On Tue, Aug 09, 2016 at 02:26:14PM -0400, Chris Mason wrote: > On 08/09/2016 02:23 PM, Hugo Mills wrote: > > Hi, Chris, > > > >On Tue, Aug 09, 2016 at 02:02:20PM -0400, Chris Mason wrote: > >>On 08/09/2016 01:27 PM, Hugo Mills wrote: > >>> Over the weekend, I started doing some maintenance on my server: I > >>>upgraded to 4.7.0, and I started deleting a device from my array, > >>>preparatory to putting in a larger one. About halfway through the > >>>operation, several kernel threads hung up for a while (resulting in > >>>"blocked for 120s" messages), and then the delete process seems to > >>>have stopped entirely, although several kernel threads are at maximum > >>>usage. > >>> > >>> After a few hours, I rebooted the machine, and left it for a day or > >>>so. I tried the delete again this afternoon, and it's done the same > >>>thing again. The full log is included below. I have a kworker and a > >>>btrfs-transaction pegged at close to 100% of a core each, and a > >>>btrfs-cleaner (and the btrfs dev del process) in D state. > >>> > >>> The FS was not under load at the time of the failure, and it passes > >>>scrub. I haven't tried a btrfs check yet. > >> > >>Thanks Hugo, can you nail down which line of code belongs to: > >> > >>btrfs_async_run_delayed_refs+0xc6 > > > > I'm having a spot of trouble with this. The btrfs on this kernel is > >built-in, and I've lost the contents of the build directory (it's done > >by an overnight build script, and it's already built a 4.8-rc1 for one > >of my other machines). > > > >(gdb) file /boot/vmlinuz-4.7.0-dirty > >BFD: /boot/vmlinuz-4.7.0-dirty: Warning: Ignoring section flag IMAGE_SCN_MEM_NOT_PAGED in section .bss > >Reading symbols from /boot/vmlinuz-4.7.0-dirty...(no debugging symbols found)...done. > >(gdb) list *btrfs_async_run_delayed_refs+0xc6 > >No symbol table is loaded. Use the "file" command. > > > > There must be a way of getting this info from here, but I'm not > >sure I know what it is. Build a new kernel from 4.7 with this > >machine's config and run gdb on the btrfs.o file? Not a problem to do, > >but it might take a little while. > > As long as you use the same gcc and config file, it'll almost always > generate the same offsets/code. You can recompile with debug > symbols on and it'll be accurate. OK. Back later. Hugo. -- Hugo Mills | Jazz is the sort of music where no-one plays hugo@... carfax.org.uk | anything the same way once. http://carfax.org.uk/ | PGP: E2AB1DE4 |
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