On Thu, 1 Jun 2023 at 13:17, Bernd Schubert <bschubert@xxxxxxx> wrote: > > Hi Miklos, > > On 5/19/22 11:39, Miklos Szeredi wrote: > > On Tue, 17 May 2022 at 12:08, Dharmendra Singh <dharamhans87@xxxxxxxxx> 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"? FUSE_OPEN_ATOMIC is a specialization of FUSE_OPEN. Does that explain my thinking? Thanks, Miklos
