Commit c7149d6b authored by Alan D. Brunelle's avatar Alan D. Brunelle Committed by Jens Axboe
Browse files

Fix remap handling by blktrace 



This patch provides more information concerning REMAP operations on block
IOs. The additional information provides clearer details at the user level,
and supports post-processing analysis in btt.

o  Adds in partition remaps on the same device.
o  Fixed up the remap information in DM to be in the right order
o  Sent up mapped-from and mapped-to device information

Signed-off-by: default avatarAlan D. Brunelle <alan.brunelle@hp.com>
Signed-off-by: default avatarJens Axboe <jens.axboe@oracle.com>
parent ec05b297

block/ll_rw_blk.c

+4 −0
Original line number Diff line number Diff line
@@ -3047,6 +3047,10 @@ static inline void blk_partition_remap(struct bio *bio) 


		bio->bi_sector += p->start_sect;

		bio->bi_bdev = bdev->bd_contains;



		blk_add_trace_remap(bdev_get_queue(bio->bi_bdev), bio,

				    bdev->bd_dev, bio->bi_sector,

				    bio->bi_sector - p->start_sect);

	}

}

drivers/md/dm.c

+2 −2
Original line number Diff line number Diff line
@@ -580,8 +580,8 @@ static void __map_bio(struct dm_target *ti, struct bio *clone, 
		/* the bio has been remapped so dispatch it */



		blk_add_trace_remap(bdev_get_queue(clone->bi_bdev), clone,

				    tio->io->bio->bi_bdev->bd_dev, sector,

				    clone->bi_sector);

				    tio->io->bio->bi_bdev->bd_dev,

				    clone->bi_sector, sector);



		generic_make_request(clone);

	} else if (r < 0 || r == DM_MAPIO_REQUEUE) {

include/linux/blktrace_api.h

+2 −1
Original line number Diff line number Diff line
@@ -105,7 +105,7 @@ struct blk_io_trace { 
 */

struct blk_io_trace_remap {

	__be32 device;

	u32 __pad;

	__be32 device_from;

	__be64 sector;

};
@@ -272,6 +272,7 @@ static inline void blk_add_trace_remap(struct request_queue *q, struct bio *bio, 
		return;



	r.device = cpu_to_be32(dev);

	r.device_from = cpu_to_be32(bio->bi_bdev->bd_dev);

	r.sector = cpu_to_be64(to);



	__blk_add_trace(bt, from, bio->bi_size, bio->bi_rw, BLK_TA_REMAP, !bio_flagged(bio, BIO_UPTODATE), sizeof(r), &r);

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