module/zfs/include/sys/zil.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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  23  */
  24
  25 /* Portions Copyright 2010 Robert Milkowski */
  26
  27 #ifndef _SYS_ZIL_H
  28 #define _SYS_ZIL_H
  29
  30 #include <sys/types.h>
  31 #include <sys/spa.h>
  32 #include <sys/zio.h>
  33 #include <sys/dmu.h>
  34
  35 #ifdef  __cplusplus
  36 extern "C" {
  37 #endif
  38
  39 /*
  40  * Intent log format:
  41  *
  42  * Each objset has its own intent log.  The log header (zil_header_t)
  43  * for objset N's intent log is kept in the Nth object of the SPA's
  44  * intent_log objset.  The log header points to a chain of log blocks,
  45  * each of which contains log records (i.e., transactions) followed by
  46  * a log block trailer (zil_trailer_t).  The format of a log record
  47  * depends on the record (or transaction) type, but all records begin
  48  * with a common structure that defines the type, length, and txg.
  49  */
  50
  51 /*
  52  * Intent log header - this on disk structure holds fields to manage
  53  * the log.  All fields are 64 bit to easily handle cross architectures.
  54  */
  55 typedef struct zil_header {
  56         uint64_t zh_claim_txg;  /* txg in which log blocks were claimed */
  57         uint64_t zh_replay_seq; /* highest replayed sequence number */
  58         blkptr_t zh_log;        /* log chain */
  59         uint64_t zh_claim_blk_seq; /* highest claimed block sequence number */
  60         uint64_t zh_flags;      /* header flags */
  61         uint64_t zh_claim_lr_seq; /* highest claimed lr sequence number */
  62         uint64_t zh_pad[3];
  63 } zil_header_t;
  64
  65 /*
  66  * zh_flags bit settings
  67  */
  68 #define ZIL_REPLAY_NEEDED       0x1     /* replay needed - internal only */
  69 #define ZIL_CLAIM_LR_SEQ_VALID  0x2     /* zh_claim_lr_seq field is valid */
  70
  71 /*
  72  * Log block chaining.
  73  *
  74  * Log blocks are chained together. Originally they were chained at the
  75  * end of the block. For performance reasons the chain was moved to the
  76  * beginning of the block which allows writes for only the data being used.
  77  * The older position is supported for backwards compatability.
  78  *
  79  * The zio_eck_t contains a zec_cksum which for the intent log is
  80  * the sequence number of this log block. A seq of 0 is invalid.
  81  * The zec_cksum is checked by the SPA against the sequence
  82  * number passed in the blk_cksum field of the blkptr_t
  83  */
  84 typedef struct zil_chain {
  85         uint64_t zc_pad;
  86         blkptr_t zc_next_blk;   /* next block in chain */
  87         uint64_t zc_nused;      /* bytes in log block used */
  88         zio_eck_t zc_eck;       /* block trailer */
  89 } zil_chain_t;
  90
  91 #define ZIL_MIN_BLKSZ   4096ULL
  92 #define ZIL_MAX_BLKSZ   SPA_MAXBLOCKSIZE
  93
  94 /*
  95  * The words of a log block checksum.
  96  */
  97 #define ZIL_ZC_GUID_0   0
  98 #define ZIL_ZC_GUID_1   1
  99 #define ZIL_ZC_OBJSET   2
 100 #define ZIL_ZC_SEQ      3
 101
 102 typedef enum zil_create {
 103         Z_FILE,
 104         Z_DIR,
 105         Z_XATTRDIR,
 106 } zil_create_t;
 107
 108 /*
 109  * size of xvattr log section.
 110  * its composed of lr_attr_t + xvattr bitmap + 2 64 bit timestamps
 111  * for create time and a single 64 bit integer for all of the attributes,
 112  * and 4 64 bit integers (32 bytes) for the scanstamp.
 113  *
 114  */
 115
 116 #define ZIL_XVAT_SIZE(mapsize) \
 117         sizeof (lr_attr_t) + (sizeof (uint32_t) * (mapsize - 1)) + \
 118         (sizeof (uint64_t) * 7)
 119
 120 /*
 121  * Size of ACL in log.  The ACE data is padded out to properly align
 122  * on 8 byte boundary.
 123  */
 124
 125 #define ZIL_ACE_LENGTH(x)       (roundup(x, sizeof (uint64_t)))
 126
 127 /*
 128  * Intent log transaction types and record structures
 129  */
 130 #define TX_CREATE               1       /* Create file */
 131 #define TX_MKDIR                2       /* Make directory */
 132 #define TX_MKXATTR              3       /* Make XATTR directory */
 133 #define TX_SYMLINK              4       /* Create symbolic link to a file */
 134 #define TX_REMOVE               5       /* Remove file */
 135 #define TX_RMDIR                6       /* Remove directory */
 136 #define TX_LINK                 7       /* Create hard link to a file */
 137 #define TX_RENAME               8       /* Rename a file */
 138 #define TX_WRITE                9       /* File write */
 139 #define TX_TRUNCATE             10      /* Truncate a file */
 140 #define TX_SETATTR              11      /* Set file attributes */
 141 #define TX_ACL_V0               12      /* Set old formatted ACL */
 142 #define TX_ACL                  13      /* Set ACL */
 143 #define TX_CREATE_ACL           14      /* create with ACL */
 144 #define TX_CREATE_ATTR          15      /* create + attrs */
 145 #define TX_CREATE_ACL_ATTR      16      /* create with ACL + attrs */
 146 #define TX_MKDIR_ACL            17      /* mkdir with ACL */
 147 #define TX_MKDIR_ATTR           18      /* mkdir with attr */
 148 #define TX_MKDIR_ACL_ATTR       19      /* mkdir with ACL + attrs */
 149 #define TX_WRITE2               20      /* dmu_sync EALREADY write */
 150 #define TX_MAX_TYPE             21      /* Max transaction type */
 151
 152 /*
 153  * The transactions for mkdir, symlink, remove, rmdir, link, and rename
 154  * may have the following bit set, indicating the original request
 155  * specified case-insensitive handling of names.
 156  */
 157 #define TX_CI   ((uint64_t)0x1 << 63) /* case-insensitive behavior requested */
 158
 159 /*
 160  * Transactions for write, truncate, setattr, acl_v0, and acl can be logged
 161  * out of order.  For convenience in the code, all such records must have
 162  * lr_foid at the same offset.
 163  */
 164 #define TX_OOO(txtype)                  \
 165         ((txtype) == TX_WRITE ||        \
 166         (txtype) == TX_TRUNCATE ||      \
 167         (txtype) == TX_SETATTR ||       \
 168         (txtype) == TX_ACL_V0 ||        \
 169         (txtype) == TX_ACL ||           \
 170         (txtype) == TX_WRITE2)
 171
 172 /*
 173  * Format of log records.
 174  * The fields are carefully defined to allow them to be aligned
 175  * and sized the same on sparc & intel architectures.
 176  * Each log record has a common structure at the beginning.
 177  *
 178  * The log record on disk (lrc_seq) holds the sequence number of all log
 179  * records which is used to ensure we don't replay the same record.
 180  */
 181 typedef struct {                        /* common log record header */
 182         uint64_t        lrc_txtype;     /* intent log transaction type */
 183         uint64_t        lrc_reclen;     /* transaction record length */
 184         uint64_t        lrc_txg;        /* dmu transaction group number */
 185         uint64_t        lrc_seq;        /* see comment above */
 186 } lr_t;
 187
 188 /*
 189  * Common start of all out-of-order record types (TX_OOO() above).
 190  */
 191 typedef struct {
 192         lr_t            lr_common;      /* common portion of log record */
 193         uint64_t        lr_foid;        /* object id */
 194 } lr_ooo_t;
 195
 196 /*
 197  * Handle option extended vattr attributes.
 198  *
 199  * Whenever new attributes are added the version number
 200  * will need to be updated as will code in
 201  * zfs_log.c and zfs_replay.c
 202  */
 203 typedef struct {
 204         uint32_t        lr_attr_masksize; /* number of elements in array */
 205         uint32_t        lr_attr_bitmap; /* First entry of array */
 206         /* remainder of array and any additional fields */
 207 } lr_attr_t;
 208
 209 /*
 210  * log record for creates without optional ACL.
 211  * This log record does support optional xvattr_t attributes.
 212  */
 213 typedef struct {
 214         lr_t            lr_common;      /* common portion of log record */
 215         uint64_t        lr_doid;        /* object id of directory */
 216         uint64_t        lr_foid;        /* object id of created file object */
 217         uint64_t        lr_mode;        /* mode of object */
 218         uint64_t        lr_uid;         /* uid of object */
 219         uint64_t        lr_gid;         /* gid of object */
 220         uint64_t        lr_gen;         /* generation (txg of creation) */
 221         uint64_t        lr_crtime[2];   /* creation time */
 222         uint64_t        lr_rdev;        /* rdev of object to create */
 223         /* name of object to create follows this */
 224         /* for symlinks, link content follows name */
 225         /* for creates with xvattr data, the name follows the xvattr info */
 226 } lr_create_t;
 227
 228 /*
 229  * FUID ACL record will be an array of ACEs from the original ACL.
 230  * If this array includes ephemeral IDs, the record will also include
 231  * an array of log-specific FUIDs to replace the ephemeral IDs.
 232  * Only one copy of each unique domain will be present, so the log-specific
 233  * FUIDs will use an index into a compressed domain table.  On replay this
 234  * information will be used to construct real FUIDs (and bypass idmap,
 235  * since it may not be available).
 236  */
 237
 238 /*
 239  * Log record for creates with optional ACL
 240  * This log record is also used for recording any FUID
 241  * information needed for replaying the create.  If the
 242  * file doesn't have any actual ACEs then the lr_aclcnt
 243  * would be zero.
 244  */
 245 typedef struct {
 246         lr_create_t     lr_create;      /* common create portion */
 247         uint64_t        lr_aclcnt;      /* number of ACEs in ACL */
 248         uint64_t        lr_domcnt;      /* number of unique domains */
 249         uint64_t        lr_fuidcnt;     /* number of real fuids */
 250         uint64_t        lr_acl_bytes;   /* number of bytes in ACL */
 251         uint64_t        lr_acl_flags;   /* ACL flags */
 252         /* lr_acl_bytes number of variable sized ace's follows */
 253         /* if create is also setting xvattr's, then acl data follows xvattr */
 254         /* if ACE FUIDs are needed then they will follow the xvattr_t */
 255         /* Following the FUIDs will be the domain table information. */
 256         /* The FUIDs for the owner and group will be in the lr_create */
 257         /* portion of the record. */
 258         /* name follows ACL data */
 259 } lr_acl_create_t;
 260
 261 typedef struct {
 262         lr_t            lr_common;      /* common portion of log record */
 263         uint64_t        lr_doid;        /* obj id of directory */
 264         /* name of object to remove follows this */
 265 } lr_remove_t;
 266
 267 typedef struct {
 268         lr_t            lr_common;      /* common portion of log record */
 269         uint64_t        lr_doid;        /* obj id of directory */
 270         uint64_t        lr_link_obj;    /* obj id of link */
 271         /* name of object to link follows this */
 272 } lr_link_t;
 273
 274 typedef struct {
 275         lr_t            lr_common;      /* common portion of log record */
 276         uint64_t        lr_sdoid;       /* obj id of source directory */
 277         uint64_t        lr_tdoid;       /* obj id of target directory */
 278         /* 2 strings: names of source and destination follow this */
 279 } lr_rename_t;
 280
 281 typedef struct {
 282         lr_t            lr_common;      /* common portion of log record */
 283         uint64_t        lr_foid;        /* file object to write */
 284         uint64_t        lr_offset;      /* offset to write to */
 285         uint64_t        lr_length;      /* user data length to write */
 286         uint64_t        lr_blkoff;      /* no longer used */
 287         blkptr_t        lr_blkptr;      /* spa block pointer for replay */
 288         /* write data will follow for small writes */
 289 } lr_write_t;
 290
 291 typedef struct {
 292         lr_t            lr_common;      /* common portion of log record */
 293         uint64_t        lr_foid;        /* object id of file to truncate */
 294         uint64_t        lr_offset;      /* offset to truncate from */
 295         uint64_t        lr_length;      /* length to truncate */
 296 } lr_truncate_t;
 297
 298 typedef struct {
 299         lr_t            lr_common;      /* common portion of log record */
 300         uint64_t        lr_foid;        /* file object to change attributes */
 301         uint64_t        lr_mask;        /* mask of attributes to set */
 302         uint64_t        lr_mode;        /* mode to set */
 303         uint64_t        lr_uid;         /* uid to set */
 304         uint64_t        lr_gid;         /* gid to set */
 305         uint64_t        lr_size;        /* size to set */
 306         uint64_t        lr_atime[2];    /* access time */
 307         uint64_t        lr_mtime[2];    /* modification time */
 308         /* optional attribute lr_attr_t may be here */
 309 } lr_setattr_t;
 310
 311 typedef struct {
 312         lr_t            lr_common;      /* common portion of log record */
 313         uint64_t        lr_foid;        /* obj id of file */
 314         uint64_t        lr_aclcnt;      /* number of acl entries */
 315         /* lr_aclcnt number of ace_t entries follow this */
 316 } lr_acl_v0_t;
 317
 318 typedef struct {
 319         lr_t            lr_common;      /* common portion of log record */
 320         uint64_t        lr_foid;        /* obj id of file */
 321         uint64_t        lr_aclcnt;      /* number of ACEs in ACL */
 322         uint64_t        lr_domcnt;      /* number of unique domains */
 323         uint64_t        lr_fuidcnt;     /* number of real fuids */
 324         uint64_t        lr_acl_bytes;   /* number of bytes in ACL */
 325         uint64_t        lr_acl_flags;   /* ACL flags */
 326         /* lr_acl_bytes number of variable sized ace's follows */
 327 } lr_acl_t;
 328
 329 /*
 330  * ZIL structure definitions, interface function prototype and globals.
 331  */
 332
 333 /*
 334  * Writes are handled in three different ways:
 335  *
 336  * WR_INDIRECT:
 337  *    In this mode, if we need to commit the write later, then the block
 338  *    is immediately written into the file system (using dmu_sync),
 339  *    and a pointer to the block is put into the log record.
 340  *    When the txg commits the block is linked in.
 341  *    This saves additionally writing the data into the log record.
 342  *    There are a few requirements for this to occur:
 343  *      - write is greater than zfs/zvol_immediate_write_sz
 344  *      - not using slogs (as slogs are assumed to always be faster
 345  *        than writing into the main pool)
 346  *      - the write occupies only one block
 347  * WR_COPIED:
 348  *    If we know we'll immediately be committing the
 349  *    transaction (FSYNC or FDSYNC), the we allocate a larger
 350  *    log record here for the data and copy the data in.
 351  * WR_NEED_COPY:
 352  *    Otherwise we don't allocate a buffer, and *if* we need to
 353  *    flush the write later then a buffer is allocated and
 354  *    we retrieve the data using the dmu.
 355  */
 356 typedef enum {
 357         WR_INDIRECT,    /* indirect - a large write (dmu_sync() data */
 358                         /* and put blkptr in log, rather than actual data) */
 359         WR_COPIED,      /* immediate - data is copied into lr_write_t */
 360         WR_NEED_COPY,   /* immediate - data needs to be copied if pushed */
 361         WR_NUM_STATES   /* number of states */
 362 } itx_wr_state_t;
 363
 364 typedef struct itx {
 365         list_node_t     itx_node;       /* linkage on zl_itx_list */
 366         void            *itx_private;   /* type-specific opaque data */
 367         itx_wr_state_t  itx_wr_state;   /* write state */
 368         uint8_t         itx_sync;       /* synchronous transaction */
 369         uint64_t        itx_sod;        /* record size on disk */
 370         uint64_t        itx_oid;        /* object id */
 371         lr_t            itx_lr;         /* common part of log record */
 372         /* followed by type-specific part of lr_xx_t and its immediate data */
 373 } itx_t;
 374
 375 typedef int zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
 376     uint64_t txg);
 377 typedef int zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
 378     uint64_t txg);
 379 typedef int zil_replay_func_t(void *, char *, boolean_t);
 380 typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);
 381
 382 extern int zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
 383     zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg);
 384
 385 extern void     zil_init(void);
 386 extern void     zil_fini(void);
 387
 388 extern zilog_t  *zil_alloc(objset_t *os, zil_header_t *zh_phys);
 389 extern void     zil_free(zilog_t *zilog);
 390
 391 extern zilog_t  *zil_open(objset_t *os, zil_get_data_t *get_data);
 392 extern void     zil_close(zilog_t *zilog);
 393
 394 extern void     zil_replay(objset_t *os, void *arg,
 395     zil_replay_func_t *replay_func[TX_MAX_TYPE]);
 396 extern boolean_t zil_replaying(zilog_t *zilog, dmu_tx_t *tx);
 397 extern void     zil_destroy(zilog_t *zilog, boolean_t keep_first);
 398 extern void     zil_rollback_destroy(zilog_t *zilog, dmu_tx_t *tx);
 399
 400 extern itx_t    *zil_itx_create(uint64_t txtype, size_t lrsize);
 401 extern void     zil_itx_destroy(itx_t *itx);
 402 extern void     zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx);
 403
 404 extern void     zil_commit(zilog_t *zilog, uint64_t oid);
 405
 406 extern int      zil_vdev_offline(const char *osname, void *txarg);
 407 extern int      zil_claim(const char *osname, void *txarg);
 408 extern int      zil_check_log_chain(const char *osname, void *txarg);
 409 extern void     zil_sync(zilog_t *zilog, dmu_tx_t *tx);
 410 extern void     zil_clean(zilog_t *zilog, uint64_t synced_txg);
 411
 412 extern int      zil_suspend(zilog_t *zilog);
 413 extern void     zil_resume(zilog_t *zilog);
 414
 415 extern void     zil_add_block(zilog_t *zilog, const blkptr_t *bp);
 416 extern int      zil_bp_tree_add(zilog_t *zilog, const blkptr_t *bp);
 417
 418 extern void     zil_set_sync(zilog_t *zilog, uint64_t syncval);
 419
 420 extern void     zil_set_logbias(zilog_t *zilog, uint64_t slogval);
 421
 422 extern int zil_replay_disable;
 423
 424 #ifdef  __cplusplus
 425 }
 426 #endif
 427
 428 #endif  /* _SYS_ZIL_H */