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Diffstat (limited to 'tools/virtiofsd/helper.c')
| -rw-r--r-- | tools/virtiofsd/helper.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c new file mode 100644 index 000000000..a8295d975 --- /dev/null +++ b/tools/virtiofsd/helper.c @@ -0,0 +1,405 @@ +/* + * 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 <sys/param.h> +#include <sys/resource.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 xattrmap=<mapping> Enable xattr mapping (enables xattr)\n" + " <mapping> is a string consists of a series of rules\n" + " e.g. -o xattrmap=:map::user.virtiofs.:\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" + " -o posix_acl/no_posix_acl Enable/Disable posix_acl. (default: disabled)\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; +} |