[src/trunk]: src/sys Add d_discard to struct bdevsw/cdevsw, and the plumbing ...

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

details:   https://anonhg.NetBSD.org/src/rev/164b4e24b77e
branches:  trunk
changeset: 330901:164b4e24b77e
user:      dholland <dholland%NetBSD.org@localhost>
date:      Fri Jul 25 07:56:14 2014 +0000

description:
Add d_discard to struct bdevsw/cdevsw, and the plumbing to access it.

Unfortunately we need d_discard in both since we need to be able to
discard from both the block and character forms of disks. I'm
increasingly thinking it would be better to restructure the ops
dispatching so each type of device (ttys, disks, tapes, etc.) has its
own function table. Then we wouldn't need to change every tty driver
to add a disk op.

diffstat:

 sys/kern/subr_devsw.c |  36 ++++++++++++++++++++++++++++++++++--
 sys/sys/conf.h        |   9 ++++++++-
 2 files changed, 42 insertions(+), 3 deletions(-)

diffs (129 lines):

diff -r 685acfa75649 -r 164b4e24b77e sys/kern/subr_devsw.c
--- a/sys/kern/subr_devsw.c     Fri Jul 25 07:49:56 2014 +0000
+++ b/sys/kern/subr_devsw.c     Fri Jul 25 07:56:14 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_devsw.c,v 1.31 2014/05/25 16:31:51 pooka Exp $    */
+/*     $NetBSD: subr_devsw.c,v 1.32 2014/07/25 07:56:14 dholland Exp $ */
 
 /*-
  * Copyright (c) 2001, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.31 2014/05/25 16:31:51 pooka Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.32 2014/07/25 07:56:14 dholland Exp $");
 
 #include <sys/param.h>
 #include <sys/conf.h>
@@ -819,6 +819,22 @@
 }
 
 int
+bdev_discard(dev_t dev, off_t pos, off_t len)
+{
+       const struct bdevsw *d;
+       int rv, mpflag;
+
+       if ((d = bdevsw_lookup(dev)) == NULL)
+               return ENXIO;
+
+       DEV_LOCK(d);
+       rv = (*d->d_discard)(dev, pos, len);
+       DEV_UNLOCK(d);
+
+       return rv;
+}
+
+int
 cdev_open(dev_t dev, int flag, int devtype, lwp_t *l)
 {
        const struct cdevsw *d;
@@ -984,6 +1000,22 @@
 }
 
 int
+cdev_discard(dev_t dev, off_t pos, off_t len)
+{
+       const struct cdevsw *d;
+       int rv, mpflag;
+
+       if ((d = cdevsw_lookup(dev)) == NULL)
+               return ENXIO;
+
+       DEV_LOCK(d);
+       rv = (*d->d_discard)(dev, pos, len);
+       DEV_UNLOCK(d);
+
+       return rv;
+}
+
+int
 cdev_type(dev_t dev)
 {
        const struct cdevsw *d;
diff -r 685acfa75649 -r 164b4e24b77e sys/sys/conf.h
--- a/sys/sys/conf.h    Fri Jul 25 07:49:56 2014 +0000
+++ b/sys/sys/conf.h    Fri Jul 25 07:56:14 2014 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: conf.h,v 1.144 2012/10/27 17:18:40 chs Exp $   */
+/*     $NetBSD: conf.h,v 1.145 2014/07/25 07:56:14 dholland Exp $      */
 
 /*-
  * Copyright (c) 1990, 1993
@@ -74,6 +74,7 @@
        int             (*d_ioctl)(dev_t, u_long, void *, int, struct lwp *);
        int             (*d_dump)(dev_t, daddr_t, void *, size_t);
        int             (*d_psize)(dev_t);
+       int             (*d_discard)(dev_t, off_t, off_t);
        int             d_flag;
 };
 
@@ -91,6 +92,7 @@
        int             (*d_poll)(dev_t, int, struct lwp *);
        paddr_t         (*d_mmap)(dev_t, off_t, int);
        int             (*d_kqfilter)(dev_t, struct knote *);
+       int             (*d_discard)(dev_t, off_t, off_t);
        int             d_flag;
 };
 
@@ -121,6 +123,7 @@
 #define        dev_type_dump(n)        int n (dev_t, daddr_t, void *, size_t)
 #define        dev_type_size(n)        int n (dev_t)
 #define        dev_type_kqfilter(n)    int n (dev_t, struct knote *)
+#define dev_type_discard(n)    int n (dev_t, off_t, off_t)
 
 #define        noopen          ((dev_type_open((*)))enodev)
 #define        noclose         ((dev_type_close((*)))enodev)
@@ -134,6 +137,7 @@
 #define        nodump          ((dev_type_dump((*)))enodev)
 #define        nosize          NULL
 #define        nokqfilter      seltrue_kqfilter
+#define nodiscard      ((dev_type_discard((*)))enodev)
 
 #define        nullopen        ((dev_type_open((*)))nullop)
 #define        nullclose       ((dev_type_close((*)))nullop)
@@ -145,6 +149,7 @@
 #define        nullmmap        ((dev_type_mmap((*)))nullop)
 #define        nulldump        ((dev_type_dump((*)))nullop)
 #define        nullkqfilter    ((dev_type_kqfilter((*)))eopnotsupp)
+#define nulldiscard    ((dev_type_discard((*)))nullop)
 
 /* device access wrappers. */
 
@@ -154,6 +159,7 @@
 dev_type_ioctl(bdev_ioctl);
 dev_type_dump(bdev_dump);
 dev_type_size(bdev_size);
+dev_type_discard(bdev_discard);
 
 dev_type_open(cdev_open);
 dev_type_close(cdev_close);
@@ -165,6 +171,7 @@
 dev_type_poll(cdev_poll);
 dev_type_mmap(cdev_mmap);
 dev_type_kqfilter(cdev_kqfilter);
+dev_type_discard(cdev_discard);
 
 int    cdev_type(dev_t);
 int    bdev_type(dev_t);