diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index b8b69266393a..208d8aa5b07e 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -283,9 +283,7 @@ static int __resolve_indirect_ref(struct btrfs_fs_info *fs_info, goto out; } - rcu_read_lock(); - root_level = btrfs_header_level(root->node); - rcu_read_unlock(); + root_level = btrfs_old_root_level(root, time_seq); if (root_level + 1 == level) goto out; diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index b33436211000..eba44b076829 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -596,6 +596,11 @@ tree_mod_log_insert_move(struct btrfs_fs_info *fs_info, if (tree_mod_dont_log(fs_info, eb)) return 0; + /* + * When we override something during the move, we log these removals. + * This can only happen when we move towards the beginning of the + * buffer, i.e. dst_slot < src_slot. + */ for (i = 0; i + dst_slot < src_slot && i < nr_items; i++) { ret = tree_mod_log_insert_key_locked(fs_info, eb, i + dst_slot, MOD_LOG_KEY_REMOVE_WHILE_MOVING); @@ -647,8 +652,6 @@ tree_mod_log_insert_root(struct btrfs_fs_info *fs_info, if (tree_mod_dont_log(fs_info, NULL)) return 0; - __tree_mod_log_free_eb(fs_info, old_root); - ret = tree_mod_alloc(fs_info, flags, &tm); if (ret < 0) goto out; @@ -926,12 +929,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, ret = btrfs_dec_ref(trans, root, buf, 1, 1); BUG_ON(ret); /* -ENOMEM */ } - /* - * don't log freeing in case we're freeing the root node, this - * is done by tree_mod_log_set_root_pointer later - */ - if (buf != root->node && btrfs_header_level(buf) != 0) - tree_mod_log_free_eb(root->fs_info, buf); + tree_mod_log_free_eb(root->fs_info, buf); clean_tree_block(trans, root, buf); *last_ref = 1; } @@ -1225,6 +1223,8 @@ tree_mod_log_rewind(struct btrfs_fs_info *fs_info, struct extent_buffer *eb, free_extent_buffer(eb); __tree_mod_log_rewind(eb_rewin, time_seq, tm); + WARN_ON(btrfs_header_nritems(eb_rewin) > + BTRFS_NODEPTRS_PER_BLOCK(fs_info->fs_root)); return eb_rewin; } @@ -1244,6 +1244,7 @@ get_old_root(struct btrfs_root *root, u64 time_seq) struct tree_mod_root *old_root = NULL; u64 old_generation = 0; u64 logical; + u32 blocksize; eb = btrfs_read_lock_root_node(root); tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); @@ -1259,14 +1260,31 @@ get_old_root(struct btrfs_root *root, u64 time_seq) } tm = tree_mod_log_search(root->fs_info, logical, time_seq); - if (old_root) + if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) { + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); + blocksize = btrfs_level_size(root, old_root->level); + eb = read_tree_block(root, logical, blocksize, 0); + if (!eb) { + pr_warn("btrfs: failed to read tree block %llu from get_old_root\n", + logical); + WARN_ON(1); + } else { + eb = btrfs_clone_extent_buffer(eb); + } + } else if (old_root) { + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); eb = alloc_dummy_extent_buffer(logical, root->nodesize); - else + } else { eb = btrfs_clone_extent_buffer(root->node); - btrfs_tree_read_unlock(root->node); - free_extent_buffer(root->node); + btrfs_tree_read_unlock(root->node); + free_extent_buffer(root->node); + } + if (!eb) return NULL; + extent_buffer_get(eb); btrfs_tree_read_lock(eb); if (old_root) { btrfs_set_header_bytenr(eb, eb->start); @@ -1279,11 +1297,28 @@ get_old_root(struct btrfs_root *root, u64 time_seq) __tree_mod_log_rewind(eb, time_seq, tm); else WARN_ON(btrfs_header_level(eb) != 0); - extent_buffer_get(eb); + WARN_ON(btrfs_header_nritems(eb) > BTRFS_NODEPTRS_PER_BLOCK(root)); return eb; } +int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq) +{ + struct tree_mod_elem *tm; + int level; + + tm = __tree_mod_log_oldest_root(root->fs_info, root, time_seq); + if (tm && tm->op == MOD_LOG_ROOT_REPLACE) { + level = tm->old_root.level; + } else { + rcu_read_lock(); + level = btrfs_header_level(root->node); + rcu_read_unlock(); + } + + return level; +} + static inline int should_cow_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf) @@ -1725,6 +1760,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, goto enospc; } + tree_mod_log_free_eb(root->fs_info, root->node); tree_mod_log_set_root_pointer(root, child); rcu_assign_pointer(root->node, child); @@ -2970,8 +3006,10 @@ static int push_node_left(struct btrfs_trans_handle *trans, push_items * sizeof(struct btrfs_key_ptr)); if (push_items < src_nritems) { - tree_mod_log_eb_move(root->fs_info, src, 0, push_items, - src_nritems - push_items); + /* + * don't call tree_mod_log_eb_move here, key removal was already + * fully logged by tree_mod_log_eb_copy above. + */ memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), btrfs_node_key_ptr_offset(push_items), (src_nritems - push_items) * diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 8a92ab1632a2..2ce1135400cf 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -3120,6 +3120,7 @@ static inline u64 btrfs_inc_tree_mod_seq(struct btrfs_fs_info *fs_info) { return atomic_inc_return(&fs_info->tree_mod_seq); } +int btrfs_old_root_level(struct btrfs_root *root, u64 time_seq); /* root-item.c */ int btrfs_find_root_ref(struct btrfs_root *tree_root,