2023-12-06 09:12:00

by Gao Xiang

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

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 <[email protected]>
---
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);
+ 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;
}

--
2.39.3


2023-12-08 05:21:24

by Yue Hu

[permalink] [raw]
Subject: Re: [PATCH 4/5] erofs: refine z_erofs_transform_plain() for sub-page block support

On Wed, 6 Dec 2023 17:10:56 +0800
Gao Xiang <[email protected]> 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 <[email protected]>
> ---
> 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;
> }
>

2023-12-08 07:34:34

by Gao Xiang

[permalink] [raw]
Subject: Re: [PATCH 4/5] erofs: refine z_erofs_transform_plain() for sub-page block support



On 2023/12/8 13:20, Yue Hu wrote:
> On Wed, 6 Dec 2023 17:10:56 +0800
> Gao Xiang <[email protected]> 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 <[email protected]>
>> ---
>> 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/[email protected]

also didn't report this.

Thanks,
Gao Xiang

2023-12-08 07:44:52

by Gao Xiang

[permalink] [raw]
Subject: Re: [PATCH 4/5] erofs: refine z_erofs_transform_plain() for sub-page block support



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/[email protected]
>
> also didn't report this.

Did you test against the latest kernel codebase?

>
> Thanks,
> Gao Xiang

2023-12-08 08:31:21

by Yue Hu

[permalink] [raw]
Subject: Re: [PATCH 4/5] erofs: refine z_erofs_transform_plain() for sub-page block support

On Fri, 8 Dec 2023 15:44:33 +0800
Gao Xiang <[email protected]> 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]
> >> ?0?2?0?2 (!!(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/[email protected]
> >
> > 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