drivers/nvme/target/io-cmd.c

   1 /*
   2  * NVMe I/O command implementation.
   3  * Copyright (c) 2015-2016 HGST, a Western Digital Company.
   4  *
   5  * This program is free software; you can redistribute it and/or modify it
   6  * under the terms and conditions of the GNU General Public License,
   7  * version 2, as published by the Free Software Foundation.
   8  *
   9  * This program is distributed in the hope it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  12  * more details.
  13  */
  14 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  15 #include <linux/blkdev.h>
  16 #include <linux/module.h>
  17 #include "nvmet.h"
  18
  19 static void nvmet_bio_done(struct bio *bio)
  20 {
  21         struct nvmet_req *req = bio->bi_private;
  22
  23         nvmet_req_complete(req,
  24                 bio->bi_error ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
  25
  26         if (bio != &req->inline_bio)
  27                 bio_put(bio);
  28 }
  29
  30 static inline u32 nvmet_rw_len(struct nvmet_req *req)
  31 {
  32         return ((u32)le16_to_cpu(req->cmd->rw.length) + 1) <<
  33                         req->ns->blksize_shift;
  34 }
  35
  36 static void nvmet_inline_bio_init(struct nvmet_req *req)
  37 {
  38         struct bio *bio = &req->inline_bio;
  39
  40         bio_init(bio, req->inline_bvec, NVMET_MAX_INLINE_BIOVEC);
  41 }
  42
  43 static void nvmet_execute_rw(struct nvmet_req *req)
  44 {
  45         int sg_cnt = req->sg_cnt;
  46         struct scatterlist *sg;
  47         struct bio *bio;
  48         sector_t sector;
  49         blk_qc_t cookie;
  50         int op, op_flags = 0, i;
  51
  52         if (!req->sg_cnt) {
  53                 nvmet_req_complete(req, 0);
  54                 return;
  55         }
  56
  57         if (req->cmd->rw.opcode == nvme_cmd_write) {
  58                 op = REQ_OP_WRITE;
  59                 op_flags = REQ_SYNC | REQ_IDLE;
  60                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  61                         op_flags |= REQ_FUA;
  62         } else {
  63                 op = REQ_OP_READ;
  64         }
  65
  66         sector = le64_to_cpu(req->cmd->rw.slba);
  67         sector <<= (req->ns->blksize_shift - 9);
  68
  69         nvmet_inline_bio_init(req);
  70         bio = &req->inline_bio;
  71         bio->bi_bdev = req->ns->bdev;
  72         bio->bi_iter.bi_sector = sector;
  73         bio->bi_private = req;
  74         bio->bi_end_io = nvmet_bio_done;
  75         bio_set_op_attrs(bio, op, op_flags);
  76
  77         for_each_sg(req->sg, sg, req->sg_cnt, i) {
  78                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
  79                                 != sg->length) {
  80                         struct bio *prev = bio;
  81
  82                         bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
  83                         bio->bi_bdev = req->ns->bdev;
  84                         bio->bi_iter.bi_sector = sector;
  85                         bio_set_op_attrs(bio, op, op_flags);
  86
  87                         bio_chain(bio, prev);
  88                         cookie = submit_bio(prev);
  89                 }
  90
  91                 sector += sg->length >> 9;
  92                 sg_cnt--;
  93         }
  94
  95         cookie = submit_bio(bio);
  96
  97         blk_mq_poll(bdev_get_queue(req->ns->bdev), cookie);
  98 }
  99
 100 static void nvmet_execute_flush(struct nvmet_req *req)
 101 {
 102         struct bio *bio;
 103
 104         nvmet_inline_bio_init(req);
 105         bio = &req->inline_bio;
 106
 107         bio->bi_bdev = req->ns->bdev;
 108         bio->bi_private = req;
 109         bio->bi_end_io = nvmet_bio_done;
 110         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 111
 112         submit_bio(bio);
 113 }
 114
 115 static u16 nvmet_discard_range(struct nvmet_ns *ns,
 116                 struct nvme_dsm_range *range, struct bio **bio)
 117 {
 118         if (__blkdev_issue_discard(ns->bdev,
 119                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 120                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 121                         GFP_KERNEL, 0, bio))
 122                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 123         return 0;
 124 }
 125
 126 static void nvmet_execute_discard(struct nvmet_req *req)
 127 {
 128         struct nvme_dsm_range range;
 129         struct bio *bio = NULL;
 130         int i;
 131         u16 status;
 132
 133         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 134                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 135                                 sizeof(range));
 136                 if (status)
 137                         break;
 138
 139                 status = nvmet_discard_range(req->ns, &range, &bio);
 140                 if (status)
 141                         break;
 142         }
 143
 144         if (bio) {
 145                 bio->bi_private = req;
 146                 bio->bi_end_io = nvmet_bio_done;
 147                 if (status) {
 148                         bio->bi_error = -EIO;
 149                         bio_endio(bio);
 150                 } else {
 151                         submit_bio(bio);
 152                 }
 153         } else {
 154                 nvmet_req_complete(req, status);
 155         }
 156 }
 157
 158 static void nvmet_execute_dsm(struct nvmet_req *req)
 159 {
 160         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 161         case NVME_DSMGMT_AD:
 162                 nvmet_execute_discard(req);
 163                 return;
 164         case NVME_DSMGMT_IDR:
 165         case NVME_DSMGMT_IDW:
 166         default:
 167                 /* Not supported yet */
 168                 nvmet_req_complete(req, 0);
 169                 return;
 170         }
 171 }
 172
 173 static void nvmet_execute_write_zeroes(struct nvmet_req *req)
 174 {
 175         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 176         struct bio *bio = NULL;
 177         u16 status = NVME_SC_SUCCESS;
 178         sector_t sector;
 179         sector_t nr_sector;
 180
 181         sector = le64_to_cpu(write_zeroes->slba) <<
 182                 (req->ns->blksize_shift - 9);
 183         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length)) <<
 184                 (req->ns->blksize_shift - 9)) + 1;
 185
 186         if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 187                                 GFP_KERNEL, &bio, true))
 188                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 189
 190         if (bio) {
 191                 bio->bi_private = req;
 192                 bio->bi_end_io = nvmet_bio_done;
 193                 submit_bio(bio);
 194         } else {
 195                 nvmet_req_complete(req, status);
 196         }
 197 }
 198
 199 int nvmet_parse_io_cmd(struct nvmet_req *req)
 200 {
 201         struct nvme_command *cmd = req->cmd;
 202
 203         if (unlikely(!(req->sq->ctrl->cc & NVME_CC_ENABLE))) {
 204                 pr_err("nvmet: got io cmd %d while CC.EN == 0\n",
 205                                 cmd->common.opcode);
 206                 req->ns = NULL;
 207                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
 208         }
 209
 210         if (unlikely(!(req->sq->ctrl->csts & NVME_CSTS_RDY))) {
 211                 pr_err("nvmet: got io cmd %d while CSTS.RDY == 0\n",
 212                                 cmd->common.opcode);
 213                 req->ns = NULL;
 214                 return NVME_SC_CMD_SEQ_ERROR | NVME_SC_DNR;
 215         }
 216
 217         req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
 218         if (!req->ns)
 219                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 220
 221         switch (cmd->common.opcode) {
 222         case nvme_cmd_read:
 223         case nvme_cmd_write:
 224                 req->execute = nvmet_execute_rw;
 225                 req->data_len = nvmet_rw_len(req);
 226                 return 0;
 227         case nvme_cmd_flush:
 228                 req->execute = nvmet_execute_flush;
 229                 req->data_len = 0;
 230                 return 0;
 231         case nvme_cmd_dsm:
 232                 req->execute = nvmet_execute_dsm;
 233                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 234                         sizeof(struct nvme_dsm_range);
 235                 return 0;
 236         case nvme_cmd_write_zeroes:
 237                 req->execute = nvmet_execute_write_zeroes;
 238                 return 0;
 239         default:
 240                 pr_err("nvmet: unhandled cmd %d\n", cmd->common.opcode);
 241                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 242         }
 243 }