Commit 72c27061 authored by Kent Overstreet's avatar Kent Overstreet
Browse files

bcache: Write out full stripes 



Now that we're tracking dirty data per stripe, we can add two
optimizations for raid5/6:

 * If a stripe is already dirty, force writes to that stripe to
   writeback mode - to help build up full stripes of dirty data

 * When flushing dirty data, preferentially write out full stripes first
   if there are any.

Signed-off-by: default avatarKent Overstreet <koverstreet@google.com>
parent 279afbad

drivers/md/bcache/bcache.h

+1 −2
Original line number Diff line number Diff line
@@ -387,8 +387,6 @@ struct keybuf_key { 
typedef bool (keybuf_pred_fn)(struct keybuf *, struct bkey *);



struct keybuf {

	keybuf_pred_fn		*key_predicate;



	struct bkey		last_scanned;

	spinlock_t		lock;
@@ -532,6 +530,7 @@ struct cached_dev { 
	unsigned		sequential_merge:1;

	unsigned		verify:1;



	unsigned		partial_stripes_expensive:1;

	unsigned		writeback_metadata:1;

	unsigned		writeback_running:1;

	unsigned char		writeback_percent;

drivers/md/bcache/btree.c

+10 −9
Original line number Diff line number Diff line
@@ -2252,7 +2252,8 @@ static inline int keybuf_nonoverlapping_cmp(struct keybuf_key *l, 
}



static int bch_btree_refill_keybuf(struct btree *b, struct btree_op *op,

				   struct keybuf *buf, struct bkey *end)

				   struct keybuf *buf, struct bkey *end,

				   keybuf_pred_fn *pred)

{

	struct btree_iter iter;

	bch_btree_iter_init(b, &iter, &buf->last_scanned);
@@ -2271,7 +2272,7 @@ static int bch_btree_refill_keybuf(struct btree *b, struct btree_op *op, 
			if (bkey_cmp(&buf->last_scanned, end) >= 0)

				break;



			if (buf->key_predicate(buf, k)) {

			if (pred(buf, k)) {

				struct keybuf_key *w;



				spin_lock(&buf->lock);
@@ -2290,7 +2291,7 @@ static int bch_btree_refill_keybuf(struct btree *b, struct btree_op *op, 
			if (!k)

				break;



			btree(refill_keybuf, k, b, op, buf, end);

			btree(refill_keybuf, k, b, op, buf, end, pred);

			/*

			 * Might get an error here, but can't really do anything

			 * and it'll get logged elsewhere. Just read what we
@@ -2308,7 +2309,7 @@ static int bch_btree_refill_keybuf(struct btree *b, struct btree_op *op, 
}



void bch_refill_keybuf(struct cache_set *c, struct keybuf *buf,

			  struct bkey *end)

		       struct bkey *end, keybuf_pred_fn *pred)

{

	struct bkey start = buf->last_scanned;

	struct btree_op op;
@@ -2316,7 +2317,7 @@ void bch_refill_keybuf(struct cache_set *c, struct keybuf *buf, 


	cond_resched();



	btree_root(refill_keybuf, c, &op, buf, end);

	btree_root(refill_keybuf, c, &op, buf, end, pred);

	closure_sync(&op.cl);



	pr_debug("found %s keys from %llu:%llu to %llu:%llu",
@@ -2402,7 +2403,8 @@ struct keybuf_key *bch_keybuf_next(struct keybuf *buf) 


struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c,

					     struct keybuf *buf,

					     struct bkey *end)

					     struct bkey *end,

					     keybuf_pred_fn *pred)

{

	struct keybuf_key *ret;
@@ -2416,15 +2418,14 @@ struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *c, 
			break;

		}



		bch_refill_keybuf(c, buf, end);

		bch_refill_keybuf(c, buf, end, pred);

	}



	return ret;

}



void bch_keybuf_init(struct keybuf *buf, keybuf_pred_fn *fn)

void bch_keybuf_init(struct keybuf *buf)

{

	buf->key_predicate	= fn;

	buf->last_scanned	= MAX_KEY;

	buf->keys		= RB_ROOT;

drivers/md/bcache/btree.h

+5 −4
Original line number Diff line number Diff line
@@ -391,13 +391,14 @@ void bch_moving_gc(struct closure *); 
int bch_btree_check(struct cache_set *, struct btree_op *);

uint8_t __bch_btree_mark_key(struct cache_set *, int, struct bkey *);



void bch_keybuf_init(struct keybuf *, keybuf_pred_fn *);

void bch_refill_keybuf(struct cache_set *, struct keybuf *, struct bkey *);

void bch_keybuf_init(struct keybuf *);

void bch_refill_keybuf(struct cache_set *, struct keybuf *, struct bkey *,

		       keybuf_pred_fn *);

bool bch_keybuf_check_overlapping(struct keybuf *, struct bkey *,

				  struct bkey *);

void bch_keybuf_del(struct keybuf *, struct keybuf_key *);

struct keybuf_key *bch_keybuf_next(struct keybuf *);

struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *,

					  struct keybuf *, struct bkey *);

struct keybuf_key *bch_keybuf_next_rescan(struct cache_set *, struct keybuf *,

					  struct bkey *, keybuf_pred_fn *);



#endif

drivers/md/bcache/debug.c

+2 −2
Original line number Diff line number Diff line
@@ -357,7 +357,7 @@ static ssize_t bch_dump_read(struct file *file, char __user *buf, 
		if (i->bytes)

			break;



		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY);

		w = bch_keybuf_next_rescan(i->c, &i->keys, &MAX_KEY, dump_pred);

		if (!w)

			break;
@@ -380,7 +380,7 @@ static int bch_dump_open(struct inode *inode, struct file *file) 


	file->private_data = i;

	i->c = c;

	bch_keybuf_init(&i->keys, dump_pred);

	bch_keybuf_init(&i->keys);

	i->keys.last_scanned = KEY(0, 0, 0);



	return 0;

drivers/md/bcache/movinggc.c

+3 −2
Original line number Diff line number Diff line
@@ -136,7 +136,8 @@ static void read_moving(struct closure *cl) 
	/* XXX: if we error, background writeback could stall indefinitely */



	while (!test_bit(CACHE_SET_STOPPING, &c->flags)) {

		w = bch_keybuf_next_rescan(c, &c->moving_gc_keys, &MAX_KEY);

		w = bch_keybuf_next_rescan(c, &c->moving_gc_keys,

					   &MAX_KEY, moving_pred);

		if (!w)

			break;
@@ -248,5 +249,5 @@ void bch_moving_gc(struct closure *cl) 


void bch_moving_init_cache_set(struct cache_set *c)

{

	bch_keybuf_init(&c->moving_gc_keys, moving_pred);

	bch_keybuf_init(&c->moving_gc_keys);

}

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