[PATCH 1/3] mbcache: use list_for_each_entry*

[PATCH 1/3] mbcache: use list_for_each_entry*

[Namhyung Kim]

Convert list_for_each*() + list_entry() to list_for_each_entry*().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
 fs/mbcache.c |   36 ++++++++++++++----------------------
 1 files changed, 14 insertions(+), 22 deletions(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index 9344474..0477c71 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -278,21 +278,18 @@ void
 mb_cache_shrink(struct block_device *bdev)
 {
 	LIST_HEAD(free_list);
-	struct list_head *l, *ltmp;
+	struct mb_cache_entry *ce, *tmp;
 
 	spin_lock(&mb_cache_spinlock);
-	list_for_each_safe(l, ltmp, &mb_cache_lru_list) {
-		struct mb_cache_entry *ce =
-			list_entry(l, struct mb_cache_entry, e_lru_list);
+	list_for_each_entry_safe(ce, tmp, &mb_cache_lru_list, e_lru_list) {
 		if (ce->e_bdev == bdev) {
 			list_move_tail(&ce->e_lru_list, &free_list);
 			__mb_cache_entry_unhash(ce);
 		}
 	}
 	spin_unlock(&mb_cache_spinlock);
-	list_for_each_safe(l, ltmp, &free_list) {
-		__mb_cache_entry_forget(list_entry(l, struct mb_cache_entry,
-						   e_lru_list), GFP_KERNEL);
+	list_for_each_entry_safe(ce, tmp, &free_list, e_lru_list) {
+		__mb_cache_entry_forget(ce, GFP_KERNEL);
 	}
 }
 
@@ -308,12 +305,10 @@ void
 mb_cache_destroy(struct mb_cache *cache)
 {
 	LIST_HEAD(free_list);
-	struct list_head *l, *ltmp;
+	struct mb_cache_entry *ce, *tmp;
 
 	spin_lock(&mb_cache_spinlock);
-	list_for_each_safe(l, ltmp, &mb_cache_lru_list) {
-		struct mb_cache_entry *ce =
-			list_entry(l, struct mb_cache_entry, e_lru_list);
+	list_for_each_entry_safe(ce, tmp, &mb_cache_lru_list, e_lru_list) {
 		if (ce->e_cache == cache) {
 			list_move_tail(&ce->e_lru_list, &free_list);
 			__mb_cache_entry_unhash(ce);
@@ -322,9 +317,8 @@ mb_cache_destroy(struct mb_cache *cache)
 	list_del(&cache->c_cache_list);
 	spin_unlock(&mb_cache_spinlock);
 
-	list_for_each_safe(l, ltmp, &free_list) {
-		__mb_cache_entry_forget(list_entry(l, struct mb_cache_entry,
-						   e_lru_list), GFP_KERNEL);
+	list_for_each_entry_safe(ce, tmp, &free_list, e_lru_list) {
+		__mb_cache_entry_forget(ce, GFP_KERNEL);
 	}
 
 	if (atomic_read(&cache->c_entry_count) > 0) {
@@ -398,16 +392,16 @@ mb_cache_entry_insert(struct mb_cache_entry *ce, struct block_device *bdev,
 {
 	struct mb_cache *cache = ce->e_cache;
 	unsigned int bucket;
-	struct list_head *l;
+	struct list_head *block_list;
+	struct mb_cache_entry *entry;
 	int error = -EBUSY;
 
 	bucket = hash_long((unsigned long)bdev + (block & 0xffffffff), 
 			   cache->c_bucket_bits);
+	block_list = &cache->c_block_hash[bucket];
 	spin_lock(&mb_cache_spinlock);
-	list_for_each_prev(l, &cache->c_block_hash[bucket]) {
-		struct mb_cache_entry *ce =
-			list_entry(l, struct mb_cache_entry, e_block_list);
-		if (ce->e_bdev == bdev && ce->e_block == block)
+	list_for_each_entry_reverse(entry, block_list, e_block_list) {
+		if (entry->e_bdev == bdev && entry->e_block == block)
 			goto out;
 	}
 	__mb_cache_entry_unhash(ce);
@@ -468,14 +462,12 @@ mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
 		   sector_t block)
 {
 	unsigned int bucket;
-	struct list_head *l;
 	struct mb_cache_entry *ce;
 
 	bucket = hash_long((unsigned long)bdev + (block & 0xffffffff),
 			   cache->c_bucket_bits);
 	spin_lock(&mb_cache_spinlock);
-	list_for_each(l, &cache->c_block_hash[bucket]) {
-		ce = list_entry(l, struct mb_cache_entry, e_block_list);
+	list_for_each_entry(ce, &cache->c_block_hash[bucket], e_block_list) {
 		if (ce->e_bdev == bdev && ce->e_block == block) {
 			DEFINE_WAIT(wait);
 
-- 
1.7.0.4

[PATCH 2/3] mbcache: remove unnecessary conditionals

[Namhyung Kim]

The commit 2aec7c523291 ("mbcache: Remove unused features") removes
MB_CACHE_INDEXES_COUNT symbol so the test will be passed always.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
 fs/mbcache.c |    6 ------
 1 files changed, 0 insertions(+), 6 deletions(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index 0477c71..c0cfc42 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -71,10 +71,8 @@ EXPORT_SYMBOL(mb_cache_entry_insert);
 EXPORT_SYMBOL(mb_cache_entry_release);
 EXPORT_SYMBOL(mb_cache_entry_free);
 EXPORT_SYMBOL(mb_cache_entry_get);
-#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)
 EXPORT_SYMBOL(mb_cache_entry_find_first);
 EXPORT_SYMBOL(mb_cache_entry_find_next);
-#endif
 
 struct mb_cache {
 	struct list_head		c_cache_list;
@@ -500,8 +498,6 @@ cleanup:
 	return ce;
 }
 
-#if !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0)
-
 static struct mb_cache_entry *
 __mb_cache_entry_find(struct list_head *l, struct list_head *head,
 		      struct block_device *bdev, unsigned int key)
@@ -604,8 +600,6 @@ mb_cache_entry_find_next(struct mb_cache_entry *prev,
 	return ce;
 }
 
-#endif  /* !defined(MB_CACHE_INDEXES_COUNT) || (MB_CACHE_INDEXES_COUNT > 0) */
-
 static int __init init_mbcache(void)
 {
 	register_shrinker(&mb_cache_shrinker);
-- 
1.7.0.4

[PATCH 3/3] mbcache: update comments

[Namhyung Kim]

Add missing arguments in some function comments and update
description of mb_cache_entry_free() because it refers obsolete
mb_cache_entry_takeout().

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
---
 fs/mbcache.c |   17 +++++++++++++++--
 1 files changed, 15 insertions(+), 2 deletions(-)

diff --git a/fs/mbcache.c b/fs/mbcache.c
index c0cfc42..ab73fff 100644
--- a/fs/mbcache.c
+++ b/fs/mbcache.c
@@ -298,6 +298,8 @@ mb_cache_shrink(struct block_device *bdev)
  * Shrinks the cache to its minimum possible size (hopefully 0 entries),
  * and then destroys it. If this was the last mbcache, un-registers the
  * mbcache from kernel memory management.
+ *
+ * @cache: cache to be destroyed
  */
 void
 mb_cache_destroy(struct mb_cache *cache)
@@ -339,6 +341,9 @@ mb_cache_destroy(struct mb_cache *cache)
  * and thus cannot be looked up yet. It should be filled with data, and
  * then inserted into the cache using mb_cache_entry_insert(). Returns NULL
  * if no more memory was available.
+ *
+ * @cache: cache the cache entry to be allocated from
+ * @gfp_flags: memory allocation flags
  */
 struct mb_cache_entry *
 mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
@@ -380,6 +385,7 @@ mb_cache_entry_alloc(struct mb_cache *cache, gfp_t gfp_flags)
  * already (this may happen after a failed lookup, but when another process
  * has inserted the same cache entry in the meantime).
  *
+ * @ce: cache entry to be inserted
  * @bdev: device the cache entry belongs to
  * @block: block number
  * @key: lookup key
@@ -422,6 +428,8 @@ out:
  * Release a handle to a cache entry. When the last handle to a cache entry
  * is released it is either freed (if it is invalid) or otherwise inserted
  * in to the lru list.
+ *
+ * @ce: cache entry to be released
  */
 void
 mb_cache_entry_release(struct mb_cache_entry *ce)
@@ -434,8 +442,9 @@ mb_cache_entry_release(struct mb_cache_entry *ce)
 /*
  * mb_cache_entry_free()
  *
- * This is equivalent to the sequence mb_cache_entry_takeout() --
- * mb_cache_entry_release().
+ * Release a handle to a cache entry and free it.
+ *
+ * @ce: cache entry to be freed
  */
 void
 mb_cache_entry_free(struct mb_cache_entry *ce)
@@ -454,6 +463,10 @@ mb_cache_entry_free(struct mb_cache_entry *ce)
  * in the cache per device and block.) Returns NULL if no such cache entry
  * exists. The returned cache entry is locked for exclusive access ("single
  * writer").
+ *
+ * @cache: cache to search
+ * @bdev: device the cache entry should belong to
+ * @block: block number
  */
 struct mb_cache_entry *
 mb_cache_entry_get(struct mb_cache *cache, struct block_device *bdev,
-- 
1.7.0.4