On Wed, Nov 16 2016 at 4:53pm -0500, Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > On 11/16/2016 01:11 PM, Mike Snitzer wrote: > >On Wed, Nov 16 2016 at 3:14pm -0500, > >Bart Van Assche <bart.vanassche@xxxxxxxxxxx> wrote: > >>After having added WARN_ON_ONCE(sq_count == 0 && mq_count == 0) > >>close to the end of dm_table_determine_type() the following output > >>appeared: > >> > >>WARNING: CPU: 0 PID: 2458 at drivers/md/dm-table.c:966 > >>dm_table_complete+0x60e/0x6b0 [dm_mod] > >>[ ... ] > >>Call Trace: > >> [<ffffffff81329b45>] dump_stack+0x68/0x93 > >> [<ffffffff810650e6>] __warn+0xc6/0xe0 > >> [<ffffffff810651b8>] warn_slowpath_null+0x18/0x20 > >> [<ffffffffa0021c8e>] dm_table_complete+0x60e/0x6b0 [dm_mod] > >> [<ffffffffa00245cd>] table_load+0x13d/0x330 [dm_mod] > >> [<ffffffffa0024490>] ? retrieve_status+0x1b0/0x1b0 [dm_mod] > >> [<ffffffffa0025145>] ctl_ioctl+0x1f5/0x520 [dm_mod] > >> [<ffffffffa002547e>] dm_ctl_ioctl+0xe/0x20 [dm_mod] > >> [<ffffffff811f26cf>] do_vfs_ioctl+0x8f/0x6b0 > >> [<ffffffff811ff41c>] ? __fget+0x10c/0x200 > >> [<ffffffff811ff310>] ? expand_files+0x2a0/0x2a0 > >> [<ffffffff811f2d2c>] SyS_ioctl+0x3c/0x70 > >> [<ffffffff8163f9aa>] entry_SYSCALL_64_fastpath+0x18/0xad > >> > >>Is it intentional that dm_table_determine_type() can get called for > >>a dm device with an empty table? > > > >What table were you trying to load when this occurred? > > > >Targets like the 'error' target don't have any devices. > > Hello Mike, > > This was the result of a table load issued by multipathd. Do you > want me to add more debug code such that the details of the table > load request are logged? No, I think it's fine. You likely have 'queue_if_no_path' configured and multipathd is loading a 'multipath' table that doesn't have any paths. -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
