Hello! I guess this is some sort of 1.8 due to the init_waitq_head call. 2.1 code is notably different in this case after LU-234 landed, namely removing mcw_entry from the list on error. The patch originates from bug 18213 and claimed as 1.8 port to 2.1, but I don't see anything like this in the 1.8 patch.
Bye, Oleg On Aug 8, 2011, at 2:07 PM, Andreas Dilger wrote: > On 2011-08-08, at 10:03 AM, chas williams - CONTRACTOR wrote: >> we have seen a few crashes that look like: >> >> [250696.381575] RIP: 0010:[<ffffffffa0a1f9e4>] [<ffffffffa0a1f9e4>] >> mdc_exit_request+0x74/0xb0 [mdc] >> ... >> [250696.381575] Call Trace: >> [250696.381575] [<ffffffffa0a25042>] >> mdc_intent_getattr_async_interpret+0x82/0x500 [mdc] >> [250696.381575] [<ffffffffa089efd0>] ptlrpc_check_set+0x200/0x1690 [ptlrpc] >> [250696.381575] [<ffffffffa08d3140>] ptlrpcd_check+0x110/0x250 [ptlrpc] >> >> and i sort of gather the problem arises from mdc_enter_request(). >> it allocates an mdc_cache_waiter on the stack and inserts it into the >> wait list and then returns. >> >> int mdc_enter_request(struct client_obd *cli) >> ... >> struct mdc_cache_waiter mcw; >> ... >> list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters); >> init_waitqueue_head(&mcw.mcw_waitq); >> >> later mdc_exit_request() finds this mcw by iterating the list. >> seeing as mcw was allocated on the stack, i dont think you can do this. >> mcw might have been reused by the time mdc_exit_request() gets around >> to removing it. > > What version of Lustre is this? > > Cheers, Andreas > -- > Andreas Dilger > Principal Engineer > Whamcloud, Inc. > > > -- Oleg Drokin Senior Software Engineer Whamcloud, Inc. _______________________________________________ Lustre-discuss mailing list Lustre-discuss@lists.lustre.org http://lists.lustre.org/mailman/listinfo/lustre-discuss