Commit 3b03f7c1 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: simplify dm_start_io_acct 



Pull common DM_IO_ACCOUNTED check out to beginning of dm_start_io_acct.
Also, use dm_tio_is_normal (and move it to dm-core.h).

Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 4857abf6

drivers/md/dm-core.h

+6 −0
Original line number Diff line number Diff line
@@ -237,6 +237,12 @@ static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit) 
	tio->flags |= (1U << bit);

}



static inline bool dm_tio_is_normal(struct dm_target_io *tio)

{

	return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&

		!dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));

}



/*

 * One of these is allocated per original bio.

 * It contains the first clone used for that original.

drivers/md/dm.c

+5 −13
Original line number Diff line number Diff line
@@ -538,17 +538,15 @@ static void dm_start_io_acct(struct dm_io *io, struct bio *clone) 


	/*

	 * Ensure IO accounting is only ever started once.

	 * Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO.

	 */

	if (!clone ||

	    likely(!dm_tio_flagged(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO))) {

		if (WARN_ON_ONCE(dm_io_flagged(io, DM_IO_ACCOUNTED)))

	if (dm_io_flagged(io, DM_IO_ACCOUNTED))

		return;



	/* Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO. */

	if (!clone || likely(dm_tio_is_normal(clone_to_tio(clone)))) {

		dm_io_set_flag(io, DM_IO_ACCOUNTED);

	} else {

		unsigned long flags;

		if (dm_io_flagged(io, DM_IO_ACCOUNTED))

			return;

		/* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */

		spin_lock_irqsave(&io->lock, flags);

		dm_io_set_flag(io, DM_IO_ACCOUNTED);
@@ -923,12 +921,6 @@ static void dm_io_complete(struct dm_io *io) 
	}

}



static inline bool dm_tio_is_normal(struct dm_target_io *tio)

{

	return (dm_tio_flagged(tio, DM_TIO_INSIDE_DM_IO) &&

		!dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));

}



/*

 * Decrements the number of outstanding ios that a bio has been

 * cloned into, completing the original io if necc.