[src/trunk]: src/sys use shared locks instead of exclusive for VOP_READ() and...

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

details:   https://anonhg.NetBSD.org/src/rev/ea876fdaab17
branches:  trunk
changeset: 515272:ea876fdaab17
user:      chs <chs%NetBSD.org@localhost>
date:      Fri Sep 21 08:02:55 2001 +0000

description:
use shared locks instead of exclusive for VOP_READ() and VOP_READDIR().

diffstat:

 sys/kern/vfs_vnops.c           |  15 ++++++++++-----
 sys/miscfs/specfs/spec_vnops.c |   4 ++--
 2 files changed, 12 insertions(+), 7 deletions(-)

diffs (61 lines):

diff -r 57a81937202a -r ea876fdaab17 sys/kern/vfs_vnops.c
--- a/sys/kern/vfs_vnops.c      Fri Sep 21 07:57:35 2001 +0000
+++ b/sys/kern/vfs_vnops.c      Fri Sep 21 08:02:55 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_vnops.c,v 1.49 2001/09/15 20:36:37 chs Exp $       */
+/*     $NetBSD: vfs_vnops.c,v 1.50 2001/09/21 08:02:55 chs Exp $       */
 
 /*
  * Copyright (c) 1982, 1986, 1989, 1993
@@ -248,8 +248,13 @@
        struct iovec aiov;
        int error;
 
-       if ((ioflg & IO_NODELOCKED) == 0)
-               vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+       if ((ioflg & IO_NODELOCKED) == 0) {
+               if (rw == UIO_READ) {
+                       vn_lock(vp, LK_SHARED | LK_RETRY);
+               } else {
+                       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+               }
+       }
        auio.uio_iov = &aiov;
        auio.uio_iovcnt = 1;
        aiov.iov_base = base;
@@ -299,7 +304,7 @@
        auio.uio_segflg = segflg;
        auio.uio_procp = p;
        auio.uio_resid = count;
-       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+       vn_lock(vp, LK_SHARED | LK_RETRY);
        auio.uio_offset = fp->f_offset;
        error = VOP_READDIR(vp, &auio, fp->f_cred, &eofflag, cookies,
                    ncookies);
@@ -384,7 +389,7 @@
                ioflag |= IO_SYNC;
        if (fp->f_flag & FALTIO)
                ioflag |= IO_ALTSEMANTICS;
-       vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+       vn_lock(vp, LK_SHARED | LK_RETRY);
        uio->uio_offset = *offset;
        count = uio->uio_resid;
        error = VOP_READ(vp, uio, ioflag, cred);
diff -r 57a81937202a -r ea876fdaab17 sys/miscfs/specfs/spec_vnops.c
--- a/sys/miscfs/specfs/spec_vnops.c    Fri Sep 21 07:57:35 2001 +0000
+++ b/sys/miscfs/specfs/spec_vnops.c    Fri Sep 21 08:02:55 2001 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: spec_vnops.c,v 1.57 2001/09/15 20:36:38 chs Exp $      */
+/*     $NetBSD: spec_vnops.c,v 1.58 2001/09/21 08:02:55 chs Exp $      */
 
 /*
  * Copyright (c) 1989, 1993
@@ -284,7 +284,7 @@
                VOP_UNLOCK(vp, 0);
                error = (*cdevsw[major(vp->v_rdev)].d_read)
                        (vp->v_rdev, uio, ap->a_ioflag);
-               vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+               vn_lock(vp, LK_SHARED | LK_RETRY);
                return (error);
 
        case VBLK: