linux-kernel - fctnl(F_SETSIG) no longer works in 2.6.17, does in 2.6.16.

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Date:	Thu, 27 Jul 2006 16:08:53 -0600
From:	Orion Poplawski <orion@...a.nwra.com>
To:	linux-kernel@...r.kernel.org
Subject:  fctnl(F_SETSIG) no longer works in 2.6.17, does in 2.6.16.

fctnl(F_SETSIG) no longer works in 2.6.17, does in 2.6.16.

The attached program (oplocktest.c) illustrates.  Compile and run with 
strace.  In another
shell do "echo >> oplockstest.c".  On 2.6.16 we get:

fcntl64(3, F_SETSIG, 0x23)              = 0
fcntl64(3, 0x400 /* F_??? */, 0x1)      = 0
nanosleep({50, 0}, 0)                   = ? ERESTART_RESTARTBLOCK (To be 
restarted)
--- SIGRT_3 (Real-time signal 1) @ 0 (0) ---
+++ killed by SIGRT_3 +++

on 2.6.17 we get:

fcntl64(3, F_SETSIG, 0x23)              = 0
fcntl64(3, 0x400 /* F_??? */, 0x1)      = 0
nanosleep({50, 0}, 0)                   = ? ERESTART_RESTARTBLOCK (To be 
restarted)
--- SIGIO (I/O possible) @ 0 (0) ---
+++ killed by SIGIO +++

The signal is no longer changed from SIGIO to SIGRT_3.

This causes problems with samba and kernel oplocks.  Windows clients get 
the dreaded "Delayed Write Failed" message when smbd dies with SIGIO.

-- 
Orion Poplawski
System Administrator                   303-415-9701 x222
Colorado Research Associates/NWRA      FAX: 303-415-9702
3380 Mitchell Lane, Boulder CO 80301   http://www.co-ra.com

View attachment "oplocktest.c" of type "text/x-csrc" (3181 bytes)