+ mm-remove-pagemovable-export.patch added to mm-unstable branch

+ mm-remove-pagemovable-export.patch added to mm-unstable branch

[Andrew Morton]

The patch titled
     Subject: mm: remove PageMovable export
has been added to the -mm mm-unstable branch.  Its filename is
     mm-remove-pagemovable-export.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-remove-pagemovable-export.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Subject: mm: remove PageMovable export
Date: Fri, 6 Jan 2023 14:59:00 +0100

The only in-kernel users that need PageMovable() to be exported are z3fold
and zsmalloc and they are only using it for dubious debugging
functionality.  So remove those usages and the export so that no driver
code accidentally thinks that they are allowed to use this symbol.

Link: https://lkml.kernel.org/r/20230106135900.3763622-1-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Vitaly Wool <vitaly.wool@konsulko.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/compaction.c |    1 -
 mm/z3fold.c     |    2 --
 mm/zsmalloc.c   |    3 ---
 3 files changed, 6 deletions(-)

--- a/mm/compaction.c~mm-remove-pagemovable-export
+++ a/mm/compaction.c
@@ -122,7 +122,6 @@ bool PageMovable(struct page *page)
 
 	return false;
 }
-EXPORT_SYMBOL(PageMovable);
 
 void __SetPageMovable(struct page *page, const struct movable_operations *mops)
 {
--- a/mm/z3fold.c~mm-remove-pagemovable-export
+++ a/mm/z3fold.c
@@ -1450,7 +1450,6 @@ static bool z3fold_page_isolate(struct p
 	struct z3fold_header *zhdr;
 	struct z3fold_pool *pool;
 
-	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(PageIsolated(page), page);
 
 	if (test_bit(PAGE_HEADLESS, &page->private))
@@ -1490,7 +1489,6 @@ static int z3fold_page_migrate(struct pa
 	struct z3fold_header *zhdr, *new_zhdr;
 	struct z3fold_pool *pool;
 
-	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(!PageIsolated(page), page);
 	VM_BUG_ON_PAGE(!test_bit(PAGE_CLAIMED, &page->private), page);
 	VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
--- a/mm/zsmalloc.c~mm-remove-pagemovable-export
+++ a/mm/zsmalloc.c
@@ -1973,7 +1973,6 @@ static bool zs_page_isolate(struct page
 	 * Page is locked so zspage couldn't be destroyed. For detail, look at
 	 * lock_zspage in free_zspage.
 	 */
-	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(PageIsolated(page), page);
 
 	zspage = get_zspage(page);
@@ -2005,7 +2004,6 @@ static int zs_page_migrate(struct page *
 	if (mode == MIGRATE_SYNC_NO_COPY)
 		return -EINVAL;
 
-	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(!PageIsolated(page), page);
 
 	/* The page is locked, so this pointer must remain valid */
@@ -2070,7 +2068,6 @@ static void zs_page_putback(struct page
 {
 	struct zspage *zspage;
 
-	VM_BUG_ON_PAGE(!PageMovable(page), page);
 	VM_BUG_ON_PAGE(!PageIsolated(page), page);
 
 	zspage = get_zspage(page);
_

Patches currently in -mm which might be from gregkh@linuxfoundation.org are

mm-remove-pagemovable-export.patch

Re: + mm-remove-pagemovable-export.patch added to mm-unstable branch

[Sergey Senozhatsky]

On (23/01/06 16:57), Andrew Morton wrote:
> The only in-kernel users that need PageMovable() to be exported are z3fold
> and zsmalloc and they are only using it for dubious debugging
> functionality.  So remove those usages and the export so that no driver
> code accidentally thinks that they are allowed to use this symbol.
> 
> Link: https://lkml.kernel.org/r/20230106135900.3763622-1-gregkh@linuxfoundation.org
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> Cc: Vitaly Wool <vitaly.wool@konsulko.com>
> Cc: Miaohe Lin <linmiaohe@huawei.com>
> Cc: Minchan Kim <minchan@kernel.org>
> Cc: Sergey Senozhatsky <senozhatsky@chromium.org>
> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>