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* [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for()
@ 2018-09-21  6:45 Qu Wenruo
  2018-09-21  6:45 ` [PATCH 2/2] btrfs: relocation: Remove redundant tree level check Qu Wenruo
  2018-09-21  6:53 ` [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Nikolay Borisov
  0 siblings, 2 replies; 5+ messages in thread
From: Qu Wenruo @ 2018-09-21  6:45 UTC (permalink / raw)
  To: linux-btrfs

And add one line comment explaining what we're doing for each loop.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/relocation.c | 15 ++++++---------
 1 file changed, 6 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 8783a1776540..d7f5a11dde20 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2997,27 +2997,25 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
 		goto out_free_blocks;
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
+	/* Kick in readahead for tree blocks with missing keys */
+	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
 		block = rb_entry(rb_node, struct tree_block, rb_node);
 		if (!block->key_ready)
 			readahead_tree_block(fs_info, block->bytenr);
-		rb_node = rb_next(rb_node);
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
+	/* Get first keys */
+	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
 		block = rb_entry(rb_node, struct tree_block, rb_node);
 		if (!block->key_ready) {
 			err = get_tree_block_key(fs_info, block);
 			if (err)
 				goto out_free_path;
 		}
-		rb_node = rb_next(rb_node);
 	}
 
-	rb_node = rb_first(blocks);
-	while (rb_node) {
+	/* Do tree relocation */
+	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
 		block = rb_entry(rb_node, struct tree_block, rb_node);
 
 		node = build_backref_tree(rc, &block->key,
@@ -3034,7 +3032,6 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
 				err = ret;
 			goto out;
 		}
-		rb_node = rb_next(rb_node);
 	}
 out:
 	err = finish_pending_nodes(trans, rc, path, err);
-- 
2.19.0

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* [PATCH 2/2] btrfs: relocation: Remove redundant tree level check
  2018-09-21  6:45 [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Qu Wenruo
@ 2018-09-21  6:45 ` Qu Wenruo
  2018-09-21  6:55   ` Nikolay Borisov
  2018-09-21  6:53 ` [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Nikolay Borisov
  1 sibling, 1 reply; 5+ messages in thread
From: Qu Wenruo @ 2018-09-21  6:45 UTC (permalink / raw)
  To: linux-btrfs

Commit 581c1760415c ("btrfs: Validate child tree block's level and first
key") has made tree block level check mandatory.

So if tree block level doesn't match, we won't get a valid extent
buffer.
The extra WARN_ON() check can be removed completely.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
 fs/btrfs/relocation.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index d7f5a11dde20..56e2fab2926d 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2911,7 +2911,6 @@ static int get_tree_block_key(struct btrfs_fs_info *fs_info,
 		free_extent_buffer(eb);
 		return -EIO;
 	}
-	WARN_ON(btrfs_header_level(eb) != block->level);
 	if (block->level == 0)
 		btrfs_item_key_to_cpu(eb, &block->key, 0);
 	else
-- 
2.19.0

^ permalink raw reply related	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for()
  2018-09-21  6:45 [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Qu Wenruo
  2018-09-21  6:45 ` [PATCH 2/2] btrfs: relocation: Remove redundant tree level check Qu Wenruo
@ 2018-09-21  6:53 ` Nikolay Borisov
  2018-09-21  6:56   ` Qu Wenruo
  1 sibling, 1 reply; 5+ messages in thread
From: Nikolay Borisov @ 2018-09-21  6:53 UTC (permalink / raw)
  To: Qu Wenruo, linux-btrfs



On 21.09.2018 09:45, Qu Wenruo wrote:
> And add one line comment explaining what we're doing for each loop.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
> ---
>  fs/btrfs/relocation.c | 15 ++++++---------
>  1 file changed, 6 insertions(+), 9 deletions(-)
> 
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index 8783a1776540..d7f5a11dde20 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -2997,27 +2997,25 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
>  		goto out_free_blocks;
>  	}
>  
> -	rb_node = rb_first(blocks);
> -	while (rb_node) {
> +	/* Kick in readahead for tree blocks with missing keys */
> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {

FYI there is already a rbtree_postorder_for_each_entry_safe functino
which allows to iterate the rb tree in post order. It provides stronger
guarantees than you actually need (namely the _safe ) but in any case it
will allows you to get rid of the "block = " line as well as the
"rb_node =" line. This will remove all superfluous code that's needed to
handle the iteration.

>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>  		if (!block->key_ready)
>  			readahead_tree_block(fs_info, block->bytenr);
> -		rb_node = rb_next(rb_node);
>  	}
>  
> -	rb_node = rb_first(blocks);
> -	while (rb_node) {
> +	/* Get first keys */
> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>  		if (!block->key_ready) {
>  			err = get_tree_block_key(fs_info, block);
>  			if (err)
>  				goto out_free_path;
>  		}
> -		rb_node = rb_next(rb_node);
>  	}
>  
> -	rb_node = rb_first(blocks);
> -	while (rb_node) {
> +	/* Do tree relocation */
> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>  
>  		node = build_backref_tree(rc, &block->key,
> @@ -3034,7 +3032,6 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
>  				err = ret;
>  			goto out;
>  		}
> -		rb_node = rb_next(rb_node);
>  	}
>  out:
>  	err = finish_pending_nodes(trans, rc, path, err);
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 2/2] btrfs: relocation: Remove redundant tree level check
  2018-09-21  6:45 ` [PATCH 2/2] btrfs: relocation: Remove redundant tree level check Qu Wenruo
@ 2018-09-21  6:55   ` Nikolay Borisov
  0 siblings, 0 replies; 5+ messages in thread
From: Nikolay Borisov @ 2018-09-21  6:55 UTC (permalink / raw)
  To: Qu Wenruo, linux-btrfs



On 21.09.2018 09:45, Qu Wenruo wrote:
> Commit 581c1760415c ("btrfs: Validate child tree block's level and first
> key") has made tree block level check mandatory.
> 
> So if tree block level doesn't match, we won't get a valid extent
> buffer.
> The extra WARN_ON() check can be removed completely.
> 
> Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
> ---
>  fs/btrfs/relocation.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
> index d7f5a11dde20..56e2fab2926d 100644
> --- a/fs/btrfs/relocation.c
> +++ b/fs/btrfs/relocation.c
> @@ -2911,7 +2911,6 @@ static int get_tree_block_key(struct btrfs_fs_info *fs_info,
>  		free_extent_buffer(eb);
>  		return -EIO;
>  	}
> -	WARN_ON(btrfs_header_level(eb) != block->level);
>  	if (block->level == 0)
>  		btrfs_item_key_to_cpu(eb, &block->key, 0);
>  	else
> 

^ permalink raw reply	[flat|nested] 5+ messages in thread

* Re: [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for()
  2018-09-21  6:53 ` [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Nikolay Borisov
@ 2018-09-21  6:56   ` Qu Wenruo
  0 siblings, 0 replies; 5+ messages in thread
From: Qu Wenruo @ 2018-09-21  6:56 UTC (permalink / raw)
  To: Nikolay Borisov, Qu Wenruo, linux-btrfs



On 2018/9/21 下午2:53, Nikolay Borisov wrote:
> 
> 
> On 21.09.2018 09:45, Qu Wenruo wrote:
>> And add one line comment explaining what we're doing for each loop.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  fs/btrfs/relocation.c | 15 ++++++---------
>>  1 file changed, 6 insertions(+), 9 deletions(-)
>>
>> diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
>> index 8783a1776540..d7f5a11dde20 100644
>> --- a/fs/btrfs/relocation.c
>> +++ b/fs/btrfs/relocation.c
>> @@ -2997,27 +2997,25 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
>>  		goto out_free_blocks;
>>  	}
>>  
>> -	rb_node = rb_first(blocks);
>> -	while (rb_node) {
>> +	/* Kick in readahead for tree blocks with missing keys */
>> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
> 
> FYI there is already a rbtree_postorder_for_each_entry_safe functino
> which allows to iterate the rb tree in post order. It provides stronger
> guarantees than you actually need (namely the _safe ) but in any case it
> will allows you to get rid of the "block = " line as well as the
> "rb_node =" line. This will remove all superfluous code that's needed to
> handle the iteration.

Great thanks!

This is much better solution, I'll use them in next version.

Thanks,
Qu

> 
>>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>>  		if (!block->key_ready)
>>  			readahead_tree_block(fs_info, block->bytenr);
>> -		rb_node = rb_next(rb_node);
>>  	}
>>  
>> -	rb_node = rb_first(blocks);
>> -	while (rb_node) {
>> +	/* Get first keys */
>> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
>>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>>  		if (!block->key_ready) {
>>  			err = get_tree_block_key(fs_info, block);
>>  			if (err)
>>  				goto out_free_path;
>>  		}
>> -		rb_node = rb_next(rb_node);
>>  	}
>>  
>> -	rb_node = rb_first(blocks);
>> -	while (rb_node) {
>> +	/* Do tree relocation */
>> +	for (rb_node = rb_first(blocks); rb_node; rb_node = rb_next(rb_node)) {
>>  		block = rb_entry(rb_node, struct tree_block, rb_node);
>>  
>>  		node = build_backref_tree(rc, &block->key,
>> @@ -3034,7 +3032,6 @@ int relocate_tree_blocks(struct btrfs_trans_handle *trans,
>>  				err = ret;
>>  			goto out;
>>  		}
>> -		rb_node = rb_next(rb_node);
>>  	}
>>  out:
>>  	err = finish_pending_nodes(trans, rc, path, err);
>>

^ permalink raw reply	[flat|nested] 5+ messages in thread

end of thread, other threads:[~2018-09-21 12:44 UTC | newest]

Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-21  6:45 [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Qu Wenruo
2018-09-21  6:45 ` [PATCH 2/2] btrfs: relocation: Remove redundant tree level check Qu Wenruo
2018-09-21  6:55   ` Nikolay Borisov
2018-09-21  6:53 ` [PATCH 1/2] btrfs: relocation: Cleanup while() loop using for() Nikolay Borisov
2018-09-21  6:56   ` Qu Wenruo

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