Re: [PATCH 09/12] ext4: simplify journal handling in ext4_setup_new_group_blocks

[Tao Ma <tm@tao.ma>]

On 07/18/2011 10:52 AM, Yongqiang Yang wrote:
> This patch simplifies journal handling in ext4_setup_new_group_blocks().
> 
> 
> Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
> ---
>  fs/ext4/resize.c |   39 ++++++++++++++++++++-------------------
>  1 files changed, 20 insertions(+), 19 deletions(-)
> 
> diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
> index c91653c..ac5b63d 100644
> --- a/fs/ext4/resize.c
> +++ b/fs/ext4/resize.c
> @@ -171,8 +171,7 @@ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
>   * If that fails, restart the transaction & regain write access for the
>   * buffer head which is used for block_bitmap modifications.
>   */
> -static int extend_or_restart_transaction(handle_t *handle, int thresh,
> -					 struct buffer_head *bh)
> +static int extend_or_restart_transaction(handle_t *handle, int thresh)
>  {
>  	int err;
>  
> @@ -183,9 +182,8 @@ static int extend_or_restart_transaction(handle_t *handle, int thresh,
>  	if (err < 0)
>  		return err;
>  	if (err) {
> -		if ((err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA)))
> -			return err;
> -		if ((err = ext4_journal_get_write_access(handle, bh)))
> +		err = ext4_journal_restart(handle, EXT4_MAX_TRANS_DATA);
> +		if (err)
>  			return err;
you removed an ext4_journal_get_write_access here, and I didn't see you
add it back anywhere.

Thanks
Tao
>  	}
>  
> @@ -222,29 +220,24 @@ static int setup_new_group_blocks(struct super_block *sb,
>  
>  	BUG_ON(input->group != sbi->s_groups_count);
>  
> -	if (IS_ERR(bh = bclean(handle, sb, input->block_bitmap))) {
> -		err = PTR_ERR(bh);
> -		goto exit_journal;
> -	}
> -
>  	/* Copy all of the GDT blocks into the backup in this group */
>  	for (i = 0, bit = 1, block = start + 1;
>  	     i < gdblocks; i++, block++, bit++) {
>  		struct buffer_head *gdb;
>  
>  		ext4_debug("update backup group %#04llx (+%d)\n", block, bit);
> -
> -		if ((err = extend_or_restart_transaction(handle, 1, bh)))
> -			goto exit_bh;
> +		err = extend_or_restart_transaction(handle, 1);
> +		if (err)
> +			goto exit_journal;
>  
>  		gdb = sb_getblk(sb, block);
>  		if (!gdb) {
>  			err = -EIO;
> -			goto exit_bh;
> +			goto exit_journal;
>  		}
>  		if ((err = ext4_journal_get_write_access(handle, gdb))) {
>  			brelse(gdb);
> -			goto exit_bh;
> +			goto exit_journal;
>  		}
>  		lock_buffer(gdb);
>  		memcpy(gdb->b_data, sbi->s_group_desc[i]->b_data, gdb->b_size);
> @@ -253,7 +246,7 @@ static int setup_new_group_blocks(struct super_block *sb,
>  		err = ext4_handle_dirty_metadata(handle, NULL, gdb);
>  		if (unlikely(err)) {
>  			brelse(gdb);
> -			goto exit_bh;
> +			goto exit_journal;
>  		}
>  		brelse(gdb);
>  	}
> @@ -264,7 +257,17 @@ static int setup_new_group_blocks(struct super_block *sb,
>  	err = sb_issue_zeroout(sb, gdblocks + start + 1, reserved_gdb,
>  			       GFP_NOFS);
>  	if (err)
> -		goto exit_bh;
> +		goto exit_journal;
> +
> +	err = extend_or_restart_transaction(handle, 2);
> +	if (err)
> +		goto exit_journal;
> +
> +	bh = bclean(handle, sb, input->block_bitmap);
> +	if (IS_ERR(bh)) {
> +		err = PTR_ERR(bh);
> +		goto exit_journal;
> +	}
>  
>  	if (ext4_bg_has_super(sb, input->group)) {
>  		ext4_debug("mark backup group tables %#04llx (+0)\n", start);
> @@ -288,8 +291,6 @@ static int setup_new_group_blocks(struct super_block *sb,
>  	ext4_set_bits(bh->b_data, input->inode_table - start,
>  		      sbi->s_itb_per_group);
>  
> -	if ((err = extend_or_restart_transaction(handle, 2, bh)))
> -		goto exit_bh;
>  
>  	ext4_mark_bitmap_end(input->blocks_count, sb->s_blocksize * 8,
>  			     bh->b_data);