| .\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl) |
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| .\" The pathconf note is from Walter Harms |
| .\" This is not a system call on Linux |
| .\" |
| .\" Modified 2004-06-23 by Michael Kerrisk <mtk.manpages@gmail.com> |
| .\" |
| .TH STATVFS 3 2017-09-15 "Linux" "Linux Programmer's Manual" |
| .SH NAME |
| statvfs, fstatvfs \- get filesystem statistics |
| .SH SYNOPSIS |
| .B #include <sys/statvfs.h> |
| .PP |
| .BI "int statvfs(const char *" path ", struct statvfs *" buf ); |
| .br |
| .BI "int fstatvfs(int " fd ", struct statvfs *" buf ); |
| .SH DESCRIPTION |
| The function |
| .BR statvfs () |
| returns information about a mounted filesystem. |
| .I path |
| is the pathname of any file within the mounted filesystem. |
| .I buf |
| is a pointer to a |
| .I statvfs |
| structure defined approximately as follows: |
| .PP |
| .in +4n |
| .EX |
| 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 */ |
| }; |
| .EE |
| .in |
| .PP |
| Here the types |
| .I fsblkcnt_t |
| and |
| .I fsfilcnt_t |
| are defined in |
| .IR <sys/types.h> . |
| Both used to be |
| .IR "unsigned long" . |
| .PP |
| The field |
| .I 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: |
| .\" XXX Keep this list in sync with statfs(2) |
| .TP |
| .B ST_MANDLOCK |
| Mandatory locking is permitted on the filesystem (see |
| .BR fcntl (2)). |
| .TP |
| .B ST_NOATIME |
| Do not update access times; see |
| .BR mount (2). |
| .TP |
| .B ST_NODEV |
| Disallow access to device special files on this filesystem. |
| .TP |
| .B ST_NODIRATIME |
| Do not update directory access times; see |
| .BR mount (2). |
| .TP |
| .B ST_NOEXEC |
| Execution of programs is disallowed on this filesystem. |
| .TP |
| .B ST_NOSUID |
| The set-user-ID and set-group-ID bits are ignored by |
| .BR exec (3) |
| for executable files on this filesystem |
| .TP |
| .B ST_RDONLY |
| This filesystem is mounted read-only. |
| .TP |
| .B ST_RELATIME |
| Update atime relative to mtime/ctime; see |
| .BR mount (2). |
| .TP |
| .B ST_SYNCHRONOUS |
| Writes are synched to the filesystem immediately (see the description of |
| .B O_SYNC |
| in |
| .BR open (2)). |
| .PP |
| It is unspecified whether all members of the returned struct |
| have meaningful values on all filesystems. |
| .PP |
| .BR fstatvfs () |
| returns the same information about an open file referenced by descriptor |
| .IR fd . |
| .SH RETURN VALUE |
| On success, zero is returned. |
| On error, \-1 is returned, and |
| .I errno |
| is set appropriately. |
| .SH ERRORS |
| .TP |
| .B EACCES |
| .RB ( statvfs ()) |
| Search permission is denied for a component of the path prefix of |
| .IR path . |
| (See also |
| .BR path_resolution (7).) |
| .TP |
| .B EBADF |
| .RB ( fstatvfs ()) |
| .I fd |
| is not a valid open file descriptor. |
| .TP |
| .B EFAULT |
| .I Buf |
| or |
| .I path |
| points to an invalid address. |
| .TP |
| .B EINTR |
| This call was interrupted by a signal; see |
| .BR signal (7). |
| .TP |
| .B EIO |
| An I/O error occurred while reading from the filesystem. |
| .TP |
| .B ELOOP |
| .RB ( statvfs ()) |
| Too many symbolic links were encountered in translating |
| .IR path . |
| .TP |
| .B ENAMETOOLONG |
| .RB ( statvfs ()) |
| .I path |
| is too long. |
| .TP |
| .B ENOENT |
| .RB ( statvfs ()) |
| The file referred to by |
| .I path |
| does not exist. |
| .TP |
| .B ENOMEM |
| Insufficient kernel memory was available. |
| .TP |
| .B ENOSYS |
| The filesystem does not support this call. |
| .TP |
| .B ENOTDIR |
| .RB ( statvfs ()) |
| A component of the path prefix of |
| .I path |
| is not a directory. |
| .TP |
| .B EOVERFLOW |
| Some values were too large to be represented in the returned struct. |
| .SH ATTRIBUTES |
| For an explanation of the terms used in this section, see |
| .BR attributes (7). |
| .TS |
| allbox; |
| lbw21 lb lb |
| l l l. |
| Interface Attribute Value |
| T{ |
| .BR statvfs (), |
| .BR fstatvfs () |
| T} Thread safety MT-Safe |
| .TE |
| .SH CONFORMING TO |
| POSIX.1-2001, POSIX.1-2008. |
| .PP |
| Only the |
| .B ST_NOSUID |
| and |
| .B ST_RDONLY |
| flags of the |
| .I f_flag |
| field are specified in POSIX.1. |
| To obtain definitions of the remaining flags, one must define |
| .BR _GNU_SOURCE . |
| .SH NOTES |
| The Linux kernel has system calls |
| .BR statfs (2) |
| and |
| .BR fstatfs (2) |
| to support this library call. |
| .PP |
| In glibc versions before 2.13, |
| .\" glibc commit 3cdaa6adb113a088fdfb87aa6d7747557eccc58d |
| .BR statvfs () |
| populated the bits of the |
| .IR f_flag |
| field by scanning the mount options shown in |
| .IR /proc/mounts . |
| However, starting with Linux 2.6.36, the underlying |
| .BR statfs (2) |
| system call provides the necessary information via the |
| .IR f_flags |
| field, and since glibc version 2.13, the |
| .BR statvfs () |
| function will use information from that field rather than scanning |
| .IR /proc/mounts . |
| .PP |
| The glibc implementations of |
| .PP |
| .in +4n |
| .EX |
| pathconf(path, _PC_REC_XFER_ALIGN); |
| pathconf(path, _PC_ALLOC_SIZE_MIN); |
| pathconf(path, _PC_REC_MIN_XFER_SIZE); |
| .EE |
| .in |
| .PP |
| respectively use the |
| .IR f_frsize , |
| .IR f_frsize , |
| and |
| .I f_bsize |
| fields returned by a call to |
| .BR statvfs () |
| with the argument |
| .IR path . |
| .SH SEE ALSO |
| .BR statfs (2) |
