[PATCH 1/2] erofs: get rid of the remaining kmap_atomic()

[PATCH 1/2] erofs: get rid of the remaining kmap_atomic()

[Gao Xiang]

It's unnecessary to use kmap_atomic() compared with kmap_local_page().
In addition, kmap_atomic() is deprecated now.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
preliminary tested with silesia dataset.

 fs/erofs/decompressor.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 2a29943fa5cc..ad53cf52d899 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -148,7 +148,7 @@ static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx,
 		*maptype = 0;
 		return inpage;
 	}
-	kunmap_atomic(inpage);
+	kunmap_local(inpage);
 	might_sleep();
 	src = erofs_vm_map_ram(rq->in, ctx->inpages);
 	if (!src)
@@ -162,7 +162,7 @@ static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx,
 	src = erofs_get_pcpubuf(ctx->inpages);
 	if (!src) {
 		DBG_BUGON(1);
-		kunmap_atomic(inpage);
+		kunmap_local(inpage);
 		return ERR_PTR(-EFAULT);
 	}
 
@@ -173,9 +173,9 @@ static void *z_erofs_lz4_handle_overlap(struct z_erofs_lz4_decompress_ctx *ctx,
 			min_t(unsigned int, total, PAGE_SIZE - *inputmargin);
 
 		if (!inpage)
-			inpage = kmap_atomic(*in);
+			inpage = kmap_local_page(*in);
 		memcpy(tmp, inpage + *inputmargin, page_copycnt);
-		kunmap_atomic(inpage);
+		kunmap_local(inpage);
 		inpage = NULL;
 		tmp += page_copycnt;
 		total -= page_copycnt;
@@ -214,7 +214,7 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx,
 	int ret, maptype;
 
 	DBG_BUGON(*rq->in == NULL);
-	headpage = kmap_atomic(*rq->in);
+	headpage = kmap_local_page(*rq->in);
 
 	/* LZ4 decompression inplace is only safe if zero_padding is enabled */
 	if (erofs_sb_has_zero_padding(EROFS_SB(rq->sb))) {
@@ -223,7 +223,7 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx,
 				min_t(unsigned int, rq->inputsize,
 				      rq->sb->s_blocksize - rq->pageofs_in));
 		if (ret) {
-			kunmap_atomic(headpage);
+			kunmap_local(headpage);
 			return ret;
 		}
 		may_inplace = !((rq->pageofs_in + rq->inputsize) &
@@ -261,7 +261,7 @@ static int z_erofs_lz4_decompress_mem(struct z_erofs_lz4_decompress_ctx *ctx,
 	}
 
 	if (maptype == 0) {
-		kunmap_atomic(headpage);
+		kunmap_local(headpage);
 	} else if (maptype == 1) {
 		vm_unmap_ram(src, ctx->inpages);
 	} else if (maptype == 2) {
@@ -289,7 +289,7 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
 	/* one optimized fast path only for non bigpcluster cases yet */
 	if (ctx.inpages == 1 && ctx.outpages == 1 && !rq->inplace_io) {
 		DBG_BUGON(!*rq->out);
-		dst = kmap_atomic(*rq->out);
+		dst = kmap_local_page(*rq->out);
 		dst_maptype = 0;
 		goto dstmap_out;
 	}
@@ -311,7 +311,7 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
 dstmap_out:
 	ret = z_erofs_lz4_decompress_mem(&ctx, dst + rq->pageofs_out);
 	if (!dst_maptype)
-		kunmap_atomic(dst);
+		kunmap_local(dst);
 	else if (dst_maptype == 2)
 		vm_unmap_ram(dst, ctx.outpages);
 	return ret;
-- 
2.24.4

[PATCH 2/2] erofs: simplify z_erofs_transform_plain()

[Gao Xiang]

Use memcpy_to_page() instead of open-coding them.

In addition, add a missing flush_dcache_page() even though almost all
modern architectures clear `PG_dcache_clean` flag for new file cache
pages so that it doesn't change anything in practice.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
preliminary tested with silesia dataset.

 fs/erofs/decompressor.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index ad53cf52d899..cfad1eac7fd9 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -328,7 +328,7 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 	const unsigned int lefthalf = rq->outputsize - righthalf;
 	const unsigned int interlaced_offset =
 		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
-	unsigned char *src, *dst;
+	u8 *src;
 
 	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
 		DBG_BUGON(1);
@@ -341,22 +341,19 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 	}
 
 	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
-	if (rq->out[0]) {
-		dst = kmap_local_page(rq->out[0]);
-		memcpy(dst + rq->pageofs_out, src + interlaced_offset,
-		       righthalf);
-		kunmap_local(dst);
-	}
+	if (rq->out[0])
+		memcpy_to_page(rq->out[0], rq->pageofs_out,
+			       src + interlaced_offset, righthalf);
 
 	if (outpages > inpages) {
 		DBG_BUGON(!rq->out[outpages - 1]);
 		if (rq->out[outpages - 1] != rq->in[inpages - 1]) {
-			dst = kmap_local_page(rq->out[outpages - 1]);
-			memcpy(dst, interlaced_offset ? src :
-					(src + righthalf), lefthalf);
-			kunmap_local(dst);
+			memcpy_to_page(rq->out[outpages - 1], 0, src +
+					(interlaced_offset ? 0 : righthalf),
+				       lefthalf);
 		} else if (!interlaced_offset) {
 			memmove(src, src + righthalf, lefthalf);
+			flush_dcache_page(rq->in[inpages - 1]);
 		}
 	}
 	kunmap_local(src);
-- 
2.24.4

Re: [PATCH 2/2] erofs: simplify z_erofs_transform_plain()

[Yue Hu]

On Wed, 28 Jun 2023 00:12:40 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> Use memcpy_to_page() instead of open-coding them.
> 
> In addition, add a missing flush_dcache_page() even though almost all
> modern architectures clear `PG_dcache_clean` flag for new file cache
> pages so that it doesn't change anything in practice.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Yue Hu <huyue2@coolpad.com>

> ---
> preliminary tested with silesia dataset.
> 
>  fs/erofs/decompressor.c | 19 ++++++++-----------
>  1 file changed, 8 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
> index ad53cf52d899..cfad1eac7fd9 100644
> --- a/fs/erofs/decompressor.c
> +++ b/fs/erofs/decompressor.c
> @@ -328,7 +328,7 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
>  	const unsigned int lefthalf = rq->outputsize - righthalf;
>  	const unsigned int interlaced_offset =
>  		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
> -	unsigned char *src, *dst;
> +	u8 *src;
>  
>  	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
>  		DBG_BUGON(1);
> @@ -341,22 +341,19 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
>  	}
>  
>  	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
> -	if (rq->out[0]) {
> -		dst = kmap_local_page(rq->out[0]);
> -		memcpy(dst + rq->pageofs_out, src + interlaced_offset,
> -		       righthalf);
> -		kunmap_local(dst);
> -	}
> +	if (rq->out[0])
> +		memcpy_to_page(rq->out[0], rq->pageofs_out,
> +			       src + interlaced_offset, righthalf);
>  
>  	if (outpages > inpages) {
>  		DBG_BUGON(!rq->out[outpages - 1]);
>  		if (rq->out[outpages - 1] != rq->in[inpages - 1]) {
> -			dst = kmap_local_page(rq->out[outpages - 1]);
> -			memcpy(dst, interlaced_offset ? src :
> -					(src + righthalf), lefthalf);
> -			kunmap_local(dst);
> +			memcpy_to_page(rq->out[outpages - 1], 0, src +
> +					(interlaced_offset ? 0 : righthalf),
> +				       lefthalf);
>  		} else if (!interlaced_offset) {
>  			memmove(src, src + righthalf, lefthalf);
> +			flush_dcache_page(rq->in[inpages - 1]);
>  		}
>  	}
>  	kunmap_local(src);

Re: [PATCH 1/2] erofs: get rid of the remaining kmap_atomic()

[Yue Hu]

On Wed, 28 Jun 2023 00:12:39 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> It's unnecessary to use kmap_atomic() compared with kmap_local_page().
> In addition, kmap_atomic() is deprecated now.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Yue Hu <huyue2@coolpad.com>

Re: [PATCH 1/2] erofs: get rid of the remaining kmap_atomic()

[Chao Yu]

On 2023/6/28 0:12, Gao Xiang wrote:
> It's unnecessary to use kmap_atomic() compared with kmap_local_page().
> In addition, kmap_atomic() is deprecated now.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,

Re: [PATCH 2/2] erofs: simplify z_erofs_transform_plain()

[Chao Yu]

On 2023/6/28 0:12, Gao Xiang wrote:
> Use memcpy_to_page() instead of open-coding them.
> 
> In addition, add a missing flush_dcache_page() even though almost all
> modern architectures clear `PG_dcache_clean` flag for new file cache
> pages so that it doesn't change anything in practice.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,