lustre/obdfilter/filter.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  linux/fs/obdfilter/filter.c
   5  *
   6  * Copyright (C) 2001, 2002 Cluster File Systems, Inc.
   7  *
   8  * This code is issued under the GNU General Public License.
   9  * See the file COPYING in this distribution
  10  *
  11  * by Peter Braam <braam@clusterfs.com>
  12  * and Andreas Dilger <adilger@clusterfs.com>
  13  */
  14
  15 #define EXPORT_SYMTAB
  16 #define DEBUG_SUBSYSTEM S_FILTER
  17
  18 #include <linux/module.h>
  19 #include <linux/pagemap.h>
  20 #include <linux/fs.h>
  21 #include <linux/dcache.h>
  22 #include <linux/obd_class.h>
  23 #include <linux/lustre_dlm.h>
  24 #include <linux/obd_filter.h>
  25 #include <linux/ext3_jbd.h>
  26 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
  27 #include <linux/extN_jbd.h>
  28 #endif
  29 #include <linux/quotaops.h>
  30 #include <linux/init.h>
  31 #include <linux/stringify.h>
  32
  33 long filter_memory;
  34
  35 #define FILTER_ROOTINO 2
  36 #define FILTER_ROOTINO_STR __stringify(FILTER_ROOTINO)
  37
  38 #define S_SHIFT 12
  39 static char *obd_type_by_mode[S_IFMT >> S_SHIFT] = {
  40         [0]                     NULL,
  41         [S_IFREG >> S_SHIFT]    "R",
  42         [S_IFDIR >> S_SHIFT]    "D",
  43         [S_IFCHR >> S_SHIFT]    "C",
  44         [S_IFBLK >> S_SHIFT]    "B",
  45         [S_IFIFO >> S_SHIFT]    "F",
  46         [S_IFSOCK >> S_SHIFT]   "S",
  47         [S_IFLNK >> S_SHIFT]    "L"
  48 };
  49
  50 static inline const char *obd_mode_to_type(int mode)
  51 {
  52         return obd_type_by_mode[(mode & S_IFMT) >> S_SHIFT];
  53 }
  54
  55 /* write the pathname into the string */
  56 static int filter_id(char *buf, obd_id id, obd_mode mode)
  57 {
  58         return sprintf(buf, "O/%s/"LPU64, obd_mode_to_type(mode), id);
  59 }
  60
  61 static inline void f_dput(struct dentry *dentry)
  62 {
  63         CDEBUG(D_INODE, "putting %s: %p, count = %d\n",
  64                dentry->d_name.name, dentry, atomic_read(&dentry->d_count) - 1);
  65         LASSERT(atomic_read(&dentry->d_count) > 0);
  66         dput(dentry);
  67 }
  68
  69 /* setup the object store with correct subdirectories */
  70 static int filter_prep(struct obd_device *obddev)
  71 {
  72         struct obd_run_ctxt saved;
  73         struct filter_obd *filter = &obddev->u.filter;
  74         struct dentry *dentry;
  75         struct dentry *root;
  76         struct file *file;
  77         struct inode *inode;
  78         int rc = 0;
  79         __u64 lastino = 2;
  80         int mode = 0;
  81
  82         push_ctxt(&saved, &filter->fo_ctxt, NULL);
  83         dentry = simple_mkdir(current->fs->pwd, "O", 0700);
  84         CDEBUG(D_INODE, "got/created O: %p\n", dentry);
  85         if (IS_ERR(dentry)) {
  86                 rc = PTR_ERR(dentry);
  87                 CERROR("cannot open/create O: rc = %d\n", rc);
  88                 GOTO(out, rc);
  89         }
  90         filter->fo_dentry_O = dentry;
  91         dentry = simple_mkdir(current->fs->pwd, "P", 0700);
  92         CDEBUG(D_INODE, "got/created P: %p\n", dentry);
  93         if (IS_ERR(dentry)) {
  94                 rc = PTR_ERR(dentry);
  95                 CERROR("cannot open/create P: rc = %d\n", rc);
  96                 GOTO(out_O, rc);
  97         }
  98         f_dput(dentry);
  99         dentry = simple_mkdir(current->fs->pwd, "D", 0700);
 100         CDEBUG(D_INODE, "got/created D: %p\n", dentry);
 101         if (IS_ERR(dentry)) {
 102                 rc = PTR_ERR(dentry);
 103                 CERROR("cannot open/create D: rc = %d\n", rc);
 104                 GOTO(out_O, rc);
 105         }
 106
 107         root = simple_mknod(dentry, FILTER_ROOTINO_STR, S_IFREG | 0755);
 108         f_dput(dentry);
 109         if (IS_ERR(root)) {
 110                 rc = PTR_ERR(root);
 111                 CERROR("OBD filter: cannot open/create root %d: rc = %d\n",
 112                        FILTER_ROOTINO, rc);
 113                 GOTO(out_O, rc);
 114         }
 115         f_dput(root);
 116
 117         /*
 118          * Create directories and/or get dentries for each object type.
 119          * This saves us from having to do multiple lookups for each one.
 120          */
 121         for (mode = 0; mode < (S_IFMT >> S_SHIFT); mode++) {
 122                 char *type = obd_type_by_mode[mode];
 123
 124                 if (!type) {
 125                         filter->fo_dentry_O_mode[mode] = NULL;
 126                         continue;
 127                 }
 128                 dentry = simple_mkdir(filter->fo_dentry_O, type, 0700);
 129                 CDEBUG(D_INODE, "got/created O/%s: %p\n", type, dentry);
 130                 if (IS_ERR(dentry)) {
 131                         rc = PTR_ERR(dentry);
 132                         CERROR("cannot create O/%s: rc = %d\n", type, rc);
 133                         GOTO(out_O_mode, rc);
 134                 }
 135                 filter->fo_dentry_O_mode[mode] = dentry;
 136         }
 137
 138         file = filp_open("D/status", O_RDWR | O_CREAT, 0700);
 139         if ( !file || IS_ERR(file) ) {
 140                 rc = PTR_ERR(file);
 141                 CERROR("OBD filter: cannot open/create status %s: rc = %d\n",
 142                        "D/status", rc);
 143                 GOTO(out_O_mode, rc);
 144         }
 145
 146         /* steal operations */
 147         inode = file->f_dentry->d_inode;
 148         filter->fo_fop = file->f_op;
 149         filter->fo_iop = inode->i_op;
 150         filter->fo_aops = inode->i_mapping->a_ops;
 151
 152         if (inode->i_size == 0) {
 153                 __u64 disk_lastino = cpu_to_le64(lastino);
 154                 ssize_t retval = file->f_op->write(file, (char *)&disk_lastino,
 155                                                    sizeof(disk_lastino),
 156                                                    &file->f_pos);
 157                 if (retval != sizeof(disk_lastino)) {
 158                         CDEBUG(D_INODE, "OBD filter: error writing lastino\n");
 159                         filp_close(file, 0);
 160                         GOTO(out_O_mode, rc = -EIO);
 161                 }
 162         } else {
 163                 __u64 disk_lastino;
 164                 ssize_t retval = file->f_op->read(file, (char *)&disk_lastino,
 165                                                   sizeof(disk_lastino),
 166                                                   &file->f_pos);
 167                 if (retval != sizeof(disk_lastino)) {
 168                         CDEBUG(D_INODE, "OBD filter: error reading lastino\n");
 169                         filp_close(file, 0);
 170                         GOTO(out_O_mode, rc = -EIO);
 171                 }
 172                 lastino = le64_to_cpu(disk_lastino);
 173         }
 174         filter->fo_lastino = lastino;
 175         filp_close(file, 0);
 176
 177         rc = 0;
 178  out:
 179         pop_ctxt(&saved);
 180
 181         return(rc);
 182
 183 out_O_mode:
 184         while (mode-- > 0) {
 185                 struct dentry *dentry = filter->fo_dentry_O_mode[mode];
 186                 if (dentry) {
 187                         f_dput(dentry);
 188                         filter->fo_dentry_O_mode[mode] = NULL;
 189                 }
 190         }
 191 out_O:
 192         f_dput(filter->fo_dentry_O);
 193         filter->fo_dentry_O = NULL;
 194         goto out;
 195 }
 196
 197 /* cleanup the filter: write last used object id to status file */
 198 static void filter_post(struct obd_device *obddev)
 199 {
 200         struct obd_run_ctxt saved;
 201         struct filter_obd *filter = &obddev->u.filter;
 202         __u64 disk_lastino;
 203         long rc;
 204         struct file *file;
 205         int mode;
 206
 207         push_ctxt(&saved, &filter->fo_ctxt, NULL);
 208         file = filp_open("D/status", O_RDWR | O_CREAT, 0700);
 209         if (IS_ERR(file)) {
 210                 CERROR("OBD filter: cannot create status file\n");
 211                 goto out;
 212         }
 213
 214         file->f_pos = 0;
 215         disk_lastino = cpu_to_le64(filter->fo_lastino);
 216         rc = file->f_op->write(file, (char *)&disk_lastino,
 217                        sizeof(disk_lastino), &file->f_pos);
 218         if (rc != sizeof(disk_lastino))
 219                 CERROR("OBD filter: error writing lastino: rc = %ld\n", rc);
 220
 221         rc = filp_close(file, NULL);
 222         if (rc)
 223                 CERROR("OBD filter: cannot close status file: rc = %ld\n", rc);
 224
 225         for (mode = 0; mode < (S_IFMT >> S_SHIFT); mode++) {
 226                 struct dentry *dentry = filter->fo_dentry_O_mode[mode];
 227                 if (dentry) {
 228                         f_dput(dentry);
 229                         filter->fo_dentry_O_mode[mode] = NULL;
 230                 }
 231         }
 232         f_dput(filter->fo_dentry_O);
 233 out:
 234         pop_ctxt(&saved);
 235 }
 236
 237
 238 static __u64 filter_next_id(struct obd_device *obddev)
 239 {
 240         obd_id id;
 241
 242         spin_lock(&obddev->u.filter.fo_lock);
 243         id = ++obddev->u.filter.fo_lastino;
 244         spin_unlock(&obddev->u.filter.fo_lock);
 245
 246         /* FIXME: write the lastino to disk here */
 247         return id;
 248 }
 249
 250 /* how to get files, dentries, inodes from object id's */
 251 /* parent i_sem is already held if needed for exclusivity */
 252 static struct dentry *filter_fid2dentry(struct obd_device *obddev,
 253                                         struct dentry *dparent,
 254                                         __u64 id, __u32 type)
 255 {
 256         struct super_block *sb = obddev->u.filter.fo_sb;
 257         struct dentry *dchild;
 258         char name[32];
 259         int len;
 260         ENTRY;
 261
 262         if (!sb || !sb->s_dev) {
 263                 CERROR("fatal: device not initialized.\n");
 264                 RETURN(ERR_PTR(-ENXIO));
 265         }
 266
 267         if (id == 0) {
 268                 CERROR("fatal: invalid object #0\n");
 269                 LBUG();
 270                 RETURN(ERR_PTR(-ESTALE));
 271         }
 272
 273         if (!(type & S_IFMT)) {
 274                 CERROR("OBD %s, object "LPU64" has bad type: %o\n",
 275                        __FUNCTION__, id, type);
 276                 RETURN(ERR_PTR(-EINVAL));
 277         }
 278
 279         len = sprintf(name, LPU64, id);
 280         CDEBUG(D_INODE, "opening object O/%s/%s\n", obd_mode_to_type(type),
 281                name);
 282         dchild = lookup_one_len(name, dparent, len);
 283         if (IS_ERR(dchild)) {
 284                 CERROR("child lookup error %ld\n", PTR_ERR(dchild));
 285                 RETURN(dchild);
 286         }
 287
 288         CDEBUG(D_INODE, "got child obj O/%s/%s: %p, count = %d\n",
 289                obd_mode_to_type(type), name, dchild,
 290                atomic_read(&dchild->d_count));
 291
 292         LASSERT(atomic_read(&dchild->d_count) > 0);
 293
 294         RETURN(dchild);
 295 }
 296
 297 static struct file *filter_obj_open(struct obd_device *obddev,
 298                                     __u64 id, __u32 type)
 299 {
 300         struct super_block *sb = obddev->u.filter.fo_sb;
 301         struct obd_run_ctxt saved;
 302         char name[24];
 303         struct file *file;
 304         ENTRY;
 305
 306         if (!sb || !sb->s_dev) {
 307                 CERROR("fatal: device not initialized.\n");
 308                 RETURN(ERR_PTR(-ENXIO));
 309         }
 310
 311         if (!id) {
 312                 CERROR("fatal: invalid obdo "LPU64"\n", id);
 313                 RETURN(ERR_PTR(-ESTALE));
 314         }
 315
 316         if (!(type & S_IFMT)) {
 317                 CERROR("OBD %s, object "LPU64" has bad type: %o\n",
 318                        __FUNCTION__, id, type);
 319                 RETURN(ERR_PTR(-EINVAL));
 320         }
 321
 322         filter_id(name, id, type);
 323         push_ctxt(&saved, &obddev->u.filter.fo_ctxt, NULL);
 324         file = filp_open(name, O_RDONLY | O_LARGEFILE, 0 /* type? */);
 325         pop_ctxt(&saved);
 326
 327         CDEBUG(D_INODE, "opening obdo %s: rc = %p\n", name, file);
 328
 329         if (IS_ERR(file))
 330                 file = NULL;
 331         RETURN(file);
 332 }
 333
 334 static struct dentry *filter_parent(struct obd_device *obddev, obd_mode mode)
 335 {
 336         struct filter_obd *filter = &obddev->u.filter;
 337
 338         return filter->fo_dentry_O_mode[(mode & S_IFMT) >> S_SHIFT];
 339 }
 340
 341
 342 /* obd methods */
 343 static int filter_connect(struct lustre_handle *conn, struct obd_device *obd,
 344                           obd_uuid_t cluuid, struct recovd_obd *recovd,
 345                           ptlrpc_recovery_cb_t recover)
 346 {
 347         int rc;
 348         ENTRY;
 349         MOD_INC_USE_COUNT;
 350         rc = class_connect(conn, obd, cluuid);
 351         if (rc)
 352                 MOD_DEC_USE_COUNT;
 353         RETURN(rc);
 354 }
 355
 356 static int filter_disconnect(struct lustre_handle *conn)
 357 {
 358         struct obd_export *export = class_conn2export(conn);
 359         int rc;
 360         ENTRY;
 361
 362         ldlm_cancel_locks_for_export(export);
 363
 364         rc = class_disconnect(conn);
 365         if (!rc)
 366                 MOD_DEC_USE_COUNT;
 367
 368         /* XXX cleanup preallocated inodes */
 369         RETURN(rc);
 370 }
 371
 372 /* mount the file system (secretly) */
 373 static int filter_setup(struct obd_device *obddev, obd_count len, void *buf)
 374 {
 375         struct obd_ioctl_data* data = buf;
 376         struct filter_obd *filter;
 377         struct vfsmount *mnt;
 378         int err = 0;
 379         ENTRY;
 380
 381         if (!data->ioc_inlbuf1 || !data->ioc_inlbuf2)
 382                 RETURN(-EINVAL);
 383
 384         MOD_INC_USE_COUNT;
 385         mnt = do_kern_mount(data->ioc_inlbuf2, 0, data->ioc_inlbuf1, NULL);
 386         err = PTR_ERR(mnt);
 387         if (IS_ERR(mnt))
 388                 GOTO(err_dec, err);
 389
 390         filter = &obddev->u.filter;;
 391         filter->fo_vfsmnt = mnt;
 392         filter->fo_fstype = strdup(data->ioc_inlbuf2);
 393         filter->fo_sb = mnt->mnt_root->d_inode->i_sb;
 394         /* XXX is this even possible if do_kern_mount succeeded? */
 395         if (!filter->fo_sb)
 396                 GOTO(err_kfree, err = -ENODEV);
 397
 398         OBD_SET_CTXT_MAGIC(&filter->fo_ctxt);
 399         filter->fo_ctxt.pwdmnt = mnt;
 400         filter->fo_ctxt.pwd = mnt->mnt_root;
 401         filter->fo_ctxt.fs = get_ds();
 402
 403         err = filter_prep(obddev);
 404         if (err)
 405                 GOTO(err_kfree, err);
 406         spin_lock_init(&filter->fo_lock);
 407
 408         obddev->obd_namespace =
 409                 ldlm_namespace_new("filter-tgt", LDLM_NAMESPACE_SERVER);
 410         if (obddev->obd_namespace == NULL)
 411                 LBUG();
 412
 413         ptlrpc_init_client(LDLM_REQUEST_PORTAL, LDLM_REPLY_PORTAL,
 414                            "filter_ldlm_client", &obddev->obd_ldlm_client);
 415
 416         RETURN(0);
 417
 418 err_kfree:
 419         kfree(filter->fo_fstype);
 420         unlock_kernel();
 421         mntput(filter->fo_vfsmnt);
 422         filter->fo_sb = 0;
 423         lock_kernel();
 424
 425 err_dec:
 426         MOD_DEC_USE_COUNT;
 427         return err;
 428 }
 429
 430
 431 static int filter_cleanup(struct obd_device * obddev)
 432 {
 433         struct super_block *sb;
 434         ENTRY;
 435
 436         if (!list_empty(&obddev->obd_exports)) {
 437                 CERROR("still has clients!\n");
 438                 class_disconnect_all(obddev);
 439                 if (!list_empty(&obddev->obd_exports)) {
 440                         CERROR("still has exports after forced cleanup?\n");
 441                         RETURN(-EBUSY);
 442                 }
 443         }
 444
 445         ldlm_namespace_free(obddev->obd_namespace);
 446
 447         sb = obddev->u.filter.fo_sb;
 448         if (!obddev->u.filter.fo_sb)
 449                 RETURN(0);
 450
 451         filter_post(obddev);
 452
 453         shrink_dcache_parent(sb->s_root);
 454         unlock_kernel();
 455         mntput(obddev->u.filter.fo_vfsmnt);
 456         obddev->u.filter.fo_sb = 0;
 457         kfree(obddev->u.filter.fo_fstype);
 458
 459         lock_kernel();
 460
 461         MOD_DEC_USE_COUNT;
 462         RETURN(0);
 463 }
 464
 465
 466 static inline void filter_from_inode(struct obdo *oa, struct inode *inode,
 467                                      int valid)
 468 {
 469         int type = oa->o_mode & S_IFMT;
 470         ENTRY;
 471
 472         CDEBUG(D_INFO, "src inode %ld (%p), dst obdo %ld valid 0x%08x\n",
 473                inode->i_ino, inode, (long)oa->o_id, valid);
 474         /* Don't copy the inode number in place of the object ID */
 475         obdo_from_inode(oa, inode, valid);
 476         oa->o_mode &= ~S_IFMT;
 477         oa->o_mode |= type;
 478
 479         if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
 480                 obd_rdev rdev = kdev_t_to_nr(inode->i_rdev);
 481                 oa->o_rdev = rdev;
 482                 oa->o_valid |= OBD_MD_FLRDEV;
 483         }
 484
 485         EXIT;
 486 }
 487
 488 static int filter_getattr(struct lustre_handle *conn, struct obdo *oa,
 489                           struct lov_stripe_md *md)
 490 {
 491         struct obd_device *obddev = class_conn2obd(conn);
 492         struct dentry *dentry;
 493         int rc = 0;
 494         ENTRY;
 495
 496         if (!class_conn2export(conn)) {
 497                 CDEBUG(D_IOCTL, "fatal: invalid client "LPX64"\n", conn->addr);
 498                 RETURN(-EINVAL);
 499         }
 500
 501         obddev = class_conn2obd(conn);
 502         dentry = filter_fid2dentry(obddev, filter_parent(obddev, oa->o_mode),
 503                                    oa->o_id, oa->o_mode);
 504         if (IS_ERR(dentry))
 505                 RETURN(PTR_ERR(dentry));
 506
 507         if (!dentry->d_inode) {
 508                 CERROR("getattr on non-existent object: "LPU64"\n", oa->o_id);
 509                 GOTO(out_getattr, rc = -ENOENT);
 510         }
 511
 512         filter_from_inode(oa, dentry->d_inode, oa->o_valid);
 513
 514 out_getattr:
 515         f_dput(dentry);
 516         RETURN(rc);
 517 }
 518
 519 static int filter_setattr(struct lustre_handle *conn, struct obdo *oa,
 520                           struct lov_stripe_md *md)
 521 {
 522         struct obd_run_ctxt saved;
 523         struct obd_device *obd = class_conn2obd(conn);
 524         struct dentry *dentry;
 525         struct iattr iattr;
 526         struct inode *inode;
 527         int rc;
 528         ENTRY;
 529
 530         iattr_from_obdo(&iattr, oa, oa->o_valid);
 531         iattr.ia_mode = (iattr.ia_mode & ~S_IFMT) | S_IFREG;
 532         dentry = filter_fid2dentry(obd, filter_parent(obd, iattr.ia_mode),
 533                                    oa->o_id, iattr.ia_mode);
 534         if (IS_ERR(dentry))
 535                 RETURN(PTR_ERR(dentry));
 536
 537         inode = dentry->d_inode;
 538         if (!inode) {
 539                 CERROR("setattr on non-existent object: "LPU64"\n", oa->o_id);
 540                 GOTO(out_setattr, rc = -ENOENT);
 541         }
 542
 543         lock_kernel();
 544         if (iattr.ia_valid & ATTR_SIZE)
 545                 down(&inode->i_sem);
 546         push_ctxt(&saved, &obd->u.filter.fo_ctxt, NULL);
 547         if (inode->i_op->setattr)
 548                 rc = inode->i_op->setattr(dentry, &iattr);
 549         else
 550                 rc = inode_setattr(inode, &iattr);
 551         pop_ctxt(&saved);
 552         if (iattr.ia_valid & ATTR_SIZE) {
 553                 up(&inode->i_sem);
 554                 oa->o_valid = OBD_MD_FLBLOCKS | OBD_MD_FLCTIME | OBD_MD_FLMTIME;
 555                 obdo_from_inode(oa, inode, oa->o_valid);
 556         }
 557         unlock_kernel();
 558
 559 out_setattr:
 560         f_dput(dentry);
 561         RETURN(rc);
 562 }
 563
 564 static int filter_open(struct lustre_handle *conn, struct obdo *oa,
 565                        struct lov_stripe_md *ea)
 566 {
 567         struct obd_export *export;
 568         struct obd_device *obd;
 569         struct dentry *dentry;
 570         /* ENTRY; */
 571
 572         export = class_conn2export(conn);
 573         if (!export) {
 574                 CDEBUG(D_IOCTL, "fatal: invalid client "LPX64"\n", conn->addr);
 575                 RETURN(-EINVAL);
 576         }
 577
 578         obd = export->exp_obd;
 579         dentry = filter_fid2dentry(obd, filter_parent(obd, oa->o_mode),
 580                                    oa->o_id, oa->o_mode);
 581         if (IS_ERR(dentry))
 582                 RETURN(PTR_ERR(dentry));
 583
 584         if (!dentry->d_inode) {
 585                 CERROR("opening non-existent objid "LPX64"\n", oa->o_id);
 586                 RETURN(-ENOENT);
 587         }
 588
 589         filter_from_inode(oa, dentry->d_inode, OBD_MD_FLSIZE | OBD_MD_FLBLOCKS |
 590                           OBD_MD_FLMTIME | OBD_MD_FLCTIME);
 591
 592         return 0;
 593 } /* filter_open */
 594
 595 static int filter_close(struct lustre_handle *conn, struct obdo *oa,
 596                         struct lov_stripe_md *ea)
 597 {
 598         struct obd_device *obd;
 599         struct dentry *dentry;
 600         /* ENTRY; */
 601
 602         obd = class_conn2obd(conn);
 603         if (!obd) {
 604                 CDEBUG(D_IOCTL, "fatal: invalid client "LPX64"\n", conn->addr);
 605                 RETURN(-EINVAL);
 606         }
 607
 608         dentry = filter_fid2dentry(obd, filter_parent(obd, oa->o_mode),
 609                                    oa->o_id, oa->o_mode);
 610         if (IS_ERR(dentry))
 611                 RETURN(PTR_ERR(dentry));
 612         LASSERT(atomic_read(&dentry->d_count) > 1);
 613
 614         f_dput(dentry);  /* for the close */
 615         f_dput(dentry);  /* for this call */
 616         return 0;
 617 } /* filter_close */
 618
 619 static int filter_create(struct lustre_handle* conn, struct obdo *oa,
 620                          struct lov_stripe_md **ea)
 621 {
 622         char name[64];
 623         struct obd_run_ctxt saved;
 624         struct dentry *new;
 625         int mode;
 626         struct obd_device *obd = class_conn2obd(conn);
 627         struct filter_obd *filter = &obd->u.filter;
 628         struct iattr;
 629         ENTRY;
 630
 631         if (!obd) {
 632                 CERROR("invalid client "LPX64"\n", conn->addr);
 633                 return -EINVAL;
 634         }
 635
 636         if (!(oa->o_mode && S_IFMT)) {
 637                 CERROR("OBD %s, object "LPU64" has bad type: %o\n",
 638                        __FUNCTION__, oa->o_id, oa->o_mode);
 639                 return -ENOENT;
 640         }
 641
 642         oa->o_id = filter_next_id(obd);
 643
 644         //filter_id(name, oa->o_id, oa->o_mode);
 645         sprintf(name, LPU64, oa->o_id);
 646         mode = (oa->o_mode & ~S_IFMT) | S_IFREG;
 647         push_ctxt(&saved, &obd->u.filter.fo_ctxt, NULL);
 648         new = simple_mknod(filter->fo_dentry_O_mode[S_IFREG >> S_SHIFT], name,
 649                            mode);
 650         pop_ctxt(&saved);
 651         if (IS_ERR(new)) {
 652                 CERROR("Error mknod obj %s, err %ld\n", name, PTR_ERR(new));
 653                 return -ENOENT;
 654         }
 655
 656         /* Set flags for fields we have set in the inode struct */
 657         oa->o_valid = OBD_MD_FLID | OBD_MD_FLBLKSZ | OBD_MD_FLBLOCKS |
 658                  OBD_MD_FLMTIME | OBD_MD_FLATIME | OBD_MD_FLCTIME;
 659         filter_from_inode(oa, new->d_inode, oa->o_valid);
 660         dput(new);
 661
 662         return 0;
 663 }
 664
 665 static int filter_destroy(struct lustre_handle *conn, struct obdo *oa,
 666                           struct lov_stripe_md *ea)
 667 {
 668         struct obd_device *obd;
 669         struct filter_obd *filter;
 670         struct obd_run_ctxt saved;
 671         struct inode *inode;
 672         struct dentry *dir_dentry, *object_dentry;
 673         int rc;
 674         ENTRY;
 675
 676         obd = class_conn2obd(conn);
 677         if (!obd) {
 678                 CERROR("invalid client "LPX64"\n", conn->addr);
 679                 RETURN(-EINVAL);
 680         }
 681
 682         CDEBUG(D_INODE, "destroying object "LPD64"\n", oa->o_id);
 683
 684         dir_dentry = filter_parent(obd, oa->o_mode);
 685         down(&dir_dentry->d_inode->i_sem);
 686
 687         object_dentry = filter_fid2dentry(obd, dir_dentry, oa->o_id,
 688                                           oa->o_mode);
 689         if (IS_ERR(object_dentry))
 690                 GOTO(out, rc = -ENOENT);
 691
 692         inode = object_dentry->d_inode;
 693         if (!inode) {
 694                 CERROR("trying to destroy negative inode "LPX64"!\n", oa->o_id);
 695                 GOTO(out, rc = -ENOENT);
 696         }
 697
 698         if (inode->i_nlink != 1) {
 699                 CERROR("destroying inode with nlink = %d\n", inode->i_nlink);
 700                 LBUG();
 701                 inode->i_nlink = 1;
 702         }
 703         inode->i_mode = S_IFREG;
 704
 705         if (atomic_read(&inode->i_count) > 1) {
 706 #warning FIXME: need to handle open-unlinked case and move to hold dir
 707                 CERROR("inode has count %d\n", atomic_read(&inode->i_count));
 708         }
 709
 710         filter = &obd->u.filter;
 711         push_ctxt(&saved, &filter->fo_ctxt, NULL);
 712
 713         rc = vfs_unlink(dir_dentry->d_inode, object_dentry);
 714         pop_ctxt(&saved);
 715         f_dput(object_dentry);
 716
 717         EXIT;
 718 out:
 719         up(&dir_dentry->d_inode->i_sem);
 720         return rc;
 721 }
 722
 723 /* NB count and offset are used for punch, but not truncate */
 724 static int filter_truncate(struct lustre_handle *conn, struct obdo *oa,
 725                            struct lov_stripe_md *md,
 726                            obd_off start, obd_off end)
 727 {
 728         int error;
 729         ENTRY;
 730
 731         if (end != OBD_OBJECT_EOF)
 732                 CERROR("PUNCH not supported, only truncate works\n");
 733
 734         CDEBUG(D_INODE, "calling truncate for object "LPX64", valid = %x, "
 735                "o_size = "LPD64"\n", oa->o_id, oa->o_valid, start);
 736         oa->o_size = start;
 737         error = filter_setattr(conn, oa, NULL);
 738         RETURN(error);
 739 }
 740
 741 static int filter_pgcache_brw(int cmd, struct lustre_handle *conn,
 742                               struct lov_stripe_md *lsm, obd_count oa_bufs,
 743                               struct brw_page *pga, brw_callback_t callback,
 744                               struct io_cb_data *data)
 745 {
 746         struct obd_run_ctxt      saved;
 747         struct super_block      *sb;
 748         int                      pnum;          /* index to pages (bufs) */
 749         unsigned long            retval;
 750         int                      error;
 751         struct file             *file;
 752         struct obd_device       *obd = class_conn2obd(conn);
 753         int pg;
 754         ENTRY;
 755
 756         if (!obd) {
 757                 CDEBUG(D_IOCTL, "invalid client "LPX64"\n", conn->addr);
 758                 RETURN(-EINVAL);
 759         }
 760
 761         sb = obd->u.filter.fo_sb;
 762         push_ctxt(&saved, &obd->u.filter.fo_ctxt, NULL);
 763         pnum = 0; /* pnum indexes buf 0..num_pages */
 764
 765         file = filter_obj_open(obd, lsm->lsm_object_id, S_IFREG);
 766         if (IS_ERR(file))
 767                 GOTO(out, retval = PTR_ERR(file));
 768
 769         /* count doubles as retval */
 770         for (pg = 0; pg < oa_bufs; pg++) {
 771                 CDEBUG(D_INODE, "OP %d obdo pgno: (%d) (%ld,"LPU64
 772                        ") off count ("LPU64",%d)\n",
 773                        cmd, pnum, file->f_dentry->d_inode->i_ino,
 774                        pga[pnum].off >> PAGE_CACHE_SHIFT, pga[pnum].off,
 775                        (int)pga[pnum].count);
 776                 if (cmd & OBD_BRW_WRITE) {
 777                         loff_t off;
 778                         char *buffer;
 779                         off = pga[pnum].off;
 780                         buffer = kmap(pga[pnum].pg);
 781                         retval = file->f_op->write(file, buffer,
 782                                                    pga[pnum].count,
 783                                                    &off);
 784                         kunmap(pga[pnum].pg);
 785                         CDEBUG(D_INODE, "retval %ld\n", retval);
 786                 } else {
 787                         loff_t off = pga[pnum].off;
 788                         char *buffer = kmap(pga[pnum].pg);
 789
 790                         if (off >= file->f_dentry->d_inode->i_size) {
 791                                 memset(buffer, 0, pga[pnum].count);
 792                                 retval = pga[pnum].count;
 793                         } else {
 794                                 retval = file->f_op->read(file, buffer,
 795                                                           pga[pnum].count, &off);
 796                         }
 797                         kunmap(pga[pnum].pg);
 798
 799                         if (retval != pga[pnum].count) {
 800                                 filp_close(file, 0);
 801                                 GOTO(out, retval = -EIO);
 802                         }
 803                         CDEBUG(D_INODE, "retval %ld\n", retval);
 804                 }
 805                 pnum++;
 806         }
 807         /* sizes and blocks are set by generic_file_write */
 808         /* ctimes/mtimes will follow with a setattr call */
 809         filp_close(file, 0);
 810
 811         /* XXX: do something with callback if it is set? */
 812
 813         EXIT;
 814 out:
 815         pop_ctxt(&saved);
 816         error = (retval >= 0) ? 0 : retval;
 817         return error;
 818 }
 819
 820 /*
 821  * Calculate the number of buffer credits needed to write multiple pages in
 822  * a single ext3/extN transaction.  No, this shouldn't be here, but as yet
 823  * ext3 doesn't have a nice API for calculating this sort of thing in advance.
 824  *
 825  * See comment above ext3_writepage_trans_blocks for details.  We assume
 826  * no data journaling is being done, but it does allow for all of the pages
 827  * being non-contiguous.  If we are guaranteed contiguous pages we could
 828  * reduce the number of (d)indirect blocks a lot.
 829  *
 830  * With N blocks per page and P pages, for each inode we have at most:
 831  * N*P indirect
 832  * min(N*P, blocksize/4 + 1) dindirect blocks
 833  * 1 tindirect
 834  *
 835  * For the entire filesystem, we have at most:
 836  * min(sum(nindir + P), ngroups) bitmap blocks (from the above)
 837  * min(sum(nindir + P), gdblocks) group descriptor blocks (from the above)
 838  * 1 inode block
 839  * 1 superblock
 840  * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quota files
 841  */
 842 static int ext3_credits_needed(struct super_block *sb, int objcount,
 843                                struct obd_ioobj *obj)
 844 {
 845         struct obd_ioobj *o = obj;
 846         int blockpp = 1 << (PAGE_CACHE_SHIFT - sb->s_blocksize_bits);
 847         int addrpp = EXT3_ADDR_PER_BLOCK(sb) * blockpp;
 848         int nbitmaps = 0;
 849         int ngdblocks = 0;
 850         int needed = objcount + 1;
 851         int i;
 852
 853         for (i = 0; i < objcount; i++, o++) {
 854                 int nblocks = o->ioo_bufcnt * blockpp;
 855                 int ndindirect = min(nblocks, addrpp + 1);
 856                 int nindir = nblocks + ndindirect + 1;
 857
 858                 nbitmaps += nindir + nblocks;
 859                 ngdblocks += nindir + nblocks;
 860
 861                 needed += nindir;
 862         }
 863
 864         /* Assumes ext3 and extN have same sb_info layout at the start. */
 865         if (nbitmaps > EXT3_SB(sb)->s_groups_count)
 866                 nbitmaps = EXT3_SB(sb)->s_groups_count;
 867         if (ngdblocks > EXT3_SB(sb)->s_gdb_count)
 868                 ngdblocks = EXT3_SB(sb)->s_gdb_count;
 869
 870         needed += nbitmaps + ngdblocks;
 871
 872 #ifdef CONFIG_QUOTA
 873         /* We assume that there will be 1 bit set in s_dquot.flags for each
 874          * quota file that is active.  This is at least true for now.
 875          */
 876         needed += hweight32(sb_any_quota_enabled(sb)) *
 877                 EXT3_SINGLEDATA_TRANS_BLOCKS;
 878 #endif
 879
 880         return needed;
 881 }
 882
 883 /* We have to start a huge journal transaction here to hold all of the
 884  * metadata for the pages being written here.  This is necessitated by
 885  * the fact that we do lots of prepare_write operations before we do
 886  * any of the matching commit_write operations, so even if we split
 887  * up to use "smaller" transactions none of them could complete until
 888  * all of them were opened.  By having a single journal transaction,
 889  * we eliminate duplicate reservations for common blocks like the
 890  * superblock and group descriptors or bitmaps.
 891  *
 892  * We will start the transaction here, but each prepare_write will
 893  * add a refcount to the transaction, and each commit_write will
 894  * remove a refcount.  The transaction will be closed when all of
 895  * the pages have been written.
 896  */
 897 static void *ext3_filter_journal_start(struct filter_obd *filter,
 898                                        int objcount, struct obd_ioobj *obj,
 899                                        int niocount, struct niobuf_remote *nb)
 900 {
 901         journal_t *journal = NULL;
 902         handle_t *handle = NULL;
 903         int needed;
 904
 905         /* It appears that some kernels have different values for
 906          * EXT*_MAX_GROUP_LOADED (either 8 or 32), so we cannot
 907          * assume anything after s_inode_bitmap_number is the same.
 908          */
 909         if (!strcmp(filter->fo_fstype, "ext3"))
 910                 journal = EXT3_SB(filter->fo_sb)->s_journal;
 911 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
 912         else if (!strcmp(filter->fo_fstype, "extN"))
 913                 journal = EXTN_SB(filter->fo_sb)->s_journal;
 914 #endif
 915         needed = ext3_credits_needed(filter->fo_sb, objcount, obj);
 916
 917         /* The number of blocks we could _possibly_ dirty can very large.
 918          * We reduce our request if it is absurd (and we couldn't get that
 919          * many credits for a single handle anyways).
 920          *
 921          * At some point we have to limit the size of I/Os sent at one time,
 922          * increase the size of the journal, or we have to calculate the
 923          * actual journal requirements more carefully by checking all of
 924          * the blocks instead of being maximally pessimistic.  It remains to
 925          * be seen if this is a real problem or not.
 926          */
 927         if (needed > journal->j_max_transaction_buffers) {
 928                 CERROR("want too many journal credits (%d) using %d instead\n",
 929                        needed, journal->j_max_transaction_buffers);
 930                 needed = journal->j_max_transaction_buffers;
 931         }
 932
 933         lock_kernel();
 934         handle = journal_start(journal, needed);
 935         unlock_kernel();
 936         if (IS_ERR(handle))
 937                 CERROR("can't get handle for %d credits: rc = %ld\n", needed,
 938                        PTR_ERR(handle));
 939
 940         return(handle);
 941 }
 942
 943 static void *filter_journal_start(void **journal_save,
 944                                   struct filter_obd *filter,
 945                                   int objcount, struct obd_ioobj *obj,
 946                                   int niocount, struct niobuf_remote *nb)
 947 {
 948         void *handle = NULL;
 949
 950         /* This may not be necessary - we probably never have a
 951          * transaction started when we enter here, so we can
 952          * remove the saving of the journal state entirely.
 953          * For now leave it in just to see if it ever happens.
 954          */
 955         *journal_save = current->journal_info;
 956         if (*journal_save) {
 957                 CERROR("Already have handle %p???\n", *journal_save);
 958                 LBUG();
 959                 current->journal_info = NULL;
 960         }
 961
 962         if (!strcmp(filter->fo_fstype, "ext3") ||
 963             !strcmp(filter->fo_fstype, "extN"))
 964                 handle = ext3_filter_journal_start(filter, objcount, obj,
 965                                                    niocount, nb);
 966         return handle;
 967 }
 968
 969 static int ext3_filter_journal_stop(void *handle)
 970 {
 971         int rc;
 972
 973         /* We got a refcount on the handle for each call to prepare_write,
 974          * so we can drop the "parent" handle here to avoid the need for
 975          * osc to call back into filterobd to close the handle.  The
 976          * remaining references will be dropped in commit_write.
 977          */
 978         lock_kernel();
 979         rc = journal_stop((handle_t *)handle);
 980         unlock_kernel();
 981
 982         return rc;
 983 }
 984
 985 static int filter_journal_stop(void *journal_save, struct filter_obd *filter,
 986                                void *handle)
 987 {
 988         int rc = 0;
 989
 990         if (!strcmp(filter->fo_fstype, "ext3") ||
 991             !strcmp(filter->fo_fstype, "extN"))
 992                 rc = ext3_filter_journal_stop(handle);
 993
 994         if (rc)
 995                 CERROR("error on journal stop: rc = %d\n", rc);
 996
 997         current->journal_info = journal_save;
 998
 999         return rc;
1000 }
1001
1002 static inline void lustre_put_page(struct page *page)
1003 {
1004         kunmap(page);
1005         page_cache_release(page);
1006 }
1007
1008
1009 #ifndef PageUptodate
1010 #define PageUptodate(page) Page_Uptodate(page)
1011 #endif
1012 static struct page *
1013 lustre_get_page_read(struct inode *inode,
1014                      struct niobuf_remote *rnb)
1015 {
1016         unsigned long index = rnb->offset >> PAGE_SHIFT;
1017         struct address_space *mapping = inode->i_mapping;
1018         struct page *page;
1019         int rc;
1020
1021         page = read_cache_page(mapping, index,
1022                                (filler_t*)mapping->a_ops->readpage, NULL);
1023         if (!IS_ERR(page)) {
1024                 wait_on_page(page);
1025                 kmap(page);
1026                 if (!PageUptodate(page)) {
1027                         CERROR("page index %lu not uptodate\n", index);
1028                         GOTO(err_page, rc = -EIO);
1029                 }
1030                 if (PageError(page)) {
1031                         CERROR("page index %lu has error\n", index);
1032                         GOTO(err_page, rc = -EIO);
1033                 }
1034         }
1035         return page;
1036
1037 err_page:
1038         lustre_put_page(page);
1039         return ERR_PTR(rc);
1040 }
1041
1042 static struct page *
1043 lustre_get_page_write(struct inode *inode, unsigned long index)
1044 {
1045         struct address_space *mapping = inode->i_mapping;
1046         struct page *page;
1047         int rc;
1048
1049         page = grab_cache_page(mapping, index); /* locked page */
1050
1051         if (!IS_ERR(page)) {
1052                 kmap(page);
1053                 /* Note: Called with "O" and "PAGE_SIZE" this is essentially
1054                  * a no-op for most filesystems, because we write the whole
1055                  * page.  For partial-page I/O this will read in the page.
1056                  */
1057                 rc = mapping->a_ops->prepare_write(NULL, page, 0, PAGE_SIZE);
1058                 if (rc) {
1059                         CERROR("page index %lu, rc = %d\n", index, rc);
1060                         if (rc != -ENOSPC)
1061                                 LBUG();
1062                         GOTO(err_unlock, rc);
1063                 }
1064                 /* XXX not sure if we need this if we are overwriting page */
1065                 if (PageError(page)) {
1066                         CERROR("error on page index %lu, rc = %d\n", index, rc);
1067                         LBUG();
1068                         GOTO(err_unlock, rc = -EIO);
1069                 }
1070         }
1071         return page;
1072
1073 err_unlock:
1074         unlock_page(page);
1075         lustre_put_page(page);
1076         return ERR_PTR(rc);
1077 }
1078
1079 static int lustre_commit_write(struct page *page, unsigned from, unsigned to)
1080 {
1081         struct inode *inode = page->mapping->host;
1082         int err;
1083
1084         err = page->mapping->a_ops->commit_write(NULL, page, from, to);
1085 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
1086         if (!err && IS_SYNC(inode))
1087                 err = waitfor_one_page(page);
1088 #else
1089 #warning ADD 2.5 waiting code here?
1090 #endif
1091         //SetPageUptodate(page); // the client commit_write will do this
1092
1093         SetPageReferenced(page);
1094         unlock_page(page);
1095         lustre_put_page(page);
1096         return err;
1097 }
1098
1099 struct page *filter_get_page_write(struct inode *inode,
1100                                    struct niobuf_remote *rnb,
1101                                    struct niobuf_local *lnb, int *pglocked)
1102 {
1103         unsigned long index = rnb->offset >> PAGE_SHIFT;
1104         struct address_space *mapping = inode->i_mapping;
1105
1106         struct page *page;
1107         int rc;
1108
1109         //ASSERT_PAGE_INDEX(index, GOTO(err, rc = -EINVAL));
1110         if (*pglocked)
1111                 page = grab_cache_page_nowait(mapping, index); /* locked page */
1112         else
1113                 page = grab_cache_page(mapping, index); /* locked page */
1114
1115
1116         /* This page is currently locked, so get a temporary page instead. */
1117         /* XXX I believe this is a very dangerous thing to do - consider if
1118          *     we had multiple writers for the same file (definitely the case
1119          *     if we are using this codepath).  If writer A locks the page,
1120          *     writer B writes to a copy (as here), writer A drops the page
1121          *     lock, and writer C grabs the lock before B does, then B will
1122          *     later overwrite the data from C, even if C had LDLM locked
1123          *     and initiated the write after B did.
1124          */
1125         if (!page) {
1126                 unsigned long addr;
1127                 CDEBUG(D_PAGE, "ino %ld page %ld locked\n", inode->i_ino,index);
1128                 addr = __get_free_pages(GFP_KERNEL, 0); /* locked page */
1129                 if (!addr) {
1130                         CERROR("no memory for a temp page\n");
1131                         LBUG();
1132                         GOTO(err, rc = -ENOMEM);
1133                 }
1134                 /* XXX debugging */
1135                 memset((void *)addr, 0xBA, PAGE_SIZE);
1136                 page = virt_to_page(addr);
1137                 kmap(page);
1138                 page->index = index;
1139                 lnb->flags |= N_LOCAL_TEMP_PAGE;
1140         } else if (!IS_ERR(page)) {
1141                 (*pglocked)++;
1142                 kmap(page);
1143
1144                 rc = mapping->a_ops->prepare_write(NULL, page,
1145                                                    rnb->offset % PAGE_SIZE,
1146                                                    rnb->len);
1147                 if (rc) {
1148                         CERROR("page index %lu, rc = %d\n", index, rc);
1149                         if (rc != -ENOSPC)
1150                                 LBUG();
1151                         GOTO(err_unlock, rc);
1152                 }
1153                 /* XXX not sure if we need this if we are overwriting page */
1154                 if (PageError(page)) {
1155                         CERROR("error on page index %lu, rc = %d\n", index, rc);
1156                         LBUG();
1157                         GOTO(err_unlock, rc = -EIO);
1158                 }
1159         }
1160         return page;
1161
1162 err_unlock:
1163         unlock_page(page);
1164         lustre_put_page(page);
1165 err:
1166         return ERR_PTR(rc);
1167 }
1168
1169 /*
1170  * We need to balance prepare_write() calls with commit_write() calls.
1171  * If the page has been prepared, but we have no data for it, we don't
1172  * want to overwrite valid data on disk, but we still need to zero out
1173  * data for space which was newly allocated.  Like part of what happens
1174  * in __block_prepare_write() for newly allocated blocks.
1175  *
1176  * XXX currently __block_prepare_write() creates buffers for all the
1177  *     pages, and the filesystems mark these buffers as BH_New if they
1178  *     were newly allocated from disk. We use the BH_New flag similarly.
1179  */
1180 static int filter_commit_write(struct page *page, unsigned from, unsigned to,
1181                                int err)
1182 {
1183 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
1184         if (err) {
1185                 unsigned block_start, block_end;
1186                 struct buffer_head *bh, *head = page->buffers;
1187                 unsigned blocksize = head->b_size;
1188                 void *addr = page_address(page);
1189
1190                 /* debugging: just seeing if this ever happens */
1191                 CERROR("called filter_commit_write for obj %ld:%ld on err %d\n",
1192                        page->index, page->mapping->host->i_ino, err);
1193
1194                 /* Currently one buffer per page, but in the future... */
1195                 for (bh = head, block_start = 0; bh != head || !block_start;
1196                      block_start = block_end, bh = bh->b_this_page) {
1197                         block_end = block_start + blocksize;
1198                         if (buffer_new(bh))
1199                                 memset(addr + block_start, 0, blocksize);
1200                 }
1201         }
1202 #endif
1203         return lustre_commit_write(page, from, to);
1204 }
1205
1206 static int filter_preprw(int cmd, struct lustre_handle *conn,
1207                          int objcount, struct obd_ioobj *obj,
1208                          int niocount, struct niobuf_remote *nb,
1209                          struct niobuf_local *res, void **desc_private)
1210 {
1211         struct obd_run_ctxt saved;
1212         struct obd_device *obd;
1213         struct obd_ioobj *o = obj;
1214         struct niobuf_remote *rnb = nb;
1215         struct niobuf_local *lnb = res;
1216         void *journal_save = NULL;
1217         int pglocked = 0;
1218         int rc = 0;
1219         int i;
1220         ENTRY;
1221
1222         obd = class_conn2obd(conn);
1223         if (!obd) {
1224                 CDEBUG(D_IOCTL, "invalid client "LPX64"\n", conn->addr);
1225                 RETURN(-EINVAL);
1226         }
1227         memset(res, 0, sizeof(*res) * niocount);
1228
1229         push_ctxt(&saved, &obd->u.filter.fo_ctxt, NULL);
1230
1231         if (cmd & OBD_BRW_WRITE) {
1232                 *desc_private = filter_journal_start(&journal_save,
1233                                                      &obd->u.filter,
1234                                                      objcount, obj, niocount,
1235                                                      nb);
1236                 if (IS_ERR(*desc_private))
1237                         GOTO(out_ctxt, rc = PTR_ERR(*desc_private));
1238         }
1239
1240         for (i = 0; i < objcount; i++, o++) {
1241                 struct dentry *dentry;
1242                 struct inode *inode;
1243                 int j;
1244
1245                 dentry = filter_fid2dentry(obd, filter_parent(obd, S_IFREG),
1246                                            o->ioo_id, S_IFREG);
1247                 if (IS_ERR(dentry))
1248                         GOTO(out_clean, rc = PTR_ERR(dentry));
1249                 inode = dentry->d_inode;
1250                 if (!inode) {
1251                         CERROR("trying to BRW to non-existent file "LPU64"\n",
1252                                o->ioo_id);
1253                         f_dput(dentry);
1254                         GOTO(out_clean, rc = -ENOENT);
1255                 }
1256
1257                 for (j = 0; j < o->ioo_bufcnt; j++, rnb++, lnb++) {
1258                         struct page *page;
1259
1260                         if (j == 0)
1261                                 lnb->dentry = dentry;
1262                         else
1263                                 lnb->dentry = dget(dentry);
1264
1265                         if (cmd & OBD_BRW_WRITE)
1266                                 page = filter_get_page_write(inode, rnb, lnb,
1267                                                              &pglocked);
1268                         else
1269                                 page = lustre_get_page_read(inode, rnb);
1270
1271                         if (IS_ERR(page)) {
1272                                 f_dput(dentry);
1273                                 GOTO(out_clean, rc = PTR_ERR(page));
1274                         }
1275
1276                         lnb->addr = page_address(page);
1277                         lnb->offset = rnb->offset;
1278                         lnb->page = page;
1279                         lnb->len = rnb->len;
1280                 }
1281         }
1282
1283 out_stop:
1284         if (cmd & OBD_BRW_WRITE) {
1285                 int err = filter_journal_stop(journal_save, &obd->u.filter,
1286                                               *desc_private);
1287                 if (!rc)
1288                         rc = err;
1289         }
1290 out_ctxt:
1291         pop_ctxt(&saved);
1292         RETURN(rc);
1293 out_clean:
1294         while (lnb-- > res) {
1295                 CERROR("error cleanup on brw\n");
1296                 f_dput(lnb->dentry);
1297                 if (cmd & OBD_BRW_WRITE)
1298                         filter_commit_write(lnb->page, 0, PAGE_SIZE, rc);
1299                 else
1300                         lustre_put_page(lnb->page);
1301         }
1302         goto out_stop;
1303 }
1304
1305 static int filter_write_locked_page(struct niobuf_local *lnb)
1306 {
1307         struct page *lpage;
1308         int rc;
1309
1310         lpage = lustre_get_page_write(lnb->dentry->d_inode, lnb->page->index);
1311         if (IS_ERR(lpage)) {
1312                 /* It is highly unlikely that we would ever get an error here.
1313                  * The page we want to get was previously locked, so it had to
1314                  * have already allocated the space, and we were just writing
1315                  * over the same data, so there would be no hole in the file.
1316                  *
1317                  * XXX: possibility of a race with truncate could exist, need
1318                  *      to check that.  There are no guarantees w.r.t.
1319                  *      write order even on a local filesystem, although the
1320                  *      normal response would be to return the number of bytes
1321                  *      successfully written and leave the rest to the app.
1322                  */
1323                 rc = PTR_ERR(lpage);
1324                 CERROR("error getting locked page index %ld: rc = %d\n",
1325                        lnb->page->index, rc);
1326                 GOTO(out, rc);
1327         }
1328
1329         /* lpage is kmapped in lustre_get_page_write() above and kunmapped in
1330          * lustre_commit_write() below, lnb->page was kmapped previously in
1331          * filter_get_page_write() and kunmapped in lustre_put_page() below.
1332          */
1333         memcpy(page_address(lpage), page_address(lnb->page), PAGE_SIZE);
1334         rc = lustre_commit_write(lpage, 0, PAGE_SIZE);
1335         if (rc)
1336                 CERROR("error committing locked page %ld: rc = %d\n",
1337                        lnb->page->index, rc);
1338 out:
1339         lustre_put_page(lnb->page);
1340
1341         return rc;
1342 }
1343
1344 static int filter_commitrw(int cmd, struct lustre_handle *conn,
1345                            int objcount, struct obd_ioobj *obj,
1346                            int niocount, struct niobuf_local *res,
1347                            void *private)
1348 {
1349         struct obd_run_ctxt saved;
1350         struct obd_ioobj *o;
1351         struct niobuf_local *r;
1352         struct obd_device *obd = class_conn2obd(conn);
1353         void *journal_save;
1354         int found_locked = 0;
1355         int rc = 0;
1356         int i;
1357         ENTRY;
1358
1359         push_ctxt(&saved, &obd->u.filter.fo_ctxt, NULL);
1360         journal_save = current->journal_info;
1361         LASSERT(!journal_save);
1362
1363         current->journal_info = private;
1364         for (i = 0, o = obj, r = res; i < objcount; i++, o++) {
1365                 int j;
1366                 for (j = 0 ; j < o->ioo_bufcnt ; j++, r++) {
1367                         struct page *page = r->page;
1368
1369                         if (!page)
1370                                 LBUG();
1371
1372                         if (r->flags & N_LOCAL_TEMP_PAGE) {
1373                                 found_locked++;
1374                                 continue;
1375                         }
1376
1377                         if (cmd & OBD_BRW_WRITE) {
1378                                 int err = filter_commit_write(page, 0,
1379                                                               r->len, 0);
1380
1381                                 if (!rc)
1382                                         rc = err;
1383                         } else
1384                                 lustre_put_page(page);
1385
1386                         f_dput(r->dentry);
1387                 }
1388         }
1389         current->journal_info = journal_save;
1390
1391         if (!found_locked)
1392                 goto out_ctxt;
1393
1394         for (i = 0, o = obj, r = res; i < objcount; i++, o++) {
1395                 int j;
1396                 for (j = 0 ; j < o->ioo_bufcnt ; j++, r++) {
1397                         int err;
1398                         if (!(r->flags & N_LOCAL_TEMP_PAGE))
1399                                 continue;
1400
1401                         err = filter_write_locked_page(r);
1402                         if (!rc)
1403                                 rc = err;
1404                         f_dput(r->dentry);
1405                 }
1406         }
1407
1408 out_ctxt:
1409         pop_ctxt(&saved);
1410         RETURN(rc);
1411 }
1412
1413 static int filter_statfs(struct lustre_handle *conn, struct obd_statfs *osfs)
1414 {
1415         struct obd_device *obd = class_conn2obd(conn);
1416         struct statfs sfs;
1417         int rc;
1418
1419         ENTRY;
1420         rc = vfs_statfs(obd->u.filter.fo_sb, &sfs);
1421         if (!rc)
1422                 statfs_pack(osfs, &sfs);
1423
1424         return rc;
1425 }
1426
1427 static int filter_get_info(struct lustre_handle *conn, obd_count keylen,
1428                            void *key, obd_count *vallen, void **val)
1429 {
1430         struct obd_device *obd;
1431         ENTRY;
1432
1433         obd = class_conn2obd(conn);
1434         if (!obd) {
1435                 CDEBUG(D_IOCTL, "invalid client "LPX64"\n", conn->addr);
1436                 RETURN(-EINVAL);
1437         }
1438
1439         if ( keylen == strlen("blocksize") &&
1440              memcmp(key, "blocksize", keylen) == 0 ) {
1441                 *vallen = sizeof(long);
1442                 *val = (void *)(long)obd->u.filter.fo_sb->s_blocksize;
1443                 RETURN(0);
1444         }
1445
1446         if ( keylen == strlen("blocksize_bits") &&
1447              memcmp(key, "blocksize_bits", keylen) == 0 ){
1448                 *vallen = sizeof(long);
1449                 *val = (void *)(long)obd->u.filter.fo_sb->s_blocksize_bits;
1450                 RETURN(0);
1451         }
1452
1453         if ( keylen == strlen("root_ino") &&
1454              memcmp(key, "root_ino", keylen) == 0 ){
1455                 *vallen = sizeof(obd_id);
1456                 *val = (void *)(obd_id)FILTER_ROOTINO;
1457                 RETURN(0);
1458         }
1459
1460         CDEBUG(D_IOCTL, "invalid key\n");
1461         RETURN(-EINVAL);
1462 }
1463
1464 int filter_copy_data(struct lustre_handle *dst_conn, struct obdo *dst,
1465                   struct lustre_handle *src_conn, struct obdo *src,
1466                   obd_size count, obd_off offset)
1467 {
1468         struct page *page;
1469         struct lov_stripe_md srcmd, dstmd;
1470         unsigned long index = 0;
1471         int err = 0;
1472
1473         memset(&srcmd, 0, sizeof(srcmd));
1474         memset(&dstmd, 0, sizeof(dstmd));
1475         srcmd.lsm_object_id = src->o_id;
1476         dstmd.lsm_object_id = dst->o_id;
1477
1478         ENTRY;
1479         CDEBUG(D_INFO, "src: ino "LPU64" blocks "LPU64", size "LPU64
1480                ", dst: ino "LPU64"\n",
1481                src->o_id, src->o_blocks, src->o_size, dst->o_id);
1482         page = alloc_page(GFP_USER);
1483         if (page == NULL)
1484                 RETURN(-ENOMEM);
1485
1486 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,5,0))
1487         while (TryLockPage(page))
1488                 ___wait_on_page(page);
1489 #else
1490         wait_on_page_locked(page);
1491 #endif
1492
1493         /* XXX with brw vector I/O, we could batch up reads and writes here,
1494          *     all we need to do is allocate multiple pages to handle the I/Os
1495          *     and arrays to handle the request parameters.
1496          */
1497         while (index < ((src->o_size + PAGE_SIZE - 1) >> PAGE_SHIFT)) {
1498                 struct brw_page pg;
1499                 struct io_cb_data *cbd = ll_init_cb();
1500
1501                 if (!cbd) {
1502                         err = -ENOMEM;
1503                         EXIT;
1504                         break;
1505                 }
1506
1507                 pg.pg = page;
1508                 pg.count = PAGE_SIZE;
1509                 pg.off = (page->index) << PAGE_SHIFT;
1510                 pg.flag = 0;
1511
1512                 page->index = index;
1513                 err = obd_brw(OBD_BRW_READ, src_conn, &srcmd, 1, &pg,
1514                               ll_sync_io_cb, cbd);
1515
1516                 if ( err ) {
1517                         EXIT;
1518                         break;
1519                 }
1520
1521                 cbd = ll_init_cb();
1522                 if (!cbd) {
1523                         err = -ENOMEM;
1524                         EXIT;
1525                         break;
1526                 }
1527                 pg.flag = OBD_BRW_CREATE;
1528                 CDEBUG(D_INFO, "Read page %ld ...\n", page->index);
1529
1530                 err = obd_brw(OBD_BRW_WRITE, dst_conn, &dstmd, 1, &pg,
1531                               ll_sync_io_cb, cbd);
1532
1533                 /* XXX should handle dst->o_size, dst->o_blocks here */
1534                 if ( err ) {
1535                         EXIT;
1536                         break;
1537                 }
1538
1539                 CDEBUG(D_INFO, "Wrote page %ld ...\n", page->index);
1540
1541                 index++;
1542         }
1543         dst->o_size = src->o_size;
1544         dst->o_blocks = src->o_blocks;
1545         dst->o_valid |= OBD_MD_FLSIZE | OBD_MD_FLBLOCKS;
1546         unlock_page(page);
1547         __free_page(page);
1548
1549         RETURN(err);
1550 }
1551
1552
1553 static struct obd_ops filter_obd_ops = {
1554         o_get_info:    filter_get_info,
1555         o_setup:       filter_setup,
1556         o_cleanup:     filter_cleanup,
1557         o_connect:     filter_connect,
1558         o_disconnect:  filter_disconnect,
1559         o_statfs:      filter_statfs,
1560         o_getattr:     filter_getattr,
1561         o_create:      filter_create,
1562         o_setattr:     filter_setattr,
1563         o_destroy:     filter_destroy,
1564         o_open:        filter_open,
1565         o_close:       filter_close,
1566         o_brw:         filter_pgcache_brw,
1567         o_punch:       filter_truncate,
1568         o_preprw:      filter_preprw,
1569         o_commitrw:    filter_commitrw
1570 #if 0
1571         o_preallocate: filter_preallocate_inodes,
1572         o_migrate:     filter_migrate,
1573         o_copy:        filter_copy_data,
1574         o_iterate:     filter_iterate
1575 #endif
1576 };
1577
1578
1579 static int __init obdfilter_init(void)
1580 {
1581         printk(KERN_INFO "Filtering OBD driver  v0.001, info@clusterfs.com\n");
1582         return class_register_type(&filter_obd_ops, OBD_FILTER_DEVICENAME);
1583 }
1584
1585 static void __exit obdfilter_exit(void)
1586 {
1587         class_unregister_type(OBD_FILTER_DEVICENAME);
1588 }
1589
1590 MODULE_AUTHOR("Cluster File Systems, Inc. <info@clusterfs.com>");
1591 MODULE_DESCRIPTION("Lustre Filtering OBD driver v1.0");
1592 MODULE_LICENSE("GPL");
1593
1594 module_init(obdfilter_init);
1595 module_exit(obdfilter_exit);