[PATCH] erofs: clean up a loop

[Gao Xiang]

Hi Dan,

On Mon, Jul 18, 2022 at 02:20:08PM +0300, Dan Carpenter wrote:
> It's easier to see what this loop is doing when the decrement is in
> the normal place.
> 
> Signed-off-by: Dan Carpenter <dan.carpenter at oracle.com>
> ---
>  fs/erofs/zdata.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index 601cfcb07c50..2691100eb231 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -419,8 +419,8 @@ static bool z_erofs_try_inplace_io(struct z_erofs_decompress_frontend *fe,
>  {
>  	struct z_erofs_pcluster *const pcl = fe->pcl;
>  
> -	while (fe->icur > 0) {
> -		if (!cmpxchg(&pcl->compressed_bvecs[--fe->icur].page,
> +	while (fe->icur--) {

Thanks for your patch!
Yet at a quick glance, on my side, that doesn't equal
to be honest...

.. What we're trying to do here is to find a free slot
for inplace i/o, but also need to leave fe->icur as 0
when going out the loop since z_erofs_try_inplace_io()
can be called again the next time when attaching
another page but it will overflow then...

Thanks,
Gao Xiang

> +		if (!cmpxchg(&pcl->compressed_bvecs[fe->icur].page,
>  			     NULL, bvec->page)) {
>  			pcl->compressed_bvecs[fe->icur] = *bvec;
>  			return true;
> -- 
> 2.35.1