SYNC(2) - man page online | system calls
Commit buffer cache to disk.
SYNC(2) Linux Programmer's Manual SYNC(2)
NAMEsync, syncfs - commit buffer cache to disk
SYNOPSIS#include <unistd.h> void sync(void); int syncfs(int fd); Feature Test Macro Requirements for glibc (see feature_test_macros(7)): sync(): _BSD_SOURCE || _XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED syncfs(): _GNU_SOURCE
DESCRIPTIONsync() causes all buffered modifications to file metadata and data to be written to the underlying filesystems. syncfs() is like sync(), but synchronizes just the filesystem containing file referred to by the open file descriptor fd.
RETURN VALUEsyncfs() returns 0 on success; on error, it returns -1 and sets errno to indicate the error.
ERRORSsync() is always successful. syncfs() can fail for at least the following reason: EBADF fd is not a valid file descriptor.
VERSIONSsyncfs() first appeared in Linux 2.6.39; library support was added to glibc in version 2.14.
CONFORMING TOsync(): POSIX.1-2001, POSIX.1-2008, SVr4, 4.3BSD. syncfs() is Linux-specific.
NOTESSince glibc 2.2.2, the Linux prototype for sync() is as listed above, following the vari‐ ous standards. In glibc 2.2.1 and earlier, it was "int sync(void)", and sync() always returned 0.
BUGSAccording to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but may return before the actual writing is done. However, since version 1.3.20 Linux does actually wait. (This still does not guarantee data integrity: modern disks have large caches.)
SEE ALSObdflush(2), fdatasync(2), fsync(2), sync(1)
Linux 2015-08-08 SYNC(2)
COLOPHONThis page is part of release 4.04 of the Linux man-pages project. A description of the project, information about reporting bugs, and the latest version of this page, can be found at http://www.kernel.org/doc/man-pages/.
|This manual||Reference||Other manuals|
aio_return(3) | apmd(8) | bdflush(2) | ctrlaltdel(8) | fclose(3) | fflush(3) | File::Sync(3pm) | fsck.minix(8) | fsync(2) | fsync(2freebsd) | guestfish(1) | guestfs(3) | lmdd(8) | loadmeter(1) | mke2fs(8) | mmap(2freebsd) | mount(2) | mount(8) | nbdkit-perl-plugin(3) | nbdkit-python-plugin(3)
|refer to||bdflush(2) | feature_test_macros(7) | fsync(2) | sync(1)|