| /* |
| * FUSE: Filesystem in Userspace |
| * Copyright (C) 2001-2007 Miklos Szeredi <miklos@szeredi.hu> |
| * |
| * Helper functions to create (simple) standalone programs. With the |
| * aid of these functions it should be possible to create full FUSE |
| * file system by implementing nothing but the request handlers. |
| |
| * This program can be distributed under the terms of the GNU LGPLv2. |
| * See the file COPYING.LIB. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "fuse_i.h" |
| #include "fuse_lowlevel.h" |
| #include "fuse_misc.h" |
| #include "fuse_opt.h" |
| |
| #include <errno.h> |
| #include <limits.h> |
| #include <stddef.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/param.h> |
| #include <sys/time.h> |
| #include <sys/resource.h> |
| #include <unistd.h> |
| |
| #define FUSE_HELPER_OPT(t, p) \ |
| { \ |
| t, offsetof(struct fuse_cmdline_opts, p), 1 \ |
| } |
| #define FUSE_HELPER_OPT_VALUE(t, p, v) \ |
| { \ |
| t, offsetof(struct fuse_cmdline_opts, p), v \ |
| } |
| |
| static const struct fuse_opt fuse_helper_opts[] = { |
| FUSE_HELPER_OPT("-h", show_help), |
| FUSE_HELPER_OPT("--help", show_help), |
| FUSE_HELPER_OPT("-V", show_version), |
| FUSE_HELPER_OPT("--version", show_version), |
| FUSE_HELPER_OPT("--print-capabilities", print_capabilities), |
| FUSE_HELPER_OPT("-d", debug), |
| FUSE_HELPER_OPT("debug", debug), |
| FUSE_HELPER_OPT("-d", foreground), |
| FUSE_HELPER_OPT("debug", foreground), |
| FUSE_OPT_KEY("-d", FUSE_OPT_KEY_KEEP), |
| FUSE_OPT_KEY("debug", FUSE_OPT_KEY_KEEP), |
| FUSE_HELPER_OPT("-f", foreground), |
| FUSE_HELPER_OPT_VALUE("--daemonize", foreground, 0), |
| FUSE_HELPER_OPT("fsname=", nodefault_subtype), |
| FUSE_OPT_KEY("fsname=", FUSE_OPT_KEY_KEEP), |
| FUSE_HELPER_OPT("subtype=", nodefault_subtype), |
| FUSE_OPT_KEY("subtype=", FUSE_OPT_KEY_KEEP), |
| FUSE_HELPER_OPT("max_idle_threads=%u", max_idle_threads), |
| FUSE_HELPER_OPT("--rlimit-nofile=%lu", rlimit_nofile), |
| FUSE_HELPER_OPT("--syslog", syslog), |
| FUSE_HELPER_OPT_VALUE("log_level=debug", log_level, FUSE_LOG_DEBUG), |
| FUSE_HELPER_OPT_VALUE("log_level=info", log_level, FUSE_LOG_INFO), |
| FUSE_HELPER_OPT_VALUE("log_level=warn", log_level, FUSE_LOG_WARNING), |
| FUSE_HELPER_OPT_VALUE("log_level=err", log_level, FUSE_LOG_ERR), |
| FUSE_OPT_END |
| }; |
| |
| struct fuse_conn_info_opts { |
| int atomic_o_trunc; |
| int no_remote_posix_lock; |
| int no_remote_flock; |
| int splice_write; |
| int splice_move; |
| int splice_read; |
| int no_splice_write; |
| int no_splice_move; |
| int no_splice_read; |
| int auto_inval_data; |
| int no_auto_inval_data; |
| int no_readdirplus; |
| int no_readdirplus_auto; |
| int async_dio; |
| int no_async_dio; |
| int writeback_cache; |
| int no_writeback_cache; |
| int async_read; |
| int sync_read; |
| unsigned max_write; |
| unsigned max_readahead; |
| unsigned max_background; |
| unsigned congestion_threshold; |
| unsigned time_gran; |
| int set_max_write; |
| int set_max_readahead; |
| int set_max_background; |
| int set_congestion_threshold; |
| int set_time_gran; |
| }; |
| |
| #define CONN_OPTION(t, p, v) \ |
| { \ |
| t, offsetof(struct fuse_conn_info_opts, p), v \ |
| } |
| static const struct fuse_opt conn_info_opt_spec[] = { |
| CONN_OPTION("max_write=%u", max_write, 0), |
| CONN_OPTION("max_write=", set_max_write, 1), |
| CONN_OPTION("max_readahead=%u", max_readahead, 0), |
| CONN_OPTION("max_readahead=", set_max_readahead, 1), |
| CONN_OPTION("max_background=%u", max_background, 0), |
| CONN_OPTION("max_background=", set_max_background, 1), |
| CONN_OPTION("congestion_threshold=%u", congestion_threshold, 0), |
| CONN_OPTION("congestion_threshold=", set_congestion_threshold, 1), |
| CONN_OPTION("sync_read", sync_read, 1), |
| CONN_OPTION("async_read", async_read, 1), |
| CONN_OPTION("atomic_o_trunc", atomic_o_trunc, 1), |
| CONN_OPTION("no_remote_lock", no_remote_posix_lock, 1), |
| CONN_OPTION("no_remote_lock", no_remote_flock, 1), |
| CONN_OPTION("no_remote_flock", no_remote_flock, 1), |
| CONN_OPTION("no_remote_posix_lock", no_remote_posix_lock, 1), |
| CONN_OPTION("splice_write", splice_write, 1), |
| CONN_OPTION("no_splice_write", no_splice_write, 1), |
| CONN_OPTION("splice_move", splice_move, 1), |
| CONN_OPTION("no_splice_move", no_splice_move, 1), |
| CONN_OPTION("splice_read", splice_read, 1), |
| CONN_OPTION("no_splice_read", no_splice_read, 1), |
| CONN_OPTION("auto_inval_data", auto_inval_data, 1), |
| CONN_OPTION("no_auto_inval_data", no_auto_inval_data, 1), |
| CONN_OPTION("readdirplus=no", no_readdirplus, 1), |
| CONN_OPTION("readdirplus=yes", no_readdirplus, 0), |
| CONN_OPTION("readdirplus=yes", no_readdirplus_auto, 1), |
| CONN_OPTION("readdirplus=auto", no_readdirplus, 0), |
| CONN_OPTION("readdirplus=auto", no_readdirplus_auto, 0), |
| CONN_OPTION("async_dio", async_dio, 1), |
| CONN_OPTION("no_async_dio", no_async_dio, 1), |
| CONN_OPTION("writeback_cache", writeback_cache, 1), |
| CONN_OPTION("no_writeback_cache", no_writeback_cache, 1), |
| CONN_OPTION("time_gran=%u", time_gran, 0), |
| CONN_OPTION("time_gran=", set_time_gran, 1), |
| FUSE_OPT_END |
| }; |
| |
| |
| void fuse_cmdline_help(void) |
| { |
| printf(" -h --help print help\n" |
| " -V --version print version\n" |
| " --print-capabilities print vhost-user.json\n" |
| " -d -o debug enable debug output (implies -f)\n" |
| " --syslog log to syslog (default stderr)\n" |
| " -f foreground operation\n" |
| " --daemonize run in background\n" |
| " -o cache=<mode> cache mode. could be one of \"auto, " |
| "always, none\"\n" |
| " default: auto\n" |
| " -o flock|no_flock enable/disable flock\n" |
| " default: no_flock\n" |
| " -o log_level=<level> log level, default to \"info\"\n" |
| " level could be one of \"debug, " |
| "info, warn, err\"\n" |
| " -o max_idle_threads the maximum number of idle worker " |
| "threads\n" |
| " allowed (default: 10)\n" |
| " -o posix_lock|no_posix_lock\n" |
| " enable/disable remote posix lock\n" |
| " default: no_posix_lock\n" |
| " -o readdirplus|no_readdirplus\n" |
| " enable/disable readirplus\n" |
| " default: readdirplus except with " |
| "cache=none\n" |
| " -o sandbox=namespace|chroot\n" |
| " sandboxing mode:\n" |
| " - namespace: mount, pid, and net\n" |
| " namespaces with pivot_root(2)\n" |
| " into shared directory\n" |
| " - chroot: chroot(2) into shared\n" |
| " directory (use in containers)\n" |
| " default: namespace\n" |
| " -o timeout=<number> I/O timeout (seconds)\n" |
| " default: depends on cache= option.\n" |
| " -o writeback|no_writeback enable/disable writeback cache\n" |
| " default: no_writeback\n" |
| " -o xattr|no_xattr enable/disable xattr\n" |
| " default: no_xattr\n" |
| " -o modcaps=CAPLIST Modify the list of capabilities\n" |
| " e.g. -o modcaps=+sys_admin:-chown\n" |
| " --rlimit-nofile=<num> set maximum number of file descriptors\n" |
| " (0 leaves rlimit unchanged)\n" |
| " default: min(1000000, fs.file-max - 16384)\n" |
| " if the current rlimit is lower\n" |
| " -o allow_direct_io|no_allow_direct_io\n" |
| " retain/discard O_DIRECT flags passed down\n" |
| " to virtiofsd from guest applications.\n" |
| " default: no_allow_direct_io\n" |
| " -o announce_submounts Announce sub-mount points to the guest\n" |
| ); |
| } |
| |
| static int fuse_helper_opt_proc(void *data, const char *arg, int key, |
| struct fuse_args *outargs) |
| { |
| (void)data; |
| (void)outargs; |
| |
| switch (key) { |
| case FUSE_OPT_KEY_NONOPT: |
| fuse_log(FUSE_LOG_ERR, "fuse: invalid argument `%s'\n", arg); |
| return -1; |
| |
| default: |
| /* Pass through unknown options */ |
| return 1; |
| } |
| } |
| |
| static unsigned long get_default_rlimit_nofile(void) |
| { |
| g_autofree gchar *file_max_str = NULL; |
| const rlim_t reserved_fds = 16384; /* leave at least this many fds free */ |
| rlim_t max_fds = 1000000; /* our default RLIMIT_NOFILE target */ |
| rlim_t file_max; |
| struct rlimit rlim; |
| |
| /* |
| * Reduce max_fds below the system-wide maximum, if necessary. This |
| * ensures there are fds available for other processes so we don't |
| * cause resource exhaustion. |
| */ |
| if (!g_file_get_contents("/proc/sys/fs/file-max", &file_max_str, |
| NULL, NULL)) { |
| fuse_log(FUSE_LOG_ERR, "can't read /proc/sys/fs/file-max\n"); |
| exit(1); |
| } |
| file_max = g_ascii_strtoull(file_max_str, NULL, 10); |
| if (file_max < 2 * reserved_fds) { |
| fuse_log(FUSE_LOG_ERR, |
| "The fs.file-max sysctl is too low (%lu) to allow a " |
| "reasonable number of open files.\n", |
| (unsigned long)file_max); |
| exit(1); |
| } |
| max_fds = MIN(file_max - reserved_fds, max_fds); |
| |
| if (getrlimit(RLIMIT_NOFILE, &rlim) < 0) { |
| fuse_log(FUSE_LOG_ERR, "getrlimit(RLIMIT_NOFILE): %m\n"); |
| exit(1); |
| } |
| |
| if (rlim.rlim_cur >= max_fds) { |
| return 0; /* we have more fds available than required! */ |
| } |
| return max_fds; |
| } |
| |
| int fuse_parse_cmdline(struct fuse_args *args, struct fuse_cmdline_opts *opts) |
| { |
| memset(opts, 0, sizeof(struct fuse_cmdline_opts)); |
| |
| opts->max_idle_threads = 10; |
| opts->rlimit_nofile = get_default_rlimit_nofile(); |
| opts->foreground = 1; |
| |
| if (fuse_opt_parse(args, opts, fuse_helper_opts, fuse_helper_opt_proc) == |
| -1) { |
| return -1; |
| } |
| |
| return 0; |
| } |
| |
| |
| int fuse_daemonize(int foreground) |
| { |
| int ret = 0, rett; |
| if (!foreground) { |
| int nullfd; |
| int waiter[2]; |
| char completed; |
| |
| if (pipe(waiter)) { |
| fuse_log(FUSE_LOG_ERR, "fuse_daemonize: pipe: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| /* |
| * demonize current process by forking it and killing the |
| * parent. This makes current process as a child of 'init'. |
| */ |
| switch (fork()) { |
| case -1: |
| fuse_log(FUSE_LOG_ERR, "fuse_daemonize: fork: %s\n", |
| strerror(errno)); |
| return -1; |
| case 0: |
| break; |
| default: |
| _exit(read(waiter[0], &completed, |
| sizeof(completed) != sizeof(completed))); |
| } |
| |
| if (setsid() == -1) { |
| fuse_log(FUSE_LOG_ERR, "fuse_daemonize: setsid: %s\n", |
| strerror(errno)); |
| return -1; |
| } |
| |
| ret = chdir("/"); |
| |
| nullfd = open("/dev/null", O_RDWR, 0); |
| if (nullfd != -1) { |
| rett = dup2(nullfd, 0); |
| if (!ret) { |
| ret = rett; |
| } |
| rett = dup2(nullfd, 1); |
| if (!ret) { |
| ret = rett; |
| } |
| rett = dup2(nullfd, 2); |
| if (!ret) { |
| ret = rett; |
| } |
| if (nullfd > 2) { |
| close(nullfd); |
| } |
| } |
| |
| /* Propagate completion of daemon initialization */ |
| completed = 1; |
| rett = write(waiter[1], &completed, sizeof(completed)); |
| if (!ret) { |
| ret = rett; |
| } |
| close(waiter[0]); |
| close(waiter[1]); |
| } else { |
| ret = chdir("/"); |
| } |
| return ret; |
| } |
| |
| void fuse_apply_conn_info_opts(struct fuse_conn_info_opts *opts, |
| struct fuse_conn_info *conn) |
| { |
| if (opts->set_max_write) { |
| conn->max_write = opts->max_write; |
| } |
| if (opts->set_max_background) { |
| conn->max_background = opts->max_background; |
| } |
| if (opts->set_congestion_threshold) { |
| conn->congestion_threshold = opts->congestion_threshold; |
| } |
| if (opts->set_time_gran) { |
| conn->time_gran = opts->time_gran; |
| } |
| if (opts->set_max_readahead) { |
| conn->max_readahead = opts->max_readahead; |
| } |
| |
| #define LL_ENABLE(cond, cap) \ |
| if (cond) \ |
| conn->want |= (cap) |
| #define LL_DISABLE(cond, cap) \ |
| if (cond) \ |
| conn->want &= ~(cap) |
| |
| LL_ENABLE(opts->splice_read, FUSE_CAP_SPLICE_READ); |
| LL_DISABLE(opts->no_splice_read, FUSE_CAP_SPLICE_READ); |
| |
| LL_ENABLE(opts->splice_write, FUSE_CAP_SPLICE_WRITE); |
| LL_DISABLE(opts->no_splice_write, FUSE_CAP_SPLICE_WRITE); |
| |
| LL_ENABLE(opts->splice_move, FUSE_CAP_SPLICE_MOVE); |
| LL_DISABLE(opts->no_splice_move, FUSE_CAP_SPLICE_MOVE); |
| |
| LL_ENABLE(opts->auto_inval_data, FUSE_CAP_AUTO_INVAL_DATA); |
| LL_DISABLE(opts->no_auto_inval_data, FUSE_CAP_AUTO_INVAL_DATA); |
| |
| LL_DISABLE(opts->no_readdirplus, FUSE_CAP_READDIRPLUS); |
| LL_DISABLE(opts->no_readdirplus_auto, FUSE_CAP_READDIRPLUS_AUTO); |
| |
| LL_ENABLE(opts->async_dio, FUSE_CAP_ASYNC_DIO); |
| LL_DISABLE(opts->no_async_dio, FUSE_CAP_ASYNC_DIO); |
| |
| LL_ENABLE(opts->writeback_cache, FUSE_CAP_WRITEBACK_CACHE); |
| LL_DISABLE(opts->no_writeback_cache, FUSE_CAP_WRITEBACK_CACHE); |
| |
| LL_ENABLE(opts->async_read, FUSE_CAP_ASYNC_READ); |
| LL_DISABLE(opts->sync_read, FUSE_CAP_ASYNC_READ); |
| |
| LL_DISABLE(opts->no_remote_posix_lock, FUSE_CAP_POSIX_LOCKS); |
| LL_DISABLE(opts->no_remote_flock, FUSE_CAP_FLOCK_LOCKS); |
| } |
| |
| struct fuse_conn_info_opts *fuse_parse_conn_info_opts(struct fuse_args *args) |
| { |
| struct fuse_conn_info_opts *opts; |
| |
| opts = calloc(1, sizeof(struct fuse_conn_info_opts)); |
| if (opts == NULL) { |
| fuse_log(FUSE_LOG_ERR, "calloc failed\n"); |
| return NULL; |
| } |
| if (fuse_opt_parse(args, opts, conn_info_opt_spec, NULL) == -1) { |
| free(opts); |
| return NULL; |
| } |
| return opts; |
| } |
