Commit a79865c6 authored by Nikolay Borisov's avatar Nikolay Borisov Committed by David Sterba
Browse files

btrfs: Remove V0 extent support 



The v0 compat code was introduced in commit 5d4f98a2
("Btrfs: Mixed back reference  (FORWARD ROLLING FORMAT CHANGE)") 9
years ago, which was merged in 2.6.31. This means that the code is
there to support filesystems which are _VERY_ old and if you are using
btrfs on such an old kernel, you have much bigger problems. This coupled
with the fact that no one is likely testing/maintining this code likely
means it has bugs lurking. All things considered I think 43 kernel
releases later it's high time this remnant of the past got removed.

This patch removes all code wrapped in #ifdefs but leaves the BUG_ONs in case
we have a v0 with no support intact as a sort of safety-net.

Signed-off-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 4de426cd

fs/btrfs/ctree.c

+1 −5
Original line number Diff line number Diff line
@@ -888,11 +888,7 @@ int btrfs_block_can_be_shared(struct btrfs_root *root, 
	     btrfs_root_last_snapshot(&root->root_item) ||

	     btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC)))

		return 1;

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&

	    btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV)

		return 1;

#endif



	return 0;

}

fs/btrfs/ctree.h

+0 −2
Original line number Diff line number Diff line
@@ -55,8 +55,6 @@ struct btrfs_ordered_sum; 


#define BTRFS_OLDEST_GENERATION	0ULL



#define BTRFS_COMPAT_EXTENT_TREE_V0



/*

 * the max metadata block size.  This limit is somewhat artificial,

 * but the memmove costs go through the roof for larger blocks.

fs/btrfs/extent-tree.c

+1 −208
Original line number Diff line number Diff line
@@ -867,17 +867,7 @@ search_again: 
			num_refs = btrfs_extent_refs(leaf, ei);

			extent_flags = btrfs_extent_flags(leaf, ei);

		} else {

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

			struct btrfs_extent_item_v0 *ei0;

			BUG_ON(item_size != sizeof(*ei0));

			ei0 = btrfs_item_ptr(leaf, path->slots[0],

					     struct btrfs_extent_item_v0);

			num_refs = btrfs_extent_refs_v0(leaf, ei0);

			/* FIXME: this isn't correct for data */

			extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF;

#else

			BUG();

#endif

		}

		BUG_ON(num_refs == 0);

	} else {
@@ -1036,89 +1026,6 @@ out_free: 
 * tree block info structure.

 */



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

static int convert_extent_item_v0(struct btrfs_trans_handle *trans,

				  struct btrfs_fs_info *fs_info,

				  struct btrfs_path *path,

				  u64 owner, u32 extra_size)

{

	struct btrfs_root *root = fs_info->extent_root;

	struct btrfs_extent_item *item;

	struct btrfs_extent_item_v0 *ei0;

	struct btrfs_extent_ref_v0 *ref0;

	struct btrfs_tree_block_info *bi;

	struct extent_buffer *leaf;

	struct btrfs_key key;

	struct btrfs_key found_key;

	u32 new_size = sizeof(*item);

	u64 refs;

	int ret;



	leaf = path->nodes[0];

	BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0));



	btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);

	ei0 = btrfs_item_ptr(leaf, path->slots[0],

			     struct btrfs_extent_item_v0);

	refs = btrfs_extent_refs_v0(leaf, ei0);



	if (owner == (u64)-1) {

		while (1) {

			if (path->slots[0] >= btrfs_header_nritems(leaf)) {

				ret = btrfs_next_leaf(root, path);

				if (ret < 0)

					return ret;

				BUG_ON(ret > 0); /* Corruption */

				leaf = path->nodes[0];

			}

			btrfs_item_key_to_cpu(leaf, &found_key,

					      path->slots[0]);

			BUG_ON(key.objectid != found_key.objectid);

			if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) {

				path->slots[0]++;

				continue;

			}

			ref0 = btrfs_item_ptr(leaf, path->slots[0],

					      struct btrfs_extent_ref_v0);

			owner = btrfs_ref_objectid_v0(leaf, ref0);

			break;

		}

	}

	btrfs_release_path(path);



	if (owner < BTRFS_FIRST_FREE_OBJECTID)

		new_size += sizeof(*bi);



	new_size -= sizeof(*ei0);

	ret = btrfs_search_slot(trans, root, &key, path,

				new_size + extra_size, 1);

	if (ret < 0)

		return ret;

	BUG_ON(ret); /* Corruption */



	btrfs_extend_item(fs_info, path, new_size);



	leaf = path->nodes[0];

	item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);

	btrfs_set_extent_refs(leaf, item, refs);

	/* FIXME: get real generation */

	btrfs_set_extent_generation(leaf, item, 0);

	if (owner < BTRFS_FIRST_FREE_OBJECTID) {

		btrfs_set_extent_flags(leaf, item,

				       BTRFS_EXTENT_FLAG_TREE_BLOCK |

				       BTRFS_BLOCK_FLAG_FULL_BACKREF);

		bi = (struct btrfs_tree_block_info *)(item + 1);

		/* FIXME: get first key of the block */

		memzero_extent_buffer(leaf, (unsigned long)bi, sizeof(*bi));

		btrfs_set_tree_block_level(leaf, bi, (int)owner);

	} else {

		btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA);

	}

	btrfs_mark_buffer_dirty(leaf);

	return 0;

}

#endif



/*

 * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required,

 * is_data == BTRFS_REF_TYPE_DATA, data type is requried,
@@ -1247,17 +1154,6 @@ again: 
	if (parent) {

		if (!ret)

			return 0;

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		key.type = BTRFS_EXTENT_REF_V0_KEY;

		btrfs_release_path(path);

		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);

		if (ret < 0) {

			err = ret;

			goto fail;

		}

		if (!ret)

			return 0;

#endif

		goto fail;

	}
@@ -1400,13 +1296,6 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, 
		ref2 = btrfs_item_ptr(leaf, path->slots[0],

				      struct btrfs_shared_data_ref);

		num_refs = btrfs_shared_data_ref_count(leaf, ref2);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {

		struct btrfs_extent_ref_v0 *ref0;

		ref0 = btrfs_item_ptr(leaf, path->slots[0],

				      struct btrfs_extent_ref_v0);

		num_refs = btrfs_ref_count_v0(leaf, ref0);

#endif

	} else {

		BUG();

	}
@@ -1422,14 +1311,6 @@ static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, 
			btrfs_set_extent_data_ref_count(leaf, ref1, num_refs);

		else if (key.type == BTRFS_SHARED_DATA_REF_KEY)

			btrfs_set_shared_data_ref_count(leaf, ref2, num_refs);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		else {

			struct btrfs_extent_ref_v0 *ref0;

			ref0 = btrfs_item_ptr(leaf, path->slots[0],

					struct btrfs_extent_ref_v0);

			btrfs_set_ref_count_v0(leaf, ref0, num_refs);

		}

#endif

		btrfs_mark_buffer_dirty(leaf);

	}

	return ret;
@@ -1469,13 +1350,6 @@ static noinline u32 extent_data_ref_count(struct btrfs_path *path, 
		ref2 = btrfs_item_ptr(leaf, path->slots[0],

				      struct btrfs_shared_data_ref);

		num_refs = btrfs_shared_data_ref_count(leaf, ref2);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	} else if (key.type == BTRFS_EXTENT_REF_V0_KEY) {

		struct btrfs_extent_ref_v0 *ref0;

		ref0 = btrfs_item_ptr(leaf, path->slots[0],

				      struct btrfs_extent_ref_v0);

		num_refs = btrfs_ref_count_v0(leaf, ref0);

#endif

	} else {

		WARN_ON(1);

	}
@@ -1503,15 +1377,6 @@ static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans, 
	ret = btrfs_search_slot(trans, root, &key, path, -1, 1);

	if (ret > 0)

		ret = -ENOENT;

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (ret == -ENOENT && parent) {

		btrfs_release_path(path);

		key.type = BTRFS_EXTENT_REF_V0_KEY;

		ret = btrfs_search_slot(trans, root, &key, path, -1, 1);

		if (ret > 0)

			ret = -ENOENT;

	}

#endif

	return ret;

}
@@ -1676,22 +1541,6 @@ again: 


	leaf = path->nodes[0];

	item_size = btrfs_item_size_nr(leaf, path->slots[0]);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (item_size < sizeof(*ei)) {

		if (!insert) {

			err = -ENOENT;

			goto out;

		}

		ret = convert_extent_item_v0(trans, fs_info, path, owner,

					     extra_size);

		if (ret < 0) {

			err = ret;

			goto out;

		}

		leaf = path->nodes[0];

		item_size = btrfs_item_size_nr(leaf, path->slots[0]);

	}

#endif

	BUG_ON(item_size < sizeof(*ei));



	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);
@@ -2416,17 +2265,6 @@ again: 


	leaf = path->nodes[0];

	item_size = btrfs_item_size_nr(leaf, path->slots[0]);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (item_size < sizeof(*ei)) {

		ret = convert_extent_item_v0(trans, fs_info, path, (u64)-1, 0);

		if (ret < 0) {

			err = ret;

			goto out;

		}

		leaf = path->nodes[0];

		item_size = btrfs_item_size_nr(leaf, path->slots[0]);

	}

#endif

	BUG_ON(item_size < sizeof(*ei));

	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);

	__run_delayed_extent_op(extent_op, leaf, ei);
@@ -3238,12 +3076,6 @@ static noinline int check_committed_ref(struct btrfs_root *root, 


	ret = 1;

	item_size = btrfs_item_size_nr(leaf, path->slots[0]);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (item_size < sizeof(*ei)) {

		WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));

		goto out;

	}

#endif

	ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item);



	if (item_size != sizeof(*ei) +
@@ -6888,11 +6720,7 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, 
				break;

			extent_slot--;

		}

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		item_size = btrfs_item_size_nr(path->nodes[0], extent_slot);

		if (found_extent && item_size < sizeof(*ei))

			found_extent = 0;

#endif



		if (!found_extent) {

			BUG_ON(iref);

			ret = remove_extent_backref(trans, path, NULL,
@@ -6968,41 +6796,6 @@ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, 


	leaf = path->nodes[0];

	item_size = btrfs_item_size_nr(leaf, extent_slot);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (item_size < sizeof(*ei)) {

		BUG_ON(found_extent || extent_slot != path->slots[0]);

		ret = convert_extent_item_v0(trans, info, path, owner_objectid,

					     0);

		if (ret < 0) {

			btrfs_abort_transaction(trans, ret);

			goto out;

		}



		btrfs_release_path(path);

		path->leave_spinning = 1;



		key.objectid = bytenr;

		key.type = BTRFS_EXTENT_ITEM_KEY;

		key.offset = num_bytes;



		ret = btrfs_search_slot(trans, extent_root, &key, path,

					-1, 1);

		if (ret) {

			btrfs_err(info,

				  "umm, got %d back from search, was looking for %llu",

				ret, bytenr);

			btrfs_print_leaf(path->nodes[0]);

		}

		if (ret < 0) {

			btrfs_abort_transaction(trans, ret);

			goto out;

		}



		extent_slot = path->slots[0];

		leaf = path->nodes[0];

		item_size = btrfs_item_size_nr(leaf, extent_slot);

	}

#endif

	BUG_ON(item_size < sizeof(*ei));

	ei = btrfs_item_ptr(leaf, extent_slot,

			    struct btrfs_extent_item);

fs/btrfs/print-tree.c

+1 −29
Original line number Diff line number Diff line
@@ -52,18 +52,8 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type) 
	u64 offset;

	int ref_index = 0;



	if (item_size < sizeof(*ei)) {

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		struct btrfs_extent_item_v0 *ei0;

		BUG_ON(item_size != sizeof(*ei0));

		ei0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_item_v0);

		pr_info("\t\textent refs %u\n",

		       btrfs_extent_refs_v0(eb, ei0));

		return;

#else

	if (item_size < sizeof(*ei))

		BUG();

#endif

	}



	ei = btrfs_item_ptr(eb, slot, struct btrfs_extent_item);

	flags = btrfs_extent_flags(eb, ei);
@@ -133,20 +123,6 @@ static void print_extent_item(struct extent_buffer *eb, int slot, int type) 
	WARN_ON(ptr > end);

}



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

static void print_extent_ref_v0(struct extent_buffer *eb, int slot)

{

	struct btrfs_extent_ref_v0 *ref0;



	ref0 = btrfs_item_ptr(eb, slot, struct btrfs_extent_ref_v0);

	printk("\t\textent back ref root %llu gen %llu owner %llu num_refs %lu\n",

		btrfs_ref_root_v0(eb, ref0),

		btrfs_ref_generation_v0(eb, ref0),

		btrfs_ref_objectid_v0(eb, ref0),

		(unsigned long)btrfs_ref_count_v0(eb, ref0));

}

#endif



static void print_uuid_item(struct extent_buffer *l, unsigned long offset,

			    u32 item_size)

{
@@ -280,11 +256,7 @@ void btrfs_print_leaf(struct extent_buffer *l) 
			       btrfs_file_extent_ram_bytes(l, fi));

			break;

		case BTRFS_EXTENT_REF_V0_KEY:

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

			print_extent_ref_v0(l, i);

#else

			BUG();

#endif

			break;

		case BTRFS_BLOCK_GROUP_ITEM_KEY:

			bi = btrfs_item_ptr(l, i,

fs/btrfs/relocation.c

+1 −150
Original line number Diff line number Diff line
@@ -586,29 +586,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, 
	return btrfs_get_fs_root(fs_info, &key, false);

}



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

static noinline_for_stack

struct btrfs_root *find_tree_root(struct reloc_control *rc,

				  struct extent_buffer *leaf,

				  struct btrfs_extent_ref_v0 *ref0)

{

	struct btrfs_root *root;

	u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);

	u64 generation = btrfs_ref_generation_v0(leaf, ref0);



	BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);



	root = read_fs_root(rc->extent_root->fs_info, root_objectid);

	BUG_ON(IS_ERR(root));



	if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&

	    generation != btrfs_root_generation(&root->root_item))

		return NULL;



	return root;

}

#endif



static noinline_for_stack

int find_inline_backref(struct extent_buffer *leaf, int slot,

			unsigned long *ptr, unsigned long *end)
@@ -621,12 +598,6 @@ int find_inline_backref(struct extent_buffer *leaf, int slot, 
	btrfs_item_key_to_cpu(leaf, &key, slot);



	item_size = btrfs_item_size_nr(leaf, slot);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (item_size < sizeof(*ei)) {

		WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));

		return 1;

	}

#endif

	ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);

	WARN_ON(!(btrfs_extent_flags(leaf, ei) &

		  BTRFS_EXTENT_FLAG_TREE_BLOCK));
@@ -811,29 +782,8 @@ again: 
			goto next;

		}



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||

		    key.type == BTRFS_EXTENT_REF_V0_KEY) {

			if (key.type == BTRFS_EXTENT_REF_V0_KEY) {

				struct btrfs_extent_ref_v0 *ref0;

				ref0 = btrfs_item_ptr(eb, path1->slots[0],

						struct btrfs_extent_ref_v0);

				if (key.objectid == key.offset) {

					root = find_tree_root(rc, eb, ref0);

					if (root && !should_ignore_root(root))

						cur->root = root;

					else

						list_add(&cur->list, &useless);

					break;

				}

				if (is_cowonly_root(btrfs_ref_root_v0(eb,

								      ref0)))

					cur->cowonly = 1;

			}

#else

		ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);

		if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {

#endif

			if (key.objectid == key.offset) {

				/*

				 * only root blocks of reloc trees use
@@ -3333,48 +3283,6 @@ int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, 
	return 0;

}



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

static int get_ref_objectid_v0(struct reloc_control *rc,

			       struct btrfs_path *path,

			       struct btrfs_key *extent_key,

			       u64 *ref_objectid, int *path_change)

{

	struct btrfs_key key;

	struct extent_buffer *leaf;

	struct btrfs_extent_ref_v0 *ref0;

	int ret;

	int slot;



	leaf = path->nodes[0];

	slot = path->slots[0];

	while (1) {

		if (slot >= btrfs_header_nritems(leaf)) {

			ret = btrfs_next_leaf(rc->extent_root, path);

			if (ret < 0)

				return ret;

			BUG_ON(ret > 0);

			leaf = path->nodes[0];

			slot = path->slots[0];

			if (path_change)

				*path_change = 1;

		}

		btrfs_item_key_to_cpu(leaf, &key, slot);

		if (key.objectid != extent_key->objectid)

			return -ENOENT;



		if (key.type != BTRFS_EXTENT_REF_V0_KEY) {

			slot++;

			continue;

		}

		ref0 = btrfs_item_ptr(leaf, slot,

				struct btrfs_extent_ref_v0);

		*ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);

		break;

	}

	return 0;

}

#endif



/*

 * helper to add a tree block to the list.

 * the major work is getting the generation and level of the block
@@ -3408,22 +3316,7 @@ static int add_tree_block(struct reloc_control *rc, 
		}

		generation = btrfs_extent_generation(eb, ei);

	} else {

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		u64 ref_owner;

		int ret;



		BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));

		ret = get_ref_objectid_v0(rc, path, extent_key,

					  &ref_owner, NULL);

		if (ret < 0)

			return ret;

		BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);

		level = (int)ref_owner;

		/* FIXME: get real generation */

		generation = 0;

#else

		BUG();

#endif

	}



	btrfs_release_path(path);
@@ -3781,11 +3674,6 @@ int add_data_references(struct reloc_control *rc, 
	eb = path->nodes[0];

	ptr = btrfs_item_ptr_offset(eb, path->slots[0]);

	end = ptr + btrfs_item_size_nr(eb, path->slots[0]);

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

	if (ptr + sizeof(struct btrfs_extent_item_v0) == end)

		ptr = end;

	else

#endif

	ptr += sizeof(struct btrfs_extent_item);



	while (ptr < end) {
@@ -3832,13 +3720,8 @@ int add_data_references(struct reloc_control *rc, 
		if (key.objectid != extent_key->objectid)

			break;



#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

		if (key.type == BTRFS_SHARED_DATA_REF_KEY ||

		    key.type == BTRFS_EXTENT_REF_V0_KEY) {

#else

		BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);

		if (key.type == BTRFS_SHARED_DATA_REF_KEY) {

#endif

			ret = __add_tree_block(rc, key.offset, blocksize,

					       blocks);

		} else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
@@ -4086,39 +3969,7 @@ restart: 
			BUG_ON(ret);



		} else {

#ifdef BTRFS_COMPAT_EXTENT_TREE_V0

			u64 ref_owner;

			int path_change = 0;



			BUG_ON(item_size !=

			       sizeof(struct btrfs_extent_item_v0));

			ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,

						  &path_change);

			if (ret < 0) {

				err = ret;

				break;

			}

			if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)

				flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;

			else

				flags = BTRFS_EXTENT_FLAG_DATA;



			if (path_change) {

				btrfs_release_path(path);



				path->search_commit_root = 1;

				path->skip_locking = 1;

				ret = btrfs_search_slot(NULL, rc->extent_root,

							&key, path, 0, 0);

				if (ret < 0) {

					err = ret;

					break;

				}

				BUG_ON(ret > 0);

			}

#else

			BUG();

#endif

		}



		if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {

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