Mailing List Archive: drbd 9.0.26 and newer fails to build on 5.4 kernels

drbd 9.0.26 and newer fails to build on 5.4 kernels

Feb 19, 2021, 10:38 AM

Post #1 of 5 (592 views)

Hi,

I tried to update the kernel for alpine 3.12-stable branch from 5.4.84
to 5.4.99. The 3rd part kernel module drbd 9.0.22-2 failed to build so
I updated it to 9.0.27-1. This passed on the x86_64 machine I tested
built it on so I pushed it.

But it failed on 32 bit arm builders:

...
In file included from ./include/linux/module.h:27,
from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_req.h:16,
from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:22:
./arch/arm/include/asm/module.h:59: warning: "MODULE_ARCH_VERMAGIC" redefined
59 | #define MODULE_ARCH_VERMAGIC \
|
In file included from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:19:
./include/linux/vermagic.h:28: note: this is the location of the previous definition
28 | #define MODULE_ARCH_VERMAGIC ""
|
GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
Building modules, stage 2.
MODPOST 2 modules
ERROR: "__aeabi_ldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
ERROR: "__aeabi_uldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
make[2]: *** [Makefile:1639: modules] Error 2
make[1]: *** [Makefile:132: kbuild] Error 2
make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
make: *** [Makefile:131: module] Error 2
>>> ERROR: drbd-lts: build failed

And on 32 bit x86:

GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
Building modules, stage 2.
MODPOST 2 modules
ERROR: "__udivdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
ERROR: "__divdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
make[2]: *** [Makefile:1639: modules] Error 2
make[1]: *** [Makefile:132: kbuild] Error 2
make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
make: *** [Makefile:131: module] Error 2
>>> ERROR: drbd-lts: build failed

I read that this can happen if do_div() is not used and libgcc is not
linked in (which I assume we shouldnt on kernel). I tried to look at
the git log if I could find anything evident but couldn't find anything.

So I tried to find older version. Turns out that the lastest version
that compiles with 5.4 kernel is 9.0.25-2, but it only compiles with
5.4.84 kernel and not the 5.4.99.

Does anyone have a clue how to solve this? If not, I guess I have to
try git bisect it.

PS. Please CC me, I'm not subscribed to the mailing list.

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Re: drbd 9.0.26 and newer fails to build on 5.4 kernels [ In reply to ]

ncopa at alpinelinux

Feb 19, 2021, 10:50 AM

Post #2 of 5 (592 views)

Permalink

On Fri, 19 Feb 2021 19:38:53 +0100
Natanael Copa <ncopa@alpinelinux.org> wrote:

> Hi,
>
> I tried to update the kernel for alpine 3.12-stable branch from 5.4.84
> to 5.4.99. The 3rd part kernel module drbd 9.0.22-2 failed to build so
> I updated it to 9.0.27-1. This passed on the x86_64 machine I tested
> built it on so I pushed it.
>
> But it failed on 32 bit arm builders:
>
> ...
> In file included from ./include/linux/module.h:27,
> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_req.h:16,
> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:22:
> ./arch/arm/include/asm/module.h:59: warning: "MODULE_ARCH_VERMAGIC" redefined
> 59 | #define MODULE_ARCH_VERMAGIC \
> |
> In file included from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:19:
> ./include/linux/vermagic.h:28: note: this is the location of the previous definition
> 28 | #define MODULE_ARCH_VERMAGIC ""
> |
> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> Building modules, stage 2.
> MODPOST 2 modules
> ERROR: "__aeabi_ldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> ERROR: "__aeabi_uldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> make[2]: *** [Makefile:1639: modules] Error 2
> make[1]: *** [Makefile:132: kbuild] Error 2
> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> make: *** [Makefile:131: module] Error 2
> >>> ERROR: drbd-lts: build failed
>
> And on 32 bit x86:
>
> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> Building modules, stage 2.
> MODPOST 2 modules
> ERROR: "__udivdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> ERROR: "__divdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> make[2]: *** [Makefile:1639: modules] Error 2
> make[1]: *** [Makefile:132: kbuild] Error 2
> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> make: *** [Makefile:131: module] Error 2
> >>> ERROR: drbd-lts: build failed
>
> I read that this can happen if do_div() is not used and libgcc is not
> linked in (which I assume we shouldnt on kernel). I tried to look at
> the git log if I could find anything evident but couldn't find anything.
>
> So I tried to find older version. Turns out that the lastest version
> that compiles with 5.4 kernel is 9.0.25-2, but it only compiles with
> 5.4.84 kernel and not the 5.4.99.
>
> Does anyone have a clue how to solve this? If not, I guess I have to
> try git bisect it.

Ugh... turns out I cannot bisect it either:

make -C /lib/modules/5.4.99-0-lts/build M=/home/ncopa/src/drbd/drbd modules
./drbd-kernel-compat/gen_compat_patch.sh: line 12: spatch: command not found
./drbd-kernel-compat/gen_compat_patch.sh: line 45: hash: spatch: not found
INFO: not trying spatch-as-a-service because you are trying
to build DRBD from a git checkout. Please install a suitable
version of coccinelle (>1.0.8) or try building from a
release tarball.
ERROR: no suitable spatch found in $PATH. Install package 'coccinelle'!
make[4]: *** [Makefile:177: drbd-kernel-compat/cocci_cache/aa41fa1c792a297895276817c34c7a38/compat.patch] Error 1
make[3]: *** [/home/ncopa/src/drbd/drbd/Kbuild:135:
/home/ncopa/src/drbd/drbd/drbd-kernel-compat/compat.patch] Error 2

Seems like coccinelle requires ocaml and apparently we don't have ocaml
for x86 so I'd need to bootstrap ocaml on 32 bit x86 to be able to
build spatch to be able to build drbd from git so I can git bisect the
problem. I guess its time to give up and say its weekend.

-nc
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Re: drbd 9.0.26 and newer fails to build on 5.4 kernels [ In reply to ]

ncopa at alpinelinux

Feb 22, 2021, 2:40 AM

Post #3 of 5 (592 views)

Permalink

On Fri, 19 Feb 2021 19:50:13 +0100
Natanael Copa <ncopa@alpinelinux.org> wrote:

> On Fri, 19 Feb 2021 19:38:53 +0100
> Natanael Copa <ncopa@alpinelinux.org> wrote:
>
> > Hi,
> >
> > I tried to update the kernel for alpine 3.12-stable branch from 5.4.84
> > to 5.4.99. The 3rd part kernel module drbd 9.0.22-2 failed to build so
> > I updated it to 9.0.27-1. This passed on the x86_64 machine I tested
> > built it on so I pushed it.
> >
> > But it failed on 32 bit arm builders:
> >
> > ...
> > In file included from ./include/linux/module.h:27,
> > from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_req.h:16,
> > from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:22:
> > ./arch/arm/include/asm/module.h:59: warning: "MODULE_ARCH_VERMAGIC" redefined
> > 59 | #define MODULE_ARCH_VERMAGIC \
> > |
> > In file included from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:19:
> > ./include/linux/vermagic.h:28: note: this is the location of the previous definition
> > 28 | #define MODULE_ARCH_VERMAGIC ""
> > |
> > GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> > CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> > LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> > Building modules, stage 2.
> > MODPOST 2 modules
> > ERROR: "__aeabi_ldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> > ERROR: "__aeabi_uldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> > make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> > make[2]: *** [Makefile:1639: modules] Error 2
> > make[1]: *** [Makefile:132: kbuild] Error 2
> > make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> > make: *** [Makefile:131: module] Error 2
> > >>> ERROR: drbd-lts: build failed
> >
> > And on 32 bit x86:
> >
> > GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> > CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> > LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> > Building modules, stage 2.
> > MODPOST 2 modules
> > ERROR: "__udivdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> > ERROR: "__divdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> > make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> > make[2]: *** [Makefile:1639: modules] Error 2
> > make[1]: *** [Makefile:132: kbuild] Error 2
> > make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> > make: *** [Makefile:131: module] Error 2
> > >>> ERROR: drbd-lts: build failed
> >
> > I read that this can happen if do_div() is not used and libgcc is not
> > linked in (which I assume we shouldnt on kernel). I tried to look at
> > the git log if I could find anything evident but couldn't find anything.
> >
> > So I tried to find older version. Turns out that the lastest version
> > that compiles with 5.4 kernel is 9.0.25-2, but it only compiles with
> > 5.4.84 kernel and not the 5.4.99.
> >
> > Does anyone have a clue how to solve this? If not, I guess I have to
> > try git bisect it.

I found the commit that introduces the issue using objdump and git log:

commit 8dc8ede32de4410e99148b39d0f960e975eeddea
Author: Joel Colledge <joel.colledge@linbit.com>
Date: Wed Nov 11 18:11:26 2020 +0100

drbd: fix slow sync when sync requests are answered quickly

It is the DIV_ROUND_UP in that commit that introduces this.

This change fixes it:
diff --git a/drbd/drbd_sender.c b/drbd/drbd_sender.c
index 30e301fb..34030870 100644
--- a/drbd/drbd_sender.c
+++ b/drbd/drbd_sender.c
@@ -687,7 +687,7 @@ static int drbd_resync_delay(struct drbd_peer_device *peer_device)
* that the rate limiting prevents any new requests
* from being made. Wait just long enough so that we
* can request some data next time. */
- delay = DIV_ROUND_UP(HZ * BM_SECT_PER_BIT, pdc->c_max_rate * 2);
+ delay = DIV_ROUND_UP((unsigned long)(HZ * BM_SECT_PER_BIT / 2), pdc->c_max_rate);
}
} else {
/* Fixed resync rate. Use the standard delay. */

As I understand, it is the compiler that converts the HZ *
BM_SECT_PER_BIT to 64 bit type which triggers the error.

As I understand the source BM_SECT_PER_BIT = 1 << (12-9) = 8, so it
should be safe to move the `* 2` on the right side to a `/ 2` on the
left, which results in HZ * 4 / pdc->c_max_rate.

HZ is to my understand seldomly (never?) set to anything above 1000?
And 1000 * 4 fits just fine in an unsigned long, so I think the above diff should be safe.

-nc
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Re: drbd 9.0.26 and newer fails to build on 5.4 kernels [ In reply to ]

christoph.boehmwalder at linbit

Feb 22, 2021, 3:37 AM

Post #4 of 5 (592 views)

Permalink

On 2/22/21 11:40 AM, Natanael Copa wrote:
> On Fri, 19 Feb 2021 19:50:13 +0100
> Natanael Copa <ncopa@alpinelinux.org> wrote:
>
>> On Fri, 19 Feb 2021 19:38:53 +0100
>> Natanael Copa <ncopa@alpinelinux.org> wrote:
>>
>>> Hi,
>>>
>>> I tried to update the kernel for alpine 3.12-stable branch from 5.4.84
>>> to 5.4.99. The 3rd part kernel module drbd 9.0.22-2 failed to build so
>>> I updated it to 9.0.27-1. This passed on the x86_64 machine I tested
>>> built it on so I pushed it.
>>>
>>> But it failed on 32 bit arm builders:
>>>
>>> ...
>>> In file included from ./include/linux/module.h:27,
>>> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_req.h:16,
>>> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:22:
>>> ./arch/arm/include/asm/module.h:59: warning: "MODULE_ARCH_VERMAGIC" redefined
>>> 59 | #define MODULE_ARCH_VERMAGIC \
>>> |
>>> In file included from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:19:
>>> ./include/linux/vermagic.h:28: note: this is the location of the previous definition
>>> 28 | #define MODULE_ARCH_VERMAGIC ""
>>> |
>>> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
>>> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
>>> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
>>> Building modules, stage 2.
>>> MODPOST 2 modules
>>> ERROR: "__aeabi_ldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
>>> ERROR: "__aeabi_uldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
>>> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
>>> make[2]: *** [Makefile:1639: modules] Error 2
>>> make[1]: *** [Makefile:132: kbuild] Error 2
>>> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
>>> make: *** [Makefile:131: module] Error 2
>>>>>> ERROR: drbd-lts: build failed
>>>
>>> And on 32 bit x86:
>>>
>>> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
>>> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
>>> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
>>> Building modules, stage 2.
>>> MODPOST 2 modules
>>> ERROR: "__udivdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
>>> ERROR: "__divdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
>>> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
>>> make[2]: *** [Makefile:1639: modules] Error 2
>>> make[1]: *** [Makefile:132: kbuild] Error 2
>>> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
>>> make: *** [Makefile:131: module] Error 2
>>>>>> ERROR: drbd-lts: build failed
>>>
>>> I read that this can happen if do_div() is not used and libgcc is not
>>> linked in (which I assume we shouldnt on kernel). I tried to look at
>>> the git log if I could find anything evident but couldn't find anything.
>>>
>>> So I tried to find older version. Turns out that the lastest version
>>> that compiles with 5.4 kernel is 9.0.25-2, but it only compiles with
>>> 5.4.84 kernel and not the 5.4.99.
>>>
>>> Does anyone have a clue how to solve this? If not, I guess I have to
>>> try git bisect it.
>
>
> I found the commit that introduces the issue using objdump and git log:
>
> commit 8dc8ede32de4410e99148b39d0f960e975eeddea
> Author: Joel Colledge <joel.colledge@linbit.com>
> Date: Wed Nov 11 18:11:26 2020 +0100
>
> drbd: fix slow sync when sync requests are answered quickly
>
>
> It is the DIV_ROUND_UP in that commit that introduces this.
>
> This change fixes it:
> diff --git a/drbd/drbd_sender.c b/drbd/drbd_sender.c
> index 30e301fb..34030870 100644
> --- a/drbd/drbd_sender.c
> +++ b/drbd/drbd_sender.c
> @@ -687,7 +687,7 @@ static int drbd_resync_delay(struct drbd_peer_device *peer_device)
> * that the rate limiting prevents any new requests
> * from being made. Wait just long enough so that we
> * can request some data next time. */
> - delay = DIV_ROUND_UP(HZ * BM_SECT_PER_BIT, pdc->c_max_rate * 2);
> + delay = DIV_ROUND_UP((unsigned long)(HZ * BM_SECT_PER_BIT / 2), pdc->c_max_rate);
> }
> } else {
> /* Fixed resync rate. Use the standard delay. */
>
>
> As I understand, it is the compiler that converts the HZ *
> BM_SECT_PER_BIT to 64 bit type which triggers the error.
>
> As I understand the source BM_SECT_PER_BIT = 1 << (12-9) = 8, so it
> should be safe to move the `* 2` on the right side to a `/ 2` on the
> left, which results in HZ * 4 / pdc->c_max_rate.
>
> HZ is to my understand seldomly (never?) set to anything above 1000?
> And 1000 * 4 fits just fine in an unsigned long, so I think the above diff should be safe.
>
> -nc
> _______________________________________________
> Star us on GITHUB: https://github.com/LINBIT
> drbd-user mailing list
> drbd-user@lists.linbit.com
> https://lists.linbit.com/mailman/listinfo/drbd-user
>

Hi Natanael,

thanks for the proposed fix! Your logic seems right to me.

I have committed it to the drbd repository, along with one other similar
fix. See
https://github.com/LINBIT/drbd/commit/4194a136b08c1f204707bdb0695fc05c0b2997e9

Are you able to test the latest git HEAD (drbd-9.0 branch) on your
infrastructure to verify that this is fixed for you?

Thanks again,
Christoph

--
Christoph Böhmwalder
LINBIT | Keeping the Digital World Running
DRBD HA — Disaster Recovery — Software defined Storage
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Re: drbd 9.0.26 and newer fails to build on 5.4 kernels [ In reply to ]

ncopa at alpinelinux

Feb 23, 2021, 2:17 AM

Post #5 of 5 (588 views)

Permalink

On Mon, 22 Feb 2021 12:37:41 +0100
Christoph B?hmwalder <christoph.boehmwalder@linbit.com> wrote:

> On 2/22/21 11:40 AM, Natanael Copa wrote:
> > On Fri, 19 Feb 2021 19:50:13 +0100
> > Natanael Copa <ncopa@alpinelinux.org> wrote:
> >
> >> On Fri, 19 Feb 2021 19:38:53 +0100
> >> Natanael Copa <ncopa@alpinelinux.org> wrote:
> >>
> >>> Hi,
> >>>
> >>> I tried to update the kernel for alpine 3.12-stable branch from 5.4.84
> >>> to 5.4.99. The 3rd part kernel module drbd 9.0.22-2 failed to build so
> >>> I updated it to 9.0.27-1. This passed on the x86_64 machine I tested
> >>> built it on so I pushed it.
> >>>
> >>> But it failed on 32 bit arm builders:
> >>>
> >>> ...
> >>> In file included from ./include/linux/module.h:27,
> >>> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_req.h:16,
> >>> from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:22:
> >>> ./arch/arm/include/asm/module.h:59: warning: "MODULE_ARCH_VERMAGIC" redefined
> >>> 59 | #define MODULE_ARCH_VERMAGIC \
> >>> |
> >>> In file included from /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_state.c:19:
> >>> ./include/linux/vermagic.h:28: note: this is the location of the previous definition
> >>> 28 | #define MODULE_ARCH_VERMAGIC ""
> >>> |
> >>> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> >>> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> >>> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> >>> Building modules, stage 2.
> >>> MODPOST 2 modules
> >>> ERROR: "__aeabi_ldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> >>> ERROR: "__aeabi_uldivmod" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> >>> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> >>> make[2]: *** [Makefile:1639: modules] Error 2
> >>> make[1]: *** [Makefile:132: kbuild] Error 2
> >>> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> >>> make: *** [Makefile:131: module] Error 2
> >>>>>> ERROR: drbd-lts: build failed
> >>>
> >>> And on 32 bit x86:
> >>>
> >>> GEN /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.c
> >>> CC [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd_buildtag.o
> >>> LD [M] /home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.o
> >>> Building modules, stage 2.
> >>> MODPOST 2 modules
> >>> ERROR: "__udivdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> >>> ERROR: "__divdi3" [/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd/drbd.ko] undefined!
> >>> make[3]: *** [scripts/Makefile.modpost:94: __modpost] Error 1
> >>> make[2]: *** [Makefile:1639: modules] Error 2
> >>> make[1]: *** [Makefile:132: kbuild] Error 2
> >>> make[1]: Leaving directory '/home/buildozer/aports/main/drbd-lts/src/drbd-9.0.27-1/drbd'
> >>> make: *** [Makefile:131: module] Error 2
> >>>>>> ERROR: drbd-lts: build failed
> >>>
> >>> I read that this can happen if do_div() is not used and libgcc is not
> >>> linked in (which I assume we shouldnt on kernel). I tried to look at
> >>> the git log if I could find anything evident but couldn't find anything.
> >>>
> >>> So I tried to find older version. Turns out that the lastest version
> >>> that compiles with 5.4 kernel is 9.0.25-2, but it only compiles with
> >>> 5.4.84 kernel and not the 5.4.99.
> >>>
> >>> Does anyone have a clue how to solve this? If not, I guess I have to
> >>> try git bisect it.
> >
> >
> > I found the commit that introduces the issue using objdump and git log:
> >
> > commit 8dc8ede32de4410e99148b39d0f960e975eeddea
> > Author: Joel Colledge <joel.colledge@linbit.com>
> > Date: Wed Nov 11 18:11:26 2020 +0100
> >
> > drbd: fix slow sync when sync requests are answered quickly
> >
> >
> > It is the DIV_ROUND_UP in that commit that introduces this.
> >
> > This change fixes it:
> > diff --git a/drbd/drbd_sender.c b/drbd/drbd_sender.c
> > index 30e301fb..34030870 100644
> > --- a/drbd/drbd_sender.c
> > +++ b/drbd/drbd_sender.c
> > @@ -687,7 +687,7 @@ static int drbd_resync_delay(struct drbd_peer_device *peer_device)
> > * that the rate limiting prevents any new requests
> > * from being made. Wait just long enough so that we
> > * can request some data next time. */
> > - delay = DIV_ROUND_UP(HZ * BM_SECT_PER_BIT, pdc->c_max_rate * 2);
> > + delay = DIV_ROUND_UP((unsigned long)(HZ * BM_SECT_PER_BIT / 2), pdc->c_max_rate);
> > }
> > } else {
> > /* Fixed resync rate. Use the standard delay. */
> >
> >
> > As I understand, it is the compiler that converts the HZ *
> > BM_SECT_PER_BIT to 64 bit type which triggers the error.
> >
> > As I understand the source BM_SECT_PER_BIT = 1 << (12-9) = 8, so it
> > should be safe to move the `* 2` on the right side to a `/ 2` on the
> > left, which results in HZ * 4 / pdc->c_max_rate.
> >
> > HZ is to my understand seldomly (never?) set to anything above 1000?
> > And 1000 * 4 fits just fine in an unsigned long, so I think the above diff should be safe.
> >
> > -nc
> > _______________________________________________
> > Star us on GITHUB: https://github.com/LINBIT
> > drbd-user mailing list
> > drbd-user@lists.linbit.com
> > https://lists.linbit.com/mailman/listinfo/drbd-user
> >
>
> Hi Natanael,
>
> thanks for the proposed fix! Your logic seems right to me.
>
> I have committed it to the drbd repository, along with one other similar
> fix. See
> https://github.com/LINBIT/drbd/commit/4194a136b08c1f204707bdb0695fc05c0b2997e9

Looks good.

> Are you able to test the latest git HEAD (drbd-9.0 branch) on your
> infrastructure to verify that this is fixed for you?

I'm sorry but I cannot build it from git on 32 bit arches due to the
spatch/coccinelle. But I did apply the proposed patch on top of 9.0.27
and it builds at least.

https://git.alpinelinux.org/aports/commit/?h=3.12-stable&id=d18a91093f667669f20812889b6a5580424eb3e1

thanks!

-nc

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