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 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->transfer_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->transfer_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->transfer_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 (!nvmet_check_data_len(req, nvmet_rw_len(req)))
 236                 return;
 237
 238         if (!req->sg_cnt || !nr_bvec) {
 239                 nvmet_req_complete(req, 0);
 240                 return;
 241         }
 242
 243         if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
 244                 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 245                                 GFP_KERNEL);
 246         else
 247                 req->f.bvec = req->inline_bvec;
 248
 249         if (unlikely(!req->f.bvec)) {
 250                 /* fallback under memory pressure */
 251                 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
 252                 req->f.mpool_alloc = true;
 253         } else
 254                 req->f.mpool_alloc = false;
 255
 256         if (req->ns->buffered_io) {
 257                 if (likely(!req->f.mpool_alloc) &&
 258                                 nvmet_file_execute_io(req, IOCB_NOWAIT))
 259                         return;
 260                 nvmet_file_submit_buffered_io(req);
 261         } else
 262                 nvmet_file_execute_io(req, 0);
 263 }
 264
 265 u16 nvmet_file_flush(struct nvmet_req *req)
 266 {
 267         return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
 268 }
 269
 270 static void nvmet_file_flush_work(struct work_struct *w)
 271 {
 272         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 273
 274         nvmet_req_complete(req, nvmet_file_flush(req));
 275 }
 276
 277 static void nvmet_file_execute_flush(struct nvmet_req *req)
 278 {
 279         if (!nvmet_check_data_len(req, 0))
 280                 return;
 281         INIT_WORK(&req->f.work, nvmet_file_flush_work);
 282         schedule_work(&req->f.work);
 283 }
 284
 285 static void nvmet_file_execute_discard(struct nvmet_req *req)
 286 {
 287         int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 288         struct nvme_dsm_range range;
 289         loff_t offset, len;
 290         u16 status = 0;
 291         int ret;
 292         int i;
 293
 294         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 295                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 296                                         sizeof(range));
 297                 if (status)
 298                         break;
 299
 300                 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 301                 len = le32_to_cpu(range.nlb);
 302                 len <<= req->ns->blksize_shift;
 303                 if (offset + len > req->ns->size) {
 304                         req->error_slba = le64_to_cpu(range.slba);
 305                         status = errno_to_nvme_status(req, -ENOSPC);
 306                         break;
 307                 }
 308
 309                 ret = vfs_fallocate(req->ns->file, mode, offset, len);
 310                 if (ret && ret != -EOPNOTSUPP) {
 311                         req->error_slba = le64_to_cpu(range.slba);
 312                         status = errno_to_nvme_status(req, ret);
 313                         break;
 314                 }
 315         }
 316
 317         nvmet_req_complete(req, status);
 318 }
 319
 320 static void nvmet_file_dsm_work(struct work_struct *w)
 321 {
 322         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 323
 324         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 325         case NVME_DSMGMT_AD:
 326                 nvmet_file_execute_discard(req);
 327                 return;
 328         case NVME_DSMGMT_IDR:
 329         case NVME_DSMGMT_IDW:
 330         default:
 331                 /* Not supported yet */
 332                 nvmet_req_complete(req, 0);
 333                 return;
 334         }
 335 }
 336
 337 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 338 {
 339         if (!nvmet_check_data_len(req, nvmet_dsm_len(req)))
 340                 return;
 341         INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 342         schedule_work(&req->f.work);
 343 }
 344
 345 static void nvmet_file_write_zeroes_work(struct work_struct *w)
 346 {
 347         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 348         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 349         int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
 350         loff_t offset;
 351         loff_t len;
 352         int ret;
 353
 354         offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
 355         len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 356                         req->ns->blksize_shift);
 357
 358         if (unlikely(offset + len > req->ns->size)) {
 359                 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 360                 return;
 361         }
 362
 363         ret = vfs_fallocate(req->ns->file, mode, offset, len);
 364         nvmet_req_complete(req, ret < 0 ? errno_to_nvme_status(req, ret) : 0);
 365 }
 366
 367 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
 368 {
 369         if (!nvmet_check_data_len(req, 0))
 370                 return;
 371         INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
 372         schedule_work(&req->f.work);
 373 }
 374
 375 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 376 {
 377         struct nvme_command *cmd = req->cmd;
 378
 379         switch (cmd->common.opcode) {
 380         case nvme_cmd_read:
 381         case nvme_cmd_write:
 382                 req->execute = nvmet_file_execute_rw;
 383                 return 0;
 384         case nvme_cmd_flush:
 385                 req->execute = nvmet_file_execute_flush;
 386                 return 0;
 387         case nvme_cmd_dsm:
 388                 req->execute = nvmet_file_execute_dsm;
 389                 return 0;
 390         case nvme_cmd_write_zeroes:
 391                 req->execute = nvmet_file_execute_write_zeroes;
 392                 return 0;
 393         default:
 394                 pr_err("unhandled cmd for file ns %d on qid %d\n",
 395                                 cmd->common.opcode, req->sq->qid);
 396                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 397                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 398         }
 399 }