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