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
/*
Unix SMB/CIFS implementation.
kernel oplock processing for Linux
Copyright (C) Andrew Tridgell 2000
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#define DBGC_CLASS DBGC_LOCKING
#include <signal.h>
#include <errno.h>
#include <sys/fcntl.h>
#include <sys/select.h>
#include <stdio.h>
#include <string.h>
#include <time.h>
typedef unsigned int uint32;
/* these can be removed when they are in glibc headers */
struct cap_user_header {
uint32 version;
int pid;
} header;
struct cap_user_data {
uint32 effective;
uint32 permitted;
uint32 inheritable;
} data;
extern int capget(struct cap_user_header * hdrp,
struct cap_user_data * datap);
extern int capset(struct cap_user_header * hdrp,
const struct cap_user_data * datap);
#ifndef F_SETLEASE
#define F_SETLEASE 1024
#endif
#ifndef F_GETLEASE
#define F_GETLEASE 1025
#endif
#ifndef CAP_LEASE
#define CAP_LEASE 28
#endif
#ifndef RT_SIGNAL_LEASE
#define RT_SIGNAL_LEASE (SIGRTMIN+1)
#endif
#ifndef F_SETSIG
#define F_SETSIG 10
#endif
/****************************************************************************
Try to gain a linux capability.
****************************************************************************/
static void set_capability(unsigned capability)
{
#ifndef _LINUX_CAPABILITY_VERSION
#define _LINUX_CAPABILITY_VERSION 0x19980330
#endif
header.version = _LINUX_CAPABILITY_VERSION;
header.pid = 0;
if (capget(&header, &data) == -1) {
printf("Unable to get kernel capabilities (%s)\n", strerror(errno));
return;
}
data.effective |= (1<<capability);
if (capset(&header, &data) == -1) {
printf("Unable to set %d capability (%s)\n",
capability, strerror(errno));
}
}
/****************************************************************************
Call SETLEASE. If we get EACCES then we try setting up the right capability and
try again
****************************************************************************/
static int linux_setlease(int fd, int leasetype)
{
int ret;
if (fcntl(fd, F_SETSIG, RT_SIGNAL_LEASE) == -1) {
printf("Failed to set signal handler for kernel lease\n");
return -1;
}
ret = fcntl(fd, F_SETLEASE, leasetype);
if (ret == -1 && errno == EACCES) {
set_capability(CAP_LEASE);
ret = fcntl(fd, F_SETLEASE, leasetype);
}
return ret;
}
int main(int argc, char **argv)
{
int fd;
fd = open("oplocktest.c", O_RDONLY);
linux_setlease(fd, 1);
struct timespec ts;
ts.tv_sec = 50;
ts.tv_nsec = 0;
nanosleep(&ts, NULL);
return(0);
}
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