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 -- 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
