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         blk_poll(bdev_get_queue(req->ns->bdev), cookie);
 120 }
 121
 122 static void nvmet_bdev_execute_flush(struct nvmet_req *req)
 123 {
 124         struct bio *bio = &req->b.inline_bio;
 125
 126         bio_init(bio, req->inline_bvec, ARRAY_SIZE(req->inline_bvec));
 127         bio_set_dev(bio, req->ns->bdev);
 128         bio->bi_private = req;
 129         bio->bi_end_io = nvmet_bio_done;
 130         bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 131
 132         submit_bio(bio);
 133 }
 134
 135 u16 nvmet_bdev_flush(struct nvmet_req *req)
 136 {
 137         if (blkdev_issue_flush(req->ns->bdev, GFP_KERNEL, NULL))
 138                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 139         return 0;
 140 }
 141
 142 static u16 nvmet_bdev_discard_range(struct nvmet_ns *ns,
 143                 struct nvme_dsm_range *range, struct bio **bio)
 144 {
 145         int ret;
 146
 147         ret = __blkdev_issue_discard(ns->bdev,
 148                         le64_to_cpu(range->slba) << (ns->blksize_shift - 9),
 149                         le32_to_cpu(range->nlb) << (ns->blksize_shift - 9),
 150                         GFP_KERNEL, 0, bio);
 151         if (ret && ret != -EOPNOTSUPP)
 152                 return NVME_SC_INTERNAL | NVME_SC_DNR;
 153         return 0;
 154 }
 155
 156 static void nvmet_bdev_execute_discard(struct nvmet_req *req)
 157 {
 158         struct nvme_dsm_range range;
 159         struct bio *bio = NULL;
 160         int i;
 161         u16 status;
 162
 163         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 164                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 165                                 sizeof(range));
 166                 if (status)
 167                         break;
 168
 169                 status = nvmet_bdev_discard_range(req->ns, &range, &bio);
 170                 if (status)
 171                         break;
 172         }
 173
 174         if (bio) {
 175                 bio->bi_private = req;
 176                 bio->bi_end_io = nvmet_bio_done;
 177                 if (status) {
 178                         bio->bi_status = BLK_STS_IOERR;
 179                         bio_endio(bio);
 180                 } else {
 181                         submit_bio(bio);
 182                 }
 183         } else {
 184                 nvmet_req_complete(req, status);
 185         }
 186 }
 187
 188 static void nvmet_bdev_execute_dsm(struct nvmet_req *req)
 189 {
 190         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 191         case NVME_DSMGMT_AD:
 192                 nvmet_bdev_execute_discard(req);
 193                 return;
 194         case NVME_DSMGMT_IDR:
 195         case NVME_DSMGMT_IDW:
 196         default:
 197                 /* Not supported yet */
 198                 nvmet_req_complete(req, 0);
 199                 return;
 200         }
 201 }
 202
 203 static void nvmet_bdev_execute_write_zeroes(struct nvmet_req *req)
 204 {
 205         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 206         struct bio *bio = NULL;
 207         u16 status = NVME_SC_SUCCESS;
 208         sector_t sector;
 209         sector_t nr_sector;
 210
 211         sector = le64_to_cpu(write_zeroes->slba) <<
 212                 (req->ns->blksize_shift - 9);
 213         nr_sector = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 214                 (req->ns->blksize_shift - 9));
 215
 216         if (__blkdev_issue_zeroout(req->ns->bdev, sector, nr_sector,
 217                                 GFP_KERNEL, &bio, 0))
 218                 status = NVME_SC_INTERNAL | NVME_SC_DNR;
 219
 220         if (bio) {
 221                 bio->bi_private = req;
 222                 bio->bi_end_io = nvmet_bio_done;
 223                 submit_bio(bio);
 224         } else {
 225                 nvmet_req_complete(req, status);
 226         }
 227 }
 228
 229 u16 nvmet_bdev_parse_io_cmd(struct nvmet_req *req)
 230 {
 231         struct nvme_command *cmd = req->cmd;
 232
 233         switch (cmd->common.opcode) {
 234         case nvme_cmd_read:
 235         case nvme_cmd_write:
 236                 req->execute = nvmet_bdev_execute_rw;
 237                 req->data_len = nvmet_rw_len(req);
 238                 return 0;
 239         case nvme_cmd_flush:
 240                 req->execute = nvmet_bdev_execute_flush;
 241                 req->data_len = 0;
 242                 return 0;
 243         case nvme_cmd_dsm:
 244                 req->execute = nvmet_bdev_execute_dsm;
 245                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 246                         sizeof(struct nvme_dsm_range);
 247                 return 0;
 248         case nvme_cmd_write_zeroes:
 249                 req->execute = nvmet_bdev_execute_write_zeroes;
 250                 return 0;
 251         default:
 252                 pr_err("unhandled cmd %d on qid %d\n", cmd->common.opcode,
 253                        req->sq->qid);
 254                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 255         }
 256 }