nvme: Deprecate spdk_nvme_ctrlr_prepare_for_reset()

Signed-off-by: Shuhei Matsumoto <smatsumoto@nvidia.com>
Change-Id: I3e5d1ef4816187b074dcf12ec4ec2dd42d880b65
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12709
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>

CHANGELOG.md

@@ -87,6 +87,11 @@ Added `msg_mempool_size` parameter to `spdk_reactors_init` and `spdk_thread_lib_
 The size of `g_spdk_msg_mempool` can now be controlled through the same-named
 user option of `spdk_app_opts` structure.
 
+### nvme
+
+The API `spdk_nvme_ctrlr_prepare_for_reset()` was deprecated. The functionality provided by the
+`spdk_nvme_ctrlr_prepare_for_reset()` was merged into the API `spdk_nvme_ctrlr_disconnect()`.
+
 ### nvmf
 
 Removed deprecated max_qpairs_per_ctrlr parameter from nvmf_create_transport RPC. Use

deprecation.md

@@ -13,3 +13,8 @@ Specific future SPDK release for the removal must be provided.
 ABI cannot be removed without providing deprecation notice for at least single SPDK release.
 
 ## Deprecation Notices {#deprecation-notices}
+
+### nvme
+
+Deprecated `spdk_nvme_ctrlr_prepare_for_reset` API, which will be removed in SPDK 22.01.
+For PCIe transport, `spdk_nvme_ctrlr_disconnect` should be used before freeing I/O qpairs.

include/spdk/nvme.h

@@ -1074,6 +1074,7 @@ int spdk_nvme_ctrlr_reset(struct spdk_nvme_ctrlr *ctrlr);
 
 /**
  * Inform the driver that the application is preparing to reset the specified NVMe controller.
+ * (Deprecated, please use spdk_nvme_ctrlr_disconnect() before freeing I/O qpairs instead.)
  *
  * This function allows the driver to make decisions knowing that a reset is about to happen.
  * For example, the pcie transport in this case could skip sending DELETE_CQ and DELETE_SQ