[src/trunk]: src/sys/dev - do disk_busy/unbusy for requested i/o, rather than...

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

details:   https://anonhg.NetBSD.org/src/rev/32b9d28f42bf
branches:  trunk
changeset: 586981:32b9d28f42bf
user:      yamt <yamt%NetBSD.org@localhost>
date:      Sat Jan 07 13:25:50 2006 +0000

description:
- do disk_busy/unbusy for requested i/o, rather than ones that we reuqest.
- on error, be conservative about b_resid.
- make vndthread static.

diffstat:

 sys/dev/vnd.c |  92 +++++++++++++++++++++++++++++-----------------------------
 1 files changed, 46 insertions(+), 46 deletions(-)

diffs (170 lines):

diff -r 674a886bdd51 -r 32b9d28f42bf sys/dev/vnd.c
--- a/sys/dev/vnd.c     Sat Jan 07 07:18:06 2006 +0000
+++ b/sys/dev/vnd.c     Sat Jan 07 13:25:50 2006 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vnd.c,v 1.125 2005/12/14 19:49:16 bouyer Exp $ */
+/*     $NetBSD: vnd.c,v 1.126 2006/01/07 13:25:50 yamt Exp $   */
 
 /*-
  * Copyright (c) 1996, 1997, 1998 The NetBSD Foundation, Inc.
@@ -133,7 +133,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.125 2005/12/14 19:49:16 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vnd.c,v 1.126 2006/01/07 13:25:50 yamt Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "fs_nfs.h"
@@ -228,7 +228,8 @@
 static void    vnd_free(void *, void *);
 #endif /* VND_COMPRESSION */
 
-void vndthread(void *);
+static void vndthread(void *);
+static void vndiodone1(struct vnd_softc *, struct vndxfer *);
 
 static dev_type_open(vndopen);
 static dev_type_close(vndclose);
@@ -463,7 +464,7 @@
        splx(s);
 }
 
-void
+static void
 vndthread(void *arg)
 {
        struct vnd_softc *vnd = arg;
@@ -550,6 +551,9 @@
                if ((flags & B_READ) == 0)
                        vn_start_write(vnd->sc_vp, &mp, V_WAIT);
 
+               /* Instrumentation. */
+               disk_busy(&vnd->sc_dkdev);
+
                /*
                 * Feed requests sequentially.
                 * We do it this way to keep from flooding NFS servers if we
@@ -645,9 +649,6 @@
                                    nbp->vb_buf.b_bcount);
 #endif
 
-                       /* Instrumentation. */
-                       disk_busy(&vnd->sc_dkdev);
-
                        if ((nbp->vb_buf.b_flags & B_READ) == 0)
                                vp->v_numoutput++;
                        VOP_STRATEGY(vp, &nbp->vb_buf);
@@ -664,12 +665,7 @@
                        vn_finished_write(mp, 0);
                vnx->vx_flags &= ~VX_BUSY;
                if (vnx->vx_pending == 0) {
-                       if (vnx->vx_error != 0) {
-                               bp->b_error = vnx->vx_error;
-                               bp->b_flags |= B_ERROR;
-                       }
-                       VND_PUTXFER(vnd, vnx);
-                       biodone(bp);
+                       vndiodone1(vnd, vnx);
                }
                continue;
 done:
@@ -683,6 +679,38 @@
        kthread_exit(0);
 }
 
+static void
+vndiodone1(struct vnd_softc *vnd, struct vndxfer *vnx)
+{
+       struct buf *bp = vnx->vx_bp;
+       int error;
+
+       if ((vnx->vx_flags & VX_BUSY) != 0) {
+               return;
+       }
+       KASSERT(bp->b_resid != 0 || vnx->vx_pending == 0);
+       if (vnx->vx_pending > 0) {
+               return;
+       }
+#ifdef DEBUG
+       if (vnddebug & VDB_IO) {
+               printf("vndiodone1: bp %p iodone: error %d\n",
+                   bp, vnx->vx_error);
+       }
+#endif
+       error = vnx->vx_error;
+       if (error != 0) {
+               bp->b_flags |= B_ERROR;
+               bp->b_error = error;
+
+               /* we don't know which sub-buf failed */
+               bp->b_resid = bp->b_bcount;
+       }
+       VND_PUTXFER(vnd, vnx);
+       disk_unbusy(&vnd->sc_dkdev, bp->b_bcount - bp->b_resid,
+           (bp->b_flags & B_READ));
+       biodone(bp);
+}
 
 static void
 vndiodone(struct buf *bp)
@@ -691,7 +719,7 @@
        struct vndxfer *vnx = (struct vndxfer *)vbp->vb_xfer;
        struct buf *pbp = vnx->vx_bp;
        struct vnd_softc *vnd = &vnd_softc[vndunit(pbp->b_dev)];
-       int s, resid;
+       int s, done;
 
        s = splbio();
 #ifdef DEBUG
@@ -703,11 +731,9 @@
                    vbp->vb_buf.b_bcount);
 #endif
 
-       resid = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid;
-       pbp->b_resid -= resid;
-       disk_unbusy(&vnd->sc_dkdev, resid, (pbp->b_flags & B_READ));
+       done = vbp->vb_buf.b_bcount - vbp->vb_buf.b_resid;
+       pbp->b_resid -= done;
        vnx->vx_pending--;
-
        if (vbp->vb_buf.b_error) {
 #ifdef DEBUG
                if (vnddebug & VDB_IO)
@@ -723,34 +749,8 @@
         * Wrap up this transaction if it has run to completion or, in
         * case of an error, when all auxiliary buffers have returned.
         */
-       if (vnx->vx_error != 0) {
-               pbp->b_flags |= B_ERROR;
-               pbp->b_error = vnx->vx_error;
-               if ((vnx->vx_flags & VX_BUSY) == 0 && vnx->vx_pending == 0) {
-
-#ifdef DEBUG
-                       if (vnddebug & VDB_IO)
-                               printf("vndiodone: pbp %p iodone: error %d\n",
-                                       pbp, vnx->vx_error);
-#endif
-                       VND_PUTXFER(vnd, vnx);
-                       biodone(pbp);
-               }
-       } else if (pbp->b_resid == 0) {
-
-#ifdef DIAGNOSTIC
-               if (vnx->vx_pending != 0)
-                       panic("vndiodone: vnx pending: %d", vnx->vx_pending);
-#endif
-
-               if ((vnx->vx_flags & VX_BUSY) == 0) {
-#ifdef DEBUG
-                       if (vnddebug & VDB_IO)
-                               printf("vndiodone: pbp %p iodone\n", pbp);
-#endif
-                       VND_PUTXFER(vnd, vnx);
-                       biodone(pbp);
-               }
+       if (vnx->vx_error != 0 || pbp->b_resid == 0) {
+               vndiodone1(vnd, vnx);
        }
 
        vnd->sc_active--;