[src/trunk]: src/sys/dev/dkwedge dk(4): Split unsafe lookups into safe subrou...

[riastradh <riastradh%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/081d3a4cf3de
branches:  trunk
changeset: 375933:081d3a4cf3de
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon May 22 14:59:25 2023 +0000

description:
dk(4): Split unsafe lookups into safe subroutines and unsafe wrappers.

No functional change intended.

Eventually we should adjust the callers to use the safe subroutines
instead and device_release when done.

diffstat:

 sys/dev/dkwedge/dk.c |  58 ++++++++++++++++++++++++++++++++++++++++++++-------
 1 files changed, 50 insertions(+), 8 deletions(-)

diffs (128 lines):

diff -r d1cf1ed5d1a6 -r 081d3a4cf3de sys/dev/dkwedge/dk.c
--- a/sys/dev/dkwedge/dk.c      Mon May 22 14:59:16 2023 +0000
+++ b/sys/dev/dkwedge/dk.c      Mon May 22 14:59:25 2023 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: dk.c,v 1.164 2023/05/22 14:59:16 riastradh Exp $       */
+/*     $NetBSD: dk.c,v 1.165 2023/05/22 14:59:25 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 1.164 2023/05/22 14:59:16 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dk.c,v 1.165 2023/05/22 14:59:25 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_dkwedge.h"
@@ -883,8 +883,8 @@ dkwedge_list(struct disk *pdk, struct dk
        return error;
 }
 
-device_t
-dkwedge_find_by_wname(const char *wname)
+static device_t
+dkwedge_find_by_wname_acquire(const char *wname)
 {
        device_t dv = NULL;
        struct dkwedge_softc *sc;
@@ -902,6 +902,7 @@ dkwedge_find_by_wname(const char *wname)
                                    device_xname(sc->sc_dev));
                                continue;
                        }
+                       device_acquire(sc->sc_dev);
                        dv = sc->sc_dev;
                }
        }
@@ -909,8 +910,8 @@ dkwedge_find_by_wname(const char *wname)
        return dv;
 }
 
-device_t
-dkwedge_find_by_parent(const char *name, size_t *i)
+static device_t
+dkwedge_find_by_parent_acquire(const char *name, size_t *i)
 {
 
        rw_enter(&dkwedges_lock, RW_READER);
@@ -920,6 +921,7 @@ dkwedge_find_by_parent(const char *name,
                        continue;
                if (strcmp(sc->sc_parent->dk_name, name) != 0)
                        continue;
+               device_acquire(sc->sc_dev);
                rw_exit(&dkwedges_lock);
                return sc->sc_dev;
        }
@@ -927,6 +929,30 @@ dkwedge_find_by_parent(const char *name,
        return NULL;
 }
 
+/* XXX unsafe */
+device_t
+dkwedge_find_by_wname(const char *wname)
+{
+       device_t dv;
+
+       if ((dv = dkwedge_find_by_wname_acquire(wname)) == NULL)
+               return NULL;
+       device_release(dv);
+       return dv;
+}
+
+/* XXX unsafe */
+device_t
+dkwedge_find_by_parent(const char *name, size_t *i)
+{
+       device_t dv;
+
+       if ((dv = dkwedge_find_by_parent_acquire(name, i)) == NULL)
+               return NULL;
+       device_release(dv);
+       return dv;
+}
+
 void
 dkwedge_print_wnames(void)
 {
@@ -1845,8 +1871,9 @@ dkdump(dev_t dev, daddr_t blkno, void *v
  *     Find wedge corresponding to the specified parent name
  *     and offset/length.
  */
-device_t
-dkwedge_find_partition(device_t parent, daddr_t startblk, uint64_t nblks)
+static device_t
+dkwedge_find_partition_acquire(device_t parent, daddr_t startblk,
+    uint64_t nblks)
 {
        struct dkwedge_softc *sc;
        int i;
@@ -1867,6 +1894,7 @@ dkwedge_find_partition(device_t parent, 
                                continue;
                        }
                        wedge = sc->sc_dev;
+                       device_acquire(wedge);
                }
        }
        rw_exit(&dkwedges_lock);
@@ -1874,6 +1902,20 @@ dkwedge_find_partition(device_t parent, 
        return wedge;
 }
 
+/* XXX unsafe */
+device_t
+dkwedge_find_partition(device_t parent, daddr_t startblk,
+    uint64_t nblks)
+{
+       device_t dv;
+
+       if ((dv = dkwedge_find_partition_acquire(parent, startblk, nblks))
+           == NULL)
+               return NULL;
+       device_release(dv);
+       return dv;
+}
+
 const char *
 dkwedge_get_parent_name(dev_t dev)
 {