kernel-packages team mailing list archive

[Rocko <rockorequin@xxxxxxxxxxx>]

I think it is still useful for ecryptfs to support the btrfs clone ioctl
for the case where both source and target higher files are in the same
ecryptfs mount, since this saves disk space.

We might be able to handle this in
fs/ecryptfs/file.c#ecryptfs_unlocked_ioctl, which gets passed the btrfs
ioctrl clone command along with the the higher target file. It
unconditionally converts it to the lower file and then passes it down to
btrfs:

  struct file *lower_file = ecryptfs_file_to_lower(file);
   ...
  if (lower_file->f_op->unlocked_ioctl)
    rc = lower_file->f_op->unlocked_ioctl(lower_file, cmd, arg);

Adding code here that returns failure if the command is BTRFS_IOC_CLONE
makes the cp --reflink=always command fail. (cp --reflink=auto then
works because cp detects the failure and does a non-clone copy, and the
same should go for the glib file copy).

However, note that:

1. When it fails to clone, ecryptfs still creates a valid but zero-byte
file after the failed clone operation, so ecryptfs should probably
remove this when it returns fail for the clone operation.

2. It shouldn't fail if the source and target files are both inside the
same ecryptfs mount.

3. Do symlinks affect it, eg if the target is a symlink outside the
ecryptfs mount that points to the higher ecryptfs file?

4. ecryptfs_compat_ioctl might possibly be affected as well since it
does the same thing as ecryptfs_unlocked_ioctl.

-- 
You received this bug notification because you are a member of Kernel
Packages, which is subscribed to linux in Ubuntu.
https://bugs.launchpad.net/bugs/1305335

Title:
  Cutting or copying files on btrfs to ecryptfs results in data loss

Status in eCryptfs:
  Confirmed
Status in The Linux Kernel:
  Unknown
Status in linux package in Ubuntu:
  Confirmed
Status in nautilus package in Ubuntu:
  Invalid

Bug description:
  I've installed a fresh copy of 14.04 beta 2 on a brand-new SSD.  I
  used btrfs as the filesystem.

  I set up a Private folder usying ecryptfs-setup-private.

  I copied a few folders into the Private folder, and the entire
  directory structure and subfolders are copied, including the files
  themselves, yet every file contains 0 bytes.

  However, I can create and save new files in the Private directory.
  Also, folders and files can be correctly copied if I use the command line cp -R.

  Thanks,
  Damon

  ProblemType: Bug
  DistroRelease: Ubuntu 14.04
  Package: nautilus 1:3.10.1-0ubuntu8
  ProcVersionSignature: Ubuntu 3.13.0-23.45-generic 3.13.8
  Uname: Linux 3.13.0-23-generic x86_64
  ApportVersion: 2.14.1-0ubuntu1
  Architecture: amd64
  CurrentDesktop: Unity
  Date: Wed Apr  9 18:12:56 2014
  EcryptfsInUse: Yes
  GsettingsChanges: b'org.gnome.nautilus.list-view' b'default-column-order' b"['name', 'size', 'type', 'date_modified', 'date_accessed', 'owner', 'group', 'permissions', 'mime_type', 'where']"
  InstallationDate: Installed on 2014-04-05 (4 days ago)
  InstallationMedia: Ubuntu 14.04 LTS "Trusty Tahr" - Beta amd64 (20140326)
  ProcEnviron:
   LANGUAGE=en_CA:en
   PATH=(custom, no user)
   XDG_RUNTIME_DIR=<set>
   LANG=en_CA.UTF-8
   SHELL=/bin/bash
  SourcePackage: nautilus
  UpgradeStatus: No upgrade log present (probably fresh install)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ecryptfs/+bug/1305335/+subscriptions