linux-ext4 - Re: [PATCH 4/4] ext4: Fold ext4_data_block_valid

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Date:   Tue, 21 Jul 2020 12:39:22 +0200
From:   Lukas Czerner <lczerner@...hat.com>
To:     Jan Kara <jack@...e.cz>
Cc:     Ted Tso <tytso@....edu>, linux-ext4@...r.kernel.org,
        Ritesh Harjani <riteshh@...ux.ibm.com>,
        Wolfgang Frisch <wolfgang.frisch@...e.com>
Subject: Re: [PATCH 4/4] ext4: Fold ext4_data_block_valid_rcu() into the
 caller

On Wed, Jul 15, 2020 at 03:18:12PM +0200, Jan Kara wrote:
> After the previous patch, ext4_data_block_valid_rcu() has a single
> caller. Fold it into it.

Looks good, thanks!

Reviewed-by: Lukas Czerner <lczerner@...hat.com>

> 
> Signed-off-by: Jan Kara <jack@...e.cz>
> ---
>  fs/ext4/block_validity.c | 67 ++++++++++++++++++++++--------------------------
>  1 file changed, 30 insertions(+), 37 deletions(-)
> 
> diff --git a/fs/ext4/block_validity.c b/fs/ext4/block_validity.c
> index 3602356cbf09..9c40214f31f9 100644
> --- a/fs/ext4/block_validity.c
> +++ b/fs/ext4/block_validity.c
> @@ -144,40 +144,6 @@ static void debug_print_tree(struct ext4_sb_info *sbi)
>  	printk(KERN_CONT "\n");
>  }
>  
> -/*
> - * Returns 1 if the passed-in block region (start_blk,
> - * start_blk+count) is valid; 0 if some part of the block region
> - * overlaps with filesystem metadata blocks.
> - */
> -static int ext4_data_block_valid_rcu(struct ext4_sb_info *sbi,
> -				     struct ext4_system_blocks *system_blks,
> -				     ext4_fsblk_t start_blk,
> -				     unsigned int count, ino_t ino)
> -{
> -	struct ext4_system_zone *entry;
> -	struct rb_node *n;
> -
> -	if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
> -	    (start_blk + count < start_blk) ||
> -	    (start_blk + count > ext4_blocks_count(sbi->s_es)))
> -		return 0;
> -
> -	if (system_blks == NULL)
> -		return 1;
> -
> -	n = system_blks->root.rb_node;
> -	while (n) {
> -		entry = rb_entry(n, struct ext4_system_zone, node);
> -		if (start_blk + count - 1 < entry->start_blk)
> -			n = n->rb_left;
> -		else if (start_blk >= (entry->start_blk + entry->count))
> -			n = n->rb_right;
> -		else
> -			return entry->ino == ino;
> -	}
> -	return 1;
> -}
> -
>  static int ext4_protect_reserved_inode(struct super_block *sb,
>  				       struct ext4_system_blocks *system_blks,
>  				       u32 ino)
> @@ -333,11 +299,24 @@ void ext4_release_system_zone(struct super_block *sb)
>  		call_rcu(&system_blks->rcu, ext4_destroy_system_zone);
>  }
>  
> +/*
> + * Returns 1 if the passed-in block region (start_blk,
> + * start_blk+count) is valid; 0 if some part of the block region
> + * overlaps with some other filesystem metadata blocks.
> + */
>  int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
>  			  unsigned int count)
>  {
> +	struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
>  	struct ext4_system_blocks *system_blks;
> -	int ret;
> +	struct ext4_system_zone *entry;
> +	struct rb_node *n;
> +	int ret = 1;
> +
> +	if ((start_blk <= le32_to_cpu(sbi->s_es->s_first_data_block)) ||
> +	    (start_blk + count < start_blk) ||
> +	    (start_blk + count > ext4_blocks_count(sbi->s_es)))
> +		return 0;
>  
>  	/*
>  	 * Lock the system zone to prevent it being released concurrently
> @@ -346,8 +325,22 @@ int ext4_inode_block_valid(struct inode *inode, ext4_fsblk_t start_blk,
>  	 */
>  	rcu_read_lock();
>  	system_blks = rcu_dereference(sbi->system_blks);
> -	ret = ext4_data_block_valid_rcu(EXT4_SB(inode->i_sb), system_blks,
> -					start_blk, count, inode->i_ino);
> +	if (system_blks == NULL)
> +		goto out_rcu;
> +
> +	n = system_blks->root.rb_node;
> +	while (n) {
> +		entry = rb_entry(n, struct ext4_system_zone, node);
> +		if (start_blk + count - 1 < entry->start_blk)
> +			n = n->rb_left;
> +		else if (start_blk >= (entry->start_blk + entry->count))
> +			n = n->rb_right;
> +		else {
> +			ret = (entry->ino == inode->i_ino);
> +			break;
> +		}
> +	}
> +out_rcu:
>  	rcu_read_unlock();
>  	return ret;
>  }
> -- 
> 2.16.4
>