Merge branch 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik...

[sfrench/cifs-2.6.git] / mm / fremap.c

diff --git a/mm/fremap.c b/mm/fremap.c
index 01e51f01b84e8c1aa83519347d3b3ea04db570c4..c395b1abf08275dc1d22a570f259f495cdb2cbc7 100644 (file)
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -20,13 +20,14 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+static void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
                        unsigned long addr, pte_t *ptep)
 {
        pte_t pte = *ptep;
-       struct page *page = NULL;
 
        if (pte_present(pte)) {
+               struct page *page;
+
                flush_cache_page(vma, addr, pte_pfn(pte));
                pte = ptep_clear_flush(vma, addr, ptep);
                page = vm_normal_page(vma, addr, pte);
@@ -35,68 +36,21 @@ static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
                                set_page_dirty(page);
                        page_remove_rmap(page, vma);
                        page_cache_release(page);
+                       update_hiwater_rss(mm);
+                       dec_mm_counter(mm, file_rss);
                }
        } else {
                if (!pte_file(pte))
                        free_swap_and_cache(pte_to_swp_entry(pte));
                pte_clear_not_present_full(mm, addr, ptep, 0);
        }
-       return !!page;
 }
 
-/*
- * Install a file page to a given virtual memory address, release any
- * previously existing mapping.
- */
-int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
-               unsigned long addr, struct page *page, pgprot_t prot)
-{
-       struct inode *inode;
-       pgoff_t size;
-       int err = -ENOMEM;
-       pte_t *pte;
-       pte_t pte_val;
-       spinlock_t *ptl;
-
-       pte = get_locked_pte(mm, addr, &ptl);
-       if (!pte)
-               goto out;
-
-       /*
-        * This page may have been truncated. Tell the
-        * caller about it.
-        */
-       err = -EINVAL;
-       inode = vma->vm_file->f_mapping->host;
-       size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-       if (!page->mapping || page->index >= size)
-               goto unlock;
-       err = -ENOMEM;
-       if (page_mapcount(page) > INT_MAX/2)
-               goto unlock;
-
-       if (pte_none(*pte) || !zap_pte(mm, vma, addr, pte))
-               inc_mm_counter(mm, file_rss);
-
-       flush_icache_page(vma, page);
-       pte_val = mk_pte(page, prot);
-       set_pte_at(mm, addr, pte, pte_val);
-       page_add_file_rmap(page);
-       update_mmu_cache(vma, addr, pte_val);
-       lazy_mmu_prot_update(pte_val);
-       err = 0;
-unlock:
-       pte_unmap_unlock(pte, ptl);
-out:
-       return err;
-}
-EXPORT_SYMBOL(install_page);
-
 /*
  * Install a file pte to a given virtual memory address, release any
  * previously existing mapping.
  */
-int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+static int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
                unsigned long addr, unsigned long pgoff, pgprot_t prot)
 {
        int err = -ENOMEM;
@@ -107,10 +61,8 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
        if (!pte)
                goto out;
 
-       if (!pte_none(*pte) && zap_pte(mm, vma, addr, pte)) {
-               update_hiwater_rss(mm);
-               dec_mm_counter(mm, file_rss);
-       }
+       if (!pte_none(*pte))
+               zap_pte(mm, vma, addr, pte);
 
        set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff));
        /*
@@ -208,8 +160,7 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
        if (vma->vm_private_data && !(vma->vm_flags & VM_NONLINEAR))
                goto out;
 
-       if ((!vma->vm_ops || !vma->vm_ops->populate) &&
-                                       !(vma->vm_flags & VM_CAN_NONLINEAR))
+       if (!vma->vm_flags & VM_CAN_NONLINEAR)
                goto out;
 
        if (end <= start || start < vma->vm_start || end > vma->vm_end)
@@ -230,6 +181,25 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
                        goto retry;
                }
                mapping = vma->vm_file->f_mapping;
+               /*
+                * page_mkclean doesn't work on nonlinear vmas, so if
+                * dirty pages need to be accounted, emulate with linear
+                * vmas.
+                */
+               if (mapping_cap_account_dirty(mapping)) {
+                       unsigned long addr;
+
+                       flags &= MAP_NONBLOCK;
+                       addr = mmap_region(vma->vm_file, start, size,
+                                       flags, vma->vm_flags, pgoff, 1);
+                       if (IS_ERR_VALUE(addr)) {
+                               err = addr;
+                       } else {
+                               BUG_ON(addr != start);
+                               err = 0;
+                       }
+                       goto out;
+               }
                spin_lock(&mapping->i_mmap_lock);
                flush_dcache_mmap_lock(mapping);
                vma->vm_flags |= VM_NONLINEAR;
@@ -239,18 +209,14 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
                spin_unlock(&mapping->i_mmap_lock);
        }
 
-       if (vma->vm_flags & VM_CAN_NONLINEAR) {
-               err = populate_range(mm, vma, start, size, pgoff);
-               if (!err && !(flags & MAP_NONBLOCK)) {
-                       if (unlikely(has_write_lock)) {
-                               downgrade_write(&mm->mmap_sem);
-                               has_write_lock = 0;
-                       }
-                       make_pages_present(start, start+size);
+       err = populate_range(mm, vma, start, size, pgoff);
+       if (!err && !(flags & MAP_NONBLOCK)) {
+               if (unlikely(has_write_lock)) {
+                       downgrade_write(&mm->mmap_sem);
+                       has_write_lock = 0;
                }
-       } else
-               err = vma->vm_ops->populate(vma, start, size, vma->vm_page_prot,
-                                               pgoff, flags & MAP_NONBLOCK);
+               make_pages_present(start, start+size);
+       }
 
        /*
         * We can't clear VM_NONLINEAR because we'd have to do