UBI: Silence an unintialized variable warning

[cascardo/linux.git] / mm / memory.c

diff --git a/mm/memory.c b/mm/memory.c
index 098f00d..305537f 100644 (file)
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -789,6 +789,46 @@ out:
        return pfn_to_page(pfn);
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
+                               pmd_t pmd)
+{
+       unsigned long pfn = pmd_pfn(pmd);
+
+       /*
+        * There is no pmd_special() but there may be special pmds, e.g.
+        * in a direct-access (dax) mapping, so let's just replicate the
+        * !HAVE_PTE_SPECIAL case from vm_normal_page() here.
+        */
+       if (unlikely(vma->vm_flags & (VM_PFNMAP|VM_MIXEDMAP))) {
+               if (vma->vm_flags & VM_MIXEDMAP) {
+                       if (!pfn_valid(pfn))
+                               return NULL;
+                       goto out;
+               } else {
+                       unsigned long off;
+                       off = (addr - vma->vm_start) >> PAGE_SHIFT;
+                       if (pfn == vma->vm_pgoff + off)
+                               return NULL;
+                       if (!is_cow_mapping(vma->vm_flags))
+                               return NULL;
+               }
+       }
+
+       if (is_zero_pfn(pfn))
+               return NULL;
+       if (unlikely(pfn > highest_memmap_pfn))
+               return NULL;
+
+       /*
+        * NOTE! We still have PageReserved() pages in the page tables.
+        * eg. VDSO mappings can cause them to exist.
+        */
+out:
+       return pfn_to_page(pfn);
+}
+#endif
+
 /*
  * copy one vm_area from one task to the other. Assumes the page tables
  * already present in the new task to be cleared in the whole range
@@ -2054,7 +2094,7 @@ static inline int wp_page_reuse(struct mm_struct *mm,
                VM_BUG_ON_PAGE(PageAnon(page), page);
                mapping = page->mapping;
                unlock_page(page);
-               page_cache_release(page);
+               put_page(page);
 
                if ((dirtied || page_mkwrite) && mapping) {
                        /*
@@ -2188,7 +2228,7 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma,
        }
 
        if (new_page)
-               page_cache_release(new_page);
+               put_page(new_page);
 
        pte_unmap_unlock(page_table, ptl);
        mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
@@ -2203,14 +2243,14 @@ static int wp_page_copy(struct mm_struct *mm, struct vm_area_struct *vma,
                                munlock_vma_page(old_page);
                        unlock_page(old_page);
                }
-               page_cache_release(old_page);
+               put_page(old_page);
        }
        return page_copied ? VM_FAULT_WRITE : 0;
 oom_free_new:
-       page_cache_release(new_page);
+       put_page(new_page);
 oom:
        if (old_page)
-               page_cache_release(old_page);
+               put_page(old_page);
        return VM_FAULT_OOM;
 }
 
@@ -2258,7 +2298,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
 {
        int page_mkwrite = 0;
 
-       page_cache_get(old_page);
+       get_page(old_page);
 
        if (vma->vm_ops && vma->vm_ops->page_mkwrite) {
                int tmp;
@@ -2267,7 +2307,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
                tmp = do_page_mkwrite(vma, old_page, address);
                if (unlikely(!tmp || (tmp &
                                      (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
-                       page_cache_release(old_page);
+                       put_page(old_page);
                        return tmp;
                }
                /*
@@ -2281,7 +2321,7 @@ static int wp_page_shared(struct mm_struct *mm, struct vm_area_struct *vma,
                if (!pte_same(*page_table, orig_pte)) {
                        unlock_page(old_page);
                        pte_unmap_unlock(page_table, ptl);
-                       page_cache_release(old_page);
+                       put_page(old_page);
                        return 0;
                }
                page_mkwrite = 1;
@@ -2341,7 +2381,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
         */
        if (PageAnon(old_page) && !PageKsm(old_page)) {
                if (!trylock_page(old_page)) {
-                       page_cache_get(old_page);
+                       get_page(old_page);
                        pte_unmap_unlock(page_table, ptl);
                        lock_page(old_page);
                        page_table = pte_offset_map_lock(mm, pmd, address,
@@ -2349,10 +2389,10 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
                        if (!pte_same(*page_table, orig_pte)) {
                                unlock_page(old_page);
                                pte_unmap_unlock(page_table, ptl);
-                               page_cache_release(old_page);
+                               put_page(old_page);
                                return 0;
                        }
-                       page_cache_release(old_page);
+                       put_page(old_page);
                }
                if (reuse_swap_page(old_page)) {
                        /*
@@ -2375,7 +2415,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct *vma,
        /*
         * Ok, we need to copy. Oh, well..
         */
-       page_cache_get(old_page);
+       get_page(old_page);
 
        pte_unmap_unlock(page_table, ptl);
        return wp_page_copy(mm, vma, address, page_table, pmd,
@@ -2400,7 +2440,6 @@ static inline void unmap_mapping_range_tree(struct rb_root *root,
 
                vba = vma->vm_pgoff;
                vea = vba + vma_pages(vma) - 1;
-               /* Assume for now that PAGE_CACHE_SHIFT == PAGE_SHIFT */
                zba = details->first_index;
                if (zba < vba)
                        zba = vba;
@@ -2619,7 +2658,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 * parallel locked swapcache.
                 */
                unlock_page(swapcache);
-               page_cache_release(swapcache);
+               put_page(swapcache);
        }
 
        if (flags & FAULT_FLAG_WRITE) {
@@ -2641,10 +2680,10 @@ out_nomap:
 out_page:
        unlock_page(page);
 out_release:
-       page_cache_release(page);
+       put_page(page);
        if (page != swapcache) {
                unlock_page(swapcache);
-               page_cache_release(swapcache);
+               put_page(swapcache);
        }
        return ret;
 }
@@ -2752,7 +2791,7 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
        if (userfaultfd_missing(vma)) {
                pte_unmap_unlock(page_table, ptl);
                mem_cgroup_cancel_charge(page, memcg, false);
-               page_cache_release(page);
+               put_page(page);
                return handle_userfault(vma, address, flags,
                                        VM_UFFD_MISSING);
        }
@@ -2771,10 +2810,10 @@ unlock:
        return 0;
 release:
        mem_cgroup_cancel_charge(page, memcg, false);
-       page_cache_release(page);
+       put_page(page);
        goto unlock;
 oom_free_page:
-       page_cache_release(page);
+       put_page(page);
 oom:
        return VM_FAULT_OOM;
 }
@@ -2807,7 +2846,7 @@ static int __do_fault(struct vm_area_struct *vma, unsigned long address,
        if (unlikely(PageHWPoison(vmf.page))) {
                if (ret & VM_FAULT_LOCKED)
                        unlock_page(vmf.page);
-               page_cache_release(vmf.page);
+               put_page(vmf.page);
                return VM_FAULT_HWPOISON;
        }
 
@@ -2996,7 +3035,7 @@ static int do_read_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        if (unlikely(!pte_same(*pte, orig_pte))) {
                pte_unmap_unlock(pte, ptl);
                unlock_page(fault_page);
-               page_cache_release(fault_page);
+               put_page(fault_page);
                return ret;
        }
        do_set_pte(vma, address, fault_page, pte, false, false);
@@ -3024,7 +3063,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                return VM_FAULT_OOM;
 
        if (mem_cgroup_try_charge(new_page, mm, GFP_KERNEL, &memcg, false)) {
-               page_cache_release(new_page);
+               put_page(new_page);
                return VM_FAULT_OOM;
        }
 
@@ -3041,7 +3080,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                pte_unmap_unlock(pte, ptl);
                if (fault_page) {
                        unlock_page(fault_page);
-                       page_cache_release(fault_page);
+                       put_page(fault_page);
                } else {
                        /*
                         * The fault handler has no page to lock, so it holds
@@ -3057,7 +3096,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        pte_unmap_unlock(pte, ptl);
        if (fault_page) {
                unlock_page(fault_page);
-               page_cache_release(fault_page);
+               put_page(fault_page);
        } else {
                /*
                 * The fault handler has no page to lock, so it holds
@@ -3068,7 +3107,7 @@ static int do_cow_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        return ret;
 uncharge_out:
        mem_cgroup_cancel_charge(new_page, memcg, false);
-       page_cache_release(new_page);
+       put_page(new_page);
        return ret;
 }
 
@@ -3096,7 +3135,7 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                tmp = do_page_mkwrite(vma, fault_page, address);
                if (unlikely(!tmp ||
                                (tmp & (VM_FAULT_ERROR | VM_FAULT_NOPAGE)))) {
-                       page_cache_release(fault_page);
+                       put_page(fault_page);
                        return tmp;
                }
        }
@@ -3105,7 +3144,7 @@ static int do_shared_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        if (unlikely(!pte_same(*pte, orig_pte))) {
                pte_unmap_unlock(pte, ptl);
                unlock_page(fault_page);
-               page_cache_release(fault_page);
+               put_page(fault_page);
                return ret;
        }
        do_set_pte(vma, address, fault_page, pte, true, false);
@@ -3736,7 +3775,7 @@ static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm,
                                                    buf, maddr + offset, bytes);
                        }
                        kunmap(page);
-                       page_cache_release(page);
+                       put_page(page);
                }
                len -= bytes;
                buf += bytes;