patch-2.4.25 linux-2.4.25/fs/xfs/xfs_log_priv.h

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diff -urN linux-2.4.24/fs/xfs/xfs_log_priv.h linux-2.4.25/fs/xfs/xfs_log_priv.h
@@ -0,0 +1,568 @@
+/*
+ * Copyright (c) 2000-2003 Silicon Graphics, Inc.  All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it would be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * Further, this software is distributed without any warranty that it is
+ * free of the rightful claim of any third person regarding infringement
+ * or the like.  Any license provided herein, whether implied or
+ * otherwise, applies only to this software file.  Patent licenses, if
+ * any, provided herein do not apply to combinations of this program with
+ * other software, or any other product whatsoever.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write the Free Software Foundation, Inc., 59
+ * Temple Place - Suite 330, Boston MA 02111-1307, USA.
+ *
+ * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
+ * Mountain View, CA  94043, or:
+ *
+ * http://www.sgi.com
+ *
+ * For further information regarding this notice, see:
+ *
+ * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
+ */
+#ifndef	__XFS_LOG_PRIV_H__
+#define __XFS_LOG_PRIV_H__
+
+struct xfs_buf;
+struct ktrace;
+struct log;
+struct xfs_buf_cancel;
+struct xfs_mount;
+
+/*
+ * Macros, structures, prototypes for internal log manager use.
+ */
+
+#define XLOG_MIN_ICLOGS		2
+#define XLOG_MED_ICLOGS		4
+#define XLOG_MAX_ICLOGS		8
+#define XLOG_CALLBACK_SIZE	10
+#define XLOG_HEADER_MAGIC_NUM	0xFEEDbabe	/* Invalid cycle number */
+#define XLOG_VERSION_1		1
+#define XLOG_VERSION_2		2		/* Large IClogs, Log sunit */
+#define XLOG_VERSION_OKBITS	(XLOG_VERSION_1 | XLOG_VERSION_2)
+#define XLOG_RECORD_BSIZE	(16*1024)	/* eventually 32k */
+#define XLOG_BIG_RECORD_BSIZE	(32*1024)	/* 32k buffers */
+#define XLOG_MAX_RECORD_BSIZE	(256*1024)
+#define XLOG_HEADER_CYCLE_SIZE	(32*1024)	/* cycle data in header */
+#define XLOG_RECORD_BSHIFT	14		/* 16384 == 1 << 14 */
+#define XLOG_BIG_RECORD_BSHIFT	15		/* 32k == 1 << 15 */
+#define XLOG_MAX_RECORD_BSHIFT	18		/* 256k == 1 << 18 */
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XLOG_BTOLRBB)
+int xlog_btolrbb(int b);
+#define XLOG_BTOLRBB(b)		xlog_btolrbb(b)
+#else
+#define XLOG_BTOLRBB(b)		(((b)+XLOG_RECORD_BSIZE-1) >> XLOG_RECORD_BSHIFT)
+#endif
+
+#define XLOG_HEADER_SIZE	512
+
+#define XLOG_REC_SHIFT(log) \
+	BTOBB(1 << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
+	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
+#define XLOG_TOTAL_REC_SHIFT(log) \
+	BTOBB(XLOG_MAX_ICLOGS << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
+	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
+
+/*
+ *  set lsns
+ */
+
+#define ASSIGN_LSN_CYCLE(lsn,cycle,arch) \
+    INT_SET(((uint *)&(lsn))[LSN_FIELD_CYCLE(arch)], arch, (cycle));
+#define ASSIGN_LSN_BLOCK(lsn,block,arch) \
+    INT_SET(((uint *)&(lsn))[LSN_FIELD_BLOCK(arch)], arch, (block));
+#define ASSIGN_ANY_LSN(lsn,cycle,block,arch)  \
+    { \
+	ASSIGN_LSN_CYCLE(lsn,cycle,arch); \
+	ASSIGN_LSN_BLOCK(lsn,block,arch); \
+    }
+#define ASSIGN_LSN(lsn,log,arch) \
+    ASSIGN_ANY_LSN(lsn,(log)->l_curr_cycle,(log)->l_curr_block,arch);
+
+#define XLOG_SET(f,b)		(((f) & (b)) == (b))
+
+#define GET_CYCLE(ptr, arch) \
+    (INT_GET(*(uint *)(ptr), arch) == XLOG_HEADER_MAGIC_NUM ? \
+	 INT_GET(*((uint *)(ptr)+1), arch) : \
+	 INT_GET(*(uint *)(ptr), arch) \
+    )
+
+#define BLK_AVG(blk1, blk2)	((blk1+blk2) >> 1)
+
+
+#ifdef __KERNEL__
+
+/*
+ * get client id from packed copy.
+ *
+ * this hack is here because the xlog_pack code copies four bytes
+ * of xlog_op_header containing the fields oh_clientid, oh_flags
+ * and oh_res2 into the packed copy.
+ *
+ * later on this four byte chunk is treated as an int and the
+ * client id is pulled out.
+ *
+ * this has endian issues, of course.
+ */
+
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define GET_CLIENT_ID(i,arch) \
+    ((i) & 0xff)
+#else
+#define GET_CLIENT_ID(i,arch) \
+    ((i) >> 24)
+#endif
+
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XLOG_GRANT_SUB_SPACE)
+void xlog_grant_sub_space(struct log *log, int bytes, int type);
+#define XLOG_GRANT_SUB_SPACE(log,bytes,type)	\
+	xlog_grant_sub_space(log,bytes,type)
+#else
+#define XLOG_GRANT_SUB_SPACE(log,bytes,type)				\
+    {									\
+	if (type == 'w') {						\
+		(log)->l_grant_write_bytes -= (bytes);			\
+		if ((log)->l_grant_write_bytes < 0) {			\
+			(log)->l_grant_write_bytes += (log)->l_logsize;	\
+			(log)->l_grant_write_cycle--;			\
+		}							\
+	} else {							\
+		(log)->l_grant_reserve_bytes -= (bytes);		\
+		if ((log)->l_grant_reserve_bytes < 0) {			\
+			(log)->l_grant_reserve_bytes += (log)->l_logsize;\
+			(log)->l_grant_reserve_cycle--;			\
+		}							\
+	 }								\
+    }
+#endif
+#if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XLOG_GRANT_ADD_SPACE)
+void xlog_grant_add_space(struct log *log, int bytes, int type);
+#define XLOG_GRANT_ADD_SPACE(log,bytes,type)	\
+	xlog_grant_add_space(log,bytes,type)
+#else
+#define XLOG_GRANT_ADD_SPACE(log,bytes,type)				\
+    {									\
+	if (type == 'w') {						\
+		(log)->l_grant_write_bytes += (bytes);			\
+		if ((log)->l_grant_write_bytes > (log)->l_logsize) {	\
+			(log)->l_grant_write_bytes -= (log)->l_logsize;	\
+			(log)->l_grant_write_cycle++;			\
+		}							\
+	} else {							\
+		(log)->l_grant_reserve_bytes += (bytes);		\
+		if ((log)->l_grant_reserve_bytes > (log)->l_logsize) {	\
+			(log)->l_grant_reserve_bytes -= (log)->l_logsize;\
+			(log)->l_grant_reserve_cycle++;			\
+		}							\
+	 }								\
+    }
+#endif
+#define XLOG_INS_TICKETQ(q,tic)				\
+    {							\
+	if (q) {					\
+		(tic)->t_next	    = (q);		\
+		(tic)->t_prev	    = (q)->t_prev;	\
+		(q)->t_prev->t_next = (tic);		\
+		(q)->t_prev	    = (tic);		\
+	} else {					\
+		(tic)->t_prev = (tic)->t_next = (tic);	\
+		(q) = (tic);				\
+	}						\
+	(tic)->t_flags |= XLOG_TIC_IN_Q;		\
+    }
+#define XLOG_DEL_TICKETQ(q,tic)				\
+    {							\
+	if ((tic) == (tic)->t_next) {			\
+		(q) = NULL;				\
+	} else {					\
+		(q) = (tic)->t_next;			\
+		(tic)->t_next->t_prev = (tic)->t_prev;	\
+		(tic)->t_prev->t_next = (tic)->t_next;	\
+	}						\
+	(tic)->t_next = (tic)->t_prev = NULL;		\
+	(tic)->t_flags &= ~XLOG_TIC_IN_Q;		\
+    }
+
+
+#define GRANT_LOCK(log)		mutex_spinlock(&(log)->l_grant_lock)
+#define GRANT_UNLOCK(log, s)	mutex_spinunlock(&(log)->l_grant_lock, s)
+#define LOG_LOCK(log)		mutex_spinlock(&(log)->l_icloglock)
+#define LOG_UNLOCK(log, s)	mutex_spinunlock(&(log)->l_icloglock, s)
+
+#define xlog_panic(args...)	cmn_err(CE_PANIC, ## args)
+#define xlog_exit(args...)	cmn_err(CE_PANIC, ## args)
+#define xlog_warn(args...)	cmn_err(CE_WARN, ## args)
+
+/*
+ * In core log state
+ */
+#define XLOG_STATE_ACTIVE    0x0001 /* Current IC log being written to */
+#define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
+#define XLOG_STATE_SYNCING   0x0004 /* This IC log is syncing */
+#define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
+#define XLOG_STATE_DO_CALLBACK \
+			     0x0010 /* Process callback functions */
+#define XLOG_STATE_CALLBACK  0x0020 /* Callback functions now */
+#define XLOG_STATE_DIRTY     0x0040 /* Dirty IC log, not ready for ACTIVE status*/
+#define XLOG_STATE_IOERROR   0x0080 /* IO error happened in sync'ing log */
+#define XLOG_STATE_ALL	     0x7FFF /* All possible valid flags */
+#define XLOG_STATE_NOTUSED   0x8000 /* This IC log not being used */
+#endif	/* __KERNEL__ */
+
+/*
+ * Flags to log operation header
+ *
+ * The first write of a new transaction will be preceded with a start
+ * record, XLOG_START_TRANS.  Once a transaction is committed, a commit
+ * record is written, XLOG_COMMIT_TRANS.  If a single region can not fit into
+ * the remainder of the current active in-core log, it is split up into
+ * multiple regions.  Each partial region will be marked with a
+ * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
+ *
+ */
+#define XLOG_START_TRANS	0x01	/* Start a new transaction */
+#define XLOG_COMMIT_TRANS	0x02	/* Commit this transaction */
+#define XLOG_CONTINUE_TRANS	0x04	/* Cont this trans into new region */
+#define XLOG_WAS_CONT_TRANS	0x08	/* Cont this trans into new region */
+#define XLOG_END_TRANS		0x10	/* End a continued transaction */
+#define XLOG_UNMOUNT_TRANS	0x20	/* Unmount a filesystem transaction */
+#define XLOG_SKIP_TRANS		(XLOG_COMMIT_TRANS | XLOG_CONTINUE_TRANS | \
+				 XLOG_WAS_CONT_TRANS | XLOG_END_TRANS | \
+				 XLOG_UNMOUNT_TRANS)
+
+#ifdef __KERNEL__
+/*
+ * Flags to log ticket
+ */
+#define XLOG_TIC_INITED		0x1	/* has been initialized */
+#define XLOG_TIC_PERM_RESERV	0x2	/* permanent reservation */
+#define XLOG_TIC_IN_Q		0x4
+#endif	/* __KERNEL__ */
+
+#define XLOG_UNMOUNT_TYPE	0x556e	/* Un for Unmount */
+
+/*
+ * Flags for log structure
+ */
+#define XLOG_CHKSUM_MISMATCH	0x1	/* used only during recovery */
+#define XLOG_ACTIVE_RECOVERY	0x2	/* in the middle of recovery */
+#define	XLOG_RECOVERY_NEEDED	0x4	/* log was recovered */
+#define XLOG_IO_ERROR		0x8	/* log hit an I/O error, and being
+					   shutdown */
+typedef __uint32_t xlog_tid_t;
+
+
+#ifdef __KERNEL__
+/*
+ * Below are states for covering allocation transactions.
+ * By covering, we mean changing the h_tail_lsn in the last on-disk
+ * log write such that no allocation transactions will be re-done during
+ * recovery after a system crash. Recovery starts at the last on-disk
+ * log write.
+ *
+ * These states are used to insert dummy log entries to cover
+ * space allocation transactions which can undo non-transactional changes
+ * after a crash. Writes to a file with space
+ * already allocated do not result in any transactions. Allocations
+ * might include space beyond the EOF. So if we just push the EOF a
+ * little, the last transaction for the file could contain the wrong
+ * size. If there is no file system activity, after an allocation
+ * transaction, and the system crashes, the allocation transaction
+ * will get replayed and the file will be truncated. This could
+ * be hours/days/... after the allocation occurred.
+ *
+ * The fix for this is to do two dummy transactions when the
+ * system is idle. We need two dummy transaction because the h_tail_lsn
+ * in the log record header needs to point beyond the last possible
+ * non-dummy transaction. The first dummy changes the h_tail_lsn to
+ * the first transaction before the dummy. The second dummy causes
+ * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
+ *
+ * These dummy transactions get committed when everything
+ * is idle (after there has been some activity).
+ *
+ * There are 5 states used to control this.
+ *
+ *  IDLE -- no logging has been done on the file system or
+ *		we are done covering previous transactions.
+ *  NEED -- logging has occurred and we need a dummy transaction
+ *		when the log becomes idle.
+ *  DONE -- we were in the NEED state and have committed a dummy
+ *		transaction.
+ *  NEED2 -- we detected that a dummy transaction has gone to the
+ *		on disk log with no other transactions.
+ *  DONE2 -- we committed a dummy transaction when in the NEED2 state.
+ *
+ * There are two places where we switch states:
+ *
+ * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
+ *	We commit the dummy transaction and switch to DONE or DONE2,
+ *	respectively. In all other states, we don't do anything.
+ *
+ * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
+ *
+ *	No matter what state we are in, if this isn't the dummy
+ *	transaction going out, the next state is NEED.
+ *	So, if we aren't in the DONE or DONE2 states, the next state
+ *	is NEED. We can't be finishing a write of the dummy record
+ *	unless it was committed and the state switched to DONE or DONE2.
+ *
+ *	If we are in the DONE state and this was a write of the
+ *		dummy transaction, we move to NEED2.
+ *
+ *	If we are in the DONE2 state and this was a write of the
+ *		dummy transaction, we move to IDLE.
+ *
+ *
+ * Writing only one dummy transaction can get appended to
+ * one file space allocation. When this happens, the log recovery
+ * code replays the space allocation and a file could be truncated.
+ * This is why we have the NEED2 and DONE2 states before going idle.
+ */
+
+#define XLOG_STATE_COVER_IDLE	0
+#define XLOG_STATE_COVER_NEED	1
+#define XLOG_STATE_COVER_DONE	2
+#define XLOG_STATE_COVER_NEED2	3
+#define XLOG_STATE_COVER_DONE2	4
+
+#define XLOG_COVER_OPS		5
+
+typedef struct xlog_ticket {
+	sv_t		   t_sema;	 /* sleep on this semaphore	 :20 */
+	struct xlog_ticket *t_next;	 /*			         : 4 */
+	struct xlog_ticket *t_prev;	 /*				 : 4 */
+	xlog_tid_t	   t_tid;	 /* transaction identifier	 : 4 */
+	int		   t_curr_res;	 /* current reservation in bytes : 4 */
+	int		   t_unit_res;	 /* unit reservation in bytes    : 4 */
+	__uint8_t	   t_ocnt;	 /* original count		 : 1 */
+	__uint8_t	   t_cnt;	 /* current count		 : 1 */
+	__uint8_t	   t_clientid;	 /* who does this belong to;	 : 1 */
+	__uint8_t	   t_flags;	 /* properties of reservation	 : 1 */
+} xlog_ticket_t;
+#endif
+
+
+typedef struct xlog_op_header {
+	xlog_tid_t oh_tid;	/* transaction id of operation	:  4 b */
+	int	   oh_len;	/* bytes in data region		:  4 b */
+	__uint8_t  oh_clientid;	/* who sent me this		:  1 b */
+	__uint8_t  oh_flags;	/*				:  1 b */
+	ushort	   oh_res2;	/* 32 bit align			:  2 b */
+} xlog_op_header_t;
+
+
+/* valid values for h_fmt */
+#define XLOG_FMT_UNKNOWN  0
+#define XLOG_FMT_LINUX_LE 1
+#define XLOG_FMT_LINUX_BE 2
+#define XLOG_FMT_IRIX_BE  3
+
+/* our fmt */
+#if __BYTE_ORDER == __LITTLE_ENDIAN
+#define XLOG_FMT XLOG_FMT_LINUX_LE
+#else
+#if __BYTE_ORDER == __BIG_ENDIAN
+#define XLOG_FMT XLOG_FMT_LINUX_BE
+#else
+#error unknown byte order
+#endif
+#endif
+
+typedef struct xlog_rec_header {
+	uint	  h_magicno;	/* log record (LR) identifier		:  4 */
+	uint	  h_cycle;	/* write cycle of log			:  4 */
+	int	  h_version;	/* LR version				:  4 */
+	int	  h_len;	/* len in bytes; should be 64-bit aligned: 4 */
+	xfs_lsn_t h_lsn;	/* lsn of this LR			:  8 */
+	xfs_lsn_t h_tail_lsn;	/* lsn of 1st LR w/ buffers not committed: 8 */
+	uint	  h_chksum;	/* may not be used; non-zero if used	:  4 */
+	int	  h_prev_block; /* block number to previous LR		:  4 */
+	int	  h_num_logops;	/* number of log operations in this LR	:  4 */
+	uint	  h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE];
+	/* new fields */
+	int       h_fmt;        /* format of log record                 :  4 */
+	uuid_t    h_fs_uuid;    /* uuid of FS                           : 16 */
+	int       h_size;	/* iclog size				:  4 */
+} xlog_rec_header_t;
+
+typedef struct xlog_rec_ext_header {
+	uint	  xh_cycle;	/* write cycle of log			: 4 */
+	uint	  xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /*	: 256 */
+} xlog_rec_ext_header_t;
+
+#ifdef __KERNEL__
+/*
+ * - A log record header is 512 bytes.  There is plenty of room to grow the
+ *	xlog_rec_header_t into the reserved space.
+ * - ic_data follows, so a write to disk can start at the beginning of
+ *	the iclog.
+ * - ic_forcesema is used to implement synchronous forcing of the iclog to disk.
+ * - ic_next is the pointer to the next iclog in the ring.
+ * - ic_bp is a pointer to the buffer used to write this incore log to disk.
+ * - ic_log is a pointer back to the global log structure.
+ * - ic_callback is a linked list of callback function/argument pairs to be
+ *	called after an iclog finishes writing.
+ * - ic_size is the full size of the header plus data.
+ * - ic_offset is the current number of bytes written to in this iclog.
+ * - ic_refcnt is bumped when someone is writing to the log.
+ * - ic_state is the state of the iclog.
+ */
+typedef struct xlog_iclog_fields {
+	sv_t			ic_forcesema;
+	sv_t			ic_writesema;
+	struct xlog_in_core	*ic_next;
+	struct xlog_in_core	*ic_prev;
+	struct xfs_buf		*ic_bp;
+	struct log		*ic_log;
+	xfs_log_callback_t	*ic_callback;
+	xfs_log_callback_t	**ic_callback_tail;
+#ifdef XFS_LOG_TRACE
+	struct ktrace		*ic_trace;
+#endif
+	int			ic_size;
+	int			ic_offset;
+	int			ic_refcnt;
+	int			ic_roundoff;
+	int			ic_bwritecnt;
+	ushort_t		ic_state;
+	char			*ic_datap;	/* pointer to iclog data */
+} xlog_iclog_fields_t;
+
+typedef union xlog_in_core2 {
+	xlog_rec_header_t	hic_header;
+	xlog_rec_ext_header_t	hic_xheader;
+	char			hic_sector[XLOG_HEADER_SIZE];
+} xlog_in_core_2_t;
+
+typedef struct xlog_in_core {
+	xlog_iclog_fields_t	hic_fields;
+	xlog_in_core_2_t	*hic_data;
+} xlog_in_core_t;
+
+/*
+ * Defines to save our code from this glop.
+ */
+#define	ic_forcesema	hic_fields.ic_forcesema
+#define ic_writesema	hic_fields.ic_writesema
+#define	ic_next		hic_fields.ic_next
+#define	ic_prev		hic_fields.ic_prev
+#define	ic_bp		hic_fields.ic_bp
+#define	ic_log		hic_fields.ic_log
+#define	ic_callback	hic_fields.ic_callback
+#define	ic_callback_tail hic_fields.ic_callback_tail
+#define	ic_trace	hic_fields.ic_trace
+#define	ic_size		hic_fields.ic_size
+#define	ic_offset	hic_fields.ic_offset
+#define	ic_refcnt	hic_fields.ic_refcnt
+#define	ic_roundoff	hic_fields.ic_roundoff
+#define	ic_bwritecnt	hic_fields.ic_bwritecnt
+#define	ic_state	hic_fields.ic_state
+#define ic_datap	hic_fields.ic_datap
+#define ic_header	hic_data->hic_header
+
+/*
+ * The reservation head lsn is not made up of a cycle number and block number.
+ * Instead, it uses a cycle number and byte number.  Logs don't expect to
+ * overflow 31 bits worth of byte offset, so using a byte number will mean
+ * that round off problems won't occur when releasing partial reservations.
+ */
+typedef struct log {
+	/* The following block of fields are changed while holding icloglock */
+	sema_t			l_flushsema;    /* iclog flushing semaphore */
+	int			l_flushcnt;	/* # of procs waiting on this
+						 * sema */
+	int			l_ticket_cnt;	/* free ticket count */
+	int			l_ticket_tcnt;	/* total ticket count */
+	int			l_covered_state;/* state of "covering disk
+						 * log entries" */
+	xlog_ticket_t		*l_freelist;    /* free list of tickets */
+	xlog_ticket_t		*l_unmount_free;/* kmem_free these addresses */
+	xlog_ticket_t		*l_tail;        /* free list of tickets */
+	xlog_in_core_t		*l_iclog;       /* head log queue	*/
+	lock_t			l_icloglock;    /* grab to change iclog state */
+	xfs_lsn_t		l_tail_lsn;     /* lsn of 1st LR with unflushed
+						 * buffers */
+	xfs_lsn_t		l_last_sync_lsn;/* lsn of last LR on disk */
+	struct xfs_mount	*l_mp;	        /* mount point */
+	struct xfs_buf		*l_xbuf;        /* extra buffer for log
+						 * wrapping */
+	struct xfs_buftarg	*l_targ;        /* buftarg of log */
+	xfs_daddr_t		l_logBBstart;   /* start block of log */
+	int			l_logsize;      /* size of log in bytes */
+	int			l_logBBsize;    /* size of log in BB chunks */
+	int			l_roundoff;	/* round off error of iclogs */
+	int			l_curr_cycle;   /* Cycle number of log writes */
+	int			l_prev_cycle;   /* Cycle number before last
+						 * block increment */
+	int			l_curr_block;   /* current logical log block */
+	int			l_prev_block;   /* previous logical log block */
+	int			l_iclog_size;	/* size of log in bytes */
+	int			l_iclog_size_log; /* log power size of log */
+	int			l_iclog_bufs;	/* number of iclog buffers */
+
+	/* The following field are used for debugging; need to hold icloglock */
+	char			*l_iclog_bak[XLOG_MAX_ICLOGS];
+
+	/* The following block of fields are changed while holding grant_lock */
+	lock_t			l_grant_lock;
+	xlog_ticket_t		*l_reserve_headq;
+	xlog_ticket_t		*l_write_headq;
+	int			l_grant_reserve_cycle;
+	int			l_grant_reserve_bytes;
+	int			l_grant_write_cycle;
+	int			l_grant_write_bytes;
+
+	/* The following fields don't need locking */
+#ifdef XFS_LOG_TRACE
+	struct ktrace		*l_trace;
+	struct ktrace		*l_grant_trace;
+#endif
+	uint			l_flags;
+	uint			l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
+	struct xfs_buf_cancel	**l_buf_cancel_table;
+	int			l_stripemask;	/* log stripe mask */
+	int			l_iclog_hsize;  /* size of iclog header */
+	int			l_iclog_heads;  /* # of iclog header sectors */
+	uint			l_sectbb_log;   /* log2 of sector size in BBs */
+	uint			l_sectbb_mask;  /* sector size (in BBs)
+						 * alignment mask */
+} xlog_t;
+
+
+/* common routines */
+extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
+extern int	 xlog_find_head(xlog_t *log, xfs_daddr_t *head_blk);
+extern int	 xlog_find_tail(xlog_t	*log,
+				xfs_daddr_t *head_blk,
+				xfs_daddr_t *tail_blk,
+				int readonly);
+extern int	 xlog_print_find_oldest(xlog_t *log, xfs_daddr_t *last_blk);
+extern int	 xlog_recover(xlog_t *log, int readonly);
+extern int	 xlog_recover_finish(xlog_t *log, int mfsi_flags);
+extern void	 xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog);
+extern void	 xlog_recover_process_iunlinks(xlog_t *log);
+
+extern struct xfs_buf *xlog_get_bp(xlog_t *, int);
+extern void	 xlog_put_bp(struct xfs_buf *);
+extern int	 xlog_bread(xlog_t *, xfs_daddr_t, int, struct xfs_buf *);
+extern xfs_caddr_t xlog_align(xlog_t *, xfs_daddr_t, int, struct xfs_buf *);
+
+#define XLOG_TRACE_GRAB_FLUSH  1
+#define XLOG_TRACE_REL_FLUSH   2
+#define XLOG_TRACE_SLEEP_FLUSH 3
+#define XLOG_TRACE_WAKE_FLUSH  4
+
+#endif	/* __KERNEL__ */
+
+#endif	/* __XFS_LOG_PRIV_H__ */

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