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From: Coly Li <colyli@suse.de>
To: axboe@kernel.dk
Cc: linux-bcache@vger.kernel.org, linux-block@vger.kernel.org,
	Coly Li <colyli@suse.de>, Hannes Reinecke <hare@suse.de>
Subject: [PATCH 04/15] bcache: remove 'int n' from parameter list of bch_bucket_alloc_set()
Date: Thu,  1 Oct 2020 14:50:45 +0800	[thread overview]
Message-ID: <20201001065056.24411-5-colyli@suse.de> (raw)
In-Reply-To: <20201001065056.24411-1-colyli@suse.de>

The parameter 'int n' from bch_bucket_alloc_set() is not cleared
defined. From the code comments n is the number of buckets to alloc, but
from the code itself 'n' is the maximum cache to iterate. Indeed all the
locations where bch_bucket_alloc_set() is called, 'n' is alwasy 1.

This patch removes the confused and unnecessary 'int n' from parameter
list of  bch_bucket_alloc_set(), and explicitly allocates only 1 bucket
for its caller.

Signed-off-by: Coly Li <colyli@suse.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
---
 drivers/md/bcache/alloc.c  | 35 +++++++++++++++--------------------
 drivers/md/bcache/bcache.h |  4 ++--
 drivers/md/bcache/btree.c  |  2 +-
 drivers/md/bcache/super.c  |  2 +-
 4 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c
index 52035a78d836..4493ff57476d 100644
--- a/drivers/md/bcache/alloc.c
+++ b/drivers/md/bcache/alloc.c
@@ -49,7 +49,7 @@
  *
  * bch_bucket_alloc() allocates a single bucket from a specific cache.
  *
- * bch_bucket_alloc_set() allocates one or more buckets from different caches
+ * bch_bucket_alloc_set() allocates one  bucket from different caches
  * out of a cache set.
  *
  * free_some_buckets() drives all the processes described above. It's called
@@ -488,34 +488,29 @@ void bch_bucket_free(struct cache_set *c, struct bkey *k)
 }
 
 int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
-			   struct bkey *k, int n, bool wait)
+			   struct bkey *k, bool wait)
 {
-	int i;
+	struct cache *ca;
+	long b;
 
 	/* No allocation if CACHE_SET_IO_DISABLE bit is set */
 	if (unlikely(test_bit(CACHE_SET_IO_DISABLE, &c->flags)))
 		return -1;
 
 	lockdep_assert_held(&c->bucket_lock);
-	BUG_ON(!n || n > c->caches_loaded || n > MAX_CACHES_PER_SET);
 
 	bkey_init(k);
 
-	/* sort by free space/prio of oldest data in caches */
-
-	for (i = 0; i < n; i++) {
-		struct cache *ca = c->cache_by_alloc[i];
-		long b = bch_bucket_alloc(ca, reserve, wait);
+	ca = c->cache_by_alloc[0];
+	b = bch_bucket_alloc(ca, reserve, wait);
+	if (b == -1)
+		goto err;
 
-		if (b == -1)
-			goto err;
+	k->ptr[0] = MAKE_PTR(ca->buckets[b].gen,
+			     bucket_to_sector(c, b),
+			     ca->sb.nr_this_dev);
 
-		k->ptr[i] = MAKE_PTR(ca->buckets[b].gen,
-				bucket_to_sector(c, b),
-				ca->sb.nr_this_dev);
-
-		SET_KEY_PTRS(k, i + 1);
-	}
+	SET_KEY_PTRS(k, 1);
 
 	return 0;
 err:
@@ -525,12 +520,12 @@ int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
 }
 
 int bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
-			 struct bkey *k, int n, bool wait)
+			 struct bkey *k, bool wait)
 {
 	int ret;
 
 	mutex_lock(&c->bucket_lock);
-	ret = __bch_bucket_alloc_set(c, reserve, k, n, wait);
+	ret = __bch_bucket_alloc_set(c, reserve, k, wait);
 	mutex_unlock(&c->bucket_lock);
 	return ret;
 }
@@ -638,7 +633,7 @@ bool bch_alloc_sectors(struct cache_set *c,
 
 		spin_unlock(&c->data_bucket_lock);
 
-		if (bch_bucket_alloc_set(c, watermark, &alloc.key, 1, wait))
+		if (bch_bucket_alloc_set(c, watermark, &alloc.key, wait))
 			return false;
 
 		spin_lock(&c->data_bucket_lock);
diff --git a/drivers/md/bcache/bcache.h b/drivers/md/bcache/bcache.h
index 4fd03d2496d8..5ff6e9573935 100644
--- a/drivers/md/bcache/bcache.h
+++ b/drivers/md/bcache/bcache.h
@@ -994,9 +994,9 @@ void bch_bucket_free(struct cache_set *c, struct bkey *k);
 
 long bch_bucket_alloc(struct cache *ca, unsigned int reserve, bool wait);
 int __bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
-			   struct bkey *k, int n, bool wait);
+			   struct bkey *k, bool wait);
 int bch_bucket_alloc_set(struct cache_set *c, unsigned int reserve,
-			 struct bkey *k, int n, bool wait);
+			 struct bkey *k, bool wait);
 bool bch_alloc_sectors(struct cache_set *c, struct bkey *k,
 		       unsigned int sectors, unsigned int write_point,
 		       unsigned int write_prio, bool wait);
diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c
index ae7611fa42bf..e2bd03408e66 100644
--- a/drivers/md/bcache/btree.c
+++ b/drivers/md/bcache/btree.c
@@ -1091,7 +1091,7 @@ struct btree *__bch_btree_node_alloc(struct cache_set *c, struct btree_op *op,
 
 	mutex_lock(&c->bucket_lock);
 retry:
-	if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, wait))
+	if (__bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, wait))
 		goto err;
 
 	bkey_put(c, &k.key);
diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 61abd6499a11..18358b67d8d6 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -486,7 +486,7 @@ static int __uuid_write(struct cache_set *c)
 	closure_init_stack(&cl);
 	lockdep_assert_held(&bch_register_lock);
 
-	if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, 1, true))
+	if (bch_bucket_alloc_set(c, RESERVE_BTREE, &k.key, true))
 		return 1;
 
 	size =  meta_bucket_pages(&c->sb) * PAGE_SECTORS;
-- 
2.26.2


  parent reply	other threads:[~2020-10-01  6:51 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-01  6:50 [PATCH 00/15] bcache patches for Linux v5.10 Coly Li
2020-10-01  6:50 ` [PATCH 01/15] bcache: share register sysfs with async register Coly Li
2020-10-01 21:19   ` Jens Axboe
2020-10-02  1:51     ` Coly Li
2020-10-01  6:50 ` [PATCH 02/15] bcache: check c->root with IS_ERR_OR_NULL() in mca_reserve() Coly Li
2020-10-01  6:50 ` [PATCH 03/15] bcache: Convert to DEFINE_SHOW_ATTRIBUTE Coly Li
2020-10-01  6:50 ` Coly Li [this message]
2020-10-01  6:50 ` [PATCH 05/15] bcache: explicitly make cache_set only have single cache Coly Li
2020-10-01  6:50 ` [PATCH 06/15] bcache: remove for_each_cache() Coly Li
2020-10-01  6:50 ` [PATCH 07/15] bcache: add set_uuid in struct cache_set Coly Li
2020-10-01  6:50 ` [PATCH 08/15] bcache: only use block_bytes() on struct cache Coly Li
2020-10-01  6:50 ` [PATCH 09/15] bcache: remove useless alloc_bucket_pages() Coly Li
2020-10-01  6:50 ` [PATCH 10/15] bcache: remove useless bucket_pages() Coly Li
2020-10-01  6:50 ` [PATCH 11/15] bcache: only use bucket_bytes() on struct cache Coly Li
2020-10-01  6:50 ` [PATCH 12/15] bcache: don't check seq numbers in register_cache_set() Coly Li
2020-10-01  6:50 ` [PATCH 13/15] bcache: remove can_attach_cache() Coly Li
2020-10-01  6:50 ` [PATCH 14/15] bcache: check and set sync status on cache's in-memory super block Coly Li
2020-10-01  6:50 ` [PATCH 15/15] bcache: remove embedded struct cache_sb from struct cache_set Coly Li
2020-10-02 20:29 ` [PATCH 00/15] bcache patches for Linux v5.10 Jens Axboe

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