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