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 scatterlist *sg) 79 { 80 bv->bv_page = sg_page(sg); 81 bv->bv_offset = sg->offset; 82 bv->bv_len = sg->length; 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, int ki_flags) 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 rw; 92 93 if (req->cmd->rw.opcode == nvme_cmd_write) { 94 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA)) 95 ki_flags |= IOCB_DSYNC; 96 call_iter = req->ns->file->f_op->write_iter; 97 rw = WRITE; 98 } else { 99 call_iter = req->ns->file->f_op->read_iter; 100 rw = READ; 101 } 102 103 iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count); 104 105 iocb->ki_pos = pos; 106 iocb->ki_filp = req->ns->file; 107 iocb->ki_flags = ki_flags | iocb_flags(req->ns->file); 108 109 return call_iter(iocb, &iter); 110 } 111 112 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2) 113 { 114 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb); 115 u16 status = NVME_SC_SUCCESS; 116 117 if (req->f.bvec != req->inline_bvec) { 118 if (likely(req->f.mpool_alloc == false)) 119 kfree(req->f.bvec); 120 else 121 mempool_free(req->f.bvec, req->ns->bvec_pool); 122 } 123 124 if (unlikely(ret != req->data_len)) 125 status = errno_to_nvme_status(req, ret); 126 nvmet_req_complete(req, status); 127 } 128 129 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) 130 { 131 ssize_t nr_bvec = req->sg_cnt; 132 unsigned long bv_cnt = 0; 133 bool is_sync = false; 134 size_t len = 0, total_len = 0; 135 ssize_t ret = 0; 136 loff_t pos; 137 int i; 138 struct scatterlist *sg; 139 140 if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC) 141 is_sync = true; 142 143 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift; 144 if (unlikely(pos + req->data_len > req->ns->size)) { 145 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 146 return true; 147 } 148 149 memset(&req->f.iocb, 0, sizeof(struct kiocb)); 150 for_each_sg(req->sg, sg, req->sg_cnt, i) { 151 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg); 152 len += req->f.bvec[bv_cnt].bv_len; 153 total_len += req->f.bvec[bv_cnt].bv_len; 154 bv_cnt++; 155 156 WARN_ON_ONCE((nr_bvec - 1) < 0); 157 158 if (unlikely(is_sync) && 159 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { 160 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0); 161 if (ret < 0) 162 goto complete; 163 164 pos += len; 165 bv_cnt = 0; 166 len = 0; 167 } 168 nr_bvec--; 169 } 170 171 if (WARN_ON_ONCE(total_len != req->data_len)) { 172 ret = -EIO; 173 goto complete; 174 } 175 176 if (unlikely(is_sync)) { 177 ret = total_len; 178 goto complete; 179 } 180 181 /* 182 * A NULL ki_complete ask for synchronous execution, which we want 183 * for the IOCB_NOWAIT case. 184 */ 185 if (!(ki_flags & IOCB_NOWAIT)) 186 req->f.iocb.ki_complete = nvmet_file_io_done; 187 188 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags); 189 190 switch (ret) { 191 case -EIOCBQUEUED: 192 return true; 193 case -EAGAIN: 194 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT))) 195 goto complete; 196 return false; 197 case -EOPNOTSUPP: 198 /* 199 * For file systems returning error -EOPNOTSUPP, handle 200 * IOCB_NOWAIT error case separately and retry without 201 * IOCB_NOWAIT. 202 */ 203 if ((ki_flags & IOCB_NOWAIT)) 204 return false; 205 break; 206 } 207 208 complete: 209 nvmet_file_io_done(&req->f.iocb, ret, 0); 210 return true; 211 } 212 213 static void nvmet_file_buffered_io_work(struct work_struct *w) 214 { 215 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 216 217 nvmet_file_execute_io(req, 0); 218 } 219 220 static void nvmet_file_submit_buffered_io(struct nvmet_req *req) 221 { 222 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work); 223 queue_work(buffered_io_wq, &req->f.work); 224 } 225 226 static void nvmet_file_execute_rw(struct nvmet_req *req) 227 { 228 ssize_t nr_bvec = req->sg_cnt; 229 230 if (!req->sg_cnt || !nr_bvec) { 231 nvmet_req_complete(req, 0); 232 return; 233 } 234 235 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC) 236 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), 237 GFP_KERNEL); 238 else 239 req->f.bvec = req->inline_bvec; 240 241 if (unlikely(!req->f.bvec)) { 242 /* fallback under memory pressure */ 243 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL); 244 req->f.mpool_alloc = true; 245 } else 246 req->f.mpool_alloc = false; 247 248 if (req->ns->buffered_io) { 249 if (likely(!req->f.mpool_alloc) && 250 nvmet_file_execute_io(req, IOCB_NOWAIT)) 251 return; 252 nvmet_file_submit_buffered_io(req); 253 } else 254 nvmet_file_execute_io(req, 0); 255 } 256 257 u16 nvmet_file_flush(struct nvmet_req *req) 258 { 259 return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1)); 260 } 261 262 static void nvmet_file_flush_work(struct work_struct *w) 263 { 264 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 265 266 nvmet_req_complete(req, nvmet_file_flush(req)); 267 } 268 269 static void nvmet_file_execute_flush(struct nvmet_req *req) 270 { 271 INIT_WORK(&req->f.work, nvmet_file_flush_work); 272 schedule_work(&req->f.work); 273 } 274 275 static void nvmet_file_execute_discard(struct nvmet_req *req) 276 { 277 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; 278 struct nvme_dsm_range range; 279 loff_t offset, len; 280 u16 status = 0; 281 int ret; 282 int i; 283 284 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) { 285 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range, 286 sizeof(range)); 287 if (status) 288 break; 289 290 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift; 291 len = le32_to_cpu(range.nlb); 292 len <<= req->ns->blksize_shift; 293 if (offset + len > req->ns->size) { 294 req->error_slba = le64_to_cpu(range.slba); 295 status = errno_to_nvme_status(req, -ENOSPC); 296 break; 297 } 298 299 ret = vfs_fallocate(req->ns->file, mode, offset, len); 300 if (ret && ret != -EOPNOTSUPP) { 301 req->error_slba = le64_to_cpu(range.slba); 302 status = errno_to_nvme_status(req, ret); 303 break; 304 } 305 } 306 307 nvmet_req_complete(req, status); 308 } 309 310 static void nvmet_file_dsm_work(struct work_struct *w) 311 { 312 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 313 314 switch (le32_to_cpu(req->cmd->dsm.attributes)) { 315 case NVME_DSMGMT_AD: 316 nvmet_file_execute_discard(req); 317 return; 318 case NVME_DSMGMT_IDR: 319 case NVME_DSMGMT_IDW: 320 default: 321 /* Not supported yet */ 322 nvmet_req_complete(req, 0); 323 return; 324 } 325 } 326 327 static void nvmet_file_execute_dsm(struct nvmet_req *req) 328 { 329 INIT_WORK(&req->f.work, nvmet_file_dsm_work); 330 schedule_work(&req->f.work); 331 } 332 333 static void nvmet_file_write_zeroes_work(struct work_struct *w) 334 { 335 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 336 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes; 337 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE; 338 loff_t offset; 339 loff_t len; 340 int ret; 341 342 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift; 343 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) << 344 req->ns->blksize_shift); 345 346 if (unlikely(offset + len > req->ns->size)) { 347 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 348 return; 349 } 350 351 ret = vfs_fallocate(req->ns->file, mode, offset, len); 352 nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0); 353 } 354 355 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req) 356 { 357 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work); 358 schedule_work(&req->f.work); 359 } 360 361 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req) 362 { 363 struct nvme_command *cmd = req->cmd; 364 365 switch (cmd->common.opcode) { 366 case nvme_cmd_read: 367 case nvme_cmd_write: 368 req->execute = nvmet_file_execute_rw; 369 req->data_len = nvmet_rw_len(req); 370 return 0; 371 case nvme_cmd_flush: 372 req->execute = nvmet_file_execute_flush; 373 req->data_len = 0; 374 return 0; 375 case nvme_cmd_dsm: 376 req->execute = nvmet_file_execute_dsm; 377 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) * 378 sizeof(struct nvme_dsm_range); 379 return 0; 380 case nvme_cmd_write_zeroes: 381 req->execute = nvmet_file_execute_write_zeroes; 382 req->data_len = 0; 383 return 0; 384 default: 385 pr_err("unhandled cmd for file ns %d on qid %d\n", 386 cmd->common.opcode, req->sq->qid); 387 req->error_loc = offsetof(struct nvme_common_command, opcode); 388 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR; 389 } 390 } 391