Merge branch 'akpm-current/current'

[karo-tx-linux.git] / kernel / futex.c

diff --git a/kernel/futex.c b/kernel/futex.c
index 684d7549825a4300ced2002a3fbec0a5698a18d1..470c06c3299a7feb5cc0598508715e453274c677 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -469,7 +469,7 @@ get_futex_key(u32 __user *uaddr, int fshared, union futex_key *key, int rw)
 {
        unsigned long address = (unsigned long)uaddr;
        struct mm_struct *mm = current->mm;
-       struct page *page, *page_head;
+       struct page *page;
        int err, ro = 0;
 
        /*
@@ -519,46 +519,9 @@ again:
        else
                err = 0;
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
-       page_head = page;
-       if (unlikely(PageTail(page))) {
-               put_page(page);
-               /* serialize against __split_huge_page_splitting() */
-               local_irq_disable();
-               if (likely(__get_user_pages_fast(address, 1, !ro, &page) == 1)) {
-                       page_head = compound_head(page);
-                       /*
-                        * page_head is valid pointer but we must pin
-                        * it before taking the PG_lock and/or
-                        * PG_compound_lock. The moment we re-enable
-                        * irqs __split_huge_page_splitting() can
-                        * return and the head page can be freed from
-                        * under us. We can't take the PG_lock and/or
-                        * PG_compound_lock on a page that could be
-                        * freed from under us.
-                        */
-                       if (page != page_head) {
-                               get_page(page_head);
-                               put_page(page);
-                       }
-                       local_irq_enable();
-               } else {
-                       local_irq_enable();
-                       goto again;
-               }
-       }
-#else
-       page_head = compound_head(page);
-       if (page != page_head) {
-               get_page(page_head);
-               put_page(page);
-       }
-#endif
-
-       lock_page(page_head);
-
+       lock_page(page);
        /*
-        * If page_head->mapping is NULL, then it cannot be a PageAnon
+        * If page->mapping is NULL, then it cannot be a PageAnon
         * page; but it might be the ZERO_PAGE or in the gate area or
         * in a special mapping (all cases which we are happy to fail);
         * or it may have been a good file page when get_user_pages_fast
@@ -570,12 +533,12 @@ again:
         *
         * The case we do have to guard against is when memory pressure made
         * shmem_writepage move it from filecache to swapcache beneath us:
-        * an unlikely race, but we do need to retry for page_head->mapping.
+        * an unlikely race, but we do need to retry for page->mapping.
         */
-       if (!page_head->mapping) {
-               int shmem_swizzled = PageSwapCache(page_head);
-               unlock_page(page_head);
-               put_page(page_head);
+       if (!page->mapping) {
+               int shmem_swizzled = PageSwapCache(page);
+               unlock_page(page);
+               put_page(page);
                if (shmem_swizzled)
                        goto again;
                return -EFAULT;
@@ -588,7 +551,7 @@ again:
         * it's a read-only handle, it's expected that futexes attach to
         * the object not the particular process.
         */
-       if (PageAnon(page_head)) {
+       if (PageAnon(page)) {
                /*
                 * A RO anonymous page will never change and thus doesn't make
                 * sense for futex operations.
@@ -603,15 +566,15 @@ again:
                key->private.address = address;
        } else {
                key->both.offset |= FUT_OFF_INODE; /* inode-based key */
-               key->shared.inode = page_head->mapping->host;
+               key->shared.inode = page->mapping->host;
                key->shared.pgoff = basepage_index(page);
        }
 
        get_futex_key_refs(key); /* implies MB (B) */
 
 out:
-       unlock_page(page_head);
-       put_page(page_head);
+       unlock_page(page);
+       put_page(page);
        return err;
 }