2 * Copyright (c) 2000-2003,2005 Silicon Graphics, Inc.
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.
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.
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
18 #ifndef __XFS_LOG_PRIV_H__
19 #define __XFS_LOG_PRIV_H__
24 struct xfs_buf_cancel
;
28 * Macros, structures, prototypes for internal log manager use.
31 #define XLOG_MIN_ICLOGS 2
32 #define XLOG_MAX_ICLOGS 8
33 #define XLOG_HEADER_MAGIC_NUM 0xFEEDbabe /* Invalid cycle number */
34 #define XLOG_VERSION_1 1
35 #define XLOG_VERSION_2 2 /* Large IClogs, Log sunit */
36 #define XLOG_VERSION_OKBITS (XLOG_VERSION_1 | XLOG_VERSION_2)
37 #define XLOG_MIN_RECORD_BSIZE (16*1024) /* eventually 32k */
38 #define XLOG_BIG_RECORD_BSIZE (32*1024) /* 32k buffers */
39 #define XLOG_MAX_RECORD_BSIZE (256*1024)
40 #define XLOG_HEADER_CYCLE_SIZE (32*1024) /* cycle data in header */
41 #define XLOG_MIN_RECORD_BSHIFT 14 /* 16384 == 1 << 14 */
42 #define XLOG_BIG_RECORD_BSHIFT 15 /* 32k == 1 << 15 */
43 #define XLOG_MAX_RECORD_BSHIFT 18 /* 256k == 1 << 18 */
44 #define XLOG_BTOLSUNIT(log, b) (((b)+(log)->l_mp->m_sb.sb_logsunit-1) / \
45 (log)->l_mp->m_sb.sb_logsunit)
46 #define XLOG_LSUNITTOB(log, su) ((su) * (log)->l_mp->m_sb.sb_logsunit)
48 #define XLOG_HEADER_SIZE 512
50 #define XLOG_REC_SHIFT(log) \
51 BTOBB(1 << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
52 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
53 #define XLOG_TOTAL_REC_SHIFT(log) \
54 BTOBB(XLOG_MAX_ICLOGS << (xfs_sb_version_haslogv2(&log->l_mp->m_sb) ? \
55 XLOG_MAX_RECORD_BSHIFT : XLOG_BIG_RECORD_BSHIFT))
58 static inline xfs_lsn_t
xlog_assign_lsn(uint cycle
, uint block
)
60 return ((xfs_lsn_t
)cycle
<< 32) | block
;
63 static inline uint
xlog_get_cycle(char *ptr
)
65 if (be32_to_cpu(*(__be32
*)ptr
) == XLOG_HEADER_MAGIC_NUM
)
66 return be32_to_cpu(*((__be32
*)ptr
+ 1));
68 return be32_to_cpu(*(__be32
*)ptr
);
71 #define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1)
76 * get client id from packed copy.
78 * this hack is here because the xlog_pack code copies four bytes
79 * of xlog_op_header containing the fields oh_clientid, oh_flags
80 * and oh_res2 into the packed copy.
82 * later on this four byte chunk is treated as an int and the
83 * client id is pulled out.
85 * this has endian issues, of course.
87 static inline uint
xlog_get_client_id(__be32 i
)
89 return be32_to_cpu(i
) >> 24;
92 #define xlog_panic(args...) cmn_err(CE_PANIC, ## args)
93 #define xlog_exit(args...) cmn_err(CE_PANIC, ## args)
94 #define xlog_warn(args...) cmn_err(CE_WARN, ## args)
99 #define XLOG_STATE_ACTIVE 0x0001 /* Current IC log being written to */
100 #define XLOG_STATE_WANT_SYNC 0x0002 /* Want to sync this iclog; no more writes */
101 #define XLOG_STATE_SYNCING 0x0004 /* This IC log is syncing */
102 #define XLOG_STATE_DONE_SYNC 0x0008 /* Done syncing to disk */
103 #define XLOG_STATE_DO_CALLBACK \
104 0x0010 /* Process callback functions */
105 #define XLOG_STATE_CALLBACK 0x0020 /* Callback functions now */
106 #define XLOG_STATE_DIRTY 0x0040 /* Dirty IC log, not ready for ACTIVE status*/
107 #define XLOG_STATE_IOERROR 0x0080 /* IO error happened in sync'ing log */
108 #define XLOG_STATE_ALL 0x7FFF /* All possible valid flags */
109 #define XLOG_STATE_NOTUSED 0x8000 /* This IC log not being used */
110 #endif /* __KERNEL__ */
113 * Flags to log operation header
115 * The first write of a new transaction will be preceded with a start
116 * record, XLOG_START_TRANS. Once a transaction is committed, a commit
117 * record is written, XLOG_COMMIT_TRANS. If a single region can not fit into
118 * the remainder of the current active in-core log, it is split up into
119 * multiple regions. Each partial region will be marked with a
120 * XLOG_CONTINUE_TRANS until the last one, which gets marked with XLOG_END_TRANS.
123 #define XLOG_START_TRANS 0x01 /* Start a new transaction */
124 #define XLOG_COMMIT_TRANS 0x02 /* Commit this transaction */
125 #define XLOG_CONTINUE_TRANS 0x04 /* Cont this trans into new region */
126 #define XLOG_WAS_CONT_TRANS 0x08 /* Cont this trans into new region */
127 #define XLOG_END_TRANS 0x10 /* End a continued transaction */
128 #define XLOG_UNMOUNT_TRANS 0x20 /* Unmount a filesystem transaction */
132 * Flags to log ticket
134 #define XLOG_TIC_INITED 0x1 /* has been initialized */
135 #define XLOG_TIC_PERM_RESERV 0x2 /* permanent reservation */
136 #define XLOG_TIC_IN_Q 0x4
138 #define XLOG_TIC_FLAGS \
139 { XLOG_TIC_INITED, "XLOG_TIC_INITED" }, \
140 { XLOG_TIC_PERM_RESERV, "XLOG_TIC_PERM_RESERV" }, \
141 { XLOG_TIC_IN_Q, "XLOG_TIC_IN_Q" }
143 #endif /* __KERNEL__ */
145 #define XLOG_UNMOUNT_TYPE 0x556e /* Un for Unmount */
148 * Flags for log structure
150 #define XLOG_CHKSUM_MISMATCH 0x1 /* used only during recovery */
151 #define XLOG_ACTIVE_RECOVERY 0x2 /* in the middle of recovery */
152 #define XLOG_RECOVERY_NEEDED 0x4 /* log was recovered */
153 #define XLOG_IO_ERROR 0x8 /* log hit an I/O error, and being
158 * Below are states for covering allocation transactions.
159 * By covering, we mean changing the h_tail_lsn in the last on-disk
160 * log write such that no allocation transactions will be re-done during
161 * recovery after a system crash. Recovery starts at the last on-disk
164 * These states are used to insert dummy log entries to cover
165 * space allocation transactions which can undo non-transactional changes
166 * after a crash. Writes to a file with space
167 * already allocated do not result in any transactions. Allocations
168 * might include space beyond the EOF. So if we just push the EOF a
169 * little, the last transaction for the file could contain the wrong
170 * size. If there is no file system activity, after an allocation
171 * transaction, and the system crashes, the allocation transaction
172 * will get replayed and the file will be truncated. This could
173 * be hours/days/... after the allocation occurred.
175 * The fix for this is to do two dummy transactions when the
176 * system is idle. We need two dummy transaction because the h_tail_lsn
177 * in the log record header needs to point beyond the last possible
178 * non-dummy transaction. The first dummy changes the h_tail_lsn to
179 * the first transaction before the dummy. The second dummy causes
180 * h_tail_lsn to point to the first dummy. Recovery starts at h_tail_lsn.
182 * These dummy transactions get committed when everything
183 * is idle (after there has been some activity).
185 * There are 5 states used to control this.
187 * IDLE -- no logging has been done on the file system or
188 * we are done covering previous transactions.
189 * NEED -- logging has occurred and we need a dummy transaction
190 * when the log becomes idle.
191 * DONE -- we were in the NEED state and have committed a dummy
193 * NEED2 -- we detected that a dummy transaction has gone to the
194 * on disk log with no other transactions.
195 * DONE2 -- we committed a dummy transaction when in the NEED2 state.
197 * There are two places where we switch states:
199 * 1.) In xfs_sync, when we detect an idle log and are in NEED or NEED2.
200 * We commit the dummy transaction and switch to DONE or DONE2,
201 * respectively. In all other states, we don't do anything.
203 * 2.) When we finish writing the on-disk log (xlog_state_clean_log).
205 * No matter what state we are in, if this isn't the dummy
206 * transaction going out, the next state is NEED.
207 * So, if we aren't in the DONE or DONE2 states, the next state
208 * is NEED. We can't be finishing a write of the dummy record
209 * unless it was committed and the state switched to DONE or DONE2.
211 * If we are in the DONE state and this was a write of the
212 * dummy transaction, we move to NEED2.
214 * If we are in the DONE2 state and this was a write of the
215 * dummy transaction, we move to IDLE.
218 * Writing only one dummy transaction can get appended to
219 * one file space allocation. When this happens, the log recovery
220 * code replays the space allocation and a file could be truncated.
221 * This is why we have the NEED2 and DONE2 states before going idle.
224 #define XLOG_STATE_COVER_IDLE 0
225 #define XLOG_STATE_COVER_NEED 1
226 #define XLOG_STATE_COVER_DONE 2
227 #define XLOG_STATE_COVER_NEED2 3
228 #define XLOG_STATE_COVER_DONE2 4
230 #define XLOG_COVER_OPS 5
233 /* Ticket reservation region accounting */
234 #define XLOG_TIC_LEN_MAX 15
238 * As would be stored in xfs_log_iovec but without the i_addr which
239 * we don't care about.
241 typedef struct xlog_res
{
242 uint r_len
; /* region length :4 */
243 uint r_type
; /* region's transaction type :4 */
246 typedef struct xlog_ticket
{
247 sv_t t_wait
; /* ticket wait queue : 20 */
248 struct xlog_ticket
*t_next
; /* :4|8 */
249 struct xlog_ticket
*t_prev
; /* :4|8 */
250 xlog_tid_t t_tid
; /* transaction identifier : 4 */
251 atomic_t t_ref
; /* ticket reference count : 4 */
252 int t_curr_res
; /* current reservation in bytes : 4 */
253 int t_unit_res
; /* unit reservation in bytes : 4 */
254 char t_ocnt
; /* original count : 1 */
255 char t_cnt
; /* current count : 1 */
256 char t_clientid
; /* who does this belong to; : 1 */
257 char t_flags
; /* properties of reservation : 1 */
258 uint t_trans_type
; /* transaction type : 4 */
260 /* reservation array fields */
261 uint t_res_num
; /* num in array : 4 */
262 uint t_res_num_ophdrs
; /* num op hdrs : 4 */
263 uint t_res_arr_sum
; /* array sum : 4 */
264 uint t_res_o_flow
; /* sum overflow : 4 */
265 xlog_res_t t_res_arr
[XLOG_TIC_LEN_MAX
]; /* array of res : 8 * 15 */
271 typedef struct xlog_op_header
{
272 __be32 oh_tid
; /* transaction id of operation : 4 b */
273 __be32 oh_len
; /* bytes in data region : 4 b */
274 __u8 oh_clientid
; /* who sent me this : 1 b */
275 __u8 oh_flags
; /* : 1 b */
276 __u16 oh_res2
; /* 32 bit align : 2 b */
280 /* valid values for h_fmt */
281 #define XLOG_FMT_UNKNOWN 0
282 #define XLOG_FMT_LINUX_LE 1
283 #define XLOG_FMT_LINUX_BE 2
284 #define XLOG_FMT_IRIX_BE 3
287 #ifdef XFS_NATIVE_HOST
288 #define XLOG_FMT XLOG_FMT_LINUX_BE
290 #define XLOG_FMT XLOG_FMT_LINUX_LE
293 typedef struct xlog_rec_header
{
294 __be32 h_magicno
; /* log record (LR) identifier : 4 */
295 __be32 h_cycle
; /* write cycle of log : 4 */
296 __be32 h_version
; /* LR version : 4 */
297 __be32 h_len
; /* len in bytes; should be 64-bit aligned: 4 */
298 __be64 h_lsn
; /* lsn of this LR : 8 */
299 __be64 h_tail_lsn
; /* lsn of 1st LR w/ buffers not committed: 8 */
300 __be32 h_chksum
; /* may not be used; non-zero if used : 4 */
301 __be32 h_prev_block
; /* block number to previous LR : 4 */
302 __be32 h_num_logops
; /* number of log operations in this LR : 4 */
303 __be32 h_cycle_data
[XLOG_HEADER_CYCLE_SIZE
/ BBSIZE
];
305 __be32 h_fmt
; /* format of log record : 4 */
306 uuid_t h_fs_uuid
; /* uuid of FS : 16 */
307 __be32 h_size
; /* iclog size : 4 */
310 typedef struct xlog_rec_ext_header
{
311 __be32 xh_cycle
; /* write cycle of log : 4 */
312 __be32 xh_cycle_data
[XLOG_HEADER_CYCLE_SIZE
/ BBSIZE
]; /* : 256 */
313 } xlog_rec_ext_header_t
;
318 * Quite misnamed, because this union lays out the actual on-disk log buffer.
320 typedef union xlog_in_core2
{
321 xlog_rec_header_t hic_header
;
322 xlog_rec_ext_header_t hic_xheader
;
323 char hic_sector
[XLOG_HEADER_SIZE
];
327 * - A log record header is 512 bytes. There is plenty of room to grow the
328 * xlog_rec_header_t into the reserved space.
329 * - ic_data follows, so a write to disk can start at the beginning of
331 * - ic_forcewait is used to implement synchronous forcing of the iclog to disk.
332 * - ic_next is the pointer to the next iclog in the ring.
333 * - ic_bp is a pointer to the buffer used to write this incore log to disk.
334 * - ic_log is a pointer back to the global log structure.
335 * - ic_callback is a linked list of callback function/argument pairs to be
336 * called after an iclog finishes writing.
337 * - ic_size is the full size of the header plus data.
338 * - ic_offset is the current number of bytes written to in this iclog.
339 * - ic_refcnt is bumped when someone is writing to the log.
340 * - ic_state is the state of the iclog.
342 * Because of cacheline contention on large machines, we need to separate
343 * various resources onto different cachelines. To start with, make the
344 * structure cacheline aligned. The following fields can be contended on
345 * by independent processes:
349 * - fields protected by the global l_icloglock
351 * so we need to ensure that these fields are located in separate cachelines.
352 * We'll put all the read-only and l_icloglock fields in the first cacheline,
353 * and move everything else out to subsequent cachelines.
355 typedef struct xlog_in_core
{
358 struct xlog_in_core
*ic_next
;
359 struct xlog_in_core
*ic_prev
;
360 struct xfs_buf
*ic_bp
;
365 unsigned short ic_state
;
366 char *ic_datap
; /* pointer to iclog data */
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
;
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
380 * The CIL context is used to aggregate per-transaction details as well be
381 * passed to the iclog for checkpoint post-commit processing. After being
382 * passed to the iclog, another context needs to be allocated for tracking the
383 * next set of transactions to be aggregated into a checkpoint.
389 xfs_lsn_t sequence
; /* chkpt sequence # */
390 xfs_lsn_t start_lsn
; /* first LSN of chkpt commit */
391 xfs_lsn_t commit_lsn
; /* chkpt commit record lsn */
392 struct xlog_ticket
*ticket
; /* chkpt ticket */
393 int nvecs
; /* number of regions */
394 int space_used
; /* aggregate size of regions */
395 struct list_head busy_extents
; /* busy extents in chkpt */
396 struct xfs_log_vec
*lv_chain
; /* logvecs being pushed */
397 xfs_log_callback_t log_cb
; /* completion callback hook. */
398 struct list_head committing
; /* ctx committing list */
402 * Committed Item List structure
404 * This structure is used to track log items that have been committed but not
405 * yet written into the log. It is used only when the delayed logging mount
408 * This structure tracks the list of committing checkpoint contexts so
409 * we can avoid the problem of having to hold out new transactions during a
410 * flush until we have a the commit record LSN of the checkpoint. We can
411 * traverse the list of committing contexts in xlog_cil_push_lsn() to find a
412 * sequence match and extract the commit LSN directly from there. If the
413 * checkpoint is still in the process of committing, we can block waiting for
414 * the commit LSN to be determined as well. This should make synchronous
415 * operations almost as efficient as the old logging methods.
419 struct list_head xc_cil
;
420 spinlock_t xc_cil_lock
;
421 struct xfs_cil_ctx
*xc_ctx
;
422 struct rw_semaphore xc_ctx_lock
;
423 struct list_head xc_committing
;
428 * The amount of log space we should the CIL to aggregate is difficult to size.
429 * Whatever we chose we have to make we can get a reservation for the log space
430 * effectively, that it is large enough to capture sufficient relogging to
431 * reduce log buffer IO significantly, but it is not too large for the log or
432 * induces too much latency when writing out through the iclogs. We track both
433 * space consumed and the number of vectors in the checkpoint context, so we
434 * need to decide which to use for limiting.
436 * Every log buffer we write out during a push needs a header reserved, which
437 * is at least one sector and more for v2 logs. Hence we need a reservation of
438 * at least 512 bytes per 32k of log space just for the LR headers. That means
439 * 16KB of reservation per megabyte of delayed logging space we will consume,
440 * plus various headers. The number of headers will vary based on the num of
441 * io vectors, so limiting on a specific number of vectors is going to result
442 * in transactions of varying size. IOWs, it is more consistent to track and
443 * limit space consumed in the log rather than by the number of objects being
444 * logged in order to prevent checkpoint ticket overruns.
446 * Further, use of static reservations through the log grant mechanism is
447 * problematic. It introduces a lot of complexity (e.g. reserve grant vs write
448 * grant) and a significant deadlock potential because regranting write space
449 * can block on log pushes. Hence if we have to regrant log space during a log
450 * push, we can deadlock.
452 * However, we can avoid this by use of a dynamic "reservation stealing"
453 * technique during transaction commit whereby unused reservation space in the
454 * transaction ticket is transferred to the CIL ctx commit ticket to cover the
455 * space needed by the checkpoint transaction. This means that we never need to
456 * specifically reserve space for the CIL checkpoint transaction, nor do we
457 * need to regrant space once the checkpoint completes. This also means the
458 * checkpoint transaction ticket is specific to the checkpoint context, rather
459 * than the CIL itself.
461 * With dynamic reservations, we can basically make up arbitrary limits for the
462 * checkpoint size so long as they don't violate any other size rules. Hence
463 * the initial maximum size for the checkpoint transaction will be set to a
464 * quarter of the log or 8MB, which ever is smaller. 8MB is an arbitrary limit
465 * right now based on the latency of writing out a large amount of data through
466 * the circular iclog buffers.
469 #define XLOG_CIL_SPACE_LIMIT(log) \
470 (min((log->l_logsize >> 2), (8 * 1024 * 1024)))
473 * The reservation head lsn is not made up of a cycle number and block number.
474 * Instead, it uses a cycle number and byte number. Logs don't expect to
475 * overflow 31 bits worth of byte offset, so using a byte number will mean
476 * that round off problems won't occur when releasing partial reservations.
479 /* The following fields don't need locking */
480 struct xfs_mount
*l_mp
; /* mount point */
481 struct xfs_ail
*l_ailp
; /* AIL log is working with */
482 struct xfs_cil
*l_cilp
; /* CIL log is working with */
483 struct xfs_buf
*l_xbuf
; /* extra buffer for log
485 struct xfs_buftarg
*l_targ
; /* buftarg of log */
487 uint l_quotaoffs_flag
; /* XFS_DQ_*, for QUOTAOFFs */
488 struct xfs_buf_cancel
**l_buf_cancel_table
;
489 int l_iclog_hsize
; /* size of iclog header */
490 int l_iclog_heads
; /* # of iclog header sectors */
491 uint l_sectBBsize
; /* sector size in BBs (2^n) */
492 int l_iclog_size
; /* size of log in bytes */
493 int l_iclog_size_log
; /* log power size of log */
494 int l_iclog_bufs
; /* number of iclog buffers */
495 xfs_daddr_t l_logBBstart
; /* start block of log */
496 int l_logsize
; /* size of log in bytes */
497 int l_logBBsize
; /* size of log in BB chunks */
499 /* The following block of fields are changed while holding icloglock */
500 sv_t l_flush_wait ____cacheline_aligned_in_smp
;
501 /* waiting for iclog flush */
502 int l_covered_state
;/* state of "covering disk
504 xlog_in_core_t
*l_iclog
; /* head log queue */
505 spinlock_t l_icloglock
; /* grab to change iclog state */
506 xfs_lsn_t l_tail_lsn
; /* lsn of 1st LR with unflushed
508 xfs_lsn_t l_last_sync_lsn
;/* lsn of last LR on disk */
509 int l_curr_cycle
; /* Cycle number of log writes */
510 int l_prev_cycle
; /* Cycle number before last
512 int l_curr_block
; /* current logical log block */
513 int l_prev_block
; /* previous logical log block */
515 /* The following block of fields are changed while holding grant_lock */
516 spinlock_t l_grant_lock ____cacheline_aligned_in_smp
;
517 xlog_ticket_t
*l_reserve_headq
;
518 xlog_ticket_t
*l_write_headq
;
519 int l_grant_reserve_cycle
;
520 int l_grant_reserve_bytes
;
521 int l_grant_write_cycle
;
522 int l_grant_write_bytes
;
524 /* The following field are used for debugging; need to hold icloglock */
526 char *l_iclog_bak
[XLOG_MAX_ICLOGS
];
531 #define XLOG_FORCED_SHUTDOWN(log) ((log)->l_flags & XLOG_IO_ERROR)
533 /* common routines */
534 extern xfs_lsn_t
xlog_assign_tail_lsn(struct xfs_mount
*mp
);
535 extern int xlog_recover(xlog_t
*log
);
536 extern int xlog_recover_finish(xlog_t
*log
);
537 extern void xlog_pack_data(xlog_t
*log
, xlog_in_core_t
*iclog
, int);
539 extern kmem_zone_t
*xfs_log_ticket_zone
;
540 struct xlog_ticket
*xlog_ticket_alloc(struct log
*log
, int unit_bytes
,
541 int count
, char client
, uint xflags
,
546 xlog_write_adv_cnt(void **ptr
, int *len
, int *off
, size_t bytes
)
553 void xlog_print_tic_res(struct xfs_mount
*mp
, struct xlog_ticket
*ticket
);
554 int xlog_write(struct log
*log
, struct xfs_log_vec
*log_vector
,
555 struct xlog_ticket
*tic
, xfs_lsn_t
*start_lsn
,
556 xlog_in_core_t
**commit_iclog
, uint flags
);
559 * Committed Item List interfaces
561 int xlog_cil_init(struct log
*log
);
562 void xlog_cil_init_post_recovery(struct log
*log
);
563 void xlog_cil_destroy(struct log
*log
);
565 int xlog_cil_push(struct log
*log
, int push_now
);
566 xfs_lsn_t
xlog_cil_push_lsn(struct log
*log
, xfs_lsn_t push_sequence
);
569 * Unmount record type is used as a pseudo transaction type for the ticket.
570 * It's value must be outside the range of XFS_TRANS_* values.
572 #define XLOG_UNMOUNT_REC_TYPE (-1U)
574 #endif /* __KERNEL__ */
576 #endif /* __XFS_LOG_PRIV_H__ */