btrfs: improve error message after failure to add delayed dir index item

[ Upstream commit 91bfe3104b8db0310f76f2dcb6aacef24c889366 ]

If we fail to add a delayed dir index item because there's already another
item with the same index number, we print an error message (and then BUG).
However that message isn't very helpful to debug anything because we don't
know what's the index number and what are the values of index counters in
the inode and its delayed inode (index_cnt fields of struct btrfs_inode
and struct btrfs_delayed_node).

So update the error message to include the index number and counters.

We actually had a recent case where this issue was hit by a syzbot report
(see the link below).

Link: https://lore.kernel.org/linux-btrfs/00000000000036e1290603e097e0@google.com/
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 2c58c3931ede ("btrfs: remove BUG() after failure to insert delayed dir index item")
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/btrfs/delayed-inode.c b/fs/btrfs/delayed-inode.c
index d2cbb7733c7d6e6183a974ca31552e907ade7835..34e843460e4dbd6f03f345a5ad8199253ea01aef 100644 (file)
--- a/fs/btrfs/delayed-inode.c
+++ b/fs/btrfs/delayed-inode.c
@@ -1506,9 +1506,10 @@ int btrfs_insert_delayed_dir_index(struct btrfs_trans_handle *trans,
        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);
+"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);
                BUG();
        }
        mutex_unlock(&delayed_node->mutex);