Re: [PATCH 1/1] ext4: Fix bs < ps issue reported with dioread_nolock mount opt

[Jan Kara <jack@suse.cz>]

On Thu 08-10-20 20:32:48, Ritesh Harjani wrote:
> left shifting m_lblk by blkbits was causing value overflow and hence
> it was not able to convert unwritten to written extent.
> So, make sure we typecast it to loff_t before do left shift operation.
> Also in func ext4_convert_unwritten_io_end_vec(), make sure to initialize
> ret variable to avoid accidentally returning an uninitialized ret.
> 
> This patch fixes the issue reported in ext4 for bs < ps with
> dioread_nolock mount option.
> 
> Fixes: c8cc88163f40df39e50c ("ext4: Add support for blocksize < pagesize in dioread_nolock")
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>

Ah, good spotting! The patch looks good. You can add:

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

								Honza

> ---
>  fs/ext4/extents.c | 2 +-
>  fs/ext4/inode.c   | 2 +-
>  2 files changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index a0481582187a..32d610cc896d 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -4769,7 +4769,7 @@ int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
>  
>  int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
>  {
> -	int ret, err = 0;
> +	int ret = 0, err = 0;
>  	struct ext4_io_end_vec *io_end_vec;
>  
>  	/*
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index bf596467c234..3021235deaa1 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -2254,7 +2254,7 @@ static int mpage_process_page(struct mpage_da_data *mpd, struct page *page,
>  					err = PTR_ERR(io_end_vec);
>  					goto out;
>  				}
> -				io_end_vec->offset = mpd->map.m_lblk << blkbits;
> +				io_end_vec->offset = (loff_t)mpd->map.m_lblk << blkbits;
>  			}
>  			*map_bh = true;
>  			goto out;
> -- 
> 2.26.2
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR