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 } 257