Messages in this thread | | | From | Bernd Schubert <> | Subject | Re: [PATCH v5 0/3] FUSE: Implement atomic lookup + open/create | Date | Thu, 1 Jun 2023 11:16:52 +0000 |
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Hi Miklos,
On 5/19/22 11:39, Miklos Szeredi wrote: > On Tue, 17 May 2022 at 12:08, Dharmendra Singh <dharamhans87@gmail.com> wrote: >> >> In FUSE, as of now, uncached lookups are expensive over the wire. >> E.g additional latencies and stressing (meta data) servers from >> thousands of clients. These lookup calls possibly can be avoided >> in some cases. Incoming three patches address this issue. >> >> >> Fist patch handles the case where we are creating a file with O_CREAT. >> Before we go for file creation, we do a lookup on the file which is most >> likely non-existent. After this lookup is done, we again go into libfuse >> to create file. Such lookups where file is most likely non-existent, can >> be avoided. > > I'd really like to see a bit wider picture... > > We have several cases, first of all let's look at plain O_CREAT > without O_EXCL (assume that there were no changes since the last > lookup for simplicity): > > [not cached, negative] > ->atomic_open() > LOOKUP > CREATE >
[...]
> [not cached] > ->atomic_open() > OPEN_ATOMIC
new patch version is eventually going through xfstests (and it finds some issues), but I have a question about wording here. Why "OPEN_ATOMIC" and not "ATOMIC_OPEN". Based on your comment @Dharmendra renamed all functions and this fuse op "open atomic" instead of "atomic open" - for my non native English this sounds rather weird. At best it should be "open atomically"?
Thanks, Bernd
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