xref: /openbmc/linux/fs/xfs/xfs_log_priv.h (revision b04b4f78)
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_MAX_ICLOGS		8
34 #define XLOG_HEADER_MAGIC_NUM	0xFEEDbabe	/* Invalid cycle number */
35 #define XLOG_VERSION_1		1
36 #define XLOG_VERSION_2		2		/* Large IClogs, Log sunit */
37 #define XLOG_VERSION_OKBITS	(XLOG_VERSION_1 | XLOG_VERSION_2)
38 #define XLOG_MIN_RECORD_BSIZE	(16*1024)	/* eventually 32k */
39 #define XLOG_BIG_RECORD_BSIZE	(32*1024)	/* 32k buffers */
40 #define XLOG_MAX_RECORD_BSIZE	(256*1024)
41 #define XLOG_HEADER_CYCLE_SIZE	(32*1024)	/* cycle data in header */
42 #define XLOG_MIN_RECORD_BSHIFT	14		/* 16384 == 1 << 14 */
43 #define XLOG_BIG_RECORD_BSHIFT	15		/* 32k == 1 << 15 */
44 #define XLOG_MAX_RECORD_BSHIFT	18		/* 256k == 1 << 18 */
45 #define XLOG_BTOLSUNIT(log, b)  (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \
46                                  (log)->l_mp->m_sb.sb_logsunit)
47 #define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit)
48 
49 #define XLOG_HEADER_SIZE	512
50 
51 #define XLOG_REC_SHIFT(log) \
52 	BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
53 	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
54 #define XLOG_TOTAL_REC_SHIFT(log) \
55 	BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
56 	 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
57 
58 
59 static inline xfs_lsn_t xlog_assign_lsn(uint cycle, uint block)
60 {
61 	return ((xfs_lsn_t)cycle << 32) | block;
62 }
63 
64 static inline uint xlog_get_cycle(char *ptr)
65 {
66 	if (be32_to_cpu(*(__be32 *)ptr) == XLOG_HEADER_MAGIC_NUM)
67 		return be32_to_cpu(*((__be32 *)ptr + 1));
68 	else
69 		return be32_to_cpu(*(__be32 *)ptr);
70 }
71 
72 #define BLK_AVG(blk1, blk2)	((blk1+blk2) >> 1)
73 
74 #ifdef __KERNEL__
75 
76 /*
77  * get client id from packed copy.
78  *
79  * this hack is here because the xlog_pack code copies four bytes
80  * of xlog_op_header containing the fields oh_clientid, oh_flags
81  * and oh_res2 into the packed copy.
82  *
83  * later on this four byte chunk is treated as an int and the
84  * client id is pulled out.
85  *
86  * this has endian issues, of course.
87  */
88 static inline uint xlog_get_client_id(__be32 i)
89 {
90 	return be32_to_cpu(i) >> 24;
91 }
92 
93 #define xlog_panic(args...)	cmn_err(CE_PANIC, ## args)
94 #define xlog_exit(args...)	cmn_err(CE_PANIC, ## args)
95 #define xlog_warn(args...)	cmn_err(CE_WARN, ## args)
96 
97 /*
98  * In core log state
99  */
100 #define XLOG_STATE_ACTIVE    0x0001 /* Current IC log being written to */
101 #define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
102 #define XLOG_STATE_SYNCING   0x0004 /* This IC log is syncing */
103 #define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
104 #define XLOG_STATE_DO_CALLBACK \
105 			     0x0010 /* Process callback functions */
106 #define XLOG_STATE_CALLBACK  0x0020 /* Callback functions now */
107 #define XLOG_STATE_DIRTY     0x0040 /* Dirty IC log, not ready for ACTIVE status*/
108 #define XLOG_STATE_IOERROR   0x0080 /* IO error happened in sync'ing log */
109 #define XLOG_STATE_ALL	     0x7FFF /* All possible valid flags */
110 #define XLOG_STATE_NOTUSED   0x8000 /* This IC log not being used */
111 #endif	/* __KERNEL__ */
112 
113 /*
114  * Flags to log operation header
115  *
116  * The first write of a new transaction will be preceded with a start
117  * record, XLOG_START_TRANS.  Once a transaction is committed, a commit
118  * record is written, XLOG_COMMIT_TRANS.  If a single region can not fit into
119  * the remainder of the current active in-core log, it is split up into
120  * multiple regions.  Each partial region will be marked with a
121  * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
122  *
123  */
124 #define XLOG_START_TRANS	0x01	/* Start a new transaction */
125 #define XLOG_COMMIT_TRANS	0x02	/* Commit this transaction */
126 #define XLOG_CONTINUE_TRANS	0x04	/* Cont this trans into new region */
127 #define XLOG_WAS_CONT_TRANS	0x08	/* Cont this trans into new region */
128 #define XLOG_END_TRANS		0x10	/* End a continued transaction */
129 #define XLOG_UNMOUNT_TRANS	0x20	/* Unmount a filesystem transaction */
130 
131 #ifdef __KERNEL__
132 /*
133  * Flags to log ticket
134  */
135 #define XLOG_TIC_INITED		0x1	/* has been initialized */
136 #define XLOG_TIC_PERM_RESERV	0x2	/* permanent reservation */
137 #define XLOG_TIC_IN_Q		0x4
138 #endif	/* __KERNEL__ */
139 
140 #define XLOG_UNMOUNT_TYPE	0x556e	/* Un for Unmount */
141 
142 /*
143  * Flags for log structure
144  */
145 #define XLOG_CHKSUM_MISMATCH	0x1	/* used only during recovery */
146 #define XLOG_ACTIVE_RECOVERY	0x2	/* in the middle of recovery */
147 #define	XLOG_RECOVERY_NEEDED	0x4	/* log was recovered */
148 #define XLOG_IO_ERROR		0x8	/* log hit an I/O error, and being
149 					   shutdown */
150 typedef __uint32_t xlog_tid_t;
151 
152 
153 #ifdef __KERNEL__
154 /*
155  * Below are states for covering allocation transactions.
156  * By covering, we mean changing the h_tail_lsn in the last on-disk
157  * log write such that no allocation transactions will be re-done during
158  * recovery after a system crash. Recovery starts at the last on-disk
159  * log write.
160  *
161  * These states are used to insert dummy log entries to cover
162  * space allocation transactions which can undo non-transactional changes
163  * after a crash. Writes to a file with space
164  * already allocated do not result in any transactions. Allocations
165  * might include space beyond the EOF. So if we just push the EOF a
166  * little, the last transaction for the file could contain the wrong
167  * size. If there is no file system activity, after an allocation
168  * transaction, and the system crashes, the allocation transaction
169  * will get replayed and the file will be truncated. This could
170  * be hours/days/... after the allocation occurred.
171  *
172  * The fix for this is to do two dummy transactions when the
173  * system is idle. We need two dummy transaction because the h_tail_lsn
174  * in the log record header needs to point beyond the last possible
175  * non-dummy transaction. The first dummy changes the h_tail_lsn to
176  * the first transaction before the dummy. The second dummy causes
177  * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
178  *
179  * These dummy transactions get committed when everything
180  * is idle (after there has been some activity).
181  *
182  * There are 5 states used to control this.
183  *
184  *  IDLE -- no logging has been done on the file system or
185  *		we are done covering previous transactions.
186  *  NEED -- logging has occurred and we need a dummy transaction
187  *		when the log becomes idle.
188  *  DONE -- we were in the NEED state and have committed a dummy
189  *		transaction.
190  *  NEED2 -- we detected that a dummy transaction has gone to the
191  *		on disk log with no other transactions.
192  *  DONE2 -- we committed a dummy transaction when in the NEED2 state.
193  *
194  * There are two places where we switch states:
195  *
196  * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
197  *	We commit the dummy transaction and switch to DONE or DONE2,
198  *	respectively. In all other states, we don't do anything.
199  *
200  * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
201  *
202  *	No matter what state we are in, if this isn't the dummy
203  *	transaction going out, the next state is NEED.
204  *	So, if we aren't in the DONE or DONE2 states, the next state
205  *	is NEED. We can't be finishing a write of the dummy record
206  *	unless it was committed and the state switched to DONE or DONE2.
207  *
208  *	If we are in the DONE state and this was a write of the
209  *		dummy transaction, we move to NEED2.
210  *
211  *	If we are in the DONE2 state and this was a write of the
212  *		dummy transaction, we move to IDLE.
213  *
214  *
215  * Writing only one dummy transaction can get appended to
216  * one file space allocation. When this happens, the log recovery
217  * code replays the space allocation and a file could be truncated.
218  * This is why we have the NEED2 and DONE2 states before going idle.
219  */
220 
221 #define XLOG_STATE_COVER_IDLE	0
222 #define XLOG_STATE_COVER_NEED	1
223 #define XLOG_STATE_COVER_DONE	2
224 #define XLOG_STATE_COVER_NEED2	3
225 #define XLOG_STATE_COVER_DONE2	4
226 
227 #define XLOG_COVER_OPS		5
228 
229 
230 /* Ticket reservation region accounting */
231 #define XLOG_TIC_LEN_MAX	15
232 
233 /*
234  * Reservation region
235  * As would be stored in xfs_log_iovec but without the i_addr which
236  * we don't care about.
237  */
238 typedef struct xlog_res {
239 	uint	r_len;	/* region length		:4 */
240 	uint	r_type;	/* region's transaction type	:4 */
241 } xlog_res_t;
242 
243 typedef struct xlog_ticket {
244 	sv_t		   t_wait;	 /* ticket wait queue            : 20 */
245 	struct xlog_ticket *t_next;	 /*			         :4|8 */
246 	struct xlog_ticket *t_prev;	 /*				 :4|8 */
247 	xlog_tid_t	   t_tid;	 /* transaction identifier	 : 4  */
248 	atomic_t	   t_ref;	 /* ticket reference count       : 4  */
249 	int		   t_curr_res;	 /* current reservation in bytes : 4  */
250 	int		   t_unit_res;	 /* unit reservation in bytes    : 4  */
251 	char		   t_ocnt;	 /* original count		 : 1  */
252 	char		   t_cnt;	 /* current count		 : 1  */
253 	char		   t_clientid;	 /* who does this belong to;	 : 1  */
254 	char		   t_flags;	 /* properties of reservation	 : 1  */
255 	uint		   t_trans_type; /* transaction type             : 4  */
256 
257         /* reservation array fields */
258 	uint		   t_res_num;                    /* num in array : 4 */
259 	uint		   t_res_num_ophdrs;		 /* num op hdrs  : 4 */
260 	uint		   t_res_arr_sum;		 /* array sum    : 4 */
261 	uint		   t_res_o_flow;		 /* sum overflow : 4 */
262 	xlog_res_t	   t_res_arr[XLOG_TIC_LEN_MAX];  /* array of res : 8 * 15 */
263 } xlog_ticket_t;
264 
265 #endif
266 
267 
268 typedef struct xlog_op_header {
269 	__be32	   oh_tid;	/* transaction id of operation	:  4 b */
270 	__be32	   oh_len;	/* bytes in data region		:  4 b */
271 	__u8	   oh_clientid;	/* who sent me this		:  1 b */
272 	__u8	   oh_flags;	/*				:  1 b */
273 	__u16	   oh_res2;	/* 32 bit align			:  2 b */
274 } xlog_op_header_t;
275 
276 
277 /* valid values for h_fmt */
278 #define XLOG_FMT_UNKNOWN  0
279 #define XLOG_FMT_LINUX_LE 1
280 #define XLOG_FMT_LINUX_BE 2
281 #define XLOG_FMT_IRIX_BE  3
282 
283 /* our fmt */
284 #ifdef XFS_NATIVE_HOST
285 #define XLOG_FMT XLOG_FMT_LINUX_BE
286 #else
287 #define XLOG_FMT XLOG_FMT_LINUX_LE
288 #endif
289 
290 typedef struct xlog_rec_header {
291 	__be32	  h_magicno;	/* log record (LR) identifier		:  4 */
292 	__be32	  h_cycle;	/* write cycle of log			:  4 */
293 	__be32	  h_version;	/* LR version				:  4 */
294 	__be32	  h_len;	/* len in bytes; should be 64-bit aligned: 4 */
295 	__be64	  h_lsn;	/* lsn of this LR			:  8 */
296 	__be64	  h_tail_lsn;	/* lsn of 1st LR w/ buffers not committed: 8 */
297 	__be32	  h_chksum;	/* may not be used; non-zero if used	:  4 */
298 	__be32	  h_prev_block; /* block number to previous LR		:  4 */
299 	__be32	  h_num_logops;	/* number of log operations in this LR	:  4 */
300 	__be32	  h_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE];
301 	/* new fields */
302 	__be32    h_fmt;        /* format of log record                 :  4 */
303 	uuid_t	  h_fs_uuid;    /* uuid of FS                           : 16 */
304 	__be32	  h_size;	/* iclog size				:  4 */
305 } xlog_rec_header_t;
306 
307 typedef struct xlog_rec_ext_header {
308 	__be32	  xh_cycle;	/* write cycle of log			: 4 */
309 	__be32	  xh_cycle_data[XLOG_HEADER_CYCLE_SIZE / BBSIZE]; /*	: 256 */
310 } xlog_rec_ext_header_t;
311 
312 #ifdef __KERNEL__
313 
314 /*
315  * Quite misnamed, because this union lays out the actual on-disk log buffer.
316  */
317 typedef union xlog_in_core2 {
318 	xlog_rec_header_t	hic_header;
319 	xlog_rec_ext_header_t	hic_xheader;
320 	char			hic_sector[XLOG_HEADER_SIZE];
321 } xlog_in_core_2_t;
322 
323 /*
324  * - A log record header is 512 bytes.  There is plenty of room to grow the
325  *	xlog_rec_header_t into the reserved space.
326  * - ic_data follows, so a write to disk can start at the beginning of
327  *	the iclog.
328  * - ic_forcewait is used to implement synchronous forcing of the iclog to disk.
329  * - ic_next is the pointer to the next iclog in the ring.
330  * - ic_bp is a pointer to the buffer used to write this incore log to disk.
331  * - ic_log is a pointer back to the global log structure.
332  * - ic_callback is a linked list of callback function/argument pairs to be
333  *	called after an iclog finishes writing.
334  * - ic_size is the full size of the header plus data.
335  * - ic_offset is the current number of bytes written to in this iclog.
336  * - ic_refcnt is bumped when someone is writing to the log.
337  * - ic_state is the state of the iclog.
338  *
339  * Because of cacheline contention on large machines, we need to separate
340  * various resources onto different cachelines. To start with, make the
341  * structure cacheline aligned. The following fields can be contended on
342  * by independent processes:
343  *
344  *	- ic_callback_*
345  *	- ic_refcnt
346  *	- fields protected by the global l_icloglock
347  *
348  * so we need to ensure that these fields are located in separate cachelines.
349  * We'll put all the read-only and l_icloglock fields in the first cacheline,
350  * and move everything else out to subsequent cachelines.
351  */
352 typedef struct xlog_in_core {
353 	sv_t			ic_force_wait;
354 	sv_t			ic_write_wait;
355 	struct xlog_in_core	*ic_next;
356 	struct xlog_in_core	*ic_prev;
357 	struct xfs_buf		*ic_bp;
358 	struct log		*ic_log;
359 	int			ic_size;
360 	int			ic_offset;
361 	int			ic_bwritecnt;
362 	unsigned short		ic_state;
363 	char			*ic_datap;	/* pointer to iclog data */
364 #ifdef XFS_LOG_TRACE
365 	struct ktrace		*ic_trace;
366 #endif
367 
368 	/* Callback structures need their own cacheline */
369 	spinlock_t		ic_callback_lock ____cacheline_aligned_in_smp;
370 	xfs_log_callback_t	*ic_callback;
371 	xfs_log_callback_t	**ic_callback_tail;
372 
373 	/* reference counts need their own cacheline */
374 	atomic_t		ic_refcnt ____cacheline_aligned_in_smp;
375 	xlog_in_core_2_t	*ic_data;
376 #define ic_header	ic_data->hic_header
377 } xlog_in_core_t;
378 
379 /*
380  * The reservation head lsn is not made up of a cycle number and block number.
381  * Instead, it uses a cycle number and byte number.  Logs don't expect to
382  * overflow 31 bits worth of byte offset, so using a byte number will mean
383  * that round off problems won't occur when releasing partial reservations.
384  */
385 typedef struct log {
386 	/* The following fields don't need locking */
387 	struct xfs_mount	*l_mp;	        /* mount point */
388 	struct xfs_ail		*l_ailp;	/* AIL log is working with */
389 	struct xfs_buf		*l_xbuf;        /* extra buffer for log
390 						 * wrapping */
391 	struct xfs_buftarg	*l_targ;        /* buftarg of log */
392 	uint			l_flags;
393 	uint			l_quotaoffs_flag; /* XFS_DQ_*, for QUOTAOFFs */
394 	struct xfs_buf_cancel	**l_buf_cancel_table;
395 	int			l_iclog_hsize;  /* size of iclog header */
396 	int			l_iclog_heads;  /* # of iclog header sectors */
397 	uint			l_sectbb_log;   /* log2 of sector size in BBs */
398 	uint			l_sectbb_mask;  /* sector size (in BBs)
399 						 * alignment mask */
400 	int			l_iclog_size;	/* size of log in bytes */
401 	int			l_iclog_size_log; /* log power size of log */
402 	int			l_iclog_bufs;	/* number of iclog buffers */
403 	xfs_daddr_t		l_logBBstart;   /* start block of log */
404 	int			l_logsize;      /* size of log in bytes */
405 	int			l_logBBsize;    /* size of log in BB chunks */
406 
407 	/* The following block of fields are changed while holding icloglock */
408 	sv_t			l_flush_wait ____cacheline_aligned_in_smp;
409 						/* waiting for iclog flush */
410 	int			l_covered_state;/* state of "covering disk
411 						 * log entries" */
412 	xlog_in_core_t		*l_iclog;       /* head log queue	*/
413 	spinlock_t		l_icloglock;    /* grab to change iclog state */
414 	xfs_lsn_t		l_tail_lsn;     /* lsn of 1st LR with unflushed
415 						 * buffers */
416 	xfs_lsn_t		l_last_sync_lsn;/* lsn of last LR on disk */
417 	int			l_curr_cycle;   /* Cycle number of log writes */
418 	int			l_prev_cycle;   /* Cycle number before last
419 						 * block increment */
420 	int			l_curr_block;   /* current logical log block */
421 	int			l_prev_block;   /* previous logical log block */
422 
423 	/* The following block of fields are changed while holding grant_lock */
424 	spinlock_t		l_grant_lock ____cacheline_aligned_in_smp;
425 	xlog_ticket_t		*l_reserve_headq;
426 	xlog_ticket_t		*l_write_headq;
427 	int			l_grant_reserve_cycle;
428 	int			l_grant_reserve_bytes;
429 	int			l_grant_write_cycle;
430 	int			l_grant_write_bytes;
431 
432 #ifdef XFS_LOG_TRACE
433 	struct ktrace		*l_grant_trace;
434 #endif
435 
436 	/* The following field are used for debugging; need to hold icloglock */
437 #ifdef DEBUG
438 	char			*l_iclog_bak[XLOG_MAX_ICLOGS];
439 #endif
440 
441 } xlog_t;
442 
443 #define XLOG_FORCED_SHUTDOWN(log)	((log)->l_flags & XLOG_IO_ERROR)
444 
445 
446 /* common routines */
447 extern xfs_lsn_t xlog_assign_tail_lsn(struct xfs_mount *mp);
448 extern int	 xlog_find_tail(xlog_t	*log,
449 				xfs_daddr_t *head_blk,
450 				xfs_daddr_t *tail_blk);
451 extern int	 xlog_recover(xlog_t *log);
452 extern int	 xlog_recover_finish(xlog_t *log);
453 extern void	 xlog_pack_data(xlog_t *log, xlog_in_core_t *iclog, int);
454 extern void	 xlog_recover_process_iunlinks(xlog_t *log);
455 
456 extern struct xfs_buf *xlog_get_bp(xlog_t *, int);
457 extern void	 xlog_put_bp(struct xfs_buf *);
458 
459 extern kmem_zone_t	*xfs_log_ticket_zone;
460 
461 /* iclog tracing */
462 #define XLOG_TRACE_GRAB_FLUSH  1
463 #define XLOG_TRACE_REL_FLUSH   2
464 #define XLOG_TRACE_SLEEP_FLUSH 3
465 #define XLOG_TRACE_WAKE_FLUSH  4
466 
467 /*
468  * Unmount record type is used as a pseudo transaction type for the ticket.
469  * It's value must be outside the range of XFS_TRANS_* values.
470  */
471 #define XLOG_UNMOUNT_REC_TYPE	(-1U)
472 
473 #endif	/* __KERNEL__ */
474 
475 #endif	/* __XFS_LOG_PRIV_H__ */
476