3 files changed, 12 insertions, 13 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index fbe501d3bd01..2c9fbe3b6eec 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2763,7 +2763,7 @@ __get_extent_map(struct inode *inode, struct page *page, size_t pg_offset,
 
         if (em_cached && *em_cached) {
                 em = *em_cached;
-                if (em->in_tree && start >= em->start &&
+                if (extent_map_in_tree(em) && start >= em->start &&
                     start < extent_map_end(em)) {
                         atomic_inc(&em->refs);
                         return em;
diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 996ad56b57db..64d08f94485d 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -51,7 +51,7 @@ struct extent_map *alloc_extent_map(void)
         em = kmem_cache_zalloc(extent_map_cache, GFP_NOFS);
         if (!em)
                 return NULL;
-        em->in_tree = 0;
+        RB_CLEAR_NODE(&em->rb_node);
         em->flags = 0;
         em->compress_type = BTRFS_COMPRESS_NONE;
         em->generation = 0;
@@ -73,7 +73,7 @@ void free_extent_map(struct extent_map *em)
                 return;
         WARN_ON(atomic_read(&em->refs) == 0);
         if (atomic_dec_and_test(&em->refs)) {
-                WARN_ON(em->in_tree);
+                WARN_ON(extent_map_in_tree(em));
                 WARN_ON(!list_empty(&em->list));
                 kmem_cache_free(extent_map_cache, em);
         }
@@ -99,8 +99,6 @@ static int tree_insert(struct rb_root *root, struct extent_map *em)
                 parent = *p;
                 entry = rb_entry(parent, struct extent_map, rb_node);
 
-                WARN_ON(!entry->in_tree);
-
                 if (em->start < entry->start)
                         p = &(*p)->rb_left;
                 else if (em->start >= extent_map_end(entry))
@@ -128,7 +126,6 @@ static int tree_insert(struct rb_root *root, struct extent_map *em)
                 if (end > entry->start && em->start < extent_map_end(entry))
                         return -EEXIST;
 
-        em->in_tree = 1;
         rb_link_node(&em->rb_node, orig_parent, p);
         rb_insert_color(&em->rb_node, root);
         return 0;
@@ -153,8 +150,6 @@ static struct rb_node *__tree_search(struct rb_root *root, u64 offset,
                 prev = n;
                 prev_entry = entry;
 
-                WARN_ON(!entry->in_tree);
-
                 if (offset < entry->start)
                         n = n->rb_left;
                 else if (offset >= extent_map_end(entry))
@@ -240,12 +235,12 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
                         em->len += merge->len;
                         em->block_len += merge->block_len;
                         em->block_start = merge->block_start;
-                        merge->in_tree = 0;
                         em->mod_len = (em->mod_len + em->mod_start) - merge->mod_start;
                         em->mod_start = merge->mod_start;
                         em->generation = max(em->generation, merge->generation);
 
                         rb_erase(&merge->rb_node, &tree->map);
+                        RB_CLEAR_NODE(&merge->rb_node);
                         free_extent_map(merge);
                 }
         }
@@ -257,7 +252,7 @@ static void try_merge_map(struct extent_map_tree *tree, struct extent_map *em)
                 em->len += merge->len;
                 em->block_len += merge->block_len;
                 rb_erase(&merge->rb_node, &tree->map);
-                merge->in_tree = 0;
+                RB_CLEAR_NODE(&merge->rb_node);
                 em->mod_len = (merge->mod_start + merge->mod_len) - em->mod_start;
                 em->generation = max(em->generation, merge->generation);
                 free_extent_map(merge);
@@ -319,7 +314,7 @@ out:
 void clear_em_logging(struct extent_map_tree *tree, struct extent_map *em)
 {
         clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
-        if (em->in_tree)
+        if (extent_map_in_tree(em))
                 try_merge_map(tree, em);
 }
 
@@ -434,6 +429,6 @@ int remove_extent_mapping(struct extent_map_tree *tree, struct extent_map *em)
         rb_erase(&em->rb_node, &tree->map);
         if (!test_bit(EXTENT_FLAG_LOGGING, &em->flags))
                 list_del_init(&em->list);
-        em->in_tree = 0;
+        RB_CLEAR_NODE(&em->rb_node);
         return ret;
 }
diff --git a/fs/btrfs/extent_map.h b/fs/btrfs/extent_map.h
index 93fba716d7f8..f0a645a14d6e 100644
--- a/fs/btrfs/extent_map.h
+++ b/fs/btrfs/extent_map.h
@@ -33,7 +33,6 @@ struct extent_map {
         unsigned long flags;
         struct block_device *bdev;
         atomic_t refs;
-        unsigned int in_tree;
         unsigned int compress_type;
         struct list_head list;
 };
@@ -44,6 +43,11 @@ struct extent_map_tree {
         rwlock_t lock;
 };
 
+static inline int extent_map_in_tree(const struct extent_map *em)
+{
+        return !RB_EMPTY_NODE(&em->rb_node);
+}
+
 static inline u64 extent_map_end(struct extent_map *em)
 {
         if (em->start + em->len < em->start)