[newnfs/client] SIGINFO aborts transfer and produces `permission denied'

[Anonymous]

Let's populate /blah with 50Mb files and send SIGINFO to cp(1) process while
copying it over nfsv3.

# uname -vm
FreeBSD 8.0-BETA1 #0: Sat Jul 4 03:55:14 UTC 2009
root at almeida.cse.buffalo.edu:/usr/obj/usr/src/sys/GENERIC i386

# mkdir /blah
# truncate -s50m /blah/foo_1
# truncate -s50m /blah/foo_2
# truncate -s50m /blah/foo_3

# echo /usr >/etc/exports
# /etc/rc.d/nfsd onestart
# mount -t newnfs -o nfsv3 0:/blah /mnt

# cp -R /mnt /aaa
[type ^T several times]
load: 0.81  cmd: cp 2305 [runnable] 1.86r 0.00u 0.62s 9% 1304k
/mnt/foo_1 -> /aaa/foo_1  25%
load: 0.90  cmd: cp 2305 [runnable] 2.43r 0.00u 0.80s 9% 1304k
/mnt/foo_1 -> /aaa/foo_1  32%
load: 0.90  cmd: cp 2305 [runnable] 2.59r 0.00u 0.85s 19% 1304k
/mnt/foo_1 -> /aaa/foo_1  34%
load: 0.90  cmd: cp 2305 [runnable] 2.76r 0.01u 0.89s 19% 1304k
/mnt/foo_1 -> /aaa/foo_1  36%
load: 0.90  cmd: cp 2305 [runnable] 2.96r 0.02u 0.94s 19% 1304k
/mnt/foo_1 -> /aaa/foo_1  39%
load: 0.90  cmd: cp 2305 [runnable] 3.14r 0.02u 1.00s 19% 1304k
/mnt/foo_1 -> /aaa/foo_1  41%
load: 0.90  cmd: cp 2305 [newnfsreq] 3.30r 0.02u 1.05s 19% 1304k
load: 0.90  cmd: cp 2305 [runnable] 3.47r 0.02u 1.08s 19% 1304k
load: 0.90  cmd: cp 2305 [runnable] 3.62r 0.02u 1.11s 19% 1304k
load: 0.90  cmd: cp 2305 [runnable] 3.81r 0.02u 1.14s 19% 1304k
load: 0.90  cmd: cp 2305 [runnable] 3.98r 0.02u 1.17s 19% 1304k
load: 0.90  cmd: cp 2305 [runnable] 4.29r 0.02u 1.22s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 4.84r 0.02u 1.35s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 5.19r 0.02u 1.49s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 5.52r 0.02u 1.63s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 6.12r 0.02u 1.88s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 6.52r 0.02u 2.05s 19% 1304k
load: 1.23  cmd: cp 2305 [runnable] 6.89r 0.02u 2.19s 19% 1304k
load: 1.69  cmd: cp 2305 [runnable] 7.40r 0.02u 2.40s 29% 1304k
load: 1.69  cmd: cp 2305 [runnable] 7.76r 0.02u 2.55s 29% 1304k
load: 1.69  cmd: cp 2305 [runnable] 8.11r 0.02u 2.70s 29% 1304k
cp: /mnt/foo_1: Permission denied
cp: /mnt/foo_2: Permission denied
cp: /mnt/foo_3: Permission denied

This one should be slightly harder to reproduce. And depending on timing
between each ^T keypress error message can differ, e.g. `Bad address' or
`Input/output error'. Of course not all files end up in /aaa

    # ls -l /aaa
    total 32912
    -rw-r--r--  1 root  wheel  33685504 Jul 16 20:26 foo_1
(this file is from different attempt, not that was aborted around 41%)

It affects both foreground and background processes. So, to abort copying
one can also try running

    # pkill -INFO cp

several times. I haven't found any other signal that affect copying
(tried SIGURG, SIGCONT, SIGCHLD, SIGIO, SIGWINCH).

Known? Or am I the only one having a bad habit typing ^T too often?