* [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves()
@ 2016-01-26 7:13 Byongho Lee
2016-01-26 8:10 ` Stefan Behrens
2016-01-26 14:58 ` Byongho Lee
0 siblings, 2 replies; 5+ messages in thread
From: Byongho Lee @ 2016-01-26 7:13 UTC (permalink / raw)
To: linux-btrfs, dsterba
Simplify expression in btrfs_csum_bytes_to_leaves().
Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
---
fs/btrfs/ctree.h | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index a9496644f47d..3ab8026280a2 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
unsigned num_items)
{
- return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
- 2 * num_items;
+ return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
}
/*
--
2.7.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves()
2016-01-26 7:13 [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves() Byongho Lee
@ 2016-01-26 8:10 ` Stefan Behrens
2016-01-26 8:46 ` Byongho Lee
2016-01-26 14:58 ` Byongho Lee
1 sibling, 1 reply; 5+ messages in thread
From: Stefan Behrens @ 2016-01-26 8:10 UTC (permalink / raw)
To: Byongho Lee, linux-btrfs, dsterba
The result of the calculation is different, which doesn't look right.
On Tue, 26 Jan 2016 16:13:17 +0900, Byongho Lee wrote:
> Simplify expression in btrfs_csum_bytes_to_leaves().
>
> Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
> ---
> fs/btrfs/ctree.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index a9496644f47d..3ab8026280a2 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
> static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
> unsigned num_items)
> {
> - return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
> - 2 * num_items;
> + return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
> }
>
> /*
>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves()
2016-01-26 8:10 ` Stefan Behrens
@ 2016-01-26 8:46 ` Byongho Lee
2016-01-26 9:03 ` Stefan Behrens
0 siblings, 1 reply; 5+ messages in thread
From: Byongho Lee @ 2016-01-26 8:46 UTC (permalink / raw)
To: Stefan Behrens; +Cc: linux-btrfs, dsterba
Hi Stefan,
Stefan Behrens writes:
> The result of the calculation is different, which doesn't look right.
>
The expression comes out this way.
(root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) * 2 * num_items
->(root->nodesize * (1 + BTRFS_MAX_LEVEL - 1)) * 2 * num_items
->(root->nodesize * (BTRFS_MAX_LEVEL)) * 2 * num_items
=>root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items
Am I missing?
>
> On Tue, 26 Jan 2016 16:13:17 +0900, Byongho Lee wrote:
>> Simplify expression in btrfs_csum_bytes_to_leaves().
>>
>> Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
>> ---
>> fs/btrfs/ctree.h | 3 +--
>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>> index a9496644f47d..3ab8026280a2 100644
>> --- a/fs/btrfs/ctree.h
>> +++ b/fs/btrfs/ctree.h
>> @@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
>> static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
>> unsigned num_items)
>> {
>> - return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
>> - 2 * num_items;
>> + return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
>> }
>>
>> /*
>>
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves()
2016-01-26 8:46 ` Byongho Lee
@ 2016-01-26 9:03 ` Stefan Behrens
0 siblings, 0 replies; 5+ messages in thread
From: Stefan Behrens @ 2016-01-26 9:03 UTC (permalink / raw)
To: Byongho Lee; +Cc: linux-btrfs, dsterba
Correction: The result of the calculation is equal, which looks right.
Sorry for overlooking the closing bracket.
Reviewed-By: Stefan Behrens <sbehrens@giantdisaster.de>
On Tue, 26 Jan 2016 17:46:00 +0900, Byongho Lee wrote:
> Stefan Behrens writes:
>
>> The result of the calculation is different, which doesn't look right.
>>
> The expression comes out this way.
> (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) * 2 * num_items
> ->(root->nodesize * (1 + BTRFS_MAX_LEVEL - 1)) * 2 * num_items
> ->(root->nodesize * (BTRFS_MAX_LEVEL)) * 2 * num_items
> =>root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items
>
> Am I missing?
>
>>
>> On Tue, 26 Jan 2016 16:13:17 +0900, Byongho Lee wrote:
>>> Simplify expression in btrfs_csum_bytes_to_leaves().
>>>
>>> Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
>>> ---
>>> fs/btrfs/ctree.h | 3 +--
>>> 1 file changed, 1 insertion(+), 2 deletions(-)
>>>
>>> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
>>> index a9496644f47d..3ab8026280a2 100644
>>> --- a/fs/btrfs/ctree.h
>>> +++ b/fs/btrfs/ctree.h
>>> @@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
>>> static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
>>> unsigned num_items)
>>> {
>>> - return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
>>> - 2 * num_items;
>>> + return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
>>> }
>>>
>>> /*
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves()
2016-01-26 7:13 [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves() Byongho Lee
2016-01-26 8:10 ` Stefan Behrens
@ 2016-01-26 14:58 ` Byongho Lee
1 sibling, 0 replies; 5+ messages in thread
From: Byongho Lee @ 2016-01-26 14:58 UTC (permalink / raw)
To: linux-btrfs, dsterba
Hi,
Please ignore this patch. Because the function's name is wrong in the
subject line. While I was writing the commit log, I copy & pasted the
first function's name showing in git diff result. I will prepare V2 soon.
Byongho Lee writes:
> Simplify expression in btrfs_csum_bytes_to_leaves().
>
> Signed-off-by: Byongho Lee <bhlee.kernel@gmail.com>
> ---
> fs/btrfs/ctree.h | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index a9496644f47d..3ab8026280a2 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -3448,8 +3448,7 @@ u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes);
> static inline u64 btrfs_calc_trans_metadata_size(struct btrfs_root *root,
> unsigned num_items)
> {
> - return (root->nodesize + root->nodesize * (BTRFS_MAX_LEVEL - 1)) *
> - 2 * num_items;
> + return root->nodesize * BTRFS_MAX_LEVEL * 2 * num_items;
> }
>
> /*
^ permalink raw reply [flat|nested] 5+ messages in thread
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2016-01-26 7:13 [PATCH] btrfs: simplify expression in btrfs_csum_bytes_to_leaves() Byongho Lee
2016-01-26 8:10 ` Stefan Behrens
2016-01-26 8:46 ` Byongho Lee
2016-01-26 9:03 ` Stefan Behrens
2016-01-26 14:58 ` Byongho Lee
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