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Add the devfs_fp_check() function which helps us get from a struct file

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to a cdev and a devsw, doing all the relevant checks along the way.

Add the check to see if fp->f_vnode->v_rdev differs from our cached
fp->f_data copy of our cdev.  If it does the device was revoked and
we return ENXIO.
This commit is contained in:
Poul-Henning Kamp 2004-11-13 23:21:54 +00:00
parent b0cccc25e5
commit aac5167c38
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=137678
1 changed files with 34 additions and 70 deletions
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104
sys/fs/devfs/devfs_vnops.c
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@ -120,6 +120,21 @@ static int devfs_write(struct vop_write_args *ap);
static vop_t **devfs_vnodeop_p;
vop_t **devfs_specop_p;
static int
devfs_fp_check(struct file *fp, struct cdev **devp, struct cdevsw **dswp)
{
*devp = fp->f_vnode->v_rdev;
if (*devp != fp->f_data)
return (ENXIO);
KASSERT((*devp)->si_refcount > 0,
("devfs: un-referenced struct cdev *(%s)", devtoname(*devp)));
*dswp = dev_refthread(*devp);
if (*dswp == NULL)
return (ENXIO);
return (0);
}
/*
* Construct the fully qualified path name relative to the mountpoint
*/
@ -342,12 +357,7 @@ devfs_close(ap)
static int
devfs_close_f(struct file *fp, struct thread *td)
{
struct cdev *dev;
dev = fp->f_data;
#if 0
printf("devfs_close_f(%s)\n", devtoname(dev));
#endif
return (vnops.fo_close(fp, td));
}
@ -481,20 +491,13 @@ devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struc
{
struct cdev *dev;
struct cdevsw *dsw;
struct vnode *vp = fp->f_vnode;
struct vnode *vp;
struct vnode *vpold;
int error;
dev = fp->f_data;
#if 0
printf("devfs_ioctl_f(%s)\n", devtoname(dev));
#endif
KASSERT(dev->si_refcount > 0,
("devfs_ioctl() on un-referenced struct cdev *(%s)",
devtoname(dev)));
dsw = dev_refthread(dev);
if (dsw == NULL)
return (ENXIO);
error = devfs_fp_check(fp, &dev, &dsw);
if (error)
return (error);
if (com == FIODTYPE) {
*(int *)data = dsw->d_flags & D_TYPEMASK;
@ -510,6 +513,7 @@ devfs_ioctl_f(struct file *fp, u_long com, void *data, struct ucred *cred, struc
if (error == ENOIOCTL)
error = ENOTTY;
if (error == 0 && com == TIOCSCTTY) {
vp = fp->f_vnode;
/* Do nothing if reassigning same control tty */
sx_slock(&proctree_lock);
@ -572,16 +576,9 @@ devfs_kqfilter_f(struct file *fp, struct knote *kn)
struct cdevsw *dsw;
int error;
dev = fp->f_data;
#if 0
printf("devfs_kqfilter_f(%s)\n", devtoname(dev));
#endif
KASSERT(dev->si_refcount > 0,
("devfs_kqfilter() on un-referenced struct cdev *(%s)",
devtoname(dev)));
dsw = dev_refthread(dev);
if (dsw == NULL)
return(0);
error = devfs_fp_check(fp, &dev, &dsw);
if (error)
return (error);
if (dsw->d_flags & D_NEEDGIANT)
mtx_lock(&Giant);
error = dsw->d_kqfilter(dev, kn);
@ -816,6 +813,7 @@ devfs_open(ap)
int a_mode;
struct ucred *a_cred;
struct thread *a_td;
int a_fdidx;
} */ *ap;
{
struct thread *td = ap->a_td;
@ -974,16 +972,9 @@ devfs_poll_f(struct file *fp, int events, struct ucred *cred, struct thread *td)
struct cdevsw *dsw;
int error;
dev = fp->f_data;
#if 0
printf("devfs_poll_f(%s)\n", devtoname(dev));
#endif
dsw = dev_refthread(dev);
if (dsw == NULL)
return (0);
KASSERT(dev->si_refcount > 0,
("devfs_poll() on un-referenced struct cdev *(%s)",
devtoname(dev)));
error = devfs_fp_check(fp, &dev, &dsw);
if (error)
return (error);
if (dsw->d_flags & D_NEEDGIANT)
mtx_lock(&Giant);
error = dsw->d_poll(dev, events, td);
@ -1061,25 +1052,11 @@ devfs_read_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, st
struct cdev *dev;
int ioflag, error, resid;
struct cdevsw *dsw;
struct vnode *vp;
dev = fp->f_data;
#if 0
/*
* Enabling this one is dangerous, syslog will log once for each
* read from /dev/klog so...
*/
printf("devfs_read_f(%s)\n", devtoname(dev));
#endif
KASSERT(dev->si_refcount > 0,
("specread() on un-referenced struct cdev *(%s)", devtoname(dev)));
dsw = dev_refthread(dev);
if (dsw == NULL)
return (ENXIO);
vp = fp->f_vnode;
error = devfs_fp_check(fp, &dev, &dsw);
if (error)
return (error);
resid = uio->uio_resid;
ioflag = 0;
if (fp->f_flag & FNONBLOCK)
ioflag |= IO_NDELAY;
@ -1210,7 +1187,7 @@ devfs_reclaim(ap)
if (de != NULL)
de->de_vnode = NULL;
vp->v_data = NULL;
if (vp->v_rdev != NULL && vp->v_rdev != NULL) {
if (vp->v_rdev != NULL) {
i = vcount(vp);
if ((vp->v_rdev->si_flags & SI_CHEAPCLONE) && i == 0 &&
(vp->v_rdev->si_flags & SI_NAMED))
@ -1426,12 +1403,7 @@ devfs_setlabel(ap)
static int
devfs_stat_f(struct file *fp, struct stat *sb, struct ucred *cred, struct thread *td)
{
struct cdev *dev;
dev = fp->f_data;
#if 0
printf("devfs_stat_f(%s)\n", devtoname(dev));
#endif
return (vnops.fo_stat(fp, sb, cred, td));
}
@ -1533,17 +1505,9 @@ devfs_write_f(struct file *fp, struct uio *uio, struct ucred *cred, int flags, s
int error, ioflag, resid;
struct cdevsw *dsw;
dev = fp->f_data;
#if 0
printf("devfs_write_f(%s)\n", devtoname(dev));
#endif
KASSERT(dev->si_refcount > 0,
("devfs_write() on un-referenced struct cdev *(%s)",
devtoname(dev)));
dsw = dev_refthread(dev);
if (dsw == NULL)
return (ENXIO);
error = devfs_fp_check(fp, &dev, &dsw);
if (error)
return (error);
KASSERT(uio->uio_td == td, ("uio_td %p is not td %p", uio->uio_td, td));
vp = fp->f_vnode;
ioflag = IO_UNIT;