Re: [PATCH v3 1/9] ext4: use FGP_WRITEBEGIN for tail block zeroing

[Jan Kara]

On Wed 08-07-26 14:20:41, Zhang Yi wrote:
> From: Zhang Yi <yi.zhang@xxxxxxxxxx>
> 
> ext4_load_tail_bh() returns a locked folio that callers immediately
> mutate through folio_zero_range() and mark_buffer_dirty().  Use
> FGP_WRITEBEGIN so that, on backing devices that require stable writes,
> __filemap_get_folio() waits for writeback to finish before returning
> the folio; on regular devices the wait is a no-op.
> 
> Signed-off-by: Zhang Yi <yi.zhang@xxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

								Honza

> ---
>  fs/ext4/inode.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index c2c2d6ac7f3d..7b2face041ef 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -4037,7 +4037,7 @@ static struct buffer_head *ext4_load_tail_bh(struct inode *inode, loff_t from)
>  	int err = 0;
>  
>  	folio = __filemap_get_folio(mapping, from >> PAGE_SHIFT,
> -				    FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
> +				    FGP_WRITEBEGIN | FGP_ACCESSED,
>  				    mapping_gfp_constraint(mapping, ~__GFP_FS));
>  	if (IS_ERR(folio))
>  		return ERR_CAST(folio);
> -- 
> 2.52.0
> 
-- 
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR