svn commit: r316528 - in head/sys: kern sys

[Konstantin Belousov]

Author: kib
Date: Wed Apr  5 16:57:53 2017
New Revision: 316528
URL: https://svnweb.freebsd.org/changeset/base/316528

Log:
  Add V_VMIO flag for vinvalbuf(9) to indicate that the flush request
  was issued during VM-initiated i/o (pageout), so that the function
  does not try to flush or remove pages or wait for the vm object
  paging-in-progress counter.
  
  Reviewed by:	markj
  Tested by:	pho
  Sponsored by:	The FreeBSD Foundation
  MFC after:	1 week
  X-Differential revision:	https://reviews.freebsd.org/D10241

Modified:
  head/sys/kern/vfs_subr.c
  head/sys/sys/vnode.h

Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c	Wed Apr  5 16:57:13 2017	(r316527)
+++ head/sys/kern/vfs_subr.c	Wed Apr  5 16:57:53 2017	(r316528)
@@ -1673,13 +1673,15 @@ bufobj_invalbuf(struct bufobj *bo, int f
 	 */
 	do {
 		bufobj_wwait(bo, 0, 0);
-		BO_UNLOCK(bo);
-		if (bo->bo_object != NULL) {
-			VM_OBJECT_WLOCK(bo->bo_object);
-			vm_object_pip_wait(bo->bo_object, "bovlbx");
-			VM_OBJECT_WUNLOCK(bo->bo_object);
+		if ((flags & V_VMIO) == 0) {
+			BO_UNLOCK(bo);
+			if (bo->bo_object != NULL) {
+				VM_OBJECT_WLOCK(bo->bo_object);
+				vm_object_pip_wait(bo->bo_object, "bovlbx");
+				VM_OBJECT_WUNLOCK(bo->bo_object);
+			}
+			BO_LOCK(bo);
 		}
-		BO_LOCK(bo);
 	} while (bo->bo_numoutput > 0);
 	BO_UNLOCK(bo);
 
@@ -1687,7 +1689,7 @@ bufobj_invalbuf(struct bufobj *bo, int f
 	 * Destroy the copy in the VM cache, too.
 	 */
 	if (bo->bo_object != NULL &&
-	    (flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0) {
+	    (flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0) {
 		VM_OBJECT_WLOCK(bo->bo_object);
 		vm_object_page_remove(bo->bo_object, 0, 0, (flags & V_SAVE) ?
 		    OBJPR_CLEANONLY : 0);
@@ -1696,7 +1698,7 @@ bufobj_invalbuf(struct bufobj *bo, int f
 
 #ifdef INVARIANTS
 	BO_LOCK(bo);
-	if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY)) == 0 &&
+	if ((flags & (V_ALT | V_NORMAL | V_CLEANONLY | V_VMIO)) == 0 &&
 	    (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
 		panic("vinvalbuf: flush failed");
 	BO_UNLOCK(bo);

Modified: head/sys/sys/vnode.h
==============================================================================
--- head/sys/sys/vnode.h	Wed Apr  5 16:57:13 2017	(r316527)
+++ head/sys/sys/vnode.h	Wed Apr  5 16:57:53 2017	(r316528)
@@ -402,6 +402,7 @@ extern int		vttoif_tab[];
 #define	V_ALT		0x0002	/* vinvalbuf: invalidate only alternate bufs */
 #define	V_NORMAL	0x0004	/* vinvalbuf: invalidate only regular bufs */
 #define	V_CLEANONLY	0x0008	/* vinvalbuf: invalidate only clean bufs */
+#define	V_VMIO		0x0010	/* vinvalbuf: called during pageout */
 #define	REVOKEALL	0x0001	/* vop_revoke: revoke all aliases */
 #define	V_WAIT		0x0001	/* vn_start_write: sleep for suspend */
 #define	V_NOWAIT	0x0002	/* vn_start_write: don't sleep for suspend */