1 files changed, 25 insertions, 14 deletions

diff --git a/fs/open.c b/fs/open.c
index 50e45bc7c4d8..22adbef7ecc2 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -247,6 +247,7 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 {
 	struct inode *inode = file_inode(file);
 	long ret;
+	loff_t sum;
 
 	if (offset < 0 || len <= 0)
 		return -EINVAL;
@@ -319,8 +320,11 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
 	if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode))
 		return -ENODEV;
 
-	/* Check for wrap through zero too */
-	if (((offset + len) > inode->i_sb->s_maxbytes) || ((offset + len) < 0))
+	/* Check for wraparound */
+	if (check_add_overflow(offset, len, &sum))
+		return -EFBIG;
+
+	if (sum > inode->i_sb->s_maxbytes)
 		return -EFBIG;
 
 	if (!file->f_op->fallocate)
@@ -982,12 +986,11 @@ static int do_dentry_open(struct file *f,
 	 */
 	if (f->f_mode & FMODE_WRITE) {
 		/*
-		 * Paired with smp_mb() in collapse_file() to ensure nr_thps
-		 * is up to date and the update to i_writecount by
-		 * get_write_access() is visible. Ensures subsequent insertion
-		 * of THPs into the page cache will fail.
+		 * Depends on full fence from get_write_access() to synchronize
+		 * against collapse_file() regarding i_writecount and nr_thps
+		 * updates. Ensures subsequent insertion of THPs into the page
+		 * cache will fail.
 		 */
-		smp_mb();
 		if (filemap_nr_thps(inode->i_mapping)) {
 			struct address_space *mapping = inode->i_mapping;
 
@@ -1004,11 +1007,6 @@ static int do_dentry_open(struct file *f,
 		}
 	}
 
-	/*
-	 * Once we return a file with FMODE_OPENED, __fput() will call
-	 * fsnotify_close(), so we need fsnotify_open() here for symmetry.
-	 */
-	fsnotify_open(f);
 	return 0;
 
 cleanup_all:
@@ -1085,8 +1083,19 @@ EXPORT_SYMBOL(file_path);
  */
 int vfs_open(const struct path *path, struct file *file)
 {
+	int ret;
+
 	file->f_path = *path;
-	return do_dentry_open(file, NULL);
+	ret = do_dentry_open(file, NULL);
+	if (!ret) {
+		/*
+		 * Once we return a file with FMODE_OPENED, __fput() will call
+		 * fsnotify_close(), so we need fsnotify_open() here for
+		 * symmetry.
+		 */
+		fsnotify_open(file);
+	}
+	return ret;
 }
 
 struct file *dentry_open(const struct path *path, int flags,
@@ -1177,8 +1186,10 @@ struct file *kernel_file_open(const struct path *path, int flags,
 	error = do_dentry_open(f, NULL);
 	if (error) {
 		fput(f);
-		f = ERR_PTR(error);
+		return ERR_PTR(error);
 	}
+
+	fsnotify_open(f);
 	return f;
 }
 EXPORT_SYMBOL_GPL(kernel_file_open);