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;
  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         if (is_pci_p2pdma_page(sg_page(req->sg)))
  82                 op_flags |= REQ_NOMERGE;
  83
  84         sector = le64_to_cpu(req->cmd->rw.slba);
  85         sector <<= (req->ns->blksize_shift - 9);
  86
  87         if (req->data_len <= NVMET_MAX_INLINE_DATA_LEN) {
  88                 bio = &req->b.inline_bio;
  89                 bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
  90         } else {
  91                 bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
  92         }
  93         bio_set_dev(bio, req->ns->bdev);
  94         bio->bi_iter.bi_sector = sector;
  95         bio->bi_private = req;
  96         bio->bi_end_io = nvmet_bio_done;
  97         bio_set_op_attrs(bio, op, op_flags);
  98
  99         for_each_sg(req->sg, sg, req->sg_cnt, i) {
 100                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 101                                 != sg->length) {
 102                         struct bio *prev = bio;
 103
 104                         bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
 105                         bio_set_dev(bio, req->ns->bdev);
 106                         bio->bi_iter.bi_sector = sector;
 107                         bio_set_op_attrs(bio, op, op_flags);
 108
 109                         bio_chain(bio, prev);
 110                         submit_bio(prev);
 111                 }
 112
 113                 sector += sg->length >> 9;
 114                 sg_cnt--;
 115         }
 116
 117         cookie = submit_bio(bio);
 118 }
 119
 120 static void nvmet_bdev_execute_flush(struct nvmet_req *req)
 121 {
 122         struct bio *bio = &req->b.inline_bio;
 123
 124         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
 125         bio_set_dev(bio, req->ns->bdev);
 126         bio->bi_private = req;
 127         bio->bi_end_io = nvmet_bio_done;
 128         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 129
 130         submit_bio(bio);
 131 }
 132
 133 u16 nvmet_bdev_flush(struct nvmet_req *req)
 134 {
 135         if (blkdev_issue_flush(req->ns->bdev, GFP_KERNEL, NULL))
 136                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 137         return 0;
 138 }
 139
 140 static u16 nvmet_bdev_discard_range(struct nvmet_ns *ns,
 141                 struct nvme_dsm_range *range, struct bio **bio)
 142 {
 143         int ret;
 144
 145         ret = __blkdev_issue_discard(ns->bdev,
 146                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 147                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 148                         GFP_KERNEL, 0, bio);
 149         if (ret && ret != -EOPNOTSUPP)
 150                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 151         return 0;
 152 }
 153
 154 static void nvmet_bdev_execute_discard(struct nvmet_req *req)
 155 {
 156         struct nvme_dsm_range range;
 157         struct bio *bio = NULL;
 158         int i;
 159         u16 status;
 160
 161         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 162                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 163                                 sizeof(range));
 164                 if (status)
 165                         break;
 166
 167                 status = nvmet_bdev_discard_range(req->ns, &range, &bio);
 168                 if (status)
 169                         break;
 170         }
 171
 172         if (bio) {
 173                 bio->bi_private = req;
 174                 bio->bi_end_io = nvmet_bio_done;
 175                 if (status) {
 176                         bio->bi_status = BLK_STS_IOERR;
 177                         bio_endio(bio);
 178                 } else {
 179                         submit_bio(bio);
 180                 }
 181         } else {
 182                 nvmet_req_complete(req, status);
 183         }
 184 }
 185
 186 static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
 187 {
 188         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 189         case NVME_DSMGMT_AD:
 190                 nvmet_bdev_execute_discard(req);
 191                 return;
 192         case NVME_DSMGMT_IDR:
 193         case NVME_DSMGMT_IDW:
 194         default:
 195                 /* Not supported yet */
 196                 nvmet_req_complete(req, 0);
 197                 return;
 198         }
 199 }
 200
 201 static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
 202 {
 203         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 204         struct bio *bio = NULL;
 205         u16 status = NVME_SC_SUCCESS;
 206         sector_t sector;
 207         sector_t nr_sector;
 208
 209         sector = le64_to_cpu(write_zeroes->slba) <<
 210                 (req->ns->blksize_shift - 9);
 211         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 212                 (req->ns->blksize_shift - 9));
 213
 214         if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 215                                 GFP_KERNEL, &bio, 0))
 216                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 217
 218         if (bio) {
 219                 bio->bi_private = req;
 220                 bio->bi_end_io = nvmet_bio_done;
 221                 submit_bio(bio);
 222         } else {
 223                 nvmet_req_complete(req, status);
 224         }
 225 }
 226
 227 u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 228 {
 229         struct nvme_command *cmd = req->cmd;
 230
 231         switch (cmd->common.opcode) {
 232         case nvme_cmd_read:
 233         case nvme_cmd_write:
 234                 req->execute = nvmet_bdev_execute_rw;
 235                 req->data_len = nvmet_rw_len(req);
 236                 return 0;
 237         case nvme_cmd_flush:
 238                 req->execute = nvmet_bdev_execute_flush;
 239                 req->data_len = 0;
 240                 return 0;
 241         case nvme_cmd_dsm:
 242                 req->execute = nvmet_bdev_execute_dsm;
 243                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 244                         sizeof(struct nvme_dsm_range);
 245                 return 0;
 246         case nvme_cmd_write_zeroes:
 247                 req->execute = nvmet_bdev_execute_write_zeroes;
 248                 return 0;
 249         default:
 250                 pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 251                        req->sq->qid);
 252                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 253         }
 254 }