Joseph Qi
2017-Sep-25 10:35 UTC
[Ocfs2-devel] [patch 1/2] ocfs2/dlm: protect 'tracking_list' by 'track_lock'
On 17/9/23 11:39, piaojun wrote:> 'dlm->tracking_list' need to be protected by 'dlm->track_lock'. > > Signed-off-by: Jun Piao <piaojun at huawei.com> > Reviewed-by: Alex Chen <alex.chen at huawei.com> > --- > fs/ocfs2/dlm/dlmdomain.c | 7 ++++++- > fs/ocfs2/dlm/dlmmaster.c | 4 ++-- > 2 files changed, 8 insertions(+), 3 deletions(-) > > diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c > index a2b19fb..b118525 100644 > --- a/fs/ocfs2/dlm/dlmdomain.c > +++ b/fs/ocfs2/dlm/dlmdomain.c > @@ -726,12 +726,17 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm) > } > > /* This list should be empty. If not, print remaining lockres */ > + spin_lock(&dlm->track_lock); > if (!list_empty(&dlm->tracking_list)) { > mlog(ML_ERROR, "Following lockres' are still on the " > "tracking list:\n"); > - list_for_each_entry(res, &dlm->tracking_list, tracking) > + list_for_each_entry(res, &dlm->tracking_list, tracking) { > + spin_unlock(&dlm->track_lock);Um... If we unlock here, the iterator still has chance to be corrupted. Thanks, Joseph> dlm_print_one_lock_resource(res); > + spin_lock(&dlm->track_lock); > + } > } > + spin_unlock(&dlm->track_lock); > > dlm_mark_domain_leaving(dlm); > dlm_leave_domain(dlm); > diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c > index 3e04279..44e7d18 100644 > --- a/fs/ocfs2/dlm/dlmmaster.c > +++ b/fs/ocfs2/dlm/dlmmaster.c > @@ -589,9 +589,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm, > > res->last_used = 0; > > - spin_lock(&dlm->spinlock); > + spin_lock(&dlm->track_lock); > list_add_tail(&res->tracking, &dlm->tracking_list); > - spin_unlock(&dlm->spinlock); > + spin_unlock(&dlm->track_lock); > > memset(res->lvb, 0, DLM_LVB_LEN); > memset(res->refmap, 0, sizeof(res->refmap)); >
piaojun
2017-Sep-26 00:39 UTC
[Ocfs2-devel] [patch 1/2] ocfs2/dlm: protect 'tracking_list' by 'track_lock'
On 2017/9/25 18:35, Joseph Qi wrote:> > > On 17/9/23 11:39, piaojun wrote: >> 'dlm->tracking_list' need to be protected by 'dlm->track_lock'. >> >> Signed-off-by: Jun Piao <piaojun at huawei.com> >> Reviewed-by: Alex Chen <alex.chen at huawei.com> >> --- >> fs/ocfs2/dlm/dlmdomain.c | 7 ++++++- >> fs/ocfs2/dlm/dlmmaster.c | 4 ++-- >> 2 files changed, 8 insertions(+), 3 deletions(-) >> >> diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c >> index a2b19fb..b118525 100644 >> --- a/fs/ocfs2/dlm/dlmdomain.c >> +++ b/fs/ocfs2/dlm/dlmdomain.c >> @@ -726,12 +726,17 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm) >> } >> >> /* This list should be empty. If not, print remaining lockres */ >> + spin_lock(&dlm->track_lock); >> if (!list_empty(&dlm->tracking_list)) { >> mlog(ML_ERROR, "Following lockres' are still on the " >> "tracking list:\n"); >> - list_for_each_entry(res, &dlm->tracking_list, tracking) >> + list_for_each_entry(res, &dlm->tracking_list, tracking) { >> + spin_unlock(&dlm->track_lock); > > Um... If we unlock here, the iterator still has chance to be corrupted. > > Thanks, > Joseph >we don't need care much about the corrupted 'tracking_list' because we have already picked up 'res' from 'tracking_list'. then we will get 'track_lock' again to prevent 'tracking_list' from being corrupted. but I'd better make sure that 'res' is not NULL before printing, just like: list_for_each_entry(res, &dlm->tracking_list, tracking) { spin_unlock(&dlm->track_lock); if (res) dlm_print_one_lock_resource(res); spin_lock(&dlm->track_lock); } Thanks Jun>> dlm_print_one_lock_resource(res); >> + spin_lock(&dlm->track_lock); >> + } >> } >> + spin_unlock(&dlm->track_lock); >> >> dlm_mark_domain_leaving(dlm); >> dlm_leave_domain(dlm); >> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c >> index 3e04279..44e7d18 100644 >> --- a/fs/ocfs2/dlm/dlmmaster.c >> +++ b/fs/ocfs2/dlm/dlmmaster.c >> @@ -589,9 +589,9 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm, >> >> res->last_used = 0; >> >> - spin_lock(&dlm->spinlock); >> + spin_lock(&dlm->track_lock); >> list_add_tail(&res->tracking, &dlm->tracking_list); >> - spin_unlock(&dlm->spinlock); >> + spin_unlock(&dlm->track_lock); >> >> memset(res->lvb, 0, DLM_LVB_LEN); >> memset(res->refmap, 0, sizeof(res->refmap)); >> > . >