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Commit ec181f67 authored by Andreas Gruenbacher's avatar Andreas Gruenbacher Committed by Darrick J. Wong
Browse files

iomap: support direct I/O to inline data 



Add support for reading from and writing to inline data to iomap_dio_rw.
This saves filesystems from having to implement fallback code for this
case.

The inline data is actually cached in the inode, so the I/O is only
direct in the sense that it doesn't go through the page cache.

Signed-off-by: default avatarAndreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
parent 09230435

fs/iomap.c

+29 −0
Original line number Diff line number Diff line
@@ -1450,6 +1450,33 @@ iomap_dio_hole_actor(loff_t length, struct iomap_dio *dio) 
	return length;

}



static loff_t

iomap_dio_inline_actor(struct inode *inode, loff_t pos, loff_t length,

		struct iomap_dio *dio, struct iomap *iomap)

{

	struct iov_iter *iter = dio->submit.iter;

	size_t copied;



	BUG_ON(pos + length > PAGE_SIZE - offset_in_page(iomap->inline_data));



	if (dio->flags & IOMAP_DIO_WRITE) {

		loff_t size = inode->i_size;



		if (pos > size)

			memset(iomap->inline_data + size, 0, pos - size);

		copied = copy_from_iter(iomap->inline_data + pos, length, iter);

		if (copied) {

			if (pos + copied > size)

				i_size_write(inode, pos + copied);

			mark_inode_dirty(inode);

		}

	} else {

		copied = copy_to_iter(iomap->inline_data + pos, length, iter);

	}

	dio->size += copied;

	return copied;

}



static loff_t

iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length,

		void *data, struct iomap *iomap)
@@ -1467,6 +1494,8 @@ iomap_dio_actor(struct inode *inode, loff_t pos, loff_t length, 
		return iomap_dio_bio_actor(inode, pos, length, dio, iomap);

	case IOMAP_MAPPED:

		return iomap_dio_bio_actor(inode, pos, length, dio, iomap);

	case IOMAP_INLINE:

		return iomap_dio_inline_actor(inode, pos, length, dio, iomap);

	default:

		WARN_ON_ONCE(1);

		return -EIO;