LOR: sys/kern/sys_generic.c:902 sys/fs/specfs/spec_vnops.c:387

[Jon Noack]

Putinas Piliponis wrote:
> Hi, with todays kernel I got this:
> Sorry if it was already reported...
> what about the web page for lor status?
>
> lock order reversal
>  1st 0xc657c838 filedesc structure (filedesc structure) @
> /usr/src/sys/kern/sys_generic.c:902
>  2nd 0xc072d060 Giant (Giant) @ /usr/src/sys/fs/specfs/spec_vnops.c:387
> Stack backtrace:
> backtrace(c06bebd7,c072d060,c06ba893,c06ba893,c06b5ac3) at backtrace+0x17
> witness_checkorder(c072d060,9,c06b5ac3,183,c06b8216) at
> witness_checkorder+0x707
> _mtx_lock_flags(c072d060,0,c06b5ac3,183,c06bf1e1) at _mtx_lock_flags+0x9b
> spec_poll(e7219afc,e7219b1c,c0580726,e7219afc,c07225c0) at spec_poll+0x14a
> spec_vnoperate(e7219afc,c07225c0,c64c9e38,40,c2274600) at
> spec_vnoperate+0x18
> vn_poll(c64a4bb0,40,c2274600,c64b2690,c2274600) at vn_poll+0x3c
> selscan(c64b2690,e7219b9c,e7219b8c,4,4) at selscan+0x11e
> kern_select(c64b2690,4,bfbfe4d0,0,0) at kern_select+0x368
> select(c64b2690,e7219d14,14,434,5) at select+0x67
> syscall(2f,2f,2f,ffffffff,0) at syscall+0x271
> Xint0x80_syscall() at Xint0x80_syscall+0x1d
> --- syscall (93), eip = 0x282d8e23, esp = 0xbfbfe47c, ebp = 0xbfbfe588 ---

I got this same one today.  Seems like this one even has a PR:
http://www.freebsd.org/cgi/query-pr.cgi?pr=kern/55175

Like I said, I'm not going to put any work into the web page until I find
someone to commit a pointer to it when you get a lock order reversal. 
Otherwise, the page is of limited value (we will still get peppered with
questions on the list).

Jon