June 16, 2017
6:14 a.m.
I just had a quick look at mount_bdev() code for Linux v3.15, mount_bdev() can return only root dentry or error.
I'm sorry I should have been clearer. I was referring to the documentation mount() where it says that the call can return something other than the root dentry. More specifically, I don't understand how the what's the purpose of the if condition checking for s_root in mount_bdev(). Apologies if this is a trivial question. Tracking the calls all the way down didn't seem to make it clearer and I couldn't find specific documentation about the interface.
Also please include the kernel version to which you are referring.
I have the 4.12-rc5 kernel. --- Shrikant