233 lines
		
	
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			233 lines
		
	
	
	
		
			7.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* fsusage.c -- return space usage of mounted file systems
 | 
						|
 | 
						|
   Copyright (C) 1991-1992, 1996, 1998-1999, 2002-2006, 2009-2023 Free Software
 | 
						|
   Foundation, Inc.
 | 
						|
 | 
						|
   This file is free software: you can redistribute it and/or modify
 | 
						|
   it under the terms of the GNU Lesser General Public License as
 | 
						|
   published by the Free Software Foundation, either version 3 of the
 | 
						|
   License, or (at your option) any later version.
 | 
						|
 | 
						|
   This file is distributed in the hope that it will be useful,
 | 
						|
   but WITHOUT ANY WARRANTY; without even the implied warranty of
 | 
						|
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 | 
						|
   GNU Lesser General Public License for more details.
 | 
						|
 | 
						|
   You should have received a copy of the GNU Lesser General Public License
 | 
						|
   along with this program.  If not, see <https://www.gnu.org/licenses/>.  */
 | 
						|
 | 
						|
#include <config.h>
 | 
						|
 | 
						|
#include "fsusage.h"
 | 
						|
 | 
						|
#include <limits.h>
 | 
						|
#include <sys/types.h>
 | 
						|
 | 
						|
#if STAT_STATVFS || STAT_STATVFS64 /* POSIX 1003.1-2001 (and later) with XSI */
 | 
						|
# include <sys/statvfs.h>
 | 
						|
#else
 | 
						|
/* Don't include backward-compatibility files unless they're needed.
 | 
						|
   Eventually we'd like to remove all this cruft.  */
 | 
						|
# include <fcntl.h>
 | 
						|
# include <unistd.h>
 | 
						|
# include <sys/stat.h>
 | 
						|
#if HAVE_SYS_PARAM_H
 | 
						|
# include <sys/param.h>
 | 
						|
#endif
 | 
						|
#if HAVE_SYS_MOUNT_H
 | 
						|
# include <sys/mount.h>
 | 
						|
#endif
 | 
						|
#if HAVE_SYS_VFS_H
 | 
						|
# include <sys/vfs.h>
 | 
						|
#endif
 | 
						|
# if HAVE_SYS_FS_S5PARAM_H      /* Fujitsu UXP/V */
 | 
						|
#  include <sys/fs/s5param.h>
 | 
						|
# endif
 | 
						|
# if HAVE_SYS_STATFS_H
 | 
						|
#  include <sys/statfs.h>
 | 
						|
# endif
 | 
						|
#endif
 | 
						|
 | 
						|
/* Many space usage primitives use all 1 bits to denote a value that is
 | 
						|
   not applicable or unknown.  Propagate this information by returning
 | 
						|
   a uintmax_t value that is all 1 bits if X is all 1 bits, even if X
 | 
						|
   is unsigned and narrower than uintmax_t.  */
 | 
						|
#define PROPAGATE_ALL_ONES(x) \
 | 
						|
  ((sizeof (x) < sizeof (uintmax_t) \
 | 
						|
    && (~ (x) == (sizeof (x) < sizeof (int) \
 | 
						|
                  ? - (1 << (sizeof (x) * CHAR_BIT)) \
 | 
						|
                  : 0))) \
 | 
						|
   ? UINTMAX_MAX : (uintmax_t) (x))
 | 
						|
 | 
						|
/* Extract the top bit of X as an uintmax_t value.  */
 | 
						|
#define EXTRACT_TOP_BIT(x) ((x) \
 | 
						|
                            & ((uintmax_t) 1 << (sizeof (x) * CHAR_BIT - 1)))
 | 
						|
 | 
						|
/* If a value is negative, many space usage primitives store it into an
 | 
						|
   integer variable by assignment, even if the variable's type is unsigned.
 | 
						|
   So, if a space usage variable X's top bit is set, convert X to the
 | 
						|
   uintmax_t value V such that (- (uintmax_t) V) is the negative of
 | 
						|
   the original value.  If X's top bit is clear, just yield X.
 | 
						|
   Use PROPAGATE_TOP_BIT if the original value might be negative;
 | 
						|
   otherwise, use PROPAGATE_ALL_ONES.  */
 | 
						|
#define PROPAGATE_TOP_BIT(x) ((x) | ~ (EXTRACT_TOP_BIT (x) - 1))
 | 
						|
 | 
						|
#ifdef STAT_STATVFS
 | 
						|
/* Return true if statvfs works.  This is false for statvfs on systems
 | 
						|
   with GNU libc on Linux kernels before 2.6.36, which stats all
 | 
						|
   preceding entries in /proc/mounts; that makes df hang if even one
 | 
						|
   of the corresponding file systems is hard-mounted but not available.  */
 | 
						|
# if ! (__linux__ && (__GLIBC__ || __UCLIBC__))
 | 
						|
/* The FRSIZE fallback is not required in this case.  */
 | 
						|
#  undef STAT_STATFS2_FRSIZE
 | 
						|
static int statvfs_works (void) { return 1; }
 | 
						|
# else
 | 
						|
#  include <string.h> /* for strverscmp */
 | 
						|
#  include <sys/utsname.h>
 | 
						|
#  include <sys/statfs.h>
 | 
						|
#  define STAT_STATFS2_BSIZE 1
 | 
						|
 | 
						|
static int
 | 
						|
statvfs_works (void)
 | 
						|
{
 | 
						|
  static int statvfs_works_cache = -1;
 | 
						|
  struct utsname name;
 | 
						|
  if (statvfs_works_cache < 0)
 | 
						|
    statvfs_works_cache = (uname (&name) == 0
 | 
						|
                           && 0 <= strverscmp (name.release, "2.6.36"));
 | 
						|
  return statvfs_works_cache;
 | 
						|
}
 | 
						|
# endif
 | 
						|
#endif
 | 
						|
 | 
						|
 | 
						|
/* Fill in the fields of FSP with information about space usage for
 | 
						|
   the file system on which FILE resides.
 | 
						|
   DISK is the device on which FILE is mounted, for space-getting
 | 
						|
   methods that need to know it.
 | 
						|
   Return 0 if successful, -1 if not.  When returning -1, ensure that
 | 
						|
   ERRNO is either a system error value, or zero if DISK is NULL
 | 
						|
   on a system that requires a non-NULL value.  */
 | 
						|
int
 | 
						|
get_fs_usage (char const *file, char const *disk, struct fs_usage *fsp)
 | 
						|
{
 | 
						|
#ifdef STAT_STATVFS     /* POSIX, except pre-2.6.36 glibc/Linux */
 | 
						|
 | 
						|
  if (statvfs_works ())
 | 
						|
    {
 | 
						|
      struct statvfs vfsd;
 | 
						|
 | 
						|
      if (statvfs (file, &vfsd) < 0)
 | 
						|
        return -1;
 | 
						|
 | 
						|
      /* f_frsize isn't guaranteed to be supported.  */
 | 
						|
      fsp->fsu_blocksize = (vfsd.f_frsize
 | 
						|
                            ? PROPAGATE_ALL_ONES (vfsd.f_frsize)
 | 
						|
                            : PROPAGATE_ALL_ONES (vfsd.f_bsize));
 | 
						|
 | 
						|
      fsp->fsu_blocks = PROPAGATE_ALL_ONES (vfsd.f_blocks);
 | 
						|
      fsp->fsu_bfree = PROPAGATE_ALL_ONES (vfsd.f_bfree);
 | 
						|
      fsp->fsu_bavail = PROPAGATE_TOP_BIT (vfsd.f_bavail);
 | 
						|
      fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (vfsd.f_bavail) != 0;
 | 
						|
      fsp->fsu_files = PROPAGATE_ALL_ONES (vfsd.f_files);
 | 
						|
      fsp->fsu_ffree = PROPAGATE_ALL_ONES (vfsd.f_ffree);
 | 
						|
      return 0;
 | 
						|
    }
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
#if defined STAT_STATVFS64            /* AIX */
 | 
						|
 | 
						|
  struct statvfs64 fsd;
 | 
						|
 | 
						|
  if (statvfs64 (file, &fsd) < 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  /* f_frsize isn't guaranteed to be supported.  */
 | 
						|
  fsp->fsu_blocksize = (fsd.f_frsize
 | 
						|
                        ? PROPAGATE_ALL_ONES (fsd.f_frsize)
 | 
						|
                        : PROPAGATE_ALL_ONES (fsd.f_bsize));
 | 
						|
 | 
						|
#elif defined STAT_STATFS3_OSF1         /* OSF/1 */
 | 
						|
 | 
						|
  struct statfs fsd;
 | 
						|
 | 
						|
  if (statfs (file, &fsd, sizeof (struct statfs)) != 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
 | 
						|
 | 
						|
#elif defined STAT_STATFS2_FRSIZE        /* 2.6 < glibc/Linux < 2.6.36 */
 | 
						|
 | 
						|
  struct statfs fsd;
 | 
						|
 | 
						|
  if (statfs (file, &fsd) < 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_frsize);
 | 
						|
 | 
						|
#elif defined STAT_STATFS2_BSIZE        /* glibc/Linux < 2.6, 4.3BSD, SunOS 4, \
 | 
						|
                                           Mac OS X < 10.4, FreeBSD < 5.0, \
 | 
						|
                                           NetBSD < 3.0, OpenBSD < 4.4 */
 | 
						|
 | 
						|
  struct statfs fsd;
 | 
						|
 | 
						|
  if (statfs (file, &fsd) < 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize);
 | 
						|
 | 
						|
# ifdef STATFS_TRUNCATES_BLOCK_COUNTS
 | 
						|
 | 
						|
  /* In SunOS 4.1.2, 4.1.3, and 4.1.3_U1, the block counts in the
 | 
						|
     struct statfs are truncated to 2GB.  These conditions detect that
 | 
						|
     truncation, presumably without botching the 4.1.1 case, in which
 | 
						|
     the values are not truncated.  The correct counts are stored in
 | 
						|
     undocumented spare fields.  */
 | 
						|
  if (fsd.f_blocks == 0x7fffffff / fsd.f_bsize && fsd.f_spare[0] > 0)
 | 
						|
    {
 | 
						|
      fsd.f_blocks = fsd.f_spare[0];
 | 
						|
      fsd.f_bfree = fsd.f_spare[1];
 | 
						|
      fsd.f_bavail = fsd.f_spare[2];
 | 
						|
    }
 | 
						|
# endif /* STATFS_TRUNCATES_BLOCK_COUNTS */
 | 
						|
 | 
						|
#elif defined STAT_STATFS2_FSIZE        /* 4.4BSD and older NetBSD */
 | 
						|
 | 
						|
  struct statfs fsd;
 | 
						|
 | 
						|
  if (statfs (file, &fsd) < 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
 | 
						|
 | 
						|
#elif defined STAT_STATFS4              /* SVR3, old Irix */
 | 
						|
 | 
						|
  struct statfs fsd;
 | 
						|
 | 
						|
  if (statfs (file, &fsd, sizeof fsd, 0) < 0)
 | 
						|
    return -1;
 | 
						|
 | 
						|
  /* Empirically, the block counts on most SVR3 and SVR3-derived
 | 
						|
     systems seem to always be in terms of 512-byte blocks,
 | 
						|
     no matter what value f_bsize has.  */
 | 
						|
   fsp->fsu_blocksize = 512;
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
#if (defined STAT_STATVFS64 || defined STAT_STATFS3_OSF1                \
 | 
						|
     || defined STAT_STATFS2_FRSIZE || defined STAT_STATFS2_BSIZE       \
 | 
						|
     || defined STAT_STATFS2_FSIZE || defined STAT_STATFS4)
 | 
						|
 | 
						|
  fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.f_blocks);
 | 
						|
  fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.f_bfree);
 | 
						|
  fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.f_bavail);
 | 
						|
  fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.f_bavail) != 0;
 | 
						|
  fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.f_files);
 | 
						|
  fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.f_ffree);
 | 
						|
 | 
						|
#endif
 | 
						|
 | 
						|
  (void) disk;  /* avoid argument-unused warning */
 | 
						|
  return 0;
 | 
						|
}
 |