vfs_sync
if (vfsops->vfs_sync == NULL) {
vfsops->vfs_sync = vfs_stdnosync;
error = (mp->mnt_op->vfs_sync)(mp, waitfor);
int vfs_sync(struct mount *mp, int waitfor);
vfs_sync_t *vfs_sync;
vfs_sync(MP, WAIT)
.vfs_sync = ext2_sync,
.vfs_sync = fuse_sync,
.vfs_sync = hammer_vfs_sync,
.vfs_sync = hammer2_vfs_sync,
.vfs_sync = ffs_sync,
.vfs_sync = msdosfs_sync,
.vfs_sync = nfs_sync,
.vfs_sync = smbfs_sync,
.vfs_sync = ffs_sync,