seaweedfs/weed/mount/weedfs_file_sync.go

package mount

import (
	"github.com/hanwen/go-fuse/v2/fuse"
)

/**
 * Flush method
 *
 * This is called on each close() of the opened file.
 *
 * Since file descriptors can be duplicated (dup, dup2, fork), for
 * one open call there may be many flush calls.
 *
 * Filesystems shouldn't assume that flush will always be called
 * after some writes, or that if will be called at all.
 *
 * fi->fh will contain the value set by the open method, or will
 * be undefined if the open method didn't set any value.
 *
 * NOTE: the name of the method is misleading, since (unlike
 * fsync) the filesystem is not forced to flush pending writes.
 * One reason to flush data is if the filesystem wants to return
 * write errors during close.  However, such use is non-portable
 * because POSIX does not require [close] to wait for delayed I/O to
 * complete.
 *
 * If the filesystem supports file locking operations (setlk,
 * getlk) it should remove all locks belonging to 'fi->owner'.
 *
 * If this request is answered with an error code of ENOSYS,
 * this is treated as success and future calls to flush() will
 * succeed automatically without being send to the filesystem
 * process.
 *
 * Valid replies:
 *   fuse_reply_err
 *
 * @param req request handle
 * @param ino the inode number
 * @param fi file information
 *
 * [close]: http://pubs.opengroup.org/onlinepubs/9699919799/functions/close.html
 */
func (wfs *WFS) Flush(cancel <-chan struct{}, in *fuse.FlushIn) fuse.Status {
	return fuse.ENOSYS
}

/**
 * Synchronize file contents
 *
 * If the datasync parameter is non-zero, then only the user data
 * should be flushed, not the meta data.
 *
 * If this request is answered with an error code of ENOSYS,
 * this is treated as success and future calls to fsync() will
 * succeed automatically without being send to the filesystem
 * process.
 *
 * Valid replies:
 *   fuse_reply_err
 *
 * @param req request handle
 * @param ino the inode number
 * @param datasync flag indicating if only data should be flushed
 * @param fi file information
 */
func (wfs *WFS) Fsync(cancel <-chan struct{}, in *fuse.FsyncIn) (code fuse.Status) {
	return fuse.ENOSYS
}