btrfs: raid56: extract rwm write bios assembly into a helper (6486d21c) · Commits · EulixOS / Software / Kernel

fs/btrfs/raid56.c

+79 −56

Original line number	Diff line number	Diff line
		@@ -1237,65 +1237,23 @@ static void generate_pq_vertical(struct btrfs_raid_bio *rbio, int sectornr)
		kunmap_local(pointers[stripe]);
		}

		/*
		* this is called from one of two situations. We either
		* have a full stripe from the higher layers, or we've read all
		* the missing bits off disk.
		*
		* This will calculate the parity and then send down any
		* changed blocks.
		*/
		static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
		static int rmw_assemble_write_bios(struct btrfs_raid_bio *rbio,
		struct bio_list *bio_list)
		{
		struct btrfs_io_context *bioc = rbio->bioc;
		struct bio *bio;
		/* The total sector number inside the full stripe. */
		int total_sector_nr;
		int stripe;
		/* Sector number inside a stripe. */
		int sectornr;
		struct bio_list bio_list;
		struct bio *bio;
		int stripe;
		int ret;

		bio_list_init(&bio_list);
		ASSERT(bio_list_size(bio_list) == 0);

		/* We should have at least one data sector. */
		ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));

		/* at this point we either have a full stripe,
		* or we've read the full stripe from the drive.
		* recalculate the parity and write the new results.
		*
		* We're not allowed to add any new bios to the
		* bio list here, anyone else that wants to
		* change this stripe needs to do their own rmw.
		*/
		spin_lock_irq(&rbio->bio_list_lock);
		set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
		spin_unlock_irq(&rbio->bio_list_lock);

		atomic_set(&rbio->error, 0);

		/*
		* now that we've set rmw_locked, run through the
		* bio list one last time and map the page pointers
		*
		* We don't cache full rbios because we're assuming
		* the higher layers are unlikely to use this area of
		* the disk again soon. If they do use it again,
		* hopefully they will send another full bio.
		*/
		index_rbio_pages(rbio);
		if (!rbio_is_full(rbio))
		cache_rbio_pages(rbio);
		else
		clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);

		for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
		generate_pq_vertical(rbio, sectornr);

		/*
		* Start writing. Make bios for everything from the higher layers (the
		* Start assembly. Make bios for everything from the higher layers (the
		* bio_list in our rbio) and our P/Q. Ignore everything else.
		*/
		for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
		@@ -1317,15 +1275,16 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
		sector = rbio_stripe_sector(rbio, stripe, sectornr);
		}

		ret = rbio_add_io_sector(rbio, &bio_list, sector, stripe,
		ret = rbio_add_io_sector(rbio, bio_list, sector, stripe,
		sectornr, REQ_OP_WRITE);
		if (ret)
		goto cleanup;
		goto error;
		}

		if (likely(!bioc->num_tgtdevs))
		goto write_data;
		if (likely(!rbio->bioc->num_tgtdevs))
		return 0;

		/* Make a copy for the replace target device. */
		for (total_sector_nr = 0; total_sector_nr < rbio->nr_sectors;
		total_sector_nr++) {
		struct sector_ptr *sector;
		@@ -1333,7 +1292,7 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
		stripe = total_sector_nr / rbio->stripe_nsectors;
		sectornr = total_sector_nr % rbio->stripe_nsectors;

		if (!bioc->tgtdev_map[stripe]) {
		if (!rbio->bioc->tgtdev_map[stripe]) {
		/*
		* We can skip the whole stripe completely, note
		* total_sector_nr will be increased by one anyway.
		@@ -1355,14 +1314,78 @@ static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
		sector = rbio_stripe_sector(rbio, stripe, sectornr);
		}

		ret = rbio_add_io_sector(rbio, &bio_list, sector,
		ret = rbio_add_io_sector(rbio, bio_list, sector,
		rbio->bioc->tgtdev_map[stripe],
		sectornr, REQ_OP_WRITE);
		if (ret)
		goto cleanup;
		goto error;
		}

		return 0;
		error:
		while ((bio = bio_list_pop(bio_list)))
		bio_put(bio);
		return -EIO;
		}

		write_data:
		/*
		* this is called from one of two situations. We either
		* have a full stripe from the higher layers, or we've read all
		* the missing bits off disk.
		*
		* This will calculate the parity and then send down any
		* changed blocks.
		*/
		static noinline void finish_rmw(struct btrfs_raid_bio *rbio)
		{
		/* The total sector number inside the full stripe. */
		/* Sector number inside a stripe. */
		int sectornr;
		struct bio_list bio_list;
		struct bio *bio;
		int ret;

		bio_list_init(&bio_list);

		/* We should have at least one data sector. */
		ASSERT(bitmap_weight(&rbio->dbitmap, rbio->stripe_nsectors));

		/* at this point we either have a full stripe,
		* or we've read the full stripe from the drive.
		* recalculate the parity and write the new results.
		*
		* We're not allowed to add any new bios to the
		* bio list here, anyone else that wants to
		* change this stripe needs to do their own rmw.
		*/
		spin_lock_irq(&rbio->bio_list_lock);
		set_bit(RBIO_RMW_LOCKED_BIT, &rbio->flags);
		spin_unlock_irq(&rbio->bio_list_lock);

		atomic_set(&rbio->error, 0);

		/*
		* now that we've set rmw_locked, run through the
		* bio list one last time and map the page pointers
		*
		* We don't cache full rbios because we're assuming
		* the higher layers are unlikely to use this area of
		* the disk again soon. If they do use it again,
		* hopefully they will send another full bio.
		*/
		index_rbio_pages(rbio);
		if (!rbio_is_full(rbio))
		cache_rbio_pages(rbio);
		else
		clear_bit(RBIO_CACHE_READY_BIT, &rbio->flags);

		for (sectornr = 0; sectornr < rbio->stripe_nsectors; sectornr++)
		generate_pq_vertical(rbio, sectornr);

		ret = rmw_assemble_write_bios(rbio, &bio_list);
		if (ret < 0)
		goto cleanup;

		atomic_set(&rbio->stripes_pending, bio_list_size(&bio_list));
		BUG_ON(atomic_read(&rbio->stripes_pending) == 0);