[PATCH] ocfs2: fix hang in dlm lock resource mastery
fixes hangs in lock mastery related to refcounting on the mle structure
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index 847dd3c..78ac3a0 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -792,7 +792,15 @@
mlog_errno(ret);
if (mle->master != O2NM_MAX_NODES) {
/* found a master ! */
- break;
+ if (mle->master <= nodenum)
+ break;
+ /* if our master request has not reached the master
+ * yet, keep going until it does. this is how the
+ * master will know that asserts are needed back to
+ * the lower nodes. */
+ mlog(0, "%s:%.*s: requests only up to %u but master "
+ "is %u, keep going\n", dlm->name, namelen,
+ lockid, nodenum, mle->master);
}
}
@@ -860,7 +868,19 @@
/* check if another node has already become the owner */
spin_lock(&res->spinlock);
if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
+ mlog(0, "%s:%.*s: owner is suddenly %u\n", dlm->name,
+ res->lockname.len, res->lockname.name, res->owner);
spin_unlock(&res->spinlock);
+ /* this will cause the master to re-assert across
+ * the whole cluster, freeing up mles */
+ ret = dlm_do_master_request(mle, res->owner);
+ if (ret < 0) {
+ /* give recovery a chance to run */
+ mlog(ML_ERROR, "link to %u went down?: %d\n", res->owner, ret);
+ msleep(500);
+ goto recheck;
+ }
+ ret = 0;
goto leave;
}
spin_unlock(&res->spinlock);
@@ -1244,13 +1264,14 @@
{
u8 response = DLM_MASTER_RESP_MAYBE;
struct dlm_ctxt *dlm = data;
- struct dlm_lock_resource *res;
+ struct dlm_lock_resource *res = NULL;
struct dlm_master_request *request = (struct dlm_master_request *) msg->buf;
struct dlm_master_list_entry *mle = NULL, *tmpmle = NULL;
char *name;
unsigned int namelen;
int found, ret;
int set_maybe;
+ int dispatch_assert = 0;
if (!dlm_grab(dlm))
return DLM_MASTER_RESP_NO;
@@ -1287,7 +1308,6 @@
}
if (res->owner == dlm->node_num) {
- u32 flags = DLM_ASSERT_MASTER_MLE_CLEANUP;
spin_unlock(&res->spinlock);
// mlog(0, "this node is the master\n");
response = DLM_MASTER_RESP_YES;
@@ -1300,16 +1320,7 @@
* caused all nodes up to this one to
* create mles. this node now needs to
* go back and clean those up. */
- mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
- dlm->node_num, res->lockname.len, res->lockname.name);
- ret = dlm_dispatch_assert_master(dlm, res, 1,
- request->node_idx,
- flags);
- if (ret < 0) {
- mlog(ML_ERROR, "failed to dispatch assert "
- "master work\n");
- response = DLM_MASTER_RESP_ERROR;
- }
+ dispatch_assert = 1;
goto send_response;
} else if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN) {
spin_unlock(&res->spinlock);
@@ -1357,9 +1368,13 @@
}
} else if (tmpmle->master != DLM_LOCK_RES_OWNER_UNKNOWN) {
set_maybe = 0;
- if (tmpmle->master == dlm->node_num)
+ if (tmpmle->master == dlm->node_num) {
response = DLM_MASTER_RESP_YES;
- else
+ /* this node will be the owner.
+ * go back and clean the mles on any
+ * other nodes */
+ dispatch_assert = 1;
+ } else
response = DLM_MASTER_RESP_NO;
} else {
// mlog(0, "this node is attempting to "
@@ -1398,8 +1413,8 @@
mle = (struct dlm_master_list_entry *)
kmem_cache_alloc(dlm_mle_cache, GFP_KERNEL);
if (!mle) {
- // bad bad bad... this sucks.
response = DLM_MASTER_RESP_ERROR;
+ mlog_errno(-ENOMEM);
goto send_response;
}
spin_lock(&dlm->spinlock);
@@ -1418,25 +1433,19 @@
// mlog(0, "mle was found\n");
set_maybe = 1;
spin_lock(&tmpmle->spinlock);
+ if (tmpmle->master == dlm->node_num) {
+ mlog(ML_ERROR, "no lockres, but an mle with this node as master!\n");
+ BUG();
+ }
if (tmpmle->type == DLM_MLE_BLOCK)
response = DLM_MASTER_RESP_NO;
else if (tmpmle->type == DLM_MLE_MIGRATION) {
mlog(0, "migration mle was found (%u->%u)\n",
tmpmle->master, tmpmle->new_master);
- if (tmpmle->master == dlm->node_num) {
- mlog(ML_ERROR, "no lockres, but migration mle "
- "says that this node is master!\n");
- BUG();
- }
/* real master can respond on its own */
response = DLM_MASTER_RESP_NO;
- } else {
- if (tmpmle->master == dlm->node_num) {
- response = DLM_MASTER_RESP_YES;
- set_maybe = 0;
- } else
- response = DLM_MASTER_RESP_MAYBE;
- }
+ } else
+ response = DLM_MASTER_RESP_MAYBE;
if (set_maybe)
set_bit(request->node_idx, tmpmle->maybe_map);
spin_unlock(&tmpmle->spinlock);
@@ -1449,6 +1458,24 @@
dlm_put_mle(tmpmle);
}
send_response:
+
+ if (dispatch_assert) {
+ if (response != DLM_MASTER_RESP_YES)
+ mlog(ML_ERROR, "invalid response %d\n", response);
+ if (!res) {
+ mlog(ML_ERROR, "bad lockres while trying to assert!\n");
+ BUG();
+ }
+ mlog(0, "%u is the owner of %.*s, cleaning everyone else\n",
+ dlm->node_num, res->lockname.len, res->lockname.name);
+ ret = dlm_dispatch_assert_master(dlm, res, 0, request->node_idx,
+ DLM_ASSERT_MASTER_MLE_CLEANUP);
+ if (ret < 0) {
+ mlog(ML_ERROR, "failed to dispatch assert master work\n");
+ response = DLM_MASTER_RESP_ERROR;
+ }
+ }
+
dlm_put(dlm);
return response;
}
@@ -1471,8 +1498,11 @@
int to, tmpret;
struct dlm_node_iter iter;
int ret = 0;
+ int reassert;
BUG_ON(namelen > O2NM_MAX_NAME_LEN);
+again:
+ reassert = 0;
/* note that if this nodemap is empty, it returns 0 */
dlm_node_iter_init(nodemap, &iter);
@@ -1504,9 +1534,17 @@
"got %d.\n", namelen, lockname, to, r);
dlm_dump_lock_resources(dlm);
BUG();
+ } else if (r == EAGAIN) {
+ mlog(0, "%.*s: node %u create mles on other "
+ "nodes and requests a re-assert\n",
+ namelen, lockname, to);
+ reassert = 1;
}
}
+ if (reassert)
+ goto again;
+
return ret;
}
@@ -1528,6 +1566,8 @@
char *name;
unsigned int namelen;
u32 flags;
+ int master_request = 0;
+ int ret = 0;
if (!dlm_grab(dlm))
return 0;
@@ -1642,11 +1682,22 @@
// mlog(0, "woo! got an assert_master from node %u!\n",
// assert->node_idx);
if (mle) {
- int extra_ref;
+ int extra_ref = 0;
+ int nn = -1;
spin_lock(&mle->spinlock);
- extra_ref = !!(mle->type == DLM_MLE_BLOCK
- || mle->type == DLM_MLE_MIGRATION);
+ if (mle->type == DLM_MLE_BLOCK || mle->type == DLM_MLE_MIGRATION)
+ extra_ref = 1;
+ else {
+ /* MASTER mle: if any bits set in the response map
+ * then the calling node needs to re-assert to clear
+ * up nodes that this node contacted */
+ while ((nn = find_next_bit (mle->response_map, O2NM_MAX_NODES,
+ nn+1)) < O2NM_MAX_NODES) {
+ if (nn != dlm->node_num && nn != assert->node_idx)
+ master_request = 1;
+ }
+ }
mle->master = assert->node_idx;
atomic_set(&mle->woken, 1);
wake_up(&mle->wq);
@@ -1677,10 +1728,15 @@
}
done:
+ ret = 0;
if (res)
dlm_lockres_put(res);
dlm_put(dlm);
- return 0;
+ if (master_request) {
+ mlog(0, "need to tell master to reassert\n");
+ ret = EAGAIN; // positive. negative would shoot down the node.
+ }
+ return ret;
kill:
/* kill the caller! */
@@ -1713,6 +1769,10 @@
item->u.am.request_from = request_from;
item->u.am.flags = flags;
+ if (ignore_higher)
+ mlog(0, "IGNORE HIGHER: %.*s\n", res->lockname.len,
+ res->lockname.name);
+
spin_lock(&dlm->work_lock);
list_add_tail(&item->list, &dlm->work_list);
spin_unlock(&dlm->work_lock);