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As VOP_STRATEGY() usually calls itself on the file system holding "/dev"

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it may deadlock on suspension of this file system.

Add fstrans type LAZY and use it for VOP_STRATEGY().

Adress PR kern/53624 (dom0 freeze on domU exit) is still there
This commit is contained in:
hannken 2019-10-11 08:04:52 +00:00
parent 18b8ffb209
commit f8da5187dc
2 changed files with 8 additions and 5 deletions
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10
sys/kern/vnode_if.sh
View File

@ -29,7 +29,7 @@ copyright="\
* SUCH DAMAGE.
*/
"
SCRIPT_ID='$NetBSD: vnode_if.sh,v 1.66 2017/06/04 08:03:26 hannken Exp $'
SCRIPT_ID='$NetBSD: vnode_if.sh,v 1.67 2019/10/11 08:04:52 hannken Exp $'
# Script to produce VFS front-end sugar.
#
@ -318,7 +318,7 @@ echo '
if [ -z "${rump}" ] ; then
echo "
enum fst_op { FST_NO, FST_YES, FST_TRY };
enum fst_op { FST_NO, FST_YES, FST_LAZY, FST_TRY };
static inline int
vop_pre(vnode_t *vp, struct mount **mp, bool *mpsafe, enum fst_op op)
@ -331,7 +331,7 @@ vop_pre(vnode_t *vp, struct mount **mp, bool *mpsafe, enum fst_op op)
KERNEL_LOCK(1, curlwp);
}
if (op == FST_YES || op == FST_TRY) {
if (op == FST_YES || op == FST_LAZY || op == FST_TRY) {
for (;;) {
*mp = vp->v_mount;
if (op == FST_TRY) {
@ -342,6 +342,8 @@ vop_pre(vnode_t *vp, struct mount **mp, bool *mpsafe, enum fst_op op)
}
return error;
}
} else if (op == FST_LAZY) {
fstrans_start_lazy(*mp);
} else {
fstrans_start(*mp);
}
@ -360,7 +362,7 @@ static inline void
vop_post(vnode_t *vp, struct mount *mp, bool mpsafe, enum fst_op op)
{
if (op == FST_YES) {
if (op == FST_YES || op == FST_LAZY) {
fstrans_done(mp);
}

3
sys/kern/vnode_if.src
View File

@ -1,4 +1,4 @@
# $NetBSD: vnode_if.src,v 1.77 2017/07/12 09:31:07 hannken Exp $
# $NetBSD: vnode_if.src,v 1.78 2019/10/11 08:04:52 hannken Exp $
#
# Copyright (c) 1992, 1993
# The Regents of the University of California. All rights reserved.
@ -436,6 +436,7 @@ vop_bmap {
#% strategy vp = = =
#
vop_strategy {
FSTRANS=LAZY
IN struct vnode *vp;
IN struct buf *bp;
};