NAME
statvfs, fstatvfs - get filesystem statisticsLIBRARY
Standard C library (libc, -lc)SYNOPSIS
#include <sys/statvfs.h>
int statvfs(const char *restrict path, struct statvfs *restrict buf); int fstatvfs(int fd, struct statvfs *buf);
DESCRIPTION
The function statvfs() returns information about a mounted filesystem. path is the pathname of any file within the mounted filesystem. buf is a pointer to a statvfs structure defined approximately as follows:struct statvfs { unsigned long f_bsize; /* Filesystem block size */ unsigned long f_frsize; /* Fragment size */ fsblkcnt_t f_blocks; /* Size of fs in f_frsize units */ fsblkcnt_t f_bfree; /* Number of free blocks */ fsblkcnt_t f_bavail; /* Number of free blocks for unprivileged users */ fsfilcnt_t f_files; /* Number of inodes */ fsfilcnt_t f_ffree; /* Number of free inodes */ fsfilcnt_t f_favail; /* Number of free inodes for unprivileged users */ unsigned long f_fsid; /* Filesystem ID */ unsigned long f_flag; /* Mount flags */ unsigned long f_namemax; /* Maximum filename length */ };
Here the types fsblkcnt_t and fsfilcnt_t are defined in <sys/types.h>. Both used to be unsigned long. The field f_flag is a bit mask indicating various options that were employed when mounting this filesystem. It contains zero or more of the following flags:
- ST_MANDLOCK
- Mandatory locking is permitted on the filesystem (see fcntl(2)).
- ST_NOATIME
- Do not update access times; see mount(2).
- ST_NODEV
- Disallow access to device special files on this filesystem.
- ST_NODIRATIME
- Do not update directory access times; see mount(2).
- ST_NOEXEC
- Execution of programs is disallowed on this filesystem.
- ST_NOSUID
- The set-user-ID and set-group-ID bits are ignored by exec(3) for executable files on this filesystem
- ST_RDONLY
- This filesystem is mounted read-only.
- ST_RELATIME
- Update atime relative to mtime/ctime; see mount(2).
- ST_SYNCHRONOUS
- Writes are synched to the filesystem immediately (see the description of O_SYNC in open(2)).
RETURN VALUE
On success, zero is returned. On error, -1 is returned, and errno is set to indicate the error.ERRORS
- EACCES
- (statvfs()) Search permission is denied for a component of the path prefix of path. (See also path_resolution(7).)
- EBADF
- (fstatvfs()) fd is not a valid open file descriptor.
- EFAULT
- Buf or path points to an invalid address.
- EINTR
- This call was interrupted by a signal; see signal(7).
- EIO
- An I/O error occurred while reading from the filesystem.
- ELOOP
- (statvfs()) Too many symbolic links were encountered in translating path.
- ENAMETOOLONG
- (statvfs()) path is too long.
- ENOENT
- (statvfs()) The file referred to by path does not exist.
- ENOMEM
- Insufficient kernel memory was available.
- ENOSYS
- The filesystem does not support this call.
- ENOTDIR
- (statvfs()) A component of the path prefix of path is not a directory.
- EOVERFLOW
- Some values were too large to be represented in the returned struct.
ATTRIBUTES
For an explanation of the terms used in this section, see attributes(7).Interface | Attribute | Value |
statvfs (), fstatvfs () | Thread safety | MT-Safe |
STANDARDS
POSIX.1-2001, POSIX.1-2008. Only the ST_NOSUID and ST_RDONLY flags of the f_flag field are specified in POSIX.1. To obtain definitions of the remaining flags, one must define _GNU_SOURCE.NOTES
The Linux kernel has system calls statfs(2) and fstatfs(2) to support this library call. Before glibc 2.13, statvfs() populated the bits of the f_flag field by scanning the mount options shown in /proc/mounts. However, starting with Linux 2.6.36, the underlying statfs(2) system call provides the necessary information via the f_flags field, and since glibc 2.13, the statvfs() function will use information from that field rather than scanning /proc/mounts. The glibc implementations ofpathconf(path, _PC_REC_XFER_ALIGN); pathconf(path, _PC_ALLOC_SIZE_MIN); pathconf(path, _PC_REC_MIN_XFER_SIZE);
respectively use the f_frsize, f_frsize, and f_bsize fields returned by a call to statvfs() with the argument path.
SEE ALSO
statfs(2)2022-12-15 | Linux man-pages 6.03 |