Merge /spare/repo/linux-2.6/
[linux-2.6] / fs / xfs / xfs_log.c
1 /*
2  * Copyright (c) 2000-2004 Silicon Graphics, Inc.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.  Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22  *
23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24  * Mountain View, CA  94043, or:
25  *
26  * http://www.sgi.com
27  *
28  * For further information regarding this notice, see:
29  *
30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31  */
32
33 /*
34  * High level interface routines for log manager
35  */
36
37 #include "xfs.h"
38 #include "xfs_macros.h"
39 #include "xfs_types.h"
40 #include "xfs_inum.h"
41 #include "xfs_ag.h"
42 #include "xfs_sb.h"
43 #include "xfs_log.h"
44 #include "xfs_trans.h"
45 #include "xfs_dir.h"
46 #include "xfs_dmapi.h"
47 #include "xfs_mount.h"
48 #include "xfs_error.h"
49 #include "xfs_log_priv.h"
50 #include "xfs_buf_item.h"
51 #include "xfs_alloc_btree.h"
52 #include "xfs_log_recover.h"
53 #include "xfs_bit.h"
54 #include "xfs_rw.h"
55 #include "xfs_trans_priv.h"
56
57
58 #define xlog_write_adv_cnt(ptr, len, off, bytes) \
59         { (ptr) += (bytes); \
60           (len) -= (bytes); \
61           (off) += (bytes);}
62
63 /* Local miscellaneous function prototypes */
64 STATIC int       xlog_bdstrat_cb(struct xfs_buf *);
65 STATIC int       xlog_commit_record(xfs_mount_t *mp, xlog_ticket_t *ticket,
66                                     xlog_in_core_t **, xfs_lsn_t *);
67 STATIC xlog_t *  xlog_alloc_log(xfs_mount_t     *mp,
68                                 xfs_buftarg_t   *log_target,
69                                 xfs_daddr_t     blk_offset,
70                                 int             num_bblks);
71 STATIC int       xlog_space_left(xlog_t *log, int cycle, int bytes);
72 STATIC int       xlog_sync(xlog_t *log, xlog_in_core_t *iclog);
73 STATIC void      xlog_unalloc_log(xlog_t *log);
74 STATIC int       xlog_write(xfs_mount_t *mp, xfs_log_iovec_t region[],
75                             int nentries, xfs_log_ticket_t tic,
76                             xfs_lsn_t *start_lsn,
77                             xlog_in_core_t **commit_iclog,
78                             uint flags);
79
80 /* local state machine functions */
81 STATIC void xlog_state_done_syncing(xlog_in_core_t *iclog, int);
82 STATIC void xlog_state_do_callback(xlog_t *log,int aborted, xlog_in_core_t *iclog);
83 STATIC int  xlog_state_get_iclog_space(xlog_t           *log,
84                                        int              len,
85                                        xlog_in_core_t   **iclog,
86                                        xlog_ticket_t    *ticket,
87                                        int              *continued_write,
88                                        int              *logoffsetp);
89 STATIC void xlog_state_put_ticket(xlog_t        *log,
90                                   xlog_ticket_t *tic);
91 STATIC int  xlog_state_release_iclog(xlog_t             *log,
92                                      xlog_in_core_t     *iclog);
93 STATIC void xlog_state_switch_iclogs(xlog_t             *log,
94                                      xlog_in_core_t *iclog,
95                                      int                eventual_size);
96 STATIC int  xlog_state_sync(xlog_t *log, xfs_lsn_t lsn, uint flags);
97 STATIC int  xlog_state_sync_all(xlog_t *log, uint flags);
98 STATIC void xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog);
99
100 /* local functions to manipulate grant head */
101 STATIC int  xlog_grant_log_space(xlog_t         *log,
102                                  xlog_ticket_t  *xtic);
103 STATIC void xlog_grant_push_ail(xfs_mount_t     *mp,
104                                 int             need_bytes);
105 STATIC void xlog_regrant_reserve_log_space(xlog_t        *log,
106                                            xlog_ticket_t *ticket);
107 STATIC int xlog_regrant_write_log_space(xlog_t          *log,
108                                          xlog_ticket_t  *ticket);
109 STATIC void xlog_ungrant_log_space(xlog_t        *log,
110                                    xlog_ticket_t *ticket);
111
112
113 /* local ticket functions */
114 STATIC void             xlog_state_ticket_alloc(xlog_t *log);
115 STATIC xlog_ticket_t    *xlog_ticket_get(xlog_t *log,
116                                          int    unit_bytes,
117                                          int    count,
118                                          char   clientid,
119                                          uint   flags);
120 STATIC void             xlog_ticket_put(xlog_t *log, xlog_ticket_t *ticket);
121
122 /* local debug functions */
123 #if defined(DEBUG) && !defined(XLOG_NOLOG)
124 STATIC void     xlog_verify_dest_ptr(xlog_t *log, __psint_t ptr);
125 STATIC void     xlog_verify_grant_head(xlog_t *log, int equals);
126 STATIC void     xlog_verify_iclog(xlog_t *log, xlog_in_core_t *iclog,
127                                   int count, boolean_t syncing);
128 STATIC void     xlog_verify_tail_lsn(xlog_t *log, xlog_in_core_t *iclog,
129                                      xfs_lsn_t tail_lsn);
130 #else
131 #define xlog_verify_dest_ptr(a,b)
132 #define xlog_verify_grant_head(a,b)
133 #define xlog_verify_iclog(a,b,c,d)
134 #define xlog_verify_tail_lsn(a,b,c)
135 #endif
136
137 STATIC int      xlog_iclogs_empty(xlog_t *log);
138
139 #ifdef DEBUG
140 int xlog_do_error = 0;
141 int xlog_req_num  = 0;
142 int xlog_error_mod = 33;
143 #endif
144
145 #define XLOG_FORCED_SHUTDOWN(log)       (log->l_flags & XLOG_IO_ERROR)
146
147 /*
148  * 0 => disable log manager
149  * 1 => enable log manager
150  * 2 => enable log manager and log debugging
151  */
152 #if defined(XLOG_NOLOG) || defined(DEBUG)
153 int   xlog_debug = 1;
154 xfs_buftarg_t *xlog_target;
155 #endif
156
157 #if defined(XFS_LOG_TRACE)
158
159 void
160 xlog_trace_loggrant(xlog_t *log, xlog_ticket_t *tic, xfs_caddr_t string)
161 {
162         unsigned long cnts;
163
164         if (!log->l_grant_trace) {
165                 log->l_grant_trace = ktrace_alloc(2048, KM_NOSLEEP);
166                 if (!log->l_grant_trace)
167                         return;
168         }
169         /* ticket counts are 1 byte each */
170         cnts = ((unsigned long)tic->t_ocnt) | ((unsigned long)tic->t_cnt) << 8;
171
172         ktrace_enter(log->l_grant_trace,
173                      (void *)tic,
174                      (void *)log->l_reserve_headq,
175                      (void *)log->l_write_headq,
176                      (void *)((unsigned long)log->l_grant_reserve_cycle),
177                      (void *)((unsigned long)log->l_grant_reserve_bytes),
178                      (void *)((unsigned long)log->l_grant_write_cycle),
179                      (void *)((unsigned long)log->l_grant_write_bytes),
180                      (void *)((unsigned long)log->l_curr_cycle),
181                      (void *)((unsigned long)log->l_curr_block),
182                      (void *)((unsigned long)CYCLE_LSN(log->l_tail_lsn)),
183                      (void *)((unsigned long)BLOCK_LSN(log->l_tail_lsn)),
184                      (void *)string,
185                      (void *)((unsigned long)tic->t_trans_type),
186                      (void *)cnts,
187                      (void *)((unsigned long)tic->t_curr_res),
188                      (void *)((unsigned long)tic->t_unit_res));
189 }
190
191 void
192 xlog_trace_iclog(xlog_in_core_t *iclog, uint state)
193 {
194         pid_t pid;
195
196         pid = current_pid();
197
198         if (!iclog->ic_trace)
199                 iclog->ic_trace = ktrace_alloc(256, KM_SLEEP);
200         ktrace_enter(iclog->ic_trace,
201                      (void *)((unsigned long)state),
202                      (void *)((unsigned long)pid),
203                      (void *)0,
204                      (void *)0,
205                      (void *)0,
206                      (void *)0,
207                      (void *)0,
208                      (void *)0,
209                      (void *)0,
210                      (void *)0,
211                      (void *)0,
212                      (void *)0,
213                      (void *)0,
214                      (void *)0,
215                      (void *)0,
216                      (void *)0);
217 }
218
219 #else
220 #define xlog_trace_loggrant(log,tic,string)
221 #define xlog_trace_iclog(iclog,state)
222 #endif /* XFS_LOG_TRACE */
223
224 /*
225  * NOTES:
226  *
227  *      1. currblock field gets updated at startup and after in-core logs
228  *              marked as with WANT_SYNC.
229  */
230
231 /*
232  * This routine is called when a user of a log manager ticket is done with
233  * the reservation.  If the ticket was ever used, then a commit record for
234  * the associated transaction is written out as a log operation header with
235  * no data.  The flag XLOG_TIC_INITED is set when the first write occurs with
236  * a given ticket.  If the ticket was one with a permanent reservation, then
237  * a few operations are done differently.  Permanent reservation tickets by
238  * default don't release the reservation.  They just commit the current
239  * transaction with the belief that the reservation is still needed.  A flag
240  * must be passed in before permanent reservations are actually released.
241  * When these type of tickets are not released, they need to be set into
242  * the inited state again.  By doing this, a start record will be written
243  * out when the next write occurs.
244  */
245 xfs_lsn_t
246 xfs_log_done(xfs_mount_t        *mp,
247              xfs_log_ticket_t   xtic,
248              void               **iclog,
249              uint               flags)
250 {
251         xlog_t          *log    = mp->m_log;
252         xlog_ticket_t   *ticket = (xfs_log_ticket_t) xtic;
253         xfs_lsn_t       lsn     = 0;
254
255 #if defined(DEBUG) || defined(XLOG_NOLOG)
256         if (!xlog_debug && xlog_target == log->l_targ)
257                 return 0;
258 #endif
259
260         if (XLOG_FORCED_SHUTDOWN(log) ||
261             /*
262              * If nothing was ever written, don't write out commit record.
263              * If we get an error, just continue and give back the log ticket.
264              */
265             (((ticket->t_flags & XLOG_TIC_INITED) == 0) &&
266              (xlog_commit_record(mp, ticket,
267                                  (xlog_in_core_t **)iclog, &lsn)))) {
268                 lsn = (xfs_lsn_t) -1;
269                 if (ticket->t_flags & XLOG_TIC_PERM_RESERV) {
270                         flags |= XFS_LOG_REL_PERM_RESERV;
271                 }
272         }
273
274
275         if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) == 0 ||
276             (flags & XFS_LOG_REL_PERM_RESERV)) {
277                 /*
278                  * Release ticket if not permanent reservation or a specifc
279                  * request has been made to release a permanent reservation.
280                  */
281                 xlog_trace_loggrant(log, ticket, "xfs_log_done: (non-permanent)");
282                 xlog_ungrant_log_space(log, ticket);
283                 xlog_state_put_ticket(log, ticket);
284         } else {
285                 xlog_trace_loggrant(log, ticket, "xfs_log_done: (permanent)");
286                 xlog_regrant_reserve_log_space(log, ticket);
287         }
288
289         /* If this ticket was a permanent reservation and we aren't
290          * trying to release it, reset the inited flags; so next time
291          * we write, a start record will be written out.
292          */
293         if ((ticket->t_flags & XLOG_TIC_PERM_RESERV) &&
294             (flags & XFS_LOG_REL_PERM_RESERV) == 0)
295                 ticket->t_flags |= XLOG_TIC_INITED;
296
297         return lsn;
298 }       /* xfs_log_done */
299
300
301 /*
302  * Force the in-core log to disk.  If flags == XFS_LOG_SYNC,
303  *      the force is done synchronously.
304  *
305  * Asynchronous forces are implemented by setting the WANT_SYNC
306  * bit in the appropriate in-core log and then returning.
307  *
308  * Synchronous forces are implemented with a semaphore.  All callers
309  * to force a given lsn to disk will wait on a semaphore attached to the
310  * specific in-core log.  When given in-core log finally completes its
311  * write to disk, that thread will wake up all threads waiting on the
312  * semaphore.
313  */
314 int
315 xfs_log_force(xfs_mount_t *mp,
316               xfs_lsn_t   lsn,
317               uint        flags)
318 {
319         int     rval;
320         xlog_t *log = mp->m_log;
321
322 #if defined(DEBUG) || defined(XLOG_NOLOG)
323         if (!xlog_debug && xlog_target == log->l_targ)
324                 return 0;
325 #endif
326
327         ASSERT(flags & XFS_LOG_FORCE);
328
329         XFS_STATS_INC(xs_log_force);
330
331         if ((log->l_flags & XLOG_IO_ERROR) == 0) {
332                 if (lsn == 0)
333                         rval = xlog_state_sync_all(log, flags);
334                 else
335                         rval = xlog_state_sync(log, lsn, flags);
336         } else {
337                 rval = XFS_ERROR(EIO);
338         }
339
340         return rval;
341
342 }       /* xfs_log_force */
343
344 /*
345  * Attaches a new iclog I/O completion callback routine during
346  * transaction commit.  If the log is in error state, a non-zero
347  * return code is handed back and the caller is responsible for
348  * executing the callback at an appropriate time.
349  */
350 int
351 xfs_log_notify(xfs_mount_t        *mp,          /* mount of partition */
352                void               *iclog_hndl,  /* iclog to hang callback off */
353                xfs_log_callback_t *cb)
354 {
355         xlog_t *log = mp->m_log;
356         xlog_in_core_t    *iclog = (xlog_in_core_t *)iclog_hndl;
357         int     abortflg, spl;
358
359 #if defined(DEBUG) || defined(XLOG_NOLOG)
360         if (!xlog_debug && xlog_target == log->l_targ)
361                 return 0;
362 #endif
363         cb->cb_next = NULL;
364         spl = LOG_LOCK(log);
365         abortflg = (iclog->ic_state & XLOG_STATE_IOERROR);
366         if (!abortflg) {
367                 ASSERT_ALWAYS((iclog->ic_state == XLOG_STATE_ACTIVE) ||
368                               (iclog->ic_state == XLOG_STATE_WANT_SYNC));
369                 cb->cb_next = NULL;
370                 *(iclog->ic_callback_tail) = cb;
371                 iclog->ic_callback_tail = &(cb->cb_next);
372         }
373         LOG_UNLOCK(log, spl);
374         return abortflg;
375 }       /* xfs_log_notify */
376
377 int
378 xfs_log_release_iclog(xfs_mount_t *mp,
379                       void        *iclog_hndl)
380 {
381         xlog_t *log = mp->m_log;
382         xlog_in_core_t    *iclog = (xlog_in_core_t *)iclog_hndl;
383
384         if (xlog_state_release_iclog(log, iclog)) {
385                 xfs_force_shutdown(mp, XFS_LOG_IO_ERROR);
386                 return(EIO);
387         }
388
389         return 0;
390 }
391
392 /*
393  *  1. Reserve an amount of on-disk log space and return a ticket corresponding
394  *      to the reservation.
395  *  2. Potentially, push buffers at tail of log to disk.
396  *
397  * Each reservation is going to reserve extra space for a log record header.
398  * When writes happen to the on-disk log, we don't subtract the length of the
399  * log record header from any reservation.  By wasting space in each
400  * reservation, we prevent over allocation problems.
401  */
402 int
403 xfs_log_reserve(xfs_mount_t      *mp,
404                 int              unit_bytes,
405                 int              cnt,
406                 xfs_log_ticket_t *ticket,
407                 __uint8_t        client,
408                 uint             flags,
409                 uint             t_type)
410 {
411         xlog_t          *log = mp->m_log;
412         xlog_ticket_t   *internal_ticket;
413         int             retval;
414
415 #if defined(DEBUG) || defined(XLOG_NOLOG)
416         if (!xlog_debug && xlog_target == log->l_targ)
417                 return 0;
418 #endif
419         retval = 0;
420         ASSERT(client == XFS_TRANSACTION || client == XFS_LOG);
421         ASSERT((flags & XFS_LOG_NOSLEEP) == 0);
422
423         if (XLOG_FORCED_SHUTDOWN(log))
424                 return XFS_ERROR(EIO);
425
426         XFS_STATS_INC(xs_try_logspace);
427
428         if (*ticket != NULL) {
429                 ASSERT(flags & XFS_LOG_PERM_RESERV);
430                 internal_ticket = (xlog_ticket_t *)*ticket;
431                 xlog_trace_loggrant(log, internal_ticket, "xfs_log_reserve: existing ticket (permanent trans)");
432                 xlog_grant_push_ail(mp, internal_ticket->t_unit_res);
433                 retval = xlog_regrant_write_log_space(log, internal_ticket);
434         } else {
435                 /* may sleep if need to allocate more tickets */
436                 internal_ticket = xlog_ticket_get(log, unit_bytes, cnt,
437                                                   client, flags);
438                 internal_ticket->t_trans_type = t_type;
439                 *ticket = internal_ticket;
440                 xlog_trace_loggrant(log, internal_ticket, 
441                         (internal_ticket->t_flags & XLOG_TIC_PERM_RESERV) ?
442                         "xfs_log_reserve: create new ticket (permanent trans)" :
443                         "xfs_log_reserve: create new ticket");
444                 xlog_grant_push_ail(mp,
445                                     (internal_ticket->t_unit_res *
446                                      internal_ticket->t_cnt));
447                 retval = xlog_grant_log_space(log, internal_ticket);
448         }
449
450         return retval;
451 }       /* xfs_log_reserve */
452
453
454 /*
455  * Mount a log filesystem
456  *
457  * mp           - ubiquitous xfs mount point structure
458  * log_target   - buftarg of on-disk log device
459  * blk_offset   - Start block # where block size is 512 bytes (BBSIZE)
460  * num_bblocks  - Number of BBSIZE blocks in on-disk log
461  *
462  * Return error or zero.
463  */
464 int
465 xfs_log_mount(xfs_mount_t       *mp,
466               xfs_buftarg_t     *log_target,
467               xfs_daddr_t       blk_offset,
468               int               num_bblks)
469 {
470         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
471                 cmn_err(CE_NOTE, "XFS mounting filesystem %s", mp->m_fsname);
472         else {
473                 cmn_err(CE_NOTE,
474                         "!Mounting filesystem \"%s\" in no-recovery mode.  Filesystem will be inconsistent.",
475                         mp->m_fsname);
476                 ASSERT(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY);
477         }
478
479         mp->m_log = xlog_alloc_log(mp, log_target, blk_offset, num_bblks);
480
481 #if defined(DEBUG) || defined(XLOG_NOLOG)
482         if (!xlog_debug) {
483                 cmn_err(CE_NOTE, "log dev: %s", XFS_BUFTARG_NAME(log_target));
484                 return 0;
485         }
486 #endif
487         /*
488          * skip log recovery on a norecovery mount.  pretend it all
489          * just worked.
490          */
491         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY)) {
492                 int     error;
493                 vfs_t   *vfsp = XFS_MTOVFS(mp);
494                 int     readonly = (vfsp->vfs_flag & VFS_RDONLY);
495
496                 if (readonly)
497                         vfsp->vfs_flag &= ~VFS_RDONLY;
498
499                 error = xlog_recover(mp->m_log, readonly);
500
501                 if (readonly)
502                         vfsp->vfs_flag |= VFS_RDONLY;
503                 if (error) {
504                         cmn_err(CE_WARN, "XFS: log mount/recovery failed: error %d", error);
505                         xlog_unalloc_log(mp->m_log);
506                         return error;
507                 }
508         }
509
510         /* Normal transactions can now occur */
511         mp->m_log->l_flags &= ~XLOG_ACTIVE_RECOVERY;
512
513         /* End mounting message in xfs_log_mount_finish */
514         return 0;
515 }       /* xfs_log_mount */
516
517 /*
518  * Finish the recovery of the file system.  This is separate from
519  * the xfs_log_mount() call, because it depends on the code in
520  * xfs_mountfs() to read in the root and real-time bitmap inodes
521  * between calling xfs_log_mount() and here.
522  *
523  * mp           - ubiquitous xfs mount point structure
524  */
525 int
526 xfs_log_mount_finish(xfs_mount_t *mp, int mfsi_flags)
527 {
528         int     error;
529
530         if (!(mp->m_flags & XFS_MOUNT_NORECOVERY))
531                 error = xlog_recover_finish(mp->m_log, mfsi_flags);
532         else {
533                 error = 0;
534                 ASSERT(XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY);
535         }
536
537         return error;
538 }
539
540 /*
541  * Unmount processing for the log.
542  */
543 int
544 xfs_log_unmount(xfs_mount_t *mp)
545 {
546         int             error;
547
548         error = xfs_log_unmount_write(mp);
549         xfs_log_unmount_dealloc(mp);
550         return (error);
551 }
552
553 /*
554  * Final log writes as part of unmount.
555  *
556  * Mark the filesystem clean as unmount happens.  Note that during relocation
557  * this routine needs to be executed as part of source-bag while the
558  * deallocation must not be done until source-end.
559  */
560
561 /*
562  * Unmount record used to have a string "Unmount filesystem--" in the
563  * data section where the "Un" was really a magic number (XLOG_UNMOUNT_TYPE).
564  * We just write the magic number now since that particular field isn't
565  * currently architecture converted and "nUmount" is a bit foo.
566  * As far as I know, there weren't any dependencies on the old behaviour.
567  */
568
569 int
570 xfs_log_unmount_write(xfs_mount_t *mp)
571 {
572         xlog_t           *log = mp->m_log;
573         xlog_in_core_t   *iclog;
574 #ifdef DEBUG
575         xlog_in_core_t   *first_iclog;
576 #endif
577         xfs_log_iovec_t  reg[1];
578         xfs_log_ticket_t tic = NULL;
579         xfs_lsn_t        lsn;
580         int              error;
581         SPLDECL(s);
582
583         /* the data section must be 32 bit size aligned */
584         struct {
585             __uint16_t magic;
586             __uint16_t pad1;
587             __uint32_t pad2; /* may as well make it 64 bits */
588         } magic = { XLOG_UNMOUNT_TYPE, 0, 0 };
589
590 #if defined(DEBUG) || defined(XLOG_NOLOG)
591         if (!xlog_debug && xlog_target == log->l_targ)
592                 return 0;
593 #endif
594
595         /*
596          * Don't write out unmount record on read-only mounts.
597          * Or, if we are doing a forced umount (typically because of IO errors).
598          */
599         if (XFS_MTOVFS(mp)->vfs_flag & VFS_RDONLY)
600                 return 0;
601
602         xfs_log_force(mp, 0, XFS_LOG_FORCE|XFS_LOG_SYNC);
603
604 #ifdef DEBUG
605         first_iclog = iclog = log->l_iclog;
606         do {
607                 if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
608                         ASSERT(iclog->ic_state & XLOG_STATE_ACTIVE);
609                         ASSERT(iclog->ic_offset == 0);
610                 }
611                 iclog = iclog->ic_next;
612         } while (iclog != first_iclog);
613 #endif
614         if (! (XLOG_FORCED_SHUTDOWN(log))) {
615                 reg[0].i_addr = (void*)&magic;
616                 reg[0].i_len  = sizeof(magic);
617                 XLOG_VEC_SET_TYPE(&reg[0], XLOG_REG_TYPE_UNMOUNT);
618
619                 error = xfs_log_reserve(mp, 600, 1, &tic, XFS_LOG, 0, 0);
620                 if (!error) {
621                         /* remove inited flag */
622                         ((xlog_ticket_t *)tic)->t_flags = 0;
623                         error = xlog_write(mp, reg, 1, tic, &lsn,
624                                            NULL, XLOG_UNMOUNT_TRANS);
625                         /*
626                          * At this point, we're umounting anyway,
627                          * so there's no point in transitioning log state
628                          * to IOERROR. Just continue...
629                          */
630                 }
631
632                 if (error) {
633                         xfs_fs_cmn_err(CE_ALERT, mp,
634                                 "xfs_log_unmount: unmount record failed");
635                 }
636
637
638                 s = LOG_LOCK(log);
639                 iclog = log->l_iclog;
640                 iclog->ic_refcnt++;
641                 LOG_UNLOCK(log, s);
642                 xlog_state_want_sync(log, iclog);
643                 (void) xlog_state_release_iclog(log, iclog);
644
645                 s = LOG_LOCK(log);
646                 if (!(iclog->ic_state == XLOG_STATE_ACTIVE ||
647                       iclog->ic_state == XLOG_STATE_DIRTY)) {
648                         if (!XLOG_FORCED_SHUTDOWN(log)) {
649                                 sv_wait(&iclog->ic_forcesema, PMEM,
650                                         &log->l_icloglock, s);
651                         } else {
652                                 LOG_UNLOCK(log, s);
653                         }
654                 } else {
655                         LOG_UNLOCK(log, s);
656                 }
657                 if (tic)
658                         xlog_state_put_ticket(log, tic);
659         } else {
660                 /*
661                  * We're already in forced_shutdown mode, couldn't
662                  * even attempt to write out the unmount transaction.
663                  *
664                  * Go through the motions of sync'ing and releasing
665                  * the iclog, even though no I/O will actually happen,
666                  * we need to wait for other log I/O's that may already
667                  * be in progress.  Do this as a separate section of
668                  * code so we'll know if we ever get stuck here that
669                  * we're in this odd situation of trying to unmount
670                  * a file system that went into forced_shutdown as
671                  * the result of an unmount..
672                  */
673                 s = LOG_LOCK(log);
674                 iclog = log->l_iclog;
675                 iclog->ic_refcnt++;
676                 LOG_UNLOCK(log, s);
677
678                 xlog_state_want_sync(log, iclog);
679                 (void) xlog_state_release_iclog(log, iclog);
680
681                 s = LOG_LOCK(log);
682
683                 if ( ! (   iclog->ic_state == XLOG_STATE_ACTIVE
684                         || iclog->ic_state == XLOG_STATE_DIRTY
685                         || iclog->ic_state == XLOG_STATE_IOERROR) ) {
686
687                                 sv_wait(&iclog->ic_forcesema, PMEM,
688                                         &log->l_icloglock, s);
689                 } else {
690                         LOG_UNLOCK(log, s);
691                 }
692         }
693
694         return 0;
695 }       /* xfs_log_unmount_write */
696
697 /*
698  * Deallocate log structures for unmount/relocation.
699  */
700 void
701 xfs_log_unmount_dealloc(xfs_mount_t *mp)
702 {
703         xlog_unalloc_log(mp->m_log);
704 }
705
706 /*
707  * Write region vectors to log.  The write happens using the space reservation
708  * of the ticket (tic).  It is not a requirement that all writes for a given
709  * transaction occur with one call to xfs_log_write().
710  */
711 int
712 xfs_log_write(xfs_mount_t *     mp,
713               xfs_log_iovec_t   reg[],
714               int               nentries,
715               xfs_log_ticket_t  tic,
716               xfs_lsn_t         *start_lsn)
717 {
718         int     error;
719         xlog_t *log = mp->m_log;
720
721 #if defined(DEBUG) || defined(XLOG_NOLOG)
722         if (!xlog_debug && xlog_target == log->l_targ) {
723                 *start_lsn = 0;
724                 return 0;
725         }
726 #endif
727         if (XLOG_FORCED_SHUTDOWN(log))
728                 return XFS_ERROR(EIO);
729
730         if ((error = xlog_write(mp, reg, nentries, tic, start_lsn, NULL, 0))) {
731                 xfs_force_shutdown(mp, XFS_LOG_IO_ERROR);
732         }
733         return (error);
734 }       /* xfs_log_write */
735
736
737 void
738 xfs_log_move_tail(xfs_mount_t   *mp,
739                   xfs_lsn_t     tail_lsn)
740 {
741         xlog_ticket_t   *tic;
742         xlog_t          *log = mp->m_log;
743         int             need_bytes, free_bytes, cycle, bytes;
744         SPLDECL(s);
745
746 #if defined(DEBUG) || defined(XLOG_NOLOG)
747         if (!xlog_debug && xlog_target == log->l_targ)
748                 return;
749 #endif
750         /* XXXsup tmp */
751         if (XLOG_FORCED_SHUTDOWN(log))
752                 return;
753         ASSERT(!XFS_FORCED_SHUTDOWN(mp));
754
755         if (tail_lsn == 0) {
756                 /* needed since sync_lsn is 64 bits */
757                 s = LOG_LOCK(log);
758                 tail_lsn = log->l_last_sync_lsn;
759                 LOG_UNLOCK(log, s);
760         }
761
762         s = GRANT_LOCK(log);
763
764         /* Also an invalid lsn.  1 implies that we aren't passing in a valid
765          * tail_lsn.
766          */
767         if (tail_lsn != 1) {
768                 log->l_tail_lsn = tail_lsn;
769         }
770
771         if ((tic = log->l_write_headq)) {
772 #ifdef DEBUG
773                 if (log->l_flags & XLOG_ACTIVE_RECOVERY)
774                         panic("Recovery problem");
775 #endif
776                 cycle = log->l_grant_write_cycle;
777                 bytes = log->l_grant_write_bytes;
778                 free_bytes = xlog_space_left(log, cycle, bytes);
779                 do {
780                         ASSERT(tic->t_flags & XLOG_TIC_PERM_RESERV);
781
782                         if (free_bytes < tic->t_unit_res && tail_lsn != 1)
783                                 break;
784                         tail_lsn = 0;
785                         free_bytes -= tic->t_unit_res;
786                         sv_signal(&tic->t_sema);
787                         tic = tic->t_next;
788                 } while (tic != log->l_write_headq);
789         }
790         if ((tic = log->l_reserve_headq)) {
791 #ifdef DEBUG
792                 if (log->l_flags & XLOG_ACTIVE_RECOVERY)
793                         panic("Recovery problem");
794 #endif
795                 cycle = log->l_grant_reserve_cycle;
796                 bytes = log->l_grant_reserve_bytes;
797                 free_bytes = xlog_space_left(log, cycle, bytes);
798                 do {
799                         if (tic->t_flags & XLOG_TIC_PERM_RESERV)
800                                 need_bytes = tic->t_unit_res*tic->t_cnt;
801                         else
802                                 need_bytes = tic->t_unit_res;
803                         if (free_bytes < need_bytes && tail_lsn != 1)
804                                 break;
805                         tail_lsn = 0;
806                         free_bytes -= need_bytes;
807                         sv_signal(&tic->t_sema);
808                         tic = tic->t_next;
809                 } while (tic != log->l_reserve_headq);
810         }
811         GRANT_UNLOCK(log, s);
812 }       /* xfs_log_move_tail */
813
814 /*
815  * Determine if we have a transaction that has gone to disk
816  * that needs to be covered. Log activity needs to be idle (no AIL and
817  * nothing in the iclogs). And, we need to be in the right state indicating
818  * something has gone out.
819  */
820 int
821 xfs_log_need_covered(xfs_mount_t *mp)
822 {
823         SPLDECL(s);
824         int             needed = 0, gen;
825         xlog_t          *log = mp->m_log;
826         vfs_t           *vfsp = XFS_MTOVFS(mp);
827
828         if (fs_frozen(vfsp) || XFS_FORCED_SHUTDOWN(mp) ||
829             (vfsp->vfs_flag & VFS_RDONLY))
830                 return 0;
831
832         s = LOG_LOCK(log);
833         if (((log->l_covered_state == XLOG_STATE_COVER_NEED) ||
834                 (log->l_covered_state == XLOG_STATE_COVER_NEED2))
835                         && !xfs_trans_first_ail(mp, &gen)
836                         && xlog_iclogs_empty(log)) {
837                 if (log->l_covered_state == XLOG_STATE_COVER_NEED)
838                         log->l_covered_state = XLOG_STATE_COVER_DONE;
839                 else {
840                         ASSERT(log->l_covered_state == XLOG_STATE_COVER_NEED2);
841                         log->l_covered_state = XLOG_STATE_COVER_DONE2;
842                 }
843                 needed = 1;
844         }
845         LOG_UNLOCK(log, s);
846         return(needed);
847 }
848
849 /******************************************************************************
850  *
851  *      local routines
852  *
853  ******************************************************************************
854  */
855
856 /* xfs_trans_tail_ail returns 0 when there is nothing in the list.
857  * The log manager must keep track of the last LR which was committed
858  * to disk.  The lsn of this LR will become the new tail_lsn whenever
859  * xfs_trans_tail_ail returns 0.  If we don't do this, we run into
860  * the situation where stuff could be written into the log but nothing
861  * was ever in the AIL when asked.  Eventually, we panic since the
862  * tail hits the head.
863  *
864  * We may be holding the log iclog lock upon entering this routine.
865  */
866 xfs_lsn_t
867 xlog_assign_tail_lsn(xfs_mount_t *mp)
868 {
869         xfs_lsn_t tail_lsn;
870         SPLDECL(s);
871         xlog_t    *log = mp->m_log;
872
873         tail_lsn = xfs_trans_tail_ail(mp);
874         s = GRANT_LOCK(log);
875         if (tail_lsn != 0) {
876                 log->l_tail_lsn = tail_lsn;
877         } else {
878                 tail_lsn = log->l_tail_lsn = log->l_last_sync_lsn;
879         }
880         GRANT_UNLOCK(log, s);
881
882         return tail_lsn;
883 }       /* xlog_assign_tail_lsn */
884
885
886 /*
887  * Return the space in the log between the tail and the head.  The head
888  * is passed in the cycle/bytes formal parms.  In the special case where
889  * the reserve head has wrapped passed the tail, this calculation is no
890  * longer valid.  In this case, just return 0 which means there is no space
891  * in the log.  This works for all places where this function is called
892  * with the reserve head.  Of course, if the write head were to ever
893  * wrap the tail, we should blow up.  Rather than catch this case here,
894  * we depend on other ASSERTions in other parts of the code.   XXXmiken
895  *
896  * This code also handles the case where the reservation head is behind
897  * the tail.  The details of this case are described below, but the end
898  * result is that we return the size of the log as the amount of space left.
899  */
900 int
901 xlog_space_left(xlog_t *log, int cycle, int bytes)
902 {
903         int free_bytes;
904         int tail_bytes;
905         int tail_cycle;
906
907         tail_bytes = BBTOB(BLOCK_LSN(log->l_tail_lsn));
908         tail_cycle = CYCLE_LSN(log->l_tail_lsn);
909         if ((tail_cycle == cycle) && (bytes >= tail_bytes)) {
910                 free_bytes = log->l_logsize - (bytes - tail_bytes);
911         } else if ((tail_cycle + 1) < cycle) {
912                 return 0;
913         } else if (tail_cycle < cycle) {
914                 ASSERT(tail_cycle == (cycle - 1));
915                 free_bytes = tail_bytes - bytes;
916         } else {
917                 /*
918                  * The reservation head is behind the tail.
919                  * In this case we just want to return the size of the
920                  * log as the amount of space left.
921                  */
922                 xfs_fs_cmn_err(CE_ALERT, log->l_mp,
923                         "xlog_space_left: head behind tail\n"
924                         "  tail_cycle = %d, tail_bytes = %d\n"
925                         "  GH   cycle = %d, GH   bytes = %d",
926                         tail_cycle, tail_bytes, cycle, bytes);
927                 ASSERT(0);
928                 free_bytes = log->l_logsize;
929         }
930         return free_bytes;
931 }       /* xlog_space_left */
932
933
934 /*
935  * Log function which is called when an io completes.
936  *
937  * The log manager needs its own routine, in order to control what
938  * happens with the buffer after the write completes.
939  */
940 void
941 xlog_iodone(xfs_buf_t *bp)
942 {
943         xlog_in_core_t  *iclog;
944         xlog_t          *l;
945         int             aborted;
946
947         iclog = XFS_BUF_FSPRIVATE(bp, xlog_in_core_t *);
948         ASSERT(XFS_BUF_FSPRIVATE2(bp, unsigned long) == (unsigned long) 2);
949         XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
950         aborted = 0;
951
952         /*
953          * Some versions of cpp barf on the recursive definition of
954          * ic_log -> hic_fields.ic_log and expand ic_log twice when
955          * it is passed through two macros.  Workaround broken cpp.
956          */
957         l = iclog->ic_log;
958
959         /*
960          * Race to shutdown the filesystem if we see an error.
961          */
962         if (XFS_TEST_ERROR((XFS_BUF_GETERROR(bp)), l->l_mp,
963                         XFS_ERRTAG_IODONE_IOERR, XFS_RANDOM_IODONE_IOERR)) {
964                 xfs_ioerror_alert("xlog_iodone", l->l_mp, bp, XFS_BUF_ADDR(bp));
965                 XFS_BUF_STALE(bp);
966                 xfs_force_shutdown(l->l_mp, XFS_LOG_IO_ERROR);
967                 /*
968                  * This flag will be propagated to the trans-committed
969                  * callback routines to let them know that the log-commit
970                  * didn't succeed.
971                  */
972                 aborted = XFS_LI_ABORTED;
973         } else if (iclog->ic_state & XLOG_STATE_IOERROR) {
974                 aborted = XFS_LI_ABORTED;
975         }
976         xlog_state_done_syncing(iclog, aborted);
977         if (!(XFS_BUF_ISASYNC(bp))) {
978                 /*
979                  * Corresponding psema() will be done in bwrite().  If we don't
980                  * vsema() here, panic.
981                  */
982                 XFS_BUF_V_IODONESEMA(bp);
983         }
984 }       /* xlog_iodone */
985
986 /*
987  * The bdstrat callback function for log bufs. This gives us a central
988  * place to trap bufs in case we get hit by a log I/O error and need to
989  * shutdown. Actually, in practice, even when we didn't get a log error,
990  * we transition the iclogs to IOERROR state *after* flushing all existing
991  * iclogs to disk. This is because we don't want anymore new transactions to be
992  * started or completed afterwards.
993  */
994 STATIC int
995 xlog_bdstrat_cb(struct xfs_buf *bp)
996 {
997         xlog_in_core_t *iclog;
998
999         iclog = XFS_BUF_FSPRIVATE(bp, xlog_in_core_t *);
1000
1001         if ((iclog->ic_state & XLOG_STATE_IOERROR) == 0) {
1002           /* note for irix bstrat will need  struct bdevsw passed
1003            * Fix the following macro if the code ever is merged
1004            */
1005             XFS_bdstrat(bp);
1006                 return 0;
1007         }
1008
1009         xfs_buftrace("XLOG__BDSTRAT IOERROR", bp);
1010         XFS_BUF_ERROR(bp, EIO);
1011         XFS_BUF_STALE(bp);
1012         xfs_biodone(bp);
1013         return (XFS_ERROR(EIO));
1014
1015
1016 }
1017
1018 /*
1019  * Return size of each in-core log record buffer.
1020  *
1021  * Low memory machines only get 2 16KB buffers.  We don't want to waste
1022  * memory here.  However, all other machines get at least 2 32KB buffers.
1023  * The number is hard coded because we don't care about the minimum
1024  * memory size, just 32MB systems.
1025  *
1026  * If the filesystem blocksize is too large, we may need to choose a
1027  * larger size since the directory code currently logs entire blocks.
1028  */
1029
1030 STATIC void
1031 xlog_get_iclog_buffer_size(xfs_mount_t  *mp,
1032                            xlog_t       *log)
1033 {
1034         int size;
1035         int xhdrs;
1036
1037 #if defined(DEBUG) || defined(XLOG_NOLOG)
1038         /*
1039          * When logbufs == 0, someone has disabled the log from the FSTAB
1040          * file.  This is not a documented feature.  We need to set xlog_debug
1041          * to zero (this deactivates the log) and set xlog_target to the
1042          * appropriate device.  Only one filesystem may be affected as such
1043          * since this is just a performance hack to test what we might be able
1044          * to get if the log were not present.
1045          */
1046         if (mp->m_logbufs == 0) {
1047                 xlog_debug = 0;
1048                 xlog_target = log->l_targ;
1049                 log->l_iclog_bufs = XLOG_MIN_ICLOGS;
1050         } else
1051 #endif
1052         {
1053                 /*
1054                  * This is the normal path.  If m_logbufs == -1, then the
1055                  * admin has chosen to use the system defaults for logbuffers.
1056                  */
1057                 if (mp->m_logbufs == -1) { 
1058                         if (xfs_physmem <= btoc(128*1024*1024)) { 
1059                                 log->l_iclog_bufs = XLOG_MIN_ICLOGS; 
1060                         } else if (xfs_physmem <= btoc(400*1024*1024)) { 
1061                                 log->l_iclog_bufs = XLOG_MED_ICLOGS; 
1062                         } else {
1063                                 /* 256K with 32K bufs */
1064                                 log->l_iclog_bufs = XLOG_MAX_ICLOGS;
1065                         }
1066                 } else
1067                         log->l_iclog_bufs = mp->m_logbufs;
1068
1069 #if defined(DEBUG) || defined(XLOG_NOLOG)
1070                 /* We are reactivating a filesystem after it was inactive */
1071                 if (log->l_targ == xlog_target) {
1072                         xlog_target = NULL;
1073                         xlog_debug = 1;
1074                 }
1075 #endif
1076         }
1077
1078         /*
1079          * Buffer size passed in from mount system call.
1080          */
1081         if (mp->m_logbsize != -1) {
1082                 size = log->l_iclog_size = mp->m_logbsize;
1083                 log->l_iclog_size_log = 0;
1084                 while (size != 1) {
1085                         log->l_iclog_size_log++;
1086                         size >>= 1;
1087                 }
1088
1089                 if (XFS_SB_VERSION_HASLOGV2(&mp->m_sb)) {
1090                         /* # headers = size / 32K
1091                          * one header holds cycles from 32K of data
1092                          */
1093
1094                         xhdrs = mp->m_logbsize / XLOG_HEADER_CYCLE_SIZE;
1095                         if (mp->m_logbsize % XLOG_HEADER_CYCLE_SIZE)
1096                                 xhdrs++;
1097                         log->l_iclog_hsize = xhdrs << BBSHIFT;
1098                         log->l_iclog_heads = xhdrs;
1099                 } else {
1100                         ASSERT(mp->m_logbsize <= XLOG_BIG_RECORD_BSIZE);
1101                         log->l_iclog_hsize = BBSIZE;
1102                         log->l_iclog_heads = 1;
1103                 }
1104                 return;
1105         }
1106
1107         /*
1108          * Special case machines that have less than 32MB of memory.
1109          * All machines with more memory use 32KB buffers.
1110          */
1111         if (xfs_physmem <= btoc(32*1024*1024)) {
1112                 /* Don't change; min configuration */
1113                 log->l_iclog_size = XLOG_RECORD_BSIZE;          /* 16k */
1114                 log->l_iclog_size_log = XLOG_RECORD_BSHIFT;
1115         } else {
1116                 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;      /* 32k */
1117                 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1118         }
1119
1120         /* the default log size is 16k or 32k which is one header sector */
1121         log->l_iclog_hsize = BBSIZE;
1122         log->l_iclog_heads = 1;
1123
1124         /*
1125          * For 16KB, we use 3 32KB buffers.  For 32KB block sizes, we use
1126          * 4 32KB buffers.  For 64KB block sizes, we use 8 32KB buffers.
1127          */
1128         if (mp->m_sb.sb_blocksize >= 16*1024) {
1129                 log->l_iclog_size = XLOG_BIG_RECORD_BSIZE;
1130                 log->l_iclog_size_log = XLOG_BIG_RECORD_BSHIFT;
1131                 if (mp->m_logbufs == -1) {
1132                         switch (mp->m_sb.sb_blocksize) {
1133                             case 16*1024:                       /* 16 KB */
1134                                 log->l_iclog_bufs = 3;
1135                                 break;
1136                             case 32*1024:                       /* 32 KB */
1137                                 log->l_iclog_bufs = 4;
1138                                 break;
1139                             case 64*1024:                       /* 64 KB */
1140                                 log->l_iclog_bufs = 8;
1141                                 break;
1142                             default:
1143                                 xlog_panic("XFS: Invalid blocksize");
1144                                 break;
1145                         }
1146                 }
1147         }
1148 }       /* xlog_get_iclog_buffer_size */
1149
1150
1151 /*
1152  * This routine initializes some of the log structure for a given mount point.
1153  * Its primary purpose is to fill in enough, so recovery can occur.  However,
1154  * some other stuff may be filled in too.
1155  */
1156 STATIC xlog_t *
1157 xlog_alloc_log(xfs_mount_t      *mp,
1158                xfs_buftarg_t    *log_target,
1159                xfs_daddr_t      blk_offset,
1160                int              num_bblks)
1161 {
1162         xlog_t                  *log;
1163         xlog_rec_header_t       *head;
1164         xlog_in_core_t          **iclogp;
1165         xlog_in_core_t          *iclog, *prev_iclog=NULL;
1166         xfs_buf_t               *bp;
1167         int                     i;
1168         int                     iclogsize;
1169
1170         log = (xlog_t *)kmem_zalloc(sizeof(xlog_t), KM_SLEEP);
1171
1172         log->l_mp          = mp;
1173         log->l_targ        = log_target;
1174         log->l_logsize     = BBTOB(num_bblks);
1175         log->l_logBBstart  = blk_offset;
1176         log->l_logBBsize   = num_bblks;
1177         log->l_covered_state = XLOG_STATE_COVER_IDLE;
1178         log->l_flags       |= XLOG_ACTIVE_RECOVERY;
1179
1180         log->l_prev_block  = -1;
1181         ASSIGN_ANY_LSN_HOST(log->l_tail_lsn, 1, 0);
1182         /* log->l_tail_lsn = 0x100000000LL; cycle = 1; current block = 0 */
1183         log->l_last_sync_lsn = log->l_tail_lsn;
1184         log->l_curr_cycle  = 1;     /* 0 is bad since this is initial value */
1185         log->l_grant_reserve_cycle = 1;
1186         log->l_grant_write_cycle = 1;
1187
1188         if (XFS_SB_VERSION_HASSECTOR(&mp->m_sb)) {
1189                 log->l_sectbb_log = mp->m_sb.sb_logsectlog - BBSHIFT;
1190                 ASSERT(log->l_sectbb_log <= mp->m_sectbb_log);
1191                 /* for larger sector sizes, must have v2 or external log */
1192                 ASSERT(log->l_sectbb_log == 0 ||
1193                         log->l_logBBstart == 0 ||
1194                         XFS_SB_VERSION_HASLOGV2(&mp->m_sb));
1195                 ASSERT(mp->m_sb.sb_logsectlog >= BBSHIFT);
1196         }
1197         log->l_sectbb_mask = (1 << log->l_sectbb_log) - 1;
1198
1199         xlog_get_iclog_buffer_size(mp, log);
1200
1201         bp = xfs_buf_get_empty(log->l_iclog_size, mp->m_logdev_targp);
1202         XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
1203         XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);
1204         XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
1205         ASSERT(XFS_BUF_ISBUSY(bp));
1206         ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
1207         log->l_xbuf = bp;
1208
1209         spinlock_init(&log->l_icloglock, "iclog");
1210         spinlock_init(&log->l_grant_lock, "grhead_iclog");
1211         initnsema(&log->l_flushsema, 0, "ic-flush");
1212         xlog_state_ticket_alloc(log);  /* wait until after icloglock inited */
1213
1214         /* log record size must be multiple of BBSIZE; see xlog_rec_header_t */
1215         ASSERT((XFS_BUF_SIZE(bp) & BBMASK) == 0);
1216
1217         iclogp = &log->l_iclog;
1218         /*
1219          * The amount of memory to allocate for the iclog structure is
1220          * rather funky due to the way the structure is defined.  It is
1221          * done this way so that we can use different sizes for machines
1222          * with different amounts of memory.  See the definition of
1223          * xlog_in_core_t in xfs_log_priv.h for details.
1224          */
1225         iclogsize = log->l_iclog_size;
1226         ASSERT(log->l_iclog_size >= 4096);
1227         for (i=0; i < log->l_iclog_bufs; i++) {
1228                 *iclogp = (xlog_in_core_t *)
1229                           kmem_zalloc(sizeof(xlog_in_core_t), KM_SLEEP);
1230                 iclog = *iclogp;
1231                 iclog->hic_data = (xlog_in_core_2_t *)
1232                           kmem_zalloc(iclogsize, KM_SLEEP);
1233
1234                 iclog->ic_prev = prev_iclog;
1235                 prev_iclog = iclog;
1236                 log->l_iclog_bak[i] = (xfs_caddr_t)&(iclog->ic_header);
1237
1238                 head = &iclog->ic_header;
1239                 memset(head, 0, sizeof(xlog_rec_header_t));
1240                 INT_SET(head->h_magicno, ARCH_CONVERT, XLOG_HEADER_MAGIC_NUM);
1241                 INT_SET(head->h_version, ARCH_CONVERT,
1242                         XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) ? 2 : 1);
1243                 INT_SET(head->h_size, ARCH_CONVERT, log->l_iclog_size);
1244                 /* new fields */
1245                 INT_SET(head->h_fmt, ARCH_CONVERT, XLOG_FMT);
1246                 memcpy(&head->h_fs_uuid, &mp->m_sb.sb_uuid, sizeof(uuid_t));
1247
1248                 bp = xfs_buf_get_empty(log->l_iclog_size, mp->m_logdev_targp);
1249                 XFS_BUF_SET_IODONE_FUNC(bp, xlog_iodone);
1250                 XFS_BUF_SET_BDSTRAT_FUNC(bp, xlog_bdstrat_cb);
1251                 XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)1);
1252                 iclog->ic_bp = bp;
1253
1254                 iclog->ic_size = XFS_BUF_SIZE(bp) - log->l_iclog_hsize;
1255                 iclog->ic_state = XLOG_STATE_ACTIVE;
1256                 iclog->ic_log = log;
1257                 iclog->ic_callback_tail = &(iclog->ic_callback);
1258                 iclog->ic_datap = (char *)iclog->hic_data + log->l_iclog_hsize;
1259
1260                 ASSERT(XFS_BUF_ISBUSY(iclog->ic_bp));
1261                 ASSERT(XFS_BUF_VALUSEMA(iclog->ic_bp) <= 0);
1262                 sv_init(&iclog->ic_forcesema, SV_DEFAULT, "iclog-force");
1263                 sv_init(&iclog->ic_writesema, SV_DEFAULT, "iclog-write");
1264
1265                 iclogp = &iclog->ic_next;
1266         }
1267         *iclogp = log->l_iclog;                 /* complete ring */
1268         log->l_iclog->ic_prev = prev_iclog;     /* re-write 1st prev ptr */
1269
1270         return log;
1271 }       /* xlog_alloc_log */
1272
1273
1274 /*
1275  * Write out the commit record of a transaction associated with the given
1276  * ticket.  Return the lsn of the commit record.
1277  */
1278 STATIC int
1279 xlog_commit_record(xfs_mount_t  *mp,
1280                    xlog_ticket_t *ticket,
1281                    xlog_in_core_t **iclog,
1282                    xfs_lsn_t    *commitlsnp)
1283 {
1284         int             error;
1285         xfs_log_iovec_t reg[1];
1286
1287         reg[0].i_addr = NULL;
1288         reg[0].i_len = 0;
1289         XLOG_VEC_SET_TYPE(&reg[0], XLOG_REG_TYPE_COMMIT);
1290
1291         ASSERT_ALWAYS(iclog);
1292         if ((error = xlog_write(mp, reg, 1, ticket, commitlsnp,
1293                                iclog, XLOG_COMMIT_TRANS))) {
1294                 xfs_force_shutdown(mp, XFS_LOG_IO_ERROR);
1295         }
1296         return (error);
1297 }       /* xlog_commit_record */
1298
1299
1300 /*
1301  * Push on the buffer cache code if we ever use more than 75% of the on-disk
1302  * log space.  This code pushes on the lsn which would supposedly free up
1303  * the 25% which we want to leave free.  We may need to adopt a policy which
1304  * pushes on an lsn which is further along in the log once we reach the high
1305  * water mark.  In this manner, we would be creating a low water mark.
1306  */
1307 void
1308 xlog_grant_push_ail(xfs_mount_t *mp,
1309                     int         need_bytes)
1310 {
1311     xlog_t      *log = mp->m_log;       /* pointer to the log */
1312     xfs_lsn_t   tail_lsn;               /* lsn of the log tail */
1313     xfs_lsn_t   threshold_lsn = 0;      /* lsn we'd like to be at */
1314     int         free_blocks;            /* free blocks left to write to */
1315     int         free_bytes;             /* free bytes left to write to */
1316     int         threshold_block;        /* block in lsn we'd like to be at */
1317     int         threshold_cycle;        /* lsn cycle we'd like to be at */
1318     int         free_threshold;
1319     SPLDECL(s);
1320
1321     ASSERT(BTOBB(need_bytes) < log->l_logBBsize);
1322
1323     s = GRANT_LOCK(log);
1324     free_bytes = xlog_space_left(log,
1325                                  log->l_grant_reserve_cycle,
1326                                  log->l_grant_reserve_bytes);
1327     tail_lsn = log->l_tail_lsn;
1328     free_blocks = BTOBBT(free_bytes);
1329
1330     /*
1331      * Set the threshold for the minimum number of free blocks in the
1332      * log to the maximum of what the caller needs, one quarter of the
1333      * log, and 256 blocks.
1334      */
1335     free_threshold = BTOBB(need_bytes);
1336     free_threshold = MAX(free_threshold, (log->l_logBBsize >> 2));
1337     free_threshold = MAX(free_threshold, 256);
1338     if (free_blocks < free_threshold) {
1339         threshold_block = BLOCK_LSN(tail_lsn) + free_threshold;
1340         threshold_cycle = CYCLE_LSN(tail_lsn);
1341         if (threshold_block >= log->l_logBBsize) {
1342             threshold_block -= log->l_logBBsize;
1343             threshold_cycle += 1;
1344         }
1345         ASSIGN_ANY_LSN_HOST(threshold_lsn, threshold_cycle,
1346                        threshold_block);
1347
1348         /* Don't pass in an lsn greater than the lsn of the last
1349          * log record known to be on disk.
1350          */
1351         if (XFS_LSN_CMP(threshold_lsn, log->l_last_sync_lsn) > 0)
1352             threshold_lsn = log->l_last_sync_lsn;
1353     }
1354     GRANT_UNLOCK(log, s);
1355
1356     /*
1357      * Get the transaction layer to kick the dirty buffers out to
1358      * disk asynchronously. No point in trying to do this if
1359      * the filesystem is shutting down.
1360      */
1361     if (threshold_lsn &&
1362         !XLOG_FORCED_SHUTDOWN(log))
1363             xfs_trans_push_ail(mp, threshold_lsn);
1364 }       /* xlog_grant_push_ail */
1365
1366
1367 /*
1368  * Flush out the in-core log (iclog) to the on-disk log in an asynchronous 
1369  * fashion.  Previously, we should have moved the current iclog
1370  * ptr in the log to point to the next available iclog.  This allows further
1371  * write to continue while this code syncs out an iclog ready to go.
1372  * Before an in-core log can be written out, the data section must be scanned
1373  * to save away the 1st word of each BBSIZE block into the header.  We replace
1374  * it with the current cycle count.  Each BBSIZE block is tagged with the
1375  * cycle count because there in an implicit assumption that drives will
1376  * guarantee that entire 512 byte blocks get written at once.  In other words,
1377  * we can't have part of a 512 byte block written and part not written.  By
1378  * tagging each block, we will know which blocks are valid when recovering
1379  * after an unclean shutdown.
1380  *
1381  * This routine is single threaded on the iclog.  No other thread can be in
1382  * this routine with the same iclog.  Changing contents of iclog can there-
1383  * fore be done without grabbing the state machine lock.  Updating the global
1384  * log will require grabbing the lock though.
1385  *
1386  * The entire log manager uses a logical block numbering scheme.  Only
1387  * log_sync (and then only bwrite()) know about the fact that the log may
1388  * not start with block zero on a given device.  The log block start offset
1389  * is added immediately before calling bwrite().
1390  */
1391
1392 int
1393 xlog_sync(xlog_t                *log,
1394           xlog_in_core_t        *iclog)
1395 {
1396         xfs_caddr_t     dptr;           /* pointer to byte sized element */
1397         xfs_buf_t       *bp;
1398         int             i, ops;
1399         uint            count;          /* byte count of bwrite */
1400         uint            count_init;     /* initial count before roundup */
1401         int             roundoff;       /* roundoff to BB or stripe */
1402         int             split = 0;      /* split write into two regions */
1403         int             error;
1404         SPLDECL(s);
1405         int             v2 = XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb);
1406
1407         XFS_STATS_INC(xs_log_writes);
1408         ASSERT(iclog->ic_refcnt == 0);
1409
1410         /* Add for LR header */
1411         count_init = log->l_iclog_hsize + iclog->ic_offset;
1412
1413         /* Round out the log write size */
1414         if (v2 && log->l_mp->m_sb.sb_logsunit > 1) {
1415                 /* we have a v2 stripe unit to use */
1416                 count = XLOG_LSUNITTOB(log, XLOG_BTOLSUNIT(log, count_init));
1417         } else {
1418                 count = BBTOB(BTOBB(count_init));
1419         }
1420         roundoff = count - count_init;
1421         ASSERT(roundoff >= 0);
1422         ASSERT((v2 && log->l_mp->m_sb.sb_logsunit > 1 && 
1423                 roundoff < log->l_mp->m_sb.sb_logsunit)
1424                 || 
1425                 (log->l_mp->m_sb.sb_logsunit <= 1 && 
1426                  roundoff < BBTOB(1)));
1427
1428         /* move grant heads by roundoff in sync */
1429         s = GRANT_LOCK(log);
1430         XLOG_GRANT_ADD_SPACE(log, roundoff, 'w');
1431         XLOG_GRANT_ADD_SPACE(log, roundoff, 'r');
1432         GRANT_UNLOCK(log, s);
1433
1434         /* put cycle number in every block */
1435         xlog_pack_data(log, iclog, roundoff); 
1436
1437         /* real byte length */
1438         if (v2) {
1439                 INT_SET(iclog->ic_header.h_len, 
1440                         ARCH_CONVERT,
1441                         iclog->ic_offset + roundoff);
1442         } else {
1443                 INT_SET(iclog->ic_header.h_len, ARCH_CONVERT, iclog->ic_offset);
1444         }
1445
1446         /* put ops count in correct order */
1447         ops = iclog->ic_header.h_num_logops;
1448         INT_SET(iclog->ic_header.h_num_logops, ARCH_CONVERT, ops);
1449
1450         bp          = iclog->ic_bp;
1451         ASSERT(XFS_BUF_FSPRIVATE2(bp, unsigned long) == (unsigned long)1);
1452         XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)2);
1453         XFS_BUF_SET_ADDR(bp, BLOCK_LSN(INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT)));
1454
1455         XFS_STATS_ADD(xs_log_blocks, BTOBB(count));
1456
1457         /* Do we need to split this write into 2 parts? */
1458         if (XFS_BUF_ADDR(bp) + BTOBB(count) > log->l_logBBsize) {
1459                 split = count - (BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp)));
1460                 count = BBTOB(log->l_logBBsize - XFS_BUF_ADDR(bp));
1461                 iclog->ic_bwritecnt = 2;        /* split into 2 writes */
1462         } else {
1463                 iclog->ic_bwritecnt = 1;
1464         }
1465         XFS_BUF_SET_PTR(bp, (xfs_caddr_t) &(iclog->ic_header), count);
1466         XFS_BUF_SET_FSPRIVATE(bp, iclog);       /* save for later */
1467         XFS_BUF_BUSY(bp);
1468         XFS_BUF_ASYNC(bp);
1469         /*
1470          * Do a disk write cache flush for the log block.
1471          * This is a bit of a sledgehammer, it would be better
1472          * to use a tag barrier here that just prevents reordering.
1473          * It may not be needed to flush the first split block in the log wrap
1474          * case, but do it anyways to be safe -AK
1475          */
1476         if (!(log->l_mp->m_flags & XFS_MOUNT_NOLOGFLUSH))
1477                 XFS_BUF_FLUSH(bp);
1478
1479         ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1480         ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1481
1482         xlog_verify_iclog(log, iclog, count, B_TRUE);
1483
1484         /* account for log which doesn't start at block #0 */
1485         XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1486         /*
1487          * Don't call xfs_bwrite here. We do log-syncs even when the filesystem
1488          * is shutting down.
1489          */
1490         XFS_BUF_WRITE(bp);
1491
1492         if ((error = XFS_bwrite(bp))) {
1493                 xfs_ioerror_alert("xlog_sync", log->l_mp, bp,
1494                                   XFS_BUF_ADDR(bp));
1495                 return (error);
1496         }
1497         if (split) {
1498                 bp              = iclog->ic_log->l_xbuf;
1499                 ASSERT(XFS_BUF_FSPRIVATE2(bp, unsigned long) ==
1500                                                         (unsigned long)1);
1501                 XFS_BUF_SET_FSPRIVATE2(bp, (unsigned long)2);
1502                 XFS_BUF_SET_ADDR(bp, 0);             /* logical 0 */
1503                 XFS_BUF_SET_PTR(bp, (xfs_caddr_t)((__psint_t)&(iclog->ic_header)+
1504                                             (__psint_t)count), split);
1505                 XFS_BUF_SET_FSPRIVATE(bp, iclog);
1506                 XFS_BUF_BUSY(bp);
1507                 XFS_BUF_ASYNC(bp);
1508                 if (!(log->l_mp->m_flags & XFS_MOUNT_NOLOGFLUSH))
1509                         XFS_BUF_FLUSH(bp);
1510                 dptr = XFS_BUF_PTR(bp);
1511                 /*
1512                  * Bump the cycle numbers at the start of each block
1513                  * since this part of the buffer is at the start of
1514                  * a new cycle.  Watch out for the header magic number
1515                  * case, though.
1516                  */
1517                 for (i=0; i<split; i += BBSIZE) {
1518                         INT_MOD(*(uint *)dptr, ARCH_CONVERT, +1);
1519                         if (INT_GET(*(uint *)dptr, ARCH_CONVERT) == XLOG_HEADER_MAGIC_NUM)
1520                                 INT_MOD(*(uint *)dptr, ARCH_CONVERT, +1);
1521                         dptr += BBSIZE;
1522                 }
1523
1524                 ASSERT(XFS_BUF_ADDR(bp) <= log->l_logBBsize-1);
1525                 ASSERT(XFS_BUF_ADDR(bp) + BTOBB(count) <= log->l_logBBsize);
1526
1527                 /* account for internal log which does't start at block #0 */
1528                 XFS_BUF_SET_ADDR(bp, XFS_BUF_ADDR(bp) + log->l_logBBstart);
1529                 XFS_BUF_WRITE(bp);
1530                 if ((error = XFS_bwrite(bp))) {
1531                         xfs_ioerror_alert("xlog_sync (split)", log->l_mp,
1532                                           bp, XFS_BUF_ADDR(bp));
1533                         return (error);
1534                 }
1535         }
1536         return (0);
1537 }       /* xlog_sync */
1538
1539
1540 /*
1541  * Unallocate a log structure
1542  */
1543 void
1544 xlog_unalloc_log(xlog_t *log)
1545 {
1546         xlog_in_core_t  *iclog, *next_iclog;
1547         xlog_ticket_t   *tic, *next_tic;
1548         int             i;
1549
1550
1551         iclog = log->l_iclog;
1552         for (i=0; i<log->l_iclog_bufs; i++) {
1553                 sv_destroy(&iclog->ic_forcesema);
1554                 sv_destroy(&iclog->ic_writesema);
1555                 xfs_buf_free(iclog->ic_bp);
1556 #ifdef XFS_LOG_TRACE
1557                 if (iclog->ic_trace != NULL) {
1558                         ktrace_free(iclog->ic_trace);
1559                 }
1560 #endif
1561                 next_iclog = iclog->ic_next;
1562                 kmem_free(iclog->hic_data, log->l_iclog_size);
1563                 kmem_free(iclog, sizeof(xlog_in_core_t));
1564                 iclog = next_iclog;
1565         }
1566         freesema(&log->l_flushsema);
1567         spinlock_destroy(&log->l_icloglock);
1568         spinlock_destroy(&log->l_grant_lock);
1569
1570         /* XXXsup take a look at this again. */
1571         if ((log->l_ticket_cnt != log->l_ticket_tcnt)  &&
1572             !XLOG_FORCED_SHUTDOWN(log)) {
1573                 xfs_fs_cmn_err(CE_WARN, log->l_mp,
1574                         "xlog_unalloc_log: (cnt: %d, total: %d)",
1575                         log->l_ticket_cnt, log->l_ticket_tcnt);
1576                 /* ASSERT(log->l_ticket_cnt == log->l_ticket_tcnt); */
1577
1578         } else {
1579                 tic = log->l_unmount_free;
1580                 while (tic) {
1581                         next_tic = tic->t_next;
1582                         kmem_free(tic, NBPP);
1583                         tic = next_tic;
1584                 }
1585         }
1586         xfs_buf_free(log->l_xbuf);
1587 #ifdef XFS_LOG_TRACE
1588         if (log->l_trace != NULL) {
1589                 ktrace_free(log->l_trace);
1590         }
1591         if (log->l_grant_trace != NULL) {
1592                 ktrace_free(log->l_grant_trace);
1593         }
1594 #endif
1595         log->l_mp->m_log = NULL;
1596         kmem_free(log, sizeof(xlog_t));
1597 }       /* xlog_unalloc_log */
1598
1599 /*
1600  * Update counters atomically now that memcpy is done.
1601  */
1602 /* ARGSUSED */
1603 static inline void
1604 xlog_state_finish_copy(xlog_t           *log,
1605                        xlog_in_core_t   *iclog,
1606                        int              record_cnt,
1607                        int              copy_bytes)
1608 {
1609         SPLDECL(s);
1610
1611         s = LOG_LOCK(log);
1612
1613         iclog->ic_header.h_num_logops += record_cnt;
1614         iclog->ic_offset += copy_bytes;
1615
1616         LOG_UNLOCK(log, s);
1617 }       /* xlog_state_finish_copy */
1618
1619
1620
1621
1622 /*
1623  * print out info relating to regions written which consume
1624  * the reservation
1625  */
1626 #if defined(XFS_LOG_RES_DEBUG)
1627 STATIC void
1628 xlog_print_tic_res(xfs_mount_t *mp, xlog_ticket_t *ticket)
1629 {
1630         uint i;
1631         uint ophdr_spc = ticket->t_res_num_ophdrs * (uint)sizeof(xlog_op_header_t);
1632
1633         /* match with XLOG_REG_TYPE_* in xfs_log.h */
1634         static char *res_type_str[XLOG_REG_TYPE_MAX] = {
1635             "bformat",
1636             "bchunk",
1637             "efi_format",
1638             "efd_format",
1639             "iformat",
1640             "icore",
1641             "iext",
1642             "ibroot",
1643             "ilocal",
1644             "iattr_ext",
1645             "iattr_broot",
1646             "iattr_local",
1647             "qformat",
1648             "dquot",
1649             "quotaoff",
1650             "LR header",
1651             "unmount",
1652             "commit",
1653             "trans header"
1654         };
1655         static char *trans_type_str[XFS_TRANS_TYPE_MAX] = {
1656             "SETATTR_NOT_SIZE",
1657             "SETATTR_SIZE",
1658             "INACTIVE",
1659             "CREATE",
1660             "CREATE_TRUNC",
1661             "TRUNCATE_FILE",
1662             "REMOVE",
1663             "LINK",
1664             "RENAME",
1665             "MKDIR",
1666             "RMDIR",
1667             "SYMLINK",
1668             "SET_DMATTRS",
1669             "GROWFS",
1670             "STRAT_WRITE",
1671             "DIOSTRAT",
1672             "WRITE_SYNC",
1673             "WRITEID",
1674             "ADDAFORK",
1675             "ATTRINVAL",
1676             "ATRUNCATE",
1677             "ATTR_SET",
1678             "ATTR_RM",
1679             "ATTR_FLAG",
1680             "CLEAR_AGI_BUCKET",
1681             "QM_SBCHANGE",
1682             "DUMMY1",
1683             "DUMMY2",
1684             "QM_QUOTAOFF",
1685             "QM_DQALLOC",
1686             "QM_SETQLIM",
1687             "QM_DQCLUSTER",
1688             "QM_QINOCREATE",
1689             "QM_QUOTAOFF_END",
1690             "SB_UNIT",
1691             "FSYNC_TS",
1692             "GROWFSRT_ALLOC",
1693             "GROWFSRT_ZERO",
1694             "GROWFSRT_FREE",
1695             "SWAPEXT"
1696         };
1697
1698         xfs_fs_cmn_err(CE_WARN, mp,
1699                         "xfs_log_write: reservation summary:\n"
1700                         "  trans type  = %s (%u)\n"
1701                         "  unit res    = %d bytes\n"
1702                         "  current res = %d bytes\n"
1703                         "  total reg   = %u bytes (o/flow = %u bytes)\n"
1704                         "  ophdrs      = %u (ophdr space = %u bytes)\n"
1705                         "  ophdr + reg = %u bytes\n"
1706                         "  num regions = %u\n",
1707                         ((ticket->t_trans_type <= 0 ||
1708                           ticket->t_trans_type > XFS_TRANS_TYPE_MAX) ?
1709                           "bad-trans-type" : trans_type_str[ticket->t_trans_type-1]),
1710                         ticket->t_trans_type,
1711                         ticket->t_unit_res,
1712                         ticket->t_curr_res,
1713                         ticket->t_res_arr_sum, ticket->t_res_o_flow,
1714                         ticket->t_res_num_ophdrs, ophdr_spc,
1715                         ticket->t_res_arr_sum + 
1716                           ticket->t_res_o_flow + ophdr_spc,
1717                         ticket->t_res_num);
1718
1719         for (i = 0; i < ticket->t_res_num; i++) {
1720                 uint r_type = ticket->t_res_arr[i].r_type; 
1721                 cmn_err(CE_WARN,
1722                             "region[%u]: %s - %u bytes\n",
1723                             i, 
1724                             ((r_type <= 0 || r_type > XLOG_REG_TYPE_MAX) ?
1725                             "bad-rtype" : res_type_str[r_type-1]),
1726                             ticket->t_res_arr[i].r_len);
1727         }
1728 }
1729 #else
1730 #define xlog_print_tic_res(mp, ticket)
1731 #endif
1732
1733 /*
1734  * Write some region out to in-core log
1735  *
1736  * This will be called when writing externally provided regions or when
1737  * writing out a commit record for a given transaction.
1738  *
1739  * General algorithm:
1740  *      1. Find total length of this write.  This may include adding to the
1741  *              lengths passed in.
1742  *      2. Check whether we violate the tickets reservation.
1743  *      3. While writing to this iclog
1744  *          A. Reserve as much space in this iclog as can get
1745  *          B. If this is first write, save away start lsn
1746  *          C. While writing this region:
1747  *              1. If first write of transaction, write start record
1748  *              2. Write log operation header (header per region)
1749  *              3. Find out if we can fit entire region into this iclog
1750  *              4. Potentially, verify destination memcpy ptr
1751  *              5. Memcpy (partial) region
1752  *              6. If partial copy, release iclog; otherwise, continue
1753  *                      copying more regions into current iclog
1754  *      4. Mark want sync bit (in simulation mode)
1755  *      5. Release iclog for potential flush to on-disk log.
1756  *
1757  * ERRORS:
1758  * 1.   Panic if reservation is overrun.  This should never happen since
1759  *      reservation amounts are generated internal to the filesystem.
1760  * NOTES:
1761  * 1. Tickets are single threaded data structures.
1762  * 2. The XLOG_END_TRANS & XLOG_CONTINUE_TRANS flags are passed down to the
1763  *      syncing routine.  When a single log_write region needs to span
1764  *      multiple in-core logs, the XLOG_CONTINUE_TRANS bit should be set
1765  *      on all log operation writes which don't contain the end of the
1766  *      region.  The XLOG_END_TRANS bit is used for the in-core log
1767  *      operation which contains the end of the continued log_write region.
1768  * 3. When xlog_state_get_iclog_space() grabs the rest of the current iclog,
1769  *      we don't really know exactly how much space will be used.  As a result,
1770  *      we don't update ic_offset until the end when we know exactly how many
1771  *      bytes have been written out.
1772  */
1773 int
1774 xlog_write(xfs_mount_t *        mp,
1775            xfs_log_iovec_t      reg[],
1776            int                  nentries,
1777            xfs_log_ticket_t     tic,
1778            xfs_lsn_t            *start_lsn,
1779            xlog_in_core_t       **commit_iclog,
1780            uint                 flags)
1781 {
1782     xlog_t           *log    = mp->m_log;
1783     xlog_ticket_t    *ticket = (xlog_ticket_t *)tic;
1784     xlog_op_header_t *logop_head;    /* ptr to log operation header */
1785     xlog_in_core_t   *iclog;         /* ptr to current in-core log */
1786     __psint_t        ptr;            /* copy address into data region */
1787     int              len;            /* # xlog_write() bytes 2 still copy */
1788     int              index;          /* region index currently copying */
1789     int              log_offset;     /* offset (from 0) into data region */
1790     int              start_rec_copy; /* # bytes to copy for start record */
1791     int              partial_copy;   /* did we split a region? */
1792     int              partial_copy_len;/* # bytes copied if split region */
1793     int              need_copy;      /* # bytes need to memcpy this region */
1794     int              copy_len;       /* # bytes actually memcpy'ing */
1795     int              copy_off;       /* # bytes from entry start */
1796     int              contwr;         /* continued write of in-core log? */
1797     int              error;
1798     int              record_cnt = 0, data_cnt = 0;
1799
1800     partial_copy_len = partial_copy = 0;
1801
1802     /* Calculate potential maximum space.  Each region gets its own
1803      * xlog_op_header_t and may need to be double word aligned.
1804      */
1805     len = 0;
1806     if (ticket->t_flags & XLOG_TIC_INITED) {    /* acct for start rec of xact */
1807         len += sizeof(xlog_op_header_t);
1808         XLOG_TIC_ADD_OPHDR(ticket);
1809     }
1810
1811     for (index = 0; index < nentries; index++) {
1812         len += sizeof(xlog_op_header_t);            /* each region gets >= 1 */
1813         XLOG_TIC_ADD_OPHDR(ticket);
1814         len += reg[index].i_len;
1815         XLOG_TIC_ADD_REGION(ticket, reg[index].i_len, reg[index].i_type);
1816     }
1817     contwr = *start_lsn = 0;
1818
1819     if (ticket->t_curr_res < len) {
1820         xlog_print_tic_res(mp, ticket);
1821 #ifdef DEBUG
1822         xlog_panic(
1823                 "xfs_log_write: reservation ran out. Need to up reservation");
1824 #else
1825         /* Customer configurable panic */
1826         xfs_cmn_err(XFS_PTAG_LOGRES, CE_ALERT, mp,
1827                 "xfs_log_write: reservation ran out. Need to up reservation");
1828         /* If we did not panic, shutdown the filesystem */
1829         xfs_force_shutdown(mp, XFS_CORRUPT_INCORE);
1830 #endif
1831     } else
1832         ticket->t_curr_res -= len;
1833
1834     for (index = 0; index < nentries; ) {
1835         if ((error = xlog_state_get_iclog_space(log, len, &iclog, ticket,
1836                                                &contwr, &log_offset)))
1837                 return (error);
1838
1839         ASSERT(log_offset <= iclog->ic_size - 1);
1840         ptr = (__psint_t) ((char *)iclog->ic_datap+log_offset);
1841
1842         /* start_lsn is the first lsn written to. That's all we need. */
1843         if (! *start_lsn)
1844             *start_lsn = INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT);
1845
1846         /* This loop writes out as many regions as can fit in the amount
1847          * of space which was allocated by xlog_state_get_iclog_space().
1848          */
1849         while (index < nentries) {
1850             ASSERT(reg[index].i_len % sizeof(__int32_t) == 0);
1851             ASSERT((__psint_t)ptr % sizeof(__int32_t) == 0);
1852             start_rec_copy = 0;
1853
1854             /* If first write for transaction, insert start record.
1855              * We can't be trying to commit if we are inited.  We can't
1856              * have any "partial_copy" if we are inited.
1857              */
1858             if (ticket->t_flags & XLOG_TIC_INITED) {
1859                 logop_head              = (xlog_op_header_t *)ptr;
1860                 INT_SET(logop_head->oh_tid, ARCH_CONVERT, ticket->t_tid);
1861                 logop_head->oh_clientid = ticket->t_clientid;
1862                 logop_head->oh_len      = 0;
1863                 logop_head->oh_flags    = XLOG_START_TRANS;
1864                 logop_head->oh_res2     = 0;
1865                 ticket->t_flags         &= ~XLOG_TIC_INITED;    /* clear bit */
1866                 record_cnt++;
1867
1868                 start_rec_copy = sizeof(xlog_op_header_t);
1869                 xlog_write_adv_cnt(ptr, len, log_offset, start_rec_copy);
1870             }
1871
1872             /* Copy log operation header directly into data section */
1873             logop_head                  = (xlog_op_header_t *)ptr;
1874             INT_SET(logop_head->oh_tid, ARCH_CONVERT, ticket->t_tid);
1875             logop_head->oh_clientid     = ticket->t_clientid;
1876             logop_head->oh_res2         = 0;
1877
1878             /* header copied directly */
1879             xlog_write_adv_cnt(ptr, len, log_offset, sizeof(xlog_op_header_t));
1880
1881             /* are we copying a commit or unmount record? */
1882             logop_head->oh_flags = flags;
1883
1884             /*
1885              * We've seen logs corrupted with bad transaction client
1886              * ids.  This makes sure that XFS doesn't generate them on.
1887              * Turn this into an EIO and shut down the filesystem.
1888              */
1889             switch (logop_head->oh_clientid)  {
1890             case XFS_TRANSACTION:
1891             case XFS_VOLUME:
1892             case XFS_LOG:
1893                 break;
1894             default:
1895                 xfs_fs_cmn_err(CE_WARN, mp,
1896                     "Bad XFS transaction clientid 0x%x in ticket 0x%p",
1897                     logop_head->oh_clientid, tic);
1898                 return XFS_ERROR(EIO);
1899             }
1900
1901             /* Partial write last time? => (partial_copy != 0)
1902              * need_copy is the amount we'd like to copy if everything could
1903              * fit in the current memcpy.
1904              */
1905             need_copy = reg[index].i_len - partial_copy_len;
1906
1907             copy_off = partial_copy_len;
1908             if (need_copy <= iclog->ic_size - log_offset) { /*complete write */
1909                 INT_SET(logop_head->oh_len, ARCH_CONVERT, copy_len = need_copy);
1910                 if (partial_copy)
1911                     logop_head->oh_flags|= (XLOG_END_TRANS|XLOG_WAS_CONT_TRANS);
1912                 partial_copy_len = partial_copy = 0;
1913             } else {                                        /* partial write */
1914                 copy_len = iclog->ic_size - log_offset;
1915                 INT_SET(logop_head->oh_len, ARCH_CONVERT, copy_len);
1916                 logop_head->oh_flags |= XLOG_CONTINUE_TRANS;
1917                 if (partial_copy)
1918                         logop_head->oh_flags |= XLOG_WAS_CONT_TRANS;
1919                 partial_copy_len += copy_len;
1920                 partial_copy++;
1921                 len += sizeof(xlog_op_header_t); /* from splitting of region */
1922                 /* account for new log op header */
1923                 ticket->t_curr_res -= sizeof(xlog_op_header_t);
1924                 XLOG_TIC_ADD_OPHDR(ticket);
1925             }
1926             xlog_verify_dest_ptr(log, ptr);
1927
1928             /* copy region */
1929             ASSERT(copy_len >= 0);
1930             memcpy((xfs_caddr_t)ptr, reg[index].i_addr + copy_off, copy_len);
1931             xlog_write_adv_cnt(ptr, len, log_offset, copy_len);
1932
1933             /* make copy_len total bytes copied, including headers */
1934             copy_len += start_rec_copy + sizeof(xlog_op_header_t);
1935             record_cnt++;
1936             data_cnt += contwr ? copy_len : 0;
1937             if (partial_copy) {                 /* copied partial region */
1938                     /* already marked WANT_SYNC by xlog_state_get_iclog_space */
1939                     xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
1940                     record_cnt = data_cnt = 0;
1941                     if ((error = xlog_state_release_iclog(log, iclog)))
1942                             return (error);
1943                     break;                      /* don't increment index */
1944             } else {                            /* copied entire region */
1945                 index++;
1946                 partial_copy_len = partial_copy = 0;
1947
1948                 if (iclog->ic_size - log_offset <= sizeof(xlog_op_header_t)) {
1949                     xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
1950                     record_cnt = data_cnt = 0;
1951                     xlog_state_want_sync(log, iclog);
1952                     if (commit_iclog) {
1953                         ASSERT(flags & XLOG_COMMIT_TRANS);
1954                         *commit_iclog = iclog;
1955                     } else if ((error = xlog_state_release_iclog(log, iclog)))
1956                            return (error);
1957                     if (index == nentries)
1958                             return 0;           /* we are done */
1959                     else
1960                             break;
1961                 }
1962             } /* if (partial_copy) */
1963         } /* while (index < nentries) */
1964     } /* for (index = 0; index < nentries; ) */
1965     ASSERT(len == 0);
1966
1967     xlog_state_finish_copy(log, iclog, record_cnt, data_cnt);
1968     if (commit_iclog) {
1969         ASSERT(flags & XLOG_COMMIT_TRANS);
1970         *commit_iclog = iclog;
1971         return 0;
1972     }
1973     return (xlog_state_release_iclog(log, iclog));
1974 }       /* xlog_write */
1975
1976
1977 /*****************************************************************************
1978  *
1979  *              State Machine functions
1980  *
1981  *****************************************************************************
1982  */
1983
1984 /* Clean iclogs starting from the head.  This ordering must be
1985  * maintained, so an iclog doesn't become ACTIVE beyond one that
1986  * is SYNCING.  This is also required to maintain the notion that we use
1987  * a counting semaphore to hold off would be writers to the log when every
1988  * iclog is trying to sync to disk.
1989  *
1990  * State Change: DIRTY -> ACTIVE
1991  */
1992 STATIC void
1993 xlog_state_clean_log(xlog_t *log)
1994 {
1995         xlog_in_core_t  *iclog;
1996         int changed = 0;
1997
1998         iclog = log->l_iclog;
1999         do {
2000                 if (iclog->ic_state == XLOG_STATE_DIRTY) {
2001                         iclog->ic_state = XLOG_STATE_ACTIVE;
2002                         iclog->ic_offset       = 0;
2003                         iclog->ic_callback      = NULL;   /* don't need to free */
2004                         /*
2005                          * If the number of ops in this iclog indicate it just
2006                          * contains the dummy transaction, we can
2007                          * change state into IDLE (the second time around).
2008                          * Otherwise we should change the state into
2009                          * NEED a dummy.
2010                          * We don't need to cover the dummy.
2011                          */
2012                         if (!changed &&
2013                            (INT_GET(iclog->ic_header.h_num_logops, ARCH_CONVERT) == XLOG_COVER_OPS)) {
2014                                 changed = 1;
2015                         } else {
2016                                 /*
2017                                  * We have two dirty iclogs so start over
2018                                  * This could also be num of ops indicates
2019                                  * this is not the dummy going out.
2020                                  */
2021                                 changed = 2;
2022                         }
2023                         iclog->ic_header.h_num_logops = 0;
2024                         memset(iclog->ic_header.h_cycle_data, 0,
2025                               sizeof(iclog->ic_header.h_cycle_data));
2026                         iclog->ic_header.h_lsn = 0;
2027                 } else if (iclog->ic_state == XLOG_STATE_ACTIVE)
2028                         /* do nothing */;
2029                 else
2030                         break;  /* stop cleaning */
2031                 iclog = iclog->ic_next;
2032         } while (iclog != log->l_iclog);
2033
2034         /* log is locked when we are called */
2035         /*
2036          * Change state for the dummy log recording.
2037          * We usually go to NEED. But we go to NEED2 if the changed indicates
2038          * we are done writing the dummy record.
2039          * If we are done with the second dummy recored (DONE2), then
2040          * we go to IDLE.
2041          */
2042         if (changed) {
2043                 switch (log->l_covered_state) {
2044                 case XLOG_STATE_COVER_IDLE:
2045                 case XLOG_STATE_COVER_NEED:
2046                 case XLOG_STATE_COVER_NEED2:
2047                         log->l_covered_state = XLOG_STATE_COVER_NEED;
2048                         break;
2049
2050                 case XLOG_STATE_COVER_DONE:
2051                         if (changed == 1)
2052                                 log->l_covered_state = XLOG_STATE_COVER_NEED2;
2053                         else
2054                                 log->l_covered_state = XLOG_STATE_COVER_NEED;
2055                         break;
2056
2057                 case XLOG_STATE_COVER_DONE2:
2058                         if (changed == 1)
2059                                 log->l_covered_state = XLOG_STATE_COVER_IDLE;
2060                         else
2061                                 log->l_covered_state = XLOG_STATE_COVER_NEED;
2062                         break;
2063
2064                 default:
2065                         ASSERT(0);
2066                 }
2067         }
2068 }       /* xlog_state_clean_log */
2069
2070 STATIC xfs_lsn_t
2071 xlog_get_lowest_lsn(
2072         xlog_t          *log)
2073 {
2074         xlog_in_core_t  *lsn_log;
2075         xfs_lsn_t       lowest_lsn, lsn;
2076
2077         lsn_log = log->l_iclog;
2078         lowest_lsn = 0;
2079         do {
2080             if (!(lsn_log->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY))) {
2081                 lsn = INT_GET(lsn_log->ic_header.h_lsn, ARCH_CONVERT);
2082                 if ((lsn && !lowest_lsn) ||
2083                     (XFS_LSN_CMP(lsn, lowest_lsn) < 0)) {
2084                         lowest_lsn = lsn;
2085                 }
2086             }
2087             lsn_log = lsn_log->ic_next;
2088         } while (lsn_log != log->l_iclog);
2089         return(lowest_lsn);
2090 }
2091
2092
2093 STATIC void
2094 xlog_state_do_callback(
2095         xlog_t          *log,
2096         int             aborted,
2097         xlog_in_core_t  *ciclog)
2098 {
2099         xlog_in_core_t     *iclog;
2100         xlog_in_core_t     *first_iclog;        /* used to know when we've
2101                                                  * processed all iclogs once */
2102         xfs_log_callback_t *cb, *cb_next;
2103         int                flushcnt = 0;
2104         xfs_lsn_t          lowest_lsn;
2105         int                ioerrors;    /* counter: iclogs with errors */
2106         int                loopdidcallbacks; /* flag: inner loop did callbacks*/
2107         int                funcdidcallbacks; /* flag: function did callbacks */
2108         int                repeats;     /* for issuing console warnings if
2109                                          * looping too many times */
2110         SPLDECL(s);
2111
2112         s = LOG_LOCK(log);
2113         first_iclog = iclog = log->l_iclog;
2114         ioerrors = 0;
2115         funcdidcallbacks = 0;
2116         repeats = 0;
2117
2118         do {
2119                 /*
2120                  * Scan all iclogs starting with the one pointed to by the
2121                  * log.  Reset this starting point each time the log is
2122                  * unlocked (during callbacks).
2123                  *
2124                  * Keep looping through iclogs until one full pass is made
2125                  * without running any callbacks.
2126                  */
2127                 first_iclog = log->l_iclog;
2128                 iclog = log->l_iclog;
2129                 loopdidcallbacks = 0;
2130                 repeats++;
2131
2132                 do {
2133
2134                         /* skip all iclogs in the ACTIVE & DIRTY states */
2135                         if (iclog->ic_state &
2136                             (XLOG_STATE_ACTIVE|XLOG_STATE_DIRTY)) {
2137                                 iclog = iclog->ic_next;
2138                                 continue;
2139                         }
2140
2141                         /*
2142                          * Between marking a filesystem SHUTDOWN and stopping
2143                          * the log, we do flush all iclogs to disk (if there
2144                          * wasn't a log I/O error). So, we do want things to
2145                          * go smoothly in case of just a SHUTDOWN  w/o a
2146                          * LOG_IO_ERROR.
2147                          */
2148                         if (!(iclog->ic_state & XLOG_STATE_IOERROR)) {
2149                                 /*
2150                                  * Can only perform callbacks in order.  Since
2151                                  * this iclog is not in the DONE_SYNC/
2152                                  * DO_CALLBACK state, we skip the rest and
2153                                  * just try to clean up.  If we set our iclog
2154                                  * to DO_CALLBACK, we will not process it when
2155                                  * we retry since a previous iclog is in the
2156                                  * CALLBACK and the state cannot change since
2157                                  * we are holding the LOG_LOCK.
2158                                  */
2159                                 if (!(iclog->ic_state &
2160                                         (XLOG_STATE_DONE_SYNC |
2161                                                  XLOG_STATE_DO_CALLBACK))) {
2162                                         if (ciclog && (ciclog->ic_state ==
2163                                                         XLOG_STATE_DONE_SYNC)) {
2164                                                 ciclog->ic_state = XLOG_STATE_DO_CALLBACK;
2165                                         }
2166                                         break;
2167                                 }
2168                                 /*
2169                                  * We now have an iclog that is in either the
2170                                  * DO_CALLBACK or DONE_SYNC states. The other
2171                                  * states (WANT_SYNC, SYNCING, or CALLBACK were
2172                                  * caught by the above if and are going to
2173                                  * clean (i.e. we aren't doing their callbacks)
2174                                  * see the above if.
2175                                  */
2176
2177                                 /*
2178                                  * We will do one more check here to see if we
2179                                  * have chased our tail around.
2180                                  */
2181
2182                                 lowest_lsn = xlog_get_lowest_lsn(log);
2183                                 if (lowest_lsn && (
2184                                         XFS_LSN_CMP(
2185                                                 lowest_lsn,
2186                                                 INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT)
2187                                         )<0)) {
2188                                         iclog = iclog->ic_next;
2189                                         continue; /* Leave this iclog for
2190                                                    * another thread */
2191                                 }
2192
2193                                 iclog->ic_state = XLOG_STATE_CALLBACK;
2194
2195                                 LOG_UNLOCK(log, s);
2196
2197                                 /* l_last_sync_lsn field protected by
2198                                  * GRANT_LOCK. Don't worry about iclog's lsn.
2199                                  * No one else can be here except us.
2200                                  */
2201                                 s = GRANT_LOCK(log);
2202                                 ASSERT(XFS_LSN_CMP(
2203                                                 log->l_last_sync_lsn,
2204                                                 INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT)
2205                                         )<=0);
2206                                 log->l_last_sync_lsn = INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT);
2207                                 GRANT_UNLOCK(log, s);
2208
2209                                 /*
2210                                  * Keep processing entries in the callback list
2211                                  * until we come around and it is empty.  We
2212                                  * need to atomically see that the list is
2213                                  * empty and change the state to DIRTY so that
2214                                  * we don't miss any more callbacks being added.
2215                                  */
2216                                 s = LOG_LOCK(log);
2217                         } else {
2218                                 ioerrors++;
2219                         }
2220                         cb = iclog->ic_callback;
2221
2222                         while (cb != 0) {
2223                                 iclog->ic_callback_tail = &(iclog->ic_callback);
2224                                 iclog->ic_callback = NULL;
2225                                 LOG_UNLOCK(log, s);
2226
2227                                 /* perform callbacks in the order given */
2228                                 for (; cb != 0; cb = cb_next) {
2229                                         cb_next = cb->cb_next;
2230                                         cb->cb_func(cb->cb_arg, aborted);
2231                                 }
2232                                 s = LOG_LOCK(log);
2233                                 cb = iclog->ic_callback;
2234                         }
2235
2236                         loopdidcallbacks++;
2237                         funcdidcallbacks++;
2238
2239                         ASSERT(iclog->ic_callback == 0);
2240                         if (!(iclog->ic_state & XLOG_STATE_IOERROR))
2241                                 iclog->ic_state = XLOG_STATE_DIRTY;
2242
2243                         /*
2244                          * Transition from DIRTY to ACTIVE if applicable.
2245                          * NOP if STATE_IOERROR.
2246                          */
2247                         xlog_state_clean_log(log);
2248
2249                         /* wake up threads waiting in xfs_log_force() */
2250                         sv_broadcast(&iclog->ic_forcesema);
2251
2252                         iclog = iclog->ic_next;
2253                 } while (first_iclog != iclog);
2254                 if (repeats && (repeats % 10) == 0) {
2255                         xfs_fs_cmn_err(CE_WARN, log->l_mp,
2256                                 "xlog_state_do_callback: looping %d", repeats);
2257                 }
2258         } while (!ioerrors && loopdidcallbacks);
2259
2260         /*
2261          * make one last gasp attempt to see if iclogs are being left in
2262          * limbo..
2263          */
2264 #ifdef DEBUG
2265         if (funcdidcallbacks) {
2266                 first_iclog = iclog = log->l_iclog;
2267                 do {
2268                         ASSERT(iclog->ic_state != XLOG_STATE_DO_CALLBACK);
2269                         /*
2270                          * Terminate the loop if iclogs are found in states
2271                          * which will cause other threads to clean up iclogs.
2272                          *
2273                          * SYNCING - i/o completion will go through logs
2274                          * DONE_SYNC - interrupt thread should be waiting for
2275                          *              LOG_LOCK
2276                          * IOERROR - give up hope all ye who enter here
2277                          */
2278                         if (iclog->ic_state == XLOG_STATE_WANT_SYNC ||
2279                             iclog->ic_state == XLOG_STATE_SYNCING ||
2280                             iclog->ic_state == XLOG_STATE_DONE_SYNC ||
2281                             iclog->ic_state == XLOG_STATE_IOERROR )
2282                                 break;
2283                         iclog = iclog->ic_next;
2284                 } while (first_iclog != iclog);
2285         }
2286 #endif
2287
2288         if (log->l_iclog->ic_state & (XLOG_STATE_ACTIVE|XLOG_STATE_IOERROR)) {
2289                 flushcnt = log->l_flushcnt;
2290                 log->l_flushcnt = 0;
2291         }
2292         LOG_UNLOCK(log, s);
2293         while (flushcnt--)
2294                 vsema(&log->l_flushsema);
2295 }       /* xlog_state_do_callback */
2296
2297
2298 /*
2299  * Finish transitioning this iclog to the dirty state.
2300  *
2301  * Make sure that we completely execute this routine only when this is
2302  * the last call to the iclog.  There is a good chance that iclog flushes,
2303  * when we reach the end of the physical log, get turned into 2 separate
2304  * calls to bwrite.  Hence, one iclog flush could generate two calls to this
2305  * routine.  By using the reference count bwritecnt, we guarantee that only
2306  * the second completion goes through.
2307  *
2308  * Callbacks could take time, so they are done outside the scope of the
2309  * global state machine log lock.  Assume that the calls to cvsema won't
2310  * take a long time.  At least we know it won't sleep.
2311  */
2312 void
2313 xlog_state_done_syncing(
2314         xlog_in_core_t  *iclog,
2315         int             aborted)
2316 {
2317         xlog_t             *log = iclog->ic_log;
2318         SPLDECL(s);
2319
2320         s = LOG_LOCK(log);
2321
2322         ASSERT(iclog->ic_state == XLOG_STATE_SYNCING ||
2323                iclog->ic_state == XLOG_STATE_IOERROR);
2324         ASSERT(iclog->ic_refcnt == 0);
2325         ASSERT(iclog->ic_bwritecnt == 1 || iclog->ic_bwritecnt == 2);
2326
2327
2328         /*
2329          * If we got an error, either on the first buffer, or in the case of
2330          * split log writes, on the second, we mark ALL iclogs STATE_IOERROR,
2331          * and none should ever be attempted to be written to disk
2332          * again.
2333          */
2334         if (iclog->ic_state != XLOG_STATE_IOERROR) {
2335                 if (--iclog->ic_bwritecnt == 1) {
2336                         LOG_UNLOCK(log, s);
2337                         return;
2338                 }
2339                 iclog->ic_state = XLOG_STATE_DONE_SYNC;
2340         }
2341
2342         /*
2343          * Someone could be sleeping prior to writing out the next
2344          * iclog buffer, we wake them all, one will get to do the
2345          * I/O, the others get to wait for the result.
2346          */
2347         sv_broadcast(&iclog->ic_writesema);
2348         LOG_UNLOCK(log, s);
2349         xlog_state_do_callback(log, aborted, iclog);    /* also cleans log */
2350 }       /* xlog_state_done_syncing */
2351
2352
2353 /*
2354  * If the head of the in-core log ring is not (ACTIVE or DIRTY), then we must
2355  * sleep.  The flush semaphore is set to the number of in-core buffers and
2356  * decremented around disk syncing.  Therefore, if all buffers are syncing,
2357  * this semaphore will cause new writes to sleep until a sync completes.
2358  * Otherwise, this code just does p() followed by v().  This approximates
2359  * a sleep/wakeup except we can't race.
2360  *
2361  * The in-core logs are used in a circular fashion. They are not used
2362  * out-of-order even when an iclog past the head is free.
2363  *
2364  * return:
2365  *      * log_offset where xlog_write() can start writing into the in-core
2366  *              log's data space.
2367  *      * in-core log pointer to which xlog_write() should write.
2368  *      * boolean indicating this is a continued write to an in-core log.
2369  *              If this is the last write, then the in-core log's offset field
2370  *              needs to be incremented, depending on the amount of data which
2371  *              is copied.
2372  */
2373 int
2374 xlog_state_get_iclog_space(xlog_t         *log,
2375                            int            len,
2376                            xlog_in_core_t **iclogp,
2377                            xlog_ticket_t  *ticket,
2378                            int            *continued_write,
2379                            int            *logoffsetp)
2380 {
2381         SPLDECL(s);
2382         int               log_offset;
2383         xlog_rec_header_t *head;
2384         xlog_in_core_t    *iclog;
2385         int               error;
2386
2387 restart:
2388         s = LOG_LOCK(log);
2389         if (XLOG_FORCED_SHUTDOWN(log)) {
2390                 LOG_UNLOCK(log, s);
2391                 return XFS_ERROR(EIO);
2392         }
2393
2394         iclog = log->l_iclog;
2395         if (! (iclog->ic_state == XLOG_STATE_ACTIVE)) {
2396                 log->l_flushcnt++;
2397                 LOG_UNLOCK(log, s);
2398                 xlog_trace_iclog(iclog, XLOG_TRACE_SLEEP_FLUSH);
2399                 XFS_STATS_INC(xs_log_noiclogs);
2400                 /* Ensure that log writes happen */
2401                 psema(&log->l_flushsema, PINOD);
2402                 goto restart;
2403         }
2404         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
2405         head = &iclog->ic_header;
2406
2407         iclog->ic_refcnt++;                     /* prevents sync */
2408         log_offset = iclog->ic_offset;
2409
2410         /* On the 1st write to an iclog, figure out lsn.  This works
2411          * if iclogs marked XLOG_STATE_WANT_SYNC always write out what they are
2412          * committing to.  If the offset is set, that's how many blocks
2413          * must be written.
2414          */
2415         if (log_offset == 0) {
2416                 ticket->t_curr_res -= log->l_iclog_hsize;
2417                 XLOG_TIC_ADD_REGION(ticket,
2418                                     log->l_iclog_hsize,
2419                                     XLOG_REG_TYPE_LRHEADER);
2420                 INT_SET(head->h_cycle, ARCH_CONVERT, log->l_curr_cycle);
2421                 ASSIGN_LSN(head->h_lsn, log);
2422                 ASSERT(log->l_curr_block >= 0);
2423         }
2424
2425         /* If there is enough room to write everything, then do it.  Otherwise,
2426          * claim the rest of the region and make sure the XLOG_STATE_WANT_SYNC
2427          * bit is on, so this will get flushed out.  Don't update ic_offset
2428          * until you know exactly how many bytes get copied.  Therefore, wait
2429          * until later to update ic_offset.
2430          *
2431          * xlog_write() algorithm assumes that at least 2 xlog_op_header_t's
2432          * can fit into remaining data section.
2433          */
2434         if (iclog->ic_size - iclog->ic_offset < 2*sizeof(xlog_op_header_t)) {
2435                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2436
2437                 /* If I'm the only one writing to this iclog, sync it to disk */
2438                 if (iclog->ic_refcnt == 1) {
2439                         LOG_UNLOCK(log, s);
2440                         if ((error = xlog_state_release_iclog(log, iclog)))
2441                                 return (error);
2442                 } else {
2443                         iclog->ic_refcnt--;
2444                         LOG_UNLOCK(log, s);
2445                 }
2446                 goto restart;
2447         }
2448
2449         /* Do we have enough room to write the full amount in the remainder
2450          * of this iclog?  Or must we continue a write on the next iclog and
2451          * mark this iclog as completely taken?  In the case where we switch
2452          * iclogs (to mark it taken), this particular iclog will release/sync
2453          * to disk in xlog_write().
2454          */
2455         if (len <= iclog->ic_size - iclog->ic_offset) {
2456                 *continued_write = 0;
2457                 iclog->ic_offset += len;
2458         } else {
2459                 *continued_write = 1;
2460                 xlog_state_switch_iclogs(log, iclog, iclog->ic_size);
2461         }
2462         *iclogp = iclog;
2463
2464         ASSERT(iclog->ic_offset <= iclog->ic_size);
2465         LOG_UNLOCK(log, s);
2466
2467         *logoffsetp = log_offset;
2468         return 0;
2469 }       /* xlog_state_get_iclog_space */
2470
2471 /*
2472  * Atomically get the log space required for a log ticket.
2473  *
2474  * Once a ticket gets put onto the reserveq, it will only return after
2475  * the needed reservation is satisfied.
2476  */
2477 STATIC int
2478 xlog_grant_log_space(xlog_t        *log,
2479                      xlog_ticket_t *tic)
2480 {
2481         int              free_bytes;
2482         int              need_bytes;
2483         SPLDECL(s);
2484 #ifdef DEBUG
2485         xfs_lsn_t        tail_lsn;
2486 #endif
2487
2488
2489 #ifdef DEBUG
2490         if (log->l_flags & XLOG_ACTIVE_RECOVERY)
2491                 panic("grant Recovery problem");
2492 #endif
2493
2494         /* Is there space or do we need to sleep? */
2495         s = GRANT_LOCK(log);
2496         xlog_trace_loggrant(log, tic, "xlog_grant_log_space: enter");
2497
2498         /* something is already sleeping; insert new transaction at end */
2499         if (log->l_reserve_headq) {
2500                 XLOG_INS_TICKETQ(log->l_reserve_headq, tic);
2501                 xlog_trace_loggrant(log, tic,
2502                                     "xlog_grant_log_space: sleep 1");
2503                 /*
2504                  * Gotta check this before going to sleep, while we're
2505                  * holding the grant lock.
2506                  */
2507                 if (XLOG_FORCED_SHUTDOWN(log))
2508                         goto error_return;
2509
2510                 XFS_STATS_INC(xs_sleep_logspace);
2511                 sv_wait(&tic->t_sema, PINOD|PLTWAIT, &log->l_grant_lock, s);
2512                 /*
2513                  * If we got an error, and the filesystem is shutting down,
2514                  * we'll catch it down below. So just continue...
2515                  */
2516                 xlog_trace_loggrant(log, tic,
2517                                     "xlog_grant_log_space: wake 1");
2518                 s = GRANT_LOCK(log);
2519         }
2520         if (tic->t_flags & XFS_LOG_PERM_RESERV)
2521                 need_bytes = tic->t_unit_res*tic->t_ocnt;
2522         else
2523                 need_bytes = tic->t_unit_res;
2524
2525 redo:
2526         if (XLOG_FORCED_SHUTDOWN(log))
2527                 goto error_return;
2528
2529         free_bytes = xlog_space_left(log, log->l_grant_reserve_cycle,
2530                                      log->l_grant_reserve_bytes);
2531         if (free_bytes < need_bytes) {
2532                 if ((tic->t_flags & XLOG_TIC_IN_Q) == 0)
2533                         XLOG_INS_TICKETQ(log->l_reserve_headq, tic);
2534                 xlog_trace_loggrant(log, tic,
2535                                     "xlog_grant_log_space: sleep 2");
2536                 XFS_STATS_INC(xs_sleep_logspace);
2537                 sv_wait(&tic->t_sema, PINOD|PLTWAIT, &log->l_grant_lock, s);
2538
2539                 if (XLOG_FORCED_SHUTDOWN(log)) {
2540                         s = GRANT_LOCK(log);
2541                         goto error_return;
2542                 }
2543
2544                 xlog_trace_loggrant(log, tic,
2545                                     "xlog_grant_log_space: wake 2");
2546                 xlog_grant_push_ail(log->l_mp, need_bytes);
2547                 s = GRANT_LOCK(log);
2548                 goto redo;
2549         } else if (tic->t_flags & XLOG_TIC_IN_Q)
2550                 XLOG_DEL_TICKETQ(log->l_reserve_headq, tic);
2551
2552         /* we've got enough space */
2553         XLOG_GRANT_ADD_SPACE(log, need_bytes, 'w');
2554         XLOG_GRANT_ADD_SPACE(log, need_bytes, 'r');
2555 #ifdef DEBUG
2556         tail_lsn = log->l_tail_lsn;
2557         /*
2558          * Check to make sure the grant write head didn't just over lap the
2559          * tail.  If the cycles are the same, we can't be overlapping.
2560          * Otherwise, make sure that the cycles differ by exactly one and
2561          * check the byte count.
2562          */
2563         if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) {
2564                 ASSERT(log->l_grant_write_cycle-1 == CYCLE_LSN(tail_lsn));
2565                 ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn)));
2566         }
2567 #endif
2568         xlog_trace_loggrant(log, tic, "xlog_grant_log_space: exit");
2569         xlog_verify_grant_head(log, 1);
2570         GRANT_UNLOCK(log, s);
2571         return 0;
2572
2573  error_return:
2574         if (tic->t_flags & XLOG_TIC_IN_Q)
2575                 XLOG_DEL_TICKETQ(log->l_reserve_headq, tic);
2576         xlog_trace_loggrant(log, tic, "xlog_grant_log_space: err_ret");
2577         /*
2578          * If we are failing, make sure the ticket doesn't have any
2579          * current reservations. We don't want to add this back when
2580          * the ticket/transaction gets cancelled.
2581          */
2582         tic->t_curr_res = 0;
2583         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
2584         GRANT_UNLOCK(log, s);
2585         return XFS_ERROR(EIO);
2586 }       /* xlog_grant_log_space */
2587
2588
2589 /*
2590  * Replenish the byte reservation required by moving the grant write head.
2591  *
2592  *
2593  */
2594 STATIC int
2595 xlog_regrant_write_log_space(xlog_t        *log,
2596                              xlog_ticket_t *tic)
2597 {
2598         SPLDECL(s);
2599         int             free_bytes, need_bytes;
2600         xlog_ticket_t   *ntic;
2601 #ifdef DEBUG
2602         xfs_lsn_t       tail_lsn;
2603 #endif
2604
2605         tic->t_curr_res = tic->t_unit_res;
2606         XLOG_TIC_RESET_RES(tic);
2607
2608         if (tic->t_cnt > 0)
2609                 return (0);
2610
2611 #ifdef DEBUG
2612         if (log->l_flags & XLOG_ACTIVE_RECOVERY)
2613                 panic("regrant Recovery problem");
2614 #endif
2615
2616         s = GRANT_LOCK(log);
2617         xlog_trace_loggrant(log, tic, "xlog_regrant_write_log_space: enter");
2618
2619         if (XLOG_FORCED_SHUTDOWN(log))
2620                 goto error_return;
2621
2622         /* If there are other waiters on the queue then give them a
2623          * chance at logspace before us. Wake up the first waiters,
2624          * if we do not wake up all the waiters then go to sleep waiting
2625          * for more free space, otherwise try to get some space for
2626          * this transaction.
2627          */
2628
2629         if ((ntic = log->l_write_headq)) {
2630                 free_bytes = xlog_space_left(log, log->l_grant_write_cycle,
2631                                              log->l_grant_write_bytes);
2632                 do {
2633                         ASSERT(ntic->t_flags & XLOG_TIC_PERM_RESERV);
2634
2635                         if (free_bytes < ntic->t_unit_res)
2636                                 break;
2637                         free_bytes -= ntic->t_unit_res;
2638                         sv_signal(&ntic->t_sema);
2639                         ntic = ntic->t_next;
2640                 } while (ntic != log->l_write_headq);
2641
2642                 if (ntic != log->l_write_headq) {
2643                         if ((tic->t_flags & XLOG_TIC_IN_Q) == 0)
2644                                 XLOG_INS_TICKETQ(log->l_write_headq, tic);
2645
2646                         xlog_trace_loggrant(log, tic,
2647                                     "xlog_regrant_write_log_space: sleep 1");
2648                         XFS_STATS_INC(xs_sleep_logspace);
2649                         sv_wait(&tic->t_sema, PINOD|PLTWAIT,
2650                                 &log->l_grant_lock, s);
2651
2652                         /* If we're shutting down, this tic is already
2653                          * off the queue */
2654                         if (XLOG_FORCED_SHUTDOWN(log)) {
2655                                 s = GRANT_LOCK(log);
2656                                 goto error_return;
2657                         }
2658
2659                         xlog_trace_loggrant(log, tic,
2660                                     "xlog_regrant_write_log_space: wake 1");
2661                         xlog_grant_push_ail(log->l_mp, tic->t_unit_res);
2662                         s = GRANT_LOCK(log);
2663                 }
2664         }
2665
2666         need_bytes = tic->t_unit_res;
2667
2668 redo:
2669         if (XLOG_FORCED_SHUTDOWN(log))
2670                 goto error_return;
2671
2672         free_bytes = xlog_space_left(log, log->l_grant_write_cycle,
2673                                      log->l_grant_write_bytes);
2674         if (free_bytes < need_bytes) {
2675                 if ((tic->t_flags & XLOG_TIC_IN_Q) == 0)
2676                         XLOG_INS_TICKETQ(log->l_write_headq, tic);
2677                 XFS_STATS_INC(xs_sleep_logspace);
2678                 sv_wait(&tic->t_sema, PINOD|PLTWAIT, &log->l_grant_lock, s);
2679
2680                 /* If we're shutting down, this tic is already off the queue */
2681                 if (XLOG_FORCED_SHUTDOWN(log)) {
2682                         s = GRANT_LOCK(log);
2683                         goto error_return;
2684                 }
2685
2686                 xlog_trace_loggrant(log, tic,
2687                                     "xlog_regrant_write_log_space: wake 2");
2688                 xlog_grant_push_ail(log->l_mp, need_bytes);
2689                 s = GRANT_LOCK(log);
2690                 goto redo;
2691         } else if (tic->t_flags & XLOG_TIC_IN_Q)
2692                 XLOG_DEL_TICKETQ(log->l_write_headq, tic);
2693
2694         XLOG_GRANT_ADD_SPACE(log, need_bytes, 'w'); /* we've got enough space */
2695 #ifdef DEBUG
2696         tail_lsn = log->l_tail_lsn;
2697         if (CYCLE_LSN(tail_lsn) != log->l_grant_write_cycle) {
2698                 ASSERT(log->l_grant_write_cycle-1 == CYCLE_LSN(tail_lsn));
2699                 ASSERT(log->l_grant_write_bytes <= BBTOB(BLOCK_LSN(tail_lsn)));
2700         }
2701 #endif
2702
2703         xlog_trace_loggrant(log, tic, "xlog_regrant_write_log_space: exit");
2704         xlog_verify_grant_head(log, 1);
2705         GRANT_UNLOCK(log, s);
2706         return (0);
2707
2708
2709  error_return:
2710         if (tic->t_flags & XLOG_TIC_IN_Q)
2711                 XLOG_DEL_TICKETQ(log->l_reserve_headq, tic);
2712         xlog_trace_loggrant(log, tic, "xlog_regrant_write_log_space: err_ret");
2713         /*
2714          * If we are failing, make sure the ticket doesn't have any
2715          * current reservations. We don't want to add this back when
2716          * the ticket/transaction gets cancelled.
2717          */
2718         tic->t_curr_res = 0;
2719         tic->t_cnt = 0; /* ungrant will give back unit_res * t_cnt. */
2720         GRANT_UNLOCK(log, s);
2721         return XFS_ERROR(EIO);
2722 }       /* xlog_regrant_write_log_space */
2723
2724
2725 /* The first cnt-1 times through here we don't need to
2726  * move the grant write head because the permanent
2727  * reservation has reserved cnt times the unit amount.
2728  * Release part of current permanent unit reservation and
2729  * reset current reservation to be one units worth.  Also
2730  * move grant reservation head forward.
2731  */
2732 STATIC void
2733 xlog_regrant_reserve_log_space(xlog_t        *log,
2734                                xlog_ticket_t *ticket)
2735 {
2736         SPLDECL(s);
2737
2738         xlog_trace_loggrant(log, ticket,
2739                             "xlog_regrant_reserve_log_space: enter");
2740         if (ticket->t_cnt > 0)
2741                 ticket->t_cnt--;
2742
2743         s = GRANT_LOCK(log);
2744         XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'w');
2745         XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'r');
2746         ticket->t_curr_res = ticket->t_unit_res;
2747         XLOG_TIC_RESET_RES(ticket);
2748         xlog_trace_loggrant(log, ticket,
2749                             "xlog_regrant_reserve_log_space: sub current res");
2750         xlog_verify_grant_head(log, 1);
2751
2752         /* just return if we still have some of the pre-reserved space */
2753         if (ticket->t_cnt > 0) {
2754                 GRANT_UNLOCK(log, s);
2755                 return;
2756         }
2757
2758         XLOG_GRANT_ADD_SPACE(log, ticket->t_unit_res, 'r');
2759         xlog_trace_loggrant(log, ticket,
2760                             "xlog_regrant_reserve_log_space: exit");
2761         xlog_verify_grant_head(log, 0);
2762         GRANT_UNLOCK(log, s);
2763         ticket->t_curr_res = ticket->t_unit_res;
2764         XLOG_TIC_RESET_RES(ticket);
2765 }       /* xlog_regrant_reserve_log_space */
2766
2767
2768 /*
2769  * Give back the space left from a reservation.
2770  *
2771  * All the information we need to make a correct determination of space left
2772  * is present.  For non-permanent reservations, things are quite easy.  The
2773  * count should have been decremented to zero.  We only need to deal with the
2774  * space remaining in the current reservation part of the ticket.  If the
2775  * ticket contains a permanent reservation, there may be left over space which
2776  * needs to be released.  A count of N means that N-1 refills of the current
2777  * reservation can be done before we need to ask for more space.  The first
2778  * one goes to fill up the first current reservation.  Once we run out of
2779  * space, the count will stay at zero and the only space remaining will be
2780  * in the current reservation field.
2781  */
2782 STATIC void
2783 xlog_ungrant_log_space(xlog_t        *log,
2784                        xlog_ticket_t *ticket)
2785 {
2786         SPLDECL(s);
2787
2788         if (ticket->t_cnt > 0)
2789                 ticket->t_cnt--;
2790
2791         s = GRANT_LOCK(log);
2792         xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: enter");
2793
2794         XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'w');
2795         XLOG_GRANT_SUB_SPACE(log, ticket->t_curr_res, 'r');
2796
2797         xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: sub current");
2798
2799         /* If this is a permanent reservation ticket, we may be able to free
2800          * up more space based on the remaining count.
2801          */
2802         if (ticket->t_cnt > 0) {
2803                 ASSERT(ticket->t_flags & XLOG_TIC_PERM_RESERV);
2804                 XLOG_GRANT_SUB_SPACE(log, ticket->t_unit_res*ticket->t_cnt,'w');
2805                 XLOG_GRANT_SUB_SPACE(log, ticket->t_unit_res*ticket->t_cnt,'r');
2806         }
2807
2808         xlog_trace_loggrant(log, ticket, "xlog_ungrant_log_space: exit");
2809         xlog_verify_grant_head(log, 1);
2810         GRANT_UNLOCK(log, s);
2811         xfs_log_move_tail(log->l_mp, 1);
2812 }       /* xlog_ungrant_log_space */
2813
2814
2815 /*
2816  * Atomically put back used ticket.
2817  */
2818 void
2819 xlog_state_put_ticket(xlog_t        *log,
2820                       xlog_ticket_t *tic)
2821 {
2822         unsigned long s;
2823
2824         s = LOG_LOCK(log);
2825         xlog_ticket_put(log, tic);
2826         LOG_UNLOCK(log, s);
2827 }       /* xlog_state_put_ticket */
2828
2829 /*
2830  * Flush iclog to disk if this is the last reference to the given iclog and
2831  * the WANT_SYNC bit is set.
2832  *
2833  * When this function is entered, the iclog is not necessarily in the
2834  * WANT_SYNC state.  It may be sitting around waiting to get filled.
2835  *
2836  *
2837  */
2838 int
2839 xlog_state_release_iclog(xlog_t         *log,
2840                          xlog_in_core_t *iclog)
2841 {
2842         SPLDECL(s);
2843         int             sync = 0;       /* do we sync? */
2844
2845         xlog_assign_tail_lsn(log->l_mp);
2846
2847         s = LOG_LOCK(log);
2848
2849         if (iclog->ic_state & XLOG_STATE_IOERROR) {
2850                 LOG_UNLOCK(log, s);
2851                 return XFS_ERROR(EIO);
2852         }
2853
2854         ASSERT(iclog->ic_refcnt > 0);
2855         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE ||
2856                iclog->ic_state == XLOG_STATE_WANT_SYNC);
2857
2858         if (--iclog->ic_refcnt == 0 &&
2859             iclog->ic_state == XLOG_STATE_WANT_SYNC) {
2860                 sync++;
2861                 iclog->ic_state = XLOG_STATE_SYNCING;
2862                 INT_SET(iclog->ic_header.h_tail_lsn, ARCH_CONVERT, log->l_tail_lsn);
2863                 xlog_verify_tail_lsn(log, iclog, log->l_tail_lsn);
2864                 /* cycle incremented when incrementing curr_block */
2865         }
2866
2867         LOG_UNLOCK(log, s);
2868
2869         /*
2870          * We let the log lock go, so it's possible that we hit a log I/O
2871          * error or someother SHUTDOWN condition that marks the iclog
2872          * as XLOG_STATE_IOERROR before the bwrite. However, we know that
2873          * this iclog has consistent data, so we ignore IOERROR
2874          * flags after this point.
2875          */
2876         if (sync) {
2877                 return xlog_sync(log, iclog);
2878         }
2879         return (0);
2880
2881 }       /* xlog_state_release_iclog */
2882
2883
2884 /*
2885  * This routine will mark the current iclog in the ring as WANT_SYNC
2886  * and move the current iclog pointer to the next iclog in the ring.
2887  * When this routine is called from xlog_state_get_iclog_space(), the
2888  * exact size of the iclog has not yet been determined.  All we know is
2889  * that every data block.  We have run out of space in this log record.
2890  */
2891 STATIC void
2892 xlog_state_switch_iclogs(xlog_t         *log,
2893                          xlog_in_core_t *iclog,
2894                          int            eventual_size)
2895 {
2896         ASSERT(iclog->ic_state == XLOG_STATE_ACTIVE);
2897         if (!eventual_size)
2898                 eventual_size = iclog->ic_offset;
2899         iclog->ic_state = XLOG_STATE_WANT_SYNC;
2900         INT_SET(iclog->ic_header.h_prev_block, ARCH_CONVERT, log->l_prev_block);
2901         log->l_prev_block = log->l_curr_block;
2902         log->l_prev_cycle = log->l_curr_cycle;
2903
2904         /* roll log?: ic_offset changed later */
2905         log->l_curr_block += BTOBB(eventual_size)+BTOBB(log->l_iclog_hsize);
2906
2907         /* Round up to next log-sunit */
2908         if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) &&
2909             log->l_mp->m_sb.sb_logsunit > 1) {
2910                 __uint32_t sunit_bb = BTOBB(log->l_mp->m_sb.sb_logsunit);
2911                 log->l_curr_block = roundup(log->l_curr_block, sunit_bb);
2912         }
2913
2914         if (log->l_curr_block >= log->l_logBBsize) {
2915                 log->l_curr_cycle++;
2916                 if (log->l_curr_cycle == XLOG_HEADER_MAGIC_NUM)
2917                         log->l_curr_cycle++;
2918                 log->l_curr_block -= log->l_logBBsize;
2919                 ASSERT(log->l_curr_block >= 0);
2920         }
2921         ASSERT(iclog == log->l_iclog);
2922         log->l_iclog = iclog->ic_next;
2923 }       /* xlog_state_switch_iclogs */
2924
2925
2926 /*
2927  * Write out all data in the in-core log as of this exact moment in time.
2928  *
2929  * Data may be written to the in-core log during this call.  However,
2930  * we don't guarantee this data will be written out.  A change from past
2931  * implementation means this routine will *not* write out zero length LRs.
2932  *
2933  * Basically, we try and perform an intelligent scan of the in-core logs.
2934  * If we determine there is no flushable data, we just return.  There is no
2935  * flushable data if:
2936  *
2937  *      1. the current iclog is active and has no data; the previous iclog
2938  *              is in the active or dirty state.
2939  *      2. the current iclog is drity, and the previous iclog is in the
2940  *              active or dirty state.
2941  *
2942  * We may sleep (call psema) if:
2943  *
2944  *      1. the current iclog is not in the active nor dirty state.
2945  *      2. the current iclog dirty, and the previous iclog is not in the
2946  *              active nor dirty state.
2947  *      3. the current iclog is active, and there is another thread writing
2948  *              to this particular iclog.
2949  *      4. a) the current iclog is active and has no other writers
2950  *         b) when we return from flushing out this iclog, it is still
2951  *              not in the active nor dirty state.
2952  */
2953 STATIC int
2954 xlog_state_sync_all(xlog_t *log, uint flags)
2955 {
2956         xlog_in_core_t  *iclog;
2957         xfs_lsn_t       lsn;
2958         SPLDECL(s);
2959
2960         s = LOG_LOCK(log);
2961
2962         iclog = log->l_iclog;
2963         if (iclog->ic_state & XLOG_STATE_IOERROR) {
2964                 LOG_UNLOCK(log, s);
2965                 return XFS_ERROR(EIO);
2966         }
2967
2968         /* If the head iclog is not active nor dirty, we just attach
2969          * ourselves to the head and go to sleep.
2970          */
2971         if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2972             iclog->ic_state == XLOG_STATE_DIRTY) {
2973                 /*
2974                  * If the head is dirty or (active and empty), then
2975                  * we need to look at the previous iclog.  If the previous
2976                  * iclog is active or dirty we are done.  There is nothing
2977                  * to sync out.  Otherwise, we attach ourselves to the
2978                  * previous iclog and go to sleep.
2979                  */
2980                 if (iclog->ic_state == XLOG_STATE_DIRTY ||
2981                     (iclog->ic_refcnt == 0 && iclog->ic_offset == 0)) {
2982                         iclog = iclog->ic_prev;
2983                         if (iclog->ic_state == XLOG_STATE_ACTIVE ||
2984                             iclog->ic_state == XLOG_STATE_DIRTY)
2985                                 goto no_sleep;
2986                         else
2987                                 goto maybe_sleep;
2988                 } else {
2989                         if (iclog->ic_refcnt == 0) {
2990                                 /* We are the only one with access to this
2991                                  * iclog.  Flush it out now.  There should
2992                                  * be a roundoff of zero to show that someone
2993                                  * has already taken care of the roundoff from
2994                                  * the previous sync.
2995                                  */
2996                                 iclog->ic_refcnt++;
2997                                 lsn = INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT);
2998                                 xlog_state_switch_iclogs(log, iclog, 0);
2999                                 LOG_UNLOCK(log, s);
3000
3001                                 if (xlog_state_release_iclog(log, iclog))
3002                                         return XFS_ERROR(EIO);
3003                                 s = LOG_LOCK(log);
3004                                 if (INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT) == lsn &&
3005                                     iclog->ic_state != XLOG_STATE_DIRTY)
3006                                         goto maybe_sleep;
3007                                 else
3008                                         goto no_sleep;
3009                         } else {
3010                                 /* Someone else is writing to this iclog.
3011                                  * Use its call to flush out the data.  However,
3012                                  * the other thread may not force out this LR,
3013                                  * so we mark it WANT_SYNC.
3014                                  */
3015                                 xlog_state_switch_iclogs(log, iclog, 0);
3016                                 goto maybe_sleep;
3017                         }
3018                 }
3019         }
3020
3021         /* By the time we come around again, the iclog could've been filled
3022          * which would give it another lsn.  If we have a new lsn, just
3023          * return because the relevant data has been flushed.
3024          */
3025 maybe_sleep:
3026         if (flags & XFS_LOG_SYNC) {
3027                 /*
3028                  * We must check if we're shutting down here, before
3029                  * we wait, while we're holding the LOG_LOCK.
3030                  * Then we check again after waking up, in case our
3031                  * sleep was disturbed by a bad news.
3032                  */
3033                 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3034                         LOG_UNLOCK(log, s);
3035                         return XFS_ERROR(EIO);
3036                 }
3037                 XFS_STATS_INC(xs_log_force_sleep);
3038                 sv_wait(&iclog->ic_forcesema, PINOD, &log->l_icloglock, s);
3039                 /*
3040                  * No need to grab the log lock here since we're
3041                  * only deciding whether or not to return EIO
3042                  * and the memory read should be atomic.
3043                  */
3044                 if (iclog->ic_state & XLOG_STATE_IOERROR)
3045                         return XFS_ERROR(EIO);
3046
3047         } else {
3048
3049 no_sleep:
3050                 LOG_UNLOCK(log, s);
3051         }
3052         return 0;
3053 }       /* xlog_state_sync_all */
3054
3055
3056 /*
3057  * Used by code which implements synchronous log forces.
3058  *
3059  * Find in-core log with lsn.
3060  *      If it is in the DIRTY state, just return.
3061  *      If it is in the ACTIVE state, move the in-core log into the WANT_SYNC
3062  *              state and go to sleep or return.
3063  *      If it is in any other state, go to sleep or return.
3064  *
3065  * If filesystem activity goes to zero, the iclog will get flushed only by
3066  * bdflush().
3067  */
3068 int
3069 xlog_state_sync(xlog_t    *log,
3070                 xfs_lsn_t lsn,
3071                 uint      flags)
3072 {
3073     xlog_in_core_t      *iclog;
3074     int                 already_slept = 0;
3075     SPLDECL(s);
3076
3077
3078 try_again:
3079     s = LOG_LOCK(log);
3080     iclog = log->l_iclog;
3081
3082     if (iclog->ic_state & XLOG_STATE_IOERROR) {
3083             LOG_UNLOCK(log, s);
3084             return XFS_ERROR(EIO);
3085     }
3086
3087     do {
3088         if (INT_GET(iclog->ic_header.h_lsn, ARCH_CONVERT) != lsn) {
3089             iclog = iclog->ic_next;
3090             continue;
3091         }
3092
3093         if (iclog->ic_state == XLOG_STATE_DIRTY) {
3094                 LOG_UNLOCK(log, s);
3095                 return 0;
3096         }
3097
3098         if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3099                 /*
3100                  * We sleep here if we haven't already slept (e.g.
3101                  * this is the first time we've looked at the correct
3102                  * iclog buf) and the buffer before us is going to
3103                  * be sync'ed. The reason for this is that if we
3104                  * are doing sync transactions here, by waiting for
3105                  * the previous I/O to complete, we can allow a few
3106                  * more transactions into this iclog before we close
3107                  * it down.
3108                  *
3109                  * Otherwise, we mark the buffer WANT_SYNC, and bump
3110                  * up the refcnt so we can release the log (which drops
3111                  * the ref count).  The state switch keeps new transaction
3112                  * commits from using this buffer.  When the current commits
3113                  * finish writing into the buffer, the refcount will drop to
3114                  * zero and the buffer will go out then.
3115                  */
3116                 if (!already_slept &&
3117                     (iclog->ic_prev->ic_state & (XLOG_STATE_WANT_SYNC |
3118                                                  XLOG_STATE_SYNCING))) {
3119                         ASSERT(!(iclog->ic_state & XLOG_STATE_IOERROR));
3120                         XFS_STATS_INC(xs_log_force_sleep);
3121                         sv_wait(&iclog->ic_prev->ic_writesema, PSWP,
3122                                 &log->l_icloglock, s);
3123                         already_slept = 1;
3124                         goto try_again;
3125                 } else {
3126                         iclog->ic_refcnt++;
3127                         xlog_state_switch_iclogs(log, iclog, 0);
3128                         LOG_UNLOCK(log, s);
3129                         if (xlog_state_release_iclog(log, iclog))
3130                                 return XFS_ERROR(EIO);
3131                         s = LOG_LOCK(log);
3132                 }
3133         }
3134
3135         if ((flags & XFS_LOG_SYNC) && /* sleep */
3136             !(iclog->ic_state & (XLOG_STATE_ACTIVE | XLOG_STATE_DIRTY))) {
3137
3138                 /*
3139                  * Don't wait on the forcesema if we know that we've
3140                  * gotten a log write error.
3141                  */
3142                 if (iclog->ic_state & XLOG_STATE_IOERROR) {
3143                         LOG_UNLOCK(log, s);
3144                         return XFS_ERROR(EIO);
3145                 }
3146                 XFS_STATS_INC(xs_log_force_sleep);
3147                 sv_wait(&iclog->ic_forcesema, PSWP, &log->l_icloglock, s);
3148                 /*
3149                  * No need to grab the log lock here since we're
3150                  * only deciding whether or not to return EIO
3151                  * and the memory read should be atomic.
3152                  */
3153                 if (iclog->ic_state & XLOG_STATE_IOERROR)
3154                         return XFS_ERROR(EIO);
3155         } else {                /* just return */
3156                 LOG_UNLOCK(log, s);
3157         }
3158         return 0;
3159
3160     } while (iclog != log->l_iclog);
3161
3162     LOG_UNLOCK(log, s);
3163     return (0);
3164 }       /* xlog_state_sync */
3165
3166
3167 /*
3168  * Called when we want to mark the current iclog as being ready to sync to
3169  * disk.
3170  */
3171 void
3172 xlog_state_want_sync(xlog_t *log, xlog_in_core_t *iclog)
3173 {
3174         SPLDECL(s);
3175
3176         s = LOG_LOCK(log);
3177
3178         if (iclog->ic_state == XLOG_STATE_ACTIVE) {
3179                 xlog_state_switch_iclogs(log, iclog, 0);
3180         } else {
3181                 ASSERT(iclog->ic_state &
3182                         (XLOG_STATE_WANT_SYNC|XLOG_STATE_IOERROR));
3183         }
3184
3185         LOG_UNLOCK(log, s);
3186 }       /* xlog_state_want_sync */
3187
3188
3189
3190 /*****************************************************************************
3191  *
3192  *              TICKET functions
3193  *
3194  *****************************************************************************
3195  */
3196
3197 /*
3198  *      Algorithm doesn't take into account page size. ;-(
3199  */
3200 STATIC void
3201 xlog_state_ticket_alloc(xlog_t *log)
3202 {
3203         xlog_ticket_t   *t_list;
3204         xlog_ticket_t   *next;
3205         xfs_caddr_t     buf;
3206         uint            i = (NBPP / sizeof(xlog_ticket_t)) - 2;
3207         SPLDECL(s);
3208
3209         /*
3210          * The kmem_zalloc may sleep, so we shouldn't be holding the
3211          * global lock.  XXXmiken: may want to use zone allocator.
3212          */
3213         buf = (xfs_caddr_t) kmem_zalloc(NBPP, KM_SLEEP);
3214
3215         s = LOG_LOCK(log);
3216
3217         /* Attach 1st ticket to Q, so we can keep track of allocated memory */
3218         t_list = (xlog_ticket_t *)buf;
3219         t_list->t_next = log->l_unmount_free;
3220         log->l_unmount_free = t_list++;
3221         log->l_ticket_cnt++;
3222         log->l_ticket_tcnt++;
3223
3224         /* Next ticket becomes first ticket attached to ticket free list */
3225         if (log->l_freelist != NULL) {
3226                 ASSERT(log->l_tail != NULL);
3227                 log->l_tail->t_next = t_list;
3228         } else {
3229                 log->l_freelist = t_list;
3230         }
3231         log->l_ticket_cnt++;
3232         log->l_ticket_tcnt++;
3233
3234         /* Cycle through rest of alloc'ed memory, building up free Q */
3235         for ( ; i > 0; i--) {
3236                 next = t_list + 1;
3237                 t_list->t_next = next;
3238                 t_list = next;
3239                 log->l_ticket_cnt++;
3240                 log->l_ticket_tcnt++;
3241         }
3242         t_list->t_next = NULL;
3243         log->l_tail = t_list;
3244         LOG_UNLOCK(log, s);
3245 }       /* xlog_state_ticket_alloc */
3246
3247
3248 /*
3249  * Put ticket into free list
3250  *
3251  * Assumption: log lock is held around this call.
3252  */
3253 STATIC void
3254 xlog_ticket_put(xlog_t          *log,
3255                 xlog_ticket_t   *ticket)
3256 {
3257         sv_destroy(&ticket->t_sema);
3258
3259         /*
3260          * Don't think caching will make that much difference.  It's
3261          * more important to make debug easier.
3262          */
3263 #if 0
3264         /* real code will want to use LIFO for caching */
3265         ticket->t_next = log->l_freelist;
3266         log->l_freelist = ticket;
3267         /* no need to clear fields */
3268 #else
3269         /* When we debug, it is easier if tickets are cycled */
3270         ticket->t_next     = NULL;
3271         if (log->l_tail != 0) {
3272                 log->l_tail->t_next = ticket;
3273         } else {
3274                 ASSERT(log->l_freelist == 0);
3275                 log->l_freelist = ticket;
3276         }
3277         log->l_tail         = ticket;
3278 #endif /* DEBUG */
3279         log->l_ticket_cnt++;
3280 }       /* xlog_ticket_put */
3281
3282
3283 /*
3284  * Grab ticket off freelist or allocation some more
3285  */
3286 xlog_ticket_t *
3287 xlog_ticket_get(xlog_t          *log,
3288                 int             unit_bytes,
3289                 int             cnt,
3290                 char            client,
3291                 uint            xflags)
3292 {
3293         xlog_ticket_t   *tic;
3294         uint            num_headers;
3295         SPLDECL(s);
3296
3297  alloc:
3298         if (log->l_freelist == NULL)
3299                 xlog_state_ticket_alloc(log);           /* potentially sleep */
3300
3301         s = LOG_LOCK(log);
3302         if (log->l_freelist == NULL) {
3303                 LOG_UNLOCK(log, s);
3304                 goto alloc;
3305         }
3306         tic             = log->l_freelist;
3307         log->l_freelist = tic->t_next;
3308         if (log->l_freelist == NULL)
3309                 log->l_tail = NULL;
3310         log->l_ticket_cnt--;
3311         LOG_UNLOCK(log, s);
3312
3313         /*
3314          * Permanent reservations have up to 'cnt'-1 active log operations
3315          * in the log.  A unit in this case is the amount of space for one
3316          * of these log operations.  Normal reservations have a cnt of 1
3317          * and their unit amount is the total amount of space required.
3318          *
3319          * The following lines of code account for non-transaction data
3320          * which occupy space in the on-disk log.
3321          *
3322          * Normal form of a transaction is:
3323          * <oph><trans-hdr><start-oph><reg1-oph><reg1><reg2-oph>...<commit-oph>
3324          * and then there are LR hdrs, split-recs and roundoff at end of syncs.
3325          *
3326          * We need to account for all the leadup data and trailer data
3327          * around the transaction data.
3328          * And then we need to account for the worst case in terms of using
3329          * more space.
3330          * The worst case will happen if:
3331          * - the placement of the transaction happens to be such that the
3332          *   roundoff is at its maximum
3333          * - the transaction data is synced before the commit record is synced
3334          *   i.e. <transaction-data><roundoff> | <commit-rec><roundoff>
3335          *   Therefore the commit record is in its own Log Record.
3336          *   This can happen as the commit record is called with its
3337          *   own region to xlog_write().
3338          *   This then means that in the worst case, roundoff can happen for
3339          *   the commit-rec as well.
3340          *   The commit-rec is smaller than padding in this scenario and so it is
3341          *   not added separately.
3342          */
3343
3344         /* for trans header */
3345         unit_bytes += sizeof(xlog_op_header_t);
3346         unit_bytes += sizeof(xfs_trans_header_t);
3347
3348         /* for start-rec */
3349         unit_bytes += sizeof(xlog_op_header_t);
3350
3351         /* for LR headers */
3352         num_headers = ((unit_bytes + log->l_iclog_size-1) >> log->l_iclog_size_log);
3353         unit_bytes += log->l_iclog_hsize * num_headers;
3354
3355         /* for commit-rec LR header - note: padding will subsume the ophdr */
3356         unit_bytes += log->l_iclog_hsize;
3357
3358         /* for split-recs - ophdrs added when data split over LRs */
3359         unit_bytes += sizeof(xlog_op_header_t) * num_headers;
3360
3361         /* for roundoff padding for transaction data and one for commit record */
3362         if (XFS_SB_VERSION_HASLOGV2(&log->l_mp->m_sb) &&
3363             log->l_mp->m_sb.sb_logsunit > 1) {
3364                 /* log su roundoff */
3365                 unit_bytes += 2*log->l_mp->m_sb.sb_logsunit;
3366         } else {
3367                 /* BB roundoff */
3368                 unit_bytes += 2*BBSIZE;
3369         }
3370
3371         tic->t_unit_res         = unit_bytes;
3372         tic->t_curr_res         = unit_bytes;
3373         tic->t_cnt              = cnt;
3374         tic->t_ocnt             = cnt;
3375         tic->t_tid              = (xlog_tid_t)((__psint_t)tic & 0xffffffff);
3376         tic->t_clientid         = client;
3377         tic->t_flags            = XLOG_TIC_INITED;
3378         tic->t_trans_type       = 0;
3379         if (xflags & XFS_LOG_PERM_RESERV)
3380                 tic->t_flags |= XLOG_TIC_PERM_RESERV;
3381         sv_init(&(tic->t_sema), SV_DEFAULT, "logtick");
3382
3383         XLOG_TIC_RESET_RES(tic);
3384
3385         return tic;
3386 }       /* xlog_ticket_get */
3387
3388
3389 /******************************************************************************
3390  *
3391  *              Log debug routines
3392  *
3393  ******************************************************************************
3394  */
3395 #if defined(DEBUG) && !defined(XLOG_NOLOG)
3396 /*
3397  * Make sure that the destination ptr is within the valid data region of
3398  * one of the iclogs.  This uses backup pointers stored in a different
3399  * part of the log in case we trash the log structure.
3400  */
3401 void
3402 xlog_verify_dest_ptr(xlog_t     *log,
3403                      __psint_t  ptr)
3404 {
3405         int i;
3406         int good_ptr = 0;
3407
3408         for (i=0; i < log->l_iclog_bufs; i++) {
3409                 if (ptr >= (__psint_t)log->l_iclog_bak[i] &&
3410                     ptr <= (__psint_t)log->l_iclog_bak[i]+log->l_iclog_size)
3411                         good_ptr++;
3412         }
3413         if (! good_ptr)
3414                 xlog_panic("xlog_verify_dest_ptr: invalid ptr");
3415 }       /* xlog_verify_dest_ptr */
3416
3417 STATIC void
3418 xlog_verify_grant_head(xlog_t *log, int equals)
3419 {
3420     if (log->l_grant_reserve_cycle == log->l_grant_write_cycle) {
3421         if (equals)
3422             ASSERT(log->l_grant_reserve_bytes >= log->l_grant_write_bytes);
3423         else
3424             ASSERT(log->l_grant_reserve_bytes > log->l_grant_write_bytes);
3425     } else {
3426         ASSERT(log->l_grant_reserve_cycle-1 == log->l_grant_write_cycle);
3427         ASSERT(log->l_grant_write_bytes >= log->l_grant_reserve_bytes);
3428     }
3429 }       /* xlog_verify_grant_head */
3430
3431 /* check if it will fit */
3432 STATIC void
3433 xlog_verify_tail_lsn(xlog_t         *log,
3434                      xlog_in_core_t *iclog,
3435                      xfs_lsn_t      tail_lsn)
3436 {
3437     int blocks;
3438
3439     if (CYCLE_LSN(tail_lsn) == log->l_prev_cycle) {
3440         blocks =
3441             log->l_logBBsize - (log->l_prev_block - BLOCK_LSN(tail_lsn));
3442         if (blocks < BTOBB(iclog->ic_offset)+BTOBB(log->l_iclog_hsize))
3443             xlog_panic("xlog_verify_tail_lsn: ran out of log space");
3444     } else {
3445         ASSERT(CYCLE_LSN(tail_lsn)+1 == log->l_prev_cycle);
3446
3447         if (BLOCK_LSN(tail_lsn) == log->l_prev_block)
3448             xlog_panic("xlog_verify_tail_lsn: tail wrapped");
3449
3450         blocks = BLOCK_LSN(tail_lsn) - log->l_prev_block;
3451         if (blocks < BTOBB(iclog->ic_offset) + 1)
3452             xlog_panic("xlog_verify_tail_lsn: ran out of log space");
3453     }
3454 }       /* xlog_verify_tail_lsn */
3455
3456 /*
3457  * Perform a number of checks on the iclog before writing to disk.
3458  *
3459  * 1. Make sure the iclogs are still circular
3460  * 2. Make sure we have a good magic number
3461  * 3. Make sure we don't have magic numbers in the data
3462  * 4. Check fields of each log operation header for:
3463  *      A. Valid client identifier
3464  *      B. tid ptr value falls in valid ptr space (user space code)
3465  *      C. Length in log record header is correct according to the
3466  *              individual operation headers within record.
3467  * 5. When a bwrite will occur within 5 blocks of the front of the physical
3468  *      log, check the preceding blocks of the physical log to make sure all
3469  *      the cycle numbers agree with the current cycle number.
3470  */
3471 STATIC void
3472 xlog_verify_iclog(xlog_t         *log,
3473                   xlog_in_core_t *iclog,
3474                   int            count,
3475                   boolean_t      syncing)
3476 {
3477         xlog_op_header_t        *ophead;
3478         xlog_in_core_t          *icptr;
3479         xlog_in_core_2_t        *xhdr;
3480         xfs_caddr_t             ptr;
3481         xfs_caddr_t             base_ptr;
3482         __psint_t               field_offset;
3483         __uint8_t               clientid;
3484         int                     len, i, j, k, op_len;
3485         int                     idx;
3486         SPLDECL(s);
3487
3488         /* check validity of iclog pointers */
3489         s = LOG_LOCK(log);
3490         icptr = log->l_iclog;
3491         for (i=0; i < log->l_iclog_bufs; i++) {
3492                 if (icptr == 0)
3493                         xlog_panic("xlog_verify_iclog: invalid ptr");
3494                 icptr = icptr->ic_next;
3495         }
3496         if (icptr != log->l_iclog)
3497                 xlog_panic("xlog_verify_iclog: corrupt iclog ring");
3498         LOG_UNLOCK(log, s);
3499
3500         /* check log magic numbers */
3501         ptr = (xfs_caddr_t) &(iclog->ic_header);
3502         if (INT_GET(*(uint *)ptr, ARCH_CONVERT) != XLOG_HEADER_MAGIC_NUM)
3503                 xlog_panic("xlog_verify_iclog: invalid magic num");
3504
3505         for (ptr += BBSIZE; ptr < ((xfs_caddr_t)&(iclog->ic_header))+count;
3506              ptr += BBSIZE) {
3507                 if (INT_GET(*(uint *)ptr, ARCH_CONVERT) == XLOG_HEADER_MAGIC_NUM)
3508                         xlog_panic("xlog_verify_iclog: unexpected magic num");
3509         }
3510
3511         /* check fields */
3512         len = INT_GET(iclog->ic_header.h_num_logops, ARCH_CONVERT);
3513         ptr = iclog->ic_datap;
3514         base_ptr = ptr;
3515         ophead = (xlog_op_header_t *)ptr;
3516         xhdr = (xlog_in_core_2_t *)&iclog->ic_header;
3517         for (i = 0; i < len; i++) {
3518                 ophead = (xlog_op_header_t *)ptr;
3519
3520                 /* clientid is only 1 byte */
3521                 field_offset = (__psint_t)
3522                                ((xfs_caddr_t)&(ophead->oh_clientid) - base_ptr);
3523                 if (syncing == B_FALSE || (field_offset & 0x1ff)) {
3524                         clientid = ophead->oh_clientid;
3525                 } else {
3526                         idx = BTOBBT((xfs_caddr_t)&(ophead->oh_clientid) - iclog->ic_datap);
3527                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3528                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3529                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3530                                 clientid = GET_CLIENT_ID(xhdr[j].hic_xheader.xh_cycle_data[k], ARCH_CONVERT);
3531                         } else {
3532                                 clientid = GET_CLIENT_ID(iclog->ic_header.h_cycle_data[idx], ARCH_CONVERT);
3533                         }
3534                 }
3535                 if (clientid != XFS_TRANSACTION && clientid != XFS_LOG)
3536                         cmn_err(CE_WARN, "xlog_verify_iclog: invalid clientid %d op 0x%p offset 0x%x", clientid, ophead, field_offset);
3537
3538                 /* check length */
3539                 field_offset = (__psint_t)
3540                                ((xfs_caddr_t)&(ophead->oh_len) - base_ptr);
3541                 if (syncing == B_FALSE || (field_offset & 0x1ff)) {
3542                         op_len = INT_GET(ophead->oh_len, ARCH_CONVERT);
3543                 } else {
3544                         idx = BTOBBT((__psint_t)&ophead->oh_len -
3545                                     (__psint_t)iclog->ic_datap);
3546                         if (idx >= (XLOG_HEADER_CYCLE_SIZE / BBSIZE)) {
3547                                 j = idx / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3548                                 k = idx % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
3549                                 op_len = INT_GET(xhdr[j].hic_xheader.xh_cycle_data[k], ARCH_CONVERT);
3550                         } else {
3551                                 op_len = INT_GET(iclog->ic_header.h_cycle_data[idx], ARCH_CONVERT);
3552                         }
3553                 }
3554                 ptr += sizeof(xlog_op_header_t) + op_len;
3555         }
3556 }       /* xlog_verify_iclog */
3557 #endif /* DEBUG && !XLOG_NOLOG */
3558
3559 /*
3560  * Mark all iclogs IOERROR. LOG_LOCK is held by the caller.
3561  */
3562 STATIC int
3563 xlog_state_ioerror(
3564         xlog_t  *log)
3565 {
3566         xlog_in_core_t  *iclog, *ic;
3567
3568         iclog = log->l_iclog;
3569         if (! (iclog->ic_state & XLOG_STATE_IOERROR)) {
3570                 /*
3571                  * Mark all the incore logs IOERROR.
3572                  * From now on, no log flushes will result.
3573                  */
3574                 ic = iclog;
3575                 do {
3576                         ic->ic_state = XLOG_STATE_IOERROR;
3577                         ic = ic->ic_next;
3578                 } while (ic != iclog);
3579                 return (0);
3580         }
3581         /*
3582          * Return non-zero, if state transition has already happened.
3583          */
3584         return (1);
3585 }
3586
3587 /*
3588  * This is called from xfs_force_shutdown, when we're forcibly
3589  * shutting down the filesystem, typically because of an IO error.
3590  * Our main objectives here are to make sure that:
3591  *      a. the filesystem gets marked 'SHUTDOWN' for all interested
3592  *         parties to find out, 'atomically'.
3593  *      b. those who're sleeping on log reservations, pinned objects and
3594  *          other resources get woken up, and be told the bad news.
3595  *      c. nothing new gets queued up after (a) and (b) are done.
3596  *      d. if !logerror, flush the iclogs to disk, then seal them off
3597  *         for business.
3598  */
3599 int
3600 xfs_log_force_umount(
3601         struct xfs_mount        *mp,
3602         int                     logerror)
3603 {
3604         xlog_ticket_t   *tic;
3605         xlog_t          *log;
3606         int             retval;
3607         SPLDECL(s);
3608         SPLDECL(s2);
3609
3610         log = mp->m_log;
3611
3612         /*
3613          * If this happens during log recovery, don't worry about
3614          * locking; the log isn't open for business yet.
3615          */
3616         if (!log ||
3617             log->l_flags & XLOG_ACTIVE_RECOVERY) {
3618                 mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3619                 XFS_BUF_DONE(mp->m_sb_bp);
3620                 return (0);
3621         }
3622
3623         /*
3624          * Somebody could've already done the hard work for us.
3625          * No need to get locks for this.
3626          */
3627         if (logerror && log->l_iclog->ic_state & XLOG_STATE_IOERROR) {
3628                 ASSERT(XLOG_FORCED_SHUTDOWN(log));
3629                 return (1);
3630         }
3631         retval = 0;
3632         /*
3633          * We must hold both the GRANT lock and the LOG lock,
3634          * before we mark the filesystem SHUTDOWN and wake
3635          * everybody up to tell the bad news.
3636          */
3637         s = GRANT_LOCK(log);
3638         s2 = LOG_LOCK(log);
3639         mp->m_flags |= XFS_MOUNT_FS_SHUTDOWN;
3640         XFS_BUF_DONE(mp->m_sb_bp);
3641         /*
3642          * This flag is sort of redundant because of the mount flag, but
3643          * it's good to maintain the separation between the log and the rest
3644          * of XFS.
3645          */
3646         log->l_flags |= XLOG_IO_ERROR;
3647
3648         /*
3649          * If we hit a log error, we want to mark all the iclogs IOERROR
3650          * while we're still holding the loglock.
3651          */
3652         if (logerror)
3653                 retval = xlog_state_ioerror(log);
3654         LOG_UNLOCK(log, s2);
3655
3656         /*
3657          * We don't want anybody waiting for log reservations
3658          * after this. That means we have to wake up everybody
3659          * queued up on reserve_headq as well as write_headq.
3660          * In addition, we make sure in xlog_{re}grant_log_space
3661          * that we don't enqueue anything once the SHUTDOWN flag
3662          * is set, and this action is protected by the GRANTLOCK.
3663          */
3664         if ((tic = log->l_reserve_headq)) {
3665                 do {
3666                         sv_signal(&tic->t_sema);
3667                         tic = tic->t_next;
3668                 } while (tic != log->l_reserve_headq);
3669         }
3670
3671         if ((tic = log->l_write_headq)) {
3672                 do {
3673                         sv_signal(&tic->t_sema);
3674                         tic = tic->t_next;
3675                 } while (tic != log->l_write_headq);
3676         }
3677         GRANT_UNLOCK(log, s);
3678
3679         if (! (log->l_iclog->ic_state & XLOG_STATE_IOERROR)) {
3680                 ASSERT(!logerror);
3681                 /*
3682                  * Force the incore logs to disk before shutting the
3683                  * log down completely.
3684                  */
3685                 xlog_state_sync_all(log, XFS_LOG_FORCE|XFS_LOG_SYNC);
3686                 s2 = LOG_LOCK(log);
3687                 retval = xlog_state_ioerror(log);
3688                 LOG_UNLOCK(log, s2);
3689         }
3690         /*
3691          * Wake up everybody waiting on xfs_log_force.
3692          * Callback all log item committed functions as if the
3693          * log writes were completed.
3694          */
3695         xlog_state_do_callback(log, XFS_LI_ABORTED, NULL);
3696
3697 #ifdef XFSERRORDEBUG
3698         {
3699                 xlog_in_core_t  *iclog;
3700
3701                 s = LOG_LOCK(log);
3702                 iclog = log->l_iclog;
3703                 do {
3704                         ASSERT(iclog->ic_callback == 0);
3705                         iclog = iclog->ic_next;
3706                 } while (iclog != log->l_iclog);
3707                 LOG_UNLOCK(log, s);
3708         }
3709 #endif
3710         /* return non-zero if log IOERROR transition had already happened */
3711         return (retval);
3712 }
3713
3714 STATIC int
3715 xlog_iclogs_empty(xlog_t *log)
3716 {
3717         xlog_in_core_t  *iclog;
3718
3719         iclog = log->l_iclog;
3720         do {
3721                 /* endianness does not matter here, zero is zero in
3722                  * any language.
3723                  */
3724                 if (iclog->ic_header.h_num_logops)
3725                         return(0);
3726                 iclog = iclog->ic_next;
3727         } while (iclog != log->l_iclog);
3728         return(1);
3729 }