Messages in this thread | | | From | David Howells <> | Subject | Re: [PATCH 2/9] vfs: export do_splice_direct() to modules | Date | Tue, 19 Mar 2013 11:04:10 +0000 |
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Miklos Szeredi <miklos@szeredi.hu> wrote:
> > BTW, I wonder what's the right locking for that sucker; overlayfs is > > probably too heavy - we are talking about copying a file from one fs to > > another, which can obviously take quite a while, so holding ->i_mutex on > > _parent_ all along is asking for very serious contention. > > Copy up is a once-in-a-lifetime event for an object. Optimizing it is > way down in the list of things to do. I'd drop splice in a jiffy if > it's in the way.
Yes, but it could block the parent directory for a long time. I suspect it's fine if you can RCU walk through the parent, but if you have to grab a lock on it...
David
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