ocfs2/dlm: Create debugfs dirs
[safe/jmp/linux-2.6] / fs / ocfs2 / dlm / dlmdomain.c
index 19b57a6..c137d69 100644 (file)
@@ -33,6 +33,7 @@
 #include <linux/spinlock.h>
 #include <linux/delay.h>
 #include <linux/err.h>
+#include <linux/debugfs.h>
 
 #include "cluster/heartbeat.h"
 #include "cluster/nodemanager.h"
@@ -40,8 +41,8 @@
 
 #include "dlmapi.h"
 #include "dlmcommon.h"
-
 #include "dlmdomain.h"
+#include "dlmdebug.h"
 
 #include "dlmver.h"
 
@@ -123,6 +124,17 @@ DEFINE_SPINLOCK(dlm_domain_lock);
 LIST_HEAD(dlm_domains);
 static DECLARE_WAIT_QUEUE_HEAD(dlm_domain_events);
 
+/*
+ * The supported protocol version for DLM communication.  Running domains
+ * will have a negotiated version with the same major number and a minor
+ * number equal or smaller.  The dlm_ctxt->dlm_locking_proto field should
+ * be used to determine what a running domain is actually using.
+ */
+static const struct dlm_protocol_version dlm_protocol = {
+       .pv_major = 1,
+       .pv_minor = 0,
+};
+
 #define DLM_DOMAIN_BACKOFF_MS 200
 
 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
@@ -133,13 +145,17 @@ static int dlm_cancel_join_handler(struct o2net_msg *msg, u32 len, void *data,
                                   void **ret_data);
 static int dlm_exit_domain_handler(struct o2net_msg *msg, u32 len, void *data,
                                   void **ret_data);
+static int dlm_protocol_compare(struct dlm_protocol_version *existing,
+                               struct dlm_protocol_version *request);
 
 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm);
 
 void __dlm_unhash_lockres(struct dlm_lock_resource *lockres)
 {
-       hlist_del_init(&lockres->hash_node);
-       dlm_lockres_put(lockres);
+       if (!hlist_unhashed(&lockres->hash_node)) {
+               hlist_del_init(&lockres->hash_node);
+               dlm_lockres_put(lockres);
+       }
 }
 
 void __dlm_insert_lockres(struct dlm_ctxt *dlm,
@@ -283,6 +299,8 @@ static int dlm_wait_on_domain_helper(const char *domain)
 
 static void dlm_free_ctxt_mem(struct dlm_ctxt *dlm)
 {
+       dlm_destroy_debugfs_subroot(dlm);
+
        if (dlm->lockres_hash)
                dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
 
@@ -428,11 +446,10 @@ redo_bucket:
 
                        dlm_lockres_put(res);
 
-                       cond_resched_lock(&dlm->spinlock);
-
                        if (dropped)
                                goto redo_bucket;
                }
+               cond_resched_lock(&dlm->spinlock);
                num += n;
                mlog(0, "%s: touched %d lockreses in bucket %d "
                     "(tot=%d)\n", dlm->name, n, i, num);
@@ -630,6 +647,7 @@ int dlm_shutting_down(struct dlm_ctxt *dlm)
 void dlm_unregister_domain(struct dlm_ctxt *dlm)
 {
        int leave = 0;
+       struct dlm_lock_resource *res;
 
        spin_lock(&dlm_domain_lock);
        BUG_ON(dlm->dlm_state != DLM_CTXT_JOINED);
@@ -655,8 +673,19 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm)
                dlm_kick_thread(dlm, NULL);
 
                while (dlm_migrate_all_locks(dlm)) {
+                       /* Give dlm_thread time to purge the lockres' */
+                       msleep(500);
                        mlog(0, "%s: more migration to do\n", dlm->name);
                }
+
+               /* 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 "
+                            "tracking list:\n");
+                       list_for_each_entry(res, &dlm->tracking_list, tracking)
+                               dlm_print_one_lock_resource(res);
+               }
+
                dlm_mark_domain_leaving(dlm);
                dlm_leave_domain(dlm);
                dlm_complete_dlm_shutdown(dlm);
@@ -665,12 +694,78 @@ void dlm_unregister_domain(struct dlm_ctxt *dlm)
 }
 EXPORT_SYMBOL_GPL(dlm_unregister_domain);
 
+static int dlm_query_join_proto_check(char *proto_type, int node,
+                                     struct dlm_protocol_version *ours,
+                                     struct dlm_protocol_version *request)
+{
+       int rc;
+       struct dlm_protocol_version proto = *request;
+
+       if (!dlm_protocol_compare(ours, &proto)) {
+               mlog(0,
+                    "node %u wanted to join with %s locking protocol "
+                    "%u.%u, we respond with %u.%u\n",
+                    node, proto_type,
+                    request->pv_major,
+                    request->pv_minor,
+                    proto.pv_major, proto.pv_minor);
+               request->pv_minor = proto.pv_minor;
+               rc = 0;
+       } else {
+               mlog(ML_NOTICE,
+                    "Node %u wanted to join with %s locking "
+                    "protocol %u.%u, but we have %u.%u, disallowing\n",
+                    node, proto_type,
+                    request->pv_major,
+                    request->pv_minor,
+                    ours->pv_major,
+                    ours->pv_minor);
+               rc = 1;
+       }
+
+       return rc;
+}
+
+/*
+ * struct dlm_query_join_packet is made up of four one-byte fields.  They
+ * are effectively in big-endian order already.  However, little-endian
+ * machines swap them before putting the packet on the wire (because
+ * query_join's response is a status, and that status is treated as a u32
+ * on the wire).  Thus, a big-endian and little-endian machines will treat
+ * this structure differently.
+ *
+ * The solution is to have little-endian machines swap the structure when
+ * converting from the structure to the u32 representation.  This will
+ * result in the structure having the correct format on the wire no matter
+ * the host endian format.
+ */
+static void dlm_query_join_packet_to_wire(struct dlm_query_join_packet *packet,
+                                         u32 *wire)
+{
+       union dlm_query_join_response response;
+
+       response.packet = *packet;
+       *wire = cpu_to_be32(response.intval);
+}
+
+static void dlm_query_join_wire_to_packet(u32 wire,
+                                         struct dlm_query_join_packet *packet)
+{
+       union dlm_query_join_response response;
+
+       response.intval = cpu_to_be32(wire);
+       *packet = response.packet;
+}
+
 static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
                                  void **ret_data)
 {
        struct dlm_query_join_request *query;
-       enum dlm_query_join_response response;
+       struct dlm_query_join_packet packet = {
+               .code = JOIN_DISALLOW,
+       };
        struct dlm_ctxt *dlm = NULL;
+       u32 response;
        u8 nodenum;
 
        query = (struct dlm_query_join_request *) msg->buf;
@@ -687,11 +782,11 @@ static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
                mlog(0, "node %u is not in our live map yet\n",
                     query->node_idx);
 
-               response = JOIN_DISALLOW;
+               packet.code = JOIN_DISALLOW;
                goto respond;
        }
 
-       response = JOIN_OK_NO_MAP;
+       packet.code = JOIN_OK_NO_MAP;
 
        spin_lock(&dlm_domain_lock);
        dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
@@ -707,7 +802,10 @@ static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
        while (nodenum < O2NM_MAX_NODES) {
                if (test_bit(nodenum, dlm->domain_map)) {
                        if (!byte_test_bit(nodenum, query->node_map)) {
-                               response = JOIN_DISALLOW;
+                               mlog(0, "disallow join as node %u does not "
+                                    "have node %u in its nodemap\n",
+                                    query->node_idx, nodenum);
+                               packet.code = JOIN_DISALLOW;
                                goto unlock_respond;
                        }
                }
@@ -727,30 +825,44 @@ static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data,
                        /*If this is a brand new context and we
                         * haven't started our join process yet, then
                         * the other node won the race. */
-                       response = JOIN_OK_NO_MAP;
+                       packet.code = JOIN_OK_NO_MAP;
                } else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
                        /* Disallow parallel joins. */
-                       response = JOIN_DISALLOW;
+                       packet.code = JOIN_DISALLOW;
                } else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
-                       mlog(ML_NOTICE, "node %u trying to join, but recovery "
+                       mlog(0, "node %u trying to join, but recovery "
                             "is ongoing.\n", bit);
-                       response = JOIN_DISALLOW;
+                       packet.code = JOIN_DISALLOW;
                } else if (test_bit(bit, dlm->recovery_map)) {
-                       mlog(ML_NOTICE, "node %u trying to join, but it "
+                       mlog(0, "node %u trying to join, but it "
                             "still needs recovery.\n", bit);
-                       response = JOIN_DISALLOW;
+                       packet.code = JOIN_DISALLOW;
                } else if (test_bit(bit, dlm->domain_map)) {
-                       mlog(ML_NOTICE, "node %u trying to join, but it "
+                       mlog(0, "node %u trying to join, but it "
                             "is still in the domain! needs recovery?\n",
                             bit);
-                       response = JOIN_DISALLOW;
+                       packet.code = JOIN_DISALLOW;
                } else {
                        /* Alright we're fully a part of this domain
                         * so we keep some state as to who's joining
                         * and indicate to him that needs to be fixed
                         * up. */
-                       response = JOIN_OK;
-                       __dlm_set_joining_node(dlm, query->node_idx);
+
+                       /* Make sure we speak compatible locking protocols.  */
+                       if (dlm_query_join_proto_check("DLM", bit,
+                                                      &dlm->dlm_locking_proto,
+                                                      &query->dlm_proto)) {
+                               packet.code = JOIN_PROTOCOL_MISMATCH;
+                       } else if (dlm_query_join_proto_check("fs", bit,
+                                                             &dlm->fs_locking_proto,
+                                                             &query->fs_proto)) {
+                               packet.code = JOIN_PROTOCOL_MISMATCH;
+                       } else {
+                               packet.dlm_minor = query->dlm_proto.pv_minor;
+                               packet.fs_minor = query->fs_proto.pv_minor;
+                               packet.code = JOIN_OK;
+                               __dlm_set_joining_node(dlm, query->node_idx);
+                       }
                }
 
                spin_unlock(&dlm->spinlock);
@@ -759,8 +871,9 @@ unlock_respond:
        spin_unlock(&dlm_domain_lock);
 
 respond:
-       mlog(0, "We respond with %u\n", response);
+       mlog(0, "We respond with %u\n", packet.code);
 
+       dlm_query_join_packet_to_wire(&packet, &response);
        return response;
 }
 
@@ -866,7 +979,7 @@ static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
                         sizeof(unsigned long))) {
                mlog(ML_ERROR,
                     "map_size %u != BITS_TO_LONGS(O2NM_MAX_NODES) %u\n",
-                    map_size, BITS_TO_LONGS(O2NM_MAX_NODES));
+                    map_size, (unsigned)BITS_TO_LONGS(O2NM_MAX_NODES));
                return -EINVAL;
        }
 
@@ -893,10 +1006,12 @@ static int dlm_send_join_cancels(struct dlm_ctxt *dlm,
 
 static int dlm_request_join(struct dlm_ctxt *dlm,
                            int node,
-                           enum dlm_query_join_response *response)
+                           enum dlm_query_join_response_code *response)
 {
-       int status, retval;
+       int status;
        struct dlm_query_join_request join_msg;
+       struct dlm_query_join_packet packet;
+       u32 join_resp;
 
        mlog(0, "querying node %d\n", node);
 
@@ -904,16 +1019,20 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
        join_msg.node_idx = dlm->node_num;
        join_msg.name_len = strlen(dlm->name);
        memcpy(join_msg.domain, dlm->name, join_msg.name_len);
+       join_msg.dlm_proto = dlm->dlm_locking_proto;
+       join_msg.fs_proto = dlm->fs_locking_proto;
 
        /* copy live node map to join message */
        byte_copymap(join_msg.node_map, dlm->live_nodes_map, O2NM_MAX_NODES);
 
        status = o2net_send_message(DLM_QUERY_JOIN_MSG, DLM_MOD_KEY, &join_msg,
-                                   sizeof(join_msg), node, &retval);
+                                   sizeof(join_msg), node,
+                                   &join_resp);
        if (status < 0 && status != -ENOPROTOOPT) {
                mlog_errno(status);
                goto bail;
        }
+       dlm_query_join_wire_to_packet(join_resp, &packet);
 
        /* -ENOPROTOOPT from the net code means the other side isn't
            listening for our message type -- that's fine, it means
@@ -922,18 +1041,43 @@ static int dlm_request_join(struct dlm_ctxt *dlm,
        if (status == -ENOPROTOOPT) {
                status = 0;
                *response = JOIN_OK_NO_MAP;
-       } else if (retval == JOIN_DISALLOW ||
-                  retval == JOIN_OK ||
-                  retval == JOIN_OK_NO_MAP) {
-               *response = retval;
+       } else if (packet.code == JOIN_DISALLOW ||
+                  packet.code == JOIN_OK_NO_MAP) {
+               *response = packet.code;
+       } else if (packet.code == JOIN_PROTOCOL_MISMATCH) {
+               mlog(ML_NOTICE,
+                    "This node requested DLM locking protocol %u.%u and "
+                    "filesystem locking protocol %u.%u.  At least one of "
+                    "the protocol versions on node %d is not compatible, "
+                    "disconnecting\n",
+                    dlm->dlm_locking_proto.pv_major,
+                    dlm->dlm_locking_proto.pv_minor,
+                    dlm->fs_locking_proto.pv_major,
+                    dlm->fs_locking_proto.pv_minor,
+                    node);
+               status = -EPROTO;
+               *response = packet.code;
+       } else if (packet.code == JOIN_OK) {
+               *response = packet.code;
+               /* Use the same locking protocol as the remote node */
+               dlm->dlm_locking_proto.pv_minor = packet.dlm_minor;
+               dlm->fs_locking_proto.pv_minor = packet.fs_minor;
+               mlog(0,
+                    "Node %d responds JOIN_OK with DLM locking protocol "
+                    "%u.%u and fs locking protocol %u.%u\n",
+                    node,
+                    dlm->dlm_locking_proto.pv_major,
+                    dlm->dlm_locking_proto.pv_minor,
+                    dlm->fs_locking_proto.pv_major,
+                    dlm->fs_locking_proto.pv_minor);
        } else {
                status = -EINVAL;
-               mlog(ML_ERROR, "invalid response %d from node %u\n", retval,
-                    node);
+               mlog(ML_ERROR, "invalid response %d from node %u\n",
+                    packet.code, node);
        }
 
        mlog(0, "status %d, node %d response is %d\n", status, node,
-                 *response);
+            *response);
 
 bail:
        return status;
@@ -1002,7 +1146,7 @@ struct domain_join_ctxt {
 
 static int dlm_should_restart_join(struct dlm_ctxt *dlm,
                                   struct domain_join_ctxt *ctxt,
-                                  enum dlm_query_join_response response)
+                                  enum dlm_query_join_response_code response)
 {
        int ret;
 
@@ -1028,7 +1172,7 @@ static int dlm_try_to_join_domain(struct dlm_ctxt *dlm)
 {
        int status = 0, tmpstat, node;
        struct domain_join_ctxt *ctxt;
-       enum dlm_query_join_response response;
+       enum dlm_query_join_response_code response = JOIN_DISALLOW;
 
        mlog_entry("%p", dlm);
 
@@ -1122,8 +1266,8 @@ bail:
 
 static void dlm_unregister_domain_handlers(struct dlm_ctxt *dlm)
 {
-       o2hb_unregister_callback(&dlm->dlm_hb_up);
-       o2hb_unregister_callback(&dlm->dlm_hb_down);
+       o2hb_unregister_callback(NULL, &dlm->dlm_hb_up);
+       o2hb_unregister_callback(NULL, &dlm->dlm_hb_down);
        o2net_unregister_handler_list(&dlm->dlm_domain_handlers);
 }
 
@@ -1135,13 +1279,13 @@ static int dlm_register_domain_handlers(struct dlm_ctxt *dlm)
 
        o2hb_setup_callback(&dlm->dlm_hb_down, O2HB_NODE_DOWN_CB,
                            dlm_hb_node_down_cb, dlm, DLM_HB_NODE_DOWN_PRI);
-       status = o2hb_register_callback(&dlm->dlm_hb_down);
+       status = o2hb_register_callback(NULL, &dlm->dlm_hb_down);
        if (status)
                goto bail;
 
        o2hb_setup_callback(&dlm->dlm_hb_up, O2HB_NODE_UP_CB,
                            dlm_hb_node_up_cb, dlm, DLM_HB_NODE_UP_PRI);
-       status = o2hb_register_callback(&dlm->dlm_hb_up);
+       status = o2hb_register_callback(NULL, &dlm->dlm_hb_up);
        if (status)
                goto bail;
 
@@ -1261,6 +1405,8 @@ bail:
 static int dlm_join_domain(struct dlm_ctxt *dlm)
 {
        int status;
+       unsigned int backoff;
+       unsigned int total_backoff = 0;
 
        BUG_ON(!dlm);
 
@@ -1292,18 +1438,27 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
        }
 
        do {
-               unsigned int backoff;
                status = dlm_try_to_join_domain(dlm);
 
                /* If we're racing another node to the join, then we
                 * need to back off temporarily and let them
                 * complete. */
+#define        DLM_JOIN_TIMEOUT_MSECS  90000
                if (status == -EAGAIN) {
                        if (signal_pending(current)) {
                                status = -ERESTARTSYS;
                                goto bail;
                        }
 
+                       if (total_backoff >
+                           msecs_to_jiffies(DLM_JOIN_TIMEOUT_MSECS)) {
+                               status = -ERESTARTSYS;
+                               mlog(ML_NOTICE, "Timed out joining dlm domain "
+                                    "%s after %u msecs\n", dlm->name,
+                                    jiffies_to_msecs(total_backoff));
+                               goto bail;
+                       }
+
                        /*
                         * <chip> After you!
                         * <dale> No, after you!
@@ -1313,6 +1468,7 @@ static int dlm_join_domain(struct dlm_ctxt *dlm)
                         */
                        backoff = (unsigned int)(jiffies & 0x3);
                        backoff *= DLM_DOMAIN_BACKOFF_MS;
+                       total_backoff += backoff;
                        mlog(0, "backoff %d\n", backoff);
                        msleep(backoff);
                }
@@ -1341,6 +1497,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
                                u32 key)
 {
        int i;
+       int ret;
        struct dlm_ctxt *dlm = NULL;
 
        dlm = kzalloc(sizeof(*dlm), GFP_KERNEL);
@@ -1373,6 +1530,15 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
        dlm->key = key;
        dlm->node_num = o2nm_this_node();
 
+       ret = dlm_create_debugfs_subroot(dlm);
+       if (ret < 0) {
+               dlm_free_pagevec((void **)dlm->lockres_hash, DLM_HASH_PAGES);
+               kfree(dlm->name);
+               kfree(dlm);
+               dlm = NULL;
+               goto leave;
+       }
+
        spin_lock_init(&dlm->spinlock);
        spin_lock_init(&dlm->master_lock);
        spin_lock_init(&dlm->ast_lock);
@@ -1383,6 +1549,7 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
        INIT_LIST_HEAD(&dlm->reco.node_data);
        INIT_LIST_HEAD(&dlm->purge_list);
        INIT_LIST_HEAD(&dlm->dlm_domain_handlers);
+       INIT_LIST_HEAD(&dlm->tracking_list);
        dlm->reco.state = 0;
 
        INIT_LIST_HEAD(&dlm->pending_asts);
@@ -1432,10 +1599,38 @@ leave:
 }
 
 /*
- * dlm_register_domain: one-time setup per "domain"
+ * Compare a requested locking protocol version against the current one.
+ *
+ * If the major numbers are different, they are incompatible.
+ * If the current minor is greater than the request, they are incompatible.
+ * If the current minor is less than or equal to the request, they are
+ * compatible, and the requester should run at the current minor version.
+ */
+static int dlm_protocol_compare(struct dlm_protocol_version *existing,
+                               struct dlm_protocol_version *request)
+{
+       if (existing->pv_major != request->pv_major)
+               return 1;
+
+       if (existing->pv_minor > request->pv_minor)
+               return 1;
+
+       if (existing->pv_minor < request->pv_minor)
+               request->pv_minor = existing->pv_minor;
+
+       return 0;
+}
+
+/*
+ * dlm_register_domain: one-time setup per "domain".
+ *
+ * The filesystem passes in the requested locking version via proto.
+ * If registration was successful, proto will contain the negotiated
+ * locking protocol.
  */
 struct dlm_ctxt * dlm_register_domain(const char *domain,
-                              u32 key)
+                              u32 key,
+                              struct dlm_protocol_version *fs_proto)
 {
        int ret;
        struct dlm_ctxt *dlm = NULL;
@@ -1478,6 +1673,15 @@ retry:
                        goto retry;
                }
 
+               if (dlm_protocol_compare(&dlm->fs_locking_proto, fs_proto)) {
+                       mlog(ML_ERROR,
+                            "Requested locking protocol version is not "
+                            "compatible with already registered domain "
+                            "\"%s\"\n", domain);
+                       ret = -EPROTO;
+                       goto leave;
+               }
+
                __dlm_get(dlm);
                dlm->num_joins++;
 
@@ -1508,6 +1712,13 @@ retry:
        list_add_tail(&dlm->list, &dlm_domains);
        spin_unlock(&dlm_domain_lock);
 
+       /*
+        * Pass the locking protocol version into the join.  If the join
+        * succeeds, it will have the negotiated protocol set.
+        */
+       dlm->dlm_locking_proto = dlm_protocol;
+       dlm->fs_locking_proto = *fs_proto;
+
        ret = dlm_join_domain(dlm);
        if (ret) {
                mlog_errno(ret);
@@ -1515,6 +1726,9 @@ retry:
                goto leave;
        }
 
+       /* Tell the caller what locking protocol we negotiated */
+       *fs_proto = dlm->fs_locking_proto;
+
        ret = 0;
 leave:
        if (new_ctxt)
@@ -1626,21 +1840,49 @@ static int __init dlm_init(void)
        dlm_print_version();
 
        status = dlm_init_mle_cache();
-       if (status)
-               return -1;
+       if (status) {
+               mlog(ML_ERROR, "Could not create o2dlm_mle slabcache\n");
+               goto error;
+       }
+
+       status = dlm_init_master_caches();
+       if (status) {
+               mlog(ML_ERROR, "Could not create o2dlm_lockres and "
+                    "o2dlm_lockname slabcaches\n");
+               goto error;
+       }
+
+       status = dlm_init_lock_cache();
+       if (status) {
+               mlog(ML_ERROR, "Count not create o2dlm_lock slabcache\n");
+               goto error;
+       }
 
        status = dlm_register_net_handlers();
        if (status) {
-               dlm_destroy_mle_cache();
-               return -1;
+               mlog(ML_ERROR, "Unable to register network handlers\n");
+               goto error;
        }
 
+       status = dlm_create_debugfs_root();
+       if (status)
+               goto error;
+
        return 0;
+error:
+       dlm_unregister_net_handlers();
+       dlm_destroy_lock_cache();
+       dlm_destroy_master_caches();
+       dlm_destroy_mle_cache();
+       return -1;
 }
 
 static void __exit dlm_exit (void)
 {
+       dlm_destroy_debugfs_root();
        dlm_unregister_net_handlers();
+       dlm_destroy_lock_cache();
+       dlm_destroy_master_caches();
        dlm_destroy_mle_cache();
 }