freebsd-skq/sys/fs/devfs/devfs_vnops.c
2000-09-18 09:40:01 +00:00

720 lines
17 KiB
C

#define DEBUG 1
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* Copyright (c) 2000
* Poul-Henning Kamp. All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)kernfs_vnops.c 8.15 (Berkeley) 5/21/95
* From: FreeBSD: src/sys/miscfs/kernfs/kernfs_vnops.c 1.43
*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/time.h>
#include <sys/conf.h>
#include <sys/vnode.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/dirent.h>
#include <fs/devfs/devfs.h>
static int devfs_access __P((struct vop_access_args *ap));
static int devfs_badop __P((void));
static int devfs_getattr __P((struct vop_getattr_args *ap));
static int devfs_lookupx __P((struct vop_lookup_args *ap));
static int devfs_print __P((struct vop_print_args *ap));
static int devfs_read __P((struct vop_read_args *ap));
static int devfs_readdir __P((struct vop_readdir_args *ap));
static int devfs_readlink __P((struct vop_readlink_args *ap));
static int devfs_reclaim __P((struct vop_reclaim_args *ap));
static int devfs_remove __P((struct vop_remove_args *ap));
static int devfs_revoke __P((struct vop_revoke_args *ap));
static int devfs_setattr __P((struct vop_setattr_args *ap));
static int devfs_symlink __P((struct vop_symlink_args *ap));
int
devfs_allocv(struct devfs_dirent *de, struct mount *mp, struct vnode **vpp, struct proc *p)
{
int error;
struct vnode *vp;
dev_t dev;
if (p == NULL)
p = curproc; /* XXX */
loop:
vp = de->de_vnode;
if (vp != NULL) {
if (vget(vp, LK_EXCLUSIVE, p ? p : curproc))
goto loop;
*vpp = vp;
return (0);
}
if (de->de_dirent->d_type == DT_CHR) {
dev = *devfs_itod(de->de_inode);
if (dev == NULL)
return (ENOENT);
} else {
dev = NODEV;
}
error = getnewvnode(VT_DEVFS, mp, devfs_vnodeop_p, &vp);
if (error != 0) {
printf("devfs_allocv: failed to allocate new vnode\n");
return (error);
}
if (de->de_dirent->d_type == DT_CHR) {
vp->v_type = VCHR;
vp = addaliasu(vp, dev->si_udev);
vp->v_op = devfs_specop_p;
} else if (de->de_dirent->d_type == DT_DIR) {
vp->v_type = VDIR;
} else if (de->de_dirent->d_type == DT_LNK) {
vp->v_type = VLNK;
} else {
vp->v_type = VBAD;
}
vp->v_data = de;
de->de_vnode = vp;
vhold(vp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
*vpp = vp;
return (0);
}
static int
devfs_access(ap)
struct vop_access_args /* {
struct vnode *a_vp;
int a_mode;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct devfs_dirent *de;
de = vp->v_data;
if (vp->v_type == VDIR)
de = de->de_dir;
return (vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
ap->a_mode, ap->a_cred, NULL));
}
static int
devfs_getattr(ap)
struct vop_getattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
int error = 0;
struct devfs_dirent *de;
dev_t dev;
de = vp->v_data;
if (vp->v_type == VDIR)
de = de->de_dir;
bzero((caddr_t) vap, sizeof(*vap));
vattr_null(vap);
vap->va_uid = de->de_uid;
vap->va_gid = de->de_gid;
vap->va_mode = de->de_mode;
vap->va_size = 0;
vap->va_blocksize = DEV_BSIZE;
vap->va_type = vp->v_type;
if (vp->v_type != VCHR) {
vap->va_atime = de->de_atime;
vap->va_mtime = de->de_mtime;
vap->va_ctime = de->de_ctime;
} else {
dev = vp->v_rdev;
vap->va_atime = dev->si_atime;
vap->va_mtime = dev->si_mtime;
vap->va_ctime = dev->si_ctime;
vap->va_rdev = dev->si_udev;
}
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_bytes = 0;
vap->va_nlink = de->de_links;
vap->va_fileid = de->de_inode;
#ifdef DEBUG
if (error)
printf("devfs_getattr: return error %d\n", error);
#endif
return (error);
}
static int
devfs_lookupx(ap)
struct vop_lookup_args /* {
struct vnode * a_dvp;
struct vnode ** a_vpp;
struct componentname * a_cnp;
} */ *ap;
{
struct componentname *cnp;
struct vnode *dvp, **vpp;
struct proc *p;
struct devfs_dirent *de, *dd;
struct devfs_mount *dmp;
dev_t cdev;
int error, cloned, i, flags, nameiop;
char specname[SPECNAMELEN + 1], *pname;
cnp = ap->a_cnp;
vpp = ap->a_vpp;
dvp = ap->a_dvp;
pname = cnp->cn_nameptr;
p = cnp->cn_proc;
flags = cnp->cn_flags;
nameiop = cnp->cn_nameiop;
dmp = VFSTODEVFS(dvp->v_mount);
cloned = 0;
dd = dvp->v_data;
*vpp = NULLVP;
if (nameiop == RENAME)
return (EOPNOTSUPP);
if (dvp->v_type != VDIR)
return (ENOTDIR);
if ((flags & ISDOTDOT) && (dvp->v_flag & VROOT))
return (EIO);
error = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, cnp->cn_proc);
if (error)
return (error);
if (cnp->cn_namelen == 1 && *pname == '.') {
if (nameiop != LOOKUP)
return (EINVAL);
*vpp = dvp;
VREF(dvp);
return (0);
}
if (flags & ISDOTDOT) {
if (nameiop != LOOKUP)
return (EINVAL);
VOP_UNLOCK(dvp, 0, p);
de = TAILQ_FIRST(&dd->de_dlist); /* "." */
de = TAILQ_NEXT(de, de_list); /* ".." */
de = de->de_dir;
error = devfs_allocv(de, dvp->v_mount, vpp, p);
if (error) {
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
}
if ((flags & LOCKPARENT) && (flags & ISLASTCN))
error = vn_lock(dvp, LK_EXCLUSIVE, p);
if (error)
vput(*vpp);
return (error);
}
devfs_populate(dmp);
dd = dvp->v_data;
TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
if (cnp->cn_namelen != de->de_dirent->d_namlen)
continue;
if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
de->de_dirent->d_namlen) != 0)
continue;
goto found;
}
/*
* OK, we didn't have an entry for the name we were asked for
* so we try to see if anybody can create it on demand.
* We need to construct the full "devname" for this device
* relative to "basedir" or the clone functions would not
* be able to tell "/dev/foo" from "/dev/bar/foo"
*/
i = SPECNAMELEN;
specname[i] = '\0';
i -= cnp->cn_namelen;
if (i < 0)
goto notfound;
bcopy(cnp->cn_nameptr, specname + i, cnp->cn_namelen);
de = dd;
while (de != dmp->dm_basedir) {
i--;
if (i < 0)
goto notfound;
specname[i] = '/';
i -= de->de_dirent->d_namlen;
if (i < 0)
goto notfound;
bcopy(de->de_dirent->d_name, specname + i,
de->de_dirent->d_namlen);
de = TAILQ_FIRST(&de->de_dlist); /* "." */
de = TAILQ_NEXT(de, de_list); /* ".." */
de = de->de_dir;
}
#if 0
printf("Finished specname: %d \"%s\"\n", i, specname + i);
#endif
cdev = NODEV;
EVENTHANDLER_INVOKE(dev_clone, specname + i,
strlen(specname + i), &cdev);
#if 0
printf("cloned %s -> %p %s\n", specname + i, cdev,
cdev == NODEV ? "NODEV" : cdev->si_name);
#endif
if (cdev == NODEV)
goto notfound;
devfs_populate(dmp);
dd = dvp->v_data;
TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
if (cnp->cn_namelen != de->de_dirent->d_namlen)
continue;
if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
de->de_dirent->d_namlen) != 0)
continue;
goto found;
}
notfound:
if ((nameiop == CREATE || nameiop == RENAME) &&
(flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
cnp->cn_flags |= SAVENAME;
if (!(flags & LOCKPARENT))
VOP_UNLOCK(dvp, 0, p);
return (EJUSTRETURN);
}
return (ENOENT);
found:
if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, p);
if (error)
return (error);
if (*vpp == dvp) {
VREF(dvp);
*vpp = dvp;
return (0);
}
error = devfs_allocv(de, dvp->v_mount, vpp, p);
if (error)
return (error);
if (!(flags & LOCKPARENT))
VOP_UNLOCK(dvp, 0, p);
return (0);
}
error = devfs_allocv(de, dvp->v_mount, vpp, p);
if (error)
return (error);
if (!(flags & LOCKPARENT) || !(flags & ISLASTCN))
VOP_UNLOCK(dvp, 0, p);
return (0);
}
static int
devfs_lookup(struct vop_lookup_args *ap)
{
int j;
struct devfs_mount *dmp;
dmp = VFSTODEVFS(ap->a_dvp->v_mount);
lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
j = devfs_lookupx(ap);
lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
return (j);
}
/* ARGSUSED */
static int
devfs_print(ap)
struct vop_print_args /* {
struct vnode *a_vp;
} */ *ap;
{
printf("tag VT_DEVFS, devfs vnode\n");
return (0);
}
static int
devfs_read(ap)
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
struct ucred *a_cred;
} */ *ap;
{
if (ap->a_vp->v_type != VDIR)
return (EINVAL);
return (VOP_READDIR(ap->a_vp, ap->a_uio, ap->a_cred, NULL, NULL, NULL));
}
static int
devfs_readdir(ap)
struct vop_readdir_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cred;
int *a_eofflag;
int *a_ncookies;
u_long **a_cookies;
} */ *ap;
{
int error;
struct uio *uio;
struct dirent *dp;
struct devfs_dirent *dd;
struct devfs_dirent *de;
struct devfs_mount *dmp;
off_t off;
if (ap->a_vp->v_type != VDIR)
return (ENOTDIR);
if (ap->a_ncookies)
return (EOPNOTSUPP);
uio = ap->a_uio;
if (uio->uio_offset < 0)
return (EINVAL);
dmp = VFSTODEVFS(ap->a_vp->v_mount);
lockmgr(&dmp->dm_lock, LK_SHARED, 0, curproc);
devfs_populate(dmp);
error = 0;
de = ap->a_vp->v_data;
dd = TAILQ_FIRST(&de->de_dlist);
off = 0;
while (dd != NULL) {
if (dd->de_dirent->d_type == DT_DIR)
de = dd->de_dir;
else
de = dd;
dp = dd->de_dirent;
if (dp->d_reclen > uio->uio_resid)
break;
dp->d_fileno = de->de_inode;
if (off >= uio->uio_offset) {
error = uiomove((caddr_t)dp, dp->d_reclen, uio);
if (error)
break;
}
off += dp->d_reclen;
dd = TAILQ_NEXT(dd, de_list);
}
lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
uio->uio_offset = off;
return (error);
}
static int
devfs_readlink(ap)
struct vop_readlink_args /* {
struct vnode *a_vp;
struct uio *a_uio;
struct ucred *a_cead;
} */ *ap;
{
int error;
struct devfs_dirent *de;
de = ap->a_vp->v_data;
error = uiomove(de->de_symlink, strlen(de->de_symlink) + 1, ap->a_uio);
return (error);
}
static int
devfs_reclaim(ap)
struct vop_reclaim_args /* {
struct vnode *a_vp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct devfs_dirent *de;
de = vp->v_data;
if (de != NULL && de->de_flags & DE_ORPHAN) {
if (de->de_symlink)
FREE(de->de_symlink, M_DEVFS);
FREE(de, M_DEVFS);
}
vp->v_data = NULL;
return (0);
}
static int
devfs_remove(ap)
struct vop_remove_args /* {
struct vnode *a_dvp;
struct vnode *a_vp;
struct componentname *a_cnp;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct devfs_dirent *dd;
struct devfs_dirent *de, **dep;
struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
dd = ap->a_dvp->v_data;
de = vp->v_data;
TAILQ_REMOVE(&dd->de_dlist, de, de_list);
dep = devfs_itode(dmp, de->de_inode);
if (dep != NULL)
*dep = DE_DELETED;
de->de_flags |= DE_ORPHAN;
vdrop(de->de_vnode);
lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
return (0);
}
/*
* Revoke is called on a tty when a terminal session ends. The vnode
* is orphaned by setting v_op to deadfs so we need to let go of it
* as well so that we create a new one next time around.
*/
static int
devfs_revoke(ap)
struct vop_revoke_args /* {
struct vnode *a_vp;
int a_flags;
} */ *ap;
{
struct vnode *vp = ap->a_vp;
struct devfs_dirent *de;
de = vp->v_data;
if (!(de->de_flags & DE_ORPHAN))
vdrop(de->de_vnode);
de->de_vnode = NULL;
vop_revoke(ap);
return (0);
}
static int
devfs_setattr(ap)
struct vop_setattr_args /* {
struct vnode *a_vp;
struct vattr *a_vap;
struct ucred *a_cred;
struct proc *a_p;
} */ *ap;
{
struct devfs_dirent *de;
struct vattr *vap;
int c, error;
uid_t uid;
gid_t gid;
vap = ap->a_vap;
if ((vap->va_type != VNON) ||
(vap->va_nlink != VNOVAL) ||
(vap->va_fsid != VNOVAL) ||
(vap->va_fileid != VNOVAL) ||
(vap->va_blocksize != VNOVAL) ||
(vap->va_flags != VNOVAL && vap->va_flags != 0) ||
(vap->va_rdev != VNOVAL) ||
((int)vap->va_bytes != VNOVAL) ||
(vap->va_gen != VNOVAL)) {
return (EINVAL);
}
de = ap->a_vp->v_data;
if (ap->a_vp->v_type == VDIR)
de = de->de_dir;
error = c = 0;
if (vap->va_uid == (uid_t)VNOVAL)
uid = de->de_uid;
else
uid = vap->va_uid;
if (vap->va_gid == (gid_t)VNOVAL)
gid = de->de_gid;
else
gid = vap->va_gid;
if (uid != de->de_uid || gid != de->de_gid) {
if (((ap->a_cred->cr_uid != de->de_uid) || uid != de->de_uid ||
(gid != de->de_gid && !groupmember(gid, ap->a_cred))) &&
(error = suser(ap->a_p)) != 0)
return (error);
de->de_uid = uid;
de->de_gid = gid;
c = 1;
}
if (vap->va_mode != (mode_t)VNOVAL) {
if ((ap->a_cred->cr_uid != de->de_uid) &&
(error = suser(ap->a_p)))
return (error);
de->de_mode = vap->va_mode;
c = 1;
}
if (vap->va_atime.tv_sec != VNOVAL) {
if ((ap->a_cred->cr_uid != de->de_uid) &&
(error = suser(ap->a_p)))
return (error);
de->de_atime = vap->va_atime;
c = 1;
}
if (vap->va_mtime.tv_sec != VNOVAL) {
if ((ap->a_cred->cr_uid != de->de_uid) &&
(error = suser(ap->a_p)))
return (error);
de->de_mtime = vap->va_mtime;
c = 1;
}
if (c)
getnanotime(&de->de_ctime);
return (0);
}
static int
devfs_symlink(ap)
struct vop_symlink_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
struct vattr *a_vap;
char *a_target;
} */ *ap;
{
int i;
struct devfs_dirent *dd;
struct devfs_dirent *de;
struct devfs_mount *dmp;
dmp = VFSTODEVFS(ap->a_dvp->v_mount);
dd = ap->a_dvp->v_data;
de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
de->de_uid = 0;
de->de_gid = 0;
de->de_mode = 0642;
de->de_inode = dmp->dm_inode++;
de->de_dirent->d_type = DT_LNK;
i = strlen(ap->a_target) + 1;
MALLOC(de->de_symlink, char *, i, M_DEVFS, M_WAITOK);
bcopy(ap->a_target, de->de_symlink, i);
lockmgr(&dmp->dm_lock, LK_EXCLUSIVE, 0, curproc);
TAILQ_INSERT_TAIL(&dd->de_dlist, de, de_list);
devfs_allocv(de, ap->a_dvp->v_mount, ap->a_vpp, 0);
lockmgr(&dmp->dm_lock, LK_RELEASE, 0, curproc);
return (0);
}
/*
* DEVFS "should never get here" operation
*/
static int
devfs_badop()
{
return (EIO);
}
vop_t **devfs_vnodeop_p;
static struct vnodeopv_entry_desc devfs_vnodeop_entries[] = {
{ &vop_default_desc, (vop_t *) vop_defaultop },
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_bmap_desc, (vop_t *) devfs_badop },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_lookup_desc, (vop_t *) devfs_lookup },
{ &vop_pathconf_desc, (vop_t *) vop_stdpathconf },
{ &vop_print_desc, (vop_t *) devfs_print },
{ &vop_read_desc, (vop_t *) devfs_read },
{ &vop_readdir_desc, (vop_t *) devfs_readdir },
{ &vop_readlink_desc, (vop_t *) devfs_readlink },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_remove_desc, (vop_t *) devfs_remove },
{ &vop_revoke_desc, (vop_t *) devfs_revoke },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ &vop_symlink_desc, (vop_t *) devfs_symlink },
{ NULL, NULL }
};
static struct vnodeopv_desc devfs_vnodeop_opv_desc =
{ &devfs_vnodeop_p, devfs_vnodeop_entries };
VNODEOP_SET(devfs_vnodeop_opv_desc);
#if 0
int
foo(ap)
struct vop_generic_args *ap;
{
int i;
i = spec_vnoperate(ap);
printf("foo(%s) = %d\n", ap->a_desc->vdesc_name, i);
return (i);
}
#endif
vop_t **devfs_specop_p;
static struct vnodeopv_entry_desc devfs_specop_entries[] = {
#if 1
{ &vop_default_desc, (vop_t *) spec_vnoperate },
#else
{ &vop_default_desc, (vop_t *) foo },
{ &vop_lock_desc, (vop_t *) spec_vnoperate },
{ &vop_unlock_desc, (vop_t *) spec_vnoperate },
{ &vop_lease_desc, (vop_t *) spec_vnoperate },
{ &vop_strategy_desc, (vop_t *) spec_vnoperate },
{ &vop_bmap_desc, (vop_t *) spec_vnoperate },
#endif
{ &vop_access_desc, (vop_t *) devfs_access },
{ &vop_getattr_desc, (vop_t *) devfs_getattr },
{ &vop_print_desc, (vop_t *) devfs_print },
{ &vop_reclaim_desc, (vop_t *) devfs_reclaim },
{ &vop_remove_desc, (vop_t *) devfs_remove },
{ &vop_revoke_desc, (vop_t *) devfs_revoke },
{ &vop_setattr_desc, (vop_t *) devfs_setattr },
{ NULL, NULL }
};
static struct vnodeopv_desc devfs_specop_opv_desc =
{ &devfs_specop_p, devfs_specop_entries };
VNODEOP_SET(devfs_specop_opv_desc);