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_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 }