git: 7c09d62011bb - stable/13 - Handle ERELOOKUP from VOP_FSYNC() in several other places

From: Konstantin Belousov <kib_at_FreeBSD.org>
Date: Sun, 22 Jan 2023 09:19:22 UTC
The branch stable/13 has been updated by kib:

URL: https://cgit.FreeBSD.org/src/commit/?id=7c09d62011bb084d3f7127edf2942bf6c9c3a6e2

commit 7c09d62011bb084d3f7127edf2942bf6c9c3a6e2
Author:     Konstantin Belousov <kib@FreeBSD.org>
AuthorDate: 2023-01-18 21:09:10 +0000
Commit:     Konstantin Belousov <kib@FreeBSD.org>
CommitDate: 2023-01-22 09:18:09 +0000

    Handle ERELOOKUP from VOP_FSYNC() in several other places
    
    (cherry picked from commit 6189672e600814fec4cc165d25ae050fb2f3a999)
---
 sys/dev/md/md.c    | 12 +++++++-----
 sys/vm/vm_object.c | 19 +++++++++++++++++--
 2 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/sys/dev/md/md.c b/sys/dev/md/md.c
index f44a2e940faa..243ac2be72d9 100644
--- a/sys/dev/md/md.c
+++ b/sys/dev/md/md.c
@@ -911,11 +911,13 @@ mdstart_vnode(struct md_s *sc, struct bio *bp)
 	 */
 
 	if (bp->bio_cmd == BIO_FLUSH) {
-		(void) vn_start_write(vp, &mp, V_WAIT);
-		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
-		error = VOP_FSYNC(vp, MNT_WAIT, td);
-		VOP_UNLOCK(vp);
-		vn_finished_write(mp);
+		do {
+			(void) vn_start_write(vp, &mp, V_WAIT);
+			vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+			error = VOP_FSYNC(vp, MNT_WAIT, td);
+			VOP_UNLOCK(vp);
+			vn_finished_write(mp);
+		} while (error == ERELOOKUP);
 		return (error);
 	}
 
diff --git a/sys/vm/vm_object.c b/sys/vm/vm_object.c
index 97803afc40fe..e7097be7b115 100644
--- a/sys/vm/vm_object.c
+++ b/sys/vm/vm_object.c
@@ -1254,8 +1254,23 @@ vm_object_sync(vm_object_t object, vm_ooffset_t offset, vm_size_t size,
 		res = vm_object_page_clean(object, offset, offset + size,
 		    flags);
 		VM_OBJECT_WUNLOCK(object);
-		if (fsync_after)
-			error = VOP_FSYNC(vp, MNT_WAIT, curthread);
+		if (fsync_after) {
+			for (;;) {
+				error = VOP_FSYNC(vp, MNT_WAIT, curthread);
+				if (error != ERELOOKUP)
+					break;
+
+				/*
+				 * Allow SU/bufdaemon to handle more
+				 * dependencies in the meantime.
+				 */
+				VOP_UNLOCK(vp);
+				vn_finished_write(mp);
+
+				(void)vn_start_write(vp, &mp, V_WAIT);
+				vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
+			}
+		}
 		VOP_UNLOCK(vp);
 		vn_finished_write(mp);
 		if (error != 0)