Commit 82ca875d authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Andrew Morton
Browse files

zram: refactor highlevel read and write handling 

Instead of having an outer loop in __zram_make_request and then branch out
for reads vs writes for each loop iteration in zram_bvec_rw, split the
main handler into separat zram_bio_read and zram_bio_write handlers that
also include the functionality formerly in zram_bvec_rw.

Link: https://lkml.kernel.org/r/20230411171459.567614-8-hch@lst.de


Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Acked-by: default avatarMinchan Kim <minchan@kernel.org>
Reviewed-by: default avatarSergey Senozhatsky <senozhatsky@chromium.org>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 57de7bd8

drivers/block/zram/zram_drv.c

+30 −28
Original line number Diff line number Diff line
@@ -1921,38 +1921,34 @@ static void zram_bio_discard(struct zram *zram, struct bio *bio) 
	bio_endio(bio);

}



/*

 * Returns errno if it has some problem. Otherwise return 0 or 1.

 * Returns 0 if IO request was done synchronously

 * Returns 1 if IO request was successfully submitted.

 */

static int zram_bvec_rw(struct zram *zram, struct bio_vec *bvec, u32 index,

			int offset, enum req_op op, struct bio *bio)

static void zram_bio_read(struct zram *zram, struct bio *bio)

{

	int ret;

	struct bvec_iter iter;

	struct bio_vec bv;

	unsigned long start_time;



	if (!op_is_write(op)) {

		ret = zram_bvec_read(zram, bvec, index, offset, bio);

		if (unlikely(ret < 0)) {

	start_time = bio_start_io_acct(bio);

	bio_for_each_segment(bv, bio, iter) {

		u32 index = iter.bi_sector >> SECTORS_PER_PAGE_SHIFT;

		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<

				SECTOR_SHIFT;



		if (zram_bvec_read(zram, &bv, index, offset, bio) < 0) {

			atomic64_inc(&zram->stats.failed_reads);

			return ret;

		}

		flush_dcache_page(bvec->bv_page);

	} else {

		ret = zram_bvec_write(zram, bvec, index, offset, bio);

		if (unlikely(ret < 0)) {

			atomic64_inc(&zram->stats.failed_writes);

			return ret;

		}

			bio->bi_status = BLK_STS_IOERR;

			break;

		}

		flush_dcache_page(bv.bv_page);



		zram_slot_lock(zram, index);

		zram_accessed(zram, index);

		zram_slot_unlock(zram, index);

	return 0;

	}

	bio_end_io_acct(bio, start_time);

	bio_endio(bio);

}



static void __zram_make_request(struct zram *zram, struct bio *bio)

static void zram_bio_write(struct zram *zram, struct bio *bio)

{

	struct bvec_iter iter;

	struct bio_vec bv;
@@ -1964,11 +1960,15 @@ static void __zram_make_request(struct zram *zram, struct bio *bio) 
		u32 offset = (iter.bi_sector & (SECTORS_PER_PAGE - 1)) <<

				SECTOR_SHIFT;



		if (zram_bvec_rw(zram, &bv, index, offset, bio_op(bio),

				bio) < 0) {

		if (zram_bvec_write(zram, &bv, index, offset, bio) < 0) {

			atomic64_inc(&zram->stats.failed_writes);

			bio->bi_status = BLK_STS_IOERR;

			break;

		}



		zram_slot_lock(zram, index);

		zram_accessed(zram, index);

		zram_slot_unlock(zram, index);

	}

	bio_end_io_acct(bio, start_time);

	bio_endio(bio);
@@ -1983,8 +1983,10 @@ static void zram_submit_bio(struct bio *bio) 


	switch (bio_op(bio)) {

	case REQ_OP_READ:

		zram_bio_read(zram, bio);

		break;

	case REQ_OP_WRITE:

		__zram_make_request(zram, bio);

		zram_bio_write(zram, bio);

		break;

	case REQ_OP_DISCARD:

	case REQ_OP_WRITE_ZEROES: