On Wed, Nov 16 2016 at 3:14pm -0500, Bart Van Assche <bart.vanass...@sandisk.com> wrote:
> On 11/16/2016 06:54 AM, Mike Snitzer wrote: > >On Tue, Nov 15 2016 at 6:33pm -0500, > >Bart Van Assche <bart.vanass...@sandisk.com> wrote: > >>+/* > >>+ * Returns true if all paths are blk-mq devices. Returns false if all paths > >>+ * are single queue block devices or if there are no paths. > >>+ */ > > > >This code isn't specific to multipath. So "paths" is misplaced. > >"devices" is more appropriate. Not seeing the need for the comment to > >be honest. The function name is pretty descriptive. > > > >> bool dm_table_all_blk_mq_devices(struct dm_table *t) > >> { > >> return t->all_blk_mq; > > Hello Mike, > > 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. -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel