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lofs_vnops.c
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lofs_vnops.c
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/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2008 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/*
* Copyright 2011 Joyent, Inc.
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/errno.h>
#include <sys/vnode.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/uio.h>
#include <sys/cred.h>
#include <sys/pathname.h>
#include <sys/debug.h>
#include <sys/cmn_err.h>
#include <sys/fs/lofs_node.h>
#include <sys/fs/lofs_info.h>
#include <fs/fs_subr.h>
#include <vm/as.h>
#include <vm/seg.h>
static int lowervn(vnode_t *, cred_t *, vnode_t **);
static pathname_t *relpn(pathname_t *, vnode_t *);
/*
* These are the vnode ops routines which implement the vnode interface to
* the looped-back file system. These routines just take their parameters,
* and then calling the appropriate real vnode routine(s) to do the work.
*/
static int
lo_open(vnode_t **vpp, int flag, struct cred *cr, caller_context_t *ct)
{
vnode_t *vp = *vpp;
vnode_t *rvp;
vnode_t *oldvp;
int error;
#ifdef LODEBUG
lo_dprint(4, "lo_open vp %p cnt=%d realvp %p cnt=%d\n",
vp, vp->v_count, realvp(vp), realvp(vp)->v_count);
#endif
oldvp = vp;
vp = rvp = realvp(vp);
/*
* Need to hold new reference to vp since VOP_OPEN() may
* decide to release it.
*/
VN_HOLD(vp);
error = VOP_OPEN(&rvp, flag, cr, ct);
if (!error && rvp != vp) {
/*
* the FS which we called should have released the
* new reference on vp
*/
*vpp = makelonode(rvp, vtoli(oldvp->v_vfsp), 0);
if ((*vpp)->v_type == VDIR) {
/*
* Copy over any looping flags to the new lnode.
*/
(vtol(*vpp))->lo_looping |= (vtol(oldvp))->lo_looping;
}
if (IS_DEVVP(*vpp)) {
vnode_t *svp;
svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
VN_RELE(*vpp);
if (svp == NULL)
error = ENOSYS;
else
*vpp = svp;
}
VN_RELE(oldvp);
} else {
ASSERT(rvp->v_count > 1);
VN_RELE(rvp);
}
return (error);
}
static int
lo_close(
vnode_t *vp,
int flag,
int count,
offset_t offset,
struct cred *cr,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_close vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_CLOSE(vp, flag, count, offset, cr, ct));
}
static int
lo_read(vnode_t *vp, struct uio *uiop, int ioflag, struct cred *cr,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_read vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_READ(vp, uiop, ioflag, cr, ct));
}
static int
lo_write(vnode_t *vp, struct uio *uiop, int ioflag, struct cred *cr,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_write vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_WRITE(vp, uiop, ioflag, cr, ct));
}
static int
lo_ioctl(
vnode_t *vp,
int cmd,
intptr_t arg,
int flag,
struct cred *cr,
int *rvalp,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_ioctl vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_IOCTL(vp, cmd, arg, flag, cr, rvalp, ct));
}
static int
lo_setfl(vnode_t *vp, int oflags, int nflags, cred_t *cr, caller_context_t *ct)
{
vp = realvp(vp);
return (VOP_SETFL(vp, oflags, nflags, cr, ct));
}
static int
lo_getattr(
vnode_t *vp,
struct vattr *vap,
int flags,
struct cred *cr,
caller_context_t *ct)
{
int error;
#ifdef LODEBUG
lo_dprint(4, "lo_getattr vp %p realvp %p\n", vp, realvp(vp));
#endif
if (error = VOP_GETATTR(realvp(vp), vap, flags, cr, ct))
return (error);
return (0);
}
static int
lo_setattr(
vnode_t *vp,
struct vattr *vap,
int flags,
struct cred *cr,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_setattr vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_SETATTR(vp, vap, flags, cr, ct));
}
static int
lo_access(
vnode_t *vp,
int mode,
int flags,
struct cred *cr,
caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_access vp %p realvp %p\n", vp, realvp(vp));
#endif
if (mode & VWRITE) {
if (vp->v_type == VREG && vn_is_readonly(vp))
return (EROFS);
}
vp = realvp(vp);
return (VOP_ACCESS(vp, mode, flags, cr, ct));
}
static int
lo_fsync(vnode_t *vp, int syncflag, struct cred *cr, caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_fsync vp %p realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_FSYNC(vp, syncflag, cr, ct));
}
/*ARGSUSED*/
static void
lo_inactive(vnode_t *vp, struct cred *cr, caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_inactive %p, realvp %p\n", vp, realvp(vp));
#endif
freelonode(vtol(vp));
}
/* ARGSUSED */
static int
lo_fid(vnode_t *vp, struct fid *fidp, caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_fid %p, realvp %p\n", vp, realvp(vp));
#endif
vp = realvp(vp);
return (VOP_FID(vp, fidp, ct));
}
/*
* Given a vnode of lofs type, lookup nm name and
* return a shadow vnode (of lofs type) of the
* real vnode found.
*
* Due to the nature of lofs, there is a potential
* looping in path traversal.
*
* starting from the mount point of an lofs;
* a loop is defined to be a traversal path
* where the mount point or the real vnode of
* the root of this lofs is encountered twice.
* Once at the start of traversal and second
* when the looping is found.
*
* When a loop is encountered, a shadow of the
* covered vnode is returned to stop the looping.
*
* This normally works, but with the advent of
* the new automounter, returning the shadow of the
* covered vnode (autonode, in this case) does not
* stop the loop. Because further lookup on this
* lonode will cause the autonode to call lo_lookup()
* on the lonode covering it.
*
* example "/net/jurassic/net/jurassic" is a loop.
* returning the shadow of the autonode corresponding to
* "/net/jurassic/net/jurassic" will not terminate the
* loop. To solve this problem we allow the loop to go
* through one more level component lookup. Whichever
* directory is then looked up in "/net/jurassic/net/jurassic"
* the vnode returned is the vnode covered by the autonode
* "net" and this will terminate the loop.
*
* Lookup for dot dot has to be dealt with separately.
* It will be nice to have a "one size fits all" kind
* of solution, so that we don't have so many ifs statement
* in the lo_lookup() to handle dotdot. But, since
* there are so many special cases to handle different
* kinds looping above, we need special codes to handle
* dotdot lookup as well.
*/
static int
lo_lookup(
vnode_t *dvp,
char *nm,
vnode_t **vpp,
struct pathname *pnp,
int flags,
vnode_t *rdir,
struct cred *cr,
caller_context_t *ct,
int *direntflags,
pathname_t *realpnp)
{
vnode_t *vp = NULL, *tvp = NULL, *nonlovp;
int error, is_indirectloop;
vnode_t *realdvp = realvp(dvp);
struct loinfo *li = vtoli(dvp->v_vfsp);
int looping = 0;
int autoloop = 0;
int doingdotdot = 0;
int nosub = 0;
int mkflag = 0;
/*
* If name is empty and no XATTR flags are set, then return
* dvp (empty name == lookup "."). If an XATTR flag is set
* then we need to call VOP_LOOKUP to get the xattr dir.
*/
if (nm[0] == '\0' && ! (flags & (CREATE_XATTR_DIR|LOOKUP_XATTR))) {
VN_HOLD(dvp);
*vpp = dvp;
return (0);
}
if (nm[0] == '.' && nm[1] == '.' && nm[2] == '\0') {
doingdotdot++;
/*
* Handle ".." out of mounted filesystem
*/
while ((realdvp->v_flag & VROOT) && realdvp != rootdir) {
realdvp = realdvp->v_vfsp->vfs_vnodecovered;
ASSERT(realdvp != NULL);
}
}
*vpp = NULL; /* default(error) case */
/*
* Do the normal lookup
*/
if (error = VOP_LOOKUP(realdvp, nm, &vp, pnp, flags, rdir, cr,
ct, direntflags, realpnp)) {
if (vfs_optionisset(dvp->v_vfsp, MNTOPT_LOFS_UNION, NULL)) {
vnode_t *lvp;
/* XXX: Are we crapping on the better error here? */
if ((error = lowervn(dvp, cr, &lvp) != 0)) {
vp = NULL;
goto out;
}
error = VOP_LOOKUP(lvp, nm, &vp, pnp,
flags, rdir, cr, ct, direntflags, realpnp);
VN_RELE(lvp);
if (error) {
vp = NULL;
goto out;
}
/*
* XXX: I think we should: realdvp = lvp here
*
* I don't follow all the implications in the loop
* detection, below, and I'm not sure what we'd need
* to do with lvp's reference count, but I think
* realdvp being lvp is necessary for the rest of this
* to continue to do the right things with loops.
*/
} else {
vp = NULL;
goto out;
}
}
/*
* We do this check here to avoid returning a stale file handle to the
* caller.
*/
if (nm[0] == '.' && nm[1] == '\0') {
ASSERT(vp == realdvp);
VN_HOLD(dvp);
VN_RELE(vp);
*vpp = dvp;
return (0);
}
if (doingdotdot) {
if ((vtol(dvp))->lo_looping & LO_LOOPING) {
vfs_t *vfsp;
error = vn_vfsrlock_wait(realdvp);
if (error)
goto out;
vfsp = vn_mountedvfs(realdvp);
/*
* In the standard case if the looping flag is set and
* performing dotdot we would be returning from a
* covered vnode, implying vfsp could not be null. The
* exceptions being if we have looping and overlay
* mounts or looping and covered file systems.
*/
if (vfsp == NULL) {
/*
* Overlay mount or covered file system,
* so just make the shadow node.
*/
vn_vfsunlock(realdvp);
*vpp = makelonode(vp, li, 0);
(vtol(*vpp))->lo_looping |= LO_LOOPING;
return (0);
}
/*
* When looping get the actual found vnode
* instead of the vnode covered.
* Here we have to hold the lock for realdvp
* since an unmount during the traversal to the
* root vnode would turn *vfsp into garbage
* which would be fatal.
*/
error = VFS_ROOT(vfsp, &tvp);
vn_vfsunlock(realdvp);
if (error)
goto out;
if ((tvp == li->li_rootvp) && (vp == realvp(tvp))) {
/*
* we're back at the real vnode
* of the rootvp
*
* return the rootvp
* Ex: /mnt/mnt/..
* where / has been lofs-mounted
* onto /mnt. Return the lofs
* node mounted at /mnt.
*/
*vpp = tvp;
VN_RELE(vp);
return (0);
} else {
/*
* We are returning from a covered
* node whose vfs_mountedhere is
* not pointing to vfs of the current
* root vnode.
* This is a condn where in we
* returned a covered node say Zc
* but Zc is not the cover of current
* root.
* i.e.., if X is the root vnode
* lookup(Zc,"..") is taking us to
* X.
* Ex: /net/X/net/X/Y
*
* If LO_AUTOLOOP (autofs/lofs looping detected)
* has been set then we are encountering the
* cover of Y (Y being any directory vnode
* under /net/X/net/X/).
* When performing a dotdot set the
* returned vp to the vnode covered
* by the mounted lofs, ie /net/X/net/X
*/
VN_RELE(tvp);
if ((vtol(dvp))->lo_looping & LO_AUTOLOOP) {
VN_RELE(vp);
vp = li->li_rootvp;
vp = vp->v_vfsp->vfs_vnodecovered;
VN_HOLD(vp);
*vpp = makelonode(vp, li, 0);
(vtol(*vpp))->lo_looping |= LO_LOOPING;
return (0);
}
}
} else {
/*
* No frills just make the shadow node.
*/
*vpp = makelonode(vp, li, 0);
return (0);
}
}
nosub = (vtoli(dvp->v_vfsp)->li_flag & LO_NOSUB);
/*
* If this vnode is mounted on, then we
* traverse to the vnode which is the root of
* the mounted file system.
*/
if (!nosub && (error = traverse(&vp)))
goto out;
/*
* Make a lnode for the real vnode.
*/
if (vp->v_type != VDIR || nosub) {
*vpp = makelonode(vp, li, 0);
if (IS_DEVVP(*vpp)) {
vnode_t *svp;
svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
VN_RELE(*vpp);
if (svp == NULL)
error = ENOSYS;
else
*vpp = svp;
}
return (error);
}
/*
* if the found vnode (vp) is not of type lofs
* then we're just going to make a shadow of that
* vp and get out.
*
* If the found vnode (vp) is of lofs type, and
* we're not doing dotdot, check if we are
* looping.
*/
if (!doingdotdot && vfs_matchops(vp->v_vfsp, lo_vfsops)) {
/*
* Check if we're looping, i.e.
* vp equals the root vp of the lofs, directly
* or indirectly, return the covered node.
*/
if (!((vtol(dvp))->lo_looping & LO_LOOPING)) {
if (vp == li->li_rootvp) {
/*
* Direct looping condn.
* Ex:- X is / mounted directory so lookup of
* /X/X is a direct looping condn.
*/
tvp = vp;
vp = vp->v_vfsp->vfs_vnodecovered;
VN_HOLD(vp);
VN_RELE(tvp);
looping++;
} else {
/*
* Indirect looping can be defined as
* real lookup returning rootvp of the current
* tree in any level of recursion.
*
* This check is useful if there are multiple
* levels of lofs indirections. Suppose vnode X
* in the current lookup has as its real vnode
* another lofs node. Y = realvp(X) Y should be
* a lofs node for the check to continue or Y
* is not the rootvp of X.
* Ex:- say X and Y are two vnodes
* say real(Y) is X and real(X) is Z
* parent vnode for X and Y is Z
* lookup(Y,"path") say we are looking for Y
* again under Y and we have to return Yc.
* but the lookup of Y under Y doesnot return
* Y the root vnode again here is why.
* 1. lookup(Y,"path of Y") will go to
* 2. lookup(real(Y),"path of Y") and then to
* 3. lookup(real(X),"path of Y").
* and now what lookup level 1 sees is the
* outcome of 2 but the vnode Y is due to
* lookup(Z,"path of Y") so we have to skip
* intermediate levels to find if in any level
* there is a looping.
*/
is_indirectloop = 0;
nonlovp = vp;
while (
vfs_matchops(nonlovp->v_vfsp, lo_vfsops) &&
!(is_indirectloop)) {
if (li->li_rootvp == nonlovp) {
is_indirectloop++;
break;
}
nonlovp = realvp(nonlovp);
}
if (is_indirectloop) {
VN_RELE(vp);
vp = nonlovp;
vp = vp->v_vfsp->vfs_vnodecovered;
VN_HOLD(vp);
looping++;
}
}
} else {
/*
* come here only because of the interaction between
* the autofs and lofs.
*
* Lookup of "/net/X/net/X" will return a shadow of
* an autonode X_a which we call X_l.
*
* Lookup of anything under X_l, will trigger a call to
* auto_lookup(X_a,nm) which will eventually call
* lo_lookup(X_lr,nm) where X_lr is the root vnode of
* the current lofs.
*
* We come here only when we are called with X_l as dvp
* and look for something underneath.
*
* Now that an autofs/lofs looping condition has been
* identified any directory vnode contained within
* dvp will be set to the vnode covered by the
* mounted autofs. Thus all directories within dvp
* will appear empty hence teminating the looping.
* The LO_AUTOLOOP flag is set on the returned lonode
* to indicate the termination of the autofs/lofs
* looping. This is required for the correct behaviour
* when performing a dotdot.
*/
realdvp = realvp(dvp);
while (vfs_matchops(realdvp->v_vfsp, lo_vfsops)) {
realdvp = realvp(realdvp);
}
error = VFS_ROOT(realdvp->v_vfsp, &tvp);
if (error)
goto out;
/*
* tvp now contains the rootvp of the vfs of the
* real vnode of dvp. The directory vnode vp is set
* to the covered vnode to terminate looping. No
* distinction is made between any vp as all directory
* vnodes contained in dvp are returned as the covered
* vnode.
*/
VN_RELE(vp);
vp = tvp; /* possibly is an autonode */
/*
* Need to find the covered vnode
*/
if (vp->v_vfsp->vfs_vnodecovered == NULL) {
/*
* We don't have a covered vnode so this isn't
* an autonode. To find the autonode simply
* find the vnode covered by the lofs rootvp.
*/
vp = li->li_rootvp;
vp = vp->v_vfsp->vfs_vnodecovered;
VN_RELE(tvp);
error = VFS_ROOT(vp->v_vfsp, &tvp);
if (error)
goto out;
vp = tvp; /* now this is an autonode */
if (vp->v_vfsp->vfs_vnodecovered == NULL) {
/*
* Still can't find a covered vnode.
* Fail the lookup, or we'd loop.
*/
error = ENOENT;
goto out;
}
}
vp = vp->v_vfsp->vfs_vnodecovered;
VN_HOLD(vp);
VN_RELE(tvp);
/*
* Force the creation of a new lnode even if the hash
* table contains a lnode that references this vnode.
*/
mkflag = LOF_FORCE;
autoloop++;
}
}
*vpp = makelonode(vp, li, mkflag);
if ((looping) ||
(((vtol(dvp))->lo_looping & LO_LOOPING) && !doingdotdot)) {
(vtol(*vpp))->lo_looping |= LO_LOOPING;
}
if (autoloop) {
(vtol(*vpp))->lo_looping |= LO_AUTOLOOP;
}
out:
if (error != 0 && vp != NULL)
VN_RELE(vp);
#ifdef LODEBUG
lo_dprint(4,
"lo_lookup dvp %x realdvp %x nm '%s' newvp %x real vp %x error %d\n",
dvp, realvp(dvp), nm, *vpp, vp, error);
#endif
return (error);
}
/*ARGSUSED*/
static int
lo_create(
vnode_t *dvp,
char *nm,
struct vattr *va,
enum vcexcl exclusive,
int mode,
vnode_t **vpp,
struct cred *cr,
int flag,
caller_context_t *ct,
vsecattr_t *vsecp)
{
int error;
vnode_t *vp = NULL;
#ifdef LODEBUG
lo_dprint(4, "lo_create vp %p realvp %p\n", dvp, realvp(dvp));
#endif
if (*nm == '\0') {
ASSERT(vpp && dvp == *vpp);
vp = realvp(*vpp);
}
error = VOP_CREATE(realvp(dvp), nm, va, exclusive, mode, &vp, cr, flag,
ct, vsecp);
if (!error) {
*vpp = makelonode(vp, vtoli(dvp->v_vfsp), 0);
if (IS_DEVVP(*vpp)) {
vnode_t *svp;
svp = specvp(*vpp, (*vpp)->v_rdev, (*vpp)->v_type, cr);
VN_RELE(*vpp);
if (svp == NULL)
error = ENOSYS;
else
*vpp = svp;
}
}
return (error);
}
static int
lo_remove(
vnode_t *dvp,
char *nm,
struct cred *cr,
caller_context_t *ct,
int flags)
{
#ifdef LODEBUG
lo_dprint(4, "lo_remove vp %p realvp %p\n", dvp, realvp(dvp));
#endif
dvp = realvp(dvp);
return (VOP_REMOVE(dvp, nm, cr, ct, flags));
}
static int
lo_link(
vnode_t *tdvp,
vnode_t *vp,
char *tnm,
struct cred *cr,
caller_context_t *ct,
int flags)
{
vnode_t *realvp;
#ifdef LODEBUG
lo_dprint(4, "lo_link vp %p realvp %p\n", vp, realvp(vp));
#endif
/*
* The source and destination vnodes may be in different lofs
* filesystems sharing the same underlying filesystem, so we need to
* make sure that the filesystem containing the source vnode is not
* mounted read-only (vn_link() has already checked the target vnode).
*
* In a situation such as:
*
* /data - regular filesystem
* /foo - lofs mount of /data/foo
* /bar - read-only lofs mount of /data/bar
*
* This disallows a link from /bar/somefile to /foo/somefile,
* which would otherwise allow changes to somefile on the read-only
* mounted /bar.
*/
if (vn_is_readonly(vp)) {
return (EROFS);
}
while (vn_matchops(vp, lo_vnodeops)) {
vp = realvp(vp);
}
/*
* In the case where the source vnode is on another stacking
* filesystem (such as specfs), the loop above will
* terminate before finding the true underlying vnode.
*
* We use VOP_REALVP here to continue the search.
*/
if (VOP_REALVP(vp, &realvp, ct) == 0)
vp = realvp;
while (vn_matchops(tdvp, lo_vnodeops)) {
tdvp = realvp(tdvp);
}
if (vp->v_vfsp != tdvp->v_vfsp)
return (EXDEV);
return (VOP_LINK(tdvp, vp, tnm, cr, ct, flags));
}
static int
lo_rename(
vnode_t *odvp,
char *onm,
vnode_t *ndvp,
char *nnm,
struct cred *cr,
caller_context_t *ct,
int flags)
{
vnode_t *tnvp;
#ifdef LODEBUG
lo_dprint(4, "lo_rename vp %p realvp %p\n", odvp, realvp(odvp));
#endif
/*
* If we are coming from a loop back mounted fs, that has been
* mounted in the same filesystem as where we want to move to,
* and that filesystem is read/write, but the lofs filesystem is
* read only, we don't want to allow a rename of the file. The
* vn_rename code checks to be sure the target is read/write already
* so that is not necessary here. However, consider the following
* example:
* / - regular root fs
* /foo - directory in root
* /foo/bar - file in foo directory(in root fs)
* /baz - directory in root
* mount -F lofs -o ro /foo /baz - all still in root
* directory
* The fact that we mounted /foo on /baz read only should stop us
* from renaming the file /foo/bar /bar, but it doesn't since
* / is read/write. We are still renaming here since we are still
* in the same filesystem, it is just that we do not check to see
* if the filesystem we are coming from in this case is read only.
*/
if (odvp->v_vfsp->vfs_flag & VFS_RDONLY)
return (EROFS);
/*
* We need to make sure we're not trying to remove a mount point for a
* filesystem mounted on top of lofs, which only we know about.
*/
if (vn_matchops(ndvp, lo_vnodeops)) /* Not our problem. */
goto rename;
/*
* XXXci - Once case-insensitive behavior is implemented, it should
* be added here.
*/
if (VOP_LOOKUP(ndvp, nnm, &tnvp, NULL, 0, NULL, cr,
ct, NULL, NULL) != 0)
goto rename;
if (tnvp->v_type != VDIR) {
VN_RELE(tnvp);
goto rename;
}
if (vn_mountedvfs(tnvp)) {
VN_RELE(tnvp);
return (EBUSY);
}
VN_RELE(tnvp);
rename:
/*
* Since the case we're dealing with above can happen at any layer in
* the stack of lofs filesystems, we need to recurse down the stack,
* checking to see if there are any instances of a filesystem mounted on
* top of lofs. In order to keep on using the lofs version of
* VOP_RENAME(), we make sure that while the target directory is of type
* lofs, the source directory (the one used for getting the fs-specific
* version of VOP_RENAME()) is also of type lofs.
*/
if (vn_matchops(ndvp, lo_vnodeops)) {
ndvp = realvp(ndvp); /* Check the next layer */
} else {
/*
* We can go fast here
*/
while (vn_matchops(odvp, lo_vnodeops)) {
odvp = realvp(odvp);
}
if (odvp->v_vfsp != ndvp->v_vfsp)
return (EXDEV);
}
return (VOP_RENAME(odvp, onm, ndvp, nnm, cr, ct, flags));
}
static int
lo_mkdir(
vnode_t *dvp,
char *nm,
struct vattr *va,
vnode_t **vpp,
struct cred *cr,
caller_context_t *ct,
int flags,
vsecattr_t *vsecp)
{
int error;
#ifdef LODEBUG
lo_dprint(4, "lo_mkdir vp %p realvp %p\n", dvp, realvp(dvp));
#endif
error = VOP_MKDIR(realvp(dvp), nm, va, vpp, cr, ct, flags, vsecp);
if (!error)
*vpp = makelonode(*vpp, vtoli(dvp->v_vfsp), 0);
return (error);
}
static int
lo_realvp(vnode_t *vp, vnode_t **vpp, caller_context_t *ct)
{
#ifdef LODEBUG
lo_dprint(4, "lo_realvp %p\n", vp);
#endif
while (vn_matchops(vp, lo_vnodeops))
vp = realvp(vp);
if (VOP_REALVP(vp, vpp, ct) != 0)
*vpp = vp;
return (0);
}
static int
lo_rmdir(
vnode_t *dvp,
char *nm,
vnode_t *cdir,
struct cred *cr,
caller_context_t *ct,
int flags)
{
vnode_t *rvp = cdir;
#ifdef LODEBUG
lo_dprint(4, "lo_rmdir vp %p realvp %p\n", dvp, realvp(dvp));
#endif
/* if cdir is lofs vnode ptr get its real vnode ptr */
if (vn_matchops(dvp, vn_getops(rvp)))
(void) lo_realvp(cdir, &rvp, ct);
dvp = realvp(dvp);
return (VOP_RMDIR(dvp, nm, rvp, cr, ct, flags));
}
static int
lo_symlink(
vnode_t *dvp,
char *lnm,
struct vattr *tva,
char *tnm,
struct cred *cr,
caller_context_t *ct,
int flags)
{
#ifdef LODEBUG
lo_dprint(4, "lo_symlink vp %p realvp %p\n", dvp, realvp(dvp));
#endif
dvp = realvp(dvp);
return (VOP_SYMLINK(dvp, lnm, tva, tnm, cr, ct, flags));
}
static int
lo_readlink(
vnode_t *vp,
struct uio *uiop,
struct cred *cr,
caller_context_t *ct)
{
vp = realvp(vp);
return (VOP_READLINK(vp, uiop, cr, ct));
}
static pathname_t *
relpn(pathname_t *pn, vnode_t *relvp)
{
pathname_t vpn;
pathname_t *ret = NULL;
char pncomp[MAXNAMELEN];
char vncomp[MAXNAMELEN];
if (pn_get(relvp->v_path, UIO_SYSSPACE, &vpn) != 0)
return NULL;
/*
* If the paths match, the relative path from one to the other
* is explicitly ".".
*
* XXX: This feels wrong
*/
if (strcmp(pn->pn_path, relvp->v_path) == 0) {
ret = kmem_zalloc(sizeof (pathname_t), KM_SLEEP);