Update the clear_soft_dirty() and clear_soft_dirty_pmd() to optionally
clear and return the status if page is dirty.
Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxxxxxxxx>
---
fs/proc/task_mmu.c | 84 +--------------------------------
include/linux/mm_inline.h | 99 +++++++++++++++++++++++++++++++++++++++
2 files changed, 101 insertions(+), 82 deletions(-)
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f8cd58846a28..94d5761cc369 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1076,86 +1076,6 @@ struct clear_refs_private {
enum clear_refs_types type;
};
-#ifdef CONFIG_MEM_SOFT_DIRTY
-
-static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
-{
- struct page *page;
-
- if (!pte_write(pte))
- return false;
- if (!is_cow_mapping(vma->vm_flags))
- return false;
- if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
- return false;
- page = vm_normal_page(vma, addr, pte);
- if (!page)
- return false;
- return page_maybe_dma_pinned(page);
-}
-
-static inline void clear_soft_dirty(struct vm_area_struct *vma,
- unsigned long addr, pte_t *pte)
-{
- /*
- * The soft-dirty tracker uses #PF-s to catch writes
- * to pages, so write-protect the pte as well. See the
- * Documentation/admin-guide/mm/soft-dirty.rst for full description
- * of how soft-dirty works.
- */
- pte_t ptent = *pte;
-
- if (pte_present(ptent)) {
- pte_t old_pte;
-
- if (pte_is_pinned(vma, addr, ptent))
- return;
- old_pte = ptep_modify_prot_start(vma, addr, pte);
- ptent = pte_wrprotect(old_pte);
- ptent = pte_clear_soft_dirty(ptent);
- ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
- } else if (is_swap_pte(ptent)) {
- ptent = pte_swp_clear_soft_dirty(ptent);
- set_pte_at(vma->vm_mm, addr, pte, ptent);
- }
-}
-#else
-static inline void clear_soft_dirty(struct vm_area_struct *vma,
- unsigned long addr, pte_t *pte)
-{
-}
-#endif
-
-#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
-static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
- unsigned long addr, pmd_t *pmdp)
-{
- pmd_t old, pmd = *pmdp;
-
- if (pmd_present(pmd)) {
- /* See comment in change_huge_pmd() */
- old = pmdp_invalidate(vma, addr, pmdp);
- if (pmd_dirty(old))
- pmd = pmd_mkdirty(pmd);
- if (pmd_young(old))
- pmd = pmd_mkyoung(pmd);
-
- pmd = pmd_wrprotect(pmd);
- pmd = pmd_clear_soft_dirty(pmd);
-
- set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
- } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
- pmd = pmd_swp_clear_soft_dirty(pmd);
- set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
- }
-}
-#else
-static inline void clear_soft_dirty_pmd(struct vm_area_struct *vma,
- unsigned long addr, pmd_t *pmdp)
-{
-}
-#endif
-
static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
unsigned long end, struct mm_walk *walk)
{
@@ -1168,7 +1088,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
ptl = pmd_trans_huge_lock(pmd, vma);
if (ptl) {
if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
- clear_soft_dirty_pmd(vma, addr, pmd);
+ check_soft_dirty_pmd(vma, addr, pmd, true);
goto out;
}
@@ -1194,7 +1114,7 @@ static int clear_refs_pte_range(pmd_t *pmd, unsigned long addr,
ptent = *pte;
if (cp->type == CLEAR_REFS_SOFT_DIRTY) {
- clear_soft_dirty(vma, addr, pte);
+ check_soft_dirty(vma, addr, pte, true);
continue;
}
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 7b25b53c474a..65014c347a94 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -360,4 +360,103 @@ pte_install_uffd_wp_if_needed(struct vm_area_struct *vma, unsigned long addr,
#endif
}
+#ifdef CONFIG_MEM_SOFT_DIRTY
+static inline bool pte_is_pinned(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+ struct page *page;
+
+ if (!pte_write(pte))
+ return false;
+ if (!is_cow_mapping(vma->vm_flags))
+ return false;
+ if (likely(!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags)))
+ return false;
+ page = vm_normal_page(vma, addr, pte);
+ if (!page)
+ return false;
+ return page_maybe_dma_pinned(page);
+}
+
+static inline bool check_soft_dirty(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *pte, bool clear)
+{
+ /*
+ * The soft-dirty tracker uses #PF-s to catch writes
+ * to pages, so write-protect the pte as well. See the
+ * Documentation/admin-guide/mm/soft-dirty.rst for full description
+ * of how soft-dirty works.
+ */
+ pte_t ptent = *pte;
+ int dirty = 0;
+
+ if (pte_present(ptent)) {
+ pte_t old_pte;
+
+ dirty = pte_soft_dirty(ptent);
+
+ if (dirty && clear && !pte_is_pinned(vma, addr, ptent)) {
+ old_pte = ptep_modify_prot_start(vma, addr, pte);
+ ptent = pte_wrprotect(old_pte);
+ ptent = pte_clear_soft_dirty(ptent);
+ ptep_modify_prot_commit(vma, addr, pte, old_pte, ptent);
+ }
+ } else if (is_swap_pte(ptent)) {
+ dirty = pte_swp_soft_dirty(ptent);
+
+ if (dirty && clear) {
+ ptent = pte_swp_clear_soft_dirty(ptent);
+ set_pte_at(vma->vm_mm, addr, pte, ptent);
+ }
+ }
+
+ return !!dirty;
+}
+#else
+static inline bool check_soft_dirty(struct vm_area_struct *vma,
+ unsigned long addr, pte_t *pte, bool clear)
+{
+ return false;
+}
+#endif
+
+#if defined(CONFIG_MEM_SOFT_DIRTY) && defined(CONFIG_TRANSPARENT_HUGEPAGE)
+static inline bool check_soft_dirty_pmd(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmdp, bool clear)
+{
+ pmd_t old, pmd = *pmdp;
+ int dirty = 0;
+
+ if (pmd_present(pmd)) {
+ dirty = pmd_soft_dirty(pmd);
+ if (dirty && clear) {
+ /* See comment in change_huge_pmd() */
+ old = pmdp_invalidate(vma, addr, pmdp);
+ if (pmd_dirty(old))
+ pmd = pmd_mkdirty(pmd);
+ if (pmd_young(old))
+ pmd = pmd_mkyoung(pmd);
+
+ pmd = pmd_wrprotect(pmd);
+ pmd = pmd_clear_soft_dirty(pmd);
+
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ }
+ } else if (is_migration_entry(pmd_to_swp_entry(pmd))) {
+ dirty = pmd_swp_soft_dirty(pmd);
+
+ if (dirty && clear) {
+ pmd = pmd_swp_clear_soft_dirty(pmd);
+ set_pmd_at(vma->vm_mm, addr, pmdp, pmd);
+ }
+ }
+ return !!dirty;
+}
+#else
+static inline bool check_soft_dirty_pmd(struct vm_area_struct *vma,
+ unsigned long addr, pmd_t *pmdp, bool clear)
+{
+ return false;
+}
+#endif
+
#endif
--
2.30.2
