1 files changed, 24 insertions, 17 deletions

diff --git a/mm/shmem.c b/mm/shmem.c
index 6c10f1d92251..0b6db162083c 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -2052,9 +2052,10 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	/*
 	 * Our priority is to support MAP_SHARED mapped hugely;
 	 * and support MAP_PRIVATE mapped hugely too, until it is COWed.
-	 * But if caller specified an address hint, respect that as before.
+	 * But if caller specified an address hint and we allocated area there
+	 * successfully, respect that as before.
 	 */
-	if (uaddr)
+	if (uaddr == addr)
 		return addr;
 
 	if (shmem_huge != SHMEM_HUGE_FORCE) {
@@ -2088,7 +2089,7 @@ unsigned long shmem_get_unmapped_area(struct file *file,
 	if (inflated_len < len)
 		return addr;
 
-	inflated_addr = get_area(NULL, 0, inflated_len, 0, flags);
+	inflated_addr = get_area(NULL, uaddr, inflated_len, 0, flags);
 	if (IS_ERR_VALUE(inflated_addr))
 		return addr;
 	if (inflated_addr & ~PAGE_MASK)
@@ -2657,31 +2658,33 @@ static void shmem_tag_pins(struct address_space *mapping)
 	void **slot;
 	pgoff_t start;
 	struct page *page;
+	unsigned int tagged = 0;
 
 	lru_add_drain();
 	start = 0;
-	rcu_read_lock();
 
+	spin_lock_irq(&mapping->tree_lock);
 	radix_tree_for_each_slot(slot, &mapping->page_tree, &iter, start) {
-		page = radix_tree_deref_slot(slot);
+		page = radix_tree_deref_slot_protected(slot, &mapping->tree_lock);
 		if (!page || radix_tree_exception(page)) {
 			if (radix_tree_deref_retry(page)) {
 				slot = radix_tree_iter_retry(&iter);
 				continue;
 			}
 		} else if (page_count(page) - page_mapcount(page) > 1) {
-			spin_lock_irq(&mapping->tree_lock);
 			radix_tree_tag_set(&mapping->page_tree, iter.index,
 					   SHMEM_TAG_PINNED);
-			spin_unlock_irq(&mapping->tree_lock);
 		}
 
-		if (need_resched()) {
-			slot = radix_tree_iter_resume(slot, &iter);
-			cond_resched_rcu();
-		}
+		if (++tagged % 1024)
+			continue;
+
+		slot = radix_tree_iter_resume(slot, &iter);
+		spin_unlock_irq(&mapping->tree_lock);
+		cond_resched();
+		spin_lock_irq(&mapping->tree_lock);
 	}
-	rcu_read_unlock();
+	spin_unlock_irq(&mapping->tree_lock);
 }
 
 /*
@@ -2893,7 +2896,7 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
 		}
 
 		shmem_falloc.waitq = &shmem_falloc_waitq;
-		shmem_falloc.start = unmap_start >> PAGE_SHIFT;
+		shmem_falloc.start = (u64)unmap_start >> PAGE_SHIFT;
 		shmem_falloc.next = (unmap_end + 1) >> PAGE_SHIFT;
 		spin_lock(&inode->i_lock);
 		inode->i_private = &shmem_falloc;
@@ -3096,16 +3099,20 @@ static int shmem_create(struct inode *dir, struct dentry *dentry, umode_t mode,
 static int shmem_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry)
 {
 	struct inode *inode = d_inode(old_dentry);
-	int ret;
+	int ret = 0;
 
 	/*
 	 * No ordinary (disk based) filesystem counts links as inodes;
 	 * but each new link needs a new dentry, pinning lowmem, and
 	 * tmpfs dentries cannot be pruned until they are unlinked.
+	 * But if an O_TMPFILE file is linked into the tmpfs, the
+	 * first link must skip that, to get the accounting right.
 	 */
-	ret = shmem_reserve_inode(inode->i_sb);
-	if (ret)
-		goto out;
+	if (inode->i_nlink) {
+		ret = shmem_reserve_inode(inode->i_sb);
+		if (ret)
+			goto out;
+	}
 
 	dir->i_size += BOGO_DIRENT_SIZE;
 	inode->i_ctime = dir->i_ctime = dir->i_mtime = current_time(inode);