Unverified Commit d1f9893f authored by Joanne Koong's avatar Joanne Koong Committed by Christian Brauner
Browse files

iomap: store read/readahead bio generically 



Store the iomap_readpage_ctx bio generically as a "void *read_ctx".
This makes the read/readahead interface more generic, which allows it to
be used by filesystems that may not be block-based and may not have
CONFIG_BLOCK set.

Signed-off-by: default avatarJoanne Koong <joannelkoong@gmail.com>
Tested-by: default avatar <syzbot@syzkaller.appspotmail.com>
Reviewed-by: default avatarDarrick J. Wong <djwong@kernel.org>
Signed-off-by: default avatarChristian Brauner <brauner@kernel.org>
parent 7588469b

fs/iomap/buffered-io.c

+14 −15
Original line number Diff line number Diff line
@@ -363,13 +363,13 @@ static void iomap_read_end_io(struct bio *bio) 
struct iomap_readpage_ctx {

	struct folio		*cur_folio;

	bool			cur_folio_in_bio;

	struct bio		*bio;

	void			*read_ctx;

	struct readahead_control *rac;

};



static void iomap_bio_submit_read(struct iomap_readpage_ctx *ctx)

{

	struct bio *bio = ctx->bio;

	struct bio *bio = ctx->read_ctx;



	if (bio)

		submit_bio(bio);
@@ -384,6 +384,7 @@ static void iomap_bio_read_folio_range(const struct iomap_iter *iter, 
	size_t poff = offset_in_folio(folio, pos);

	loff_t length = iomap_length(iter);

	sector_t sector;

	struct bio *bio = ctx->read_ctx;



	ctx->cur_folio_in_bio = true;

	if (ifs) {
@@ -393,9 +394,8 @@ static void iomap_bio_read_folio_range(const struct iomap_iter *iter, 
	}



	sector = iomap_sector(iomap, pos);

	if (!ctx->bio ||

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

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

	if (!bio || bio_end_sector(bio) != sector ||

	    !bio_add_folio(bio, folio, plen, poff)) {

		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);
@@ -404,22 +404,21 @@ static void iomap_bio_read_folio_range(const struct iomap_iter *iter, 


		if (ctx->rac) /* same as readahead_gfp_mask */

			gfp |= __GFP_NORETRY | __GFP_NOWARN;

		ctx->bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs),

				     REQ_OP_READ, gfp);

		bio = bio_alloc(iomap->bdev, bio_max_segs(nr_vecs), REQ_OP_READ,

				     gfp);

		/*

		 * If the bio_alloc fails, try it again for a single page to

		 * avoid having to deal with partial page reads.  This emulates

		 * what do_mpage_read_folio does.

		 */

		if (!ctx->bio) {

			ctx->bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ,

					     orig_gfp);

		}

		if (!bio)

			bio = bio_alloc(iomap->bdev, 1, REQ_OP_READ, orig_gfp);

		if (ctx->rac)

			ctx->bio->bi_opf |= REQ_RAHEAD;

		ctx->bio->bi_iter.bi_sector = sector;

		ctx->bio->bi_end_io = iomap_read_end_io;

		bio_add_folio_nofail(ctx->bio, folio, plen, poff);

			bio->bi_opf |= REQ_RAHEAD;

		bio->bi_iter.bi_sector = sector;

		bio->bi_end_io = iomap_read_end_io;

		bio_add_folio_nofail(bio, folio, plen, poff);

		ctx->read_ctx = bio;

	}

}