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-rw-r--r--mm/rmap.c80
1 files changed, 43 insertions, 37 deletions
diff --git a/mm/rmap.c b/mm/rmap.c
index 795f9d5f8386..2d29a57d29e8 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -20,28 +20,29 @@
/*
* Lock ordering in mm:
*
- * inode->i_mutex (while writing or truncating, not reading or faulting)
+ * inode->i_rwsem (while writing or truncating, not reading or faulting)
* mm->mmap_lock
- * page->flags PG_locked (lock_page) * (see huegtlbfs below)
- * hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
- * mapping->i_mmap_rwsem
- * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
- * anon_vma->rwsem
- * mm->page_table_lock or pte_lock
- * swap_lock (in swap_duplicate, swap_info_get)
- * mmlist_lock (in mmput, drain_mmlist and others)
- * mapping->private_lock (in __set_page_dirty_buffers)
- * lock_page_memcg move_lock (in __set_page_dirty_buffers)
- * i_pages lock (widely used)
- * lruvec->lru_lock (in lock_page_lruvec_irq)
- * inode->i_lock (in set_page_dirty's __mark_inode_dirty)
- * bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
- * sb_lock (within inode_lock in fs/fs-writeback.c)
- * i_pages lock (widely used, in set_page_dirty,
- * in arch-dependent flush_dcache_mmap_lock,
- * within bdi.wb->list_lock in __sync_single_inode)
+ * mapping->invalidate_lock (in filemap_fault)
+ * page->flags PG_locked (lock_page) * (see hugetlbfs below)
+ * hugetlbfs_i_mmap_rwsem_key (in huge_pmd_share)
+ * mapping->i_mmap_rwsem
+ * hugetlb_fault_mutex (hugetlbfs specific page fault mutex)
+ * anon_vma->rwsem
+ * mm->page_table_lock or pte_lock
+ * swap_lock (in swap_duplicate, swap_info_get)
+ * mmlist_lock (in mmput, drain_mmlist and others)
+ * mapping->private_lock (in __set_page_dirty_buffers)
+ * lock_page_memcg move_lock (in __set_page_dirty_buffers)
+ * i_pages lock (widely used)
+ * lruvec->lru_lock (in lock_page_lruvec_irq)
+ * inode->i_lock (in set_page_dirty's __mark_inode_dirty)
+ * bdi.wb->list_lock (in set_page_dirty's __mark_inode_dirty)
+ * sb_lock (within inode_lock in fs/fs-writeback.c)
+ * i_pages lock (widely used, in set_page_dirty,
+ * in arch-dependent flush_dcache_mmap_lock,
+ * within bdi.wb->list_lock in __sync_single_inode)
*
- * anon_vma->rwsem,mapping->i_mutex (memory_failure, collect_procs_anon)
+ * anon_vma->rwsem,mapping->i_mmap_rwsem (memory_failure, collect_procs_anon)
* ->tasklist_lock
* pte map lock
*
@@ -1440,21 +1441,20 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
/*
* If the page is mlock()d, we cannot swap it out.
*/
- if (!(flags & TTU_IGNORE_MLOCK)) {
- if (vma->vm_flags & VM_LOCKED) {
- /* PTE-mapped THP are never marked as mlocked */
- if (!PageTransCompound(page) ||
- (PageHead(page) && !PageDoubleMap(page))) {
- /*
- * Holding pte lock, we do *not* need
- * mmap_lock here
- */
- mlock_vma_page(page);
- }
- ret = false;
- page_vma_mapped_walk_done(&pvmw);
- break;
- }
+ if (!(flags & TTU_IGNORE_MLOCK) &&
+ (vma->vm_flags & VM_LOCKED)) {
+ /*
+ * PTE-mapped THP are never marked as mlocked: so do
+ * not set it on a DoubleMap THP, nor on an Anon THP
+ * (which may still be PTE-mapped after DoubleMap was
+ * cleared). But stop unmapping even in those cases.
+ */
+ if (!PageTransCompound(page) || (PageHead(page) &&
+ !PageDoubleMap(page) && !PageAnon(page)))
+ mlock_vma_page(page);
+ page_vma_mapped_walk_done(&pvmw);
+ ret = false;
+ break;
}
/* Unexpected PMD-mapped THP? */
@@ -1986,8 +1986,10 @@ static bool page_mlock_one(struct page *page, struct vm_area_struct *vma,
*/
if (vma->vm_flags & VM_LOCKED) {
/*
- * PTE-mapped THP are never marked as mlocked, but
- * this function is never called when PageDoubleMap().
+ * PTE-mapped THP are never marked as mlocked; but
+ * this function is never called on a DoubleMap THP,
+ * nor on an Anon THP (which may still be PTE-mapped
+ * after DoubleMap was cleared).
*/
mlock_vma_page(page);
/*
@@ -2022,6 +2024,10 @@ void page_mlock(struct page *page)
VM_BUG_ON_PAGE(!PageLocked(page) || PageLRU(page), page);
VM_BUG_ON_PAGE(PageCompound(page) && PageDoubleMap(page), page);
+ /* Anon THP are only marked as mlocked when singly mapped */
+ if (PageTransCompound(page) && PageAnon(page))
+ return;
+
rmap_walk(page, &rwc);
}