linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

[Marc MERLIN]

My laptop oopsed due to a wireless bug

When I rebooted, the system came back ok, and seemed to work, but soon went
to read only with the error in the subject line.

I have hourly snapshots for each of the 5 subvolumes in that btrfs
filesystem.

How do I recover from this? Revert all the snapshots one hour, find/guess
which one caused the problem somehow and revert just that one? (the error
message didn't give a subvolume or directory).

Also, before I do this, is there debug info I can get off my system?

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/  

Re: linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

[Marc MERLIN]

On Tue, Aug 14, 2012 at 11:23:14AM -0700, Marc MERLIN wrote:
> My laptop oopsed due to a wireless bug
> 
> When I rebooted, the system came back ok, and seemed to work, but soon went
> to read only with the error in the subject line.
> 
> I have hourly snapshots for each of the 5 subvolumes in that btrfs
> filesystem.
> 
> How do I recover from this? Revert all the snapshots one hour, find/guess
> which one caused the problem somehow and revert just that one? (the error
> message didn't give a subvolume or directory).
> 
> Also, before I do this, is there debug info I can get off my system?

I'm likely to have to do this tonight to get back to a working system.

If someone wants debug info before I lose it potentially, please ask soon ;)

Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/  

Re: linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

[Liu Bo]

On 08/15/2012 10:48 AM, Marc MERLIN wrote:
> On Tue, Aug 14, 2012 at 11:23:14AM -0700, Marc MERLIN wrote:
>> My laptop oopsed due to a wireless bug
>>
>> When I rebooted, the system came back ok, and seemed to work, but soon went
>> to read only with the error in the subject line.
>>
>> I have hourly snapshots for each of the 5 subvolumes in that btrfs
>> filesystem.
>>
>> How do I recover from this? Revert all the snapshots one hour, find/guess
>> which one caused the problem somehow and revert just that one? (the error
>> message didn't give a subvolume or directory).
>>
>> Also, before I do this, is there debug info I can get off my system?
> 
> I'm likely to have to do this tonight to get back to a working system.
> 
> If someone wants debug info before I lose it potentially, please ask soon ;)
> 
> Marc
> 

What does the 'ret' shows?  Is it -ENOSPC?

thanks,
liubo

Re: linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

[Marc MERLIN]

On Wed, Aug 15, 2012 at 11:02:31AM +0800, Liu Bo wrote:
> On 08/15/2012 10:48 AM, Marc MERLIN wrote:
> > On Tue, Aug 14, 2012 at 11:23:14AM -0700, Marc MERLIN wrote:
> >> My laptop oopsed due to a wireless bug
> >>
> >> When I rebooted, the system came back ok, and seemed to work, but soon went
> >> to read only with the error in the subject line.
> >>
> >> I have hourly snapshots for each of the 5 subvolumes in that btrfs
> >> filesystem.
> >>
> >> How do I recover from this? Revert all the snapshots one hour, find/guess
> >> which one caused the problem somehow and revert just that one? (the error
> >> message didn't give a subvolume or directory).
> >>
> >> Also, before I do this, is there debug info I can get off my system?
> > 
> > I'm likely to have to do this tonight to get back to a working system.
> > 
> > If someone wants debug info before I lose it potentially, please ask soon ;)
> 
> What does the 'ret' shows?  Is it -ENOSPC?

I got nothing else in my logs.

I powered the laptop back on and it came up like nothing ever happened.

[   15.626700] device label btrfs_pool1 devid 1 transid 10222 /dev/mapper/cryptroot
[   15.627161] btrfs: disk space caching is enabled
[   15.631704] btrfs: bdev /dev/mapper/cryptroot errs: wr 0, rd 0, flush 0, corrupt 0, gen 0

It looks like the SSD was loose inside the laptop (the tray that holds it isn't quite the
right size it seems).
I think it may not have had a good connection, but what's interesting is that I 
got absolutely no lower level errors in dmesg (which didn't get written to disk).

All that said, I think it may just have been a write error due to a hardware 
connection problem (no way to prove this now).
If there is nothing suspicious in the code around that line, let's just ignore 
my report.

For what it's worth, I do have plenty of space left:
Label: 'btrfs_pool1'  uuid: 92584fa9-85cd-4df6-b182-d32198b76a0b
	Total devices 1 FS bytes used 227.44GB
	devid    1 size 441.70GB used 297.04GB path /dev/dm-0

Thanks for your reply.
Marc
-- 
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
                                      .... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/  

Re: linux 3.5.0: BTRFS error in compress_file_range:581 (failed to join transaction)

[David Sterba]

On Tue, Aug 14, 2012 at 09:00:53PM -0700, Marc MERLIN wrote:
> > What does the 'ret' shows?  Is it -ENOSPC?
> 
> I got nothing else in my logs.

Unless it was a second error from a filesystem that went RO, there
should be more than the "Failed to join transaction" message, and the
first occurence of some transaction abort would spit some stacktrace as
well.

As you wrote in next paragraphs, it was probably a cable disconnection, so my
bet is on EIO, and the transaction abort did the right things, so

> I powered the laptop back on and it came up like nothing ever happened.

s/I/you/
.

(besides the few uncommitted changes)


david