/*
* Free reference to unionfs layer
*/
static int
unionfs_unmount(struct mount *mp, int mntflags)
{
struct unionfs_mount *ump;
int error;
int num;
int freeing;
int flags;
UNIONFSDEBUG("unionfs_unmount: mp = %p\n", (void *)mp);
ump = MOUNTTOUNIONFSMOUNT(mp);
flags = 0;
if (mntflags & MNT_FORCE)
flags |= FORCECLOSE;
/* vflush (no need to call vrele) */
for (freeing = 0; (error = vflush(mp, 1, flags, curthread)) != 0;) {
num = mp->mnt_nvnodelistsize;
if (num == freeing)
break;
freeing = num;
}
if (error)
return (error);
free(ump, M_UNIONFSMNT);
mp->mnt_data = 0;
return (0);
}
static int
unionfs_statfs(struct mount *mp, struct statfs *sbp)
{
struct unionfs_mount *ump;
int error;
struct statfs *mstat;
uint64_t lbsize;
ump = MOUNTTOUNIONFSMOUNT(mp);
UNIONFSDEBUG("unionfs_statfs(mp = %p, lvp = %p, uvp = %p)\n",
(void *)mp, (void *)ump->um_lowervp, (void *)ump->um_uppervp);
mstat = malloc(sizeof(struct statfs), M_STATFS, M_WAITOK | M_ZERO);
error = VFS_STATFS(ump->um_lowervp->v_mount, mstat);
if (error) {
free(mstat, M_STATFS);
return (error);
}
/* now copy across the "interesting" information and fake the rest */
sbp->f_blocks = mstat->f_blocks;
sbp->f_files = mstat->f_files;
lbsize = mstat->f_bsize;
error = VFS_STATFS(ump->um_uppervp->v_mount, mstat);
if (error) {
free(mstat, M_STATFS);
return (error);
}
/*
* The FS type etc is copy from upper vfs.
* (write able vfs have priority)
*/
sbp->f_type = mstat->f_type;
sbp->f_flags = mstat->f_flags;
sbp->f_bsize = mstat->f_bsize;
sbp->f_iosize = mstat->f_iosize;
if (mstat->f_bsize != lbsize)
sbp->f_blocks = ((off_t)sbp->f_blocks * lbsize) /
mstat->f_bsize;
sbp->f_blocks += mstat->f_blocks;
sbp->f_bfree = mstat->f_bfree;
sbp->f_bavail = mstat->f_bavail;
sbp->f_files += mstat->f_files;
sbp->f_ffree = mstat->f_ffree;
free(mstat, M_STATFS);
return (0);
}
static int
unionfs_root(struct mount *mp, int flags, struct vnode **vpp)
{
struct unionfs_mount *ump;
struct vnode *vp;
ump = MOUNTTOUNIONFSMOUNT(mp);
vp = ump->um_rootvp;
UNIONFSDEBUG("unionfs_root: rootvp=%p locked=%x\n",
vp, VOP_ISLOCKED(vp));
vref(vp);
if (flags & LK_TYPE_MASK)
vn_lock(vp, flags);
*vpp = vp;
return (0);
}
static int
unionfs_lookup(void *v)
{
struct vop_lookup_args *ap = v;
int iswhiteout;
int lockflag;
int error , uerror, lerror;
u_long nameiop;
u_long cnflags, cnflagsbk;
struct unionfs_node *dunp;
struct vnode *dvp, *udvp, *ldvp, *vp, *uvp, *lvp, *dtmpvp;
struct vattr va;
struct componentname *cnp;
iswhiteout = 0;
lockflag = 0;
error = uerror = lerror = ENOENT;
cnp = ap->a_cnp;
nameiop = cnp->cn_nameiop;
cnflags = cnp->cn_flags;
dvp = ap->a_dvp;
dunp = VTOUNIONFS(dvp);
udvp = dunp->un_uppervp;
ldvp = dunp->un_lowervp;
vp = uvp = lvp = NULLVP;
*(ap->a_vpp) = NULLVP;
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: enter: nameiop=%ld, flags=%lx, path=%s\n", nameiop, cnflags, cnp->cn_nameptr);
if (dvp->v_type != VDIR)
return (ENOTDIR);
/*
* If read-only and op is not LOOKUP, will return EROFS.
*/
if ((cnflags & ISLASTCN) &&
(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
LOOKUP != nameiop)
return (EROFS);
/*
* lookup dotdot
*/
if (cnflags & ISDOTDOT) {
if (LOOKUP != nameiop && udvp == NULLVP)
return (EROFS);
if (udvp != NULLVP) {
dtmpvp = udvp;
if (ldvp != NULLVP)
VOP_UNLOCK(ldvp);
}
else
dtmpvp = ldvp;
error = VOP_LOOKUP(dtmpvp, &vp, cnp);
if (dtmpvp == udvp && ldvp != NULLVP) {
VOP_UNLOCK(udvp);
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
}
if (error == 0) {
/*
* Exchange lock and reference from vp to
* dunp->un_dvp. vp is upper/lower vnode, but it
* will need to return the unionfs vnode.
*/
if (nameiop == DELETE || nameiop == RENAME)
VOP_UNLOCK(vp);
vrele(vp);
VOP_UNLOCK(dvp);
*(ap->a_vpp) = dunp->un_dvp;
vref(dunp->un_dvp);
vn_lock(dunp->un_dvp, LK_EXCLUSIVE | LK_RETRY);
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
} else if (error == ENOENT && nameiop != CREATE)
cache_enter(dvp, NULLVP, cnp->cn_nameptr,
cnp->cn_namelen, cnp->cn_flags);
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
return (error);
}
/*
* lookup upper layer
*/
if (udvp != NULLVP) {
uerror = VOP_LOOKUP(udvp, &uvp, cnp);
if (uerror == 0) {
if (udvp == uvp) { /* is dot */
vrele(uvp);
*(ap->a_vpp) = dvp;
vref(dvp);
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", uerror);
return (uerror);
}
}
/* check whiteout */
if (uerror == ENOENT || uerror == EJUSTRETURN)
if (cnp->cn_flags & ISWHITEOUT)
iswhiteout = 1; /* don't lookup lower */
if (iswhiteout == 0 && ldvp != NULLVP)
if (VOP_GETATTR(udvp, &va, cnp->cn_cred) == 0 &&
(va.va_flags & OPAQUE))
iswhiteout = 1; /* don't lookup lower */
#if 0
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: debug: whiteout=%d, path=%s\n", iswhiteout, cnp->cn_nameptr);
#endif
}
/*
* lookup lower layer
*/
if (ldvp != NULLVP && !(cnflags & DOWHITEOUT) && iswhiteout == 0) {
/* always op is LOOKUP */
cnp->cn_nameiop = LOOKUP;
cnflagsbk = cnp->cn_flags;
cnp->cn_flags = cnflags;
lerror = VOP_LOOKUP(ldvp, &lvp, cnp);
cnp->cn_nameiop = nameiop;
if (udvp != NULLVP && (uerror == 0 || uerror == EJUSTRETURN))
cnp->cn_flags = cnflagsbk;
if (lerror == 0) {
if (ldvp == lvp) { /* is dot */
if (uvp != NULLVP)
vrele(uvp); /* no need? */
vrele(lvp);
*(ap->a_vpp) = dvp;
vref(dvp);
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", lerror);
if (uvp != NULL)
VOP_UNLOCK(uvp);
return (lerror);
}
}
}
/*
* check lookup result
*/
if (uvp == NULLVP && lvp == NULLVP) {
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n",
(udvp != NULLVP ? uerror : lerror));
return (udvp != NULLVP ? uerror : lerror);
}
/*
* check vnode type
*/
if (uvp != NULLVP && lvp != NULLVP && uvp->v_type != lvp->v_type) {
vput(lvp);
lvp = NULLVP;
}
/*
* check shadow dir
*/
if (uerror != 0 && uerror != EJUSTRETURN && udvp != NULLVP &&
lerror == 0 && lvp != NULLVP && lvp->v_type == VDIR &&
!(dvp->v_mount->mnt_flag & MNT_RDONLY) &&
(1 < cnp->cn_namelen || '.' != *(cnp->cn_nameptr))) {
/* get unionfs vnode in order to create a new shadow dir. */
error = unionfs_nodeget(dvp->v_mount, NULLVP, lvp, dvp, &vp,
cnp);
if (error != 0)
goto unionfs_lookup_out;
error = unionfs_mkshadowdir(MOUNTTOUNIONFSMOUNT(dvp->v_mount),
udvp, VTOUNIONFS(vp), cnp);
if (error != 0) {
UNIONFSDEBUG("unionfs_lookup: Unable to create shadow dir.");
vput(vp);
goto unionfs_lookup_out;
}
}
/*
* get unionfs vnode.
*/
else {
if (uvp != NULLVP)
error = uerror;
else
error = lerror;
if (error != 0)
goto unionfs_lookup_out;
error = unionfs_nodeget(dvp->v_mount, uvp, lvp, dvp, &vp, cnp);
if (error != 0) {
UNIONFSDEBUG("unionfs_lookup: Unable to create unionfs vnode.");
goto unionfs_lookup_out;
}
}
*(ap->a_vpp) = vp;
cache_enter(dvp, vp, cnp->cn_nameptr, cnp->cn_namelen,
cnp->cn_flags);
/* XXXAD lock status on error */
unionfs_lookup_out:
if (uvp != NULLVP)
vrele(uvp);
if (lvp != NULLVP)
vrele(lvp);
if (error == ENOENT && nameiop != CREATE)
cache_enter(dvp, NULLVP, cnp->cn_nameptr, cnp->cn_namelen,
cnp->cn_flags);
UNIONFS_INTERNAL_DEBUG("unionfs_lookup: leave (%d)\n", error);
return (error);
}
/*
* Initialize
*/
int
unionfs_init(struct vfsconf *vfsp)
{
UNIONFSDEBUG("unionfs_init\n"); /* printed during system boot */
return (0);
}
/*
* Mount unionfs layer.
*/
static int
unionfs_domount(struct mount *mp)
{
int error;
struct vnode *lowerrootvp;
struct vnode *upperrootvp;
struct unionfs_mount *ump;
struct thread *td;
char *target;
char *tmp;
char *ep;
int len;
size_t done;
int below;
uid_t uid;
gid_t gid;
u_short udir;
u_short ufile;
unionfs_copymode copymode;
unionfs_whitemode whitemode;
struct componentname fakecn;
struct nameidata nd, *ndp;
struct vattr va;
UNIONFSDEBUG("unionfs_mount(mp = %p)\n", (void *)mp);
error = 0;
below = 0;
uid = 0;
gid = 0;
udir = 0;
ufile = 0;
copymode = UNIONFS_TRANSPARENT; /* default */
whitemode = UNIONFS_WHITE_ALWAYS;
ndp = &nd;
td = curthread;
if (mp->mnt_flag & MNT_ROOTFS) {
vfs_mount_error(mp, "Cannot union mount root filesystem");
return (EOPNOTSUPP);
}
/*
* Update is a no operation.
*/
if (mp->mnt_flag & MNT_UPDATE) {
vfs_mount_error(mp, "unionfs does not support mount update");
return (EOPNOTSUPP);
}
/*
* Get argument
*/
error = vfs_getopt(mp->mnt_optnew, "target", (void **)&target, &len);
if (error)
error = vfs_getopt(mp->mnt_optnew, "from", (void **)&target,
&len);
if (error || target[len - 1] != '\0') {
vfs_mount_error(mp, "Invalid target");
return (EINVAL);
}
if (vfs_getopt(mp->mnt_optnew, "below", NULL, NULL) == 0)
below = 1;
if (vfs_getopt(mp->mnt_optnew, "udir", (void **)&tmp, NULL) == 0) {
if (tmp != NULL)
udir = (mode_t)strtol(tmp, &ep, 8);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid udir");
return (EINVAL);
}
udir &= S_IRWXU | S_IRWXG | S_IRWXO;
}
if (vfs_getopt(mp->mnt_optnew, "ufile", (void **)&tmp, NULL) == 0) {
if (tmp != NULL)
ufile = (mode_t)strtol(tmp, &ep, 8);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid ufile");
return (EINVAL);
}
ufile &= S_IRWXU | S_IRWXG | S_IRWXO;
}
/* check umask, uid and gid */
if (udir == 0 && ufile != 0)
udir = ufile;
if (ufile == 0 && udir != 0)
ufile = udir;
vn_lock(mp->mnt_vnodecovered, LK_SHARED | LK_RETRY);
error = VOP_GETATTR(mp->mnt_vnodecovered, &va, mp->mnt_cred);
if (!error) {
if (udir == 0)
udir = va.va_mode;
if (ufile == 0)
ufile = va.va_mode;
uid = va.va_uid;
gid = va.va_gid;
}
VOP_UNLOCK(mp->mnt_vnodecovered, 0);
if (error)
return (error);
if (mp->mnt_cred->cr_ruid == 0) { /* root only */
if (vfs_getopt(mp->mnt_optnew, "uid", (void **)&tmp,
NULL) == 0) {
if (tmp != NULL)
uid = (uid_t)strtol(tmp, &ep, 10);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid uid");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "gid", (void **)&tmp,
NULL) == 0) {
if (tmp != NULL)
gid = (gid_t)strtol(tmp, &ep, 10);
if (tmp == NULL || *ep) {
vfs_mount_error(mp, "Invalid gid");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "copymode", (void **)&tmp,
NULL) == 0) {
if (tmp == NULL) {
vfs_mount_error(mp, "Invalid copymode");
return (EINVAL);
} else if (strcasecmp(tmp, "traditional") == 0)
copymode = UNIONFS_TRADITIONAL;
else if (strcasecmp(tmp, "transparent") == 0)
copymode = UNIONFS_TRANSPARENT;
else if (strcasecmp(tmp, "masquerade") == 0)
copymode = UNIONFS_MASQUERADE;
else {
vfs_mount_error(mp, "Invalid copymode");
return (EINVAL);
}
}
if (vfs_getopt(mp->mnt_optnew, "whiteout", (void **)&tmp,
NULL) == 0) {
if (tmp == NULL) {
vfs_mount_error(mp, "Invalid whiteout mode");
return (EINVAL);
} else if (strcasecmp(tmp, "always") == 0)
whitemode = UNIONFS_WHITE_ALWAYS;
else if (strcasecmp(tmp, "whenneeded") == 0)
whitemode = UNIONFS_WHITE_WHENNEEDED;
else {
vfs_mount_error(mp, "Invalid whiteout mode");
return (EINVAL);
}
}
}
/* If copymode is UNIONFS_TRADITIONAL, uid/gid is mounted user. */
if (copymode == UNIONFS_TRADITIONAL) {
uid = mp->mnt_cred->cr_ruid;
gid = mp->mnt_cred->cr_rgid;
}
UNIONFSDEBUG("unionfs_mount: uid=%d, gid=%d\n", uid, gid);
UNIONFSDEBUG("unionfs_mount: udir=0%03o, ufile=0%03o\n", udir, ufile);
UNIONFSDEBUG("unionfs_mount: copymode=%d\n", copymode);
/*
* Find upper node
*/
NDINIT(ndp, LOOKUP, FOLLOW | LOCKLEAF, UIO_SYSSPACE, target, td);
if ((error = namei(ndp)))
return (error);
NDFREE(ndp, NDF_ONLY_PNBUF);
/* get root vnodes */
lowerrootvp = mp->mnt_vnodecovered;
upperrootvp = ndp->ni_vp;
/* create unionfs_mount */
ump = (struct unionfs_mount *)malloc(sizeof(struct unionfs_mount),
M_UNIONFSMNT, M_WAITOK | M_ZERO);
/*
* Save reference
*/
if (below) {
VOP_UNLOCK(upperrootvp, 0);
vn_lock(lowerrootvp, LK_EXCLUSIVE | LK_RETRY);
ump->um_lowervp = upperrootvp;
ump->um_uppervp = lowerrootvp;
} else {
ump->um_lowervp = lowerrootvp;
ump->um_uppervp = upperrootvp;
}
ump->um_rootvp = NULLVP;
ump->um_uid = uid;
ump->um_gid = gid;
ump->um_udir = udir;
ump->um_ufile = ufile;
ump->um_copymode = copymode;
ump->um_whitemode = whitemode;
MNT_ILOCK(mp);
if ((lowerrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE) &&
(upperrootvp->v_mount->mnt_kern_flag & MNTK_MPSAFE))
mp->mnt_kern_flag |= MNTK_MPSAFE;
MNT_IUNLOCK(mp);
mp->mnt_data = ump;
/*
* Copy upper layer's RDONLY flag.
*/
mp->mnt_flag |= ump->um_uppervp->v_mount->mnt_flag & MNT_RDONLY;
/*
* Check whiteout
*/
if ((mp->mnt_flag & MNT_RDONLY) == 0) {
memset(&fakecn, 0, sizeof(fakecn));
fakecn.cn_nameiop = LOOKUP;
fakecn.cn_thread = td;
error = VOP_WHITEOUT(ump->um_uppervp, &fakecn, LOOKUP);
if (error) {
if (below) {
VOP_UNLOCK(ump->um_uppervp, 0);
vrele(upperrootvp);
} else
vput(ump->um_uppervp);
free(ump, M_UNIONFSMNT);
mp->mnt_data = NULL;
return (error);
}
}
/*
* Unlock the node
*/
VOP_UNLOCK(ump->um_uppervp, 0);
/*
* Get the unionfs root vnode.
*/
error = unionfs_nodeget(mp, ump->um_uppervp, ump->um_lowervp,
NULLVP, &(ump->um_rootvp), NULL, td);
vrele(upperrootvp);
if (error) {
free(ump, M_UNIONFSMNT);
mp->mnt_data = NULL;
return (error);
}
/*
* Check mnt_flag
*/
if ((ump->um_lowervp->v_mount->mnt_flag & MNT_LOCAL) &&
(ump->um_uppervp->v_mount->mnt_flag & MNT_LOCAL))
mp->mnt_flag |= MNT_LOCAL;
/*
* Get new fsid
*/
vfs_getnewfsid(mp);
len = MNAMELEN - 1;
tmp = mp->mnt_stat.f_mntfromname;
copystr((below ? "<below>:" : "<above>:"), tmp, len, &done);
len -= done - 1;
tmp += done - 1;
copystr(target, tmp, len, NULL);
UNIONFSDEBUG("unionfs_mount: from %s, on %s\n",
mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname);
return (0);
}