Commit 8ccee8c1 authored by Luis Chamberlain's avatar Luis Chamberlain Committed by Andrew Morton
Browse files

shmem: set shmem_writepage() variables early 

shmem_writepage() sets up variables typically used *after* a possible huge
page split.  However even if that does happen the address space mapping
should not change, and the inode does not change either.  So it should be
safe to set that from the very beginning.

This commit makes no functional changes.

Link: https://lkml.kernel.org/r/20230309230545.2930737-3-mcgrof@kernel.org


Signed-off-by: default avatarLuis Chamberlain <mcgrof@kernel.org>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarChristian Brauner <brauner@kernel.org>
Tested-by: default avatarXin Hao <xhao@linux.alibaba.com>
Reviewed-by: default avatarDavidlohr Bueso <dave@stgolabs.net>
Cc: Adam Manzanares <a.manzanares@samsung.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1f514bee

mm/shmem.c

+3 −6
Original line number Diff line number Diff line
@@ -1331,9 +1331,9 @@ int shmem_unuse(unsigned int type) 
static int shmem_writepage(struct page *page, struct writeback_control *wbc)

{

	struct folio *folio = page_folio(page);

	struct shmem_inode_info *info;

	struct address_space *mapping;

	struct inode *inode;

	struct address_space *mapping = folio->mapping;

	struct inode *inode = mapping->host;

	struct shmem_inode_info *info = SHMEM_I(inode);

	swp_entry_t swap;

	pgoff_t index;
@@ -1351,10 +1351,7 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc) 
		folio_clear_dirty(folio);

	}



	mapping = folio->mapping;

	index = folio->index;

	inode = mapping->host;

	info = SHMEM_I(inode);

	if (info->flags & VM_LOCKED)

		goto redirty;

	if (!total_swap_pages)