mm: use find_get_incore_page in memcontrol (f5df8635) · Commits · 戴 / test

The current code does not protect against swapoff of the underlying swap device, so this is a bug fix as well as a worthwhile reduction in code complexity. Signed-off-by:

Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Huang Ying <ying.huang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: William Kucharski <william.kucharski@oracle.com> Link: https://lkml.kernel.org/r/20200910183318.20139-3-willy@infradead.org Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

mm/memcontrol.c

+2 −22

Original line number	Diff line number	Diff line
		@@ -5539,35 +5539,15 @@ static struct page mc_handle_swap_pte(struct vm_area_struct vma,
		static struct page mc_handle_file_pte(struct vm_area_struct vma,
		unsigned long addr, pte_t ptent, swp_entry_t *entry)
		{
		struct page *page = NULL;
		struct address_space *mapping;
		pgoff_t pgoff;

		if (!vma->vm_file) /* anonymous vma */
		return NULL;
		if (!(mc.flags & MOVE_FILE))
		return NULL;

		mapping = vma->vm_file->f_mapping;
		pgoff = linear_page_index(vma, addr);

		/* page is moved even if it's not RSS of this task(page-faulted). */
		#ifdef CONFIG_SWAP
		/* shmem/tmpfs may report page out on swap: account for that too. */
		if (shmem_mapping(mapping)) {
		page = find_get_entry(mapping, pgoff);
		if (xa_is_value(page)) {
		swp_entry_t swp = radix_to_swp_entry(page);
		*entry = swp;
		page = find_get_page(swap_address_space(swp),
		swp_offset(swp));
		}
		} else
		page = find_get_page(mapping, pgoff);
		#else
		page = find_get_page(mapping, pgoff);
		#endif
		return page;
		return find_get_incore_page(vma->vm_file->f_mapping,
		linear_page_index(vma, addr));
		}

		/**

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