diff mbox series

[4/5] erofs: refine z_erofs_transform_plain() for sub-page block support

Message ID 20231206091057.87027-5-hsiangkao@linux.alibaba.com
State New
Headers
Series erofs: basic sub-page compressed data support |

Commit Message

Gao Xiang Dec. 6, 2023, 9:10 a.m. UTC 
  Sub-page block support is still unusable even with previous commits if
interlaced PLAIN pclusters exist.  Such pclusters can be found if the
fragment feature is enabled.

This commit tries to handle "the head part" of interlaced PLAIN
pclusters first: it was once explained in commit fdffc091e6f9 ("erofs:
support interlaced uncompressed data for compressed files").

It uses a unique way for both shifted and interlaced PLAIN pclusters.
As an added bonus, PLAIN pclusters larger than the block size is also
supported now for the upcoming large lclusters.

Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
---
 fs/erofs/decompressor.c | 81 ++++++++++++++++++++++++-----------------
 1 file changed, 48 insertions(+), 33 deletions(-)

Comments

Yue Hu Dec. 8, 2023, 5:20 a.m. UTC | #1 
On Wed,  6 Dec 2023 17:10:56 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> Sub-page block support is still unusable even with previous commits if
> interlaced PLAIN pclusters exist.  Such pclusters can be found if the
> fragment feature is enabled.
> 
> This commit tries to handle "the head part" of interlaced PLAIN
> pclusters first: it was once explained in commit fdffc091e6f9 ("erofs:
> support interlaced uncompressed data for compressed files").
> 
> It uses a unique way for both shifted and interlaced PLAIN pclusters.
> As an added bonus, PLAIN pclusters larger than the block size is also
> supported now for the upcoming large lclusters.
> 
> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
> ---
>  fs/erofs/decompressor.c | 81 ++++++++++++++++++++++++-----------------
>  1 file changed, 48 insertions(+), 33 deletions(-)
> 
> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
> index 021be5feb1bc..5ec11f5024b7 100644
> --- a/fs/erofs/decompressor.c
> +++ b/fs/erofs/decompressor.c
> @@ -319,43 +319,58 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
>  static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
>  				   struct page **pagepool)
>  {
> -	const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT;
> -	const unsigned int outpages =
> +	const unsigned int nrpages_in =
> +		PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT;
> +	const unsigned int nrpages_out =
>  		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
> -	const unsigned int righthalf = min_t(unsigned int, rq->outputsize,
> -					     PAGE_SIZE - rq->pageofs_out);
> -	const unsigned int lefthalf = rq->outputsize - righthalf;
> -	const unsigned int interlaced_offset =
> -		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
> -	u8 *src;
> -
> -	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
> -		DBG_BUGON(1);
> -		return -EFSCORRUPTED;
> -	}
> -
> -	if (rq->out[0] == *rq->in) {
> -		DBG_BUGON(rq->pageofs_out);
> -		return 0;
> +	const unsigned int bs = rq->sb->s_blocksize;
> +	unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt;
> +	u8 *kin;
> +
> +	DBG_BUGON(rq->outputsize > rq->inputsize);
> +	if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
> +		cur = bs - (rq->pageofs_out & (bs - 1));
> +		pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
> +		cur = min(cur, rq->outputsize);
> +		if (cur && rq->out[0]) {
> +			kin = kmap_local_page(rq->in[nrpages_in - 1]);
> +			if (rq->out[0] == rq->in[nrpages_in - 1]) {
> +				memmove(kin + rq->pageofs_out, kin + pi, cur);
> +				flush_dcache_page(rq->out[0]);
> +			} else {
> +				memcpy_to_page(rq->out[0], rq->pageofs_out,
> +					       kin + pi, cur);
> +			}
> +			kunmap_local(kin);
> +		}
> +		rq->outputsize -= cur;
>  	}
>  
> -	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
> -	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]) {
> -			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]);
> -		}
> +	for (; rq->outputsize; rq->pageofs_in = 0, cur += PAGE_SIZE, ni++) {
> +		insz = min(PAGE_SIZE - rq->pageofs_in, rq->outputsize);

min_t(unsigned int, ,)?

../include/linux/minmax.h:21:28: error: comparison of distinct pointer types lacks a cast [-Werror]
  (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))


> +		rq->outputsize -= insz;
> +		if (!rq->in[ni])
> +			continue;
> +		kin = kmap_local_page(rq->in[ni]);
> +		pi = 0;
> +		do {
> +			no = (rq->pageofs_out + cur + pi) >> PAGE_SHIFT;
> +			po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK;
> +			DBG_BUGON(no >= nrpages_out);
> +			cnt = min(insz - pi, PAGE_SIZE - po);

ditto

> +			if (rq->out[no] == rq->in[ni]) {
> +				memmove(kin + po,
> +					kin + rq->pageofs_in + pi, cnt);
> +				flush_dcache_page(rq->out[no]);
> +			} else if (rq->out[no]) {
> +				memcpy_to_page(rq->out[no], po,
> +					       kin + rq->pageofs_in + pi, cnt);
> +			}
> +			pi += cnt;
> +		} while (pi < insz);
> +		kunmap_local(kin);
>  	}
> -	kunmap_local(src);
> +	DBG_BUGON(ni > nrpages_in);
>  	return 0;
>  }
>
Gao Xiang Dec. 8, 2023, 7:34 a.m. UTC | #2 
On 2023/12/8 13:20, Yue Hu wrote:
> On Wed,  6 Dec 2023 17:10:56 +0800
> Gao Xiang <hsiangkao@linux.alibaba.com> wrote:
> 
>> Sub-page block support is still unusable even with previous commits if
>> interlaced PLAIN pclusters exist.  Such pclusters can be found if the
>> fragment feature is enabled.
>>
>> This commit tries to handle "the head part" of interlaced PLAIN
>> pclusters first: it was once explained in commit fdffc091e6f9 ("erofs:
>> support interlaced uncompressed data for compressed files").
>>
>> It uses a unique way for both shifted and interlaced PLAIN pclusters.
>> As an added bonus, PLAIN pclusters larger than the block size is also
>> supported now for the upcoming large lclusters.
>>
>> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
>> ---
>>   fs/erofs/decompressor.c | 81 ++++++++++++++++++++++++-----------------
>>   1 file changed, 48 insertions(+), 33 deletions(-)
>>
>> diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
>> index 021be5feb1bc..5ec11f5024b7 100644
>> --- a/fs/erofs/decompressor.c
>> +++ b/fs/erofs/decompressor.c
>> @@ -319,43 +319,58 @@ static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
>>   static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
>>   				   struct page **pagepool)
>>   {
>> -	const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT;
>> -	const unsigned int outpages =
>> +	const unsigned int nrpages_in =
>> +		PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT;
>> +	const unsigned int nrpages_out =
>>   		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
>> -	const unsigned int righthalf = min_t(unsigned int, rq->outputsize,
>> -					     PAGE_SIZE - rq->pageofs_out);
>> -	const unsigned int lefthalf = rq->outputsize - righthalf;
>> -	const unsigned int interlaced_offset =
>> -		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
>> -	u8 *src;
>> -
>> -	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
>> -		DBG_BUGON(1);
>> -		return -EFSCORRUPTED;
>> -	}
>> -
>> -	if (rq->out[0] == *rq->in) {
>> -		DBG_BUGON(rq->pageofs_out);
>> -		return 0;
>> +	const unsigned int bs = rq->sb->s_blocksize;
>> +	unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt;
>> +	u8 *kin;
>> +
>> +	DBG_BUGON(rq->outputsize > rq->inputsize);
>> +	if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
>> +		cur = bs - (rq->pageofs_out & (bs - 1));
>> +		pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
>> +		cur = min(cur, rq->outputsize);
>> +		if (cur && rq->out[0]) {
>> +			kin = kmap_local_page(rq->in[nrpages_in - 1]);
>> +			if (rq->out[0] == rq->in[nrpages_in - 1]) {
>> +				memmove(kin + rq->pageofs_out, kin + pi, cur);
>> +				flush_dcache_page(rq->out[0]);
>> +			} else {
>> +				memcpy_to_page(rq->out[0], rq->pageofs_out,
>> +					       kin + pi, cur);
>> +			}
>> +			kunmap_local(kin);
>> +		}
>> +		rq->outputsize -= cur;
>>   	}
>>   
>> -	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
>> -	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]) {
>> -			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]);
>> -		}
>> +	for (; rq->outputsize; rq->pageofs_in = 0, cur += PAGE_SIZE, ni++) {
>> +		insz = min(PAGE_SIZE - rq->pageofs_in, rq->outputsize);
> 
> min_t(unsigned int, ,)?
> 
> ../include/linux/minmax.h:21:28: error: comparison of distinct pointer types lacks a cast [-Werror]
>    (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))

What compiler version are you using? I didn't find any error
and
https://lore.kernel.org/linux-erofs/202312080122.iCCXzSuE-lkp@intel.com

also didn't report this.

Thanks,
Gao Xiang
Gao Xiang Dec. 8, 2023, 7:44 a.m. UTC | #3 
On 2023/12/8 15:34, Gao Xiang wrote:
> 
> 

...

>> min_t(unsigned int, ,)?
>>
>> ../include/linux/minmax.h:21:28: error: comparison of distinct pointer types lacks a cast [-Werror]
>>    (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
> 
> What compiler version are you using? I didn't find any error
> and
> https://lore.kernel.org/linux-erofs/202312080122.iCCXzSuE-lkp@intel.com
> 
> also didn't report this.

Did you test against the latest kernel codebase?

> 
> Thanks,
> Gao Xiang
Yue Hu Dec. 8, 2023, 8:30 a.m. UTC | #4 
On Fri, 8 Dec 2023 15:44:33 +0800
Gao Xiang <hsiangkao@linux.alibaba.com> wrote:

> On 2023/12/8 15:34, Gao Xiang wrote:
> > 
> >   
> 
> ...
> 
> >> min_t(unsigned int, ,)?
> >>
> >> ../include/linux/minmax.h:21:28: error: comparison of distinct pointer types lacks a cast [-Werror]
> >>    (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))  
> > 
> > What compiler version are you using? I didn't find any error
> > and
> > https://lore.kernel.org/linux-erofs/202312080122.iCCXzSuE-lkp@intel.com
> > 
> > also didn't report this.  
> 
> Did you test against the latest kernel codebase?

Sorry, it's my testing environment issue, please ignore the noise.

Thanks.

> 
> > 
> > Thanks,
> > Gao Xiang
diff mbox series

Patch

diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 021be5feb1bc..5ec11f5024b7 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -319,43 +319,58 @@  static int z_erofs_lz4_decompress(struct z_erofs_decompress_req *rq,
 static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq,
 				   struct page **pagepool)
 {
-	const unsigned int inpages = PAGE_ALIGN(rq->inputsize) >> PAGE_SHIFT;
-	const unsigned int outpages =
+	const unsigned int nrpages_in =
+		PAGE_ALIGN(rq->pageofs_in + rq->inputsize) >> PAGE_SHIFT;
+	const unsigned int nrpages_out =
 		PAGE_ALIGN(rq->pageofs_out + rq->outputsize) >> PAGE_SHIFT;
-	const unsigned int righthalf = min_t(unsigned int, rq->outputsize,
-					     PAGE_SIZE - rq->pageofs_out);
-	const unsigned int lefthalf = rq->outputsize - righthalf;
-	const unsigned int interlaced_offset =
-		rq->alg == Z_EROFS_COMPRESSION_SHIFTED ? 0 : rq->pageofs_out;
-	u8 *src;
-
-	if (outpages > 2 && rq->alg == Z_EROFS_COMPRESSION_SHIFTED) {
-		DBG_BUGON(1);
-		return -EFSCORRUPTED;
-	}
-
-	if (rq->out[0] == *rq->in) {
-		DBG_BUGON(rq->pageofs_out);
-		return 0;
+	const unsigned int bs = rq->sb->s_blocksize;
+	unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt;
+	u8 *kin;
+
+	DBG_BUGON(rq->outputsize > rq->inputsize);
+	if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) {
+		cur = bs - (rq->pageofs_out & (bs - 1));
+		pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK;
+		cur = min(cur, rq->outputsize);
+		if (cur && rq->out[0]) {
+			kin = kmap_local_page(rq->in[nrpages_in - 1]);
+			if (rq->out[0] == rq->in[nrpages_in - 1]) {
+				memmove(kin + rq->pageofs_out, kin + pi, cur);
+				flush_dcache_page(rq->out[0]);
+			} else {
+				memcpy_to_page(rq->out[0], rq->pageofs_out,
+					       kin + pi, cur);
+			}
+			kunmap_local(kin);
+		}
+		rq->outputsize -= cur;
 	}
 
-	src = kmap_local_page(rq->in[inpages - 1]) + rq->pageofs_in;
-	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]) {
-			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]);
-		}
+	for (; rq->outputsize; rq->pageofs_in = 0, cur += PAGE_SIZE, ni++) {
+		insz = min(PAGE_SIZE - rq->pageofs_in, rq->outputsize);
+		rq->outputsize -= insz;
+		if (!rq->in[ni])
+			continue;
+		kin = kmap_local_page(rq->in[ni]);
+		pi = 0;
+		do {
+			no = (rq->pageofs_out + cur + pi) >> PAGE_SHIFT;
+			po = (rq->pageofs_out + cur + pi) & ~PAGE_MASK;
+			DBG_BUGON(no >= nrpages_out);
+			cnt = min(insz - pi, PAGE_SIZE - po);
+			if (rq->out[no] == rq->in[ni]) {
+				memmove(kin + po,
+					kin + rq->pageofs_in + pi, cnt);
+				flush_dcache_page(rq->out[no]);
+			} else if (rq->out[no]) {
+				memcpy_to_page(rq->out[no], po,
+					       kin + rq->pageofs_in + pi, cnt);
+			}
+			pi += cnt;
+		} while (pi < insz);
+		kunmap_local(kin);
 	}
-	kunmap_local(src);
+	DBG_BUGON(ni > nrpages_in);
 	return 0;
 }