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diff --git a/man2/fsync.2 b/man2/fsync.2 deleted file mode 100644 index 8566ef7..0000000 --- a/man2/fsync.2 +++ /dev/null @@ -1,200 +0,0 @@ -.\" Copyright 1993 Rickard E. Faith (faith@cs.unc.edu) and -.\" and Copyright 2006 Michael Kerrisk <mtk.manpages@gmail.com> -.\" -.\" SPDX-License-Identifier: Linux-man-pages-copyleft -.\" -.\" Modified 21 Aug 1994 by Michael Chastain <mec@shell.portal.com>: -.\" Removed note about old libc (pre-4.5.26) translating to 'sync'. -.\" Modified 15 Apr 1995 by Michael Chastain <mec@shell.portal.com>: -.\" Added `see also' section. -.\" Modified 13 Apr 1996 by Markus Kuhn <mskuhn@cip.informatik.uni-erlangen.de> -.\" Added remarks about fdatasync. -.\" Modified 31 Jan 1997 by Eric S. Raymond <esr@thyrsus.com> -.\" Modified 18 Apr 2001 by Andi Kleen -.\" Fix description to describe what it really does; add a few caveats. -.\" 2006-04-28, mtk, substantial rewrite of various parts. -.\" 2012-02-27 Various changes by Christoph Hellwig <hch@lst.de> -.\" -.TH fsync 2 2023-10-31 "Linux man-pages 6.7" -.SH NAME -fsync, fdatasync \- synchronize a file's in-core state with storage device -.SH LIBRARY -Standard C library -.RI ( libc ", " \-lc ) -.SH SYNOPSIS -.nf -.B #include <unistd.h> -.P -.BI "int fsync(int " fd ); -.P -.BI "int fdatasync(int " fd ); -.fi -.P -.RS -4 -Feature Test Macro Requirements for glibc (see -.BR feature_test_macros (7)): -.RE -.P -.nf -.BR fsync (): - glibc 2.16 and later: - No feature test macros need be defined - glibc up to and including 2.15: - _BSD_SOURCE || _XOPEN_SOURCE - || /* Since glibc 2.8: */ _POSIX_C_SOURCE >= 200112L -.fi -.P -.BR fdatasync (): -.nf - _POSIX_C_SOURCE >= 199309L || _XOPEN_SOURCE >= 500 -.fi -.SH DESCRIPTION -.BR fsync () -transfers ("flushes") all modified in-core data of -(i.e., modified buffer cache pages for) the -file referred to by the file descriptor -.I fd -to the disk device (or other permanent storage device) so that all -changed information can be retrieved even if the system crashes or -is rebooted. -This includes writing through or flushing a disk cache if present. -The call blocks until the device reports that the transfer has completed. -.P -As well as flushing the file data, -.BR fsync () -also flushes the metadata information associated with the file (see -.BR inode (7)). -.P -Calling -.BR fsync () -does not necessarily ensure -that the entry in the directory containing the file has also reached disk. -For that an explicit -.BR fsync () -on a file descriptor for the directory is also needed. -.P -.BR fdatasync () -is similar to -.BR fsync (), -but does not flush modified metadata unless that metadata -is needed in order to allow a subsequent data retrieval to be -correctly handled. -For example, changes to -.I st_atime -or -.I st_mtime -(respectively, time of last access and -time of last modification; see -.BR inode (7)) -do not require flushing because they are not necessary for -a subsequent data read to be handled correctly. -On the other hand, a change to the file size -.RI ( st_size , -as made by say -.BR ftruncate (2)), -would require a metadata flush. -.P -The aim of -.BR fdatasync () -is to reduce disk activity for applications that do not -require all metadata to be synchronized with the disk. -.SH RETURN VALUE -On success, these system calls return zero. -On error, \-1 is returned, and -.I errno -is set to indicate the error. -.SH ERRORS -.TP -.B EBADF -.I fd -is not a valid open file descriptor. -.TP -.B EINTR -The function was interrupted by a signal; see -.BR signal (7). -.TP -.B EIO -An error occurred during synchronization. -This error may relate to data written to some other file descriptor -on the same file. -Since Linux 4.13, -.\" commit 088737f44bbf6378745f5b57b035e57ee3dc4750 -errors from write-back will be reported to -all file descriptors that might have written the data which triggered -the error. -Some filesystems (e.g., NFS) keep close track of which data -came through which file descriptor, and give more precise reporting. -Other filesystems (e.g., most local filesystems) will report errors to -all file descriptors that were open on the file when the error was recorded. -.TP -.B ENOSPC -Disk space was exhausted while synchronizing. -.TP -.B EROFS -.TQ -.B EINVAL -.I fd -is bound to a special file (e.g., a pipe, FIFO, or socket) -which does not support synchronization. -.TP -.B ENOSPC -.TQ -.B EDQUOT -.I fd -is bound to a file on NFS or another filesystem which does not allocate -space at the time of a -.BR write (2) -system call, and some previous write failed due to insufficient -storage space. -.SH VERSIONS -On POSIX systems on which -.BR fdatasync () -is available, -.B _POSIX_SYNCHRONIZED_IO -is defined in -.I <unistd.h> -to a value greater than 0. -(See also -.BR sysconf (3).) -.\" POSIX.1-2001: It shall be defined to -1 or 0 or 200112L. -.\" -1: unavailable, 0: ask using sysconf(). -.\" glibc defines them to 1. -.SH STANDARDS -POSIX.1-2008. -.SH HISTORY -POSIX.1-2001, 4.2BSD. -.P -In Linux 2.2 and earlier, -.BR fdatasync () -is equivalent to -.BR fsync (), -and so has no performance advantage. -.P -The -.BR fsync () -implementations in older kernels and lesser used filesystems -do not know how to flush disk caches. -In these cases disk caches need to be disabled using -.BR hdparm (8) -or -.BR sdparm (8) -to guarantee safe operation. -.P -Under AT&T UNIX System V Release 4 -.I fd -needs to be opened for writing. -This is by itself incompatible with the original BSD interface -and forbidden by POSIX, -but nevertheless survives in HP-UX and AIX. -.SH SEE ALSO -.BR sync (1), -.BR bdflush (2), -.BR open (2), -.BR posix_fadvise (2), -.BR pwritev (2), -.BR sync (2), -.BR sync_file_range (2), -.BR fflush (3), -.BR fileno (3), -.BR hdparm (8), -.BR mount (8) |