quota deadlock on 6.1-RC1

[Dmitry Morozovsky]

On Sun, 7 May 2006, Dmitry Morozovsky wrote:

DM> KK> > Also, as an FYI, several quota-related snapshot fixes went into CVS in the 
DM> KK> > last 24-48 hours.  Once they've settled for a few weeks, and assuming they 
DM> KK> > don't have complex dependencies, they will get merged to RELENG_6. 
DM> KK> > Presumably if there is sufficient demand, and they adequately address the 
DM> KK> > reports of deadlocks with quotas+snapshots, they could be merged to 
DM> KK> > RELENG_6_1 as an errata update.
DM> KK> 
DM> KK> The fixes seem to indeed correct all the deadlocks I was seeing.  I
DM> KK> don't have time to produce a 6.x patch now though, but it should be a
DM> KK> simple matter for someone else to do.
DM> 
DM> FWIW, for me it is much stabler too, at least in normal load patterns.  I'll 
DM> spend a bit of time to stress-test this on our Samba quota-enabled server 
DM> during our long weekend (today-to-Tuesday) to catch possible rare races.

Alas, it is locked again:

root at office:~# ps axlww | grep snap
    0    32     0   0  -4  0     0     8 snaplk DL    ??    0:04.55 [bufdaemon]
    0    35     0   0  -4  0     0     8 snaplk DL    ??    0:01.11 [softdepflush]
    0 45080 45061   0  -4  0  5980  2768 snaplk D     ??    0:00.09 /usr/local/sbin/smbd -D
    0 46040 46039   0  -4  0  4492  3616 snaplk D+    p1    0:15.04 rsync -av /ar/winroot/distrib/ /st/winroot/tmp/distrib-temp/
 1002 46116   726   0  -4  0  1612  1144 snaplk D+    p3    0:00.00 ls -GF -la /st/.snap/

Unfortunately, this was with non-debug kernel. I'm trying to reproduce the lock 
with debug kernel right now, but still with no luck - sometimes machine is 
almost hangs but up to now revives 4 or 5 times.

Sincerely,
D.Marck                                     [DM5020, MCK-RIPE, DM3-RIPN]
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*** Dmitry Morozovsky --- D.Marck --- Wild Woozle --- marck at rinet.ru ***
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