diff options
Diffstat (limited to 'fs/btrfs/ctree.c')
-rw-r--r-- | fs/btrfs/ctree.c | 429 |
1 files changed, 273 insertions, 156 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 2ff2961b1183..a4cb4b642987 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -37,8 +37,6 @@ static int push_node_left(struct btrfs_trans_handle *trans, static int balance_node_right(struct btrfs_trans_handle *trans, struct extent_buffer *dst_buf, struct extent_buffer *src_buf); -static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, - int level, int slot); static const struct btrfs_csums { u16 size; @@ -150,13 +148,19 @@ static inline void copy_leaf_items(const struct extent_buffer *dst, nr_items * sizeof(struct btrfs_item)); } +/* This exists for btrfs-progs usages. */ +u16 btrfs_csum_type_size(u16 type) +{ + return btrfs_csums[type].size; +} + int btrfs_super_csum_size(const struct btrfs_super_block *s) { u16 t = btrfs_super_csum_type(s); /* * csum type is validated at mount time */ - return btrfs_csums[t].size; + return btrfs_csum_type_size(t); } const char *btrfs_super_csum_name(u16 csum_type) @@ -417,9 +421,13 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, &refs, &flags); if (ret) return ret; - if (refs == 0) { - ret = -EROFS; - btrfs_handle_fs_error(fs_info, ret, NULL); + if (unlikely(refs == 0)) { + btrfs_crit(fs_info, + "found 0 references for tree block at bytenr %llu level %d root %llu", + buf->start, btrfs_header_level(buf), + btrfs_root_id(root)); + ret = -EUCLEAN; + btrfs_abort_transaction(trans, ret); return ret; } } else { @@ -464,10 +472,7 @@ static noinline int update_ref_for_cow(struct btrfs_trans_handle *trans, return ret; } if (new_flags != 0) { - int level = btrfs_header_level(buf); - - ret = btrfs_set_disk_extent_flags(trans, buf, - new_flags, level); + ret = btrfs_set_disk_extent_flags(trans, buf, new_flags); if (ret) return ret; } @@ -583,9 +588,14 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, btrfs_header_backref_rev(buf) < BTRFS_MIXED_BACKREF_REV) parent_start = buf->start; - atomic_inc(&cow->refs); ret = btrfs_tree_mod_log_insert_root(root->node, cow, true); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(cow); + free_extent_buffer(cow); + btrfs_abort_transaction(trans, ret); + return ret; + } + atomic_inc(&cow->refs); rcu_assign_pointer(root->node, cow); btrfs_free_tree_block(trans, btrfs_root_id(root), buf, @@ -594,8 +604,14 @@ static noinline int __btrfs_cow_block(struct btrfs_trans_handle *trans, add_root_to_dirty_list(root); } else { WARN_ON(trans->transid != btrfs_header_generation(parent)); - btrfs_tree_mod_log_insert_key(parent, parent_slot, - BTRFS_MOD_LOG_KEY_REPLACE); + ret = btrfs_tree_mod_log_insert_key(parent, parent_slot, + BTRFS_MOD_LOG_KEY_REPLACE); + if (ret) { + btrfs_tree_unlock(cow); + free_extent_buffer(cow); + btrfs_abort_transaction(trans, ret); + return ret; + } btrfs_set_node_blockptr(parent, parent_slot, cow->start); btrfs_set_node_ptr_generation(parent, parent_slot, @@ -1028,8 +1044,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, child = btrfs_read_node_slot(mid, 0); if (IS_ERR(child)) { ret = PTR_ERR(child); - btrfs_handle_fs_error(fs_info, ret, NULL); - goto enospc; + goto out; } btrfs_tree_lock(child); @@ -1038,11 +1053,16 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (ret) { btrfs_tree_unlock(child); free_extent_buffer(child); - goto enospc; + goto out; } ret = btrfs_tree_mod_log_insert_root(root->node, child, true); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(child); + free_extent_buffer(child); + btrfs_abort_transaction(trans, ret); + goto out; + } rcu_assign_pointer(root->node, child); add_root_to_dirty_list(root); @@ -1070,7 +1090,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (IS_ERR(left)) { ret = PTR_ERR(left); left = NULL; - goto enospc; + goto out; } __btrfs_tree_lock(left, BTRFS_NESTING_LEFT); @@ -1079,7 +1099,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, BTRFS_NESTING_LEFT_COW); if (wret) { ret = wret; - goto enospc; + goto out; } } @@ -1088,7 +1108,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (IS_ERR(right)) { ret = PTR_ERR(right); right = NULL; - goto enospc; + goto out; } __btrfs_tree_lock(right, BTRFS_NESTING_RIGHT); @@ -1097,7 +1117,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, BTRFS_NESTING_RIGHT_COW); if (wret) { ret = wret; - goto enospc; + goto out; } } @@ -1119,7 +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); - 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); @@ -1130,7 +1155,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_node_key(right, &right_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto out; + } btrfs_set_node_key(parent, &right_key, pslot + 1); btrfs_mark_buffer_dirty(parent); } @@ -1145,15 +1173,19 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, * otherwise we would have pulled some pointers from the * right */ - if (!left) { - ret = -EROFS; - btrfs_handle_fs_error(fs_info, ret, NULL); - goto enospc; + if (unlikely(!left)) { + btrfs_crit(fs_info, +"missing left child when middle child only has 1 item, parent bytenr %llu level %d mid bytenr %llu root %llu", + parent->start, btrfs_header_level(parent), + mid->start, btrfs_root_id(root)); + ret = -EUCLEAN; + btrfs_abort_transaction(trans, ret); + goto out; } wret = balance_node_right(trans, mid, left); if (wret < 0) { ret = wret; - goto enospc; + goto out; } if (wret == 1) { wret = push_node_left(trans, left, mid, 1); @@ -1165,7 +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); - 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); @@ -1176,7 +1213,10 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, btrfs_node_key(mid, &mid_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + goto out; + } btrfs_set_node_key(parent, &mid_key, pslot); btrfs_mark_buffer_dirty(parent); } @@ -1202,7 +1242,7 @@ static noinline int balance_level(struct btrfs_trans_handle *trans, if (orig_ptr != btrfs_node_blockptr(path->nodes[level], path->slots[level])) BUG(); -enospc: +out: if (right) { btrfs_tree_unlock(right); free_extent_buffer(right); @@ -1278,7 +1318,12 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, btrfs_node_key(mid, &disk_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(left); + free_extent_buffer(left); + btrfs_abort_transaction(trans, ret); + return ret; + } btrfs_set_node_key(parent, &disk_key, pslot); btrfs_mark_buffer_dirty(parent); if (btrfs_header_nritems(left) > orig_slot) { @@ -1333,7 +1378,12 @@ static noinline int push_nodes_for_insert(struct btrfs_trans_handle *trans, btrfs_node_key(right, &disk_key, 0); ret = btrfs_tree_mod_log_insert_key(parent, pslot + 1, BTRFS_MOD_LOG_KEY_REPLACE); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_tree_unlock(right); + free_extent_buffer(right); + btrfs_abort_transaction(trans, ret); + return ret; + } btrfs_set_node_key(parent, &disk_key, pslot + 1); btrfs_mark_buffer_dirty(parent); @@ -2379,6 +2429,87 @@ done: } /* + * Search the tree again to find a leaf with smaller keys. + * Returns 0 if it found something. + * Returns 1 if there are no smaller keys. + * Returns < 0 on error. + * + * This may release the path, and so you may lose any locks held at the + * time you call it. + */ +static int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) +{ + struct btrfs_key key; + struct btrfs_key orig_key; + struct btrfs_disk_key found_key; + int ret; + + btrfs_item_key_to_cpu(path->nodes[0], &key, 0); + orig_key = key; + + if (key.offset > 0) { + key.offset--; + } else if (key.type > 0) { + key.type--; + key.offset = (u64)-1; + } else if (key.objectid > 0) { + key.objectid--; + key.type = (u8)-1; + key.offset = (u64)-1; + } else { + return 1; + } + + btrfs_release_path(path); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret <= 0) + return ret; + + /* + * Previous key not found. Even if we were at slot 0 of the leaf we had + * before releasing the path and calling btrfs_search_slot(), we now may + * be in a slot pointing to the same original key - this can happen if + * after we released the path, one of more items were moved from a + * sibling leaf into the front of the leaf we had due to an insertion + * (see push_leaf_right()). + * If we hit this case and our slot is > 0 and just decrement the slot + * so that the caller does not process the same key again, which may or + * may not break the caller, depending on its logic. + */ + if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { + btrfs_item_key(path->nodes[0], &found_key, path->slots[0]); + ret = comp_keys(&found_key, &orig_key); + if (ret == 0) { + if (path->slots[0] > 0) { + path->slots[0]--; + return 0; + } + /* + * At slot 0, same key as before, it means orig_key is + * the lowest, leftmost, key in the tree. We're done. + */ + return 1; + } + } + + btrfs_item_key(path->nodes[0], &found_key, 0); + ret = comp_keys(&found_key, &key); + /* + * We might have had an item with the previous key in the tree right + * before we released our path. And after we released our path, that + * item might have been pushed to the first slot (0) of the leaf we + * were holding due to a tree balance. Alternatively, an item with the + * previous key can exist as the only element of a leaf (big fat item). + * Therefore account for these 2 cases, so that our callers (like + * btrfs_previous_item) don't miss an existing item with a key matching + * the previous key we computed above. + */ + if (ret <= 0) + return 0; + return 1; +} + +/* * helper to use instead of search slot if no exact match is needed but * instead the next or previous item should be returned. * When find_higher is true, the next higher item is returned, the next lower @@ -2552,6 +2683,7 @@ void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, if (slot > 0) { btrfs_item_key(eb, &disk_key, slot - 1); if (unlikely(comp_keys(&disk_key, new_key) >= 0)) { + btrfs_print_leaf(eb); btrfs_crit(fs_info, "slot %u key (%llu %u %llu) new key (%llu %u %llu)", slot, btrfs_disk_key_objectid(&disk_key), @@ -2559,13 +2691,13 @@ void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, btrfs_disk_key_offset(&disk_key), new_key->objectid, new_key->type, new_key->offset); - btrfs_print_leaf(eb); BUG(); } } if (slot < btrfs_header_nritems(eb) - 1) { btrfs_item_key(eb, &disk_key, slot + 1); if (unlikely(comp_keys(&disk_key, new_key) <= 0)) { + btrfs_print_leaf(eb); btrfs_crit(fs_info, "slot %u key (%llu %u %llu) new key (%llu %u %llu)", slot, btrfs_disk_key_objectid(&disk_key), @@ -2573,7 +2705,6 @@ void btrfs_set_item_key_safe(struct btrfs_fs_info *fs_info, btrfs_disk_key_offset(&disk_key), new_key->objectid, new_key->type, new_key->offset); - btrfs_print_leaf(eb); BUG(); } } @@ -2626,7 +2757,7 @@ static bool check_sibling_keys(struct extent_buffer *left, btrfs_item_key_to_cpu(right, &right_first, 0); } - if (btrfs_comp_cpu_keys(&left_last, &right_first) >= 0) { + if (unlikely(btrfs_comp_cpu_keys(&left_last, &right_first) >= 0)) { btrfs_crit(left->fs_info, "left extent buffer:"); btrfs_print_tree(left, false); btrfs_crit(left->fs_info, "right extent buffer:"); @@ -2703,8 +2834,8 @@ static int push_node_left(struct btrfs_trans_handle *trans, if (push_items < src_nritems) { /* - * Don't call btrfs_tree_mod_log_insert_move() here, key removal - * was already fully logged by btrfs_tree_mod_log_eb_copy() above. + * btrfs_tree_mod_log_eb_copy handles logging the move, so we + * don't need to do an explicit tree mod log operation for it. */ memmove_extent_buffer(src, btrfs_node_key_ptr_offset(src, 0), btrfs_node_key_ptr_offset(src, push_items), @@ -2765,8 +2896,11 @@ static int balance_node_right(struct btrfs_trans_handle *trans, btrfs_abort_transaction(trans, ret); return ret; } - ret = btrfs_tree_mod_log_insert_move(dst, push_items, 0, dst_nritems); - BUG_ON(ret < 0); + + /* + * btrfs_tree_mod_log_eb_copy handles logging the move, so we don't + * need to do an explicit tree mod log operation for it. + */ memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(dst, push_items), btrfs_node_key_ptr_offset(dst, 0), (dst_nritems) * @@ -2840,7 +2974,12 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, old = root->node; ret = btrfs_tree_mod_log_insert_root(root->node, c, false); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_free_tree_block(trans, btrfs_root_id(root), c, 0, 1); + btrfs_tree_unlock(c); + free_extent_buffer(c); + return ret; + } rcu_assign_pointer(root->node, c); /* the super has an extra ref to root->node */ @@ -2861,10 +3000,10 @@ static noinline int insert_new_root(struct btrfs_trans_handle *trans, * slot and level indicate where you want the key to go, and * blocknr is the block the key points to. */ -static void insert_ptr(struct btrfs_trans_handle *trans, - struct btrfs_path *path, - struct btrfs_disk_key *key, u64 bytenr, - int slot, int level) +static int insert_ptr(struct btrfs_trans_handle *trans, + struct btrfs_path *path, + struct btrfs_disk_key *key, u64 bytenr, + int slot, int level) { struct extent_buffer *lower; int nritems; @@ -2880,7 +3019,10 @@ static void insert_ptr(struct btrfs_trans_handle *trans, if (level) { ret = btrfs_tree_mod_log_insert_move(lower, slot + 1, slot, nritems - slot); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + return ret; + } } memmove_extent_buffer(lower, btrfs_node_key_ptr_offset(lower, slot + 1), @@ -2890,7 +3032,10 @@ static void insert_ptr(struct btrfs_trans_handle *trans, if (level) { ret = btrfs_tree_mod_log_insert_key(lower, slot, BTRFS_MOD_LOG_KEY_ADD); - BUG_ON(ret < 0); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + return ret; + } } btrfs_set_node_key(lower, key, slot); btrfs_set_node_blockptr(lower, slot, bytenr); @@ -2898,6 +3043,8 @@ static void insert_ptr(struct btrfs_trans_handle *trans, btrfs_set_node_ptr_generation(lower, slot, trans->transid); btrfs_set_header_nritems(lower, nritems + 1); btrfs_mark_buffer_dirty(lower); + + return 0; } /* @@ -2962,6 +3109,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans, ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid); if (ret) { + btrfs_tree_unlock(split); + free_extent_buffer(split); btrfs_abort_transaction(trans, ret); return ret; } @@ -2975,8 +3124,13 @@ static noinline int split_node(struct btrfs_trans_handle *trans, btrfs_mark_buffer_dirty(c); btrfs_mark_buffer_dirty(split); - insert_ptr(trans, path, &disk_key, split->start, - path->slots[level + 1] + 1, level + 1); + ret = insert_ptr(trans, path, &disk_key, split->start, + path->slots[level + 1] + 1, level + 1); + if (ret < 0) { + btrfs_tree_unlock(split); + free_extent_buffer(split); + return ret; + } if (path->slots[level] >= mid) { path->slots[level] -= mid; @@ -2996,7 +3150,7 @@ static noinline int split_node(struct btrfs_trans_handle *trans, * and nr indicate which items in the leaf to check. This totals up the * space used both by the item structs and the item data */ -static int leaf_space_used(struct extent_buffer *l, int start, int nr) +static int leaf_space_used(const struct extent_buffer *l, int start, int nr) { int data_len; int nritems = btrfs_header_nritems(l); @@ -3016,7 +3170,7 @@ static int leaf_space_used(struct extent_buffer *l, int start, int nr) * the start of the leaf data. IOW, how much room * the leaf has left for both items and data */ -noinline int btrfs_leaf_free_space(struct extent_buffer *leaf) +int btrfs_leaf_free_space(const struct extent_buffer *leaf) { struct btrfs_fs_info *fs_info = leaf->fs_info; int nritems = btrfs_header_nritems(leaf); @@ -3453,16 +3607,17 @@ out: * split the path's leaf in two, making sure there is at least data_size * available for the resulting leaf level of the path. */ -static noinline void copy_for_split(struct btrfs_trans_handle *trans, - struct btrfs_path *path, - struct extent_buffer *l, - struct extent_buffer *right, - int slot, int mid, int nritems) +static noinline int copy_for_split(struct btrfs_trans_handle *trans, + struct btrfs_path *path, + struct extent_buffer *l, + struct extent_buffer *right, + int slot, int mid, int nritems) { struct btrfs_fs_info *fs_info = trans->fs_info; int data_copy_size; int rt_data_off; int i; + int ret; struct btrfs_disk_key disk_key; struct btrfs_map_token token; @@ -3487,7 +3642,9 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, btrfs_set_header_nritems(l, mid); btrfs_item_key(right, &disk_key, 0); - insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); + ret = insert_ptr(trans, path, &disk_key, right->start, path->slots[1] + 1, 1); + if (ret < 0) + return ret; btrfs_mark_buffer_dirty(right); btrfs_mark_buffer_dirty(l); @@ -3505,6 +3662,8 @@ static noinline void copy_for_split(struct btrfs_trans_handle *trans, } BUG_ON(path->slots[0] < 0); + + return 0; } /* @@ -3703,8 +3862,13 @@ again: if (split == 0) { if (mid <= slot) { btrfs_set_header_nritems(right, 0); - insert_ptr(trans, path, &disk_key, - right->start, path->slots[1] + 1, 1); + ret = insert_ptr(trans, path, &disk_key, + right->start, path->slots[1] + 1, 1); + if (ret < 0) { + btrfs_tree_unlock(right); + free_extent_buffer(right); + return ret; + } btrfs_tree_unlock(path->nodes[0]); free_extent_buffer(path->nodes[0]); path->nodes[0] = right; @@ -3712,8 +3876,13 @@ again: path->slots[1] += 1; } else { btrfs_set_header_nritems(right, 0); - insert_ptr(trans, path, &disk_key, - right->start, path->slots[1], 1); + ret = insert_ptr(trans, path, &disk_key, + right->start, path->slots[1], 1); + if (ret < 0) { + btrfs_tree_unlock(right); + free_extent_buffer(right); + return ret; + } btrfs_tree_unlock(path->nodes[0]); free_extent_buffer(path->nodes[0]); path->nodes[0] = right; @@ -3729,7 +3898,12 @@ again: return ret; } - copy_for_split(trans, path, l, right, slot, mid, nritems); + ret = copy_for_split(trans, path, l, right, slot, mid, nritems); + if (ret < 0) { + btrfs_tree_unlock(right); + free_extent_buffer(right); + return ret; + } if (split == 2) { BUG_ON(num_doubles != 0); @@ -3826,7 +4000,12 @@ static noinline int split_item(struct btrfs_path *path, struct btrfs_disk_key disk_key; leaf = path->nodes[0]; - BUG_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item)); + /* + * Shouldn't happen because the caller must have previously called + * setup_leaf_for_split() to make room for the new item in the leaf. + */ + if (WARN_ON(btrfs_leaf_free_space(leaf) < sizeof(struct btrfs_item))) + return -ENOSPC; orig_slot = path->slots[0]; orig_offset = btrfs_item_offset(leaf, path->slots[0]); @@ -4273,9 +4452,11 @@ int btrfs_duplicate_item(struct btrfs_trans_handle *trans, * * the tree should have been previously balanced so the deletion does not * empty a node. + * + * This is exported for use inside btrfs-progs, don't un-export it. */ -static void 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; @@ -4286,7 +4467,10 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, 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), @@ -4296,7 +4480,10 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, } 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--; @@ -4312,6 +4499,7 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, fixup_low_keys(path, &disk_key, level + 1); } btrfs_mark_buffer_dirty(parent); + return 0; } /* @@ -4324,13 +4512,17 @@ static void del_ptr(struct btrfs_root *root, struct btrfs_path *path, * 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); - 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 @@ -4343,6 +4535,7 @@ 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 @@ -4392,7 +4585,9 @@ 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); @@ -4416,7 +4611,7 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, /* push_leaf_left fixes the path. * make sure the path still points to our leaf - * for possible call to del_ptr below + * for possible call to btrfs_del_ptr below */ slot = path->slots[1]; atomic_inc(&leaf->refs); @@ -4453,7 +4648,9 @@ 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 { @@ -4474,86 +4671,6 @@ int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, } /* - * search the tree again to find a leaf with lesser keys - * returns 0 if it found something or 1 if there are no lesser leaves. - * returns < 0 on io errors. - * - * This may release the path, and so you may lose any locks held at the - * time you call it. - */ -int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) -{ - struct btrfs_key key; - struct btrfs_key orig_key; - struct btrfs_disk_key found_key; - int ret; - - btrfs_item_key_to_cpu(path->nodes[0], &key, 0); - orig_key = key; - - if (key.offset > 0) { - key.offset--; - } else if (key.type > 0) { - key.type--; - key.offset = (u64)-1; - } else if (key.objectid > 0) { - key.objectid--; - key.type = (u8)-1; - key.offset = (u64)-1; - } else { - return 1; - } - - btrfs_release_path(path); - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret <= 0) - return ret; - - /* - * Previous key not found. Even if we were at slot 0 of the leaf we had - * before releasing the path and calling btrfs_search_slot(), we now may - * be in a slot pointing to the same original key - this can happen if - * after we released the path, one of more items were moved from a - * sibling leaf into the front of the leaf we had due to an insertion - * (see push_leaf_right()). - * If we hit this case and our slot is > 0 and just decrement the slot - * so that the caller does not process the same key again, which may or - * may not break the caller, depending on its logic. - */ - if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) { - btrfs_item_key(path->nodes[0], &found_key, path->slots[0]); - ret = comp_keys(&found_key, &orig_key); - if (ret == 0) { - if (path->slots[0] > 0) { - path->slots[0]--; - return 0; - } - /* - * At slot 0, same key as before, it means orig_key is - * the lowest, leftmost, key in the tree. We're done. - */ - return 1; - } - } - - btrfs_item_key(path->nodes[0], &found_key, 0); - ret = comp_keys(&found_key, &key); - /* - * We might have had an item with the previous key in the tree right - * before we released our path. And after we released our path, that - * item might have been pushed to the first slot (0) of the leaf we - * were holding due to a tree balance. Alternatively, an item with the - * previous key can exist as the only element of a leaf (big fat item). - * Therefore account for these 2 cases, so that our callers (like - * btrfs_previous_item) don't miss an existing item with a key matching - * the previous key we computed above. - */ - if (ret <= 0) - return 0; - return 1; -} - -/* * A helper function to walk down the tree starting at min_key, and looking * for nodes or leaves that are have a minimum transaction id. * This is used by the btree defrag code, and tree logging |