drivers/nvme/target/io-cmd-bdev.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 int nvmet_bdev_ns_enable(struct nvmet_ns *ns)
  20 {
  21         int ret;
  22
  23         ns->bdev = blkdev_get_by_path(ns->device_path,
  24                         FMODE_READ | FMODE_WRITE, NULL);
  25         if (IS_ERR(ns->bdev)) {
  26                 ret = PTR_ERR(ns->bdev);
  27                 if (ret != -ENOTBLK) {
  28                         pr_err("failed to open block device %s: (%ld)\n",
  29                                         ns->device_path, PTR_ERR(ns->bdev));
  30                 }
  31                 ns->bdev = NULL;
  32                 return ret;
  33         }
  34         ns->size = i_size_read(ns->bdev->bd_inode);
  35         ns->blksize_shift = blksize_bits(bdev_logical_block_size(ns->bdev));
  36         return 0;
  37 }
  38
  39 void nvmet_bdev_ns_disable(struct nvmet_ns *ns)
  40 {
  41         if (ns->bdev) {
  42                 blkdev_put(ns->bdev, FMODE_WRITE | FMODE_READ);
  43                 ns->bdev = NULL;
  44         }
  45 }
  46
  47 static void nvmet_bio_done(struct bio *bio)
  48 {
  49         struct nvmet_req *req = bio->bi_private;
  50
  51         nvmet_req_complete(req,
  52                 bio->bi_status ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
  53
  54         if (bio != &req->b.inline_bio)
  55                 bio_put(bio);
  56 }
  57
  58 static void nvmet_bdev_execute_rw(struct nvmet_req *req)
  59 {
  60         int sg_cnt = req->sg_cnt;
  61         struct bio *bio = &req->b.inline_bio;
  62         struct scatterlist *sg;
  63         sector_t sector;
  64         blk_qc_t cookie;
  65         int op, op_flags = 0, i;
  66
  67         if (!req->sg_cnt) {
  68                 nvmet_req_complete(req, 0);
  69                 return;
  70         }
  71
  72         if (req->cmd->rw.opcode == nvme_cmd_write) {
  73                 op = REQ_OP_WRITE;
  74                 op_flags = REQ_SYNC | REQ_IDLE;
  75                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  76                         op_flags |= REQ_FUA;
  77         } else {
  78                 op = REQ_OP_READ;
  79         }
  80
  81         sector = le64_to_cpu(req->cmd->rw.slba);
  82         sector <<= (req->ns->blksize_shift - 9);
  83
  84         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
  85         bio_set_dev(bio, req->ns->bdev);
  86         bio->bi_iter.bi_sector = sector;
  87         bio->bi_private = req;
  88         bio->bi_end_io = nvmet_bio_done;
  89         bio_set_op_attrs(bio, op, op_flags);
  90
  91         for_each_sg(req->sg, sg, req->sg_cnt, i) {
  92                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
  93                                 != sg->length) {
  94                         struct bio *prev = bio;
  95
  96                         bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
  97                         bio_set_dev(bio, req->ns->bdev);
  98                         bio->bi_iter.bi_sector = sector;
  99                         bio_set_op_attrs(bio, op, op_flags);
 100
 101                         bio_chain(bio, prev);
 102                         submit_bio(prev);
 103                 }
 104
 105                 sector += sg->length >> 9;
 106                 sg_cnt--;
 107         }
 108
 109         cookie = submit_bio(bio);
 110
 111         blk_poll(bdev_get_queue(req->ns->bdev), cookie);
 112 }
 113
 114 static void nvmet_bdev_execute_flush(struct nvmet_req *req)
 115 {
 116         struct bio *bio = &req->b.inline_bio;
 117
 118         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
 119         bio_set_dev(bio, req->ns->bdev);
 120         bio->bi_private = req;
 121         bio->bi_end_io = nvmet_bio_done;
 122         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 123
 124         submit_bio(bio);
 125 }
 126
 127 u16 nvmet_bdev_flush(struct nvmet_req *req)
 128 {
 129         if (blkdev_issue_flush(req->ns->bdev, GFP_KERNEL, NULL))
 130                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 131         return 0;
 132 }
 133
 134 static u16 nvmet_bdev_discard_range(struct nvmet_ns *ns,
 135                 struct nvme_dsm_range *range, struct bio **bio)
 136 {
 137         int ret;
 138
 139         ret = __blkdev_issue_discard(ns->bdev,
 140                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 141                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 142                         GFP_KERNEL, 0, bio);
 143         if (ret && ret != -EOPNOTSUPP)
 144                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 145         return 0;
 146 }
 147
 148 static void nvmet_bdev_execute_discard(struct nvmet_req *req)
 149 {
 150         struct nvme_dsm_range range;
 151         struct bio *bio = NULL;
 152         int i;
 153         u16 status;
 154
 155         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 156                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 157                                 sizeof(range));
 158                 if (status)
 159                         break;
 160
 161                 status = nvmet_bdev_discard_range(req->ns, &range, &bio);
 162                 if (status)
 163                         break;
 164         }
 165
 166         if (bio) {
 167                 bio->bi_private = req;
 168                 bio->bi_end_io = nvmet_bio_done;
 169                 if (status) {
 170                         bio->bi_status = BLK_STS_IOERR;
 171                         bio_endio(bio);
 172                 } else {
 173                         submit_bio(bio);
 174                 }
 175         } else {
 176                 nvmet_req_complete(req, status);
 177         }
 178 }
 179
 180 static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
 181 {
 182         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 183         case NVME_DSMGMT_AD:
 184                 nvmet_bdev_execute_discard(req);
 185                 return;
 186         case NVME_DSMGMT_IDR:
 187         case NVME_DSMGMT_IDW:
 188         default:
 189                 /* Not supported yet */
 190                 nvmet_req_complete(req, 0);
 191                 return;
 192         }
 193 }
 194
 195 static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
 196 {
 197         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 198         struct bio *bio = NULL;
 199         u16 status = NVME_SC_SUCCESS;
 200         sector_t sector;
 201         sector_t nr_sector;
 202
 203         sector = le64_to_cpu(write_zeroes->slba) <<
 204                 (req->ns->blksize_shift - 9);
 205         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 206                 (req->ns->blksize_shift - 9));
 207
 208         if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 209                                 GFP_KERNEL, &bio, 0))
 210                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 211
 212         if (bio) {
 213                 bio->bi_private = req;
 214                 bio->bi_end_io = nvmet_bio_done;
 215                 submit_bio(bio);
 216         } else {
 217                 nvmet_req_complete(req, status);
 218         }
 219 }
 220
 221 u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 222 {
 223         struct nvme_command *cmd = req->cmd;
 224
 225         switch (cmd->common.opcode) {
 226         case nvme_cmd_read:
 227         case nvme_cmd_write:
 228                 req->execute = nvmet_bdev_execute_rw;
 229                 req->data_len = nvmet_rw_len(req);
 230                 return 0;
 231         case nvme_cmd_flush:
 232                 req->execute = nvmet_bdev_execute_flush;
 233                 req->data_len = 0;
 234                 return 0;
 235         case nvme_cmd_dsm:
 236                 req->execute = nvmet_bdev_execute_dsm;
 237                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 238                         sizeof(struct nvme_dsm_range);
 239                 return 0;
 240         case nvme_cmd_write_zeroes:
 241                 req->execute = nvmet_bdev_execute_write_zeroes;
 242                 req->data_len = 0;
 243                 return 0;
 244         default:
 245                 pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 246                        req->sq->qid);
 247                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 248         }
 249 }