On Thu, Sep 14, 2017 at 11:50:46AM +0200, Andreas Gruenbacher wrote:

+int ext4_inline_data_iomap(struct inode *inode, struct iomap *iomap)
+{
+	__u64 addr;
+	int error = -EAGAIN;
+	struct ext4_iloc iloc;
+
+	down_read(&EXT4_I(inode)->xattr_sem);
+	if (!ext4_has_inline_data(inode))
+		goto out;

	....

+out:
+	up_read(&EXT4_I(inode)->xattr_sem);
+	return error;
+}

If we race with the inline data flag getting cleared,
ext4_iomap_begin() will return with -EAGAIN.  As near as I can tell,
this will get reflected all the way up to userspace, instead of having
the retry happen in the kernel.  Is this intentional?

It looks like a user visible change, no?

						- Ted