From: Hugh Dickins <hugh@veritas.com>
Clean up mremap move's copy_one_pte:
- get_one_pte_map_nested already weeded out the pte_none case,
now don't even call copy_one_pte if it has nothing to do.
- check pfn_valid before passing page to page_remove_rmap.
---
25-akpm/mm/mremap.c | 31 ++++++++++++-------------------
1 files changed, 12 insertions(+), 19 deletions(-)
diff -puN mm/mremap.c~mremap-copy_one_pte-fix mm/mremap.c
--- 25/mm/mremap.c~mremap-copy_one_pte-fix Tue Mar 30 16:04:14 2004
+++ 25-akpm/mm/mremap.c Tue Mar 30 16:04:14 2004
@@ -79,31 +79,21 @@ static inline pte_t *alloc_one_pte_map(s
return pte;
}
-static int
+static void
copy_one_pte(struct vm_area_struct *vma, unsigned long old_addr,
pte_t *src, pte_t *dst, struct pte_chain **pte_chainp)
{
- int error = 0;
- pte_t pte;
- struct page *page = NULL;
-
- if (pte_present(*src))
- page = pte_page(*src);
+ pte_t pte = ptep_clear_flush(vma, old_addr, src);
+ set_pte(dst, pte);
- if (!pte_none(*src)) {
- if (page)
+ if (pte_present(pte)) {
+ unsigned long pfn = pte_pfn(pte);
+ if (pfn_valid(pfn)) {
+ struct page *page = pfn_to_page(pfn);
page_remove_rmap(page, src);
- pte = ptep_clear_flush(vma, old_addr, src);
- if (!dst) {
- /* No dest? We must put it back. */
- dst = src;
- error++;
- }
- set_pte(dst, pte);
- if (page)
*pte_chainp = page_add_rmap(page, dst, *pte_chainp);
+ }
}
- return error;
}
static int
@@ -140,8 +130,11 @@ move_one_page(struct vm_area_struct *vma
* page_table_lock, we should re-check the src entry...
*/
if (src) {
- error = copy_one_pte(vma, old_addr, src,
+ if (dst)
+ copy_one_pte(vma, old_addr, src,
dst, &pte_chain);
+ else
+ error = -ENOMEM;
pte_unmap_nested(src);
}
pte_unmap(dst);
_