[ceph.git] / ceph / src / rbd_fuse / rbd-fuse.cc

/*
 * rbd-fuse
 */
#include "include/int_types.h"

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <string.h>
#include <sys/types.h>
#include <unistd.h>
#include <getopt.h>
#include <assert.h>
#include <string>
#include <mutex>
#include <limits.h>

#if defined(__FreeBSD__)
#include <sys/param.h>
#endif

#include "include/compat.h"
#include "include/rbd/librbd.h"
#include "include/ceph_assert.h"

#include "common/ceph_argparse.h"
#include "common/ceph_context.h"
#include "include/ceph_fuse.h"

#include "global/global_init.h"
#include "global/global_context.h"

static int gotrados = 0;
char *pool_name;
char *nspace_name;
char *mount_image_name;
rados_t cluster;
rados_ioctx_t ioctx;

std::mutex readdir_lock;

struct rbd_stat {
        u_char valid;
        rbd_image_info_t rbd_info;
};

struct rbd_options {
        char *pool_name;
        char *nspace_name;
        char *image_name;
};

struct rbd_image {
        char *image_name;
        struct rbd_image *next;
};
struct rbd_image_data {
        struct rbd_image *images;
        rbd_image_spec_t *image_specs;
        size_t image_spec_count;
};
struct rbd_image_data rbd_image_data;

struct rbd_openimage {
        char *image_name;
        rbd_image_t image;
        struct rbd_stat rbd_stat;
};
#define MAX_RBD_IMAGES          128
struct rbd_openimage opentbl[MAX_RBD_IMAGES];

struct rbd_options rbd_options = {(char*) "rbd", (char*) "", NULL};

#define rbdsize(fd)     opentbl[fd].rbd_stat.rbd_info.size
#define rbdblksize(fd)  opentbl[fd].rbd_stat.rbd_info.obj_size
#define rbdblkcnt(fd)   opentbl[fd].rbd_stat.rbd_info.num_objs

uint64_t imagesize = 1024ULL * 1024 * 1024;
uint64_t imageorder = 22ULL;
uint64_t imagefeatures = 1ULL;

// Minimize calls to rbd_list: marks bracketing of opendir/<ops>/releasedir
int in_opendir;

/* prototypes */
int connect_to_cluster(rados_t *pcluster);
void enumerate_images(struct rbd_image_data *data);
int open_rbd_image(const char *image_name);
int find_openrbd(const char *path);

void simple_err(const char *msg, int err);

void
enumerate_images(struct rbd_image_data *data)
{
        struct rbd_image **head = &data->images;
        struct rbd_image *im, *next;
        int ret;

        if (*head != NULL) {
                for (im = *head; im != NULL;) {
                        next = im->next;
                        free(im);
                        im = next;
                }
                *head = NULL;
                rbd_image_spec_list_cleanup(data->image_specs,
                                            data->image_spec_count);
                free(data->image_specs);
                data->image_specs = NULL;
                data->image_spec_count = 0;
        }

        while (true) {
                ret = rbd_list2(ioctx, data->image_specs,
                                &data->image_spec_count);
                if (ret == -ERANGE) {
                        data->image_specs = static_cast<rbd_image_spec_t *>(
                                realloc(data->image_specs,
                                        sizeof(rbd_image_spec_t) * data->image_spec_count));
                } else if (ret < 0) {
                        simple_err("Failed to list images", ret);
                } else {
                        break;
                }
        }

        if (*nspace_name != '\0') {
            fprintf(stderr, "pool/namespace %s/%s: ", pool_name, nspace_name);
        } else {
            fprintf(stderr, "pool %s: ", pool_name);
        }
        for (size_t idx = 0; idx < data->image_spec_count; ++idx) {
                if ((mount_image_name == NULL) ||
                    ((strlen(mount_image_name) > 0) &&
                    (strcmp(data->image_specs[idx].name, mount_image_name) == 0))) {
                        fprintf(stderr, "%s, ", data->image_specs[idx].name);
                        im = static_cast<rbd_image*>(malloc(sizeof(*im)));
                        im->image_name = data->image_specs[idx].name;
                        im->next = *head;
                        *head = im;
                }
        }
        fprintf(stderr, "\n");
}

int
find_openrbd(const char *path)
{
        int i;

        /* find in opentbl[] entry if already open */
        for (i = 0; i < MAX_RBD_IMAGES; i++) {
                if ((opentbl[i].image_name != NULL) &&
                    (strcmp(opentbl[i].image_name, path) == 0)) {
                        return i;
                }
        }
        return -1;
}

int
open_rbd_image(const char *image_name)
{
        struct rbd_image *im;
        struct rbd_openimage *rbd = NULL;
        int fd;

        if (image_name == (char *)NULL) 
                return -1;

        // relies on caller to keep rbd_image_data up to date
        for (im = rbd_image_data.images; im != NULL; im = im->next) {
                if (strcmp(im->image_name, image_name) == 0) {
                        break;
                }
        }
        if (im == NULL)
                return -1;

        /* find in opentbl[] entry if already open */
        if ((fd = find_openrbd(image_name)) != -1) {
                rbd = &opentbl[fd];
        } else {
                int i;
                // allocate an opentbl[] and open the image
                for (i = 0; i < MAX_RBD_IMAGES; i++) {
                        if (opentbl[i].image == NULL) {
                                fd = i;
                                rbd = &opentbl[fd];
                                rbd->image_name = strdup(image_name);
                                break;
                        }
                }
                if (i == MAX_RBD_IMAGES || !rbd)
                        return -1;
                int ret = rbd_open(ioctx, rbd->image_name, &(rbd->image), NULL);
                if (ret < 0) {
                        simple_err("open_rbd_image: can't open: ", ret);
                        return ret;
                }
        }
        rbd_stat(rbd->image, &(rbd->rbd_stat.rbd_info),
                 sizeof(rbd_image_info_t));
        rbd->rbd_stat.valid = 1;
        return fd;
}

static void
iter_images(void *cookie,
            void (*iter)(void *cookie, const char *image))
{
        struct rbd_image *im;

        readdir_lock.lock();

        for (im = rbd_image_data.images; im != NULL; im = im->next)
                iter(cookie, im->image_name);
        readdir_lock.unlock();
}

static void count_images_cb(void *cookie, const char *image)
{
        (*((unsigned int *)cookie))++;
}

static int count_images(void)
{
        unsigned int count = 0;

        readdir_lock.lock();
        enumerate_images(&rbd_image_data);
        readdir_lock.unlock();

        iter_images(&count, count_images_cb);
        return count;
}

extern "C" {

static int rbdfs_getattr(const char *path, struct stat *stbuf
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
                         , struct fuse_file_info *fi
#endif
                        )
{
        int fd;
        time_t now;

        if (!gotrados)
                return -ENXIO;

        if (path[0] == 0)
                return -ENOENT;

        memset(stbuf, 0, sizeof(struct stat));

        if (strcmp(path, "/") == 0) {

                now = time(NULL);
                stbuf->st_mode = S_IFDIR + 0755;
                stbuf->st_nlink = 2+count_images();
                stbuf->st_uid = getuid();
                stbuf->st_gid = getgid();
                stbuf->st_size = 1024;
                stbuf->st_blksize = 1024;
                stbuf->st_blocks = 1;
                stbuf->st_atime = now;
                stbuf->st_mtime = now;
                stbuf->st_ctime = now;

                return 0;
        }

        if (!in_opendir) {
                readdir_lock.lock();
                enumerate_images(&rbd_image_data);
                readdir_lock.unlock();
        }
        fd = open_rbd_image(path + 1);
        if (fd < 0)
                return -ENOENT;

        now = time(NULL);
        stbuf->st_mode = S_IFREG | 0666;
        stbuf->st_nlink = 1;
        stbuf->st_uid = getuid();
        stbuf->st_gid = getgid();
        stbuf->st_size = rbdsize(fd);
        stbuf->st_blksize = rbdblksize(fd);
        stbuf->st_blocks = rbdblkcnt(fd);
        stbuf->st_atime = now;
        stbuf->st_mtime = now;
        stbuf->st_ctime = now;

        return 0;
}


static int rbdfs_open(const char *path, struct fuse_file_info *fi)
{
        int fd;

        if (!gotrados)
                return -ENXIO;

        if (path[0] == 0)
                return -ENOENT;

        readdir_lock.lock();
        enumerate_images(&rbd_image_data);
        readdir_lock.unlock();
        fd = open_rbd_image(path + 1);
        if (fd < 0)
                return -ENOENT;

        fi->fh = fd;
        return 0;
}

static int rbdfs_read(const char *path, char *buf, size_t size,
                        off_t offset, struct fuse_file_info *fi)
{
        size_t numread;
        struct rbd_openimage *rbd;

        if (!gotrados)
                return -ENXIO;

        rbd = &opentbl[fi->fh];
        numread = 0;
        while (size > 0) {
                ssize_t ret;

                ret = rbd_read(rbd->image, offset, size, buf);

                if (ret <= 0)
                        break;
                buf += ret;
                size -= ret;
                offset += ret;
                numread += ret;
        }

        return numread;
}

static int rbdfs_write(const char *path, const char *buf, size_t size,
                         off_t offset, struct fuse_file_info *fi)
{
        size_t numwritten;
        struct rbd_openimage *rbd;

        if (!gotrados)
                return -ENXIO;

        rbd = &opentbl[fi->fh];
        numwritten = 0;
        while (size > 0) {
                ssize_t ret;

                if ((size_t)(offset + size) > rbdsize(fi->fh)) {
                        int r;
                        fprintf(stderr, "rbdfs_write resizing %s to 0x%" PRIxMAX "\n",
                                path, offset+size);
                        r = rbd_resize(rbd->image, offset+size);
                        if (r < 0)
                                return r;

                        r = rbd_stat(rbd->image, &(rbd->rbd_stat.rbd_info),
                                 sizeof(rbd_image_info_t));
                        if (r < 0)
                                return r;
                }
                ret = rbd_write(rbd->image, offset, size, buf);

                if (ret < 0)
                        break;
                buf += ret;
                size -= ret;
                offset += ret;
                numwritten += ret;
        }

        return numwritten;
}

static void rbdfs_statfs_image_cb(void *num, const char *image)
{
        int     fd;

        ((uint64_t *)num)[0]++;

        fd = open_rbd_image(image);
        if (fd >= 0)
                ((uint64_t *)num)[1] += rbdsize(fd);
}

static int rbdfs_statfs(const char *path, struct statvfs *buf)
{
        uint64_t num[2];

        if (!gotrados)
                return -ENXIO;

        num[0] = 1;
        num[1] = 0;
        readdir_lock.lock();
        enumerate_images(&rbd_image_data);
        readdir_lock.unlock();
        iter_images(num, rbdfs_statfs_image_cb);

#define RBDFS_BSIZE     4096
        buf->f_bsize = RBDFS_BSIZE;
        buf->f_frsize = RBDFS_BSIZE;
        buf->f_blocks = num[1] / RBDFS_BSIZE;
        buf->f_bfree = 0;
        buf->f_bavail = 0;
        buf->f_files = num[0];
        buf->f_ffree = 0;
        buf->f_favail = 0;
        buf->f_fsid = 0;
        buf->f_flag = 0;
        buf->f_namemax = PATH_MAX;

        return 0;
}

static int rbdfs_fsync(const char *path, int datasync,
                         struct fuse_file_info *fi)
{
        if (!gotrados)
                return -ENXIO;
        rbd_flush(opentbl[fi->fh].image);
        return 0;
}

static int rbdfs_opendir(const char *path, struct fuse_file_info *fi)
{
        // only one directory, so global "in_opendir" flag should be fine
        readdir_lock.lock();
        in_opendir++;
        enumerate_images(&rbd_image_data);
        readdir_lock.unlock();
        return 0;
}

struct rbdfs_readdir_info {
        void *buf;
        fuse_fill_dir_t filler;
};

static void rbdfs_readdir_cb(void *_info, const char *name)
{
        struct rbdfs_readdir_info *info = (struct rbdfs_readdir_info*) _info;

        filler_compat(info->filler, info->buf, name, NULL, 0);
}

static int rbdfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                         off_t offset, struct fuse_file_info *fi
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
                         , enum fuse_readdir_flags
#endif
                         )
{
        struct rbdfs_readdir_info info = { buf, filler };

        if (!gotrados)
                return -ENXIO;
        if (!in_opendir)
                fprintf(stderr, "in readdir, but not inside opendir?\n");

        if (strcmp(path, "/") != 0)
                return -ENOENT;

        filler_compat(filler, buf, ".", NULL, 0);
        filler_compat(filler, buf, "..", NULL, 0);
        iter_images(&info, rbdfs_readdir_cb);

        return 0;
}
static int rbdfs_releasedir(const char *path, struct fuse_file_info *fi)
{
        // see opendir comments
        readdir_lock.lock();
        in_opendir--;
        readdir_lock.unlock();
        return 0;
}

void *
rbdfs_init(struct fuse_conn_info *conn
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
           , struct fuse_config *cfg
#endif
          )
{
        int ret;

        // init cannot fail, so if we fail here, gotrados remains at 0,
        // causing other operations to fail immediately with ENXIO

        ret = connect_to_cluster(&cluster);
        if (ret < 0)
                exit(90);

        pool_name = rbd_options.pool_name;
        nspace_name = rbd_options.nspace_name;
        mount_image_name = rbd_options.image_name;
        ret = rados_ioctx_create(cluster, pool_name, &ioctx);
        if (ret < 0)
                exit(91);
#if FUSE_VERSION >= FUSE_MAKE_VERSION(2, 8) && FUSE_VERSION < FUSE_MAKE_VERSION(3, 0)
        conn->want |= FUSE_CAP_BIG_WRITES;
#endif
        rados_ioctx_set_namespace(ioctx, nspace_name);
        gotrados = 1;

        // init's return value shows up in fuse_context.private_data,
        // also to void (*destroy)(void *); useful?
        return NULL;
}

void
rbdfs_destroy(void *unused)
{
        if (!gotrados)
                return;
        for (int i = 0; i < MAX_RBD_IMAGES; ++i) {
                if (opentbl[i].image) {
                        rbd_close(opentbl[i].image);
                        opentbl[i].image = NULL;
                }
        }
        rados_ioctx_destroy(ioctx);
        rados_shutdown(cluster);
}

int
rbdfs_checkname(const char *checkname)
{
    const char *extra[] = {"@", "/"};
    std::string strCheckName(checkname);
    
    if (strCheckName.empty())
        return -EINVAL;

    unsigned int sz = sizeof(extra) / sizeof(const char*);
    for (unsigned int i = 0; i < sz; i++)
    {
        std::string ex(extra[i]);
        if (std::string::npos != strCheckName.find(ex))
            return -EINVAL;
    }

    return 0;
}

// return -errno on error.  fi->fh is not set until open time

int
rbdfs_create(const char *path, mode_t mode, struct fuse_file_info *fi)
{
         int r;
         int order = imageorder;

         r = rbdfs_checkname(path+1);
         if (r != 0)
         {
            return r;  
         }

         r = rbd_create2(ioctx, path+1, imagesize, imagefeatures, &order);
         return r;
}

int
rbdfs_rename(const char *path, const char *destname
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
             , unsigned int flags
#endif
            )
{
    int r;

    r = rbdfs_checkname(destname+1);
    if (r != 0)
    {
      return r;
    }

    if (strcmp(path, "/") == 0)
        return -EINVAL;

    return rbd_rename(ioctx, path+1, destname+1);
}

int
rbdfs_utimens(const char *path, const struct timespec tv[2]
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
              , struct fuse_file_info *fi
#endif
             )
{
        // called on create; not relevant
        return 0;
}

int
rbdfs_unlink(const char *path)
{
        int fd = find_openrbd(path+1);
        if (fd != -1) {
                struct rbd_openimage *rbd = &opentbl[fd];
                rbd_close(rbd->image);
                rbd->image = 0;
                free(rbd->image_name);
                rbd->rbd_stat.valid = 0;
        }
        return rbd_remove(ioctx, path+1);
}


int
rbdfs_truncate(const char *path, off_t size
#if FUSE_VERSION >= FUSE_MAKE_VERSION(3, 0)
               , struct fuse_file_info *fi
#endif
              )
{
        int fd;
        int r;
        struct rbd_openimage *rbd;

        if ((fd = open_rbd_image(path+1)) < 0)
                return -ENOENT;

        rbd = &opentbl[fd];
        fprintf(stderr, "truncate %s to %" PRIdMAX " (0x%" PRIxMAX ")\n",
          path, size, size);
        r = rbd_resize(rbd->image, size);
        if (r < 0)
                return r;

        r = rbd_stat(rbd->image, &(rbd->rbd_stat.rbd_info),
                 sizeof(rbd_image_info_t));
        if (r < 0)
                return r;
        return 0;
}

/**
 * set an xattr on path, with name/value, length size.
 * Presumably flags are from Linux, as in XATTR_CREATE or 
 * XATTR_REPLACE (both "set", but fail if exist vs fail if not exist.
 *
 * We accept xattrs only on the root node.
 *
 * All values converted with strtoull, so can be expressed in any base
 */

struct rbdfuse_attr {
        char *attrname;
        uint64_t *attrvalp;
} attrs[] = {
    { (char*) "user.rbdfuse.imagesize", &imagesize },
    { (char*) "user.rbdfuse.imageorder", &imageorder },
    { (char*) "user.rbdfuse.imagefeatures", &imagefeatures },
    { NULL, NULL }
};

int
rbdfs_setxattr(const char *path, const char *name, const char *value,
               size_t size,
               int flags
#if defined(DARWIN)
               ,uint32_t pos
#endif
    )
{
        struct rbdfuse_attr *ap;
        if (strcmp(path, "/") != 0)
                return -EINVAL;

        for (ap = attrs; ap->attrname != NULL; ap++) {
                if (strcmp(name, ap->attrname) == 0) {
                        *ap->attrvalp = strtoull(value, NULL, 0);
                        fprintf(stderr, "rbd-fuse: %s set to 0x%" PRIx64 "\n",
                                ap->attrname, *ap->attrvalp);
                        return 0;
                }
        }
        return -EINVAL;
}

int
rbdfs_getxattr(const char *path, const char *name, char *value,
                 size_t size
#if defined(DARWIN)
               ,uint32_t position
#endif
  )
{
        struct rbdfuse_attr *ap;
        char buf[128];
        // allow gets on other files; ls likes to ask for things like
        // security.*

        for (ap = attrs; ap->attrname != NULL; ap++) {
                if (strcmp(name, ap->attrname) == 0) {
                        sprintf(buf, "%" PRIu64, *ap->attrvalp);
                        if (value != NULL && size >= strlen(buf))
                                strcpy(value, buf);
                        fprintf(stderr, "rbd-fuse: get %s\n", ap->attrname);
                        return (strlen(buf));
                }
        }
        return 0;
}

int
rbdfs_listxattr(const char *path, char *list, size_t len)
{
        struct rbdfuse_attr *ap;
        size_t required_len = 0;

        if (strcmp(path, "/") != 0)
                return -EINVAL;

        for (ap = attrs; ap->attrname != NULL; ap++)
                required_len += strlen(ap->attrname) + 1;
        if (len >= required_len) {
                for (ap = attrs; ap->attrname != NULL; ap++) {
                        sprintf(list, "%s", ap->attrname);
                        list += strlen(ap->attrname) + 1;
                }
        }
        return required_len;
}

const static struct fuse_operations rbdfs_oper = {
  getattr:    rbdfs_getattr,
  readlink:   0,
#if FUSE_VERSION < FUSE_MAKE_VERSION(3, 0)
  getdir:     0,
#endif
  mknod:      0,
  mkdir:      0,
  unlink:     rbdfs_unlink,
  rmdir:      0,
  symlink:    0,
  rename:     rbdfs_rename,
  link:       0,
  chmod:      0,
  chown:      0,
  truncate:   rbdfs_truncate,
#if FUSE_VERSION < FUSE_MAKE_VERSION(3, 0)
  utime:      0,
#endif
  open:       rbdfs_open,
  read:       rbdfs_read,
  write:      rbdfs_write,
  statfs:     rbdfs_statfs,
  flush:      0,
  release:    0,
  fsync:      rbdfs_fsync,
  setxattr:   rbdfs_setxattr,
  getxattr:   rbdfs_getxattr,
  listxattr:  rbdfs_listxattr,
  removexattr: 0,
  opendir:    rbdfs_opendir,
  readdir:    rbdfs_readdir,
  releasedir: rbdfs_releasedir,
  fsyncdir:   0,
  init:       rbdfs_init,
  destroy:    rbdfs_destroy,
  access:     0,
  create:     rbdfs_create,
#if FUSE_VERSION < FUSE_MAKE_VERSION(3, 0)
  ftruncate:  0,
  fgetattr:   0,
#endif
  lock:       0,
  utimens:    rbdfs_utimens,
  /* skip unimplemented */
};

} /* extern "C" */

enum {
        KEY_HELP,
        KEY_VERSION,
        KEY_RADOS_POOLNAME,
        KEY_RADOS_POOLNAME_LONG,
        KEY_RADOS_NSPACENAME,
        KEY_RADOS_NSPACENAME_LONG,
        KEY_RBD_IMAGENAME,
        KEY_RBD_IMAGENAME_LONG
};

static struct fuse_opt rbdfs_opts[] = {
        FUSE_OPT_KEY("-h", KEY_HELP),
        FUSE_OPT_KEY("--help", KEY_HELP),
        FUSE_OPT_KEY("-V", KEY_VERSION),
        FUSE_OPT_KEY("--version", KEY_VERSION),
        {"-p %s", offsetof(struct rbd_options, pool_name), KEY_RADOS_POOLNAME},
        {"--poolname=%s", offsetof(struct rbd_options, pool_name),
         KEY_RADOS_POOLNAME_LONG},
        {"-s %s", offsetof(struct rbd_options, nspace_name), KEY_RADOS_NSPACENAME},
        {"--namespace=%s", offsetof(struct rbd_options, nspace_name),
         KEY_RADOS_NSPACENAME_LONG},
        {"-r %s", offsetof(struct rbd_options, image_name), KEY_RBD_IMAGENAME},
        {"--image=%s", offsetof(struct rbd_options, image_name),
        KEY_RBD_IMAGENAME_LONG},
        FUSE_OPT_END
};

static void usage(const char *progname)
{
        fprintf(stderr,
"Usage: %s mountpoint [options]\n"
"\n"
"General options:\n"
"    -h   --help            print help\n"
"    -V   --version         print version\n"
"    -c   --conf            ceph configuration file [/etc/ceph/ceph.conf]\n"
"    -p   --poolname        rados pool name [rbd]\n"
"    -s   --namespace       rados namespace name []\n"
"    -r   --image           RBD image name\n"
"\n", progname);
}

static int rbdfs_opt_proc(void *data, const char *arg, int key,
                            struct fuse_args *outargs)
{
        if (key == KEY_HELP) {
                usage(outargs->argv[0]);
                fuse_opt_add_arg(outargs, "-ho");
                fuse_main(outargs->argc, outargs->argv, &rbdfs_oper, NULL);
                exit(1);
        }

        if (key == KEY_VERSION) {
                fuse_opt_add_arg(outargs, "--version");
                fuse_main(outargs->argc, outargs->argv, &rbdfs_oper, NULL);
                exit(0);
        }

        if (key == KEY_RADOS_POOLNAME) {
                if (rbd_options.pool_name != NULL) {
                        free(rbd_options.pool_name);
                        rbd_options.pool_name = NULL;
                }
                rbd_options.pool_name = strdup(arg+2);
                return 0;
        }

        if (key == KEY_RADOS_NSPACENAME) {
                if (rbd_options.nspace_name != NULL) {
                        free(rbd_options.nspace_name);
                        rbd_options.nspace_name = NULL;
                }
                rbd_options.nspace_name = strdup(arg+2);
                return 0;
        }

        if (key == KEY_RBD_IMAGENAME) {
                if (rbd_options.image_name!= NULL) {
                        free(rbd_options.image_name);
                        rbd_options.image_name = NULL;
                }
                rbd_options.image_name = strdup(arg+2);
                return 0;
        }

        return 1;
}

void
simple_err(const char *msg, int err)
{
        fprintf(stderr, "%s: %s\n", msg, strerror(-err));
        return;
}

int
connect_to_cluster(rados_t *pcluster)
{
        int r;
        global_init_postfork_start(g_ceph_context);
        common_init_finish(g_ceph_context);
        global_init_postfork_finish(g_ceph_context);

        r = rados_create_with_context(pcluster, g_ceph_context);
        if (r < 0) {
                simple_err("Could not create cluster handle", r);
                return r;
        }

        r = rados_connect(*pcluster);
        if (r < 0) {
                simple_err("Error connecting to cluster", r);
                rados_shutdown(*pcluster);
                return r;
        }

        return 0;
}

int main(int argc, const char *argv[])
{
        memset(&rbd_image_data, 0, sizeof(rbd_image_data));

        // librados will filter out -f/-d options from command-line
        std::map<std::string, bool> filter_args = {
                {"-f", false},
                {"-d", false}};

        std::vector<const char*> arg_vector;
        for (auto idx = 0; idx < argc; ++idx) {
                auto it = filter_args.find(argv[idx]);
                if (it != filter_args.end()) {
                        it->second = true;
                }
                arg_vector.push_back(argv[idx]);
        }

        auto cct = global_init(NULL, arg_vector, CEPH_ENTITY_TYPE_CLIENT,
                               CODE_ENVIRONMENT_DAEMON,
                               CINIT_FLAG_UNPRIVILEGED_DAEMON_DEFAULTS);
        g_ceph_context->_conf.set_val_or_die("pid_file", "");
        g_ceph_context->_conf.set_val_or_die("daemonize", "true");

        if (global_init_prefork(g_ceph_context) < 0) {
                fprintf(stderr, "Failed to initialize librados\n");
                exit(1);
        }

        for (auto& it : filter_args) {
                if (it.second) {
                        arg_vector.push_back(it.first.c_str());
                }
        }

        struct fuse_args args = FUSE_ARGS_INIT((int)arg_vector.size(),
                                               (char**)&arg_vector.front());
        if (fuse_opt_parse(&args, &rbd_options, rbdfs_opts,
                           rbdfs_opt_proc) == -1) {
                exit(1);
        }

        return fuse_main(args.argc, args.argv, &rbdfs_oper, NULL);
}