On Thu 01-09-22 21:34:54, 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.zh...@huawei.com>

Looks good. Feel free to add:

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

                                                                Honza

> ---
>  fs/buffer.c | 12 +++++-------
>  1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/buffer.c b/fs/buffer.c
> index a6bc769e665d..aec568b3ae52 100644
> --- a/fs/buffer.c
> +++ b/fs/buffer.c
> @@ -562,7 +562,7 @@ void write_boundary_block(struct block_device *bdev,
>       struct buffer_head *bh = __find_get_block(bdev, bblock + 1, blocksize);
>       if (bh) {
>               if (buffer_dirty(bh))
> -                     ll_rw_block(REQ_OP_WRITE, 1, &bh);
> +                     write_dirty_buffer(bh, 0);
>               put_bh(bh);
>       }
>  }
> @@ -1342,7 +1342,7 @@ 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);
> +             bh_readahead(bh, REQ_RAHEAD);
>               brelse(bh);
>       }
>  }
> @@ -2022,7 +2022,7 @@ int __block_write_begin_int(struct folio *folio, loff_t 
> pos, unsigned len,
>               if (!buffer_uptodate(bh) && !buffer_delay(bh) &&
>                   !buffer_unwritten(bh) &&
>                    (block_start < from || block_end > to)) {
> -                     ll_rw_block(REQ_OP_READ, 1, &bh);
> +                     bh_read_nowait(bh, 0);
>                       *wait_bh++=bh;
>               }
>       }
> @@ -2582,11 +2582,9 @@ int block_truncate_page(struct address_space *mapping,
>               set_buffer_uptodate(bh);
>  
>       if (!buffer_uptodate(bh) && !buffer_delay(bh) && !buffer_unwritten(bh)) 
> {
> -             err = -EIO;
> -             ll_rw_block(REQ_OP_READ, 1, &bh);
> -             wait_on_buffer(bh);
> +             err = bh_read(bh, 0);
>               /* Uhhuh. Read error. Complain and punt. */
> -             if (!buffer_uptodate(bh))
> +             if (err < 0)
>                       goto unlock;
>       }
>  
> -- 
> 2.31.1
> 
-- 
Jan Kara <j...@suse.com>
SUSE Labs, CR

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