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glibc/sysdeps/unix/sysv/linux/internal_statvfs.c
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/* Copyright (C) 1998-2016 Free Software Foundation, Inc. | |
This file is part of the GNU C Library. | |
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1998. | |
The GNU C Library 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 2.1 of the License, or (at your option) any later version. | |
The GNU C Library 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 the GNU C Library; if not, see | |
<http://www.gnu.org/licenses/>. */ | |
#include <assert.h> | |
#include <errno.h> | |
#include <mntent.h> | |
#include <paths.h> | |
#include <stdbool.h> | |
#include <stdio_ext.h> | |
#include <string.h> | |
#include <sys/mount.h> | |
#include <sys/stat.h> | |
#include <sys/statfs.h> | |
#include <sys/statvfs.h> | |
#include "linux_fsinfo.h" | |
#include <kernel-features.h> | |
/* Special internal-only bit value. */ | |
#define ST_VALID 0x0020 | |
#ifndef STATFS | |
# define STATFS statfs | |
# define STATVFS statvfs | |
# define INTERNAL_STATVFS __internal_statvfs | |
# ifndef __ASSUME_STATFS_F_FLAGS | |
int | |
__statvfs_getflags (const char *name, int fstype, int fd) | |
{ | |
struct stat64 st; | |
if ((fd < 0 ? stat64 (name, &st) : fstat64 (fd, &st)) < 0) | |
return 0; | |
const char *fsname = NULL; | |
const char *fsname2 = NULL; | |
const char *fsname3 = NULL; | |
/* Map the filesystem type we got from the statfs call to a string. */ | |
switch (fstype) | |
{ | |
case EXT2_SUPER_MAGIC: | |
fsname = "ext4"; | |
fsname2 = "ext3"; | |
fsname3 = "ext2"; | |
break; | |
case DEVPTS_SUPER_MAGIC: | |
fsname= "devpts"; | |
break; | |
case SHMFS_SUPER_MAGIC: | |
fsname = "tmpfs"; | |
break; | |
case PROC_SUPER_MAGIC: | |
fsname = "proc"; | |
break; | |
case USBDEVFS_SUPER_MAGIC: | |
fsname = "usbdevfs"; | |
break; | |
case AUTOFS_SUPER_MAGIC: | |
fsname = "autofs"; | |
break; | |
case NFS_SUPER_MAGIC: | |
fsname = "nfs"; | |
break; | |
case SYSFS_MAGIC: | |
fsname = "sysfs"; | |
break; | |
case REISERFS_SUPER_MAGIC: | |
fsname = "reiserfs"; | |
break; | |
case XFS_SUPER_MAGIC: | |
fsname = "xfs"; | |
break; | |
case JFS_SUPER_MAGIC: | |
fsname = "jfs"; | |
break; | |
case HPFS_SUPER_MAGIC: | |
fsname = "hpfs"; | |
break; | |
case DEVFS_SUPER_MAGIC: | |
fsname = "devfs"; | |
break; | |
case ISOFS_SUPER_MAGIC: | |
fsname = "iso9660"; | |
break; | |
case MSDOS_SUPER_MAGIC: | |
fsname = "msdos"; | |
break; | |
case NTFS_SUPER_MAGIC: | |
fsname = "ntfs"; | |
break; | |
case LOGFS_MAGIC_U32: | |
fsname = "logfs"; | |
break; | |
case BTRFS_SUPER_MAGIC: | |
fsname = "btrfs"; | |
break; | |
case CGROUP_SUPER_MAGIC: | |
fsname = "cgroup"; | |
break; | |
case LUSTRE_SUPER_MAGIC: | |
fsname = "lustre"; | |
break; | |
case F2FS_SUPER_MAGIC: | |
fsname = "f2fs"; | |
break; | |
case EFIVARFS_MAGIC: | |
fsname = "efivarfs"; | |
break; | |
} | |
FILE *mtab = __setmntent ("/proc/mounts", "r"); | |
if (mtab == NULL) | |
mtab = __setmntent (_PATH_MOUNTED, "r"); | |
int result = 0; | |
if (mtab != NULL) | |
{ | |
bool success = false; | |
struct mntent mntbuf; | |
char tmpbuf[1024]; | |
/* No locking needed. */ | |
(void) __fsetlocking (mtab, FSETLOCKING_BYCALLER); | |
again: | |
while (__getmntent_r (mtab, &mntbuf, tmpbuf, sizeof (tmpbuf))) | |
{ | |
/* In a first round we look for a given mount point, if | |
we have a name. */ | |
if (name != NULL && strcmp (name, mntbuf.mnt_dir) != 0) | |
continue; | |
/* We need to look at the entry only if the filesystem | |
name matches. If we have a filesystem name. */ | |
else if (fsname != NULL | |
&& strcmp (fsname, mntbuf.mnt_type) != 0 | |
&& (fsname2 == NULL | |
|| strcmp (fsname2, mntbuf.mnt_type) != 0) | |
&& (fsname3 == NULL | |
|| strcmp (fsname3, mntbuf.mnt_type) != 0)) | |
continue; | |
/* Find out about the device the current entry is for. */ | |
struct stat64 fsst; | |
if (stat64 (mntbuf.mnt_dir, &fsst) >= 0 | |
&& st.st_dev == fsst.st_dev) | |
{ | |
/* Bingo, we found the entry for the device FD is on. | |
Now interpret the option string. */ | |
char *cp = mntbuf.mnt_opts; | |
char *opt; | |
while ((opt = strsep (&cp, ",")) != NULL) | |
if (strcmp (opt, "ro") == 0) | |
result |= ST_RDONLY; | |
else if (strcmp (opt, "nosuid") == 0) | |
result |= ST_NOSUID; | |
else if (strcmp (opt, "noexec") == 0) | |
result |= ST_NOEXEC; | |
else if (strcmp (opt, "nodev") == 0) | |
result |= ST_NODEV; | |
else if (strcmp (opt, "sync") == 0) | |
result |= ST_SYNCHRONOUS; | |
else if (strcmp (opt, "mand") == 0) | |
result |= ST_MANDLOCK; | |
else if (strcmp (opt, "noatime") == 0) | |
result |= ST_NOATIME; | |
else if (strcmp (opt, "nodiratime") == 0) | |
result |= ST_NODIRATIME; | |
else if (strcmp (opt, "relatime") == 0) | |
result |= ST_RELATIME; | |
/* We can stop looking for more entries. */ | |
success = true; | |
break; | |
} | |
} | |
/* Maybe the kernel names for the filesystems changed or the | |
statvfs call got a name which was not the mount point. Check | |
again, this time without checking for name matches first. */ | |
if (! success && (name != NULL || fsname != NULL)) | |
{ | |
if (name != NULL) | |
/* Try without a mount point name. */ | |
name = NULL; | |
else | |
{ | |
/* Try without a filesystem name. */ | |
assert (fsname != NULL); | |
fsname = fsname2 = fsname3 = NULL; | |
} | |
/* It is not strictly allowed to use rewind here. But | |
this code is part of the implementation so it is | |
acceptable. */ | |
rewind (mtab); | |
goto again; | |
} | |
/* Close the file. */ | |
__endmntent (mtab); | |
} | |
return result; | |
} | |
# endif | |
#else | |
extern int __statvfs_getflags (const char *name, int fstype, int fd); | |
#endif | |
void | |
INTERNAL_STATVFS (const char *name, struct STATVFS *buf, | |
struct STATFS *fsbuf, int fd) | |
{ | |
/* Now fill in the fields we have information for. */ | |
buf->f_bsize = fsbuf->f_bsize; | |
/* Linux has the f_frsize size only in later version of the kernel. | |
If the value is not filled in use f_bsize. */ | |
buf->f_frsize = fsbuf->f_frsize ?: fsbuf->f_bsize; | |
buf->f_blocks = fsbuf->f_blocks; | |
buf->f_bfree = fsbuf->f_bfree; | |
buf->f_bavail = fsbuf->f_bavail; | |
buf->f_files = fsbuf->f_files; | |
buf->f_ffree = fsbuf->f_ffree; | |
if (sizeof (buf->f_fsid) == sizeof (fsbuf->f_fsid)) | |
/* The shifting uses 'unsigned long long int' even though the target | |
field might only have 32 bits. This is OK since the 'if' branch | |
is not used in this case but the compiler would still generate | |
warnings. */ | |
buf->f_fsid = ((fsbuf->f_fsid.__val[0] | |
& ((1ULL << (8 * sizeof (fsbuf->f_fsid.__val[0]))) - 1)) | |
| ((unsigned long long int) fsbuf->f_fsid.__val[1] | |
<< (8 * (sizeof (buf->f_fsid) | |
- sizeof (fsbuf->f_fsid.__val[0]))))); | |
else | |
/* We cannot help here. The statvfs element is not large enough to | |
contain both words of the statfs f_fsid field. */ | |
buf->f_fsid = fsbuf->f_fsid.__val[0]; | |
#ifdef _STATVFSBUF_F_UNUSED | |
buf->__f_unused = 0; | |
#endif | |
buf->f_namemax = fsbuf->f_namelen; | |
memset (buf->__f_spare, '\0', sizeof (buf->__f_spare)); | |
/* What remains to do is to fill the fields f_favail and f_flag. */ | |
/* XXX I have no idea how to compute f_favail. Any idea??? */ | |
buf->f_favail = buf->f_ffree; | |
#ifndef __ASSUME_STATFS_F_FLAGS | |
if ((fsbuf->f_flags & ST_VALID) == 0) | |
/* Determining the flags is tricky. We have to read /proc/mounts or | |
the /etc/mtab file and search for the entry which matches the given | |
file. The way we can test for matching filesystem is using the | |
device number. */ | |
buf->f_flag = __statvfs_getflags (name, fsbuf->f_type, fd); | |
else | |
#endif | |
buf->f_flag = fsbuf->f_flags ^ ST_VALID; | |
} |