Commit 53f2c206 authored by Boris Burkov's avatar Boris Burkov Committed by David Sterba
Browse files

btrfs: stash ordered extent in dio_data during iomap dio 



While it is not feasible for an ordered extent to survive across the
calls btrfs_direct_write makes into __iomap_dio_rw, it is still helpful
to stash it on the dio_data in between creating it in iomap_begin and
finishing it in either end_io or iomap_end.

The specific use I have in mind is that we can check if a particular bio
is partial in submit_io without unconditionally looking up the ordered
extent. This is a preparatory patch for a later patch which does just
that.

Reviewed-by: default avatarNaohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: default avatarJosef Bacik <josef@toxicpanda.com>
Tested-by: default avatarJohannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: default avatarBoris Burkov <boris@bur.io>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
parent 8725bddf

fs/btrfs/inode.c

+23 −13
Original line number Diff line number Diff line
@@ -79,6 +79,7 @@ struct btrfs_iget_args { 
struct btrfs_dio_data {

	ssize_t submitted;

	struct extent_changeset *data_reserved;

	struct btrfs_ordered_extent *ordered;

	bool data_space_reserved;

	bool nocow_done;

};
@@ -6965,6 +6966,7 @@ struct extent_map *btrfs_get_extent(struct btrfs_inode *inode, 
}



static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode,

						  struct btrfs_dio_data *dio_data,

						  const u64 start,

						  const u64 len,

						  const u64 orig_start,
@@ -6975,7 +6977,7 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, 
						  const int type)

{

	struct extent_map *em = NULL;

	int ret;

	struct btrfs_ordered_extent *ordered;



	if (type != BTRFS_ORDERED_NOCOW) {

		em = create_io_em(inode, start, len, orig_start, block_start,
@@ -6985,18 +6987,21 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, 
		if (IS_ERR(em))

			goto out;

	}

	ret = btrfs_add_ordered_extent(inode, start, len, len, block_start,

				       block_len, 0,

	ordered = btrfs_alloc_ordered_extent(inode, start, len, len,

					     block_start, block_len, 0,

					     (1 << type) |

					     (1 << BTRFS_ORDERED_DIRECT),

					     BTRFS_COMPRESS_NONE);

	if (ret) {

	if (IS_ERR(ordered)) {

		if (em) {

			free_extent_map(em);

			btrfs_drop_extent_map_range(inode, start,

						    start + len - 1, false);

		}

		em = ERR_PTR(ret);

		em = ERR_CAST(ordered);

	} else {

		ASSERT(!dio_data->ordered);

		dio_data->ordered = ordered;

	}

 out:
@@ -7004,6 +7009,7 @@ static struct extent_map *btrfs_create_dio_extent(struct btrfs_inode *inode, 
}



static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode,

						  struct btrfs_dio_data *dio_data,

						  u64 start, u64 len)

{

	struct btrfs_root *root = inode->root;
@@ -7019,7 +7025,7 @@ static struct extent_map *btrfs_new_extent_direct(struct btrfs_inode *inode, 
	if (ret)

		return ERR_PTR(ret);



	em = btrfs_create_dio_extent(inode, start, ins.offset, start,

	em = btrfs_create_dio_extent(inode, dio_data, start, ins.offset, start,

				     ins.objectid, ins.offset, ins.offset,

				     ins.offset, BTRFS_ORDERED_REGULAR);

	btrfs_dec_block_group_reservations(fs_info, ins.objectid);
@@ -7364,7 +7370,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, 
		}

		space_reserved = true;



		em2 = btrfs_create_dio_extent(BTRFS_I(inode), start, len,

		em2 = btrfs_create_dio_extent(BTRFS_I(inode), dio_data, start, len,

					      orig_start, block_start,

					      len, orig_block_len,

					      ram_bytes, type);
@@ -7406,7 +7412,7 @@ static int btrfs_get_blocks_direct_write(struct extent_map **map, 
			goto out;

		space_reserved = true;



		em = btrfs_new_extent_direct(BTRFS_I(inode), start, len);

		em = btrfs_new_extent_direct(BTRFS_I(inode), dio_data, start, len);

		if (IS_ERR(em)) {

			ret = PTR_ERR(em);

			goto out;
@@ -7712,6 +7718,10 @@ static int btrfs_dio_iomap_end(struct inode *inode, loff_t pos, loff_t length, 
				      pos + length - 1, NULL);

		ret = -ENOTBLK;

	}

	if (write) {

		btrfs_put_ordered_extent(dio_data->ordered);

		dio_data->ordered = NULL;

	}



	if (write)

		extent_changeset_free(dio_data->data_reserved);
@@ -7773,7 +7783,7 @@ static const struct iomap_dio_ops btrfs_dio_ops = { 


ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_before)

{

	struct btrfs_dio_data data;

	struct btrfs_dio_data data = { 0 };



	return iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,

			    IOMAP_DIO_PARTIAL, &data, done_before);
@@ -7782,7 +7792,7 @@ ssize_t btrfs_dio_read(struct kiocb *iocb, struct iov_iter *iter, size_t done_be 
struct iomap_dio *btrfs_dio_write(struct kiocb *iocb, struct iov_iter *iter,

				  size_t done_before)

{

	struct btrfs_dio_data data;

	struct btrfs_dio_data data = { 0 };



	return __iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dio_ops,

			    IOMAP_DIO_PARTIAL, &data, done_before);