fs/jfs/jfs_logmgr.c

   1 /*
   2  *   Copyright (C) International Business Machines Corp., 2000-2004
   3  *   Portions Copyright (C) Christoph Hellwig, 2001-2002
   4  *
   5  *   This program is free software;  you can redistribute it and/or modify
   6  *   it under the terms of the GNU General Public License as published by
   7  *   the Free Software Foundation; either version 2 of the License, or
   8  *   (at your option) any later version.
   9  *
  10  *   This program is distributed in the hope that it will be useful,
  11  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  12  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  13  *   the GNU General Public License for more details.
  14  *
  15  *   You should have received a copy of the GNU General Public License
  16  *   along with this program;  if not, write to the Free Software
  17  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  18  */
  19
  20 /*
  21  *      jfs_logmgr.c: log manager
  22  *
  23  * for related information, see transaction manager (jfs_txnmgr.c), and
  24  * recovery manager (jfs_logredo.c).
  25  *
  26  * note: for detail, RTFS.
  27  *
  28  *      log buffer manager:
  29  * special purpose buffer manager supporting log i/o requirements.
  30  * per log serial pageout of logpage
  31  * queuing i/o requests and redrive i/o at iodone
  32  * maintain current logpage buffer
  33  * no caching since append only
  34  * appropriate jfs buffer cache buffers as needed
  35  *
  36  *      group commit:
  37  * transactions which wrote COMMIT records in the same in-memory
  38  * log page during the pageout of previous/current log page(s) are
  39  * committed together by the pageout of the page.
  40  *
  41  *      TBD lazy commit:
  42  * transactions are committed asynchronously when the log page
  43  * containing it COMMIT is paged out when it becomes full;
  44  *
  45  *      serialization:
  46  * . a per log lock serialize log write.
  47  * . a per log lock serialize group commit.
  48  * . a per log lock serialize log open/close;
  49  *
  50  *      TBD log integrity:
  51  * careful-write (ping-pong) of last logpage to recover from crash
  52  * in overwrite.
  53  * detection of split (out-of-order) write of physical sectors
  54  * of last logpage via timestamp at end of each sector
  55  * with its mirror data array at trailer).
  56  *
  57  *      alternatives:
  58  * lsn - 64-bit monotonically increasing integer vs
  59  * 32-bit lspn and page eor.
  60  */
  61
  62 #include <linux/fs.h>
  63 #include <linux/blkdev.h>
  64 #include <linux/interrupt.h>
  65 #include <linux/smp_lock.h>
  66 #include <linux/completion.h>
  67 #include <linux/buffer_head.h>          /* for sync_blockdev() */
  68 #include <linux/bio.h>
  69 #include <linux/suspend.h>
  70 #include <linux/delay.h>
  71 #include "jfs_incore.h"
  72 #include "jfs_filsys.h"
  73 #include "jfs_metapage.h"
  74 #include "jfs_txnmgr.h"
  75 #include "jfs_debug.h"
  76
  77
  78 /*
  79  * lbuf's ready to be redriven.  Protected by log_redrive_lock (jfsIO thread)
  80  */
  81 static struct lbuf *log_redrive_list;
  82 static DEFINE_SPINLOCK(log_redrive_lock);
  83 DECLARE_WAIT_QUEUE_HEAD(jfs_IO_thread_wait);
  84
  85
  86 /*
  87  *      log read/write serialization (per log)
  88  */
  89 #define LOG_LOCK_INIT(log)      init_MUTEX(&(log)->loglock)
  90 #define LOG_LOCK(log)           down(&((log)->loglock))
  91 #define LOG_UNLOCK(log)         up(&((log)->loglock))
  92
  93
  94 /*
  95  *      log group commit serialization (per log)
  96  */
  97
  98 #define LOGGC_LOCK_INIT(log)    spin_lock_init(&(log)->gclock)
  99 #define LOGGC_LOCK(log)         spin_lock_irq(&(log)->gclock)
 100 #define LOGGC_UNLOCK(log)       spin_unlock_irq(&(log)->gclock)
 101 #define LOGGC_WAKEUP(tblk)      wake_up_all(&(tblk)->gcwait)
 102
 103 /*
 104  *      log sync serialization (per log)
 105  */
 106 #define LOGSYNC_DELTA(logsize)          min((logsize)/8, 128*LOGPSIZE)
 107 #define LOGSYNC_BARRIER(logsize)        ((logsize)/4)
 108 /*
 109 #define LOGSYNC_DELTA(logsize)          min((logsize)/4, 256*LOGPSIZE)
 110 #define LOGSYNC_BARRIER(logsize)        ((logsize)/2)
 111 */
 112
 113
 114 /*
 115  *      log buffer cache synchronization
 116  */
 117 static DEFINE_SPINLOCK(jfsLCacheLock);
 118
 119 #define LCACHE_LOCK(flags)      spin_lock_irqsave(&jfsLCacheLock, flags)
 120 #define LCACHE_UNLOCK(flags)    spin_unlock_irqrestore(&jfsLCacheLock, flags)
 121
 122 /*
 123  * See __SLEEP_COND in jfs_locks.h
 124  */
 125 #define LCACHE_SLEEP_COND(wq, cond, flags)      \
 126 do {                                            \
 127         if (cond)                               \
 128                 break;                          \
 129         __SLEEP_COND(wq, cond, LCACHE_LOCK(flags), LCACHE_UNLOCK(flags)); \
 130 } while (0)
 131
 132 #define LCACHE_WAKEUP(event)    wake_up(event)
 133
 134
 135 /*
 136  *      lbuf buffer cache (lCache) control
 137  */
 138 /* log buffer manager pageout control (cumulative, inclusive) */
 139 #define lbmREAD         0x0001
 140 #define lbmWRITE        0x0002  /* enqueue at tail of write queue;
 141                                  * init pageout if at head of queue;
 142                                  */
 143 #define lbmRELEASE      0x0004  /* remove from write queue
 144                                  * at completion of pageout;
 145                                  * do not free/recycle it yet:
 146                                  * caller will free it;
 147                                  */
 148 #define lbmSYNC         0x0008  /* do not return to freelist
 149                                  * when removed from write queue;
 150                                  */
 151 #define lbmFREE         0x0010  /* return to freelist
 152                                  * at completion of pageout;
 153                                  * the buffer may be recycled;
 154                                  */
 155 #define lbmDONE         0x0020
 156 #define lbmERROR        0x0040
 157 #define lbmGC           0x0080  /* lbmIODone to perform post-GC processing
 158                                  * of log page
 159                                  */
 160 #define lbmDIRECT       0x0100
 161
 162 /*
 163  * Global list of active external journals
 164  */
 165 static LIST_HEAD(jfs_external_logs);
 166 static struct jfs_log *dummy_log = NULL;
 167 static DECLARE_MUTEX(jfs_log_sem);
 168
 169 /*
 170  * external references
 171  */
 172 extern void txLazyUnlock(struct tblock * tblk);
 173 extern int jfs_stop_threads;
 174 extern struct completion jfsIOwait;
 175 extern int jfs_tlocks_low;
 176
 177 /*
 178  * forward references
 179  */
 180 static int lmWriteRecord(struct jfs_log * log, struct tblock * tblk,
 181                          struct lrd * lrd, struct tlock * tlck);
 182
 183 static int lmNextPage(struct jfs_log * log);
 184 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
 185                            int activate);
 186
 187 static int open_inline_log(struct super_block *sb);
 188 static int open_dummy_log(struct super_block *sb);
 189 static int lbmLogInit(struct jfs_log * log);
 190 static void lbmLogShutdown(struct jfs_log * log);
 191 static struct lbuf *lbmAllocate(struct jfs_log * log, int);
 192 static void lbmFree(struct lbuf * bp);
 193 static void lbmfree(struct lbuf * bp);
 194 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp);
 195 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag, int cant_block);
 196 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag);
 197 static int lbmIOWait(struct lbuf * bp, int flag);
 198 static bio_end_io_t lbmIODone;
 199 static void lbmStartIO(struct lbuf * bp);
 200 static void lmGCwrite(struct jfs_log * log, int cant_block);
 201 static int lmLogSync(struct jfs_log * log, int nosyncwait);
 202
 203
 204
 205 /*
 206  *      statistics
 207  */
 208 #ifdef CONFIG_JFS_STATISTICS
 209 static struct lmStat {
 210         uint commit;            /* # of commit */
 211         uint pagedone;          /* # of page written */
 212         uint submitted;         /* # of pages submitted */
 213         uint full_page;         /* # of full pages submitted */
 214         uint partial_page;      /* # of partial pages submitted */
 215 } lmStat;
 216 #endif
 217
 218
 219 /*
 220  * NAME:        lmLog()
 221  *
 222  * FUNCTION:    write a log record;
 223  *
 224  * PARAMETER:
 225  *
 226  * RETURN:      lsn - offset to the next log record to write (end-of-log);
 227  *              -1  - error;
 228  *
 229  * note: todo: log error handler
 230  */
 231 int lmLog(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
 232           struct tlock * tlck)
 233 {
 234         int lsn;
 235         int diffp, difft;
 236         struct metapage *mp = NULL;
 237         unsigned long flags;
 238
 239         jfs_info("lmLog: log:0x%p tblk:0x%p, lrd:0x%p tlck:0x%p",
 240                  log, tblk, lrd, tlck);
 241
 242         LOG_LOCK(log);
 243
 244         /* log by (out-of-transaction) JFS ? */
 245         if (tblk == NULL)
 246                 goto writeRecord;
 247
 248         /* log from page ? */
 249         if (tlck == NULL ||
 250             tlck->type & tlckBTROOT || (mp = tlck->mp) == NULL)
 251                 goto writeRecord;
 252
 253         /*
 254          *      initialize/update page/transaction recovery lsn
 255          */
 256         lsn = log->lsn;
 257
 258         LOGSYNC_LOCK(log, flags);
 259
 260         /*
 261          * initialize page lsn if first log write of the page
 262          */
 263         if (mp->lsn == 0) {
 264                 mp->log = log;
 265                 mp->lsn = lsn;
 266                 log->count++;
 267
 268                 /* insert page at tail of logsynclist */
 269                 list_add_tail(&mp->synclist, &log->synclist);
 270         }
 271
 272         /*
 273          *      initialize/update lsn of tblock of the page
 274          *
 275          * transaction inherits oldest lsn of pages associated
 276          * with allocation/deallocation of resources (their
 277          * log records are used to reconstruct allocation map
 278          * at recovery time: inode for inode allocation map,
 279          * B+-tree index of extent descriptors for block
 280          * allocation map);
 281          * allocation map pages inherit transaction lsn at
 282          * commit time to allow forwarding log syncpt past log
 283          * records associated with allocation/deallocation of
 284          * resources only after persistent map of these map pages
 285          * have been updated and propagated to home.
 286          */
 287         /*
 288          * initialize transaction lsn:
 289          */
 290         if (tblk->lsn == 0) {
 291                 /* inherit lsn of its first page logged */
 292                 tblk->lsn = mp->lsn;
 293                 log->count++;
 294
 295                 /* insert tblock after the page on logsynclist */
 296                 list_add(&tblk->synclist, &mp->synclist);
 297         }
 298         /*
 299          * update transaction lsn:
 300          */
 301         else {
 302                 /* inherit oldest/smallest lsn of page */
 303                 logdiff(diffp, mp->lsn, log);
 304                 logdiff(difft, tblk->lsn, log);
 305                 if (diffp < difft) {
 306                         /* update tblock lsn with page lsn */
 307                         tblk->lsn = mp->lsn;
 308
 309                         /* move tblock after page on logsynclist */
 310                         list_move(&tblk->synclist, &mp->synclist);
 311                 }
 312         }
 313
 314         LOGSYNC_UNLOCK(log, flags);
 315
 316         /*
 317          *      write the log record
 318          */
 319       writeRecord:
 320         lsn = lmWriteRecord(log, tblk, lrd, tlck);
 321
 322         /*
 323          * forward log syncpt if log reached next syncpt trigger
 324          */
 325         logdiff(diffp, lsn, log);
 326         if (diffp >= log->nextsync)
 327                 lsn = lmLogSync(log, 0);
 328
 329         /* update end-of-log lsn */
 330         log->lsn = lsn;
 331
 332         LOG_UNLOCK(log);
 333
 334         /* return end-of-log address */
 335         return lsn;
 336 }
 337
 338 /*
 339  * NAME:        lmWriteRecord()
 340  *
 341  * FUNCTION:    move the log record to current log page
 342  *
 343  * PARAMETER:   cd      - commit descriptor
 344  *
 345  * RETURN:      end-of-log address
 346  *
 347  * serialization: LOG_LOCK() held on entry/exit
 348  */
 349 static int
 350 lmWriteRecord(struct jfs_log * log, struct tblock * tblk, struct lrd * lrd,
 351               struct tlock * tlck)
 352 {
 353         int lsn = 0;            /* end-of-log address */
 354         struct lbuf *bp;        /* dst log page buffer */
 355         struct logpage *lp;     /* dst log page */
 356         caddr_t dst;            /* destination address in log page */
 357         int dstoffset;          /* end-of-log offset in log page */
 358         int freespace;          /* free space in log page */
 359         caddr_t p;              /* src meta-data page */
 360         caddr_t src;
 361         int srclen;
 362         int nbytes;             /* number of bytes to move */
 363         int i;
 364         int len;
 365         struct linelock *linelock;
 366         struct lv *lv;
 367         struct lvd *lvd;
 368         int l2linesize;
 369
 370         len = 0;
 371
 372         /* retrieve destination log page to write */
 373         bp = (struct lbuf *) log->bp;
 374         lp = (struct logpage *) bp->l_ldata;
 375         dstoffset = log->eor;
 376
 377         /* any log data to write ? */
 378         if (tlck == NULL)
 379                 goto moveLrd;
 380
 381         /*
 382          *      move log record data
 383          */
 384         /* retrieve source meta-data page to log */
 385         if (tlck->flag & tlckPAGELOCK) {
 386                 p = (caddr_t) (tlck->mp->data);
 387                 linelock = (struct linelock *) & tlck->lock;
 388         }
 389         /* retrieve source in-memory inode to log */
 390         else if (tlck->flag & tlckINODELOCK) {
 391                 if (tlck->type & tlckDTREE)
 392                         p = (caddr_t) &JFS_IP(tlck->ip)->i_dtroot;
 393                 else
 394                         p = (caddr_t) &JFS_IP(tlck->ip)->i_xtroot;
 395                 linelock = (struct linelock *) & tlck->lock;
 396         }
 397 #ifdef  _JFS_WIP
 398         else if (tlck->flag & tlckINLINELOCK) {
 399
 400                 inlinelock = (struct inlinelock *) & tlck;
 401                 p = (caddr_t) & inlinelock->pxd;
 402                 linelock = (struct linelock *) & tlck;
 403         }
 404 #endif                          /* _JFS_WIP */
 405         else {
 406                 jfs_err("lmWriteRecord: UFO tlck:0x%p", tlck);
 407                 return 0;       /* Probably should trap */
 408         }
 409         l2linesize = linelock->l2linesize;
 410
 411       moveData:
 412         ASSERT(linelock->index <= linelock->maxcnt);
 413
 414         lv = linelock->lv;
 415         for (i = 0; i < linelock->index; i++, lv++) {
 416                 if (lv->length == 0)
 417                         continue;
 418
 419                 /* is page full ? */
 420                 if (dstoffset >= LOGPSIZE - LOGPTLRSIZE) {
 421                         /* page become full: move on to next page */
 422                         lmNextPage(log);
 423
 424                         bp = log->bp;
 425                         lp = (struct logpage *) bp->l_ldata;
 426                         dstoffset = LOGPHDRSIZE;
 427                 }
 428
 429                 /*
 430                  * move log vector data
 431                  */
 432                 src = (u8 *) p + (lv->offset << l2linesize);
 433                 srclen = lv->length << l2linesize;
 434                 len += srclen;
 435                 while (srclen > 0) {
 436                         freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
 437                         nbytes = min(freespace, srclen);
 438                         dst = (caddr_t) lp + dstoffset;
 439                         memcpy(dst, src, nbytes);
 440                         dstoffset += nbytes;
 441
 442                         /* is page not full ? */
 443                         if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
 444                                 break;
 445
 446                         /* page become full: move on to next page */
 447                         lmNextPage(log);
 448
 449                         bp = (struct lbuf *) log->bp;
 450                         lp = (struct logpage *) bp->l_ldata;
 451                         dstoffset = LOGPHDRSIZE;
 452
 453                         srclen -= nbytes;
 454                         src += nbytes;
 455                 }
 456
 457                 /*
 458                  * move log vector descriptor
 459                  */
 460                 len += 4;
 461                 lvd = (struct lvd *) ((caddr_t) lp + dstoffset);
 462                 lvd->offset = cpu_to_le16(lv->offset);
 463                 lvd->length = cpu_to_le16(lv->length);
 464                 dstoffset += 4;
 465                 jfs_info("lmWriteRecord: lv offset:%d length:%d",
 466                          lv->offset, lv->length);
 467         }
 468
 469         if ((i = linelock->next)) {
 470                 linelock = (struct linelock *) lid_to_tlock(i);
 471                 goto moveData;
 472         }
 473
 474         /*
 475          *      move log record descriptor
 476          */
 477       moveLrd:
 478         lrd->length = cpu_to_le16(len);
 479
 480         src = (caddr_t) lrd;
 481         srclen = LOGRDSIZE;
 482
 483         while (srclen > 0) {
 484                 freespace = (LOGPSIZE - LOGPTLRSIZE) - dstoffset;
 485                 nbytes = min(freespace, srclen);
 486                 dst = (caddr_t) lp + dstoffset;
 487                 memcpy(dst, src, nbytes);
 488
 489                 dstoffset += nbytes;
 490                 srclen -= nbytes;
 491
 492                 /* are there more to move than freespace of page ? */
 493                 if (srclen)
 494                         goto pageFull;
 495
 496                 /*
 497                  * end of log record descriptor
 498                  */
 499
 500                 /* update last log record eor */
 501                 log->eor = dstoffset;
 502                 bp->l_eor = dstoffset;
 503                 lsn = (log->page << L2LOGPSIZE) + dstoffset;
 504
 505                 if (lrd->type & cpu_to_le16(LOG_COMMIT)) {
 506                         tblk->clsn = lsn;
 507                         jfs_info("wr: tclsn:0x%x, beor:0x%x", tblk->clsn,
 508                                  bp->l_eor);
 509
 510                         INCREMENT(lmStat.commit);       /* # of commit */
 511
 512                         /*
 513                          * enqueue tblock for group commit:
 514                          *
 515                          * enqueue tblock of non-trivial/synchronous COMMIT
 516                          * at tail of group commit queue
 517                          * (trivial/asynchronous COMMITs are ignored by
 518                          * group commit.)
 519                          */
 520                         LOGGC_LOCK(log);
 521
 522                         /* init tblock gc state */
 523                         tblk->flag = tblkGC_QUEUE;
 524                         tblk->bp = log->bp;
 525                         tblk->pn = log->page;
 526                         tblk->eor = log->eor;
 527
 528                         /* enqueue transaction to commit queue */
 529                         list_add_tail(&tblk->cqueue, &log->cqueue);
 530
 531                         LOGGC_UNLOCK(log);
 532                 }
 533
 534                 jfs_info("lmWriteRecord: lrd:0x%04x bp:0x%p pn:%d eor:0x%x",
 535                         le16_to_cpu(lrd->type), log->bp, log->page, dstoffset);
 536
 537                 /* page not full ? */
 538                 if (dstoffset < LOGPSIZE - LOGPTLRSIZE)
 539                         return lsn;
 540
 541               pageFull:
 542                 /* page become full: move on to next page */
 543                 lmNextPage(log);
 544
 545                 bp = (struct lbuf *) log->bp;
 546                 lp = (struct logpage *) bp->l_ldata;
 547                 dstoffset = LOGPHDRSIZE;
 548                 src += nbytes;
 549         }
 550
 551         return lsn;
 552 }
 553
 554
 555 /*
 556  * NAME:        lmNextPage()
 557  *
 558  * FUNCTION:    write current page and allocate next page.
 559  *
 560  * PARAMETER:   log
 561  *
 562  * RETURN:      0
 563  *
 564  * serialization: LOG_LOCK() held on entry/exit
 565  */
 566 static int lmNextPage(struct jfs_log * log)
 567 {
 568         struct logpage *lp;
 569         int lspn;               /* log sequence page number */
 570         int pn;                 /* current page number */
 571         struct lbuf *bp;
 572         struct lbuf *nextbp;
 573         struct tblock *tblk;
 574
 575         /* get current log page number and log sequence page number */
 576         pn = log->page;
 577         bp = log->bp;
 578         lp = (struct logpage *) bp->l_ldata;
 579         lspn = le32_to_cpu(lp->h.page);
 580
 581         LOGGC_LOCK(log);
 582
 583         /*
 584          *      write or queue the full page at the tail of write queue
 585          */
 586         /* get the tail tblk on commit queue */
 587         if (list_empty(&log->cqueue))
 588                 tblk = NULL;
 589         else
 590                 tblk = list_entry(log->cqueue.prev, struct tblock, cqueue);
 591
 592         /* every tblk who has COMMIT record on the current page,
 593          * and has not been committed, must be on commit queue
 594          * since tblk is queued at commit queueu at the time
 595          * of writing its COMMIT record on the page before
 596          * page becomes full (even though the tblk thread
 597          * who wrote COMMIT record may have been suspended
 598          * currently);
 599          */
 600
 601         /* is page bound with outstanding tail tblk ? */
 602         if (tblk && tblk->pn == pn) {
 603                 /* mark tblk for end-of-page */
 604                 tblk->flag |= tblkGC_EOP;
 605
 606                 if (log->cflag & logGC_PAGEOUT) {
 607                         /* if page is not already on write queue,
 608                          * just enqueue (no lbmWRITE to prevent redrive)
 609                          * buffer to wqueue to ensure correct serial order
 610                          * of the pages since log pages will be added
 611                          * continuously
 612                          */
 613                         if (bp->l_wqnext == NULL)
 614                                 lbmWrite(log, bp, 0, 0);
 615                 } else {
 616                         /*
 617                          * No current GC leader, initiate group commit
 618                          */
 619                         log->cflag |= logGC_PAGEOUT;
 620                         lmGCwrite(log, 0);
 621                 }
 622         }
 623         /* page is not bound with outstanding tblk:
 624          * init write or mark it to be redriven (lbmWRITE)
 625          */
 626         else {
 627                 /* finalize the page */
 628                 bp->l_ceor = bp->l_eor;
 629                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
 630                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE, 0);
 631         }
 632         LOGGC_UNLOCK(log);
 633
 634         /*
 635          *      allocate/initialize next page
 636          */
 637         /* if log wraps, the first data page of log is 2
 638          * (0 never used, 1 is superblock).
 639          */
 640         log->page = (pn == log->size - 1) ? 2 : pn + 1;
 641         log->eor = LOGPHDRSIZE; /* ? valid page empty/full at logRedo() */
 642
 643         /* allocate/initialize next log page buffer */
 644         nextbp = lbmAllocate(log, log->page);
 645         nextbp->l_eor = log->eor;
 646         log->bp = nextbp;
 647
 648         /* initialize next log page */
 649         lp = (struct logpage *) nextbp->l_ldata;
 650         lp->h.page = lp->t.page = cpu_to_le32(lspn + 1);
 651         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
 652
 653         return 0;
 654 }
 655
 656
 657 /*
 658  * NAME:        lmGroupCommit()
 659  *
 660  * FUNCTION:    group commit
 661  *      initiate pageout of the pages with COMMIT in the order of
 662  *      page number - redrive pageout of the page at the head of
 663  *      pageout queue until full page has been written.
 664  *
 665  * RETURN:
 666  *
 667  * NOTE:
 668  *      LOGGC_LOCK serializes log group commit queue, and
 669  *      transaction blocks on the commit queue.
 670  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
 671  */
 672 int lmGroupCommit(struct jfs_log * log, struct tblock * tblk)
 673 {
 674         int rc = 0;
 675
 676         LOGGC_LOCK(log);
 677
 678         /* group committed already ? */
 679         if (tblk->flag & tblkGC_COMMITTED) {
 680                 if (tblk->flag & tblkGC_ERROR)
 681                         rc = -EIO;
 682
 683                 LOGGC_UNLOCK(log);
 684                 return rc;
 685         }
 686         jfs_info("lmGroup Commit: tblk = 0x%p, gcrtc = %d", tblk, log->gcrtc);
 687
 688         if (tblk->xflag & COMMIT_LAZY)
 689                 tblk->flag |= tblkGC_LAZY;
 690
 691         if ((!(log->cflag & logGC_PAGEOUT)) && (!list_empty(&log->cqueue)) &&
 692             (!(tblk->xflag & COMMIT_LAZY) || test_bit(log_FLUSH, &log->flag)
 693              || jfs_tlocks_low)) {
 694                 /*
 695                  * No pageout in progress
 696                  *
 697                  * start group commit as its group leader.
 698                  */
 699                 log->cflag |= logGC_PAGEOUT;
 700
 701                 lmGCwrite(log, 0);
 702         }
 703
 704         if (tblk->xflag & COMMIT_LAZY) {
 705                 /*
 706                  * Lazy transactions can leave now
 707                  */
 708                 LOGGC_UNLOCK(log);
 709                 return 0;
 710         }
 711
 712         /* lmGCwrite gives up LOGGC_LOCK, check again */
 713
 714         if (tblk->flag & tblkGC_COMMITTED) {
 715                 if (tblk->flag & tblkGC_ERROR)
 716                         rc = -EIO;
 717
 718                 LOGGC_UNLOCK(log);
 719                 return rc;
 720         }
 721
 722         /* upcount transaction waiting for completion
 723          */
 724         log->gcrtc++;
 725         tblk->flag |= tblkGC_READY;
 726
 727         __SLEEP_COND(tblk->gcwait, (tblk->flag & tblkGC_COMMITTED),
 728                      LOGGC_LOCK(log), LOGGC_UNLOCK(log));
 729
 730         /* removed from commit queue */
 731         if (tblk->flag & tblkGC_ERROR)
 732                 rc = -EIO;
 733
 734         LOGGC_UNLOCK(log);
 735         return rc;
 736 }
 737
 738 /*
 739  * NAME:        lmGCwrite()
 740  *
 741  * FUNCTION:    group commit write
 742  *      initiate write of log page, building a group of all transactions
 743  *      with commit records on that page.
 744  *
 745  * RETURN:      None
 746  *
 747  * NOTE:
 748  *      LOGGC_LOCK must be held by caller.
 749  *      N.B. LOG_LOCK is NOT held during lmGroupCommit().
 750  */
 751 static void lmGCwrite(struct jfs_log * log, int cant_write)
 752 {
 753         struct lbuf *bp;
 754         struct logpage *lp;
 755         int gcpn;               /* group commit page number */
 756         struct tblock *tblk;
 757         struct tblock *xtblk = NULL;
 758
 759         /*
 760          * build the commit group of a log page
 761          *
 762          * scan commit queue and make a commit group of all
 763          * transactions with COMMIT records on the same log page.
 764          */
 765         /* get the head tblk on the commit queue */
 766         gcpn = list_entry(log->cqueue.next, struct tblock, cqueue)->pn;
 767
 768         list_for_each_entry(tblk, &log->cqueue, cqueue) {
 769                 if (tblk->pn != gcpn)
 770                         break;
 771
 772                 xtblk = tblk;
 773
 774                 /* state transition: (QUEUE, READY) -> COMMIT */
 775                 tblk->flag |= tblkGC_COMMIT;
 776         }
 777         tblk = xtblk;           /* last tblk of the page */
 778
 779         /*
 780          * pageout to commit transactions on the log page.
 781          */
 782         bp = (struct lbuf *) tblk->bp;
 783         lp = (struct logpage *) bp->l_ldata;
 784         /* is page already full ? */
 785         if (tblk->flag & tblkGC_EOP) {
 786                 /* mark page to free at end of group commit of the page */
 787                 tblk->flag &= ~tblkGC_EOP;
 788                 tblk->flag |= tblkGC_FREE;
 789                 bp->l_ceor = bp->l_eor;
 790                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
 791                 lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmGC,
 792                          cant_write);
 793                 INCREMENT(lmStat.full_page);
 794         }
 795         /* page is not yet full */
 796         else {
 797                 bp->l_ceor = tblk->eor; /* ? bp->l_ceor = bp->l_eor; */
 798                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_ceor);
 799                 lbmWrite(log, bp, lbmWRITE | lbmGC, cant_write);
 800                 INCREMENT(lmStat.partial_page);
 801         }
 802 }
 803
 804 /*
 805  * NAME:        lmPostGC()
 806  *
 807  * FUNCTION:    group commit post-processing
 808  *      Processes transactions after their commit records have been written
 809  *      to disk, redriving log I/O if necessary.
 810  *
 811  * RETURN:      None
 812  *
 813  * NOTE:
 814  *      This routine is called a interrupt time by lbmIODone
 815  */
 816 static void lmPostGC(struct lbuf * bp)
 817 {
 818         unsigned long flags;
 819         struct jfs_log *log = bp->l_log;
 820         struct logpage *lp;
 821         struct tblock *tblk, *temp;
 822
 823         //LOGGC_LOCK(log);
 824         spin_lock_irqsave(&log->gclock, flags);
 825         /*
 826          * current pageout of group commit completed.
 827          *
 828          * remove/wakeup transactions from commit queue who were
 829          * group committed with the current log page
 830          */
 831         list_for_each_entry_safe(tblk, temp, &log->cqueue, cqueue) {
 832                 if (!(tblk->flag & tblkGC_COMMIT))
 833                         break;
 834                 /* if transaction was marked GC_COMMIT then
 835                  * it has been shipped in the current pageout
 836                  * and made it to disk - it is committed.
 837                  */
 838
 839                 if (bp->l_flag & lbmERROR)
 840                         tblk->flag |= tblkGC_ERROR;
 841
 842                 /* remove it from the commit queue */
 843                 list_del(&tblk->cqueue);
 844                 tblk->flag &= ~tblkGC_QUEUE;
 845
 846                 if (tblk == log->flush_tblk) {
 847                         /* we can stop flushing the log now */
 848                         clear_bit(log_FLUSH, &log->flag);
 849                         log->flush_tblk = NULL;
 850                 }
 851
 852                 jfs_info("lmPostGC: tblk = 0x%p, flag = 0x%x", tblk,
 853                          tblk->flag);
 854
 855                 if (!(tblk->xflag & COMMIT_FORCE))
 856                         /*
 857                          * Hand tblk over to lazy commit thread
 858                          */
 859                         txLazyUnlock(tblk);
 860                 else {
 861                         /* state transition: COMMIT -> COMMITTED */
 862                         tblk->flag |= tblkGC_COMMITTED;
 863
 864                         if (tblk->flag & tblkGC_READY)
 865                                 log->gcrtc--;
 866
 867                         LOGGC_WAKEUP(tblk);
 868                 }
 869
 870                 /* was page full before pageout ?
 871                  * (and this is the last tblk bound with the page)
 872                  */
 873                 if (tblk->flag & tblkGC_FREE)
 874                         lbmFree(bp);
 875                 /* did page become full after pageout ?
 876                  * (and this is the last tblk bound with the page)
 877                  */
 878                 else if (tblk->flag & tblkGC_EOP) {
 879                         /* finalize the page */
 880                         lp = (struct logpage *) bp->l_ldata;
 881                         bp->l_ceor = bp->l_eor;
 882                         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
 883                         jfs_info("lmPostGC: calling lbmWrite");
 884                         lbmWrite(log, bp, lbmWRITE | lbmRELEASE | lbmFREE,
 885                                  1);
 886                 }
 887
 888         }
 889
 890         /* are there any transactions who have entered lnGroupCommit()
 891          * (whose COMMITs are after that of the last log page written.
 892          * They are waiting for new group commit (above at (SLEEP 1))
 893          * or lazy transactions are on a full (queued) log page,
 894          * select the latest ready transaction as new group leader and
 895          * wake her up to lead her group.
 896          */
 897         if ((!list_empty(&log->cqueue)) &&
 898             ((log->gcrtc > 0) || (tblk->bp->l_wqnext != NULL) ||
 899              test_bit(log_FLUSH, &log->flag) || jfs_tlocks_low))
 900                 /*
 901                  * Call lmGCwrite with new group leader
 902                  */
 903                 lmGCwrite(log, 1);
 904
 905         /* no transaction are ready yet (transactions are only just
 906          * queued (GC_QUEUE) and not entered for group commit yet).
 907          * the first transaction entering group commit
 908          * will elect herself as new group leader.
 909          */
 910         else
 911                 log->cflag &= ~logGC_PAGEOUT;
 912
 913         //LOGGC_UNLOCK(log);
 914         spin_unlock_irqrestore(&log->gclock, flags);
 915         return;
 916 }
 917
 918 /*
 919  * NAME:        lmLogSync()
 920  *
 921  * FUNCTION:    write log SYNCPT record for specified log
 922  *      if new sync address is available
 923  *      (normally the case if sync() is executed by back-ground
 924  *      process).
 925  *      if not, explicitly run jfs_blogsync() to initiate
 926  *      getting of new sync address.
 927  *      calculate new value of i_nextsync which determines when
 928  *      this code is called again.
 929  *
 930  * PARAMETERS:  log     - log structure
 931  *              nosyncwait - 1 if called asynchronously
 932  *
 933  * RETURN:      0
 934  *
 935  * serialization: LOG_LOCK() held on entry/exit
 936  */
 937 static int lmLogSync(struct jfs_log * log, int nosyncwait)
 938 {
 939         int logsize;
 940         int written;            /* written since last syncpt */
 941         int free;               /* free space left available */
 942         int delta;              /* additional delta to write normally */
 943         int more;               /* additional write granted */
 944         struct lrd lrd;
 945         int lsn;
 946         struct logsyncblk *lp;
 947         struct jfs_sb_info *sbi;
 948         unsigned long flags;
 949
 950         /* push dirty metapages out to disk */
 951         list_for_each_entry(sbi, &log->sb_list, log_list) {
 952                 filemap_flush(sbi->ipbmap->i_mapping);
 953                 filemap_flush(sbi->ipimap->i_mapping);
 954                 filemap_flush(sbi->direct_inode->i_mapping);
 955         }
 956
 957         /*
 958          *      forward syncpt
 959          */
 960         /* if last sync is same as last syncpt,
 961          * invoke sync point forward processing to update sync.
 962          */
 963
 964         if (log->sync == log->syncpt) {
 965                 LOGSYNC_LOCK(log, flags);
 966                 if (list_empty(&log->synclist))
 967                         log->sync = log->lsn;
 968                 else {
 969                         lp = list_entry(log->synclist.next,
 970                                         struct logsyncblk, synclist);
 971                         log->sync = lp->lsn;
 972                 }
 973                 LOGSYNC_UNLOCK(log, flags);
 974
 975         }
 976
 977         /* if sync is different from last syncpt,
 978          * write a SYNCPT record with syncpt = sync.
 979          * reset syncpt = sync
 980          */
 981         if (log->sync != log->syncpt) {
 982                 lrd.logtid = 0;
 983                 lrd.backchain = 0;
 984                 lrd.type = cpu_to_le16(LOG_SYNCPT);
 985                 lrd.length = 0;
 986                 lrd.log.syncpt.sync = cpu_to_le32(log->sync);
 987                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
 988
 989                 log->syncpt = log->sync;
 990         } else
 991                 lsn = log->lsn;
 992
 993         /*
 994          *      setup next syncpt trigger (SWAG)
 995          */
 996         logsize = log->logsize;
 997
 998         logdiff(written, lsn, log);
 999         free = logsize - written;
1000         delta = LOGSYNC_DELTA(logsize);
1001         more = min(free / 2, delta);
1002         if (more < 2 * LOGPSIZE) {
1003                 jfs_warn("\n ... Log Wrap ... Log Wrap ... Log Wrap ...\n");
1004                 /*
1005                  *      log wrapping
1006                  *
1007                  * option 1 - panic ? No.!
1008                  * option 2 - shutdown file systems
1009                  *            associated with log ?
1010                  * option 3 - extend log ?
1011                  */
1012                 /*
1013                  * option 4 - second chance
1014                  *
1015                  * mark log wrapped, and continue.
1016                  * when all active transactions are completed,
1017                  * mark log vaild for recovery.
1018                  * if crashed during invalid state, log state
1019                  * implies invald log, forcing fsck().
1020                  */
1021                 /* mark log state log wrap in log superblock */
1022                 /* log->state = LOGWRAP; */
1023
1024                 /* reset sync point computation */
1025                 log->syncpt = log->sync = lsn;
1026                 log->nextsync = delta;
1027         } else
1028                 /* next syncpt trigger = written + more */
1029                 log->nextsync = written + more;
1030
1031         /* return if lmLogSync() from outside of transaction, e.g., sync() */
1032         if (nosyncwait)
1033                 return lsn;
1034
1035         /* if number of bytes written from last sync point is more
1036          * than 1/4 of the log size, stop new transactions from
1037          * starting until all current transactions are completed
1038          * by setting syncbarrier flag.
1039          */
1040         if (written > LOGSYNC_BARRIER(logsize) && logsize > 32 * LOGPSIZE) {
1041                 set_bit(log_SYNCBARRIER, &log->flag);
1042                 jfs_info("log barrier on: lsn=0x%x syncpt=0x%x", lsn,
1043                          log->syncpt);
1044                 /*
1045                  * We may have to initiate group commit
1046                  */
1047                 jfs_flush_journal(log, 0);
1048         }
1049
1050         return lsn;
1051 }
1052
1053 /*
1054  * NAME:        jfs_syncpt
1055  *
1056  * FUNCTION:    write log SYNCPT record for specified log
1057  *
1058  * PARAMETERS:  log     - log structure
1059  */
1060 void jfs_syncpt(struct jfs_log *log)
1061 {       LOG_LOCK(log);
1062         lmLogSync(log, 1);
1063         LOG_UNLOCK(log);
1064 }
1065
1066 /*
1067  * NAME:        lmLogOpen()
1068  *
1069  * FUNCTION:    open the log on first open;
1070  *      insert filesystem in the active list of the log.
1071  *
1072  * PARAMETER:   ipmnt   - file system mount inode
1073  *              iplog   - log inode (out)
1074  *
1075  * RETURN:
1076  *
1077  * serialization:
1078  */
1079 int lmLogOpen(struct super_block *sb)
1080 {
1081         int rc;
1082         struct block_device *bdev;
1083         struct jfs_log *log;
1084         struct jfs_sb_info *sbi = JFS_SBI(sb);
1085
1086         if (sbi->flag & JFS_NOINTEGRITY)
1087                 return open_dummy_log(sb);
1088
1089         if (sbi->mntflag & JFS_INLINELOG)
1090                 return open_inline_log(sb);
1091
1092         down(&jfs_log_sem);
1093         list_for_each_entry(log, &jfs_external_logs, journal_list) {
1094                 if (log->bdev->bd_dev == sbi->logdev) {
1095                         if (memcmp(log->uuid, sbi->loguuid,
1096                                    sizeof(log->uuid))) {
1097                                 jfs_warn("wrong uuid on JFS journal\n");
1098                                 up(&jfs_log_sem);
1099                                 return -EINVAL;
1100                         }
1101                         /*
1102                          * add file system to log active file system list
1103                          */
1104                         if ((rc = lmLogFileSystem(log, sbi, 1))) {
1105                                 up(&jfs_log_sem);
1106                                 return rc;
1107                         }
1108                         goto journal_found;
1109                 }
1110         }
1111
1112         if (!(log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL))) {
1113                 up(&jfs_log_sem);
1114                 return -ENOMEM;
1115         }
1116         memset(log, 0, sizeof(struct jfs_log));
1117         INIT_LIST_HEAD(&log->sb_list);
1118         init_waitqueue_head(&log->syncwait);
1119
1120         /*
1121          *      external log as separate logical volume
1122          *
1123          * file systems to log may have n-to-1 relationship;
1124          */
1125
1126         bdev = open_by_devnum(sbi->logdev, FMODE_READ|FMODE_WRITE);
1127         if (IS_ERR(bdev)) {
1128                 rc = -PTR_ERR(bdev);
1129                 goto free;
1130         }
1131
1132         if ((rc = bd_claim(bdev, log))) {
1133                 goto close;
1134         }
1135
1136         log->bdev = bdev;
1137         memcpy(log->uuid, sbi->loguuid, sizeof(log->uuid));
1138
1139         /*
1140          * initialize log:
1141          */
1142         if ((rc = lmLogInit(log)))
1143                 goto unclaim;
1144
1145         list_add(&log->journal_list, &jfs_external_logs);
1146
1147         /*
1148          * add file system to log active file system list
1149          */
1150         if ((rc = lmLogFileSystem(log, sbi, 1)))
1151                 goto shutdown;
1152
1153 journal_found:
1154         LOG_LOCK(log);
1155         list_add(&sbi->log_list, &log->sb_list);
1156         sbi->log = log;
1157         LOG_UNLOCK(log);
1158
1159         up(&jfs_log_sem);
1160         return 0;
1161
1162         /*
1163          *      unwind on error
1164          */
1165       shutdown:         /* unwind lbmLogInit() */
1166         list_del(&log->journal_list);
1167         lbmLogShutdown(log);
1168
1169       unclaim:
1170         bd_release(bdev);
1171
1172       close:            /* close external log device */
1173         blkdev_put(bdev);
1174
1175       free:             /* free log descriptor */
1176         up(&jfs_log_sem);
1177         kfree(log);
1178
1179         jfs_warn("lmLogOpen: exit(%d)", rc);
1180         return rc;
1181 }
1182
1183 static int open_inline_log(struct super_block *sb)
1184 {
1185         struct jfs_log *log;
1186         int rc;
1187
1188         if (!(log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL)))
1189                 return -ENOMEM;
1190         memset(log, 0, sizeof(struct jfs_log));
1191         INIT_LIST_HEAD(&log->sb_list);
1192         init_waitqueue_head(&log->syncwait);
1193
1194         set_bit(log_INLINELOG, &log->flag);
1195         log->bdev = sb->s_bdev;
1196         log->base = addressPXD(&JFS_SBI(sb)->logpxd);
1197         log->size = lengthPXD(&JFS_SBI(sb)->logpxd) >>
1198             (L2LOGPSIZE - sb->s_blocksize_bits);
1199         log->l2bsize = sb->s_blocksize_bits;
1200         ASSERT(L2LOGPSIZE >= sb->s_blocksize_bits);
1201
1202         /*
1203          * initialize log.
1204          */
1205         if ((rc = lmLogInit(log))) {
1206                 kfree(log);
1207                 jfs_warn("lmLogOpen: exit(%d)", rc);
1208                 return rc;
1209         }
1210
1211         list_add(&JFS_SBI(sb)->log_list, &log->sb_list);
1212         JFS_SBI(sb)->log = log;
1213
1214         return rc;
1215 }
1216
1217 static int open_dummy_log(struct super_block *sb)
1218 {
1219         int rc;
1220
1221         down(&jfs_log_sem);
1222         if (!dummy_log) {
1223                 dummy_log = kmalloc(sizeof(struct jfs_log), GFP_KERNEL);
1224                 if (!dummy_log) {
1225                         up(&jfs_log_sem);
1226                         return -ENOMEM;
1227                 }
1228                 memset(dummy_log, 0, sizeof(struct jfs_log));
1229                 INIT_LIST_HEAD(&dummy_log->sb_list);
1230                 init_waitqueue_head(&dummy_log->syncwait);
1231                 dummy_log->no_integrity = 1;
1232                 /* Make up some stuff */
1233                 dummy_log->base = 0;
1234                 dummy_log->size = 1024;
1235                 rc = lmLogInit(dummy_log);
1236                 if (rc) {
1237                         kfree(dummy_log);
1238                         dummy_log = NULL;
1239                         up(&jfs_log_sem);
1240                         return rc;
1241                 }
1242         }
1243
1244         LOG_LOCK(dummy_log);
1245         list_add(&JFS_SBI(sb)->log_list, &dummy_log->sb_list);
1246         JFS_SBI(sb)->log = dummy_log;
1247         LOG_UNLOCK(dummy_log);
1248         up(&jfs_log_sem);
1249
1250         return 0;
1251 }
1252
1253 /*
1254  * NAME:        lmLogInit()
1255  *
1256  * FUNCTION:    log initialization at first log open.
1257  *
1258  *      logredo() (or logformat()) should have been run previously.
1259  *      initialize the log from log superblock.
1260  *      set the log state in the superblock to LOGMOUNT and
1261  *      write SYNCPT log record.
1262  *
1263  * PARAMETER:   log     - log structure
1264  *
1265  * RETURN:      0       - if ok
1266  *              -EINVAL - bad log magic number or superblock dirty
1267  *              error returned from logwait()
1268  *
1269  * serialization: single first open thread
1270  */
1271 int lmLogInit(struct jfs_log * log)
1272 {
1273         int rc = 0;
1274         struct lrd lrd;
1275         struct logsuper *logsuper;
1276         struct lbuf *bpsuper;
1277         struct lbuf *bp;
1278         struct logpage *lp;
1279         int lsn = 0;
1280
1281         jfs_info("lmLogInit: log:0x%p", log);
1282
1283         /* initialize the group commit serialization lock */
1284         LOGGC_LOCK_INIT(log);
1285
1286         /* allocate/initialize the log write serialization lock */
1287         LOG_LOCK_INIT(log);
1288
1289         LOGSYNC_LOCK_INIT(log);
1290
1291         INIT_LIST_HEAD(&log->synclist);
1292
1293         INIT_LIST_HEAD(&log->cqueue);
1294         log->flush_tblk = NULL;
1295
1296         log->count = 0;
1297
1298         /*
1299          * initialize log i/o
1300          */
1301         if ((rc = lbmLogInit(log)))
1302                 return rc;
1303
1304         if (!test_bit(log_INLINELOG, &log->flag))
1305                 log->l2bsize = L2LOGPSIZE;
1306
1307         /* check for disabled journaling to disk */
1308         if (log->no_integrity) {
1309                 /*
1310                  * Journal pages will still be filled.  When the time comes
1311                  * to actually do the I/O, the write is not done, and the
1312                  * endio routine is called directly.
1313                  */
1314                 bp = lbmAllocate(log , 0);
1315                 log->bp = bp;
1316                 bp->l_pn = bp->l_eor = 0;
1317         } else {
1318                 /*
1319                  * validate log superblock
1320                  */
1321                 if ((rc = lbmRead(log, 1, &bpsuper)))
1322                         goto errout10;
1323
1324                 logsuper = (struct logsuper *) bpsuper->l_ldata;
1325
1326                 if (logsuper->magic != cpu_to_le32(LOGMAGIC)) {
1327                         jfs_warn("*** Log Format Error ! ***");
1328                         rc = -EINVAL;
1329                         goto errout20;
1330                 }
1331
1332                 /* logredo() should have been run successfully. */
1333                 if (logsuper->state != cpu_to_le32(LOGREDONE)) {
1334                         jfs_warn("*** Log Is Dirty ! ***");
1335                         rc = -EINVAL;
1336                         goto errout20;
1337                 }
1338
1339                 /* initialize log from log superblock */
1340                 if (test_bit(log_INLINELOG,&log->flag)) {
1341                         if (log->size != le32_to_cpu(logsuper->size)) {
1342                                 rc = -EINVAL;
1343                                 goto errout20;
1344                         }
1345                         jfs_info("lmLogInit: inline log:0x%p base:0x%Lx "
1346                                  "size:0x%x", log,
1347                                  (unsigned long long) log->base, log->size);
1348                 } else {
1349                         if (memcmp(logsuper->uuid, log->uuid, 16)) {
1350                                 jfs_warn("wrong uuid on JFS log device");
1351                                 goto errout20;
1352                         }
1353                         log->size = le32_to_cpu(logsuper->size);
1354                         log->l2bsize = le32_to_cpu(logsuper->l2bsize);
1355                         jfs_info("lmLogInit: external log:0x%p base:0x%Lx "
1356                                  "size:0x%x", log,
1357                                  (unsigned long long) log->base, log->size);
1358                 }
1359
1360                 log->page = le32_to_cpu(logsuper->end) / LOGPSIZE;
1361                 log->eor = le32_to_cpu(logsuper->end) - (LOGPSIZE * log->page);
1362
1363                 /*
1364                  * initialize for log append write mode
1365                  */
1366                 /* establish current/end-of-log page/buffer */
1367                 if ((rc = lbmRead(log, log->page, &bp)))
1368                         goto errout20;
1369
1370                 lp = (struct logpage *) bp->l_ldata;
1371
1372                 jfs_info("lmLogInit: lsn:0x%x page:%d eor:%d:%d",
1373                          le32_to_cpu(logsuper->end), log->page, log->eor,
1374                          le16_to_cpu(lp->h.eor));
1375
1376                 log->bp = bp;
1377                 bp->l_pn = log->page;
1378                 bp->l_eor = log->eor;
1379
1380                 /* if current page is full, move on to next page */
1381                 if (log->eor >= LOGPSIZE - LOGPTLRSIZE)
1382                         lmNextPage(log);
1383
1384                 /*
1385                  * initialize log syncpoint
1386                  */
1387                 /*
1388                  * write the first SYNCPT record with syncpoint = 0
1389                  * (i.e., log redo up to HERE !);
1390                  * remove current page from lbm write queue at end of pageout
1391                  * (to write log superblock update), but do not release to
1392                  * freelist;
1393                  */
1394                 lrd.logtid = 0;
1395                 lrd.backchain = 0;
1396                 lrd.type = cpu_to_le16(LOG_SYNCPT);
1397                 lrd.length = 0;
1398                 lrd.log.syncpt.sync = 0;
1399                 lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1400                 bp = log->bp;
1401                 bp->l_ceor = bp->l_eor;
1402                 lp = (struct logpage *) bp->l_ldata;
1403                 lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1404                 lbmWrite(log, bp, lbmWRITE | lbmSYNC, 0);
1405                 if ((rc = lbmIOWait(bp, 0)))
1406                         goto errout30;
1407
1408                 /*
1409                  * update/write superblock
1410                  */
1411                 logsuper->state = cpu_to_le32(LOGMOUNT);
1412                 log->serial = le32_to_cpu(logsuper->serial) + 1;
1413                 logsuper->serial = cpu_to_le32(log->serial);
1414                 lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1415                 if ((rc = lbmIOWait(bpsuper, lbmFREE)))
1416                         goto errout30;
1417         }
1418
1419         /* initialize logsync parameters */
1420         log->logsize = (log->size - 2) << L2LOGPSIZE;
1421         log->lsn = lsn;
1422         log->syncpt = lsn;
1423         log->sync = log->syncpt;
1424         log->nextsync = LOGSYNC_DELTA(log->logsize);
1425
1426         jfs_info("lmLogInit: lsn:0x%x syncpt:0x%x sync:0x%x",
1427                  log->lsn, log->syncpt, log->sync);
1428
1429         /*
1430          * initialize for lazy/group commit
1431          */
1432         log->clsn = lsn;
1433
1434         return 0;
1435
1436         /*
1437          *      unwind on error
1438          */
1439       errout30:         /* release log page */
1440         log->wqueue = NULL;
1441         bp->l_wqnext = NULL;
1442         lbmFree(bp);
1443
1444       errout20:         /* release log superblock */
1445         lbmFree(bpsuper);
1446
1447       errout10:         /* unwind lbmLogInit() */
1448         lbmLogShutdown(log);
1449
1450         jfs_warn("lmLogInit: exit(%d)", rc);
1451         return rc;
1452 }
1453
1454
1455 /*
1456  * NAME:        lmLogClose()
1457  *
1458  * FUNCTION:    remove file system <ipmnt> from active list of log <iplog>
1459  *              and close it on last close.
1460  *
1461  * PARAMETER:   sb      - superblock
1462  *
1463  * RETURN:      errors from subroutines
1464  *
1465  * serialization:
1466  */
1467 int lmLogClose(struct super_block *sb)
1468 {
1469         struct jfs_sb_info *sbi = JFS_SBI(sb);
1470         struct jfs_log *log = sbi->log;
1471         struct block_device *bdev;
1472         int rc = 0;
1473
1474         jfs_info("lmLogClose: log:0x%p", log);
1475
1476         down(&jfs_log_sem);
1477         LOG_LOCK(log);
1478         list_del(&sbi->log_list);
1479         LOG_UNLOCK(log);
1480         sbi->log = NULL;
1481
1482         /*
1483          * We need to make sure all of the "written" metapages
1484          * actually make it to disk
1485          */
1486         sync_blockdev(sb->s_bdev);
1487
1488         if (test_bit(log_INLINELOG, &log->flag)) {
1489                 /*
1490                  *      in-line log in host file system
1491                  */
1492                 rc = lmLogShutdown(log);
1493                 kfree(log);
1494                 goto out;
1495         }
1496
1497         if (!log->no_integrity)
1498                 lmLogFileSystem(log, sbi, 0);
1499
1500         if (!list_empty(&log->sb_list))
1501                 goto out;
1502
1503         /*
1504          * TODO: ensure that the dummy_log is in a state to allow
1505          * lbmLogShutdown to deallocate all the buffers and call
1506          * kfree against dummy_log.  For now, leave dummy_log & its
1507          * buffers in memory, and resuse if another no-integrity mount
1508          * is requested.
1509          */
1510         if (log->no_integrity)
1511                 goto out;
1512
1513         /*
1514          *      external log as separate logical volume
1515          */
1516         list_del(&log->journal_list);
1517         bdev = log->bdev;
1518         rc = lmLogShutdown(log);
1519
1520         bd_release(bdev);
1521         blkdev_put(bdev);
1522
1523         kfree(log);
1524
1525       out:
1526         up(&jfs_log_sem);
1527         jfs_info("lmLogClose: exit(%d)", rc);
1528         return rc;
1529 }
1530
1531
1532 /*
1533  * NAME:        jfs_flush_journal()
1534  *
1535  * FUNCTION:    initiate write of any outstanding transactions to the journal
1536  *              and optionally wait until they are all written to disk
1537  *
1538  *              wait == 0  flush until latest txn is committed, don't wait
1539  *              wait == 1  flush until latest txn is committed, wait
1540  *              wait > 1   flush until all txn's are complete, wait
1541  */
1542 void jfs_flush_journal(struct jfs_log *log, int wait)
1543 {
1544         int i;
1545         struct tblock *target = NULL;
1546         struct jfs_sb_info *sbi;
1547
1548         /* jfs_write_inode may call us during read-only mount */
1549         if (!log)
1550                 return;
1551
1552         jfs_info("jfs_flush_journal: log:0x%p wait=%d", log, wait);
1553
1554         LOGGC_LOCK(log);
1555
1556         if (!list_empty(&log->cqueue)) {
1557                 /*
1558                  * This ensures that we will keep writing to the journal as long
1559                  * as there are unwritten commit records
1560                  */
1561                 target = list_entry(log->cqueue.prev, struct tblock, cqueue);
1562
1563                 if (test_bit(log_FLUSH, &log->flag)) {
1564                         /*
1565                          * We're already flushing.
1566                          * if flush_tblk is NULL, we are flushing everything,
1567                          * so leave it that way.  Otherwise, update it to the
1568                          * latest transaction
1569                          */
1570                         if (log->flush_tblk)
1571                                 log->flush_tblk = target;
1572                 } else {
1573                         /* Only flush until latest transaction is committed */
1574                         log->flush_tblk = target;
1575                         set_bit(log_FLUSH, &log->flag);
1576
1577                         /*
1578                          * Initiate I/O on outstanding transactions
1579                          */
1580                         if (!(log->cflag & logGC_PAGEOUT)) {
1581                                 log->cflag |= logGC_PAGEOUT;
1582                                 lmGCwrite(log, 0);
1583                         }
1584                 }
1585         }
1586         if ((wait > 1) || test_bit(log_SYNCBARRIER, &log->flag)) {
1587                 /* Flush until all activity complete */
1588                 set_bit(log_FLUSH, &log->flag);
1589                 log->flush_tblk = NULL;
1590         }
1591
1592         if (wait && target && !(target->flag & tblkGC_COMMITTED)) {
1593                 DECLARE_WAITQUEUE(__wait, current);
1594
1595                 add_wait_queue(&target->gcwait, &__wait);
1596                 set_current_state(TASK_UNINTERRUPTIBLE);
1597                 LOGGC_UNLOCK(log);
1598                 schedule();
1599                 current->state = TASK_RUNNING;
1600                 LOGGC_LOCK(log);
1601                 remove_wait_queue(&target->gcwait, &__wait);
1602         }
1603         LOGGC_UNLOCK(log);
1604
1605         if (wait < 2)
1606                 return;
1607
1608         list_for_each_entry(sbi, &log->sb_list, log_list) {
1609                 filemap_fdatawrite(sbi->ipbmap->i_mapping);
1610                 filemap_fdatawrite(sbi->ipimap->i_mapping);
1611                 filemap_fdatawrite(sbi->direct_inode->i_mapping);
1612         }
1613
1614         /*
1615          * If there was recent activity, we may need to wait
1616          * for the lazycommit thread to catch up
1617          */
1618         if ((!list_empty(&log->cqueue)) || !list_empty(&log->synclist)) {
1619                 for (i = 0; i < 200; i++) {     /* Too much? */
1620                         msleep(250);
1621                         if (list_empty(&log->cqueue) &&
1622                             list_empty(&log->synclist))
1623                                 break;
1624                 }
1625         }
1626         assert(list_empty(&log->cqueue));
1627         if (!list_empty(&log->synclist)) {
1628                 struct logsyncblk *lp;
1629
1630                 list_for_each_entry(lp, &log->synclist, synclist) {
1631                         if (lp->xflag & COMMIT_PAGE) {
1632                                 struct metapage *mp = (struct metapage *)lp;
1633                                 dump_mem("orphan metapage", lp,
1634                                          sizeof(struct metapage));
1635                                 dump_mem("page", mp->page, sizeof(struct page));
1636                         }
1637                         else
1638                                 dump_mem("orphan tblock", lp,
1639                                          sizeof(struct tblock));
1640                 }
1641 //              current->state = TASK_INTERRUPTIBLE;
1642 //              schedule();
1643         }
1644         //assert(list_empty(&log->synclist));
1645         clear_bit(log_FLUSH, &log->flag);
1646 }
1647
1648 /*
1649  * NAME:        lmLogShutdown()
1650  *
1651  * FUNCTION:    log shutdown at last LogClose().
1652  *
1653  *              write log syncpt record.
1654  *              update super block to set redone flag to 0.
1655  *
1656  * PARAMETER:   log     - log inode
1657  *
1658  * RETURN:      0       - success
1659  *
1660  * serialization: single last close thread
1661  */
1662 int lmLogShutdown(struct jfs_log * log)
1663 {
1664         int rc;
1665         struct lrd lrd;
1666         int lsn;
1667         struct logsuper *logsuper;
1668         struct lbuf *bpsuper;
1669         struct lbuf *bp;
1670         struct logpage *lp;
1671
1672         jfs_info("lmLogShutdown: log:0x%p", log);
1673
1674         jfs_flush_journal(log, 2);
1675
1676         /*
1677          * write the last SYNCPT record with syncpoint = 0
1678          * (i.e., log redo up to HERE !)
1679          */
1680         lrd.logtid = 0;
1681         lrd.backchain = 0;
1682         lrd.type = cpu_to_le16(LOG_SYNCPT);
1683         lrd.length = 0;
1684         lrd.log.syncpt.sync = 0;
1685
1686         lsn = lmWriteRecord(log, NULL, &lrd, NULL);
1687         bp = log->bp;
1688         lp = (struct logpage *) bp->l_ldata;
1689         lp->h.eor = lp->t.eor = cpu_to_le16(bp->l_eor);
1690         lbmWrite(log, log->bp, lbmWRITE | lbmRELEASE | lbmSYNC, 0);
1691         lbmIOWait(log->bp, lbmFREE);
1692         log->bp = NULL;
1693
1694         /*
1695          * synchronous update log superblock
1696          * mark log state as shutdown cleanly
1697          * (i.e., Log does not need to be replayed).
1698          */
1699         if ((rc = lbmRead(log, 1, &bpsuper)))
1700                 goto out;
1701
1702         logsuper = (struct logsuper *) bpsuper->l_ldata;
1703         logsuper->state = cpu_to_le32(LOGREDONE);
1704         logsuper->end = cpu_to_le32(lsn);
1705         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1706         rc = lbmIOWait(bpsuper, lbmFREE);
1707
1708         jfs_info("lmLogShutdown: lsn:0x%x page:%d eor:%d",
1709                  lsn, log->page, log->eor);
1710
1711       out:
1712         /*
1713          * shutdown per log i/o
1714          */
1715         lbmLogShutdown(log);
1716
1717         if (rc) {
1718                 jfs_warn("lmLogShutdown: exit(%d)", rc);
1719         }
1720         return rc;
1721 }
1722
1723
1724 /*
1725  * NAME:        lmLogFileSystem()
1726  *
1727  * FUNCTION:    insert (<activate> = true)/remove (<activate> = false)
1728  *      file system into/from log active file system list.
1729  *
1730  * PARAMETE:    log     - pointer to logs inode.
1731  *              fsdev   - kdev_t of filesystem.
1732  *              serial  - pointer to returned log serial number
1733  *              activate - insert/remove device from active list.
1734  *
1735  * RETURN:      0       - success
1736  *              errors returned by vms_iowait().
1737  */
1738 static int lmLogFileSystem(struct jfs_log * log, struct jfs_sb_info *sbi,
1739                            int activate)
1740 {
1741         int rc = 0;
1742         int i;
1743         struct logsuper *logsuper;
1744         struct lbuf *bpsuper;
1745         char *uuid = sbi->uuid;
1746
1747         /*
1748          * insert/remove file system device to log active file system list.
1749          */
1750         if ((rc = lbmRead(log, 1, &bpsuper)))
1751                 return rc;
1752
1753         logsuper = (struct logsuper *) bpsuper->l_ldata;
1754         if (activate) {
1755                 for (i = 0; i < MAX_ACTIVE; i++)
1756                         if (!memcmp(logsuper->active[i].uuid, NULL_UUID, 16)) {
1757                                 memcpy(logsuper->active[i].uuid, uuid, 16);
1758                                 sbi->aggregate = i;
1759                                 break;
1760                         }
1761                 if (i == MAX_ACTIVE) {
1762                         jfs_warn("Too many file systems sharing journal!");
1763                         lbmFree(bpsuper);
1764                         return -EMFILE; /* Is there a better rc? */
1765                 }
1766         } else {
1767                 for (i = 0; i < MAX_ACTIVE; i++)
1768                         if (!memcmp(logsuper->active[i].uuid, uuid, 16)) {
1769                                 memcpy(logsuper->active[i].uuid, NULL_UUID, 16);
1770                                 break;
1771                         }
1772                 if (i == MAX_ACTIVE) {
1773                         jfs_warn("Somebody stomped on the journal!");
1774                         lbmFree(bpsuper);
1775                         return -EIO;
1776                 }
1777
1778         }
1779
1780         /*
1781          * synchronous write log superblock:
1782          *
1783          * write sidestream bypassing write queue:
1784          * at file system mount, log super block is updated for
1785          * activation of the file system before any log record
1786          * (MOUNT record) of the file system, and at file system
1787          * unmount, all meta data for the file system has been
1788          * flushed before log super block is updated for deactivation
1789          * of the file system.
1790          */
1791         lbmDirectWrite(log, bpsuper, lbmWRITE | lbmRELEASE | lbmSYNC);
1792         rc = lbmIOWait(bpsuper, lbmFREE);
1793
1794         return rc;
1795 }
1796
1797 /*
1798  *              log buffer manager (lbm)
1799  *              ------------------------
1800  *
1801  * special purpose buffer manager supporting log i/o requirements.
1802  *
1803  * per log write queue:
1804  * log pageout occurs in serial order by fifo write queue and
1805  * restricting to a single i/o in pregress at any one time.
1806  * a circular singly-linked list
1807  * (log->wrqueue points to the tail, and buffers are linked via
1808  * bp->wrqueue field), and
1809  * maintains log page in pageout ot waiting for pageout in serial pageout.
1810  */
1811
1812 /*
1813  *      lbmLogInit()
1814  *
1815  * initialize per log I/O setup at lmLogInit()
1816  */
1817 static int lbmLogInit(struct jfs_log * log)
1818 {                               /* log inode */
1819         int i;
1820         struct lbuf *lbuf;
1821
1822         jfs_info("lbmLogInit: log:0x%p", log);
1823
1824         /* initialize current buffer cursor */
1825         log->bp = NULL;
1826
1827         /* initialize log device write queue */
1828         log->wqueue = NULL;
1829
1830         /*
1831          * Each log has its own buffer pages allocated to it.  These are
1832          * not managed by the page cache.  This ensures that a transaction
1833          * writing to the log does not block trying to allocate a page from
1834          * the page cache (for the log).  This would be bad, since page
1835          * allocation waits on the kswapd thread that may be committing inodes
1836          * which would cause log activity.  Was that clear?  I'm trying to
1837          * avoid deadlock here.
1838          */
1839         init_waitqueue_head(&log->free_wait);
1840
1841         log->lbuf_free = NULL;
1842
1843         for (i = 0; i < LOGPAGES;) {
1844                 char *buffer;
1845                 uint offset;
1846                 struct page *page;
1847
1848                 buffer = (char *) get_zeroed_page(GFP_KERNEL);
1849                 if (buffer == NULL)
1850                         goto error;
1851                 page = virt_to_page(buffer);
1852                 for (offset = 0; offset < PAGE_SIZE; offset += LOGPSIZE) {
1853                         lbuf = kmalloc(sizeof(struct lbuf), GFP_KERNEL);
1854                         if (lbuf == NULL) {
1855                                 if (offset == 0)
1856                                         free_page((unsigned long) buffer);
1857                                 goto error;
1858                         }
1859                         if (offset) /* we already have one reference */
1860                                 get_page(page);
1861                         lbuf->l_offset = offset;
1862                         lbuf->l_ldata = buffer + offset;
1863                         lbuf->l_page = page;
1864                         lbuf->l_log = log;
1865                         init_waitqueue_head(&lbuf->l_ioevent);
1866
1867                         lbuf->l_freelist = log->lbuf_free;
1868                         log->lbuf_free = lbuf;
1869                         i++;
1870                 }
1871         }
1872
1873         return (0);
1874
1875       error:
1876         lbmLogShutdown(log);
1877         return -ENOMEM;
1878 }
1879
1880
1881 /*
1882  *      lbmLogShutdown()
1883  *
1884  * finalize per log I/O setup at lmLogShutdown()
1885  */
1886 static void lbmLogShutdown(struct jfs_log * log)
1887 {
1888         struct lbuf *lbuf;
1889
1890         jfs_info("lbmLogShutdown: log:0x%p", log);
1891
1892         lbuf = log->lbuf_free;
1893         while (lbuf) {
1894                 struct lbuf *next = lbuf->l_freelist;
1895                 __free_page(lbuf->l_page);
1896                 kfree(lbuf);
1897                 lbuf = next;
1898         }
1899 }
1900
1901
1902 /*
1903  *      lbmAllocate()
1904  *
1905  * allocate an empty log buffer
1906  */
1907 static struct lbuf *lbmAllocate(struct jfs_log * log, int pn)
1908 {
1909         struct lbuf *bp;
1910         unsigned long flags;
1911
1912         /*
1913          * recycle from log buffer freelist if any
1914          */
1915         LCACHE_LOCK(flags);
1916         LCACHE_SLEEP_COND(log->free_wait, (bp = log->lbuf_free), flags);
1917         log->lbuf_free = bp->l_freelist;
1918         LCACHE_UNLOCK(flags);
1919
1920         bp->l_flag = 0;
1921
1922         bp->l_wqnext = NULL;
1923         bp->l_freelist = NULL;
1924
1925         bp->l_pn = pn;
1926         bp->l_blkno = log->base + (pn << (L2LOGPSIZE - log->l2bsize));
1927         bp->l_ceor = 0;
1928
1929         return bp;
1930 }
1931
1932
1933 /*
1934  *      lbmFree()
1935  *
1936  * release a log buffer to freelist
1937  */
1938 static void lbmFree(struct lbuf * bp)
1939 {
1940         unsigned long flags;
1941
1942         LCACHE_LOCK(flags);
1943
1944         lbmfree(bp);
1945
1946         LCACHE_UNLOCK(flags);
1947 }
1948
1949 static void lbmfree(struct lbuf * bp)
1950 {
1951         struct jfs_log *log = bp->l_log;
1952
1953         assert(bp->l_wqnext == NULL);
1954
1955         /*
1956          * return the buffer to head of freelist
1957          */
1958         bp->l_freelist = log->lbuf_free;
1959         log->lbuf_free = bp;
1960
1961         wake_up(&log->free_wait);
1962         return;
1963 }
1964
1965
1966 /*
1967  * NAME:        lbmRedrive
1968  *
1969  * FUNCTION:    add a log buffer to the the log redrive list
1970  *
1971  * PARAMETER:
1972  *     bp       - log buffer
1973  *
1974  * NOTES:
1975  *      Takes log_redrive_lock.
1976  */
1977 static inline void lbmRedrive(struct lbuf *bp)
1978 {
1979         unsigned long flags;
1980
1981         spin_lock_irqsave(&log_redrive_lock, flags);
1982         bp->l_redrive_next = log_redrive_list;
1983         log_redrive_list = bp;
1984         spin_unlock_irqrestore(&log_redrive_lock, flags);
1985
1986         wake_up(&jfs_IO_thread_wait);
1987 }
1988
1989
1990 /*
1991  *      lbmRead()
1992  */
1993 static int lbmRead(struct jfs_log * log, int pn, struct lbuf ** bpp)
1994 {
1995         struct bio *bio;
1996         struct lbuf *bp;
1997
1998         /*
1999          * allocate a log buffer
2000          */
2001         *bpp = bp = lbmAllocate(log, pn);
2002         jfs_info("lbmRead: bp:0x%p pn:0x%x", bp, pn);
2003
2004         bp->l_flag |= lbmREAD;
2005
2006         bio = bio_alloc(GFP_NOFS, 1);
2007
2008         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2009         bio->bi_bdev = log->bdev;
2010         bio->bi_io_vec[0].bv_page = bp->l_page;
2011         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2012         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2013
2014         bio->bi_vcnt = 1;
2015         bio->bi_idx = 0;
2016         bio->bi_size = LOGPSIZE;
2017
2018         bio->bi_end_io = lbmIODone;
2019         bio->bi_private = bp;
2020         submit_bio(READ_SYNC, bio);
2021
2022         wait_event(bp->l_ioevent, (bp->l_flag != lbmREAD));
2023
2024         return 0;
2025 }
2026
2027
2028 /*
2029  *      lbmWrite()
2030  *
2031  * buffer at head of pageout queue stays after completion of
2032  * partial-page pageout and redriven by explicit initiation of
2033  * pageout by caller until full-page pageout is completed and
2034  * released.
2035  *
2036  * device driver i/o done redrives pageout of new buffer at
2037  * head of pageout queue when current buffer at head of pageout
2038  * queue is released at the completion of its full-page pageout.
2039  *
2040  * LOGGC_LOCK() serializes lbmWrite() by lmNextPage() and lmGroupCommit().
2041  * LCACHE_LOCK() serializes xflag between lbmWrite() and lbmIODone()
2042  */
2043 static void lbmWrite(struct jfs_log * log, struct lbuf * bp, int flag,
2044                      int cant_block)
2045 {
2046         struct lbuf *tail;
2047         unsigned long flags;
2048
2049         jfs_info("lbmWrite: bp:0x%p flag:0x%x pn:0x%x", bp, flag, bp->l_pn);
2050
2051         /* map the logical block address to physical block address */
2052         bp->l_blkno =
2053             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2054
2055         LCACHE_LOCK(flags);             /* disable+lock */
2056
2057         /*
2058          * initialize buffer for device driver
2059          */
2060         bp->l_flag = flag;
2061
2062         /*
2063          *      insert bp at tail of write queue associated with log
2064          *
2065          * (request is either for bp already/currently at head of queue
2066          * or new bp to be inserted at tail)
2067          */
2068         tail = log->wqueue;
2069
2070         /* is buffer not already on write queue ? */
2071         if (bp->l_wqnext == NULL) {
2072                 /* insert at tail of wqueue */
2073                 if (tail == NULL) {
2074                         log->wqueue = bp;
2075                         bp->l_wqnext = bp;
2076                 } else {
2077                         log->wqueue = bp;
2078                         bp->l_wqnext = tail->l_wqnext;
2079                         tail->l_wqnext = bp;
2080                 }
2081
2082                 tail = bp;
2083         }
2084
2085         /* is buffer at head of wqueue and for write ? */
2086         if ((bp != tail->l_wqnext) || !(flag & lbmWRITE)) {
2087                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2088                 return;
2089         }
2090
2091         LCACHE_UNLOCK(flags);   /* unlock+enable */
2092
2093         if (cant_block)
2094                 lbmRedrive(bp);
2095         else if (flag & lbmSYNC)
2096                 lbmStartIO(bp);
2097         else {
2098                 LOGGC_UNLOCK(log);
2099                 lbmStartIO(bp);
2100                 LOGGC_LOCK(log);
2101         }
2102 }
2103
2104
2105 /*
2106  *      lbmDirectWrite()
2107  *
2108  * initiate pageout bypassing write queue for sidestream
2109  * (e.g., log superblock) write;
2110  */
2111 static void lbmDirectWrite(struct jfs_log * log, struct lbuf * bp, int flag)
2112 {
2113         jfs_info("lbmDirectWrite: bp:0x%p flag:0x%x pn:0x%x",
2114                  bp, flag, bp->l_pn);
2115
2116         /*
2117          * initialize buffer for device driver
2118          */
2119         bp->l_flag = flag | lbmDIRECT;
2120
2121         /* map the logical block address to physical block address */
2122         bp->l_blkno =
2123             log->base + (bp->l_pn << (L2LOGPSIZE - log->l2bsize));
2124
2125         /*
2126          *      initiate pageout of the page
2127          */
2128         lbmStartIO(bp);
2129 }
2130
2131
2132 /*
2133  * NAME:        lbmStartIO()
2134  *
2135  * FUNCTION:    Interface to DD strategy routine
2136  *
2137  * RETURN:      none
2138  *
2139  * serialization: LCACHE_LOCK() is NOT held during log i/o;
2140  */
2141 static void lbmStartIO(struct lbuf * bp)
2142 {
2143         struct bio *bio;
2144         struct jfs_log *log = bp->l_log;
2145
2146         jfs_info("lbmStartIO\n");
2147
2148         bio = bio_alloc(GFP_NOFS, 1);
2149         bio->bi_sector = bp->l_blkno << (log->l2bsize - 9);
2150         bio->bi_bdev = log->bdev;
2151         bio->bi_io_vec[0].bv_page = bp->l_page;
2152         bio->bi_io_vec[0].bv_len = LOGPSIZE;
2153         bio->bi_io_vec[0].bv_offset = bp->l_offset;
2154
2155         bio->bi_vcnt = 1;
2156         bio->bi_idx = 0;
2157         bio->bi_size = LOGPSIZE;
2158
2159         bio->bi_end_io = lbmIODone;
2160         bio->bi_private = bp;
2161
2162         /* check if journaling to disk has been disabled */
2163         if (log->no_integrity) {
2164                 bio->bi_size = 0;
2165                 lbmIODone(bio, 0, 0);
2166         } else {
2167                 submit_bio(WRITE_SYNC, bio);
2168                 INCREMENT(lmStat.submitted);
2169         }
2170 }
2171
2172
2173 /*
2174  *      lbmIOWait()
2175  */
2176 static int lbmIOWait(struct lbuf * bp, int flag)
2177 {
2178         unsigned long flags;
2179         int rc = 0;
2180
2181         jfs_info("lbmIOWait1: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2182
2183         LCACHE_LOCK(flags);             /* disable+lock */
2184
2185         LCACHE_SLEEP_COND(bp->l_ioevent, (bp->l_flag & lbmDONE), flags);
2186
2187         rc = (bp->l_flag & lbmERROR) ? -EIO : 0;
2188
2189         if (flag & lbmFREE)
2190                 lbmfree(bp);
2191
2192         LCACHE_UNLOCK(flags);   /* unlock+enable */
2193
2194         jfs_info("lbmIOWait2: bp:0x%p flag:0x%x:0x%x", bp, bp->l_flag, flag);
2195         return rc;
2196 }
2197
2198 /*
2199  *      lbmIODone()
2200  *
2201  * executed at INTIODONE level
2202  */
2203 static int lbmIODone(struct bio *bio, unsigned int bytes_done, int error)
2204 {
2205         struct lbuf *bp = bio->bi_private;
2206         struct lbuf *nextbp, *tail;
2207         struct jfs_log *log;
2208         unsigned long flags;
2209
2210         if (bio->bi_size)
2211                 return 1;
2212
2213         /*
2214          * get back jfs buffer bound to the i/o buffer
2215          */
2216         jfs_info("lbmIODone: bp:0x%p flag:0x%x", bp, bp->l_flag);
2217
2218         LCACHE_LOCK(flags);             /* disable+lock */
2219
2220         bp->l_flag |= lbmDONE;
2221
2222         if (!test_bit(BIO_UPTODATE, &bio->bi_flags)) {
2223                 bp->l_flag |= lbmERROR;
2224
2225                 jfs_err("lbmIODone: I/O error in JFS log");
2226         }
2227
2228         bio_put(bio);
2229
2230         /*
2231          *      pagein completion
2232          */
2233         if (bp->l_flag & lbmREAD) {
2234                 bp->l_flag &= ~lbmREAD;
2235
2236                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2237
2238                 /* wakeup I/O initiator */
2239                 LCACHE_WAKEUP(&bp->l_ioevent);
2240
2241                 return 0;
2242         }
2243
2244         /*
2245          *      pageout completion
2246          *
2247          * the bp at the head of write queue has completed pageout.
2248          *
2249          * if single-commit/full-page pageout, remove the current buffer
2250          * from head of pageout queue, and redrive pageout with
2251          * the new buffer at head of pageout queue;
2252          * otherwise, the partial-page pageout buffer stays at
2253          * the head of pageout queue to be redriven for pageout
2254          * by lmGroupCommit() until full-page pageout is completed.
2255          */
2256         bp->l_flag &= ~lbmWRITE;
2257         INCREMENT(lmStat.pagedone);
2258
2259         /* update committed lsn */
2260         log = bp->l_log;
2261         log->clsn = (bp->l_pn << L2LOGPSIZE) + bp->l_ceor;
2262
2263         if (bp->l_flag & lbmDIRECT) {
2264                 LCACHE_WAKEUP(&bp->l_ioevent);
2265                 LCACHE_UNLOCK(flags);
2266                 return 0;
2267         }
2268
2269         tail = log->wqueue;
2270
2271         /* single element queue */
2272         if (bp == tail) {
2273                 /* remove head buffer of full-page pageout
2274                  * from log device write queue
2275                  */
2276                 if (bp->l_flag & lbmRELEASE) {
2277                         log->wqueue = NULL;
2278                         bp->l_wqnext = NULL;
2279                 }
2280         }
2281         /* multi element queue */
2282         else {
2283                 /* remove head buffer of full-page pageout
2284                  * from log device write queue
2285                  */
2286                 if (bp->l_flag & lbmRELEASE) {
2287                         nextbp = tail->l_wqnext = bp->l_wqnext;
2288                         bp->l_wqnext = NULL;
2289
2290                         /*
2291                          * redrive pageout of next page at head of write queue:
2292                          * redrive next page without any bound tblk
2293                          * (i.e., page w/o any COMMIT records), or
2294                          * first page of new group commit which has been
2295                          * queued after current page (subsequent pageout
2296                          * is performed synchronously, except page without
2297                          * any COMMITs) by lmGroupCommit() as indicated
2298                          * by lbmWRITE flag;
2299                          */
2300                         if (nextbp->l_flag & lbmWRITE) {
2301                                 /*
2302                                  * We can't do the I/O at interrupt time.
2303                                  * The jfsIO thread can do it
2304                                  */
2305                                 lbmRedrive(nextbp);
2306                         }
2307                 }
2308         }
2309
2310         /*
2311          *      synchronous pageout:
2312          *
2313          * buffer has not necessarily been removed from write queue
2314          * (e.g., synchronous write of partial-page with COMMIT):
2315          * leave buffer for i/o initiator to dispose
2316          */
2317         if (bp->l_flag & lbmSYNC) {
2318                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2319
2320                 /* wakeup I/O initiator */
2321                 LCACHE_WAKEUP(&bp->l_ioevent);
2322         }
2323
2324         /*
2325          *      Group Commit pageout:
2326          */
2327         else if (bp->l_flag & lbmGC) {
2328                 LCACHE_UNLOCK(flags);
2329                 lmPostGC(bp);
2330         }
2331
2332         /*
2333          *      asynchronous pageout:
2334          *
2335          * buffer must have been removed from write queue:
2336          * insert buffer at head of freelist where it can be recycled
2337          */
2338         else {
2339                 assert(bp->l_flag & lbmRELEASE);
2340                 assert(bp->l_flag & lbmFREE);
2341                 lbmfree(bp);
2342
2343                 LCACHE_UNLOCK(flags);   /* unlock+enable */
2344         }
2345
2346         return 0;
2347 }
2348
2349 int jfsIOWait(void *arg)
2350 {
2351         struct lbuf *bp;
2352
2353         daemonize("jfsIO");
2354
2355         complete(&jfsIOwait);
2356
2357         do {
2358                 DECLARE_WAITQUEUE(wq, current);
2359
2360                 spin_lock_irq(&log_redrive_lock);
2361                 while ((bp = log_redrive_list) != 0) {
2362                         log_redrive_list = bp->l_redrive_next;
2363                         bp->l_redrive_next = NULL;
2364                         spin_unlock_irq(&log_redrive_lock);
2365                         lbmStartIO(bp);
2366                         spin_lock_irq(&log_redrive_lock);
2367                 }
2368                 if (current->flags & PF_FREEZE) {
2369                         spin_unlock_irq(&log_redrive_lock);
2370                         refrigerator(PF_FREEZE);
2371                 } else {
2372                         add_wait_queue(&jfs_IO_thread_wait, &wq);
2373                         set_current_state(TASK_INTERRUPTIBLE);
2374                         spin_unlock_irq(&log_redrive_lock);
2375                         schedule();
2376                         current->state = TASK_RUNNING;
2377                         remove_wait_queue(&jfs_IO_thread_wait, &wq);
2378                 }
2379         } while (!jfs_stop_threads);
2380
2381         jfs_info("jfsIOWait being killed!");
2382         complete_and_exit(&jfsIOwait, 0);
2383 }
2384
2385 /*
2386  * NAME:        lmLogFormat()/jfs_logform()
2387  *
2388  * FUNCTION:    format file system log
2389  *
2390  * PARAMETERS:
2391  *      log     - volume log
2392  *      logAddress - start address of log space in FS block
2393  *      logSize - length of log space in FS block;
2394  *
2395  * RETURN:      0       - success
2396  *              -EIO    - i/o error
2397  *
2398  * XXX: We're synchronously writing one page at a time.  This needs to
2399  *      be improved by writing multiple pages at once.
2400  */
2401 int lmLogFormat(struct jfs_log *log, s64 logAddress, int logSize)
2402 {
2403         int rc = -EIO;
2404         struct jfs_sb_info *sbi;
2405         struct logsuper *logsuper;
2406         struct logpage *lp;
2407         int lspn;               /* log sequence page number */
2408         struct lrd *lrd_ptr;
2409         int npages = 0;
2410         struct lbuf *bp;
2411
2412         jfs_info("lmLogFormat: logAddress:%Ld logSize:%d",
2413                  (long long)logAddress, logSize);
2414
2415         sbi = list_entry(log->sb_list.next, struct jfs_sb_info, log_list);
2416
2417         /* allocate a log buffer */
2418         bp = lbmAllocate(log, 1);
2419
2420         npages = logSize >> sbi->l2nbperpage;
2421
2422         /*
2423          *      log space:
2424          *
2425          * page 0 - reserved;
2426          * page 1 - log superblock;
2427          * page 2 - log data page: A SYNC log record is written
2428          *          into this page at logform time;
2429          * pages 3-N - log data page: set to empty log data pages;
2430          */
2431         /*
2432          *      init log superblock: log page 1
2433          */
2434         logsuper = (struct logsuper *) bp->l_ldata;
2435
2436         logsuper->magic = cpu_to_le32(LOGMAGIC);
2437         logsuper->version = cpu_to_le32(LOGVERSION);
2438         logsuper->state = cpu_to_le32(LOGREDONE);
2439         logsuper->flag = cpu_to_le32(sbi->mntflag);     /* ? */
2440         logsuper->size = cpu_to_le32(npages);
2441         logsuper->bsize = cpu_to_le32(sbi->bsize);
2442         logsuper->l2bsize = cpu_to_le32(sbi->l2bsize);
2443         logsuper->end = cpu_to_le32(2 * LOGPSIZE + LOGPHDRSIZE + LOGRDSIZE);
2444
2445         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2446         bp->l_blkno = logAddress + sbi->nbperpage;
2447         lbmStartIO(bp);
2448         if ((rc = lbmIOWait(bp, 0)))
2449                 goto exit;
2450
2451         /*
2452          *      init pages 2 to npages-1 as log data pages:
2453          *
2454          * log page sequence number (lpsn) initialization:
2455          *
2456          * pn:   0     1     2     3                 n-1
2457          *       +-----+-----+=====+=====+===.....===+=====+
2458          * lspn:             N-1   0     1           N-2
2459          *                   <--- N page circular file ---->
2460          *
2461          * the N (= npages-2) data pages of the log is maintained as
2462          * a circular file for the log records;
2463          * lpsn grows by 1 monotonically as each log page is written
2464          * to the circular file of the log;
2465          * and setLogpage() will not reset the page number even if
2466          * the eor is equal to LOGPHDRSIZE. In order for binary search
2467          * still work in find log end process, we have to simulate the
2468          * log wrap situation at the log format time.
2469          * The 1st log page written will have the highest lpsn. Then
2470          * the succeeding log pages will have ascending order of
2471          * the lspn starting from 0, ... (N-2)
2472          */
2473         lp = (struct logpage *) bp->l_ldata;
2474         /*
2475          * initialize 1st log page to be written: lpsn = N - 1,
2476          * write a SYNCPT log record is written to this page
2477          */
2478         lp->h.page = lp->t.page = cpu_to_le32(npages - 3);
2479         lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE + LOGRDSIZE);
2480
2481         lrd_ptr = (struct lrd *) &lp->data;
2482         lrd_ptr->logtid = 0;
2483         lrd_ptr->backchain = 0;
2484         lrd_ptr->type = cpu_to_le16(LOG_SYNCPT);
2485         lrd_ptr->length = 0;
2486         lrd_ptr->log.syncpt.sync = 0;
2487
2488         bp->l_blkno += sbi->nbperpage;
2489         bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2490         lbmStartIO(bp);
2491         if ((rc = lbmIOWait(bp, 0)))
2492                 goto exit;
2493
2494         /*
2495          *      initialize succeeding log pages: lpsn = 0, 1, ..., (N-2)
2496          */
2497         for (lspn = 0; lspn < npages - 3; lspn++) {
2498                 lp->h.page = lp->t.page = cpu_to_le32(lspn);
2499                 lp->h.eor = lp->t.eor = cpu_to_le16(LOGPHDRSIZE);
2500
2501                 bp->l_blkno += sbi->nbperpage;
2502                 bp->l_flag = lbmWRITE | lbmSYNC | lbmDIRECT;
2503                 lbmStartIO(bp);
2504                 if ((rc = lbmIOWait(bp, 0)))
2505                         goto exit;
2506         }
2507
2508         rc = 0;
2509 exit:
2510         /*
2511          *      finalize log
2512          */
2513         /* release the buffer */
2514         lbmFree(bp);
2515
2516         return rc;
2517 }
2518
2519 #ifdef CONFIG_JFS_STATISTICS
2520 int jfs_lmstats_read(char *buffer, char **start, off_t offset, int length,
2521                       int *eof, void *data)
2522 {
2523         int len = 0;
2524         off_t begin;
2525
2526         len += sprintf(buffer,
2527                        "JFS Logmgr stats\n"
2528                        "================\n"
2529                        "commits = %d\n"
2530                        "writes submitted = %d\n"
2531                        "writes completed = %d\n"
2532                        "full pages submitted = %d\n"
2533                        "partial pages submitted = %d\n",
2534                        lmStat.commit,
2535                        lmStat.submitted,
2536                        lmStat.pagedone,
2537                        lmStat.full_page,
2538                        lmStat.partial_page);
2539
2540         begin = offset;
2541         *start = buffer + begin;
2542         len -= begin;
2543
2544         if (len > length)
2545                 len = length;
2546         else
2547                 *eof = 1;
2548
2549         if (len < 0)
2550                 len = 0;
2551
2552         return len;
2553 }
2554 #endif /* CONFIG_JFS_STATISTICS */