2013-04-19 02:29:42

by majianpeng

Subject: [PATCH] fs/buffer.c: Remove the unnecessary init operation after allocating buffer_head.

Because alloc struct buffer_head using kmem_cache_zalloc,so it's not need to
call 'init_buffer(bh, NULL, NULL)'.

Signed-off-by: Jianpeng Ma <[email protected]>
---
fs/buffer.c | 2 --
fs/jbd/journal.c | 1 -
fs/jbd2/journal.c | 1 -
3 files changed, 4 deletions(-)

diff --git a/fs/buffer.c b/fs/buffer.c
index b4dcb34..52b7739 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -865,8 +865,6 @@ try_again:

/* Link the buffer to its page */
set_bh_page(bh, page, offset);
-
- init_buffer(bh, NULL, NULL);
}
return head;
/*
diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
index 81cc7ea..0c3fe90 100644
--- a/fs/jbd/journal.c
+++ b/fs/jbd/journal.c
@@ -311,7 +311,6 @@ int journal_write_metadata_buffer(transaction_t *transaction,
new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
/* keep subsequent assertions sane */
new_bh->b_state = 0;
- init_buffer(new_bh, NULL, NULL);
atomic_set(&new_bh->b_count, 1);
new_jh = journal_add_journal_head(new_bh); /* This sleeps */

diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index ed10991..95120c6 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -368,7 +368,6 @@ retry_alloc:

/* keep subsequent assertions sane */
new_bh->b_state = 0;
- init_buffer(new_bh, NULL, NULL);
atomic_set(&new_bh->b_count, 1);
new_jh = jbd2_journal_add_journal_head(new_bh); /* This sleeps */

--
1.8.2.rc2.4.g7799588

2013-04-19 14:48:19

by Jan Kara

Subject: Re: [PATCH] fs/buffer.c: Remove the unnecessary init operation after allocating buffer_head.

On Fri 19-04-13 10:29:36, majianpeng wrote:
> Because alloc struct buffer_head using kmem_cache_zalloc,so it's not need to
> call 'init_buffer(bh, NULL, NULL)'.
>
> Signed-off-by: Jianpeng Ma <[email protected]>
> ---
> fs/buffer.c | 2 --
> fs/jbd/journal.c | 1 -
> fs/jbd2/journal.c | 1 -
> 3 files changed, 4 deletions(-)
>
> diff --git a/fs/buffer.c b/fs/buffer.c
> index b4dcb34..52b7739 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -865,8 +865,6 @@ try_again:
>
> /* Link the buffer to its page */
> set_bh_page(bh, page, offset);
> -
> - init_buffer(bh, NULL, NULL);
> }
> return head;
> /*
> diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
> index 81cc7ea..0c3fe90 100644
> --- a/fs/jbd/journal.c
> +++ b/fs/jbd/journal.c
> @@ -311,7 +311,6 @@ int journal_write_metadata_buffer(transaction_t *transaction,
> new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
> /* keep subsequent assertions sane */
> new_bh->b_state = 0;
> - init_buffer(new_bh, NULL, NULL);
You can also remove b_state = 0 , can't you?

> atomic_set(&new_bh->b_count, 1);
> new_jh = journal_add_journal_head(new_bh); /* This sleeps */
>
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index ed10991..95120c6 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -368,7 +368,6 @@ retry_alloc:
>
> /* keep subsequent assertions sane */
> new_bh->b_state = 0;
> - init_buffer(new_bh, NULL, NULL);
And the same here. Otherwise the patch looks OK.

Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR

2013-04-22 00:57:25

by majianpeng

Subject: Re: [PATCH] fs/buffer.c: Remove the unnecessary init operation after allocating buffer_head.

On 04/19/2013 10:48 PM, Jan Kara wrote:
> On Fri 19-04-13 10:29:36, majianpeng wrote:
>> Because alloc struct buffer_head using kmem_cache_zalloc,so it's not need to
>> call 'init_buffer(bh, NULL, NULL)'.
>>
>> Signed-off-by: Jianpeng Ma <[email protected]>
>> ---
>> fs/buffer.c | 2 --
>> fs/jbd/journal.c | 1 -
>> fs/jbd2/journal.c | 1 -
>> 3 files changed, 4 deletions(-)
>>
>> diff --git a/fs/buffer.c b/fs/buffer.c
>> index b4dcb34..52b7739 100644
>> --- a/fs/buffer.c
>> +++ b/fs/buffer.c
>> @@ -865,8 +865,6 @@ try_again:
>>
>> /* Link the buffer to its page */
>> set_bh_page(bh, page, offset);
>> -
>> - init_buffer(bh, NULL, NULL);
>> }
>> return head;
>> /*
>> diff --git a/fs/jbd/journal.c b/fs/jbd/journal.c
>> index 81cc7ea..0c3fe90 100644
>> --- a/fs/jbd/journal.c
>> +++ b/fs/jbd/journal.c
>> @@ -311,7 +311,6 @@ int journal_write_metadata_buffer(transaction_t *transaction,
>> new_bh = alloc_buffer_head(GFP_NOFS|__GFP_NOFAIL);
>> /* keep subsequent assertions sane */
>> new_bh->b_state = 0;
>> - init_buffer(new_bh, NULL, NULL);
> You can also remove b_state = 0 , can't you?
>
>> atomic_set(&new_bh->b_count, 1);
>> new_jh = journal_add_journal_head(new_bh); /* This sleeps */
>>
>> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
>> index ed10991..95120c6 100644
>> --- a/fs/jbd2/journal.c
>> +++ b/fs/jbd2/journal.c
>> @@ -368,7 +368,6 @@ retry_alloc:
>>
>> /* keep subsequent assertions sane */
>> new_bh->b_state = 0;
>> - init_buffer(new_bh, NULL, NULL);
> And the same here. Otherwise the patch looks OK.
>
> Honza
Thanks your suggestions.I'll resend .

Thanks!
Jianpeng