diff mbox

[2/4] Btrfs: check if directory has already been created smarter

Message ID 1393486780-17811-2-git-send-email-bo.li.liu@oracle.com (mailing list archive)
State New, archived
Headers show

Commit Message

Liu Bo Feb. 27, 2014, 7:39 a.m. UTC
Currently to check whether a directory has been created, we search
DIR_INDEX items one by one to check if children has been processed.

Try to picture such a scenario:
   .
   |-- dir            (ino X)
         |-- foo_1    (ino X+1)
         |-- ...
         |-- foo_k    (ino X+k)

With the current way, we have to check all the k DIR_INDEX items
to find it is a fresh new one.

So this introduced a rbtree to store those directories which are
created out of order, and in the above case, we just need an O(logn)
search instead of O(1) search.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
---
 fs/btrfs/send.c | 87 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 43 insertions(+), 44 deletions(-)

Comments

Liu Bo Feb. 27, 2014, 7:44 a.m. UTC | #1
Sorry for the noise, it should be PATCH 1/2 and PATCH 2/2.

-liubo

On Thu, Feb 27, 2014 at 03:39:40PM +0800, Liu Bo wrote:
> Currently to check whether a directory has been created, we search
> DIR_INDEX items one by one to check if children has been processed.
> 
> Try to picture such a scenario:
>    .
>    |-- dir            (ino X)
>          |-- foo_1    (ino X+1)
>          |-- ...
>          |-- foo_k    (ino X+k)
> 
> With the current way, we have to check all the k DIR_INDEX items
> to find it is a fresh new one.
> 
> So this introduced a rbtree to store those directories which are
> created out of order, and in the above case, we just need an O(logn)
> search instead of O(1) search.
> 
> Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
> ---
>  fs/btrfs/send.c | 87 ++++++++++++++++++++++++++++-----------------------------
>  1 file changed, 43 insertions(+), 44 deletions(-)
> 
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index 33063d1..fcad93c 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -175,6 +175,9 @@ struct send_ctx {
>  	 * own move/rename can be performed.
>  	 */
>  	struct rb_root waiting_dir_moves;
> +
> +	/* directories which are created out of order, check did_create_dir() */
> +	struct rb_root out_of_order;
>  };
>  
>  struct pending_dir_move {
> @@ -2494,56 +2497,40 @@ out:
>   */
>  static int did_create_dir(struct send_ctx *sctx, u64 dir)
>  {
> -	int ret = 0;
> -	struct btrfs_path *path = NULL;
> -	struct btrfs_key key;
> -	struct btrfs_key found_key;
> -	struct btrfs_key di_key;
> -	struct extent_buffer *eb;
> -	struct btrfs_dir_item *di;
> -	int slot;
> +	struct rb_node **p = &sctx->out_of_order.rb_node;
> +	struct rb_node *parent = NULL;
> +	struct send_dir_node *entry = NULL;
> +	int cur_is_dir = !!(dir == sctx->cur_ino);
>  
> -	path = alloc_path_for_send();
> -	if (!path) {
> -		ret = -ENOMEM;
> -		goto out;
> -	}
> +	verbose_printk("dir=%llu cur_ino=%llu send_progress=%llu\n",
> +		 dir, sctx->cur_ino, sctx->send_progress);
>  
> -	key.objectid = dir;
> -	key.type = BTRFS_DIR_INDEX_KEY;
> -	key.offset = 0;
> -	while (1) {
> -		ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
> -				1, 0);
> -		if (ret < 0)
> -			goto out;
> -		if (!ret) {
> -			eb = path->nodes[0];
> -			slot = path->slots[0];
> -			btrfs_item_key_to_cpu(eb, &found_key, slot);
> -		}
> -		if (ret || found_key.objectid != key.objectid ||
> -		    found_key.type != key.type) {
> -			ret = 0;
> -			goto out;
> +	while (*p) {
> +		parent = *p;
> +		entry = rb_entry(parent, struct send_dir_node, node);
> +		if (dir < entry->ino) {
> +			p = &(*p)->rb_left;
> +		} else if (dir > entry->ino) {
> +			p = &(*p)->rb_right;
> +		} else {
> +			if (cur_is_dir) {
> +				rb_erase(&entry->node, &sctx->out_of_order);
> +				kfree(entry);
> +			}
> +			return 1;
>  		}
> +	}
>  
> -		di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
> -		btrfs_dir_item_key_to_cpu(eb, di, &di_key);
> -
> -		if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
> -		    di_key.objectid < sctx->send_progress) {
> -			ret = 1;
> -			goto out;
> -		}
> +	if (!cur_is_dir) {
> +		entry = kmalloc(sizeof(*entry), GFP_NOFS);
> +		if (!entry)
> +			return -ENOMEM;
> +		entry->ino = dir;
>  
> -		key.offset = found_key.offset + 1;
> -		btrfs_release_path(path);
> +		rb_link_node(&entry->node, parent, p);
> +		rb_insert_color(&entry->node, &sctx->out_of_order);
>  	}
> -
> -out:
> -	btrfs_free_path(path);
> -	return ret;
> +	return 0;
>  }
>  
>  /*
> @@ -5340,6 +5327,7 @@ long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
>  
>  	sctx->pending_dir_moves = RB_ROOT;
>  	sctx->waiting_dir_moves = RB_ROOT;
> +	sctx->out_of_order = RB_ROOT;
>  
>  	sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
>  			(arg->clone_sources_count + 1));
> @@ -5477,6 +5465,17 @@ out:
>  		kfree(dm);
>  	}
>  
> +	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->out_of_order));
> +	while (sctx && !RB_EMPTY_ROOT(&sctx->out_of_order)) {
> +		struct rb_node *n;
> +		struct send_dir_node *entry;
> +
> +		n = rb_first(&sctx->out_of_order);
> +		entry = rb_entry(n, struct send_dir_node, node);
> +		rb_erase(&entry->node, &sctx->out_of_order);
> +		kfree(entry);
> +	}
> +
>  	if (sort_clone_roots) {
>  		for (i = 0; i < sctx->clone_roots_cnt; i++)
>  			btrfs_root_dec_send_in_progress(
> -- 
> 1.8.2.1
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 33063d1..fcad93c 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -175,6 +175,9 @@  struct send_ctx {
 	 * own move/rename can be performed.
 	 */
 	struct rb_root waiting_dir_moves;
+
+	/* directories which are created out of order, check did_create_dir() */
+	struct rb_root out_of_order;
 };
 
 struct pending_dir_move {
@@ -2494,56 +2497,40 @@  out:
  */
 static int did_create_dir(struct send_ctx *sctx, u64 dir)
 {
-	int ret = 0;
-	struct btrfs_path *path = NULL;
-	struct btrfs_key key;
-	struct btrfs_key found_key;
-	struct btrfs_key di_key;
-	struct extent_buffer *eb;
-	struct btrfs_dir_item *di;
-	int slot;
+	struct rb_node **p = &sctx->out_of_order.rb_node;
+	struct rb_node *parent = NULL;
+	struct send_dir_node *entry = NULL;
+	int cur_is_dir = !!(dir == sctx->cur_ino);
 
-	path = alloc_path_for_send();
-	if (!path) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	verbose_printk("dir=%llu cur_ino=%llu send_progress=%llu\n",
+		 dir, sctx->cur_ino, sctx->send_progress);
 
-	key.objectid = dir;
-	key.type = BTRFS_DIR_INDEX_KEY;
-	key.offset = 0;
-	while (1) {
-		ret = btrfs_search_slot_for_read(sctx->send_root, &key, path,
-				1, 0);
-		if (ret < 0)
-			goto out;
-		if (!ret) {
-			eb = path->nodes[0];
-			slot = path->slots[0];
-			btrfs_item_key_to_cpu(eb, &found_key, slot);
-		}
-		if (ret || found_key.objectid != key.objectid ||
-		    found_key.type != key.type) {
-			ret = 0;
-			goto out;
+	while (*p) {
+		parent = *p;
+		entry = rb_entry(parent, struct send_dir_node, node);
+		if (dir < entry->ino) {
+			p = &(*p)->rb_left;
+		} else if (dir > entry->ino) {
+			p = &(*p)->rb_right;
+		} else {
+			if (cur_is_dir) {
+				rb_erase(&entry->node, &sctx->out_of_order);
+				kfree(entry);
+			}
+			return 1;
 		}
+	}
 
-		di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
-		btrfs_dir_item_key_to_cpu(eb, di, &di_key);
-
-		if (di_key.type != BTRFS_ROOT_ITEM_KEY &&
-		    di_key.objectid < sctx->send_progress) {
-			ret = 1;
-			goto out;
-		}
+	if (!cur_is_dir) {
+		entry = kmalloc(sizeof(*entry), GFP_NOFS);
+		if (!entry)
+			return -ENOMEM;
+		entry->ino = dir;
 
-		key.offset = found_key.offset + 1;
-		btrfs_release_path(path);
+		rb_link_node(&entry->node, parent, p);
+		rb_insert_color(&entry->node, &sctx->out_of_order);
 	}
-
-out:
-	btrfs_free_path(path);
-	return ret;
+	return 0;
 }
 
 /*
@@ -5340,6 +5327,7 @@  long btrfs_ioctl_send(struct file *mnt_file, void __user *arg_)
 
 	sctx->pending_dir_moves = RB_ROOT;
 	sctx->waiting_dir_moves = RB_ROOT;
+	sctx->out_of_order = RB_ROOT;
 
 	sctx->clone_roots = vzalloc(sizeof(struct clone_root) *
 			(arg->clone_sources_count + 1));
@@ -5477,6 +5465,17 @@  out:
 		kfree(dm);
 	}
 
+	WARN_ON(sctx && !ret && !RB_EMPTY_ROOT(&sctx->out_of_order));
+	while (sctx && !RB_EMPTY_ROOT(&sctx->out_of_order)) {
+		struct rb_node *n;
+		struct send_dir_node *entry;
+
+		n = rb_first(&sctx->out_of_order);
+		entry = rb_entry(n, struct send_dir_node, node);
+		rb_erase(&entry->node, &sctx->out_of_order);
+		kfree(entry);
+	}
+
 	if (sort_clone_roots) {
 		for (i = 0; i < sctx->clone_roots_cnt; i++)
 			btrfs_root_dec_send_in_progress(