static void __btrfs_remove_delayed_item(struct btrfs_delayed_item *delayed_item)
{
+ struct btrfs_delayed_node *delayed_node = delayed_item->delayed_node;
struct rb_root_cached *root;
struct btrfs_delayed_root *delayed_root;
if (RB_EMPTY_NODE(&delayed_item->rb_node))
return;
- delayed_root = delayed_item->delayed_node->root->fs_info->delayed_root;
+ /* If it's in a rbtree, then we need to have delayed node locked. */
+ lockdep_assert_held(&delayed_node->mutex);
+
+ delayed_root = delayed_node->root->fs_info->delayed_root;
BUG_ON(!delayed_root);
if (delayed_item->type == BTRFS_DELAYED_INSERTION_ITEM)
- root = &delayed_item->delayed_node->ins_root;
+ root = &delayed_node->ins_root;
else
- root = &delayed_item->delayed_node->del_root;
+ root = &delayed_node->del_root;
rb_erase_cached(&delayed_item->rb_node, root);
RB_CLEAR_NODE(&delayed_item->rb_node);
- delayed_item->delayed_node->count--;
+ delayed_node->count--;
finish_one_item(delayed_root);
}
ret = __btrfs_commit_inode_delayed_items(trans, path,
curr_node);
if (ret) {
- btrfs_release_delayed_node(curr_node);
- curr_node = NULL;
btrfs_abort_transaction(trans, ret);
break;
}
prev_node = curr_node;
curr_node = btrfs_next_delayed_node(curr_node);
+ /*
+ * See the comment below about releasing path before releasing
+ * node. If the commit of delayed items was successful the path
+ * should always be released, but in case of an error, it may
+ * point to locked extent buffers (a leaf at the very least).
+ */
+ ASSERT(path->nodes[0] == NULL);
btrfs_release_delayed_node(prev_node);
}
+ /*
+ * Release the path to avoid a potential deadlock and lockdep splat when
+ * releasing the delayed node, as that requires taking the delayed node's
+ * mutex. If another task starts running delayed items before we take
+ * the mutex, it will first lock the mutex and then it may try to lock
+ * the same btree path (leaf).
+ */
+ btrfs_free_path(path);
+
if (curr_node)
btrfs_release_delayed_node(curr_node);
- btrfs_free_path(path);
trans->block_rsv = block_rsv;
return ret;
btrfs_wq_run_delayed_node(delayed_root, fs_info, BTRFS_DELAYED_BATCH);
}
-/* Will return 0 or -ENOMEM */
+static void btrfs_release_dir_index_item_space(struct btrfs_trans_handle *trans)
+{
+ struct btrfs_fs_info *fs_info = trans->fs_info;
+ const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
+
+ if (test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags))
+ return;
+
+ /*
+ * Adding the new dir index item does not require touching another
+ * leaf, so we can release 1 unit of metadata that was previously
+ * reserved when starting the transaction. This applies only to
+ * the case where we had a transaction start and excludes the
+ * transaction join case (when replaying log trees).
+ */
+ trace_btrfs_space_reservation(fs_info, "transaction",
+ trans->transid, bytes, 0);
+ btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
+ ASSERT(trans->bytes_reserved >= bytes);
+ trans->bytes_reserved -= bytes;
+}
+
+/* Will return 0, -ENOMEM or -EEXIST (index number collision, unexpected). */
int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
const char *name, int name_len,
struct btrfs_inode *dir,
mutex_lock(&delayed_node->mutex);
+ /*
+ * First attempt to insert the delayed item. This is to make the error
+ * handling path simpler in case we fail (-EEXIST). There's no risk of
+ * any other task coming in and running the delayed item before we do
+ * the metadata space reservation below, because we are holding the
+ * delayed node's mutex and that mutex must also be locked before the
+ * node's delayed items can be run.
+ */
+ ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
+ if (unlikely(ret)) {
+ btrfs_err(trans->fs_info,
+"error adding delayed dir index item, name: %.*s, index: %llu, root: %llu, dir: %llu, dir->index_cnt: %llu, delayed_node->index_cnt: %llu, error: %d",
+ name_len, name, index, btrfs_root_id(delayed_node->root),
+ delayed_node->inode_id, dir->index_cnt,
+ delayed_node->index_cnt, ret);
+ btrfs_release_delayed_item(delayed_item);
+ btrfs_release_dir_index_item_space(trans);
+ mutex_unlock(&delayed_node->mutex);
+ goto release_node;
+ }
+
if (delayed_node->index_item_leaves == 0 ||
delayed_node->curr_index_batch_size + data_len > leaf_data_size) {
delayed_node->curr_index_batch_size = data_len;
* impossible.
*/
if (WARN_ON(ret)) {
- mutex_unlock(&delayed_node->mutex);
btrfs_release_delayed_item(delayed_item);
+ mutex_unlock(&delayed_node->mutex);
goto release_node;
}
delayed_node->index_item_leaves++;
- } else if (!test_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags)) {
- const u64 bytes = btrfs_calc_insert_metadata_size(fs_info, 1);
-
- /*
- * Adding the new dir index item does not require touching another
- * leaf, so we can release 1 unit of metadata that was previously
- * reserved when starting the transaction. This applies only to
- * the case where we had a transaction start and excludes the
- * transaction join case (when replaying log trees).
- */
- trace_btrfs_space_reservation(fs_info, "transaction",
- trans->transid, bytes, 0);
- btrfs_block_rsv_release(fs_info, trans->block_rsv, bytes, NULL);
- ASSERT(trans->bytes_reserved >= bytes);
- trans->bytes_reserved -= bytes;
- }
-
- ret = __btrfs_add_delayed_item(delayed_node, delayed_item);
- if (unlikely(ret)) {
- btrfs_err(trans->fs_info,
- "err add delayed dir index item(name: %.*s) into the insertion tree of the delayed node(root id: %llu, inode id: %llu, errno: %d)",
- name_len, name, delayed_node->root->root_key.objectid,
- delayed_node->inode_id, ret);
- BUG();
+ } else {
+ btrfs_release_dir_index_item_space(trans);
}
mutex_unlock(&delayed_node->mutex);
git.samba.org / sfrench / cifs-2.6.git / blobdiff