On 17 Jun, Alfred Perlstein wrote: > * Don Lewis <[EMAIL PROTECTED]> [030617 13:06] wrote: >> On 17 Jun, Alfred Perlstein wrote: >> > * Don Lewis <[EMAIL PROTECTED]> [030617 12:00] wrote: >> >> It's not legal to attempt to aquire Giant in fdrop_locked(), while >> >> FILE_LOCK() is held. The problem is that FILE_LOCK uses the mutex pool, >> >> which should only be used for leaf mutexes. >> >> >> >> It also looks like there is a potential for a lock order reversal if >> >> some callers aquire Giant before FILE_LOCK() and fdrop_locked() does the >> >> opposite. >> >> >> >> It also appears that witness ignores the mutex pool ... >> > >> > Yes, but I think the fix is as simple as just dropping the FILE_LOCK >> > after the decrement as we're the last holders of it, can you try >> > this: >> >> I like simple fixes, especially when the code shrinks ;-) >> >> Unfortunately, I think your point about this only happening because this >> process is the last holder of the file means that this doesn't explain >> Peter's deadlock. > > You can still deadlock because another file's mutex may hash to the same > location.
... or some other user of the mutex pool that happens to hold Giant. I'm in favor of committing your patch, though I think it should be commented to indicate why it is safe to play with fp after the mutex has been unlocked. _______________________________________________ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "[EMAIL PROTECTED]"
