Merge master.kernel.org:/pub/scm/linux/kernel/git/acme/net-2.6
[pandora-kernel.git] / fs / ocfs2 / dlm / dlmmaster.c
index 847dd3c..f784177 100644 (file)
@@ -47,7 +47,6 @@
 
 #include "dlmapi.h"
 #include "dlmcommon.h"
-#include "dlmdebug.h"
 #include "dlmdomain.h"
 
 #define MLOG_MASK_PREFIX (ML_DLM|ML_DLM_MASTER)
@@ -74,6 +73,7 @@ struct dlm_master_list_entry
        wait_queue_head_t wq;
        atomic_t woken;
        struct kref mle_refs;
+       int inuse;
        unsigned long maybe_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
        unsigned long vote_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
        unsigned long response_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
@@ -127,18 +127,30 @@ static inline int dlm_mle_equal(struct dlm_ctxt *dlm,
        return 1;
 }
 
-#if 0
-/* Code here is included but defined out as it aids debugging */
+#define dlm_print_nodemap(m)  _dlm_print_nodemap(m,#m)
+static void _dlm_print_nodemap(unsigned long *map, const char *mapname)
+{
+       int i;
+       printk("%s=[ ", mapname);
+       for (i=0; i<O2NM_MAX_NODES; i++)
+               if (test_bit(i, map))
+                       printk("%d ", i);
+       printk("]");
+}
 
-void dlm_print_one_mle(struct dlm_master_list_entry *mle)
+static void dlm_print_one_mle(struct dlm_master_list_entry *mle)
 {
-       int i = 0, refs;
+       int refs;
        char *type;
        char attached;
        u8 master;
        unsigned int namelen;
        const char *name;
        struct kref *k;
+       unsigned long *maybe = mle->maybe_map,
+                     *vote = mle->vote_map,
+                     *resp = mle->response_map,
+                     *node = mle->node_map;
 
        k = &mle->mle_refs;
        if (mle->type == DLM_MLE_BLOCK)
@@ -159,18 +171,29 @@ void dlm_print_one_mle(struct dlm_master_list_entry *mle)
                name = mle->u.res->lockname.name;
        }
 
-       mlog(ML_NOTICE, "  #%3d: %3s  %3d  %3u   %3u %c    (%d)%.*s\n",
-                 i, type, refs, master, mle->new_master, attached,
-                 namelen, namelen, name);
+       mlog(ML_NOTICE, "%.*s: %3s refs=%3d mas=%3u new=%3u evt=%c inuse=%d ",
+                 namelen, name, type, refs, master, mle->new_master, attached,
+                 mle->inuse);
+       dlm_print_nodemap(maybe);
+       printk(", ");
+       dlm_print_nodemap(vote);
+       printk(", ");
+       dlm_print_nodemap(resp);
+       printk(", ");
+       dlm_print_nodemap(node);
+       printk(", ");
+       printk("\n");
 }
 
+#if 0
+/* Code here is included but defined out as it aids debugging */
+
 static void dlm_dump_mles(struct dlm_ctxt *dlm)
 {
        struct dlm_master_list_entry *mle;
        struct list_head *iter;
        
        mlog(ML_NOTICE, "dumping all mles for domain %s:\n", dlm->name);
-       mlog(ML_NOTICE, "  ####: type refs owner new events? lockname nodemap votemap respmap maybemap\n");
        spin_lock(&dlm->master_lock);
        list_for_each(iter, &dlm->master_list) {
                mle = list_entry(iter, struct dlm_master_list_entry, list);
@@ -239,6 +262,8 @@ static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
 static int dlm_mark_lockres_migrating(struct dlm_ctxt *dlm,
                                       struct dlm_lock_resource *res,
                                       u8 target);
+static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
+                                      struct dlm_lock_resource *res);
 
 
 int dlm_is_host_down(int errno)
@@ -312,6 +337,31 @@ static inline void dlm_mle_detach_hb_events(struct dlm_ctxt *dlm,
        spin_unlock(&dlm->spinlock);
 }
 
+static void dlm_get_mle_inuse(struct dlm_master_list_entry *mle)
+{
+       struct dlm_ctxt *dlm;
+       dlm = mle->dlm;
+
+       assert_spin_locked(&dlm->spinlock);
+       assert_spin_locked(&dlm->master_lock);
+       mle->inuse++;
+       kref_get(&mle->mle_refs);
+}
+
+static void dlm_put_mle_inuse(struct dlm_master_list_entry *mle)
+{
+       struct dlm_ctxt *dlm;
+       dlm = mle->dlm;
+
+       spin_lock(&dlm->spinlock);
+       spin_lock(&dlm->master_lock);
+       mle->inuse--;
+       __dlm_put_mle(mle);
+       spin_unlock(&dlm->master_lock);
+       spin_unlock(&dlm->spinlock);
+
+}
+
 /* remove from list and free */
 static void __dlm_put_mle(struct dlm_master_list_entry *mle)
 {
@@ -320,9 +370,14 @@ static void __dlm_put_mle(struct dlm_master_list_entry *mle)
 
        assert_spin_locked(&dlm->spinlock);
        assert_spin_locked(&dlm->master_lock);
-       BUG_ON(!atomic_read(&mle->mle_refs.refcount));
-
-       kref_put(&mle->mle_refs, dlm_mle_release);
+       if (!atomic_read(&mle->mle_refs.refcount)) {
+               /* this may or may not crash, but who cares.
+                * it's a BUG. */
+               mlog(ML_ERROR, "bad mle: %p\n", mle);
+               dlm_print_one_mle(mle);
+               BUG();
+       } else
+               kref_put(&mle->mle_refs, dlm_mle_release);
 }
 
 
@@ -365,6 +420,7 @@ static void dlm_init_mle(struct dlm_master_list_entry *mle,
        memset(mle->response_map, 0, sizeof(mle->response_map));
        mle->master = O2NM_MAX_NODES;
        mle->new_master = O2NM_MAX_NODES;
+       mle->inuse = 0;
 
        if (mle->type == DLM_MLE_MASTER) {
                BUG_ON(!res);
@@ -562,6 +618,28 @@ static void dlm_lockres_release(struct kref *kref)
        mlog(0, "destroying lockres %.*s\n", res->lockname.len,
             res->lockname.name);
 
+       if (!hlist_unhashed(&res->hash_node) ||
+           !list_empty(&res->granted) ||
+           !list_empty(&res->converting) ||
+           !list_empty(&res->blocked) ||
+           !list_empty(&res->dirty) ||
+           !list_empty(&res->recovering) ||
+           !list_empty(&res->purge)) {
+               mlog(ML_ERROR,
+                    "Going to BUG for resource %.*s."
+                    "  We're on a list! [%c%c%c%c%c%c%c]\n",
+                    res->lockname.len, res->lockname.name,
+                    !hlist_unhashed(&res->hash_node) ? 'H' : ' ',
+                    !list_empty(&res->granted) ? 'G' : ' ',
+                    !list_empty(&res->converting) ? 'C' : ' ',
+                    !list_empty(&res->blocked) ? 'B' : ' ',
+                    !list_empty(&res->dirty) ? 'D' : ' ',
+                    !list_empty(&res->recovering) ? 'R' : ' ',
+                    !list_empty(&res->purge) ? 'P' : ' ');
+
+               dlm_print_one_lock_resource(res);
+       }
+
        /* By the time we're ready to blow this guy away, we shouldn't
         * be on any lists. */
        BUG_ON(!hlist_unhashed(&res->hash_node));
@@ -577,11 +655,6 @@ static void dlm_lockres_release(struct kref *kref)
        kfree(res);
 }
 
-void dlm_lockres_get(struct dlm_lock_resource *res)
-{
-       kref_get(&res->refs);
-}
-
 void dlm_lockres_put(struct dlm_lock_resource *res)
 {
        kref_put(&res->refs, dlm_lockres_release);
@@ -601,7 +674,7 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
        memcpy(qname, name, namelen);
 
        res->lockname.len = namelen;
-       res->lockname.hash = full_name_hash(name, namelen);
+       res->lockname.hash = dlm_lockid_hash(name, namelen);
 
        init_waitqueue_head(&res->wq);
        spin_lock_init(&res->spinlock);
@@ -635,11 +708,11 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
 {
        struct dlm_lock_resource *res;
 
-       res = kmalloc(sizeof(struct dlm_lock_resource), GFP_KERNEL);
+       res = kmalloc(sizeof(struct dlm_lock_resource), GFP_NOFS);
        if (!res)
                return NULL;
 
-       res->lockname.name = kmalloc(namelen, GFP_KERNEL);
+       res->lockname.name = kmalloc(namelen, GFP_NOFS);
        if (!res->lockname.name) {
                kfree(res);
                return NULL;
@@ -667,6 +740,7 @@ struct dlm_lock_resource *dlm_new_lockres(struct dlm_ctxt *dlm,
  */
 struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
                                          const char *lockid,
+                                         int namelen,
                                          int flags)
 {
        struct dlm_lock_resource *tmpres=NULL, *res=NULL;
@@ -675,18 +749,19 @@ struct dlm_lock_resource * dlm_get_lock_resource(struct dlm_ctxt *dlm,
        int blocked = 0;
        int ret, nodenum;
        struct dlm_node_iter iter;
-       unsigned int namelen;
+       unsigned int hash;
        int tries = 0;
+       int bit, wait_on_recovery = 0;
 
        BUG_ON(!lockid);
 
-       namelen = strlen(lockid);
+       hash = dlm_lockid_hash(lockid, namelen);
 
        mlog(0, "get lockres %s (len %d)\n", lockid, namelen);
 
 lookup:
        spin_lock(&dlm->spinlock);
-       tmpres = __dlm_lookup_lockres(dlm, lockid, namelen);
+       tmpres = __dlm_lookup_lockres(dlm, lockid, namelen, hash);
        if (tmpres) {
                spin_unlock(&dlm->spinlock);
                mlog(0, "found in hash!\n");
@@ -701,7 +776,7 @@ lookup:
                mlog(0, "allocating a new resource\n");
                /* nothing found and we need to allocate one. */
                alloc_mle = (struct dlm_master_list_entry *)
-                       kmem_cache_alloc(dlm_mle_cache, GFP_KERNEL);
+                       kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
                if (!alloc_mle)
                        goto leave;
                res = dlm_new_lockres(dlm, lockid, namelen);
@@ -762,6 +837,18 @@ lookup:
                dlm_init_mle(mle, DLM_MLE_MASTER, dlm, res, NULL, 0);
                set_bit(dlm->node_num, mle->maybe_map);
                list_add(&mle->list, &dlm->master_list);
+
+               /* still holding the dlm spinlock, check the recovery map
+                * to see if there are any nodes that still need to be 
+                * considered.  these will not appear in the mle nodemap
+                * but they might own this lockres.  wait on them. */
+               bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
+               if (bit < O2NM_MAX_NODES) {
+                       mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
+                            "recover before lock mastery can begin\n",
+                            dlm->name, namelen, (char *)lockid, bit);
+                       wait_on_recovery = 1;
+               }
        }
 
        /* at this point there is either a DLM_MLE_BLOCK or a
@@ -775,15 +862,51 @@ lookup:
         * if so, the creator of the BLOCK may try to put the last
         * ref at this time in the assert master handler, so we
         * need an extra one to keep from a bad ptr deref. */
-       dlm_get_mle(mle);
+       dlm_get_mle_inuse(mle);
        spin_unlock(&dlm->master_lock);
        spin_unlock(&dlm->spinlock);
 
+redo_request:
+       while (wait_on_recovery) {
+               /* any cluster changes that occurred after dropping the
+                * dlm spinlock would be detectable be a change on the mle,
+                * so we only need to clear out the recovery map once. */
+               if (dlm_is_recovery_lock(lockid, namelen)) {
+                       mlog(ML_NOTICE, "%s: recovery map is not empty, but "
+                            "must master $RECOVERY lock now\n", dlm->name);
+                       if (!dlm_pre_master_reco_lockres(dlm, res))
+                               wait_on_recovery = 0;
+                       else {
+                               mlog(0, "%s: waiting 500ms for heartbeat state "
+                                   "change\n", dlm->name);
+                               msleep(500);
+                       }
+                       continue;
+               } 
+
+               dlm_kick_recovery_thread(dlm);
+               msleep(1000);
+               dlm_wait_for_recovery(dlm);
+
+               spin_lock(&dlm->spinlock);
+               bit = find_next_bit(dlm->recovery_map, O2NM_MAX_NODES, 0);
+               if (bit < O2NM_MAX_NODES) {
+                       mlog(ML_NOTICE, "%s:%.*s: at least one node (%d) to"
+                            "recover before lock mastery can begin\n",
+                            dlm->name, namelen, (char *)lockid, bit);
+                       wait_on_recovery = 1;
+               } else
+                       wait_on_recovery = 0;
+               spin_unlock(&dlm->spinlock);
+
+               if (wait_on_recovery)
+                       dlm_wait_for_node_recovery(dlm, bit, 10000);
+       }
+
        /* must wait for lock to be mastered elsewhere */
        if (blocked)
                goto wait;
 
-redo_request:
        ret = -EINVAL;
        dlm_node_iter_init(mle->vote_map, &iter);
        while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
@@ -792,7 +915,15 @@ redo_request:
                        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);
                }
        }
 
@@ -800,6 +931,7 @@ wait:
        /* keep going until the response map includes all nodes */
        ret = dlm_wait_for_lock_mastery(dlm, res, mle, &blocked);
        if (ret < 0) {
+               wait_on_recovery = 1;
                mlog(0, "%s:%.*s: node map changed, redo the "
                     "master request now, blocked=%d\n",
                     dlm->name, res->lockname.len,
@@ -810,7 +942,7 @@ wait:
                             dlm->name, res->lockname.len, 
                             res->lockname.name, blocked);
                        dlm_print_one_lock_resource(res);
-                       /* dlm_print_one_mle(mle); */
+                       dlm_print_one_mle(mle);
                        tries = 0;
                }
                goto redo_request;
@@ -824,7 +956,7 @@ wait:
        dlm_mle_detach_hb_events(dlm, mle);
        dlm_put_mle(mle);
        /* put the extra ref */
-       dlm_put_mle(mle);
+       dlm_put_mle_inuse(mle);
 
 wake_waiters:
        spin_lock(&res->spinlock);
@@ -860,7 +992,21 @@ recheck:
        /* 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 */
+               if (res->owner != dlm->node_num) {
+                       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);
@@ -894,6 +1040,12 @@ recheck:
                     "rechecking now\n", dlm->name, res->lockname.len,
                     res->lockname.name);
                goto recheck;
+       } else {
+               if (!voting_done) {
+                       mlog(0, "map not changed and voting not done "
+                            "for %s:%.*s\n", dlm->name, res->lockname.len,
+                            res->lockname.name);
+               }
        }
 
        if (m != O2NM_MAX_NODES) {
@@ -1061,18 +1213,6 @@ static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
                        set_bit(node, mle->vote_map);
                } else {
                        mlog(ML_ERROR, "node down! %d\n", node);
-
-                       /* if the node wasn't involved in mastery skip it,
-                        * but clear it out from the maps so that it will
-                        * not affect mastery of this lockres */
-                       clear_bit(node, mle->response_map);
-                       clear_bit(node, mle->vote_map);
-                       if (!test_bit(node, mle->maybe_map))
-                               goto next;
-
-                       /* if we're already blocked on lock mastery, and the
-                        * dead node wasn't the expected master, or there is
-                        * another node in the maybe_map, keep waiting */
                        if (blocked) {
                                int lowest = find_next_bit(mle->maybe_map,
                                                       O2NM_MAX_NODES, 0);
@@ -1080,54 +1220,53 @@ static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
                                /* act like it was never there */
                                clear_bit(node, mle->maybe_map);
 
-                               if (node != lowest)
-                                       goto next;
-
-                               mlog(ML_ERROR, "expected master %u died while "
-                                    "this node was blocked waiting on it!\n",
-                                    node);
-                               lowest = find_next_bit(mle->maybe_map,
-                                                      O2NM_MAX_NODES,
-                                                      lowest+1);
-                               if (lowest < O2NM_MAX_NODES) {
-                                       mlog(0, "still blocked. waiting "
-                                            "on %u now\n", lowest);
-                                       goto next;
+                               if (node == lowest) {
+                                       mlog(0, "expected master %u died"
+                                           " while this node was blocked "
+                                           "waiting on it!\n", node);
+                                       lowest = find_next_bit(mle->maybe_map,
+                                                       O2NM_MAX_NODES,
+                                                       lowest+1);
+                                       if (lowest < O2NM_MAX_NODES) {
+                                               mlog(0, "%s:%.*s:still "
+                                                    "blocked. waiting on %u "
+                                                    "now\n", dlm->name,
+                                                    res->lockname.len,
+                                                    res->lockname.name,
+                                                    lowest);
+                                       } else {
+                                               /* mle is an MLE_BLOCK, but
+                                                * there is now nothing left to
+                                                * block on.  we need to return
+                                                * all the way back out and try
+                                                * again with an MLE_MASTER.
+                                                * dlm_do_local_recovery_cleanup
+                                                * has already run, so the mle
+                                                * refcount is ok */
+                                               mlog(0, "%s:%.*s: no "
+                                                    "longer blocking. try to "
+                                                    "master this here\n",
+                                                    dlm->name,
+                                                    res->lockname.len,
+                                                    res->lockname.name);
+                                               mle->type = DLM_MLE_MASTER;
+                                               mle->u.res = res;
+                                       }
                                }
-
-                               /* mle is an MLE_BLOCK, but there is now
-                                * nothing left to block on.  we need to return
-                                * all the way back out and try again with
-                                * an MLE_MASTER. dlm_do_local_recovery_cleanup
-                                * has already run, so the mle refcount is ok */
-                               mlog(0, "no longer blocking. we can "
-                                    "try to master this here\n");
-                               mle->type = DLM_MLE_MASTER;
-                               memset(mle->maybe_map, 0,
-                                      sizeof(mle->maybe_map));
-                               memset(mle->response_map, 0,
-                                      sizeof(mle->maybe_map));
-                               memcpy(mle->vote_map, mle->node_map,
-                                      sizeof(mle->node_map));
-                               mle->u.res = res;
-                               set_bit(dlm->node_num, mle->maybe_map);
-
-                               ret = -EAGAIN;
-                               goto next;
                        }
 
-                       clear_bit(node, mle->maybe_map);
-                       if (node > dlm->node_num)
-                               goto next;
-
-                       mlog(0, "dead node in map!\n");
-                       /* yuck. go back and re-contact all nodes
-                        * in the vote_map, removing this node. */
-                       memset(mle->response_map, 0,
-                              sizeof(mle->response_map));
+                       /* now blank out everything, as if we had never
+                        * contacted anyone */
+                       memset(mle->maybe_map, 0, sizeof(mle->maybe_map));
+                       memset(mle->response_map, 0, sizeof(mle->response_map));
+                       /* reset the vote_map to the current node_map */
+                       memcpy(mle->vote_map, mle->node_map,
+                              sizeof(mle->node_map));
+                       /* put myself into the maybe map */
+                       if (mle->type != DLM_MLE_BLOCK)
+                               set_bit(dlm->node_num, mle->maybe_map);
                }
                ret = -EAGAIN;
-next:
                node = dlm_bitmap_diff_iter_next(&bdi, &sc);
        }
        return ret;
@@ -1244,13 +1383,14 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
 {
        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;
+       unsigned int namelen, hash;
        int found, ret;
        int set_maybe;
+       int dispatch_assert = 0;
 
        if (!dlm_grab(dlm))
                return DLM_MASTER_RESP_NO;
@@ -1262,6 +1402,7 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
        name = request->name;
        namelen = request->namelen;
+       hash = dlm_lockid_hash(name, namelen);
 
        if (namelen > DLM_LOCKID_NAME_MAX) {
                response = DLM_IVBUFLEN;
@@ -1270,7 +1411,7 @@ int dlm_master_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
 way_up_top:
        spin_lock(&dlm->spinlock);
-       res = __dlm_lookup_lockres(dlm, name, namelen);
+       res = __dlm_lookup_lockres(dlm, name, namelen, hash);
        if (res) {
                spin_unlock(&dlm->spinlock);
 
@@ -1287,7 +1428,6 @@ way_up_top:
                }
 
                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 +1440,7 @@ way_up_top:
                         * 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 +1488,13 @@ way_up_top:
                        }
                } 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 "
@@ -1396,21 +1531,18 @@ way_up_top:
                        spin_unlock(&dlm->spinlock);
 
                        mle = (struct dlm_master_list_entry *)
-                               kmem_cache_alloc(dlm_mle_cache, GFP_KERNEL);
+                               kmem_cache_alloc(dlm_mle_cache, GFP_NOFS);
                        if (!mle) {
-                               // bad bad bad... this sucks.
                                response = DLM_MASTER_RESP_ERROR;
+                               mlog_errno(-ENOMEM);
                                goto send_response;
                        }
-                       spin_lock(&dlm->spinlock);
-                       dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL,
-                                        name, namelen);
-                       spin_unlock(&dlm->spinlock);
                        goto way_up_top;
                }
 
                // mlog(0, "this is second time thru, already allocated, "
                // "add the block.\n");
+               dlm_init_mle(mle, DLM_MLE_BLOCK, dlm, NULL, name, namelen);
                set_bit(request->node_idx, mle->maybe_map);
                list_add(&mle->list, &dlm->master_list);
                response = DLM_MASTER_RESP_NO;
@@ -1418,25 +1550,19 @@ way_up_top:
                // 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 +1575,24 @@ way_up_top:
                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;
 }
@@ -1471,13 +1615,18 @@ static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname,
        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);
        while ((to = dlm_node_iter_next(&iter)) >= 0) {
                int r = 0;
+               struct dlm_master_list_entry *mle = NULL;
+
                mlog(0, "sending assert master to %d (%.*s)\n", to,
                     namelen, lockname);
                memset(&assert, 0, sizeof(assert));
@@ -1489,24 +1638,40 @@ static int dlm_do_assert_master(struct dlm_ctxt *dlm, const char *lockname,
                tmpret = o2net_send_message(DLM_ASSERT_MASTER_MSG, dlm->key,
                                            &assert, sizeof(assert), to, &r);
                if (tmpret < 0) {
-                       mlog(ML_ERROR, "assert_master returned %d!\n", tmpret);
+                       mlog(0, "assert_master returned %d!\n", tmpret);
                        if (!dlm_is_host_down(tmpret)) {
-                               mlog(ML_ERROR, "unhandled error!\n");
+                               mlog(ML_ERROR, "unhandled error=%d!\n", tmpret);
                                BUG();
                        }
                        /* a node died.  finish out the rest of the nodes. */
-                       mlog(ML_ERROR, "link to %d went down!\n", to);
+                       mlog(0, "link to %d went down!\n", to);
                        /* any nonzero status return will do */
                        ret = tmpret;
                } else if (r < 0) {
                        /* ok, something horribly messed.  kill thyself. */
                        mlog(ML_ERROR,"during assert master of %.*s to %u, "
                             "got %d.\n", namelen, lockname, to, r);
-                       dlm_dump_lock_resources(dlm);
+                       spin_lock(&dlm->spinlock);
+                       spin_lock(&dlm->master_lock);
+                       if (dlm_find_mle(dlm, &mle, (char *)lockname,
+                                        namelen)) {
+                               dlm_print_one_mle(mle);
+                               __dlm_put_mle(mle);
+                       }
+                       spin_unlock(&dlm->master_lock);
+                       spin_unlock(&dlm->spinlock);
                        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;
 }
 
@@ -1526,14 +1691,17 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
        struct dlm_assert_master *assert = (struct dlm_assert_master *)msg->buf;
        struct dlm_lock_resource *res = NULL;
        char *name;
-       unsigned int namelen;
+       unsigned int namelen, hash;
        u32 flags;
+       int master_request = 0;
+       int ret = 0;
 
        if (!dlm_grab(dlm))
                return 0;
 
        name = assert->name;
        namelen = assert->namelen;
+       hash = dlm_lockid_hash(name, namelen);
        flags = be32_to_cpu(assert->flags);
 
        if (namelen > DLM_LOCKID_NAME_MAX) {
@@ -1558,7 +1726,7 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
                if (bit >= O2NM_MAX_NODES) {
                        /* not necessarily an error, though less likely.
                         * could be master just re-asserting. */
-                       mlog(ML_ERROR, "no bits set in the maybe_map, but %u "
+                       mlog(0, "no bits set in the maybe_map, but %u "
                             "is asserting! (%.*s)\n", assert->node_idx,
                             namelen, name);
                } else if (bit != assert->node_idx) {
@@ -1570,19 +1738,36 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
                                 * number winning the mastery will respond
                                 * YES to mastery requests, but this node
                                 * had no way of knowing.  let it pass. */
-                               mlog(ML_ERROR, "%u is the lowest node, "
+                               mlog(0, "%u is the lowest node, "
                                     "%u is asserting. (%.*s)  %u must "
                                     "have begun after %u won.\n", bit,
                                     assert->node_idx, namelen, name, bit,
                                     assert->node_idx);
                        }
                }
+               if (mle->type == DLM_MLE_MIGRATION) {
+                       if (flags & DLM_ASSERT_MASTER_MLE_CLEANUP) {
+                               mlog(0, "%s:%.*s: got cleanup assert"
+                                    " from %u for migration\n",
+                                    dlm->name, namelen, name,
+                                    assert->node_idx);
+                       } else if (!(flags & DLM_ASSERT_MASTER_FINISH_MIGRATION)) {
+                               mlog(0, "%s:%.*s: got unrelated assert"
+                                    " from %u for migration, ignoring\n",
+                                    dlm->name, namelen, name,
+                                    assert->node_idx);
+                               __dlm_put_mle(mle);
+                               spin_unlock(&dlm->master_lock);
+                               spin_unlock(&dlm->spinlock);
+                               goto done;
+                       }       
+               }
        }
        spin_unlock(&dlm->master_lock);
 
        /* ok everything checks out with the MLE
         * now check to see if there is a lockres */
-       res = __dlm_lookup_lockres(dlm, name, namelen);
+       res = __dlm_lookup_lockres(dlm, name, namelen, hash);
        if (res) {
                spin_lock(&res->spinlock);
                if (res->state & DLM_LOCK_RES_RECOVERING)  {
@@ -1591,7 +1776,8 @@ int dlm_assert_master_handler(struct o2net_msg *msg, u32 len, void *data)
                        goto kill;
                }
                if (!mle) {
-                       if (res->owner != assert->node_idx) {
+                       if (res->owner != DLM_LOCK_RES_OWNER_UNKNOWN &&
+                           res->owner != assert->node_idx) {
                                mlog(ML_ERROR, "assert_master from "
                                          "%u, but current owner is "
                                          "%u! (%.*s)\n",
@@ -1642,54 +1828,108 @@ ok:
        // 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;
+               int rr, err = 0;
                
                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);
                spin_unlock(&mle->spinlock);
 
-               if (mle->type == DLM_MLE_MIGRATION && res) {
-                       mlog(0, "finishing off migration of lockres %.*s, "
-                            "from %u to %u\n",
-                              res->lockname.len, res->lockname.name,
-                              dlm->node_num, mle->new_master);
+               if (res) {
                        spin_lock(&res->spinlock);
-                       res->state &= ~DLM_LOCK_RES_MIGRATING;
-                       dlm_change_lockres_owner(dlm, res, mle->new_master);
-                       BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
+                       if (mle->type == DLM_MLE_MIGRATION) {
+                               mlog(0, "finishing off migration of lockres %.*s, "
+                                       "from %u to %u\n",
+                                       res->lockname.len, res->lockname.name,
+                                       dlm->node_num, mle->new_master);
+                               res->state &= ~DLM_LOCK_RES_MIGRATING;
+                               dlm_change_lockres_owner(dlm, res, mle->new_master);
+                               BUG_ON(res->state & DLM_LOCK_RES_DIRTY);
+                       } else {
+                               dlm_change_lockres_owner(dlm, res, mle->master);
+                       }
                        spin_unlock(&res->spinlock);
                }
-               /* master is known, detach if not already detached */
-               dlm_mle_detach_hb_events(dlm, mle);
-               dlm_put_mle(mle);
-               
+
+               /* master is known, detach if not already detached.
+                * ensures that only one assert_master call will happen
+                * on this mle. */
+               spin_lock(&dlm->spinlock);
+               spin_lock(&dlm->master_lock);
+
+               rr = atomic_read(&mle->mle_refs.refcount);
+               if (mle->inuse > 0) {
+                       if (extra_ref && rr < 3)
+                               err = 1;
+                       else if (!extra_ref && rr < 2)
+                               err = 1;
+               } else {
+                       if (extra_ref && rr < 2)
+                               err = 1;
+                       else if (!extra_ref && rr < 1)
+                               err = 1;
+               }
+               if (err) {
+                       mlog(ML_ERROR, "%s:%.*s: got assert master from %u "
+                            "that will mess up this node, refs=%d, extra=%d, "
+                            "inuse=%d\n", dlm->name, namelen, name,
+                            assert->node_idx, rr, extra_ref, mle->inuse);
+                       dlm_print_one_mle(mle);
+               }
+               list_del_init(&mle->list);
+               __dlm_mle_detach_hb_events(dlm, mle);
+               __dlm_put_mle(mle);
                if (extra_ref) {
                        /* the assert master message now balances the extra
                         * ref given by the master / migration request message.
                         * if this is the last put, it will be removed
                         * from the list. */
-                       dlm_put_mle(mle);
+                       __dlm_put_mle(mle);
+               }
+               spin_unlock(&dlm->master_lock);
+               spin_unlock(&dlm->spinlock);
+       } else if (res) {
+               if (res->owner != assert->node_idx) {
+                       mlog(0, "assert_master from %u, but current "
+                            "owner is %u (%.*s), no mle\n", assert->node_idx,
+                            res->owner, namelen, name);
                }
        }
 
 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! */
+       mlog(ML_ERROR, "Bad message received from another node.  Dumping state "
+            "and killing the other node now!  This node is OK and can continue.\n");
+       __dlm_print_one_lock_resource(res);
        spin_unlock(&res->spinlock);
        spin_unlock(&dlm->spinlock);
        dlm_lockres_put(res);
-       mlog(ML_ERROR, "Bad message received from another node.  Dumping state "
-            "and killing the other node now!  This node is OK and can continue.\n");
-       dlm_dump_lock_resources(dlm);
        dlm_put(dlm);
        return -EINVAL;
 }
@@ -1699,7 +1939,7 @@ int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
                               int ignore_higher, u8 request_from, u32 flags)
 {
        struct dlm_work_item *item;
-       item = kcalloc(1, sizeof(*item), GFP_KERNEL);
+       item = kcalloc(1, sizeof(*item), GFP_NOFS);
        if (!item)
                return -ENOMEM;
 
@@ -1713,11 +1953,15 @@ int dlm_dispatch_assert_master(struct dlm_ctxt *dlm,
        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);
 
-       schedule_work(&dlm->dispatched_work);
+       queue_work(dlm->dlm_worker, &dlm->dispatched_work);
        return 0;
 }
 
@@ -1758,6 +2002,23 @@ static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
                }
        }
 
+       /*
+        * If we're migrating this lock to someone else, we are no
+        * longer allowed to assert out own mastery.  OTOH, we need to
+        * prevent migration from starting while we're still asserting
+        * our dominance.  The reserved ast delays migration.
+        */
+       spin_lock(&res->spinlock);
+       if (res->state & DLM_LOCK_RES_MIGRATING) {
+               mlog(0, "Someone asked us to assert mastery, but we're "
+                    "in the middle of migration.  Skipping assert, "
+                    "the new master will handle that.\n");
+               spin_unlock(&res->spinlock);
+               goto put;
+       } else
+               __dlm_lockres_reserve_ast(res);
+       spin_unlock(&res->spinlock);
+
        /* this call now finishes out the nodemap
         * even if one or more nodes die */
        mlog(0, "worker about to master %.*s here, this=%u\n",
@@ -1767,14 +2028,75 @@ static void dlm_assert_master_worker(struct dlm_work_item *item, void *data)
                                   nodemap, flags);
        if (ret < 0) {
                /* no need to restart, we are done */
-               mlog_errno(ret);
+               if (!dlm_is_host_down(ret))
+                       mlog_errno(ret);
        }
 
+       /* Ok, we've asserted ourselves.  Let's let migration start. */
+       dlm_lockres_release_ast(dlm, res);
+
+put:
        dlm_lockres_put(res);
 
        mlog(0, "finished with dlm_assert_master_worker\n");
 }
 
+/* SPECIAL CASE for the $RECOVERY lock used by the recovery thread.
+ * We cannot wait for node recovery to complete to begin mastering this
+ * lockres because this lockres is used to kick off recovery! ;-)
+ * So, do a pre-check on all living nodes to see if any of those nodes
+ * think that $RECOVERY is currently mastered by a dead node.  If so,
+ * we wait a short time to allow that node to get notified by its own
+ * heartbeat stack, then check again.  All $RECOVERY lock resources
+ * mastered by dead nodes are purged when the hearbeat callback is 
+ * fired, so we can know for sure that it is safe to continue once
+ * the node returns a live node or no node.  */
+static int dlm_pre_master_reco_lockres(struct dlm_ctxt *dlm,
+                                      struct dlm_lock_resource *res)
+{
+       struct dlm_node_iter iter;
+       int nodenum;
+       int ret = 0;
+       u8 master = DLM_LOCK_RES_OWNER_UNKNOWN;
+
+       spin_lock(&dlm->spinlock);
+       dlm_node_iter_init(dlm->domain_map, &iter);
+       spin_unlock(&dlm->spinlock);
+
+       while ((nodenum = dlm_node_iter_next(&iter)) >= 0) {
+               /* do not send to self */
+               if (nodenum == dlm->node_num)
+                       continue;
+               ret = dlm_do_master_requery(dlm, res, nodenum, &master);
+               if (ret < 0) {
+                       mlog_errno(ret);
+                       if (!dlm_is_host_down(ret))
+                               BUG();
+                       /* host is down, so answer for that node would be
+                        * DLM_LOCK_RES_OWNER_UNKNOWN.  continue. */
+                       ret = 0;
+               }
+
+               if (master != DLM_LOCK_RES_OWNER_UNKNOWN) {
+                       /* check to see if this master is in the recovery map */
+                       spin_lock(&dlm->spinlock);
+                       if (test_bit(master, dlm->recovery_map)) {
+                               mlog(ML_NOTICE, "%s: node %u has not seen "
+                                    "node %u go down yet, and thinks the "
+                                    "dead node is mastering the recovery "
+                                    "lock.  must wait.\n", dlm->name,
+                                    nodenum, master);
+                               ret = -EAGAIN;
+                       }
+                       spin_unlock(&dlm->spinlock);
+                       mlog(0, "%s: reco lock master is %u\n", dlm->name, 
+                            master);
+                       break;
+               }
+       }
+       return ret;
+}
+
 
 /*
  * DLM_MIGRATE_LOCKRES
@@ -1853,14 +2175,14 @@ int dlm_migrate_lockres(struct dlm_ctxt *dlm, struct dlm_lock_resource *res,
         */
 
        ret = -ENOMEM;
-       mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_KERNEL);
+       mres = (struct dlm_migratable_lockres *) __get_free_page(GFP_NOFS);
        if (!mres) {
                mlog_errno(ret);
                goto leave;
        }
 
        mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
-                                                               GFP_KERNEL);
+                                                               GFP_NOFS);
        if (!mle) {
                mlog_errno(ret);
                goto leave;
@@ -1954,7 +2276,7 @@ fail:
         * take both dlm->spinlock and dlm->master_lock */
        spin_lock(&dlm->spinlock);
        spin_lock(&dlm->master_lock);
-       dlm_get_mle(mle);
+       dlm_get_mle_inuse(mle);
        spin_unlock(&dlm->master_lock);
        spin_unlock(&dlm->spinlock);
 
@@ -1971,7 +2293,10 @@ fail:
                /* migration failed, detach and clean up mle */
                dlm_mle_detach_hb_events(dlm, mle);
                dlm_put_mle(mle);
-               dlm_put_mle(mle);
+               dlm_put_mle_inuse(mle);
+               spin_lock(&res->spinlock);
+               res->state &= ~DLM_LOCK_RES_MIGRATING;
+               spin_unlock(&res->spinlock);
                goto leave;
        }
 
@@ -2001,8 +2326,8 @@ fail:
                        /* avoid hang during shutdown when migrating lockres 
                         * to a node which also goes down */
                        if (dlm_is_node_dead(dlm, target)) {
-                               mlog(0, "%s:%.*s: expected migration target %u "
-                                    "is no longer up.  restarting.\n",
+                               mlog(0, "%s:%.*s: expected migration "
+                                    "target %u is no longer up, restarting\n",
                                     dlm->name, res->lockname.len,
                                     res->lockname.name, target);
                                ret = -ERESTARTSYS;
@@ -2012,7 +2337,10 @@ fail:
                        /* migration failed, detach and clean up mle */
                        dlm_mle_detach_hb_events(dlm, mle);
                        dlm_put_mle(mle);
-                       dlm_put_mle(mle);
+                       dlm_put_mle_inuse(mle);
+                       spin_lock(&res->spinlock);
+                       res->state &= ~DLM_LOCK_RES_MIGRATING;
+                       spin_unlock(&res->spinlock);
                        goto leave;
                }
                /* TODO: if node died: stop, clean up, return error */
@@ -2028,7 +2356,7 @@ fail:
 
        /* master is known, detach if not already detached */
        dlm_mle_detach_hb_events(dlm, mle);
-       dlm_put_mle(mle);
+       dlm_put_mle_inuse(mle);
        ret = 0;
 
        dlm_lockres_calc_usage(dlm, res);
@@ -2047,7 +2375,6 @@ leave:
        mlog(0, "returning %d\n", ret);
        return ret;
 }
-EXPORT_SYMBOL_GPL(dlm_migrate_lockres);
 
 int dlm_lock_basts_flushed(struct dlm_ctxt *dlm, struct dlm_lock *lock)
 {
@@ -2299,7 +2626,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
        struct dlm_migrate_request *migrate = (struct dlm_migrate_request *) msg->buf;
        struct dlm_master_list_entry *mle = NULL, *oldmle = NULL;
        const char *name;
-       unsigned int namelen;
+       unsigned int namelen, hash;
        int ret = 0;
 
        if (!dlm_grab(dlm))
@@ -2307,10 +2634,11 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
        name = migrate->name;
        namelen = migrate->namelen;
+       hash = dlm_lockid_hash(name, namelen);
 
        /* preallocate.. if this fails, abort */
        mle = (struct dlm_master_list_entry *) kmem_cache_alloc(dlm_mle_cache,
-                                                        GFP_KERNEL);
+                                                        GFP_NOFS);
 
        if (!mle) {
                ret = -ENOMEM;
@@ -2319,7 +2647,7 @@ int dlm_migrate_request_handler(struct o2net_msg *msg, u32 len, void *data)
 
        /* check for pre-existing lock */
        spin_lock(&dlm->spinlock);
-       res = __dlm_lookup_lockres(dlm, name, namelen);
+       res = __dlm_lookup_lockres(dlm, name, namelen, hash);
        spin_lock(&dlm->master_lock);
 
        if (res) {
@@ -2417,6 +2745,7 @@ static int dlm_add_migration_mle(struct dlm_ctxt *dlm,
                        /* remove it from the list so that only one
                         * mle will be found */
                        list_del_init(&tmp->list);
+                       __dlm_mle_detach_hb_events(dlm, mle);
                }
                spin_unlock(&tmp->spinlock);
        }
@@ -2438,6 +2767,7 @@ void dlm_clean_master_list(struct dlm_ctxt *dlm, u8 dead_node)
        struct list_head *iter, *iter2;
        struct dlm_master_list_entry *mle;
        struct dlm_lock_resource *res;
+       unsigned int hash;
 
        mlog_entry("dlm=%s, dead node=%u\n", dlm->name, dead_node);
 top:
@@ -2477,7 +2807,7 @@ top:
                                 * may result in the mle being unlinked and
                                 * freed, but there may still be a process
                                 * waiting in the dlmlock path which is fine. */
-                               mlog(ML_ERROR, "node %u was expected master\n",
+                               mlog(0, "node %u was expected master\n",
                                     dead_node);
                                atomic_set(&mle->woken, 1);
                                spin_unlock(&mle->spinlock);
@@ -2510,19 +2840,21 @@ top:
 
                /* remove from the list early.  NOTE: unlinking
                 * list_head while in list_for_each_safe */
+               __dlm_mle_detach_hb_events(dlm, mle);
                spin_lock(&mle->spinlock);
                list_del_init(&mle->list);
                atomic_set(&mle->woken, 1);
                spin_unlock(&mle->spinlock);
                wake_up(&mle->wq);
 
-               mlog(0, "node %u died during migration from "
-                    "%u to %u!\n", dead_node,
+               mlog(0, "%s: node %u died during migration from "
+                    "%u to %u!\n", dlm->name, dead_node,
                     mle->master, mle->new_master);
                /* if there is a lockres associated with this
                 * mle, find it and set its owner to UNKNOWN */
+               hash = dlm_lockid_hash(mle->u.name.name, mle->u.name.len);
                res = __dlm_lookup_lockres(dlm, mle->u.name.name,
-                                       mle->u.name.len);
+                                          mle->u.name.len, hash);
                if (res) {
                        /* unfortunately if we hit this rare case, our
                         * lock ordering is messed.  we need to drop