From 751a27615ddaaf95519565d83bac65b8aafab9e8 Mon Sep 17 00:00:00 2001 From: Filipe Manana Date: Thu, 8 Jun 2023 11:27:49 +0100 Subject: [PATCH] btrfs: do not BUG_ON() on tree mod log failures at btrfs_del_ptr() At btrfs_del_ptr(), instead of doing a BUG_ON() in case we fail to record tree mod log operations, do a transaction abort and return the error to the callers. There's really no need for the BUG_ON() as we can release all resources in the context of all callers, and we have to abort because other future tree searches that use the tree mod log (btrfs_search_old_slot()) may get inconsistent results if other operations modify the tree after that failure and before the tree mod log based search. This implies btrfs_del_ptr() return an int instead of void, and making all callers check for returned errors. Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/ctree.c | 52 +++++++++++++++++++++++++++++++++++++++------------- fs/btrfs/ctree.h | 4 ++-- 2 files changed, 41 insertions(+), 15 deletions(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index e075e6994d79..190dd90a88eb 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1139,7 +1139,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (btrfs_header_nritems(right) == 0) { btrfs_clear_buffer_dirty(trans, right); btrfs_tree_unlock(right); - btrfs_del_ptr(root, path, level + 1, pslot + 1); + ret = btrfs_del_ptr(trans, root, path, level + 1, pslot + 1); + if (ret < 0) { + free_extent_buffer_stale(right); + right = NULL; + goto out; + } root_sub_used(root, right->len); btrfs_free_tree_block(trans, btrfs_root_id(root), right, 0, 1); @@ -1192,7 +1197,12 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (btrfs_header_nritems(mid) == 0) { btrfs_clear_buffer_dirty(trans, mid); btrfs_tree_unlock(mid); - btrfs_del_ptr(root, path, level + 1, pslot); + ret = btrfs_del_ptr(trans, root, path, level + 1, pslot); + if (ret < 0) { + free_extent_buffer_stale(mid); + mid = NULL; + goto out; + } root_sub_used(root, mid->len); btrfs_free_tree_block(trans, btrfs_root_id(root), mid, 0, 1); free_extent_buffer_stale(mid); @@ -4440,8 +4450,8 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans, * * This is exported for use inside btrfs-progs, don't un-export it. */ -void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, - int slot) +int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_path *path, int level, int slot) { struct extent_buffer *parent = path->nodes[level]; u32 nritems; @@ -4452,7 +4462,10 @@ void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, if (level) { ret = btrfs_tree_mod_log_insert_move(parent, slot, slot + 1, nritems - slot - 1); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + return ret; + } } memmove_extent_buffer(parent, btrfs_node_key_ptr_offset(parent, slot), @@ -4462,7 +4475,10 @@ void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, } else if (level) { ret = btrfs_tree_mod_log_insert_key(parent, slot, BTRFS_MOD_LOG_KEY_REMOVE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + return ret; + } } nritems--; @@ -4478,6 +4494,7 @@ void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, fixup_low_keys(path, &disk_key, level + 1); } btrfs_mark_buffer_dirty(parent); + return 0; } /* @@ -4490,13 +4507,17 @@ void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, * The path must have already been setup for deleting the leaf, including * all the proper balancing. path->nodes[1] must be locked. */ -static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, - struct btrfs_root *root, - struct btrfs_path *path, - struct extent_buffer *leaf) +static noinline int btrfs_del_leaf(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct extent_buffer *leaf) { + int ret; + WARN_ON(btrfs_header_generation(leaf) != trans->transid); - btrfs_del_ptr(root, path, 1, path->slots[1]); + ret = btrfs_del_ptr(trans, root, path, 1, path->slots[1]); + if (ret < 0) + return ret; /* * btrfs_free_extent is expensive, we want to make sure we @@ -4509,6 +4530,7 @@ static noinline void btrfs_del_leaf(struct btrfs_trans_handle *trans, atomic_inc(&leaf->refs); btrfs_free_tree_block(trans, btrfs_root_id(root), leaf, 0, 1); free_extent_buffer_stale(leaf); + return 0; } /* * delete the item at the leaf level in path. If that empties @@ -4558,7 +4580,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, btrfs_set_header_level(leaf, 0); } else { btrfs_clear_buffer_dirty(trans, leaf); - btrfs_del_leaf(trans, root, path, leaf); + ret = btrfs_del_leaf(trans, root, path, leaf); + if (ret < 0) + return ret; } } else { int used = leaf_space_used(leaf, 0, nritems); @@ -4619,7 +4643,9 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, if (btrfs_header_nritems(leaf) == 0) { path->slots[1] = slot; - btrfs_del_leaf(trans, root, path, leaf); + ret = btrfs_del_leaf(trans, root, path, leaf); + if (ret < 0) + return ret; free_extent_buffer(leaf); ret = 0; } else { diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 5af61480dde6..f2d2b313bde5 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -541,8 +541,8 @@ int btrfs_copy_root(struct btrfs_trans_handle *trans, struct extent_buffer **cow_ret, u64 new_root_objectid); int btrfs_block_can_be_shared(struct btrfs_root *root, struct extent_buffer *buf); -void btrfs_del_ptr(struct btrfs_root *root, struct btrfs_path *path, int level, - int slot); +int btrfs_del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct btrfs_path *path, int level, int slot); void btrfs_extend_item(struct btrfs_path *path, u32 data_size); void btrfs_truncate_item(struct btrfs_path *path, u32 new_size, int from_end); int btrfs_split_item(struct btrfs_trans_handle *trans, -- 2.11.0