Re: ffs_truncate3 panics

From: Rick Macklem <rmacklem_at_uoguelph.ca> Date: Fri, 10 Aug 2018 12:08:33 +0000 · This archive was generated by hypermail 2.4.0 : Wed May 19 2021 - 11:41:17 UTC

Konstantin Belousov wrote:
>On Thu, Aug 09, 2018 at 08:38:50PM +0000, Rick Macklem wrote:
>> I did notice that my code locks the vnode first and then calls vn_start_write()
>>  for the vn_extattr_set() calls, whereas the syscall code locks the vnode after the vn_start_write() call.
>>
>> Does that matter?
>
>Yes, it matter.  It would cause deadlocks when corresponding filesystem
>is suspended in parallel with NFSD activities.  vn_start_write() is a lock,
>and the correct lock order is vn_start_write()->vnode lock.
Ok, thanks, I'll work on a patch to fix this LOR.

rick