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 int nvmet_file_ns_revalidate(struct nvmet_ns *ns) 17 { 18 struct kstat stat; 19 int ret; 20 21 ret = vfs_getattr(&ns->file->f_path, &stat, STATX_SIZE, 22 AT_STATX_FORCE_SYNC); 23 if (!ret) 24 ns->size = stat.size; 25 return ret; 26 } 27 28 void nvmet_file_ns_disable(struct nvmet_ns *ns) 29 { 30 if (ns->file) { 31 if (ns->buffered_io) 32 flush_workqueue(buffered_io_wq); 33 mempool_destroy(ns->bvec_pool); 34 ns->bvec_pool = NULL; 35 kmem_cache_destroy(ns->bvec_cache); 36 ns->bvec_cache = NULL; 37 fput(ns->file); 38 ns->file = NULL; 39 } 40 } 41 42 int nvmet_file_ns_enable(struct nvmet_ns *ns) 43 { 44 int flags = O_RDWR | O_LARGEFILE; 45 int ret; 46 47 if (!ns->buffered_io) 48 flags |= O_DIRECT; 49 50 ns->file = filp_open(ns->device_path, flags, 0); 51 if (IS_ERR(ns->file)) { 52 ret = PTR_ERR(ns->file); 53 pr_err("failed to open file %s: (%d)\n", 54 ns->device_path, ret); 55 ns->file = NULL; 56 return ret; 57 } 58 59 ret = nvmet_file_ns_revalidate(ns); 60 if (ret) 61 goto err; 62 63 /* 64 * i_blkbits can be greater than the universally accepted upper bound, 65 * so make sure we export a sane namespace lba_shift. 66 */ 67 ns->blksize_shift = min_t(u8, 68 file_inode(ns->file)->i_blkbits, 12); 69 70 ns->bvec_cache = kmem_cache_create("nvmet-bvec", 71 NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec), 72 0, SLAB_HWCACHE_ALIGN, NULL); 73 if (!ns->bvec_cache) { 74 ret = -ENOMEM; 75 goto err; 76 } 77 78 ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab, 79 mempool_free_slab, ns->bvec_cache); 80 81 if (!ns->bvec_pool) { 82 ret = -ENOMEM; 83 goto err; 84 } 85 86 return ret; 87 err: 88 ns->size = 0; 89 ns->blksize_shift = 0; 90 nvmet_file_ns_disable(ns); 91 return ret; 92 } 93 94 static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg) 95 { 96 bv->bv_page = sg_page(sg); 97 bv->bv_offset = sg->offset; 98 bv->bv_len = sg->length; 99 } 100 101 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos, 102 unsigned long nr_segs, size_t count, int ki_flags) 103 { 104 struct kiocb *iocb = &req->f.iocb; 105 ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter); 106 struct iov_iter iter; 107 int rw; 108 109 if (req->cmd->rw.opcode == nvme_cmd_write) { 110 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA)) 111 ki_flags |= IOCB_DSYNC; 112 call_iter = req->ns->file->f_op->write_iter; 113 rw = WRITE; 114 } else { 115 call_iter = req->ns->file->f_op->read_iter; 116 rw = READ; 117 } 118 119 iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count); 120 121 iocb->ki_pos = pos; 122 iocb->ki_filp = req->ns->file; 123 iocb->ki_flags = ki_flags | iocb_flags(req->ns->file); 124 125 return call_iter(iocb, &iter); 126 } 127 128 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2) 129 { 130 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb); 131 u16 status = NVME_SC_SUCCESS; 132 133 if (req->f.bvec != req->inline_bvec) { 134 if (likely(req->f.mpool_alloc == false)) 135 kfree(req->f.bvec); 136 else 137 mempool_free(req->f.bvec, req->ns->bvec_pool); 138 } 139 140 if (unlikely(ret != req->transfer_len)) 141 status = errno_to_nvme_status(req, ret); 142 nvmet_req_complete(req, status); 143 } 144 145 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) 146 { 147 ssize_t nr_bvec = req->sg_cnt; 148 unsigned long bv_cnt = 0; 149 bool is_sync = false; 150 size_t len = 0, total_len = 0; 151 ssize_t ret = 0; 152 loff_t pos; 153 int i; 154 struct scatterlist *sg; 155 156 if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC) 157 is_sync = true; 158 159 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift; 160 if (unlikely(pos + req->transfer_len > req->ns->size)) { 161 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 162 return true; 163 } 164 165 memset(&req->f.iocb, 0, sizeof(struct kiocb)); 166 for_each_sg(req->sg, sg, req->sg_cnt, i) { 167 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg); 168 len += req->f.bvec[bv_cnt].bv_len; 169 total_len += req->f.bvec[bv_cnt].bv_len; 170 bv_cnt++; 171 172 WARN_ON_ONCE((nr_bvec - 1) < 0); 173 174 if (unlikely(is_sync) && 175 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { 176 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0); 177 if (ret < 0) 178 goto complete; 179 180 pos += len; 181 bv_cnt = 0; 182 len = 0; 183 } 184 nr_bvec--; 185 } 186 187 if (WARN_ON_ONCE(total_len != req->transfer_len)) { 188 ret = -EIO; 189 goto complete; 190 } 191 192 if (unlikely(is_sync)) { 193 ret = total_len; 194 goto complete; 195 } 196 197 /* 198 * A NULL ki_complete ask for synchronous execution, which we want 199 * for the IOCB_NOWAIT case. 200 */ 201 if (!(ki_flags & IOCB_NOWAIT)) 202 req->f.iocb.ki_complete = nvmet_file_io_done; 203 204 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags); 205 206 switch (ret) { 207 case -EIOCBQUEUED: 208 return true; 209 case -EAGAIN: 210 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT))) 211 goto complete; 212 return false; 213 case -EOPNOTSUPP: 214 /* 215 * For file systems returning error -EOPNOTSUPP, handle 216 * IOCB_NOWAIT error case separately and retry without 217 * IOCB_NOWAIT. 218 */ 219 if ((ki_flags & IOCB_NOWAIT)) 220 return false; 221 break; 222 } 223 224 complete: 225 nvmet_file_io_done(&req->f.iocb, ret, 0); 226 return true; 227 } 228 229 static void nvmet_file_buffered_io_work(struct work_struct *w) 230 { 231 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 232 233 nvmet_file_execute_io(req, 0); 234 } 235 236 static void nvmet_file_submit_buffered_io(struct nvmet_req *req) 237 { 238 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work); 239 queue_work(buffered_io_wq, &req->f.work); 240 } 241 242 static void nvmet_file_execute_rw(struct nvmet_req *req) 243 { 244 ssize_t nr_bvec = req->sg_cnt; 245 246 if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req))) 247 return; 248 249 if (!req->sg_cnt || !nr_bvec) { 250 nvmet_req_complete(req, 0); 251 return; 252 } 253 254 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC) 255 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), 256 GFP_KERNEL); 257 else 258 req->f.bvec = req->inline_bvec; 259 260 if (unlikely(!req->f.bvec)) { 261 /* fallback under memory pressure */ 262 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL); 263 req->f.mpool_alloc = true; 264 } else 265 req->f.mpool_alloc = false; 266 267 if (req->ns->buffered_io) { 268 if (likely(!req->f.mpool_alloc) && 269 nvmet_file_execute_io(req, IOCB_NOWAIT)) 270 return; 271 nvmet_file_submit_buffered_io(req); 272 } else 273 nvmet_file_execute_io(req, 0); 274 } 275 276 u16 nvmet_file_flush(struct nvmet_req *req) 277 { 278 return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1)); 279 } 280 281 static void nvmet_file_flush_work(struct work_struct *w) 282 { 283 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 284 285 nvmet_req_complete(req, nvmet_file_flush(req)); 286 } 287 288 static void nvmet_file_execute_flush(struct nvmet_req *req) 289 { 290 if (!nvmet_check_transfer_len(req, 0)) 291 return; 292 INIT_WORK(&req->f.work, nvmet_file_flush_work); 293 schedule_work(&req->f.work); 294 } 295 296 static void nvmet_file_execute_discard(struct nvmet_req *req) 297 { 298 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; 299 struct nvme_dsm_range range; 300 loff_t offset, len; 301 u16 status = 0; 302 int ret; 303 int i; 304 305 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) { 306 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range, 307 sizeof(range)); 308 if (status) 309 break; 310 311 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift; 312 len = le32_to_cpu(range.nlb); 313 len <<= req->ns->blksize_shift; 314 if (offset + len > req->ns->size) { 315 req->error_slba = le64_to_cpu(range.slba); 316 status = errno_to_nvme_status(req, -ENOSPC); 317 break; 318 } 319 320 ret = vfs_fallocate(req->ns->file, mode, offset, len); 321 if (ret && ret != -EOPNOTSUPP) { 322 req->error_slba = le64_to_cpu(range.slba); 323 status = errno_to_nvme_status(req, ret); 324 break; 325 } 326 } 327 328 nvmet_req_complete(req, status); 329 } 330 331 static void nvmet_file_dsm_work(struct work_struct *w) 332 { 333 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 334 335 switch (le32_to_cpu(req->cmd->dsm.attributes)) { 336 case NVME_DSMGMT_AD: 337 nvmet_file_execute_discard(req); 338 return; 339 case NVME_DSMGMT_IDR: 340 case NVME_DSMGMT_IDW: 341 default: 342 /* Not supported yet */ 343 nvmet_req_complete(req, 0); 344 return; 345 } 346 } 347 348 static void nvmet_file_execute_dsm(struct nvmet_req *req) 349 { 350 if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req))) 351 return; 352 INIT_WORK(&req->f.work, nvmet_file_dsm_work); 353 schedule_work(&req->f.work); 354 } 355 356 static void nvmet_file_write_zeroes_work(struct work_struct *w) 357 { 358 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 359 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes; 360 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE; 361 loff_t offset; 362 loff_t len; 363 int ret; 364 365 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift; 366 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) << 367 req->ns->blksize_shift); 368 369 if (unlikely(offset + len > req->ns->size)) { 370 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 371 return; 372 } 373 374 ret = vfs_fallocate(req->ns->file, mode, offset, len); 375 nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0); 376 } 377 378 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req) 379 { 380 if (!nvmet_check_transfer_len(req, 0)) 381 return; 382 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work); 383 schedule_work(&req->f.work); 384 } 385 386 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req) 387 { 388 struct nvme_command *cmd = req->cmd; 389 390 switch (cmd->common.opcode) { 391 case nvme_cmd_read: 392 case nvme_cmd_write: 393 req->execute = nvmet_file_execute_rw; 394 return 0; 395 case nvme_cmd_flush: 396 req->execute = nvmet_file_execute_flush; 397 return 0; 398 case nvme_cmd_dsm: 399 req->execute = nvmet_file_execute_dsm; 400 return 0; 401 case nvme_cmd_write_zeroes: 402 req->execute = nvmet_file_execute_write_zeroes; 403 return 0; 404 default: 405 return nvmet_report_invalid_opcode(req); 406 } 407 } 408