[Ocfs2-devel] [PATCH] ocfs2: Fix locking for res->tracking and dlm->tracking_list
Ashish Samant
ashish.samant at oracle.com
Thu Jun 21 16:57:09 PDT 2018
In dlm_init_lockres() and dlm_unregister_domain() we access and modify
res->tracking and dlm->tracking_list without holding dlm->track_lock.
This can cause list corruptions and can end up in kernel panic.
Fix this by locking res->tracking and dlm->tracking_list with
dlm->track_lock at all places.
Signed-off-by: Ashish Samant <ashish.samant at oracle.com>
---
fs/ocfs2/dlm/dlmdomain.c | 2 ++
fs/ocfs2/dlm/dlmmaster.c | 4 ++--
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index 2acd58b..cfb1edd 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -723,6 +723,7 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm)
mlog(0, "%s: more migration to do\n", dlm->name);
}
+ spin_lock(&dlm->track_lock);
/* This list should be empty. If not, print remaining lockres */
if (!list_empty(&dlm->tracking_list)) {
mlog(ML_ERROR, "Following lockres' are still on the "
@@ -730,6 +731,7 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm)
list_for_each_entry(res, &dlm->tracking_list, tracking)
dlm_print_one_lock_resource(res);
}
+ 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 aaca094..826f056 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -584,9 +584,9 @@ 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));
--
1.9.1
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