Comments on: Lessfs-1.0.5 is available for download.

By: Pete

Pete — Mon, 15 Mar 2010 20:29:32 +0000

Alright! I can’t wait for the fix!

By the way, kudos on lessfs. Even with this bug, I am still happy with it.

By: Pete

Pete — Mon, 15 Mar 2010 20:27:16 +0000

FYI – I copied the same files into a non-lessfs share via Samba and the issue did not happen (ls -s reported a non-zero block count). So this does appear to be a Windows -> Samba -> Lessfs issue.

By: Mark

Mark — Mon, 15 Mar 2010 20:25:29 +0000

I have been able to reproduce it.
You need to copy the data from a windows system to samba->lessfs

root@jupiter:/mnt# du . -s -h
1.4G .
root@jupiter:/mnt# du .
359394 ./test2
0 ./test3
1381240 .
root@jupiter:/mnt# cd test3
root@jupiter:/mnt/test3# du . -s -h
0 .

Directory test2 contains the same files as test3
Hmm…. Files that take no space at all.

It’s official, we have found a bug.

Mark.

By: Pete

Pete — Mon, 15 Mar 2010 20:18:56 +0000

Mark,
I only tested copying files from the wonderful Windows XP OS. I do believe that Windows is a key player in this.

By: Mark

Mark — Mon, 15 Mar 2010 19:50:33 +0000

Hi Pete,

I tried to reproduce the problem with a very simple smb.conf configuration.

[global]
workgroup = MYGROUP
server string = Samba Server Version %v
interfaces = eth0
security = SHARE
auth methods = guest
passdb backend = tdbsam
hosts allow = 127.0.0.1
cups options = raw

[fusedata]
comment = videodata
path = /fuse
force user = samba
read only = No
guest ok = Yes

After starting samba I mounted the samba share:
mount -t cifs //127.0.0.1/fusedata /mnt

Copying and moving data to /mnt works without problems as well as ‘du’.
Can you confirm that you need to use the wonderful windows OS to reproduce the problem?

Thanks in advance,

Mark

By: Pete

Pete — Mon, 15 Mar 2010 19:49:06 +0000

Mark,
AIO is neither explicitly enabled nor disabled in my smb.conf.

By: Mark

Mark — Mon, 15 Mar 2010 19:22:39 +0000

Hi Pete,

Thanks for testing this.
I will setup samba and test lessfs with full debugging. It probably has to do with lessfs not updating the filesize on every write. Do you have aio enabled in smb.conf?

By: Pete

Pete — Mon, 15 Mar 2010 17:28:29 +0000

Mark, I just discovered some more information about the problem. The problem is apparent when using the “ls -s” command too, which displays the file’s size by the number of blocks. That results in a zero block size for each file that is either copied or moved into a samba/lessfs file share.

If I move the file within lessfs, the problem remains. But if I move the file outside of the lessfs folder, the problem is permanently fixed, even if I move it back into the lessfs folder, the problem never recurs. Somehow, it’s the number of blocks that’s not being set. That must be the corrupt or missing attribute.

Pete

By: Pete

Pete — Mon, 15 Mar 2010 12:24:15 +0000

Mark, I agree. When I do move operations from within a Linux environment, it all works. My guess is that it’s a Lessfs/Samba issue as well. All of the affected files were moved (cut/paste) into the deduped share that was served up through Samba. If you can’t reproduce it, let me know. I might be able to make a live-cd environment where the error is reproducible in for you.

By: Mark

Mark — Sun, 14 Mar 2010 13:30:10 +0000

When I do move operations from a local filesystem to lessfs it all works.
Are the file sizes correct when you look at them with : stat?

It looks like this is a lessfs/samba related issue.

Can you do some basic tests with and without samba?