/
spec_vnops.c
1372 lines (1206 loc) · 31.5 KB
/
spec_vnops.c
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/* $NetBSD: spec_vnops.c,v 1.183 2021/07/18 23:57:14 dholland Exp $ */
/*-
* Copyright (c) 2008 The NetBSD Foundation, Inc.
* All rights reserved.
*
* 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
*/
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. 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.
*
* @(#)spec_vnops.c 8.15 (Berkeley) 7/14/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: spec_vnops.c,v 1.183 2021/07/18 23:57:14 dholland Exp $");
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode_impl.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/poll.h>
#include <sys/file.h>
#include <sys/disklabel.h>
#include <sys/disk.h>
#include <sys/lockf.h>
#include <sys/tty.h>
#include <sys/kauth.h>
#include <sys/fstrans.h>
#include <sys/module.h>
#include <miscfs/genfs/genfs.h>
#include <miscfs/specfs/specdev.h>
/* symbolic sleep message strings for devices */
const char devopn[] = "devopn";
const char devio[] = "devio";
const char devwait[] = "devwait";
const char devin[] = "devin";
const char devout[] = "devout";
const char devioc[] = "devioc";
const char devcls[] = "devcls";
#define SPECHSZ 64
#if ((SPECHSZ&(SPECHSZ-1)) == 0)
#define SPECHASH(rdev) (((rdev>>5)+(rdev))&(SPECHSZ-1))
#else
#define SPECHASH(rdev) (((unsigned)((rdev>>5)+(rdev)))%SPECHSZ)
#endif
static vnode_t *specfs_hash[SPECHSZ];
extern struct mount *dead_rootmount;
/*
* This vnode operations vector is used for special device nodes
* created from whole cloth by the kernel. For the ops vector for
* vnodes built from special devices found in a filesystem, see (e.g)
* ffs_specop_entries[] in ffs_vnops.c or the equivalent for other
* filesystems.
*/
int (**spec_vnodeop_p)(void *);
const struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_parsepath_desc, genfs_parsepath }, /* parsepath */
{ &vop_lookup_desc, spec_lookup }, /* lookup */
{ &vop_create_desc, genfs_badop }, /* create */
{ &vop_mknod_desc, genfs_badop }, /* mknod */
{ &vop_open_desc, spec_open }, /* open */
{ &vop_close_desc, spec_close }, /* close */
{ &vop_access_desc, genfs_ebadf }, /* access */
{ &vop_accessx_desc, genfs_ebadf }, /* accessx */
{ &vop_getattr_desc, genfs_ebadf }, /* getattr */
{ &vop_setattr_desc, genfs_ebadf }, /* setattr */
{ &vop_read_desc, spec_read }, /* read */
{ &vop_write_desc, spec_write }, /* write */
{ &vop_fallocate_desc, genfs_eopnotsupp }, /* fallocate */
{ &vop_fdiscard_desc, spec_fdiscard }, /* fdiscard */
{ &vop_fcntl_desc, genfs_fcntl }, /* fcntl */
{ &vop_ioctl_desc, spec_ioctl }, /* ioctl */
{ &vop_poll_desc, spec_poll }, /* poll */
{ &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */
{ &vop_revoke_desc, genfs_revoke }, /* revoke */
{ &vop_mmap_desc, spec_mmap }, /* mmap */
{ &vop_fsync_desc, spec_fsync }, /* fsync */
{ &vop_seek_desc, spec_seek }, /* seek */
{ &vop_remove_desc, genfs_badop }, /* remove */
{ &vop_link_desc, genfs_badop }, /* link */
{ &vop_rename_desc, genfs_badop }, /* rename */
{ &vop_mkdir_desc, genfs_badop }, /* mkdir */
{ &vop_rmdir_desc, genfs_badop }, /* rmdir */
{ &vop_symlink_desc, genfs_badop }, /* symlink */
{ &vop_readdir_desc, genfs_badop }, /* readdir */
{ &vop_readlink_desc, genfs_badop }, /* readlink */
{ &vop_abortop_desc, genfs_badop }, /* abortop */
{ &vop_inactive_desc, spec_inactive }, /* inactive */
{ &vop_reclaim_desc, spec_reclaim }, /* reclaim */
{ &vop_lock_desc, genfs_nolock }, /* lock */
{ &vop_unlock_desc, genfs_nounlock }, /* unlock */
{ &vop_bmap_desc, spec_bmap }, /* bmap */
{ &vop_strategy_desc, spec_strategy }, /* strategy */
{ &vop_print_desc, spec_print }, /* print */
{ &vop_islocked_desc, genfs_noislocked }, /* islocked */
{ &vop_pathconf_desc, spec_pathconf }, /* pathconf */
{ &vop_advlock_desc, spec_advlock }, /* advlock */
{ &vop_bwrite_desc, vn_bwrite }, /* bwrite */
{ &vop_getpages_desc, genfs_getpages }, /* getpages */
{ &vop_putpages_desc, genfs_putpages }, /* putpages */
{ NULL, NULL }
};
const struct vnodeopv_desc spec_vnodeop_opv_desc =
{ &spec_vnodeop_p, spec_vnodeop_entries };
static kauth_listener_t rawio_listener;
/* Returns true if vnode is /dev/mem or /dev/kmem. */
bool
iskmemvp(struct vnode *vp)
{
return ((vp->v_type == VCHR) && iskmemdev(vp->v_rdev));
}
/*
* Returns true if dev is /dev/mem or /dev/kmem.
*/
int
iskmemdev(dev_t dev)
{
/* mem_no is emitted by config(8) to generated devsw.c */
extern const int mem_no;
/* minor 14 is /dev/io on i386 with COMPAT_10 */
return (major(dev) == mem_no && (minor(dev) < 2 || minor(dev) == 14));
}
static int
rawio_listener_cb(kauth_cred_t cred, kauth_action_t action, void *cookie,
void *arg0, void *arg1, void *arg2, void *arg3)
{
int result;
result = KAUTH_RESULT_DEFER;
if ((action != KAUTH_DEVICE_RAWIO_SPEC) &&
(action != KAUTH_DEVICE_RAWIO_PASSTHRU))
return result;
/* Access is mandated by permissions. */
result = KAUTH_RESULT_ALLOW;
return result;
}
void
spec_init(void)
{
rawio_listener = kauth_listen_scope(KAUTH_SCOPE_DEVICE,
rawio_listener_cb, NULL);
}
/*
* Initialize a vnode that represents a device.
*/
void
spec_node_init(vnode_t *vp, dev_t rdev)
{
specnode_t *sn;
specdev_t *sd;
vnode_t *vp2;
vnode_t **vpp;
KASSERT(vp->v_type == VBLK || vp->v_type == VCHR);
KASSERT(vp->v_specnode == NULL);
/*
* Search the hash table for this device. If known, add a
* reference to the device structure. If not known, create
* a new entry to represent the device. In all cases add
* the vnode to the hash table.
*/
sn = kmem_alloc(sizeof(*sn), KM_SLEEP);
sd = kmem_alloc(sizeof(*sd), KM_SLEEP);
mutex_enter(&device_lock);
vpp = &specfs_hash[SPECHASH(rdev)];
for (vp2 = *vpp; vp2 != NULL; vp2 = vp2->v_specnext) {
KASSERT(vp2->v_specnode != NULL);
if (rdev == vp2->v_rdev && vp->v_type == vp2->v_type) {
break;
}
}
if (vp2 == NULL) {
/* No existing record, create a new one. */
sd->sd_rdev = rdev;
sd->sd_mountpoint = NULL;
sd->sd_lockf = NULL;
sd->sd_refcnt = 1;
sd->sd_opencnt = 0;
sd->sd_bdevvp = NULL;
sn->sn_dev = sd;
sd = NULL;
} else {
/* Use the existing record. */
sn->sn_dev = vp2->v_specnode->sn_dev;
sn->sn_dev->sd_refcnt++;
}
/* Insert vnode into the hash chain. */
sn->sn_opencnt = 0;
sn->sn_rdev = rdev;
sn->sn_gone = false;
vp->v_specnode = sn;
vp->v_specnext = *vpp;
*vpp = vp;
mutex_exit(&device_lock);
/* Free the record we allocated if unused. */
if (sd != NULL) {
kmem_free(sd, sizeof(*sd));
}
}
/*
* Lookup a vnode by device number and return it referenced.
*/
int
spec_node_lookup_by_dev(enum vtype type, dev_t dev, vnode_t **vpp)
{
int error;
vnode_t *vp;
mutex_enter(&device_lock);
for (vp = specfs_hash[SPECHASH(dev)]; vp; vp = vp->v_specnext) {
if (type == vp->v_type && dev == vp->v_rdev) {
mutex_enter(vp->v_interlock);
/* If clean or being cleaned, then ignore it. */
if (vdead_check(vp, VDEAD_NOWAIT) == 0)
break;
mutex_exit(vp->v_interlock);
}
}
KASSERT(vp == NULL || mutex_owned(vp->v_interlock));
if (vp == NULL) {
mutex_exit(&device_lock);
return ENOENT;
}
/*
* If it is an opened block device return the opened vnode.
*/
if (type == VBLK && vp->v_specnode->sn_dev->sd_bdevvp != NULL) {
mutex_exit(vp->v_interlock);
vp = vp->v_specnode->sn_dev->sd_bdevvp;
mutex_enter(vp->v_interlock);
}
mutex_exit(&device_lock);
error = vcache_vget(vp);
if (error != 0)
return error;
*vpp = vp;
return 0;
}
/*
* Lookup a vnode by file system mounted on and return it referenced.
*/
int
spec_node_lookup_by_mount(struct mount *mp, vnode_t **vpp)
{
int i, error;
vnode_t *vp, *vq;
mutex_enter(&device_lock);
for (i = 0, vq = NULL; i < SPECHSZ && vq == NULL; i++) {
for (vp = specfs_hash[i]; vp; vp = vp->v_specnext) {
if (vp->v_type != VBLK)
continue;
vq = vp->v_specnode->sn_dev->sd_bdevvp;
if (vq != NULL &&
vq->v_specnode->sn_dev->sd_mountpoint == mp)
break;
vq = NULL;
}
}
if (vq == NULL) {
mutex_exit(&device_lock);
return ENOENT;
}
mutex_enter(vq->v_interlock);
mutex_exit(&device_lock);
error = vcache_vget(vq);
if (error != 0)
return error;
*vpp = vq;
return 0;
}
/*
* Get the file system mounted on this block device.
*/
struct mount *
spec_node_getmountedfs(vnode_t *devvp)
{
struct mount *mp;
KASSERT(devvp->v_type == VBLK);
mp = devvp->v_specnode->sn_dev->sd_mountpoint;
return mp;
}
/*
* Set the file system mounted on this block device.
*/
void
spec_node_setmountedfs(vnode_t *devvp, struct mount *mp)
{
struct dkwedge_info dkw;
KASSERT(devvp->v_type == VBLK);
KASSERT(devvp->v_specnode->sn_dev->sd_mountpoint == NULL || mp == NULL);
devvp->v_specnode->sn_dev->sd_mountpoint = mp;
if (mp == NULL)
return;
if (bdev_ioctl(devvp->v_rdev, DIOCGWEDGEINFO, &dkw, FREAD, curlwp) != 0)
return;
strlcpy(mp->mnt_stat.f_mntfromlabel, dkw.dkw_wname,
sizeof(mp->mnt_stat.f_mntfromlabel));
}
/*
* A vnode representing a special device is going away. Close
* the device if the vnode holds it open.
*/
void
spec_node_revoke(vnode_t *vp)
{
specnode_t *sn;
specdev_t *sd;
sn = vp->v_specnode;
sd = sn->sn_dev;
KASSERT(vp->v_type == VBLK || vp->v_type == VCHR);
KASSERT(vp->v_specnode != NULL);
KASSERT(sn->sn_gone == false);
mutex_enter(&device_lock);
KASSERT(sn->sn_opencnt <= sd->sd_opencnt);
if (sn->sn_opencnt != 0) {
sd->sd_opencnt -= (sn->sn_opencnt - 1);
sn->sn_opencnt = 1;
sn->sn_gone = true;
mutex_exit(&device_lock);
VOP_CLOSE(vp, FNONBLOCK, NOCRED);
mutex_enter(&device_lock);
KASSERT(sn->sn_opencnt == 0);
}
mutex_exit(&device_lock);
}
/*
* A vnode representing a special device is being recycled.
* Destroy the specfs component.
*/
void
spec_node_destroy(vnode_t *vp)
{
specnode_t *sn;
specdev_t *sd;
vnode_t **vpp, *vp2;
int refcnt;
sn = vp->v_specnode;
sd = sn->sn_dev;
KASSERT(vp->v_type == VBLK || vp->v_type == VCHR);
KASSERT(vp->v_specnode != NULL);
KASSERT(sn->sn_opencnt == 0);
mutex_enter(&device_lock);
/* Remove from the hash and destroy the node. */
vpp = &specfs_hash[SPECHASH(vp->v_rdev)];
for (vp2 = *vpp;; vp2 = vp2->v_specnext) {
if (vp2 == NULL) {
panic("spec_node_destroy: corrupt hash");
}
if (vp2 == vp) {
KASSERT(vp == *vpp);
*vpp = vp->v_specnext;
break;
}
if (vp2->v_specnext == vp) {
vp2->v_specnext = vp->v_specnext;
break;
}
}
sn = vp->v_specnode;
vp->v_specnode = NULL;
refcnt = sd->sd_refcnt--;
KASSERT(refcnt > 0);
mutex_exit(&device_lock);
/* If the device is no longer in use, destroy our record. */
if (refcnt == 1) {
KASSERT(sd->sd_opencnt == 0);
KASSERT(sd->sd_bdevvp == NULL);
kmem_free(sd, sizeof(*sd));
}
kmem_free(sn, sizeof(*sn));
}
/*
* Trivial lookup routine that always fails.
*/
int
spec_lookup(void *v)
{
struct vop_lookup_v2_args /* {
struct vnode *a_dvp;
struct vnode **a_vpp;
struct componentname *a_cnp;
} */ *ap = v;
*ap->a_vpp = NULL;
return (ENOTDIR);
}
typedef int (*spec_ioctl_t)(dev_t, u_long, void *, int, struct lwp *);
/*
* Open a special file.
*/
/* ARGSUSED */
int
spec_open(void *v)
{
struct vop_open_args /* {
struct vnode *a_vp;
int a_mode;
kauth_cred_t a_cred;
} */ *ap = v;
struct lwp *l;
struct vnode *vp;
dev_t dev;
int error;
enum kauth_device_req req;
specnode_t *sn;
specdev_t *sd;
spec_ioctl_t ioctl;
u_int gen;
const char *name;
struct partinfo pi;
l = curlwp;
vp = ap->a_vp;
dev = vp->v_rdev;
sn = vp->v_specnode;
sd = sn->sn_dev;
name = NULL;
gen = 0;
/*
* Don't allow open if fs is mounted -nodev.
*/
if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
return (ENXIO);
switch (ap->a_mode & (FREAD | FWRITE)) {
case FREAD | FWRITE:
req = KAUTH_REQ_DEVICE_RAWIO_SPEC_RW;
break;
case FWRITE:
req = KAUTH_REQ_DEVICE_RAWIO_SPEC_WRITE;
break;
default:
req = KAUTH_REQ_DEVICE_RAWIO_SPEC_READ;
break;
}
switch (vp->v_type) {
case VCHR:
error = kauth_authorize_device_spec(ap->a_cred, req, vp);
if (error != 0)
return (error);
/*
* Character devices can accept opens from multiple
* vnodes.
*/
mutex_enter(&device_lock);
if (sn->sn_gone) {
mutex_exit(&device_lock);
return (EBADF);
}
sd->sd_opencnt++;
sn->sn_opencnt++;
mutex_exit(&device_lock);
if (cdev_type(dev) == D_TTY)
vp->v_vflag |= VV_ISTTY;
VOP_UNLOCK(vp);
do {
const struct cdevsw *cdev;
gen = module_gen;
error = cdev_open(dev, ap->a_mode, S_IFCHR, l);
if (error != ENXIO)
break;
/* Check if we already have a valid driver */
mutex_enter(&device_lock);
cdev = cdevsw_lookup(dev);
mutex_exit(&device_lock);
if (cdev != NULL)
break;
/* Get device name from devsw_conv array */
if ((name = cdevsw_getname(major(dev))) == NULL)
break;
/* Try to autoload device module */
(void) module_autoload(name, MODULE_CLASS_DRIVER);
} while (gen != module_gen);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
break;
case VBLK:
error = kauth_authorize_device_spec(ap->a_cred, req, vp);
if (error != 0)
return (error);
/*
* For block devices, permit only one open. The buffer
* cache cannot remain self-consistent with multiple
* vnodes holding a block device open.
*
* Treat zero opencnt with non-NULL mountpoint as open.
* This may happen after forced detach of a mounted device.
*/
mutex_enter(&device_lock);
if (sn->sn_gone) {
mutex_exit(&device_lock);
return (EBADF);
}
if (sd->sd_opencnt != 0 || sd->sd_mountpoint != NULL) {
mutex_exit(&device_lock);
return EBUSY;
}
sn->sn_opencnt = 1;
sd->sd_opencnt = 1;
sd->sd_bdevvp = vp;
mutex_exit(&device_lock);
do {
const struct bdevsw *bdev;
gen = module_gen;
error = bdev_open(dev, ap->a_mode, S_IFBLK, l);
if (error != ENXIO)
break;
/* Check if we already have a valid driver */
mutex_enter(&device_lock);
bdev = bdevsw_lookup(dev);
mutex_exit(&device_lock);
if (bdev != NULL)
break;
/* Get device name from devsw_conv array */
if ((name = bdevsw_getname(major(dev))) == NULL)
break;
VOP_UNLOCK(vp);
/* Try to autoload device module */
(void) module_autoload(name, MODULE_CLASS_DRIVER);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
} while (gen != module_gen);
break;
case VNON:
case VLNK:
case VDIR:
case VREG:
case VBAD:
case VFIFO:
case VSOCK:
default:
return 0;
}
mutex_enter(&device_lock);
if (sn->sn_gone) {
if (error == 0)
error = EBADF;
} else if (error != 0) {
sd->sd_opencnt--;
sn->sn_opencnt--;
if (vp->v_type == VBLK)
sd->sd_bdevvp = NULL;
}
mutex_exit(&device_lock);
if (cdev_type(dev) != D_DISK || error != 0)
return error;
ioctl = vp->v_type == VCHR ? cdev_ioctl : bdev_ioctl;
error = (*ioctl)(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, curlwp);
if (error == 0)
uvm_vnp_setsize(vp, (voff_t)pi.pi_secsize * pi.pi_size);
return 0;
}
/*
* Vnode op for read
*/
/* ARGSUSED */
int
spec_read(void *v)
{
struct vop_read_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct lwp *l = curlwp;
struct buf *bp;
daddr_t bn;
int bsize, bscale;
struct partinfo pi;
int n, on;
int error = 0;
int i, nra;
daddr_t lastbn, *rablks;
int *rasizes;
int nrablks, ratogo;
KASSERT(uio->uio_rw == UIO_READ);
KASSERTMSG(VMSPACE_IS_KERNEL_P(uio->uio_vmspace) ||
uio->uio_vmspace == curproc->p_vmspace,
"vmspace belongs to neither kernel nor curproc");
if (uio->uio_resid == 0)
return (0);
switch (vp->v_type) {
case VCHR:
VOP_UNLOCK(vp);
error = cdev_read(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_SHARED | LK_RETRY);
return (error);
case VBLK:
KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp);
if (uio->uio_offset < 0)
return (EINVAL);
if (bdev_ioctl(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, l) == 0)
bsize = imin(imax(pi.pi_bsize, DEV_BSIZE), MAXBSIZE);
else
bsize = BLKDEV_IOSIZE;
bscale = bsize >> DEV_BSHIFT;
nra = uimax(16 * MAXPHYS / bsize - 1, 511);
rablks = kmem_alloc(nra * sizeof(*rablks), KM_SLEEP);
rasizes = kmem_alloc(nra * sizeof(*rasizes), KM_SLEEP);
lastbn = ((uio->uio_offset + uio->uio_resid - 1) >> DEV_BSHIFT)
&~ (bscale - 1);
nrablks = ratogo = 0;
do {
bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1);
on = uio->uio_offset % bsize;
n = uimin((unsigned)(bsize - on), uio->uio_resid);
if (ratogo == 0) {
nrablks = uimin((lastbn - bn) / bscale, nra);
ratogo = nrablks;
for (i = 0; i < nrablks; ++i) {
rablks[i] = bn + (i+1) * bscale;
rasizes[i] = bsize;
}
error = breadn(vp, bn, bsize,
rablks, rasizes, nrablks,
0, &bp);
} else {
if (ratogo > 0)
--ratogo;
error = bread(vp, bn, bsize, 0, &bp);
}
if (error)
break;
n = uimin(n, bsize - bp->b_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
brelse(bp, 0);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
kmem_free(rablks, nra * sizeof(*rablks));
kmem_free(rasizes, nra * sizeof(*rasizes));
return (error);
default:
panic("spec_read type");
}
/* NOTREACHED */
}
/*
* Vnode op for write
*/
/* ARGSUSED */
int
spec_write(void *v)
{
struct vop_write_args /* {
struct vnode *a_vp;
struct uio *a_uio;
int a_ioflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct lwp *l = curlwp;
struct buf *bp;
daddr_t bn;
int bsize, bscale;
struct partinfo pi;
int n, on;
int error = 0;
KASSERT(uio->uio_rw == UIO_WRITE);
KASSERTMSG(VMSPACE_IS_KERNEL_P(uio->uio_vmspace) ||
uio->uio_vmspace == curproc->p_vmspace,
"vmspace belongs to neither kernel nor curproc");
switch (vp->v_type) {
case VCHR:
VOP_UNLOCK(vp);
error = cdev_write(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
return (error);
case VBLK:
KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp);
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
if (bdev_ioctl(vp->v_rdev, DIOCGPARTINFO, &pi, FREAD, l) == 0)
bsize = imin(imax(pi.pi_bsize, DEV_BSIZE), MAXBSIZE);
else
bsize = BLKDEV_IOSIZE;
bscale = bsize >> DEV_BSHIFT;
do {
bn = (uio->uio_offset >> DEV_BSHIFT) &~ (bscale - 1);
on = uio->uio_offset % bsize;
n = uimin((unsigned)(bsize - on), uio->uio_resid);
if (n == bsize)
bp = getblk(vp, bn, bsize, 0, 0);
else
error = bread(vp, bn, bsize, B_MODIFY, &bp);
if (error) {
return (error);
}
n = uimin(n, bsize - bp->b_resid);
error = uiomove((char *)bp->b_data + on, n, uio);
if (error)
brelse(bp, 0);
else {
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
error = bp->b_error;
}
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_write type");
}
/* NOTREACHED */
}
/*
* fdiscard, which on disk devices becomes TRIM.
*/
int
spec_fdiscard(void *v)
{
struct vop_fdiscard_args /* {
struct vnode *a_vp;
off_t a_pos;
off_t a_len;
} */ *ap = v;
struct vnode *vp;
dev_t dev;
vp = ap->a_vp;
dev = NODEV;
mutex_enter(vp->v_interlock);
if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode != NULL) {
dev = vp->v_rdev;
}
mutex_exit(vp->v_interlock);
if (dev == NODEV) {
return ENXIO;
}
switch (vp->v_type) {
case VCHR:
// this is not stored for character devices
//KASSERT(vp == vp->v_specnode->sn_dev->sd_cdevvp);
return cdev_discard(dev, ap->a_pos, ap->a_len);
case VBLK:
KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp);
return bdev_discard(dev, ap->a_pos, ap->a_len);
default:
panic("spec_fdiscard: not a device\n");
}
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
int
spec_ioctl(void *v)
{
struct vop_ioctl_args /* {
struct vnode *a_vp;
u_long a_command;
void *a_data;
int a_fflag;
kauth_cred_t a_cred;
} */ *ap = v;
struct vnode *vp;
dev_t dev;
/*
* Extract all the info we need from the vnode, taking care to
* avoid a race with VOP_REVOKE().
*/
vp = ap->a_vp;
dev = NODEV;
mutex_enter(vp->v_interlock);
if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode) {
dev = vp->v_rdev;
}
mutex_exit(vp->v_interlock);
if (dev == NODEV) {
return ENXIO;
}
switch (vp->v_type) {
case VCHR:
return cdev_ioctl(dev, ap->a_command, ap->a_data,
ap->a_fflag, curlwp);
case VBLK:
KASSERT(vp == vp->v_specnode->sn_dev->sd_bdevvp);
return bdev_ioctl(dev, ap->a_command, ap->a_data,
ap->a_fflag, curlwp);
default:
panic("spec_ioctl");
/* NOTREACHED */
}
}
/* ARGSUSED */
int
spec_poll(void *v)
{
struct vop_poll_args /* {
struct vnode *a_vp;
int a_events;
} */ *ap = v;
struct vnode *vp;
dev_t dev;
/*
* Extract all the info we need from the vnode, taking care to
* avoid a race with VOP_REVOKE().
*/
vp = ap->a_vp;
dev = NODEV;
mutex_enter(vp->v_interlock);
if (vdead_check(vp, VDEAD_NOWAIT) == 0 && vp->v_specnode) {
dev = vp->v_rdev;
}
mutex_exit(vp->v_interlock);
if (dev == NODEV) {
return POLLERR;
}
switch (vp->v_type) {
case VCHR:
return cdev_poll(dev, ap->a_events, curlwp);
default:
return (genfs_poll(v));
}
}
/* ARGSUSED */
int
spec_kqfilter(void *v)
{
struct vop_kqfilter_args /* {
struct vnode *a_vp;
struct proc *a_kn;
} */ *ap = v;
dev_t dev;
switch (ap->a_vp->v_type) {
case VCHR:
dev = ap->a_vp->v_rdev;
return cdev_kqfilter(dev, ap->a_kn);
default: