On Fri, Apr 15, 2016 at 09:28:49AM -0600, Chris Murphy wrote: > Note this is a testing VM, no user data is at risk > > https://bugzilla.kernel.org/show_bug.cgi?id=116331 >From the call stack we can tell that btrfs_root_bytenr() returns 0 somehow. And this comes from btrfs_recover_relocation() reading the root on which reloc_root is snapshoted, and it's not the FS tree, might be a snapshot root or subvolume root. Looks like our COW fails for that root. Thanks, -liubo > > Gist is this is a new Btrfs file system, and while -o recovery,ro > permits mount, it can't be repaired, and btrfs-image fails also. A > normal mount results in a call trace, which is what the subject is set > to, and the bug contains the complete dmesg for that. > > File system starts as: > openSUSE-Tumbleweed-GNOME-Live-x86_64-Snapshot20160307-Media.iso > Creation time btrfs-progs 4.4.1, kernel 4.4.3. > > Very light usage for several weeks, but includes scrubs and balance > with no errors. Today, while using YaST2 to remove packages, there was > a complete system hang. After 30 minutes I force quit the VM. > Subsequent boots fail. > > I then moved to booting Fedora 24 (prerelease) for troubleshooting, to > use kernel 4.5.0 and progs 4.5.1. > > mount fails/crashes, with trace > mount -o recovery fails/crashes, with trace > mount -o recovery,ro works (!) and I can dig up the journals from the > YaST2 hang which includes some Btrfs csum errors, I think during the > hang. > > btrfs-image fails > btrfs-debug-tree mostly works, the bug report contains a URL for that file > > btrfs check --repair finds but doesn't fix the problem, > --init-extent-tree crashes > > So it's pretty messy fixing wise. But so far -o recovery,ro is letting > me extract important things like the journal. > > -- > Chris Murphy > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" 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-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
