VM: add common helper function to create the page tables

This logic was duplicated four times, for no good reason.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/fs/exec.c b/fs/exec.c
index 1f8a9fd..22533cc 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -306,9 +306,6 @@ void install_arg_page(struct vm_area_struct *vma,
                        struct page *page, unsigned long address)
 {
        struct mm_struct *mm = vma->vm_mm;
                        struct page *page, unsigned long address)
 {
        struct mm_struct *mm = vma->vm_mm;

-       pgd_t * pgd;
-       pud_t * pud;
-       pmd_t * pmd;

        pte_t * pte;
        spinlock_t *ptl;
 
        pte_t * pte;
        spinlock_t *ptl;
 


@@ -316,14 +313,7 @@ void install_arg_page(struct vm_area_struct *vma,
                goto out;
 
        flush_dcache_page(page);
                goto out;
 
        flush_dcache_page(page);

-       pgd = pgd_offset(mm, address);
-       pud = pud_alloc(mm, pgd, address);
-       if (!pud)
-               goto out;
-       pmd = pmd_alloc(mm, pud, address);
-       if (!pmd)
-               goto out;
-       pte = pte_alloc_map_lock(mm, pmd, address, &ptl);
+       pte = get_locked_pte(mm, address, &ptl);

        if (!pte)
                goto out;
        if (!pte_none(*pte)) {
        if (!pte)
                goto out;
        if (!pte_none(*pte)) {

diff --git a/include/linux/mm.h b/include/linux/mm.h
index 74f90d7..0e73f15 100644 (file)
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -742,6 +742,8 @@ struct shrinker;
 extern struct shrinker *set_shrinker(int, shrinker_t);
 extern void remove_shrinker(struct shrinker *shrinker);
 
 extern struct shrinker *set_shrinker(int, shrinker_t);
 extern void remove_shrinker(struct shrinker *shrinker);
 

+extern pte_t *FASTCALL(get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl));
+

 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);
 int __pud_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd, unsigned long address);

diff --git a/mm/fremap.c b/mm/fremap.c
index f851775..9f381e5 100644 (file)
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -55,20 +55,10 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
        pgoff_t size;
        int err = -ENOMEM;
        pte_t *pte;
        pgoff_t size;
        int err = -ENOMEM;
        pte_t *pte;

-       pmd_t *pmd;
-       pud_t *pud;
-       pgd_t *pgd;

        pte_t pte_val;
        spinlock_t *ptl;
 
        pte_t pte_val;
        spinlock_t *ptl;
 

-       pgd = pgd_offset(mm, addr);
-       pud = pud_alloc(mm, pgd, addr);
-       if (!pud)
-               goto out;
-       pmd = pmd_alloc(mm, pud, addr);
-       if (!pmd)
-               goto out;
-       pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+       pte = get_locked_pte(mm, addr, &ptl);

        if (!pte)
                goto out;
 
        if (!pte)
                goto out;
 


@@ -110,20 +100,10 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 {
        int err = -ENOMEM;
        pte_t *pte;
 {
        int err = -ENOMEM;
        pte_t *pte;

-       pmd_t *pmd;
-       pud_t *pud;
-       pgd_t *pgd;

        pte_t pte_val;
        spinlock_t *ptl;
 
        pte_t pte_val;
        spinlock_t *ptl;
 

-       pgd = pgd_offset(mm, addr);
-       pud = pud_alloc(mm, pgd, addr);
-       if (!pud)
-               goto out;
-       pmd = pmd_alloc(mm, pud, addr);
-       if (!pmd)
-               goto out;
-       pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+       pte = get_locked_pte(mm, addr, &ptl);

        if (!pte)
                goto out;
 
        if (!pte)
                goto out;
 

diff --git a/mm/memory.c b/mm/memory.c
index 990e7dc..74f95ae 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1146,6 +1146,18 @@ int zeromap_page_range(struct vm_area_struct *vma,
        return err;
 }
 
        return err;
 }
 

+pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr, spinlock_t **ptl)
+{
+       pgd_t * pgd = pgd_offset(mm, addr);
+       pud_t * pud = pud_alloc(mm, pgd, addr);
+       if (pud) {
+               pmd_t * pmd = pmd_alloc(mm, pgd, addr);
+               if (pmd)
+                       return pte_alloc_map_lock(mm, pmd, addr, ptl);
+       }
+       return NULL;
+}
+

 /*
  * This is the old fallback for page remapping.
  *
 /*
  * This is the old fallback for page remapping.
  *


@@ -1156,10 +1168,7 @@ int zeromap_page_range(struct vm_area_struct *vma,
 static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
 {
        int retval;
 static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *page, pgprot_t prot)
 {
        int retval;

-       pgd_t * pgd;
-       pud_t * pud;
-       pmd_t * pmd;  
-       pte_t * pte;
+       pte_t *pte;

        spinlock_t *ptl;  
 
        retval = -EINVAL;
        spinlock_t *ptl;  
 
        retval = -EINVAL;


@@ -1167,14 +1176,7 @@ static int insert_page(struct mm_struct *mm, unsigned long addr, struct page *pa
                goto out;
        retval = -ENOMEM;
        flush_dcache_page(page);
                goto out;
        retval = -ENOMEM;
        flush_dcache_page(page);

-       pgd = pgd_offset(mm, addr);
-       pud = pud_alloc(mm, pgd, addr);
-       if (!pud)
-               goto out;
-       pmd = pmd_alloc(mm, pud, addr);
-       if (!pmd)
-               goto out;
-       pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
+       pte = get_locked_pte(mm, addr, &ptl);

        if (!pte)
                goto out;
        retval = -EBUSY;
        if (!pte)
                goto out;
        retval = -EBUSY;