Merge commit 'v2.6.28-rc2' into core/locking

Conflicts:
	arch/um/include/asm/system.h

1 files changed, 79 insertions, 46 deletions

diff --git a/mm/memory.c b/mm/memory.c
index b8fdf4e5e65..fc031d68327 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1129,12 +1129,17 @@ static inline int use_zero_page(struct vm_area_struct *vma)
         return !vma->vm_ops || !vma->vm_ops->fault;
 }
 
-int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
-                unsigned long start, int len, int write, int force,
+
+
+int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+                     unsigned long start, int len, int flags,
                 struct page **pages, struct vm_area_struct **vmas)
 {
         int i;
-        unsigned int vm_flags;
+        unsigned int vm_flags = 0;
+        int write = !!(flags & GUP_FLAGS_WRITE);
+        int force = !!(flags & GUP_FLAGS_FORCE);
+        int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
 
         if (len <= 0)
                 return 0;
@@ -1158,7 +1163,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         pud_t *pud;
                         pmd_t *pmd;
                         pte_t *pte;
-                        if (write) /* user gate pages are read-only */
+
+                        /* user gate pages are read-only */
+                        if (!ignore && write)
                                 return i ? : -EFAULT;
                         if (pg > TASK_SIZE)
                                 pgd = pgd_offset_k(pg);
@@ -1190,8 +1197,9 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         continue;
                 }
 
-                if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
-                                || !(vm_flags & vma->vm_flags))
+                if (!vma ||
+                    (vma->vm_flags & (VM_IO | VM_PFNMAP)) ||
+                    (!ignore && !(vm_flags & vma->vm_flags)))
                         return i ? : -EFAULT;
 
                 if (is_vm_hugetlb_page(vma)) {
@@ -1266,6 +1274,23 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
         } while (len);
         return i;
 }
+
+int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
+                unsigned long start, int len, int write, int force,
+                struct page **pages, struct vm_area_struct **vmas)
+{
+        int flags = 0;
+
+        if (write)
+                flags |= GUP_FLAGS_WRITE;
+        if (force)
+                flags |= GUP_FLAGS_FORCE;
+
+        return __get_user_pages(tsk, mm,
+                                start, len, flags,
+                                pages, vmas);
+}
+
 EXPORT_SYMBOL(get_user_pages);
 
 pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
@@ -1296,18 +1321,14 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
         pte_t *pte;
         spinlock_t *ptl;
 
-        retval = mem_cgroup_charge(page, mm, GFP_KERNEL);
-        if (retval)
-                goto out;
-
         retval = -EINVAL;
         if (PageAnon(page))
-                goto out_uncharge;
+                goto out;
         retval = -ENOMEM;
         flush_dcache_page(page);
         pte = get_locked_pte(mm, addr, &ptl);
         if (!pte)
-                goto out_uncharge;
+                goto out;
         retval = -EBUSY;
         if (!pte_none(*pte))
                 goto out_unlock;
@@ -1323,8 +1344,6 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr,
         return retval;
 out_unlock:
         pte_unmap_unlock(pte, ptl);
-out_uncharge:
-        mem_cgroup_uncharge_page(page);
 out:
         return retval;
 }
@@ -1858,6 +1877,15 @@ gotten:
         new_page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, address);
         if (!new_page)
                 goto oom;
+        /*
+         * Don't let another task, with possibly unlocked vma,
+         * keep the mlocked page.
+         */
+        if (vma->vm_flags & VM_LOCKED) {
+                lock_page(old_page);    /* for LRU manipulation */
+                clear_page_mlock(old_page);
+                unlock_page(old_page);
+        }
         cow_user_page(new_page, old_page, address, vma);
         __SetPageUptodate(new_page);
 
@@ -1886,11 +1914,13 @@ gotten:
                  * thread doing COW.
                  */
                 ptep_clear_flush_notify(vma, address, page_table);
-                set_pte_at(mm, address, page_table, entry);
-                update_mmu_cache(vma, address, entry);
-                lru_cache_add_active(new_page);
+                SetPageSwapBacked(new_page);
+                lru_cache_add_active_or_unevictable(new_page, vma);
                 page_add_new_anon_rmap(new_page, vma, address);
 
+//TODO:  is this safe?  do_anonymous_page() does it this way.
+                set_pte_at(mm, address, page_table, entry);
+                update_mmu_cache(vma, address, entry);
                 if (old_page) {
                         /*
                          * Only after switching the pte to the new page may
@@ -2288,16 +2318,17 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
                 count_vm_event(PGMAJFAULT);
         }
 
+        mark_page_accessed(page);
+
+        lock_page(page);
+        delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
+
         if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
-                delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
                 ret = VM_FAULT_OOM;
+                unlock_page(page);
                 goto out;
         }
 
-        mark_page_accessed(page);
-        lock_page(page);
-        delayacct_clear_flag(DELAYACCT_PF_SWAPIN);
-
         /*
          * Back out if somebody else already faulted in this pte.
          */
@@ -2324,7 +2355,7 @@ static int do_swap_page(struct mm_struct *mm, struct vm_area_struct *vma,
         page_add_anon_rmap(page, vma, address);
 
         swap_free(entry);
-        if (vm_swap_full())
+        if (vm_swap_full() || (vma->vm_flags & VM_LOCKED) || PageMlocked(page))
                 remove_exclusive_swap_page(page);
         unlock_page(page);
 
@@ -2382,7 +2413,8 @@ static int do_anonymous_page(struct mm_struct *mm, struct vm_area_struct *vma,
         if (!pte_none(*page_table))
                 goto release;
         inc_mm_counter(mm, anon_rss);
-        lru_cache_add_active(page);
+        SetPageSwapBacked(page);
+        lru_cache_add_active_or_unevictable(page, vma);
         page_add_new_anon_rmap(page, vma, address);
         set_pte_at(mm, address, page_table, entry);
 
@@ -2423,6 +2455,7 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
         struct page *page;
         pte_t entry;
         int anon = 0;
+        int charged = 0;
         struct page *dirty_page = NULL;
         struct vm_fault vmf;
         int ret;
@@ -2463,6 +2496,18 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                 ret = VM_FAULT_OOM;
                                 goto out;
                         }
+                        if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
+                                ret = VM_FAULT_OOM;
+                                page_cache_release(page);
+                                goto out;
+                        }
+                        charged = 1;
+                        /*
+                         * Don't let another task, with possibly unlocked vma,
+                         * keep the mlocked page.
+                         */
+                        if (vma->vm_flags & VM_LOCKED)
+                                clear_page_mlock(vmf.page);
                         copy_user_highpage(page, vmf.page, address, vma);
                         __SetPageUptodate(page);
                 } else {
@@ -2497,11 +2542,6 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 
         }
 
-        if (mem_cgroup_charge(page, mm, GFP_KERNEL)) {
-                ret = VM_FAULT_OOM;
-                goto out;
-        }
-
         page_table = pte_offset_map_lock(mm, pmd, address, &ptl);
 
         /*
@@ -2520,11 +2560,11 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                 entry = mk_pte(page, vma->vm_page_prot);
                 if (flags & FAULT_FLAG_WRITE)
                         entry = maybe_mkwrite(pte_mkdirty(entry), vma);
-                set_pte_at(mm, address, page_table, entry);
                 if (anon) {
-                        inc_mm_counter(mm, anon_rss);
-                        lru_cache_add_active(page);
-                        page_add_new_anon_rmap(page, vma, address);
+                        inc_mm_counter(mm, anon_rss);
+                        SetPageSwapBacked(page);
+                        lru_cache_add_active_or_unevictable(page, vma);
+                        page_add_new_anon_rmap(page, vma, address);
                 } else {
                         inc_mm_counter(mm, file_rss);
                         page_add_file_rmap(page);
@@ -2533,11 +2573,14 @@ static int __do_fault(struct mm_struct *mm, struct vm_area_struct *vma,
                                 get_page(dirty_page);
                         }
                 }
+//TODO:  is this safe?  do_anonymous_page() does it this way.
+                set_pte_at(mm, address, page_table, entry);
 
                 /* no need to invalidate: a not-present page won't be cached */
                 update_mmu_cache(vma, address, entry);
         } else {
-                mem_cgroup_uncharge_page(page);
+                if (charged)
+                        mem_cgroup_uncharge_page(page);
                 if (anon)
                         page_cache_release(page);
                 else
@@ -2772,19 +2815,9 @@ int make_pages_present(unsigned long addr, unsigned long end)
         len = DIV_ROUND_UP(end, PAGE_SIZE) - addr/PAGE_SIZE;
         ret = get_user_pages(current, current->mm, addr,
                         len, write, 0, NULL, NULL);
-        if (ret < 0) {
-                /*
-                   SUS require strange return value to mlock
-                    - invalid addr generate to ENOMEM.
-                    - out of memory should generate EAGAIN.
-                */
-                if (ret == -EFAULT)
-                        ret = -ENOMEM;
-                else if (ret == -ENOMEM)
-                        ret = -EAGAIN;
+        if (ret < 0)
                 return ret;
-        }
-        return ret == len ? 0 : -ENOMEM;
+        return ret == len ? 0 : -EFAULT;
 }
 
 #if !defined(__HAVE_ARCH_GATE_AREA)