Commit 655f3aad authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: switch dm_target_io booleans over to proper flags 



Add flags to dm_target_io and manage them using the same pattern used
for bi_flags in struct bio.

Signed-off-by: default avatarMike Snitzer <snitzer@kernel.org>
parent 82f6cdcc

drivers/md/dm-core.h

+19 −2
Original line number Diff line number Diff line
@@ -215,12 +215,29 @@ struct dm_target_io { 
	struct dm_io *io;

	struct dm_target *ti;

	unsigned int *len_ptr;

	bool inside_dm_io:1;

	bool is_duplicate_bio:1;

	unsigned short flags;

	sector_t old_sector;

	struct bio clone;

};



/*

 * dm_target_io flags

 */

enum {

	DM_TIO_INSIDE_DM_IO,

	DM_TIO_IS_DUPLICATE_BIO

};



static inline bool dm_tio_flagged(struct dm_target_io *tio, unsigned int bit)

{

	return (tio->flags & (1U << bit)) != 0;

}



static inline void dm_tio_set_flag(struct dm_target_io *tio, unsigned int bit)

{

	tio->flags |= (1U << bit);

}



/*

 * One of these is allocated per original bio.

 * It contains the first clone used for that original.

drivers/md/dm.c

+19 −12
Original line number Diff line number Diff line
@@ -94,7 +94,7 @@ static inline struct dm_target_io *clone_to_tio(struct bio *clone) 


void *dm_per_bio_data(struct bio *bio, size_t data_size)

{

	if (!clone_to_tio(bio)->inside_dm_io)

	if (!dm_tio_flagged(clone_to_tio(bio), DM_TIO_INSIDE_DM_IO))

		return (char *)bio - DM_TARGET_IO_BIO_OFFSET - data_size;

	return (char *)bio - DM_IO_BIO_OFFSET - data_size;

}
@@ -538,9 +538,10 @@ 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 is_duplicate_bio.

	 * Expect no possibility for race unless DM_TIO_IS_DUPLICATE_BIO.

	 */

	if (!clone || likely(!clone_to_tio(clone)->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)))

			return;

		dm_io_set_flag(io, DM_IO_ACCOUNTED);
@@ -548,7 +549,7 @@ static void dm_start_io_acct(struct dm_io *io, struct bio *clone) 
		unsigned long flags;

		if (dm_io_flagged(io, DM_IO_ACCOUNTED))

			return;

		/* Can afford locking given is_duplicate_bio */

		/* Can afford locking given DM_TIO_IS_DUPLICATE_BIO */

		spin_lock_irqsave(&io->startio_lock, flags);

		dm_io_set_flag(io, DM_IO_ACCOUNTED);

		spin_unlock_irqrestore(&io->startio_lock, flags);
@@ -571,7 +572,8 @@ static struct dm_io *alloc_io(struct mapped_device *md, struct bio *bio) 
	clone = bio_alloc_clone(bio->bi_bdev, bio, GFP_NOIO, &md->io_bs);



	tio = clone_to_tio(clone);

	tio->inside_dm_io = true;

	tio->flags = 0;

	dm_tio_set_flag(tio, DM_TIO_INSIDE_DM_IO);

	tio->io = NULL;



	io = container_of(tio, struct dm_io, tio);
@@ -618,14 +620,13 @@ static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti, 
		clone->bi_opf &= ~REQ_DM_POLL_LIST;



		tio = clone_to_tio(clone);

		tio->inside_dm_io = false;

		tio->flags = 0; /* also clears DM_TIO_INSIDE_DM_IO */

	}



	tio->magic = DM_TIO_MAGIC;

	tio->io = ci->io;

	tio->ti = ti;

	tio->target_bio_nr = target_bio_nr;

	tio->is_duplicate_bio = false;

	tio->len_ptr = len;

	tio->old_sector = 0;
@@ -640,7 +641,7 @@ static struct bio *alloc_tio(struct clone_info *ci, struct dm_target *ti, 


static void free_tio(struct bio *clone)

{

	if (clone_to_tio(clone)->inside_dm_io)

	if (dm_tio_flagged(clone_to_tio(clone), DM_TIO_INSIDE_DM_IO))

		return;

	bio_put(clone);

}
@@ -917,6 +918,12 @@ 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.
@@ -1180,7 +1187,7 @@ void dm_accept_partial_bio(struct bio *bio, unsigned n_sectors) 
	struct dm_target_io *tio = clone_to_tio(bio);

	unsigned bi_size = bio->bi_iter.bi_size >> SECTOR_SHIFT;



	BUG_ON(tio->is_duplicate_bio);

	BUG_ON(dm_tio_flagged(tio, DM_TIO_IS_DUPLICATE_BIO));

	BUG_ON(op_is_zone_mgmt(bio_op(bio)));

	BUG_ON(bio_op(bio) == REQ_OP_ZONE_APPEND);

	BUG_ON(bi_size > *tio->len_ptr);
@@ -1362,13 +1369,13 @@ static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, 
		break;

	case 1:

		clone = alloc_tio(ci, ti, 0, len, GFP_NOIO);

		clone_to_tio(clone)->is_duplicate_bio = true;

		dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);

		__map_bio(clone);

		break;

	default:

		alloc_multiple_bios(&blist, ci, ti, num_bios, len);

		while ((clone = bio_list_pop(&blist))) {

			clone_to_tio(clone)->is_duplicate_bio = true;

			dm_tio_set_flag(clone_to_tio(clone), DM_TIO_IS_DUPLICATE_BIO);

			__map_bio(clone);

		}

		break;
@@ -1648,7 +1655,7 @@ static void dm_submit_bio(struct bio *bio) 
static bool dm_poll_dm_io(struct dm_io *io, struct io_comp_batch *iob,

			  unsigned int flags)

{

	WARN_ON_ONCE(!io->tio.inside_dm_io);

	WARN_ON_ONCE(!dm_tio_is_normal(&io->tio));



	/* don't poll if the mapped io is done */

	if (atomic_read(&io->io_count) > 1)