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_status ? 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_execute_rw(struct nvmet_req *req)
  37 {
  38         int sg_cnt = req->sg_cnt;
  39         struct bio *bio = &req->inline_bio;
  40         struct scatterlist *sg;
  41         sector_t sector;
  42         blk_qc_t cookie;
  43         int op, op_flags = 0, i;
  44
  45         if (!req->sg_cnt) {
  46                 nvmet_req_complete(req, 0);
  47                 return;
  48         }
  49
  50         if (req->cmd->rw.opcode == nvme_cmd_write) {
  51                 op = REQ_OP_WRITE;
  52                 op_flags = REQ_SYNC | REQ_IDLE;
  53                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  54                         op_flags |= REQ_FUA;
  55         } else {
  56                 op = REQ_OP_READ;
  57         }
  58
  59         sector = le64_to_cpu(req->cmd->rw.slba);
  60         sector <<= (req->ns->blksize_shift - 9);
  61
  62         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
  63         bio_set_dev(bio, req->ns->bdev);
  64         bio->bi_iter.bi_sector = sector;
  65         bio->bi_private = req;
  66         bio->bi_end_io = nvmet_bio_done;
  67         bio_set_op_attrs(bio, op, op_flags);
  68
  69         for_each_sg(req->sg, sg, req->sg_cnt, i) {
  70                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
  71                                 != sg->length) {
  72                         struct bio *prev = bio;
  73
  74                         bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
  75                         bio_set_dev(bio, req->ns->bdev);
  76                         bio->bi_iter.bi_sector = sector;
  77                         bio_set_op_attrs(bio, op, op_flags);
  78
  79                         bio_chain(bio, prev);
  80                         submit_bio(prev);
  81                 }
  82
  83                 sector += sg->length >> 9;
  84                 sg_cnt--;
  85         }
  86
  87         cookie = submit_bio(bio);
  88
  89         blk_poll(bdev_get_queue(req->ns->bdev), cookie);
  90 }
  91
  92 static void nvmet_execute_flush(struct nvmet_req *req)
  93 {
  94         struct bio *bio = &req->inline_bio;
  95
  96         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
  97         bio_set_dev(bio, req->ns->bdev);
  98         bio->bi_private = req;
  99         bio->bi_end_io = nvmet_bio_done;
 100         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 101
 102         submit_bio(bio);
 103 }
 104
 105 static u16 nvmet_discard_range(struct nvmet_ns *ns,
 106                 struct nvme_dsm_range *range, struct bio **bio)
 107 {
 108         int ret;
 109
 110         ret = __blkdev_issue_discard(ns->bdev,
 111                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 112                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 113                         GFP_KERNEL, 0, bio);
 114         if (ret && ret != -EOPNOTSUPP)
 115                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 116         return 0;
 117 }
 118
 119 static void nvmet_execute_discard(struct nvmet_req *req)
 120 {
 121         struct nvme_dsm_range range;
 122         struct bio *bio = NULL;
 123         int i;
 124         u16 status;
 125
 126         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 127                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 128                                 sizeof(range));
 129                 if (status)
 130                         break;
 131
 132                 status = nvmet_discard_range(req->ns, &range, &bio);
 133                 if (status)
 134                         break;
 135         }
 136
 137         if (bio) {
 138                 bio->bi_private = req;
 139                 bio->bi_end_io = nvmet_bio_done;
 140                 if (status) {
 141                         bio->bi_status = BLK_STS_IOERR;
 142                         bio_endio(bio);
 143                 } else {
 144                         submit_bio(bio);
 145                 }
 146         } else {
 147                 nvmet_req_complete(req, status);
 148         }
 149 }
 150
 151 static void nvmet_execute_dsm(struct nvmet_req *req)
 152 {
 153         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 154         case NVME_DSMGMT_AD:
 155                 nvmet_execute_discard(req);
 156                 return;
 157         case NVME_DSMGMT_IDR:
 158         case NVME_DSMGMT_IDW:
 159         default:
 160                 /* Not supported yet */
 161                 nvmet_req_complete(req, 0);
 162                 return;
 163         }
 164 }
 165
 166 static void nvmet_execute_write_zeroes(struct nvmet_req *req)
 167 {
 168         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 169         struct bio *bio = NULL;
 170         u16 status = NVME_SC_SUCCESS;
 171         sector_t sector;
 172         sector_t nr_sector;
 173
 174         sector = le64_to_cpu(write_zeroes->slba) <<
 175                 (req->ns->blksize_shift - 9);
 176         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length)) <<
 177                 (req->ns->blksize_shift - 9)) + 1;
 178
 179         if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 180                                 GFP_KERNEL, &bio, 0))
 181                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 182
 183         if (bio) {
 184                 bio->bi_private = req;
 185                 bio->bi_end_io = nvmet_bio_done;
 186                 submit_bio(bio);
 187         } else {
 188                 nvmet_req_complete(req, status);
 189         }
 190 }
 191
 192 u16 nvmet_parse_io_cmd(struct nvmet_req *req)
 193 {
 194         struct nvme_command *cmd = req->cmd;
 195         u16 ret;
 196
 197         ret = nvmet_check_ctrl_status(req, cmd);
 198         if (unlikely(ret)) {
 199                 req->ns = NULL;
 200                 return ret;
 201         }
 202
 203         req->ns = nvmet_find_namespace(req->sq->ctrl, cmd->rw.nsid);
 204         if (unlikely(!req->ns))
 205                 return NVME_SC_INVALID_NS | NVME_SC_DNR;
 206
 207         switch (cmd->common.opcode) {
 208         case nvme_cmd_read:
 209         case nvme_cmd_write:
 210                 req->execute = nvmet_execute_rw;
 211                 req->data_len = nvmet_rw_len(req);
 212                 return 0;
 213         case nvme_cmd_flush:
 214                 req->execute = nvmet_execute_flush;
 215                 req->data_len = 0;
 216                 return 0;
 217         case nvme_cmd_dsm:
 218                 req->execute = nvmet_execute_dsm;
 219                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 220                         sizeof(struct nvme_dsm_range);
 221                 return 0;
 222         case nvme_cmd_write_zeroes:
 223                 req->execute = nvmet_execute_write_zeroes;
 224                 return 0;
 225         default:
 226                 pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 227                        req->sq->qid);
 228                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 229         }
 230 }