4 files changed, 20 insertions, 25 deletions

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index e6fbbd74b716..7e607416755a 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3481,8 +3481,8 @@ void btrfs_put_block_group_cache(struct btrfs_fs_info *info);
 u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo);
 int btrfs_error_unpin_extent_range(struct btrfs_root *root,
                                    u64 start, u64 end);
-int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
-                               u64 num_bytes, u64 *actual_bytes);
+int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
+                         u64 num_bytes, u64 *actual_bytes);
 int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans,
                             struct btrfs_root *root, u64 type);
 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range);
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 30965120772b..8c63419a7f70 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4121,12 +4121,6 @@ again:
                 if (ret)
                         break;
 
-                /* opt_discard */
-                if (btrfs_test_opt(root, DISCARD))
-                        ret = btrfs_error_discard_extent(root, start,
-                                                         end + 1 - start,
-                                                         NULL);
-
                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
                 btrfs_error_unpin_extent_range(root, start, end);
                 cond_resched();
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 222d6aea4a8a..a80b97100d90 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -1889,8 +1889,8 @@ static int btrfs_issue_discard(struct block_device *bdev,
         return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0);
 }
 
-static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
-                                u64 num_bytes, u64 *actual_bytes)
+int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
+                         u64 num_bytes, u64 *actual_bytes)
 {
         int ret;
         u64 discarded_bytes = 0;
@@ -5727,7 +5727,8 @@ void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans,
         update_global_block_rsv(fs_info);
 }
 
-static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
+static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end,
+                              const bool return_free_space)
 {
         struct btrfs_fs_info *fs_info = root->fs_info;
         struct btrfs_block_group_cache *cache = NULL;
@@ -5751,7 +5752,8 @@ static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 
                 if (start < cache->last_byte_to_unpin) {
                         len = min(len, cache->last_byte_to_unpin - start);
-                        btrfs_add_free_space(cache, start, len);
+                        if (return_free_space)
+                                btrfs_add_free_space(cache, start, len);
                 }
 
                 start += len;
@@ -5815,7 +5817,7 @@ int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans,
                                                    end + 1 - start, NULL);
 
                 clear_extent_dirty(unpin, start, end, GFP_NOFS);
-                unpin_extent_range(root, start, end);
+                unpin_extent_range(root, start, end, true);
                 cond_resched();
         }
 
@@ -8872,6 +8874,7 @@ int btrfs_free_block_groups(struct btrfs_fs_info *info)
                                        cache_node);
                 rb_erase(&block_group->cache_node,
                          &info->block_group_cache_tree);
+                RB_CLEAR_NODE(&block_group->cache_node);
                 spin_unlock(&info->block_group_cache_lock);
 
                 down_write(&block_group->space_info->groups_sem);
@@ -9130,6 +9133,7 @@ int btrfs_read_block_groups(struct btrfs_root *root)
                         spin_lock(&info->block_group_cache_lock);
                         rb_erase(&cache->cache_node,
                                  &info->block_group_cache_tree);
+                        RB_CLEAR_NODE(&cache->cache_node);
                         spin_unlock(&info->block_group_cache_lock);
                         btrfs_put_block_group(cache);
                         goto error;
@@ -9271,6 +9275,7 @@ int btrfs_make_block_group(struct btrfs_trans_handle *trans,
                 spin_lock(&root->fs_info->block_group_cache_lock);
                 rb_erase(&cache->cache_node,
                          &root->fs_info->block_group_cache_tree);
+                RB_CLEAR_NODE(&cache->cache_node);
                 spin_unlock(&root->fs_info->block_group_cache_lock);
                 btrfs_put_block_group(cache);
                 return ret;
@@ -9690,13 +9695,7 @@ out:
 
 int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end)
 {
-        return unpin_extent_range(root, start, end);
-}
-
-int btrfs_error_discard_extent(struct btrfs_root *root, u64 bytenr,
-                               u64 num_bytes, u64 *actual_bytes)
-{
-        return btrfs_discard_extent(root, bytenr, num_bytes, actual_bytes);
+        return unpin_extent_range(root, start, end, false);
 }
 
 int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range)
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c
index 030847bf7cec..d6c03f7f136b 100644
--- a/fs/btrfs/free-space-cache.c
+++ b/fs/btrfs/free-space-cache.c
@@ -2966,8 +2966,8 @@ static int do_trimming(struct btrfs_block_group_cache *block_group,
         spin_unlock(&block_group->lock);
         spin_unlock(&space_info->lock);
 
-        ret = btrfs_error_discard_extent(fs_info->extent_root,
-                                         start, bytes, &trimmed);
+        ret = btrfs_discard_extent(fs_info->extent_root,
+                                   start, bytes, &trimmed);
         if (!ret)
                 *total_trimmed += trimmed;
 
@@ -3185,16 +3185,18 @@ out:
 
                 spin_unlock(&block_group->lock);
 
+                lock_chunks(block_group->fs_info->chunk_root);
                 em_tree = &block_group->fs_info->mapping_tree.map_tree;
                 write_lock(&em_tree->lock);
                 em = lookup_extent_mapping(em_tree, block_group->key.objectid,
                                            1);
                 BUG_ON(!em); /* logic error, can't happen */
+                /*
+                 * remove_extent_mapping() will delete us from the pinned_chunks
+                 * list, which is protected by the chunk mutex.
+                 */
                 remove_extent_mapping(em_tree, em);
                 write_unlock(&em_tree->lock);
-
-                lock_chunks(block_group->fs_info->chunk_root);
-                list_del_init(&em->list);
                 unlock_chunks(block_group->fs_info->chunk_root);
 
                 /* once for us and once for the tree */