gl/fsusage.c

   1 /* fsusage.c -- return space usage of mounted file systems
   2
   3    Copyright (C) 1991-1992, 1996, 1998-1999, 2002-2006, 2009
   4    Free Software Foundation, Inc.
   5
   6    This program is free software: you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 3 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19 #include <config.h>
  20
  21 #include "fsusage.h"
  22
  23 #include <limits.h>
  24 #include <sys/types.h>
  25
  26 #if STAT_STATVFS                /* POSIX 1003.1-2001 (and later) with XSI */
  27 # include <sys/statvfs.h>
  28 #else
  29 /* Don't include backward-compatibility files unless they're needed.
  30    Eventually we'd like to remove all this cruft.  */
  31 # include <fcntl.h>
  32 # include <unistd.h>
  33 # include <sys/stat.h>
  34 # if HAVE_SYS_PARAM_H
  35 #  include <sys/param.h>
  36 # endif
  37 # if HAVE_SYS_MOUNT_H
  38 #  include <sys/mount.h>
  39 # endif
  40 # if HAVE_SYS_VFS_H
  41 #  include <sys/vfs.h>
  42 # endif
  43 # if HAVE_SYS_FS_S5PARAM_H      /* Fujitsu UXP/V */
  44 #  include <sys/fs/s5param.h>
  45 # endif
  46 # if defined HAVE_SYS_FILSYS_H && !defined _CRAY
  47 #  include <sys/filsys.h>       /* SVR2 */
  48 # endif
  49 # if HAVE_SYS_STATFS_H
  50 #  include <sys/statfs.h>
  51 # endif
  52 # if HAVE_DUSTAT_H              /* AIX PS/2 */
  53 #  include <sys/dustat.h>
  54 # endif
  55 # include "full-read.h"
  56 #endif
  57
  58 /* The results of open() in this file are not used with fchdir,
  59    therefore save some unnecessary work in fchdir.c.  */
  60 #undef open
  61 #undef close
  62
  63 /* Many space usage primitives use all 1 bits to denote a value that is
  64    not applicable or unknown.  Propagate this information by returning
  65    a uintmax_t value that is all 1 bits if X is all 1 bits, even if X
  66    is unsigned and narrower than uintmax_t.  */
  67 #define PROPAGATE_ALL_ONES(x) \
  68   ((sizeof (x) < sizeof (uintmax_t) \
  69     && (~ (x) == (sizeof (x) < sizeof (int) \
  70                   ? - (1 << (sizeof (x) * CHAR_BIT)) \
  71                   : 0))) \
  72    ? UINTMAX_MAX : (uintmax_t) (x))
  73
  74 /* Extract the top bit of X as an uintmax_t value.  */
  75 #define EXTRACT_TOP_BIT(x) ((x) \
  76                             & ((uintmax_t) 1 << (sizeof (x) * CHAR_BIT - 1)))
  77
  78 /* If a value is negative, many space usage primitives store it into an
  79    integer variable by assignment, even if the variable's type is unsigned.
  80    So, if a space usage variable X's top bit is set, convert X to the
  81    uintmax_t value V such that (- (uintmax_t) V) is the negative of
  82    the original value.  If X's top bit is clear, just yield X.
  83    Use PROPAGATE_TOP_BIT if the original value might be negative;
  84    otherwise, use PROPAGATE_ALL_ONES.  */
  85 #define PROPAGATE_TOP_BIT(x) ((x) | ~ (EXTRACT_TOP_BIT (x) - 1))
  86
  87 /* Fill in the fields of FSP with information about space usage for
  88    the file system on which FILE resides.
  89    DISK is the device on which FILE is mounted, for space-getting
  90    methods that need to know it.
  91    Return 0 if successful, -1 if not.  When returning -1, ensure that
  92    ERRNO is either a system error value, or zero if DISK is NULL
  93    on a system that requires a non-NULL value.  */
  94 int
  95 get_fs_usage (char const *file, char const *disk, struct fs_usage *fsp)
  96 {
  97 #if defined STAT_STATVFS                /* POSIX */
  98
  99   struct statvfs fsd;
 100
 101   if (statvfs (file, &fsd) < 0)
 102     return -1;
 103
 104   /* f_frsize isn't guaranteed to be supported.  */
 105   fsp->fsu_blocksize = (fsd.f_frsize
 106                         ? PROPAGATE_ALL_ONES (fsd.f_frsize)
 107                         : PROPAGATE_ALL_ONES (fsd.f_bsize));
 108
 109 #elif defined STAT_STATFS2_FS_DATA      /* Ultrix */
 110
 111   struct fs_data fsd;
 112
 113   if (statfs (file, &fsd) != 1)
 114     return -1;
 115
 116   fsp->fsu_blocksize = 1024;
 117   fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.fd_req.btot);
 118   fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.fd_req.bfree);
 119   fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.fd_req.bfreen);
 120   fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.fd_req.bfreen) != 0;
 121   fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.fd_req.gtot);
 122   fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.fd_req.gfree);
 123
 124 #elif defined STAT_READ_FILSYS          /* SVR2 */
 125 # ifndef SUPERBOFF
 126 #  define SUPERBOFF (SUPERB * 512)
 127 # endif
 128
 129   struct filsys fsd;
 130   int fd;
 131
 132   if (! disk)
 133     {
 134       errno = 0;
 135       return -1;
 136     }
 137
 138   fd = open (disk, O_RDONLY);
 139   if (fd < 0)
 140     return -1;
 141   lseek (fd, (off_t) SUPERBOFF, 0);
 142   if (full_read (fd, (char *) &fsd, sizeof fsd) != sizeof fsd)
 143     {
 144       close (fd);
 145       return -1;
 146     }
 147   close (fd);
 148
 149   fsp->fsu_blocksize = (fsd.s_type == Fs2b ? 1024 : 512);
 150   fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.s_fsize);
 151   fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.s_tfree);
 152   fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.s_tfree);
 153   fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.s_tfree) != 0;
 154   fsp->fsu_files = (fsd.s_isize == -1
 155                     ? UINTMAX_MAX
 156                     : (fsd.s_isize - 2) * INOPB * (fsd.s_type == Fs2b ? 2 : 1));
 157   fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.s_tinode);
 158
 159 #elif defined STAT_STATFS3_OSF1
 160
 161   struct statfs fsd;
 162
 163   if (statfs (file, &fsd, sizeof (struct statfs)) != 0)
 164     return -1;
 165
 166   fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
 167
 168 #elif defined STAT_STATFS2_BSIZE        /* 4.3BSD, SunOS 4, HP-UX, AIX */
 169
 170   struct statfs fsd;
 171
 172   if (statfs (file, &fsd) < 0)
 173     return -1;
 174
 175   fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize);
 176
 177 # ifdef STATFS_TRUNCATES_BLOCK_COUNTS
 178
 179   /* In SunOS 4.1.2, 4.1.3, and 4.1.3_U1, the block counts in the
 180      struct statfs are truncated to 2GB.  These conditions detect that
 181      truncation, presumably without botching the 4.1.1 case, in which
 182      the values are not truncated.  The correct counts are stored in
 183      undocumented spare fields.  */
 184   if (fsd.f_blocks == 0x7fffffff / fsd.f_bsize && fsd.f_spare[0] > 0)
 185     {
 186       fsd.f_blocks = fsd.f_spare[0];
 187       fsd.f_bfree = fsd.f_spare[1];
 188       fsd.f_bavail = fsd.f_spare[2];
 189     }
 190 # endif /* STATFS_TRUNCATES_BLOCK_COUNTS */
 191
 192 #elif defined STAT_STATFS2_FSIZE        /* 4.4BSD */
 193
 194   struct statfs fsd;
 195
 196   if (statfs (file, &fsd) < 0)
 197     return -1;
 198
 199   fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
 200
 201 #elif defined STAT_STATFS4              /* SVR3, Dynix, Irix, AIX */
 202
 203 # if !_AIX && !defined _SEQUENT_ && !defined DOLPHIN
 204 #  define f_bavail f_bfree
 205 # endif
 206
 207   struct statfs fsd;
 208
 209   if (statfs (file, &fsd, sizeof fsd, 0) < 0)
 210     return -1;
 211
 212   /* Empirically, the block counts on most SVR3 and SVR3-derived
 213      systems seem to always be in terms of 512-byte blocks,
 214      no matter what value f_bsize has.  */
 215 # if _AIX || defined _CRAY
 216    fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize);
 217 # else
 218    fsp->fsu_blocksize = 512;
 219 # endif
 220
 221 #endif
 222
 223 #if (defined STAT_STATVFS \
 224      || (!defined STAT_STATFS2_FS_DATA && !defined STAT_READ_FILSYS))
 225
 226   fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.f_blocks);
 227   fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.f_bfree);
 228   fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.f_bavail);
 229   fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.f_bavail) != 0;
 230   fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.f_files);
 231   fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.f_ffree);
 232
 233 #endif
 234
 235   (void) disk;  /* avoid argument-unused warning */
 236   return 0;
 237 }
 238
 239 #if defined _AIX && defined _I386
 240 /* AIX PS/2 does not supply statfs.  */
 241
 242 int
 243 statfs (char *file, struct statfs *fsb)
 244 {
 245   struct stat stats;
 246   struct dustat fsd;
 247
 248   if (stat (file, &stats) != 0)
 249     return -1;
 250   if (dustat (stats.st_dev, 0, &fsd, sizeof (fsd)))
 251     return -1;
 252   fsb->f_type   = 0;
 253   fsb->f_bsize  = fsd.du_bsize;
 254   fsb->f_blocks = fsd.du_fsize - fsd.du_isize;
 255   fsb->f_bfree  = fsd.du_tfree;
 256   fsb->f_bavail = fsd.du_tfree;
 257   fsb->f_files  = (fsd.du_isize - 2) * fsd.du_inopb;
 258   fsb->f_ffree  = fsd.du_tinode;
 259   fsb->f_fsid.val[0] = fsd.du_site;
 260   fsb->f_fsid.val[1] = fsd.du_pckno;
 261   return 0;
 262 }
 263
 264 #endif /* _AIX && _I386 */