Stratis 3.0.0 Release Notes

mulhern, Stratis Team

Stratis 3.0.0 includes many internal improvements, bug fixes, and user-visible changes.

Users of the Stratis CLI may observe the following changes:

• It is now possible to set the filesystem logical size when creating a filesystem.
• It is possible to rebind a pool using a Clevis tang server or with a key in the kernel keyring.
• Filesystem and pool list output have been extended and improved. The pool listing includes an Alerts column. Currently this column is used to indicate whether the pool is in a restricted operation mode. A new subcommand, stratis pool explain, which provides a fuller explanation of the codes displayed in the Alerts column has been added. The filesystem listing now displays a filesystem's logical size.
• With encrypted pools it was previously possible for the display of block device paths to change format if stratisd was restarted after an encrypted pool had been created. Now the display of the block device paths is consistent across stratisd restarts.

In stratisd 3.0.0 the D-Bus API has undergone a revision and the prior interfaces are all removed. The FetchProperties interfaces that were supported by all objects have been removed. The values that were previously obtainable via the FetchProperties methods are now conventional D-Bus properties. The possible values of error codes returned by the D-Bus methods have been reduced to 0 and 1, with the usual interpretation.

stratisd 3.0.0 includes a number of significant internal improvements and a few bug fixes.

stratisd bug fixes:

• Previously the Stratis release included a dracut.conf.d file which made the Stratis dracut modules required in the initramfs. The consequence of this was that the initramfs could not be built unless all files required for the Stratis modules were present; if the initramfs is not built a reboot will fail. That file has been removed in this release.
• The --prompt option was not passed to stratis-min in the stratis-fstab-setup script; this prevented the user from entering the password necessary to unlock an encrypted pool during boot. This is no longer the case.
• Previously, stratisd did not increase the amount of space allocated to its spare metadata device when its in-use thinpool metadata device was extended. In some situations, when setting up a pool, stratisd might attempt a repair operation on the thinpool metadata device; if the space allocated for the spare metadata device was not large enough to accommodate all the metadata, then the repair operation would fail. Now the space allocated for the spare metadata device is increased whenever the metadata device is extended.
• stratisd was not immediately updating the devicemapper device stack when a cache was initialized with the result that the cache was not immediately put in use. This is no longer the case.
• stratisd was not immediately updating the Clevis encryption info associated with a pool on a command to bind an encrypted pool with Clevis. This problem has been corrected.
• stratisd was sending an incorrect D-Bus signal on a pool name change; this has been fixed.
• Previously, when stratisd-min, which runs during boot before D-Bus functionality is available, gave way to stratisd when the D-Bus had been set up, it was possible for inconsistencies to arise if the Stratis engine was performing an operation which required invoking a distinct executable. The executable might be terminated during its execution, and stratisd-min would take the action appropriate to the command failure before exiting. Now, systemd is instructed to send a kill signal only to stratisd-min and not to any of stratisd-min's child processes when shutting down stratisd-min.
• Previously, if the same device was specified using two different paths when creating or extending a pool the different paths would be interpreted as two different devices and an error would be returned when stratisd attempted to initialize the device a second time. Now, the different paths are canonicalized eagerly, and converted into a single canonical representation of the device, stratisd initializes the device only once, and no error is returned.
• Previously, stratisd did not report all existing object paths in the result of a D-Bus Introspect() call. This was due to a bug in version 0.9.1 and previous of stratisd's dbus-tree dependency. stratisd now requires dbus-tree 0.9.2, so all nodes are reported.

Other stratisd improvements:

• Previously, stratisd relied entirely on udev information when deciding whether a storage device was not in use by another application and could safely be overwritten with Stratis metadata. Now it performs a supplementary check using libblkid and exits with an error if libblkid reports that the device is in use.
• Handling of errors returned by internal methods is improved; a chaining mechanism has been introduced and the error chains can be scrutinized programatically to identify expected scenarios like rollback failures.
• A set of states indicating that a pool has reduced capability have been added internally and are published on the D-Bus. A pool's capability is reduced on an error being returned internally which contains, somewhere in its chain, the appropriate identifying error variant.
• The code used to roll back failed encryption operations on a list of pool devices has been refactored and generalized. It is now capable of returning an error that can be used to identify a restricted pool capability due to a rollback failure.
• stratisd uses sha-256 instead of sha-1 for Clevis-related encryption operations to conform with Clevis's own usage.
• stratisd exits more elegantly and less frequently if it encounters an error during execution of the distinct tasks that are assigned to the individual threads that it manages internally.
• In preparation for edition 2021 of the Rust language, stratisd source code has been updated to conform entirely to edition 2018 recommendations.

NOTE: stratisd depends directly on the chrono crate against which RUSTSEC-2020-0159 has been filed. We have demonstrated that stratisd is not affected by this CVE by building and testing stratisd against a clone of the chrono crate from which all the code affected by the CVE has been removed, proving that stratisd has no dependency on that code.

Please consult the stratisd and stratis-cli changelogs for additional information about the 3.0.0 release.

We would like to thank mvollmer for contributions to this release.