Re: [PATCH] mempolicy.h: Remove unnecessary header file inclusions

[SeongJae Park <sj@kernel.org>]

Hi Junie,


On Fri, 6 Dec 2024 23:53:49 +0800 Junjie Fu <fujunjie1@qq.com> wrote:

> Originally, linux/mempolicy.h included linux/pagemap.h because vma_migratable()
> was implemented inline within the header, requiring mapping_gfp_mask()
> function to implement vma_migratable(). Now that vma_migratable() is only
> declared in linux/mempolicy.h and its implementation has been moved to mempolicy.c,
> the inclusion of linux/pagemap.h in the header is no longer necessary.
> 
> Additionally, since mempolicy.c includes internal.h, and internal.h already
> includes linux/pagemap.h, so there is no need to modify mempolicy.c after
> removing the direct inclusion of linux/pagemap.h from linux/mempolicy.h
> 
> Signed-off-by: Junjie Fu <fujunjie1@qq.com>
> ---
>  include/linux/mempolicy.h | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
> index ce9885e0178a..d36877557b00 100644
> --- a/include/linux/mempolicy.h
> +++ b/include/linux/mempolicy.h
> @@ -12,7 +12,6 @@
>  #include <linux/rbtree.h>
>  #include <linux/spinlock.h>
>  #include <linux/nodemask.h>
> -#include <linux/pagemap.h>
>  #include <uapi/linux/mempolicy.h>

I noticed kunit UM build errors as below on mm-unstable, and git bisect points
this patch.

    $ ./tools/testing/kunit/kunit.py run --kunitconfig ./mm/damon/tests/
    [...]
    fs/aio.c:525:71: error: ‘FGP_CREAT’ undeclared (first use in this function); did you mean ‘IPC_CREAT’?
      525 |                                             FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
          |                                                                       ^~~~~~~~~
          |                                                                       IPC_CREAT
    fs/aio.c:532:17: error: implicit declaration of function ‘folio_end_read’; did you mean ‘folio_test_head’? [-Werror=implicit-function-declaration]
      532 |                 folio_end_read(folio, true);
          |                 ^~~~~~~~~~~~~~
          |                 folio_test_head
    [...]

I also confirmed including pagemap.h on fs/aio.c as below fixes the issue.  I
would like to hear you or others opinions though, since I'm not familiar with
the inclusion routes of the file.

diff --git a/fs/aio.c b/fs/aio.c
index 50671640b588..9fad51dc823f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -39,6 +39,7 @@
 #include <linux/compat.h>
 #include <linux/migrate.h>
 #include <linux/ramfs.h>
+#include <linux/pagemap.h>
 #include <linux/percpu-refcount.h>
 #include <linux/mount.h>
 #include <linux/pseudo_fs.h>


Thanks,
SJ

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