split mmap

This is a straightforward split of do_mmap_pgoff() into two functions:

 - do_mmap_pgoff() checks the parameters, and calculates the vma
   flags.  Then it calls

 - mmap_region(), which does the actual mapping

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 19 insertions, 6 deletions

diff --git a/mm/mmap.c b/mm/mmap.c
index 9f70c8e8c871..144b4a290f2c 100644
--- 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 +1024,24 @@ 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);
+
+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:
@@ -1175,8 +1190,6 @@ unacct_error:
         return error;
 }
 
-EXPORT_SYMBOL(do_mmap_pgoff);
-
 /* Get an address range which is currently unmapped.
  * For shmat() with addr=0.
  *