Commit 3aa9c659 authored by Matthew Wilcox (Oracle)'s avatar Matthew Wilcox (Oracle)
Browse files

iomap: Convert readahead and readpage to use a folio 



Handle folios of arbitrary size instead of working in PAGE_SIZE units.
readahead_folio() decreases the page refcount for you, so this is not
quite a mechanical change.

Signed-off-by: default avatarMatthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
parent 874628a2

fs/iomap/buffered-io.c

+26 −27
Original line number Diff line number Diff line
@@ -188,8 +188,8 @@ static void iomap_read_end_io(struct bio *bio) 
}



struct iomap_readpage_ctx {

	struct page		*cur_page;

	bool			cur_page_in_bio;

	struct folio		*cur_folio;

	bool			cur_folio_in_bio;

	struct bio		*bio;

	struct readahead_control *rac;

};
@@ -252,8 +252,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, 
	const struct iomap *iomap = &iter->iomap;

	loff_t pos = iter->pos + offset;

	loff_t length = iomap_length(iter) - offset;

	struct page *page = ctx->cur_page;

	struct folio *folio = page_folio(page);

	struct folio *folio = ctx->cur_folio;

	struct iomap_page *iop;

	loff_t orig_pos = pos;

	size_t poff, plen;
@@ -274,7 +273,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, 
		goto done;

	}



	ctx->cur_page_in_bio = true;

	ctx->cur_folio_in_bio = true;

	if (iop)

		atomic_add(plen, &iop->read_bytes_pending);
@@ -282,7 +281,7 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, 
	if (!ctx->bio ||

	    bio_end_sector(ctx->bio) != sector ||

	    !bio_add_folio(ctx->bio, folio, plen, poff)) {

		gfp_t gfp = mapping_gfp_constraint(page->mapping, GFP_KERNEL);

		gfp_t gfp = mapping_gfp_constraint(folio->mapping, GFP_KERNEL);

		gfp_t orig_gfp = gfp;

		unsigned int nr_vecs = DIV_ROUND_UP(length, PAGE_SIZE);
@@ -321,30 +320,31 @@ static loff_t iomap_readpage_iter(const struct iomap_iter *iter, 
int

iomap_readpage(struct page *page, const struct iomap_ops *ops)

{

	struct folio *folio = page_folio(page);

	struct iomap_iter iter = {

		.inode		= page->mapping->host,

		.pos		= page_offset(page),

		.len		= PAGE_SIZE,

		.inode		= folio->mapping->host,

		.pos		= folio_pos(folio),

		.len		= folio_size(folio),

	};

	struct iomap_readpage_ctx ctx = {

		.cur_page	= page,

		.cur_folio	= folio,

	};

	int ret;



	trace_iomap_readpage(page->mapping->host, 1);

	trace_iomap_readpage(iter.inode, 1);



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

		iter.processed = iomap_readpage_iter(&iter, &ctx, 0);



	if (ret < 0)

		SetPageError(page);

		folio_set_error(folio);



	if (ctx.bio) {

		submit_bio(ctx.bio);

		WARN_ON_ONCE(!ctx.cur_page_in_bio);

		WARN_ON_ONCE(!ctx.cur_folio_in_bio);

	} else {

		WARN_ON_ONCE(ctx.cur_page_in_bio);

		unlock_page(page);

		WARN_ON_ONCE(ctx.cur_folio_in_bio);

		folio_unlock(folio);

	}



	/*
@@ -363,15 +363,15 @@ static loff_t iomap_readahead_iter(const struct iomap_iter *iter, 
	loff_t done, ret;



	for (done = 0; done < length; done += ret) {

		if (ctx->cur_page && offset_in_page(iter->pos + done) == 0) {

			if (!ctx->cur_page_in_bio)

				unlock_page(ctx->cur_page);

			put_page(ctx->cur_page);

			ctx->cur_page = NULL;

		if (ctx->cur_folio &&

		    offset_in_folio(ctx->cur_folio, iter->pos + done) == 0) {

			if (!ctx->cur_folio_in_bio)

				folio_unlock(ctx->cur_folio);

			ctx->cur_folio = NULL;

		}

		if (!ctx->cur_page) {

			ctx->cur_page = readahead_page(ctx->rac);

			ctx->cur_page_in_bio = false;

		if (!ctx->cur_folio) {

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

			ctx->cur_folio_in_bio = false;

		}

		ret = iomap_readpage_iter(iter, ctx, done);

		if (ret <= 0)
@@ -414,10 +414,9 @@ void iomap_readahead(struct readahead_control *rac, const struct iomap_ops *ops) 


	if (ctx.bio)

		submit_bio(ctx.bio);

	if (ctx.cur_page) {

		if (!ctx.cur_page_in_bio)

			unlock_page(ctx.cur_page);

		put_page(ctx.cur_page);

	if (ctx.cur_folio) {

		if (!ctx.cur_folio_in_bio)

			folio_unlock(ctx.cur_folio);

	}

}

EXPORT_SYMBOL_GPL(iomap_readahead);