Re: [PATCH 04/14] gfs2: replace ll_rw_block()

From: Jan Kara <jack@suse.cz>
To: Zhang Yi <yi.zhang@huawei.com>
Cc: linux-ext4@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	linux-kernel@vger.kernel.org, cluster-devel@redhat.com,
	ntfs3@lists.linux.dev, ocfs2-devel@oss.oracle.com,
	reiserfs-devel@vger.kernel.org, jack@suse.cz, tytso@mit.edu,
	akpm@linux-foundation.org, axboe@kernel.dk,
	viro@zeniv.linux.org.uk, rpeterso@redhat.com,
	agruenba@redhat.com, almaz.alexandrovich@paragon-software.com,
	mark@fasheh.com, dushistov@mail.ru, hch@infradead.org,
	chengzhihao1@huawei.com, yukuai3@huawei.com
Subject: Re: [PATCH 04/14] gfs2: replace ll_rw_block()
Date: Wed, 31 Aug 2022 12:52:34 +0200	[thread overview]
Message-ID: <20220831105234.suazqjzqnb2r65ow@quack3> (raw)
In-Reply-To: <20220831072111.3569680-5-yi.zhang@huawei.com>

On Wed 31-08-22 15:21:01, Zhang Yi wrote:
> ll_rw_block() is not safe for the sync read path because it cannot
> guarantee that always submitting read IO if the buffer has been locked,
> so stop using it. We also switch to new bh_readahead() helper for the
> readahead path.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good to me. Feel free to add:

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

								Honza

> ---
>  fs/gfs2/meta_io.c | 6 ++----
>  fs/gfs2/quota.c   | 4 +---
>  2 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/gfs2/meta_io.c b/fs/gfs2/meta_io.c
> index 7e70e0ba5a6c..07e882aa7ebd 100644
> --- a/fs/gfs2/meta_io.c
> +++ b/fs/gfs2/meta_io.c
> @@ -525,8 +525,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
>  
>  	if (buffer_uptodate(first_bh))
>  		goto out;
> -	if (!buffer_locked(first_bh))
> -		ll_rw_block(REQ_OP_READ | REQ_META | REQ_PRIO, 1, &first_bh);
> +	bh_read_nowait(first_bh, REQ_META | REQ_PRIO);
>  
>  	dblock++;
>  	extlen--;
> @@ -535,8 +534,7 @@ struct buffer_head *gfs2_meta_ra(struct gfs2_glock *gl, u64 dblock, u32 extlen)
>  		bh = gfs2_getbuf(gl, dblock, CREATE);
>  
>  		if (!buffer_uptodate(bh) && !buffer_locked(bh))
> -			ll_rw_block(REQ_OP_READ | REQ_RAHEAD | REQ_META |
> -				    REQ_PRIO, 1, &bh);
> +			bh_readahead(bh, REQ_RAHEAD | REQ_META | REQ_PRIO);
>  		brelse(bh);
>  		dblock++;
>  		extlen--;
> diff --git a/fs/gfs2/quota.c b/fs/gfs2/quota.c
> index f201eaf59d0d..0c2ef4226aba 100644
> --- a/fs/gfs2/quota.c
> +++ b/fs/gfs2/quota.c
> @@ -746,9 +746,7 @@ static int gfs2_write_buf_to_page(struct gfs2_inode *ip, unsigned long index,
>  		if (PageUptodate(page))
>  			set_buffer_uptodate(bh);
>  		if (!buffer_uptodate(bh)) {
> -			ll_rw_block(REQ_OP_READ | REQ_META | REQ_PRIO, 1, &bh);
> -			wait_on_buffer(bh);
> -			if (!buffer_uptodate(bh))
> +			if (bh_read(bh, REQ_META | REQ_PRIO))
>  				goto unlock_out;
>  		}
>  		if (gfs2_is_jdata(ip))
> -- 
> 2.31.1
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR