| /* fsusage.c -- return space usage of mounted file systems |
| |
| Copyright (C) 1991-1992, 1996, 1998-1999, 2002-2006, 2009-2020 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 |
| the Free Software Foundation; either version 3 of the License, or |
| (at your option) any later version. |
| |
| This program 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 General Public License for more details. |
| |
| You should have received a copy of the GNU 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. */ |
| # if defined _CRAY |
| fsp->fsu_blocksize = PROPAGATE_ALL_ONES (fsd.f_bsize); |
| # else |
| fsp->fsu_blocksize = 512; |
| # endif |
| |
| #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; |
| } |