ocfs2: Change the recovery map to an array of node numbers.

The old recovery map was a bitmap of node numbers.  This was sufficient
for the maximum node number of 254.  Going forward, we want node numbers
to be UINT32.  Thus, we need a new recovery map.

Note that we can't keep track of slots here.  We must write down the
node number to recovery *before* we get the locks needed to convert a
node number into a slot number.

The recovery map is now an array of unsigned ints, max_slots in size.
It moves to journal.c with the rest of recovery.

Because it needs to be initialized, we move all of recovery initialization
into a new function, ocfs2_recovery_init().  This actually cleans up
ocfs2_initialize_super() a little as well.  Following on, recovery cleaup
becomes part of ocfs2_recovery_exit().

A number of node map functions are rendered obsolete and are removed.

Finally, waiting on recovery is wrapped in a function rather than naked
checks on the recovery_event.  This is a cleanup from Mark.

Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>

7 files changed, 182 insertions, 170 deletions

diff --git a/fs/ocfs2/dlmglue.c b/fs/ocfs2/dlmglue.c
index 1a80fa9e7c9..15a5167e051 100644
--- a/fs/ocfs2/dlmglue.c
+++ b/fs/ocfs2/dlmglue.c
@@ -1950,8 +1950,7 @@ int ocfs2_inode_lock_full(struct inode *inode,
                 goto local;
 
         if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
-                wait_event(osb->recovery_event,
-                           ocfs2_node_map_is_empty(osb, &osb->recovery_map));
+                ocfs2_wait_for_recovery(osb);
 
         lockres = &OCFS2_I(inode)->ip_inode_lockres;
         level = ex ? LKM_EXMODE : LKM_PRMODE;
@@ -1974,8 +1973,7 @@ int ocfs2_inode_lock_full(struct inode *inode,
          * committed to owning this lock so we don't allow signals to
          * abort the operation. */
         if (!(arg_flags & OCFS2_META_LOCK_RECOVERY))
-                wait_event(osb->recovery_event,
-                           ocfs2_node_map_is_empty(osb, &osb->recovery_map));
+                ocfs2_wait_for_recovery(osb);
 
 local:
         /*
diff --git a/fs/ocfs2/heartbeat.c b/fs/ocfs2/heartbeat.c
index 0758daf64da..80de2397c16 100644
--- a/fs/ocfs2/heartbeat.c
+++ b/fs/ocfs2/heartbeat.c
@@ -48,7 +48,6 @@ static inline void __ocfs2_node_map_set_bit(struct ocfs2_node_map *map,
                                             int bit);
 static inline void __ocfs2_node_map_clear_bit(struct ocfs2_node_map *map,
                                               int bit);
-static inline int __ocfs2_node_map_is_empty(struct ocfs2_node_map *map);
 
 /* special case -1 for now
  * TODO: should *really* make sure the calling func never passes -1!!  */
@@ -62,7 +61,6 @@ static void ocfs2_node_map_init(struct ocfs2_node_map *map)
 void ocfs2_init_node_maps(struct ocfs2_super *osb)
 {
         spin_lock_init(&osb->node_map_lock);
-        ocfs2_node_map_init(&osb->recovery_map);
         ocfs2_node_map_init(&osb->osb_recovering_orphan_dirs);
 }
 
@@ -192,112 +190,3 @@ int ocfs2_node_map_test_bit(struct ocfs2_super *osb,
         return ret;
 }
 
-static inline int __ocfs2_node_map_is_empty(struct ocfs2_node_map *map)
-{
-        int bit;
-        bit = find_next_bit(map->map, map->num_nodes, 0);
-        if (bit < map->num_nodes)
-                return 0;
-        return 1;
-}
-
-int ocfs2_node_map_is_empty(struct ocfs2_super *osb,
-                            struct ocfs2_node_map *map)
-{
-        int ret;
-        BUG_ON(map->num_nodes == 0);
-        spin_lock(&osb->node_map_lock);
-        ret = __ocfs2_node_map_is_empty(map);
-        spin_unlock(&osb->node_map_lock);
-        return ret;
-}
-
-#if 0
-
-static void __ocfs2_node_map_dup(struct ocfs2_node_map *target,
-                                 struct ocfs2_node_map *from)
-{
-        BUG_ON(from->num_nodes == 0);
-        ocfs2_node_map_init(target);
-        __ocfs2_node_map_set(target, from);
-}
-
-/* returns 1 if bit is the only bit set in target, 0 otherwise */
-int ocfs2_node_map_is_only(struct ocfs2_super *osb,
-                           struct ocfs2_node_map *target,
-                           int bit)
-{
-        struct ocfs2_node_map temp;
-        int ret;
-
-        spin_lock(&osb->node_map_lock);
-        __ocfs2_node_map_dup(&temp, target);
-        __ocfs2_node_map_clear_bit(&temp, bit);
-        ret = __ocfs2_node_map_is_empty(&temp);
-        spin_unlock(&osb->node_map_lock);
-
-        return ret;
-}
-
-static void __ocfs2_node_map_set(struct ocfs2_node_map *target,
-                                 struct ocfs2_node_map *from)
-{
-        int num_longs, i;
-
-        BUG_ON(target->num_nodes != from->num_nodes);
-        BUG_ON(target->num_nodes == 0);
-
-        num_longs = BITS_TO_LONGS(target->num_nodes);
-        for (i = 0; i < num_longs; i++)
-                target->map[i] = from->map[i];
-}
-
-#endif  /*  0  */
-
-/* Returns whether the recovery bit was actually set - it may not be
- * if a node is still marked as needing recovery */
-int ocfs2_recovery_map_set(struct ocfs2_super *osb,
-                           int num)
-{
-        int set = 0;
-
-        spin_lock(&osb->node_map_lock);
-
-        if (!test_bit(num, osb->recovery_map.map)) {
-            __ocfs2_node_map_set_bit(&osb->recovery_map, num);
-            set = 1;
-        }
-
-        spin_unlock(&osb->node_map_lock);
-
-        return set;
-}
-
-void ocfs2_recovery_map_clear(struct ocfs2_super *osb,
-                              int num)
-{
-        ocfs2_node_map_clear_bit(osb, &osb->recovery_map, num);
-}
-
-int ocfs2_node_map_iterate(struct ocfs2_super *osb,
-                           struct ocfs2_node_map *map,
-                           int idx)
-{
-        int i = idx;
-
-        idx = O2NM_INVALID_NODE_NUM;
-        spin_lock(&osb->node_map_lock);
-        if ((i != O2NM_INVALID_NODE_NUM) &&
-            (i >= 0) &&
-            (i < map->num_nodes)) {
-                while(i < map->num_nodes) {
-                        if (test_bit(i, map->map)) {
-                                idx = i;
-                                break;
-                        }
-                        i++;
-                }
-        }
-        spin_unlock(&osb->node_map_lock);
-        return idx;
-}
diff --git a/fs/ocfs2/heartbeat.h b/fs/ocfs2/heartbeat.h
index eac63aed761..98d8ffc995b 100644
--- a/fs/ocfs2/heartbeat.h
+++ b/fs/ocfs2/heartbeat.h
@@ -33,8 +33,6 @@ void ocfs2_stop_heartbeat(struct ocfs2_super *osb);
 
 /* node map functions - used to keep track of mounted and in-recovery
  * nodes. */
-int ocfs2_node_map_is_empty(struct ocfs2_super *osb,
-                            struct ocfs2_node_map *map);
 void ocfs2_node_map_set_bit(struct ocfs2_super *osb,
                             struct ocfs2_node_map *map,
                             int bit);
@@ -44,17 +42,5 @@ void ocfs2_node_map_clear_bit(struct ocfs2_super *osb,
 int ocfs2_node_map_test_bit(struct ocfs2_super *osb,
                             struct ocfs2_node_map *map,
                             int bit);
-int ocfs2_node_map_iterate(struct ocfs2_super *osb,
-                           struct ocfs2_node_map *map,
-                           int idx);
-static inline int ocfs2_node_map_first_set_bit(struct ocfs2_super *osb,
-                                               struct ocfs2_node_map *map)
-{
-        return ocfs2_node_map_iterate(osb, map, 0);
-}
-int ocfs2_recovery_map_set(struct ocfs2_super *osb,
-                           int num);
-void ocfs2_recovery_map_clear(struct ocfs2_super *osb,
-                              int num);
 
 #endif /* OCFS2_HEARTBEAT_H */
diff --git a/fs/ocfs2/journal.c b/fs/ocfs2/journal.c
index ed0c6d0850d..ca4c0ea5a4c 100644
--- a/fs/ocfs2/journal.c
+++ b/fs/ocfs2/journal.c
@@ -64,6 +64,137 @@ static int ocfs2_recover_orphans(struct ocfs2_super *osb,
                                  int slot);
 static int ocfs2_commit_thread(void *arg);
 
+
+/*
+ * The recovery_list is a simple linked list of node numbers to recover.
+ * It is protected by the recovery_lock.
+ */
+
+struct ocfs2_recovery_map {
+        int rm_used;
+        unsigned int *rm_entries;
+};
+
+int ocfs2_recovery_init(struct ocfs2_super *osb)
+{
+        struct ocfs2_recovery_map *rm;
+
+        mutex_init(&osb->recovery_lock);
+        osb->disable_recovery = 0;
+        osb->recovery_thread_task = NULL;
+        init_waitqueue_head(&osb->recovery_event);
+
+        rm = kzalloc(sizeof(struct ocfs2_recovery_map) +
+                     osb->max_slots * sizeof(unsigned int),
+                     GFP_KERNEL);
+        if (!rm) {
+                mlog_errno(-ENOMEM);
+                return -ENOMEM;
+        }
+
+        rm->rm_entries = (unsigned int *)((char *)rm +
+                                          sizeof(struct ocfs2_recovery_map));
+        osb->recovery_map = rm;
+
+        return 0;
+}
+
+/* we can't grab the goofy sem lock from inside wait_event, so we use
+ * memory barriers to make sure that we'll see the null task before
+ * being woken up */
+static int ocfs2_recovery_thread_running(struct ocfs2_super *osb)
+{
+        mb();
+        return osb->recovery_thread_task != NULL;
+}
+
+void ocfs2_recovery_exit(struct ocfs2_super *osb)
+{
+        struct ocfs2_recovery_map *rm;
+
+        /* disable any new recovery threads and wait for any currently
+         * running ones to exit. Do this before setting the vol_state. */
+        mutex_lock(&osb->recovery_lock);
+        osb->disable_recovery = 1;
+        mutex_unlock(&osb->recovery_lock);
+        wait_event(osb->recovery_event, !ocfs2_recovery_thread_running(osb));
+
+        /* At this point, we know that no more recovery threads can be
+         * launched, so wait for any recovery completion work to
+         * complete. */
+        flush_workqueue(ocfs2_wq);
+
+        /*
+         * Now that recovery is shut down, and the osb is about to be
+         * freed,  the osb_lock is not taken here.
+         */
+        rm = osb->recovery_map;
+        /* XXX: Should we bug if there are dirty entries? */
+
+        kfree(rm);
+}
+
+static int __ocfs2_recovery_map_test(struct ocfs2_super *osb,
+                                     unsigned int node_num)
+{
+        int i;
+        struct ocfs2_recovery_map *rm = osb->recovery_map;
+
+        assert_spin_locked(&osb->osb_lock);
+
+        for (i = 0; i < rm->rm_used; i++) {
+                if (rm->rm_entries[i] == node_num)
+                        return 1;
+        }
+
+        return 0;
+}
+
+/* Behaves like test-and-set.  Returns the previous value */
+static int ocfs2_recovery_map_set(struct ocfs2_super *osb,
+                                  unsigned int node_num)
+{
+        struct ocfs2_recovery_map *rm = osb->recovery_map;
+
+        spin_lock(&osb->osb_lock);
+        if (__ocfs2_recovery_map_test(osb, node_num)) {
+                spin_unlock(&osb->osb_lock);
+                return 1;
+        }
+
+        /* XXX: Can this be exploited? Not from o2dlm... */
+        BUG_ON(rm->rm_used >= osb->max_slots);
+
+        rm->rm_entries[rm->rm_used] = node_num;
+        rm->rm_used++;
+        spin_unlock(&osb->osb_lock);
+
+        return 0;
+}
+
+static void ocfs2_recovery_map_clear(struct ocfs2_super *osb,
+                                     unsigned int node_num)
+{
+        int i;
+        struct ocfs2_recovery_map *rm = osb->recovery_map;
+
+        spin_lock(&osb->osb_lock);
+
+        for (i = 0; i < rm->rm_used; i++) {
+                if (rm->rm_entries[i] == node_num)
+                        break;
+        }
+
+        if (i < rm->rm_used) {
+                /* XXX: be careful with the pointer math */
+                memmove(&(rm->rm_entries[i]), &(rm->rm_entries[i + 1]),
+                        (rm->rm_used - i - 1) * sizeof(unsigned int));
+                rm->rm_used--;
+        }
+
+        spin_unlock(&osb->osb_lock);
+}
+
 static int ocfs2_commit_cache(struct ocfs2_super *osb)
 {
         int status = 0;
@@ -650,6 +781,23 @@ bail:
         return status;
 }
 
+static int ocfs2_recovery_completed(struct ocfs2_super *osb)
+{
+        int empty;
+        struct ocfs2_recovery_map *rm = osb->recovery_map;
+
+        spin_lock(&osb->osb_lock);
+        empty = (rm->rm_used == 0);
+        spin_unlock(&osb->osb_lock);
+
+        return empty;
+}
+
+void ocfs2_wait_for_recovery(struct ocfs2_super *osb)
+{
+        wait_event(osb->recovery_event, ocfs2_recovery_completed(osb));
+}
+
 /*
  * JBD Might read a cached version of another nodes journal file. We
  * don't want this as this file changes often and we get no
@@ -848,6 +996,7 @@ static int __ocfs2_recovery_thread(void *arg)
 {
         int status, node_num;
         struct ocfs2_super *osb = arg;
+        struct ocfs2_recovery_map *rm = osb->recovery_map;
 
         mlog_entry_void();
 
@@ -863,26 +1012,29 @@ restart:
                 goto bail;
         }
 
-        while(!ocfs2_node_map_is_empty(osb, &osb->recovery_map)) {
-                node_num = ocfs2_node_map_first_set_bit(osb,
-                                                        &osb->recovery_map);
-                if (node_num == O2NM_INVALID_NODE_NUM) {
-                        mlog(0, "Out of nodes to recover.\n");
-                        break;
-                }
+        spin_lock(&osb->osb_lock);
+        while (rm->rm_used) {
+                /* It's always safe to remove entry zero, as we won't
+                 * clear it until ocfs2_recover_node() has succeeded. */
+                node_num = rm->rm_entries[0];
+                spin_unlock(&osb->osb_lock);
 
                 status = ocfs2_recover_node(osb, node_num);
-                if (status < 0) {
+                if (!status) {
+                        ocfs2_recovery_map_clear(osb, node_num);
+                } else {
                         mlog(ML_ERROR,
                              "Error %d recovering node %d on device (%u,%u)!\n",
                              status, node_num,
                              MAJOR(osb->sb->s_dev), MINOR(osb->sb->s_dev));
                         mlog(ML_ERROR, "Volume requires unmount.\n");
-                        continue;
                 }
 
-                ocfs2_recovery_map_clear(osb, node_num);
+                spin_lock(&osb->osb_lock);
         }
+        spin_unlock(&osb->osb_lock);
+        mlog(0, "All nodes recovered\n");
+
         ocfs2_super_unlock(osb, 1);
 
         /* We always run recovery on our own orphan dir - the dead
@@ -893,8 +1045,7 @@ restart:
 
 bail:
         mutex_lock(&osb->recovery_lock);
-        if (!status &&
-            !ocfs2_node_map_is_empty(osb, &osb->recovery_map)) {
+        if (!status && !ocfs2_recovery_completed(osb)) {
                 mutex_unlock(&osb->recovery_lock);
                 goto restart;
         }
@@ -924,8 +1075,8 @@ void ocfs2_recovery_thread(struct ocfs2_super *osb, int node_num)
 
         /* People waiting on recovery will wait on
          * the recovery map to empty. */
-        if (!ocfs2_recovery_map_set(osb, node_num))
-                mlog(0, "node %d already be in recovery.\n", node_num);
+        if (ocfs2_recovery_map_set(osb, node_num))
+                mlog(0, "node %d already in recovery map.\n", node_num);
 
         mlog(0, "starting recovery thread...\n");
 
@@ -1197,7 +1348,7 @@ int ocfs2_mark_dead_nodes(struct ocfs2_super *osb)
                 if (status == -ENOENT)
                         continue;
 
-                if (ocfs2_node_map_test_bit(osb, &osb->recovery_map, node_num))
+                if (__ocfs2_recovery_map_test(osb, node_num))
                         continue;
                 spin_unlock(&osb->osb_lock);
 
diff --git a/fs/ocfs2/journal.h b/fs/ocfs2/journal.h
index 220f3e818e7..db82be2532e 100644
--- a/fs/ocfs2/journal.h
+++ b/fs/ocfs2/journal.h
@@ -134,6 +134,10 @@ static inline void ocfs2_inode_set_new(struct ocfs2_super *osb,
 
 /* Exported only for the journal struct init code in super.c. Do not call. */
 void ocfs2_complete_recovery(struct work_struct *work);
+void ocfs2_wait_for_recovery(struct ocfs2_super *osb);
+
+int ocfs2_recovery_init(struct ocfs2_super *osb);
+void ocfs2_recovery_exit(struct ocfs2_super *osb);
 
 /*
  *  Journal Control:
diff --git a/fs/ocfs2/ocfs2.h b/fs/ocfs2/ocfs2.h
index ee3f675a421..c6ed8c35de0 100644
--- a/fs/ocfs2/ocfs2.h
+++ b/fs/ocfs2/ocfs2.h
@@ -180,6 +180,7 @@ enum ocfs2_mount_options
 
 struct ocfs2_journal;
 struct ocfs2_slot_info;
+struct ocfs2_recovery_map;
 struct ocfs2_super
 {
         struct task_struct *commit_task;
@@ -191,7 +192,6 @@ struct ocfs2_super
         struct ocfs2_slot_info *slot_info;
 
         spinlock_t node_map_lock;
-        struct ocfs2_node_map recovery_map;
 
         u64 root_blkno;
         u64 system_dir_blkno;
@@ -226,6 +226,7 @@ struct ocfs2_super
 
         atomic_t vol_state;
         struct mutex recovery_lock;
+        struct ocfs2_recovery_map *recovery_map;
         struct task_struct *recovery_thread_task;
         int disable_recovery;
         wait_queue_head_t checkpoint_event;
diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index fad37af2af9..1a4c7c7850f 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1224,15 +1224,6 @@ leave:
         return status;
 }
 
-/* we can't grab the goofy sem lock from inside wait_event, so we use
- * memory barriers to make sure that we'll see the null task before
- * being woken up */
-static int ocfs2_recovery_thread_running(struct ocfs2_super *osb)
-{
-        mb();
-        return osb->recovery_thread_task != NULL;
-}
-
 static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err)
 {
         int tmp;
@@ -1249,17 +1240,8 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err)
 
         ocfs2_truncate_log_shutdown(osb);
 
-        /* disable any new recovery threads and wait for any currently
-         * running ones to exit. Do this before setting the vol_state. */
-        mutex_lock(&osb->recovery_lock);
-        osb->disable_recovery = 1;
-        mutex_unlock(&osb->recovery_lock);
-        wait_event(osb->recovery_event, !ocfs2_recovery_thread_running(osb));
-
-        /* At this point, we know that no more recovery threads can be
-         * launched, so wait for any recovery completion work to
-         * complete. */
-        flush_workqueue(ocfs2_wq);
+        /* This will disable recovery and flush any recovery work. */
+        ocfs2_recovery_exit(osb);
 
         ocfs2_journal_shutdown(osb);
 
@@ -1368,7 +1350,6 @@ static int ocfs2_initialize_super(struct super_block *sb,
         osb->s_sectsize_bits = blksize_bits(sector_size);
         BUG_ON(!osb->s_sectsize_bits);
 
-        init_waitqueue_head(&osb->recovery_event);
         spin_lock_init(&osb->dc_task_lock);
         init_waitqueue_head(&osb->dc_event);
         osb->dc_work_sequence = 0;
@@ -1388,10 +1369,12 @@ static int ocfs2_initialize_super(struct super_block *sb,
         snprintf(osb->dev_str, sizeof(osb->dev_str), "%u,%u",
                  MAJOR(osb->sb->s_dev), MINOR(osb->sb->s_dev));
 
-        mutex_init(&osb->recovery_lock);
-
-        osb->disable_recovery = 0;
-        osb->recovery_thread_task = NULL;
+        status = ocfs2_recovery_init(osb);
+        if (status) {
+                mlog(ML_ERROR, "Unable to initialize recovery state\n");
+                mlog_errno(status);
+                goto bail;
+        }
 
         init_waitqueue_head(&osb->checkpoint_event);
         atomic_set(&osb->needs_checkpoint, 0);