module/zfs/include/sys/zio.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 /*
  23  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27 #ifndef _ZIO_H
  28 #define _ZIO_H
  29
  30 #include <sys/zfs_context.h>
  31 #include <sys/spa.h>
  32 #include <sys/txg.h>
  33 #include <sys/avl.h>
  34 #include <sys/fs/zfs.h>
  35 #include <sys/zio_impl.h>
  36
  37 #ifdef  __cplusplus
  38 extern "C" {
  39 #endif
  40
  41 #define ZBT_MAGIC       0x210da7ab10c7a11ULL    /* zio data bloc tail */
  42
  43 typedef struct zio_block_tail {
  44         uint64_t        zbt_magic;      /* for validation, endianness   */
  45         zio_cksum_t     zbt_cksum;      /* 256-bit checksum             */
  46 } zio_block_tail_t;
  47
  48 /*
  49  * Gang block headers are self-checksumming and contain an array
  50  * of block pointers.
  51  */
  52 #define SPA_GANGBLOCKSIZE       SPA_MINBLOCKSIZE
  53 #define SPA_GBH_NBLKPTRS        ((SPA_GANGBLOCKSIZE - \
  54         sizeof (zio_block_tail_t)) / sizeof (blkptr_t))
  55 #define SPA_GBH_FILLER          ((SPA_GANGBLOCKSIZE - \
  56         sizeof (zio_block_tail_t) - \
  57         (SPA_GBH_NBLKPTRS * sizeof (blkptr_t))) /\
  58         sizeof (uint64_t))
  59
  60 typedef struct zio_gbh {
  61         blkptr_t                zg_blkptr[SPA_GBH_NBLKPTRS];
  62         uint64_t                zg_filler[SPA_GBH_FILLER];
  63         zio_block_tail_t        zg_tail;
  64 } zio_gbh_phys_t;
  65
  66 enum zio_checksum {
  67         ZIO_CHECKSUM_INHERIT = 0,
  68         ZIO_CHECKSUM_ON,
  69         ZIO_CHECKSUM_OFF,
  70         ZIO_CHECKSUM_LABEL,
  71         ZIO_CHECKSUM_GANG_HEADER,
  72         ZIO_CHECKSUM_ZILOG,
  73         ZIO_CHECKSUM_FLETCHER_2,
  74         ZIO_CHECKSUM_FLETCHER_4,
  75         ZIO_CHECKSUM_SHA256,
  76         ZIO_CHECKSUM_FUNCTIONS
  77 };
  78
  79 #define ZIO_CHECKSUM_ON_VALUE   ZIO_CHECKSUM_FLETCHER_2
  80 #define ZIO_CHECKSUM_DEFAULT    ZIO_CHECKSUM_ON
  81
  82 enum zio_compress {
  83         ZIO_COMPRESS_INHERIT = 0,
  84         ZIO_COMPRESS_ON,
  85         ZIO_COMPRESS_OFF,
  86         ZIO_COMPRESS_LZJB,
  87         ZIO_COMPRESS_EMPTY,
  88         ZIO_COMPRESS_GZIP_1,
  89         ZIO_COMPRESS_GZIP_2,
  90         ZIO_COMPRESS_GZIP_3,
  91         ZIO_COMPRESS_GZIP_4,
  92         ZIO_COMPRESS_GZIP_5,
  93         ZIO_COMPRESS_GZIP_6,
  94         ZIO_COMPRESS_GZIP_7,
  95         ZIO_COMPRESS_GZIP_8,
  96         ZIO_COMPRESS_GZIP_9,
  97         ZIO_COMPRESS_FUNCTIONS
  98 };
  99
 100 #define ZIO_COMPRESS_ON_VALUE   ZIO_COMPRESS_LZJB
 101 #define ZIO_COMPRESS_DEFAULT    ZIO_COMPRESS_OFF
 102
 103 #define ZIO_FAILURE_MODE_WAIT           0
 104 #define ZIO_FAILURE_MODE_CONTINUE       1
 105 #define ZIO_FAILURE_MODE_PANIC          2
 106
 107 #define ZIO_PRIORITY_NOW                (zio_priority_table[0])
 108 #define ZIO_PRIORITY_SYNC_READ          (zio_priority_table[1])
 109 #define ZIO_PRIORITY_SYNC_WRITE         (zio_priority_table[2])
 110 #define ZIO_PRIORITY_ASYNC_READ         (zio_priority_table[3])
 111 #define ZIO_PRIORITY_ASYNC_WRITE        (zio_priority_table[4])
 112 #define ZIO_PRIORITY_FREE               (zio_priority_table[5])
 113 #define ZIO_PRIORITY_CACHE_FILL         (zio_priority_table[6])
 114 #define ZIO_PRIORITY_LOG_WRITE          (zio_priority_table[7])
 115 #define ZIO_PRIORITY_RESILVER           (zio_priority_table[8])
 116 #define ZIO_PRIORITY_SCRUB              (zio_priority_table[9])
 117 #define ZIO_PRIORITY_TABLE_SIZE         10
 118
 119 #define ZIO_FLAG_MUSTSUCCEED            0x00000
 120 #define ZIO_FLAG_CANFAIL                0x00001
 121 #define ZIO_FLAG_SPECULATIVE            0x00002
 122 #define ZIO_FLAG_CONFIG_WRITER          0x00004
 123 #define ZIO_FLAG_DONT_RETRY             0x00008
 124
 125 #define ZIO_FLAG_DONT_CACHE             0x00010
 126 #define ZIO_FLAG_DONT_QUEUE             0x00020
 127 #define ZIO_FLAG_DONT_AGGREGATE         0x00040
 128 #define ZIO_FLAG_DONT_PROPAGATE         0x00080
 129
 130 #define ZIO_FLAG_IO_BYPASS              0x00100
 131 #define ZIO_FLAG_IO_REPAIR              0x00200
 132 #define ZIO_FLAG_IO_RETRY               0x00400
 133 #define ZIO_FLAG_IO_REWRITE             0x00800
 134
 135 #define ZIO_FLAG_SELF_HEAL              0x01000
 136 #define ZIO_FLAG_RESILVER               0x02000
 137 #define ZIO_FLAG_SCRUB                  0x04000
 138 #define ZIO_FLAG_SCRUB_THREAD           0x08000
 139
 140 #define ZIO_FLAG_PROBE                  0x10000
 141 #define ZIO_FLAG_GANG_CHILD             0x20000
 142 #define ZIO_FLAG_RAW                    0x40000
 143
 144 #define ZIO_FLAG_GANG_INHERIT           \
 145         (ZIO_FLAG_CANFAIL |             \
 146         ZIO_FLAG_SPECULATIVE |          \
 147         ZIO_FLAG_CONFIG_WRITER |        \
 148         ZIO_FLAG_DONT_RETRY |           \
 149         ZIO_FLAG_DONT_CACHE |           \
 150         ZIO_FLAG_DONT_AGGREGATE |       \
 151         ZIO_FLAG_SELF_HEAL |            \
 152         ZIO_FLAG_RESILVER |             \
 153         ZIO_FLAG_SCRUB |                \
 154         ZIO_FLAG_SCRUB_THREAD)
 155
 156 #define ZIO_FLAG_VDEV_INHERIT           \
 157         (ZIO_FLAG_GANG_INHERIT |        \
 158         ZIO_FLAG_IO_REPAIR |            \
 159         ZIO_FLAG_IO_RETRY |             \
 160         ZIO_FLAG_PROBE)
 161
 162 #define ZIO_FLAG_AGG_INHERIT            \
 163         (ZIO_FLAG_DONT_AGGREGATE |      \
 164         ZIO_FLAG_IO_REPAIR |            \
 165         ZIO_FLAG_SELF_HEAL |            \
 166         ZIO_FLAG_RESILVER |             \
 167         ZIO_FLAG_SCRUB |                \
 168         ZIO_FLAG_SCRUB_THREAD)
 169
 170 #define ZIO_PIPELINE_CONTINUE           0x100
 171 #define ZIO_PIPELINE_STOP               0x101
 172
 173 #define ZIO_GANG_CHILD_FLAGS(zio)                               \
 174         (((zio)->io_flags & ZIO_FLAG_GANG_INHERIT) |            \
 175         ZIO_FLAG_GANG_CHILD | ZIO_FLAG_CANFAIL)
 176
 177 enum zio_child {
 178         ZIO_CHILD_VDEV = 0,
 179         ZIO_CHILD_GANG,
 180         ZIO_CHILD_LOGICAL,
 181         ZIO_CHILD_TYPES
 182 };
 183
 184 enum zio_wait_type {
 185         ZIO_WAIT_READY = 0,
 186         ZIO_WAIT_DONE,
 187         ZIO_WAIT_TYPES
 188 };
 189
 190 /*
 191  * We'll take the unused errnos, 'EBADE' and 'EBADR' (from the Convergent
 192  * graveyard) to indicate checksum errors and fragmentation.
 193  */
 194 #define ECKSUM  EBADE
 195 #define EFRAGS  EBADR
 196
 197 typedef struct zio zio_t;
 198 typedef void zio_done_func_t(zio_t *zio);
 199
 200 extern uint8_t zio_priority_table[ZIO_PRIORITY_TABLE_SIZE];
 201 extern char *zio_type_name[ZIO_TYPES];
 202
 203 /*
 204  * A bookmark is a four-tuple <objset, object, level, blkid> that uniquely
 205  * identifies any block in the pool.  By convention, the meta-objset (MOS)
 206  * is objset 0, the meta-dnode is object 0, the root block (osphys_t) is
 207  * level -1 of the meta-dnode, and intent log blocks (which are chained
 208  * off the root block) have blkid == sequence number.  In summary:
 209  *
 210  *      mos is objset 0
 211  *      meta-dnode is object 0
 212  *      root block is <objset, 0, -1, 0>
 213  *      intent log is <objset, 0, -1, ZIL sequence number>
 214  *
 215  * Note: this structure is called a bookmark because its first purpose was
 216  * to remember where to resume a pool-wide traverse.  The absolute ordering
 217  * for block visitation during traversal is defined in compare_bookmark().
 218  *
 219  * Note: this structure is passed between userland and the kernel.
 220  * Therefore it must not change size or alignment between 32/64 bit
 221  * compilation options.
 222  */
 223 typedef struct zbookmark {
 224         uint64_t        zb_objset;
 225         uint64_t        zb_object;
 226         int64_t         zb_level;
 227         uint64_t        zb_blkid;
 228 } zbookmark_t;
 229
 230 typedef struct zio_prop {
 231         enum zio_checksum       zp_checksum;
 232         enum zio_compress       zp_compress;
 233         dmu_object_type_t       zp_type;
 234         uint8_t                 zp_level;
 235         uint8_t                 zp_ndvas;
 236 } zio_prop_t;
 237
 238 typedef struct zio_gang_node {
 239         zio_gbh_phys_t          *gn_gbh;
 240         struct zio_gang_node    *gn_child[SPA_GBH_NBLKPTRS];
 241 } zio_gang_node_t;
 242
 243 typedef zio_t *zio_gang_issue_func_t(zio_t *zio, blkptr_t *bp,
 244     zio_gang_node_t *gn, void *data);
 245
 246 typedef void zio_transform_func_t(zio_t *zio, void *data, uint64_t size);
 247
 248 typedef struct zio_transform {
 249         void                    *zt_orig_data;
 250         uint64_t                zt_orig_size;
 251         uint64_t                zt_bufsize;
 252         zio_transform_func_t    *zt_transform;
 253         struct zio_transform    *zt_next;
 254 } zio_transform_t;
 255
 256 typedef int zio_pipe_stage_t(zio_t *zio);
 257
 258 /*
 259  * The io_reexecute flags are distinct from io_flags because the child must
 260  * be able to propagate them to the parent.  The normal io_flags are local
 261  * to the zio, not protected by any lock, and not modifiable by children;
 262  * the reexecute flags are protected by io_lock, modifiable by children,
 263  * and always propagated -- even when ZIO_FLAG_DONT_PROPAGATE is set.
 264  */
 265 #define ZIO_REEXECUTE_NOW       0x01
 266 #define ZIO_REEXECUTE_SUSPEND   0x02
 267
 268 typedef struct zio_link {
 269         zio_t           *zl_parent;
 270         zio_t           *zl_child;
 271         list_node_t     zl_parent_node;
 272         list_node_t     zl_child_node;
 273 } zio_link_t;
 274
 275 struct zio {
 276         /* Core information about this I/O */
 277         zbookmark_t     io_bookmark;
 278         zio_prop_t      io_prop;
 279         zio_type_t      io_type;
 280         enum zio_child  io_child_type;
 281         int             io_cmd;
 282         uint8_t         io_priority;
 283         uint8_t         io_reexecute;
 284         uint8_t         io_async_root;
 285         uint8_t         io_state[ZIO_WAIT_TYPES];
 286         uint64_t        io_txg;
 287         spa_t           *io_spa;
 288         blkptr_t        *io_bp;
 289         blkptr_t        io_bp_copy;
 290         list_t          io_parent_list;
 291         list_t          io_child_list;
 292         zio_link_t      *io_walk_link;
 293         zio_t           *io_logical;
 294         zio_transform_t *io_transform_stack;
 295
 296         /* Callback info */
 297         zio_done_func_t *io_ready;
 298         zio_done_func_t *io_done;
 299         void            *io_private;
 300         blkptr_t        io_bp_orig;
 301
 302         /* Data represented by this I/O */
 303         void            *io_data;
 304         uint64_t        io_size;
 305
 306         /* Stuff for the vdev stack */
 307         vdev_t          *io_vd;
 308         void            *io_vsd;
 309         zio_done_func_t *io_vsd_free;
 310         uint64_t        io_offset;
 311         uint64_t        io_deadline;
 312         avl_node_t      io_offset_node;
 313         avl_node_t      io_deadline_node;
 314         avl_tree_t      *io_vdev_tree;
 315
 316         /* Internal pipeline state */
 317         int             io_flags;
 318         zio_stage_t     io_stage;
 319         uint32_t        io_pipeline;
 320         int             io_orig_flags;
 321         zio_stage_t     io_orig_stage;
 322         uint32_t        io_orig_pipeline;
 323         int             io_error;
 324         int             io_child_error[ZIO_CHILD_TYPES];
 325         uint64_t        io_children[ZIO_CHILD_TYPES][ZIO_WAIT_TYPES];
 326         uint64_t        *io_stall;
 327         zio_gang_node_t *io_gang_tree;
 328         void            *io_executor;
 329         void            *io_waiter;
 330         kmutex_t        io_lock;
 331         kcondvar_t      io_cv;
 332
 333         /* FMA state */
 334         uint64_t        io_ena;
 335 };
 336
 337 extern zio_t *zio_null(zio_t *pio, spa_t *spa, vdev_t *vd,
 338     zio_done_func_t *done, void *private, int flags);
 339
 340 extern zio_t *zio_root(spa_t *spa,
 341     zio_done_func_t *done, void *private, int flags);
 342
 343 extern zio_t *zio_read(zio_t *pio, spa_t *spa, const blkptr_t *bp, void *data,
 344     uint64_t size, zio_done_func_t *done, void *private,
 345     int priority, int flags, const zbookmark_t *zb);
 346
 347 extern zio_t *zio_write(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 348     void *data, uint64_t size, zio_prop_t *zp,
 349     zio_done_func_t *ready, zio_done_func_t *done, void *private,
 350     int priority, int flags, const zbookmark_t *zb);
 351
 352 extern zio_t *zio_rewrite(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 353     void *data, uint64_t size, zio_done_func_t *done, void *private,
 354     int priority, int flags, zbookmark_t *zb);
 355
 356 extern void zio_skip_write(zio_t *zio);
 357
 358 extern zio_t *zio_free(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 359     zio_done_func_t *done, void *private, int flags);
 360
 361 extern zio_t *zio_claim(zio_t *pio, spa_t *spa, uint64_t txg, blkptr_t *bp,
 362     zio_done_func_t *done, void *private, int flags);
 363
 364 extern zio_t *zio_ioctl(zio_t *pio, spa_t *spa, vdev_t *vd, int cmd,
 365     zio_done_func_t *done, void *private, int priority, int flags);
 366
 367 extern zio_t *zio_read_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 368     uint64_t size, void *data, int checksum,
 369     zio_done_func_t *done, void *private, int priority, int flags,
 370     boolean_t labels);
 371
 372 extern zio_t *zio_write_phys(zio_t *pio, vdev_t *vd, uint64_t offset,
 373     uint64_t size, void *data, int checksum,
 374     zio_done_func_t *done, void *private, int priority, int flags,
 375     boolean_t labels);
 376
 377 extern int zio_alloc_blk(spa_t *spa, uint64_t size, blkptr_t *new_bp,
 378     blkptr_t *old_bp, uint64_t txg);
 379 extern void zio_free_blk(spa_t *spa, blkptr_t *bp, uint64_t txg);
 380 extern void zio_flush(zio_t *zio, vdev_t *vd);
 381
 382 extern int zio_wait(zio_t *zio);
 383 extern void zio_nowait(zio_t *zio);
 384 extern void zio_execute(zio_t *zio);
 385 extern void zio_interrupt(zio_t *zio);
 386
 387 extern zio_t *zio_walk_parents(zio_t *cio);
 388 extern zio_t *zio_walk_children(zio_t *pio);
 389 extern zio_t *zio_unique_parent(zio_t *cio);
 390 extern void zio_add_child(zio_t *pio, zio_t *cio);
 391
 392 extern void *zio_buf_alloc(size_t size);
 393 extern void zio_buf_free(void *buf, size_t size);
 394 extern void *zio_data_buf_alloc(size_t size);
 395 extern void zio_data_buf_free(void *buf, size_t size);
 396
 397 extern void zio_resubmit_stage_async(void *);
 398
 399 extern zio_t *zio_vdev_child_io(zio_t *zio, blkptr_t *bp, vdev_t *vd,
 400     uint64_t offset, void *data, uint64_t size, int type, int priority,
 401     int flags, zio_done_func_t *done, void *private);
 402
 403 extern zio_t *zio_vdev_delegated_io(vdev_t *vd, uint64_t offset,
 404     void *data, uint64_t size, int type, int priority,
 405     int flags, zio_done_func_t *done, void *private);
 406
 407 extern void zio_vdev_io_bypass(zio_t *zio);
 408 extern void zio_vdev_io_reissue(zio_t *zio);
 409 extern void zio_vdev_io_redone(zio_t *zio);
 410
 411 extern void zio_checksum_verified(zio_t *zio);
 412 extern int zio_worst_error(int e1, int e2);
 413
 414 extern uint8_t zio_checksum_select(uint8_t child, uint8_t parent);
 415 extern uint8_t zio_compress_select(uint8_t child, uint8_t parent);
 416
 417 extern void zio_suspend(spa_t *spa, zio_t *zio);
 418 extern void zio_resume(spa_t *spa);
 419 extern void zio_resume_wait(spa_t *spa);
 420
 421 /*
 422  * Initial setup and teardown.
 423  */
 424 extern void zio_init(void);
 425 extern void zio_fini(void);
 426
 427 /*
 428  * Fault injection
 429  */
 430 struct zinject_record;
 431 extern uint32_t zio_injection_enabled;
 432 extern int zio_inject_fault(char *name, int flags, int *id,
 433     struct zinject_record *record);
 434 extern int zio_inject_list_next(int *id, char *name, size_t buflen,
 435     struct zinject_record *record);
 436 extern int zio_clear_fault(int id);
 437 extern int zio_handle_fault_injection(zio_t *zio, int error);
 438 extern int zio_handle_device_injection(vdev_t *vd, int error);
 439 extern int zio_handle_label_injection(zio_t *zio, int error);
 440
 441 #ifdef  __cplusplus
 442 }
 443 #endif
 444
 445 #endif  /* _ZIO_H */