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