C++ VOP_ISLOCKED函数代码示例

/*
 * genfs_rename_exit: Unlock everything we locked for rename.
 *
 * fdvp and tdvp must be referenced.
 *
 * On entry, everything is locked, and fvp and tvp referenced.
 *
 * On exit, everything is unlocked, and fvp and tvp are released.
 */
static void
genfs_rename_exit(const struct genfs_rename_ops *ops,
    struct mount *mp,
    struct vnode *fdvp, struct vnode *fvp,
    struct vnode *tdvp, struct vnode *tvp)
{

	(void)ops;
	KASSERT(ops != NULL);
	KASSERT(mp != NULL);
	KASSERT(fdvp != NULL);
	KASSERT(fvp != NULL);
	KASSERT(fdvp != fvp);
	KASSERT(fdvp != tvp);
	KASSERT(tdvp != tvp);
	KASSERT(tdvp != fvp);
	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));

	if ((tvp != NULL) && (tvp != fvp))
		VOP_UNLOCK(tvp);
	VOP_UNLOCK(fvp);
	if (tvp != NULL)
		vrele(tvp);
	if (tdvp != fdvp)
		VOP_UNLOCK(tdvp);
	vrele(fvp);
	VOP_UNLOCK(fdvp);
}

/*
 * udf_gro_remove_check_permitted: check whether a remove is permitted given
 * our credentials.
 */
static int
udf_gro_remove_check_permitted(struct mount *mp, kauth_cred_t cred,
    struct vnode *dvp, struct vnode *vp)
{
	struct udf_node *dir_node = VTOI(dvp);
	struct udf_node *udf_node = VTOI(vp);
	mode_t dmode;
	uid_t duid, uid;
	gid_t gdummy;

	(void)mp;
	KASSERT(mp != NULL);
	KASSERT(dvp != NULL);
	KASSERT(vp != NULL);
	KASSERT(dvp != vp);
	KASSERT(dvp->v_type == VDIR);
	KASSERT(vp->v_type != VDIR);
	KASSERT(dvp->v_mount == mp);
	KASSERT(vp->v_mount == mp);
	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);

	DPRINTF(CALL, ("udf_gro_remove_check_permitted called\n"));
	dmode = udf_getaccessmode(dir_node);

	udf_getownership(dir_node, &duid, &gdummy);
	udf_getownership(udf_node, &uid,  &gdummy);

	return genfs_ufslike_remove_check_permitted(cred,
	    dvp, dmode, duid,
	    vp, uid);
}

/*
 * udf_gro_remove: rename an object over another link to itself, effectively
 * removing just the original link.
 */
static int
udf_gro_remove(struct mount *mp, kauth_cred_t cred,
    struct vnode *dvp, struct componentname *cnp, void *de, struct vnode *vp)
{
	struct udf_node *dir_node, *udf_node;

	KASSERT(mp != NULL);
	KASSERT(dvp != NULL);
	KASSERT(cnp != NULL);
	KASSERT(vp != NULL);
	KASSERT(dvp != vp);
	KASSERT(dvp->v_mount == mp);
	KASSERT(vp->v_mount == mp);
	KASSERT(dvp->v_type == VDIR);
	KASSERT(vp->v_type != VDIR);
	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);

	DPRINTF(CALL, ("udf_gro_remove called\n"));

	dir_node = VTOI(dvp);
	udf_node = VTOI(vp);
	udf_dir_detach(dir_node->ump, dir_node, udf_node, cnp);

	return 0;
}

/*
 * genfs_ufslike_remove_check_permitted: Check whether a remove is
 * permitted given our credentials, assuming UFS-like permission and
 * ownership semantics.
 *
 * Everything must be locked and referenced.
 */
int
genfs_ufslike_remove_check_permitted(kauth_cred_t cred,
    struct vnode *dvp, mode_t dmode, uid_t duid,
    struct vnode *vp, uid_t uid)
{
	int error;

	KASSERT(dvp != NULL);
	KASSERT(vp != NULL);
	KASSERT(dvp != vp);
	KASSERT(dvp->v_type == VDIR);
	KASSERT(vp->v_type != VDIR);
	KASSERT(dvp->v_mount == vp->v_mount);
	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);

	/*
	 * We need to write to the directory to remove from it.
	 */
	error = VOP_ACCESS(dvp, VWRITE, cred);
	if (error)
		return error;

	error = genfs_ufslike_check_sticky(cred, dmode, duid, vp, uid);
	if (error)
		return error;

	return 0;
}

/*
 * udf_gro_rename_check_possible: check whether a rename is possible
 * independent of credentials.
 */
static int
udf_gro_rename_check_possible(struct mount *mp,
    struct vnode *fdvp, struct vnode *fvp,
    struct vnode *tdvp, struct vnode *tvp)
{
	(void)mp;
	KASSERT(mp != NULL);
	KASSERT(fdvp != NULL);
	KASSERT(fvp != NULL);
	KASSERT(tdvp != NULL);
	KASSERT(fdvp != fvp);
	KASSERT(fdvp != tvp);
	KASSERT(tdvp != fvp);
	KASSERT(tdvp != tvp);
	KASSERT(fvp != tvp);
	KASSERT(fdvp->v_type == VDIR);
	KASSERT(tdvp->v_type == VDIR);
	KASSERT(fdvp->v_mount == mp);
	KASSERT(fvp->v_mount == mp);
	KASSERT(tdvp->v_mount == mp);
	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));

	DPRINTF(CALL, ("udf_gro_rename_check_possible called\n"));

	/* flags not implemented since they are not defined (yet) in UDF */
	return 0;
}

/*
 * udf_gro_directory_empty_p: return true if the directory vp is empty. dvp is
 * its parent.
 *
 * vp and dvp must be locked and referenced.
 */
static bool
udf_gro_directory_empty_p(struct mount *mp, kauth_cred_t cred,
    struct vnode *vp, struct vnode *dvp)
{
	struct udf_node *udf_node = VTOI(vp);
	int error, isempty;

	KASSERT(mp != NULL);
	KASSERT(vp != NULL);
	KASSERT(dvp != NULL);
	KASSERT(vp != dvp);
	KASSERT(vp->v_mount == mp);
	KASSERT(dvp->v_mount == mp);
	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(dvp) == LK_EXCLUSIVE);

	DPRINTF(CALL, ("udf_gro_directory_empty_p called\n"));
	/* make sure our `leaf' node's hash is populated */
	dirhash_get(&udf_node->dir_hash);
	error = udf_dirhash_fill(udf_node);
	if (error) {
		dirhash_put(udf_node->dir_hash);
		/* VERY unlikely, answer its not empty */
		return 0;
	}

	/* check to see if the directory is empty */
	isempty = dirhash_dir_isempty(udf_node->dir_hash);
	dirhash_put(udf_node->dir_hash);

	return isempty;
}

/*
 * udf_gro_rename_check_permitted: check whether a rename is permitted given
 * our credentials.
 */
static int
udf_gro_rename_check_permitted(struct mount *mp, kauth_cred_t cred,
    struct vnode *fdvp, struct vnode *fvp,
    struct vnode *tdvp, struct vnode *tvp)
{
	struct udf_node *fdir_node = VTOI(fdvp);
	struct udf_node *tdir_node = VTOI(tdvp);
	struct udf_node *f_node = VTOI(fvp);
	struct udf_node *t_node = (tvp? VTOI(tvp): NULL);
	mode_t fdmode, tdmode;
	uid_t fduid, tduid, fuid, tuid;
	gid_t gdummy;

	(void)mp;
	KASSERT(mp != NULL);
	KASSERT(fdvp != NULL);
	KASSERT(fvp != NULL);
	KASSERT(tdvp != NULL);
	KASSERT(fdvp != fvp);
	KASSERT(fdvp != tvp);
	KASSERT(tdvp != fvp);
	KASSERT(tdvp != tvp);
	KASSERT(fvp != tvp);
	KASSERT(fdvp->v_type == VDIR);
	KASSERT(tdvp->v_type == VDIR);
	KASSERT(fdvp->v_mount == mp);
	KASSERT(fvp->v_mount == mp);
	KASSERT(tdvp->v_mount == mp);
	KASSERT((tvp == NULL) || (tvp->v_mount == mp));
	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));

	DPRINTF(CALL, ("udf_gro_rename_check_permitted called\n"));
	fdmode = udf_getaccessmode(fdir_node);
	tdmode = udf_getaccessmode(tdir_node);

	udf_getownership(fdir_node, &fduid, &gdummy);
	udf_getownership(tdir_node, &tduid, &gdummy);
	udf_getownership(f_node,    &fuid, &gdummy);

	tuid = 0;
	if (t_node)
		udf_getownership(t_node, &tuid, &gdummy);

	return genfs_ufslike_rename_check_permitted(cred,
	    fdvp, fdmode, fduid,
	    fvp,  fuid,
	    tdvp, tdmode, tduid,
	    tvp,  tuid);
}

int
adosfs_access(void *v)
{
	struct vop_access_args /* {
		struct vnode *a_vp;
		int  a_mode;
		kauth_cred_t a_cred;
	} */ *sp = v;
	struct anode *ap;
	struct vnode *vp = sp->a_vp;
	int error;

#ifdef ADOSFS_DIAGNOSTIC
	advopprint(sp);
#endif

	ap = VTOA(vp);
#ifdef DIAGNOSTIC
	if (!VOP_ISLOCKED(vp)) {
		vprint("adosfs_access: not locked", sp->a_vp);
		panic("adosfs_access: not locked");
	}
#endif

	error = adosfs_check_possible(vp, ap, sp->a_mode);
	if (error)
		return error;

	error = adosfs_check_permitted(vp, ap, sp->a_mode, sp->a_cred);

#ifdef ADOSFS_DIAGNOSTIC
	printf(" %d)", error);
#endif
	return(error);
}

/*
 * genfs_rename_knote: Note events about the various vnodes in a
 * rename.  To be called by gro_rename on success.  The only pair of
 * vnodes that may be identical is {fdvp, tdvp}.  deleted_p is true iff
 * the rename overwrote the last link to tvp.
 */
void
genfs_rename_knote(struct vnode *fdvp, struct vnode *fvp,
    struct vnode *tdvp, struct vnode *tvp, bool deleted_p)
{
	long fdvp_events, tdvp_events;
	bool directory_p, reparent_p, replaced_p;

	KASSERT(fdvp != NULL);
	KASSERT(fvp != NULL);
	KASSERT(tdvp != NULL);
	KASSERT(fdvp != fvp);
	KASSERT(fdvp != tvp);
	KASSERT(tdvp != fvp);
	KASSERT(tdvp != tvp);
	KASSERT(fvp != tvp);
	KASSERT(VOP_ISLOCKED(fdvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(fvp) == LK_EXCLUSIVE);
	KASSERT(VOP_ISLOCKED(tdvp) == LK_EXCLUSIVE);
	KASSERT((tvp == NULL) || (VOP_ISLOCKED(tvp) == LK_EXCLUSIVE));

	directory_p = (fvp->v_type == VDIR);
	reparent_p = (fdvp != tdvp);
	replaced_p = (tvp != NULL);

	KASSERT((tvp == NULL) || (directory_p == (tvp->v_type == VDIR)));
	KASSERT(!deleted_p || replaced_p);

	fdvp_events = NOTE_WRITE;
	if (directory_p && reparent_p)
		fdvp_events |= NOTE_LINK;
	VN_KNOTE(fdvp, fdvp_events);

	VN_KNOTE(fvp, NOTE_RENAME);

	if (reparent_p) {
		tdvp_events = NOTE_WRITE;
		if (!replaced_p) {
			tdvp_events |= NOTE_EXTEND;
			if (directory_p)
				tdvp_events |= NOTE_LINK;
		}
		VN_KNOTE(tdvp, tdvp_events);
	}

	if (replaced_p)
		VN_KNOTE(tvp, (deleted_p? NOTE_DELETE : NOTE_LINK));
}

int VOP_RMDIR(struct vnode *dvp, struct vnode *vp, struct componentname *cnp)
{
	struct vop_rmdir_args a;
	a.a_desc = VDESC(vop_rmdir);
	a.a_dvp = dvp;
#ifdef VFSDEBUG
	if ((dvp->v_flag & VLOCKSWORK) && !VOP_ISLOCKED(dvp))
		panic("vop_rmdir: dvp");
#endif
	a.a_vp = vp;
#ifdef VFSDEBUG
	if ((vp->v_flag & VLOCKSWORK) && !VOP_ISLOCKED(vp))
		panic("vop_rmdir: vp");
#endif
	a.a_cnp = cnp;
	return (VCALL(dvp, VOFFSET(vop_rmdir), &a));
}

/*
 * genfs_rename_enter: Look up fcnp in fdvp, and store the lookup
 * results in *fde_ret and the associated vnode in *fvp_ret; fail if
 * not found.  Look up tcnp in tdvp, and store the lookup results in
 * *tde_ret and the associated vnode in *tvp_ret; store null instead if
 * not found.  Fail if anything has been mounted on any of the nodes
 * involved.
 *
 * fdvp and tdvp must be referenced.
 *
 * On entry, nothing is locked.
 *
 * On success, everything is locked, and *fvp_ret, and *tvp_ret if
 * nonnull, are referenced.  The only pairs of vnodes that may be
 * identical are {fdvp, tdvp} and {fvp, tvp}.
 *
 * On failure, everything remains as was.
 *
 * Locking everything including the source and target nodes is
 * necessary to make sure that, e.g., link count updates are OK.  The
 * locking order is, in general, ancestor-first, matching the order you
 * need to use to look up a descendant anyway.
 */
static int
genfs_rename_enter(const struct genfs_rename_ops *ops,
    struct mount *mp, kauth_cred_t cred,
    struct vnode *fdvp, struct componentname *fcnp,
    void *fde_ret, struct vnode **fvp_ret,
    struct vnode *tdvp, struct componentname *tcnp,
    void *tde_ret, struct vnode **tvp_ret)
{
	int error;

	KASSERT(mp != NULL);
	KASSERT(fdvp != NULL);
	KASSERT(fcnp != NULL);
	KASSERT(fvp_ret != NULL);
	KASSERT(tdvp != NULL);
	KASSERT(tcnp != NULL);
	KASSERT(tvp_ret != NULL);
	KASSERT(fvp_ret != tvp_ret);
	KASSERT(fdvp->v_type == VDIR);
	KASSERT(tdvp->v_type == VDIR);
	KASSERT(fdvp->v_mount == mp);
	KASSERT(tdvp->v_mount == mp);

	if (fdvp == tdvp)
		error = genfs_rename_enter_common(ops, mp, cred, fdvp,
		    fcnp, fde_ret, fvp_ret,
		    tcnp, tde_ret, tvp_ret);
	else
		error = genfs_rename_enter_separate(ops, mp, cred,
		    fdvp, fcnp, fde_ret, fvp_ret,
		    tdvp, tcnp, tde_ret, tvp_ret);

	if (error)
		return error;

	KASSERT(*fvp_ret != NULL);
	KASSERT(VOP_ISLOCKED(*fvp_ret) == LK_EXCLUSIVE);
	KASSERT((*tvp_ret == NULL) || (VOP_ISLOCKED(*tvp_ret) == LK_EXCLUSIVE));
	KASSERT(*fvp_ret != fdvp);
	KASSERT(*fvp_ret != tdvp);
	KASSERT(*tvp_ret != fdvp);
	KASSERT(*tvp_ret != tdvp);
	return 0;
}

/*
 * udf_rmdired_p: check whether the directory vp has been rmdired.
 *
 * vp must be locked and referenced.
 */
static bool
udf_rmdired_p(struct vnode *vp)
{
	DPRINTF(CALL, ("udf_rmdired_p called\n"));

	KASSERT(vp != NULL);
	KASSERT(VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
	KASSERT(vp->v_type == VDIR);

	return (VTOI(vp)->i_flags & IN_DELETED);
}

int
RUMP_VOP_ISLOCKED(struct vnode *vp)
{
	int error;

	rump_schedule();
	error = VOP_ISLOCKED(vp);
	rump_unschedule();

	return error;
}

int
ulfs_bufio(enum uio_rw rw, struct vnode *vp, void *buf, size_t len, off_t off,
    int ioflg, kauth_cred_t cred, size_t *aresid, struct lwp *l)
{
	struct iovec iov;
	struct uio uio;
	int error;

	KASSERT(ISSET(ioflg, IO_NODELOCKED));
	KASSERT(VOP_ISLOCKED(vp));
	KASSERT(rw != UIO_WRITE || VOP_ISLOCKED(vp) == LK_EXCLUSIVE);

	iov.iov_base = buf;
	iov.iov_len = len;
	uio.uio_iov = &iov;
	uio.uio_iovcnt = 1;
	uio.uio_resid = len;
	uio.uio_offset = off;
	uio.uio_rw = rw;
	UIO_SETUP_SYSSPACE(&uio);

	switch (rw) {
	case UIO_READ:
		error = lfs_bufrd(vp, &uio, ioflg, cred);
		break;
	case UIO_WRITE:
		error = lfs_bufwr(vp, &uio, ioflg, cred);
		break;
	default:
		panic("invalid uio rw: %d", (int)rw);
	}

	if (aresid)
		*aresid = uio.uio_resid;
	else if (uio.uio_resid && error == 0)
		error = EIO;

	KASSERT(VOP_ISLOCKED(vp));
	KASSERT(rw != UIO_WRITE || VOP_ISLOCKED(vp) == LK_EXCLUSIVE);
	return error;
}