[fuse-devel] FW: Problem with concurrent ls calls to a basic fuse device

[Pielage, F. <fio...@go...>]

A colleague of mine is experiencing the following problem use fuse.
Can anyone advise?

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From: Clark, Steven L=20
Sent: 15 June 2006 12:22
To: Pielage, Fiona
Subject: Problem with concurrent ls calls to a basic fuse device


Hi there,
=20
I've encountered a problem when trying to do some concurrency testing of
a FUSE device I've been working on. The test in question creates two
threads and performs a set of ls calls to the device for several
iterations checking the results each time.
=20
Most of the time the test seems to work fine, but from time to time the
test just hangs, and worse than that ends up hanging the entire box,
forcing a reboot. Initially I was concerned that the problem was within
my own code so I inserted lots of trace messages to see which of my
methods the hang was occurring in. I was surprised to discover that the
hang  occurs completely outside my code, which implies that it is
occurring somewhere in the FUSE code.
=20
What I'm seeing with the trace is that the hang occurs directly after a
call to getattr has finished. Running the device in debug mode shows
that the getattr has completed successfully, but it then doesn't go on
to call either opendir or readdir, and at this point the hang could
occur before either of those calls.
=20
If I run the device in single threaded mode I can't reproduce the
problem at all which suggests that this is a multithreading issue.
=20
My only concern is over the version of compiler we are using for our
development code. The linux kernel (SUSE SLES 9 SP2) is compiled using
gcc 3.3.3 as is the FUSE library. Our developed code is compiled using
gcc 3.4.5. Could this cause a problem? If so could someone please
explain what that problem is?
=20
Thanks in advance for your time,
=20
Steve Clark
ste...@go...