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