module/os/linux/zfs/vdev_file.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or https://opensource.org/licenses/CDDL-1.0.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  * Copyright (c) 2011, 2020 by Delphix. All rights reserved.
  24  */
  25
  26 #include <sys/zfs_context.h>
  27 #include <sys/spa.h>
  28 #include <sys/spa_impl.h>
  29 #include <sys/vdev_file.h>
  30 #include <sys/vdev_impl.h>
  31 #include <sys/vdev_trim.h>
  32 #include <sys/zio.h>
  33 #include <sys/fs/zfs.h>
  34 #include <sys/fm/fs/zfs.h>
  35 #include <sys/abd.h>
  36 #include <sys/fcntl.h>
  37 #include <sys/vnode.h>
  38 #include <sys/zfs_file.h>
  39 #ifdef _KERNEL
  40 #include <linux/falloc.h>
  41 #endif
  42 /*
  43  * Virtual device vector for files.
  44  */
  45
  46 static taskq_t *vdev_file_taskq;
  47
  48 /*
  49  * By default, the logical/physical ashift for file vdevs is set to
  50  * SPA_MINBLOCKSHIFT (9). This allows all file vdevs to use 512B (1 << 9)
  51  * blocksizes. Users may opt to change one or both of these for testing
  52  * or performance reasons. Care should be taken as these values will
  53  * impact the vdev_ashift setting which can only be set at vdev creation
  54  * time.
  55  */
  56 static uint_t vdev_file_logical_ashift = SPA_MINBLOCKSHIFT;
  57 static uint_t vdev_file_physical_ashift = SPA_MINBLOCKSHIFT;
  58
  59 static void
  60 vdev_file_hold(vdev_t *vd)
  61 {
  62         ASSERT(vd->vdev_path != NULL);
  63 }
  64
  65 static void
  66 vdev_file_rele(vdev_t *vd)
  67 {
  68         ASSERT(vd->vdev_path != NULL);
  69 }
  70
  71 static mode_t
  72 vdev_file_open_mode(spa_mode_t spa_mode)
  73 {
  74         mode_t mode = 0;
  75
  76         if ((spa_mode & SPA_MODE_READ) && (spa_mode & SPA_MODE_WRITE)) {
  77                 mode = O_RDWR;
  78         } else if (spa_mode & SPA_MODE_READ) {
  79                 mode = O_RDONLY;
  80         } else if (spa_mode & SPA_MODE_WRITE) {
  81                 mode = O_WRONLY;
  82         }
  83
  84         return (mode | O_LARGEFILE);
  85 }
  86
  87 static int
  88 vdev_file_open(vdev_t *vd, uint64_t *psize, uint64_t *max_psize,
  89     uint64_t *logical_ashift, uint64_t *physical_ashift)
  90 {
  91         vdev_file_t *vf;
  92         zfs_file_t *fp;
  93         zfs_file_attr_t zfa;
  94         int error;
  95
  96         /*
  97          * Rotational optimizations only make sense on block devices.
  98          */
  99         vd->vdev_nonrot = B_TRUE;
 100
 101         /*
 102          * Allow TRIM on file based vdevs.  This may not always be supported,
 103          * since it depends on your kernel version and underlying filesystem
 104          * type but it is always safe to attempt.
 105          */
 106         vd->vdev_has_trim = B_TRUE;
 107
 108         /*
 109          * Disable secure TRIM on file based vdevs.  There is no way to
 110          * request this behavior from the underlying filesystem.
 111          */
 112         vd->vdev_has_securetrim = B_FALSE;
 113
 114         /*
 115          * We must have a pathname, and it must be absolute.
 116          */
 117         if (vd->vdev_path == NULL || vd->vdev_path[0] != '/') {
 118                 vd->vdev_stat.vs_aux = VDEV_AUX_BAD_LABEL;
 119                 return (SET_ERROR(EINVAL));
 120         }
 121
 122         /*
 123          * Reopen the device if it's not currently open.  Otherwise,
 124          * just update the physical size of the device.
 125          */
 126         if (vd->vdev_tsd != NULL) {
 127                 ASSERT(vd->vdev_reopening);
 128                 vf = vd->vdev_tsd;
 129                 goto skip_open;
 130         }
 131
 132         vf = vd->vdev_tsd = kmem_zalloc(sizeof (vdev_file_t), KM_SLEEP);
 133
 134         /*
 135          * We always open the files from the root of the global zone, even if
 136          * we're in a local zone.  If the user has gotten to this point, the
 137          * administrator has already decided that the pool should be available
 138          * to local zone users, so the underlying devices should be as well.
 139          */
 140         ASSERT(vd->vdev_path != NULL && vd->vdev_path[0] == '/');
 141
 142         error = zfs_file_open(vd->vdev_path,
 143             vdev_file_open_mode(spa_mode(vd->vdev_spa)), 0, &fp);
 144         if (error) {
 145                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 146                 return (error);
 147         }
 148
 149         vf->vf_file = fp;
 150
 151 #ifdef _KERNEL
 152         /*
 153          * Make sure it's a regular file.
 154          */
 155         if (zfs_file_getattr(fp, &zfa)) {
 156                 return (SET_ERROR(ENODEV));
 157         }
 158         if (!S_ISREG(zfa.zfa_mode)) {
 159                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 160                 return (SET_ERROR(ENODEV));
 161         }
 162 #endif
 163
 164 skip_open:
 165
 166         error =  zfs_file_getattr(vf->vf_file, &zfa);
 167         if (error) {
 168                 vd->vdev_stat.vs_aux = VDEV_AUX_OPEN_FAILED;
 169                 return (error);
 170         }
 171
 172         *max_psize = *psize = zfa.zfa_size;
 173         *logical_ashift = vdev_file_logical_ashift;
 174         *physical_ashift = vdev_file_physical_ashift;
 175
 176         return (0);
 177 }
 178
 179 static void
 180 vdev_file_close(vdev_t *vd)
 181 {
 182         vdev_file_t *vf = vd->vdev_tsd;
 183
 184         if (vd->vdev_reopening || vf == NULL)
 185                 return;
 186
 187         if (vf->vf_file != NULL) {
 188                 (void) zfs_file_close(vf->vf_file);
 189         }
 190
 191         vd->vdev_delayed_close = B_FALSE;
 192         kmem_free(vf, sizeof (vdev_file_t));
 193         vd->vdev_tsd = NULL;
 194 }
 195
 196 static void
 197 vdev_file_io_strategy(void *arg)
 198 {
 199         zio_t *zio = (zio_t *)arg;
 200         vdev_t *vd = zio->io_vd;
 201         vdev_file_t *vf = vd->vdev_tsd;
 202         ssize_t resid;
 203         void *buf;
 204         loff_t off;
 205         ssize_t size;
 206         int err;
 207
 208         off = zio->io_offset;
 209         size = zio->io_size;
 210         resid = 0;
 211
 212         if (zio->io_type == ZIO_TYPE_READ) {
 213                 buf = abd_borrow_buf(zio->io_abd, zio->io_size);
 214                 err = zfs_file_pread(vf->vf_file, buf, size, off, &resid);
 215                 abd_return_buf_copy(zio->io_abd, buf, size);
 216         } else {
 217                 buf = abd_borrow_buf_copy(zio->io_abd, zio->io_size);
 218                 err = zfs_file_pwrite(vf->vf_file, buf, size, off, &resid);
 219                 abd_return_buf(zio->io_abd, buf, size);
 220         }
 221         zio->io_error = err;
 222         if (resid != 0 && zio->io_error == 0)
 223                 zio->io_error = SET_ERROR(ENOSPC);
 224
 225         zio_delay_interrupt(zio);
 226 }
 227
 228 static void
 229 vdev_file_io_fsync(void *arg)
 230 {
 231         zio_t *zio = (zio_t *)arg;
 232         vdev_file_t *vf = zio->io_vd->vdev_tsd;
 233
 234         zio->io_error = zfs_file_fsync(vf->vf_file, O_SYNC | O_DSYNC);
 235
 236         zio_interrupt(zio);
 237 }
 238
 239 static void
 240 vdev_file_io_start(zio_t *zio)
 241 {
 242         vdev_t *vd = zio->io_vd;
 243         vdev_file_t *vf = vd->vdev_tsd;
 244
 245         if (zio->io_type == ZIO_TYPE_FLUSH) {
 246                 /* XXPOLICY */
 247                 if (!vdev_readable(vd)) {
 248                         zio->io_error = SET_ERROR(ENXIO);
 249                         zio_interrupt(zio);
 250                         return;
 251                 }
 252
 253                 if (zfs_nocacheflush) {
 254                         zio_execute(zio);
 255                         return;
 256                 }
 257
 258                 /*
 259                  * We cannot safely call vfs_fsync() when PF_FSTRANS
 260                  * is set in the current context.  Filesystems like
 261                  * XFS include sanity checks to verify it is not
 262                  * already set, see xfs_vm_writepage().  Therefore
 263                  * the sync must be dispatched to a different context.
 264                  */
 265                 if (__spl_pf_fstrans_check()) {
 266                         VERIFY3U(taskq_dispatch(vdev_file_taskq,
 267                             vdev_file_io_fsync, zio, TQ_SLEEP), !=,
 268                             TASKQID_INVALID);
 269                         return;
 270                 }
 271
 272                 zio->io_error = zfs_file_fsync(vf->vf_file, O_SYNC | O_DSYNC);
 273
 274                 zio_execute(zio);
 275                 return;
 276         } else if (zio->io_type == ZIO_TYPE_TRIM) {
 277                 ASSERT3U(zio->io_size, !=, 0);
 278                 zio->io_error = zfs_file_deallocate(vf->vf_file,
 279                     zio->io_offset, zio->io_size);
 280                 zio_execute(zio);
 281                 return;
 282         }
 283
 284         zio->io_target_timestamp = zio_handle_io_delay(zio);
 285
 286         VERIFY3U(taskq_dispatch(vdev_file_taskq, vdev_file_io_strategy, zio,
 287             TQ_SLEEP), !=, TASKQID_INVALID);
 288 }
 289
 290 static void
 291 vdev_file_io_done(zio_t *zio)
 292 {
 293         (void) zio;
 294 }
 295
 296 vdev_ops_t vdev_file_ops = {
 297         .vdev_op_init = NULL,
 298         .vdev_op_fini = NULL,
 299         .vdev_op_open = vdev_file_open,
 300         .vdev_op_close = vdev_file_close,
 301         .vdev_op_asize = vdev_default_asize,
 302         .vdev_op_min_asize = vdev_default_min_asize,
 303         .vdev_op_min_alloc = NULL,
 304         .vdev_op_io_start = vdev_file_io_start,
 305         .vdev_op_io_done = vdev_file_io_done,
 306         .vdev_op_state_change = NULL,
 307         .vdev_op_need_resilver = NULL,
 308         .vdev_op_hold = vdev_file_hold,
 309         .vdev_op_rele = vdev_file_rele,
 310         .vdev_op_remap = NULL,
 311         .vdev_op_xlate = vdev_default_xlate,
 312         .vdev_op_rebuild_asize = NULL,
 313         .vdev_op_metaslab_init = NULL,
 314         .vdev_op_config_generate = NULL,
 315         .vdev_op_nparity = NULL,
 316         .vdev_op_ndisks = NULL,
 317         .vdev_op_type = VDEV_TYPE_FILE,         /* name of this vdev type */
 318         .vdev_op_leaf = B_TRUE                  /* leaf vdev */
 319 };
 320
 321 void
 322 vdev_file_init(void)
 323 {
 324         vdev_file_taskq = taskq_create("z_vdev_file", MAX(boot_ncpus, 16),
 325             minclsyspri, boot_ncpus, INT_MAX, TASKQ_DYNAMIC);
 326
 327         VERIFY(vdev_file_taskq);
 328 }
 329
 330 void
 331 vdev_file_fini(void)
 332 {
 333         taskq_destroy(vdev_file_taskq);
 334 }
 335
 336 /*
 337  * From userland we access disks just like files.
 338  */
 339 #ifndef _KERNEL
 340
 341 vdev_ops_t vdev_disk_ops = {
 342         .vdev_op_init = NULL,
 343         .vdev_op_fini = NULL,
 344         .vdev_op_open = vdev_file_open,
 345         .vdev_op_close = vdev_file_close,
 346         .vdev_op_asize = vdev_default_asize,
 347         .vdev_op_min_asize = vdev_default_min_asize,
 348         .vdev_op_min_alloc = NULL,
 349         .vdev_op_io_start = vdev_file_io_start,
 350         .vdev_op_io_done = vdev_file_io_done,
 351         .vdev_op_state_change = NULL,
 352         .vdev_op_need_resilver = NULL,
 353         .vdev_op_hold = vdev_file_hold,
 354         .vdev_op_rele = vdev_file_rele,
 355         .vdev_op_remap = NULL,
 356         .vdev_op_xlate = vdev_default_xlate,
 357         .vdev_op_rebuild_asize = NULL,
 358         .vdev_op_metaslab_init = NULL,
 359         .vdev_op_config_generate = NULL,
 360         .vdev_op_nparity = NULL,
 361         .vdev_op_ndisks = NULL,
 362         .vdev_op_type = VDEV_TYPE_DISK,         /* name of this vdev type */
 363         .vdev_op_leaf = B_TRUE                  /* leaf vdev */
 364 };
 365
 366 #endif
 367
 368 ZFS_MODULE_PARAM(zfs_vdev_file, vdev_file_, logical_ashift, UINT, ZMOD_RW,
 369         "Logical ashift for file-based devices");
 370 ZFS_MODULE_PARAM(zfs_vdev_file, vdev_file_, physical_ashift, UINT, ZMOD_RW,
 371         "Physical ashift for file-based devices");