Re: [PATCH v2 10/14] udf: replace ll_rw_block()

Jan Kara
2022-09-01T15:58:50Z

On Thu 01-09-22 21:35:01, Zhang Yi wrote:
> ll_rw_block() is not safe for the sync read path because it cannot
> guarantee that submitting read IO if the buffer has been locked. We
> could get false positive EIO after wait_on_buffer() if the buffer has
> been locked by others. So stop using ll_rw_block(). We also switch to
> new bh_readahead_batch() helper for the buffer array readahead path.
>
> Signed-off-by: Zhang Yi <yi.zhang@huawei.com>

Looks good to me.

Honza

> ---
> fs/udf/dir.c | 2 +-
> fs/udf/directory.c | 2 +-
> fs/udf/inode.c | 8 +-------
> 3 files changed, 3 insertions(+), 9 deletions(-)
>
> diff --git a/fs/udf/dir.c b/fs/udf/dir.c
> index cad3772f9dbe..be640f4b2f2c 100644
> --- a/fs/udf/dir.c
> +++ b/fs/udf/dir.c
> @@ -130,7 +130,7 @@ static int udf_readdir(struct file *file, struct dir_context *ctx)
> brelse(tmp);
> }
> if (num) {
> - ll_rw_block(REQ_OP_READ | REQ_RAHEAD, num, bha);
> + bh_readahead_batch(num, bha, REQ_RAHEAD);
> for (i = 0; i < num; i++)
> brelse(bha[i]);
> }
> diff --git a/fs/udf/directory.c b/fs/udf/directory.c
> index a2adf6293093..16bcf2c6b8b3 100644
> --- a/fs/udf/directory.c
> +++ b/fs/udf/directory.c
> @@ -89,7 +89,7 @@ struct fileIdentDesc *udf_fileident_read(struct inode *dir, loff_t *nf_pos,
> brelse(tmp);
> }
> if (num) {
> - ll_rw_block(REQ_OP_READ | REQ_RAHEAD, num, bha);
> + bh_readahead_batch(num, bha, REQ_RAHEAD);
> for (i = 0; i < num; i++)
> brelse(bha[i]);
> }
> diff --git a/fs/udf/inode.c b/fs/udf/inode.c
> index 8d06daed549f..dce6ae9ae306 100644
> --- a/fs/udf/inode.c
> +++ b/fs/udf/inode.c
> @@ -1211,13 +1211,7 @@ struct buffer_head *udf_bread(struct inode *inode, udf_pblk_t block,
> if (!bh)
> return NULL;
>
> - if (buffer_uptodate(bh))
> - return bh;
> -
> - ll_rw_block(REQ_OP_READ, 1, &bh);
> -
> - wait_on_buffer(bh);
> - if (buffer_uptodate(bh))
> + if (bh_read(bh, 0) >= 0)
> return bh;
>
> brelse(bh);
> --
> 2.31.1
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR