1 /* fsusage.c -- return space usage of mounted file systems
3 Copyright (C) 1991-1992, 1996, 1998-1999, 2002-2006, 2009-2012 Free Software
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.
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.
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/>. */
24 #include <sys/types.h>
26 #if STAT_STATVFS || STAT_STATVFS64 /* POSIX 1003.1-2001 (and later) with XSI */
27 # include <sys/statvfs.h>
29 /* Don't include backward-compatibility files unless they're needed.
30 Eventually we'd like to remove all this cruft. */
33 # include <sys/stat.h>
34 # if HAVE_SYS_FS_S5PARAM_H /* Fujitsu UXP/V */
35 # include <sys/fs/s5param.h>
37 # if defined HAVE_SYS_FILSYS_H && !defined _CRAY
38 # include <sys/filsys.h> /* SVR2 */
40 # if HAVE_SYS_STATFS_H
41 # include <sys/statfs.h>
43 # if HAVE_DUSTAT_H /* AIX PS/2 */
44 # include <sys/dustat.h>
46 # include "full-read.h"
49 /* These files are needed for 2.6 < glibc/Linux < 2.6.36, even though
50 it has statvfs, because they are used by the fallback. */
52 # include <sys/param.h>
55 # include <sys/mount.h>
61 /* The results of open() in this file are not used with fchdir,
62 therefore save some unnecessary work in fchdir.c. */
66 /* Many space usage primitives use all 1 bits to denote a value that is
67 not applicable or unknown. Propagate this information by returning
68 a uintmax_t value that is all 1 bits if X is all 1 bits, even if X
69 is unsigned and narrower than uintmax_t. */
70 #define PROPAGATE_ALL_ONES(x) \
71 ((sizeof (x) < sizeof (uintmax_t) \
72 && (~ (x) == (sizeof (x) < sizeof (int) \
73 ? - (1 << (sizeof (x) * CHAR_BIT)) \
75 ? UINTMAX_MAX : (uintmax_t) (x))
77 /* Extract the top bit of X as an uintmax_t value. */
78 #define EXTRACT_TOP_BIT(x) ((x) \
79 & ((uintmax_t) 1 << (sizeof (x) * CHAR_BIT - 1)))
81 /* If a value is negative, many space usage primitives store it into an
82 integer variable by assignment, even if the variable's type is unsigned.
83 So, if a space usage variable X's top bit is set, convert X to the
84 uintmax_t value V such that (- (uintmax_t) V) is the negative of
85 the original value. If X's top bit is clear, just yield X.
86 Use PROPAGATE_TOP_BIT if the original value might be negative;
87 otherwise, use PROPAGATE_ALL_ONES. */
88 #define PROPAGATE_TOP_BIT(x) ((x) | ~ (EXTRACT_TOP_BIT (x) - 1))
91 /* Return true if statvfs works. This is false for statvfs on systems
92 with GNU libc on Linux kernels before 2.6.36, which stats all
93 preceding entries in /proc/mounts; that makes df hang if even one
94 of the corresponding file systems is hard-mounted but not available. */
95 # if ! (__linux__ && (__GLIBC__ || __UCLIBC__))
96 static int statvfs_works (void) { return 1; }
98 # include <string.h> /* for strverscmp */
99 # include <sys/utsname.h>
100 # include <sys/statfs.h>
101 # define STAT_STATFS2_BSIZE 1
106 static int statvfs_works_cache = -1;
108 if (statvfs_works_cache < 0)
109 statvfs_works_cache = (uname (&name) == 0
110 && 0 <= strverscmp (name.release, "2.6.36"));
111 return statvfs_works_cache;
117 /* Fill in the fields of FSP with information about space usage for
118 the file system on which FILE resides.
119 DISK is the device on which FILE is mounted, for space-getting
120 methods that need to know it.
121 Return 0 if successful, -1 if not. When returning -1, ensure that
122 ERRNO is either a system error value, or zero if DISK is NULL
123 on a system that requires a non-NULL value. */
125 get_fs_usage (char const *file, char const *disk, struct fs_usage *fsp)
127 #ifdef STAT_STATVFS /* POSIX, except pre-2.6.36 glibc/Linux */
129 if (statvfs_works ())
133 if (statvfs (file, &vfsd) < 0)
136 /* f_frsize isn't guaranteed to be supported. */
137 fsp->fsu_blocksize = (vfsd.f_frsize
138 ? PROPAGATE_ALL_ONES (vfsd.f_frsize)
139 : PROPAGATE_ALL_ONES (vfsd.f_bsize));
141 fsp->fsu_blocks = PROPAGATE_ALL_ONES (vfsd.f_blocks);
142 fsp->fsu_bfree = PROPAGATE_ALL_ONES (vfsd.f_bfree);
143 fsp->fsu_bavail = PROPAGATE_TOP_BIT (vfsd.f_bavail);
144 fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (vfsd.f_bavail) != 0;
145 fsp->fsu_files = PROPAGATE_ALL_ONES (vfsd.f_files);
146 fsp->fsu_ffree = PROPAGATE_ALL_ONES (vfsd.f_ffree);
152 #if defined STAT_STATVFS64 /* AIX */
154 struct statvfs64 fsd;
156 if (statvfs64 (file, &fsd) < 0)
159 /* f_frsize isn't guaranteed to be supported. */
160 fsp->fsu_blocksize = (fsd.f_frsize
161 ? PROPAGATE_ALL_ONES (fsd.f_frsize)
162 : PROPAGATE_ALL_ONES (fsd.f_bsize));
164 #elif defined STAT_STATFS2_FS_DATA /* Ultrix */
168 if (statfs (file, &fsd) != 1)
171 fsp->fsu_blocksize = 1024;
172 fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.fd_req.btot);
173 fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.fd_req.bfree);
174 fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.fd_req.bfreen);
175 fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.fd_req.bfreen) != 0;
176 fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.fd_req.gtot);
177 fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.fd_req.gfree);
179 #elif defined STAT_READ_FILSYS /* SVR2 */
181 # define SUPERBOFF (SUPERB * 512)
193 fd = open (disk, O_RDONLY);
196 lseek (fd, (off_t) SUPERBOFF, 0);
197 if (full_read (fd, (char *) &fsd, sizeof fsd) != sizeof fsd)
204 fsp->fsu_blocksize = (fsd.s_type == Fs2b ? 1024 : 512);
205 fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.s_fsize);
206 fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.s_tfree);
207 fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.s_tfree);
208 fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.s_tfree) != 0;
209 fsp->fsu_files = (fsd.s_isize == -1
211 : (fsd.s_isize - 2) * INOPB * (fsd.s_type == Fs2b ? 2 : 1));
212 fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.s_tinode);
214 #elif defined STAT_STATFS3_OSF1 /* OSF/1 */
218 if (statfs (file, &fsd, sizeof (struct statfs)) != 0)
221 fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
223 #elif defined STAT_STATFS2_FRSIZE /* 2.6 < glibc/Linux < 2.6.36 */
227 if (statfs (file, &fsd) < 0)
230 fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_frsize);
232 #elif defined STAT_STATFS2_BSIZE /* glibc/Linux < 2.6, 4.3BSD, SunOS 4, \
233 Mac OS X < 10.4, FreeBSD < 5.0, \
234 NetBSD < 3.0, OpenBSD < 4.4 */
238 if (statfs (file, &fsd) < 0)
241 fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize);
243 # ifdef STATFS_TRUNCATES_BLOCK_COUNTS
245 /* In SunOS 4.1.2, 4.1.3, and 4.1.3_U1, the block counts in the
246 struct statfs are truncated to 2GB. These conditions detect that
247 truncation, presumably without botching the 4.1.1 case, in which
248 the values are not truncated. The correct counts are stored in
249 undocumented spare fields. */
250 if (fsd.f_blocks == 0x7fffffff / fsd.f_bsize && fsd.f_spare[0] > 0)
252 fsd.f_blocks = fsd.f_spare[0];
253 fsd.f_bfree = fsd.f_spare[1];
254 fsd.f_bavail = fsd.f_spare[2];
256 # endif /* STATFS_TRUNCATES_BLOCK_COUNTS */
258 #elif defined STAT_STATFS2_FSIZE /* 4.4BSD and older NetBSD */
262 if (statfs (file, &fsd) < 0)
265 fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_fsize);
267 #elif defined STAT_STATFS4 /* SVR3, Dynix, old Irix, old AIX, \
270 # if !_AIX && !defined _SEQUENT_ && !defined DOLPHIN
271 # define f_bavail f_bfree
276 if (statfs (file, &fsd, sizeof fsd, 0) < 0)
279 /* Empirically, the block counts on most SVR3 and SVR3-derived
280 systems seem to always be in terms of 512-byte blocks,
281 no matter what value f_bsize has. */
282 # if _AIX || defined _CRAY
283 fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize);
285 fsp->fsu_blocksize = 512;
290 #if (defined STAT_STATVFS64 \
291 || (!defined STAT_STATFS2_FS_DATA && !defined STAT_READ_FILSYS))
293 fsp->fsu_blocks = PROPAGATE_ALL_ONES (fsd.f_blocks);
294 fsp->fsu_bfree = PROPAGATE_ALL_ONES (fsd.f_bfree);
295 fsp->fsu_bavail = PROPAGATE_TOP_BIT (fsd.f_bavail);
296 fsp->fsu_bavail_top_bit_set = EXTRACT_TOP_BIT (fsd.f_bavail) != 0;
297 fsp->fsu_files = PROPAGATE_ALL_ONES (fsd.f_files);
298 fsp->fsu_ffree = PROPAGATE_ALL_ONES (fsd.f_ffree);
302 (void) disk; /* avoid argument-unused warning */
306 #if defined _AIX && defined _I386
307 /* AIX PS/2 does not supply statfs. */
310 statfs (char *file, struct statfs *fsb)
315 if (stat (file, &stats) != 0)
317 if (dustat (stats.st_dev, 0, &fsd, sizeof (fsd)))
320 fsb->f_bsize = fsd.du_bsize;
321 fsb->f_blocks = fsd.du_fsize - fsd.du_isize;
322 fsb->f_bfree = fsd.du_tfree;
323 fsb->f_bavail = fsd.du_tfree;
324 fsb->f_files = (fsd.du_isize - 2) * fsd.du_inopb;
325 fsb->f_ffree = fsd.du_tinode;
326 fsb->f_fsid.val[0] = fsd.du_site;
327 fsb->f_fsid.val[1] = fsd.du_pckno;
331 #endif /* _AIX && _I386 */