I don't consider rmdirent to be a case that we need to highly optimize,
so if it helps to lookup the name and do the getattr beforehand, that's
cool by me. I'm sure somewhere out there there is a rmdir test that
we'll do a little worse on, but whatever.
You'll still have to getattr again after the rmdirent to make sure that
the directory is still empty though, in case someone sneaks in between
the first getattr and the rmdirent and creates something.
rob
Sam Lang wrote:
On Dec 19, 2005, at 3:51 PM, Julian Martin Kunkel wrote:
Hi,
1. rmdirent(object name,parent handle) => object handle
2. getattr(object handle) => attr
3. remove(object handle) => ENOTEMPTY
4. crdirent(object_handle)
Ahh, you are right. I didn't realize that the attributes weren't read
until after removing the directory entry. With that being the case it
would have to come after step 2) as you say, although that isn't as
helpful as if we had the information earlier.
I don't think this would be helpful because it won't change something.
If a
client breaks after step 1 the directory object is gone, even if it has
objects inside.
Currently you check whether the directory is empty directly after step 2.
It would save the remove roundtrip (step 3 from the list above), since
we first check the attr and discover the directory isn't empty.
From my opinion the problem is that you don't check the directory
state before
you remove in step 1 the directory entry.
Yes of course you can't do this because you get the object handle while
rmdirent.
A idea would be to first lookup the object name to get the object
handle and
then getattr (handle) and then look if it's empty or not (like it is
currently done).
I think this adds a roundtrip, doesn't it? The rmdirent acts as a
lookup in the current code, so we get a two-for-one there. The only
reason I can think of for doing this would be that the name cache would
prevent the over-the-wire lookup, and then the attr cache would return
the attributes, so the is-empty check could potentially be done (given
cache hits) without any over-the-wire operations. Right now we bypass
the name cache. Not sure what's most optimal here.
-sam
If it's empty do rmdirent and then remove object. The
mechanism with the ENOTEMPTY and crdirent can be keept in case somebody
creates a object in that directory while another client checked the
number of
directory entries with getattr.
Julian
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