Merge tag 'ext4_for_linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

Pull ext4 updates from Ted Ts'o:
 "Many cleanups and bug fixes in ext4, especially for the fast commit
  feature.

  Also some performance improvements; in particular, improving IOPS and
  throughput on fast devices running Async Direct I/O by up to 20% by
  optimizing jbd2_transaction_committed()"

* tag 'ext4_for_linus-6.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (40 commits)
  ext4: make sure the first directory block is not a hole
  ext4: check dot and dotdot of dx_root before making dir indexed
  ext4: sanity check for NULL pointer after ext4_force_shutdown
  jbd2: increase maximum transaction size
  jbd2: drop pointless shrinker batch initialization
  jbd2: avoid infinite transaction commit loop
  jbd2: precompute number of transaction descriptor blocks
  jbd2: make jbd2_journal_get_max_txn_bufs() internal
  jbd2: avoid mount failed when commit block is partial submitted
  ext4: avoid writing unitialized memory to disk in EA inodes
  ext4: don't track ranges in fast_commit if inode has inlined data
  ext4: fix possible tid_t sequence overflows
  ext4: use ext4_update_inode_fsync_trans() helper in inode creation
  ext4: add missing MODULE_DESCRIPTION()
  jbd2: add missing MODULE_DESCRIPTION()
  ext4: use memtostr_pad() for s_volume_name
  jbd2: speed up jbd2_transaction_committed()
  ext4: make ext4_da_map_blocks() buffer_head unaware
  ext4: make ext4_insert_delayed_block() insert multi-blocks
  ext4: factor out a helper to check the cluster allocation state
  ...

fs/buffer.c

@@ -2184,6 +2184,8 @@ static void __block_commit_write(struct folio *folio, size_t from, size_t to)
 	struct buffer_head *bh, *head;
 
 	bh = head = folio_buffers(folio);
+	if (!bh)
+		return;
 	blocksize = bh->b_size;
 
 	block_start = 0;