lib/libsffs/misc.c

   1 /* This file contains miscellaneous file system call handlers.
   2  *
   3  * The entry points into this file are:
   4  *   do_fstatfs         perform the FSTATFS file system call
   5  *   do_statvfs         perform the STATVFS file system call
   6  *
   7  * Created:
   8  *   April 2009 (D.C. van Moolenbroek)
   9  */
  10
  11 #include "inc.h"
  12
  13 #include <sys/statfs.h>
  14 #include <sys/statvfs.h>
  15
  16 /*===========================================================================*
  17  *                              do_fstatfs                                   *
  18  *===========================================================================*/
  19 int do_fstatfs()
  20 {
  21 /* Retrieve file system statistics.
  22  */
  23   struct statfs statfs;
  24
  25   statfs.f_bsize = BLOCK_SIZE; /* arbitrary block size constant */
  26
  27   return sys_safecopyto(m_in.m_source, m_in.REQ_GRANT, 0,
  28         (vir_bytes) &statfs, sizeof(statfs));
  29 }
  30
  31 /*===========================================================================*
  32  *                              do_statvfs                                   *
  33  *===========================================================================*/
  34 int do_statvfs()
  35 {
  36 /* Retrieve file system statistics.
  37  */
  38   struct statvfs statvfs;
  39   struct inode *ino;
  40   char path[PATH_MAX];
  41   u64_t free, total;
  42   int r;
  43
  44   /* Unfortunately, we cannot be any more specific than this, because we are
  45    * not given an inode number. Statistics of individual shared folders can
  46    * only be obtained by making sure that the root of the file system is an
  47    * actual share, and not a list of available shares.
  48    */
  49   if ((ino = find_inode(ROOT_INODE_NR)) == NULL)
  50         return EINVAL;
  51
  52   if ((r = verify_inode(ino, path, NULL)) != OK)
  53         return r;
  54
  55   if ((r = sffs_table->t_queryvol(path, &free, &total)) != OK)
  56         return r;
  57
  58   memset(&statvfs, 0, sizeof(statvfs));
  59
  60   /* Returning zero for unknown values seems to be the convention. However, we
  61    * do have to use a nonzero block size, even though it is entirely arbitrary.
  62    */
  63   statvfs.f_bsize = BLOCK_SIZE;
  64   statvfs.f_frsize = BLOCK_SIZE;
  65   statvfs.f_blocks = div64u(total, BLOCK_SIZE);
  66   statvfs.f_bfree = div64u(free, BLOCK_SIZE);
  67   statvfs.f_bavail = statvfs.f_bfree;
  68   statvfs.f_files = 0;
  69   statvfs.f_ffree = 0;
  70   statvfs.f_favail = 0;
  71   statvfs.f_fsid = state.s_dev;
  72   statvfs.f_flag = state.s_read_only ? ST_RDONLY : 0;
  73   statvfs.f_flag |= ST_NOTRUNC;
  74   statvfs.f_namemax = NAME_MAX;
  75
  76   return sys_safecopyto(m_in.m_source, m_in.REQ_GRANT, 0,
  77         (vir_bytes) &statvfs, sizeof(statvfs));
  78 }