[PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Wang shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

It can be guranteed that inode->i_sb should not be null in vfs.
So here the check about it is overhead.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
 fs/ext2/balloc.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 1c36139..22993a0 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -1239,10 +1239,6 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
 
 	*errp = -ENOSPC;
 	sb = inode->i_sb;
-	if (!sb) {
-		printk("ext2_new_blocks: nonexistent device");
-		return 0;
-	}
 
 	/*
 	 * Check quota for allocation of this block.
-- 
1.7.11.7

[PATCH 2/3] Ext2: mark inode dirty after the function dquot_free_block_nodirty is called

[Wang shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

We should mark inode dirty after the function dquot_free_block_nodirty
is called.Besides,add a check whether it is necessary to call
dquot_free_block_nodirty functon.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
 fs/ext2/balloc.c | 15 ++++++++++-----
 fs/ext2/xattr.c  |  1 +
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 22993a0..9d372bf 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -568,8 +568,11 @@ do_more:
 	}
 error_return:
 	brelse(bitmap_bh);
-	release_blocks(sb, freed);
-	dquot_free_block_nodirty(inode, freed);
+	if (freed) {
+		release_blocks(sb, freed);
+		dquot_free_block_nodirty(inode, freed);
+		mark_inode_dirty(inode);
+	}
 }
 
 /**
@@ -1412,9 +1415,11 @@ allocated:
 
 	*errp = 0;
 	brelse(bitmap_bh);
-	dquot_free_block_nodirty(inode, *count-num);
-	mark_inode_dirty(inode);
-	*count = num;
+	if (num < *count) {
+		dquot_free_block_nodirty(inode, *count-num);
+		mark_inode_dirty(inode);
+		*count = num;
+	}
 	return ret_block;
 
 io_error:
diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
index b6754db..4c4cda9 100644
--- a/fs/ext2/xattr.c
+++ b/fs/ext2/xattr.c
@@ -795,6 +795,7 @@ ext2_xattr_delete_inode(struct inode *inode)
 		if (IS_SYNC(inode))
 			sync_dirty_buffer(bh);
 		dquot_free_block_nodirty(inode, 1);
+		mark_inode_dirty(inode);
 	}
 	EXT2_I(inode)->i_file_acl = 0;
 
-- 
1.7.11.7

Re: [PATCH 2/3] Ext2: mark inode dirty after the function dquot_free_block_nodirty is called

[Jan Kara]

  Hello,

On Wed 06-02-13 14:14:27, Wang shilong wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> We should mark inode dirty after the function dquot_free_block_nodirty
> is called.Besides,add a check whether it is necessary to call
> dquot_free_block_nodirty functon.
  Thanks for the patch. Just one comment below.

> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
>  fs/ext2/balloc.c | 15 ++++++++++-----
>  fs/ext2/xattr.c  |  1 +
>  2 files changed, 11 insertions(+), 5 deletions(-)
> 
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index 22993a0..9d372bf 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -568,8 +568,11 @@ do_more:
>  	}
>  error_return:
>  	brelse(bitmap_bh);
> -	release_blocks(sb, freed);
> -	dquot_free_block_nodirty(inode, freed);
> +	if (freed) {
> +		release_blocks(sb, freed);
> +		dquot_free_block_nodirty(inode, freed);
> +		mark_inode_dirty(inode);
> +	}
>  }
>  
>  /**
> @@ -1412,9 +1415,11 @@ allocated:
>  
>  	*errp = 0;
>  	brelse(bitmap_bh);
> -	dquot_free_block_nodirty(inode, *count-num);
> -	mark_inode_dirty(inode);
> -	*count = num;
> +	if (num < *count) {
> +		dquot_free_block_nodirty(inode, *count-num);
> +		mark_inode_dirty(inode);
> +		*count = num;
> +	}
>  	return ret_block;
>  
>  io_error:
> diff --git a/fs/ext2/xattr.c b/fs/ext2/xattr.c
> index b6754db..4c4cda9 100644
> --- a/fs/ext2/xattr.c
> +++ b/fs/ext2/xattr.c
> @@ -795,6 +795,7 @@ ext2_xattr_delete_inode(struct inode *inode)
>  		if (IS_SYNC(inode))
>  			sync_dirty_buffer(bh);
>  		dquot_free_block_nodirty(inode, 1);
> +		mark_inode_dirty(inode);
>  	}
>  	EXT2_I(inode)->i_file_acl = 0;
  This isn't necessary as the function is meant to be called only when
inode is going to be deleted and thus there's no point in marking it dirty.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

[PATCH 3/3] Ext2: remove the static function release_blocks to optimize the kernel

[Wang shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

Because the static function 'release_blocks' is only called
when releasing blocks,it will be more simple and efficient to
call the function 'percpu_counter_add' directly.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
 fs/ext2/balloc.c | 11 +----------
 1 file changed, 1 insertion(+), 10 deletions(-)

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 9d372bf..d5a6afd 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -159,15 +159,6 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
 	return bh;
 }
 
-static void release_blocks(struct super_block *sb, int count)
-{
-	if (count) {
-		struct ext2_sb_info *sbi = EXT2_SB(sb);
-
-		percpu_counter_add(&sbi->s_freeblocks_counter, count);
-	}
-}

Re: [PATCH 3/3] Ext2: remove the static function release_blocks to optimize the kernel

[Jan Kara]

On Wed 06-02-13 14:14:28, Wang shilong wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> Because the static function 'release_blocks' is only called
> when releasing blocks,it will be more simple and efficient to
> call the function 'percpu_counter_add' directly.
  Thanks. The patch looks good. Just it depends on the previous patch so
please resend it once with the previous one fixed. Thanks.

								Honza

> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
>  fs/ext2/balloc.c | 11 +----------
>  1 file changed, 1 insertion(+), 10 deletions(-)
> 
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index 9d372bf..d5a6afd 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -159,15 +159,6 @@ read_block_bitmap(struct super_block *sb, unsigned int block_group)
>  	return bh;
>  }
>  
> -static void release_blocks(struct super_block *sb, int count)
> -{
> -	if (count) {
> -		struct ext2_sb_info *sbi = EXT2_SB(sb);
> -
> -		percpu_counter_add(&sbi->s_freeblocks_counter, count);
> -	}
> -}
> -
>  static void group_adjust_blocks(struct super_block *sb, int group_no,
>  	struct ext2_group_desc *desc, struct buffer_head *bh, int count)
>  {
> @@ -569,7 +560,7 @@ do_more:
>  error_return:
>  	brelse(bitmap_bh);
>  	if (freed) {
> -		release_blocks(sb, freed);
> +		percpu_counter_add(&sbi->s_freeblocks_counter, freed);
>  		dquot_free_block_nodirty(inode, freed);
>  		mark_inode_dirty(inode);
>  	}
> -- 
> 1.7.11.7
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

Re: [PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Jan Kara]

On Wed 06-02-13 14:14:26, Wang shilong wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> It can be guranteed that inode->i_sb should not be null in vfs.
> So here the check about it is overhead.
  This patch looks good. I've added it to my tree.

								Honza
> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
>  fs/ext2/balloc.c | 4 ----
>  1 file changed, 4 deletions(-)
> 
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index 1c36139..22993a0 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -1239,10 +1239,6 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,
>  
>  	*errp = -ENOSPC;
>  	sb = inode->i_sb;
> -	if (!sb) {
> -		printk("ext2_new_blocks: nonexistent device");
> -		return 0;
> -	}
>  
>  	/*
>  	 * Check quota for allocation of this block.
> -- 
> 1.7.11.7
> 
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR

[PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Wang Shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

It can be guranteed that inode->i_sb should not be null in vfs.
So here the check about it is overhead.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---
fs/ext2/balloc.c | 4 ----
1 file changed, 4 deletions(-)

diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
index 1c36139..22993a0 100644
--- a/fs/ext2/balloc.c
+++ b/fs/ext2/balloc.c
@@ -1239,10 +1239,6 @@ ext2_fsblk_t ext2_new_blocks(struct inode *inode, ext2_fsblk_t goal,

*errp = -ENOSPC;
sb = inode->i_sb;
- if (!sb) {
- printk("ext2_new_blocks: nonexistent device");
- return 0;
- }

/*
* Check quota for allocation of this block.
-- 
1.7.11.7

[PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Wang Shilong]

From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>

It can be guranteed that inode->i_sb should not be null in vfs.
So here the check about it is overhead.

Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
---

sorry about wrong format patch， i will resend it later.

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Re: [PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Zheng Liu]

On Wed, Feb 06, 2013 at 12:22:47PM -0800, Wang Shilong wrote:
> From: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> 
> It can be guranteed that inode->i_sb should not be null in vfs.
> So here the check about it is overhead.
> 
> Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com>
> ---
> 
> sorry about wrong format patch， i will resend it later.

Hi Shilong,

If you want to re-send a patch series, add [RESEND] in subject, please.
Because it could make us know which is the latest one. :-)

Regards,
                                                - Zheng
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Re: [PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Theodore Ts'o]

On Wed, Feb 06, 2013 at 02:56:46PM +0800, Zheng Liu wrote:
> 
> If you want to re-send a patch series, add [RESEND] in subject, please.
> Because it could make us know which is the latest one. :-)

Ideally, use RESEND if you haven't changed the patch series since the
last time you've sent it.  If you have changed it, please use [PATCH
v2], [PATCH v3], etc.

Thanks,

						- Ted

Re: [PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[shilong wang]

2013/2/7 Theodore Ts'o <tytso@mit.edu>:
> On Wed, Feb 06, 2013 at 02:56:46PM +0800, Zheng Liu wrote:
>>
>> If you want to re-send a patch series, add [RESEND] in subject, please.
>> Because it could make us know which is the latest one. :-)
>
> Ideally, use RESEND if you haven't changed the patch series since the
> last time you've sent it.  If you have changed it, please use [PATCH
> v2], [PATCH v3], etc.

I get it..
Thanks, thanks every one  for teaching me so much...

Now i am trying to do something for ext4 development in my leisure time..
Since i don't know anything about filesystem before.. i have to study
about it from minix to ext2..ext3..ext4..btrfs..

However, it still seems a little hard for me to figure everything out
just by reading code... So i wonder where i can get
some papers or articles about the new concept of filesystems.. for
example extent management or something else for ext4..etc
Maybe it helps a lot for me...

Thanks,
Wang

>
> Thanks,
>
>                                                 - Ted

Re: [PATCH 1/3] Ext2: remove the overhead check about sb in the function ext2_new_blocks

[Zheng Liu]

On Thu, Feb 07, 2013 at 11:22:21PM +0800, shilong wang wrote:
> 2013/2/7 Theodore Ts'o <tytso@mit.edu>:
> > On Wed, Feb 06, 2013 at 02:56:46PM +0800, Zheng Liu wrote:
> >>
> >> If you want to re-send a patch series, add [RESEND] in subject, please.
> >> Because it could make us know which is the latest one. :-)
> >
> > Ideally, use RESEND if you haven't changed the patch series since the
> > last time you've sent it.  If you have changed it, please use [PATCH
> > v2], [PATCH v3], etc.
> 
> I get it..
> Thanks, thanks every one  for teaching me so much...
> 
> Now i am trying to do something for ext4 development in my leisure time..
> Since i don't know anything about filesystem before.. i have to study
> about it from minix to ext2..ext3..ext4..btrfs..
> 
> However, it still seems a little hard for me to figure everything out
> just by reading code... So i wonder where i can get
> some papers or articles about the new concept of filesystems.. for
> example extent management or something else for ext4..etc
> Maybe it helps a lot for me...

This link (https://ext4.wiki.kernel.org/index.php/Main_Page) might be
useful for you.

Regards,
                                                - Zheng