Re: [PATCH v2] src: fix detached_mounts_propagation compile errors

[Gao Xiang <hsiangkao@linux.alibaba.com>]

Hi Zorro,

On 2023/4/22 21:54, Zorro Lang wrote:
> On Thu, Apr 20, 2023 at 10:11:06AM +0800, Gao Xiang wrote:
>> Newer glibc such as glibc 2.36 also defines 'struct mount_attr'
>> in addition to <linux/mount.h>.  It will report as below when
>> compiling with old linux kernel headers (without idmapped mounts,
>> such as kernel-headers 5.10.134) but with newer glibc (here checked
>> with glibc 2.36.6):
>>
>>      [CC]    detached_mounts_propagation
>> In file included from detached_mounts_propagation.c:29:
>> vfs/missing.h:115:8: error: redefinition of 'struct mount_attr'
>>    115 | struct mount_attr {
>>        |        ^~~~~~~~~~
>> In file included from detached_mounts_propagation.c:23:
>> /usr/include/sys/mount.h:210:8: note: originally defined here
>>    210 | struct mount_attr
>>        |        ^~~~~~~~~~
>> gmake[3]: *** [Makefile:102: detached_mounts_propagation] Error 1
>> gmake[2]: *** [include/buildrules:31: src] Error 2
>> make[1]: *** [Makefile:51: default] Error 2
>> make: *** [Makefile:49: default] Error 2
>>
>> Let's get rid of <linux/mount.h> as Christian suggested to avoid
>> potential incompatibility between these two headers.
>>
>> Cc: Christian Brauner <brauner@kernel.org>
>> Cc: "Yang Xu (Fujitsu)" <xuyang2018.jy@fujitsu.com>
>> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
>> ---
> 
> This patch works on latest fedora, but it cause fstests can't be built on
> RHEL-8 [1] and RHEL-9 [2], please check this incompatible problem.

I don't have RHEL-8 and RHEL-9 enviroment at hand, it seems that

#include <sys/mount.h> in vfs/missing.h

and xfs/xfs.h uapi header file causes more conflicts now.



So could you help check if _updating configure.ac only_ resolves
the problem?  I will recheck this as well.

Thanks,
Gao Xiang

> 
> Thanks,
> Zorro
> 
> [1]
> ...
> Building include
> Building lib
> Building ltp
> Building src
>      [CC]    feature
> In file included from /usr/include/linux/fs.h:18,
>                   from /usr/include/xfs/linux.h:30,
>                   from /usr/include/xfs/xfs.h:9,
>                   from global.h:13,
>                   from feature.c:29:
> /usr/include/sys/mount.h:35:3: error: expected identifier before numeric constant
>     MS_RDONLY = 1,  /* Mount read-only.  */
>     ^~~~~~~~~
> gmake[2]: *** [Makefile:112: feature] Error 1
> gmake[1]: *** [include/buildrules:31: src] Error 2
> make: *** [Makefile:51: default] Error 2
> 
> [2]
> ...
> Building include
> Building lib
> Building ltp
> Building src
>      [CC]    feature
> In file included from /usr/include/linux/fs.h:19,
>                   from /usr/include/xfs/linux.h:36,
>                   from /usr/include/xfs/xfs.h:9,
>                   from global.h:13,
>                   from feature.c:29:
> /usr/include/sys/mount.h:35:3: error: expected identifier before numeric constant
>     35 |   MS_RDONLY = 1,                /* Mount read-only.  */
>        |   ^~~~~~~~~
> In file included from feature.c:49:
> vfs/missing.h:116:8: error: redefinition of 'struct mount_attr'
>    116 | struct mount_attr {
>        |        ^~~~~~~~~~
> In file included from /usr/include/linux/fs.h:19,
>                   from /usr/include/xfs/linux.h:36,
>                   from /usr/include/xfs/xfs.h:9,
>                   from global.h:13,
>                   from feature.c:29:
> /usr/include/linux/mount.h:128:8: note: originally defined here
>    128 | struct mount_attr {
>        |        ^~~~~~~~~~
> gmake[2]: *** [Makefile:112: feature] Error 1
> gmake[1]: *** [include/buildrules:31: src] Error 2
> make: *** [Makefile:51: default] Error 2
> 
> 
>>   configure.ac                      | 2 +-
>>   src/detached_mounts_propagation.c | 1 -
>>   src/vfs/missing.h                 | 1 +
>>   3 files changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/configure.ac b/configure.ac
>> index 4687d8a3..bb29f37e 100644
>> --- a/configure.ac
>> +++ b/configure.ac
>> @@ -74,7 +74,7 @@ AC_HAVE_FIEXCHANGE
>>   
>>   AC_CHECK_FUNCS([renameat2])
>>   AC_CHECK_FUNCS([reallocarray])
>> -AC_CHECK_TYPES([struct mount_attr], [], [], [[#include <linux/mount.h>]])
>> +AC_CHECK_TYPES([struct mount_attr], [], [], [[#include <sys/mount.h>]])
>>   AC_CHECK_TYPES([struct btrfs_qgroup_limit], [], [], [[
>>   #include <stddef.h>
>>   #include <linux/btrfs.h>
>> diff --git a/src/detached_mounts_propagation.c b/src/detached_mounts_propagation.c
>> index 17db2c02..4041c75f 100644
>> --- a/src/detached_mounts_propagation.c
>> +++ b/src/detached_mounts_propagation.c
>> @@ -20,7 +20,6 @@
>>   #include <stdio.h>
>>   #include <stdlib.h>
>>   #include <string.h>
>> -#include <sys/mount.h>
>>   #include <sys/stat.h>
>>   #include <sys/syscall.h>
>>   #include <sys/types.h>
>> diff --git a/src/vfs/missing.h b/src/vfs/missing.h
>> index 059e742d..04ab33d1 100644
>> --- a/src/vfs/missing.h
>> +++ b/src/vfs/missing.h
>> @@ -18,6 +18,7 @@
>>   #include <sys/types.h>
>>   #include <syscall.h>
>>   #include <unistd.h>
>> +#include <sys/mount.h>
>>   
>>   #ifndef __NR_mount_setattr
>>   	#if defined __alpha__
>> -- 
>> 2.24.4
>>