On Mon, Nov 23, 2015 at 03:15:56PM +0100, Jan Kara wrote: > On Fri 20-11-15 14:03:44, Dave Chinner wrote: > > On Thu, Nov 19, 2015 at 04:18:13PM -0800, Dan Williams wrote: > > > WARNING: CPU: 0 PID: 2133 at fs/fs-writeback.c:2065 __mark_inode_dirty+0x261/0x350() > > > bdi-block not registered > > ^^^^^^^^^^^^^^^^^^^^^^^^ > > > [..] > > > Call Trace: > > > [<ffffffff81459f62>] dump_stack+0x44/0x62 > > > [<ffffffff810a2052>] warn_slowpath_common+0x82/0xc0 > > > [<ffffffff810a20ec>] warn_slowpath_fmt+0x5c/0x80 > > > [<ffffffff812831a1>] __mark_inode_dirty+0x261/0x350 > > > [<ffffffff8126d109>] generic_update_time+0x79/0xd0 > > > [<ffffffff8126d28d>] file_update_time+0xbd/0x110 > > > [<ffffffff812e4bc8>] ext4_dax_fault+0x68/0x110 > > > [<ffffffff811f816e>] __do_fault+0x4e/0xf0 > > > [<ffffffff811fc2a7>] handle_mm_fault+0x5e7/0x1b50 > > > [<ffffffff811fbd11>] ? handle_mm_fault+0x51/0x1b50 > > > [<ffffffff810689c1>] __do_page_fault+0x191/0x3f0 > > > [<ffffffff81068cef>] trace_do_page_fault+0x4f/0x120 > > > [<ffffffff8106314a>] do_async_page_fault+0x1a/0xa0 > > > [<ffffffff81902678>] async_page_fault+0x28/0x30 > > > > Doesn't this indicate some problem at the block/bdi level? > > __mark_inode_dirty() should not throw warnings like this regardless > > of where it is called from... > > The warning warns that we are dirtying inodes against a backing device that > advertises it does writeback but is not registered with writeback code (so > flusher does not run for it). That makes sense but people seem to be > experimenting a lot with removing devices under filesystems lately and so > this warning triggers. Probably we have to refine it to not trigger for > such cases... Or, alternatively, have the block devices inform the filesystem that it no longer has a valid bdi backing it. That way the filesystem can error out at a higher layer and we never get to the point of trying to mark an inode dirty when the backing device has been unplugged... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
