Re: btrfs_destroy_inode warn (outstanding extents)

[Dave Jones]

On Wed, Nov 23, 2016 at 02:58:45PM -0500, Dave Jones wrote:
 > On Wed, Nov 23, 2016 at 02:34:19PM -0500, Dave Jones wrote:
 > 
 >  > [  317.689216] BUG: Bad page state in process kworker/u8:8  pfn:4d8fd4
 >  > trace from just before this happened. Does this shed any light ?
 >  > 
 >  > https://codemonkey.org.uk/junk/trace.txt
 > 
 > crap, I just noticed the timestamps in the trace come from quite a bit
 > later.  I'll tweak the code to do the taint checking/ftrace stop after
 > every syscall, that should narrow the window some more.
 > 
 > Getting closer..

Ok, this is getting more like it.
http://codemonkey.org.uk/junk/btrfs-destroy-inode-outstanding-extents.txt

Also same bug, different run, but a different traceview http://codemonkey.org.uk/junk/btrfs-destroy-inode-outstanding-extents-function-graph.txt

(function-graph screws up the RIP for some reason, 'return_to_handler'
 should actually be btrfs_destroy_inode)


Anyways, I've got some code that works pretty well for dumping the
ftrace buffer now when things go awry.  I just need to run it enough
times that I hit that bad page state instead of this, or a lockdep bug first.

	Dave