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Remove internal use of 'write_access' in mm/memory.c

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The fault handling routines really want more fine-grained flags than a
single "was it a write fault" boolean - the callers will want to set
flags like "you can return a retry error" etc.

And that's actually how the VM works internally, but right now the
top-level fault handling functions in mm/memory.c all pass just the
'write_access' boolean around.

This switches them over to pass around the FAULT_FLAG_xyzzy 'flags'
variable instead.  The 'write_access' calling convention still exists
for the exported 'handle_mm_fault()' function, but that is next.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Linus Torvalds 2009-04-10 08:43:11 -07:00
parent 232086b199
commit 30c9f3a9fa
1 changed files with 21 additions and 21 deletions
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42
mm/memory.c
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@ -2496,7 +2496,7 @@ int vmtruncate_range(struct inode *inode, loff_t offset, loff_t end)
*/
static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access, pte_t orig_pte)
unsigned int flags, pte_t orig_pte)
{
spinlock_t *ptl;
struct page *page;
@ -2572,9 +2572,9 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
inc_mm_counter(mm, anon_rss);
pte = mk_pte(page, vma->vm_page_prot);
if (write_access && reuse_swap_page(page)) {
if ((flags & FAULT_FLAG_WRITE) && reuse_swap_page(page)) {
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
write_access = 0;
flags &= ~FAULT_FLAG_WRITE;
}
flush_icache_page(vma, page);
set_pte_at(mm, address, page_table, pte);
@ -2587,7 +2587,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
try_to_free_swap(page);
unlock_page(page);
if (write_access) {
if (flags & FAULT_FLAG_WRITE) {
ret |= do_wp_page(mm, vma, address, page_table, pmd, ptl, pte);
if (ret & VM_FAULT_ERROR)
ret &= VM_FAULT_ERROR;
@ -2616,7 +2616,7 @@ out_page:
*/
static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access)
unsigned int flags)
{
struct page *page;
spinlock_t *ptl;
@ -2776,7 +2776,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
* due to the bad i386 page protection. But it's valid
* for other architectures too.
*
* Note that if write_access is true, we either now have
* Note that if FAULT_FLAG_WRITE is set, we either now have
* an exclusive copy of the page, or this is a shared mapping,
* so we can make it writable and dirty to avoid having to
* handle that later.
@ -2847,11 +2847,10 @@ unwritable_page:
static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access, pte_t orig_pte)
unsigned int flags, pte_t orig_pte)
{
pgoff_t pgoff = (((address & PAGE_MASK)
- vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff;
unsigned int flags = (write_access ? FAULT_FLAG_WRITE : 0);
pte_unmap(page_table);
return __do_fault(mm, vma, address, pmd, pgoff, flags, orig_pte);
@ -2868,12 +2867,12 @@ static int do_linear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
*/
static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
unsigned long address, pte_t *page_table, pmd_t *pmd,
int write_access, pte_t orig_pte)
unsigned int flags, pte_t orig_pte)
{
unsigned int flags = FAULT_FLAG_NONLINEAR |
(write_access ? FAULT_FLAG_WRITE : 0);
pgoff_t pgoff;
flags |= FAULT_FLAG_NONLINEAR;
if (!pte_unmap_same(mm, pmd, page_table, orig_pte))
return 0;
@ -2904,7 +2903,7 @@ static int do_nonlinear_fault(struct mm_struct *mm, struct vm_area_struct *vma,
*/
static inline int handle_pte_fault(struct mm_struct *mm,
struct vm_area_struct *vma, unsigned long address,
pte_t *pte, pmd_t *pmd, int write_access)
pte_t *pte, pmd_t *pmd, unsigned int flags)
{
pte_t entry;
spinlock_t *ptl;
@ -2915,30 +2914,30 @@ static inline int handle_pte_fault(struct mm_struct *mm,
if (vma->vm_ops) {
if (likely(vma->vm_ops->fault))
return do_linear_fault(mm, vma, address,
pte, pmd, write_access, entry);
pte, pmd, flags, entry);
}
return do_anonymous_page(mm, vma, address,
pte, pmd, write_access);
pte, pmd, flags);
}
if (pte_file(entry))
return do_nonlinear_fault(mm, vma, address,
pte, pmd, write_access, entry);
pte, pmd, flags, entry);
return do_swap_page(mm, vma, address,
pte, pmd, write_access, entry);
pte, pmd, flags, entry);
}
ptl = pte_lockptr(mm, pmd);
spin_lock(ptl);
if (unlikely(!pte_same(*pte, entry)))
goto unlock;
if (write_access) {
if (flags & FAULT_FLAG_WRITE) {
if (!pte_write(entry))
return do_wp_page(mm, vma, address,
pte, pmd, ptl, entry);
entry = pte_mkdirty(entry);
}
entry = pte_mkyoung(entry);
if (ptep_set_access_flags(vma, address, pte, entry, write_access)) {
if (ptep_set_access_flags(vma, address, pte, entry, flags & FAULT_FLAG_WRITE)) {
update_mmu_cache(vma, address, entry);
} else {
/*
@ -2947,7 +2946,7 @@ static inline int handle_pte_fault(struct mm_struct *mm,
* This still avoids useless tlb flushes for .text page faults
* with threads.
*/
if (write_access)
if (flags & FAULT_FLAG_WRITE)
flush_tlb_page(vma, address);
}
unlock:
@ -2965,13 +2964,14 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
unsigned int flags = write_access ? FAULT_FLAG_WRITE : 0;
__set_current_state(TASK_RUNNING);
count_vm_event(PGFAULT);
if (unlikely(is_vm_hugetlb_page(vma)))
return hugetlb_fault(mm, vma, address, write_access);
return hugetlb_fault(mm, vma, address, flags);
pgd = pgd_offset(mm, address);
pud = pud_alloc(mm, pgd, address);
@ -2984,7 +2984,7 @@ int handle_mm_fault(struct mm_struct *mm, struct vm_area_struct *vma,
if (!pte)
return VM_FAULT_OOM;
return handle_pte_fault(mm, vma, address, pte, pmd, write_access);
return handle_pte_fault(mm, vma, address, pte, pmd, flags);
}
#ifndef __PAGETABLE_PUD_FOLDED