CVS commit: src/sys/kern

[Juergen Hannken-Illjes]

Module Name:    src
Committed By:   hannken
Date:           Wed May 17 12:45:03 UTC 2017

Modified Files:
        src/sys/kern: vfs_mount.c

Log Message:
Suspend file system while unmounting.  This way no operations run
on the mounted file system during unmount and all operations see
the state before or after the (possibly failed) unmount.


To generate a diff of this commit:
cvs rdiff -u -r1.61 -r1.62 src/sys/kern/vfs_mount.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.


Modified files:

Index: src/sys/kern/vfs_mount.c
diff -u src/sys/kern/vfs_mount.c:1.61 src/sys/kern/vfs_mount.c:1.62
--- src/sys/kern/vfs_mount.c:1.61	Sun May  7 08:26:58 2017
+++ src/sys/kern/vfs_mount.c	Wed May 17 12:45:03 2017
@@ -1,4 +1,4 @@
-/*	$NetBSD: vfs_mount.c,v 1.61 2017/05/07 08:26:58 hannken Exp $	*/
+/*	$NetBSD: vfs_mount.c,v 1.62 2017/05/17 12:45:03 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 1.61 2017/05/07 08:26:58 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.62 2017/05/17 12:45:03 hannken Exp $");
 
 #include <sys/param.h>
 #include <sys/kernel.h>
@@ -599,7 +599,7 @@ vflush(struct mount *mp, vnode_t *skipvp
 		 * First, flush out any vnode references from the
 		 * deferred vrele list.
 		 */
-		vfs_drainvnodes();
+		vrele_flush(mp);
 
 		vfs_vnode_iterator_init(mp, &marker);
 
@@ -875,6 +875,12 @@ dounmount(struct mount *mp, int flags, s
 	 */
 	mutex_enter(&syncer_mutex);
 
+	error = vfs_suspend(mp, 0);
+	if (error) {
+		mutex_exit(&syncer_mutex);
+		return error;
+	}
+
 	/*
 	 * Abort unmount attempt when the filesystem is in use
 	 */
@@ -882,6 +888,7 @@ dounmount(struct mount *mp, int flags, s
 	if (mp->mnt_busynest != 0) {
 		mutex_exit(&mp->mnt_unmounting);
 		mutex_exit(&syncer_mutex);
+		vfs_resume(mp);
 		return EBUSY;
 	}
 
@@ -933,6 +940,7 @@ dounmount(struct mount *mp, int flags, s
 			vfs_syncer_add_to_worklist(mp);
 		mp->mnt_flag |= async;
 		mutex_exit(&mp->mnt_updating);
+		vfs_resume(mp);
 		if (used_syncer)
 			mutex_exit(&syncer_mutex);
 		if (used_extattr) {
@@ -955,6 +963,7 @@ dounmount(struct mount *mp, int flags, s
 	 */
 	mp->mnt_iflag |= IMNT_GONE;
 	mutex_exit(&mp->mnt_unmounting);
+	vfs_resume(mp);
 
 	if ((coveredvp = mp->mnt_vnodecovered) != NULLVP) {
 		vn_lock(coveredvp, LK_EXCLUSIVE | LK_RETRY);