Re: [PATCH, RFC] support discard in non-journal ext4

[Coly Li <coly.li@suse.de>]

On 05/13/2010 01:00 PM, Jiaying Zhang Wrote:
> This patch issues discard request for freed blocks in ext4_free_blocks()
> if ext4 is mounted with discard option and without journal.
> 
> Author: Jiaying Zhang <jiayingz@google.com>
> Date:   Wed May 12 21:11:46 2010 -0700
> 
>     Issue discard request in ext4_free_blocks() when ext4 has no journal and
>     is mounted with discard option.
>     
>     Signed-off-by: Jiaying Zhang <jiayingz@google.com>
> 
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index a291cc3..d51b79a 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -2513,6 +2513,22 @@ int ext4_mb_release(struct super_block *sb)
>  	return 0;
>  }
>  
> +static void ext4_issue_discard(struct super_block *sb, ext4_group_t block_group,
> +		ext4_grpblk_t block, int count)
> +{
> +	int ret;
> +	ext4_fsblk_t discard_block;
> +
> +	discard_block = block + ext4_group_first_block_no(sb, block_group);
> +	trace_ext4_discard_blocks(sb,
> +			(unsigned long long) discard_block, count);
> +	ret = sb_issue_discard(sb, discard_block, count);
> +	if (ret == EOPNOTSUPP) {
> +		ext4_warning(sb, "discard not supported, disabling");
> +		clear_opt(EXT4_SB(sb)->s_mount_opt, DISCARD);
> +	}
> +}
> +

How about make it as an inline routine? Thanks.

-- 
Coly Li
SuSE Labs