Commit 00425dd9 authored by Qu Wenruo's avatar Qu Wenruo Committed by David Sterba
Browse files

btrfs: raid56: introduce btrfs_raid_bio::bio_sectors 



This new member is going to fully replace bio_pages in the future, but
for now let's keep them co-exist, until the full switch is done.

Currently cache_rbio_pages() and index_rbio_pages() will also populate
the new array.

And cache_rbio_pages() need to record which sectors are uptodate, so we
also need to introduce sector_ptr::uptodate bit.

To avoid extra memory usage, we let the new @uptodate bit to share bits
with @pgoff.  Now pgoff only has at most 31 bits, which is already more
than enough, as even for 256K page size, we only need 18 bits.

Signed-off-by: default avatarQu Wenruo <wqu@suse.com>
Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent eb357060

fs/btrfs/raid56.c

+55 −2
Original line number Original line Diff line number Diff line
@@ -59,7 +59,8 @@ struct btrfs_stripe_hash_table { 
 */

 */

struct sector_ptr {

struct sector_ptr {

	struct page *page;

	struct page *page;

	unsigned int pgoff;

	unsigned int pgoff:24;

	unsigned int uptodate:8;

};

};





enum btrfs_rbio_ops {

enum btrfs_rbio_ops {
@@ -174,6 +175,9 @@ struct btrfs_raid_bio { 
	 */

	 */

	struct page **stripe_pages;

	struct page **stripe_pages;





	/* Pointers to the sectors in the bio_list, for faster lookup */

	struct sector_ptr *bio_sectors;



	/*

	/*

	 * pointers to the pages in the bio_list.  Stored

	 * pointers to the pages in the bio_list.  Stored

	 * here for faster lookup

	 * here for faster lookup
@@ -284,6 +288,24 @@ static void cache_rbio_pages(struct btrfs_raid_bio *rbio) 
		copy_highpage(rbio->stripe_pages[i], rbio->bio_pages[i]);

		copy_highpage(rbio->stripe_pages[i], rbio->bio_pages[i]);

		SetPageUptodate(rbio->stripe_pages[i]);

		SetPageUptodate(rbio->stripe_pages[i]);

	}

	}



	/*

	 * This work is duplicated with the above loop, will be removed when

	 * the switch is done.

	 */

	for (i = 0; i < rbio->nr_sectors; i++) {

		/* Some range not covered by bio (partial write), skip it */

		if (!rbio->bio_sectors[i].page)

			continue;



		ASSERT(rbio->stripe_sectors[i].page);

		memcpy_page(rbio->stripe_sectors[i].page,

			    rbio->stripe_sectors[i].pgoff,

			    rbio->bio_sectors[i].page,

			    rbio->bio_sectors[i].pgoff,

			    rbio->bioc->fs_info->sectorsize);

		rbio->stripe_sectors[i].uptodate = 1;

	}

	set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);

	set_bit(RBIO_CACHE_READY_BIT, &rbio->flags);

}

}
@@ -1012,7 +1034,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info, 




	rbio = kzalloc(sizeof(*rbio) +

	rbio = kzalloc(sizeof(*rbio) +

		       sizeof(*rbio->stripe_pages) * num_pages +

		       sizeof(*rbio->stripe_pages) * num_pages +

		       sizeof(*rbio->bio_pages) * num_pages +

		       sizeof(*rbio->bio_sectors) * num_sectors +

		       sizeof(*rbio->stripe_sectors) * num_sectors +

		       sizeof(*rbio->stripe_sectors) * num_sectors +

		       sizeof(*rbio->finish_pointers) * real_stripes +

		       sizeof(*rbio->finish_pointers) * real_stripes +

		       sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_nsectors) +

		       sizeof(*rbio->dbitmap) * BITS_TO_LONGS(stripe_nsectors) +
@@ -1050,6 +1072,7 @@ static struct btrfs_raid_bio *alloc_rbio(struct btrfs_fs_info *fs_info, 
	} while (0)

	} while (0)

	CONSUME_ALLOC(rbio->stripe_pages, num_pages);

	CONSUME_ALLOC(rbio->stripe_pages, num_pages);

	CONSUME_ALLOC(rbio->bio_pages, num_pages);

	CONSUME_ALLOC(rbio->bio_pages, num_pages);

	CONSUME_ALLOC(rbio->bio_sectors, num_sectors);

	CONSUME_ALLOC(rbio->stripe_sectors, num_sectors);

	CONSUME_ALLOC(rbio->stripe_sectors, num_sectors);

	CONSUME_ALLOC(rbio->finish_pointers, real_stripes);

	CONSUME_ALLOC(rbio->finish_pointers, real_stripes);

	CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_nsectors));

	CONSUME_ALLOC(rbio->dbitmap, BITS_TO_LONGS(stripe_nsectors));
@@ -1166,6 +1189,32 @@ static void validate_rbio_for_rmw(struct btrfs_raid_bio *rbio) 
	}

	}

}

}





static void index_one_bio(struct btrfs_raid_bio *rbio, struct bio *bio)

{

	const u32 sectorsize = rbio->bioc->fs_info->sectorsize;

	struct bio_vec bvec;

	struct bvec_iter iter;

	u32 offset = (bio->bi_iter.bi_sector << SECTOR_SHIFT) -

		     rbio->bioc->raid_map[0];



	if (bio_flagged(bio, BIO_CLONED))

		bio->bi_iter = btrfs_bio(bio)->iter;



	bio_for_each_segment(bvec, bio, iter) {

		u32 bvec_offset;



		for (bvec_offset = 0; bvec_offset < bvec.bv_len;

		     bvec_offset += sectorsize, offset += sectorsize) {

			int index = offset / sectorsize;

			struct sector_ptr *sector = &rbio->bio_sectors[index];



			sector->page = bvec.bv_page;

			sector->pgoff = bvec.bv_offset + bvec_offset;

			ASSERT(sector->pgoff < PAGE_SIZE);

		}

	}

}



/*

/*

 * helper function to walk our bio list and populate the bio_pages array with

 * helper function to walk our bio list and populate the bio_pages array with

 * the result.  This seems expensive, but it is faster than constantly

 * the result.  This seems expensive, but it is faster than constantly
@@ -1196,6 +1245,10 @@ static void index_rbio_pages(struct btrfs_raid_bio *rbio) 
			i++;

			i++;

		}

		}

	}

	}

	/* This loop will replace above loop when the full switch is done */

	bio_list_for_each(bio, &rbio->bio_list)

		index_one_bio(rbio, bio);



	spin_unlock_irq(&rbio->bio_list_lock);

	spin_unlock_irq(&rbio->bio_list_lock);

}

}