FreeBSD: Implement xattr=sa #11997

ghost · 2021-05-04T17:25:05Z

Motivation and Context

Feature parity.

Description

Implement xattr=sa similarly to how it has been done for Linux.

I have split the changes into several commits to produce more readable diffs.

How Has This Been Tested?

ZTS, some manual testing of xattrs on a pool transferred between Linux and FreeBSD.

Types of changes

Bug fix (non-breaking change which fixes an issue)
New feature (non-breaking change which adds functionality)
Performance enhancement (non-breaking change which improves efficiency)
Code cleanup (non-breaking change which makes code smaller or more readable)
Breaking change (fix or feature that would cause existing functionality to change)
Library ABI change (libzfs, libzfs_core, libnvpair, libuutil and libzfsbootenv)
Documentation (a change to man pages or other documentation)

Checklist:

My code follows the OpenZFS code style requirements.
I have updated the documentation accordingly.
I have read the contributing document.
I have added tests to cover my changes.
I have run the ZFS Test Suite with this change applied.
All commit messages are properly formatted and contain Signed-off-by.

ghost · 2021-05-04T17:28:46Z

TODO:

Update documentation
Squash some of the commits
Write a decent commit message

amotin

The last iteration looks good to me.

ghost · 2021-05-06T17:15:11Z

Rebased
Added mention in zfsprops(8)
Squashed dependent commits
Added a commit message with some context

The kernel will use the xattr property by default when not overridden by a mount option. Signed-off-by: Ryan Moeller <ryan@iXsystems.com>

Signed-off-by: Ryan Moeller <ryan@iXsystems.com>

FreeBSD historically has not cared about the xattr property; it was always treated as xattr=on. With xattr=on, xattrs are stored as files in a hidden xattr directory. With xattr=sa, xattrs are stored as system attributes and get cached in nvlists during xattr operations. This makes SA xattrs simpler and more efficient to manipulate. FreeBSD needs to implement the SA xattr operations for feature parity with Linux and to ensure that SA xattrs are accessible when migrated or replicated from Linux. Following the example set by Linux, refactor our existing extattr vnops to split off the parts handling dir style xattrs, and add the corresponding SA handling parts. Signed-off-by: Ryan Moeller <ryan@iXsystems.com>

ghost · 2021-05-12T20:30:03Z

Rebased

behlendorf

It's great to see this implemented for FreeBSD! I'd just suggest going through the ZTS tests and making sure all of the tests which us xattr=sa are now enabled for FreeBSD. My recollection is we may have disabled some of these tests by moving them from the common.run file to the linux.run file or wrapping them with is_linux.

ghost · 2021-05-13T14:26:43Z

Somewhat amusingly, we've been running the tests that set xattr=sa on FreeBSD this whole time, they just haven't been respecting the property. During development I did confirm with debug messages that we are using the new SA code when appropriate now.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes #11997

FreeBSD historically has not cared about the xattr property; it was always treated as xattr=on. With xattr=on, xattrs are stored as files in a hidden xattr directory. With xattr=sa, xattrs are stored as system attributes and get cached in nvlists during xattr operations. This makes SA xattrs simpler and more efficient to manipulate. FreeBSD needs to implement the SA xattr operations for feature parity with Linux and to ensure that SA xattrs are accessible when migrated or replicated from Linux. Following the example set by Linux, refactor our existing extattr vnops to split off the parts handling dir style xattrs, and add the corresponding SA handling parts. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes #11997

The kernel will use the xattr property by default when not overridden by a mount option. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes openzfs#11997

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes openzfs#11997

FreeBSD historically has not cared about the xattr property; it was always treated as xattr=on. With xattr=on, xattrs are stored as files in a hidden xattr directory. With xattr=sa, xattrs are stored as system attributes and get cached in nvlists during xattr operations. This makes SA xattrs simpler and more efficient to manipulate. FreeBSD needs to implement the SA xattr operations for feature parity with Linux and to ensure that SA xattrs are accessible when migrated or replicated from Linux. Following the example set by Linux, refactor our existing extattr vnops to split off the parts handling dir style xattrs, and add the corresponding SA handling parts. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Reviewed-by: Alexander Motin <mav@FreeBSD.org> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes openzfs#11997