mm: wrap follow_pte() using __cond_lock()

[net-next-2.6.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 92cc54e9413713027d52cf5e9a482085cc25ad00..861f7982dd54db7bfad268386185fe1829db01bd 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1591,7 +1591,7 @@ struct page *get_dump_page(unsigned long addr)
 }
 #endif /* CONFIG_ELF_CORE */
 
-pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
+pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
                        spinlock_t **ptl)
 {
        pgd_t * pgd = pgd_offset(mm, addr);
@@ -2108,6 +2108,7 @@ static inline void cow_user_page(struct page *dst, struct page *src, unsigned lo
 static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                unsigned long address, pte_t *page_table, pmd_t *pmd,
                spinlock_t *ptl, pte_t orig_pte)
+       __releases(ptl)
 {
        struct page *old_page, *new_page;
        pte_t entry;
@@ -2627,6 +2628,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
        struct page *page, *swapcache = NULL;
        swp_entry_t entry;
        pte_t pte;
+       int locked;
        struct mem_cgroup *ptr = NULL;
        int exclusive = 0;
        int ret = 0;
@@ -2677,8 +2679,12 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                goto out_release;
        }
 
-       lock_page(page);
+       locked = lock_page_or_retry(page, mm, flags);
        delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+       if (!locked) {
+               ret |= VM_FAULT_RETRY;
+               goto out_release;
+       }
 
        /*
         * Make sure try_to_free_swap or reuse_swap_page or swapoff did not
@@ -2927,7 +2933,8 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        vmf.page = NULL;
 
        ret = vma->vm_ops->fault(vma, &vmf);
-       if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))
+       if (unlikely(ret & (VM_FAULT_ERROR | VM_FAULT_NOPAGE |
+                           VM_FAULT_RETRY)))
                return ret;
 
        if (unlikely(PageHWPoison(vmf.page))) {
@@ -3344,7 +3351,7 @@ int in_gate_area_no_task(unsigned long addr)
 
 #endif /* __HAVE_ARCH_GATE_AREA */
 
-static int follow_pte(struct mm_struct *mm, unsigned long address,
+static int __follow_pte(struct mm_struct *mm, unsigned long address,
                pte_t **ptepp, spinlock_t **ptlp)
 {
        pgd_t *pgd;
@@ -3381,6 +3388,17 @@ out:
        return -EINVAL;
 }
 
+static inline int follow_pte(struct mm_struct *mm, unsigned long address,
+                            pte_t **ptepp, spinlock_t **ptlp)
+{
+       int res;
+
+       /* (void) is needed to make gcc happy */
+       (void) __cond_lock(*ptlp,
+                          !(res = __follow_pte(mm, address, ptepp, ptlp)));
+       return res;
+}
+
 /**
  * follow_pfn - look up PFN at a user virtual address
  * @vma: memory mapping