Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

[linux.git] / mm / mmap.c

diff --git a/mm/mmap.c b/mm/mmap.c
index 9f70c8e8c871c272047fdc4c969f285299b58926..b6537211b9ccfdfcf1f7d9d63c5891ba89e483e7 100644 (file)
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -894,14 +894,11 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
                        unsigned long flags, unsigned long pgoff)
 {
        struct mm_struct * mm = current->mm;
-       struct vm_area_struct * vma, * prev;
        struct inode *inode;
        unsigned int vm_flags;
-       int correct_wcount = 0;
        int error;
-       struct rb_node ** rb_link, * rb_parent;
        int accountable = 1;
-       unsigned long charged = 0, reqprot = prot;
+       unsigned long reqprot = prot;
 
        /*
         * Does the application expect PROT_READ to imply PROT_EXEC?
@@ -1027,6 +1024,58 @@ unsigned long do_mmap_pgoff(struct file * file, unsigned long addr,
        if (error)
                return error;
 
+       return mmap_region(file, addr, len, flags, vm_flags, pgoff,
+                          accountable);
+}
+EXPORT_SYMBOL(do_mmap_pgoff);
+
+/*
+ * Some shared mappigns will want the pages marked read-only
+ * to track write events. If so, we'll downgrade vm_page_prot
+ * to the private version (using protection_map[] without the
+ * VM_SHARED bit).
+ */
+int vma_wants_writenotify(struct vm_area_struct *vma)
+{
+       unsigned int vm_flags = vma->vm_flags;
+
+       /* If it was private or non-writable, the write bit is already clear */
+       if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
+               return 0;
+
+       /* The backer wishes to know when pages are first written to? */
+       if (vma->vm_ops && vma->vm_ops->page_mkwrite)
+               return 1;
+
+       /* The open routine did something to the protections already? */
+       if (pgprot_val(vma->vm_page_prot) !=
+           pgprot_val(protection_map[vm_flags &
+                   (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]))
+               return 0;
+
+       /* Specialty mapping? */
+       if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))
+               return 0;
+
+       /* Can the mapping track the dirty pages? */
+       return vma->vm_file && vma->vm_file->f_mapping &&
+               mapping_cap_account_dirty(vma->vm_file->f_mapping);
+}
+
+
+unsigned long mmap_region(struct file *file, unsigned long addr,
+                         unsigned long len, unsigned long flags,
+                         unsigned int vm_flags, unsigned long pgoff,
+                         int accountable)
+{
+       struct mm_struct *mm = current->mm;
+       struct vm_area_struct *vma, *prev;
+       int correct_wcount = 0;
+       int error;
+       struct rb_node **rb_link, *rb_parent;
+       unsigned long charged = 0;
+       struct inode *inode =  file ? file->f_path.dentry->d_inode : NULL;
+
        /* Clear old maps */
        error = -ENOMEM;
 munmap_back:
@@ -1150,12 +1199,8 @@ out:
                mm->locked_vm += len >> PAGE_SHIFT;
                make_pages_present(addr, addr + len);
        }
-       if (flags & MAP_POPULATE) {
-               up_write(&mm->mmap_sem);
-               sys_remap_file_pages(addr, len, 0,
-                                       pgoff, flags & MAP_NONBLOCK);
-               down_write(&mm->mmap_sem);
-       }
+       if ((flags & MAP_POPULATE) && !(flags & MAP_NONBLOCK))
+               make_pages_present(addr, addr + len);
        return addr;
 
 unmap_and_free_vma:
@@ -1175,8 +1220,6 @@ unacct_error:
        return error;
 }
 
-EXPORT_SYMBOL(do_mmap_pgoff);
-
 /* Get an address range which is currently unmapped.
  * For shmat() with addr=0.
  *
@@ -1562,33 +1605,11 @@ int expand_upwards(struct vm_area_struct *vma, unsigned long address)
 }
 #endif /* CONFIG_STACK_GROWSUP || CONFIG_IA64 */
 
-#ifdef CONFIG_STACK_GROWSUP
-int expand_stack(struct vm_area_struct *vma, unsigned long address)
-{
-       return expand_upwards(vma, address);
-}
-
-struct vm_area_struct *
-find_extend_vma(struct mm_struct *mm, unsigned long addr)
-{
-       struct vm_area_struct *vma, *prev;
-
-       addr &= PAGE_MASK;
-       vma = find_vma_prev(mm, addr, &prev);
-       if (vma && (vma->vm_start <= addr))
-               return vma;
-       if (!prev || expand_stack(prev, addr))
-               return NULL;
-       if (prev->vm_flags & VM_LOCKED) {
-               make_pages_present(addr, prev->vm_end);
-       }
-       return prev;
-}
-#else
 /*
  * vma is the first one with address < vma->vm_start.  Have to extend vma.
  */
-int expand_stack(struct vm_area_struct *vma, unsigned long address)
+static inline int expand_downwards(struct vm_area_struct *vma,
+                                  unsigned long address)
 {
        int error;
 
@@ -1625,6 +1646,38 @@ int expand_stack(struct vm_area_struct *vma, unsigned long address)
        return error;
 }
 
+int expand_stack_downwards(struct vm_area_struct *vma, unsigned long address)
+{
+       return expand_downwards(vma, address);
+}
+
+#ifdef CONFIG_STACK_GROWSUP
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+       return expand_upwards(vma, address);
+}
+
+struct vm_area_struct *
+find_extend_vma(struct mm_struct *mm, unsigned long addr)
+{
+       struct vm_area_struct *vma, *prev;
+
+       addr &= PAGE_MASK;
+       vma = find_vma_prev(mm, addr, &prev);
+       if (vma && (vma->vm_start <= addr))
+               return vma;
+       if (!prev || expand_stack(prev, addr))
+               return NULL;
+       if (prev->vm_flags & VM_LOCKED)
+               make_pages_present(addr, prev->vm_end);
+       return prev;
+}
+#else
+int expand_stack(struct vm_area_struct *vma, unsigned long address)
+{
+       return expand_downwards(vma, address);
+}
+
 struct vm_area_struct *
 find_extend_vma(struct mm_struct * mm, unsigned long addr)
 {
@@ -1642,9 +1695,8 @@ find_extend_vma(struct mm_struct * mm, unsigned long addr)
        start = vma->vm_start;
        if (expand_stack(vma, addr))
                return NULL;
-       if (vma->vm_flags & VM_LOCKED) {
+       if (vma->vm_flags & VM_LOCKED)
                make_pages_present(addr, start);
-       }
        return vma;
 }
 #endif