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