Deprecation

ABI and API Deprecation

This document details the policy for maintaining stability of SPDK ABI and API.

Major ABI version can change at most once for each SPDK release. ABI versions are managed separately for each library and follow Semantic Versioning.

API and ABI deprecation notices shall be posted in the next section. Each entry must describe what will be removed and can suggest the future use or alternative. Specific future SPDK release for the removal must be provided. ABI cannot be removed without providing deprecation notice for at least single SPDK release.

Deprecated code paths must be registered with SPDK_LOG_DEPRECATION_REGISTER() and logged with SPDK_LOG_DEPRECATED(). The tag used with these macros will appear in the SPDK log at the warn level when SPDK_LOG_DEPRECATED() is called, subject to rate limits. The tags can be matched with the level 4 headers below.

Deprecation Notices

bdev

bdev_get_iostat

--name option will be removed in the 26.05 release. --names option should be used instead, it allows providing array of devices names to obtain statistics from.

spdk_bdev_initialize, spdk_bdev_finish, spdk_bdev_unregister, spdk_bdev_unregister_by_name

Calling these functions from any thread is deprecated and will be disallowed in v26.05. These functions should be called from the SPDK app thread.

gpt

old_gpt_guid

Deprecated the SPDK partition type GUID 7c5222bd-8f5d-4087-9c00-bf9843c7b58c. Partitions of this type have bdevs created that are one block less than the actual size of the partition. Existing partitions using the deprecated GUID can continue to use that GUID; support for the deprecated GUID will remain in SPDK indefinitely, and will continue to exhibit the off-by-one bug so that on-disk metadata layouts based on the incorrect size are not affected.

See GitHub issue 2801 for additional details on the bug.

New SPDK partition types should use GUID 6527994e-2c5a-4eec-9613-8f5944074e8b which will create a bdev of the correct size.

nvme

nvme_spec.h

spdk_nvme_ctrlr_data, spdk_nvme_cdata_oacs

LPA, OACS, CMIC bits are updated to NVMe 2.2 definitions. The old bit names will be removed in 26.05 release.

spdk_nvme_ns_data

NMIC, RESCAP, FPI and NSATTR bits are updated to NVMe 2.2 definitions. The old bit names will be removed in 26.05 release.

nvmf

disable_compare

vfio_user transport specific option is deprecated and will be removed in v26.05. Use masked_oncs option on nvmf_create_transport RPC, or oncs on spdk_nvmf_transport_opts C API instead.

nvmf_transport.h

spdk_nvmf_ctrlr_connect

spdk_nvmf_ctrlr_connect() is deprecated and will be removed in 26.05 release.

app/spdk_nvme_perf

perf_g_option

The -G command line option is deprecated and will be removed in the v26.05 release. Use --log-level debug -T nvme instead.