On Thu, Jan 9, 2020 at 8:15 PM Al Viro viro@zeniv.linux.org.uk wrote:
Hmm. If that's the case, maybe they should be marked implicitly as O_PATH when opened?
I thought you wanted O_PATH as starting point to have mounts traversed? Confused...
No, I'm confused. I meant "non-O_PATH", just got the rules reversed in my mind.
So cwd/root would always act as it non-O_PATH, and only using an actual fd would look at the O_PATH flag, and if it was set would walk the mountpoints.
<grabs Bach> Right, he simply transcribes v7 iget().
So I suspect that you are right - your variant of iget was pretty much one-to-one implementation of Bach's description of v7 iget.
Ok, that makes sense. My copy of Bach literally had the system call list "marked off" when I implemented them back when.
I may still have that paperbook copy somewhere. I don't _think_ I'd have thrown it out, it has sentimental value.
I think that in a perfect world, the O_PATH'ness of '42' would be the deciding factor. Wouldn't those be the best and most consistent semantics?
And then 'cwd'/'root' always have the O_PATH behavior.
See above - unless I'm misparsing you, you wanted mount traversals in the starting point if it's ...at() with O_PATH fd.
.. and see above, it was just my confusion about the sense of O_PATH.
For cwd and root the situation is opposite - we do NOT traverse mounts for those. And that's really too late to change.
Oh, absolutely.
[ snip some more about your automount digging. Looks about right, but I'm not going to make a peep after getting O_PATH reversed ;) ]
Linus