1 files changed, 16 insertions, 143 deletions

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index b5baff0dccfe..84d7ca1fe0ba 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -147,10 +147,11 @@ noinline void btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p)
 struct extent_buffer *btrfs_root_node(struct btrfs_root *root)
 {
         struct extent_buffer *eb;
-        spin_lock(&root->node_lock);
-        eb = root->node;
+
+        rcu_read_lock();
+        eb = rcu_dereference(root->node);
         extent_buffer_get(eb);
-        spin_unlock(&root->node_lock);
+        rcu_read_unlock();
         return eb;
 }
 
@@ -165,14 +166,8 @@ struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root)
         while (1) {
                 eb = btrfs_root_node(root);
                 btrfs_tree_lock(eb);
-
-                spin_lock(&root->node_lock);
-                if (eb == root->node) {
-                        spin_unlock(&root->node_lock);
+                if (eb == root->node)
                         break;
-                }
-                spin_unlock(&root->node_lock);
-
                 btrfs_tree_unlock(eb);
                 free_extent_buffer(eb);
         }
@@ -458,10 +453,8 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans,
                 else
                         parent_start = 0;
 
-                spin_lock(&root->node_lock);
-                root->node = cow;
                 extent_buffer_get(cow);
-                spin_unlock(&root->node_lock);
+                rcu_assign_pointer(root->node, cow);
 
                 btrfs_free_tree_block(trans, root, buf, parent_start,
                                       last_ref);
@@ -542,6 +535,9 @@ noinline int btrfs_cow_block(struct btrfs_trans_handle *trans,
 
         ret = __btrfs_cow_block(trans, root, buf, parent,
                                  parent_slot, cow_ret, search_start, 0);
+
+        trace_btrfs_cow_block(root, buf, *cow_ret);
+
         return ret;
 }
 
@@ -686,6 +682,8 @@ int btrfs_realloc_node(struct btrfs_trans_handle *trans,
                         if (!cur) {
                                 cur = read_tree_block(root, blocknr,
                                                          blocksize, gen);
+                                if (!cur)
+                                        return -EIO;
                         } else if (!uptodate) {
                                 btrfs_read_buffer(cur, gen);
                         }
@@ -732,122 +730,6 @@ static inline unsigned int leaf_data_end(struct btrfs_root *root,
         return btrfs_item_offset_nr(leaf, nr - 1);
 }
 
-/*
- * extra debugging checks to make sure all the items in a key are
- * well formed and in the proper order
- */
-static int check_node(struct btrfs_root *root, struct btrfs_path *path,
-                      int level)
-{
-        struct extent_buffer *parent = NULL;
-        struct extent_buffer *node = path->nodes[level];
-        struct btrfs_disk_key parent_key;
-        struct btrfs_disk_key node_key;
-        int parent_slot;
-        int slot;
-        struct btrfs_key cpukey;
-        u32 nritems = btrfs_header_nritems(node);
-
-        if (path->nodes[level + 1])
-                parent = path->nodes[level + 1];
-
-        slot = path->slots[level];
-        BUG_ON(nritems == 0);
-        if (parent) {
-                parent_slot = path->slots[level + 1];
-                btrfs_node_key(parent, &parent_key, parent_slot);
-                btrfs_node_key(node, &node_key, 0);
-                BUG_ON(memcmp(&parent_key, &node_key,
-                              sizeof(struct btrfs_disk_key)));
-                BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
-                       btrfs_header_bytenr(node));
-        }
-        BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root));
-        if (slot != 0) {
-                btrfs_node_key_to_cpu(node, &cpukey, slot - 1);
-                btrfs_node_key(node, &node_key, slot);
-                BUG_ON(comp_keys(&node_key, &cpukey) <= 0);
-        }
-        if (slot < nritems - 1) {
-                btrfs_node_key_to_cpu(node, &cpukey, slot + 1);
-                btrfs_node_key(node, &node_key, slot);
-                BUG_ON(comp_keys(&node_key, &cpukey) >= 0);
-        }
-        return 0;
-}
-
-/*
- * extra checking to make sure all the items in a leaf are
- * well formed and in the proper order
- */
-static int check_leaf(struct btrfs_root *root, struct btrfs_path *path,
-                      int level)
-{
-        struct extent_buffer *leaf = path->nodes[level];
-        struct extent_buffer *parent = NULL;
-        int parent_slot;
-        struct btrfs_key cpukey;
-        struct btrfs_disk_key parent_key;
-        struct btrfs_disk_key leaf_key;
-        int slot = path->slots[0];
-
-        u32 nritems = btrfs_header_nritems(leaf);
-
-        if (path->nodes[level + 1])
-                parent = path->nodes[level + 1];
-
-        if (nritems == 0)
-                return 0;
-
-        if (parent) {
-                parent_slot = path->slots[level + 1];
-                btrfs_node_key(parent, &parent_key, parent_slot);
-                btrfs_item_key(leaf, &leaf_key, 0);
-
-                BUG_ON(memcmp(&parent_key, &leaf_key,
-                       sizeof(struct btrfs_disk_key)));
-                BUG_ON(btrfs_node_blockptr(parent, parent_slot) !=
-                       btrfs_header_bytenr(leaf));
-        }
-        if (slot != 0 && slot < nritems - 1) {
-                btrfs_item_key(leaf, &leaf_key, slot);
-                btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1);
-                if (comp_keys(&leaf_key, &cpukey) <= 0) {
-                        btrfs_print_leaf(root, leaf);
-                        printk(KERN_CRIT "slot %d offset bad key\n", slot);
-                        BUG_ON(1);
-                }
-                if (btrfs_item_offset_nr(leaf, slot - 1) !=
-                       btrfs_item_end_nr(leaf, slot)) {
-                        btrfs_print_leaf(root, leaf);
-                        printk(KERN_CRIT "slot %d offset bad\n", slot);
-                        BUG_ON(1);
-                }
-        }
-        if (slot < nritems - 1) {
-                btrfs_item_key(leaf, &leaf_key, slot);
-                btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1);
-                BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0);
-                if (btrfs_item_offset_nr(leaf, slot) !=
-                        btrfs_item_end_nr(leaf, slot + 1)) {
-                        btrfs_print_leaf(root, leaf);
-                        printk(KERN_CRIT "slot %d offset bad\n", slot);
-                        BUG_ON(1);
-                }
-        }
-        BUG_ON(btrfs_item_offset_nr(leaf, 0) +
-               btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root));
-        return 0;
-}
-
-static noinline int check_block(struct btrfs_root *root,
-                                struct btrfs_path *path, int level)
-{
-        return 0;
-        if (level == 0)
-                return check_leaf(root, path, level);
-        return check_node(root, path, level);
-}
 
 /*
  * search for key in the extent_buffer.  The items start at offset p,
@@ -1046,9 +928,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                         goto enospc;
                 }
 
-                spin_lock(&root->node_lock);
-                root->node = child;
-                spin_unlock(&root->node_lock);
+                rcu_assign_pointer(root->node, child);
 
                 add_root_to_dirty_list(root);
                 btrfs_tree_unlock(child);
@@ -1188,7 +1068,6 @@ static noinline int balance_level(struct btrfs_trans_handle *trans,
                 }
         }
         /* double check we haven't messed things up */
-        check_block(root, path, level);
         if (orig_ptr !=
             btrfs_node_blockptr(path->nodes[level], path->slots[level]))
                 BUG();
@@ -1798,12 +1677,6 @@ cow_done:
                 if (!cow)
                         btrfs_unlock_up_safe(p, level + 1);
 
-                ret = check_block(root, p, level);
-                if (ret) {
-                        ret = -1;
-                        goto done;
-                }
-
                 ret = bin_search(b, key, level, &slot);
 
                 if (level != 0) {
@@ -2130,10 +2003,8 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans,
 
         btrfs_mark_buffer_dirty(c);
 
-        spin_lock(&root->node_lock);
         old = root->node;
-        root->node = c;
-        spin_unlock(&root->node_lock);
+        rcu_assign_pointer(root->node, c);
 
         /* the super has an extra ref to root->node */
         free_extent_buffer(old);
@@ -3840,7 +3711,8 @@ int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root
         unsigned long ptr;
 
         path = btrfs_alloc_path();
-        BUG_ON(!path);
+        if (!path)
+                return -ENOMEM;
         ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size);
         if (!ret) {
                 leaf = path->nodes[0];
@@ -4217,6 +4089,7 @@ find_next_key:
                 }
                 btrfs_set_path_blocking(path);
                 cur = read_node_slot(root, cur, slot);
+                BUG_ON(!cur);
 
                 btrfs_tree_lock(cur);