Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs

Pull btrfs fixes from Chris Mason:
"We've got more bug fixes in my for-linus branch:

One of these fixes another corner of the compression oops from last
time. Miao nailed down some problems with concurrent snapshot
deletion and drive balancing.

I kept out one of his patches for more testing, but these are all
stable"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix oops caused by the space balance and dead roots
Btrfs: insert orphan roots into fs radix tree
Btrfs: limit delalloc pages outside of find_delalloc_range
Btrfs: use right root when checking for hash collision

fs/btrfs/disk-io.c

···
 	return ret;
 }
 
-struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
-					      struct btrfs_key *location)
+struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
+				     struct btrfs_key *location,
+				     bool check_ref)
 {
 	struct btrfs_root *root;
 	int ret;
···
 again:
 	root = btrfs_lookup_fs_root(fs_info, location->objectid);
 	if (root) {
-		if (btrfs_root_refs(&root->root_item) == 0)
+		if (check_ref && btrfs_root_refs(&root->root_item) == 0)
 			return ERR_PTR(-ENOENT);
 		return root;
 	}
···
 	if (IS_ERR(root))
 		return root;
 
-	if (btrfs_root_refs(&root->root_item) == 0) {
+	if (check_ref && btrfs_root_refs(&root->root_item) == 0) {
 		ret = -ENOENT;
 		goto fail;
 	}

fs/btrfs/disk-io.h

···
 int btrfs_init_fs_root(struct btrfs_root *root);
 int btrfs_insert_fs_root(struct btrfs_fs_info *fs_info,
 			 struct btrfs_root *root);
-struct btrfs_root *btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
-					      struct btrfs_key *location);
+
+struct btrfs_root *btrfs_get_fs_root(struct btrfs_fs_info *fs_info,
+				     struct btrfs_key *key,
+				     bool check_ref);
+static inline struct btrfs_root *
+btrfs_read_fs_root_no_name(struct btrfs_fs_info *fs_info,
+			   struct btrfs_key *location)
+{
+	return btrfs_get_fs_root(fs_info, location, true);
+}
+
 int btrfs_cleanup_fs_roots(struct btrfs_fs_info *fs_info);
 void btrfs_btree_balance_dirty(struct btrfs_root *root);
 void btrfs_btree_balance_dirty_nodelay(struct btrfs_root *root);

fs/btrfs/extent_io.c

···
 		cur_start = state->end + 1;
 		node = rb_next(node);
 		total_bytes += state->end - state->start + 1;
-		if (total_bytes >= max_bytes) {
-			*end = *start + max_bytes - 1;
+		if (total_bytes >= max_bytes)
 			break;
-		}
 		if (!node)
 			break;
 	}
···
 
 	/*
 	 * make sure to limit the number of pages we try to lock down
-	 * if we're looping.
 	 */
-	if (delalloc_end + 1 - delalloc_start > max_bytes && loops)
-		delalloc_end = delalloc_start + PAGE_CACHE_SIZE - 1;
+	if (delalloc_end + 1 - delalloc_start > max_bytes)
+		delalloc_end = delalloc_start + max_bytes - 1;
 
 	/* step two, lock all the pages after the page that has start */
 	ret = lock_delalloc_pages(inode, locked_page,
···
 		 */
 		free_extent_state(cached_state);
 		if (!loops) {
-			unsigned long offset = (*start) & (PAGE_CACHE_SIZE - 1);
-			max_bytes = PAGE_CACHE_SIZE - offset;
+			max_bytes = PAGE_CACHE_SIZE;
 			loops = 1;
 			goto again;
 		} else {

fs/btrfs/inode.c

···
 
 
 	/* check for collisions, even if the  name isn't there */
-	ret = btrfs_check_dir_item_collision(root, new_dir->i_ino,
+	ret = btrfs_check_dir_item_collision(dest, new_dir->i_ino,
 			     new_dentry->d_name.name,
 			     new_dentry->d_name.len);
 

fs/btrfs/relocation.c

···
 	else
 		key.offset = (u64)-1;
 
-	return btrfs_read_fs_root_no_name(fs_info, &key);
+	return btrfs_get_fs_root(fs_info, &key, false);
 }
 
 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0

fs/btrfs/root-tree.c

···
 			continue;
 		}
 
-		if (btrfs_root_refs(&root->root_item) == 0) {
-			btrfs_add_dead_root(root);
-			continue;
-		}
-
 		err = btrfs_init_fs_root(root);
 		if (err) {
 			btrfs_free_fs_root(root);
···
 			btrfs_free_fs_root(root);
 			break;
 		}
+
+		if (btrfs_root_refs(&root->root_item) == 0)
+			btrfs_add_dead_root(root);
 	}
 
 	btrfs_free_path(path);