1) on server lock file X
2) on client lock file X
blocks
3) on client send interrupt to process doing locking
locking syscall restarted, continues blocking
4) on server release lock on file X
on client lock is acquired
5) on client release lock on file X
6) on client lock file X
blocks
Everything up to the last step is fine, but something goes wrong
during the final unlock. Stopping the nfs-server removes the stray
lock.
Here's a trace on the server:
lockd: request from 192.168.1.1, port=862
lockd: LOCK called
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nsm_monitor(tucsk)
lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: found file 0ad074c0 (count 0)
lockd: nlmsvc_lock(ubda/96317, ty=1, pi=1, 0-99, bl=1)
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1
lockd: get host tucsk
lockd: created block 0aeabf80...
lockd: vfs_lock_file returned 1
lockd: nlmsvc_insert_block(0aeabf80, -1)
lockd: release host tucsk
lockd: nlmsvc_lock returned 50331648
lockd: LOCK status 3
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 2)
lockd: request from 192.168.1.1, port=862
lockd: CANCEL called
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: found file 0ad074c0 (count 1)
lockd: nlmsvc_cancel(ubda/96317, pi=1, 0-99)
lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1
lockd: check f=0ad074c0 pd=1 0-99 ty=1 cookie=36120000
lockd: unlinking block 0aeabf80...
lockd: freeing block 0aeabf80...
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 2)
lockd: CANCEL status 0
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 1)
lockd: closing file ubda/96317
lockd: request from 192.168.1.1, port=862
lockd: LOCK called
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nsm_monitor(tucsk)
lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: found file 0ad074c0 (count 0)
lockd: nlmsvc_lock(ubda/96317, ty=1, pi=2, 0-99, bl=1)
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nlmsvc_lookup_block f=0ad074c0 pd=2 0-99 ty=1
lockd: get host tucsk
lockd: created block 0aeab240...
lockd: vfs_lock_file returned 0
lockd: freeing block 0aeab240...
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 2)
lockd: release host tucsk
lockd: nlmsvc_lock returned 0
lockd: LOCK status 0
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 1)
lockd: request from 192.168.1.1, port=862
lockd: UNLOCK called
lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
lockd: get host tucsk
lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
lockd: found file 0ad074c0 (count 0)
lockd: nlmsvc_unlock(ubda/96317, pi=3, 0-9223372036854775807)
lockd: nlmsvc_cancel(ubda/96317, pi=3, 0-9223372036854775807)
lockd: nlmsvc_lookup_block f=0ad074c0 pd=3 0-9223372036854775807 ty=2
lockd: UNLOCK status 0
lockd: release host tucsk
lockd: nlm_release_file(0ad074c0, ct = 1)
Everything looks normal, yet...
This is 100% reproducable for me (ext3 exported over nfs, server and
client: 2.6-git).
Miklos
> We brought up this specific issue a few weeks ago in this thread:
>
> http://marc.info/?l=linux-nfs&m=120663578712912&w=2
>
> While we had a fix that tested out properly (third reply in the
> thread), I believe Trond fixed this recently in a more "correct"
> method with this patch (and series):
>
> http://marc.info/?l=linux-nfs&m=120726349027607&w=2
>
> We haven't had the opportunity to check Tronds' patch yet though.
Thanks for the info.
1) I pulled the devel branch of nfs-2.6.git and tested the same setup,
with exactly the same result as previously.
2) then I added your patch on top of that, which did change something
but not really for the better: now even the restarted lock request
doesn't succeed after the interrupt.
According to my suspicion, this is an issue in the server, while both
referenced patches touch only the client.
Appended little test program which I'm trying out locking with.
Miklos
---
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>
#include <signal.h>
static void int_handler(int s)
{
(void) s;
fprintf(stderr, "signal caught\n");
}
int main(int argc, char *argv[])
{
char *filename = argv[1];
int res;
int fd;
if (argc != 2) {
fprintf(stderr, "usage: %s filename\n", argv[0]);
return 1;
}
signal(SIGINT, int_handler);
fd = open(filename, O_RDWR | O_CREAT, 0666);
if (fd == -1) {
perror("open");
return 1;
}
res = lockf(fd, F_LOCK, 100);
if (res == -1) {
perror("lockf");
return 1;
}
printf("locked\n");
pause();
return 0;
}
We brought up this specific issue a few weeks ago in this thread:
http://marc.info/?l=linux-nfs&m=120663578712912&w=2
While we had a fix that tested out properly (third reply in the
thread), I believe Trond fixed this recently in a more "correct"
method with this patch (and series):
http://marc.info/?l=linux-nfs&m=120726349027607&w=2
We haven't had the opportunity to check Tronds' patch yet though.
-Aaron
On Thu, Apr 17, 2008 at 1:44 PM, Miklos Szeredi <[email protected]> wrote:
> 1) on server lock file X
> 2) on client lock file X
> blocks
> 3) on client send interrupt to process doing locking
> locking syscall restarted, continues blocking
> 4) on server release lock on file X
> on client lock is acquired
> 5) on client release lock on file X
> 6) on client lock file X
> blocks
>
> Everything up to the last step is fine, but something goes wrong
> during the final unlock. Stopping the nfs-server removes the stray
> lock.
>
> Here's a trace on the server:
>
> lockd: request from 192.168.1.1, port=862
> lockd: LOCK called
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nsm_monitor(tucsk)
> lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: found file 0ad074c0 (count 0)
> lockd: nlmsvc_lock(ubda/96317, ty=1, pi=1, 0-99, bl=1)
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1
> lockd: get host tucsk
> lockd: created block 0aeabf80...
> lockd: vfs_lock_file returned 1
> lockd: nlmsvc_insert_block(0aeabf80, -1)
> lockd: release host tucsk
> lockd: nlmsvc_lock returned 50331648
> lockd: LOCK status 3
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 2)
> lockd: request from 192.168.1.1, port=862
> lockd: CANCEL called
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: found file 0ad074c0 (count 1)
> lockd: nlmsvc_cancel(ubda/96317, pi=1, 0-99)
> lockd: nlmsvc_lookup_block f=0ad074c0 pd=1 0-99 ty=1
> lockd: check f=0ad074c0 pd=1 0-99 ty=1 cookie=36120000
> lockd: unlinking block 0aeabf80...
> lockd: freeing block 0aeabf80...
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 2)
> lockd: CANCEL status 0
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 1)
> lockd: closing file ubda/96317
> lockd: request from 192.168.1.1, port=862
> lockd: LOCK called
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nsm_monitor(tucsk)
> lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: creating file for (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: found file 0ad074c0 (count 0)
> lockd: nlmsvc_lock(ubda/96317, ty=1, pi=2, 0-99, bl=1)
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nlmsvc_lookup_block f=0ad074c0 pd=2 0-99 ty=1
> lockd: get host tucsk
> lockd: created block 0aeab240...
> lockd: vfs_lock_file returned 0
> lockd: freeing block 0aeab240...
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 2)
> lockd: release host tucsk
> lockd: nlmsvc_lock returned 0
> lockd: LOCK status 0
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 1)
> lockd: request from 192.168.1.1, port=862
> lockd: UNLOCK called
> lockd: nlm_lookup_host(192.168.1.2->192.168.1.1, p=6, v=4, my role=server, name=tucsk)
> lockd: get host tucsk
> lockd: nlm_lookup_file (02000001 00006200 00000002 0001783d 7f54ef79 00017801 d06c5915 00000000)
> lockd: found file 0ad074c0 (count 0)
> lockd: nlmsvc_unlock(ubda/96317, pi=3, 0-9223372036854775807)
> lockd: nlmsvc_cancel(ubda/96317, pi=3, 0-9223372036854775807)
> lockd: nlmsvc_lookup_block f=0ad074c0 pd=3 0-9223372036854775807 ty=2
> lockd: UNLOCK status 0
> lockd: release host tucsk
> lockd: nlm_release_file(0ad074c0, ct = 1)
>
>
> Everything looks normal, yet...
>
> This is 100% reproducable for me (ext3 exported over nfs, server and
> client: 2.6-git).
>
> Miklos
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