[PATCH 0/2] block, md: Better handle REQ_OP_FLUSH

[Song Liu <song@kernel.org>]

A recent bug report [1] shows md is handling a flush from bcachefs as read:

bch2_journal_write=>
  submit_bio=>
    ...
    md_handle_request =>
      raid5_make_request =>
        chunk_aligned_read =>
          raid5_read_one_chunk =>
	    ...

It appears md code only checks REQ_PREFLUSH for flush requests, which
doesn't cover all cases. OTOH, op_is_flush() doesn't check REQ_OP_FLUSH
either.

Fix this by:
1) Check REQ_PREFLUSH in op_is_flush();
2) Use op_is_flush() in md code.

Thanks,
Song

[1] https://bugzilla.kernel.org/show_bug.cgi?id=218184

Song Liu (2):
  block: Check REQ_OP_FLUSH in op_is_flush()
  md: Use op_is_flush() to check flush bio

 drivers/md/raid0.c        | 2 +-
 drivers/md/raid1.c        | 2 +-
 drivers/md/raid10.c       | 2 +-
 drivers/md/raid5.c        | 2 +-
 include/linux/blk_types.h | 3 ++-
 5 files changed, 6 insertions(+), 5 deletions(-)

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2.34.1