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                 mempool_destroy(ns->bvec_pool);
  20                 ns->bvec_pool = NULL;
  21                 kmem_cache_destroy(ns->bvec_cache);
  22                 ns->bvec_cache = NULL;
  23                 fput(ns->file);
  24                 ns->file = NULL;
  25         }
  26 }
  27
  28 int nvmet_file_ns_enable(struct nvmet_ns *ns)
  29 {
  30         int ret;
  31         struct kstat stat;
  32
  33         ns->file = filp_open(ns->device_path,
  34                         O_RDWR | O_LARGEFILE | O_DIRECT, 0);
  35         if (IS_ERR(ns->file)) {
  36                 pr_err("failed to open file %s: (%ld)\n",
  37                                 ns->device_path, PTR_ERR(ns->file));
  38                 return PTR_ERR(ns->file);
  39         }
  40
  41         ret = vfs_getattr(&ns->file->f_path,
  42                         &stat, STATX_SIZE, AT_STATX_FORCE_SYNC);
  43         if (ret)
  44                 goto err;
  45
  46         ns->size = stat.size;
  47         ns->blksize_shift = file_inode(ns->file)->i_blkbits;
  48
  49         ns->bvec_cache = kmem_cache_create("nvmet-bvec",
  50                         NVMET_MAX_MPOOL_BVEC * sizeof(struct bio_vec),
  51                         0, SLAB_HWCACHE_ALIGN, NULL);
  52         if (!ns->bvec_cache) {
  53                 ret = -ENOMEM;
  54                 goto err;
  55         }
  56
  57         ns->bvec_pool = mempool_create(NVMET_MIN_MPOOL_OBJ, mempool_alloc_slab,
  58                         mempool_free_slab, ns->bvec_cache);
  59
  60         if (!ns->bvec_pool) {
  61                 ret = -ENOMEM;
  62                 goto err;
  63         }
  64
  65         return ret;
  66 err:
  67         ns->size = 0;
  68         ns->blksize_shift = 0;
  69         nvmet_file_ns_disable(ns);
  70         return ret;
  71 }
  72
  73 static void nvmet_file_init_bvec(struct bio_vec *bv, struct sg_page_iter *iter)
  74 {
  75         bv->bv_page = sg_page_iter_page(iter);
  76         bv->bv_offset = iter->sg->offset;
  77         bv->bv_len = PAGE_SIZE - iter->sg->offset;
  78 }
  79
  80 static ssize_t nvmet_file_submit_bvec(struct nvmet_req *req, loff_t pos,
  81                 unsigned long nr_segs, size_t count)
  82 {
  83         struct kiocb *iocb = &req->f.iocb;
  84         ssize_t (*call_iter)(struct kiocb *iocb, struct iov_iter *iter);
  85         struct iov_iter iter;
  86         int ki_flags = 0, rw;
  87         ssize_t ret;
  88
  89         if (req->cmd->rw.opcode == nvme_cmd_write) {
  90                 if (req->cmd->rw.control & cpu_to_le16(NVME_RW_FUA))
  91                         ki_flags = IOCB_DSYNC;
  92                 call_iter = req->ns->file->f_op->write_iter;
  93                 rw = WRITE;
  94         } else {
  95                 call_iter = req->ns->file->f_op->read_iter;
  96                 rw = READ;
  97         }
  98
  99         iov_iter_bvec(&iter, ITER_BVEC | rw, req->f.bvec, nr_segs, count);
 100
 101         iocb->ki_pos = pos;
 102         iocb->ki_filp = req->ns->file;
 103         iocb->ki_flags = IOCB_DIRECT | ki_flags;
 104
 105         ret = call_iter(iocb, &iter);
 106
 107         if (ret != -EIOCBQUEUED && iocb->ki_complete)
 108                 iocb->ki_complete(iocb, ret, 0);
 109
 110         return ret;
 111 }
 112
 113 static void nvmet_file_io_done(struct kiocb *iocb, long ret, long ret2)
 114 {
 115         struct nvmet_req *req = container_of(iocb, struct nvmet_req, f.iocb);
 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         nvmet_req_complete(req, ret != req->data_len ?
 125                         NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 126 }
 127
 128 static void nvmet_file_execute_rw(struct nvmet_req *req)
 129 {
 130         ssize_t nr_bvec = DIV_ROUND_UP(req->data_len, PAGE_SIZE);
 131         struct sg_page_iter sg_pg_iter;
 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
 138         if (!req->sg_cnt || !nr_bvec) {
 139                 nvmet_req_complete(req, 0);
 140                 return;
 141         }
 142
 143         if (nr_bvec > NVMET_MAX_INLINE_BIOVEC)
 144                 req->f.bvec = kmalloc_array(nr_bvec, sizeof(struct bio_vec),
 145                                 GFP_KERNEL);
 146         else
 147                 req->f.bvec = req->inline_bvec;
 148
 149         req->f.mpool_alloc = false;
 150         if (unlikely(!req->f.bvec)) {
 151                 /* fallback under memory pressure */
 152                 req->f.bvec = mempool_alloc(req->ns->bvec_pool, GFP_KERNEL);
 153                 req->f.mpool_alloc = true;
 154                 if (nr_bvec > NVMET_MAX_MPOOL_BVEC)
 155                         is_sync = true;
 156         }
 157
 158         pos = le64_to_cpu(req->cmd->rw.slba) << req->ns->blksize_shift;
 159
 160         memset(&req->f.iocb, 0, sizeof(struct kiocb));
 161         for_each_sg_page(req->sg, &sg_pg_iter, req->sg_cnt, 0) {
 162                 nvmet_file_init_bvec(&req->f.bvec[bv_cnt], &sg_pg_iter);
 163                 len += req->f.bvec[bv_cnt].bv_len;
 164                 total_len += req->f.bvec[bv_cnt].bv_len;
 165                 bv_cnt++;
 166
 167                 WARN_ON_ONCE((nr_bvec - 1) < 0);
 168
 169                 if (unlikely(is_sync) &&
 170                     (nr_bvec - 1 == 0 || bv_cnt == NVMET_MAX_MPOOL_BVEC)) {
 171                         ret = nvmet_file_submit_bvec(req, pos, bv_cnt, len);
 172                         if (ret < 0)
 173                                 goto out;
 174                         pos += len;
 175                         bv_cnt = 0;
 176                         len = 0;
 177                 }
 178                 nr_bvec--;
 179         }
 180
 181         if (WARN_ON_ONCE(total_len != req->data_len))
 182                 ret = -EIO;
 183 out:
 184         if (unlikely(is_sync || ret)) {
 185                 nvmet_file_io_done(&req->f.iocb, ret < 0 ? ret : total_len, 0);
 186                 return;
 187         }
 188         req->f.iocb.ki_complete = nvmet_file_io_done;
 189         nvmet_file_submit_bvec(req, pos, bv_cnt, total_len);
 190 }
 191
 192 static void nvmet_file_flush_work(struct work_struct *w)
 193 {
 194         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 195         int ret;
 196
 197         ret = vfs_fsync(req->ns->file, 1);
 198
 199         nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 200 }
 201
 202 static void nvmet_file_execute_flush(struct nvmet_req *req)
 203 {
 204         INIT_WORK(&req->f.work, nvmet_file_flush_work);
 205         schedule_work(&req->f.work);
 206 }
 207
 208 static void nvmet_file_execute_discard(struct nvmet_req *req)
 209 {
 210         int mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE;
 211         struct nvme_dsm_range range;
 212         loff_t offset;
 213         loff_t len;
 214         int i, ret;
 215
 216         for (i = 0; i <= le32_to_cpu(req->cmd->dsm.nr); i++) {
 217                 if (nvmet_copy_from_sgl(req, i * sizeof(range), &range,
 218                                         sizeof(range)))
 219                         break;
 220                 offset = le64_to_cpu(range.slba) << req->ns->blksize_shift;
 221                 len = le32_to_cpu(range.nlb) << req->ns->blksize_shift;
 222                 ret = vfs_fallocate(req->ns->file, mode, offset, len);
 223                 if (ret)
 224                         break;
 225         }
 226
 227         nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 228 }
 229
 230 static void nvmet_file_dsm_work(struct work_struct *w)
 231 {
 232         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 233
 234         switch (le32_to_cpu(req->cmd->dsm.attributes)) {
 235         case NVME_DSMGMT_AD:
 236                 nvmet_file_execute_discard(req);
 237                 return;
 238         case NVME_DSMGMT_IDR:
 239         case NVME_DSMGMT_IDW:
 240         default:
 241                 /* Not supported yet */
 242                 nvmet_req_complete(req, 0);
 243                 return;
 244         }
 245 }
 246
 247 static void nvmet_file_execute_dsm(struct nvmet_req *req)
 248 {
 249         INIT_WORK(&req->f.work, nvmet_file_dsm_work);
 250         schedule_work(&req->f.work);
 251 }
 252
 253 static void nvmet_file_write_zeroes_work(struct work_struct *w)
 254 {
 255         struct nvmet_req *req = container_of(w, struct nvmet_req, f.work);
 256         struct nvme_write_zeroes_cmd *write_zeroes = &req->cmd->write_zeroes;
 257         int mode = FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE;
 258         loff_t offset;
 259         loff_t len;
 260         int ret;
 261
 262         offset = le64_to_cpu(write_zeroes->slba) << req->ns->blksize_shift;
 263         len = (((sector_t)le16_to_cpu(write_zeroes->length) + 1) <<
 264                         req->ns->blksize_shift);
 265
 266         ret = vfs_fallocate(req->ns->file, mode, offset, len);
 267         nvmet_req_complete(req, ret < 0 ? NVME_SC_INTERNAL | NVME_SC_DNR : 0);
 268 }
 269
 270 static void nvmet_file_execute_write_zeroes(struct nvmet_req *req)
 271 {
 272         INIT_WORK(&req->f.work, nvmet_file_write_zeroes_work);
 273         schedule_work(&req->f.work);
 274 }
 275
 276 u16 nvmet_file_parse_io_cmd(struct nvmet_req *req)
 277 {
 278         struct nvme_command *cmd = req->cmd;
 279
 280         switch (cmd->common.opcode) {
 281         case nvme_cmd_read:
 282         case nvme_cmd_write:
 283                 req->execute = nvmet_file_execute_rw;
 284                 req->data_len = nvmet_rw_len(req);
 285                 return 0;
 286         case nvme_cmd_flush:
 287                 req->execute = nvmet_file_execute_flush;
 288                 req->data_len = 0;
 289                 return 0;
 290         case nvme_cmd_dsm:
 291                 req->execute = nvmet_file_execute_dsm;
 292                 req->data_len = (le32_to_cpu(cmd->dsm.nr) + 1) *
 293                         sizeof(struct nvme_dsm_range);
 294                 return 0;
 295         case nvme_cmd_write_zeroes:
 296                 req->execute = nvmet_file_execute_write_zeroes;
 297                 req->data_len = 0;
 298                 return 0;
 299         default:
 300                 pr_err("unhandled cmd for file ns %d on qid %d\n",
 301                                 cmd->common.opcode, req->sq->qid);
 302                 return NVME_SC_INVALID_OPCODE | NVME_SC_DNR;
 303         }
 304 }