Module Name: src
Committed By: riastradh
Date: Fri Apr 21 18:30:52 UTC 2023
Modified Files:
src/sys/dev/dkwedge: dk.c
Log Message:
dk(4): Use disk_begindetach and rely on vdevgone to close instances.
The first step is to decide whether we can detach (if forced, yes; if
not forced, only if not already open), and prevent new opens if so.
There's no need to start closing open instances at this point --
we're just making a decision to detach, and preventing new opens by
transitioning state that dkopen will respect[*].
The second step is to force all open instances to close. This is
done by vdevgone. By the time vdevgone returns, there can be no open
instances, so if there _were_ any, closing them via vdevgone will
have passed through dklastclose.
After that point, there can be no opens and no I/O operations, so
dk_openmask must already be zero and the bufq must be empty.
Thus, there's no need to have an explicit call to dklastclose (via
dkwedge_cleanup_parent) before or after making the decision to
detach.
[*] Currently access to this state is racy: nothing serializes
dkwedge_detach's state transition with dkopen's test. TBD in a
separate commit shortly.
To generate a diff of this commit:
cvs rdiff -u -r1.142 -r1.143 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:1.142 src/sys/dev/dkwedge/dk.c:1.143
--- src/sys/dev/dkwedge/dk.c:1.142 Fri Apr 21 18:30:32 2023
+++ src/sys/dev/dkwedge/dk.c Fri Apr 21 18:30:52 2023
@@ -1,4 +1,4 @@
-/* $NetBSD: dk.c,v 1.142 2023/04/21 18:30:32 riastradh Exp $ */
+/* $NetBSD: dk.c,v 1.143 2023/04/21 18:30:52 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 1.142 2023/04/21 18:30:32 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.143 2023/04/21 18:30:52 riastradh Exp $");
#ifdef _KERNEL_OPT
#include "opt_dkwedge.h"
@@ -108,7 +108,6 @@ static void dkminphys(struct buf *);
static int dkfirstopen(struct dkwedge_softc *, int);
static void dklastclose(struct dkwedge_softc *);
-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);
@@ -668,28 +667,6 @@ dkwedge_del1(struct dkwedge_info *dkw, i
return config_detach(sc->sc_dev, flags);
}
-static int
-dkwedge_cleanup_parent(struct dkwedge_softc *sc, int flags)
-{
- struct disk *dk = &sc->sc_dk;
- int rc;
-
- rc = 0;
- mutex_enter(&dk->dk_openlock);
- if (dk->dk_openmask == 0) {
- /* nothing to do */
- } else if ((flags & DETACH_FORCE) == 0) {
- rc = EBUSY;
- } else {
- mutex_enter(&sc->sc_parent->dk_rawlock);
- dklastclose(sc);
- mutex_exit(&sc->sc_parent->dk_rawlock);
- }
- mutex_exit(&sc->sc_dk.dk_openlock);
-
- return rc;
-}
-
/*
* dkwedge_detach:
*
@@ -709,7 +686,8 @@ dkwedge_detach(device_t self, int flags)
}
if (unit == ndkwedges)
rc = ENXIO;
- else if ((rc = dkwedge_cleanup_parent(sc, flags)) == 0) {
+ else if ((rc = disk_begindetach(&sc->sc_dk, /*lastclose*/NULL, self,
+ flags)) == 0) {
/* Mark the wedge as dying. */
sc->sc_state = DKW_STATE_DYING;
}
@@ -742,8 +720,17 @@ dkwedge_detach(device_t self, int flags)
vdevgone(bmaj, unit, unit, VBLK);
vdevgone(cmaj, unit, unit, VCHR);
- /* Clean up the parent. */
- dkwedge_cleanup_parent(sc, flags | DETACH_FORCE);
+ /*
+ * At this point, all block device opens have been closed,
+ * synchronously flushing any buffered writes; and all
+ * character device I/O operations have completed
+ * synchronously, and character device opens have been closed.
+ *
+ * So there can be no more opens or queued buffers by now.
+ */
+ KASSERT(sc->sc_dk.dk_openmask == 0);
+ KASSERT(bufq_peek(sc->sc_bufq) == NULL);
+ bufq_drain(sc->sc_bufq);
/* Announce our departure. */
aprint_normal("%s at %s (%s) deleted\n", device_xname(sc->sc_dev),
