On 2018/11/2 上午4:40, Attila Vangel wrote: > Hi, > > Somehow my btrfs partition got broken. I use Arch, so my kernel is > quite new (4.18.x). > I don't remember exactly the sequence of events. At some point it was > accessible in read-only, but unfortunately I did not take backup > immediately. dmesg log from that time: > > [ 62.602388] BTRFS warning (device nvme0n1p2): block group > 103923318784 has wrong amount of free space > [ 62.602390] BTRFS warning (device nvme0n1p2): failed to load free > space cache for block group 103923318784, rebuilding it now > [ 108.039188] BTRFS error (device nvme0n1p2): bad tree block start 0 > 18812026880 > [ 108.039227] BTRFS: error (device nvme0n1p2) in > __btrfs_free_extent:7010: errno=-5 IO failure
Normally we shouldn't call __btrfs_free_extent() during mount. It looks like it's caused by log tree replay. You could try to mount the fs with -o ro,nologreplay to see if you could still mount the fs RO without log replay. If it goes well, at least you could access the files. > [ 108.039241] BTRFS info (device nvme0n1p2): forced readonly > [ 108.039250] BTRFS: error (device nvme0n1p2) in > btrfs_run_delayed_refs:3076: errno=-5 IO failure > > At the next reboot it failed to mount. Problem may have been that at > some point I booted to another distro with older kernel (4.15.x, > 4.14.52) and unfortunately attempted some checks/repairs (?) e.g. from > gparted, and at that time I did not know it could be destructive.> > Anyway, currently it fails to mount (even with ro and/or recovery), > btrfs check results in "checksum verify failed" and "bad tree block" > errors, Full btrfs check result please. > btrfs restore resulted in "We have looped trying to restore > files in" errors for a dozen of paths then exit. So at least btrfs-restore is working. This normally means the fs is not completely corrupted, and essential trees are at least OK. Still need that "btrfs check" output (along with "btrfs check --mode=lowmem") to determine what to do. Thanks, Qu > > Is there some hope to save data from the filesystem, and if so, how? > > BTW I checked some diagnostics commands regarding my SSD with the nvme > client and from that it seems there are no hardware problems. > > Your help is highly appreciated. > > Cheers, > Attila >
signature.asc
Description: OpenPGP digital signature
