Commit 4db7cdc8 authored by Sandeep K Sinha's avatar Sandeep K Sinha Committed by NeilBrown
Browse files

md: Removing num_sector and replacing start_sector with end_sector 



Remove num_sectors from dev_info and replace start_sector with
end_sector.  This makes a lot of comparisons much simpler.

Signed-off-by: default avatarSandeep K Sinha <sandeepksinha@gmail.com>
Signed-off-by: default avatarNeilBrown <neilb@suse.de>
parent 45d4582f

drivers/md/linear.c

+18 −19
Original line number Diff line number Diff line
@@ -32,7 +32,7 @@ static inline dev_info_t *which_dev(mddev_t *mddev, sector_t sector) 


	hash = conf->disks;



	while (sector >= hash->num_sectors + hash->start_sector)

	while (sector >= hash->end_sector)

		hash++;

	return hash;

}
@@ -55,7 +55,7 @@ static int linear_mergeable_bvec(struct request_queue *q, 
	sector_t sector = bvm->bi_sector + get_start_sect(bvm->bi_bdev);



	dev0 = which_dev(mddev, sector);

	maxsectors = dev0->num_sectors - (sector - dev0->start_sector);

	maxsectors = dev0->end_sector - sector;



	if (maxsectors < bio_sectors)

		maxsectors = 0;
@@ -141,10 +141,9 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks) 
		    queue_max_sectors(mddev->queue) > (PAGE_SIZE>>9))

			blk_queue_max_sectors(mddev->queue, PAGE_SIZE>>9);



		disk->num_sectors = rdev->sectors;

		conf->array_sectors += rdev->sectors;



		cnt++;



	}

	if (cnt != raid_disks) {

		printk("linear: not enough drives present. Aborting!\n");
@@ -154,11 +153,12 @@ static linear_conf_t *linear_conf(mddev_t *mddev, int raid_disks) 
	/*

	 * Here we calculate the device offsets.

	 */

	conf->disks[0].start_sector = 0;

	conf->disks[0].end_sector = conf->disks[0].rdev->sectors;



	for (i = 1; i < raid_disks; i++)

		conf->disks[i].start_sector =

			conf->disks[i-1].start_sector +

			conf->disks[i-1].num_sectors;

		conf->disks[i].end_sector =

			conf->disks[i-1].end_sector +

			conf->disks[i].rdev->sectors;



	return conf;
@@ -235,6 +235,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio) 
	const int rw = bio_data_dir(bio);

	mddev_t *mddev = q->queuedata;

	dev_info_t *tmp_dev;

	sector_t start_sector;

	int cpu;



	if (unlikely(bio_barrier(bio))) {
@@ -249,32 +250,30 @@ static int linear_make_request (struct request_queue *q, struct bio *bio) 
	part_stat_unlock();



	tmp_dev = which_dev(mddev, bio->bi_sector);

	start_sector = tmp_dev->end_sector - tmp_dev->rdev->sectors;



	if (unlikely(bio->bi_sector >= (tmp_dev->num_sectors +

					tmp_dev->start_sector)

		     || (bio->bi_sector <

			 tmp_dev->start_sector))) {

	if (unlikely(bio->bi_sector >= (tmp_dev->end_sector)

		     || (bio->bi_sector < start_sector))) {

		char b[BDEVNAME_SIZE];



		printk("linear_make_request: Sector %llu out of bounds on "

			"dev %s: %llu sectors, offset %llu\n",

			(unsigned long long)bio->bi_sector,

			bdevname(tmp_dev->rdev->bdev, b),

			(unsigned long long)tmp_dev->num_sectors,

			(unsigned long long)tmp_dev->start_sector);

			(unsigned long long)tmp_dev->rdev->sectors,

			(unsigned long long)start_sector);

		bio_io_error(bio);

		return 0;

	}

	if (unlikely(bio->bi_sector + (bio->bi_size >> 9) >

		     tmp_dev->start_sector + tmp_dev->num_sectors)) {

		     tmp_dev->end_sector)) {

		/* This bio crosses a device boundary, so we have to

		 * split it.

		 */

		struct bio_pair *bp;



		bp = bio_split(bio,

			       tmp_dev->start_sector + tmp_dev->num_sectors

			       - bio->bi_sector);

			       tmp_dev->end_sector - bio->bi_sector);



		if (linear_make_request(q, &bp->bio1))

			generic_make_request(&bp->bio1);
@@ -285,7 +284,7 @@ static int linear_make_request (struct request_queue *q, struct bio *bio) 
	}

		    

	bio->bi_bdev = tmp_dev->rdev->bdev;

	bio->bi_sector = bio->bi_sector - tmp_dev->start_sector

	bio->bi_sector = bio->bi_sector - start_sector

		+ tmp_dev->rdev->data_offset;



	return 1;

drivers/md/linear.h

+1 −2
Original line number Diff line number Diff line
@@ -3,8 +3,7 @@ 


struct dev_info {

	mdk_rdev_t	*rdev;

	sector_t	num_sectors;

	sector_t	start_sector;

	sector_t	end_sector;

};



typedef struct dev_info dev_info_t;