drivers/nvme/target/io-cmd-file.c

   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                 pr_err("unhandled cmd for file ns %d on qid %d\n",
 404                                 cmd->common.opcode, req->sq->qid);
 405                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 406                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 407         }
 408 }