Unverified Commit e0e15340 authored by Joanne Koong's avatar Joanne Koong Committed by Christian Brauner
Browse files

iomap: iterate over folio mapping in iomap_readpage_iter() 



Iterate over all non-uptodate ranges of a folio mapping in a single call
to iomap_readpage_iter() instead of leaving the partial iteration to the
caller.

Signed-off-by: default avatarJoanne Koong <joannelkoong@gmail.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent d1f9893f

fs/iomap/buffered-io.c

+25 −28
Original line number Diff line number Diff line
@@ -430,6 +430,7 @@ static int iomap_readpage_iter(struct iomap_iter *iter, 
	loff_t length = iomap_length(iter);

	struct folio *folio = ctx->cur_folio;

	size_t poff, plen;

	loff_t count;

	int ret;



	if (iomap->type == IOMAP_INLINE) {
@@ -439,12 +440,22 @@ static int iomap_readpage_iter(struct iomap_iter *iter, 
		return iomap_iter_advance(iter, length);

	}



	/* zero post-eof blocks as the page may be mapped */

	ifs_alloc(iter->inode, folio, iter->flags);

	iomap_adjust_read_range(iter->inode, folio, &pos, length, &poff, &plen);



	length = min_t(loff_t, length,

			folio_size(folio) - offset_in_folio(folio, pos));

	while (length) {

		iomap_adjust_read_range(iter->inode, folio, &pos, length, &poff,

				&plen);



		count = pos - iter->pos + plen;

		if (WARN_ON_ONCE(count > length))

			return -EIO;



		if (plen == 0)

		goto done;

			return iomap_iter_advance(iter, count);



		/* zero post-eof blocks as the page may be mapped */

		if (iomap_block_needs_zeroing(iter, pos)) {

			folio_zero_range(folio, poff, plen);

			iomap_set_range_uptodate(folio, poff, plen);
@@ -452,28 +463,12 @@ static int iomap_readpage_iter(struct iomap_iter *iter, 
			iomap_bio_read_folio_range(iter, ctx, pos, plen);

		}



done:

	/*

	 * Move the caller beyond our range so that it keeps making progress.

	 * For that, we have to include any leading non-uptodate ranges, but

	 * we can skip trailing ones as they will be handled in the next

	 * iteration.

	 */

	length = pos - iter->pos + plen;

	return iomap_iter_advance(iter, length);

}



static int iomap_read_folio_iter(struct iomap_iter *iter,

		struct iomap_readpage_ctx *ctx)

{

	int ret;



	while (iomap_length(iter)) {

		ret = iomap_readpage_iter(iter, ctx);

		ret = iomap_iter_advance(iter, count);

		if (ret)

			return ret;

		length -= count;

		pos = iter->pos;

	}



	return 0;

}
@@ -492,7 +487,7 @@ int iomap_read_folio(struct folio *folio, const struct iomap_ops *ops) 
	trace_iomap_readpage(iter.inode, 1);



	while ((ret = iomap_iter(&iter, ops)) > 0)

		iter.status = iomap_read_folio_iter(&iter, &ctx);

		iter.status = iomap_readpage_iter(&iter, &ctx);



	iomap_bio_submit_read(&ctx);
@@ -522,6 +517,8 @@ static int iomap_readahead_iter(struct iomap_iter *iter, 
		}

		if (!ctx->cur_folio) {

			ctx->cur_folio = readahead_folio(ctx->rac);

			if (WARN_ON_ONCE(!ctx->cur_folio))

				return -EINVAL;

			ctx->cur_folio_in_bio = false;

		}

		ret = iomap_readpage_iter(iter, ctx);