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freebsd-dev/sys/fs/devfs/devfs_vnops.c
Gordon Bergling 8ea3ceda76 fs: fix a few common typos in source code comments 
- s/quadradically/quadratically/
- s/persistant/persistent/

Obtained from:	NetBSD
MFC after:	3 days
2022-02-06 13:48:31 +01:00

2117 lines
47 KiB
C
Raw Blame History

/*-
* SPDX-License-Identifier: BSD-2-Clause-FreeBSD
*
* Copyright (c) 2000-2004
* Poul-Henning Kamp. All rights reserved.
* Copyright (c) 1989, 1992-1993, 1995
* The Regents of the University of California. 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
*
* $FreeBSD$
*/
/*
* TODO:
* mkdir: want it ?
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/conf.h>
#include <sys/dirent.h>
#include <sys/eventhandler.h>
#include <sys/fcntl.h>
#include <sys/file.h>
#include <sys/filedesc.h>
#include <sys/filio.h>
#include <sys/jail.h>
#include <sys/kernel.h>
#include <sys/limits.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mman.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/priv.h>
#include <sys/proc.h>
#include <sys/stat.h>
#include <sys/sx.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/ttycom.h>
#include <sys/unistd.h>
#include <sys/vnode.h>
static struct vop_vector devfs_vnodeops;
static struct vop_vector devfs_specops;
static struct fileops devfs_ops_f;
#include <fs/devfs/devfs.h>
#include <fs/devfs/devfs_int.h>
#include <security/mac/mac_framework.h>
#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>
static MALLOC_DEFINE(M_CDEVPDATA, "DEVFSP", "Metainfo for cdev-fp data");
struct mtx devfs_de_interlock;
MTX_SYSINIT(devfs_de_interlock, &devfs_de_interlock, "devfs interlock", MTX_DEF);
struct sx clone_drain_lock;
SX_SYSINIT(clone_drain_lock, &clone_drain_lock, "clone events drain lock");
struct mtx cdevpriv_mtx;
MTX_SYSINIT(cdevpriv_mtx, &cdevpriv_mtx, "cdevpriv lock", MTX_DEF);
SYSCTL_DECL(_vfs_devfs);
static int devfs_dotimes;
SYSCTL_INT(_vfs_devfs, OID_AUTO, dotimes, CTLFLAG_RW,
&devfs_dotimes, 0, "Update timestamps on DEVFS with default precision");
/*
* Update devfs node timestamp. Note that updates are unlocked and
* stat(2) could see partially updated times.
*/
static void
devfs_timestamp(struct timespec *tsp)
{
time_t ts;
if (devfs_dotimes) {
vfs_timestamp(tsp);
} else {
ts = time_second;
if (tsp->tv_sec != ts) {
tsp->tv_sec = ts;
tsp->tv_nsec = 0;
}
}
}
static int
devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp,
int *ref)
{
*dswp = devvn_refthread(fp->f_vnode, devp, ref);
if (*dswp == NULL || *devp != fp->f_data) {
if (*dswp != NULL)
dev_relthread(*devp, *ref);
return (ENXIO);
}
KASSERT((*devp)->si_refcount > 0,
("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
if (*dswp == NULL)
return (ENXIO);
curthread->td_fpop = fp;
return (0);
}
int
devfs_get_cdevpriv(void **datap)
{
struct file *fp;
struct cdev_privdata *p;
int error;
fp = curthread->td_fpop;
if (fp == NULL)
return (EBADF);
p = fp->f_cdevpriv;
if (p != NULL) {
error = 0;
*datap = p->cdpd_data;
} else
error = ENOENT;
return (error);
}
int
devfs_set_cdevpriv(void *priv, d_priv_dtor_t *priv_dtr)
{
struct file *fp;
struct cdev_priv *cdp;
struct cdev_privdata *p;
int error;
fp = curthread->td_fpop;
if (fp == NULL)
return (ENOENT);
cdp = cdev2priv((struct cdev *)fp->f_data);
p = malloc(sizeof(struct cdev_privdata), M_CDEVPDATA, M_WAITOK);
p->cdpd_data = priv;
p->cdpd_dtr = priv_dtr;
p->cdpd_fp = fp;
mtx_lock(&cdevpriv_mtx);
if (fp->f_cdevpriv == NULL) {
LIST_INSERT_HEAD(&cdp->cdp_fdpriv, p, cdpd_list);
fp->f_cdevpriv = p;
mtx_unlock(&cdevpriv_mtx);
error = 0;
} else {
mtx_unlock(&cdevpriv_mtx);
free(p, M_CDEVPDATA);
error = EBUSY;
}
return (error);
}
void
devfs_destroy_cdevpriv(struct cdev_privdata *p)
{
mtx_assert(&cdevpriv_mtx, MA_OWNED);
KASSERT(p->cdpd_fp->f_cdevpriv == p,
("devfs_destoy_cdevpriv %p != %p", p->cdpd_fp->f_cdevpriv, p));
p->cdpd_fp->f_cdevpriv = NULL;
LIST_REMOVE(p, cdpd_list);
mtx_unlock(&cdevpriv_mtx);
(p->cdpd_dtr)(p->cdpd_data);
free(p, M_CDEVPDATA);
}
static void
devfs_fpdrop(struct file *fp)
{
struct cdev_privdata *p;
mtx_lock(&cdevpriv_mtx);
if ((p = fp->f_cdevpriv) == NULL) {
mtx_unlock(&cdevpriv_mtx);
return;
}
devfs_destroy_cdevpriv(p);
}
void
devfs_clear_cdevpriv(void)
{
struct file *fp;
fp = curthread->td_fpop;
if (fp == NULL)
return;
devfs_fpdrop(fp);
}
static void
devfs_usecount_add(struct vnode *vp)
{
struct devfs_dirent *de;
struct cdev *dev;
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
VNPASS(vp->v_type == VCHR || vp->v_type == VBAD, vp);
if (VN_IS_DOOMED(vp)) {
goto out_unlock;
}
de = vp->v_data;
dev = vp->v_rdev;
MPASS(de != NULL);
MPASS(dev != NULL);
dev->si_usecount++;
de->de_usecount++;
out_unlock:
VI_UNLOCK(vp);
mtx_unlock(&devfs_de_interlock);
}
static void
devfs_usecount_subl(struct vnode *vp)
{
struct devfs_dirent *de;
struct cdev *dev;
mtx_assert(&devfs_de_interlock, MA_OWNED);
ASSERT_VI_LOCKED(vp, __func__);
VNPASS(vp->v_type == VCHR || vp->v_type == VBAD, vp);
de = vp->v_data;
dev = vp->v_rdev;
if (de == NULL)
return;
if (dev == NULL) {
MPASS(de->de_usecount == 0);
return;
}
if (dev->si_usecount < de->de_usecount)
panic("%s: si_usecount underflow for dev %p "
"(has %ld, dirent has %d)\n",
__func__, dev, dev->si_usecount, de->de_usecount);
if (VN_IS_DOOMED(vp)) {
dev->si_usecount -= de->de_usecount;
de->de_usecount = 0;
} else {
if (de->de_usecount == 0)
panic("%s: de_usecount underflow for dev %p\n",
__func__, dev);
dev->si_usecount--;
de->de_usecount--;
}
}
static void
devfs_usecount_sub(struct vnode *vp)
{
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
devfs_usecount_subl(vp);
VI_UNLOCK(vp);
mtx_unlock(&devfs_de_interlock);
}
static int
devfs_usecountl(struct vnode *vp)
{
VNPASS(vp->v_type == VCHR, vp);
mtx_assert(&devfs_de_interlock, MA_OWNED);
ASSERT_VI_LOCKED(vp, __func__);
return (vp->v_rdev->si_usecount);
}
int
devfs_usecount(struct vnode *vp)
{
int count;
VNPASS(vp->v_type == VCHR, vp);
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
count = devfs_usecountl(vp);
VI_UNLOCK(vp);
mtx_unlock(&devfs_de_interlock);
return (count);
}
void
devfs_ctty_ref(struct vnode *vp)
{
vrefact(vp);
devfs_usecount_add(vp);
}
void
devfs_ctty_unref(struct vnode *vp)
{
devfs_usecount_sub(vp);
vrele(vp);
}
/*
* On success devfs_populate_vp() returns with dmp->dm_lock held.
*/
static int
devfs_populate_vp(struct vnode *vp)
{
struct devfs_dirent *de;
struct devfs_mount *dmp;
int locked;
ASSERT_VOP_LOCKED(vp, "devfs_populate_vp");
dmp = VFSTODEVFS(vp->v_mount);
if (!devfs_populate_needed(dmp)) {
sx_xlock(&dmp->dm_lock);
goto out_nopopulate;
}
locked = VOP_ISLOCKED(vp);
sx_xlock(&dmp->dm_lock);
DEVFS_DMP_HOLD(dmp);
/* Can't call devfs_populate() with the vnode lock held. */
VOP_UNLOCK(vp);
devfs_populate(dmp);
sx_xunlock(&dmp->dm_lock);
vn_lock(vp, locked | LK_RETRY);
sx_xlock(&dmp->dm_lock);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
return (ERESTART);
}
out_nopopulate:
if (VN_IS_DOOMED(vp)) {
sx_xunlock(&dmp->dm_lock);
return (ERESTART);
}
de = vp->v_data;
KASSERT(de != NULL,
("devfs_populate_vp: vp->v_data == NULL but vnode not doomed"));
if ((de->de_flags & DE_DOOMED) != 0) {
sx_xunlock(&dmp->dm_lock);
return (ERESTART);
}
return (0);
}
static int
devfs_vptocnp(struct vop_vptocnp_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vnode **dvp = ap->a_vpp;
struct devfs_mount *dmp;
char *buf = ap->a_buf;
size_t *buflen = ap->a_buflen;
struct devfs_dirent *dd, *de;
int i, error;
dmp = VFSTODEVFS(vp->v_mount);
error = devfs_populate_vp(vp);
if (error != 0)
return (error);
if (vp->v_type != VCHR && vp->v_type != VDIR) {
error = ENOENT;
goto finished;
}
dd = vp->v_data;
if (vp->v_type == VDIR && dd == dmp->dm_rootdir) {
*dvp = vp;
vref(*dvp);
goto finished;
}
i = *buflen;
i -= dd->de_dirent->d_namlen;
if (i < 0) {
error = ENOMEM;
goto finished;
}
bcopy(dd->de_dirent->d_name, buf + i, dd->de_dirent->d_namlen);
*buflen = i;
de = devfs_parent_dirent(dd);
if (de == NULL) {
error = ENOENT;
goto finished;
}
mtx_lock(&devfs_de_interlock);
*dvp = de->de_vnode;
if (*dvp != NULL) {
VI_LOCK(*dvp);
mtx_unlock(&devfs_de_interlock);
vholdl(*dvp);
VI_UNLOCK(*dvp);
vref(*dvp);
vdrop(*dvp);
} else {
mtx_unlock(&devfs_de_interlock);
error = ENOENT;
}
finished:
sx_xunlock(&dmp->dm_lock);
return (error);
}
/*
* Construct the fully qualified path name relative to the mountpoint.
* If a NULL cnp is provided, no '/' is appended to the resulting path.
*/
char *
devfs_fqpn(char *buf, struct devfs_mount *dmp, struct devfs_dirent *dd,
struct componentname *cnp)
{
int i;
struct devfs_dirent *de;
sx_assert(&dmp->dm_lock, SA_LOCKED);
i = SPECNAMELEN;
buf[i] = '\0';
if (cnp != NULL)
i -= cnp->cn_namelen;
if (i < 0)
return (NULL);
if (cnp != NULL)
bcopy(cnp->cn_nameptr, buf + i, cnp->cn_namelen);
de = dd;
while (de != dmp->dm_rootdir) {
if (cnp != NULL || i < SPECNAMELEN) {
i--;
if (i < 0)
return (NULL);
buf[i] = '/';
}
i -= de->de_dirent->d_namlen;
if (i < 0)
return (NULL);
bcopy(de->de_dirent->d_name, buf + i,
de->de_dirent->d_namlen);
de = devfs_parent_dirent(de);
if (de == NULL)
return (NULL);
}
return (buf + i);
}
static int
devfs_allocv_drop_refs(int drop_dm_lock, struct devfs_mount *dmp,
struct devfs_dirent *de)
{
int not_found;
not_found = 0;
if (de->de_flags & DE_DOOMED)
not_found = 1;
if (DEVFS_DE_DROP(de)) {
KASSERT(not_found == 1, ("DEVFS de dropped but not doomed"));
devfs_dirent_free(de);
}
if (DEVFS_DMP_DROP(dmp)) {
KASSERT(not_found == 1,
("DEVFS mount struct freed before dirent"));
not_found = 2;
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
}
if (not_found == 1 || (drop_dm_lock && not_found != 2))
sx_unlock(&dmp->dm_lock);
return (not_found);
}
/*
* devfs_allocv shall be entered with dmp->dm_lock held, and it drops
* it on return.
*/
int
devfs_allocv(struct devfs_dirent *de, struct mount *mp, int lockmode,
struct vnode **vpp)
{
int error;
struct vnode *vp;
struct cdev *dev;
struct devfs_mount *dmp;
struct cdevsw *dsw;
enum vgetstate vs;
dmp = VFSTODEVFS(mp);
if (de->de_flags & DE_DOOMED) {
sx_xunlock(&dmp->dm_lock);
return (ENOENT);
}
loop:
DEVFS_DE_HOLD(de);
DEVFS_DMP_HOLD(dmp);
mtx_lock(&devfs_de_interlock);
vp = de->de_vnode;
if (vp != NULL) {
vs = vget_prep(vp);
mtx_unlock(&devfs_de_interlock);
sx_xunlock(&dmp->dm_lock);
vget_finish(vp, lockmode | LK_RETRY, vs);
sx_xlock(&dmp->dm_lock);
if (devfs_allocv_drop_refs(0, dmp, de)) {
vput(vp);
return (ENOENT);
}
else if (VN_IS_DOOMED(vp)) {
mtx_lock(&devfs_de_interlock);
if (de->de_vnode == vp) {
de->de_vnode = NULL;
vp->v_data = NULL;
}
mtx_unlock(&devfs_de_interlock);
vput(vp);
goto loop;
}
sx_xunlock(&dmp->dm_lock);
*vpp = vp;
return (0);
}
mtx_unlock(&devfs_de_interlock);
if (de->de_dirent->d_type == DT_CHR) {
if (!(de->de_cdp->cdp_flags & CDP_ACTIVE)) {
devfs_allocv_drop_refs(1, dmp, de);
return (ENOENT);
}
dev = &de->de_cdp->cdp_c;
} else {
dev = NULL;
}
error = getnewvnode("devfs", mp, &devfs_vnodeops, &vp);
if (error != 0) {
devfs_allocv_drop_refs(1, dmp, de);
printf("devfs_allocv: failed to allocate new vnode\n");
return (error);
}
if (de->de_dirent->d_type == DT_CHR) {
vp->v_type = VCHR;
VI_LOCK(vp);
dev_lock();
dev_refl(dev);
/* XXX: v_rdev should be protect by vnode lock */
vp->v_rdev = dev;
VNPASS(vp->v_usecount == 1, vp);
/* Special casing of ttys for deadfs. Probably redundant. */
dsw = dev->si_devsw;
if (dsw != NULL && (dsw->d_flags & D_TTY) != 0)
vp->v_vflag |= VV_ISTTY;
dev_unlock();
VI_UNLOCK(vp);
if ((dev->si_flags & SI_ETERNAL) != 0)
vp->v_vflag |= VV_ETERNALDEV;
vp->v_op = &devfs_specops;
} 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;
}
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY | LK_NOWITNESS);
VN_LOCK_ASHARE(vp);
mtx_lock(&devfs_de_interlock);
vp->v_data = de;
de->de_vnode = vp;
mtx_unlock(&devfs_de_interlock);
error = insmntque1(vp, mp);
if (error != 0) {
mtx_lock(&devfs_de_interlock);
vp->v_data = NULL;
de->de_vnode = NULL;
mtx_unlock(&devfs_de_interlock);
vgone(vp);
vput(vp);
(void) devfs_allocv_drop_refs(1, dmp, de);
return (error);
}
if (devfs_allocv_drop_refs(0, dmp, de)) {
vput(vp);
return (ENOENT);
}
#ifdef MAC
mac_devfs_vnode_associate(mp, de, vp);
#endif
sx_xunlock(&dmp->dm_lock);
*vpp = vp;
return (0);
}
static int
devfs_access(struct vop_access_args *ap)
{
struct vnode *vp = ap->a_vp;
struct devfs_dirent *de;
struct proc *p;
int error;
de = vp->v_data;
if (vp->v_type == VDIR)
de = de->de_dir;
error = vaccess(vp->v_type, de->de_mode, de->de_uid, de->de_gid,
ap->a_accmode, ap->a_cred);
if (error == 0)
return (0);
if (error != EACCES)
return (error);
p = ap->a_td->td_proc;
/* We do, however, allow access to the controlling terminal */
PROC_LOCK(p);
if (!(p->p_flag & P_CONTROLT)) {
PROC_UNLOCK(p);
return (error);
}
if (p->p_session->s_ttydp == de->de_cdp)
error = 0;
PROC_UNLOCK(p);
return (error);
}
_Static_assert(((FMASK | FCNTLFLAGS) & (FLASTCLOSE | FREVOKE)) == 0,
"devfs-only flag reuse failed");
static int
devfs_close(struct vop_close_args *ap)
{
struct vnode *vp = ap->a_vp, *oldvp;
struct thread *td = ap->a_td;
struct proc *p;
struct cdev *dev = vp->v_rdev;
struct cdevsw *dsw;
struct devfs_dirent *de = vp->v_data;
int dflags, error, ref, vp_locked;
/*
* XXX: Don't call d_close() if we were called because of
* XXX: insmntque() failure.
*/
if (vp->v_data == NULL)
return (0);
/*
* Hack: a tty device that is a controlling terminal
* has a reference from the session structure.
* We cannot easily tell that a character device is
* a controlling terminal, unless it is the closing
* process' controlling terminal. In that case,
* if the reference count is 2 (this last descriptor
* plus the session), release the reference from the session.
*/
if (de->de_usecount == 2 && td != NULL) {
p = td->td_proc;
PROC_LOCK(p);
if (vp == p->p_session->s_ttyvp) {
PROC_UNLOCK(p);
oldvp = NULL;
sx_xlock(&proctree_lock);
if (vp == p->p_session->s_ttyvp) {
SESS_LOCK(p->p_session);
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
if (devfs_usecountl(vp) == 2 && !VN_IS_DOOMED(vp)) {
p->p_session->s_ttyvp = NULL;
p->p_session->s_ttydp = NULL;
oldvp = vp;
}
VI_UNLOCK(vp);
mtx_unlock(&devfs_de_interlock);
SESS_UNLOCK(p->p_session);
}
sx_xunlock(&proctree_lock);
if (oldvp != NULL)
devfs_ctty_unref(oldvp);
} else
PROC_UNLOCK(p);
}
/*
* We do not want to really close the device if it
* is still in use unless we are trying to close it
* forcibly. Since every use (buffer, vnode, swap, cmap)
* holds a reference to the vnode, and because we mark
* any other vnodes that alias this device, when the
* sum of the reference counts on all the aliased
* vnodes descends to one, we are on last close.
*/
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
dflags = 0;
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
if (devfs_usecountl(vp) == 1)
dflags |= FLASTCLOSE;
devfs_usecount_subl(vp);
mtx_unlock(&devfs_de_interlock);
if (VN_IS_DOOMED(vp)) {
/* Forced close. */
dflags |= FREVOKE | FNONBLOCK;
} else if (dsw->d_flags & D_TRACKCLOSE) {
/* Keep device updated on status. */
} else if ((dflags & FLASTCLOSE) == 0) {
VI_UNLOCK(vp);
dev_relthread(dev, ref);
return (0);
}
vholdnz(vp);
VI_UNLOCK(vp);
vp_locked = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp);
KASSERT(dev->si_refcount > 0,
("devfs_close() on un-referenced struct cdev *(%s)", devtoname(dev)));
error = dsw->d_close(dev, ap->a_fflag | dflags, S_IFCHR, td);
dev_relthread(dev, ref);
vn_lock(vp, vp_locked | LK_RETRY);
vdrop(vp);
return (error);
}
static int
devfs_close_f(struct file *fp, struct thread *td)
{
int error;
struct file *fpop;
/*
* NB: td may be NULL if this descriptor is closed due to
* garbage collection from a closed UNIX domain socket.
*/
fpop = curthread->td_fpop;
curthread->td_fpop = fp;
error = vnops.fo_close(fp, td);
curthread->td_fpop = fpop;
/*
* The f_cdevpriv cannot be assigned non-NULL value while we
* are destroying the file.
*/
if (fp->f_cdevpriv != NULL)
devfs_fpdrop(fp);
return (error);
}
static int
devfs_getattr(struct vop_getattr_args *ap)
{
struct vnode *vp = ap->a_vp;
struct vattr *vap = ap->a_vap;
struct devfs_dirent *de;
struct devfs_mount *dmp;
struct cdev *dev;
struct timeval boottime;
int error;
error = devfs_populate_vp(vp);
if (error != 0)
return (error);
dmp = VFSTODEVFS(vp->v_mount);
sx_xunlock(&dmp->dm_lock);
de = vp->v_data;
KASSERT(de != NULL, ("Null dirent in devfs_getattr vp=%p", vp));
if (vp->v_type == VDIR) {
de = de->de_dir;
KASSERT(de != NULL,
("Null dir dirent in devfs_getattr vp=%p", vp));
}
vap->va_uid = de->de_uid;
vap->va_gid = de->de_gid;
vap->va_mode = de->de_mode;
if (vp->v_type == VLNK)
vap->va_size = strlen(de->de_symlink);
else if (vp->v_type == VDIR)
vap->va_size = vap->va_bytes = DEV_BSIZE;
else
vap->va_size = 0;
if (vp->v_type != VDIR)
vap->va_bytes = 0;
vap->va_blocksize = DEV_BSIZE;
vap->va_type = vp->v_type;
getboottime(&boottime);
#define fix(aa) \
do { \
if ((aa).tv_sec <= 3600) { \
(aa).tv_sec = boottime.tv_sec; \
(aa).tv_nsec = boottime.tv_usec * 1000; \
} \
} while (0)
if (vp->v_type != VCHR) {
fix(de->de_atime);
vap->va_atime = de->de_atime;
fix(de->de_mtime);
vap->va_mtime = de->de_mtime;
fix(de->de_ctime);
vap->va_ctime = de->de_ctime;
} else {
dev = vp->v_rdev;
fix(dev->si_atime);
vap->va_atime = dev->si_atime;
fix(dev->si_mtime);
vap->va_mtime = dev->si_mtime;
fix(dev->si_ctime);
vap->va_ctime = dev->si_ctime;
vap->va_rdev = cdev2priv(dev)->cdp_inode;
}
vap->va_gen = 0;
vap->va_flags = 0;
vap->va_filerev = 0;
vap->va_nlink = de->de_links;
vap->va_fileid = de->de_inode;
return (error);
}
/* ARGSUSED */
static int
devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struct thread *td)
{
struct file *fpop;
int error;
fpop = td->td_fpop;
td->td_fpop = fp;
error = vnops.fo_ioctl(fp, com, data, cred, td);
td->td_fpop = fpop;
return (error);
}
void *
fiodgname_buf_get_ptr(void *fgnp, u_long com)
{
union {
struct fiodgname_arg fgn;
#ifdef COMPAT_FREEBSD32
struct fiodgname_arg32 fgn32;
#endif
} *fgnup;
fgnup = fgnp;
switch (com) {
case FIODGNAME:
return (fgnup->fgn.buf);
#ifdef COMPAT_FREEBSD32
case FIODGNAME_32:
return ((void *)(uintptr_t)fgnup->fgn32.buf);
#endif
default:
panic("Unhandled ioctl command %ld", com);
}
}
static int
devfs_ioctl(struct vop_ioctl_args *ap)
{
struct fiodgname_arg *fgn;
struct vnode *vpold, *vp;
struct cdevsw *dsw;
struct thread *td;
struct session *sess;
struct cdev *dev;
int error, ref, i;
const char *p;
u_long com;
vp = ap->a_vp;
com = ap->a_command;
td = ap->a_td;
dsw = devvn_refthread(vp, &dev, &ref);
if (dsw == NULL)
return (ENXIO);
KASSERT(dev->si_refcount > 0,
("devfs: un-referenced struct cdev *(%s)", devtoname(dev)));
switch (com) {
case FIODTYPE:
*(int *)ap->a_data = dsw->d_flags & D_TYPEMASK;
error = 0;
break;
case FIODGNAME:
#ifdef COMPAT_FREEBSD32
case FIODGNAME_32:
#endif
fgn = ap->a_data;
p = devtoname(dev);
i = strlen(p) + 1;
if (i > fgn->len)
error = EINVAL;
else
error = copyout(p, fiodgname_buf_get_ptr(fgn, com), i);
break;
default:
error = dsw->d_ioctl(dev, com, ap->a_data, ap->a_fflag, td);
}
dev_relthread(dev, ref);
if (error == ENOIOCTL)
error = ENOTTY;
if (error == 0 && com == TIOCSCTTY) {
/*
* Do nothing if reassigning same control tty, or if the
* control tty has already disappeared. If it disappeared,
* it's because we were racing with TIOCNOTTY. TIOCNOTTY
* already took care of releasing the old vnode and we have
* nothing left to do.
*/
sx_slock(&proctree_lock);
sess = td->td_proc->p_session;
if (sess->s_ttyvp == vp || sess->s_ttyp == NULL) {
sx_sunlock(&proctree_lock);
return (0);
}
devfs_ctty_ref(vp);
SESS_LOCK(sess);
vpold = sess->s_ttyvp;
sess->s_ttyvp = vp;
sess->s_ttydp = cdev2priv(dev);
SESS_UNLOCK(sess);
sx_sunlock(&proctree_lock);
/* Get rid of reference to old control tty */
if (vpold)
devfs_ctty_unref(vpold);
}
return (error);
}
/* ARGSUSED */
static int
devfs_kqfilter_f(struct file *fp, struct knote *kn)
{
struct cdev *dev;
struct cdevsw *dsw;
int error, ref;
struct file *fpop;
struct thread *td;
td = curthread;
fpop = td->td_fpop;
error = devfs_fp_check(fp, &dev, &dsw, &ref);
if (error)
return (error);
error = dsw->d_kqfilter(dev, kn);
td->td_fpop = fpop;
dev_relthread(dev, ref);
return (error);
}
static inline int
devfs_prison_check(struct devfs_dirent *de, struct thread *td)
{
struct cdev_priv *cdp;
struct ucred *dcr;
struct proc *p;
int error;
cdp = de->de_cdp;
if (cdp == NULL)
return (0);
dcr = cdp->cdp_c.si_cred;
if (dcr == NULL)
return (0);
error = prison_check(td->td_ucred, dcr);
if (error == 0)
return (0);
/* We do, however, allow access to the controlling terminal */
p = td->td_proc;
PROC_LOCK(p);
if (!(p->p_flag & P_CONTROLT)) {
PROC_UNLOCK(p);
return (error);
}
if (p->p_session->s_ttydp == cdp)
error = 0;
PROC_UNLOCK(p);
return (error);
}
static int
devfs_lookupx(struct vop_lookup_args *ap, int *dm_unlock)
{
struct componentname *cnp;
struct vnode *dvp, **vpp;
struct thread *td;
struct devfs_dirent *de, *dd;
struct devfs_dirent **dde;
struct devfs_mount *dmp;
struct mount *mp;
struct cdev *cdev;
int error, flags, nameiop, dvplocked;
char specname[SPECNAMELEN + 1], *pname;
td = curthread;
cnp = ap->a_cnp;
vpp = ap->a_vpp;
dvp = ap->a_dvp;
pname = cnp->cn_nameptr;
flags = cnp->cn_flags;
nameiop = cnp->cn_nameiop;
mp = dvp->v_mount;
dmp = VFSTODEVFS(mp);
dd = dvp->v_data;
*vpp = NULLVP;
if ((flags & ISLASTCN) && nameiop == RENAME)
return (EOPNOTSUPP);
if (dvp->v_type != VDIR)
return (ENOTDIR);
if ((flags & ISDOTDOT) && (dvp->v_vflag & VV_ROOT))
return (EIO);
error = vn_dir_check_exec(dvp, cnp);
if (error != 0)
return (error);
if (cnp->cn_namelen == 1 && *pname == '.') {
if ((flags & ISLASTCN) && nameiop != LOOKUP)
return (EINVAL);
*vpp = dvp;
VREF(dvp);
return (0);
}
if (flags & ISDOTDOT) {
if ((flags & ISLASTCN) && nameiop != LOOKUP)
return (EINVAL);
de = devfs_parent_dirent(dd);
if (de == NULL)
return (ENOENT);
dvplocked = VOP_ISLOCKED(dvp);
VOP_UNLOCK(dvp);
error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK,
vpp);
*dm_unlock = 0;
vn_lock(dvp, dvplocked | LK_RETRY);
return (error);
}
dd = dvp->v_data;
de = devfs_find(dd, cnp->cn_nameptr, cnp->cn_namelen, 0);
while (de == NULL) { /* While(...) so we can use break */
if (nameiop == DELETE)
return (ENOENT);
/*
* 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.
*/
pname = devfs_fqpn(specname, dmp, dd, cnp);
if (pname == NULL)
break;
cdev = NULL;
DEVFS_DMP_HOLD(dmp);
sx_xunlock(&dmp->dm_lock);
sx_slock(&clone_drain_lock);
EVENTHANDLER_INVOKE(dev_clone,
td->td_ucred, pname, strlen(pname), &cdev);
sx_sunlock(&clone_drain_lock);
if (cdev == NULL)
sx_xlock(&dmp->dm_lock);
else if (devfs_populate_vp(dvp) != 0) {
*dm_unlock = 0;
sx_xlock(&dmp->dm_lock);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
} else
sx_xunlock(&dmp->dm_lock);
dev_rel(cdev);
return (ENOENT);
}
if (DEVFS_DMP_DROP(dmp)) {
*dm_unlock = 0;
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
if (cdev != NULL)
dev_rel(cdev);
return (ENOENT);
}
if (cdev == NULL)
break;
dev_lock();
dde = &cdev2priv(cdev)->cdp_dirents[dmp->dm_idx];
if (dde != NULL && *dde != NULL)
de = *dde;
dev_unlock();
dev_rel(cdev);
break;
}
if (de == NULL || de->de_flags & DE_WHITEOUT) {
if ((nameiop == CREATE || nameiop == RENAME) &&
(flags & (LOCKPARENT | WANTPARENT)) && (flags & ISLASTCN)) {
cnp->cn_flags |= SAVENAME;
return (EJUSTRETURN);
}
return (ENOENT);
}
if (devfs_prison_check(de, td))
return (ENOENT);
if ((cnp->cn_nameiop == DELETE) && (flags & ISLASTCN)) {
error = VOP_ACCESS(dvp, VWRITE, cnp->cn_cred, td);
if (error)
return (error);
if (*vpp == dvp) {
VREF(dvp);
*vpp = dvp;
return (0);
}
}
error = devfs_allocv(de, mp, cnp->cn_lkflags & LK_TYPE_MASK, vpp);
*dm_unlock = 0;
return (error);
}
static int
devfs_lookup(struct vop_lookup_args *ap)
{
int j;
struct devfs_mount *dmp;
int dm_unlock;
if (devfs_populate_vp(ap->a_dvp) != 0)
return (ENOTDIR);
dmp = VFSTODEVFS(ap->a_dvp->v_mount);
dm_unlock = 1;
j = devfs_lookupx(ap, &dm_unlock);
if (dm_unlock == 1)
sx_xunlock(&dmp->dm_lock);
return (j);
}
static int
devfs_mknod(struct vop_mknod_args *ap)
{
struct componentname *cnp;
struct vnode *dvp, **vpp;
struct devfs_dirent *dd, *de;
struct devfs_mount *dmp;
int error;
/*
* The only type of node we should be creating here is a
* character device, for anything else return EOPNOTSUPP.
*/
if (ap->a_vap->va_type != VCHR)
return (EOPNOTSUPP);
dvp = ap->a_dvp;
dmp = VFSTODEVFS(dvp->v_mount);
cnp = ap->a_cnp;
vpp = ap->a_vpp;
dd = dvp->v_data;
error = ENOENT;
sx_xlock(&dmp->dm_lock);
TAILQ_FOREACH(de, &dd->de_dlist, de_list) {
if (cnp->cn_namelen != de->de_dirent->d_namlen)
continue;
if (de->de_dirent->d_type == DT_CHR &&
(de->de_cdp->cdp_flags & CDP_ACTIVE) == 0)
continue;
if (bcmp(cnp->cn_nameptr, de->de_dirent->d_name,
de->de_dirent->d_namlen) != 0)
continue;
if (de->de_flags & DE_WHITEOUT)
break;
goto notfound;
}
if (de == NULL)
goto notfound;
de->de_flags &= ~DE_WHITEOUT;
error = devfs_allocv(de, dvp->v_mount, LK_EXCLUSIVE, vpp);
return (error);
notfound:
sx_xunlock(&dmp->dm_lock);
return (error);
}
/* ARGSUSED */
static int
devfs_open(struct vop_open_args *ap)
{
struct thread *td = ap->a_td;
struct vnode *vp = ap->a_vp;
struct cdev *dev = vp->v_rdev;
struct file *fp = ap->a_fp;
int error, ref, vlocked;
struct cdevsw *dsw;
struct file *fpop;
if (vp->v_type == VBLK)
return (ENXIO);
if (dev == NULL)
return (ENXIO);
/* Make this field valid before any I/O in d_open. */
if (dev->si_iosize_max == 0)
dev->si_iosize_max = DFLTPHYS;
dsw = dev_refthread(dev, &ref);
if (dsw == NULL)
return (ENXIO);
if (fp == NULL && dsw->d_fdopen != NULL) {
dev_relthread(dev, ref);
return (ENXIO);
}
if (vp->v_type == VCHR)
devfs_usecount_add(vp);
vlocked = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp);
fpop = td->td_fpop;
td->td_fpop = fp;
if (fp != NULL) {
fp->f_data = dev;
fp->f_vnode = vp;
}
if (dsw->d_fdopen != NULL)
error = dsw->d_fdopen(dev, ap->a_mode, td, fp);
else
error = dsw->d_open(dev, ap->a_mode, S_IFCHR, td);
/* Clean up any cdevpriv upon error. */
if (error != 0)
devfs_clear_cdevpriv();
td->td_fpop = fpop;
vn_lock(vp, vlocked | LK_RETRY);
if (error != 0 && vp->v_type == VCHR)
devfs_usecount_sub(vp);
dev_relthread(dev, ref);
if (error != 0) {
if (error == ERESTART)
error = EINTR;
return (error);
}
#if 0 /* /dev/console */
KASSERT(fp != NULL, ("Could not vnode bypass device on NULL fp"));
#else
if (fp == NULL)
return (error);
#endif
if (fp->f_ops == &badfileops)
finit(fp, fp->f_flag, DTYPE_VNODE, dev, &devfs_ops_f);
return (error);
}
static int
devfs_pathconf(struct vop_pathconf_args *ap)
{
switch (ap->a_name) {
case _PC_FILESIZEBITS:
*ap->a_retval = 64;
return (0);
case _PC_NAME_MAX:
*ap->a_retval = NAME_MAX;
return (0);
case _PC_LINK_MAX:
*ap->a_retval = INT_MAX;
return (0);
case _PC_SYMLINK_MAX:
*ap->a_retval = MAXPATHLEN;
return (0);
case _PC_MAX_CANON:
if (ap->a_vp->v_vflag & VV_ISTTY) {
*ap->a_retval = MAX_CANON;
return (0);
}
return (EINVAL);
case _PC_MAX_INPUT:
if (ap->a_vp->v_vflag & VV_ISTTY) {
*ap->a_retval = MAX_INPUT;
return (0);
}
return (EINVAL);
case _PC_VDISABLE:
if (ap->a_vp->v_vflag & VV_ISTTY) {
*ap->a_retval = _POSIX_VDISABLE;
return (0);
}
return (EINVAL);
case _PC_MAC_PRESENT:
#ifdef MAC
/*
* If MAC is enabled, devfs automatically supports
* trivial non-persistent label storage.
*/
*ap->a_retval = 1;
#else
*ap->a_retval = 0;
#endif
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
default:
return (vop_stdpathconf(ap));
}
/* NOTREACHED */
}
/* ARGSUSED */
static int
devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
{
struct cdev *dev;
struct cdevsw *dsw;
int error, ref;
struct file *fpop;
fpop = td->td_fpop;
error = devfs_fp_check(fp, &dev, &dsw, &ref);
if (error != 0) {
error = vnops.fo_poll(fp, events, cred, td);
return (error);
}
error = dsw->d_poll(dev, events, td);
td->td_fpop = fpop;
dev_relthread(dev, ref);
return(error);
}
/*
* Print out the contents of a special device vnode.
*/
static int
devfs_print(struct vop_print_args *ap)
{
printf("\tdev %s\n", devtoname(ap->a_vp->v_rdev));
return (0);
}
static int
devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred,
int flags, struct thread *td)
{
struct cdev *dev;
int ioflag, error, ref;
ssize_t resid;
struct cdevsw *dsw;
struct file *fpop;
if (uio->uio_resid > DEVFS_IOSIZE_MAX)
return (EINVAL);
fpop = td->td_fpop;
error = devfs_fp_check(fp, &dev, &dsw, &ref);
if (error != 0) {
error = vnops.fo_read(fp, uio, cred, flags, td);
return (error);
}
resid = uio->uio_resid;
ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT);
if (ioflag & O_DIRECT)
ioflag |= IO_DIRECT;
foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
error = dsw->d_read(dev, uio, ioflag);
if (uio->uio_resid != resid || (error == 0 && resid != 0))
devfs_timestamp(&dev->si_atime);
td->td_fpop = fpop;
dev_relthread(dev, ref);
foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF_R);
return (error);
}
static int
devfs_readdir(struct vop_readdir_args *ap)
{
int error;
struct uio *uio;
struct dirent *dp;
struct devfs_dirent *dd;
struct devfs_dirent *de;
struct devfs_mount *dmp;
off_t off;
int *tmp_ncookies = NULL;
if (ap->a_vp->v_type != VDIR)
return (ENOTDIR);
uio = ap->a_uio;
if (uio->uio_offset < 0)
return (EINVAL);
/*
* XXX: This is a temporary hack to get around this filesystem not
* supporting cookies. We store the location of the ncookies pointer
* in a temporary variable before calling vfs_subr.c:vfs_read_dirent()
* and set the number of cookies to 0. We then set the pointer to
* NULL so that vfs_read_dirent doesn't try to call realloc() on
* ap->a_cookies. Later in this function, we restore the ap->a_ncookies
* pointer to its original location before returning to the caller.
*/
if (ap->a_ncookies != NULL) {
tmp_ncookies = ap->a_ncookies;
*ap->a_ncookies = 0;
ap->a_ncookies = NULL;
}
dmp = VFSTODEVFS(ap->a_vp->v_mount);
if (devfs_populate_vp(ap->a_vp) != 0) {
if (tmp_ncookies != NULL)
ap->a_ncookies = tmp_ncookies;
return (EIO);
}
error = 0;
de = ap->a_vp->v_data;
off = 0;
TAILQ_FOREACH(dd, &de->de_dlist, de_list) {
KASSERT(dd->de_cdp != (void *)0xdeadc0de, ("%s %d\n", __func__, __LINE__));
if (dd->de_flags & (DE_COVERED | DE_WHITEOUT))
continue;
if (devfs_prison_check(dd, uio->uio_td))
continue;
if (dd->de_dirent->d_type == DT_DIR)
de = dd->de_dir;
else
de = dd;
dp = dd->de_dirent;
MPASS(dp->d_reclen == GENERIC_DIRSIZ(dp));
if (dp->d_reclen > uio->uio_resid)
break;
dp->d_fileno = de->de_inode;
/* NOTE: d_off is the offset for the *next* entry. */
dp->d_off = off + dp->d_reclen;
if (off >= uio->uio_offset) {
error = vfs_read_dirent(ap, dp, off);
if (error)
break;
}
off += dp->d_reclen;
}
sx_xunlock(&dmp->dm_lock);
uio->uio_offset = off;
/*
* Restore ap->a_ncookies if it wasn't originally NULL in the first
* place.
*/
if (tmp_ncookies != NULL)
ap->a_ncookies = tmp_ncookies;
return (error);
}
static int
devfs_readlink(struct vop_readlink_args *ap)
{
struct devfs_dirent *de;
de = ap->a_vp->v_data;
return (uiomove(de->de_symlink, strlen(de->de_symlink), ap->a_uio));
}
static void
devfs_reclaiml(struct vnode *vp)
{
struct devfs_dirent *de;
mtx_assert(&devfs_de_interlock, MA_OWNED);
de = vp->v_data;
if (de != NULL) {
MPASS(de->de_usecount == 0);
de->de_vnode = NULL;
vp->v_data = NULL;
}
}
static int
devfs_reclaim(struct vop_reclaim_args *ap)
{
struct vnode *vp;
vp = ap->a_vp;
mtx_lock(&devfs_de_interlock);
devfs_reclaiml(vp);
mtx_unlock(&devfs_de_interlock);
return (0);
}
static int
devfs_reclaim_vchr(struct vop_reclaim_args *ap)
{
struct vnode *vp;
struct cdev *dev;
vp = ap->a_vp;
MPASS(vp->v_type == VCHR);
mtx_lock(&devfs_de_interlock);
VI_LOCK(vp);
devfs_usecount_subl(vp);
devfs_reclaiml(vp);
mtx_unlock(&devfs_de_interlock);
dev_lock();
dev = vp->v_rdev;
vp->v_rdev = NULL;
dev_unlock();
VI_UNLOCK(vp);
if (dev != NULL)
dev_rel(dev);
return (0);
}
static int
devfs_remove(struct vop_remove_args *ap)
{
struct vnode *dvp = ap->a_dvp;
struct vnode *vp = ap->a_vp;
struct devfs_dirent *dd;
struct devfs_dirent *de, *de_covered;
struct devfs_mount *dmp = VFSTODEVFS(vp->v_mount);
ASSERT_VOP_ELOCKED(dvp, "devfs_remove");
ASSERT_VOP_ELOCKED(vp, "devfs_remove");
sx_xlock(&dmp->dm_lock);
dd = ap->a_dvp->v_data;
de = vp->v_data;
if (de->de_cdp == NULL) {
TAILQ_REMOVE(&dd->de_dlist, de, de_list);
if (de->de_dirent->d_type == DT_LNK) {
de_covered = devfs_find(dd, de->de_dirent->d_name,
de->de_dirent->d_namlen, 0);
if (de_covered != NULL)
de_covered->de_flags &= ~DE_COVERED;
}
/* We need to unlock dvp because devfs_delete() may lock it. */
VOP_UNLOCK(vp);
if (dvp != vp)
VOP_UNLOCK(dvp);
devfs_delete(dmp, de, 0);
sx_xunlock(&dmp->dm_lock);
if (dvp != vp)
vn_lock(dvp, LK_EXCLUSIVE | LK_RETRY);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
} else {
de->de_flags |= DE_WHITEOUT;
sx_xunlock(&dmp->dm_lock);
}
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(struct vop_revoke_args *ap)
{
struct vnode *vp = ap->a_vp, *vp2;
struct cdev *dev;
struct cdev_priv *cdp;
struct devfs_dirent *de;
enum vgetstate vs;
u_int i;
KASSERT((ap->a_flags & REVOKEALL) != 0, ("devfs_revoke !REVOKEALL"));
dev = vp->v_rdev;
cdp = cdev2priv(dev);
dev_lock();
cdp->cdp_inuse++;
dev_unlock();
vhold(vp);
vgone(vp);
vdrop(vp);
VOP_UNLOCK(vp);
loop:
for (;;) {
mtx_lock(&devfs_de_interlock);
dev_lock();
vp2 = NULL;
for (i = 0; i <= cdp->cdp_maxdirent; i++) {
de = cdp->cdp_dirents[i];
if (de == NULL)
continue;
vp2 = de->de_vnode;
if (vp2 != NULL) {
dev_unlock();
vs = vget_prep(vp2);
mtx_unlock(&devfs_de_interlock);
if (vget_finish(vp2, LK_EXCLUSIVE, vs) != 0)
goto loop;
vhold(vp2);
vgone(vp2);
vdrop(vp2);
vput(vp2);
break;
}
}
if (vp2 != NULL) {
continue;
}
dev_unlock();
mtx_unlock(&devfs_de_interlock);
break;
}
dev_lock();
cdp->cdp_inuse--;
if (!(cdp->cdp_flags & CDP_ACTIVE) && cdp->cdp_inuse == 0) {
TAILQ_REMOVE(&cdevp_list, cdp, cdp_list);
dev_unlock();
dev_rel(&cdp->cdp_c);
} else
dev_unlock();
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
return (0);
}
static int
devfs_rioctl(struct vop_ioctl_args *ap)
{
struct vnode *vp;
struct devfs_mount *dmp;
int error;
vp = ap->a_vp;
vn_lock(vp, LK_SHARED | LK_RETRY);
if (VN_IS_DOOMED(vp)) {
VOP_UNLOCK(vp);
return (EBADF);
}
dmp = VFSTODEVFS(vp->v_mount);
sx_xlock(&dmp->dm_lock);
VOP_UNLOCK(vp);
DEVFS_DMP_HOLD(dmp);
devfs_populate(dmp);
if (DEVFS_DMP_DROP(dmp)) {
sx_xunlock(&dmp->dm_lock);
devfs_unmount_final(dmp);
return (ENOENT);
}
error = devfs_rules_ioctl(dmp, ap->a_command, ap->a_data, ap->a_td);
sx_xunlock(&dmp->dm_lock);
return (error);
}
static int
devfs_rread(struct vop_read_args *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_setattr(struct vop_setattr_args *ap)
{
struct devfs_dirent *de;
struct vattr *vap;
struct vnode *vp;
struct thread *td;
int c, error;
uid_t uid;
gid_t gid;
vap = ap->a_vap;
vp = ap->a_vp;
td = curthread;
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);
}
error = devfs_populate_vp(vp);
if (error != 0)
return (error);
de = vp->v_data;
if (vp->v_type == VDIR)
de = de->de_dir;
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 = priv_check(td, PRIV_VFS_CHOWN);
if (error != 0)
goto ret;
}
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 = priv_check(td, PRIV_VFS_ADMIN);
if (error != 0)
goto ret;
}
de->de_mode = vap->va_mode;
c = 1;
}
if (vap->va_atime.tv_sec != VNOVAL || vap->va_mtime.tv_sec != VNOVAL) {
error = vn_utimes_perm(vp, vap, ap->a_cred, td);
if (error != 0)
goto ret;
if (vap->va_atime.tv_sec != VNOVAL) {
if (vp->v_type == VCHR)
vp->v_rdev->si_atime = vap->va_atime;
else
de->de_atime = vap->va_atime;
}
if (vap->va_mtime.tv_sec != VNOVAL) {
if (vp->v_type == VCHR)
vp->v_rdev->si_mtime = vap->va_mtime;
else
de->de_mtime = vap->va_mtime;
}
c = 1;
}
if (c) {
if (vp->v_type == VCHR)
vfs_timestamp(&vp->v_rdev->si_ctime);
else
vfs_timestamp(&de->de_mtime);
}
ret:
sx_xunlock(&VFSTODEVFS(vp->v_mount)->dm_lock);
return (error);
}
#ifdef MAC
static int
devfs_setlabel(struct vop_setlabel_args *ap)
{
struct vnode *vp;
struct devfs_dirent *de;
vp = ap->a_vp;
de = vp->v_data;
mac_vnode_relabel(ap->a_cred, vp, ap->a_label);
mac_devfs_update(vp->v_mount, de, vp);
return (0);
}
#endif
static int
devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred)
{
return (vnops.fo_stat(fp, sb, cred));
}
static int
devfs_symlink(struct vop_symlink_args *ap)
{
int i, error;
struct devfs_dirent *dd;
struct devfs_dirent *de, *de_covered, *de_dotdot;
struct devfs_mount *dmp;
error = priv_check(curthread, PRIV_DEVFS_SYMLINK);
if (error)
return(error);
dmp = VFSTODEVFS(ap->a_dvp->v_mount);
if (devfs_populate_vp(ap->a_dvp) != 0)
return (ENOENT);
dd = ap->a_dvp->v_data;
de = devfs_newdirent(ap->a_cnp->cn_nameptr, ap->a_cnp->cn_namelen);
de->de_flags = DE_USER;
de->de_uid = 0;
de->de_gid = 0;
de->de_mode = 0755;
de->de_inode = alloc_unr(devfs_inos);
de->de_dir = dd;
de->de_dirent->d_type = DT_LNK;
i = strlen(ap->a_target) + 1;
de->de_symlink = malloc(i, M_DEVFS, M_WAITOK);
bcopy(ap->a_target, de->de_symlink, i);
#ifdef MAC
mac_devfs_create_symlink(ap->a_cnp->cn_cred, dmp->dm_mount, dd, de);
#endif
de_covered = devfs_find(dd, de->de_dirent->d_name,
de->de_dirent->d_namlen, 0);
if (de_covered != NULL) {
if ((de_covered->de_flags & DE_USER) != 0) {
devfs_delete(dmp, de, DEVFS_DEL_NORECURSE);
sx_xunlock(&dmp->dm_lock);
return (EEXIST);
}
KASSERT((de_covered->de_flags & DE_COVERED) == 0,
("devfs_symlink: entry %p already covered", de_covered));
de_covered->de_flags |= DE_COVERED;
}
de_dotdot = TAILQ_FIRST(&dd->de_dlist); /* "." */
de_dotdot = TAILQ_NEXT(de_dotdot, de_list); /* ".." */
TAILQ_INSERT_AFTER(&dd->de_dlist, de_dotdot, de, de_list);
devfs_dir_ref_de(dmp, dd);
devfs_rules_apply(dmp, de);
return (devfs_allocv(de, ap->a_dvp->v_mount, LK_EXCLUSIVE, ap->a_vpp));
}
static int
devfs_truncate_f(struct file *fp, off_t length, struct ucred *cred, struct thread *td)
{
return (vnops.fo_truncate(fp, length, cred, td));
}
static int
devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred,
int flags, struct thread *td)
{
struct cdev *dev;
int error, ioflag, ref;
ssize_t resid;
struct cdevsw *dsw;
struct file *fpop;
if (uio->uio_resid > DEVFS_IOSIZE_MAX)
return (EINVAL);
fpop = td->td_fpop;
error = devfs_fp_check(fp, &dev, &dsw, &ref);
if (error != 0) {
error = vnops.fo_write(fp, uio, cred, flags, td);
return (error);
}
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
ioflag = fp->f_flag & (O_NONBLOCK | O_DIRECT | O_FSYNC);
if (ioflag & O_DIRECT)
ioflag |= IO_DIRECT;
foffset_lock_uio(fp, uio, flags | FOF_NOLOCK);
resid = uio->uio_resid;
error = dsw->d_write(dev, uio, ioflag);
if (uio->uio_resid != resid || (error == 0 && resid != 0)) {
devfs_timestamp(&dev->si_ctime);
dev->si_mtime = dev->si_ctime;
}
td->td_fpop = fpop;
dev_relthread(dev, ref);
foffset_unlock_uio(fp, uio, flags | FOF_NOLOCK | FOF_NEXTOFF_W);
return (error);
}
static int
devfs_mmap_f(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
struct thread *td)
{
struct cdev *dev;
struct cdevsw *dsw;
struct mount *mp;
struct vnode *vp;
struct file *fpop;
vm_object_t object;
vm_prot_t maxprot;
int error, ref;
vp = fp->f_vnode;
/*
* Ensure that file and memory protections are
* compatible.
*/
mp = vp->v_mount;
if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
maxprot = VM_PROT_NONE;
if ((prot & VM_PROT_EXECUTE) != 0)
return (EACCES);
} else
maxprot = VM_PROT_EXECUTE;
if ((fp->f_flag & FREAD) != 0)
maxprot |= VM_PROT_READ;
else if ((prot & VM_PROT_READ) != 0)
return (EACCES);
/*
* If we are sharing potential changes via MAP_SHARED and we
* are trying to get write permission although we opened it
* without asking for it, bail out.
*
* Note that most character devices always share mappings.
* The one exception is that D_MMAP_ANON devices
* (i.e. /dev/zero) permit private writable mappings.
*
* Rely on vm_mmap_cdev() to fail invalid MAP_PRIVATE requests
* as well as updating maxprot to permit writing for
* D_MMAP_ANON devices rather than doing that here.
*/
if ((flags & MAP_SHARED) != 0) {
if ((fp->f_flag & FWRITE) != 0)
maxprot |= VM_PROT_WRITE;
else if ((prot & VM_PROT_WRITE) != 0)
return (EACCES);
}
maxprot &= cap_maxprot;
fpop = td->td_fpop;
error = devfs_fp_check(fp, &dev, &dsw, &ref);
if (error != 0)
return (error);
error = vm_mmap_cdev(td, size, prot, &maxprot, &flags, dev, dsw, &foff,
&object);
td->td_fpop = fpop;
dev_relthread(dev, ref);
if (error != 0)
return (error);
error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
foff, FALSE, td);
if (error != 0)
vm_object_deallocate(object);
return (error);
}
dev_t
dev2udev(struct cdev *x)
{
if (x == NULL)
return (NODEV);
return (cdev2priv(x)->cdp_inode);
}
static struct fileops devfs_ops_f = {
.fo_read = devfs_read_f,
.fo_write = devfs_write_f,
.fo_truncate = devfs_truncate_f,
.fo_ioctl = devfs_ioctl_f,
.fo_poll = devfs_poll_f,
.fo_kqfilter = devfs_kqfilter_f,
.fo_stat = devfs_stat_f,
.fo_close = devfs_close_f,
.fo_chmod = vn_chmod,
.fo_chown = vn_chown,
.fo_sendfile = vn_sendfile,
.fo_seek = vn_seek,
.fo_fill_kinfo = vn_fill_kinfo,
.fo_mmap = devfs_mmap_f,
.fo_flags = DFLAG_PASSABLE | DFLAG_SEEKABLE
};
/* Vops for non-CHR vnodes in /dev. */
static struct vop_vector devfs_vnodeops = {
.vop_default = &default_vnodeops,
.vop_access = devfs_access,
.vop_getattr = devfs_getattr,
.vop_ioctl = devfs_rioctl,
.vop_lookup = devfs_lookup,
.vop_mknod = devfs_mknod,
.vop_pathconf = devfs_pathconf,
.vop_read = devfs_rread,
.vop_readdir = devfs_readdir,
.vop_readlink = devfs_readlink,
.vop_reclaim = devfs_reclaim,
.vop_remove = devfs_remove,
.vop_revoke = devfs_revoke,
.vop_setattr = devfs_setattr,
#ifdef MAC
.vop_setlabel = devfs_setlabel,
#endif
.vop_symlink = devfs_symlink,
.vop_vptocnp = devfs_vptocnp,
.vop_lock1 = vop_lock,
.vop_unlock = vop_unlock,
.vop_islocked = vop_islocked,
.vop_add_writecount = vop_stdadd_writecount_nomsync,
};
VFS_VOP_VECTOR_REGISTER(devfs_vnodeops);
/* Vops for VCHR vnodes in /dev. */
static struct vop_vector devfs_specops = {
.vop_default = &default_vnodeops,
.vop_access = devfs_access,
.vop_bmap = VOP_PANIC,
.vop_close = devfs_close,
.vop_create = VOP_PANIC,
.vop_fsync = vop_stdfsync,
.vop_getattr = devfs_getattr,
.vop_ioctl = devfs_ioctl,
.vop_link = VOP_PANIC,
.vop_mkdir = VOP_PANIC,
.vop_mknod = VOP_PANIC,
.vop_open = devfs_open,
.vop_pathconf = devfs_pathconf,
.vop_poll = dead_poll,
.vop_print = devfs_print,
.vop_read = dead_read,
.vop_readdir = VOP_PANIC,
.vop_readlink = VOP_PANIC,
.vop_reallocblks = VOP_PANIC,
.vop_reclaim = devfs_reclaim_vchr,
.vop_remove = devfs_remove,
.vop_rename = VOP_PANIC,
.vop_revoke = devfs_revoke,
.vop_rmdir = VOP_PANIC,
.vop_setattr = devfs_setattr,
#ifdef MAC
.vop_setlabel = devfs_setlabel,
#endif
.vop_strategy = VOP_PANIC,
.vop_symlink = VOP_PANIC,
.vop_vptocnp = devfs_vptocnp,
.vop_write = dead_write,
.vop_lock1 = vop_lock,
.vop_unlock = vop_unlock,
.vop_islocked = vop_islocked,
.vop_add_writecount = vop_stdadd_writecount_nomsync,
};
VFS_VOP_VECTOR_REGISTER(devfs_specops);
/*
* Our calling convention to the device drivers used to be that we passed
* vnode.h IO_* flags to read()/write(), but we're moving to fcntl.h O_
* flags instead since that's what open(), close() and ioctl() takes and
* we don't really want vnode.h in device drivers.
* We solved the source compatibility by redefining some vnode flags to
* be the same as the fcntl ones and by sending down the bitwise OR of
* the respective fcntl/vnode flags. These CTASSERTS make sure nobody
* pulls the rug out under this.
*/
CTASSERT(O_NONBLOCK == IO_NDELAY);
CTASSERT(O_FSYNC == IO_SYNC);
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