pagemap: pass mm into pagewalkers

We need this at least for huge page detection for now, because powerpc
needs the vm_area_struct to be able to determine whether a virtual address
is referring to a huge page (its pmd_huge() doesn't work).

It might also come in handy for some of the other users.

Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 22 insertions, 20 deletions

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index 0afd2387e507..d5878bed7841 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -3,14 +3,14 @@
 #include <linux/sched.h>
 
 static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
-                          const struct mm_walk *walk, void *private)
+                          struct mm_walk *walk)
 {
         pte_t *pte;
         int err = 0;
 
         pte = pte_offset_map(pmd, addr);
         for (;;) {
-                err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, private);
+                err = walk->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
                 if (err)
                        break;
                 addr += PAGE_SIZE;
@@ -24,7 +24,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
 }
 
 static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
-                          const struct mm_walk *walk, void *private)
+                          struct mm_walk *walk)
 {
         pmd_t *pmd;
         unsigned long next;
@@ -35,15 +35,15 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
                 next = pmd_addr_end(addr, end);
                 if (pmd_none_or_clear_bad(pmd)) {
                         if (walk->pte_hole)
-                                err = walk->pte_hole(addr, next, private);
+                                err = walk->pte_hole(addr, next, walk);
                         if (err)
                                 break;
                         continue;
                 }
                 if (walk->pmd_entry)
-                        err = walk->pmd_entry(pmd, addr, next, private);
+                        err = walk->pmd_entry(pmd, addr, next, walk);
                 if (!err && walk->pte_entry)
-                        err = walk_pte_range(pmd, addr, next, walk, private);
+                        err = walk_pte_range(pmd, addr, next, walk);
                 if (err)
                         break;
         } while (pmd++, addr = next, addr != end);
@@ -52,7 +52,7 @@ static int walk_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
 }
 
 static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
-                          const struct mm_walk *walk, void *private)
+                          struct mm_walk *walk)
 {
         pud_t *pud;
         unsigned long next;
@@ -63,15 +63,15 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
                 next = pud_addr_end(addr, end);
                 if (pud_none_or_clear_bad(pud)) {
                         if (walk->pte_hole)
-                                err = walk->pte_hole(addr, next, private);
+                                err = walk->pte_hole(addr, next, walk);
                         if (err)
                                 break;
                         continue;
                 }
                 if (walk->pud_entry)
-                        err = walk->pud_entry(pud, addr, next, private);
+                        err = walk->pud_entry(pud, addr, next, walk);
                 if (!err && (walk->pmd_entry || walk->pte_entry))
-                        err = walk_pmd_range(pud, addr, next, walk, private);
+                        err = walk_pmd_range(pud, addr, next, walk);
                 if (err)
                         break;
         } while (pud++, addr = next, addr != end);
@@ -85,15 +85,15 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
  * @addr: starting address
  * @end: ending address
  * @walk: set of callbacks to invoke for each level of the tree
- * @private: private data passed to the callback function
  *
  * Recursively walk the page table for the memory area in a VMA,
  * calling supplied callbacks. Callbacks are called in-order (first
  * PGD, first PUD, first PMD, first PTE, second PTE... second PMD,
  * etc.). If lower-level callbacks are omitted, walking depth is reduced.
  *
- * Each callback receives an entry pointer, the start and end of the
- * associated range, and a caller-supplied private data pointer.
+ * Each callback receives an entry pointer and the start and end of the
+ * associated range, and a copy of the original mm_walk for access to
+ * the ->private or ->mm fields.
  *
  * No locks are taken, but the bottom level iterator will map PTE
  * directories from highmem if necessary.
@@ -101,9 +101,8 @@ static int walk_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end,
  * If any callback returns a non-zero value, the walk is aborted and
  * the return value is propagated back to the caller. Otherwise 0 is returned.
  */
-int walk_page_range(const struct mm_struct *mm,
-                    unsigned long addr, unsigned long end,
-                    const struct mm_walk *walk, void *private)
+int walk_page_range(unsigned long addr, unsigned long end,
+                    struct mm_walk *walk)
 {
         pgd_t *pgd;
         unsigned long next;
@@ -112,21 +111,24 @@ int walk_page_range(const struct mm_struct *mm,
         if (addr >= end)
                 return err;
 
-        pgd = pgd_offset(mm, addr);
+        if (!walk->mm)
+                return -EINVAL;
+
+        pgd = pgd_offset(walk->mm, addr);
         do {
                 next = pgd_addr_end(addr, end);
                 if (pgd_none_or_clear_bad(pgd)) {
                         if (walk->pte_hole)
-                                err = walk->pte_hole(addr, next, private);
+                                err = walk->pte_hole(addr, next, walk);
                         if (err)
                                 break;
                         continue;
                 }
                 if (walk->pgd_entry)
-                        err = walk->pgd_entry(pgd, addr, next, private);
+                        err = walk->pgd_entry(pgd, addr, next, walk);
                 if (!err &&
                     (walk->pud_entry || walk->pmd_entry || walk->pte_entry))
-                        err = walk_pud_range(pgd, addr, next, walk, private);
+                        err = walk_pud_range(pgd, addr, next, walk);
                 if (err)
                         break;
         } while (pgd++, addr = next, addr != end);