Re: [PATCH 03/14] fs/buffer: replace ll_rw_block()

[Jan Kara <jack@suse.cz>]

On Wed 31-08-22 15:21:00, Zhang Yi wrote:
> ll_rw_block() is not safe for the sync IO path because it skip buffers
> which has been locked by others, it could lead to false positive EIO
> when submitting read IO. So stop using ll_rw_block(), switch to use new
> helpers which could guarantee buffer locked and submit IO if needed.
> 
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
> ---
>  fs/buffer.c | 13 ++++++-------
>  1 file changed, 6 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index a663191903ed..e14adc638bfe 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
...
> @@ -1342,7 +1342,8 @@ void __breadahead(struct block_device *bdev, sector_t block, unsigned size)
>  {
>  	struct buffer_head *bh = __getblk(bdev, block, size);
>  	if (likely(bh)) {
> -		ll_rw_block(REQ_OP_READ | REQ_RAHEAD, 1, &bh);
> +		if (trylock_buffer(bh))
> +			__bh_read(bh, REQ_RAHEAD, false);

I suppose this can be bh_readahead()?

>  		brelse(bh);
>  	}
>  }

Otherwise the patch looks good.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR