On Fri, Jun 16, 2017 at 08:35:10PM +0200, Luis R. Rodriguez wrote: > On Fri, Jun 16, 2017 at 12:54:45PM +0200, Carlos Maiolino wrote: > > When a buffer has been failed during writeback, the inode items into it > > are kept flush locked, and are never resubmitted due the flush lock, so, > > if any buffer fails to be written, the items in AIL are never written to > > disk and never unlocked. > > > > This causes unmount operation to hang due these items flush locked in AIL, > > What type of hang? If it has occurred in production is there a trace somewhere? > what does it look like? > > You said you would work on an xfstest for this, how's that going? Otherewise > a commit log description of how to reproduce would be useful. I'm curious for an xfstest too, but I think Carlos /did/ tell us how to reproduce -- create a thinp device, format XFS, fill it up, and try to unmount. I don't think there /is/ much of a trace, just xfsaild doing nothing and a bunch of ail items that are flush locked and stuck that way. > > but this also causes the items in AIL to never be written back, even when > > the IO device comes back to normal. > > > > I've been testing this patch with a DM-thin device, creating a > > filesystem larger than the real device. > > > > When writing enough data to fill the DM-thin device, XFS receives ENOSPC > > errors from the device, and keep spinning on xfsaild (when 'retry > > forever' configuration is set). > > > > At this point, the filesystem can not be unmounted because of the flush locked > > items in AIL, but worse, the items in AIL are never retried at all > > (once xfs_inode_item_push() will skip the items that are flush locked), > > even if the underlying DM-thin device is expanded to the proper size. > > Jeesh. > > If the above issue is a real hang, shoudl we not consider a sensible stable fix > to start off with ? Huh? I thought this series is supposed to be the fix. --D > > Luis > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
