zfs/sys/zil.h

	zil.h revision 3a8a1de4a7950ac5cf7ca65f761e324145e7237b
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#ifndef _SYS_ZIL_H
#define _SYS_ZIL_H

#pragma ident   "%Z%%M% %I% %E% SMI"

#include <sys/types.h>
#include <sys/spa.h>
#include <sys/zio.h>
#include <sys/dmu.h>

#ifdef  __cplusplus
extern "C" {
#endif

/*
 * Intent log format:
 *
 * Each objset has its own intent log.  The log header (zil_header_t)
 * for objset N's intent log is kept in the Nth object of the SPA's
 * intent_log objset.  The log header points to a chain of log blocks,
 * each of which contains log records (i.e., transactions) followed by
 * a log block trailer (zil_trailer_t).  The format of a log record
 * depends on the record (or transaction) type, but all records begin
 * with a common structure that defines the type, length, and txg.
 */

/*
 * Intent log header - this on disk structure holds fields to manage
 * the log.  All fields are 64 bit to easily handle cross architectures.
 */
typedef struct zil_header {
    uint64_t zh_claim_txg;  /* txg in which log blocks were claimed */
    uint64_t zh_replay_seq; /* highest replayed sequence number */
    blkptr_t zh_log;    /* log chain */
    uint64_t zh_claim_seq;  /* highest claimed sequence number */
    uint64_t zh_pad[5];
} zil_header_t;

/*
 * Log block trailer - structure at the end of the header and each log block
 *
 * The zit_bt contains a zbt_cksum which for the intent log is
 * the sequence number of this log block. A seq of 0 is invalid.
 * The zbt_cksum is checked by the SPA against the sequence
 * number passed in the blk_cksum field of the blkptr_t
 */
typedef struct zil_trailer {
    uint64_t zit_pad;
    blkptr_t zit_next_blk;  /* next block in chain */
    uint64_t zit_nused; /* bytes in log block used */
    zio_block_tail_t zit_bt; /* block trailer */
} zil_trailer_t;

#define ZIL_MIN_BLKSZ   4096ULL
#define ZIL_MAX_BLKSZ   SPA_MAXBLOCKSIZE
#define ZIL_BLK_DATA_SZ(lwb)    ((lwb)->lwb_sz - sizeof (zil_trailer_t))

/*
 * The words of a log block checksum.
 */
#define ZIL_ZC_GUID_0   0
#define ZIL_ZC_GUID_1   1
#define ZIL_ZC_OBJSET   2
#define ZIL_ZC_SEQ  3

/*
 * Intent log transaction types and record structures
 */
#define TX_CREATE   1       /* Create file */
#define TX_MKDIR    2       /* Make directory */
#define TX_MKXATTR  3       /* Make XATTR directory */
#define TX_SYMLINK  4       /* Create symbolic link to a file */
#define TX_REMOVE   5       /* Remove file */
#define TX_RMDIR    6       /* Remove directory */
#define TX_LINK     7       /* Create hard link to a file */
#define TX_RENAME   8       /* Rename a file */
#define TX_WRITE    9       /* File write */
#define TX_TRUNCATE 10      /* Truncate a file */
#define TX_SETATTR  11      /* Set file attributes */
#define TX_ACL      12      /* Set acl */
#define TX_MAX_TYPE 13      /* Max transaction type */

/*
 * Format of log records.
 * The fields are carefully defined to allow them to be aligned
 * and sized the same on sparc & intel architectures.
 * Each log record has a common structure at the beginning.
 *
 * Note, lrc_seq holds two different sequence numbers. Whilst in memory
 * it contains the transaction sequence number.  The log record on
 * disk holds the sequence number of all log records which is used to
 * ensure we don't replay the same record.  The two sequence numbers are
 * different because the transactions can now be pushed out of order.
 */
typedef struct {            /* common log record header */
    uint64_t    lrc_txtype; /* intent log transaction type */
    uint64_t    lrc_reclen; /* transaction record length */
    uint64_t    lrc_txg;    /* dmu transaction group number */
    uint64_t    lrc_seq;    /* see comment above */
} lr_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_doid;    /* object id of directory */
    uint64_t    lr_foid;    /* object id of created file object */
    uint64_t    lr_mode;    /* mode of object */
    uint64_t    lr_uid;     /* uid of object */
    uint64_t    lr_gid;     /* gid of object */
    uint64_t    lr_gen;     /* generation (txg of creation) */
    uint64_t    lr_crtime[2];   /* creation time */
    uint64_t    lr_rdev;    /* rdev of object to create */
    /* name of object to create follows this */
    /* for symlinks, link content follows name */
} lr_create_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_doid;    /* obj id of directory */
    /* name of object to remove follows this */
} lr_remove_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_doid;    /* obj id of directory */
    uint64_t    lr_link_obj;    /* obj id of link */
    /* name of object to link follows this */
} lr_link_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_sdoid;   /* obj id of source directory */
    uint64_t    lr_tdoid;   /* obj id of target directory */
    /* 2 strings: names of source and destination follow this */
} lr_rename_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_foid;    /* file object to write */
    uint64_t    lr_offset;  /* offset to write to */
    uint64_t    lr_length;  /* user data length to write */
    uint64_t    lr_blkoff;  /* offset represented by lr_blkptr */
    blkptr_t    lr_blkptr;  /* spa block pointer for replay */
    /* write data will follow for small writes */
} lr_write_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_foid;    /* object id of file to truncate */
    uint64_t    lr_offset;  /* offset to truncate from */
    uint64_t    lr_length;  /* length to truncate */
} lr_truncate_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_foid;    /* file object to change attributes */
    uint64_t    lr_mask;    /* mask of attributes to set */
    uint64_t    lr_mode;    /* mode to set */
    uint64_t    lr_uid;     /* uid to set */
    uint64_t    lr_gid;     /* gid to set */
    uint64_t    lr_size;    /* size to set */
    uint64_t    lr_atime[2];    /* access time */
    uint64_t    lr_mtime[2];    /* modification time */
} lr_setattr_t;

typedef struct {
    lr_t        lr_common;  /* common portion of log record */
    uint64_t    lr_foid;    /* obj id of file */
    uint64_t    lr_aclcnt;  /* number of acl entries */
    /* lr_aclcnt number of ace_t entries follow this */
} lr_acl_t;

/*
 * ZIL structure definitions, interface function prototype and globals.
 */

/*
 * ZFS intent log transaction structure
 */
typedef enum {
    WR_INDIRECT,    /* indirect - a large write (dmu_sync() data */
            /* and put blkptr in log, rather than actual data) */
    WR_COPIED,  /* immediate - data is copied into lr_write_t */
    WR_NEED_COPY,   /* immediate - data needs to be copied if pushed */
} itx_wr_state_t;

typedef struct itx {
    list_node_t itx_node;   /* linkage on zl_itx_list */
    void        *itx_private;   /* type-specific opaque data */
    itx_wr_state_t  itx_wr_state;   /* write state */
    uint8_t     itx_sync;   /* synchronous transaction */
    lr_t        itx_lr;     /* common part of log record */
    /* followed by type-specific part of lr_xx_t and its immediate data */
} itx_t;


/*
 * zgd_t is passed through dmu_sync() to the callback routine zfs_get_done()
 * to handle the cleanup of the dmu_sync() buffer write
 */
typedef struct {
    zilog_t     *zgd_zilog; /* zilog */
    blkptr_t    *zgd_bp;    /* block pointer */
    struct rl   *zgd_rl;    /* range lock */
} zgd_t;


typedef void zil_parse_blk_func_t(zilog_t *zilog, blkptr_t *bp, void *arg,
    uint64_t txg);
typedef void zil_parse_lr_func_t(zilog_t *zilog, lr_t *lr, void *arg,
    uint64_t txg);
typedef int zil_replay_func_t();
typedef int zil_get_data_t(void *arg, lr_write_t *lr, char *dbuf, zio_t *zio);

extern uint64_t zil_parse(zilog_t *zilog, zil_parse_blk_func_t *parse_blk_func,
    zil_parse_lr_func_t *parse_lr_func, void *arg, uint64_t txg);

extern void zil_init(void);
extern void zil_fini(void);

extern zilog_t  *zil_alloc(objset_t *os, zil_header_t *zh_phys);
extern void zil_free(zilog_t *zilog);

extern zilog_t  *zil_open(objset_t *os, zil_get_data_t *get_data);
extern void zil_close(zilog_t *zilog);

extern void zil_replay(objset_t *os, void *arg, uint64_t *txgp,
    zil_replay_func_t *replay_func[TX_MAX_TYPE]);
extern void zil_destroy(zilog_t *zilog, boolean_t keep_first);
extern void zil_rollback_destroy(zilog_t *zilog, dmu_tx_t *tx);

extern itx_t    *zil_itx_create(int txtype, size_t lrsize);
extern uint64_t zil_itx_assign(zilog_t *zilog, itx_t *itx, dmu_tx_t *tx);

extern void zil_commit(zilog_t *zilog, uint64_t seq, uint64_t oid);

extern int  zil_claim(char *osname, void *txarg);
extern void zil_sync(zilog_t *zilog, dmu_tx_t *tx);
extern void zil_clean(zilog_t *zilog);
extern int  zil_is_committed(zilog_t *zilog);

extern int  zil_suspend(zilog_t *zilog);
extern void zil_resume(zilog_t *zilog);

extern void zil_add_vdev(zilog_t *zilog, uint64_t vdev);

extern int zil_disable;

#ifdef  __cplusplus
}
#endif

#endif  /* _SYS_ZIL_H */