {
234 fuse_log(FUSE_LOG_ERR,
235 "The fs.file-max sysctl is too low (%lu) to allow a "
236 "reasonable number of open files.\n",
237 (unsigned long)file_max);
238 exit(1);
239 }
240 max_fds = MIN(file_max - reserved_fds, max_fds);
241
242 if (getrlimit(RLIMIT_NOFILE, &rlim) < 0) {
243 fuse_log(FUSE_LOG_ERR, "getrlimit(RLIMIT_NOFILE): %m\n");
244 exit(1);
245 }
246
247 if (rlim.rlim_cur >= max_fds) {
248 return 0;
249 }
250 return max_fds;
251}
252
253int fuse_parse_cmdline(struct fuse_args *args, struct fuse_cmdline_opts *opts)
254{
255 memset(opts, 0, sizeof(struct fuse_cmdline_opts));
256
257 opts->max_idle_threads = 10;
258 opts->rlimit_nofile = get_default_rlimit_nofile();
259 opts->foreground = 1;
260
261 if (fuse_opt_parse(args, opts, fuse_helper_opts, fuse_helper_opt_proc) ==
262 -1) {
263 return -1;
264 }
265
266 return 0;
267}
268
269
270int fuse_daemonize(int foreground)
271{
272 int ret = 0, rett;
273 if (!foreground) {
274 int nullfd;
275 int waiter[2];
276 char completed;
277
278 if (pipe(waiter)) {
279 fuse_log(FUSE_LOG_ERR, "fuse_daemonize: pipe: %s\n",
280 strerror(errno));
281 return -1;
282 }
283
284
285
286
287
288 switch (fork()) {
289 case -1:
290 fuse_log(FUSE_LOG_ERR, "fuse_daemonize: fork: %s\n",
291 strerror(errno));
292 return -1;
293 case 0:
294 break;
295 default:
296 _exit(read(waiter[0], &completed,
297 sizeof(completed) != sizeof(completed)));
298 }
299
300 if (setsid() == -1) {
301 fuse_log(FUSE_LOG_ERR, "fuse_daemonize: setsid: %s\n",
302 strerror(errno));
303 return -1;
304 }
305
306 ret = chdir("/");
307
308 nullfd = open("/dev/null", O_RDWR, 0);
309 if (nullfd != -1) {
310 rett = dup2(nullfd, 0);
311 if (!ret) {
312 ret = rett;
313 }
314 rett = dup2(nullfd, 1);
315 if (!ret) {
316 ret = rett;
317 }
318 rett = dup2(nullfd, 2);
319 if (!ret) {
320 ret = rett;
321 }
322 if (nullfd > 2) {
323 close(nullfd);
324 }
325 }
326
327
328 completed = 1;
329 rett = write(waiter[1], &completed, sizeof(completed));
330 if (!ret) {
331 ret = rett;
332 }
333 close(waiter[0]);
334 close(waiter[1]);
335 } else {
336 ret = chdir("/");
337 }
338 return ret;
339}
340
341void fuse_apply_conn_info_opts(struct fuse_conn_info_opts *opts,
342 struct fuse_conn_info *conn)
343{
344 if (opts->set_max_write) {
345 conn->max_write = opts->max_write;
346 }
347 if (opts->set_max_background) {
348 conn->max_background = opts->max_background;
349 }
350 if (opts->set_congestion_threshold) {
351 conn->congestion_threshold = opts->congestion_threshold;
352 }
353 if (opts->set_time_gran) {
354 conn->time_gran = opts->time_gran;
355 }
356 if (opts->set_max_readahead) {
357 conn->max_readahead = opts->max_readahead;
358 }
359
360#define LL_ENABLE(cond, cap) \
361 if (cond) \
362 conn->want |= (cap)
363#define LL_DISABLE(cond, cap) \
364 if (cond) \
365 conn->want &= ~(cap)
366
367 LL_ENABLE(opts->splice_read, FUSE_CAP_SPLICE_READ);
368 LL_DISABLE(opts->no_splice_read, FUSE_CAP_SPLICE_READ);
369
370 LL_ENABLE(opts->splice_write, FUSE_CAP_SPLICE_WRITE);
371 LL_DISABLE(opts->no_splice_write, FUSE_CAP_SPLICE_WRITE);
372
373 LL_ENABLE(opts->splice_move, FUSE_CAP_SPLICE_MOVE);
374 LL_DISABLE(opts->no_splice_move, FUSE_CAP_SPLICE_MOVE);
375
376 LL_ENABLE(opts->auto_inval_data, FUSE_CAP_AUTO_INVAL_DATA);
377 LL_DISABLE(opts->no_auto_inval_data, FUSE_CAP_AUTO_INVAL_DATA);
378
379 LL_DISABLE(opts->no_readdirplus, FUSE_CAP_READDIRPLUS);
380 LL_DISABLE(opts->no_readdirplus_auto, FUSE_CAP_READDIRPLUS_AUTO);
381
382 LL_ENABLE(opts->async_dio, FUSE_CAP_ASYNC_DIO);
383 LL_DISABLE(opts->no_async_dio, FUSE_CAP_ASYNC_DIO);
384
385 LL_ENABLE(opts->writeback_cache, FUSE_CAP_WRITEBACK_CACHE);
386 LL_DISABLE(opts->no_writeback_cache, FUSE_CAP_WRITEBACK_CACHE);
387
388 LL_ENABLE(opts->async_read, FUSE_CAP_ASYNC_READ);
389 LL_DISABLE(opts->sync_read, FUSE_CAP_ASYNC_READ);
390
391 LL_DISABLE(opts->no_remote_posix_lock, FUSE_CAP_POSIX_LOCKS);
392 LL_DISABLE(opts->no_remote_flock, FUSE_CAP_FLOCK_LOCKS);
393}
394
395struct fuse_conn_info_opts *fuse_parse_conn_info_opts(struct fuse_args *args)
396{
397 struct fuse_conn_info_opts *opts;
398
399 opts = calloc(1, sizeof(struct fuse_conn_info_opts));
400 if (opts == NULL) {
401 fuse_log(FUSE_LOG_ERR, "calloc failed\n");
402 return NULL;
403 }
404 if (fuse_opt_parse(args, opts, conn_info_opt_spec, NULL) == -1) {
405 free(opts);
406 return NULL;
407 }
408 return opts;
409}
410
