xref: /illumos-gate/usr/src/uts/common/fs/zfs/sys/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 */