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 } 314