C++ VP_TO_TMPFS_NODE函数代码示例

int
tmpfs_access(struct vop_access_args *v)
{
	struct vnode *vp = v->a_vp;
	accmode_t accmode = v->a_accmode;
	struct ucred *cred = v->a_cred;

	int error;
	struct tmpfs_node *node;

	MPASS(VOP_ISLOCKED(vp));

	node = VP_TO_TMPFS_NODE(vp);

	switch (vp->v_type) {
	case VDIR:
		/* FALLTHROUGH */
	case VLNK:
		/* FALLTHROUGH */
	case VREG:
		if (accmode & VWRITE && vp->v_mount->mnt_flag & MNT_RDONLY) {
			error = EROFS;
			goto out;
		}
		break;

	case VBLK:
		/* FALLTHROUGH */
	case VCHR:
		/* FALLTHROUGH */
	case VSOCK:
		/* FALLTHROUGH */
	case VFIFO:
		break;

	default:
		error = EINVAL;
		goto out;
	}

	if (accmode & VWRITE && node->tn_flags & IMMUTABLE) {
		error = EPERM;
		goto out;
	}

	error = vaccess(vp->v_type, node->tn_mode, node->tn_uid,
	    node->tn_gid, accmode, cred, NULL);

out:
	MPASS(VOP_ISLOCKED(vp));

	return error;
}

static int
tmpfs_write(struct vop_write_args *v)
{
	struct vnode *vp;
	struct uio *uio;
	struct tmpfs_node *node;
	off_t oldsize;
	int error, ioflag;
	boolean_t extended;

	vp = v->a_vp;
	uio = v->a_uio;
	ioflag = v->a_ioflag;
	error = 0;
	node = VP_TO_TMPFS_NODE(vp);
	oldsize = node->tn_size;

	if (uio->uio_offset < 0 || vp->v_type != VREG)
		return (EINVAL);
	if (uio->uio_resid == 0)
		return (0);
	if (ioflag & IO_APPEND)
		uio->uio_offset = node->tn_size;
	if (uio->uio_offset + uio->uio_resid >
	  VFS_TO_TMPFS(vp->v_mount)->tm_maxfilesize)
		return (EFBIG);
	if (vn_rlimit_fsize(vp, uio, uio->uio_td))
		return (EFBIG);
	extended = uio->uio_offset + uio->uio_resid > node->tn_size;
	if (extended) {
		error = tmpfs_reg_resize(vp, uio->uio_offset + uio->uio_resid,
		    FALSE);
		if (error != 0)
			goto out;
	}

	error = uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio);
	node->tn_status |= TMPFS_NODE_ACCESSED | TMPFS_NODE_MODIFIED |
	    (extended ? TMPFS_NODE_CHANGED : 0);
	if (node->tn_mode & (S_ISUID | S_ISGID)) {
		if (priv_check_cred(v->a_cred, PRIV_VFS_RETAINSUGID, 0))
			node->tn_mode &= ~(S_ISUID | S_ISGID);
	}
	if (error != 0)
		(void)tmpfs_reg_resize(vp, oldsize, TRUE);

out:
	MPASS(IMPLIES(error == 0, uio->uio_resid == 0));
	MPASS(IMPLIES(error != 0, oldsize == node->tn_size));

	return (error);
}

/*
 * Destroys the association between the vnode vp and the node it
 * references.
 */
void
tmpfs_free_vp(struct vnode *vp)
{
	struct tmpfs_node *node;

	node = VP_TO_TMPFS_NODE(vp);

	TMPFS_NODE_LOCK(node);
	KKASSERT(lockinuse(TMPFS_NODE_MTX(node)));
	node->tn_vnode = NULL;
	vp->v_data = NULL;
	TMPFS_NODE_UNLOCK(node);
}

int
tmpfs_spec_close(void *v)
{
	struct vop_close_args /* {
		struct vnode	*a_vp;
		int		a_fflag;
		kauth_cred_t	a_cred;
	} */ *ap = v;
	struct vnode *vp = ap->a_vp;

	tmpfs_update(VP_TO_TMPFS_NODE(vp), NULL);
	return (spec_close(ap));
}

int
tmpfs_setattr(struct vop_setattr_args *v)
{
	struct vnode *vp = v->a_vp;
	struct vattr *vap = v->a_vap;
	struct ucred *cred = v->a_cred;
	struct tmpfs_node *node = VP_TO_TMPFS_NODE(vp);
	int error = 0;
	int kflags = 0;

	if (error == 0 && (vap->va_flags != VNOVAL)) {
		error = tmpfs_chflags(vp, vap->va_flags, cred);
		kflags |= NOTE_ATTRIB;
	}

	if (error == 0 && (vap->va_size != VNOVAL)) {
		if (vap->va_size > node->tn_size)
			kflags |= NOTE_WRITE | NOTE_EXTEND;
		else
			kflags |= NOTE_WRITE;
		error = tmpfs_chsize(vp, vap->va_size, cred);
	}

	if (error == 0 && (vap->va_uid != (uid_t)VNOVAL ||
			   vap->va_gid != (gid_t)VNOVAL)) {
		error = tmpfs_chown(vp, vap->va_uid, vap->va_gid, cred);
		kflags |= NOTE_ATTRIB;
	}

	if (error == 0 && (vap->va_mode != (mode_t)VNOVAL)) {
		error = tmpfs_chmod(vp, vap->va_mode, cred);
		kflags |= NOTE_ATTRIB;
	}

	if (error == 0 && ((vap->va_atime.tv_sec != VNOVAL &&
	    vap->va_atime.tv_nsec != VNOVAL) ||
	    (vap->va_mtime.tv_sec != VNOVAL &&
	    vap->va_mtime.tv_nsec != VNOVAL) )) {
		error = tmpfs_chtimes(vp, &vap->va_atime, &vap->va_mtime,
				      vap->va_vaflags, cred);
		kflags |= NOTE_ATTRIB;
	}

	/* Update the node times.  We give preference to the error codes
	 * generated by this function rather than the ones that may arise
	 * from tmpfs_update. */
	tmpfs_update(vp);
	tmpfs_knote(vp, kflags);

	return error;
}

int
tmpfs_spec_write(void *v)
{
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int a_ioflag;
		kauth_cred_t a_cred;
	} */ *ap = v;
	struct vnode *vp = ap->a_vp;

	tmpfs_update(VP_TO_TMPFS_NODE(vp), TMPFS_NODE_MODIFIED);
	return (spec_write(ap));
}

int
tmpfs_fifo_write(void *v)
{
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int a_ioflag;
		kauth_cred_t a_cred;
	} */ *ap = v;
	vnode_t *vp = ap->a_vp;

	VP_TO_TMPFS_NODE(vp)->tn_status |= TMPFS_NODE_MODIFIED;
	return VOCALL(fifo_vnodeop_p, VOFFSET(vop_write), v);
}

static int
tmpfs_inactive(struct vop_inactive_args *v)
{
	struct vnode *vp;
	struct tmpfs_node *node;

	vp = v->a_vp;
	node = VP_TO_TMPFS_NODE(vp);
	if (node->tn_links == 0)
		vrecycle(vp);
	else
		tmpfs_check_mtime(vp);
	return (0);
}

int
tmpfs_spec_read(void *v)
{
	struct vop_read_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int a_ioflag;
		kauth_cred_t a_cred;
	} */ *ap = v;
	struct vnode *vp = ap->a_vp;

	VP_TO_TMPFS_NODE(vp)->tn_status |= TMPFS_NODE_ACCESSED;
	return (spec_read(ap));
}

int
tmpfs_fifo_write(void *v)
{
	struct vop_write_args /* {
		struct vnode *a_vp;
		struct uio *a_uio;
		int a_ioflag;
		kauth_cred_t a_cred;
	} */ *ap = v;
	struct vnode *vp = ap->a_vp;

	VP_TO_TMPFS_NODE(vp)->tn_status |= TMPFS_NODE_MODIFIED;
	return (fifo_write(v));
}

static int
tmpfs_link(struct vop_link_args *v)
{
	struct vnode *dvp = v->a_tdvp;
	struct vnode *vp = v->a_vp;
	struct componentname *cnp = v->a_cnp;

	int error;
	struct tmpfs_dirent *de;
	struct tmpfs_node *node;

	MPASS(VOP_ISLOCKED(dvp));
	MPASS(cnp->cn_flags & HASBUF);
	MPASS(dvp != vp); /* XXX When can this be false? */
	node = VP_TO_TMPFS_NODE(vp);

	/* Ensure that we do not overflow the maximum number of links imposed
	 * by the system. */
	MPASS(node->tn_links <= LINK_MAX);
	if (node->tn_links == LINK_MAX) {
		error = EMLINK;
		goto out;
	}

	/* We cannot create links of files marked immutable or append-only. */
	if (node->tn_flags & (IMMUTABLE | APPEND)) {
		error = EPERM;
		goto out;
	}

	/* Allocate a new directory entry to represent the node. */
	error = tmpfs_alloc_dirent(VFS_TO_TMPFS(vp->v_mount), node,
	    cnp->cn_nameptr, cnp->cn_namelen, &de);
	if (error != 0)
		goto out;

	/* Insert the new directory entry into the appropriate directory. */
	if (cnp->cn_flags & ISWHITEOUT)
		tmpfs_dir_whiteout_remove(dvp, cnp);
	tmpfs_dir_attach(dvp, de);

	/* vp link count has changed, so update node times. */
	node->tn_status |= TMPFS_NODE_CHANGED;
	tmpfs_update(vp);

	error = 0;

out:
	return error;
}

/*
 * Change size of the given vnode.
 * Caller should execute tmpfs_update on vp after a successful execution.
 * The vnode must be locked on entry and remain locked on exit.
 */
int
tmpfs_chsize(struct vnode *vp, u_quad_t size, struct ucred *cred)
{
	int error;
	struct tmpfs_node *node;

	KKASSERT(vn_islocked(vp));

	node = VP_TO_TMPFS_NODE(vp);

	/* Decide whether this is a valid operation based on the file type. */
	error = 0;
	switch (vp->v_type) {
	case VDIR:
		return EISDIR;

	case VREG:
		if (vp->v_mount->mnt_flag & MNT_RDONLY)
			return EROFS;
		break;

	case VBLK:
		/* FALLTHROUGH */
	case VCHR:
		/* FALLTHROUGH */
	case VFIFO:
		/* Allow modifications of special files even if in the file
		 * system is mounted read-only (we are not modifying the
		 * files themselves, but the objects they represent). */
		return 0;

	default:
		/* Anything else is unsupported. */
		return EOPNOTSUPP;
	}

	/* Immutable or append-only files cannot be modified, either. */
	if (node->tn_flags & (IMMUTABLE | APPEND))
		return EPERM;

	error = tmpfs_truncate(vp, size);
	/* tmpfs_truncate will raise the NOTE_EXTEND and NOTE_ATTRIB kevents
	 * for us, as will update tn_status; no need to do that here. */

	KKASSERT(vn_islocked(vp));

	return error;
}

static int
tmpfs_inactive(struct vop_inactive_args *v)
{
	struct vnode *vp = v->a_vp;

	struct tmpfs_node *node;

	MPASS(VOP_ISLOCKED(vp));

	node = VP_TO_TMPFS_NODE(vp);

	if (node->tn_links == 0)
		vrecycle(vp);

	return 0;
}

/*
 * The strategy function is typically only called when memory pressure
 * forces the system to attempt to pageout pages.  It can also be called
 * by [n]vtruncbuf() when a truncation cuts a page in half.  Normal write
 * operations
 */
static int
tmpfs_strategy(struct vop_strategy_args *ap)
{
	struct bio *bio = ap->a_bio;
	struct bio *nbio;
	struct buf *bp = bio->bio_buf;
	struct vnode *vp = ap->a_vp;
	struct tmpfs_node *node;
	vm_object_t uobj;
	vm_page_t m;
	int i;

	if (vp->v_type != VREG) {
		bp->b_resid = bp->b_bcount;
		bp->b_flags |= B_ERROR | B_INVAL;
		bp->b_error = EINVAL;
		biodone(bio);
		return(0);
	}

	lwkt_gettoken(&vp->v_mount->mnt_token);
	node = VP_TO_TMPFS_NODE(vp);

	uobj = node->tn_reg.tn_aobj;

	/*
	 * Don't bother flushing to swap if there is no swap, just
	 * ensure that the pages are marked as needing a commit (still).
	 */
	if (bp->b_cmd == BUF_CMD_WRITE && vm_swap_size == 0) {
		for (i = 0; i < bp->b_xio.xio_npages; ++i) {
			m = bp->b_xio.xio_pages[i];
			vm_page_need_commit(m);
		}
		bp->b_resid = 0;
		bp->b_error = 0;
		biodone(bio);
	} else {
		nbio = push_bio(bio);
		nbio->bio_done = tmpfs_strategy_done;
		nbio->bio_offset = bio->bio_offset;
		swap_pager_strategy(uobj, nbio);
	}

	lwkt_reltoken(&vp->v_mount->mnt_token);
	return 0;
}

static int
tmpfs_read(struct vop_read_args *v)
{
	struct vnode *vp;
	struct uio *uio;
	struct tmpfs_node *node;

	vp = v->a_vp;
	if (vp->v_type != VREG)
		return (EISDIR);
	uio = v->a_uio;
	if (uio->uio_offset < 0)
		return (EINVAL);
	node = VP_TO_TMPFS_NODE(vp);
	node->tn_status |= TMPFS_NODE_ACCESSED;
	return (uiomove_object(node->tn_reg.tn_aobj, node->tn_size, uio));
}