Re: [f2fs-dev] Fwd: fsck.f2fs fails with "can't find valid checkpoint"

[Jaegeuk K. <ja...@ke...>]

On 07/04, Jaegeuk Kim wrote:
> + f2fs mailing list
> 
> ---------- Forwarded message ----------
> From: Marcelo "Marc" Ranolfi <mar...@gm...>
> Date: 2017-07-04 18:52 GMT-07:00
> Subject: Fwd: fsck.f2fs fails with "can't find valid checkpoint"
> To: Jaegeuk Kim <jae...@gm...>
> 
> 
> 
> ---------- Forwarded message ----------
> From: Marcelo "Marc" Ranolfi <mar...@gm...>
> Date: Tue, Jul 4, 2017 at 3:54 PM
> Subject: fsck.f2fs fails with "can't find valid checkpoint"
> To: lin...@li...
> 
> 
> (reposting because yesterday's email didn't work)
> 
> Gentlemen,
> 
> I was using F2FS in my system when it crashed, and since then, I can't boot
> it, nor mount the root partition, and fsck doesn't help. I'm typing this
> from a live CD.
> 
> The system is Arch Linux with the 4.12-rc7 kernel (I was compiling the
> stable kernel when it crashed). I posted about it here (
> https://unix.stackexchange.com/questions/375114/f2fs-lost-d
> ata-wont-mount-and-fsck-doesnt-work) but that probably won't help much.
> The gist of the story is that I'm trying these commands, from the arch iso
> image:
> 
> cryptsetup open /dev/sda3 csystem

So, you did encrypt the disk, and then got sudden power-off.

> fsck.f2fs -f /dev/mapper/csystem

After then, fsck.f2fs can't find checkpoint, which means your encrypted disk is
severely damaged. Once such the encrypted disk has been crashed, it's very
difficult to recover there-in files from filesystem level, since checkpoint in
f2fs is not recoverable. Because, we don't expect two checkpoint copies were
crashed at the same time.

How's your fsck.f2fs -d 3 result? And, can you share your image? If it's not
easy to recover checkpoint manually, I think it needs to write a tool to scan
whole disk to find recoverable files. But, it'll take time.

Thanks,

> 
> and instead of repairing, it reports:
> 
> [f2fs_do_mount:2018] Can't find valid checkpoint
> 
> The documentation available in the Kernel tree (
> https://github.com/torvalds/linux/blob/master/Documentation
> /filesystems/f2fs.txt) says under fsck.f2fs:
> "Note that, initial version of the tool does not fix any inconsistency."
> 
> However that's not mentioned in the following sources:
> https://www.mankier.com/8/fsck.f2fs
> https://lkml.org/lkml/2014/9/20/104
> 
> I suppose the Kernel doc is outdated, since from inspecting the fsck source
> code, I think it should work.
> 
> 
> So, I'd like to know whether I'm facing a bug in the tool, or if something
> specific to my case is preventing the tool to work. And of course, I'm
> really in need of having my files back.
> 
> I'm a programmer so please let me know if I can be of any help, if need be.
> 
> 
> Yours faithfully
> Marcelo "Marc" Ranolfi