On 1/25/16, Jan Kara <jack@xxxxxxx> wrote: > On Sat 23-01-16 09:42:52, Jeff Merkey wrote: >> If I leave the system in the debugger console overnight with all the >> processors suspended for about 8 hours, then type go, the following >> bug shows up during file I/O. This particular bug showed up while >> using git to update some branches. >> >> I have only seen this bug once and I attempted to reproduce it to get >> a trace dump but have not been able to trigger it again. The NULL >> pointer is RDI set to NULL while trying to obtain a lock. >> >> (2)> .z grab_journal >> ffffffffa00bb740 t jbd2_journal_grab_journal_head [jbd2] >> (2)> u ffffffffa00bb740 >> jbd2|jbd2_journal_grab_journal_head: >> 0xffffffffa00bb740 0F1F440000 nop DWORD PTR [rax+rax]=0x0 >> 0xffffffffa00bb745 55 push rbp >> 0xffffffffa00bb746 4889E5 mov rbp,rsp >> <<<<<<<<<<<< Crashes here with RDI set to NULL >> 0xffffffffa00bb749 F00FBA2F18 lock bts DWORD PTR [rdi]=0x0,0x18 >> <<<<<<<<<<<< > > Thanks for report. Ok, this means jbd2_journal_grab_journal_head() got > called with 'bh == NULL'. That is certainly wrong but unless we know a full > stack trace, it's hard to guess what went wrong. > > Honza > > -- > Jan Kara <jack@xxxxxxxx> > SUSE Labs, CR > I have a system setup to get a better trace if it triggers again. When it happened the first time I was not able to get a good dump. If it triggers again, I'll send you the trace. So far it has not triggered. :-) Jeff -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
