bcache: Zero less memory

Another minor performance optimization

Signed-off-by: Kent Overstreet <kmo@daterainc.com>

drivers/md/bcache/closure.h

@@ -347,14 +347,6 @@ do {								\
 	do_closure_init(_cl, parent, running);			\
 } while (0)
 
-/**
- * __closure_init() - Initialize a closure, skipping the memset()
- *
- * May be used instead of closure_init() when memory has already been zeroed.
- */
-#define __closure_init(cl, parent)				\
-	closure_init_type(cl, parent, true)
-
 /**
  * closure_init() - Initialize a closure, setting the refcount to 1
  * @cl:		closure to initialize
@@ -362,10 +354,7 @@ do {								\
  *		lifetime; may be NULL.
  */
 #define closure_init(cl, parent)				\
-do {								\
-	memset((cl), 0, sizeof(*(cl)));				\
-	__closure_init(cl, parent);				\
-} while (0)
+	closure_init_type(cl, parent, true)
 
 static inline void closure_init_stack(struct closure *cl)
 {

drivers/md/bcache/request.c

@@ -597,14 +597,12 @@ struct search {
 	/* Stack frame for bio_complete */
 	struct closure		cl;
 
-	struct bcache_device	*d;
-
 	struct bbio		bio;
 	struct bio		*orig_bio;
 	struct bio		*cache_miss;
+	struct bcache_device	*d;
 
 	unsigned		insert_bio_sectors;
-
 	unsigned		recoverable:1;
 	unsigned		write:1;
 	unsigned		read_dirty_data:1;
@@ -712,10 +710,13 @@ static void cache_lookup(struct closure *cl)
 {
 	struct search *s = container_of(cl, struct search, iop.cl);
 	struct bio *bio = &s->bio.bio;
+	int ret;
 
-	int ret = bch_btree_map_keys(&s->op, s->iop.c,
-				     &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0),
-				     cache_lookup_fn, MAP_END_KEY);
+	bch_btree_op_init(&s->op, -1);
+
+	ret = bch_btree_map_keys(&s->op, s->iop.c,
+				 &KEY(s->iop.inode, bio->bi_iter.bi_sector, 0),
+				 cache_lookup_fn, MAP_END_KEY);
 	if (ret == -EAGAIN)
 		continue_at(cl, cache_lookup, bcache_wq);
 
@@ -756,12 +757,12 @@ static void bio_complete(struct search *s)
 	}
 }
 
-static void do_bio_hook(struct search *s)
+static void do_bio_hook(struct search *s, struct bio *orig_bio)
 {
 	struct bio *bio = &s->bio.bio;
 
 	bio_init(bio);
-	__bio_clone_fast(bio, s->orig_bio);
+	__bio_clone_fast(bio, orig_bio);
 	bio->bi_end_io		= request_endio;
 	bio->bi_private		= &s->cl;
 
@@ -780,26 +781,32 @@ static void search_free(struct closure *cl)
 	mempool_free(s, s->d->c->search);
 }
 
-static struct search *search_alloc(struct bio *bio, struct bcache_device *d)
+static inline struct search *search_alloc(struct bio *bio,
+					  struct bcache_device *d)
 {
 	struct search *s;
 
 	s = mempool_alloc(d->c->search, GFP_NOIO);
-	memset(s, 0, offsetof(struct search, iop.insert_keys));
 
-	__closure_init(&s->cl, NULL);
+	closure_init(&s->cl, NULL);
+	do_bio_hook(s, bio);
 
-	s->iop.inode		= d->id;
-	s->iop.c		= d->c;
-	s->d			= d;
-	s->op.lock		= -1;
-	s->iop.write_point	= hash_long((unsigned long) current, 16);
 	s->orig_bio		= bio;
-	s->write		= (bio->bi_rw & REQ_WRITE) != 0;
-	s->iop.flush_journal	= (bio->bi_rw & (REQ_FLUSH|REQ_FUA)) != 0;
+	s->cache_miss		= NULL;
+	s->d			= d;
 	s->recoverable		= 1;
+	s->write		= (bio->bi_rw & REQ_WRITE) != 0;
+	s->read_dirty_data	= 0;
 	s->start_time		= jiffies;
-	do_bio_hook(s);
+
+	s->iop.c		= d->c;
+	s->iop.bio		= NULL;
+	s->iop.inode		= d->id;
+	s->iop.write_point	= hash_long((unsigned long) current, 16);
+	s->iop.write_prio	= 0;
+	s->iop.error		= 0;
+	s->iop.flags		= 0;
+	s->iop.flush_journal	= (bio->bi_rw & (REQ_FLUSH|REQ_FUA)) != 0;
 
 	return s;
 }
@@ -845,7 +852,7 @@ static void cached_dev_read_error(struct closure *cl)
 		trace_bcache_read_retry(s->orig_bio);
 
 		s->iop.error = 0;
-		do_bio_hook(s);
+		do_bio_hook(s, s->orig_bio);
 
 		/* XXX: invalidate cache */
 

drivers/md/bcache/request.h

@@ -13,17 +13,22 @@ struct data_insert_op {
 	uint16_t		write_prio;
 	short			error;
 
-	unsigned		bypass:1;
-	unsigned		writeback:1;
-	unsigned		flush_journal:1;
-	unsigned		csum:1;
+	union {
+		uint16_t	flags;
 
-	unsigned		replace:1;
-	unsigned		replace_collision:1;
+	struct {
+		unsigned	bypass:1;
+		unsigned	writeback:1;
+		unsigned	flush_journal:1;
+		unsigned	csum:1;
 
-	unsigned		insert_data_done:1;
+		unsigned	replace:1;
+		unsigned	replace_collision:1;
+
+		unsigned	insert_data_done:1;
+	};
+	};
 
-	/* Anything past this point won't get zeroed in search_alloc() */
 	struct keylist		insert_keys;
 	BKEY_PADDED(replace_key);
 };