From 1814dddf208e92828e42a08e1b41505556db18d3 Mon Sep 17 00:00:00 2001
From: mckusick <mckusick@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Fri, 2 Feb 2018 01:28:14 +0000
Subject: [PATCH] MFC of 328444.

Eliminate "fsync: giving up on dirty" messages.


git-svn-id: svn://svn.freebsd.org/base/stable/10@328765 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 sys/kern/vfs_default.c | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/sys/kern/vfs_default.c b/sys/kern/vfs_default.c
index 166ed65b1..1cfa8bf3c 100644
--- a/sys/kern/vfs_default.c
+++ b/sys/kern/vfs_default.c
@@ -639,13 +639,21 @@ vop_stdfsync(ap)
 		struct thread *a_td;
 	} */ *ap;
 {
-	struct vnode *vp = ap->a_vp;
-	struct buf *bp;
+	struct vnode *vp;
+	struct buf *bp, *nbp;
 	struct bufobj *bo;
-	struct buf *nbp;
-	int error = 0;
-	int maxretry = 1000;     /* large, arbitrarily chosen */
+	struct mount *mp;
+	int error, maxretry;
 
+	error = 0;
+	maxretry = 10000;     /* large, arbitrarily chosen */
+	vp = ap->a_vp;
+	mp = NULL;
+	if (vp->v_type == VCHR) {
+		VI_LOCK(vp);
+		mp = vp->v_rdev->si_mountpt;
+		VI_UNLOCK(vp);
+	}
 	bo = &vp->v_bufobj;
 	BO_LOCK(bo);
 loop1:
@@ -688,6 +696,8 @@ vop_stdfsync(ap)
 			bremfree(bp);
 			bawrite(bp);
 		}
+		if (maxretry < 1000)
+			pause("dirty", hz < 1000 ? 1 : hz / 1000);
 		BO_LOCK(bo);
 		goto loop2;
 	}
@@ -709,7 +719,8 @@ vop_stdfsync(ap)
 			TAILQ_FOREACH(bp, &bo->bo_dirty.bv_hd, b_bobufs)
 				if ((error = bp->b_error) == 0)
 					continue;
-			if (error == 0 && --maxretry >= 0)
+			if ((mp != NULL && mp->mnt_secondary_writes > 0) ||
+			    (error == 0 && --maxretry >= 0))
 				goto loop1;
 			error = EAGAIN;
 		}
-- 
2.45.0