On Fri, 2008-01-18 at 11:38 +0100, Miklos Szeredi wrote:
how about:
diff --git a/mm/msync.c b/mm/msync.c
index 144a757..a1b3fc6 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -14,6 +14,122 @@
#include <linux/syscalls.h>
#include <linux/sched.h>
+unsigned long masync_pte_range(struct vm_area_struct *vma, pmd_t *pdm,
+ unsigned long addr, unsigned long end)
+{
+ pte_t *pte;
+ spinlock_t *ptl;
+
+ pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ arch_enter_lazy_mmu_mode();
+ do {
+ pte_t ptent = *pte;
+
+ if (pte_none(ptent))
+ continue;
+
+ if (!pte_present(ptent))
+ continue;
+
+ if (pte_dirty(ptent) && pte_write(ptent)) {
+ flush_cache_page(vma, addr, pte_pfn(ptent));
+ ptent = ptep_clear_flush(vma, addr, pte);
+ ptent = pte_wrprotect(ptent);
+ set_pte_at(vma->vm_mnm, addr, pte, ptent);
+ }
+ } while (pte++, addr += PAGE_SIZE, addr != end);
+ arch_leave_lazy_mmu_mode();
+ pte_unmap_unlock(pte - 1, ptl);
+
+ return addr;
+}
+
+unsigned long masync_pmd_range(struct vm_area_struct *vma, pud_t *pud,
+ unsigned long addr, unsigned long end)
+{
+ pmd_t *pmd;
+ unsigned long next;
+
+ pmd = pmd_offset(pud, addr);
+ do {
+ next = pmd_addr_end(addr, end);
+ if (pmd_none_or_clear_bad(pmd))
+ continue;
+ next = masync_pte_range(vma, pmd, addr, next);
+ } while (pmd++, addr = next, addr != end);
+
+ return addr;
+}
+
+unsigned long masync_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
+ unsigned long addr, unsigned long end)
+{
+ pud_t *pud;
+ unsigned long next;
+
+ pud = pud_offset(pgd, addr);
+ do {
+ next = pud_addr_end(addr, end);
+ if (pud_none_or_clear_bad(pud))
+ continue;
+ next = masync_pmd_range(vma, pud, addr, next);
+ } while (pud++, addr = next, addr != end);
+
+ return addr;
+}
+
+unsigned long masync_pgd_range()
+{
+ pgd_t *pgd;
+ unsigned long next;
+
+ pgd = pgd_offset(vma->vm_mm, addr);
+ do {
+ next = pgd_addr_end(addr, end);
+ if (pgd_none_of_clear_bad(pgd))
+ continue;
+ next = masync_pud_range(vma, pgd, addr, next);
+ } while (pgd++, addr = next, addr != end);
+
+ return addr;
+}
+
+int masync_vma_one(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ if (start < vma->vm_start)
+ start = vma->vm_start;
+
+ if (end > vma->vm_end)
+ end = vma->vm_end;
+
+ masync_pgd_range(vma, start, end);
+
+ return 0;
+}
+
+int masync_vma(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ struct address_space *mapping;
+ struct vm_area_struct *vma_iter;
+
+ if (!(vma->vm_flags & VM_SHARED))
+ return 0;
+
+ mapping = vma->vm_file->f_mapping;
+
+ if (!mapping_cap_account_dirty(mapping))
+ return 0;
+
+ spin_lock(&mapping->i_mmap_lock);
+ vma_prio_tree_foreach(vma_iter, &iter, &mapping->i_mmap, start, end)
+ masync_vma_one(vma_iter, start, end);
+ spin_unlock(&mapping->i_mmap_lock);
+
+ return 0;
+}
+
/*
* MS_SYNC syncs the entire file - including mappings.
*
--
