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Date:   Thu, 13 Apr 2023 11:46:24 -0700
From:   Luis Chamberlain <mcgrof@kernel.org>
To:     Christian Brauner <brauner@kernel.org>
Cc:     Kefeng Wang <wangkefeng.wang@huawei.com>,
        linux-fsdevel@vger.kernel.org,
        Andrew Morton <akpm@linux-foundation.org>,
        linux-kernel@vger.kernel.org,
        Alexander Viro <viro@zeniv.linux.org.uk>
Subject: Re: [PATCH] fs: fix sysctls.c built
Message-ID: <ZDhOAKZK+P4IFDJp@bombadil.infradead.org>
References: <20230331084502.155284-1-wangkefeng.wang@huawei.com>
 <66c0e8b6-64d1-5be6-cd4d-9700d84e1b84@huawei.com>
 <20230412-sympathie-haltbar-da2d2183067b@brauner>
 <ZDg2m/U1NasHfK4j@bombadil.infradead.org>
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Sender: Luis Chamberlain <mcgrof@infradead.org>
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On Thu, Apr 13, 2023 at 10:06:35AM -0700, Luis Chamberlain wrote:
> On Wed, Apr 12, 2023 at 11:19:56AM +0200, Christian Brauner wrote:
> > On Tue, Apr 11, 2023 at 12:14:44PM +0800, Kefeng Wang wrote:
> > > /proc/sys/fs/overflowuid and overflowgid  will be lost without
> > > building this file, kindly ping, any comments, thanks.
> > > 
> > > 
> > > On 2023/3/31 16:45, Kefeng Wang wrote:
> > > > 'obj-$(CONFIG_SYSCTL) += sysctls.o' must be moved after "obj-y :=",
> > > > or it won't be built as it is overwrited.
> > > > 
> > > > Fixes: ab171b952c6e ("fs: move namespace sysctls and declare fs base directory")
> > > > Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
> > > > ---
> > > >   fs/Makefile | 3 +--
> > > >   1 file changed, 1 insertion(+), 2 deletions(-)
> > > > 
> > > > diff --git a/fs/Makefile b/fs/Makefile
> > > > index 05f89b5c962f..8d4736fcc766 100644
> > > > --- a/fs/Makefile
> > > > +++ b/fs/Makefile
> > > > @@ -6,7 +6,6 @@
> > > >   # Rewritten to use lists instead of if-statements.
> > > >   #
> > > > -obj-$(CONFIG_SYSCTL)		+= sysctls.o
> > > >   obj-y :=	open.o read_write.o file_table.o super.o \
> > > >   		char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
> > > > @@ -50,7 +49,7 @@ obj-$(CONFIG_FS_MBCACHE)	+= mbcache.o
> > > >   obj-$(CONFIG_FS_POSIX_ACL)	+= posix_acl.o
> > > >   obj-$(CONFIG_NFS_COMMON)	+= nfs_common/
> > > >   obj-$(CONFIG_COREDUMP)		+= coredump.o
> > > > -obj-$(CONFIG_SYSCTL)		+= drop_caches.o
> > > > +obj-$(CONFIG_SYSCTL)		+= drop_caches.o sysctls.o
> > > >   obj-$(CONFIG_FHANDLE)		+= fhandle.o
> > > >   obj-y				+= iomap/
> > 
> > Given the description in
> > ab171b952c6e ("fs: move namespace sysctls and declare fs base directory")
> > you probably want to move this earlier.
> 
> I was being *way* too cautious and I was wrong, so I'll take Kefang's patch as
> I can verify now that order does not matter and his patch is correct.
> I've corrected the documentation and clarified this on sysctl-next and
> so reflected on linux-next too with these two patches:
> 
> sysctl: clarify register_sysctl_init() base directory order
> https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/commit/?h=sysctl-next-20230413&id=8ae59580f2b0529b6dd1a1cda6b838cfb268cb87
> 
> proc_sysctl: move helper which creates required subdirectories
> https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/commit/?h=sysctl-next-20230413&id=f4c09b14073513efd581459520a01c4c88cb24d7
> 
> proc_sysctl: update docs for __register_sysctl_table()
> https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/commit/?h=sysctl-next-20230413&id=d59d91edd67ec4cef62f26249510fe08b291ae72
> 
> proc_sysctl: enhance documentation
> https://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux.git/commit/?h=sysctl-next-20230413&id=eb472aa0678fd03321093bffeb9c7fd7f5035844
> 
> And so something we can do eventually is do away with all the base stuff.
> For now it's fine, it's not creating an issue.

Come to think of it all the above patches except the one that moves code
("proc_sysctl: move helper which creates required subdirectories") are
stable fix candidates prior to Kefeng's patch. I'll also update Kefeng's
patch to mention stable down to v5.17 and update the other patches with
the respective stable tag as well.

  Luis