[dm-crypt] Drive ran out of storage, now has space missing

[dm-crypt] Drive ran out of storage, now has space missing

[Nick Semenkovich]

A few days ago, a batch process I was running accidentally exhausted
100% of my partition's storage. One directory on this partition is
encrypted with dm-crypt.


After killing the process, I tried to free up some space by deleting
files from the encrypted directory. Strangely, after RM-ing ~4 GB of
files, I noticed that "df -h" showed that there wasn't any additional
free space.

df's "Used" column value was decreasing, but the "Avail" column wasn't
increasing.

When I RM-ed files outside of the encrypted directory (but on the same
partition), "df -h" behaved normally (with "Used" decreasing as
"Avail" increased).

dmesg had many messages of the type:
[  140.267890] ecryptfs_encrypt_page: Error attempting to write lower
page; rc = [-28]
[  140.267894] ecryptfs_write_end: Error encrypting page (upper index
[0x0000000000000000])

Those messages stopped appearing (after space was freed and I
rebooted), but now there are intermittent messages of the type:
[18819.518304] Valid eCryptfs headers not found in file header region
or xattr region
[18819.518311] Either the lower file is not in a valid eCryptfs
format, or the key could not be retrieved. Plaintext passthrough mode
is not enabled; returning -EIO


As of now, dm-crypt seems to be working fine, and all the encrypted
files (that i know of) are completely accessible.

However, the dmesg warning still appears intermittently (is there any
way to identify what file access is causing it?).

** More importantly, the ~4 GB of files (that I deleted during the
out-of-storage event), seems to have vanished from accessible storage:

$ df -h
...
/var/encrypted/.Private
                       74G   40G   30G  58% /var/encrypted
...


Any advice?

Best,
Nick

Re: [dm-crypt] Drive ran out of storage, now has space missing

[Arno Wagner]

On Sat, Aug 28, 2010 at 06:56:58PM -0500, Nick Semenkovich wrote:
> A few days ago, a batch process I was running accidentally exhausted
> 100% of my partition's storage. One directory on this partition is
> encrypted with dm-crypt.

Aem, dm-crypt does not support directory encryption. You
must have a dm-crypt'ed partition or file mounted on that 
directory.
 
> After killing the process, I tried to free up some space by deleting
> files from the encrypted directory. Strangely, after RM-ing ~4 GB of
> files, I noticed that "df -h" showed that there wasn't any additional
> free space.

See above. You deleted from the wrong partition.

> df's "Used" column value was decreasing, but the "Avail" column wasn't
> increasing.

Are you sure? That should not happen. Unless you read "used" for
the encrypted device and "avail" for the non-encrypted device.
 
> When I RM-ed files outside of the encrypted directory (but on the same
> partition), "df -h" behaved normally (with "Used" decreasing as
> "Avail" increased).

See above.

> dmesg had many messages of the type:
> [  140.267890] ecryptfs_encrypt_page: Error attempting to write lower
> page; rc = [-28]
> [  140.267894] ecryptfs_write_end: Error encrypting page (upper index
> [0x0000000000000000])

I have no idea what these mean, but they are likely unrelated
to your other issue.

Arno
-- 
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name 
GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25 338F
----
Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans

If it's in the news, don't worry about it.  The very definition of 
"news" is "something that hardly ever happens." -- Bruce Schneier 

Re: [dm-crypt] Drive ran out of storage, now has space missing

[Nick Semenkovich]

Whoops. I clearly meant ecryptfs, and apologize for the spam.

Best,
Nick