diff --git a/fs/file.c b/fs/file.c
index b241ea7f1aa4..3da91a112bab 100644
--- a/fs/file.c
+++ b/fs/file.c
@@ -795,7 +795,7 @@ unsigned long __fdget_pos(unsigned int fd)
 	unsigned long v = __fdget(fd);
 	struct file *file = (struct file *)(v & ~3);
 
-	if (file && !(file->f_mode & FMODE_STREAM)) {
+	if (file && (file->f_mode & FMODE_ATOMIC_POS)) {
 		if (file_count(file) > 1) {
 			v |= FDPUT_POS_UNLOCK;
 			mutex_lock(&file->f_pos_lock);
diff --git a/fs/open.c b/fs/open.c
index 5c68282ea79e..b62f5c0923a8 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -771,6 +771,10 @@ static int do_dentry_open(struct file *f,
 		f->f_mode |= FMODE_WRITER;
 	}
 
+	/* POSIX.1-2008/SUSv4 Section XSI 2.9.7 */
+	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode))
+		f->f_mode |= FMODE_ATOMIC_POS;
+
 	f->f_op = fops_get(inode->i_fop);
 	if (WARN_ON(!f->f_op)) {
 		error = -ENODEV;
@@ -1252,7 +1256,7 @@ EXPORT_SYMBOL(nonseekable_open);
  */
 int stream_open(struct inode *inode, struct file *filp)
 {
-	filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE);
+	filp->f_mode &= ~(FMODE_LSEEK | FMODE_PREAD | FMODE_PWRITE | FMODE_ATOMIC_POS);
 	filp->f_mode |= FMODE_STREAM;
 	return 0;
 }
diff --git a/include/linux/fs.h b/include/linux/fs.h
index dde6dc4492a0..ae6c5c37f3ae 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -148,6 +148,8 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
 /* File is opened with O_PATH; almost nothing can be done with it */
 #define FMODE_PATH		((__force fmode_t)0x4000)
 
+/* File needs atomic accesses to f_pos */
+#define FMODE_ATOMIC_POS	((__force fmode_t)0x8000)
 /* Write access to underlying fs */
 #define FMODE_WRITER		((__force fmode_t)0x10000)
 /* Has read method(s) */