Commit e49c7c37 authored by Kent Overstreet's avatar Kent Overstreet Committed by Kent Overstreet
Browse files

bcache: FUA fixes 



Journal writes need to be marked FUA, not just REQ_FLUSH. And btree node
writes have... weird ordering requirements.

Signed-off-by: default avatarKent Overstreet <koverstreet@google.com>
parent cecd628d

drivers/md/bcache/btree.c

+22 −3
Original line number Diff line number Diff line
@@ -328,10 +328,25 @@ static void do_btree_node_write(struct btree *b) 


	b->bio->bi_end_io	= btree_node_write_endio;

	b->bio->bi_private	= &b->io.cl;

	b->bio->bi_rw	= REQ_META|WRITE_SYNC;

	b->bio->bi_rw		= REQ_META|WRITE_SYNC|REQ_FUA;

	b->bio->bi_size		= set_blocks(i, b->c) * block_bytes(b->c);

	bch_bio_map(b->bio, i);



	/*

	 * If we're appending to a leaf node, we don't technically need FUA -

	 * this write just needs to be persisted before the next journal write,

	 * which will be marked FLUSH|FUA.

	 *

	 * Similarly if we're writing a new btree root - the pointer is going to

	 * be in the next journal entry.

	 *

	 * But if we're writing a new btree node (that isn't a root) or

	 * appending to a non leaf btree node, we need either FUA or a flush

	 * when we write the parent with the new pointer. FUA is cheaper than a

	 * flush, and writes appending to leaf nodes aren't blocking anything so

	 * just make all btree node writes FUA to keep things sane.

	 */



	bkey_copy(&k.key, &b->key);

	SET_PTR_OFFSET(&k.key, 0, PTR_OFFSET(&k.key, 0) + bset_offset(b, i));
@@ -2092,6 +2107,9 @@ int bch_btree_insert(struct btree_op *op, struct cache_set *c) 
void bch_btree_set_root(struct btree *b)

{

	unsigned i;

	struct closure cl;



	closure_init_stack(&cl);



	trace_bcache_btree_set_root(b);
@@ -2107,7 +2125,8 @@ void bch_btree_set_root(struct btree *b) 
	b->c->root = b;

	__bkey_put(b->c, &b->key);



	bch_journal_meta(b->c, NULL);

	bch_journal_meta(b->c, &cl);

	closure_sync(&cl);

}



/* Cache lookup */

drivers/md/bcache/journal.c

+1 −1
Original line number Diff line number Diff line
@@ -620,7 +620,7 @@ static void journal_write_unlocked(struct closure *cl) 
		bio_reset(bio);

		bio->bi_sector	= PTR_OFFSET(k, i);

		bio->bi_bdev	= ca->bdev;

		bio->bi_rw	= REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH;

		bio->bi_rw	= REQ_WRITE|REQ_SYNC|REQ_META|REQ_FLUSH|REQ_FUA;

		bio->bi_size	= sectors << 9;



		bio->bi_end_io	= journal_write_endio;

drivers/md/bcache/request.c

+12 −1
Original line number Diff line number Diff line
@@ -1035,8 +1035,19 @@ static void request_write(struct cached_dev *dc, struct search *s) 


		closure_bio_submit(bio, cl, s->d);

	} else {

		s->op.cache_bio = bio;

		bch_writeback_add(dc);



		if (s->op.flush_journal) {

			/* Also need to send a flush to the backing device */

			s->op.cache_bio = bio_clone_bioset(bio, GFP_NOIO,

							   dc->disk.bio_split);



			bio->bi_size = 0;

			bio->bi_vcnt = 0;

			closure_bio_submit(bio, cl, s->d);

		} else {

			s->op.cache_bio = bio;

		}

	}

out:

	closure_call(&s->op.cl, bch_insert_data, NULL, cl);