hostfs_user.c

Go to the documentation of this file.

/*
 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <stddef.h>
#include <unistd.h>
#include <dirent.h>
#include <errno.h>
#include <fcntl.h>
#include <string.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/vfs.h>
#include "hostfs.h"
#include <utime.h>

static void stat64_to_hostfs(const struct stat64 *buf, struct hostfs_stat *p)
{
    p->ino = buf->st_ino;
    p->mode = buf->st_mode;
    p->nlink = buf->st_nlink;
    p->uid = buf->st_uid;
    p->gid = buf->st_gid;
    p->size = buf->st_size;
    p->atime.tv_sec = buf->st_atime;
    p->atime.tv_nsec = 0;
    p->ctime.tv_sec = buf->st_ctime;
    p->ctime.tv_nsec = 0;
    p->mtime.tv_sec = buf->st_mtime;
    p->mtime.tv_nsec = 0;
    p->blksize = buf->st_blksize;
    p->blocks = buf->st_blocks;
    p->maj = os_major(buf->st_rdev);
    p->min = os_minor(buf->st_rdev);
}

int stat_file(const char *path, struct hostfs_stat *p, int fd)
{
    struct stat64 buf;

    if (fd >= 0) {
        if (fstat64(fd, &buf) < 0)
            return -errno;
    } else if (lstat64(path, &buf) < 0) {
        return -errno;
    }
    stat64_to_hostfs(&buf, p);
    return 0;
}

int access_file(char *path, int r, int w, int x)
{
    int mode = 0;

    if (r)
        mode = R_OK;
    if (w)
        mode |= W_OK;
    if (x)
        mode |= X_OK;
    if (access(path, mode) != 0)
        return -errno;
    else return 0;
}

int open_file(char *path, int r, int w, int append)
{
    int mode = 0, fd;

    if (r && !w)
        mode = O_RDONLY;
    else if (!r && w)
        mode = O_WRONLY;
    else if (r && w)
        mode = O_RDWR;
    else panic("Impossible mode in open_file");

    if (append)
        mode |= O_APPEND;
    fd = open64(path, mode);
    if (fd < 0)
        return -errno;
    else return fd;
}

void *open_dir(char *path, int *err_out)
{
    DIR *dir;

    dir = opendir(path);
    *err_out = errno;

    return dir;
}

char *read_dir(void *stream, unsigned long long *pos,
           unsigned long long *ino_out, int *len_out,
           unsigned int *type_out)
{
    DIR *dir = stream;
    struct dirent *ent;

    seekdir(dir, *pos);
    ent = readdir(dir);
    if (ent == NULL)
        return NULL;
    *len_out = strlen(ent->d_name);
    *ino_out = ent->d_ino;
    *type_out = ent->d_type;
    *pos = telldir(dir);
    return ent->d_name;
}

int read_file(int fd, unsigned long long *offset, char *buf, int len)
{
    int n;

    n = pread64(fd, buf, len, *offset);
    if (n < 0)
        return -errno;
    *offset += n;
    return n;
}

int write_file(int fd, unsigned long long *offset, const char *buf, int len)
{
    int n;

    n = pwrite64(fd, buf, len, *offset);
    if (n < 0)
        return -errno;
    *offset += n;
    return n;
}

int lseek_file(int fd, long long offset, int whence)
{
    int ret;

    ret = lseek64(fd, offset, whence);
    if (ret < 0)
        return -errno;
    return 0;
}

int fsync_file(int fd, int datasync)
{
    int ret;
    if (datasync)
        ret = fdatasync(fd);
    else
        ret = fsync(fd);

    if (ret < 0)
        return -errno;
    return 0;
}

int replace_file(int oldfd, int fd)
{
    return dup2(oldfd, fd);
}

void close_file(void *stream)
{
    close(*((int *) stream));
}

void close_dir(void *stream)
{
    closedir(stream);
}

int file_create(char *name, int ur, int uw, int ux, int gr,
        int gw, int gx, int or, int ow, int ox)
{
    int mode, fd;

    mode = 0;
    mode |= ur ? S_IRUSR : 0;
    mode |= uw ? S_IWUSR : 0;
    mode |= ux ? S_IXUSR : 0;
    mode |= gr ? S_IRGRP : 0;
    mode |= gw ? S_IWGRP : 0;
    mode |= gx ? S_IXGRP : 0;
    mode |= or ? S_IROTH : 0;
    mode |= ow ? S_IWOTH : 0;
    mode |= ox ? S_IXOTH : 0;
    fd = open64(name, O_CREAT | O_RDWR, mode);
    if (fd < 0)
        return -errno;
    return fd;
}

int set_attr(const char *file, struct hostfs_iattr *attrs, int fd)
{
    struct hostfs_stat st;
    struct timeval times[2];
    int err, ma;

    if (attrs->ia_valid & HOSTFS_ATTR_MODE) {
        if (fd >= 0) {
            if (fchmod(fd, attrs->ia_mode) != 0)
                return -errno;
        } else if (chmod(file, attrs->ia_mode) != 0) {
            return -errno;
        }
    }
    if (attrs->ia_valid & HOSTFS_ATTR_UID) {
        if (fd >= 0) {
            if (fchown(fd, attrs->ia_uid, -1))
                return -errno;
        } else if (chown(file, attrs->ia_uid, -1)) {
            return -errno;
        }
    }
    if (attrs->ia_valid & HOSTFS_ATTR_GID) {
        if (fd >= 0) {
            if (fchown(fd, -1, attrs->ia_gid))
                return -errno;
        } else if (chown(file, -1, attrs->ia_gid)) {
            return -errno;
        }
    }
    if (attrs->ia_valid & HOSTFS_ATTR_SIZE) {
        if (fd >= 0) {
            if (ftruncate(fd, attrs->ia_size))
                return -errno;
        } else if (truncate(file, attrs->ia_size)) {
            return -errno;
        }
    }

    /*
     * Update accessed and/or modified time, in two parts: first set
     * times according to the changes to perform, and then call futimes()
     * or utimes() to apply them.
     */
    ma = (HOSTFS_ATTR_ATIME_SET | HOSTFS_ATTR_MTIME_SET);
    if (attrs->ia_valid & ma) {
        err = stat_file(file, &st, fd);
        if (err != 0)
            return err;

        times[0].tv_sec = st.atime.tv_sec;
        times[0].tv_usec = st.atime.tv_nsec / 1000;
        times[1].tv_sec = st.mtime.tv_sec;
        times[1].tv_usec = st.mtime.tv_nsec / 1000;

        if (attrs->ia_valid & HOSTFS_ATTR_ATIME_SET) {
            times[0].tv_sec = attrs->ia_atime.tv_sec;
            times[0].tv_usec = attrs->ia_atime.tv_nsec / 1000;
        }
        if (attrs->ia_valid & HOSTFS_ATTR_MTIME_SET) {
            times[1].tv_sec = attrs->ia_mtime.tv_sec;
            times[1].tv_usec = attrs->ia_mtime.tv_nsec / 1000;
        }

        if (fd >= 0) {
            if (futimes(fd, times) != 0)
                return -errno;
        } else if (utimes(file, times) != 0) {
            return -errno;
        }
    }

    /* Note: ctime is not handled */
    if (attrs->ia_valid & (HOSTFS_ATTR_ATIME | HOSTFS_ATTR_MTIME)) {
        err = stat_file(file, &st, fd);
        attrs->ia_atime = st.atime;
        attrs->ia_mtime = st.mtime;
        if (err != 0)
            return err;
    }
    return 0;
}

int make_symlink(const char *from, const char *to)
{
    int err;

    err = symlink(to, from);
    if (err)
        return -errno;
    return 0;
}

int unlink_file(const char *file)
{
    int err;

    err = unlink(file);
    if (err)
        return -errno;
    return 0;
}

int do_mkdir(const char *file, int mode)
{
    int err;

    err = mkdir(file, mode);
    if (err)
        return -errno;
    return 0;
}

int do_rmdir(const char *file)
{
    int err;

    err = rmdir(file);
    if (err)
        return -errno;
    return 0;
}

int do_mknod(const char *file, int mode, unsigned int major, unsigned int minor)
{
    int err;

    err = mknod(file, mode, os_makedev(major, minor));
    if (err)
        return -errno;
    return 0;
}

int link_file(const char *to, const char *from)
{
    int err;

    err = link(to, from);
    if (err)
        return -errno;
    return 0;
}

int hostfs_do_readlink(char *file, char *buf, int size)
{
    int n;

    n = readlink(file, buf, size);
    if (n < 0)
        return -errno;
    if (n < size)
        buf[n] = '\0';
    return n;
}

int rename_file(char *from, char *to)
{
    int err;

    err = rename(from, to);
    if (err < 0)
        return -errno;
    return 0;
}

int do_statfs(char *root, long *bsize_out, long long *blocks_out,
          long long *bfree_out, long long *bavail_out,
          long long *files_out, long long *ffree_out,
          void *fsid_out, int fsid_size, long *namelen_out)
{
    struct statfs64 buf;
    int err;

    err = statfs64(root, &buf);
    if (err < 0)
        return -errno;

    *bsize_out = buf.f_bsize;
    *blocks_out = buf.f_blocks;
    *bfree_out = buf.f_bfree;
    *bavail_out = buf.f_bavail;
    *files_out = buf.f_files;
    *ffree_out = buf.f_ffree;
    memcpy(fsid_out, &buf.f_fsid,
           sizeof(buf.f_fsid) > fsid_size ? fsid_size :
           sizeof(buf.f_fsid));
    *namelen_out = buf.f_namelen;

    return 0;
}