Messages in this thread | | | Date | Sun, 5 May 2013 11:23:18 +0200 | From | Ingo Molnar <> | Subject | Re: [PATCH 1/2] freezer: add unsafe versions of freezable helpers |
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* Colin Cross <ccross@android.com> wrote:
> NFS calls the freezable helpers with locks held, which is unsafe > and caused lockdep warnings when 6aa9707 "lockdep: check that no > locks held at freeze time" was applied (reverted in dbf520a). > Add new *_unsafe versions of the helpers that will not run the > lockdep test when 6aa9707 is reapplied, and call them from NFS. > > Signed-off-by: Colin Cross <ccross@android.com> > --- > fs/nfs/inode.c | 2 +- > fs/nfs/nfs3proc.c | 2 +- > fs/nfs/nfs4proc.c | 4 ++-- > include/linux/freezer.h | 42 +++++++++++++++++++++++++++++++++++++++++- > net/sunrpc/sched.c | 2 +- > 5 files changed, 46 insertions(+), 6 deletions(-) > > diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c > index 1f94167..53cbee5 100644 > --- a/fs/nfs/inode.c > +++ b/fs/nfs/inode.c > @@ -79,7 +79,7 @@ int nfs_wait_bit_killable(void *word) > { > if (fatal_signal_pending(current)) > return -ERESTARTSYS; > - freezable_schedule(); > + freezable_schedule_unsafe();
I'd suggest naming such variants _unkillable() instead of _unsafe().
There's nothing inherently 'unsafe' about it: the user asked for a hard NFS mount and is getting it: with the side effect that it exposes the machine to network delays in a 'hard' way as well. Which means suspend may block indefinitely as well on network failure.
So it's two conflicting user requirements: 'hard NFS mount' and 'suspend now'. We pick the lesser evil, the requirement that is considered higher prio: the hard NFS mount in this case.
Thanks,
Ingo
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