include/sys/vdev_draid.h

   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 http://www.opensolaris.org/os/licensing.
  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) 2016, Intel Corporation.
  23  * Copyright (c) 2020 by Lawrence Livermore National Security, LLC.
  24  */
  25
  26 #ifndef _SYS_VDEV_DRAID_H
  27 #define _SYS_VDEV_DRAID_H
  28
  29 #include <sys/types.h>
  30 #include <sys/abd.h>
  31 #include <sys/nvpair.h>
  32 #include <sys/zio.h>
  33 #include <sys/vdev_impl.h>
  34 #include <sys/vdev_raidz_impl.h>
  35 #include <sys/vdev.h>
  36
  37 #ifdef  __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 /*
  42  * Constants required to generate and use dRAID permutations.
  43  */
  44 #define VDEV_DRAID_SEED                 0xd7a1d5eed
  45 #define VDEV_DRAID_MAX_MAPS             254
  46 #define VDEV_DRAID_ROWSHIFT             SPA_MAXBLOCKSHIFT
  47 #define VDEV_DRAID_ROWHEIGHT            (1ULL << VDEV_DRAID_ROWSHIFT)
  48 #define VDEV_DRAID_REFLOW_RESERVE       (2 * VDEV_DRAID_ROWHEIGHT)
  49
  50 /*
  51  * dRAID permutation map.
  52  */
  53 typedef struct draid_map {
  54         uint64_t dm_children;   /* # of permuation columns */
  55         uint64_t dm_nperms;     /* # of permutation rows */
  56         uint64_t dm_seed;       /* dRAID map seed */
  57         uint64_t dm_checksum;   /* Checksum of generated map */
  58         uint8_t *dm_perms;      /* base permutation array */
  59 } draid_map_t;
  60
  61 /*
  62  * dRAID configuration.
  63  */
  64 typedef struct vdev_draid_config {
  65         /*
  66          * Values read from the dRAID nvlist configuration.
  67          */
  68         uint64_t vdc_ndata;             /* # of data devices in group */
  69         uint64_t vdc_nparity;           /* # of parity devices in group */
  70         uint64_t vdc_nspares;           /* # of distributed spares */
  71         uint64_t vdc_children;          /* # of children */
  72         uint64_t vdc_ngroups;           /* # groups per slice */
  73
  74         /*
  75          * Immutable derived constants.
  76          */
  77         uint8_t *vdc_perms;             /* permutation array */
  78         uint64_t vdc_nperms;            /* # of permutations */
  79         uint64_t vdc_groupwidth;        /* = data + parity */
  80         uint64_t vdc_ndisks;            /* = children - spares */
  81         uint64_t vdc_groupsz;           /* = groupwidth * DRAID_ROWSIZE */
  82         uint64_t vdc_devslicesz;        /* = (groupsz * groups) / ndisks */
  83 } vdev_draid_config_t;
  84
  85 /*
  86  * Functions for handling dRAID permutation maps.
  87  */
  88 extern uint64_t vdev_draid_rand(uint64_t *);
  89 extern int vdev_draid_lookup_map(uint64_t, const draid_map_t **);
  90 extern int vdev_draid_generate_perms(const draid_map_t *, uint8_t **);
  91
  92 /*
  93  * General dRAID support functions.
  94  */
  95 extern boolean_t vdev_draid_readable(vdev_t *, uint64_t);
  96 extern boolean_t vdev_draid_missing(vdev_t *, uint64_t, uint64_t, uint64_t);
  97 extern uint64_t vdev_draid_asize_to_psize(vdev_t *, uint64_t);
  98 extern void vdev_draid_map_alloc_empty(zio_t *, struct raidz_row *);
  99 extern nvlist_t *vdev_draid_read_config_spare(vdev_t *);
 100
 101 /* Functions for dRAID distributed spares. */
 102 extern vdev_t *vdev_draid_spare_get_child(vdev_t *, uint64_t);
 103 extern vdev_t *vdev_draid_spare_get_parent(vdev_t *);
 104 extern int vdev_draid_spare_create(nvlist_t *, vdev_t *, uint64_t *, uint64_t);
 105
 106 #ifdef  __cplusplus
 107 }
 108 #endif
 109
 110 #endif /* _SYS_VDEV_DRAID_H */