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Date: Sat, 17 Jun 2017 14:08:14 +0200
From: Christoph Hellwig <hch@lst.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
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Subject: odd sysfs find behavior, was: Re: [PATCH v6 00/10] Implement NVMe
        Namespace Descriptor Identification
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On Fri, Jun 16, 2017 at 10:28:28PM +0900, Linus Torvalds wrote:
> Hmm. The *traditional* reason for this particular 'find' oddity is
> that find has an optimization which will look at the nlink count of a
> directory to decide how many subdirectories it can have.

It looks like sysfs maintains i_nlink properly as far as I can tell.
But I noticed another things that's even more weird:

root@testvm:~/nvmetcli# find /sys -name uuid
root@testvm:~/nvmetcli# find /sys -name uuid
/sys/devices/virtual/nvme-fabrics/ctl/nvme2/nvme2n1/uuid

so just repeating the find a second time makes it work!  Looks like
there is some sort of lazy population scheme in sysfs..