Make it work after lockmgr -> vlockmgr conversion:
- Initialize si_vnlock in si_mount_init(). - Also initialize vl_recursecnt to zero. - Destroy it only in si_mount_dtor(). - Simplify the v_lock <-> si_vnlock exchange. - Don't abuse the overall error variable for LK_NOWAIT errors. - ffs_snapremove: release the vnode one instead of three times.
This commit is contained in:
hannken
parent
d738ece669
commit
a524d758da
@ -1,4 +1,4 @@
|
||||
/* $NetBSD: ffs_snapshot.c,v 1.64 2008/01/30 14:50:28 ad Exp $ */
|
||||
/* $NetBSD: ffs_snapshot.c,v 1.65 2008/01/30 17:20:04 hannken Exp $ */
|
||||
|
||||
/*
|
||||
* Copyright 2000 Marshall Kirk McKusick. All Rights Reserved.
|
||||
@ -38,7 +38,7 @@
|
||||
*/
|
||||
|
||||
#include <sys/cdefs.h>
|
||||
__KERNEL_RCSID(0, "$NetBSD: ffs_snapshot.c,v 1.64 2008/01/30 14:50:28 ad Exp $");
|
||||
__KERNEL_RCSID(0, "$NetBSD: ffs_snapshot.c,v 1.65 2008/01/30 17:20:04 hannken Exp $");
|
||||
|
||||
#if defined(_KERNEL_OPT)
|
||||
#include "opt_ffs.h"
|
||||
@ -183,6 +183,9 @@ si_mount_init(struct mount *mp)
|
||||
if (new != NULL) {
|
||||
TAILQ_INIT(&new->si_snapshots);
|
||||
mutex_init(&new->si_lock, MUTEX_DEFAULT, IPL_NONE);
|
||||
rw_init(&new->si_vnlock.vl_lock);
|
||||
new->si_vnlock.vl_canrecurse = 1;
|
||||
new->si_vnlock.vl_recursecnt = 0;
|
||||
new->si_gen = 0;
|
||||
new->si_snapblklist = NULL;
|
||||
mount_setspecific(mp, si_mount_data_key, new);
|
||||
@ -513,23 +516,10 @@ ffs_snapshot(struct mount *mp, struct vnode *vp,
|
||||
MNT_IUNLOCK(mp);
|
||||
vnfree(mvp);
|
||||
/*
|
||||
* If there already exist snapshots on this filesystem, grab a
|
||||
* reference to their shared lock. If this is the first snapshot
|
||||
* on this filesystem, we need to allocate a lock for the snapshots
|
||||
* to share. In either case, acquire the snapshot lock and give
|
||||
* up our original private lock.
|
||||
* Acquire the snapshot lock and give up our original private lock.
|
||||
*/
|
||||
mutex_enter(&si->si_lock);
|
||||
if ((xp = TAILQ_FIRST(&si->si_snapshots)) != NULL) {
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = ITOV(xp)->v_vnlock;
|
||||
} else {
|
||||
rw_init(&si->si_vnlock.vl_lock);
|
||||
si->si_vnlock.vl_canrecurse = 1;
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = &si->si_vnlock;
|
||||
}
|
||||
mutex_exit(&si->si_lock);
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = &si->si_vnlock;
|
||||
vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY);
|
||||
vlockmgr(&vp->v_lock, LK_RELEASE);
|
||||
/*
|
||||
@ -538,7 +528,9 @@ ffs_snapshot(struct mount *mp, struct vnode *vp,
|
||||
* This list will be refined below, but this preliminary one will
|
||||
* keep us out of deadlock until the full one is ready.
|
||||
*/
|
||||
if (xp == NULL) {
|
||||
mutex_enter(&si->si_lock);
|
||||
if ((xp = TAILQ_FIRST(&si->si_snapshots)) == NULL) {
|
||||
mutex_exit(&si->si_lock);
|
||||
snapblklist = malloc(
|
||||
snaplistsize * sizeof(ufs2_daddr_t), M_UFSMNT, M_WAITOK);
|
||||
blkp = &snapblklist[1];
|
||||
@ -559,8 +551,7 @@ ffs_snapshot(struct mount *mp, struct vnode *vp,
|
||||
if (si->si_snapblklist != NULL)
|
||||
panic("ffs_snapshot: non-empty list");
|
||||
si->si_snapblklist = snapblklist;
|
||||
} else
|
||||
mutex_enter(&si->si_lock);
|
||||
}
|
||||
/*
|
||||
* Record snapshot inode. Since this is the newest snapshot,
|
||||
* it must be placed at the end of the list.
|
||||
@ -1456,6 +1447,7 @@ ffs_snapremove(struct vnode *vp)
|
||||
TAILQ_REMOVE(&si->si_snapshots, ip, i_nextsnap);
|
||||
ip->i_nextsnap.tqe_prev = 0;
|
||||
lkp = vp->v_vnlock;
|
||||
KASSERT(lkp == &si->si_vnlock);
|
||||
vp->v_vnlock = &vp->v_lock;
|
||||
vlockmgr(lkp, LK_RELEASE);
|
||||
if (TAILQ_FIRST(&si->si_snapshots) != 0) {
|
||||
@ -1466,11 +1458,8 @@ ffs_snapremove(struct vnode *vp)
|
||||
si->si_snapblklist = 0;
|
||||
si->si_gen++;
|
||||
mutex_exit(&si->si_lock);
|
||||
vlockmgr(lkp, LK_RELEASE);
|
||||
fscow_disestablish(mp, ffs_copyonwrite, devvp);
|
||||
mutex_enter(&si->si_lock);
|
||||
vlockmgr(lkp, LK_RELEASE);
|
||||
rw_destroy(&lkp->vl_lock);
|
||||
}
|
||||
si->si_gen++;
|
||||
mutex_exit(&si->si_lock);
|
||||
@ -1565,8 +1554,7 @@ retry:
|
||||
TAILQ_FOREACH(ip, &si->si_snapshots, i_nextsnap) {
|
||||
vp = ITOV(ip);
|
||||
if (snapshot_locked == 0) {
|
||||
error = VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT);
|
||||
if (error != 0) {
|
||||
if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
|
||||
mutex_exit(&si->si_lock);
|
||||
kpause("snaplock", false, 1, NULL);
|
||||
mutex_enter(&si->si_lock);
|
||||
@ -1810,21 +1798,11 @@ ffs_snapshot_mount(struct mount *mp)
|
||||
ip->i_snapblklist = &snapblklist[0];
|
||||
|
||||
/*
|
||||
* If there already exist snapshots on this filesystem, grab a
|
||||
* reference to their shared lock. If this is the first snapshot
|
||||
* on this filesystem, we need to allocate a lock for the
|
||||
* snapshots to share. In either case, acquire the snapshot
|
||||
* lock and give up our original private lock.
|
||||
* Acquire the snapshot lock and give up our original
|
||||
* private lock.
|
||||
*/
|
||||
if ((xp = TAILQ_FIRST(&si->si_snapshots)) != NULL) {
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = ITOV(xp)->v_vnlock;
|
||||
} else {
|
||||
rw_init(&si->si_vnlock.vl_lock);
|
||||
si->si_vnlock.vl_canrecurse = 1;
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = &si->si_vnlock;
|
||||
}
|
||||
VI_LOCK(vp);
|
||||
vp->v_vnlock = &si->si_vnlock;
|
||||
vn_lock(vp, LK_INTERLOCK | LK_EXCLUSIVE | LK_RETRY);
|
||||
vlockmgr(&vp->v_lock, LK_RELEASE);
|
||||
/*
|
||||
@ -1961,8 +1939,7 @@ retry:
|
||||
if (bp->b_vp == vp)
|
||||
continue;
|
||||
if (snapshot_locked == 0) {
|
||||
error = VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT);
|
||||
if (error != 0) {
|
||||
if (VOP_LOCK(vp, LK_EXCLUSIVE | LK_NOWAIT) != 0) {
|
||||
mutex_exit(&si->si_lock);
|
||||
kpause("snaplock", false, 1, NULL);
|
||||
mutex_enter(&si->si_lock);
|
||||
|
||||
Loading…
Reference in New Issue
Block a user