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 u16 blk_to_nvme_status(struct nvmet_req *req, blk_status_t blk_sts)
  48 {
  49         u16 status = NVME_SC_SUCCESS;
  50
  51         if (likely(blk_sts == BLK_STS_OK))
  52                 return status;
  53         /*
  54          * Right now there exists M : 1 mapping between block layer error
  55          * to the NVMe status code (see nvme_error_status()). For consistency,
  56          * when we reverse map we use most appropriate NVMe Status code from
  57          * the group of the NVMe staus codes used in the nvme_error_status().
  58          */
  59         switch (blk_sts) {
  60         case BLK_STS_NOSPC:
  61                 status = NVME_SC_CAP_EXCEEDED | NVME_SC_DNR;
  62                 req->error_loc = offsetof(struct nvme_rw_command, length);
  63                 break;
  64         case BLK_STS_TARGET:
  65                 status = NVME_SC_LBA_RANGE | NVME_SC_DNR;
  66                 req->error_loc = offsetof(struct nvme_rw_command, slba);
  67                 break;
  68         case BLK_STS_NOTSUPP:
  69                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  70                 switch (req->cmd->common.opcode) {
  71                 case nvme_cmd_dsm:
  72                 case nvme_cmd_write_zeroes:
  73                         status = NVME_SC_ONCS_NOT_SUPPORTED | NVME_SC_DNR;
  74                         break;
  75                 default:
  76                         status = NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
  77                 }
  78                 break;
  79         case BLK_STS_MEDIUM:
  80                 status = NVME_SC_ACCESS_DENIED;
  81                 req->error_loc = offsetof(struct nvme_rw_command, nsid);
  82                 break;
  83         case BLK_STS_IOERR:
  84                 /* fallthru */
  85         default:
  86                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
  87                 req->error_loc = offsetof(struct nvme_common_command, opcode);
  88         }
  89
  90         switch (req->cmd->common.opcode) {
  91         case nvme_cmd_read:
  92         case nvme_cmd_write:
  93                 req->error_slba = le64_to_cpu(req->cmd->rw.slba);
  94                 break;
  95         case nvme_cmd_write_zeroes:
  96                 req->error_slba =
  97                         le64_to_cpu(req->cmd->write_zeroes.slba);
  98                 break;
  99         default:
 100                 req->error_slba = 0;
 101         }
 102         return status;
 103 }
 104
 105 static void nvmet_bio_done(struct bio *bio)
 106 {
 107         struct nvmet_req *req = bio->bi_private;
 108
 109         nvmet_req_complete(req, blk_to_nvme_status(req, bio->bi_status));
 110         if (bio != &req->b.inline_bio)
 111                 bio_put(bio);
 112 }
 113
 114 static void nvmet_bdev_execute_rw(struct nvmet_req *req)
 115 {
 116         int sg_cnt = req->sg_cnt;
 117         struct bio *bio;
 118         struct scatterlist *sg;
 119         sector_t sector;
 120         int op, op_flags = 0, i;
 121
 122         if (!req->sg_cnt) {
 123                 nvmet_req_complete(req, 0);
 124                 return;
 125         }
 126
 127         if (req->cmd->rw.opcode == nvme_cmd_write) {
 128                 op = REQ_OP_WRITE;
 129                 op_flags = REQ_SYNC | REQ_IDLE;
 130                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
 131                         op_flags |= REQ_FUA;
 132         } else {
 133                 op = REQ_OP_READ;
 134         }
 135
 136         if (is_pci_p2pdma_page(sg_page(req->sg)))
 137                 op_flags |= REQ_NOMERGE;
 138
 139         sector = le64_to_cpu(req->cmd->rw.slba);
 140         sector <<= (req->ns->blksize_shift - 9);
 141
 142         if (req->data_len <= NVMET_MAX_INLINE_DATA_LEN) {
 143                 bio = &req->b.inline_bio;
 144                 bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
 145         } else {
 146                 bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
 147         }
 148         bio_set_dev(bio, req->ns->bdev);
 149         bio->bi_iter.bi_sector = sector;
 150         bio->bi_private = req;
 151         bio->bi_end_io = nvmet_bio_done;
 152         bio_set_op_attrs(bio, op, op_flags);
 153
 154         for_each_sg(req->sg, sg, req->sg_cnt, i) {
 155                 while (bio_add_page(bio, sg_page(sg), sg->length, sg->offset)
 156                                 != sg->length) {
 157                         struct bio *prev = bio;
 158
 159                         bio = bio_alloc(GFP_KERNEL, min(sg_cnt, BIO_MAX_PAGES));
 160                         bio_set_dev(bio, req->ns->bdev);
 161                         bio->bi_iter.bi_sector = sector;
 162                         bio_set_op_attrs(bio, op, op_flags);
 163
 164                         bio_chain(bio, prev);
 165                         submit_bio(prev);
 166                 }
 167
 168                 sector += sg->length >> 9;
 169                 sg_cnt--;
 170         }
 171
 172         submit_bio(bio);
 173 }
 174
 175 static void nvmet_bdev_execute_flush(struct nvmet_req *req)
 176 {
 177         struct bio *bio = &req->b.inline_bio;
 178
 179         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
 180         bio_set_dev(bio, req->ns->bdev);
 181         bio->bi_private = req;
 182         bio->bi_end_io = nvmet_bio_done;
 183         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 184
 185         submit_bio(bio);
 186 }
 187
 188 u16 nvmet_bdev_flush(struct nvmet_req *req)
 189 {
 190         if (blkdev_issue_flush(req->ns->bdev, GFP_KERNEL, NULL))
 191                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 192         return 0;
 193 }
 194
 195 static u16 nvmet_bdev_discard_range(struct nvmet_req *req,
 196                 struct nvme_dsm_range *range, struct bio **bio)
 197 {
 198         struct nvmet_ns *ns = req->ns;
 199         int ret;
 200
 201         ret = __blkdev_issue_discard(ns->bdev,
 202                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 203                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 204                         GFP_KERNEL, 0, bio);
 205
 206         if (ret)
 207                 req->error_slba = le64_to_cpu(range->slba);
 208
 209         return blk_to_nvme_status(req, errno_to_blk_status(ret));
 210 }
 211
 212 static void nvmet_bdev_execute_discard(struct nvmet_req *req)
 213 {
 214         struct nvme_dsm_range range;
 215         struct bio *bio = NULL;
 216         int i;
 217         u16 status;
 218
 219         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 220                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 221                                 sizeof(range));
 222                 if (status)
 223                         break;
 224
 225                 status = nvmet_bdev_discard_range(req, &range, &bio);
 226                 if (status)
 227                         break;
 228         }
 229
 230         if (bio) {
 231                 bio->bi_private = req;
 232                 bio->bi_end_io = nvmet_bio_done;
 233                 if (status) {
 234                         bio->bi_status = BLK_STS_IOERR;
 235                         bio_endio(bio);
 236                 } else {
 237                         submit_bio(bio);
 238                 }
 239         } else {
 240                 nvmet_req_complete(req, status);
 241         }
 242 }
 243
 244 static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
 245 {
 246         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 247         case NVME_DSMGMT_AD:
 248                 nvmet_bdev_execute_discard(req);
 249                 return;
 250         case NVME_DSMGMT_IDR:
 251         case NVME_DSMGMT_IDW:
 252         default:
 253                 /* Not supported yet */
 254                 nvmet_req_complete(req, 0);
 255                 return;
 256         }
 257 }
 258
 259 static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
 260 {
 261         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 262         struct bio *bio = NULL;
 263         u16 status = NVME_SC_SUCCESS;
 264         sector_t sector;
 265         sector_t nr_sector;
 266         int ret;
 267
 268         sector = le64_to_cpu(write_zeroes->slba) <<
 269                 (req->ns->blksize_shift - 9);
 270         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 271                 (req->ns->blksize_shift - 9));
 272
 273         ret = __blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 274                         GFP_KERNEL, &bio, 0);
 275         status = blk_to_nvme_status(req, errno_to_blk_status(ret));
 276         if (bio) {
 277                 bio->bi_private = req;
 278                 bio->bi_end_io = nvmet_bio_done;
 279                 submit_bio(bio);
 280         } else {
 281                 nvmet_req_complete(req, status);
 282         }
 283 }
 284
 285 u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 286 {
 287         struct nvme_command *cmd = req->cmd;
 288
 289         switch (cmd->common.opcode) {
 290         case nvme_cmd_read:
 291         case nvme_cmd_write:
 292                 req->execute = nvmet_bdev_execute_rw;
 293                 req->data_len = nvmet_rw_len(req);
 294                 return 0;
 295         case nvme_cmd_flush:
 296                 req->execute = nvmet_bdev_execute_flush;
 297                 req->data_len = 0;
 298                 return 0;
 299         case nvme_cmd_dsm:
 300                 req->execute = nvmet_bdev_execute_dsm;
 301                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 302                         sizeof(struct nvme_dsm_range);
 303                 return 0;
 304         case nvme_cmd_write_zeroes:
 305                 req->execute = nvmet_bdev_execute_write_zeroes;
 306                 return 0;
 307         default:
 308                 pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 309                        req->sq->qid);
 310                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 311                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 312         }
 313 }