[src/pgoyette-localcount]: src/sys/dev Call device_release() in appropriate e...

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

details:   https://anonhg.NetBSD.org/src/rev/e662e0881930
branches:  pgoyette-localcount
changeset: 852858:e662e0881930
user:      pgoyette <pgoyette%NetBSD.org@localhost>
date:      Sun Jul 24 10:44:57 2016 +0000

description:
Call device_release() in appropriate error paths.

In the module initialization code, make the bmajor/cmajor variables
global so they can be shared with the rump component initialization.

diffstat:

 sys/dev/cgd.c |  62 +++++++++++++++++++++++++++++++++++++---------------------
 1 files changed, 39 insertions(+), 23 deletions(-)

diffs (181 lines):

diff -r b21f3116f18c -r e662e0881930 sys/dev/cgd.c
--- a/sys/dev/cgd.c     Sun Jul 24 10:37:10 2016 +0000
+++ b/sys/dev/cgd.c     Sun Jul 24 10:44:57 2016 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: cgd.c,v 1.108.2.12 2016/07/24 00:14:08 pgoyette Exp $ */
+/* $NetBSD: cgd.c,v 1.108.2.13 2016/07/24 10:44:57 pgoyette Exp $ */
 
 /*-
  * Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -30,7 +30,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.108.2.12 2016/07/24 00:14:08 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: cgd.c,v 1.108.2.13 2016/07/24 10:44:57 pgoyette Exp $");
 
 #include <sys/types.h>
 #include <sys/param.h>
@@ -179,6 +179,13 @@
 
 /* The code */
 
+/*
+ * Lookup the device and return it's softc.  If the device doesn't
+ * exist, spawn it.
+ *
+ * In either case, the device is "acquired", and must be "released"
+ * by the caller after it is finished with the softc.
+ */
 static struct cgd_softc *
 getcgd_softc(dev_t dev, device_t *self)
 {
@@ -208,7 +215,9 @@
 static void
 cgd_attach(device_t parent, device_t self, void *aux)
 {
-       struct cgd_softc *sc = device_private(self);
+       struct cgd_softc *sc;
+
+       sc = device_private(self);
 
        mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_BIO);
        dk_init(&sc->sc_dksc, self, DKTYPE_CGD);
@@ -220,6 +229,10 @@
 }
 
 
+/*
+ * The caller must hold a reference to the device's localcount.  the
+ * reference is released if the device is available for detach.
+ */
 static int
 cgd_detach(device_t self, int flags)
 {
@@ -238,6 +251,7 @@
        disk_destroy(&dksc->sc_dkdev);
        mutex_destroy(&sc->sc_lock);
 
+       device_release(self);
        return 0;
 }
 
@@ -256,6 +270,7 @@
 cgd_spawn(int unit, device_t *self)
 {
        cfdata_t cf;
+       struct cgd_softc *sc;
 
        cf = malloc(sizeof(*cf), M_DEVBUF, M_WAITOK);
        cf->cf_name = cgd_cd.cd_name;
@@ -269,12 +284,14 @@
        *self = device_lookup_acquire(&cgd_cd, unit);
        if (self == NULL)
                return NULL;
-       else
+       else {
                /*
                 * Note that we return while still holding a reference
                 * to the device!
                 */
-               return device_private(*self);
+               sc = device_private(*self);
+               return sc;
+       }
 }
 
 static int
@@ -285,10 +302,10 @@
 
        cf = device_cfdata(dev);
        error = config_detach(dev, DETACH_QUIET);
-       if (error)
-               return error;
-       free(cf, M_DEVBUF);
-       return 0;
+       if (error == 0)
+               free(cf, M_DEVBUF);
+
+       return error;
 }
 
 static int
@@ -325,11 +342,10 @@
                if ((error = cgd_destroy(cs->sc_dksc.sc_dev)) != 0) {
                        aprint_error_dev(dksc->sc_dev,
                            "unable to detach instance\n");
-                       device_release(self);
                        return error;
                }
-       }
-       device_release(self);
+       } else
+               device_release(self);
        return 0;
 }
 
@@ -597,8 +613,10 @@
            (unsigned long long)dev, uio, flags));
        GETCGD_SOFTC(cs, dev, self);
        dksc = &cs->sc_dksc;
-       if (!DK_ATTACHED(dksc))
+       if (!DK_ATTACHED(dksc)) {
+               device_release(self);
                return ENXIO;
+       }
        error = physio(cgdstrategy, NULL, dev, B_READ, minphys, uio);
        device_release(self);
        return error;
@@ -1104,6 +1122,8 @@
 
 #ifdef _MODULE
 CFDRIVER_DECL(cgd, DV_DISK, NULL);
+
+devmajor_t cgd_bmajor = -1, cgd_cmajor = -1;
 #endif
 
 static int
@@ -1111,10 +1131,6 @@
 {
        int error = 0;
 
-#ifdef _MODULE
-       devmajor_t bmajor = -1, cmajor = -1;
-#endif
-
        switch (cmd) {
        case MODULE_CMD_INIT:
 #ifdef _MODULE
@@ -1133,8 +1149,8 @@
                /*
                 * Attach the {b,c}devsw's
                 */
-               error = devsw_attach("cgd", &cgd_bdevsw, &bmajor,
-                   &cgd_cdevsw, &cmajor);
+               error = devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
+                   &cgd_cdevsw, &cgd_cmajor);
 
                /*
                 * If devsw_attach fails, remove from autoconf database
@@ -1161,8 +1177,8 @@
                 */
                error = config_cfattach_detach(cgd_cd.cd_name, &cgd_ca);
                if (error) {
-                       error = devsw_attach("cgd", &cgd_bdevsw, &bmajor,
-                           &cgd_cdevsw, &cmajor);
+                       error = devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
+                           &cgd_cdevsw, &cgd_cmajor);
                        aprint_error("%s: failed to detach %s cfattach, "
                            "error %d\n", __func__, cgd_cd.cd_name, error);
                        break;
@@ -1170,8 +1186,8 @@
                error = config_cfdriver_detach(&cgd_cd);
                if (error) {
                        config_cfattach_attach(cgd_cd.cd_name, &cgd_ca);
-                       devsw_attach("cgd", &cgd_bdevsw, &bmajor,
-                           &cgd_cdevsw, &cmajor);
+                       devsw_attach("cgd", &cgd_bdevsw, &cgd_bmajor,
+                           &cgd_cdevsw, &cgd_cmajor);
                        aprint_error("%s: failed to detach %s cfdriver, "
                            "error %d\n", __func__, cgd_cd.cd_name, error);
                        break;