1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * NVMe Over Fabrics Target File I/O commands implementation. 4 * Copyright (c) 2017-2018 Western Digital Corporation or its 5 * affiliates. 6 */ 7 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 8 #include <linux/uio.h> 9 #include <linux/falloc.h> 10 #include <linux/file.h> 11 #include "nvmet.h" 12 13 #define NVMET_MAX_MPOOL_BVEC 16 14 #define NVMET_MIN_MPOOL_OBJ 16 15 16 void nvmet_file_ns_disable(struct nvmet_ns *ns) 17 { 18 if (ns->file) { 19 if (ns->buffered_io) 20 flush_workqueue(buffered_io_wq); 21 mempool_destroy(ns->bvec_pool); 22 ns->bvec_pool = NULL; 23 kmem_cache_destroy(ns->bvec_cache); 24 ns->bvec_cache = NULL; 25 fput(ns->file); 26 ns->file = NULL; 27 } 28 } 29 30 int nvmet_file_ns_enable(struct nvmet_ns *ns) 31 { 32 int flags = O_RDWR | O_LARGEFILE; 33 struct kstat stat; 34 int ret; 35 36 if (!ns->buffered_io) 37 flags |= O_DIRECT; 38 39 ns->file = filp_open(ns->device_path, flags, 0); 40 if (IS_ERR(ns->file)) { 41 pr_err("failed to open file %s: (%ld)\n", 42 ns->device_path, PTR_ERR(ns->file)); 43 return PTR_ERR(ns->file); 44 } 45 46 ret = vfs_getattr(&ns->file->f_path, 47 &stat, STATX_SIZE, AT_STATX_FORCE_SYNC); 48 if (ret) 49 goto err; 50 51 ns->size = stat.size; 52 ns->blksize_shift = file_inode(ns->file)->i_blkbits; 53 54 ns->bvec_cache = kmem_cache_create("nvmet-bvec", 55 NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec), 56 0, SLAB_HWCACHE_ALIGN, NULL); 57 if (!ns->bvec_cache) { 58 ret = -ENOMEM; 59 goto err; 60 } 61 62 ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab, 63 mempool_free_slab, ns->bvec_cache); 64 65 if (!ns->bvec_pool) { 66 ret = -ENOMEM; 67 goto err; 68 } 69 70 return ret; 71 err: 72 ns->size = 0; 73 ns->blksize_shift = 0; 74 nvmet_file_ns_disable(ns); 75 return ret; 76 } 77 78 static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter) 79 { 80 bv->bv_page = sg_page_iter_page(iter); 81 bv->bv_offset = iter->sg->offset; 82 bv->bv_len = PAGE_SIZE - iter->sg->offset; 83 } 84 85 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos, 86 unsigned long nr_segs, size_t count) 87 { 88 struct kiocb *iocb = &req->f.iocb; 89 ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter); 90 struct iov_iter iter; 91 int ki_flags = 0, rw; 92 ssize_t ret; 93 94 if (req->cmd->rw.opcode == nvme_cmd_write) { 95 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA)) 96 ki_flags = IOCB_DSYNC; 97 call_iter = req->ns->file->f_op->write_iter; 98 rw = WRITE; 99 } else { 100 call_iter = req->ns->file->f_op->read_iter; 101 rw = READ; 102 } 103 104 iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count); 105 106 iocb->ki_pos = pos; 107 iocb->ki_filp = req->ns->file; 108 iocb->ki_flags = ki_flags | iocb_flags(req->ns->file); 109 110 ret = call_iter(iocb, &iter); 111 112 if (ret != -EIOCBQUEUED && iocb->ki_complete) 113 iocb->ki_complete(iocb, ret, 0); 114 115 return ret; 116 } 117 118 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2) 119 { 120 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb); 121 122 if (req->f.bvec != req->inline_bvec) { 123 if (likely(req->f.mpool_alloc == false)) 124 kfree(req->f.bvec); 125 else 126 mempool_free(req->f.bvec, req->ns->bvec_pool); 127 } 128 129 nvmet_req_complete(req, ret != req->data_len ? 130 NVME_SC_INTERNAL | NVME_SC_DNR : 0); 131 } 132 133 static void nvmet_file_execute_rw(struct nvmet_req *req) 134 { 135 ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE); 136 struct sg_page_iter sg_pg_iter; 137 unsigned long bv_cnt = 0; 138 bool is_sync = false; 139 size_t len = 0, total_len = 0; 140 ssize_t ret = 0; 141 loff_t pos; 142 143 if (!req->sg_cnt || !nr_bvec) { 144 nvmet_req_complete(req, 0); 145 return; 146 } 147 148 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift; 149 if (unlikely(pos + req->data_len > req->ns->size)) { 150 nvmet_req_complete(req, NVME_SC_LBA_RANGE | NVME_SC_DNR); 151 return; 152 } 153 154 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC) 155 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), 156 GFP_KERNEL); 157 else 158 req->f.bvec = req->inline_bvec; 159 160 req->f.mpool_alloc = false; 161 if (unlikely(!req->f.bvec)) { 162 /* fallback under memory pressure */ 163 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL); 164 req->f.mpool_alloc = true; 165 if (nr_bvec > NVMET_MAX_MPOOL_BVEC) 166 is_sync = true; 167 } 168 169 memset(&req->f.iocb, 0, sizeof(struct kiocb)); 170 for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) { 171 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter); 172 len += req->f.bvec[bv_cnt].bv_len; 173 total_len += req->f.bvec[bv_cnt].bv_len; 174 bv_cnt++; 175 176 WARN_ON_ONCE((nr_bvec - 1) < 0); 177 178 if (unlikely(is_sync) && 179 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { 180 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len); 181 if (ret < 0) 182 goto out; 183 pos += len; 184 bv_cnt = 0; 185 len = 0; 186 } 187 nr_bvec--; 188 } 189 190 if (WARN_ON_ONCE(total_len != req->data_len)) 191 ret = -EIO; 192 out: 193 if (unlikely(is_sync || ret)) { 194 nvmet_file_io_done(&req->f.iocb, ret < 0 ? ret : total_len, 0); 195 return; 196 } 197 req->f.iocb.ki_complete = nvmet_file_io_done; 198 nvmet_file_submit_bvec(req, pos, bv_cnt, total_len); 199 } 200 201 static void nvmet_file_buffered_io_work(struct work_struct *w) 202 { 203 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 204 205 nvmet_file_execute_rw(req); 206 } 207 208 static void nvmet_file_execute_rw_buffered_io(struct nvmet_req *req) 209 { 210 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work); 211 queue_work(buffered_io_wq, &req->f.work); 212 } 213 214 u16 nvmet_file_flush(struct nvmet_req *req) 215 { 216 if (vfs_fsync(req->ns->file, 1) < 0) 217 return NVME_SC_INTERNAL | NVME_SC_DNR; 218 return 0; 219 } 220 221 static void nvmet_file_flush_work(struct work_struct *w) 222 { 223 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 224 225 nvmet_req_complete(req, nvmet_file_flush(req)); 226 } 227 228 static void nvmet_file_execute_flush(struct nvmet_req *req) 229 { 230 INIT_WORK(&req->f.work, nvmet_file_flush_work); 231 schedule_work(&req->f.work); 232 } 233 234 static void nvmet_file_execute_discard(struct nvmet_req *req) 235 { 236 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; 237 struct nvme_dsm_range range; 238 loff_t offset, len; 239 u16 ret; 240 int i; 241 242 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) { 243 ret = nvmet_copy_from_sgl(req, i * sizeof(range), &range, 244 sizeof(range)); 245 if (ret) 246 break; 247 248 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift; 249 len = le32_to_cpu(range.nlb); 250 len <<= req->ns->blksize_shift; 251 if (offset + len > req->ns->size) { 252 ret = NVME_SC_LBA_RANGE | NVME_SC_DNR; 253 break; 254 } 255 256 if (vfs_fallocate(req->ns->file, mode, offset, len)) { 257 ret = NVME_SC_INTERNAL | NVME_SC_DNR; 258 break; 259 } 260 } 261 262 nvmet_req_complete(req, ret); 263 } 264 265 static void nvmet_file_dsm_work(struct work_struct *w) 266 { 267 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 268 269 switch (le32_to_cpu(req->cmd->dsm.attributes)) { 270 case NVME_DSMGMT_AD: 271 nvmet_file_execute_discard(req); 272 return; 273 case NVME_DSMGMT_IDR: 274 case NVME_DSMGMT_IDW: 275 default: 276 /* Not supported yet */ 277 nvmet_req_complete(req, 0); 278 return; 279 } 280 } 281 282 static void nvmet_file_execute_dsm(struct nvmet_req *req) 283 { 284 INIT_WORK(&req->f.work, nvmet_file_dsm_work); 285 schedule_work(&req->f.work); 286 } 287 288 static void nvmet_file_write_zeroes_work(struct work_struct *w) 289 { 290 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 291 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes; 292 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE; 293 loff_t offset; 294 loff_t len; 295 int ret; 296 297 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift; 298 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) << 299 req->ns->blksize_shift); 300 301 if (unlikely(offset + len > req->ns->size)) { 302 nvmet_req_complete(req, NVME_SC_LBA_RANGE | NVME_SC_DNR); 303 return; 304 } 305 306 ret = vfs_fallocate(req->ns->file, mode, offset, len); 307 nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0); 308 } 309 310 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req) 311 { 312 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work); 313 schedule_work(&req->f.work); 314 } 315 316 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req) 317 { 318 struct nvme_command *cmd = req->cmd; 319 320 switch (cmd->common.opcode) { 321 case nvme_cmd_read: 322 case nvme_cmd_write: 323 if (req->ns->buffered_io) 324 req->execute = nvmet_file_execute_rw_buffered_io; 325 else 326 req->execute = nvmet_file_execute_rw; 327 req->data_len = nvmet_rw_len(req); 328 return 0; 329 case nvme_cmd_flush: 330 req->execute = nvmet_file_execute_flush; 331 req->data_len = 0; 332 return 0; 333 case nvme_cmd_dsm: 334 req->execute = nvmet_file_execute_dsm; 335 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) * 336 sizeof(struct nvme_dsm_range); 337 return 0; 338 case nvme_cmd_write_zeroes: 339 req->execute = nvmet_file_execute_write_zeroes; 340 req->data_len = 0; 341 return 0; 342 default: 343 pr_err("unhandled cmd for file ns %d on qid %d\n", 344 cmd->common.opcode, req->sq->qid); 345 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; 346 } 347 } 348