TIP: Compressing portage using squashfs: initscript method

[mv]

If umount fails, squash_dir-10.6 will now sleep for 1s and retry (and repeat this procedure). Moreover, it attempts now to check whether the directory is already umounted and skip the umount if this is the case. I guess, in most cases this is the desired behavior although perhaps some strange error situations are not cought now.

[js08]

[aakef]

Are you sure 0.23 vs. 0.24/0.25 are linked against the very same libfuse? I assume the kernel is definitely the same? Are you able to create a test case for me? So I already know the unionfs-fuse command and now I know that ?it is not only the umount issue. But I still do not have the slightest idea, what is actually your problem. Saying that 0.23 works, but that 0.24/0.25 fail is not sufficient, I'm afraid.

1) How does it fail, what are the symptoms?

2) If it fails, can you check using 'ps ax | grep unionfs' if unionfs is still running?

3) Depending on 2)

a) If it is running, does it show in 'top' a high cpu usage?

b) If it is not running anymore, you should get

#define ENOTCONN 107 /* Transport endpoint is not connected */
bernd@bathl Ph.D>errno 108
#define ESHUTDOWN 108 /* Cannot send after transport endpoint shutdown */


on accessing the union path

4) What do I need to do to reproduce it?

4.1) If it is not easy to reproduce, are you willing to run debug commands yourself? So recompile it with debug symbols (-g) and -DDebug (using cmake that should be easy). And then runing it either in valgrind or gdb and provide me the output.


Thanks,
Bernd

[js08]

[mv]

[js08]

[js08]

[aakef]

Hmm, can't reproduce it

/dev/loop0 on /tmpa/gentoo/portage.ro type squashfs (rw)
unionfs on /tmpa/gentoo/portage type fuse.unionfs (rw,nosuid,nodev,allow_other,default_permissions)


/home/bernd/src/unionfs-fuse/unionfs/BUILD/src/unionfs -d -o cow -o allow_other -o use_ino -o nonempty -o hide_meta_dir /tmpa/gent/portage.rw=RW:/tmpa/gentoo/portage.ro=RO /tmpa/gentoo/portage

bathl:/tmpa/gentoo# /home/bernd/src/unionfs-fuse/unionfs/BUILD/src/unionfs --version
Debug mode, log will be written to ./unionfs_debug.log
unionfs-fuse version: 0.25
FUSE library version: 2.7.4
fusermount version: 2.7.4
using FUSE kernel interface version 7.8

bathl:~# rsync -a rsync://rsync.europe.gentoo.org/gentoo-portage /tmpa/gentoo/portage/

-========== B Y T E M A R K H O S T I N G M I R R O R ==========-

bathl:~# rsync -a rsync://rsync.europe.gentoo.org/gentoo-portage /tmpa/gentoo/portage/
Server name: tux.rainside.sk
IP address: 212.89.225.155
System: Intel(R) Pentium(R) D CPU 2.80GHz, 4GB RAM
Bandwidth: 1 Gbit/s
Server location: Bratislava, Slovakia
Contact: kominek@rainside.sk

Please note: common gentoo-netiquette says you should not sync
more than once a day. Users who abuse the rsync.gentoo.org
rotation may be added to a temporary ban list.


I think I need to update libfuse and to check what then happens.

[mv]

I think it is related with the way rsync accesses files - I suppose it keeps some filehandle open which collides with cow or something similiar. Here is a script for which rsync reports a nonexistent dir, although it exists. I tried the same without the squashfs, and the error did no occur. However, with aufs2 there is also no such error, so it is somewhat the interplay between squashfs, unionfs-fuse, and rsync which matters:

[js08]

[aakef]

Martin, thanks a bunch for your reproducer script. While running it in debug mode, I noticed a few new bugs in 0.25. I could only reproduce it with the script after I added this line

ln -s readonly/a/1 readonly/a/link_1

I think I will add the script to our regression test script.

So now the issue: http://podgorny.cz/~bernd/hg/hgwebdir.cgi/0.25/rev/fc2f284a0fff

I have not the slightest idea how that could ever work in 0.23, but this is a kernel (or glibc) bug and not unionfs related.

Please check out the recent 0.25alpha version and please report if it works or not.

Thanks,
Bernd

[js08]

Is it possible to upload/send you the output of ddd/gdb and the concerning console output?

I have created at least one which ends in an empty /usr/portage directory.

EDIT:
Since I didn't find an upload page here or on radek's website I uploaded the tar-file to uploaded.to

http://ul.to/7j52bl/unionfs-fuse.100525.out.tgz
_________________
Train Hard Or Don't Train At All

[aakef]

Thanks for the logs, I think you used Martins previously compiled version, right? The bug will be most probably gone, if you rebuild using the current hg-version (0.25 branch). For example here:

utimens /app-dicts/stardict-freedict-eng-swe 1274740792.000000000
1274738977.000000000
unique: 16404, error: -2 (No such file or directory), outsize: 16
unique: 16405, opcode: OPENDIR (27), nodeid: 4868, insize: 48

Definitely 'fixed' in 0.25-hg. As it is not a unionfs bug, but a kernel/glibc issue, I simply disabled the error for now. If the issue still exists, I would appreciate further debug logs. However, debugging must be enabled for the build, that way unionfs will provide lots of information what it does internally. Maybe it will be a good idea, if I simply also check for "-d" in unionfs (so far libfuse reads it) and enable debug information without the need to recompile...

Thanks,
Bernd

[js08]

[aakef]

Hi all,

just would like to ask if you have got a chance to try out the recent 0.25-hg version already?

Thanks,
Bernd

[mv]

[js08]

works fine.
_________________
Train Hard Or Don't Train At All

[aakef]

Great, thanks for testing it. Btw, the 'official' to hide the .unionfs directory is "-o hide_meta_files". The reason are .fuse... files, which are created, if an open file gets deleted. A ubuntu user who also works with squashfs run into those files and so we need to blacklist those as well. "-o hide_meta_dir" still works, but is deprecated.


Cheers,
Bernd

[mv]

[msalerno]

sys-fs/squash_dir-10.8
sys-fs/squashfs-tools-4.0
sys-fs/fuse-2.8.1
sys-fs/unionfs-fuse-0.24

I'm currently using these scripts to compress portage. I had no issue with the install, but the majority of the time when I do an emerge --sync or an eix-sync, I get lots of "failed: Too many open files (24)"

"rsync: mkstemp "/usr/portage/xfce-base/xfce4-meta/.Manifest.gr8fut" failed: Too many open files (24)"

"lsof -u root / | wc -l" currently shows >1700 open files. I have not messed with my limits.

[aakef]

Hmm, too many open files by rsync? That's a bit weird. When you get this, could you please check /proc/`pidof unionfs`/fd if there are open filedescriptors left over? If not, or if those reduce within a few seconds, then it is linux cache and the gentoo script will need to specify the option "-o max_files=number" (e.g number=16384").
But if those FDs stay, then it is bug in unionfs-fuse. If that is true, could you please tell me what kind of file those are (the links /proc/fs/fd will tell you).

Yesterday I also pushed an new debug patches into the 0.25alpha branch, if you would enable debugging with that "-o /tmp/debug_file", we could check why those files are not closed.


Thanks,
Bernd

[samonli]

sys-fs/squash_dir-10.8
sys-fs/squashfs-tools-4.0
sys-fs/fuse-2.8.1
sys-fs/unionfs-fuse-0.25-9999

/etc/conf.d/squash_portage:
DIRECTORY="/usr/portage"
DIR_CHANGE="${DIRECTORY}.changes"
DIR_SQUASH="${DIRECTORY}.readonly"
THRESHOLD=40000

/etc/init.d/squash_portage start:

[mv]

[samonli]

Sorry,my mistake,i miss the "" for ORDER in /etc/conf.d/squash_portage

Correct:
ORDER="unionfs-fuse unionfs funionfs aufs"

my:
ORDER=unionfs-fuse unionfs funionfs aufs

Thanks very much!

[msalerno]

Currently getting too many open files.

/proc/`pidof unionfs`/fd
ls -1 | wc -l
1024