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