Bug #1676
closedtmpfs fsstress panic
0%
Description
tmpfs panic-ed on an fsstress run fairly quickly; the tmpfs volume was limited 
to 256MB, the VM had 512MB of RAM and 512MB of swap. I was unable to grab 
coredumps, since there is no dump device configured yet.
I'm somewhat confused by the backtrace; tmpfs_nrename doesn't take more than 1 
argument and it never directly calls lockmgr; vn_lock does...
Panic: 
Fatal trap 12: page fault while in kernel mode
fault virtual address    = 0x6c
fault code        = supervisor read, page not present
instruction pointer    = 0x8:0xc0312fd5
stack pointer        = 0x10:0xcca55b3c
frame pointer        = 0x10:0xcca55b4c
code segment        = base 0x0, limit 0xfffff, type 0x1b
            = DPL 0, pres 1, def32 1, gran 1
processor eflags    = interrupt enabled, IOPL = 0
current process        = 882 (fsstress)
current thread        = pri 6
kernel: type 12 trap, code=0
Stopped at    lockmgr+0x8b:    movl 0x4(%ebx),%ecx
db> where
lockmgr(68,6,cca55b78,c0378bfb,c9ef2ba0) at lockmgr+0x8b
tmpfs_nrename(cca55bc0,cca55bb4,c9e2a2b4,c9e2a2b4,c1756d70) at tmpfs_rename+0x9
vop_nrename(c1753e30,cca55c80,cca55c48,ccad7ce8,ccad9c28) at vop_nrename+0x55
kern_rename(cca55c80,cca55c48,ccaaecd8,c9e2a098,c15c63f8) at kern_rename+0x273
sys_rename(cca55cf0,6,f4cb,0,c9e2cd98) at sys_rename+0x45
syscall2(cca55d40) at syscall2+0x20e
Xint0x80_syscall() at Xint0x80_syscall+0x36
db>
       Updated by dillon over 15 years ago
      Updated by dillon over 15 years ago
      
    
    :New submission from Venkatesh Srinivas <me@acm.jhu.edu>:
:
:tmpfs panic-ed on an fsstress run fairly quickly; the tmpfs volume was limited 
:to 256MB, the VM had 512MB of RAM and 512MB of swap. I was unable to grab 
:coredumps, since there is no dump device configured yet.
:
:I'm somewhat confused by the backtrace; tmpfs_nrename doesn't take more than 1 
:argument and it never directly calls lockmgr; vn_lock does...
We're gonna start needing kernel dumps to really track these down.
    If you send me a private email with your ssh public key and prefered
    username I will set up a leaf.dragonflybsd.org shell account for
    you that you can upload cores into.-Matt
       Updated by vsrinivas over 15 years ago
      Updated by vsrinivas over 15 years ago
      
    
    I repeated this on another VM, with 768MB of RAM and 2GB of swap. This time, I 
was able to get a coredump.
       Updated by dillon over 15 years ago
      Updated by dillon over 15 years ago
      
    
    :Venkatesh Srinivas <me@acm.jhu.edu> added the comment:
:
:I repeated this on another VM, with 768MB of RAM and 2GB of swap. This time, I 
:was able to get a coredump.
:
:http://endeavour.zapto.org/dfly/tmpfs_panic.20100218/
This was a bug in the tmpfs_rename() code which I fixed late yesterday.-Matt