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 <linux/fs.h> 12 #include "nvmet.h" 13 14 #define NVMET_MAX_MPOOL_BVEC 16 15 #define NVMET_MIN_MPOOL_OBJ 16 16 17 int nvmet_file_ns_revalidate(struct nvmet_ns *ns) 18 { 19 struct kstat stat; 20 int ret; 21 22 ret = vfs_getattr(&ns->file->f_path, &stat, STATX_SIZE, 23 AT_STATX_FORCE_SYNC); 24 if (!ret) 25 ns->size = stat.size; 26 return ret; 27 } 28 29 void nvmet_file_ns_disable(struct nvmet_ns *ns) 30 { 31 if (ns->file) { 32 if (ns->buffered_io) 33 flush_workqueue(buffered_io_wq); 34 mempool_destroy(ns->bvec_pool); 35 ns->bvec_pool = NULL; 36 kmem_cache_destroy(ns->bvec_cache); 37 ns->bvec_cache = NULL; 38 fput(ns->file); 39 ns->file = NULL; 40 } 41 } 42 43 int nvmet_file_ns_enable(struct nvmet_ns *ns) 44 { 45 int flags = O_RDWR | O_LARGEFILE; 46 int ret; 47 48 if (!ns->buffered_io) 49 flags |= O_DIRECT; 50 51 ns->file = filp_open(ns->device_path, flags, 0); 52 if (IS_ERR(ns->file)) { 53 ret = PTR_ERR(ns->file); 54 pr_err("failed to open file %s: (%d)\n", 55 ns->device_path, ret); 56 ns->file = NULL; 57 return ret; 58 } 59 60 ret = nvmet_file_ns_revalidate(ns); 61 if (ret) 62 goto err; 63 64 /* 65 * i_blkbits can be greater than the universally accepted upper bound, 66 * so make sure we export a sane namespace lba_shift. 67 */ 68 ns->blksize_shift = min_t(u8, 69 file_inode(ns->file)->i_blkbits, 12); 70 71 ns->bvec_cache = kmem_cache_create("nvmet-bvec", 72 NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec), 73 0, SLAB_HWCACHE_ALIGN, NULL); 74 if (!ns->bvec_cache) { 75 ret = -ENOMEM; 76 goto err; 77 } 78 79 ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab, 80 mempool_free_slab, ns->bvec_cache); 81 82 if (!ns->bvec_pool) { 83 ret = -ENOMEM; 84 goto err; 85 } 86 87 return ret; 88 err: 89 ns->size = 0; 90 ns->blksize_shift = 0; 91 nvmet_file_ns_disable(ns); 92 return ret; 93 } 94 95 static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg) 96 { 97 bv->bv_page = sg_page(sg); 98 bv->bv_offset = sg->offset; 99 bv->bv_len = sg->length; 100 } 101 102 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos, 103 unsigned long nr_segs, size_t count, int ki_flags) 104 { 105 struct kiocb *iocb = &req->f.iocb; 106 ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter); 107 struct iov_iter iter; 108 int rw; 109 110 if (req->cmd->rw.opcode == nvme_cmd_write) { 111 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA)) 112 ki_flags |= IOCB_DSYNC; 113 call_iter = req->ns->file->f_op->write_iter; 114 rw = WRITE; 115 } else { 116 call_iter = req->ns->file->f_op->read_iter; 117 rw = READ; 118 } 119 120 iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count); 121 122 iocb->ki_pos = pos; 123 iocb->ki_filp = req->ns->file; 124 iocb->ki_flags = ki_flags | iocb_flags(req->ns->file); 125 126 return call_iter(iocb, &iter); 127 } 128 129 static void nvmet_file_io_done(struct kiocb *iocb, long ret) 130 { 131 struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb); 132 u16 status = NVME_SC_SUCCESS; 133 134 if (req->f.bvec != req->inline_bvec) { 135 if (likely(req->f.mpool_alloc == false)) 136 kfree(req->f.bvec); 137 else 138 mempool_free(req->f.bvec, req->ns->bvec_pool); 139 } 140 141 if (unlikely(ret != req->transfer_len)) 142 status = errno_to_nvme_status(req, ret); 143 nvmet_req_complete(req, status); 144 } 145 146 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags) 147 { 148 ssize_t nr_bvec = req->sg_cnt; 149 unsigned long bv_cnt = 0; 150 bool is_sync = false; 151 size_t len = 0, total_len = 0; 152 ssize_t ret = 0; 153 loff_t pos; 154 int i; 155 struct scatterlist *sg; 156 157 if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC) 158 is_sync = true; 159 160 pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift; 161 if (unlikely(pos + req->transfer_len > req->ns->size)) { 162 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 163 return true; 164 } 165 166 memset(&req->f.iocb, 0, sizeof(struct kiocb)); 167 for_each_sg(req->sg, sg, req->sg_cnt, i) { 168 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg); 169 len += req->f.bvec[bv_cnt].bv_len; 170 total_len += req->f.bvec[bv_cnt].bv_len; 171 bv_cnt++; 172 173 WARN_ON_ONCE((nr_bvec - 1) < 0); 174 175 if (unlikely(is_sync) && 176 (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) { 177 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0); 178 if (ret < 0) 179 goto complete; 180 181 pos += len; 182 bv_cnt = 0; 183 len = 0; 184 } 185 nr_bvec--; 186 } 187 188 if (WARN_ON_ONCE(total_len != req->transfer_len)) { 189 ret = -EIO; 190 goto complete; 191 } 192 193 if (unlikely(is_sync)) { 194 ret = total_len; 195 goto complete; 196 } 197 198 /* 199 * A NULL ki_complete ask for synchronous execution, which we want 200 * for the IOCB_NOWAIT case. 201 */ 202 if (!(ki_flags & IOCB_NOWAIT)) 203 req->f.iocb.ki_complete = nvmet_file_io_done; 204 205 ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags); 206 207 switch (ret) { 208 case -EIOCBQUEUED: 209 return true; 210 case -EAGAIN: 211 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT))) 212 goto complete; 213 return false; 214 case -EOPNOTSUPP: 215 /* 216 * For file systems returning error -EOPNOTSUPP, handle 217 * IOCB_NOWAIT error case separately and retry without 218 * IOCB_NOWAIT. 219 */ 220 if ((ki_flags & IOCB_NOWAIT)) 221 return false; 222 break; 223 } 224 225 complete: 226 nvmet_file_io_done(&req->f.iocb, ret); 227 return true; 228 } 229 230 static void nvmet_file_buffered_io_work(struct work_struct *w) 231 { 232 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 233 234 nvmet_file_execute_io(req, 0); 235 } 236 237 static void nvmet_file_submit_buffered_io(struct nvmet_req *req) 238 { 239 INIT_WORK(&req->f.work, nvmet_file_buffered_io_work); 240 queue_work(buffered_io_wq, &req->f.work); 241 } 242 243 static void nvmet_file_execute_rw(struct nvmet_req *req) 244 { 245 ssize_t nr_bvec = req->sg_cnt; 246 247 if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req))) 248 return; 249 250 if (!req->sg_cnt || !nr_bvec) { 251 nvmet_req_complete(req, 0); 252 return; 253 } 254 255 if (nr_bvec > NVMET_MAX_INLINE_BIOVEC) 256 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec), 257 GFP_KERNEL); 258 else 259 req->f.bvec = req->inline_bvec; 260 261 if (unlikely(!req->f.bvec)) { 262 /* fallback under memory pressure */ 263 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL); 264 req->f.mpool_alloc = true; 265 } else 266 req->f.mpool_alloc = false; 267 268 if (req->ns->buffered_io) { 269 if (likely(!req->f.mpool_alloc) && 270 (req->ns->file->f_mode & FMODE_NOWAIT) && 271 nvmet_file_execute_io(req, IOCB_NOWAIT)) 272 return; 273 nvmet_file_submit_buffered_io(req); 274 } else 275 nvmet_file_execute_io(req, 0); 276 } 277 278 u16 nvmet_file_flush(struct nvmet_req *req) 279 { 280 return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1)); 281 } 282 283 static void nvmet_file_flush_work(struct work_struct *w) 284 { 285 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 286 287 nvmet_req_complete(req, nvmet_file_flush(req)); 288 } 289 290 static void nvmet_file_execute_flush(struct nvmet_req *req) 291 { 292 if (!nvmet_check_transfer_len(req, 0)) 293 return; 294 INIT_WORK(&req->f.work, nvmet_file_flush_work); 295 schedule_work(&req->f.work); 296 } 297 298 static void nvmet_file_execute_discard(struct nvmet_req *req) 299 { 300 int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; 301 struct nvme_dsm_range range; 302 loff_t offset, len; 303 u16 status = 0; 304 int ret; 305 int i; 306 307 for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) { 308 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range, 309 sizeof(range)); 310 if (status) 311 break; 312 313 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift; 314 len = le32_to_cpu(range.nlb); 315 len <<= req->ns->blksize_shift; 316 if (offset + len > req->ns->size) { 317 req->error_slba = le64_to_cpu(range.slba); 318 status = errno_to_nvme_status(req, -ENOSPC); 319 break; 320 } 321 322 ret = vfs_fallocate(req->ns->file, mode, offset, len); 323 if (ret && ret != -EOPNOTSUPP) { 324 req->error_slba = le64_to_cpu(range.slba); 325 status = errno_to_nvme_status(req, ret); 326 break; 327 } 328 } 329 330 nvmet_req_complete(req, status); 331 } 332 333 static void nvmet_file_dsm_work(struct work_struct *w) 334 { 335 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 336 337 switch (le32_to_cpu(req->cmd->dsm.attributes)) { 338 case NVME_DSMGMT_AD: 339 nvmet_file_execute_discard(req); 340 return; 341 case NVME_DSMGMT_IDR: 342 case NVME_DSMGMT_IDW: 343 default: 344 /* Not supported yet */ 345 nvmet_req_complete(req, 0); 346 return; 347 } 348 } 349 350 static void nvmet_file_execute_dsm(struct nvmet_req *req) 351 { 352 if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req))) 353 return; 354 INIT_WORK(&req->f.work, nvmet_file_dsm_work); 355 schedule_work(&req->f.work); 356 } 357 358 static void nvmet_file_write_zeroes_work(struct work_struct *w) 359 { 360 struct nvmet_req *req = container_of(w, struct nvmet_req, f.work); 361 struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes; 362 int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE; 363 loff_t offset; 364 loff_t len; 365 int ret; 366 367 offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift; 368 len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) << 369 req->ns->blksize_shift); 370 371 if (unlikely(offset + len > req->ns->size)) { 372 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC)); 373 return; 374 } 375 376 ret = vfs_fallocate(req->ns->file, mode, offset, len); 377 nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0); 378 } 379 380 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req) 381 { 382 if (!nvmet_check_transfer_len(req, 0)) 383 return; 384 INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work); 385 schedule_work(&req->f.work); 386 } 387 388 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req) 389 { 390 switch (req->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