bcache: Refactor read request code a bit (cdd972b1) · Commits · 戴 / test

drivers/md/bcache/request.c

+35 −36

Original line number	Diff line number	Diff line
		@@ -884,7 +884,7 @@ skip:

		/* Process reads */

		static void cached_dev_read_complete(struct closure *cl)
		static void cached_dev_cache_miss_done(struct closure *cl)
		{
		struct search *s = container_of(cl, struct search, cl);

		@@ -902,9 +902,10 @@ static void cached_dev_read_complete(struct closure *cl)
		cached_dev_bio_complete(cl);
		}

		static void request_read_error(struct closure *cl)
		static void cached_dev_read_error(struct closure *cl)
		{
		struct search *s = container_of(cl, struct search, cl);
		struct bio *bio = &s->bio.bio;
		struct bio_vec *bv;
		int i;

		@@ -928,20 +929,20 @@ static void request_read_error(struct closure *cl)

		/* XXX: invalidate cache */

		closure_bio_submit(&s->bio.bio, &s->cl, s->d);
		closure_bio_submit(bio, cl, s->d);
		}

		continue_at(cl, cached_dev_read_complete, NULL);
		continue_at(cl, cached_dev_cache_miss_done, NULL);
		}

		static void request_read_done(struct closure *cl)
		static void cached_dev_read_done(struct closure *cl)
		{
		struct search *s = container_of(cl, struct search, cl);
		struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);

		/*
		* s->cache_bio != NULL implies that we had a cache miss; cache_bio now
		* contains data ready to be inserted into the cache.
		* We had a cache miss; cache_bio now contains data ready to be inserted
		* into the cache.
		*
		* First, we copy the data we just read from cache_bio's bounce buffers
		* to the buffers the original bio pointed to:
		@@ -971,10 +972,10 @@ static void request_read_done(struct closure *cl)
		closure_call(&s->op.cl, bch_insert_data, NULL, cl);
		}

		continue_at(cl, cached_dev_read_complete, NULL);
		continue_at(cl, cached_dev_cache_miss_done, NULL);
		}

		static void request_read_done_bh(struct closure *cl)
		static void cached_dev_read_done_bh(struct closure *cl)
		{
		struct search *s = container_of(cl, struct search, cl);
		struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
		@@ -983,11 +984,11 @@ static void request_read_done_bh(struct closure *cl)
		trace_bcache_read(s->orig_bio, !s->cache_miss, s->op.bypass);

		if (s->error)
		continue_at_nobarrier(cl, request_read_error, bcache_wq);
		continue_at_nobarrier(cl, cached_dev_read_error, bcache_wq);
		else if (s->op.cache_bio \|\| verify(dc, &s->bio.bio))
		continue_at_nobarrier(cl, request_read_done, bcache_wq);
		continue_at_nobarrier(cl, cached_dev_read_done, bcache_wq);
		else
		continue_at_nobarrier(cl, cached_dev_read_complete, NULL);
		continue_at_nobarrier(cl, cached_dev_bio_complete, NULL);
		}

		static int cached_dev_cache_miss(struct btree b, struct search s,
		@@ -996,7 +997,7 @@ static int cached_dev_cache_miss(struct btree b, struct search s,
		int ret = 0;
		unsigned reada = 0;
		struct cached_dev *dc = container_of(s->d, struct cached_dev, disk);
		struct bio *miss;
		struct bio miss, cache_bio;

		if (s->cache_miss \|\| s->op.bypass) {
		miss = bch_bio_split(bio, sectors, GFP_NOIO, s->d->bio_split);
		@@ -1027,33 +1028,31 @@ static int cached_dev_cache_miss(struct btree b, struct search s,
		/* btree_search_recurse()'s btree iterator is no good anymore */
		ret = -EINTR;

		s->op.cache_bio = bio_alloc_bioset(GFP_NOWAIT,
		cache_bio = bio_alloc_bioset(GFP_NOWAIT,
		DIV_ROUND_UP(s->cache_bio_sectors, PAGE_SECTORS),
		dc->disk.bio_split);

		if (!s->op.cache_bio)
		if (!cache_bio)
		goto out_submit;

		s->op.cache_bio->bi_sector = miss->bi_sector;
		s->op.cache_bio->bi_bdev = miss->bi_bdev;
		s->op.cache_bio->bi_size = s->cache_bio_sectors << 9;
		cache_bio->bi_sector = miss->bi_sector;
		cache_bio->bi_bdev = miss->bi_bdev;
		cache_bio->bi_size = s->cache_bio_sectors << 9;

		s->op.cache_bio->bi_end_io = request_endio;
		s->op.cache_bio->bi_private = &s->cl;
		cache_bio->bi_end_io = request_endio;
		cache_bio->bi_private = &s->cl;

		bch_bio_map(s->op.cache_bio, NULL);
		if (bio_alloc_pages(s->op.cache_bio, __GFP_NOWARN\|GFP_NOIO))
		bch_bio_map(cache_bio, NULL);
		if (bio_alloc_pages(cache_bio, __GFP_NOWARN\|GFP_NOIO))
		goto out_put;

		s->cache_miss = miss;
		bio_get(s->op.cache_bio);

		closure_bio_submit(s->op.cache_bio, &s->cl, s->d);
		s->op.cache_bio = cache_bio;
		bio_get(cache_bio);
		closure_bio_submit(cache_bio, &s->cl, s->d);

		return ret;
		out_put:
		bio_put(s->op.cache_bio);
		s->op.cache_bio = NULL;
		bio_put(cache_bio);
		out_submit:
		miss->bi_end_io = request_endio;
		miss->bi_private = &s->cl;
		@@ -1061,12 +1060,12 @@ out_submit:
		return ret;
		}

		static void request_read(struct cached_dev dc, struct search s)
		static void cached_dev_read(struct cached_dev dc, struct search s)
		{
		struct closure *cl = &s->cl;

		closure_call(&s->op.cl, btree_read_async, NULL, cl);
		continue_at(cl, request_read_done_bh, NULL);
		continue_at(cl, cached_dev_read_done_bh, NULL);
		}

		/* Process writes */
		@@ -1080,7 +1079,7 @@ static void cached_dev_write_complete(struct closure *cl)
		cached_dev_bio_complete(cl);
		}

		static void request_write(struct cached_dev dc, struct search s)
		static void cached_dev_write(struct cached_dev dc, struct search s)
		{
		struct closure *cl = &s->cl;
		struct bio *bio = &s->bio.bio;
		@@ -1152,7 +1151,7 @@ static void request_write(struct cached_dev dc, struct search s)
		continue_at(cl, cached_dev_write_complete, NULL);
		}

		static void request_nodata(struct cached_dev dc, struct search s)
		static void cached_dev_nodata(struct cached_dev dc, struct search s)
		{
		struct closure *cl = &s->cl;
		struct bio *bio = &s->bio.bio;
		@@ -1188,14 +1187,14 @@ static void cached_dev_make_request(struct request_queue q, struct bio bio)
		trace_bcache_request_start(s, bio);

		if (!bio->bi_size)
		request_nodata(dc, s);
		cached_dev_nodata(dc, s);
		else {
		s->op.bypass = check_should_bypass(dc, s);

		if (rw)
		request_write(dc, s);
		cached_dev_write(dc, s);
		else
		request_read(dc, s);
		cached_dev_read(dc, s);
		}
		} else {
		if ((bio->bi_rw & REQ_DISCARD) &&

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