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-rw-r--r--tools/virtiofsd/helper.c349
1 files changed, 349 insertions, 0 deletions
diff --git a/tools/virtiofsd/helper.c b/tools/virtiofsd/helper.c
new file mode 100644
index 0000000000..0801cf752c
--- /dev/null
+++ b/tools/virtiofsd/helper.c
@@ -0,0 +1,349 @@
+/*
+ * 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 <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("--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 norace                  disable racy fallback\n"
+           "                               default: false\n"
+           "    -o posix_lock|no_posix_lock\n"
+           "                               enable/disable remote posix lock\n"
+           "                               default: posix_lock\n"
+           "    -o readdirplus|no_readdirplus\n"
+           "                               enable/disable readirplus\n"
+           "                               default: readdirplus except with "
+           "cache=none\n"
+           "    -o timeout=<number>        I/O timeout (second)\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"
+           );
+}
+
+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;
+    }
+}
+
+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->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;
+}