sys/cddl/contrib/opensolaris/uts/common/fs/zfs/sys/vdev_impl.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 2007 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 #ifndef _SYS_VDEV_IMPL_H
  27 #define _SYS_VDEV_IMPL_H
  28
  29 #pragma ident   "%Z%%M% %I%     %E% SMI"
  30
  31 #include <sys/avl.h>
  32 #include <sys/dmu.h>
  33 #include <sys/metaslab.h>
  34 #include <sys/nvpair.h>
  35 #include <sys/space_map.h>
  36 #include <sys/vdev.h>
  37 #include <sys/dkio.h>
  38 #include <sys/uberblock_impl.h>
  39
  40 #ifdef  __cplusplus
  41 extern "C" {
  42 #endif
  43
  44 /*
  45  * Virtual device descriptors.
  46  *
  47  * All storage pool operations go through the virtual device framework,
  48  * which provides data replication and I/O scheduling.
  49  */
  50
  51 /*
  52  * Forward declarations that lots of things need.
  53  */
  54 typedef struct vdev_queue vdev_queue_t;
  55 typedef struct vdev_cache vdev_cache_t;
  56 typedef struct vdev_cache_entry vdev_cache_entry_t;
  57
  58 /*
  59  * Virtual device operations
  60  */
  61 typedef int     vdev_open_func_t(vdev_t *vd, uint64_t *size, uint64_t *ashift);
  62 typedef void    vdev_close_func_t(vdev_t *vd);
  63 typedef uint64_t vdev_asize_func_t(vdev_t *vd, uint64_t psize);
  64 typedef void    vdev_io_start_func_t(zio_t *zio);
  65 typedef void    vdev_io_done_func_t(zio_t *zio);
  66 typedef void    vdev_state_change_func_t(vdev_t *vd, int, int);
  67
  68 typedef struct vdev_ops {
  69         vdev_open_func_t                *vdev_op_open;
  70         vdev_close_func_t               *vdev_op_close;
  71         vdev_asize_func_t               *vdev_op_asize;
  72         vdev_io_start_func_t            *vdev_op_io_start;
  73         vdev_io_done_func_t             *vdev_op_io_done;
  74         vdev_state_change_func_t        *vdev_op_state_change;
  75         char                            vdev_op_type[16];
  76         boolean_t                       vdev_op_leaf;
  77 } vdev_ops_t;
  78
  79 /*
  80  * Virtual device properties
  81  */
  82 struct vdev_cache_entry {
  83         char            *ve_data;
  84         uint64_t        ve_offset;
  85         uint64_t        ve_lastused;
  86         avl_node_t      ve_offset_node;
  87         avl_node_t      ve_lastused_node;
  88         uint32_t        ve_hits;
  89         uint16_t        ve_missed_update;
  90         zio_t           *ve_fill_io;
  91 };
  92
  93 struct vdev_cache {
  94         avl_tree_t      vc_offset_tree;
  95         avl_tree_t      vc_lastused_tree;
  96         kmutex_t        vc_lock;
  97 };
  98
  99 struct vdev_queue {
 100         avl_tree_t      vq_deadline_tree;
 101         avl_tree_t      vq_read_tree;
 102         avl_tree_t      vq_write_tree;
 103         avl_tree_t      vq_pending_tree;
 104         kmutex_t        vq_lock;
 105 };
 106
 107 /*
 108  * Virtual device descriptor
 109  */
 110 struct vdev {
 111         /*
 112          * Common to all vdev types.
 113          */
 114         uint64_t        vdev_id;        /* child number in vdev parent  */
 115         uint64_t        vdev_guid;      /* unique ID for this vdev      */
 116         uint64_t        vdev_guid_sum;  /* self guid + all child guids  */
 117         uint64_t        vdev_asize;     /* allocatable device capacity  */
 118         uint64_t        vdev_ashift;    /* block alignment shift        */
 119         uint64_t        vdev_state;     /* see VDEV_STATE_* #defines    */
 120         uint64_t        vdev_prevstate; /* used when reopening a vdev   */
 121         vdev_ops_t      *vdev_ops;      /* vdev operations              */
 122         spa_t           *vdev_spa;      /* spa for this vdev            */
 123         void            *vdev_tsd;      /* type-specific data           */
 124         vdev_t          *vdev_top;      /* top-level vdev               */
 125         vdev_t          *vdev_parent;   /* parent vdev                  */
 126         vdev_t          **vdev_child;   /* array of children            */
 127         uint64_t        vdev_children;  /* number of children           */
 128         space_map_t     vdev_dtl_map;   /* dirty time log in-core state */
 129         space_map_t     vdev_dtl_scrub; /* DTL for scrub repair writes  */
 130         vdev_stat_t     vdev_stat;      /* virtual device statistics    */
 131
 132         /*
 133          * Top-level vdev state.
 134          */
 135         uint64_t        vdev_ms_array;  /* metaslab array object        */
 136         uint64_t        vdev_ms_shift;  /* metaslab size shift          */
 137         uint64_t        vdev_ms_count;  /* number of metaslabs          */
 138         metaslab_group_t *vdev_mg;      /* metaslab group               */
 139         metaslab_t      **vdev_ms;      /* metaslab array               */
 140         txg_list_t      vdev_ms_list;   /* per-txg dirty metaslab lists */
 141         txg_list_t      vdev_dtl_list;  /* per-txg dirty DTL lists      */
 142         txg_node_t      vdev_txg_node;  /* per-txg dirty vdev linkage   */
 143         uint8_t         vdev_reopen_wanted; /* async reopen wanted?     */
 144         list_node_t     vdev_dirty_node; /* config dirty list           */
 145         uint64_t        vdev_deflate_ratio; /* deflation ratio (x512)   */
 146
 147         /*
 148          * Leaf vdev state.
 149          */
 150         uint64_t        vdev_psize;     /* physical device capacity     */
 151         space_map_obj_t vdev_dtl;       /* dirty time log on-disk state */
 152         txg_node_t      vdev_dtl_node;  /* per-txg dirty DTL linkage    */
 153         uint64_t        vdev_wholedisk; /* true if this is a whole disk */
 154         uint64_t        vdev_offline;   /* device taken offline?        */
 155         uint64_t        vdev_nparity;   /* number of parity devices for raidz */
 156         char            *vdev_path;     /* vdev path (if any)           */
 157         char            *vdev_devid;    /* vdev devid (if any)          */
 158         uint64_t        vdev_fault_arg; /* fault injection paramater    */
 159         int             vdev_fault_mask; /* zio types to fault          */
 160         uint8_t         vdev_fault_mode; /* fault injection mode        */
 161         uint8_t         vdev_cache_active; /* vdev_cache and vdev_queue */
 162         uint8_t         vdev_tmpoffline; /* device taken offline temporarily? */
 163         uint8_t         vdev_detached;  /* device detached?             */
 164         uint64_t        vdev_isspare;   /* was a hot spare */
 165         vdev_queue_t    vdev_queue;     /* I/O deadline schedule queue  */
 166         vdev_cache_t    vdev_cache;     /* physical block cache         */
 167         uint64_t        vdev_not_present; /* not present during import  */
 168         hrtime_t        vdev_last_try;  /* last reopen time             */
 169         boolean_t       vdev_nowritecache; /* true if flushwritecache failed */
 170
 171         /*
 172          * For DTrace to work in userland (libzpool) context, these fields must
 173          * remain at the end of the structure.  DTrace will use the kernel's
 174          * CTF definition for 'struct vdev', and since the size of a kmutex_t is
 175          * larger in userland, the offsets for the rest fields would be
 176          * incorrect.
 177          */
 178         kmutex_t        vdev_dtl_lock;  /* vdev_dtl_{map,resilver}      */
 179         kmutex_t        vdev_stat_lock; /* vdev_stat                    */
 180 };
 181
 182 #define VDEV_SKIP_SIZE          (8 << 10)
 183 #define VDEV_BOOT_HEADER_SIZE   (8 << 10)
 184 #define VDEV_PHYS_SIZE          (112 << 10)
 185 #define VDEV_UBERBLOCK_RING     (128 << 10)
 186
 187 #define VDEV_UBERBLOCK_SHIFT(vd)        \
 188         MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
 189 #define VDEV_UBERBLOCK_COUNT(vd)        \
 190         (VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
 191 #define VDEV_UBERBLOCK_OFFSET(vd, n)    \
 192         offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
 193 #define VDEV_UBERBLOCK_SIZE(vd)         (1ULL << VDEV_UBERBLOCK_SHIFT(vd))
 194
 195 /* ZFS boot block */
 196 #define VDEV_BOOT_MAGIC         0x2f5b007b10cULL
 197 #define VDEV_BOOT_VERSION       1               /* version number       */
 198
 199 typedef struct vdev_boot_header {
 200         uint64_t        vb_magic;               /* VDEV_BOOT_MAGIC      */
 201         uint64_t        vb_version;             /* VDEV_BOOT_VERSION    */
 202         uint64_t        vb_offset;              /* start offset (bytes) */
 203         uint64_t        vb_size;                /* size (bytes)         */
 204         char            vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
 205 } vdev_boot_header_t;
 206
 207 typedef struct vdev_phys {
 208         char            vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
 209         zio_block_tail_t vp_zbt;
 210 } vdev_phys_t;
 211
 212 typedef struct vdev_label {
 213         char            vl_pad[VDEV_SKIP_SIZE];                 /*   8K */
 214         vdev_boot_header_t vl_boot_header;                      /*   8K */
 215         vdev_phys_t     vl_vdev_phys;                           /* 112K */
 216         char            vl_uberblock[VDEV_UBERBLOCK_RING];      /* 128K */
 217 } vdev_label_t;                                                 /* 256K total */
 218
 219 /*
 220  * vdev_dirty() flags
 221  */
 222 #define VDD_METASLAB    0x01
 223 #define VDD_DTL         0x02
 224
 225 /*
 226  * Size and offset of embedded boot loader region on each label.
 227  * The total size of the first two labels plus the boot area is 4MB.
 228  */
 229 #define VDEV_BOOT_OFFSET        (2 * sizeof (vdev_label_t))
 230 #define VDEV_BOOT_SIZE          (7ULL << 19)                    /* 3.5M */
 231
 232 /*
 233  * Size of label regions at the start and end of each leaf device.
 234  */
 235 #define VDEV_LABEL_START_SIZE   (2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
 236 #define VDEV_LABEL_END_SIZE     (2 * sizeof (vdev_label_t))
 237 #define VDEV_LABELS             4
 238
 239 #define VDEV_ALLOC_LOAD         0
 240 #define VDEV_ALLOC_ADD          1
 241 #define VDEV_ALLOC_SPARE        2
 242
 243 /*
 244  * Allocate or free a vdev
 245  */
 246 extern int vdev_alloc(spa_t *spa, vdev_t **vdp, nvlist_t *config,
 247     vdev_t *parent, uint_t id, int alloctype);
 248 extern void vdev_free(vdev_t *vd);
 249
 250 /*
 251  * Add or remove children and parents
 252  */
 253 extern void vdev_add_child(vdev_t *pvd, vdev_t *cvd);
 254 extern void vdev_remove_child(vdev_t *pvd, vdev_t *cvd);
 255 extern void vdev_compact_children(vdev_t *pvd);
 256 extern vdev_t *vdev_add_parent(vdev_t *cvd, vdev_ops_t *ops);
 257 extern void vdev_remove_parent(vdev_t *cvd);
 258
 259 /*
 260  * vdev sync load and sync
 261  */
 262 extern void vdev_load(vdev_t *vd);
 263 extern void vdev_sync(vdev_t *vd, uint64_t txg);
 264 extern void vdev_sync_done(vdev_t *vd, uint64_t txg);
 265 extern void vdev_dirty(vdev_t *vd, int flags, void *arg, uint64_t txg);
 266
 267 /*
 268  * Available vdev types.
 269  */
 270 extern vdev_ops_t vdev_root_ops;
 271 extern vdev_ops_t vdev_mirror_ops;
 272 extern vdev_ops_t vdev_replacing_ops;
 273 extern vdev_ops_t vdev_raidz_ops;
 274 #ifdef _KERNEL
 275 extern vdev_ops_t vdev_geom_ops;
 276 #else
 277 extern vdev_ops_t vdev_disk_ops;
 278 extern vdev_ops_t vdev_file_ops;
 279 #endif
 280 extern vdev_ops_t vdev_missing_ops;
 281 extern vdev_ops_t vdev_spare_ops;
 282
 283 /*
 284  * Common size functions
 285  */
 286 extern uint64_t vdev_default_asize(vdev_t *vd, uint64_t psize);
 287 extern uint64_t vdev_get_rsize(vdev_t *vd);
 288
 289 /*
 290  * zdb uses this tunable, so it must be declared here to make lint happy.
 291  */
 292 extern int zfs_vdev_cache_size;
 293
 294 #ifdef  __cplusplus
 295 }
 296 #endif
 297
 298 #endif  /* _SYS_VDEV_IMPL_H */