From: Yue Hu <[email protected]>
mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
compacted_4b_initial > totalidx, kernel should be aligned with it
accordingly.
Signed-off-by: Yue Hu <[email protected]>
---
fs/erofs/zmap.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
index 9fb98d8..4f941b6 100644
--- a/fs/erofs/zmap.c
+++ b/fs/erofs/zmap.c
@@ -369,7 +369,10 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
if (compacted_4b_initial == 32 / 4)
compacted_4b_initial = 0;
- if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
+ if (compacted_4b_initial > totalidx) {
+ compacted_4b_initial = 0;
+ compacted_2b = 0;
+ } else if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
else
compacted_2b = 0;
--
1.9.1
Hi Yue,
On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> From: Yue Hu <[email protected]>
>
> mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> compacted_4b_initial > totalidx, kernel should be aligned with it
> accordingly.
There is no difference between compacted_4b_initial or compacted_4b_end
for compacted 4B. Since in this way totalidx for compact 2B won't larger
than 16 (number of lclusters in a compacted 2B pack.)
So it can be handled in either compacted_4b_initial or compacted_4b_end
cases, because there are all compacted 4B.
Thanks,
Gao Xiang
>
> Signed-off-by: Yue Hu <[email protected]>
> ---
> fs/erofs/zmap.c | 5 ++++-
> 1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> index 9fb98d8..4f941b6 100644
> --- a/fs/erofs/zmap.c
> +++ b/fs/erofs/zmap.c
> @@ -369,7 +369,10 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> if (compacted_4b_initial == 32 / 4)
> compacted_4b_initial = 0;
>
> - if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> + if (compacted_4b_initial > totalidx) {
> + compacted_4b_initial = 0;
> + compacted_2b = 0;
> + } else if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> else
> compacted_2b = 0;
> --
> 1.9.1
On Mon, 13 Sep 2021 16:48:45 +0800
Gao Xiang <[email protected]> wrote:
> Hi Yue,
>
> On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> > From: Yue Hu <[email protected]>
> >
> > mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> > compacted_4b_initial > totalidx, kernel should be aligned with it
> > accordingly.
>
> There is no difference between compacted_4b_initial or compacted_4b_end
> for compacted 4B. Since in this way totalidx for compact 2B won't larger
> than 16 (number of lclusters in a compacted 2B pack.)
However, we can see compacted_2b is a big number for this case. It should
be pointless.
Thanks.
>
> So it can be handled in either compacted_4b_initial or compacted_4b_end
> cases, because there are all compacted 4B.
>
> Thanks,
> Gao Xiang
>
> >
> > Signed-off-by: Yue Hu <[email protected]>
> > ---
> > fs/erofs/zmap.c | 5 ++++-
> > 1 file changed, 4 insertions(+), 1 deletion(-)
> >
> > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > index 9fb98d8..4f941b6 100644
> > --- a/fs/erofs/zmap.c
> > +++ b/fs/erofs/zmap.c
> > @@ -369,7 +369,10 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > if (compacted_4b_initial == 32 / 4)
> > compacted_4b_initial = 0;
> >
> > - if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > + if (compacted_4b_initial > totalidx) {
> > + compacted_4b_initial = 0;
> > + compacted_2b = 0;
> > + } else if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > else
> > compacted_2b = 0;
> > --
> > 1.9.1
On Mon, Sep 13, 2021 at 05:00:16PM +0800, Yue Hu wrote:
> On Mon, 13 Sep 2021 16:48:45 +0800
> Gao Xiang <[email protected]> wrote:
>
> > Hi Yue,
> >
> > On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> > > From: Yue Hu <[email protected]>
> > >
> > > mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> > > compacted_4b_initial > totalidx, kernel should be aligned with it
> > > accordingly.
> >
> > There is no difference between compacted_4b_initial or compacted_4b_end
> > for compacted 4B. Since in this way totalidx for compact 2B won't larger
> > than 16 (number of lclusters in a compacted 2B pack.)
>
> However, we can see compacted_2b is a big number for this case. It should
> be pointless.
Does it has some real impact?
compacted_4b_initial is only used for the alignment use for the
first compacted_2b so that each compacted_2b pack won't cross
the block (page) boundary. And compacted_4b_end is for the last
lclusters aren't fitted in any compacted_2b pack.
If compacted_4b_initial > totalidx, I think the whole indexes
would be compacted 4B and handled in
if (lcn < compacted_4b_initial) {
amortizedshift = 2;
goto out;
}
Thanks,
Gao Xiang
>
> Thanks.
>
> >
> > So it can be handled in either compacted_4b_initial or compacted_4b_end
> > cases, because there are all compacted 4B.
> >
> > Thanks,
> > Gao Xiang
> >
> > >
> > > Signed-off-by: Yue Hu <[email protected]>
> > > ---
> > > fs/erofs/zmap.c | 5 ++++-
> > > 1 file changed, 4 insertions(+), 1 deletion(-)
> > >
> > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > index 9fb98d8..4f941b6 100644
> > > --- a/fs/erofs/zmap.c
> > > +++ b/fs/erofs/zmap.c
> > > @@ -369,7 +369,10 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > > if (compacted_4b_initial == 32 / 4)
> > > compacted_4b_initial = 0;
> > >
> > > - if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > + if (compacted_4b_initial > totalidx) {
> > > + compacted_4b_initial = 0;
> > > + compacted_2b = 0;
> > > + } else if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > > else
> > > compacted_2b = 0;
> > > --
> > > 1.9.1
On Mon, 13 Sep 2021 19:19:16 +0800
Gao Xiang <[email protected]> wrote:
> Hi Yue,
>
> On Mon, Sep 13, 2021 at 06:58:36PM +0800, Yue Hu wrote:
> > Hi Xiang,
> >
> > On Mon, 13 Sep 2021 17:11:24 +0800
> > Gao Xiang <[email protected]> wrote:
> >
> > > On Mon, Sep 13, 2021 at 05:00:16PM +0800, Yue Hu wrote:
> > > > On Mon, 13 Sep 2021 16:48:45 +0800
> > > > Gao Xiang <[email protected]> wrote:
> > > >
> > > > > Hi Yue,
> > > > >
> > > > > On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> > > > > > From: Yue Hu <[email protected]>
> > > > > >
> > > > > > mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> > > > > > compacted_4b_initial > totalidx, kernel should be aligned with it
> > > > > > accordingly.
> > > > >
> > > > > There is no difference between compacted_4b_initial or compacted_4b_end
> > > > > for compacted 4B. Since in this way totalidx for compact 2B won't larger
> > > > > than 16 (number of lclusters in a compacted 2B pack.)
> > > >
> > > > However, we can see compacted_2b is a big number for this case. It should
> > > > be pointless.
> > >
> > > Does it has some real impact?
> >
> > No real impact to correct result.
> >
> > >
> > > compacted_4b_initial is only used for the alignment use for the
> > > first compacted_2b so that each compacted_2b pack won't cross
> > > the block (page) boundary. And compacted_4b_end is for the last
> > > lclusters aren't fitted in any compacted_2b pack.
> > >
> > > If compacted_4b_initial > totalidx, I think the whole indexes
> > > would be compacted 4B and handled in
> > >
> > > if (lcn < compacted_4b_initial) {
> > > amortizedshift = 2;
> > > goto out;
> > > }
> >
> > Yes, it is.
> >
> > My point is why we need compacted_2b here for this case. If it's
> > not helpful/used for next code logic, we should remove/avoid it.
> > I think that may cause some misunderstanding and consume unneeded
> > CPU resources.
>
> Okay, make sense. If the number of compacted_2b misleads, how about
> just
>
> if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
> compacted_4b_initial <= totalidx) {
> compacted_2b = ...;
> } else {
> compacted_2b = 0;
> }
Looks good. So, the patch title may change a little.
>
> , and refine the commit message to point out the following facts for
> other folks:
>
> - compacted_4b_initial is used contain the very first lclusters in order
> to fulfill the alignment of the first compacted_2b pack;
>
> - compacted_4b_end is used for the last lclusters which aren't fitted in
> the previous compacted_2b packs;
>
> - if compacted_4b_initial > totalidx, the whole indexes will be compacted
> 4B and handled with compacted_4b_initial.
Ok, will add these facts above in v2.
Thanks.
>
> Thanks,
> Gao Xiang
>
> >
> > Thanks.
Hi Xiang,
On Mon, 13 Sep 2021 17:11:24 +0800
Gao Xiang <[email protected]> wrote:
> On Mon, Sep 13, 2021 at 05:00:16PM +0800, Yue Hu wrote:
> > On Mon, 13 Sep 2021 16:48:45 +0800
> > Gao Xiang <[email protected]> wrote:
> >
> > > Hi Yue,
> > >
> > > On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> > > > From: Yue Hu <[email protected]>
> > > >
> > > > mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> > > > compacted_4b_initial > totalidx, kernel should be aligned with it
> > > > accordingly.
> > >
> > > There is no difference between compacted_4b_initial or compacted_4b_end
> > > for compacted 4B. Since in this way totalidx for compact 2B won't larger
> > > than 16 (number of lclusters in a compacted 2B pack.)
> >
> > However, we can see compacted_2b is a big number for this case. It should
> > be pointless.
>
> Does it has some real impact?
No real impact to correct result.
>
> compacted_4b_initial is only used for the alignment use for the
> first compacted_2b so that each compacted_2b pack won't cross
> the block (page) boundary. And compacted_4b_end is for the last
> lclusters aren't fitted in any compacted_2b pack.
>
> If compacted_4b_initial > totalidx, I think the whole indexes
> would be compacted 4B and handled in
>
> if (lcn < compacted_4b_initial) {
> amortizedshift = 2;
> goto out;
> }
Yes, it is.
My point is why we need compacted_2b here for this case. If it's
not helpful/used for next code logic, we should remove/avoid it.
I think that may cause some misunderstanding and consume unneeded
CPU resources.
Thanks.
>
> Thanks,
> Gao Xiang
>
> >
> > Thanks.
> >
> > >
> > > So it can be handled in either compacted_4b_initial or compacted_4b_end
> > > cases, because there are all compacted 4B.
> > >
> > > Thanks,
> > > Gao Xiang
> > >
> > > >
> > > > Signed-off-by: Yue Hu <[email protected]>
> > > > ---
> > > > fs/erofs/zmap.c | 5 ++++-
> > > > 1 file changed, 4 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c
> > > > index 9fb98d8..4f941b6 100644
> > > > --- a/fs/erofs/zmap.c
> > > > +++ b/fs/erofs/zmap.c
> > > > @@ -369,7 +369,10 @@ static int compacted_load_cluster_from_disk(struct z_erofs_maprecorder *m,
> > > > if (compacted_4b_initial == 32 / 4)
> > > > compacted_4b_initial = 0;
> > > >
> > > > - if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > > + if (compacted_4b_initial > totalidx) {
> > > > + compacted_4b_initial = 0;
> > > > + compacted_2b = 0;
> > > > + } else if (vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B)
> > > > compacted_2b = rounddown(totalidx - compacted_4b_initial, 16);
> > > > else
> > > > compacted_2b = 0;
> > > > --
> > > > 1.9.1
Hi Yue,
On Mon, Sep 13, 2021 at 06:58:36PM +0800, Yue Hu wrote:
> Hi Xiang,
>
> On Mon, 13 Sep 2021 17:11:24 +0800
> Gao Xiang <[email protected]> wrote:
>
> > On Mon, Sep 13, 2021 at 05:00:16PM +0800, Yue Hu wrote:
> > > On Mon, 13 Sep 2021 16:48:45 +0800
> > > Gao Xiang <[email protected]> wrote:
> > >
> > > > Hi Yue,
> > > >
> > > > On Mon, Sep 13, 2021 at 03:24:05PM +0800, Yue Hu wrote:
> > > > > From: Yue Hu <[email protected]>
> > > > >
> > > > > mkfs.erofs will treat compacted_4b_initial & compacted_2b as 0 if
> > > > > compacted_4b_initial > totalidx, kernel should be aligned with it
> > > > > accordingly.
> > > >
> > > > There is no difference between compacted_4b_initial or compacted_4b_end
> > > > for compacted 4B. Since in this way totalidx for compact 2B won't larger
> > > > than 16 (number of lclusters in a compacted 2B pack.)
> > >
> > > However, we can see compacted_2b is a big number for this case. It should
> > > be pointless.
> >
> > Does it has some real impact?
>
> No real impact to correct result.
>
> >
> > compacted_4b_initial is only used for the alignment use for the
> > first compacted_2b so that each compacted_2b pack won't cross
> > the block (page) boundary. And compacted_4b_end is for the last
> > lclusters aren't fitted in any compacted_2b pack.
> >
> > If compacted_4b_initial > totalidx, I think the whole indexes
> > would be compacted 4B and handled in
> >
> > if (lcn < compacted_4b_initial) {
> > amortizedshift = 2;
> > goto out;
> > }
>
> Yes, it is.
>
> My point is why we need compacted_2b here for this case. If it's
> not helpful/used for next code logic, we should remove/avoid it.
> I think that may cause some misunderstanding and consume unneeded
> CPU resources.
Okay, make sense. If the number of compacted_2b misleads, how about
just
if ((vi->z_advise & Z_EROFS_ADVISE_COMPACTED_2B) &&
compacted_4b_initial <= totalidx) {
compacted_2b = ...;
} else {
compacted_2b = 0;
}
, and refine the commit message to point out the following facts for
other folks:
- compacted_4b_initial is used contain the very first lclusters in order
to fulfill the alignment of the first compacted_2b pack;
- compacted_4b_end is used for the last lclusters which aren't fitted in
the previous compacted_2b packs;
- if compacted_4b_initial > totalidx, the whole indexes will be compacted
4B and handled with compacted_4b_initial.
Thanks,
Gao Xiang
>
> Thanks.