[PATCHv4 0/3] btrfs: remove unneeded variable and if possbile

[PATCHv4 0/3] btrfs: remove unneeded variable and if possbile

[zhong jiang]

v3->v4:
 -  btrfs_destroy_delayed_refs return value would be actually needed.
    so just remove the unneeded variable "ret" and modify the subject

v2->v3:
 - repost the patches with detailed commit message.

v1->v2:
 - Fix v1 issue that forget to return after remove the variable "ret".

zhong jiang (3):
  btrfs: remove unneeded variable "ret" in btrfs_destroy_delayed_refs
  btrfs: change btrfs_free_reserved_bytes to be void funtion
  btrfs: change btrfs_pin_log_trans to be void function

 fs/btrfs/disk-io.c     | 5 ++---
 fs/btrfs/extent-tree.c | 6 ++----
 fs/btrfs/tree-log.c    | 5 +----
 fs/btrfs/tree-log.h    | 2 +-
 4 files changed, 6 insertions(+), 12 deletions(-)

-- 
1.7.12.4

[PATCHv4 1/3] btrfs: remove unneeded variable "ret" in btrfs_destroy_delayed_refs

[zhong jiang]

btrfs_destroy_delayed_refs defines the variable "ret" for return value,
but it is not modified after initialization. So it is safe to drop the
unneeded value "ret".

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/btrfs/disk-io.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 5124c15..6cdc23a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -4192,7 +4192,6 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 	struct rb_node *node;
 	struct btrfs_delayed_ref_root *delayed_refs;
 	struct btrfs_delayed_ref_node *ref;
-	int ret = 0;
 
 	delayed_refs = &trans->delayed_refs;
 
@@ -4200,7 +4199,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 	if (atomic_read(&delayed_refs->num_entries) == 0) {
 		spin_unlock(&delayed_refs->lock);
 		btrfs_info(fs_info, "delayed_refs has NO entry");
-		return ret;
+		return 0;
 	}
 
 	while ((node = rb_first(&delayed_refs->href_root)) != NULL) {
@@ -4255,7 +4254,7 @@ static int btrfs_destroy_delayed_refs(struct btrfs_transaction *trans,
 
 	spin_unlock(&delayed_refs->lock);
 
-	return ret;
+	return 0;
 }
 
 static void btrfs_destroy_delalloc_inodes(struct btrfs_root *root)
-- 
1.7.12.4

[PATCHv4 2/3] btrfs: change btrfs_free_reserved_bytes to be void funtion

[zhong jiang]

btrfs_free_reserved_bytes use the variable "ret" for return return value,
but it is not modified after initialzation. Further, I find that any of
the callers do not handle the return value, so it is safe to drop the
unneeded "ret" and make it to be void function.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/btrfs/extent-tree.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f77226d..ff305f5 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -6464,11 +6464,10 @@ static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache,
  * reserve set to 0 in order to clear the reservation.
  */
 
-static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
-				     u64 num_bytes, int delalloc)
+static void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
+				      u64 num_bytes, int delalloc)
 {
 	struct btrfs_space_info *space_info = cache->space_info;
-	int ret = 0;
 
 	spin_lock(&space_info->lock);
 	spin_lock(&cache->lock);
@@ -6481,7 +6480,6 @@ static int btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache,
 		cache->delalloc_bytes -= num_bytes;
 	spin_unlock(&cache->lock);
 	spin_unlock(&space_info->lock);
-	return ret;
 }
 void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info)
 {
-- 
1.7.12.4

[PATCHv4 3/3] btrfs: change btrfs_pin_log_trans to be void function

[zhong jiang]

btrfs_pin_log_trans defines the variable "ret" for return value,
but it is not modified after initialization. Further, I find that
any of the callers do not handle the return value, so it is safe
to drop the unneeded "ret" and make it to be void function.

Signed-off-by: zhong jiang <zhongjiang@huawei.com>
---
 fs/btrfs/tree-log.c | 5 +----
 fs/btrfs/tree-log.h | 2 +-
 2 files changed, 2 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 1650dc4..4ed7379 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -205,14 +205,11 @@ static int join_running_log_trans(struct btrfs_root *root)
  * until you call btrfs_end_log_trans() or it makes any future
  * log transactions wait until you call btrfs_end_log_trans()
  */
-int btrfs_pin_log_trans(struct btrfs_root *root)
+void btrfs_pin_log_trans(struct btrfs_root *root)
 {
-	int ret = -ENOENT;
-
 	mutex_lock(&root->log_mutex);
 	atomic_inc(&root->log_writers);
 	mutex_unlock(&root->log_mutex);
-	return ret;
 }
 
 /*
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index 122e68b..8977678 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -65,7 +65,7 @@ int btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
 			       const char *name, int name_len,
 			       struct btrfs_inode *inode, u64 dirid);
 void btrfs_end_log_trans(struct btrfs_root *root);
-int btrfs_pin_log_trans(struct btrfs_root *root);
+void btrfs_pin_log_trans(struct btrfs_root *root);
 void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
 			     struct btrfs_inode *dir, struct btrfs_inode *inode,
 			     int for_rename);
-- 
1.7.12.4

Re: [PATCHv4 1/3] btrfs: remove unneeded variable "ret" in btrfs_destroy_delayed_refs

[David Sterba]

On Fri, Aug 17, 2018 at 12:37:13AM +0800, zhong jiang wrote:
> btrfs_destroy_delayed_refs defines the variable "ret" for return value,
> but it is not modified after initialization. So it is safe to drop the
> unneeded value "ret".

No it's not, please read my previous reply again.

Re: [PATCHv4 0/3] btrfs: remove unneeded variable and if possbile

[David Sterba]

On Fri, Aug 17, 2018 at 12:37:12AM +0800, zhong jiang wrote:
> v3->v4:
>  -  btrfs_destroy_delayed_refs return value would be actually needed.
>     so just remove the unneeded variable "ret" and modify the subject
> 
> v2->v3:
>  - repost the patches with detailed commit message.
> 
> v1->v2:
>  - Fix v1 issue that forget to return after remove the variable "ret".
> 
> zhong jiang (3):
>   btrfs: remove unneeded variable "ret" in btrfs_destroy_delayed_refs
>   btrfs: change btrfs_free_reserved_bytes to be void funtion
>   btrfs: change btrfs_pin_log_trans to be void function

Patches 2 and 3 applied, thanks, but the first one dropped.