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

From: Jan Kara
Date: Wed Sep 07 2016 - 09:16:38 EST


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@xxxxxxxxx>

The patch looks good to me. You can add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

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@xxxxxxxx>
SUSE Labs, CR