[haiku-bugs] Re: [Haiku] #5262: PANIC: vnode 3:7895866 already exists (node = 0xe0044000, vnode->node = 0xe008bbf4)!

  • From: "mmlr" <trac@xxxxxxxxxxxx>
  • Date: Wed, 29 Jun 2011 10:58:51 -0000

#5262: PANIC: vnode 3:7895866 already exists (node = 0xe0044000, vnode->node =
   Reporter:  justeco           |      Owner:  axeld
       Type:  bug               |     Status:  new
   Priority:  critical          |  Milestone:  R1
  Component:  File Systems/BFS  |    Version:  R1/Development
 Resolution:                    |   Keywords:
 Blocked By:                    |   Blocking:
Has a Patch:  0                 |   Platform:  x86

Comment (by mmlr):

 Replying to [comment:7 ttcoder]:
 > As to 1), I'll file a proper ticket after confirming (or maybe update
 this ticket, not sure whether the symptoms warrant a new ticket or not),
 but I'm 99% sure of the following:
 > - if I use the deskbar's Shutdown/Power off menu item, Haiku shuts down
 without doing a BFS 'sync' (or whatever it is called), resulting in
 trouble at next cold start: at a minimum I get checkfs shouting about
 TrackerSettings, tracker_shelf ..etc (i.e. the kind of things that are
 written to disk when you shutdown) but most times I get dropped to KDL
 with the 'vnode PANIC', and it takes 2 "continue" to resume bootup.
 > - if I use "Restart System" and THEN press the off switch on the tower
 (at e.g. BIOS POST time) then at next boot Haiku is 100% good.

 As mentioned above this is likely related to the specific hardware. It
 sounds a lot like a disk write-cache that is not flushed and lost when the
 power turns off, while it still manages to fully flush when rebooting and
 then turning off a bit later in the BIOS screen. I'm not sure how this
 flush can be enforced, but I faintly remember seeing some SCSI/ATA flags
 that can be set to enforce write synchronization that could help here (and
 might even already be employed when doing a sync).

 Another thing that probably doesn't help in this case is that the sync
 operation that takes place on shutdown (the "Tidying things up a bit" part
 in the shutdown status window) is run at the very beginning, i.e. while
 all applications are still running. So apps that store their settings on
 quit (like Tracker) don't really get that into this sync. Unmounting the
 FS still triggers the syncing of course, it just makes it more likely that
 the sync happens "too late" in this case.

Ticket URL: <http://dev.haiku-os.org/ticket/5262#comment:11>
Haiku <http://dev.haiku-os.org>
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