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 sg_page_iter *iter)
  79 {
  80         bv->bv_page = sg_page_iter_page(iter);
  81         bv->bv_offset = iter->sg->offset;
  82         bv->bv_len = PAGE_SIZE - iter->sg->offset;
  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)
  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 ki_flags = 0, rw;
  92         ssize_t ret;
  93
  94         if (req->cmd->rw.opcode == nvme_cmd_write) {
  95                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  96                         ki_flags = IOCB_DSYNC;
  97                 call_iter = req->ns->file->f_op->write_iter;
  98                 rw = WRITE;
  99         } else {
 100                 call_iter = req->ns->file->f_op->read_iter;
 101                 rw = READ;
 102         }
 103
 104         iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
 105
 106         iocb->ki_pos = pos;
 107         iocb->ki_filp = req->ns->file;
 108         iocb->ki_flags = ki_flags | iocb_flags(req->ns->file);
 109
 110         ret = call_iter(iocb, &iter);
 111
 112         if (ret != -EIOCBQUEUED && iocb->ki_complete)
 113                 iocb->ki_complete(iocb, ret, 0);
 114
 115         return ret;
 116 }
 117
 118 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 119 {
 120         struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
 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         nvmet_req_complete(req, ret != req->data_len ?
 130                         NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 131 }
 132
 133 static void nvmet_file_execute_rw(struct nvmet_req *req)
 134 {
 135         ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
 136         struct sg_page_iter sg_pg_iter;
 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
 143         if (!req->sg_cnt || !nr_bvec) {
 144                 nvmet_req_complete(req, 0);
 145                 return;
 146         }
 147
 148         if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
 149                 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 150                                 GFP_KERNEL);
 151         else
 152                 req->f.bvec = req->inline_bvec;
 153
 154         req->f.mpool_alloc = false;
 155         if (unlikely(!req->f.bvec)) {
 156                 /* fallback under memory pressure */
 157                 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
 158                 req->f.mpool_alloc = true;
 159                 if (nr_bvec > NVMET_MAX_MPOOL_BVEC)
 160                         is_sync = true;
 161         }
 162
 163         pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 164
 165         memset(&req->f.iocb, 0, sizeof(struct kiocb));
 166         for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) {
 167                 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter);
 168                 len += req->f.bvec[bv_cnt].bv_len;
 169                 total_len += req->f.bvec[bv_cnt].bv_len;
 170                 bv_cnt++;
 171
 172                 WARN_ON_ONCE((nr_bvec - 1) < 0);
 173
 174                 if (unlikely(is_sync) &&
 175                     (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
 176                         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len);
 177                         if (ret < 0)
 178                                 goto out;
 179                         pos += len;
 180                         bv_cnt = 0;
 181                         len = 0;
 182                 }
 183                 nr_bvec--;
 184         }
 185
 186         if (WARN_ON_ONCE(total_len != req->data_len))
 187                 ret = -EIO;
 188 out:
 189         if (unlikely(is_sync || ret)) {
 190                 nvmet_file_io_done(&req->f.iocb, ret < 0 ? ret : total_len, 0);
 191                 return;
 192         }
 193         req->f.iocb.ki_complete = nvmet_file_io_done;
 194         nvmet_file_submit_bvec(req, pos, bv_cnt, total_len);
 195 }
 196
 197 static void nvmet_file_buffered_io_work(struct work_struct *w)
 198 {
 199         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 200
 201         nvmet_file_execute_rw(req);
 202 }
 203
 204 static void nvmet_file_execute_rw_buffered_io(struct nvmet_req *req)
 205 {
 206         INIT_WORK(&req->f.work, nvmet_file_buffered_io_work);
 207         queue_work(buffered_io_wq, &req->f.work);
 208 }
 209
 210 static void nvmet_file_flush_work(struct work_struct *w)
 211 {
 212         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 213         int ret;
 214
 215         ret = vfs_fsync(req->ns->file, 1);
 216
 217         nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 218 }
 219
 220 static void nvmet_file_execute_flush(struct nvmet_req *req)
 221 {
 222         INIT_WORK(&req->f.work, nvmet_file_flush_work);
 223         schedule_work(&req->f.work);
 224 }
 225
 226 static void nvmet_file_execute_discard(struct nvmet_req *req)
 227 {
 228         int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 229         struct nvme_dsm_range range;
 230         loff_t offset, len;
 231         u16 ret;
 232         int i;
 233
 234         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 235                 ret = nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 236                                         sizeof(range));
 237                 if (ret)
 238                         break;
 239                 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 240                 len = le32_to_cpu(range.nlb) << req->ns->blksize_shift;
 241                 if (vfs_fallocate(req->ns->file, mode, offset, len)) {
 242                         ret = NVME_SC_INTERNAL | NVME_SC_DNR;
 243                         break;
 244                 }
 245         }
 246
 247         nvmet_req_complete(req, ret);
 248 }
 249
 250 static void nvmet_file_dsm_work(struct work_struct *w)
 251 {
 252         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 253
 254         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 255         case NVME_DSMGMT_AD:
 256                 nvmet_file_execute_discard(req);
 257                 return;
 258         case NVME_DSMGMT_IDR:
 259         case NVME_DSMGMT_IDW:
 260         default:
 261                 /* Not supported yet */
 262                 nvmet_req_complete(req, 0);
 263                 return;
 264         }
 265 }
 266
 267 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 268 {
 269         INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 270         schedule_work(&req->f.work);
 271 }
 272
 273 static void nvmet_file_write_zeroes_work(struct work_struct *w)
 274 {
 275         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 276         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 277         int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
 278         loff_t offset;
 279         loff_t len;
 280         int ret;
 281
 282         offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
 283         len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 284                         req->ns->blksize_shift);
 285
 286         ret = vfs_fallocate(req->ns->file, mode, offset, len);
 287         nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 288 }
 289
 290 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
 291 {
 292         INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
 293         schedule_work(&req->f.work);
 294 }
 295
 296 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 297 {
 298         struct nvme_command *cmd = req->cmd;
 299
 300         switch (cmd->common.opcode) {
 301         case nvme_cmd_read:
 302         case nvme_cmd_write:
 303                 if (req->ns->buffered_io)
 304                         req->execute = nvmet_file_execute_rw_buffered_io;
 305                 else
 306                         req->execute = nvmet_file_execute_rw;
 307                 req->data_len = nvmet_rw_len(req);
 308                 return 0;
 309         case nvme_cmd_flush:
 310                 req->execute = nvmet_file_execute_flush;
 311                 req->data_len = 0;
 312                 return 0;
 313         case nvme_cmd_dsm:
 314                 req->execute = nvmet_file_execute_dsm;
 315                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 316                         sizeof(struct nvme_dsm_range);
 317                 return 0;
 318         case nvme_cmd_write_zeroes:
 319                 req->execute = nvmet_file_execute_write_zeroes;
 320                 req->data_len = 0;
 321                 return 0;
 322         default:
 323                 pr_err("unhandled cmd for file ns %d on qid %d\n",
 324                                 cmd->common.opcode, req->sq->qid);
 325                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 326         }
 327 }