rump_etfs(3) - NetBSD Manual Pages

RUMP_ETFS(3)            NetBSD Library Functions Manual           RUMP_ETFS(3)


NAME

     rump_etfs -- rump host file system interface


LIBRARY

     rump kernel (librump, -lrump)


SYNOPSIS

     #include <rump/rump.h>

     int
     rump_pub_etfs_register(const char *key, const char *hostpath,
         enum rump_etfs_type ftype);

     int
     rump_pub_etfs_register_withsize(const char *key, const char *hostpath,
         enum rump_etfs_type ftype, uint64_t begin, uint64_t size);

     int
     rump_pub_etfs_remove(const char *key);


DESCRIPTION

     The rump ExtraTerrestrial File System (rump_etfs) is used to provide
     access to the host file system namespace within a rump kernel.

     The operation is based on registered key values which each map to a
     hostpath.  A key must be an absolute path (i.e. begin with ``/'').  Mul-
     tiple leading slashes are collapsed to one (i.e.  ``/key'' is the same as
     ``//key'').  The rest of the path, including slashes, is compared verba-
     tim (i.e.  ``/key/path'' does not match ``/key//path'').

     The hostpath is interpreted in host system context for the current work-
     ing directory and can be either absolute or relative.

     The ftype parameter specifies how etfs file will be presented and does
     not have to match the host type, although some limitations apply.  Possi-
     ble values are:

     RUMP_ETFS_REG             regular file.

     RUMP_ETFS_BLK             block device.  This is often used when mapping
                               file system images.

     RUMP_ETFS_CHR             character device.

     RUMP_ETFS_DIR             directory.  This option is valid only when
                               hostpath is a directory.  The immediate chil-
                               dren of the host directory will be accessible
                               inside a rump kernel.

     RUMP_ETFS_DIR_SUBDIRS     directory.  This option is valid only when
                               hostpath is a directory.  This option recur-
                               sively applies to all subdirectories, and
                               allows a rump kernel to access an entire direc-
                               tory tree.

     The interfaces are:

     rump_pub_etfs_register(key, hostpath, ftype)
           Map key to a file of type ftype with the contents of hostpath.

     rump_pub_etfs_register_withsize(key, hostpath, ftype, begin, size)
           Like the above, but map only [begin, begin+size] from hostpath.
           This is useful when mapping disk images where only one partition is
           relevant to the application.  If size is given the special value
           RUMP_ETFS_SIZE_ENDOFF, the underlying file is mapped from begin to
           the end of the file.

     rump_pub_etfs_remove(key)
           Remove etfs mapping for key.  This routine may be called only if
           the file related to the mapping is not in use.


EXAMPLES

     Map a host image file to a mountable /dev/harddisk path using window off-
     sets from the disklabel.

           rump_pub_etfs_register_withsize("/dev/harddisk", "disk.img",
               RUMP_ETFS_BLK,
               pp->p_offset << DEV_BSHIFT, pp->p_size << DEV_BSHIFT);

     Make the host kernel module directory hierarchy available within the rump
     kernel.

           rump_pub_etfs_register("/stand/i386/5.99.41",
               "/stand/i386/5.99.41", RUMP_ETFS_DIR_SUBDIRS);


SEE ALSO

     rump(3)


HISTORY

     rump_etfs first appeared in NetBSD 6.0.

NetBSD 6.0                     February 3, 2011                     NetBSD 6.0