Aren/NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Add flag VRELEL_FORCE_RELE to vrelel() to force release and

Browse Source 
use it from vdrain_vrele() and vrele_flush() to prevent a
possible live lock from vrele_flush().
This commit is contained in:
hannken 2017-03-30 09:14:08 +00:00
parent a644d1ecc8
commit cf9ded4af4
1 changed files with 12 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/kern/vfs_vnode.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: vfs_vnode.c,v 1.77 2017/03/30 09:12:21 hannken Exp $ */
/* $NetBSD: vfs_vnode.c,v 1.78 2017/03/30 09:14:08 hannken Exp $ */
/*-
* Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
@ -156,7 +156,7 @@
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.77 2017/03/30 09:12:21 hannken Exp $");
__KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.78 2017/03/30 09:14:08 hannken Exp $");
#include <sys/param.h>
#include <sys/kernel.h>
@ -184,6 +184,7 @@ __KERNEL_RCSID(0, "$NetBSD: vfs_vnode.c,v 1.77 2017/03/30 09:12:21 hannken Exp $
/* Flags to vrelel. */
#define VRELEL_ASYNC_RELE 0x0001 /* Always defer to vrele thread. */
#define VRELEL_FORCE_RELE 0x0002 /* Must always succeed. */
u_int numvnodes __cacheline_aligned;
@ -482,7 +483,8 @@ vrele_flush(struct mount *mp)
TAILQ_INSERT_TAIL(vip->vi_lrulisthd, vip, vi_lrulist);
mutex_exit(&vdrain_lock);
vrele(VIMPL_TO_VNODE(vip));
mutex_enter(VIMPL_TO_VNODE(vip)->v_interlock);
vrelel(VIMPL_TO_VNODE(vip), VRELEL_FORCE_RELE);
mutex_enter(&vdrain_lock);
}
@ -523,8 +525,10 @@ vdrain_remove(vnode_t *vp)
mutex_exit(&vdrain_lock);
if (vcache_vget(vp) == 0) {
if (!vrecycle(vp))
vrele(vp);
if (!vrecycle(vp)) {
mutex_enter(vp->v_interlock);
vrelel(vp, VRELEL_FORCE_RELE);
}
}
fstrans_done(mp);
@ -561,7 +565,7 @@ vdrain_vrele(vnode_t *vp)
mutex_exit(&vdrain_lock);
mutex_enter(vp->v_interlock);
vrelel(vp, 0);
vrelel(vp, VRELEL_FORCE_RELE);
fstrans_done(mp);
mutex_enter(&vdrain_lock);
@ -704,7 +708,7 @@ vrelel(vnode_t *vp, int flags)
if ((curlwp == uvm.pagedaemon_lwp) ||
(flags & VRELEL_ASYNC_RELE) != 0) {
defer = true;
} else if (curlwp == vdrain_lwp) {
} else if ((flags & VRELEL_FORCE_RELE) != 0) {
/*
* We have to try harder.
*/
@ -723,7 +727,7 @@ vrelel(vnode_t *vp, int flags)
}
KASSERT(mutex_owned(vp->v_interlock));
KASSERT(! (curlwp == vdrain_lwp && defer));
KASSERT(! ((flags & VRELEL_FORCE_RELE) != 0 && defer));
if (defer) {
/*