diff mbox series

erofs: don't calculate new start when expanding read length

Message ID 20230525055147.13220-1-zbestahu@gmail.com
State New
Headers
Series erofs: don't calculate new start when expanding read length |

Commit Message

Yue Hu May 25, 2023, 5:51 a.m. UTC 
  From: Yue Hu <huyue2@coolpad.com>

We only expand the trailing edge and not the leading edge.  So no need
to obtain new start again.  Let's use the existing ->headoffset instead.

Signed-off-by: Yue Hu <huyue2@coolpad.com>
---
 fs/erofs/zdata.c | 12 +++++-------
 1 file changed, 5 insertions(+), 7 deletions(-)

Comments

Gao Xiang May 25, 2023, 5:56 a.m. UTC | #1 
On 2023/5/25 22:51, Yue Hu wrote:
> From: Yue Hu <huyue2@coolpad.com>
> 
> We only expand the trailing edge and not the leading edge.  So no need
> to obtain new start again.  Let's use the existing ->headoffset instead.
> 
> Signed-off-by: Yue Hu <huyue2@coolpad.com>
> ---
>   fs/erofs/zdata.c | 12 +++++-------
>   1 file changed, 5 insertions(+), 7 deletions(-)
> 
> diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> index 874fee35af32..bab8dcb8e848 100644
> --- a/fs/erofs/zdata.c
> +++ b/fs/erofs/zdata.c
> @@ -1828,26 +1828,24 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
>   {
>   	struct inode *inode = f->inode;
>   	struct erofs_map_blocks *map = &f->map;
> -	erofs_off_t cur, end;
> +	erofs_off_t cur, end, headoffset = f->headoffset;


That is not quite useful, or could you merge this info the original patch?

Thanks,
Gao Xiang

>   	int err;
>   
>   	if (backmost) {
>   		if (rac)
> -			end = f->headoffset + readahead_length(rac) - 1;
> +			end = headoffset + readahead_length(rac) - 1;
>   		else
> -			end = f->headoffset + PAGE_SIZE - 1;
> +			end = headoffset + PAGE_SIZE - 1;
>   		map->m_la = end;
>   		err = z_erofs_map_blocks_iter(inode, map,
>   					      EROFS_GET_BLOCKS_READMORE);
>   		if (err)
>   			return;
>   
> -		/* expend ra for the trailing edge if readahead */
> +		/* expand ra for the trailing edge if readahead */
>   		if (rac) {
> -			loff_t newstart = readahead_pos(rac);
> -
>   			cur = round_up(map->m_la + map->m_llen, PAGE_SIZE);
> -			readahead_expand(rac, newstart, cur - newstart);
> +			readahead_expand(rac, headoffset, cur - headoffset);
>   			return;
>   		}
>   		end = round_up(end, PAGE_SIZE);
Yue Hu May 25, 2023, 7:06 a.m. UTC | #2 
On Thu, 25 May 2023 13:56:14 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> On 2023/5/25 22:51, Yue Hu wrote:
> > From: Yue Hu <huyue2@coolpad.com>
> > 
> > We only expand the trailing edge and not the leading edge.  So no need
> > to obtain new start again.  Let's use the existing ->headoffset instead.
> > 
> > Signed-off-by: Yue Hu <huyue2@coolpad.com>
> > ---
> >   fs/erofs/zdata.c | 12 +++++-------
> >   1 file changed, 5 insertions(+), 7 deletions(-)
> > 
> > diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
> > index 874fee35af32..bab8dcb8e848 100644
> > --- a/fs/erofs/zdata.c
> > +++ b/fs/erofs/zdata.c
> > @@ -1828,26 +1828,24 @@ static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
> >   {
> >   	struct inode *inode = f->inode;
> >   	struct erofs_map_blocks *map = &f->map;
> > -	erofs_off_t cur, end;
> > +	erofs_off_t cur, end, headoffset = f->headoffset;  
> 
> 
> That is not quite useful, or could you merge this info the original patch?

Okay, i will do the merge later.

> 
> Thanks,
> Gao Xiang
> 
> >   	int err;
> >   
> >   	if (backmost) {
> >   		if (rac)
> > -			end = f->headoffset + readahead_length(rac) - 1;
> > +			end = headoffset + readahead_length(rac) - 1;
> >   		else
> > -			end = f->headoffset + PAGE_SIZE - 1;
> > +			end = headoffset + PAGE_SIZE - 1;
> >   		map->m_la = end;
> >   		err = z_erofs_map_blocks_iter(inode, map,
> >   					      EROFS_GET_BLOCKS_READMORE);
> >   		if (err)
> >   			return;
> >   
> > -		/* expend ra for the trailing edge if readahead */
> > +		/* expand ra for the trailing edge if readahead */
> >   		if (rac) {
> > -			loff_t newstart = readahead_pos(rac);
> > -
> >   			cur = round_up(map->m_la + map->m_llen, PAGE_SIZE);
> > -			readahead_expand(rac, newstart, cur - newstart);
> > +			readahead_expand(rac, headoffset, cur - headoffset);
> >   			return;
> >   		}
> >   		end = round_up(end, PAGE_SIZE);
diff mbox series

Patch

diff --git a/fs/erofs/zdata.c b/fs/erofs/zdata.c
index 874fee35af32..bab8dcb8e848 100644
--- a/fs/erofs/zdata.c
+++ b/fs/erofs/zdata.c
@@ -1828,26 +1828,24 @@  static void z_erofs_pcluster_readmore(struct z_erofs_decompress_frontend *f,
 {
 	struct inode *inode = f->inode;
 	struct erofs_map_blocks *map = &f->map;
-	erofs_off_t cur, end;
+	erofs_off_t cur, end, headoffset = f->headoffset;
 	int err;
 
 	if (backmost) {
 		if (rac)
-			end = f->headoffset + readahead_length(rac) - 1;
+			end = headoffset + readahead_length(rac) - 1;
 		else
-			end = f->headoffset + PAGE_SIZE - 1;
+			end = headoffset + PAGE_SIZE - 1;
 		map->m_la = end;
 		err = z_erofs_map_blocks_iter(inode, map,
 					      EROFS_GET_BLOCKS_READMORE);
 		if (err)
 			return;
 
-		/* expend ra for the trailing edge if readahead */
+		/* expand ra for the trailing edge if readahead */
 		if (rac) {
-			loff_t newstart = readahead_pos(rac);
-
 			cur = round_up(map->m_la + map->m_llen, PAGE_SIZE);
-			readahead_expand(rac, newstart, cur - newstart);
+			readahead_expand(rac, headoffset, cur - headoffset);
 			return;
 		}
 		end = round_up(end, PAGE_SIZE);