dm: update dm_process_bio() to split bio if in ->make_request_fn() (568c73a3) · Commits · 戴 / test

drivers/md/dm.c

+66 −27

Original line number	Diff line number	Diff line
		@@ -1533,6 +1533,22 @@ static int __send_write_zeroes(struct clone_info ci, struct dm_target ti)
		return __send_changing_extent_only(ci, ti, get_num_write_zeroes_bios(ti), false);
		}

		static bool is_abnormal_io(struct bio *bio)
		{
		bool r = false;

		switch (bio_op(bio)) {
		case REQ_OP_DISCARD:
		case REQ_OP_SECURE_ERASE:
		case REQ_OP_WRITE_SAME:
		case REQ_OP_WRITE_ZEROES:
		r = true;
		break;
		}

		return r;
		}

		static bool __process_abnormal_io(struct clone_info ci, struct dm_target ti,
		int *result)
		{
		@@ -1565,7 +1581,7 @@ static int __split_and_process_non_flush(struct clone_info *ci)
		if (!dm_target_is_valid(ti))
		return -EIO;

		if (unlikely(__process_abnormal_io(ci, ti, &r)))
		if (__process_abnormal_io(ci, ti, &r))
		return r;

		len = min_t(sector_t, max_io_len(ci->sector, ti), ci->sector_count);
		@@ -1601,13 +1617,6 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
		blk_qc_t ret = BLK_QC_T_NONE;
		int error = 0;

		if (unlikely(!map)) {
		bio_io_error(bio);
		return ret;
		}

		blk_queue_split(md->queue, &bio);

		init_clone_info(&ci, md, map, bio);

		if (bio->bi_opf & REQ_PREFLUSH) {
		@@ -1675,18 +1684,13 @@ static blk_qc_t __split_and_process_bio(struct mapped_device *md,
		* Optimized variant of __split_and_process_bio that leverages the
		* fact that targets that use it do _not_ have a need to split bios.
		*/
		static blk_qc_t __process_bio(struct mapped_device *md,
		struct dm_table map, struct bio bio)
		static blk_qc_t __process_bio(struct mapped_device md, struct dm_table map,
		struct bio bio, struct dm_target ti)
		{
		struct clone_info ci;
		blk_qc_t ret = BLK_QC_T_NONE;
		int error = 0;

		if (unlikely(!map)) {
		bio_io_error(bio);
		return ret;
		}

		init_clone_info(&ci, md, map, bio);

		if (bio->bi_opf & REQ_PREFLUSH) {
		@@ -1704,21 +1708,11 @@ static blk_qc_t __process_bio(struct mapped_device *md,
		error = __send_empty_flush(&ci);
		/* dec_pending submits any data associated with flush */
		} else {
		struct dm_target *ti = md->immutable_target;
		struct dm_target_io *tio;

		/*
		* Defend against IO still getting in during teardown
		* - as was seen for a time with nvme-fcloop
		*/
		if (WARN_ON_ONCE(!ti \|\| !dm_target_is_valid(ti))) {
		error = -EIO;
		goto out;
		}

		ci.bio = bio;
		ci.sector_count = bio_sectors(bio);
		if (unlikely(__process_abnormal_io(&ci, ti, &error)))
		if (__process_abnormal_io(&ci, ti, &error))
		goto out;

		tio = alloc_tio(&ci, ti, 0, GFP_NOIO);
		@@ -1730,11 +1724,56 @@ out:
		return ret;
		}

		static void dm_queue_split(struct mapped_device md, struct dm_target ti, struct bio **bio)
		{
		unsigned len, sector_count;

		sector_count = bio_sectors(*bio);
		len = min_t(sector_t, max_io_len((*bio)->bi_iter.bi_sector, ti), sector_count);

		if (sector_count > len) {
		struct bio split = bio_split(bio, len, GFP_NOIO, &md->queue->bio_split);

		bio_chain(split, *bio);
		trace_block_split(md->queue, split, (*bio)->bi_iter.bi_sector);
		generic_make_request(*bio);
		*bio = split;
		}
		}

		static blk_qc_t dm_process_bio(struct mapped_device *md,
		struct dm_table map, struct bio bio)
		{
		blk_qc_t ret = BLK_QC_T_NONE;
		struct dm_target *ti = md->immutable_target;

		if (unlikely(!map)) {
		bio_io_error(bio);
		return ret;
		}

		if (!ti) {
		ti = dm_table_find_target(map, bio->bi_iter.bi_sector);
		if (unlikely(!ti \|\| !dm_target_is_valid(ti))) {
		bio_io_error(bio);
		return ret;
		}
		}

		/*
		* If in ->make_request_fn we need to use blk_queue_split(), otherwise
		* queue_limits for abnormal requests (e.g. discard, writesame, etc)
		* won't be imposed.
		*/
		if (current->bio_list) {
		if (is_abnormal_io(bio))
		blk_queue_split(md->queue, &bio);
		else
		dm_queue_split(md, ti, &bio);
		}

		if (dm_get_md_type(md) == DM_TYPE_NVME_BIO_BASED)
		return __process_bio(md, map, bio);
		return __process_bio(md, map, bio, ti);
		else
		return __split_and_process_bio(md, map, bio);
		}

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