Module Name: src
Committed By: riastradh
Date: Sat Apr 22 13:11:50 UTC 2023
Modified Files:
src/sys/dev/dkwedge: dk.c
Log Message:
dk(4): Convert tests to assertions in various devsw operations.
.d_cancel, .d_strategy, .d_read, .d_write, .d_ioctl, and .d_discard
are only ever used between successful .d_open return and entry to
.d_close. .d_open doesn't return until sc is nonnull and sc_state is
RUNNING, and dkwedge_detach waits for the last .d_close before
setting sc_state to DEAD. So there is no possibility for sc to be
null or for sc_state to be anything other than RUNNING or DYING.
There is a small functional change here but only in the event of a
race: in the short window between when dkwedge_detach is entered, and
when .d_close runs, any I/O operations (read, write, ioctl, &c.) may
be issued that would have failed with ENXIO before.
This shouldn't matter for anything: disk I/O operations are supposed
to complete reasonably promptly, and these operations _could_ have
begun milliseconds prior, before dkwedge_detach was entered, so it's
not a significant distinction.
Notes:
- .d_open must still contend with trying to open a nonexistent wedge,
of course.
- .d_close must also contend with closing a nonexistent wedge, in
case there were two calls to open in quick succession and the first
failed while the second hadn't yet determined it would fail.
- .d_size and .d_dump are used from ddb without any open/close.
To generate a diff of this commit:
cvs rdiff -u -r1.149 -r1.150 src/sys/dev/dkwedge/dk.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/dev/dkwedge/dk.c
diff -u src/sys/dev/dkwedge/dk.c:1.149 src/sys/dev/dkwedge/dk.c:1.150
--- src/sys/dev/dkwedge/dk.c:1.149 Sat Apr 22 12:33:46 2023
+++ src/sys/dev/dkwedge/dk.c Sat Apr 22 13:11:50 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: dk.c,v 1.149 2023/04/22 12:33:46 riastradh Exp $ */
+/* $NetBSD: dk.c,v 1.150 2023/04/22 13:11:50 riastradh 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 1.149 2023/04/22 12:33:46 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.150 2023/04/22 13:11:50 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_dkwedge.h"
@@ -1423,6 +1423,8 @@ dkcancel(dev_t dev, int flags, int fmt,
KASSERT(sc != NULL);
KASSERT(sc->sc_dev != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
/*
* Disk I/O is expected to complete or fail within a reasonable
@@ -1448,16 +1450,10 @@ dkstrategy(struct buf *bp)
struct dkwedge_softc *sc = dkwedge_lookup(bp->b_dev);
uint64_t p_size, p_offset;
- if (sc == NULL) {
- bp->b_error = ENXIO;
- goto done;
- }
-
- if (sc->sc_state != DKW_STATE_RUNNING ||
- sc->sc_parent->dk_rawvp == NULL) {
- bp->b_error = ENXIO;
- goto done;
- }
+ KASSERT(sc != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
+ KASSERT(sc->sc_parent->dk_rawvp != NULL);
/* If it's an empty transfer, wake up the top half now. */
if (bp->b_bcount == 0)
@@ -1647,12 +1643,11 @@ dkminphys(struct buf *bp)
static int
dkread(dev_t dev, struct uio *uio, int flags)
{
- struct dkwedge_softc *sc = dkwedge_lookup(dev);
+ struct dkwedge_softc *sc __diagused = dkwedge_lookup(dev);
- if (sc == NULL)
- return ENXIO;
- if (sc->sc_state != DKW_STATE_RUNNING)
- return ENXIO;
+ KASSERT(sc != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
return physio(dkstrategy, NULL, dev, B_READ, dkminphys, uio);
}
@@ -1665,12 +1660,11 @@ dkread(dev_t dev, struct uio *uio, int f
static int
dkwrite(dev_t dev, struct uio *uio, int flags)
{
- struct dkwedge_softc *sc = dkwedge_lookup(dev);
+ struct dkwedge_softc *sc __diagused = dkwedge_lookup(dev);
- if (sc == NULL)
- return ENXIO;
- if (sc->sc_state != DKW_STATE_RUNNING)
- return ENXIO;
+ KASSERT(sc != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
return physio(dkstrategy, NULL, dev, B_WRITE, dkminphys, uio);
}
@@ -1686,12 +1680,10 @@ dkioctl(dev_t dev, u_long cmd, void *dat
struct dkwedge_softc *sc = dkwedge_lookup(dev);
int error = 0;
- if (sc == NULL)
- return ENXIO;
- if (sc->sc_state != DKW_STATE_RUNNING)
- return ENXIO;
- if (sc->sc_parent->dk_rawvp == NULL)
- return ENXIO;
+ KASSERT(sc != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
+ KASSERT(sc->sc_parent->dk_rawvp != NULL);
/*
* We pass NODEV instead of our device to indicate we don't
@@ -1763,12 +1755,10 @@ dkdiscard(dev_t dev, off_t pos, off_t le
off_t offset, maxlen;
int error;
- if (sc == NULL)
- return ENXIO;
- if (sc->sc_state != DKW_STATE_RUNNING)
- return ENXIO;
- if (sc->sc_parent->dk_rawvp == NULL)
- return ENXIO;
+ KASSERT(sc != NULL);
+ KASSERT(sc->sc_state != DKW_STATE_LARVAL);
+ KASSERT(sc->sc_state != DKW_STATE_DEAD);
+ KASSERT(sc->sc_parent->dk_rawvp != NULL);
/* XXX check bounds on size/offset up front */
shift = (sc->sc_parent->dk_blkshift + DEV_BSHIFT);
