Bug#799838: linux-image-3.16.0-4-amd64: NFS rename sometimes hangs for 15 seconds

[Vincent Lefevre <vincent@vinc17.net>]

Here are the traces done at my lab. I recall the test between
hosts A and B (see the prompt):

A% echo foo > file1
A% cp file1 file2
B% cat file2
A% time mv file1 file2

Test 1:
  A = Debian 8 - debian-8_20.pcap (15s delay between the 2 RENAME)
  B = Debian 7 - debian-7_20.pcap

Test 2:
  A = Debian 7 - debian-7_22.pcap (~ 0.1s delay between the 2 RENAME)
  B = Debian 8 - debian-8_22.pcap

In both cases, there is a NFS4ERR_DELAY and the RENAME is retried,
but on Debian 8, it is retried only after 15 seconds.

Note: If the test is done in a directory that has just been created,
there is never any delay.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)

Attachment: debian-8_20.pcap
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Attachment: debian-7_20.pcap
Description: Binary data

Attachment: debian-7_22.pcap
Description: Binary data

Attachment: debian-8_22.pcap
Description: Binary data