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         ns->blksize_shift = file_inode(ns->file)->i_blkbits;
  53
  54         ns->bvec_cache = kmem_cache_create("nvmet-bvec",
  55                         NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
  56                         0, SLAB_HWCACHE_ALIGN, NULL);
  57         if (!ns->bvec_cache) {
  58                 ret = -ENOMEM;
  59                 goto err;
  60         }
  61
  62         ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
  63                         mempool_free_slab, ns->bvec_cache);
  64
  65         if (!ns->bvec_pool) {
  66                 ret = -ENOMEM;
  67                 goto err;
  68         }
  69
  70         return ret;
  71 err:
  72         ns->size = 0;
  73         ns->blksize_shift = 0;
  74         nvmet_file_ns_disable(ns);
  75         return ret;
  76 }
  77
  78 static void nvmet_file_init_bvec(struct bio_vec *bv, struct scatterlist *sg)
  79 {
  80         bv->bv_page = sg_page(sg);
  81         bv->bv_offset = sg->offset;
  82         bv->bv_len = sg->length;
  83 }
  84
  85 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
  86                 unsigned long nr_segs, size_t count, int ki_flags)
  87 {
  88         struct kiocb *iocb = &req->f.iocb;
  89         ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
  90         struct iov_iter iter;
  91         int rw;
  92
  93         if (req->cmd->rw.opcode == nvme_cmd_write) {
  94                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  95                         ki_flags |= IOCB_DSYNC;
  96                 call_iter = req->ns->file->f_op->write_iter;
  97                 rw = WRITE;
  98         } else {
  99                 call_iter = req->ns->file->f_op->read_iter;
 100                 rw = READ;
 101         }
 102
 103         iov_iter_bvec(&iter, rw, req->f.bvec, nr_segs, count);
 104
 105         iocb->ki_pos = pos;
 106         iocb->ki_filp = req->ns->file;
 107         iocb->ki_flags = ki_flags | iocb_flags(req->ns->file);
 108
 109         return call_iter(iocb, &iter);
 110 }
 111
 112 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 113 {
 114         struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
 115         u16 status = NVME_SC_SUCCESS;
 116
 117         if (req->f.bvec != req->inline_bvec) {
 118                 if (likely(req->f.mpool_alloc == false))
 119                         kfree(req->f.bvec);
 120                 else
 121                         mempool_free(req->f.bvec, req->ns->bvec_pool);
 122         }
 123
 124         if (unlikely(ret != req->data_len))
 125                 status = errno_to_nvme_status(req, ret);
 126         nvmet_req_complete(req, status);
 127 }
 128
 129 static bool nvmet_file_execute_io(struct nvmet_req *req, int ki_flags)
 130 {
 131         ssize_t nr_bvec = req->sg_cnt;
 132         unsigned long bv_cnt = 0;
 133         bool is_sync = false;
 134         size_t len = 0, total_len = 0;
 135         ssize_t ret = 0;
 136         loff_t pos;
 137         int i;
 138         struct scatterlist *sg;
 139
 140         if (req->f.mpool_alloc && nr_bvec > NVMET_MAX_MPOOL_BVEC)
 141                 is_sync = true;
 142
 143         pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 144         if (unlikely(pos + req->data_len > req->ns->size)) {
 145                 nvmet_req_complete(req, errno_to_nvme_status(req, -ENOSPC));
 146                 return true;
 147         }
 148
 149         memset(&req->f.iocb, 0, sizeof(struct kiocb));
 150         for_each_sg(req->sg, sg, req->sg_cnt, i) {
 151                 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], sg);
 152                 len += req->f.bvec[bv_cnt].bv_len;
 153                 total_len += req->f.bvec[bv_cnt].bv_len;
 154                 bv_cnt++;
 155
 156                 WARN_ON_ONCE((nr_bvec - 1) < 0);
 157
 158                 if (unlikely(is_sync) &&
 159                     (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
 160                         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len, 0);
 161                         if (ret < 0)
 162                                 goto complete;
 163
 164                         pos += len;
 165                         bv_cnt = 0;
 166                         len = 0;
 167                 }
 168                 nr_bvec--;
 169         }
 170
 171         if (WARN_ON_ONCE(total_len != req->data_len)) {
 172                 ret = -EIO;
 173                 goto complete;
 174         }
 175
 176         if (unlikely(is_sync)) {
 177                 ret = total_len;
 178                 goto complete;
 179         }
 180
 181         /*
 182          * A NULL ki_complete ask for synchronous execution, which we want
 183          * for the IOCB_NOWAIT case.
 184          */
 185         if (!(ki_flags & IOCB_NOWAIT))
 186                 req->f.iocb.ki_complete = nvmet_file_io_done;
 187
 188         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, total_len, ki_flags);
 189
 190         switch (ret) {
 191         case -EIOCBQUEUED:
 192                 return true;
 193         case -EAGAIN:
 194                 if (WARN_ON_ONCE(!(ki_flags & IOCB_NOWAIT)))
 195                         goto complete;
 196                 return false;
 197         case -EOPNOTSUPP:
 198                 /*
 199                  * For file systems returning error -EOPNOTSUPP, handle
 200                  * IOCB_NOWAIT error case separately and retry without
 201                  * IOCB_NOWAIT.
 202                  */
 203                 if ((ki_flags & IOCB_NOWAIT))
 204                         return false;
 205                 break;
 206         }
 207
 208 complete:
 209         nvmet_file_io_done(&req->f.iocb, ret, 0);
 210         return true;
 211 }
 212
 213 static void nvmet_file_buffered_io_work(struct work_struct *w)
 214 {
 215         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 216
 217         nvmet_file_execute_io(req, 0);
 218 }
 219
 220 static void nvmet_file_submit_buffered_io(struct nvmet_req *req)
 221 {
 222         INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
 223         queue_work(buffered_io_wq, &req->f.work);
 224 }
 225
 226 static void nvmet_file_execute_rw(struct nvmet_req *req)
 227 {
 228         ssize_t nr_bvec = req->sg_cnt;
 229
 230         if (!req->sg_cnt || !nr_bvec) {
 231                 nvmet_req_complete(req, 0);
 232                 return;
 233         }
 234
 235         if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
 236                 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 237                                 GFP_KERNEL);
 238         else
 239                 req->f.bvec = req->inline_bvec;
 240
 241         if (unlikely(!req->f.bvec)) {
 242                 /* fallback under memory pressure */
 243                 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
 244                 req->f.mpool_alloc = true;
 245         } else
 246                 req->f.mpool_alloc = false;
 247
 248         if (req->ns->buffered_io) {
 249                 if (likely(!req->f.mpool_alloc) &&
 250                                 nvmet_file_execute_io(req, IOCB_NOWAIT))
 251                         return;
 252                 nvmet_file_submit_buffered_io(req);
 253         } else
 254                 nvmet_file_execute_io(req, 0);
 255 }
 256
 257 u16 nvmet_file_flush(struct nvmet_req *req)
 258 {
 259         return errno_to_nvme_status(req, vfs_fsync(req->ns->file, 1));
 260 }
 261
 262 static void nvmet_file_flush_work(struct work_struct *w)
 263 {
 264         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 265
 266         nvmet_req_complete(req, nvmet_file_flush(req));
 267 }
 268
 269 static void nvmet_file_execute_flush(struct nvmet_req *req)
 270 {
 271         INIT_WORK(&req->f.work, nvmet_file_flush_work);
 272         schedule_work(&req->f.work);
 273 }
 274
 275 static void nvmet_file_execute_discard(struct nvmet_req *req)
 276 {
 277         int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 278         struct nvme_dsm_range range;
 279         loff_t offset, len;
 280         u16 status = 0;
 281         int ret;
 282         int i;
 283
 284         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 285                 status = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 286                                         sizeof(range));
 287                 if (status)
 288                         break;
 289
 290                 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 291                 len = le32_to_cpu(range.nlb);
 292                 len <<= req->ns->blksize_shift;
 293                 if (offset + len > req->ns->size) {
 294                         req->error_slba = le64_to_cpu(range.slba);
 295                         status = errno_to_nvme_status(req, -ENOSPC);
 296                         break;
 297                 }
 298
 299                 ret = vfs_fallocate(req->ns->file, mode, offset, len);
 300                 if (ret && ret != -EOPNOTSUPP) {
 301                         req->error_slba = le64_to_cpu(range.slba);
 302                         status = errno_to_nvme_status(req, ret);
 303                         break;
 304                 }
 305         }
 306
 307         nvmet_req_complete(req, status);
 308 }
 309
 310 static void nvmet_file_dsm_work(struct work_struct *w)
 311 {
 312         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 313
 314         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 315         case NVME_DSMGMT_AD:
 316                 nvmet_file_execute_discard(req);
 317                 return;
 318         case NVME_DSMGMT_IDR:
 319         case NVME_DSMGMT_IDW:
 320         default:
 321                 /* Not supported yet */
 322                 nvmet_req_complete(req, 0);
 323                 return;
 324         }
 325 }
 326
 327 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 328 {
 329         INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 330         schedule_work(&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         INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
 358         schedule_work(&req->f.work);
 359 }
 360
 361 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 362 {
 363         struct nvme_command *cmd = req->cmd;
 364
 365         switch (cmd->common.opcode) {
 366         case nvme_cmd_read:
 367         case nvme_cmd_write:
 368                 req->execute = nvmet_file_execute_rw;
 369                 req->data_len = nvmet_rw_len(req);
 370                 return 0;
 371         case nvme_cmd_flush:
 372                 req->execute = nvmet_file_execute_flush;
 373                 req->data_len = 0;
 374                 return 0;
 375         case nvme_cmd_dsm:
 376                 req->execute = nvmet_file_execute_dsm;
 377                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 378                         sizeof(struct nvme_dsm_range);
 379                 return 0;
 380         case nvme_cmd_write_zeroes:
 381                 req->execute = nvmet_file_execute_write_zeroes;
 382                 req->data_len = 0;
 383                 return 0;
 384         default:
 385                 pr_err("unhandled cmd for file ns %d on qid %d\n",
 386                                 cmd->common.opcode, req->sq->qid);
 387                 req->error_loc = offsetof(struct nvme_common_command, opcode);
 388                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 389         }
 390 }