/* fsusage.c -- return space usage of mounted filesystems
- Copyright (C) 1991, 1992, 1996, 1998 Free Software Foundation, Inc.
+ Copyright (C) 1991, 1992, 1996, 1998, 1999 Free Software Foundation, Inc.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
#include <sys/stat.h>
#include "fsusage.h"
+#if HAVE_LIMITS_H
+# include <limits.h>
+#endif
+#ifndef CHAR_BIT
+# define CHAR_BIT 8
+#endif
+
int statfs ();
#if HAVE_SYS_PARAM_H
/* 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 the argument is all 1 bits,
- even if the argument is unsigned and smaller than unitmax_t. */
+ even if the argument is unsigned and smaller than uintmax_t. */
#define PROPAGATE_ALL_ONES(x) ((x) == -1 ? (uintmax_t) -1 : (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))
+
int safe_read ();
/* Fill in the fields of FSP with information about space usage for
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 (path, disk, fsp)
- const char *path;
- const char *disk;
- struct fs_usage *fsp;
+get_fs_usage (const char *path, const char *disk, struct fs_usage *fsp)
{
#ifdef STAT_STATFS3_OSF1
fsp->fsu_blocksize = 1024;
fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.fd_req.btot);
fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.fd_req.bfree);
- fsp->fsu_bavail = PROPAGATE_ALL_ONES (fsd.fd_req.bfreen);
+ fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.fd_req.bfreen);
+ fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.fd_req.bfreen) != 0;
fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.fd_req.gtot);
fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.fd_req.gfree);
}
close (fd);
- fsp->fsu_blocksize = fsd.s_type == Fs2b ? 1024 : 512;
+ fsp->fsu_blocksize = (fsd.s_type == Fs2b ? 1024 : 512);
fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.s_fsize);
fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.s_tfree);
- fsp->fsu_bavail = PROPAGATE_ALL_ONES (fsd.s_tfree);
+ fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.s_tfree);
+ fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.s_tfree) != 0;
fsp->fsu_files = (fsd.s_isize == -1
? (uintmax_t) -1
: (fsd.s_isize - 2) * INOPB * (fsd.s_type == Fs2b ? 2 : 1));
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 == 0x1fffff && fsd.f_spare[0] > 0)
+ 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];
fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.f_blocks);
fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.f_bfree);
- fsp->fsu_bavail = PROPAGATE_ALL_ONES (fsd.f_bavail);
+ 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);
/* AIX PS/2 does not supply statfs. */
int
-statfs (path, fsb)
- char *path;
- struct statfs *fsb;
+statfs (char *path, struct statfs *fsb)
{
struct stat stats;
struct dustat fsd;