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