From e1e5e5641e6f271321aec257ed26a72715e4a8c2 Mon Sep 17 00:00:00 2001 From: Keith Busch Date: Thu, 19 Feb 2015 13:39:03 -0700 Subject: NVMe: Metadata format support Adds support for NVMe metadata formats and exposes block devices for all namespaces regardless of their format. Namespace formats that are unusable will have disk capacity set to 0, but a handle to the block device is created to simplify device management. A namespace is not usable when the format requires host interleave block and metadata in single buffer, has no provisioned storage, or has better data but failed to register with blk integrity. The namespace has to be scanned in two phases to support separate metadata formats. The first establishes the sector size and capacity prior to invoking add_disk. If metadata is required, the capacity will be temporarilly set to 0 until it can be revalidated and registered with the integrity extenstions after add_disk completes. The driver relies on the integrity extensions to provide the metadata buffer. NVMe requires this be a single physically contiguous region, so only one integrity segment is allowed per command. If the metadata is used for T10 PI, the driver provides mappings to save and restore the reftag physical block translation. The driver provides no-op functions for generate and verify if metadata is not used for protection information. This way the setup is always provided by the block layer. If a request does not supply a required metadata buffer, the command is failed with bad address. This could only happen if a user manually disables verify/generate on such a disk. The only exception to where this is okay is if the controller is capable of stripping/generating the metadata, which is possible on some types of formats. The metadata scatter gather list now occupies the spot in the nvme_iod that used to be used to link retryable IOD's, but we don't do that anymore, so the field was unused. Signed-off-by: Keith Busch --- include/linux/nvme.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include/linux/nvme.h') diff --git a/include/linux/nvme.h b/include/linux/nvme.h index 19a5d4b23209..cca264db2478 100644 --- a/include/linux/nvme.h +++ b/include/linux/nvme.h @@ -121,6 +121,7 @@ struct nvme_ns { unsigned ns_id; int lba_shift; int ms; + int pi_type; u64 mode_select_num_blocks; u32 mode_select_block_len; }; @@ -138,6 +139,7 @@ struct nvme_iod { int nents; /* Used in scatterlist */ int length; /* Of data, in bytes */ dma_addr_t first_dma; + struct scatterlist meta_sg[1]; /* metadata requires single contiguous buffer */ struct scatterlist sg[0]; }; -- cgit v1.2.3