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 <linux/fs.h>
  12 #include "nvmet.h"
  13
  14 #define NVMET_MAX_MPOOL_BVEC            16
  15 #define NVMET_MIN_MPOOL_OBJ             16
  16
  17 void nvmet_file_ns_revalidate(struct nvmet_ns *ns)
  18 {
  19         ns->size = i_size_read(ns->file->f_mapping->host);
  20 }
  21
  22 void nvmet_file_ns_disable(struct nvmet_ns *ns)
  23 {
  24         if (ns->file) {
  25                 if (ns->buffered_io)
  26                         flush_workqueue(buffered_io_wq);
  27                 mempool_destroy(ns->bvec_pool);
  28                 ns->bvec_pool = NULL;
  29                 kmem_cache_destroy(ns->bvec_cache);
  30                 ns->bvec_cache = NULL;
  31                 fput(ns->file);
  32                 ns->file = NULL;
  33         }
  34 }
  35
  36 int nvmet_file_ns_enable(struct nvmet_ns *ns)
  37 {
  38         int flags = O_RDWR | O_LARGEFILE;
  39         int ret = 0;
  40
  41         if (!ns->buffered_io)
  42                 flags |= O_DIRECT;
  43
  44         ns->file = filp_open(ns->device_path, flags, 0);
  45         if (IS_ERR(ns->file)) {
  46                 ret = PTR_ERR(ns->file);
  47                 pr_err("failed to open file %s: (%d)\n",
  48                         ns->device_path, ret);
  49                 ns->file = NULL;
  50                 return ret;
  51         }
  52
  53         nvmet_file_ns_revalidate(ns);
  54
  55         /*
  56          * i_blkbits can be greater than the universally accepted upper bound,
  57          * so make sure we export a sane namespace lba_shift.
  58          */
  59         ns->blksize_shift = min_t(u8,
  60                         file_inode(ns->file)->i_blkbits, 12);
  61
  62         ns->bvec_cache = kmem_cache_create("nvmet-bvec",
  63                         NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
  64                         0, SLAB_HWCACHE_ALIGN, NULL);
  65         if (!ns->bvec_cache) {
  66                 ret = -ENOMEM;
  67                 goto err;
  68         }
  69
  70         ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
  71                         mempool_free_slab, ns->bvec_cache);
  72
  73         if (!ns->bvec_pool) {
  74                 ret = -ENOMEM;
  75                 goto err;
  76         }
  77
  78         return ret;
  79 err:
  80         ns->size = 0;
  81         ns->blksize_shift = 0;
  82         nvmet_file_ns_disable(ns);
  83         return ret;
  84 }
  85
  86 static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg)
  87 {
  88         bv->bv_page = sg_page(sg);
  89         bv->bv_offset = sg->offset;
  90         bv->bv_len = sg->length;
  91 }
  92
  93 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
  94                 unsigned long nr_segs, size_t count, int ki_flags)
  95 {
  96         struct kiocb *iocb = &req->f.iocb;
  97         ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
  98         struct iov_iter iter;
  99         int rw;
 100
 101         if (req->cmd->rw.opcode == nvme_cmd_write) {
 102                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
 103                         ki_flags |= IOCB_DSYNC;
 104                 call_iter = req->ns->file->f_op->write_iter;
 105                 rw = WRITE;
 106         } else {
 107                 call_iter = req->ns->file->f_op->read_iter;
 108                 rw = READ;
 109         }
 110
 111         iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
 112
 113         iocb->ki_pos = pos;
 114         iocb->ki_filp = req->ns->file;
 115         iocb->ki_flags = ki_flags | iocb->ki_filp->f_iocb_flags;
 116
 117         return call_iter(iocb, &iter);
 118 }
 119
 120 static void nvmet_file_io_done(struct kiocb *iocb, long ret)
 121 {
 122         struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
 123         u16 status = NVME_SC_SUCCESS;
 124
 125         if (req->f.bvec != req->inline_bvec) {
 126                 if (likely(req->f.mpool_alloc == false))
 127                         kfree(req->f.bvec);
 128                 else
 129                         mempool_free(req->f.bvec, req->ns->bvec_pool);
 130         }
 131
 132         if (unlikely(ret != req->transfer_len))
 133                 status = errno_to_nvme_status(req, ret);
 134         nvmet_req_complete(req, status);
 135 }
 136
 137 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
 138 {
 139         ssize_t nr_bvec = req->sg_cnt;
 140         unsigned long bv_cnt = 0;
 141         bool is_sync = false;
 142         size_t len = 0, total_len = 0;
 143         ssize_t ret = 0;
 144         loff_t pos;
 145         int i;
 146         struct scatterlist *sg;
 147
 148         if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
 149                 is_sync = true;
 150
 151         pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 152         if (unlikely(pos + req->transfer_len > req->ns->size)) {
 153                 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 154                 return true;
 155         }
 156
 157         memset(&req->f.iocb, 0, sizeof(struct kiocb));
 158         for_each_sg(req->sg, sg, req->sg_cnt, i) {
 159                 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
 160                 len += req->f.bvec[bv_cnt].bv_len;
 161                 total_len += req->f.bvec[bv_cnt].bv_len;
 162                 bv_cnt++;
 163
 164                 WARN_ON_ONCE((nr_bvec - 1) < 0);
 165
 166                 if (unlikely(is_sync) &&
 167                     (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
 168                         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0);
 169                         if (ret < 0)
 170                                 goto complete;
 171
 172                         pos += len;
 173                         bv_cnt = 0;
 174                         len = 0;
 175                 }
 176                 nr_bvec--;
 177         }
 178
 179         if (WARN_ON_ONCE(total_len != req->transfer_len)) {
 180                 ret = -EIO;
 181                 goto complete;
 182         }
 183
 184         if (unlikely(is_sync)) {
 185                 ret = total_len;
 186                 goto complete;
 187         }
 188
 189         /*
 190          * A NULL ki_complete ask for synchronous execution, which we want
 191          * for the IOCB_NOWAIT case.
 192          */
 193         if (!(ki_flags & IOCB_NOWAIT))
 194                 req->f.iocb.ki_complete = nvmet_file_io_done;
 195
 196         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags);
 197
 198         switch (ret) {
 199         case -EIOCBQUEUED:
 200                 return true;
 201         case -EAGAIN:
 202                 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
 203                         goto complete;
 204                 return false;
 205         case -EOPNOTSUPP:
 206                 /*
 207                  * For file systems returning error -EOPNOTSUPP, handle
 208                  * IOCB_NOWAIT error case separately and retry without
 209                  * IOCB_NOWAIT.
 210                  */
 211                 if ((ki_flags & IOCB_NOWAIT))
 212                         return false;
 213                 break;
 214         }
 215
 216 complete:
 217         nvmet_file_io_done(&req->f.iocb, ret);
 218         return true;
 219 }
 220
 221 static void nvmet_file_buffered_io_work(struct work_struct *w)
 222 {
 223         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 224
 225         nvmet_file_execute_io(req, 0);
 226 }
 227
 228 static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
 229 {
 230         INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
 231         queue_work(buffered_io_wq, &req->f.work);
 232 }
 233
 234 static void nvmet_file_execute_rw(struct nvmet_req *req)
 235 {
 236         ssize_t nr_bvec = req->sg_cnt;
 237
 238         if (!nvmet_check_transfer_len(req, nvmet_rw_data_len(req)))
 239                 return;
 240
 241         if (!req->sg_cnt || !nr_bvec) {
 242                 nvmet_req_complete(req, 0);
 243                 return;
 244         }
 245
 246         if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
 247                 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 248                                 GFP_KERNEL);
 249         else
 250                 req->f.bvec = req->inline_bvec;
 251
 252         if (unlikely(!req->f.bvec)) {
 253                 /* fallback under memory pressure */
 254                 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
 255                 req->f.mpool_alloc = true;
 256         } else
 257                 req->f.mpool_alloc = false;
 258
 259         if (req->ns->buffered_io) {
 260                 if (likely(!req->f.mpool_alloc) &&
 261                     (req->ns->file->f_mode & FMODE_NOWAIT) &&
 262                     nvmet_file_execute_io(req, IOCB_NOWAIT))
 263                         return;
 264                 nvmet_file_submit_buffered_io(req);
 265         } else
 266                 nvmet_file_execute_io(req, 0);
 267 }
 268
 269 u16 nvmet_file_flush(struct nvmet_req *req)
 270 {
 271         return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
 272 }
 273
 274 static void nvmet_file_flush_work(struct work_struct *w)
 275 {
 276         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 277
 278         nvmet_req_complete(req, nvmet_file_flush(req));
 279 }
 280
 281 static void nvmet_file_execute_flush(struct nvmet_req *req)
 282 {
 283         if (!nvmet_check_transfer_len(req, 0))
 284                 return;
 285         INIT_WORK(&req->f.work, nvmet_file_flush_work);
 286         queue_work(nvmet_wq, &req->f.work);
 287 }
 288
 289 static void nvmet_file_execute_discard(struct nvmet_req *req)
 290 {
 291         int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 292         struct nvme_dsm_range range;
 293         loff_t offset, len;
 294         u16 status = 0;
 295         int ret;
 296         int i;
 297
 298         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 299                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 300                                         sizeof(range));
 301                 if (status)
 302                         break;
 303
 304                 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 305                 len = le32_to_cpu(range.nlb);
 306                 len <<= req->ns->blksize_shift;
 307                 if (offset + len > req->ns->size) {
 308                         req->error_slba = le64_to_cpu(range.slba);
 309                         status = errno_to_nvme_status(req, -ENOSPC);
 310                         break;
 311                 }
 312
 313                 ret = vfs_fallocate(req->ns->file, mode, offset, len);
 314                 if (ret && ret != -EOPNOTSUPP) {
 315                         req->error_slba = le64_to_cpu(range.slba);
 316                         status = errno_to_nvme_status(req, ret);
 317                         break;
 318                 }
 319         }
 320
 321         nvmet_req_complete(req, status);
 322 }
 323
 324 static void nvmet_file_dsm_work(struct work_struct *w)
 325 {
 326         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 327
 328         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 329         case NVME_DSMGMT_AD:
 330                 nvmet_file_execute_discard(req);
 331                 return;
 332         case NVME_DSMGMT_IDR:
 333         case NVME_DSMGMT_IDW:
 334         default:
 335                 /* Not supported yet */
 336                 nvmet_req_complete(req, 0);
 337                 return;
 338         }
 339 }
 340
 341 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 342 {
 343         if (!nvmet_check_data_len_lte(req, nvmet_dsm_len(req)))
 344                 return;
 345         INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 346         queue_work(nvmet_wq, &req->f.work);
 347 }
 348
 349 static void nvmet_file_write_zeroes_work(struct work_struct *w)
 350 {
 351         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 352         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 353         int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
 354         loff_t offset;
 355         loff_t len;
 356         int ret;
 357
 358         offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
 359         len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 360                         req->ns->blksize_shift);
 361
 362         if (unlikely(offset + len > req->ns->size)) {
 363                 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 364                 return;
 365         }
 366
 367         ret = vfs_fallocate(req->ns->file, mode, offset, len);
 368         nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
 369 }
 370
 371 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
 372 {
 373         if (!nvmet_check_transfer_len(req, 0))
 374                 return;
 375         INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
 376         queue_work(nvmet_wq, &req->f.work);
 377 }
 378
 379 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 380 {
 381         switch (req->cmd->common.opcode) {
 382         case nvme_cmd_read:
 383         case nvme_cmd_write:
 384                 req->execute = nvmet_file_execute_rw;
 385                 return 0;
 386         case nvme_cmd_flush:
 387                 req->execute = nvmet_file_execute_flush;
 388                 return 0;
 389         case nvme_cmd_dsm:
 390                 req->execute = nvmet_file_execute_dsm;
 391                 return 0;
 392         case nvme_cmd_write_zeroes:
 393                 req->execute = nvmet_file_execute_write_zeroes;
 394                 return 0;
 395         default:
 396                 return nvmet_report_invalid_opcode(req);
 397         }
 398 }