Re: Trying to mount hangs

[Pierre Abbat <phma@bezitopo.org>]

On Thursday, May 21, 2020 9:32:54 PM EDT Qu Wenruo wrote:
> Considering your btrfs check reports no serious problem, the hang looks
> strange.
> 
> The remaining possibility is the log tree.
> 
> You could try to boot using any liveCD with new enough kernel, then
> btrfs ins dump-super <device> | grep log_root

I can do that booted normally from the M.2. The output is
log_root                862339072
log_root_transid        0
log_root_level          0

> If the result is not 0, then try btrfs rescue zero-log, then try mount
> again.

You seem to be misunderstanding me. I'm not trying to fix the broken filesystem; 
I already recovered the files to a new drive. I'm trying to give you enough 
information to reproduce the hang in mount, so that you can fix the bug. If I 
have to copy the entire filesystem to an external drive and ship it, I'll do 
that, but I'm hoping that some smaller amount of data that I can upload in a 
few hours would be sufficient.

When I write a function that reads a file of a certain format, unless it's a 
static file like a list of all primes less than 65536 with associated data, I 
fuzz it so that, if it's given a file that's not exactly in that format, it 
won't hang or crash.

Pierre
-- 
li fi'u vu'u fi'u fi'u du li pa