Commit f1c29379 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by David Sterba
Browse files

btrfs: properly abstract the parity raid bio handling 



The parity raid write/recover functionality is currently not very well
abstracted from the bio submission and completion handling in volumes.c:

 - the raid56 code directly completes the original btrfs_bio fed into
   btrfs_submit_bio instead of dispatching back to volumes.c
 - the raid56 code consumes the bioc and bio_counter references taken
   by volumes.c, which also leads to special casing of the calls from
   the scrub code into the raid56 code

To fix this up supply a bi_end_io handler that calls back into the
volumes.c machinery, which then puts the bioc, decrements the bio_counter
and completes the original bio, and updates the scrub code to also
take ownership of the bioc and bio_counter in all cases.

Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
Reviewed-by: default avatarAnand Jain <anand.jain@oracle.com>
Tested-by: default avatarNikolay Borisov <nborisov@suse.com>
Tested-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent c3a62baf

fs/btrfs/raid56.c

+7 −38
Original line number Diff line number Diff line
@@ -275,7 +275,6 @@ static void merge_rbio(struct btrfs_raid_bio *dest, 
	/* Also inherit the bitmaps from @victim. */

	bitmap_or(&dest->dbitmap, &victim->dbitmap, &dest->dbitmap,

		  dest->stripe_nsectors);

	dest->generic_bio_cnt += victim->generic_bio_cnt;

	bio_list_init(&victim->bio_list);

}
@@ -814,8 +813,6 @@ static void rbio_orig_end_io(struct btrfs_raid_bio *rbio, blk_status_t err) 
	struct bio *cur = bio_list_get(&rbio->bio_list);

	struct bio *extra;



	if (rbio->generic_bio_cnt)

		btrfs_bio_counter_sub(rbio->bioc->fs_info, rbio->generic_bio_cnt);

	/*

	 * Clear the data bitmap, as the rbio may be cached for later usage.

	 * do this before before unlock_stripe() so there will be no new bio
@@ -946,6 +943,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info, 
	spin_lock_init(&rbio->bio_list_lock);

	INIT_LIST_HEAD(&rbio->stripe_cache);

	INIT_LIST_HEAD(&rbio->hash_list);

	btrfs_get_bioc(bioc);

	rbio->bioc = bioc;

	rbio->nr_pages = num_pages;

	rbio->nr_sectors = num_sectors;
@@ -1813,15 +1811,12 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) 


	rbio = alloc_rbio(fs_info, bioc);

	if (IS_ERR(rbio)) {

		btrfs_put_bioc(bioc);

		ret = PTR_ERR(rbio);

		goto out_dec_counter;

		goto fail;

	}

	rbio->operation = BTRFS_RBIO_WRITE;

	rbio_add_bio(rbio, bio);



	rbio->generic_bio_cnt = 1;



	/*

	 * don't plug on full rbios, just get them out the door

	 * as quickly as we can
@@ -1829,7 +1824,7 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) 
	if (rbio_is_full(rbio)) {

		ret = full_stripe_write(rbio);

		if (ret)

			goto out_dec_counter;

			goto fail;

		return;

	}
@@ -1844,13 +1839,12 @@ void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc) 
	} else {

		ret = __raid56_parity_write(rbio);

		if (ret)

			goto out_dec_counter;

			goto fail;

	}



	return;



out_dec_counter:

	btrfs_bio_counter_dec(fs_info);

fail:

	bio->bi_status = errno_to_blk_status(ret);

	bio_endio(bio);

}
@@ -2198,18 +2192,11 @@ static int __raid56_parity_recover(struct btrfs_raid_bio *rbio) 
 * of the drive.

 */

void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,

			   int mirror_num, bool generic_io)

			   int mirror_num)

{

	struct btrfs_fs_info *fs_info = bioc->fs_info;

	struct btrfs_raid_bio *rbio;



	if (generic_io) {

		ASSERT(bioc->mirror_num == mirror_num);

		btrfs_bio(bio)->mirror_num = mirror_num;

	} else {

		btrfs_get_bioc(bioc);

	}



	rbio = alloc_rbio(fs_info, bioc);

	if (IS_ERR(rbio)) {

		bio->bi_status = errno_to_blk_status(PTR_ERR(rbio));
@@ -2225,14 +2212,11 @@ void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, 
"%s could not find the bad stripe in raid56 so that we cannot recover any more (bio has logical %llu len %llu, bioc has map_type %llu)",

			   __func__, bio->bi_iter.bi_sector << 9,

			   (u64)bio->bi_iter.bi_size, bioc->map_type);

		kfree(rbio);

		__free_raid_bio(rbio);

		bio->bi_status = BLK_STS_IOERR;

		goto out_end_bio;

	}



	if (generic_io)

		rbio->generic_bio_cnt = 1;



	/*

	 * Loop retry:

	 * for 'mirror == 2', reconstruct from all other stripes.
@@ -2261,8 +2245,6 @@ void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc, 
	return;



out_end_bio:

	btrfs_bio_counter_dec(fs_info);

	btrfs_put_bioc(bioc);

	bio_endio(bio);

}
@@ -2326,13 +2308,6 @@ struct btrfs_raid_bio *raid56_parity_alloc_scrub_rbio(struct bio *bio, 
	ASSERT(i < rbio->real_stripes);



	bitmap_copy(&rbio->dbitmap, dbitmap, stripe_nsectors);



	/*

	 * We have already increased bio_counter when getting bioc, record it

	 * so we can free it at rbio_orig_end_io().

	 */

	rbio->generic_bio_cnt = 1;



	return rbio;

}
@@ -2772,12 +2747,6 @@ raid56_alloc_missing_rbio(struct bio *bio, struct btrfs_io_context *bioc) 
		return NULL;

	}



	/*

	 * When we get bioc, we have already increased bio_counter, record it

	 * so we can free it at rbio_orig_end_io()

	 */

	rbio->generic_bio_cnt = 1;



	return rbio;

}

fs/btrfs/raid56.h

+1 −3
Original line number Diff line number Diff line
@@ -89,8 +89,6 @@ struct btrfs_raid_bio { 
	 */

	int bio_list_bytes;



	int generic_bio_cnt;



	refcount_t refs;



	atomic_t stripes_pending;
@@ -166,7 +164,7 @@ static inline int nr_data_stripes(const struct map_lookup *map) 
struct btrfs_device;



void raid56_parity_recover(struct bio *bio, struct btrfs_io_context *bioc,

			   int mirror_num, bool generic_io);

			   int mirror_num);

void raid56_parity_write(struct bio *bio, struct btrfs_io_context *bioc);



void raid56_add_scrub_pages(struct btrfs_raid_bio *rbio, struct page *page,

fs/btrfs/scrub.c

+5 −3
Original line number Diff line number Diff line
@@ -1568,8 +1568,7 @@ static int scrub_submit_raid56_bio_wait(struct btrfs_fs_info *fs_info, 
				 SECTOR_SHIFT;

	bio->bi_private = &done;

	bio->bi_end_io = scrub_bio_wait_endio;

	raid56_parity_recover(bio, sector->recover->bioc,

			      sector->sblock->mirror_num, false);

	raid56_parity_recover(bio, sector->recover->bioc, sector->sblock->mirror_num);



	wait_for_completion_io(&done);

	return blk_status_to_errno(bio->bi_status);
@@ -2285,6 +2284,7 @@ static void scrub_missing_raid56_end_io(struct bio *bio) 
	struct scrub_block *sblock = bio->bi_private;

	struct btrfs_fs_info *fs_info = sblock->sctx->fs_info;



	btrfs_bio_counter_dec(fs_info);

	if (bio->bi_status)

		sblock->no_io_error_seen = 0;
@@ -2385,6 +2385,7 @@ static void scrub_missing_raid56_pages(struct scrub_block *sblock) 
	scrub_block_get(sblock);

	scrub_pending_bio_inc(sctx);

	raid56_submit_missing_rbio(rbio);

	btrfs_put_bioc(bioc);

	return;



rbio_out:
@@ -2924,6 +2925,7 @@ static void scrub_parity_bio_endio_worker(struct work_struct *work) 
						    work);

	struct scrub_ctx *sctx = sparity->sctx;



	btrfs_bio_counter_dec(sctx->fs_info);

	scrub_free_parity(sparity);

	scrub_pending_bio_dec(sctx);

}
@@ -2974,6 +2976,7 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity) 
					      sparity->scrub_dev,

					      &sparity->dbitmap,

					      sparity->nsectors);

	btrfs_put_bioc(bioc);

	if (!rbio)

		goto rbio_out;
@@ -2985,7 +2988,6 @@ static void scrub_parity_check_and_repair(struct scrub_parity *sparity) 
	bio_put(bio);

bioc_out:

	btrfs_bio_counter_dec(fs_info);

	btrfs_put_bioc(bioc);

	bitmap_or(&sparity->ebitmap, &sparity->ebitmap, &sparity->dbitmap,

		  sparity->nsectors);

	spin_lock(&sctx->stat_lock);

fs/btrfs/volumes.c

+17 −1
Original line number Diff line number Diff line
@@ -6684,6 +6684,20 @@ static void btrfs_end_bio_work(struct work_struct *work) 
	bio_endio(&bbio->bio);

}



static void btrfs_raid56_end_io(struct bio *bio)

{

	struct btrfs_io_context *bioc = bio->bi_private;

	struct btrfs_bio *bbio = btrfs_bio(bio);



	btrfs_bio_counter_dec(bioc->fs_info);

	bbio->mirror_num = bioc->mirror_num;

	bio->bi_end_io = bioc->end_io;

	bio->bi_private = bioc->private;

	bio->bi_end_io(bio);



	btrfs_put_bioc(bioc);

}



static void btrfs_end_bio(struct bio *bio)

{

	struct btrfs_io_stripe *stripe = bio->bi_private;
@@ -6817,10 +6831,12 @@ void btrfs_submit_bio(struct btrfs_fs_info *fs_info, struct bio *bio, int mirror 


	if ((bioc->map_type & BTRFS_BLOCK_GROUP_RAID56_MASK) &&

	    ((btrfs_op(bio) == BTRFS_MAP_WRITE) || (mirror_num > 1))) {

		bio->bi_private = bioc;

		bio->bi_end_io = btrfs_raid56_end_io;

		if (btrfs_op(bio) == BTRFS_MAP_WRITE)

			raid56_parity_write(bio, bioc);

		else

			raid56_parity_recover(bio, bioc, mirror_num, true);

			raid56_parity_recover(bio, bioc, mirror_num);

		return;

	}