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No longer access the disk driver directly. 

If there is an open wedge, temporarily reference its vnode.
Otherwise try to open the block device.
This commit is contained in:
mlelstv 2015-08-22 07:48:14 +00:00
parent 862a433dd4
commit 1e8c46e3c4
1 changed files with 83 additions and 31 deletions
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114
sys/dev/dkwedge/dk.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: dk.c,v 1.81 2015/08/22 07:42:46 mlelstv Exp $ */
/* $NetBSD: dk.c,v 1.82 2015/08/22 07:48:14 mlelstv Exp $ */
/*-
* Copyright (c) 2004, 2005, 2006, 2007 The NetBSD Foundation, Inc.
@ -30,7 +30,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.81 2015/08/22 07:42:46 mlelstv Exp $");
__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.82 2015/08/22 07:48:14 mlelstv Exp $");
#ifdef _KERNEL_OPT
#include "opt_dkwedge.h"
@ -102,6 +102,8 @@ static int dkwedge_cleanup_parent(struct dkwedge_softc *, int);
static int dkwedge_detach(device_t, int);
static void dkwedge_delall1(struct disk *, bool);
static int dkwedge_del1(struct dkwedge_info *, int);
static struct vnode *dk_open_parent(dev_t, int);
static int dk_close_parent(struct vnode *, int);
static dev_type_open(dkopen);
static dev_type_close(dkclose);
@ -945,34 +947,58 @@ dkwedge_read(struct disk *pdk, struct vnode *vp, daddr_t blkno,
{
buf_t *bp;
int error;
bool isopen;
dev_t bdev;
struct vnode *bdevvp;
/*
* The kernel cannot read from a character device vnode
* as physio() only handles user memory.
*
* Determine the corresponding block device and call into
* the driver directly.
* If the block device has already been opened by a wedge
* use that vnode and temporarily bump the open counter.
*
* Otherwise try to open the block device.
*/
bp = getiobuf(vp, true);
bdev = devsw_chr2blk(vp->v_rdev);
mutex_enter(&pdk->dk_rawlock);
if (pdk->dk_rawopens != 0) {
KASSERT(pdk->dk_rawvp != NULL);
isopen = true;
++pdk->dk_rawopens;
bdevvp = pdk->dk_rawvp;
} else {
isopen = false;
bdevvp = dk_open_parent(bdev, FREAD);
}
mutex_exit(&pdk->dk_rawlock);
if (bdevvp == NULL)
return EBUSY;
bp = getiobuf(bdevvp, true);
bp->b_flags = B_READ;
bp->b_cflags = BC_BUSY;
bp->b_dev = devsw_chr2blk(vp->v_rdev);
bp->b_dev = bdev;
bp->b_data = tbuf;
bp->b_bufsize = bp->b_bcount = len;
bp->b_blkno = blkno;
bp->b_cylinder = 0;
bp->b_error = 0;
error = bdev_open(bp->b_dev, FREAD, S_IFBLK, curlwp);
if (error)
return error;
bdev_strategy(bp);
VOP_STRATEGY(bdevvp, bp);
error = biowait(bp);
putiobuf(bp);
bdev_close(bp->b_dev, FREAD, S_IFBLK, curlwp);
mutex_enter(&pdk->dk_rawlock);
if (isopen) {
--pdk->dk_rawopens;
} else {
dk_close_parent(bdevvp, FREAD);
}
mutex_exit(&pdk->dk_rawlock);
return error;
}
@ -995,6 +1021,48 @@ dkwedge_lookup(dev_t dev)
return (dkwedges[unit]);
}
static struct vnode *
dk_open_parent(dev_t dev, int mode)
{
struct vnode *vp;
int error;
error = bdevvp(dev, &vp);
if (error)
return NULL;
error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error) {
vrele(vp);
return NULL;
}
error = VOP_OPEN(vp, mode, NOCRED);
if (error) {
vput(vp);
return NULL;
}
/* VOP_OPEN() doesn't do this for us. */
if (mode & FWRITE) {
mutex_enter(vp->v_interlock);
vp->v_writecount++;
mutex_exit(vp->v_interlock);
}
VOP_UNLOCK(vp);
return vp;
}
static int
dk_close_parent(struct vnode *vp, int mode)
{
int error;
error = vn_close(vp, mode, NOCRED);
return error;
}
/*
* dkopen: [devsw entry point]
*
@ -1023,24 +1091,9 @@ dkopen(dev_t dev, int flags, int fmt, struct lwp *l)
if (sc->sc_dk.dk_openmask == 0) {
if (sc->sc_parent->dk_rawopens == 0) {
KASSERT(sc->sc_parent->dk_rawvp == NULL);
error = bdevvp(sc->sc_pdev, &vp);
if (error)
vp = dk_open_parent(sc->sc_pdev, FREAD | FWRITE);
if (vp == NULL)
goto popen_fail;
error = vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
if (error) {
vrele(vp);
goto popen_fail;
}
error = VOP_OPEN(vp, FREAD | FWRITE, NOCRED);
if (error) {
vput(vp);
goto popen_fail;
}
/* VOP_OPEN() doesn't do this for us. */
mutex_enter(vp->v_interlock);
vp->v_writecount++;
mutex_exit(vp->v_interlock);
VOP_UNLOCK(vp);
sc->sc_parent->dk_rawvp = vp;
}
sc->sc_parent->dk_rawopens++;
@ -1076,8 +1129,7 @@ dklastclose(struct dkwedge_softc *sc)
if (doclose) {
KASSERT(sc->sc_parent->dk_rawvp != NULL);
error = vn_close(sc->sc_parent->dk_rawvp,
FREAD | FWRITE, NOCRED);
dk_close_parent(sc->sc_parent->dk_rawvp, FREAD | FWRITE);
sc->sc_parent->dk_rawvp = NULL;
}