Re: [PATCH] jbd2: move more common code into journal_init_common()

[Jan Kara <jack@suse.cz>]

On Wed 07-09-16 20:41:13, Geliang Tang wrote:
> There are some repetitive code in jbd2_journal_init_dev() and
> jbd2_journal_init_inode(). So this patch moves the common code into
> journal_init_common() helper to simplify the code. And fix the coding
> style warnings reported by checkpatch.pl by the way.
> 
> Signed-off-by: Geliang Tang <geliangtang@gmail.com>

The patch looks good to me. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza

> ---
>  fs/jbd2/journal.c | 136 +++++++++++++++++++++---------------------------------
>  1 file changed, 53 insertions(+), 83 deletions(-)
> 
> diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
> index 46261a6..07e14ef 100644
> --- a/fs/jbd2/journal.c
> +++ b/fs/jbd2/journal.c
> @@ -1090,11 +1090,15 @@ static void jbd2_stats_proc_exit(journal_t *journal)
>   * very few fields yet: that has to wait until we have created the
>   * journal structures from from scratch, or loaded them from disk. */
>  
> -static journal_t * journal_init_common (void)
> +static journal_t *journal_init_common(struct block_device *bdev,
> +			struct block_device *fs_dev,
> +			unsigned long long start, int len, int blocksize)
>  {
>  	static struct lock_class_key jbd2_trans_commit_key;
>  	journal_t *journal;
>  	int err;
> +	struct buffer_head *bh;
> +	int n;
>  
>  	journal = kzalloc(sizeof(*journal), GFP_KERNEL);
>  	if (!journal)
> @@ -1131,6 +1135,35 @@ static journal_t * journal_init_common (void)
>  	lockdep_init_map(&journal->j_trans_commit_map, "jbd2_handle",
>  			 &jbd2_trans_commit_key, 0);
>  
> +	/* journal descriptor can store up to n blocks -bzzz */
> +	journal->j_blocksize = blocksize;
> +	journal->j_dev = bdev;
> +	journal->j_fs_dev = fs_dev;
> +	journal->j_blk_offset = start;
> +	journal->j_maxlen = len;
> +	jbd2_stats_proc_init(journal);
> +	n = journal->j_blocksize / sizeof(journal_block_tag_t);
> +	journal->j_wbufsize = n;
> +	journal->j_wbuf = kmalloc_array(n, sizeof(struct buffer_head *),
> +					GFP_KERNEL);
> +	if (!journal->j_wbuf) {
> +		jbd2_stats_proc_exit(journal);
> +		kfree(journal);
> +		return NULL;
> +	}
> +
> +	bh = getblk_unmovable(journal->j_dev, start, journal->j_blocksize);
> +	if (!bh) {
> +		pr_err("%s: Cannot get buffer for journal superblock\n",
> +			__func__);
> +		kfree(journal->j_wbuf);
> +		jbd2_stats_proc_exit(journal);
> +		kfree(journal);
> +		return NULL;
> +	}
> +	journal->j_sb_buffer = bh;
> +	journal->j_superblock = (journal_superblock_t *)bh->b_data;
> +
>  	return journal;
>  }
>  
> @@ -1157,51 +1190,20 @@ static journal_t * journal_init_common (void)
>   *  range of blocks on an arbitrary block device.
>   *
>   */
> -journal_t * jbd2_journal_init_dev(struct block_device *bdev,
> +journal_t *jbd2_journal_init_dev(struct block_device *bdev,
>  			struct block_device *fs_dev,
>  			unsigned long long start, int len, int blocksize)
>  {
> -	journal_t *journal = journal_init_common();
> -	struct buffer_head *bh;
> -	int n;
> +	journal_t *journal;
>  
> +	journal = journal_init_common(bdev, fs_dev, start, len, blocksize);
>  	if (!journal)
>  		return NULL;
>  
> -	/* journal descriptor can store up to n blocks -bzzz */
> -	journal->j_blocksize = blocksize;
> -	journal->j_dev = bdev;
> -	journal->j_fs_dev = fs_dev;
> -	journal->j_blk_offset = start;
> -	journal->j_maxlen = len;
>  	bdevname(journal->j_dev, journal->j_devname);
>  	strreplace(journal->j_devname, '/', '!');
> -	jbd2_stats_proc_init(journal);
> -	n = journal->j_blocksize / sizeof(journal_block_tag_t);
> -	journal->j_wbufsize = n;
> -	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
> -	if (!journal->j_wbuf) {
> -		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
> -			__func__);
> -		goto out_err;
> -	}
> -
> -	bh = __getblk(journal->j_dev, start, journal->j_blocksize);
> -	if (!bh) {
> -		printk(KERN_ERR
> -		       "%s: Cannot get buffer for journal superblock\n",
> -		       __func__);
> -		goto out_err;
> -	}
> -	journal->j_sb_buffer = bh;
> -	journal->j_superblock = (journal_superblock_t *)bh->b_data;
>  
>  	return journal;
> -out_err:
> -	kfree(journal->j_wbuf);
> -	jbd2_stats_proc_exit(journal);
> -	kfree(journal);
> -	return NULL;
>  }
>  
>  /**
> @@ -1212,67 +1214,35 @@ out_err:
>   * the journal.  The inode must exist already, must support bmap() and
>   * must have all data blocks preallocated.
>   */
> -journal_t * jbd2_journal_init_inode (struct inode *inode)
> +journal_t *jbd2_journal_init_inode(struct inode *inode)
>  {
> -	struct buffer_head *bh;
> -	journal_t *journal = journal_init_common();
> +	journal_t *journal;
>  	char *p;
> -	int err;
> -	int n;
>  	unsigned long long blocknr;
>  
> +	blocknr = bmap(inode, 0);
> +	if (!blocknr) {
> +		pr_err("%s: Cannot locate journal superblock\n",
> +			__func__);
> +		return NULL;
> +	}
> +
> +	jbd_debug(1, "JBD2: inode %s/%ld, size %lld, bits %d, blksize %ld\n",
> +		  inode->i_sb->s_id, inode->i_ino, (long long) inode->i_size,
> +		  inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
> +
> +	journal = journal_init_common(inode->i_sb->s_bdev, inode->i_sb->s_bdev,
> +			blocknr, inode->i_size >> inode->i_sb->s_blocksize_bits,
> +			inode->i_sb->s_blocksize);
>  	if (!journal)
>  		return NULL;
>  
> -	journal->j_dev = journal->j_fs_dev = inode->i_sb->s_bdev;
>  	journal->j_inode = inode;
>  	bdevname(journal->j_dev, journal->j_devname);
>  	p = strreplace(journal->j_devname, '/', '!');
>  	sprintf(p, "-%lu", journal->j_inode->i_ino);
> -	jbd_debug(1,
> -		  "journal %p: inode %s/%ld, size %Ld, bits %d, blksize %ld\n",
> -		  journal, inode->i_sb->s_id, inode->i_ino,
> -		  (long long) inode->i_size,
> -		  inode->i_sb->s_blocksize_bits, inode->i_sb->s_blocksize);
> -
> -	journal->j_maxlen = inode->i_size >> inode->i_sb->s_blocksize_bits;
> -	journal->j_blocksize = inode->i_sb->s_blocksize;
> -	jbd2_stats_proc_init(journal);
> -
> -	/* journal descriptor can store up to n blocks -bzzz */
> -	n = journal->j_blocksize / sizeof(journal_block_tag_t);
> -	journal->j_wbufsize = n;
> -	journal->j_wbuf = kmalloc(n * sizeof(struct buffer_head*), GFP_KERNEL);
> -	if (!journal->j_wbuf) {
> -		printk(KERN_ERR "%s: Can't allocate bhs for commit thread\n",
> -			__func__);
> -		goto out_err;
> -	}
> -
> -	err = jbd2_journal_bmap(journal, 0, &blocknr);
> -	/* If that failed, give up */
> -	if (err) {
> -		printk(KERN_ERR "%s: Cannot locate journal superblock\n",
> -		       __func__);
> -		goto out_err;
> -	}
> -
> -	bh = getblk_unmovable(journal->j_dev, blocknr, journal->j_blocksize);
> -	if (!bh) {
> -		printk(KERN_ERR
> -		       "%s: Cannot get buffer for journal superblock\n",
> -		       __func__);
> -		goto out_err;
> -	}
> -	journal->j_sb_buffer = bh;
> -	journal->j_superblock = (journal_superblock_t *)bh->b_data;
>  
>  	return journal;
> -out_err:
> -	kfree(journal->j_wbuf);
> -	jbd2_stats_proc_exit(journal);
> -	kfree(journal);
> -	return NULL;
>  }
>  
>  /*
> -- 
> 2.7.4
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR