xref: /openbmc/linux/fs/xfs/xfs_log_priv.h (revision 64c70b1c)
1 /*
2  * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
3  * All Rights Reserved.
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU General Public License as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it would be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write the Free Software Foundation,
16  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
17  */
18 #ifndef	__XFS_LOG_PRIV_H__
19 #define __XFS_LOG_PRIV_H__
20 
21 struct xfs_buf;
22 struct ktrace;
23 struct log;
24 struct xlog_ticket;
25 struct xfs_buf_cancel;
26 struct xfs_mount;
27 
28 /*
29  * Macros, structures, prototypes for internal log manager use.
30  */
31 
32 #define XLOG_MIN_ICLOGS		2
33 #define XLOG_MED_ICLOGS		4
34 #define XLOG_MAX_ICLOGS		8
35 #define XLOG_HEADER_MAGIC_NUM	0xFEEDbabe	/* Invalid cycle number */
36 #define XLOG_VERSION_1		1
37 #define XLOG_VERSION_2		2		/* Large IClogs, Log sunit */
38 #define XLOG_VERSION_OKBITS	(XLOG_VERSION_1 | XLOG_VERSION_2)
39 #define XLOG_RECORD_BSIZE	(16*1024)	/* eventually 32k */
40 #define XLOG_BIG_RECORD_BSIZE	(32*1024)	/* 32k buffers */
41 #define XLOG_MAX_RECORD_BSIZE	(256*1024)
42 #define XLOG_HEADER_CYCLE_SIZE	(32*1024)	/* cycle data in header */
43 #define XLOG_RECORD_BSHIFT	14		/* 16384 == 1 << 14 */
44 #define XLOG_BIG_RECORD_BSHIFT	15		/* 32k == 1 << 15 */
45 #define XLOG_MAX_RECORD_BSHIFT	18		/* 256k == 1 << 18 */
46 #define XLOG_BTOLSUNIT(log, b)  (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \
47                                  (log)->l_mp->m_sb.sb_logsunit)
48 #define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit)
49 
50 #define XLOG_HEADER_SIZE	512
51 
52 #define XLOG_REC_SHIFT(log) \
53 	BTOBB(1 << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
54 	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
55 #define XLOG_TOTAL_REC_SHIFT(log) \
56 	BTOBB(XLOG_MAX_ICLOGS << (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? \
57 	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
58 
59 /*
60  *  set lsns
61  */
62 
63 #define ASSIGN_ANY_LSN_HOST(lsn,cycle,block)  \
64     { \
65 	(lsn) = ((xfs_lsn_t)(cycle)<<32)|(block); \
66     }
67 #define ASSIGN_ANY_LSN_DISK(lsn,cycle,block)  \
68     { \
69 	INT_SET(((uint *)&(lsn))[0], ARCH_CONVERT, (cycle)); \
70 	INT_SET(((uint *)&(lsn))[1], ARCH_CONVERT, (block)); \
71     }
72 #define ASSIGN_LSN(lsn,log) \
73     ASSIGN_ANY_LSN_DISK(lsn,(log)->l_curr_cycle,(log)->l_curr_block);
74 
75 #define XLOG_SET(f,b)		(((f) & (b)) == (b))
76 
77 #define GET_CYCLE(ptr, arch) \
78     (INT_GET(*(uint *)(ptr), arch) == XLOG_HEADER_MAGIC_NUM ? \
79 	 INT_GET(*((uint *)(ptr)+1), arch) : \
80 	 INT_GET(*(uint *)(ptr), arch) \
81     )
82 
83 #define BLK_AVG(blk1, blk2)	((blk1+blk2) >> 1)
84 
85 
86 #ifdef __KERNEL__
87 
88 /*
89  * get client id from packed copy.
90  *
91  * this hack is here because the xlog_pack code copies four bytes
92  * of xlog_op_header containing the fields oh_clientid, oh_flags
93  * and oh_res2 into the packed copy.
94  *
95  * later on this four byte chunk is treated as an int and the
96  * client id is pulled out.
97  *
98  * this has endian issues, of course.
99  */
100 
101 #ifndef XFS_NATIVE_HOST
102 #define GET_CLIENT_ID(i,arch) \
103     ((i) & 0xff)
104 #else
105 #define GET_CLIENT_ID(i,arch) \
106     ((i) >> 24)
107 #endif
108 
109 #define GRANT_LOCK(log)		mutex_spinlock(&(log)->l_grant_lock)
110 #define GRANT_UNLOCK(log, s)	mutex_spinunlock(&(log)->l_grant_lock, s)
111 #define LOG_LOCK(log)		mutex_spinlock(&(log)->l_icloglock)
112 #define LOG_UNLOCK(log, s)	mutex_spinunlock(&(log)->l_icloglock, s)
113 
114 #define xlog_panic(args...)	cmn_err(CE_PANIC, ## args)
115 #define xlog_exit(args...)	cmn_err(CE_PANIC, ## args)
116 #define xlog_warn(args...)	cmn_err(CE_WARN, ## args)
117 
118 /*
119  * In core log state
120  */
121 #define XLOG_STATE_ACTIVE    0x0001 /* Current IC log being written to */
122 #define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
123 #define XLOG_STATE_SYNCING   0x0004 /* This IC log is syncing */
124 #define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
125 #define XLOG_STATE_DO_CALLBACK \
126 			     0x0010 /* Process callback functions */
127 #define XLOG_STATE_CALLBACK  0x0020 /* Callback functions now */
128 #define XLOG_STATE_DIRTY     0x0040 /* Dirty IC log, not ready for ACTIVE status*/
129 #define XLOG_STATE_IOERROR   0x0080 /* IO error happened in sync'ing log */
130 #define XLOG_STATE_ALL	     0x7FFF /* All possible valid flags */
131 #define XLOG_STATE_NOTUSED   0x8000 /* This IC log not being used */
132 #endif	/* __KERNEL__ */
133 
134 /*
135  * Flags to log operation header
136  *
137  * The first write of a new transaction will be preceded with a start
138  * record, XLOG_START_TRANS.  Once a transaction is committed, a commit
139  * record is written, XLOG_COMMIT_TRANS.  If a single region can not fit into
140  * the remainder of the current active in-core log, it is split up into
141  * multiple regions.  Each partial region will be marked with a
142  * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
143  *
144  */
145 #define XLOG_START_TRANS	0x01	/* Start a new transaction */
146 #define XLOG_COMMIT_TRANS	0x02	/* Commit this transaction */
147 #define XLOG_CONTINUE_TRANS	0x04	/* Cont this trans into new region */
148 #define XLOG_WAS_CONT_TRANS	0x08	/* Cont this trans into new region */
149 #define XLOG_END_TRANS		0x10	/* End a continued transaction */
150 #define XLOG_UNMOUNT_TRANS	0x20	/* Unmount a filesystem transaction */
151 
152 #ifdef __KERNEL__
153 /*
154  * Flags to log ticket
155  */
156 #define XLOG_TIC_INITED		0x1	/* has been initialized */
157 #define XLOG_TIC_PERM_RESERV	0x2	/* permanent reservation */
158 #define XLOG_TIC_IN_Q		0x4
159 #endif	/* __KERNEL__ */
160 
161 #define XLOG_UNMOUNT_TYPE	0x556e	/* Un for Unmount */
162 
163 /*
164  * Flags for log structure
165  */
166 #define XLOG_CHKSUM_MISMATCH	0x1	/* used only during recovery */
167 #define XLOG_ACTIVE_RECOVERY	0x2	/* in the middle of recovery */
168 #define	XLOG_RECOVERY_NEEDED	0x4	/* log was recovered */
169 #define XLOG_IO_ERROR		0x8	/* log hit an I/O error, and being
170 					   shutdown */
171 typedef __uint32_t xlog_tid_t;
172 
173 
174 #ifdef __KERNEL__
175 /*
176  * Below are states for covering allocation transactions.
177  * By covering, we mean changing the h_tail_lsn in the last on-disk
178  * log write such that no allocation transactions will be re-done during
179  * recovery after a system crash. Recovery starts at the last on-disk
180  * log write.
181  *
182  * These states are used to insert dummy log entries to cover
183  * space allocation transactions which can undo non-transactional changes
184  * after a crash. Writes to a file with space
185  * already allocated do not result in any transactions. Allocations
186  * might include space beyond the EOF. So if we just push the EOF a
187  * little, the last transaction for the file could contain the wrong
188  * size. If there is no file system activity, after an allocation
189  * transaction, and the system crashes, the allocation transaction
190  * will get replayed and the file will be truncated. This could
191  * be hours/days/... after the allocation occurred.
192  *
193  * The fix for this is to do two dummy transactions when the
194  * system is idle. We need two dummy transaction because the h_tail_lsn
195  * in the log record header needs to point beyond the last possible
196  * non-dummy transaction. The first dummy changes the h_tail_lsn to
197  * the first transaction before the dummy. The second dummy causes
198  * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
199  *
200  * These dummy transactions get committed when everything
201  * is idle (after there has been some activity).
202  *
203  * There are 5 states used to control this.
204  *
205  *  IDLE -- no logging has been done on the file system or
206  *		we are done covering previous transactions.
207  *  NEED -- logging has occurred and we need a dummy transaction
208  *		when the log becomes idle.
209  *  DONE -- we were in the NEED state and have committed a dummy
210  *		transaction.
211  *  NEED2 -- we detected that a dummy transaction has gone to the
212  *		on disk log with no other transactions.
213  *  DONE2 -- we committed a dummy transaction when in the NEED2 state.
214  *
215  * There are two places where we switch states:
216  *
217  * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
218  *	We commit the dummy transaction and switch to DONE or DONE2,
219  *	respectively. In all other states, we don't do anything.
220  *
221  * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
222  *
223  *	No matter what state we are in, if this isn't the dummy
224  *	transaction going out, the next state is NEED.
225  *	So, if we aren't in the DONE or DONE2 states, the next state
226  *	is NEED. We can't be finishing a write of the dummy record
227  *	unless it was committed and the state switched to DONE or DONE2.
228  *
229  *	If we are in the DONE state and this was a write of the
230  *		dummy transaction, we move to NEED2.
231  *
232  *	If we are in the DONE2 state and this was a write of the
233  *		dummy transaction, we move to IDLE.
234  *
235  *
236  * Writing only one dummy transaction can get appended to
237  * one file space allocation. When this happens, the log recovery
238  * code replays the space allocation and a file could be truncated.
239  * This is why we have the NEED2 and DONE2 states before going idle.
240  */
241 
242 #define XLOG_STATE_COVER_IDLE	0
243 #define XLOG_STATE_COVER_NEED	1
244 #define XLOG_STATE_COVER_DONE	2
245 #define XLOG_STATE_COVER_NEED2	3
246 #define XLOG_STATE_COVER_DONE2	4
247 
248 #define XLOG_COVER_OPS		5
249 
250 
251 /* Ticket reservation region accounting */
252 #define XLOG_TIC_LEN_MAX	15
253 #define XLOG_TIC_RESET_RES(t) ((t)->t_res_num = \
254 				(t)->t_res_arr_sum = (t)->t_res_num_ophdrs = 0)
255 #define XLOG_TIC_ADD_OPHDR(t) ((t)->t_res_num_ophdrs++)
256 #define XLOG_TIC_ADD_REGION(t, len, type)				\
257 	do {								\
258 		if ((t)->t_res_num == XLOG_TIC_LEN_MAX) { 		\
259 			/* add to overflow and start again */		\
260 			(t)->t_res_o_flow += (t)->t_res_arr_sum;	\
261 			(t)->t_res_num = 0;				\
262 			(t)->t_res_arr_sum = 0;				\
263 		}							\
264 		(t)->t_res_arr[(t)->t_res_num].r_len = (len);		\
265 		(t)->t_res_arr[(t)->t_res_num].r_type = (type);		\
266 		(t)->t_res_arr_sum += (len);				\
267 		(t)->t_res_num++;					\
268 	} while (0)
269 
270 /*
271  * Reservation region
272  * As would be stored in xfs_log_iovec but without the i_addr which
273  * we don't care about.
274  */
275 typedef struct xlog_res {
276 	uint	r_len;	/* region length		:4 */
277 	uint	r_type;	/* region's transaction type	:4 */
278 } xlog_res_t;
279 
280 typedef struct xlog_ticket {
281 	sv_t		   t_sema;	 /* sleep on this semaphore      : 20 */
282  	struct xlog_ticket *t_next;	 /*			         :4|8 */
283 	struct xlog_ticket *t_prev;	 /*				 :4|8 */
284 	xlog_tid_t	   t_tid;	 /* transaction identifier	 : 4  */
285 	int		   t_curr_res;	 /* current reservation in bytes : 4  */
286 	int		   t_unit_res;	 /* unit reservation in bytes    : 4  */
287 	char		   t_ocnt;	 /* original count		 : 1  */
288 	char		   t_cnt;	 /* current count		 : 1  */
289 	char		   t_clientid;	 /* who does this belong to;	 : 1  */
290 	char		   t_flags;	 /* properties of reservation	 : 1  */
291 	uint		   t_trans_type; /* transaction type             : 4  */
292 
293         /* reservation array fields */
294 	uint		   t_res_num;                    /* num in array : 4 */
295 	uint		   t_res_num_ophdrs;		 /* num op hdrs  : 4 */
296 	uint		   t_res_arr_sum;		 /* array sum    : 4 */
297 	uint		   t_res_o_flow;		 /* sum overflow : 4 */
298 	xlog_res_t	   t_res_arr[XLOG_TIC_LEN_MAX];  /* array of res : 8 * 15 */
299 } xlog_ticket_t;
300 
301 #endif
302 
303 
304 typedef struct xlog_op_header {
305 	xlog_tid_t oh_tid;	/* transaction id of operation	:  4 b */
306 	int	   oh_len;	/* bytes in data region		:  4 b */
307 	__uint8_t  oh_clientid;	/* who sent me this		:  1 b */
308 	__uint8_t  oh_flags;	/*				:  1 b */
309 	ushort	   oh_res2;	/* 32 bit align			:  2 b */
310 } xlog_op_header_t;
311 
312 
313 /* valid values for h_fmt */
314 #define XLOG_FMT_UNKNOWN  0
315 #define XLOG_FMT_LINUX_LE 1
316 #define XLOG_FMT_LINUX_BE 2
317 #define XLOG_FMT_IRIX_BE  3
318 
319 /* our fmt */
320 #ifdef XFS_NATIVE_HOST
321 #define XLOG_FMT XLOG_FMT_LINUX_BE
322 #else
323 #define XLOG_FMT XLOG_FMT_LINUX_LE
324 #endif
325 
326 typedef struct xlog_rec_header {
327 	uint	  h_magicno;	/* log record (LR) identifier		:  4 */
328 	uint	  h_cycle;	/* write cycle of log			:  4 */
329 	int	  h_version;	/* LR version				:  4 */
330 	int	  h_len;	/* len in bytes; should be 64-bit aligned: 4 */
331 	xfs_lsn_t h_lsn;	/* lsn of this LR			:  8 */
332 	xfs_lsn_t h_tail_lsn;	/* lsn of 1st LR w/ buffers not committed: 8 */
333 	uint	  h_chksum;	/* may not be used; non-zero if used	:  4 */
334 	int	  h_prev_block; /* block number to previous LR		:  4 */
335 	int	  h_num_logops;	/* number of log operations in this LR	:  4 */
336 	uint	  h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE];
337 	/* new fields */
338 	int       h_fmt;        /* format of log record                 :  4 */
339 	uuid_t    h_fs_uuid;    /* uuid of FS                           : 16 */
340 	int       h_size;	/* iclog size				:  4 */
341 } xlog_rec_header_t;
342 
343 typedef struct xlog_rec_ext_header {
344 	uint	  xh_cycle;	/* write cycle of log			: 4 */
345 	uint	  xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /*	: 256 */
346 } xlog_rec_ext_header_t;
347 
348 #ifdef __KERNEL__
349 /*
350  * - A log record header is 512 bytes.  There is plenty of room to grow the
351  *	xlog_rec_header_t into the reserved space.
352  * - ic_data follows, so a write to disk can start at the beginning of
353  *	the iclog.
354  * - ic_forcesema is used to implement synchronous forcing of the iclog to disk.
355  * - ic_next is the pointer to the next iclog in the ring.
356  * - ic_bp is a pointer to the buffer used to write this incore log to disk.
357  * - ic_log is a pointer back to the global log structure.
358  * - ic_callback is a linked list of callback function/argument pairs to be
359  *	called after an iclog finishes writing.
360  * - ic_size is the full size of the header plus data.
361  * - ic_offset is the current number of bytes written to in this iclog.
362  * - ic_refcnt is bumped when someone is writing to the log.
363  * - ic_state is the state of the iclog.
364  */
365 typedef struct xlog_iclog_fields {
366 	sv_t			ic_forcesema;
367 	sv_t			ic_writesema;
368 	struct xlog_in_core	*ic_next;
369 	struct xlog_in_core	*ic_prev;
370 	struct xfs_buf		*ic_bp;
371 	struct log		*ic_log;
372 	xfs_log_callback_t	*ic_callback;
373 	xfs_log_callback_t	**ic_callback_tail;
374 #ifdef XFS_LOG_TRACE
375 	struct ktrace		*ic_trace;
376 #endif
377 	int			ic_size;
378 	int			ic_offset;
379 	int			ic_refcnt;
380 	int			ic_bwritecnt;
381 	ushort_t		ic_state;
382 	char			*ic_datap;	/* pointer to iclog data */
383 } xlog_iclog_fields_t;
384 
385 typedef union xlog_in_core2 {
386 	xlog_rec_header_t	hic_header;
387 	xlog_rec_ext_header_t	hic_xheader;
388 	char			hic_sector[XLOG_HEADER_SIZE];
389 } xlog_in_core_2_t;
390 
391 typedef struct xlog_in_core {
392 	xlog_iclog_fields_t	hic_fields;
393 	xlog_in_core_2_t	*hic_data;
394 } xlog_in_core_t;
395 
396 /*
397  * Defines to save our code from this glop.
398  */
399 #define	ic_forcesema	hic_fields.ic_forcesema
400 #define ic_writesema	hic_fields.ic_writesema
401 #define	ic_next		hic_fields.ic_next
402 #define	ic_prev		hic_fields.ic_prev
403 #define	ic_bp		hic_fields.ic_bp
404 #define	ic_log		hic_fields.ic_log
405 #define	ic_callback	hic_fields.ic_callback
406 #define	ic_callback_tail hic_fields.ic_callback_tail
407 #define	ic_trace	hic_fields.ic_trace
408 #define	ic_size		hic_fields.ic_size
409 #define	ic_offset	hic_fields.ic_offset
410 #define	ic_refcnt	hic_fields.ic_refcnt
411 #define	ic_bwritecnt	hic_fields.ic_bwritecnt
412 #define	ic_state	hic_fields.ic_state
413 #define ic_datap	hic_fields.ic_datap
414 #define ic_header	hic_data->hic_header
415 
416 /*
417  * The reservation head lsn is not made up of a cycle number and block number.
418  * Instead, it uses a cycle number and byte number.  Logs don't expect to
419  * overflow 31 bits worth of byte offset, so using a byte number will mean
420  * that round off problems won't occur when releasing partial reservations.
421  */
422 typedef struct log {
423 	/* The following block of fields are changed while holding icloglock */
424 	sema_t			l_flushsema;    /* iclog flushing semaphore */
425 	int			l_flushcnt;	/* # of procs waiting on this
426 						 * sema */
427 	int			l_ticket_cnt;	/* free ticket count */
428 	int			l_ticket_tcnt;	/* total ticket count */
429 	int			l_covered_state;/* state of "covering disk
430 						 * log entries" */
431 	xlog_ticket_t		*l_freelist;    /* free list of tickets */
432 	xlog_ticket_t		*l_unmount_free;/* kmem_free these addresses */
433 	xlog_ticket_t		*l_tail;        /* free list of tickets */
434 	xlog_in_core_t		*l_iclog;       /* head log queue	*/
435 	lock_t			l_icloglock;    /* grab to change iclog state */
436 	xfs_lsn_t		l_tail_lsn;     /* lsn of 1st LR with unflushed
437 						 * buffers */
438 	xfs_lsn_t		l_last_sync_lsn;/* lsn of last LR on disk */
439 	struct xfs_mount	*l_mp;	        /* mount point */
440 	struct xfs_buf		*l_xbuf;        /* extra buffer for log
441 						 * wrapping */
442 	struct xfs_buftarg	*l_targ;        /* buftarg of log */
443 	xfs_daddr_t		l_logBBstart;   /* start block of log */
444 	int			l_logsize;      /* size of log in bytes */
445 	int			l_logBBsize;    /* size of log in BB chunks */
446 	int			l_curr_cycle;   /* Cycle number of log writes */
447 	int			l_prev_cycle;   /* Cycle number before last
448 						 * block increment */
449 	int			l_curr_block;   /* current logical log block */
450 	int			l_prev_block;   /* previous logical log block */
451 	int			l_iclog_size;	/* size of log in bytes */
452 	int			l_iclog_size_log; /* log power size of log */
453 	int			l_iclog_bufs;	/* number of iclog buffers */
454 
455 	/* The following field are used for debugging; need to hold icloglock */
456 	char			*l_iclog_bak[XLOG_MAX_ICLOGS];
457 
458 	/* The following block of fields are changed while holding grant_lock */
459 	lock_t			l_grant_lock;
460 	xlog_ticket_t		*l_reserve_headq;
461 	xlog_ticket_t		*l_write_headq;
462 	int			l_grant_reserve_cycle;
463 	int			l_grant_reserve_bytes;
464 	int			l_grant_write_cycle;
465 	int			l_grant_write_bytes;
466 
467 	/* The following fields don't need locking */
468 #ifdef XFS_LOG_TRACE
469 	struct ktrace		*l_trace;
470 	struct ktrace		*l_grant_trace;
471 #endif
472 	uint			l_flags;
473 	uint			l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
474 	struct xfs_buf_cancel	**l_buf_cancel_table;
475 	int			l_iclog_hsize;  /* size of iclog header */
476 	int			l_iclog_heads;  /* # of iclog header sectors */
477 	uint			l_sectbb_log;   /* log2 of sector size in BBs */
478 	uint			l_sectbb_mask;  /* sector size (in BBs)
479 						 * alignment mask */
480 } xlog_t;
481 
482 #define XLOG_FORCED_SHUTDOWN(log)	((log)->l_flags & XLOG_IO_ERROR)
483 
484 
485 /* common routines */
486 extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
487 extern int	 xlog_find_tail(xlog_t	*log,
488 				xfs_daddr_t *head_blk,
489 				xfs_daddr_t *tail_blk);
490 extern int	 xlog_recover(xlog_t *log);
491 extern int	 xlog_recover_finish(xlog_t *log, int mfsi_flags);
492 extern void	 xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int);
493 extern void	 xlog_recover_process_iunlinks(xlog_t *log);
494 
495 extern struct xfs_buf *xlog_get_bp(xlog_t *, int);
496 extern void	 xlog_put_bp(struct xfs_buf *);
497 extern int	 xlog_bread(xlog_t *, xfs_daddr_t, int, struct xfs_buf *);
498 
499 /* iclog tracing */
500 #define XLOG_TRACE_GRAB_FLUSH  1
501 #define XLOG_TRACE_REL_FLUSH   2
502 #define XLOG_TRACE_SLEEP_FLUSH 3
503 #define XLOG_TRACE_WAKE_FLUSH  4
504 
505 /*
506  * Unmount record type is used as a pseudo transaction type for the ticket.
507  * It's value must be outside the range of XFS_TRANS_* values.
508  */
509 #define XLOG_UNMOUNT_REC_TYPE	(-1U)
510 
511 #endif	/* __KERNEL__ */
512 
513 #endif	/* __XFS_LOG_PRIV_H__ */
514