SYNC(2) - Linux man page online | System calls
Commit filesystem caches to disk.
SYNC(2) Linux Programmer's Manual SYNC(2)
Linux 2017-09-15 SYNC(2)
NAMEsync, syncfs - commit filesystem caches 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(): _XOPEN_SOURCE >= 500 || /* Since glibc 2.19: */ _DEFAULT_SOURCE || /* Glibc versions <= 2.19: */ _BSD_SOURCE syncfs(): _GNU_SOURCE
DESCRIPTIONsync() causes all pending modifications to filesystem metadata and cached file 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. According to the standard specification (e.g., POSIX.1-2001), sync() schedules the writes, but may return before the actual writing is done. However Linux waits for I/O comple‐ tions, and thus sync() or syncfs() provide the same guarantees as fsync called on every file in the system or filesystem respectively.
BUGSBefore version 1.3.20 Linux did not wait for I/O to complete before returning.
SEE ALSOsync(1), fdatasync(2), fsync(2)
COLOPHONThis page is part of release 4.15 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 https://www.kernel.org/doc/man-pages/.
|This manual||Reference||Other manuals|
aio_return(3) | apmd(8) | bdflush(2) | ctrlaltdel(8) | fclose(3) | fdatasync(2freebsd) | 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) | nfs(5)
|refer to||feature_test_macros(7) | fsync(2) | sync(1)|