Patchwork [v2,07/11] fs/ext4: use rbtree postorder iteration helper instead of opencoding

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Submitter Cody P Schafer
Date Nov. 7, 2013, 1:42 a.m.
Message ID <1383788572-25938-8-git-send-email-cody@linux.vnet.ibm.com>
Download mbox | patch
Permalink /patch/289108/
State Not Applicable
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Comments

Cody P Schafer - Nov. 7, 2013, 1:42 a.m.
Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
of opencoding an alternate postorder iteration that modifies the tree

Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
---
 fs/ext4/block_validity.c | 33 ++++-----------------------------
 fs/ext4/dir.c            | 35 +++++------------------------------
 2 files changed, 9 insertions(+), 59 deletions(-)
Jan Kara - Nov. 7, 2013, 9:28 a.m.
On Wed 06-11-13 17:42:36, Cody P Schafer wrote:
> Use rbtree_postorder_for_each_entry_safe() to destroy the rbtree instead
> of opencoding an alternate postorder iteration that modifies the tree
  The patch looks good. You can add:
Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> 
> Signed-off-by: Cody P Schafer <cody@linux.vnet.ibm.com>
> ---
>  fs/ext4/block_validity.c | 33 ++++-----------------------------
>  fs/ext4/dir.c            | 35 +++++------------------------------
>  2 files changed, 9 insertions(+), 59 deletions(-)
> 
> diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
> index 3f11656..41eb9dc 100644
> --- a/fs/ext4/block_validity.c
> +++ b/fs/ext4/block_validity.c
> @@ -180,37 +180,12 @@ int ext4_setup_system_zone(struct super_block *sb)
>  /* Called when the filesystem is unmounted */
>  void ext4_release_system_zone(struct super_block *sb)
>  {
> -	struct rb_node	*n = EXT4_SB(sb)->system_blks.rb_node;
> -	struct rb_node	*parent;
> -	struct ext4_system_zone	*entry;
> +	struct ext4_system_zone	*entry, *n;
>  
> -	while (n) {
> -		/* Do the node's children first */
> -		if (n->rb_left) {
> -			n = n->rb_left;
> -			continue;
> -		}
> -		if (n->rb_right) {
> -			n = n->rb_right;
> -			continue;
> -		}
> -		/*
> -		 * The node has no children; free it, and then zero
> -		 * out parent's link to it.  Finally go to the
> -		 * beginning of the loop and try to free the parent
> -		 * node.
> -		 */
> -		parent = rb_parent(n);
> -		entry = rb_entry(n, struct ext4_system_zone, node);
> +	rbtree_postorder_for_each_entry_safe(entry, n,
> +			&EXT4_SB(sb)->system_blks, node)
>  		kmem_cache_free(ext4_system_zone_cachep, entry);
> -		if (!parent)
> -			EXT4_SB(sb)->system_blks = RB_ROOT;
> -		else if (parent->rb_left == n)
> -			parent->rb_left = NULL;
> -		else if (parent->rb_right == n)
> -			parent->rb_right = NULL;
> -		n = parent;
> -	}
> +
>  	EXT4_SB(sb)->system_blks = RB_ROOT;
>  }
>  
> diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
> index 680bb33..d638c57 100644
> --- a/fs/ext4/dir.c
> +++ b/fs/ext4/dir.c
> @@ -353,41 +353,16 @@ struct fname {
>   */
>  static void free_rb_tree_fname(struct rb_root *root)
>  {
> -	struct rb_node	*n = root->rb_node;
> -	struct rb_node	*parent;
> -	struct fname	*fname;
> -
> -	while (n) {
> -		/* Do the node's children first */
> -		if (n->rb_left) {
> -			n = n->rb_left;
> -			continue;
> -		}
> -		if (n->rb_right) {
> -			n = n->rb_right;
> -			continue;
> -		}
> -		/*
> -		 * The node has no children; free it, and then zero
> -		 * out parent's link to it.  Finally go to the
> -		 * beginning of the loop and try to free the parent
> -		 * node.
> -		 */
> -		parent = rb_parent(n);
> -		fname = rb_entry(n, struct fname, rb_hash);
> +	struct fname *fname, *next;
> +
> +	rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
>  		while (fname) {
>  			struct fname *old = fname;
>  			fname = fname->next;
>  			kfree(old);
>  		}
> -		if (!parent)
> -			*root = RB_ROOT;
> -		else if (parent->rb_left == n)
> -			parent->rb_left = NULL;
> -		else if (parent->rb_right == n)
> -			parent->rb_right = NULL;
> -		n = parent;
> -	}
> +
> +	*root = RB_ROOT;
>  }
>  
>  
> -- 
> 1.8.4.2
>

Patch

diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
index 3f11656..41eb9dc 100644
--- a/fs/ext4/block_validity.c
+++ b/fs/ext4/block_validity.c
@@ -180,37 +180,12 @@  int ext4_setup_system_zone(struct super_block *sb)
 /* Called when the filesystem is unmounted */
 void ext4_release_system_zone(struct super_block *sb)
 {
-	struct rb_node	*n = EXT4_SB(sb)->system_blks.rb_node;
-	struct rb_node	*parent;
-	struct ext4_system_zone	*entry;
+	struct ext4_system_zone	*entry, *n;
 
-	while (n) {
-		/* Do the node's children first */
-		if (n->rb_left) {
-			n = n->rb_left;
-			continue;
-		}
-		if (n->rb_right) {
-			n = n->rb_right;
-			continue;
-		}
-		/*
-		 * The node has no children; free it, and then zero
-		 * out parent's link to it.  Finally go to the
-		 * beginning of the loop and try to free the parent
-		 * node.
-		 */
-		parent = rb_parent(n);
-		entry = rb_entry(n, struct ext4_system_zone, node);
+	rbtree_postorder_for_each_entry_safe(entry, n,
+			&EXT4_SB(sb)->system_blks, node)
 		kmem_cache_free(ext4_system_zone_cachep, entry);
-		if (!parent)
-			EXT4_SB(sb)->system_blks = RB_ROOT;
-		else if (parent->rb_left == n)
-			parent->rb_left = NULL;
-		else if (parent->rb_right == n)
-			parent->rb_right = NULL;
-		n = parent;
-	}
+
 	EXT4_SB(sb)->system_blks = RB_ROOT;
 }
 
diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index 680bb33..d638c57 100644
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -353,41 +353,16 @@  struct fname {
  */
 static void free_rb_tree_fname(struct rb_root *root)
 {
-	struct rb_node	*n = root->rb_node;
-	struct rb_node	*parent;
-	struct fname	*fname;
-
-	while (n) {
-		/* Do the node's children first */
-		if (n->rb_left) {
-			n = n->rb_left;
-			continue;
-		}
-		if (n->rb_right) {
-			n = n->rb_right;
-			continue;
-		}
-		/*
-		 * The node has no children; free it, and then zero
-		 * out parent's link to it.  Finally go to the
-		 * beginning of the loop and try to free the parent
-		 * node.
-		 */
-		parent = rb_parent(n);
-		fname = rb_entry(n, struct fname, rb_hash);
+	struct fname *fname, *next;
+
+	rbtree_postorder_for_each_entry_safe(fname, next, root, rb_hash)
 		while (fname) {
 			struct fname *old = fname;
 			fname = fname->next;
 			kfree(old);
 		}
-		if (!parent)
-			*root = RB_ROOT;
-		else if (parent->rb_left == n)
-			parent->rb_left = NULL;
-		else if (parent->rb_right == n)
-			parent->rb_right = NULL;
-		n = parent;
-	}
+
+	*root = RB_ROOT;
 }