Module Name: src
Committed By: riastradh
Date: Sun Feb 23 08:39:28 UTC 2020
Modified Files:
src/sys/ufs/lfs: lfs_bio.c
Log Message:
Prevent new dirops while we issue lfs_flush_dirops.
lfs_flush_dirops assumes (by KASSERT((ip->i_state & IN_ADIROP) == 0))
that vnodes on the dchain will not become involved in active dirops
even while holding no other locks (lfs_lock, v_interlock), so we must
set lfs_writer here. All other callers already set lfs_writer.
We set fs->lfs_writer++ without explicitly doing lfs_writer_enter
because
(a) we already waited for the dirops to drain, and
(b) we hold lfs_lock and cannot drop it before setting lfs_writer.
To generate a diff of this commit:
cvs rdiff -u -r1.145 -r1.146 src/sys/ufs/lfs/lfs_bio.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/ufs/lfs/lfs_bio.c
diff -u src/sys/ufs/lfs/lfs_bio.c:1.145 src/sys/ufs/lfs/lfs_bio.c:1.146
--- src/sys/ufs/lfs/lfs_bio.c:1.145 Tue Feb 18 20:23:17 2020
+++ src/sys/ufs/lfs/lfs_bio.c Sun Feb 23 08:39:28 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: lfs_bio.c,v 1.145 2020/02/18 20:23:17 chs Exp $ */
+/* $NetBSD: lfs_bio.c,v 1.146 2020/02/23 08:39:28 riastradh Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001, 2002, 2003, 2008 The NetBSD Foundation, Inc.
@@ -60,7 +60,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: lfs_bio.c,v 1.145 2020/02/18 20:23:17 chs Exp $");
+__KERNEL_RCSID(0, "$NetBSD: lfs_bio.c,v 1.146 2020/02/23 08:39:28 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
@@ -653,9 +653,14 @@ lfs_check(struct vnode *vp, daddr_t blkn
/* If there are too many pending dirops, we have to flush them. */
if (fs->lfs_dirvcount > LFS_MAX_FSDIROP(fs) ||
lfs_dirvcount > LFS_MAX_DIROP || fs->lfs_diropwait > 0) {
+ KASSERT(fs->lfs_dirops == 0);
+ fs->lfs_writer++;
mutex_exit(&lfs_lock);
lfs_flush_dirops(fs);
mutex_enter(&lfs_lock);
+ if (--fs->lfs_writer == 0)
+ cv_broadcast(&fs->lfs_diropscv);
+ KASSERT(fs->lfs_dirops == 0);
} else if (locked_queue_count + INOCOUNT(fs) > LFS_MAX_BUFS ||
locked_queue_bytes + INOBYTES(fs) > LFS_MAX_BYTES ||
lfs_subsys_pages > LFS_MAX_PAGES ||
