[src/trunk]: src/sys/kern Enter fstrans from _vfs_busy() and leave from vfs_u...

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

details:   https://anonhg.NetBSD.org/src/rev/ae00dbdff9d7
branches:  trunk
changeset: 823753:ae00dbdff9d7
user:      hannken <hannken%NetBSD.org@localhost>
date:      Sun May 07 08:26:58 2017 +0000

description:
Enter fstrans from _vfs_busy() and leave from vfs_unbusy().

Adapt sched_sync() and do_sys_sync().

diffstat:

 sys/kern/vfs_mount.c    |  16 ++++++++++++----
 sys/kern/vfs_subr.c     |   9 +++------
 sys/kern/vfs_syscalls.c |   6 ++----
 3 files changed, 17 insertions(+), 14 deletions(-)

diffs (112 lines):

diff -r 35ccda504bd6 -r ae00dbdff9d7 sys/kern/vfs_mount.c
--- a/sys/kern/vfs_mount.c      Sun May 07 08:25:54 2017 +0000
+++ b/sys/kern/vfs_mount.c      Sun May 07 08:26:58 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_mount.c,v 1.60 2017/05/07 08:24:20 hannken Exp $   */
+/*     $NetBSD: vfs_mount.c,v 1.61 2017/05/07 08:26:58 hannken Exp $   */
 
 /*-
  * Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
@@ -67,7 +67,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.60 2017/05/07 08:24:20 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.61 2017/05/07 08:26:58 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -324,12 +324,19 @@
        KASSERT(mp->mnt_refcnt > 0);
 
        if (wait) {
+               fstrans_start(mp, FSTRANS_SHARED);
                mutex_enter(&mp->mnt_unmounting);
-       } else if (!mutex_tryenter(&mp->mnt_unmounting)) {
-               return EBUSY;
+       } else {
+               if (fstrans_start_nowait(mp, FSTRANS_SHARED))
+                       return EBUSY;
+               if (!mutex_tryenter(&mp->mnt_unmounting)) {
+                       fstrans_done(mp);
+                       return EBUSY;
+               }
        }
        if (__predict_false((mp->mnt_iflag & IMNT_GONE) != 0)) {
                mutex_exit(&mp->mnt_unmounting);
+               fstrans_done(mp);
                return ENOENT;
        }
        ++mp->mnt_busynest;
@@ -368,6 +375,7 @@
        KASSERT(mp->mnt_busynest != 0);
        mp->mnt_busynest--;
        mutex_exit(&mp->mnt_unmounting);
+       fstrans_done(mp);
        vfs_rele(mp);
 }
 
diff -r 35ccda504bd6 -r ae00dbdff9d7 sys/kern/vfs_subr.c
--- a/sys/kern/vfs_subr.c       Sun May 07 08:25:54 2017 +0000
+++ b/sys/kern/vfs_subr.c       Sun May 07 08:26:58 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_subr.c,v 1.463 2017/04/17 08:34:27 hannken Exp $   */
+/*     $NetBSD: vfs_subr.c,v 1.464 2017/05/07 08:26:58 hannken Exp $   */
 
 /*-
  * Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008 The NetBSD Foundation, Inc.
@@ -68,7 +68,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.463 2017/04/17 08:34:27 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.464 2017/05/07 08:26:58 hannken Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -781,10 +781,7 @@
                                continue;
                        }
                        mp->mnt_synclist_slot = sync_delay_slot(sync_delay(mp));
-                       if (fstrans_start_nowait(mp, FSTRANS_SHARED) == 0) {
-                               VFS_SYNC(mp, MNT_LAZY, curlwp->l_cred);
-                               fstrans_done(mp);
-                       }
+                       VFS_SYNC(mp, MNT_LAZY, curlwp->l_cred);
                }
                mountlist_iterator_destroy(iter);
 
diff -r 35ccda504bd6 -r ae00dbdff9d7 sys/kern/vfs_syscalls.c
--- a/sys/kern/vfs_syscalls.c   Sun May 07 08:25:54 2017 +0000
+++ b/sys/kern/vfs_syscalls.c   Sun May 07 08:26:58 2017 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_syscalls.c,v 1.514 2017/05/07 08:25:54 hannken Exp $       */
+/*     $NetBSD: vfs_syscalls.c,v 1.515 2017/05/07 08:26:58 hannken Exp $       */
 
 /*-
  * Copyright (c) 2008, 2009 The NetBSD Foundation, Inc.
@@ -70,7 +70,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.514 2017/05/07 08:25:54 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_syscalls.c,v 1.515 2017/05/07 08:26:58 hannken Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_fileassoc.h"
@@ -641,7 +641,6 @@
 
        mountlist_iterator_init(&iter);
        while ((mp = mountlist_iterator_next(iter)) != NULL) {
-               fstrans_start(mp, FSTRANS_SHARED);
                mutex_enter(&mp->mnt_updating);
                if ((mp->mnt_flag & MNT_RDONLY) == 0) {
                        asyncflag = mp->mnt_flag & MNT_ASYNC;
@@ -651,7 +650,6 @@
                                 mp->mnt_flag |= MNT_ASYNC;
                }
                mutex_exit(&mp->mnt_updating);
-               fstrans_done(mp);
        }
        mountlist_iterator_destroy(iter);
 #ifdef DEBUG