Re: [PATCH 07/14] ntfs3: replace ll_rw_block()

From: Jan Kara
Date: Wed Aug 31 2022 - 06:59:19 EST


On Wed 31-08-22 15:21:04, 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() in
> ntfs_get_block_vbo().
>
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>

Looks good to me. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/ntfs3/inode.c | 7 ++-----
> 1 file changed, 2 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
> index 51363d4e8636..bbe7d4ea1750 100644
> --- a/fs/ntfs3/inode.c
> +++ b/fs/ntfs3/inode.c
> @@ -630,12 +630,9 @@ static noinline int ntfs_get_block_vbo(struct inode *inode, u64 vbo,
> bh->b_size = block_size;
> off = vbo & (PAGE_SIZE - 1);
> set_bh_page(bh, page, off);
> - ll_rw_block(REQ_OP_READ, 1, &bh);
> - wait_on_buffer(bh);
> - if (!buffer_uptodate(bh)) {
> - err = -EIO;
> + err = bh_read(bh, 0);
> + if (err)
> goto out;
> - }
> zero_user_segment(page, off + voff, off + block_size);
> }
> }
> --
> 2.31.1
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR