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Re: PUFFS ADVLOCK is too greedy
> Emmanuel Dreyfus <manu%netbsd.org@localhost> wrote:
>> Please consider the test case below, ran on a PUFFS/perfuse/glusterfs
>> mount. A look at the PUFFS operation trace shows that the kernel sends
>> ADVLOCK for f0, f1 and m when a lock is requested on m.
> Here is where the extra ADVLOCK happen:
> sys_exit -> exit1 -> fd_free -> fd_close -> VOP_ADVLOCK
> In a nutshell, NetBSD clears locks on all file descriptor when a process
> exit, that include read-only descriptors, and FUSE filesystems seem to
> be unconfortable with that.
> I am not sure of where this should be fixed: should we avoid unlocking
> read-only files in fd_close()? That seems a good idea performance-wise.
> Or is it a desirable behavior on native filesystems while being a bug
> for FUSE filesystems? In that case, it means I need to filter the
> operation in perfused.
it seems normal for native filesystems.
RDONLY is enough to set shared locks on the file.
i think it's safe to filter them using per vnode or puffs_node
PK_ADVLOCK-like "might have posix locks" hint.
> Emmanuel Dreyfus
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