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Diffstat (limited to 'man/man3/statvfs.3')
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diff --git a/man/man3/statvfs.3 b/man/man3/statvfs.3 new file mode 100644 index 000000000..c694aeb1f --- /dev/null +++ b/man/man3/statvfs.3 @@ -0,0 +1,256 @@ +'\" t +.\" Copyright (C) 2003 Andries Brouwer (aeb@cwi.nl) +.\" +.\" SPDX-License-Identifier: Linux-man-pages-copyleft +.\" +.\" 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 (date) "Linux man-pages (unreleased)" +.SH NAME +statvfs, fstatvfs \- get filesystem statistics +.SH LIBRARY +Standard C library +.RI ( libc ", " \-lc ) +.SH SYNOPSIS +.nf +.B #include <sys/statvfs.h> +.P +.BI "int statvfs(const char *restrict " path \ +", struct statvfs *restrict " buf ); +.BI "int fstatvfs(int " fd ", struct statvfs *" buf ); +.fi +.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: +.P +.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 +.P +Here the types +.I fsblkcnt_t +and +.I fsfilcnt_t +are defined in +.IR <sys/types.h> . +Both used to be +.IR "unsigned long" . +.P +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)). +.P +It is unspecified whether all members of the returned struct +have meaningful values on all filesystems. +.P +.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 to indicate the error. +.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; +lbx lb lb +l l l. +Interface Attribute Value +T{ +.na +.nh +.BR statvfs (), +.BR fstatvfs () +T} Thread safety MT-Safe +.TE +.SH VERSIONS +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. +.P +The glibc implementations of +.P +.in +4n +.EX +pathconf(path, _PC_REC_XFER_ALIGN); +pathconf(path, _PC_ALLOC_SIZE_MIN); +pathconf(path, _PC_REC_MIN_XFER_SIZE); +.EE +.in +.P +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 . +.P +Under Linux, +.I f_favail +is always the same as +.IR f_ffree , +and there's no way for a filesystem to report otherwise. +This is not an issue, +since no filesystems with an inode root reservation exist. +.SH STANDARDS +POSIX.1-2008. +.SH HISTORY +POSIX.1-2001. +.P +Before glibc 2.13, +.\" glibc commit 3cdaa6adb113a088fdfb87aa6d7747557eccc58d +.BR statvfs () +populated the bits of the +.I 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 +.I f_flags +field, and since glibc 2.13, the +.BR statvfs () +function will use information from that field rather than scanning +.IR /proc/mounts . +.SH SEE ALSO +.BR statfs (2) |