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freebsd-nq/sys/fs/devfs/devfs_vnops.c
Konstantin Belousov 6470c8d3db Rework v_object lifecycle for vnodes. 
Current implementation of vnode_create_vobject() and
vnode_destroy_vobject() is written so that it prepared to handle the
vm object destruction for live vnode.  Practically, no filesystems use
this, except for some remnants that were present in UFS till today.
One of the consequences of that model is that each filesystem must
call vnode_destroy_vobject() in VOP_RECLAIM() or earlier, as result
all of them get rid of the v_object in reclaim.

Move the call to vnode_destroy_vobject() to vgonel() before
VOP_RECLAIM().  This makes v_object stable: either the object is NULL,
or it is valid vm object till the vnode reclamation.  Remove code from
vnode_create_vobject() to handle races with the parallel destruction.

Reviewed by:	markj
Tested by:	pho
Sponsored by:	The FreeBSD Foundation
Differential revision:	https://reviews.freebsd.org/D21412
2019-08-29 07:50:25 +00:00

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/*-
* 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 (*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);
}
/*
* 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);
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, 0);
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);
}
if ((vp->v_iflag & VI_DOOMED) != 0) {
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;
int *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);
i = *buflen;
dd = vp->v_data;
if (vp->v_type == VCHR) {
i -= strlen(dd->de_cdp->cdp_c.si_name);
if (i < 0) {
error = ENOMEM;
goto finished;
}
bcopy(dd->de_cdp->cdp_c.si_name, buf + i,
strlen(dd->de_cdp->cdp_c.si_name));
de = dd->de_dir;
} else if (vp->v_type == VDIR) {
if (dd == dmp->dm_rootdir) {
*dvp = vp;
vref(*dvp);
goto finished;
}
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);
de = dd;
} else {
error = ENOENT;
goto finished;
}
*buflen = i;
de = devfs_parent_dirent(de);
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);
}
static void
devfs_insmntque_dtr(struct vnode *vp, void *arg)
{
struct devfs_dirent *de;
de = (struct devfs_dirent *)arg;
mtx_lock(&devfs_de_interlock);
vp->v_data = NULL;
de->de_vnode = NULL;
mtx_unlock(&devfs_de_interlock);
vgone(vp);
vput(vp);
}
/*
* 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;
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) {
VI_LOCK(vp);
mtx_unlock(&devfs_de_interlock);
sx_xunlock(&dmp->dm_lock);
vget(vp, lockmode | LK_INTERLOCK | LK_RETRY, curthread);
sx_xlock(&dmp->dm_lock);
if (devfs_allocv_drop_refs(0, dmp, de)) {
vput(vp);
return (ENOENT);
}
else if ((vp->v_iflag & VI_DOOMED) != 0) {
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;
KASSERT(vp->v_usecount == 1,
("%s %d (%d)\n", __func__, __LINE__, vp->v_usecount));
dev->si_usecount += vp->v_usecount;
/* 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, devfs_insmntque_dtr, de);
if (error != 0) {
(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, NULL);
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;
int dflags, error, ref, vp_locked;
/*
* XXX: Don't call d_close() if we were called because of
* XXX: insmntque1() 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 (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);
VI_LOCK(vp);
if (count_dev(dev) == 2 &&
(vp->v_iflag & VI_DOOMED) == 0) {
p->p_session->s_ttyvp = NULL;
p->p_session->s_ttydp = NULL;
oldvp = vp;
}
VI_UNLOCK(vp);
SESS_UNLOCK(p->p_session);
}
sx_xunlock(&proctree_lock);
if (oldvp != NULL)
vrele(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;
VI_LOCK(vp);
if (vp->v_iflag & VI_DOOMED) {
/* Forced close. */
dflags |= FREVOKE | FNONBLOCK;
} else if (dsw->d_flags & D_TRACKCLOSE) {
/* Keep device updated on status. */
} else if (count_dev(dev) > 1) {
VI_UNLOCK(vp);
dev_relthread(dev, ref);
return (0);
}
if (count_dev(dev) == 1)
dflags |= FLASTCLOSE;
vholdl(vp);
VI_UNLOCK(vp);
vp_locked = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp, 0);
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 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 */
sx_slock(&proctree_lock);
if (td->td_proc->p_session->s_ttyvp == vp) {
sx_sunlock(&proctree_lock);
return (0);
}
vpold = td->td_proc->p_session->s_ttyvp;
VREF(vp);
SESS_LOCK(td->td_proc->p_session);
td->td_proc->p_session->s_ttyvp = vp;
td->td_proc->p_session->s_ttydp = cdev2priv(dev);
SESS_UNLOCK(td->td_proc->p_session);
sx_sunlock(&proctree_lock);
/* Get rid of reference to old control tty */
if (vpold)
vrele(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;
cnp = ap->a_cnp;
vpp = ap->a_vpp;
dvp = ap->a_dvp;
pname = cnp->cn_nameptr;
td = cnp->cn_thread;
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 = VOP_ACCESS(dvp, VEXEC, cnp->cn_cred, td);
if (error)
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, 0);
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;
struct mtx *mtxp;
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);
}
vlocked = VOP_ISLOCKED(vp);
VOP_UNLOCK(vp, 0);
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);
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);
mtxp = mtx_pool_find(mtxpool_sleep, fp);
/*
* Hint to the dofilewrite() to not force the buffer draining
* on the writer to the file. Most likely, the write would
* not need normal buffers.
*/
mtx_lock(mtxp);
fp->f_vnread_flags |= FDEVFS_VNODE;
mtx_unlock(mtxp);
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-persistant 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);
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 int
devfs_reclaim(struct vop_reclaim_args *ap)
{
struct vnode *vp;
struct devfs_dirent *de;
vp = ap->a_vp;
mtx_lock(&devfs_de_interlock);
de = vp->v_data;
if (de != NULL) {
de->de_vnode = NULL;
vp->v_data = NULL;
}
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);
devfs_reclaim(ap);
VI_LOCK(vp);
dev_lock();
dev = vp->v_rdev;
vp->v_rdev = NULL;
if (dev != NULL)
dev->si_usecount -= vp->v_usecount;
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, 0);
if (dvp != vp)
VOP_UNLOCK(dvp, 0);
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;
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,0);
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();
VI_LOCK(vp2);
mtx_unlock(&devfs_de_interlock);
if (vget(vp2, LK_EXCLUSIVE | LK_INTERLOCK,
curthread))
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 (vp->v_iflag & VI_DOOMED) {
VOP_UNLOCK(vp, 0);
return (EBADF);
}
dmp = VFSTODEVFS(vp->v_mount);
sx_xlock(&dmp->dm_lock);
VOP_UNLOCK(vp, 0);
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, struct thread *td)
{
return (vnops.fo_stat(fp, sb, cred, td));
}
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);
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,
};
/* 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,
};
/*
* 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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