linux/fs/jfs/jfs_imap.c
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   1/*
   2 *   Copyright (C) International Business Machines Corp., 2000-2004
   3 *
   4 *   This program is free software;  you can redistribute it and/or modify
   5 *   it under the terms of the GNU General Public License as published by
   6 *   the Free Software Foundation; either version 2 of the License, or
   7 *   (at your option) any later version.
   8 *
   9 *   This program is distributed in the hope that it will be useful,
  10 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
  11 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  12 *   the GNU General Public License for more details.
  13 *
  14 *   You should have received a copy of the GNU General Public License
  15 *   along with this program;  if not, write to the Free Software
  16 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  17 */
  18
  19/*
  20 *      jfs_imap.c: inode allocation map manager
  21 *
  22 * Serialization:
  23 *   Each AG has a simple lock which is used to control the serialization of
  24 *      the AG level lists.  This lock should be taken first whenever an AG
  25 *      level list will be modified or accessed.
  26 *
  27 *   Each IAG is locked by obtaining the buffer for the IAG page.
  28 *
  29 *   There is also a inode lock for the inode map inode.  A read lock needs to
  30 *      be taken whenever an IAG is read from the map or the global level
  31 *      information is read.  A write lock needs to be taken whenever the global
  32 *      level information is modified or an atomic operation needs to be used.
  33 *
  34 *      If more than one IAG is read at one time, the read lock may not
  35 *      be given up until all of the IAG's are read.  Otherwise, a deadlock
  36 *      may occur when trying to obtain the read lock while another thread
  37 *      holding the read lock is waiting on the IAG already being held.
  38 *
  39 *   The control page of the inode map is read into memory by diMount().
  40 *      Thereafter it should only be modified in memory and then it will be
  41 *      written out when the filesystem is unmounted by diUnmount().
  42 */
  43
  44#include <linux/fs.h>
  45#include <linux/buffer_head.h>
  46#include <linux/pagemap.h>
  47#include <linux/quotaops.h>
  48#include <linux/slab.h>
  49
  50#include "jfs_incore.h"
  51#include "jfs_inode.h"
  52#include "jfs_filsys.h"
  53#include "jfs_dinode.h"
  54#include "jfs_dmap.h"
  55#include "jfs_imap.h"
  56#include "jfs_metapage.h"
  57#include "jfs_superblock.h"
  58#include "jfs_debug.h"
  59
  60/*
  61 * imap locks
  62 */
  63/* iag free list lock */
  64#define IAGFREE_LOCK_INIT(imap)         mutex_init(&imap->im_freelock)
  65#define IAGFREE_LOCK(imap)              mutex_lock(&imap->im_freelock)
  66#define IAGFREE_UNLOCK(imap)            mutex_unlock(&imap->im_freelock)
  67
  68/* per ag iag list locks */
  69#define AG_LOCK_INIT(imap,index)        mutex_init(&(imap->im_aglock[index]))
  70#define AG_LOCK(imap,agno)              mutex_lock(&imap->im_aglock[agno])
  71#define AG_UNLOCK(imap,agno)            mutex_unlock(&imap->im_aglock[agno])
  72
  73/*
  74 * forward references
  75 */
  76static int diAllocAG(struct inomap *, int, bool, struct inode *);
  77static int diAllocAny(struct inomap *, int, bool, struct inode *);
  78static int diAllocBit(struct inomap *, struct iag *, int);
  79static int diAllocExt(struct inomap *, int, struct inode *);
  80static int diAllocIno(struct inomap *, int, struct inode *);
  81static int diFindFree(u32, int);
  82static int diNewExt(struct inomap *, struct iag *, int);
  83static int diNewIAG(struct inomap *, int *, int, struct metapage **);
  84static void duplicateIXtree(struct super_block *, s64, int, s64 *);
  85
  86static int diIAGRead(struct inomap * imap, int, struct metapage **);
  87static int copy_from_dinode(struct dinode *, struct inode *);
  88static void copy_to_dinode(struct dinode *, struct inode *);
  89
  90/*
  91 * NAME:        diMount()
  92 *
  93 * FUNCTION:    initialize the incore inode map control structures for
  94 *              a fileset or aggregate init time.
  95 *
  96 *              the inode map's control structure (dinomap) is
  97 *              brought in from disk and placed in virtual memory.
  98 *
  99 * PARAMETERS:
 100 *      ipimap  - pointer to inode map inode for the aggregate or fileset.
 101 *
 102 * RETURN VALUES:
 103 *      0       - success
 104 *      -ENOMEM - insufficient free virtual memory.
 105 *      -EIO    - i/o error.
 106 */
 107int diMount(struct inode *ipimap)
 108{
 109        struct inomap *imap;
 110        struct metapage *mp;
 111        int index;
 112        struct dinomap_disk *dinom_le;
 113
 114        /*
 115         * allocate/initialize the in-memory inode map control structure
 116         */
 117        /* allocate the in-memory inode map control structure. */
 118        imap = kmalloc(sizeof(struct inomap), GFP_KERNEL);
 119        if (imap == NULL) {
 120                jfs_err("diMount: kmalloc returned NULL!");
 121                return -ENOMEM;
 122        }
 123
 124        /* read the on-disk inode map control structure. */
 125
 126        mp = read_metapage(ipimap,
 127                           IMAPBLKNO << JFS_SBI(ipimap->i_sb)->l2nbperpage,
 128                           PSIZE, 0);
 129        if (mp == NULL) {
 130                kfree(imap);
 131                return -EIO;
 132        }
 133
 134        /* copy the on-disk version to the in-memory version. */
 135        dinom_le = (struct dinomap_disk *) mp->data;
 136        imap->im_freeiag = le32_to_cpu(dinom_le->in_freeiag);
 137        imap->im_nextiag = le32_to_cpu(dinom_le->in_nextiag);
 138        atomic_set(&imap->im_numinos, le32_to_cpu(dinom_le->in_numinos));
 139        atomic_set(&imap->im_numfree, le32_to_cpu(dinom_le->in_numfree));
 140        imap->im_nbperiext = le32_to_cpu(dinom_le->in_nbperiext);
 141        imap->im_l2nbperiext = le32_to_cpu(dinom_le->in_l2nbperiext);
 142        for (index = 0; index < MAXAG; index++) {
 143                imap->im_agctl[index].inofree =
 144                    le32_to_cpu(dinom_le->in_agctl[index].inofree);
 145                imap->im_agctl[index].extfree =
 146                    le32_to_cpu(dinom_le->in_agctl[index].extfree);
 147                imap->im_agctl[index].numinos =
 148                    le32_to_cpu(dinom_le->in_agctl[index].numinos);
 149                imap->im_agctl[index].numfree =
 150                    le32_to_cpu(dinom_le->in_agctl[index].numfree);
 151        }
 152
 153        /* release the buffer. */
 154        release_metapage(mp);
 155
 156        /*
 157         * allocate/initialize inode allocation map locks
 158         */
 159        /* allocate and init iag free list lock */
 160        IAGFREE_LOCK_INIT(imap);
 161
 162        /* allocate and init ag list locks */
 163        for (index = 0; index < MAXAG; index++) {
 164                AG_LOCK_INIT(imap, index);
 165        }
 166
 167        /* bind the inode map inode and inode map control structure
 168         * to each other.
 169         */
 170        imap->im_ipimap = ipimap;
 171        JFS_IP(ipimap)->i_imap = imap;
 172
 173        return (0);
 174}
 175
 176
 177/*
 178 * NAME:        diUnmount()
 179 *
 180 * FUNCTION:    write to disk the incore inode map control structures for
 181 *              a fileset or aggregate at unmount time.
 182 *
 183 * PARAMETERS:
 184 *      ipimap  - pointer to inode map inode for the aggregate or fileset.
 185 *
 186 * RETURN VALUES:
 187 *      0       - success
 188 *      -ENOMEM - insufficient free virtual memory.
 189 *      -EIO    - i/o error.
 190 */
 191int diUnmount(struct inode *ipimap, int mounterror)
 192{
 193        struct inomap *imap = JFS_IP(ipimap)->i_imap;
 194
 195        /*
 196         * update the on-disk inode map control structure
 197         */
 198
 199        if (!(mounterror || isReadOnly(ipimap)))
 200                diSync(ipimap);
 201
 202        /*
 203         * Invalidate the page cache buffers
 204         */
 205        truncate_inode_pages(ipimap->i_mapping, 0);
 206
 207        /*
 208         * free in-memory control structure
 209         */
 210        kfree(imap);
 211
 212        return (0);
 213}
 214
 215
 216/*
 217 *      diSync()
 218 */
 219int diSync(struct inode *ipimap)
 220{
 221        struct dinomap_disk *dinom_le;
 222        struct inomap *imp = JFS_IP(ipimap)->i_imap;
 223        struct metapage *mp;
 224        int index;
 225
 226        /*
 227         * write imap global conrol page
 228         */
 229        /* read the on-disk inode map control structure */
 230        mp = get_metapage(ipimap,
 231                          IMAPBLKNO << JFS_SBI(ipimap->i_sb)->l2nbperpage,
 232                          PSIZE, 0);
 233        if (mp == NULL) {
 234                jfs_err("diSync: get_metapage failed!");
 235                return -EIO;
 236        }
 237
 238        /* copy the in-memory version to the on-disk version */
 239        dinom_le = (struct dinomap_disk *) mp->data;
 240        dinom_le->in_freeiag = cpu_to_le32(imp->im_freeiag);
 241        dinom_le->in_nextiag = cpu_to_le32(imp->im_nextiag);
 242        dinom_le->in_numinos = cpu_to_le32(atomic_read(&imp->im_numinos));
 243        dinom_le->in_numfree = cpu_to_le32(atomic_read(&imp->im_numfree));
 244        dinom_le->in_nbperiext = cpu_to_le32(imp->im_nbperiext);
 245        dinom_le->in_l2nbperiext = cpu_to_le32(imp->im_l2nbperiext);
 246        for (index = 0; index < MAXAG; index++) {
 247                dinom_le->in_agctl[index].inofree =
 248                    cpu_to_le32(imp->im_agctl[index].inofree);
 249                dinom_le->in_agctl[index].extfree =
 250                    cpu_to_le32(imp->im_agctl[index].extfree);
 251                dinom_le->in_agctl[index].numinos =
 252                    cpu_to_le32(imp->im_agctl[index].numinos);
 253                dinom_le->in_agctl[index].numfree =
 254                    cpu_to_le32(imp->im_agctl[index].numfree);
 255        }
 256
 257        /* write out the control structure */
 258        write_metapage(mp);
 259
 260        /*
 261         * write out dirty pages of imap
 262         */
 263        filemap_write_and_wait(ipimap->i_mapping);
 264
 265        diWriteSpecial(ipimap, 0);
 266
 267        return (0);
 268}
 269
 270
 271/*
 272 * NAME:        diRead()
 273 *
 274 * FUNCTION:    initialize an incore inode from disk.
 275 *
 276 *              on entry, the specifed incore inode should itself
 277 *              specify the disk inode number corresponding to the
 278 *              incore inode (i.e. i_number should be initialized).
 279 *
 280 *              this routine handles incore inode initialization for
 281 *              both "special" and "regular" inodes.  special inodes
 282 *              are those required early in the mount process and
 283 *              require special handling since much of the file system
 284 *              is not yet initialized.  these "special" inodes are
 285 *              identified by a NULL inode map inode pointer and are
 286 *              actually initialized by a call to diReadSpecial().
 287 *
 288 *              for regular inodes, the iag describing the disk inode
 289 *              is read from disk to determine the inode extent address
 290 *              for the disk inode.  with the inode extent address in
 291 *              hand, the page of the extent that contains the disk
 292 *              inode is read and the disk inode is copied to the
 293 *              incore inode.
 294 *
 295 * PARAMETERS:
 296 *      ip      -  pointer to incore inode to be initialized from disk.
 297 *
 298 * RETURN VALUES:
 299 *      0       - success
 300 *      -EIO    - i/o error.
 301 *      -ENOMEM - insufficient memory
 302 *
 303 */
 304int diRead(struct inode *ip)
 305{
 306        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
 307        int iagno, ino, extno, rc;
 308        struct inode *ipimap;
 309        struct dinode *dp;
 310        struct iag *iagp;
 311        struct metapage *mp;
 312        s64 blkno, agstart;
 313        struct inomap *imap;
 314        int block_offset;
 315        int inodes_left;
 316        unsigned long pageno;
 317        int rel_inode;
 318
 319        jfs_info("diRead: ino = %ld", ip->i_ino);
 320
 321        ipimap = sbi->ipimap;
 322        JFS_IP(ip)->ipimap = ipimap;
 323
 324        /* determine the iag number for this inode (number) */
 325        iagno = INOTOIAG(ip->i_ino);
 326
 327        /* read the iag */
 328        imap = JFS_IP(ipimap)->i_imap;
 329        IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
 330        rc = diIAGRead(imap, iagno, &mp);
 331        IREAD_UNLOCK(ipimap);
 332        if (rc) {
 333                jfs_err("diRead: diIAGRead returned %d", rc);
 334                return (rc);
 335        }
 336
 337        iagp = (struct iag *) mp->data;
 338
 339        /* determine inode extent that holds the disk inode */
 340        ino = ip->i_ino & (INOSPERIAG - 1);
 341        extno = ino >> L2INOSPEREXT;
 342
 343        if ((lengthPXD(&iagp->inoext[extno]) != imap->im_nbperiext) ||
 344            (addressPXD(&iagp->inoext[extno]) == 0)) {
 345                release_metapage(mp);
 346                return -ESTALE;
 347        }
 348
 349        /* get disk block number of the page within the inode extent
 350         * that holds the disk inode.
 351         */
 352        blkno = INOPBLK(&iagp->inoext[extno], ino, sbi->l2nbperpage);
 353
 354        /* get the ag for the iag */
 355        agstart = le64_to_cpu(iagp->agstart);
 356
 357        release_metapage(mp);
 358
 359        rel_inode = (ino & (INOSPERPAGE - 1));
 360        pageno = blkno >> sbi->l2nbperpage;
 361
 362        if ((block_offset = ((u32) blkno & (sbi->nbperpage - 1)))) {
 363                /*
 364                 * OS/2 didn't always align inode extents on page boundaries
 365                 */
 366                inodes_left =
 367                     (sbi->nbperpage - block_offset) << sbi->l2niperblk;
 368
 369                if (rel_inode < inodes_left)
 370                        rel_inode += block_offset << sbi->l2niperblk;
 371                else {
 372                        pageno += 1;
 373                        rel_inode -= inodes_left;
 374                }
 375        }
 376
 377        /* read the page of disk inode */
 378        mp = read_metapage(ipimap, pageno << sbi->l2nbperpage, PSIZE, 1);
 379        if (!mp) {
 380                jfs_err("diRead: read_metapage failed");
 381                return -EIO;
 382        }
 383
 384        /* locate the disk inode requested */
 385        dp = (struct dinode *) mp->data;
 386        dp += rel_inode;
 387
 388        if (ip->i_ino != le32_to_cpu(dp->di_number)) {
 389                jfs_error(ip->i_sb, "diRead: i_ino != di_number");
 390                rc = -EIO;
 391        } else if (le32_to_cpu(dp->di_nlink) == 0)
 392                rc = -ESTALE;
 393        else
 394                /* copy the disk inode to the in-memory inode */
 395                rc = copy_from_dinode(dp, ip);
 396
 397        release_metapage(mp);
 398
 399        /* set the ag for the inode */
 400        JFS_IP(ip)->agstart = agstart;
 401        JFS_IP(ip)->active_ag = -1;
 402
 403        return (rc);
 404}
 405
 406
 407/*
 408 * NAME:        diReadSpecial()
 409 *
 410 * FUNCTION:    initialize a 'special' inode from disk.
 411 *
 412 *              this routines handles aggregate level inodes.  The
 413 *              inode cache cannot differentiate between the
 414 *              aggregate inodes and the filesystem inodes, so we
 415 *              handle these here.  We don't actually use the aggregate
 416 *              inode map, since these inodes are at a fixed location
 417 *              and in some cases the aggregate inode map isn't initialized
 418 *              yet.
 419 *
 420 * PARAMETERS:
 421 *      sb - filesystem superblock
 422 *      inum - aggregate inode number
 423 *      secondary - 1 if secondary aggregate inode table
 424 *
 425 * RETURN VALUES:
 426 *      new inode       - success
 427 *      NULL            - i/o error.
 428 */
 429struct inode *diReadSpecial(struct super_block *sb, ino_t inum, int secondary)
 430{
 431        struct jfs_sb_info *sbi = JFS_SBI(sb);
 432        uint address;
 433        struct dinode *dp;
 434        struct inode *ip;
 435        struct metapage *mp;
 436
 437        ip = new_inode(sb);
 438        if (ip == NULL) {
 439                jfs_err("diReadSpecial: new_inode returned NULL!");
 440                return ip;
 441        }
 442
 443        if (secondary) {
 444                address = addressPXD(&sbi->ait2) >> sbi->l2nbperpage;
 445                JFS_IP(ip)->ipimap = sbi->ipaimap2;
 446        } else {
 447                address = AITBL_OFF >> L2PSIZE;
 448                JFS_IP(ip)->ipimap = sbi->ipaimap;
 449        }
 450
 451        ASSERT(inum < INOSPEREXT);
 452
 453        ip->i_ino = inum;
 454
 455        address += inum >> 3;   /* 8 inodes per 4K page */
 456
 457        /* read the page of fixed disk inode (AIT) in raw mode */
 458        mp = read_metapage(ip, address << sbi->l2nbperpage, PSIZE, 1);
 459        if (mp == NULL) {
 460                set_nlink(ip, 1);       /* Don't want iput() deleting it */
 461                iput(ip);
 462                return (NULL);
 463        }
 464
 465        /* get the pointer to the disk inode of interest */
 466        dp = (struct dinode *) (mp->data);
 467        dp += inum % 8;         /* 8 inodes per 4K page */
 468
 469        /* copy on-disk inode to in-memory inode */
 470        if ((copy_from_dinode(dp, ip)) != 0) {
 471                /* handle bad return by returning NULL for ip */
 472                set_nlink(ip, 1);       /* Don't want iput() deleting it */
 473                iput(ip);
 474                /* release the page */
 475                release_metapage(mp);
 476                return (NULL);
 477
 478        }
 479
 480        ip->i_mapping->a_ops = &jfs_metapage_aops;
 481        mapping_set_gfp_mask(ip->i_mapping, GFP_NOFS);
 482
 483        /* Allocations to metadata inodes should not affect quotas */
 484        ip->i_flags |= S_NOQUOTA;
 485
 486        if ((inum == FILESYSTEM_I) && (JFS_IP(ip)->ipimap == sbi->ipaimap)) {
 487                sbi->gengen = le32_to_cpu(dp->di_gengen);
 488                sbi->inostamp = le32_to_cpu(dp->di_inostamp);
 489        }
 490
 491        /* release the page */
 492        release_metapage(mp);
 493
 494        /*
 495         * __mark_inode_dirty expects inodes to be hashed.  Since we don't
 496         * want special inodes in the fileset inode space, we make them
 497         * appear hashed, but do not put on any lists.  hlist_del()
 498         * will work fine and require no locking.
 499         */
 500        hlist_add_fake(&ip->i_hash);
 501
 502        return (ip);
 503}
 504
 505/*
 506 * NAME:        diWriteSpecial()
 507 *
 508 * FUNCTION:    Write the special inode to disk
 509 *
 510 * PARAMETERS:
 511 *      ip - special inode
 512 *      secondary - 1 if secondary aggregate inode table
 513 *
 514 * RETURN VALUES: none
 515 */
 516
 517void diWriteSpecial(struct inode *ip, int secondary)
 518{
 519        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
 520        uint address;
 521        struct dinode *dp;
 522        ino_t inum = ip->i_ino;
 523        struct metapage *mp;
 524
 525        if (secondary)
 526                address = addressPXD(&sbi->ait2) >> sbi->l2nbperpage;
 527        else
 528                address = AITBL_OFF >> L2PSIZE;
 529
 530        ASSERT(inum < INOSPEREXT);
 531
 532        address += inum >> 3;   /* 8 inodes per 4K page */
 533
 534        /* read the page of fixed disk inode (AIT) in raw mode */
 535        mp = read_metapage(ip, address << sbi->l2nbperpage, PSIZE, 1);
 536        if (mp == NULL) {
 537                jfs_err("diWriteSpecial: failed to read aggregate inode "
 538                        "extent!");
 539                return;
 540        }
 541
 542        /* get the pointer to the disk inode of interest */
 543        dp = (struct dinode *) (mp->data);
 544        dp += inum % 8;         /* 8 inodes per 4K page */
 545
 546        /* copy on-disk inode to in-memory inode */
 547        copy_to_dinode(dp, ip);
 548        memcpy(&dp->di_xtroot, &JFS_IP(ip)->i_xtroot, 288);
 549
 550        if (inum == FILESYSTEM_I)
 551                dp->di_gengen = cpu_to_le32(sbi->gengen);
 552
 553        /* write the page */
 554        write_metapage(mp);
 555}
 556
 557/*
 558 * NAME:        diFreeSpecial()
 559 *
 560 * FUNCTION:    Free allocated space for special inode
 561 */
 562void diFreeSpecial(struct inode *ip)
 563{
 564        if (ip == NULL) {
 565                jfs_err("diFreeSpecial called with NULL ip!");
 566                return;
 567        }
 568        filemap_write_and_wait(ip->i_mapping);
 569        truncate_inode_pages(ip->i_mapping, 0);
 570        iput(ip);
 571}
 572
 573
 574
 575/*
 576 * NAME:        diWrite()
 577 *
 578 * FUNCTION:    write the on-disk inode portion of the in-memory inode
 579 *              to its corresponding on-disk inode.
 580 *
 581 *              on entry, the specifed incore inode should itself
 582 *              specify the disk inode number corresponding to the
 583 *              incore inode (i.e. i_number should be initialized).
 584 *
 585 *              the inode contains the inode extent address for the disk
 586 *              inode.  with the inode extent address in hand, the
 587 *              page of the extent that contains the disk inode is
 588 *              read and the disk inode portion of the incore inode
 589 *              is copied to the disk inode.
 590 *
 591 * PARAMETERS:
 592 *      tid -  transacation id
 593 *      ip  -  pointer to incore inode to be written to the inode extent.
 594 *
 595 * RETURN VALUES:
 596 *      0       - success
 597 *      -EIO    - i/o error.
 598 */
 599int diWrite(tid_t tid, struct inode *ip)
 600{
 601        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
 602        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
 603        int rc = 0;
 604        s32 ino;
 605        struct dinode *dp;
 606        s64 blkno;
 607        int block_offset;
 608        int inodes_left;
 609        struct metapage *mp;
 610        unsigned long pageno;
 611        int rel_inode;
 612        int dioffset;
 613        struct inode *ipimap;
 614        uint type;
 615        lid_t lid;
 616        struct tlock *ditlck, *tlck;
 617        struct linelock *dilinelock, *ilinelock;
 618        struct lv *lv;
 619        int n;
 620
 621        ipimap = jfs_ip->ipimap;
 622
 623        ino = ip->i_ino & (INOSPERIAG - 1);
 624
 625        if (!addressPXD(&(jfs_ip->ixpxd)) ||
 626            (lengthPXD(&(jfs_ip->ixpxd)) !=
 627             JFS_IP(ipimap)->i_imap->im_nbperiext)) {
 628                jfs_error(ip->i_sb, "diWrite: ixpxd invalid");
 629                return -EIO;
 630        }
 631
 632        /*
 633         * read the page of disk inode containing the specified inode:
 634         */
 635        /* compute the block address of the page */
 636        blkno = INOPBLK(&(jfs_ip->ixpxd), ino, sbi->l2nbperpage);
 637
 638        rel_inode = (ino & (INOSPERPAGE - 1));
 639        pageno = blkno >> sbi->l2nbperpage;
 640
 641        if ((block_offset = ((u32) blkno & (sbi->nbperpage - 1)))) {
 642                /*
 643                 * OS/2 didn't always align inode extents on page boundaries
 644                 */
 645                inodes_left =
 646                    (sbi->nbperpage - block_offset) << sbi->l2niperblk;
 647
 648                if (rel_inode < inodes_left)
 649                        rel_inode += block_offset << sbi->l2niperblk;
 650                else {
 651                        pageno += 1;
 652                        rel_inode -= inodes_left;
 653                }
 654        }
 655        /* read the page of disk inode */
 656      retry:
 657        mp = read_metapage(ipimap, pageno << sbi->l2nbperpage, PSIZE, 1);
 658        if (!mp)
 659                return -EIO;
 660
 661        /* get the pointer to the disk inode */
 662        dp = (struct dinode *) mp->data;
 663        dp += rel_inode;
 664
 665        dioffset = (ino & (INOSPERPAGE - 1)) << L2DISIZE;
 666
 667        /*
 668         * acquire transaction lock on the on-disk inode;
 669         * N.B. tlock is acquired on ipimap not ip;
 670         */
 671        if ((ditlck =
 672             txLock(tid, ipimap, mp, tlckINODE | tlckENTRY)) == NULL)
 673                goto retry;
 674        dilinelock = (struct linelock *) & ditlck->lock;
 675
 676        /*
 677         * copy btree root from in-memory inode to on-disk inode
 678         *
 679         * (tlock is taken from inline B+-tree root in in-memory
 680         * inode when the B+-tree root is updated, which is pointed
 681         * by jfs_ip->blid as well as being on tx tlock list)
 682         *
 683         * further processing of btree root is based on the copy
 684         * in in-memory inode, where txLog() will log from, and,
 685         * for xtree root, txUpdateMap() will update map and reset
 686         * XAD_NEW bit;
 687         */
 688
 689        if (S_ISDIR(ip->i_mode) && (lid = jfs_ip->xtlid)) {
 690                /*
 691                 * This is the special xtree inside the directory for storing
 692                 * the directory table
 693                 */
 694                xtpage_t *p, *xp;
 695                xad_t *xad;
 696
 697                jfs_ip->xtlid = 0;
 698                tlck = lid_to_tlock(lid);
 699                assert(tlck->type & tlckXTREE);
 700                tlck->type |= tlckBTROOT;
 701                tlck->mp = mp;
 702                ilinelock = (struct linelock *) & tlck->lock;
 703
 704                /*
 705                 * copy xtree root from inode to dinode:
 706                 */
 707                p = &jfs_ip->i_xtroot;
 708                xp = (xtpage_t *) &dp->di_dirtable;
 709                lv = ilinelock->lv;
 710                for (n = 0; n < ilinelock->index; n++, lv++) {
 711                        memcpy(&xp->xad[lv->offset], &p->xad[lv->offset],
 712                               lv->length << L2XTSLOTSIZE);
 713                }
 714
 715                /* reset on-disk (metadata page) xtree XAD_NEW bit */
 716                xad = &xp->xad[XTENTRYSTART];
 717                for (n = XTENTRYSTART;
 718                     n < le16_to_cpu(xp->header.nextindex); n++, xad++)
 719                        if (xad->flag & (XAD_NEW | XAD_EXTENDED))
 720                                xad->flag &= ~(XAD_NEW | XAD_EXTENDED);
 721        }
 722
 723        if ((lid = jfs_ip->blid) == 0)
 724                goto inlineData;
 725        jfs_ip->blid = 0;
 726
 727        tlck = lid_to_tlock(lid);
 728        type = tlck->type;
 729        tlck->type |= tlckBTROOT;
 730        tlck->mp = mp;
 731        ilinelock = (struct linelock *) & tlck->lock;
 732
 733        /*
 734         *      regular file: 16 byte (XAD slot) granularity
 735         */
 736        if (type & tlckXTREE) {
 737                xtpage_t *p, *xp;
 738                xad_t *xad;
 739
 740                /*
 741                 * copy xtree root from inode to dinode:
 742                 */
 743                p = &jfs_ip->i_xtroot;
 744                xp = &dp->di_xtroot;
 745                lv = ilinelock->lv;
 746                for (n = 0; n < ilinelock->index; n++, lv++) {
 747                        memcpy(&xp->xad[lv->offset], &p->xad[lv->offset],
 748                               lv->length << L2XTSLOTSIZE);
 749                }
 750
 751                /* reset on-disk (metadata page) xtree XAD_NEW bit */
 752                xad = &xp->xad[XTENTRYSTART];
 753                for (n = XTENTRYSTART;
 754                     n < le16_to_cpu(xp->header.nextindex); n++, xad++)
 755                        if (xad->flag & (XAD_NEW | XAD_EXTENDED))
 756                                xad->flag &= ~(XAD_NEW | XAD_EXTENDED);
 757        }
 758        /*
 759         *      directory: 32 byte (directory entry slot) granularity
 760         */
 761        else if (type & tlckDTREE) {
 762                dtpage_t *p, *xp;
 763
 764                /*
 765                 * copy dtree root from inode to dinode:
 766                 */
 767                p = (dtpage_t *) &jfs_ip->i_dtroot;
 768                xp = (dtpage_t *) & dp->di_dtroot;
 769                lv = ilinelock->lv;
 770                for (n = 0; n < ilinelock->index; n++, lv++) {
 771                        memcpy(&xp->slot[lv->offset], &p->slot[lv->offset],
 772                               lv->length << L2DTSLOTSIZE);
 773                }
 774        } else {
 775                jfs_err("diWrite: UFO tlock");
 776        }
 777
 778      inlineData:
 779        /*
 780         * copy inline symlink from in-memory inode to on-disk inode
 781         */
 782        if (S_ISLNK(ip->i_mode) && ip->i_size < IDATASIZE) {
 783                lv = & dilinelock->lv[dilinelock->index];
 784                lv->offset = (dioffset + 2 * 128) >> L2INODESLOTSIZE;
 785                lv->length = 2;
 786                memcpy(&dp->di_fastsymlink, jfs_ip->i_inline, IDATASIZE);
 787                dilinelock->index++;
 788        }
 789        /*
 790         * copy inline data from in-memory inode to on-disk inode:
 791         * 128 byte slot granularity
 792         */
 793        if (test_cflag(COMMIT_Inlineea, ip)) {
 794                lv = & dilinelock->lv[dilinelock->index];
 795                lv->offset = (dioffset + 3 * 128) >> L2INODESLOTSIZE;
 796                lv->length = 1;
 797                memcpy(&dp->di_inlineea, jfs_ip->i_inline_ea, INODESLOTSIZE);
 798                dilinelock->index++;
 799
 800                clear_cflag(COMMIT_Inlineea, ip);
 801        }
 802
 803        /*
 804         *      lock/copy inode base: 128 byte slot granularity
 805         */
 806        lv = & dilinelock->lv[dilinelock->index];
 807        lv->offset = dioffset >> L2INODESLOTSIZE;
 808        copy_to_dinode(dp, ip);
 809        if (test_and_clear_cflag(COMMIT_Dirtable, ip)) {
 810                lv->length = 2;
 811                memcpy(&dp->di_dirtable, &jfs_ip->i_dirtable, 96);
 812        } else
 813                lv->length = 1;
 814        dilinelock->index++;
 815
 816        /* release the buffer holding the updated on-disk inode.
 817         * the buffer will be later written by commit processing.
 818         */
 819        write_metapage(mp);
 820
 821        return (rc);
 822}
 823
 824
 825/*
 826 * NAME:        diFree(ip)
 827 *
 828 * FUNCTION:    free a specified inode from the inode working map
 829 *              for a fileset or aggregate.
 830 *
 831 *              if the inode to be freed represents the first (only)
 832 *              free inode within the iag, the iag will be placed on
 833 *              the ag free inode list.
 834 *
 835 *              freeing the inode will cause the inode extent to be
 836 *              freed if the inode is the only allocated inode within
 837 *              the extent.  in this case all the disk resource backing
 838 *              up the inode extent will be freed. in addition, the iag
 839 *              will be placed on the ag extent free list if the extent
 840 *              is the first free extent in the iag.  if freeing the
 841 *              extent also means that no free inodes will exist for
 842 *              the iag, the iag will also be removed from the ag free
 843 *              inode list.
 844 *
 845 *              the iag describing the inode will be freed if the extent
 846 *              is to be freed and it is the only backed extent within
 847 *              the iag.  in this case, the iag will be removed from the
 848 *              ag free extent list and ag free inode list and placed on
 849 *              the inode map's free iag list.
 850 *
 851 *              a careful update approach is used to provide consistency
 852 *              in the face of updates to multiple buffers.  under this
 853 *              approach, all required buffers are obtained before making
 854 *              any updates and are held until all updates are complete.
 855 *
 856 * PARAMETERS:
 857 *      ip      - inode to be freed.
 858 *
 859 * RETURN VALUES:
 860 *      0       - success
 861 *      -EIO    - i/o error.
 862 */
 863int diFree(struct inode *ip)
 864{
 865        int rc;
 866        ino_t inum = ip->i_ino;
 867        struct iag *iagp, *aiagp, *biagp, *ciagp, *diagp;
 868        struct metapage *mp, *amp, *bmp, *cmp, *dmp;
 869        int iagno, ino, extno, bitno, sword, agno;
 870        int back, fwd;
 871        u32 bitmap, mask;
 872        struct inode *ipimap = JFS_SBI(ip->i_sb)->ipimap;
 873        struct inomap *imap = JFS_IP(ipimap)->i_imap;
 874        pxd_t freepxd;
 875        tid_t tid;
 876        struct inode *iplist[3];
 877        struct tlock *tlck;
 878        struct pxd_lock *pxdlock;
 879
 880        /*
 881         * This is just to suppress compiler warnings.  The same logic that
 882         * references these variables is used to initialize them.
 883         */
 884        aiagp = biagp = ciagp = diagp = NULL;
 885
 886        /* get the iag number containing the inode.
 887         */
 888        iagno = INOTOIAG(inum);
 889
 890        /* make sure that the iag is contained within
 891         * the map.
 892         */
 893        if (iagno >= imap->im_nextiag) {
 894                print_hex_dump(KERN_ERR, "imap: ", DUMP_PREFIX_ADDRESS, 16, 4,
 895                               imap, 32, 0);
 896                jfs_error(ip->i_sb,
 897                          "diFree: inum = %d, iagno = %d, nextiag = %d",
 898                          (uint) inum, iagno, imap->im_nextiag);
 899                return -EIO;
 900        }
 901
 902        /* get the allocation group for this ino.
 903         */
 904        agno = BLKTOAG(JFS_IP(ip)->agstart, JFS_SBI(ip->i_sb));
 905
 906        /* Lock the AG specific inode map information
 907         */
 908        AG_LOCK(imap, agno);
 909
 910        /* Obtain read lock in imap inode.  Don't release it until we have
 911         * read all of the IAG's that we are going to.
 912         */
 913        IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
 914
 915        /* read the iag.
 916         */
 917        if ((rc = diIAGRead(imap, iagno, &mp))) {
 918                IREAD_UNLOCK(ipimap);
 919                AG_UNLOCK(imap, agno);
 920                return (rc);
 921        }
 922        iagp = (struct iag *) mp->data;
 923
 924        /* get the inode number and extent number of the inode within
 925         * the iag and the inode number within the extent.
 926         */
 927        ino = inum & (INOSPERIAG - 1);
 928        extno = ino >> L2INOSPEREXT;
 929        bitno = ino & (INOSPEREXT - 1);
 930        mask = HIGHORDER >> bitno;
 931
 932        if (!(le32_to_cpu(iagp->wmap[extno]) & mask)) {
 933                jfs_error(ip->i_sb,
 934                          "diFree: wmap shows inode already free");
 935        }
 936
 937        if (!addressPXD(&iagp->inoext[extno])) {
 938                release_metapage(mp);
 939                IREAD_UNLOCK(ipimap);
 940                AG_UNLOCK(imap, agno);
 941                jfs_error(ip->i_sb, "diFree: invalid inoext");
 942                return -EIO;
 943        }
 944
 945        /* compute the bitmap for the extent reflecting the freed inode.
 946         */
 947        bitmap = le32_to_cpu(iagp->wmap[extno]) & ~mask;
 948
 949        if (imap->im_agctl[agno].numfree > imap->im_agctl[agno].numinos) {
 950                release_metapage(mp);
 951                IREAD_UNLOCK(ipimap);
 952                AG_UNLOCK(imap, agno);
 953                jfs_error(ip->i_sb, "diFree: numfree > numinos");
 954                return -EIO;
 955        }
 956        /*
 957         *      inode extent still has some inodes or below low water mark:
 958         *      keep the inode extent;
 959         */
 960        if (bitmap ||
 961            imap->im_agctl[agno].numfree < 96 ||
 962            (imap->im_agctl[agno].numfree < 288 &&
 963             (((imap->im_agctl[agno].numfree * 100) /
 964               imap->im_agctl[agno].numinos) <= 25))) {
 965                /* if the iag currently has no free inodes (i.e.,
 966                 * the inode being freed is the first free inode of iag),
 967                 * insert the iag at head of the inode free list for the ag.
 968                 */
 969                if (iagp->nfreeinos == 0) {
 970                        /* check if there are any iags on the ag inode
 971                         * free list.  if so, read the first one so that
 972                         * we can link the current iag onto the list at
 973                         * the head.
 974                         */
 975                        if ((fwd = imap->im_agctl[agno].inofree) >= 0) {
 976                                /* read the iag that currently is the head
 977                                 * of the list.
 978                                 */
 979                                if ((rc = diIAGRead(imap, fwd, &amp))) {
 980                                        IREAD_UNLOCK(ipimap);
 981                                        AG_UNLOCK(imap, agno);
 982                                        release_metapage(mp);
 983                                        return (rc);
 984                                }
 985                                aiagp = (struct iag *) amp->data;
 986
 987                                /* make current head point back to the iag.
 988                                 */
 989                                aiagp->inofreeback = cpu_to_le32(iagno);
 990
 991                                write_metapage(amp);
 992                        }
 993
 994                        /* iag points forward to current head and iag
 995                         * becomes the new head of the list.
 996                         */
 997                        iagp->inofreefwd =
 998                            cpu_to_le32(imap->im_agctl[agno].inofree);
 999                        iagp->inofreeback = cpu_to_le32(-1);
1000                        imap->im_agctl[agno].inofree = iagno;
1001                }
1002                IREAD_UNLOCK(ipimap);
1003
1004                /* update the free inode summary map for the extent if
1005                 * freeing the inode means the extent will now have free
1006                 * inodes (i.e., the inode being freed is the first free
1007                 * inode of extent),
1008                 */
1009                if (iagp->wmap[extno] == cpu_to_le32(ONES)) {
1010                        sword = extno >> L2EXTSPERSUM;
1011                        bitno = extno & (EXTSPERSUM - 1);
1012                        iagp->inosmap[sword] &=
1013                            cpu_to_le32(~(HIGHORDER >> bitno));
1014                }
1015
1016                /* update the bitmap.
1017                 */
1018                iagp->wmap[extno] = cpu_to_le32(bitmap);
1019
1020                /* update the free inode counts at the iag, ag and
1021                 * map level.
1022                 */
1023                le32_add_cpu(&iagp->nfreeinos, 1);
1024                imap->im_agctl[agno].numfree += 1;
1025                atomic_inc(&imap->im_numfree);
1026
1027                /* release the AG inode map lock
1028                 */
1029                AG_UNLOCK(imap, agno);
1030
1031                /* write the iag */
1032                write_metapage(mp);
1033
1034                return (0);
1035        }
1036
1037
1038        /*
1039         *      inode extent has become free and above low water mark:
1040         *      free the inode extent;
1041         */
1042
1043        /*
1044         *      prepare to update iag list(s) (careful update step 1)
1045         */
1046        amp = bmp = cmp = dmp = NULL;
1047        fwd = back = -1;
1048
1049        /* check if the iag currently has no free extents.  if so,
1050         * it will be placed on the head of the ag extent free list.
1051         */
1052        if (iagp->nfreeexts == 0) {
1053                /* check if the ag extent free list has any iags.
1054                 * if so, read the iag at the head of the list now.
1055                 * this (head) iag will be updated later to reflect
1056                 * the addition of the current iag at the head of
1057                 * the list.
1058                 */
1059                if ((fwd = imap->im_agctl[agno].extfree) >= 0) {
1060                        if ((rc = diIAGRead(imap, fwd, &amp)))
1061                                goto error_out;
1062                        aiagp = (struct iag *) amp->data;
1063                }
1064        } else {
1065                /* iag has free extents. check if the addition of a free
1066                 * extent will cause all extents to be free within this
1067                 * iag.  if so, the iag will be removed from the ag extent
1068                 * free list and placed on the inode map's free iag list.
1069                 */
1070                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG - 1)) {
1071                        /* in preparation for removing the iag from the
1072                         * ag extent free list, read the iags preceding
1073                         * and following the iag on the ag extent free
1074                         * list.
1075                         */
1076                        if ((fwd = le32_to_cpu(iagp->extfreefwd)) >= 0) {
1077                                if ((rc = diIAGRead(imap, fwd, &amp)))
1078                                        goto error_out;
1079                                aiagp = (struct iag *) amp->data;
1080                        }
1081
1082                        if ((back = le32_to_cpu(iagp->extfreeback)) >= 0) {
1083                                if ((rc = diIAGRead(imap, back, &bmp)))
1084                                        goto error_out;
1085                                biagp = (struct iag *) bmp->data;
1086                        }
1087                }
1088        }
1089
1090        /* remove the iag from the ag inode free list if freeing
1091         * this extent cause the iag to have no free inodes.
1092         */
1093        if (iagp->nfreeinos == cpu_to_le32(INOSPEREXT - 1)) {
1094                int inofreeback = le32_to_cpu(iagp->inofreeback);
1095                int inofreefwd = le32_to_cpu(iagp->inofreefwd);
1096
1097                /* in preparation for removing the iag from the
1098                 * ag inode free list, read the iags preceding
1099                 * and following the iag on the ag inode free
1100                 * list.  before reading these iags, we must make
1101                 * sure that we already don't have them in hand
1102                 * from up above, since re-reading an iag (buffer)
1103                 * we are currently holding would cause a deadlock.
1104                 */
1105                if (inofreefwd >= 0) {
1106
1107                        if (inofreefwd == fwd)
1108                                ciagp = (struct iag *) amp->data;
1109                        else if (inofreefwd == back)
1110                                ciagp = (struct iag *) bmp->data;
1111                        else {
1112                                if ((rc =
1113                                     diIAGRead(imap, inofreefwd, &cmp)))
1114                                        goto error_out;
1115                                ciagp = (struct iag *) cmp->data;
1116                        }
1117                        assert(ciagp != NULL);
1118                }
1119
1120                if (inofreeback >= 0) {
1121                        if (inofreeback == fwd)
1122                                diagp = (struct iag *) amp->data;
1123                        else if (inofreeback == back)
1124                                diagp = (struct iag *) bmp->data;
1125                        else {
1126                                if ((rc =
1127                                     diIAGRead(imap, inofreeback, &dmp)))
1128                                        goto error_out;
1129                                diagp = (struct iag *) dmp->data;
1130                        }
1131                        assert(diagp != NULL);
1132                }
1133        }
1134
1135        IREAD_UNLOCK(ipimap);
1136
1137        /*
1138         * invalidate any page of the inode extent freed from buffer cache;
1139         */
1140        freepxd = iagp->inoext[extno];
1141        invalidate_pxd_metapages(ip, freepxd);
1142
1143        /*
1144         *      update iag list(s) (careful update step 2)
1145         */
1146        /* add the iag to the ag extent free list if this is the
1147         * first free extent for the iag.
1148         */
1149        if (iagp->nfreeexts == 0) {
1150                if (fwd >= 0)
1151                        aiagp->extfreeback = cpu_to_le32(iagno);
1152
1153                iagp->extfreefwd =
1154                    cpu_to_le32(imap->im_agctl[agno].extfree);
1155                iagp->extfreeback = cpu_to_le32(-1);
1156                imap->im_agctl[agno].extfree = iagno;
1157        } else {
1158                /* remove the iag from the ag extent list if all extents
1159                 * are now free and place it on the inode map iag free list.
1160                 */
1161                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG - 1)) {
1162                        if (fwd >= 0)
1163                                aiagp->extfreeback = iagp->extfreeback;
1164
1165                        if (back >= 0)
1166                                biagp->extfreefwd = iagp->extfreefwd;
1167                        else
1168                                imap->im_agctl[agno].extfree =
1169                                    le32_to_cpu(iagp->extfreefwd);
1170
1171                        iagp->extfreefwd = iagp->extfreeback = cpu_to_le32(-1);
1172
1173                        IAGFREE_LOCK(imap);
1174                        iagp->iagfree = cpu_to_le32(imap->im_freeiag);
1175                        imap->im_freeiag = iagno;
1176                        IAGFREE_UNLOCK(imap);
1177                }
1178        }
1179
1180        /* remove the iag from the ag inode free list if freeing
1181         * this extent causes the iag to have no free inodes.
1182         */
1183        if (iagp->nfreeinos == cpu_to_le32(INOSPEREXT - 1)) {
1184                if ((int) le32_to_cpu(iagp->inofreefwd) >= 0)
1185                        ciagp->inofreeback = iagp->inofreeback;
1186
1187                if ((int) le32_to_cpu(iagp->inofreeback) >= 0)
1188                        diagp->inofreefwd = iagp->inofreefwd;
1189                else
1190                        imap->im_agctl[agno].inofree =
1191                            le32_to_cpu(iagp->inofreefwd);
1192
1193                iagp->inofreefwd = iagp->inofreeback = cpu_to_le32(-1);
1194        }
1195
1196        /* update the inode extent address and working map
1197         * to reflect the free extent.
1198         * the permanent map should have been updated already
1199         * for the inode being freed.
1200         */
1201        if (iagp->pmap[extno] != 0) {
1202                jfs_error(ip->i_sb, "diFree: the pmap does not show inode free");
1203        }
1204        iagp->wmap[extno] = 0;
1205        PXDlength(&iagp->inoext[extno], 0);
1206        PXDaddress(&iagp->inoext[extno], 0);
1207
1208        /* update the free extent and free inode summary maps
1209         * to reflect the freed extent.
1210         * the inode summary map is marked to indicate no inodes
1211         * available for the freed extent.
1212         */
1213        sword = extno >> L2EXTSPERSUM;
1214        bitno = extno & (EXTSPERSUM - 1);
1215        mask = HIGHORDER >> bitno;
1216        iagp->inosmap[sword] |= cpu_to_le32(mask);
1217        iagp->extsmap[sword] &= cpu_to_le32(~mask);
1218
1219        /* update the number of free inodes and number of free extents
1220         * for the iag.
1221         */
1222        le32_add_cpu(&iagp->nfreeinos, -(INOSPEREXT - 1));
1223        le32_add_cpu(&iagp->nfreeexts, 1);
1224
1225        /* update the number of free inodes and backed inodes
1226         * at the ag and inode map level.
1227         */
1228        imap->im_agctl[agno].numfree -= (INOSPEREXT - 1);
1229        imap->im_agctl[agno].numinos -= INOSPEREXT;
1230        atomic_sub(INOSPEREXT - 1, &imap->im_numfree);
1231        atomic_sub(INOSPEREXT, &imap->im_numinos);
1232
1233        if (amp)
1234                write_metapage(amp);
1235        if (bmp)
1236                write_metapage(bmp);
1237        if (cmp)
1238                write_metapage(cmp);
1239        if (dmp)
1240                write_metapage(dmp);
1241
1242        /*
1243         * start transaction to update block allocation map
1244         * for the inode extent freed;
1245         *
1246         * N.B. AG_LOCK is released and iag will be released below, and
1247         * other thread may allocate inode from/reusing the ixad freed
1248         * BUT with new/different backing inode extent from the extent
1249         * to be freed by the transaction;
1250         */
1251        tid = txBegin(ipimap->i_sb, COMMIT_FORCE);
1252        mutex_lock(&JFS_IP(ipimap)->commit_mutex);
1253
1254        /* acquire tlock of the iag page of the freed ixad
1255         * to force the page NOHOMEOK (even though no data is
1256         * logged from the iag page) until NOREDOPAGE|FREEXTENT log
1257         * for the free of the extent is committed;
1258         * write FREEXTENT|NOREDOPAGE log record
1259         * N.B. linelock is overlaid as freed extent descriptor;
1260         */
1261        tlck = txLock(tid, ipimap, mp, tlckINODE | tlckFREE);
1262        pxdlock = (struct pxd_lock *) & tlck->lock;
1263        pxdlock->flag = mlckFREEPXD;
1264        pxdlock->pxd = freepxd;
1265        pxdlock->index = 1;
1266
1267        write_metapage(mp);
1268
1269        iplist[0] = ipimap;
1270
1271        /*
1272         * logredo needs the IAG number and IAG extent index in order
1273         * to ensure that the IMap is consistent.  The least disruptive
1274         * way to pass these values through  to the transaction manager
1275         * is in the iplist array.
1276         *
1277         * It's not pretty, but it works.
1278         */
1279        iplist[1] = (struct inode *) (size_t)iagno;
1280        iplist[2] = (struct inode *) (size_t)extno;
1281
1282        rc = txCommit(tid, 1, &iplist[0], COMMIT_FORCE);
1283
1284        txEnd(tid);
1285        mutex_unlock(&JFS_IP(ipimap)->commit_mutex);
1286
1287        /* unlock the AG inode map information */
1288        AG_UNLOCK(imap, agno);
1289
1290        return (0);
1291
1292      error_out:
1293        IREAD_UNLOCK(ipimap);
1294
1295        if (amp)
1296                release_metapage(amp);
1297        if (bmp)
1298                release_metapage(bmp);
1299        if (cmp)
1300                release_metapage(cmp);
1301        if (dmp)
1302                release_metapage(dmp);
1303
1304        AG_UNLOCK(imap, agno);
1305
1306        release_metapage(mp);
1307
1308        return (rc);
1309}
1310
1311/*
1312 * There are several places in the diAlloc* routines where we initialize
1313 * the inode.
1314 */
1315static inline void
1316diInitInode(struct inode *ip, int iagno, int ino, int extno, struct iag * iagp)
1317{
1318        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
1319
1320        ip->i_ino = (iagno << L2INOSPERIAG) + ino;
1321        jfs_ip->ixpxd = iagp->inoext[extno];
1322        jfs_ip->agstart = le64_to_cpu(iagp->agstart);
1323        jfs_ip->active_ag = -1;
1324}
1325
1326
1327/*
1328 * NAME:        diAlloc(pip,dir,ip)
1329 *
1330 * FUNCTION:    allocate a disk inode from the inode working map
1331 *              for a fileset or aggregate.
1332 *
1333 * PARAMETERS:
1334 *      pip     - pointer to incore inode for the parent inode.
1335 *      dir     - 'true' if the new disk inode is for a directory.
1336 *      ip      - pointer to a new inode
1337 *
1338 * RETURN VALUES:
1339 *      0       - success.
1340 *      -ENOSPC - insufficient disk resources.
1341 *      -EIO    - i/o error.
1342 */
1343int diAlloc(struct inode *pip, bool dir, struct inode *ip)
1344{
1345        int rc, ino, iagno, addext, extno, bitno, sword;
1346        int nwords, rem, i, agno;
1347        u32 mask, inosmap, extsmap;
1348        struct inode *ipimap;
1349        struct metapage *mp;
1350        ino_t inum;
1351        struct iag *iagp;
1352        struct inomap *imap;
1353
1354        /* get the pointers to the inode map inode and the
1355         * corresponding imap control structure.
1356         */
1357        ipimap = JFS_SBI(pip->i_sb)->ipimap;
1358        imap = JFS_IP(ipimap)->i_imap;
1359        JFS_IP(ip)->ipimap = ipimap;
1360        JFS_IP(ip)->fileset = FILESYSTEM_I;
1361
1362        /* for a directory, the allocation policy is to start
1363         * at the ag level using the preferred ag.
1364         */
1365        if (dir) {
1366                agno = dbNextAG(JFS_SBI(pip->i_sb)->ipbmap);
1367                AG_LOCK(imap, agno);
1368                goto tryag;
1369        }
1370
1371        /* for files, the policy starts off by trying to allocate from
1372         * the same iag containing the parent disk inode:
1373         * try to allocate the new disk inode close to the parent disk
1374         * inode, using parent disk inode number + 1 as the allocation
1375         * hint.  (we use a left-to-right policy to attempt to avoid
1376         * moving backward on the disk.)  compute the hint within the
1377         * file system and the iag.
1378         */
1379
1380        /* get the ag number of this iag */
1381        agno = BLKTOAG(JFS_IP(pip)->agstart, JFS_SBI(pip->i_sb));
1382
1383        if (atomic_read(&JFS_SBI(pip->i_sb)->bmap->db_active[agno])) {
1384                /*
1385                 * There is an open file actively growing.  We want to
1386                 * allocate new inodes from a different ag to avoid
1387                 * fragmentation problems.
1388                 */
1389                agno = dbNextAG(JFS_SBI(pip->i_sb)->ipbmap);
1390                AG_LOCK(imap, agno);
1391                goto tryag;
1392        }
1393
1394        inum = pip->i_ino + 1;
1395        ino = inum & (INOSPERIAG - 1);
1396
1397        /* back off the hint if it is outside of the iag */
1398        if (ino == 0)
1399                inum = pip->i_ino;
1400
1401        /* lock the AG inode map information */
1402        AG_LOCK(imap, agno);
1403
1404        /* Get read lock on imap inode */
1405        IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
1406
1407        /* get the iag number and read the iag */
1408        iagno = INOTOIAG(inum);
1409        if ((rc = diIAGRead(imap, iagno, &mp))) {
1410                IREAD_UNLOCK(ipimap);
1411                AG_UNLOCK(imap, agno);
1412                return (rc);
1413        }
1414        iagp = (struct iag *) mp->data;
1415
1416        /* determine if new inode extent is allowed to be added to the iag.
1417         * new inode extent can be added to the iag if the ag
1418         * has less than 32 free disk inodes and the iag has free extents.
1419         */
1420        addext = (imap->im_agctl[agno].numfree < 32 && iagp->nfreeexts);
1421
1422        /*
1423         *      try to allocate from the IAG
1424         */
1425        /* check if the inode may be allocated from the iag
1426         * (i.e. the inode has free inodes or new extent can be added).
1427         */
1428        if (iagp->nfreeinos || addext) {
1429                /* determine the extent number of the hint.
1430                 */
1431                extno = ino >> L2INOSPEREXT;
1432
1433                /* check if the extent containing the hint has backed
1434                 * inodes.  if so, try to allocate within this extent.
1435                 */
1436                if (addressPXD(&iagp->inoext[extno])) {
1437                        bitno = ino & (INOSPEREXT - 1);
1438                        if ((bitno =
1439                             diFindFree(le32_to_cpu(iagp->wmap[extno]),
1440                                        bitno))
1441                            < INOSPEREXT) {
1442                                ino = (extno << L2INOSPEREXT) + bitno;
1443
1444                                /* a free inode (bit) was found within this
1445                                 * extent, so allocate it.
1446                                 */
1447                                rc = diAllocBit(imap, iagp, ino);
1448                                IREAD_UNLOCK(ipimap);
1449                                if (rc) {
1450                                        assert(rc == -EIO);
1451                                } else {
1452                                        /* set the results of the allocation
1453                                         * and write the iag.
1454                                         */
1455                                        diInitInode(ip, iagno, ino, extno,
1456                                                    iagp);
1457                                        mark_metapage_dirty(mp);
1458                                }
1459                                release_metapage(mp);
1460
1461                                /* free the AG lock and return.
1462                                 */
1463                                AG_UNLOCK(imap, agno);
1464                                return (rc);
1465                        }
1466
1467                        if (!addext)
1468                                extno =
1469                                    (extno ==
1470                                     EXTSPERIAG - 1) ? 0 : extno + 1;
1471                }
1472
1473                /*
1474                 * no free inodes within the extent containing the hint.
1475                 *
1476                 * try to allocate from the backed extents following
1477                 * hint or, if appropriate (i.e. addext is true), allocate
1478                 * an extent of free inodes at or following the extent
1479                 * containing the hint.
1480                 *
1481                 * the free inode and free extent summary maps are used
1482                 * here, so determine the starting summary map position
1483                 * and the number of words we'll have to examine.  again,
1484                 * the approach is to allocate following the hint, so we
1485                 * might have to initially ignore prior bits of the summary
1486                 * map that represent extents prior to the extent containing
1487                 * the hint and later revisit these bits.
1488                 */
1489                bitno = extno & (EXTSPERSUM - 1);
1490                nwords = (bitno == 0) ? SMAPSZ : SMAPSZ + 1;
1491                sword = extno >> L2EXTSPERSUM;
1492
1493                /* mask any prior bits for the starting words of the
1494                 * summary map.
1495                 */
1496                mask = ONES << (EXTSPERSUM - bitno);
1497                inosmap = le32_to_cpu(iagp->inosmap[sword]) | mask;
1498                extsmap = le32_to_cpu(iagp->extsmap[sword]) | mask;
1499
1500                /* scan the free inode and free extent summary maps for
1501                 * free resources.
1502                 */
1503                for (i = 0; i < nwords; i++) {
1504                        /* check if this word of the free inode summary
1505                         * map describes an extent with free inodes.
1506                         */
1507                        if (~inosmap) {
1508                                /* an extent with free inodes has been
1509                                 * found. determine the extent number
1510                                 * and the inode number within the extent.
1511                                 */
1512                                rem = diFindFree(inosmap, 0);
1513                                extno = (sword << L2EXTSPERSUM) + rem;
1514                                rem = diFindFree(le32_to_cpu(iagp->wmap[extno]),
1515                                                 0);
1516                                if (rem >= INOSPEREXT) {
1517                                        IREAD_UNLOCK(ipimap);
1518                                        release_metapage(mp);
1519                                        AG_UNLOCK(imap, agno);
1520                                        jfs_error(ip->i_sb,
1521                                                  "diAlloc: can't find free bit "
1522                                                  "in wmap");
1523                                        return -EIO;
1524                                }
1525
1526                                /* determine the inode number within the
1527                                 * iag and allocate the inode from the
1528                                 * map.
1529                                 */
1530                                ino = (extno << L2INOSPEREXT) + rem;
1531                                rc = diAllocBit(imap, iagp, ino);
1532                                IREAD_UNLOCK(ipimap);
1533                                if (rc)
1534                                        assert(rc == -EIO);
1535                                else {
1536                                        /* set the results of the allocation
1537                                         * and write the iag.
1538                                         */
1539                                        diInitInode(ip, iagno, ino, extno,
1540                                                    iagp);
1541                                        mark_metapage_dirty(mp);
1542                                }
1543                                release_metapage(mp);
1544
1545                                /* free the AG lock and return.
1546                                 */
1547                                AG_UNLOCK(imap, agno);
1548                                return (rc);
1549
1550                        }
1551
1552                        /* check if we may allocate an extent of free
1553                         * inodes and whether this word of the free
1554                         * extents summary map describes a free extent.
1555                         */
1556                        if (addext && ~extsmap) {
1557                                /* a free extent has been found.  determine
1558                                 * the extent number.
1559                                 */
1560                                rem = diFindFree(extsmap, 0);
1561                                extno = (sword << L2EXTSPERSUM) + rem;
1562
1563                                /* allocate an extent of free inodes.
1564                                 */
1565                                if ((rc = diNewExt(imap, iagp, extno))) {
1566                                        /* if there is no disk space for a
1567                                         * new extent, try to allocate the
1568                                         * disk inode from somewhere else.
1569                                         */
1570                                        if (rc == -ENOSPC)
1571                                                break;
1572
1573                                        assert(rc == -EIO);
1574                                } else {
1575                                        /* set the results of the allocation
1576                                         * and write the iag.
1577                                         */
1578                                        diInitInode(ip, iagno,
1579                                                    extno << L2INOSPEREXT,
1580                                                    extno, iagp);
1581                                        mark_metapage_dirty(mp);
1582                                }
1583                                release_metapage(mp);
1584                                /* free the imap inode & the AG lock & return.
1585                                 */
1586                                IREAD_UNLOCK(ipimap);
1587                                AG_UNLOCK(imap, agno);
1588                                return (rc);
1589                        }
1590
1591                        /* move on to the next set of summary map words.
1592                         */
1593                        sword = (sword == SMAPSZ - 1) ? 0 : sword + 1;
1594                        inosmap = le32_to_cpu(iagp->inosmap[sword]);
1595                        extsmap = le32_to_cpu(iagp->extsmap[sword]);
1596                }
1597        }
1598        /* unlock imap inode */
1599        IREAD_UNLOCK(ipimap);
1600
1601        /* nothing doing in this iag, so release it. */
1602        release_metapage(mp);
1603
1604      tryag:
1605        /*
1606         * try to allocate anywhere within the same AG as the parent inode.
1607         */
1608        rc = diAllocAG(imap, agno, dir, ip);
1609
1610        AG_UNLOCK(imap, agno);
1611
1612        if (rc != -ENOSPC)
1613                return (rc);
1614
1615        /*
1616         * try to allocate in any AG.
1617         */
1618        return (diAllocAny(imap, agno, dir, ip));
1619}
1620
1621
1622/*
1623 * NAME:        diAllocAG(imap,agno,dir,ip)
1624 *
1625 * FUNCTION:    allocate a disk inode from the allocation group.
1626 *
1627 *              this routine first determines if a new extent of free
1628 *              inodes should be added for the allocation group, with
1629 *              the current request satisfied from this extent. if this
1630 *              is the case, an attempt will be made to do just that.  if
1631 *              this attempt fails or it has been determined that a new
1632 *              extent should not be added, an attempt is made to satisfy
1633 *              the request by allocating an existing (backed) free inode
1634 *              from the allocation group.
1635 *
1636 * PRE CONDITION: Already have the AG lock for this AG.
1637 *
1638 * PARAMETERS:
1639 *      imap    - pointer to inode map control structure.
1640 *      agno    - allocation group to allocate from.
1641 *      dir     - 'true' if the new disk inode is for a directory.
1642 *      ip      - pointer to the new inode to be filled in on successful return
1643 *                with the disk inode number allocated, its extent address
1644 *                and the start of the ag.
1645 *
1646 * RETURN VALUES:
1647 *      0       - success.
1648 *      -ENOSPC - insufficient disk resources.
1649 *      -EIO    - i/o error.
1650 */
1651static int
1652diAllocAG(struct inomap * imap, int agno, bool dir, struct inode *ip)
1653{
1654        int rc, addext, numfree, numinos;
1655
1656        /* get the number of free and the number of backed disk
1657         * inodes currently within the ag.
1658         */
1659        numfree = imap->im_agctl[agno].numfree;
1660        numinos = imap->im_agctl[agno].numinos;
1661
1662        if (numfree > numinos) {
1663                jfs_error(ip->i_sb, "diAllocAG: numfree > numinos");
1664                return -EIO;
1665        }
1666
1667        /* determine if we should allocate a new extent of free inodes
1668         * within the ag: for directory inodes, add a new extent
1669         * if there are a small number of free inodes or number of free
1670         * inodes is a small percentage of the number of backed inodes.
1671         */
1672        if (dir)
1673                addext = (numfree < 64 ||
1674                          (numfree < 256
1675                           && ((numfree * 100) / numinos) <= 20));
1676        else
1677                addext = (numfree == 0);
1678
1679        /*
1680         * try to allocate a new extent of free inodes.
1681         */
1682        if (addext) {
1683                /* if free space is not available for this new extent, try
1684                 * below to allocate a free and existing (already backed)
1685                 * inode from the ag.
1686                 */
1687                if ((rc = diAllocExt(imap, agno, ip)) != -ENOSPC)
1688                        return (rc);
1689        }
1690
1691        /*
1692         * try to allocate an existing free inode from the ag.
1693         */
1694        return (diAllocIno(imap, agno, ip));
1695}
1696
1697
1698/*
1699 * NAME:        diAllocAny(imap,agno,dir,iap)
1700 *
1701 * FUNCTION:    allocate a disk inode from any other allocation group.
1702 *
1703 *              this routine is called when an allocation attempt within
1704 *              the primary allocation group has failed. if attempts to
1705 *              allocate an inode from any allocation group other than the
1706 *              specified primary group.
1707 *
1708 * PARAMETERS:
1709 *      imap    - pointer to inode map control structure.
1710 *      agno    - primary allocation group (to avoid).
1711 *      dir     - 'true' if the new disk inode is for a directory.
1712 *      ip      - pointer to a new inode to be filled in on successful return
1713 *                with the disk inode number allocated, its extent address
1714 *                and the start of the ag.
1715 *
1716 * RETURN VALUES:
1717 *      0       - success.
1718 *      -ENOSPC - insufficient disk resources.
1719 *      -EIO    - i/o error.
1720 */
1721static int
1722diAllocAny(struct inomap * imap, int agno, bool dir, struct inode *ip)
1723{
1724        int ag, rc;
1725        int maxag = JFS_SBI(imap->im_ipimap->i_sb)->bmap->db_maxag;
1726
1727
1728        /* try to allocate from the ags following agno up to
1729         * the maximum ag number.
1730         */
1731        for (ag = agno + 1; ag <= maxag; ag++) {
1732                AG_LOCK(imap, ag);
1733
1734                rc = diAllocAG(imap, ag, dir, ip);
1735
1736                AG_UNLOCK(imap, ag);
1737
1738                if (rc != -ENOSPC)
1739                        return (rc);
1740        }
1741
1742        /* try to allocate from the ags in front of agno.
1743         */
1744        for (ag = 0; ag < agno; ag++) {
1745                AG_LOCK(imap, ag);
1746
1747                rc = diAllocAG(imap, ag, dir, ip);
1748
1749                AG_UNLOCK(imap, ag);
1750
1751                if (rc != -ENOSPC)
1752                        return (rc);
1753        }
1754
1755        /* no free disk inodes.
1756         */
1757        return -ENOSPC;
1758}
1759
1760
1761/*
1762 * NAME:        diAllocIno(imap,agno,ip)
1763 *
1764 * FUNCTION:    allocate a disk inode from the allocation group's free
1765 *              inode list, returning an error if this free list is
1766 *              empty (i.e. no iags on the list).
1767 *
1768 *              allocation occurs from the first iag on the list using
1769 *              the iag's free inode summary map to find the leftmost
1770 *              free inode in the iag.
1771 *
1772 * PRE CONDITION: Already have AG lock for this AG.
1773 *
1774 * PARAMETERS:
1775 *      imap    - pointer to inode map control structure.
1776 *      agno    - allocation group.
1777 *      ip      - pointer to new inode to be filled in on successful return
1778 *                with the disk inode number allocated, its extent address
1779 *                and the start of the ag.
1780 *
1781 * RETURN VALUES:
1782 *      0       - success.
1783 *      -ENOSPC - insufficient disk resources.
1784 *      -EIO    - i/o error.
1785 */
1786static int diAllocIno(struct inomap * imap, int agno, struct inode *ip)
1787{
1788        int iagno, ino, rc, rem, extno, sword;
1789        struct metapage *mp;
1790        struct iag *iagp;
1791
1792        /* check if there are iags on the ag's free inode list.
1793         */
1794        if ((iagno = imap->im_agctl[agno].inofree) < 0)
1795                return -ENOSPC;
1796
1797        /* obtain read lock on imap inode */
1798        IREAD_LOCK(imap->im_ipimap, RDWRLOCK_IMAP);
1799
1800        /* read the iag at the head of the list.
1801         */
1802        if ((rc = diIAGRead(imap, iagno, &mp))) {
1803                IREAD_UNLOCK(imap->im_ipimap);
1804                return (rc);
1805        }
1806        iagp = (struct iag *) mp->data;
1807
1808        /* better be free inodes in this iag if it is on the
1809         * list.
1810         */
1811        if (!iagp->nfreeinos) {
1812                IREAD_UNLOCK(imap->im_ipimap);
1813                release_metapage(mp);
1814                jfs_error(ip->i_sb,
1815                          "diAllocIno: nfreeinos = 0, but iag on freelist");
1816                return -EIO;
1817        }
1818
1819        /* scan the free inode summary map to find an extent
1820         * with free inodes.
1821         */
1822        for (sword = 0;; sword++) {
1823                if (sword >= SMAPSZ) {
1824                        IREAD_UNLOCK(imap->im_ipimap);
1825                        release_metapage(mp);
1826                        jfs_error(ip->i_sb,
1827                                  "diAllocIno: free inode not found in summary map");
1828                        return -EIO;
1829                }
1830
1831                if (~iagp->inosmap[sword])
1832                        break;
1833        }
1834
1835        /* found a extent with free inodes. determine
1836         * the extent number.
1837         */
1838        rem = diFindFree(le32_to_cpu(iagp->inosmap[sword]), 0);
1839        if (rem >= EXTSPERSUM) {
1840                IREAD_UNLOCK(imap->im_ipimap);
1841                release_metapage(mp);
1842                jfs_error(ip->i_sb, "diAllocIno: no free extent found");
1843                return -EIO;
1844        }
1845        extno = (sword << L2EXTSPERSUM) + rem;
1846
1847        /* find the first free inode in the extent.
1848         */
1849        rem = diFindFree(le32_to_cpu(iagp->wmap[extno]), 0);
1850        if (rem >= INOSPEREXT) {
1851                IREAD_UNLOCK(imap->im_ipimap);
1852                release_metapage(mp);
1853                jfs_error(ip->i_sb, "diAllocIno: free inode not found");
1854                return -EIO;
1855        }
1856
1857        /* compute the inode number within the iag.
1858         */
1859        ino = (extno << L2INOSPEREXT) + rem;
1860
1861        /* allocate the inode.
1862         */
1863        rc = diAllocBit(imap, iagp, ino);
1864        IREAD_UNLOCK(imap->im_ipimap);
1865        if (rc) {
1866                release_metapage(mp);
1867                return (rc);
1868        }
1869
1870        /* set the results of the allocation and write the iag.
1871         */
1872        diInitInode(ip, iagno, ino, extno, iagp);
1873        write_metapage(mp);
1874
1875        return (0);
1876}
1877
1878
1879/*
1880 * NAME:        diAllocExt(imap,agno,ip)
1881 *
1882 * FUNCTION:    add a new extent of free inodes to an iag, allocating
1883 *              an inode from this extent to satisfy the current allocation
1884 *              request.
1885 *
1886 *              this routine first tries to find an existing iag with free
1887 *              extents through the ag free extent list.  if list is not
1888 *              empty, the head of the list will be selected as the home
1889 *              of the new extent of free inodes.  otherwise (the list is
1890 *              empty), a new iag will be allocated for the ag to contain
1891 *              the extent.
1892 *
1893 *              once an iag has been selected, the free extent summary map
1894 *              is used to locate a free extent within the iag and diNewExt()
1895 *              is called to initialize the extent, with initialization
1896 *              including the allocation of the first inode of the extent
1897 *              for the purpose of satisfying this request.
1898 *
1899 * PARAMETERS:
1900 *      imap    - pointer to inode map control structure.
1901 *      agno    - allocation group number.
1902 *      ip      - pointer to new inode to be filled in on successful return
1903 *                with the disk inode number allocated, its extent address
1904 *                and the start of the ag.
1905 *
1906 * RETURN VALUES:
1907 *      0       - success.
1908 *      -ENOSPC - insufficient disk resources.
1909 *      -EIO    - i/o error.
1910 */
1911static int diAllocExt(struct inomap * imap, int agno, struct inode *ip)
1912{
1913        int rem, iagno, sword, extno, rc;
1914        struct metapage *mp;
1915        struct iag *iagp;
1916
1917        /* check if the ag has any iags with free extents.  if not,
1918         * allocate a new iag for the ag.
1919         */
1920        if ((iagno = imap->im_agctl[agno].extfree) < 0) {
1921                /* If successful, diNewIAG will obtain the read lock on the
1922                 * imap inode.
1923                 */
1924                if ((rc = diNewIAG(imap, &iagno, agno, &mp))) {
1925                        return (rc);
1926                }
1927                iagp = (struct iag *) mp->data;
1928
1929                /* set the ag number if this a brand new iag
1930                 */
1931                iagp->agstart =
1932                    cpu_to_le64(AGTOBLK(agno, imap->im_ipimap));
1933        } else {
1934                /* read the iag.
1935                 */
1936                IREAD_LOCK(imap->im_ipimap, RDWRLOCK_IMAP);
1937                if ((rc = diIAGRead(imap, iagno, &mp))) {
1938                        IREAD_UNLOCK(imap->im_ipimap);
1939                        jfs_error(ip->i_sb, "diAllocExt: error reading iag");
1940                        return rc;
1941                }
1942                iagp = (struct iag *) mp->data;
1943        }
1944
1945        /* using the free extent summary map, find a free extent.
1946         */
1947        for (sword = 0;; sword++) {
1948                if (sword >= SMAPSZ) {
1949                        release_metapage(mp);
1950                        IREAD_UNLOCK(imap->im_ipimap);
1951                        jfs_error(ip->i_sb,
1952                                  "diAllocExt: free ext summary map not found");
1953                        return -EIO;
1954                }
1955                if (~iagp->extsmap[sword])
1956                        break;
1957        }
1958
1959        /* determine the extent number of the free extent.
1960         */
1961        rem = diFindFree(le32_to_cpu(iagp->extsmap[sword]), 0);
1962        if (rem >= EXTSPERSUM) {
1963                release_metapage(mp);
1964                IREAD_UNLOCK(imap->im_ipimap);
1965                jfs_error(ip->i_sb, "diAllocExt: free extent not found");
1966                return -EIO;
1967        }
1968        extno = (sword << L2EXTSPERSUM) + rem;
1969
1970        /* initialize the new extent.
1971         */
1972        rc = diNewExt(imap, iagp, extno);
1973        IREAD_UNLOCK(imap->im_ipimap);
1974        if (rc) {
1975                /* something bad happened.  if a new iag was allocated,
1976                 * place it back on the inode map's iag free list, and
1977                 * clear the ag number information.
1978                 */
1979                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG)) {
1980                        IAGFREE_LOCK(imap);
1981                        iagp->iagfree = cpu_to_le32(imap->im_freeiag);
1982                        imap->im_freeiag = iagno;
1983                        IAGFREE_UNLOCK(imap);
1984                }
1985                write_metapage(mp);
1986                return (rc);
1987        }
1988
1989        /* set the results of the allocation and write the iag.
1990         */
1991        diInitInode(ip, iagno, extno << L2INOSPEREXT, extno, iagp);
1992
1993        write_metapage(mp);
1994
1995        return (0);
1996}
1997
1998
1999/*
2000 * NAME:        diAllocBit(imap,iagp,ino)
2001 *
2002 * FUNCTION:    allocate a backed inode from an iag.
2003 *
2004 *              this routine performs the mechanics of allocating a
2005 *              specified inode from a backed extent.
2006 *
2007 *              if the inode to be allocated represents the last free
2008 *              inode within the iag, the iag will be removed from the
2009 *              ag free inode list.
2010 *
2011 *              a careful update approach is used to provide consistency
2012 *              in the face of updates to multiple buffers.  under this
2013 *              approach, all required buffers are obtained before making
2014 *              any updates and are held all are updates are complete.
2015 *
2016 * PRE CONDITION: Already have buffer lock on iagp.  Already have AG lock on
2017 *      this AG.  Must have read lock on imap inode.
2018 *
2019 * PARAMETERS:
2020 *      imap    - pointer to inode map control structure.
2021 *      iagp    - pointer to iag.
2022 *      ino     - inode number to be allocated within the iag.
2023 *
2024 * RETURN VALUES:
2025 *      0       - success.
2026 *      -ENOSPC - insufficient disk resources.
2027 *      -EIO    - i/o error.
2028 */
2029static int diAllocBit(struct inomap * imap, struct iag * iagp, int ino)
2030{
2031        int extno, bitno, agno, sword, rc;
2032        struct metapage *amp = NULL, *bmp = NULL;
2033        struct iag *aiagp = NULL, *biagp = NULL;
2034        u32 mask;
2035
2036        /* check if this is the last free inode within the iag.
2037         * if so, it will have to be removed from the ag free
2038         * inode list, so get the iags preceding and following
2039         * it on the list.
2040         */
2041        if (iagp->nfreeinos == cpu_to_le32(1)) {
2042                if ((int) le32_to_cpu(iagp->inofreefwd) >= 0) {
2043                        if ((rc =
2044                             diIAGRead(imap, le32_to_cpu(iagp->inofreefwd),
2045                                       &amp)))
2046                                return (rc);
2047                        aiagp = (struct iag *) amp->data;
2048                }
2049
2050                if ((int) le32_to_cpu(iagp->inofreeback) >= 0) {
2051                        if ((rc =
2052                             diIAGRead(imap,
2053                                       le32_to_cpu(iagp->inofreeback),
2054                                       &bmp))) {
2055                                if (amp)
2056                                        release_metapage(amp);
2057                                return (rc);
2058                        }
2059                        biagp = (struct iag *) bmp->data;
2060                }
2061        }
2062
2063        /* get the ag number, extent number, inode number within
2064         * the extent.
2065         */
2066        agno = BLKTOAG(le64_to_cpu(iagp->agstart), JFS_SBI(imap->im_ipimap->i_sb));
2067        extno = ino >> L2INOSPEREXT;
2068        bitno = ino & (INOSPEREXT - 1);
2069
2070        /* compute the mask for setting the map.
2071         */
2072        mask = HIGHORDER >> bitno;
2073
2074        /* the inode should be free and backed.
2075         */
2076        if (((le32_to_cpu(iagp->pmap[extno]) & mask) != 0) ||
2077            ((le32_to_cpu(iagp->wmap[extno]) & mask) != 0) ||
2078            (addressPXD(&iagp->inoext[extno]) == 0)) {
2079                if (amp)
2080                        release_metapage(amp);
2081                if (bmp)
2082                        release_metapage(bmp);
2083
2084                jfs_error(imap->im_ipimap->i_sb,
2085                          "diAllocBit: iag inconsistent");
2086                return -EIO;
2087        }
2088
2089        /* mark the inode as allocated in the working map.
2090         */
2091        iagp->wmap[extno] |= cpu_to_le32(mask);
2092
2093        /* check if all inodes within the extent are now
2094         * allocated.  if so, update the free inode summary
2095         * map to reflect this.
2096         */
2097        if (iagp->wmap[extno] == cpu_to_le32(ONES)) {
2098                sword = extno >> L2EXTSPERSUM;
2099                bitno = extno & (EXTSPERSUM - 1);
2100                iagp->inosmap[sword] |= cpu_to_le32(HIGHORDER >> bitno);
2101        }
2102
2103        /* if this was the last free inode in the iag, remove the
2104         * iag from the ag free inode list.
2105         */
2106        if (iagp->nfreeinos == cpu_to_le32(1)) {
2107                if (amp) {
2108                        aiagp->inofreeback = iagp->inofreeback;
2109                        write_metapage(amp);
2110                }
2111
2112                if (bmp) {
2113                        biagp->inofreefwd = iagp->inofreefwd;
2114                        write_metapage(bmp);
2115                } else {
2116                        imap->im_agctl[agno].inofree =
2117                            le32_to_cpu(iagp->inofreefwd);
2118                }
2119                iagp->inofreefwd = iagp->inofreeback = cpu_to_le32(-1);
2120        }
2121
2122        /* update the free inode count at the iag, ag, inode
2123         * map levels.
2124         */
2125        le32_add_cpu(&iagp->nfreeinos, -1);
2126        imap->im_agctl[agno].numfree -= 1;
2127        atomic_dec(&imap->im_numfree);
2128
2129        return (0);
2130}
2131
2132
2133/*
2134 * NAME:        diNewExt(imap,iagp,extno)
2135 *
2136 * FUNCTION:    initialize a new extent of inodes for an iag, allocating
2137 *              the first inode of the extent for use for the current
2138 *              allocation request.
2139 *
2140 *              disk resources are allocated for the new extent of inodes
2141 *              and the inodes themselves are initialized to reflect their
2142 *              existence within the extent (i.e. their inode numbers and
2143 *              inode extent addresses are set) and their initial state
2144 *              (mode and link count are set to zero).
2145 *
2146 *              if the iag is new, it is not yet on an ag extent free list
2147 *              but will now be placed on this list.
2148 *
2149 *              if the allocation of the new extent causes the iag to
2150 *              have no free extent, the iag will be removed from the
2151 *              ag extent free list.
2152 *
2153 *              if the iag has no free backed inodes, it will be placed
2154 *              on the ag free inode list, since the addition of the new
2155 *              extent will now cause it to have free inodes.
2156 *
2157 *              a careful update approach is used to provide consistency
2158 *              (i.e. list consistency) in the face of updates to multiple
2159 *              buffers.  under this approach, all required buffers are
2160 *              obtained before making any updates and are held until all
2161 *              updates are complete.
2162 *
2163 * PRE CONDITION: Already have buffer lock on iagp.  Already have AG lock on
2164 *      this AG.  Must have read lock on imap inode.
2165 *
2166 * PARAMETERS:
2167 *      imap    - pointer to inode map control structure.
2168 *      iagp    - pointer to iag.
2169 *      extno   - extent number.
2170 *
2171 * RETURN VALUES:
2172 *      0       - success.
2173 *      -ENOSPC - insufficient disk resources.
2174 *      -EIO    - i/o error.
2175 */
2176static int diNewExt(struct inomap * imap, struct iag * iagp, int extno)
2177{
2178        int agno, iagno, fwd, back, freei = 0, sword, rc;
2179        struct iag *aiagp = NULL, *biagp = NULL, *ciagp = NULL;
2180        struct metapage *amp, *bmp, *cmp, *dmp;
2181        struct inode *ipimap;
2182        s64 blkno, hint;
2183        int i, j;
2184        u32 mask;
2185        ino_t ino;
2186        struct dinode *dp;
2187        struct jfs_sb_info *sbi;
2188
2189        /* better have free extents.
2190         */
2191        if (!iagp->nfreeexts) {
2192                jfs_error(imap->im_ipimap->i_sb, "diNewExt: no free extents");
2193                return -EIO;
2194        }
2195
2196        /* get the inode map inode.
2197         */
2198        ipimap = imap->im_ipimap;
2199        sbi = JFS_SBI(ipimap->i_sb);
2200
2201        amp = bmp = cmp = NULL;
2202
2203        /* get the ag and iag numbers for this iag.
2204         */
2205        agno = BLKTOAG(le64_to_cpu(iagp->agstart), sbi);
2206        iagno = le32_to_cpu(iagp->iagnum);
2207
2208        /* check if this is the last free extent within the
2209         * iag.  if so, the iag must be removed from the ag
2210         * free extent list, so get the iags preceding and
2211         * following the iag on this list.
2212         */
2213        if (iagp->nfreeexts == cpu_to_le32(1)) {
2214                if ((fwd = le32_to_cpu(iagp->extfreefwd)) >= 0) {
2215                        if ((rc = diIAGRead(imap, fwd, &amp)))
2216                                return (rc);
2217                        aiagp = (struct iag *) amp->data;
2218                }
2219
2220                if ((back = le32_to_cpu(iagp->extfreeback)) >= 0) {
2221                        if ((rc = diIAGRead(imap, back, &bmp)))
2222                                goto error_out;
2223                        biagp = (struct iag *) bmp->data;
2224                }
2225        } else {
2226                /* the iag has free extents.  if all extents are free
2227                 * (as is the case for a newly allocated iag), the iag
2228                 * must be added to the ag free extent list, so get
2229                 * the iag at the head of the list in preparation for
2230                 * adding this iag to this list.
2231                 */
2232                fwd = back = -1;
2233                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG)) {
2234                        if ((fwd = imap->im_agctl[agno].extfree) >= 0) {
2235                                if ((rc = diIAGRead(imap, fwd, &amp)))
2236                                        goto error_out;
2237                                aiagp = (struct iag *) amp->data;
2238                        }
2239                }
2240        }
2241
2242        /* check if the iag has no free inodes.  if so, the iag
2243         * will have to be added to the ag free inode list, so get
2244         * the iag at the head of the list in preparation for
2245         * adding this iag to this list.  in doing this, we must
2246         * check if we already have the iag at the head of
2247         * the list in hand.
2248         */
2249        if (iagp->nfreeinos == 0) {
2250                freei = imap->im_agctl[agno].inofree;
2251
2252                if (freei >= 0) {
2253                        if (freei == fwd) {
2254                                ciagp = aiagp;
2255                        } else if (freei == back) {
2256                                ciagp = biagp;
2257                        } else {
2258                                if ((rc = diIAGRead(imap, freei, &cmp)))
2259                                        goto error_out;
2260                                ciagp = (struct iag *) cmp->data;
2261                        }
2262                        if (ciagp == NULL) {
2263                                jfs_error(imap->im_ipimap->i_sb,
2264                                          "diNewExt: ciagp == NULL");
2265                                rc = -EIO;
2266                                goto error_out;
2267                        }
2268                }
2269        }
2270
2271        /* allocate disk space for the inode extent.
2272         */
2273        if ((extno == 0) || (addressPXD(&iagp->inoext[extno - 1]) == 0))
2274                hint = ((s64) agno << sbi->bmap->db_agl2size) - 1;
2275        else
2276                hint = addressPXD(&iagp->inoext[extno - 1]) +
2277                    lengthPXD(&iagp->inoext[extno - 1]) - 1;
2278
2279        if ((rc = dbAlloc(ipimap, hint, (s64) imap->im_nbperiext, &blkno)))
2280                goto error_out;
2281
2282        /* compute the inode number of the first inode within the
2283         * extent.
2284         */
2285        ino = (iagno << L2INOSPERIAG) + (extno << L2INOSPEREXT);
2286
2287        /* initialize the inodes within the newly allocated extent a
2288         * page at a time.
2289         */
2290        for (i = 0; i < imap->im_nbperiext; i += sbi->nbperpage) {
2291                /* get a buffer for this page of disk inodes.
2292                 */
2293                dmp = get_metapage(ipimap, blkno + i, PSIZE, 1);
2294                if (dmp == NULL) {
2295                        rc = -EIO;
2296                        goto error_out;
2297                }
2298                dp = (struct dinode *) dmp->data;
2299
2300                /* initialize the inode number, mode, link count and
2301                 * inode extent address.
2302                 */
2303                for (j = 0; j < INOSPERPAGE; j++, dp++, ino++) {
2304                        dp->di_inostamp = cpu_to_le32(sbi->inostamp);
2305                        dp->di_number = cpu_to_le32(ino);
2306                        dp->di_fileset = cpu_to_le32(FILESYSTEM_I);
2307                        dp->di_mode = 0;
2308                        dp->di_nlink = 0;
2309                        PXDaddress(&(dp->di_ixpxd), blkno);
2310                        PXDlength(&(dp->di_ixpxd), imap->im_nbperiext);
2311                }
2312                write_metapage(dmp);
2313        }
2314
2315        /* if this is the last free extent within the iag, remove the
2316         * iag from the ag free extent list.
2317         */
2318        if (iagp->nfreeexts == cpu_to_le32(1)) {
2319                if (fwd >= 0)
2320                        aiagp->extfreeback = iagp->extfreeback;
2321
2322                if (back >= 0)
2323                        biagp->extfreefwd = iagp->extfreefwd;
2324                else
2325                        imap->im_agctl[agno].extfree =
2326                            le32_to_cpu(iagp->extfreefwd);
2327
2328                iagp->extfreefwd = iagp->extfreeback = cpu_to_le32(-1);
2329        } else {
2330                /* if the iag has all free extents (newly allocated iag),
2331                 * add the iag to the ag free extent list.
2332                 */
2333                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG)) {
2334                        if (fwd >= 0)
2335                                aiagp->extfreeback = cpu_to_le32(iagno);
2336
2337                        iagp->extfreefwd = cpu_to_le32(fwd);
2338                        iagp->extfreeback = cpu_to_le32(-1);
2339                        imap->im_agctl[agno].extfree = iagno;
2340                }
2341        }
2342
2343        /* if the iag has no free inodes, add the iag to the
2344         * ag free inode list.
2345         */
2346        if (iagp->nfreeinos == 0) {
2347                if (freei >= 0)
2348                        ciagp->inofreeback = cpu_to_le32(iagno);
2349
2350                iagp->inofreefwd =
2351                    cpu_to_le32(imap->im_agctl[agno].inofree);
2352                iagp->inofreeback = cpu_to_le32(-1);
2353                imap->im_agctl[agno].inofree = iagno;
2354        }
2355
2356        /* initialize the extent descriptor of the extent. */
2357        PXDlength(&iagp->inoext[extno], imap->im_nbperiext);
2358        PXDaddress(&iagp->inoext[extno], blkno);
2359
2360        /* initialize the working and persistent map of the extent.
2361         * the working map will be initialized such that
2362         * it indicates the first inode of the extent is allocated.
2363         */
2364        iagp->wmap[extno] = cpu_to_le32(HIGHORDER);
2365        iagp->pmap[extno] = 0;
2366
2367        /* update the free inode and free extent summary maps
2368         * for the extent to indicate the extent has free inodes
2369         * and no longer represents a free extent.
2370         */
2371        sword = extno >> L2EXTSPERSUM;
2372        mask = HIGHORDER >> (extno & (EXTSPERSUM - 1));
2373        iagp->extsmap[sword] |= cpu_to_le32(mask);
2374        iagp->inosmap[sword] &= cpu_to_le32(~mask);
2375
2376        /* update the free inode and free extent counts for the
2377         * iag.
2378         */
2379        le32_add_cpu(&iagp->nfreeinos, (INOSPEREXT - 1));
2380        le32_add_cpu(&iagp->nfreeexts, -1);
2381
2382        /* update the free and backed inode counts for the ag.
2383         */
2384        imap->im_agctl[agno].numfree += (INOSPEREXT - 1);
2385        imap->im_agctl[agno].numinos += INOSPEREXT;
2386
2387        /* update the free and backed inode counts for the inode map.
2388         */
2389        atomic_add(INOSPEREXT - 1, &imap->im_numfree);
2390        atomic_add(INOSPEREXT, &imap->im_numinos);
2391
2392        /* write the iags.
2393         */
2394        if (amp)
2395                write_metapage(amp);
2396        if (bmp)
2397                write_metapage(bmp);
2398        if (cmp)
2399                write_metapage(cmp);
2400
2401        return (0);
2402
2403      error_out:
2404
2405        /* release the iags.
2406         */
2407        if (amp)
2408                release_metapage(amp);
2409        if (bmp)
2410                release_metapage(bmp);
2411        if (cmp)
2412                release_metapage(cmp);
2413
2414        return (rc);
2415}
2416
2417
2418/*
2419 * NAME:        diNewIAG(imap,iagnop,agno)
2420 *
2421 * FUNCTION:    allocate a new iag for an allocation group.
2422 *
2423 *              first tries to allocate the iag from the inode map
2424 *              iagfree list:
2425 *              if the list has free iags, the head of the list is removed
2426 *              and returned to satisfy the request.
2427 *              if the inode map's iag free list is empty, the inode map
2428 *              is extended to hold a new iag. this new iag is initialized
2429 *              and returned to satisfy the request.
2430 *
2431 * PARAMETERS:
2432 *      imap    - pointer to inode map control structure.
2433 *      iagnop  - pointer to an iag number set with the number of the
2434 *                newly allocated iag upon successful return.
2435 *      agno    - allocation group number.
2436 *      bpp     - Buffer pointer to be filled in with new IAG's buffer
2437 *
2438 * RETURN VALUES:
2439 *      0       - success.
2440 *      -ENOSPC - insufficient disk resources.
2441 *      -EIO    - i/o error.
2442 *
2443 * serialization:
2444 *      AG lock held on entry/exit;
2445 *      write lock on the map is held inside;
2446 *      read lock on the map is held on successful completion;
2447 *
2448 * note: new iag transaction:
2449 * . synchronously write iag;
2450 * . write log of xtree and inode of imap;
2451 * . commit;
2452 * . synchronous write of xtree (right to left, bottom to top);
2453 * . at start of logredo(): init in-memory imap with one additional iag page;
2454 * . at end of logredo(): re-read imap inode to determine
2455 *   new imap size;
2456 */
2457static int
2458diNewIAG(struct inomap * imap, int *iagnop, int agno, struct metapage ** mpp)
2459{
2460        int rc;
2461        int iagno, i, xlen;
2462        struct inode *ipimap;
2463        struct super_block *sb;
2464        struct jfs_sb_info *sbi;
2465        struct metapage *mp;
2466        struct iag *iagp;
2467        s64 xaddr = 0;
2468        s64 blkno;
2469        tid_t tid;
2470        struct inode *iplist[1];
2471
2472        /* pick up pointers to the inode map and mount inodes */
2473        ipimap = imap->im_ipimap;
2474        sb = ipimap->i_sb;
2475        sbi = JFS_SBI(sb);
2476
2477        /* acquire the free iag lock */
2478        IAGFREE_LOCK(imap);
2479
2480        /* if there are any iags on the inode map free iag list,
2481         * allocate the iag from the head of the list.
2482         */
2483        if (imap->im_freeiag >= 0) {
2484                /* pick up the iag number at the head of the list */
2485                iagno = imap->im_freeiag;
2486
2487                /* determine the logical block number of the iag */
2488                blkno = IAGTOLBLK(iagno, sbi->l2nbperpage);
2489        } else {
2490                /* no free iags. the inode map will have to be extented
2491                 * to include a new iag.
2492                 */
2493
2494                /* acquire inode map lock */
2495                IWRITE_LOCK(ipimap, RDWRLOCK_IMAP);
2496
2497                if (ipimap->i_size >> L2PSIZE != imap->im_nextiag + 1) {
2498                        IWRITE_UNLOCK(ipimap);
2499                        IAGFREE_UNLOCK(imap);
2500                        jfs_error(imap->im_ipimap->i_sb,
2501                                  "diNewIAG: ipimap->i_size is wrong");
2502                        return -EIO;
2503                }
2504
2505
2506                /* get the next available iag number */
2507                iagno = imap->im_nextiag;
2508
2509                /* make sure that we have not exceeded the maximum inode
2510                 * number limit.
2511                 */
2512                if (iagno > (MAXIAGS - 1)) {
2513                        /* release the inode map lock */
2514                        IWRITE_UNLOCK(ipimap);
2515
2516                        rc = -ENOSPC;
2517                        goto out;
2518                }
2519
2520                /*
2521                 * synchronously append new iag page.
2522                 */
2523                /* determine the logical address of iag page to append */
2524                blkno = IAGTOLBLK(iagno, sbi->l2nbperpage);
2525
2526                /* Allocate extent for new iag page */
2527                xlen = sbi->nbperpage;
2528                if ((rc = dbAlloc(ipimap, 0, (s64) xlen, &xaddr))) {
2529                        /* release the inode map lock */
2530                        IWRITE_UNLOCK(ipimap);
2531
2532                        goto out;
2533                }
2534
2535                /*
2536                 * start transaction of update of the inode map
2537                 * addressing structure pointing to the new iag page;
2538                 */
2539                tid = txBegin(sb, COMMIT_FORCE);
2540                mutex_lock(&JFS_IP(ipimap)->commit_mutex);
2541
2542                /* update the inode map addressing structure to point to it */
2543                if ((rc =
2544                     xtInsert(tid, ipimap, 0, blkno, xlen, &xaddr, 0))) {
2545                        txEnd(tid);
2546                        mutex_unlock(&JFS_IP(ipimap)->commit_mutex);
2547                        /* Free the blocks allocated for the iag since it was
2548                         * not successfully added to the inode map
2549                         */
2550                        dbFree(ipimap, xaddr, (s64) xlen);
2551
2552                        /* release the inode map lock */
2553                        IWRITE_UNLOCK(ipimap);
2554
2555                        goto out;
2556                }
2557
2558                /* update the inode map's inode to reflect the extension */
2559                ipimap->i_size += PSIZE;
2560                inode_add_bytes(ipimap, PSIZE);
2561
2562                /* assign a buffer for the page */
2563                mp = get_metapage(ipimap, blkno, PSIZE, 0);
2564                if (!mp) {
2565                        /*
2566                         * This is very unlikely since we just created the
2567                         * extent, but let's try to handle it correctly
2568                         */
2569                        xtTruncate(tid, ipimap, ipimap->i_size - PSIZE,
2570                                   COMMIT_PWMAP);
2571
2572                        txAbort(tid, 0);
2573                        txEnd(tid);
2574                        mutex_unlock(&JFS_IP(ipimap)->commit_mutex);
2575
2576                        /* release the inode map lock */
2577                        IWRITE_UNLOCK(ipimap);
2578
2579                        rc = -EIO;
2580                        goto out;
2581                }
2582                iagp = (struct iag *) mp->data;
2583
2584                /* init the iag */
2585                memset(iagp, 0, sizeof(struct iag));
2586                iagp->iagnum = cpu_to_le32(iagno);
2587                iagp->inofreefwd = iagp->inofreeback = cpu_to_le32(-1);
2588                iagp->extfreefwd = iagp->extfreeback = cpu_to_le32(-1);
2589                iagp->iagfree = cpu_to_le32(-1);
2590                iagp->nfreeinos = 0;
2591                iagp->nfreeexts = cpu_to_le32(EXTSPERIAG);
2592
2593                /* initialize the free inode summary map (free extent
2594                 * summary map initialization handled by bzero).
2595                 */
2596                for (i = 0; i < SMAPSZ; i++)
2597                        iagp->inosmap[i] = cpu_to_le32(ONES);
2598
2599                /*
2600                 * Write and sync the metapage
2601                 */
2602                flush_metapage(mp);
2603
2604                /*
2605                 * txCommit(COMMIT_FORCE) will synchronously write address
2606                 * index pages and inode after commit in careful update order
2607                 * of address index pages (right to left, bottom up);
2608                 */
2609                iplist[0] = ipimap;
2610                rc = txCommit(tid, 1, &iplist[0], COMMIT_FORCE);
2611
2612                txEnd(tid);
2613                mutex_unlock(&JFS_IP(ipimap)->commit_mutex);
2614
2615                duplicateIXtree(sb, blkno, xlen, &xaddr);
2616
2617                /* update the next available iag number */
2618                imap->im_nextiag += 1;
2619
2620                /* Add the iag to the iag free list so we don't lose the iag
2621                 * if a failure happens now.
2622                 */
2623                imap->im_freeiag = iagno;
2624
2625                /* Until we have logredo working, we want the imap inode &
2626                 * control page to be up to date.
2627                 */
2628                diSync(ipimap);
2629
2630                /* release the inode map lock */
2631                IWRITE_UNLOCK(ipimap);
2632        }
2633
2634        /* obtain read lock on map */
2635        IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
2636
2637        /* read the iag */
2638        if ((rc = diIAGRead(imap, iagno, &mp))) {
2639                IREAD_UNLOCK(ipimap);
2640                rc = -EIO;
2641                goto out;
2642        }
2643        iagp = (struct iag *) mp->data;
2644
2645        /* remove the iag from the iag free list */
2646        imap->im_freeiag = le32_to_cpu(iagp->iagfree);
2647        iagp->iagfree = cpu_to_le32(-1);
2648
2649        /* set the return iag number and buffer pointer */
2650        *iagnop = iagno;
2651        *mpp = mp;
2652
2653      out:
2654        /* release the iag free lock */
2655        IAGFREE_UNLOCK(imap);
2656
2657        return (rc);
2658}
2659
2660/*
2661 * NAME:        diIAGRead()
2662 *
2663 * FUNCTION:    get the buffer for the specified iag within a fileset
2664 *              or aggregate inode map.
2665 *
2666 * PARAMETERS:
2667 *      imap    - pointer to inode map control structure.
2668 *      iagno   - iag number.
2669 *      bpp     - point to buffer pointer to be filled in on successful
2670 *                exit.
2671 *
2672 * SERIALIZATION:
2673 *      must have read lock on imap inode
2674 *      (When called by diExtendFS, the filesystem is quiesced, therefore
2675 *       the read lock is unnecessary.)
2676 *
2677 * RETURN VALUES:
2678 *      0       - success.
2679 *      -EIO    - i/o error.
2680 */
2681static int diIAGRead(struct inomap * imap, int iagno, struct metapage ** mpp)
2682{
2683        struct inode *ipimap = imap->im_ipimap;
2684        s64 blkno;
2685
2686        /* compute the logical block number of the iag. */
2687        blkno = IAGTOLBLK(iagno, JFS_SBI(ipimap->i_sb)->l2nbperpage);
2688
2689        /* read the iag. */
2690        *mpp = read_metapage(ipimap, blkno, PSIZE, 0);
2691        if (*mpp == NULL) {
2692                return -EIO;
2693        }
2694
2695        return (0);
2696}
2697
2698/*
2699 * NAME:        diFindFree()
2700 *
2701 * FUNCTION:    find the first free bit in a word starting at
2702 *              the specified bit position.
2703 *
2704 * PARAMETERS:
2705 *      word    - word to be examined.
2706 *      start   - starting bit position.
2707 *
2708 * RETURN VALUES:
2709 *      bit position of first free bit in the word or 32 if
2710 *      no free bits were found.
2711 */
2712static int diFindFree(u32 word, int start)
2713{
2714        int bitno;
2715        assert(start < 32);
2716        /* scan the word for the first free bit. */
2717        for (word <<= start, bitno = start; bitno < 32;
2718             bitno++, word <<= 1) {
2719                if ((word & HIGHORDER) == 0)
2720                        break;
2721        }
2722        return (bitno);
2723}
2724
2725/*
2726 * NAME:        diUpdatePMap()
2727 *
2728 * FUNCTION: Update the persistent map in an IAG for the allocation or
2729 *      freeing of the specified inode.
2730 *
2731 * PRE CONDITIONS: Working map has already been updated for allocate.
2732 *
2733 * PARAMETERS:
2734 *      ipimap  - Incore inode map inode
2735 *      inum    - Number of inode to mark in permanent map
2736 *      is_free - If 'true' indicates inode should be marked freed, otherwise
2737 *                indicates inode should be marked allocated.
2738 *
2739 * RETURN VALUES:
2740 *              0 for success
2741 */
2742int
2743diUpdatePMap(struct inode *ipimap,
2744             unsigned long inum, bool is_free, struct tblock * tblk)
2745{
2746        int rc;
2747        struct iag *iagp;
2748        struct metapage *mp;
2749        int iagno, ino, extno, bitno;
2750        struct inomap *imap;
2751        u32 mask;
2752        struct jfs_log *log;
2753        int lsn, difft, diffp;
2754        unsigned long flags;
2755
2756        imap = JFS_IP(ipimap)->i_imap;
2757        /* get the iag number containing the inode */
2758        iagno = INOTOIAG(inum);
2759        /* make sure that the iag is contained within the map */
2760        if (iagno >= imap->im_nextiag) {
2761                jfs_error(ipimap->i_sb,
2762                          "diUpdatePMap: the iag is outside the map");
2763                return -EIO;
2764        }
2765        /* read the iag */
2766        IREAD_LOCK(ipimap, RDWRLOCK_IMAP);
2767        rc = diIAGRead(imap, iagno, &mp);
2768        IREAD_UNLOCK(ipimap);
2769        if (rc)
2770                return (rc);
2771        metapage_wait_for_io(mp);
2772        iagp = (struct iag *) mp->data;
2773        /* get the inode number and extent number of the inode within
2774         * the iag and the inode number within the extent.
2775         */
2776        ino = inum & (INOSPERIAG - 1);
2777        extno = ino >> L2INOSPEREXT;
2778        bitno = ino & (INOSPEREXT - 1);
2779        mask = HIGHORDER >> bitno;
2780        /*
2781         * mark the inode free in persistent map:
2782         */
2783        if (is_free) {
2784                /* The inode should have been allocated both in working
2785                 * map and in persistent map;
2786                 * the inode will be freed from working map at the release
2787                 * of last reference release;
2788                 */
2789                if (!(le32_to_cpu(iagp->wmap[extno]) & mask)) {
2790                        jfs_error(ipimap->i_sb,
2791                                  "diUpdatePMap: inode %ld not marked as "
2792                                  "allocated in wmap!", inum);
2793                }
2794                if (!(le32_to_cpu(iagp->pmap[extno]) & mask)) {
2795                        jfs_error(ipimap->i_sb,
2796                                  "diUpdatePMap: inode %ld not marked as "
2797                                  "allocated in pmap!", inum);
2798                }
2799                /* update the bitmap for the extent of the freed inode */
2800                iagp->pmap[extno] &= cpu_to_le32(~mask);
2801        }
2802        /*
2803         * mark the inode allocated in persistent map:
2804         */
2805        else {
2806                /* The inode should be already allocated in the working map
2807                 * and should be free in persistent map;
2808                 */
2809                if (!(le32_to_cpu(iagp->wmap[extno]) & mask)) {
2810                        release_metapage(mp);
2811                        jfs_error(ipimap->i_sb,
2812                                  "diUpdatePMap: the inode is not allocated in "
2813                                  "the working map");
2814                        return -EIO;
2815                }
2816                if ((le32_to_cpu(iagp->pmap[extno]) & mask) != 0) {
2817                        release_metapage(mp);
2818                        jfs_error(ipimap->i_sb,
2819                                  "diUpdatePMap: the inode is not free in the "
2820                                  "persistent map");
2821                        return -EIO;
2822                }
2823                /* update the bitmap for the extent of the allocated inode */
2824                iagp->pmap[extno] |= cpu_to_le32(mask);
2825        }
2826        /*
2827         * update iag lsn
2828         */
2829        lsn = tblk->lsn;
2830        log = JFS_SBI(tblk->sb)->log;
2831        LOGSYNC_LOCK(log, flags);
2832        if (mp->lsn != 0) {
2833                /* inherit older/smaller lsn */
2834                logdiff(difft, lsn, log);
2835                logdiff(diffp, mp->lsn, log);
2836                if (difft < diffp) {
2837                        mp->lsn = lsn;
2838                        /* move mp after tblock in logsync list */
2839                        list_move(&mp->synclist, &tblk->synclist);
2840                }
2841                /* inherit younger/larger clsn */
2842                assert(mp->clsn);
2843                logdiff(difft, tblk->clsn, log);
2844                logdiff(diffp, mp->clsn, log);
2845                if (difft > diffp)
2846                        mp->clsn = tblk->clsn;
2847        } else {
2848                mp->log = log;
2849                mp->lsn = lsn;
2850                /* insert mp after tblock in logsync list */
2851                log->count++;
2852                list_add(&mp->synclist, &tblk->synclist);
2853                mp->clsn = tblk->clsn;
2854        }
2855        LOGSYNC_UNLOCK(log, flags);
2856        write_metapage(mp);
2857        return (0);
2858}
2859
2860/*
2861 *      diExtendFS()
2862 *
2863 * function: update imap for extendfs();
2864 *
2865 * note: AG size has been increased s.t. each k old contiguous AGs are
2866 * coalesced into a new AG;
2867 */
2868int diExtendFS(struct inode *ipimap, struct inode *ipbmap)
2869{
2870        int rc, rcx = 0;
2871        struct inomap *imap = JFS_IP(ipimap)->i_imap;
2872        struct iag *iagp = NULL, *hiagp = NULL;
2873        struct bmap *mp = JFS_SBI(ipbmap->i_sb)->bmap;
2874        struct metapage *bp, *hbp;
2875        int i, n, head;
2876        int numinos, xnuminos = 0, xnumfree = 0;
2877        s64 agstart;
2878
2879        jfs_info("diExtendFS: nextiag:%d numinos:%d numfree:%d",
2880                   imap->im_nextiag, atomic_read(&imap->im_numinos),
2881                   atomic_read(&imap->im_numfree));
2882
2883        /*
2884         *      reconstruct imap
2885         *
2886         * coalesce contiguous k (newAGSize/oldAGSize) AGs;
2887         * i.e., (AGi, ..., AGj) where i = k*n and j = k*(n+1) - 1 to AGn;
2888         * note: new AG size = old AG size * (2**x).
2889         */
2890
2891        /* init per AG control information im_agctl[] */
2892        for (i = 0; i < MAXAG; i++) {
2893                imap->im_agctl[i].inofree = -1;
2894                imap->im_agctl[i].extfree = -1;
2895                imap->im_agctl[i].numinos = 0;  /* number of backed inodes */
2896                imap->im_agctl[i].numfree = 0;  /* number of free backed inodes */
2897        }
2898
2899        /*
2900         *      process each iag page of the map.
2901         *
2902         * rebuild AG Free Inode List, AG Free Inode Extent List;
2903         */
2904        for (i = 0; i < imap->im_nextiag; i++) {
2905                if ((rc = diIAGRead(imap, i, &bp))) {
2906                        rcx = rc;
2907                        continue;
2908                }
2909                iagp = (struct iag *) bp->data;
2910                if (le32_to_cpu(iagp->iagnum) != i) {
2911                        release_metapage(bp);
2912                        jfs_error(ipimap->i_sb,
2913                                  "diExtendFs: unexpected value of iagnum");
2914                        return -EIO;
2915                }
2916
2917                /* leave free iag in the free iag list */
2918                if (iagp->nfreeexts == cpu_to_le32(EXTSPERIAG)) {
2919                        release_metapage(bp);
2920                        continue;
2921                }
2922
2923                agstart = le64_to_cpu(iagp->agstart);
2924                n = agstart >> mp->db_agl2size;
2925                iagp->agstart = cpu_to_le64((s64)n << mp->db_agl2size);
2926
2927                /* compute backed inodes */
2928                numinos = (EXTSPERIAG - le32_to_cpu(iagp->nfreeexts))
2929                    << L2INOSPEREXT;
2930                if (numinos > 0) {
2931                        /* merge AG backed inodes */
2932                        imap->im_agctl[n].numinos += numinos;
2933                        xnuminos += numinos;
2934                }
2935
2936                /* if any backed free inodes, insert at AG free inode list */
2937                if ((int) le32_to_cpu(iagp->nfreeinos) > 0) {
2938                        if ((head = imap->im_agctl[n].inofree) == -1) {
2939                                iagp->inofreefwd = cpu_to_le32(-1);
2940                                iagp->inofreeback = cpu_to_le32(-1);
2941                        } else {
2942                                if ((rc = diIAGRead(imap, head, &hbp))) {
2943                                        rcx = rc;
2944                                        goto nextiag;
2945                                }
2946                                hiagp = (struct iag *) hbp->data;
2947                                hiagp->inofreeback = iagp->iagnum;
2948                                iagp->inofreefwd = cpu_to_le32(head);
2949                                iagp->inofreeback = cpu_to_le32(-1);
2950                                write_metapage(hbp);
2951                        }
2952
2953                        imap->im_agctl[n].inofree =
2954                            le32_to_cpu(iagp->iagnum);
2955
2956                        /* merge AG backed free inodes */
2957                        imap->im_agctl[n].numfree +=
2958                            le32_to_cpu(iagp->nfreeinos);
2959                        xnumfree += le32_to_cpu(iagp->nfreeinos);
2960                }
2961
2962                /* if any free extents, insert at AG free extent list */
2963                if (le32_to_cpu(iagp->nfreeexts) > 0) {
2964                        if ((head = imap->im_agctl[n].extfree) == -1) {
2965                                iagp->extfreefwd = cpu_to_le32(-1);
2966                                iagp->extfreeback = cpu_to_le32(-1);
2967                        } else {
2968                                if ((rc = diIAGRead(imap, head, &hbp))) {
2969                                        rcx = rc;
2970                                        goto nextiag;
2971                                }
2972                                hiagp = (struct iag *) hbp->data;
2973                                hiagp->extfreeback = iagp->iagnum;
2974                                iagp->extfreefwd = cpu_to_le32(head);
2975                                iagp->extfreeback = cpu_to_le32(-1);
2976                                write_metapage(hbp);
2977                        }
2978
2979                        imap->im_agctl[n].extfree =
2980                            le32_to_cpu(iagp->iagnum);
2981                }
2982
2983              nextiag:
2984                write_metapage(bp);
2985        }
2986
2987        if (xnuminos != atomic_read(&imap->im_numinos) ||
2988            xnumfree != atomic_read(&imap->im_numfree)) {
2989                jfs_error(ipimap->i_sb,
2990                          "diExtendFs: numinos or numfree incorrect");
2991                return -EIO;
2992        }
2993
2994        return rcx;
2995}
2996
2997
2998/*
2999 *      duplicateIXtree()
3000 *
3001 * serialization: IWRITE_LOCK held on entry/exit
3002 *
3003 * note: shadow page with regular inode (rel.2);
3004 */
3005static void duplicateIXtree(struct super_block *sb, s64 blkno,
3006                            int xlen, s64 *xaddr)
3007{
3008        struct jfs_superblock *j_sb;
3009        struct buffer_head *bh;
3010        struct inode *ip;
3011        tid_t tid;
3012
3013        /* if AIT2 ipmap2 is bad, do not try to update it */
3014        if (JFS_SBI(sb)->mntflag & JFS_BAD_SAIT)        /* s_flag */
3015                return;
3016        ip = diReadSpecial(sb, FILESYSTEM_I, 1);
3017        if (ip == NULL) {
3018                JFS_SBI(sb)->mntflag |= JFS_BAD_SAIT;
3019                if (readSuper(sb, &bh))
3020                        return;
3021                j_sb = (struct jfs_superblock *)bh->b_data;
3022                j_sb->s_flag |= cpu_to_le32(JFS_BAD_SAIT);
3023
3024                mark_buffer_dirty(bh);
3025                sync_dirty_buffer(bh);
3026                brelse(bh);
3027                return;
3028        }
3029
3030        /* start transaction */
3031        tid = txBegin(sb, COMMIT_FORCE);
3032        /* update the inode map addressing structure to point to it */
3033        if (xtInsert(tid, ip, 0, blkno, xlen, xaddr, 0)) {
3034                JFS_SBI(sb)->mntflag |= JFS_BAD_SAIT;
3035                txAbort(tid, 1);
3036                goto cleanup;
3037
3038        }
3039        /* update the inode map's inode to reflect the extension */
3040        ip->i_size += PSIZE;
3041        inode_add_bytes(ip, PSIZE);
3042        txCommit(tid, 1, &ip, COMMIT_FORCE);
3043      cleanup:
3044        txEnd(tid);
3045        diFreeSpecial(ip);
3046}
3047
3048/*
3049 * NAME:        copy_from_dinode()
3050 *
3051 * FUNCTION:    Copies inode info from disk inode to in-memory inode
3052 *
3053 * RETURN VALUES:
3054 *      0       - success
3055 *      -ENOMEM - insufficient memory
3056 */
3057static int copy_from_dinode(struct dinode * dip, struct inode *ip)
3058{
3059        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
3060        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
3061
3062        jfs_ip->fileset = le32_to_cpu(dip->di_fileset);
3063        jfs_ip->mode2 = le32_to_cpu(dip->di_mode);
3064        jfs_set_inode_flags(ip);
3065
3066        ip->i_mode = le32_to_cpu(dip->di_mode) & 0xffff;
3067        if (sbi->umask != -1) {
3068                ip->i_mode = (ip->i_mode & ~0777) | (0777 & ~sbi->umask);
3069                /* For directories, add x permission if r is allowed by umask */
3070                if (S_ISDIR(ip->i_mode)) {
3071                        if (ip->i_mode & 0400)
3072                                ip->i_mode |= 0100;
3073                        if (ip->i_mode & 0040)
3074                                ip->i_mode |= 0010;
3075                        if (ip->i_mode & 0004)
3076                                ip->i_mode |= 0001;
3077                }
3078        }
3079        set_nlink(ip, le32_to_cpu(dip->di_nlink));
3080
3081        jfs_ip->saved_uid = le32_to_cpu(dip->di_uid);
3082        if (sbi->uid == -1)
3083                ip->i_uid = jfs_ip->saved_uid;
3084        else {
3085                ip->i_uid = sbi->uid;
3086        }
3087
3088        jfs_ip->saved_gid = le32_to_cpu(dip->di_gid);
3089        if (sbi->gid == -1)
3090                ip->i_gid = jfs_ip->saved_gid;
3091        else {
3092                ip->i_gid = sbi->gid;
3093        }
3094
3095        ip->i_size = le64_to_cpu(dip->di_size);
3096        ip->i_atime.tv_sec = le32_to_cpu(dip->di_atime.tv_sec);
3097        ip->i_atime.tv_nsec = le32_to_cpu(dip->di_atime.tv_nsec);
3098        ip->i_mtime.tv_sec = le32_to_cpu(dip->di_mtime.tv_sec);
3099        ip->i_mtime.tv_nsec = le32_to_cpu(dip->di_mtime.tv_nsec);
3100        ip->i_ctime.tv_sec = le32_to_cpu(dip->di_ctime.tv_sec);
3101        ip->i_ctime.tv_nsec = le32_to_cpu(dip->di_ctime.tv_nsec);
3102        ip->i_blocks = LBLK2PBLK(ip->i_sb, le64_to_cpu(dip->di_nblocks));
3103        ip->i_generation = le32_to_cpu(dip->di_gen);
3104
3105        jfs_ip->ixpxd = dip->di_ixpxd;  /* in-memory pxd's are little-endian */
3106        jfs_ip->acl = dip->di_acl;      /* as are dxd's */
3107        jfs_ip->ea = dip->di_ea;
3108        jfs_ip->next_index = le32_to_cpu(dip->di_next_index);
3109        jfs_ip->otime = le32_to_cpu(dip->di_otime.tv_sec);
3110        jfs_ip->acltype = le32_to_cpu(dip->di_acltype);
3111
3112        if (S_ISCHR(ip->i_mode) || S_ISBLK(ip->i_mode)) {
3113                jfs_ip->dev = le32_to_cpu(dip->di_rdev);
3114                ip->i_rdev = new_decode_dev(jfs_ip->dev);
3115        }
3116
3117        if (S_ISDIR(ip->i_mode)) {
3118                memcpy(&jfs_ip->i_dirtable, &dip->di_dirtable, 384);
3119        } else if (S_ISREG(ip->i_mode) || S_ISLNK(ip->i_mode)) {
3120                memcpy(&jfs_ip->i_xtroot, &dip->di_xtroot, 288);
3121        } else
3122                memcpy(&jfs_ip->i_inline_ea, &dip->di_inlineea, 128);
3123
3124        /* Zero the in-memory-only stuff */
3125        jfs_ip->cflag = 0;
3126        jfs_ip->btindex = 0;
3127        jfs_ip->btorder = 0;
3128        jfs_ip->bxflag = 0;
3129        jfs_ip->blid = 0;
3130        jfs_ip->atlhead = 0;
3131        jfs_ip->atltail = 0;
3132        jfs_ip->xtlid = 0;
3133        return (0);
3134}
3135
3136/*
3137 * NAME:        copy_to_dinode()
3138 *
3139 * FUNCTION:    Copies inode info from in-memory inode to disk inode
3140 */
3141static void copy_to_dinode(struct dinode * dip, struct inode *ip)
3142{
3143        struct jfs_inode_info *jfs_ip = JFS_IP(ip);
3144        struct jfs_sb_info *sbi = JFS_SBI(ip->i_sb);
3145
3146        dip->di_fileset = cpu_to_le32(jfs_ip->fileset);
3147        dip->di_inostamp = cpu_to_le32(sbi->inostamp);
3148        dip->di_number = cpu_to_le32(ip->i_ino);
3149        dip->di_gen = cpu_to_le32(ip->i_generation);
3150        dip->di_size = cpu_to_le64(ip->i_size);
3151        dip->di_nblocks = cpu_to_le64(PBLK2LBLK(ip->i_sb, ip->i_blocks));
3152        dip->di_nlink = cpu_to_le32(ip->i_nlink);
3153        if (sbi->uid == -1)
3154                dip->di_uid = cpu_to_le32(ip->i_uid);
3155        else
3156                dip->di_uid = cpu_to_le32(jfs_ip->saved_uid);
3157        if (sbi->gid == -1)
3158                dip->di_gid = cpu_to_le32(ip->i_gid);
3159        else
3160                dip->di_gid = cpu_to_le32(jfs_ip->saved_gid);
3161        jfs_get_inode_flags(jfs_ip);
3162        /*
3163         * mode2 is only needed for storing the higher order bits.
3164         * Trust i_mode for the lower order ones
3165         */
3166        if (sbi->umask == -1)
3167                dip->di_mode = cpu_to_le32((jfs_ip->mode2 & 0xffff0000) |
3168                                           ip->i_mode);
3169        else /* Leave the original permissions alone */
3170                dip->di_mode = cpu_to_le32(jfs_ip->mode2);
3171
3172        dip->di_atime.tv_sec = cpu_to_le32(ip->i_atime.tv_sec);
3173        dip->di_atime.tv_nsec = cpu_to_le32(ip->i_atime.tv_nsec);
3174        dip->di_ctime.tv_sec = cpu_to_le32(ip->i_ctime.tv_sec);
3175        dip->di_ctime.tv_nsec = cpu_to_le32(ip->i_ctime.tv_nsec);
3176        dip->di_mtime.tv_sec = cpu_to_le32(ip->i_mtime.tv_sec);
3177        dip->di_mtime.tv_nsec = cpu_to_le32(ip->i_mtime.tv_nsec);
3178        dip->di_ixpxd = jfs_ip->ixpxd;  /* in-memory pxd's are little-endian */
3179        dip->di_acl = jfs_ip->acl;      /* as are dxd's */
3180        dip->di_ea = jfs_ip->ea;
3181        dip->di_next_index = cpu_to_le32(jfs_ip->next_index);
3182        dip->di_otime.tv_sec = cpu_to_le32(jfs_ip->otime);
3183        dip->di_otime.tv_nsec = 0;
3184        dip->di_acltype = cpu_to_le32(jfs_ip->acltype);
3185        if (S_ISCHR(ip->i_mode) || S_ISBLK(ip->i_mode))
3186                dip->di_rdev = cpu_to_le32(jfs_ip->dev);
3187}
3188
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