lustre/lvfs/lvfs_linux.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Whamcloud, Inc.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/lvfs/lvfs_linux.c
  37  *
  38  * Author: Andreas Dilger <adilger@clusterfs.com>
  39  */
  40
  41 #ifndef EXPORT_SYMTAB
  42 # define EXPORT_SYMTAB
  43 #endif
  44
  45 #define DEBUG_SUBSYSTEM S_FILTER
  46
  47 #include <linux/version.h>
  48 #include <linux/fs.h>
  49 #include <asm/unistd.h>
  50 #include <linux/slab.h>
  51 #include <linux/pagemap.h>
  52 #include <linux/quotaops.h>
  53 #include <linux/version.h>
  54 #include <libcfs/libcfs.h>
  55 #include <lustre_fsfilt.h>
  56 #include <obd.h>
  57 #include <linux/module.h>
  58 #include <linux/init.h>
  59 #include <linux/lustre_compat25.h>
  60 #include <lvfs.h>
  61 #include "lvfs_internal.h"
  62
  63 #include <obd.h>
  64 #include <lustre_lib.h>
  65 #include <lustre_quota.h>
  66
  67 __u64 obd_max_pages = 0;
  68 __u64 obd_max_alloc = 0;
  69 struct lprocfs_stats *obd_memory = NULL;
  70 cfs_spinlock_t obd_updatemax_lock = CFS_SPIN_LOCK_UNLOCKED;
  71 /* refine later and change to seqlock or simlar from libcfs */
  72
  73 /* Debugging check only needed during development */
  74 #ifdef OBD_CTXT_DEBUG
  75 # define ASSERT_CTXT_MAGIC(magic) LASSERT((magic) == OBD_RUN_CTXT_MAGIC)
  76 # define ASSERT_NOT_KERNEL_CTXT(msg) LASSERTF(!segment_eq(get_fs(), get_ds()),\
  77                                               msg)
  78 # define ASSERT_KERNEL_CTXT(msg) LASSERTF(segment_eq(get_fs(), get_ds()), msg)
  79 #else
  80 # define ASSERT_CTXT_MAGIC(magic) do {} while(0)
  81 # define ASSERT_NOT_KERNEL_CTXT(msg) do {} while(0)
  82 # define ASSERT_KERNEL_CTXT(msg) do {} while(0)
  83 #endif
  84
  85 static void push_group_info(struct lvfs_run_ctxt *save,
  86                             struct group_info *ginfo)
  87 {
  88         if (!ginfo) {
  89                 save->ngroups = current_ngroups;
  90                 current_ngroups = 0;
  91         } else {
  92                 struct cred *cred;
  93                 task_lock(current);
  94                 save->group_info = current_cred()->group_info;
  95                 if ((cred = prepare_creds())) {
  96                         cred->group_info = ginfo;
  97                         commit_creds(cred);
  98                 }
  99                 task_unlock(current);
 100         }
 101 }
 102
 103 static void pop_group_info(struct lvfs_run_ctxt *save,
 104                            struct group_info *ginfo)
 105 {
 106         if (!ginfo) {
 107                 current_ngroups = save->ngroups;
 108         } else {
 109                 struct cred *cred;
 110                 task_lock(current);
 111                 if ((cred = prepare_creds())) {
 112                         cred->group_info = save->group_info;
 113                         commit_creds(cred);
 114                 }
 115                 task_unlock(current);
 116         }
 117 }
 118
 119 /* push / pop to root of obd store */
 120 void push_ctxt(struct lvfs_run_ctxt *save, struct lvfs_run_ctxt *new_ctx,
 121                struct lvfs_ucred *uc)
 122 {
 123         //ASSERT_NOT_KERNEL_CTXT("already in kernel context!\n");
 124         ASSERT_CTXT_MAGIC(new_ctx->magic);
 125         OBD_SET_CTXT_MAGIC(save);
 126
 127         save->fs = get_fs();
 128         LASSERT(cfs_atomic_read(&cfs_fs_pwd(current->fs)->d_count));
 129         LASSERT(cfs_atomic_read(&new_ctx->pwd->d_count));
 130         save->pwd = dget(cfs_fs_pwd(current->fs));
 131         save->pwdmnt = mntget(cfs_fs_mnt(current->fs));
 132         save->luc.luc_umask = cfs_curproc_umask();
 133         save->ngroups = current_cred()->group_info->ngroups;
 134
 135         LASSERT(save->pwd);
 136         LASSERT(save->pwdmnt);
 137         LASSERT(new_ctx->pwd);
 138         LASSERT(new_ctx->pwdmnt);
 139
 140         if (uc) {
 141                 struct cred *cred;
 142                 save->luc.luc_uid = current_uid();
 143                 save->luc.luc_gid = current_gid();
 144                 save->luc.luc_fsuid = current_fsuid();
 145                 save->luc.luc_fsgid = current_fsgid();
 146                 save->luc.luc_cap = current_cap();
 147
 148                 if ((cred = prepare_creds())) {
 149                         cred->uid = uc->luc_uid;
 150                         cred->gid = uc->luc_gid;
 151                         cred->fsuid = uc->luc_fsuid;
 152                         cred->fsgid = uc->luc_fsgid;
 153                         cred->cap_effective = uc->luc_cap;
 154                         commit_creds(cred);
 155                 }
 156
 157                 push_group_info(save,
 158                                 uc->luc_ginfo ?:
 159                                 uc->luc_identity ? uc->luc_identity->mi_ginfo :
 160                                                    NULL);
 161         }
 162         current->fs->umask = 0; /* umask already applied on client */
 163         set_fs(new_ctx->fs);
 164         ll_set_fs_pwd(current->fs, new_ctx->pwdmnt, new_ctx->pwd);
 165 }
 166 EXPORT_SYMBOL(push_ctxt);
 167
 168 void pop_ctxt(struct lvfs_run_ctxt *saved, struct lvfs_run_ctxt *new_ctx,
 169               struct lvfs_ucred *uc)
 170 {
 171         ASSERT_CTXT_MAGIC(saved->magic);
 172         ASSERT_KERNEL_CTXT("popping non-kernel context!\n");
 173
 174         LASSERTF(cfs_fs_pwd(current->fs) == new_ctx->pwd, "%p != %p\n",
 175                  cfs_fs_pwd(current->fs), new_ctx->pwd);
 176         LASSERTF(cfs_fs_mnt(current->fs) == new_ctx->pwdmnt, "%p != %p\n",
 177                  cfs_fs_mnt(current->fs), new_ctx->pwdmnt);
 178
 179         set_fs(saved->fs);
 180         ll_set_fs_pwd(current->fs, saved->pwdmnt, saved->pwd);
 181
 182         dput(saved->pwd);
 183         mntput(saved->pwdmnt);
 184         current->fs->umask = saved->luc.luc_umask;
 185         if (uc) {
 186                 struct cred *cred;
 187                 if ((cred = prepare_creds())) {
 188                         cred->uid = saved->luc.luc_uid;
 189                         cred->gid = saved->luc.luc_gid;
 190                         cred->fsuid = saved->luc.luc_fsuid;
 191                         cred->fsgid = saved->luc.luc_fsgid;
 192                         cred->cap_effective = saved->luc.luc_cap;
 193                         commit_creds(cred);
 194                 }
 195
 196                 pop_group_info(saved,
 197                                uc->luc_ginfo ?:
 198                                uc->luc_identity ? uc->luc_identity->mi_ginfo :
 199                                                   NULL);
 200         }
 201 }
 202 EXPORT_SYMBOL(pop_ctxt);
 203
 204 /* utility to make a file */
 205 struct dentry *simple_mknod(struct dentry *dir, char *name, int mode, int fix)
 206 {
 207         struct dentry *dchild;
 208         int err = 0;
 209         ENTRY;
 210
 211         // ASSERT_KERNEL_CTXT("kernel doing mknod outside kernel context\n");
 212         CDEBUG(D_INODE, "creating file %.*s\n", (int)strlen(name), name);
 213
 214         dchild = ll_lookup_one_len(name, dir, strlen(name));
 215         if (IS_ERR(dchild))
 216                 GOTO(out_up, dchild);
 217
 218         if (dchild->d_inode) {
 219                 int old_mode = dchild->d_inode->i_mode;
 220                 if (!S_ISREG(old_mode))
 221                         GOTO(out_err, err = -EEXIST);
 222
 223                 /* Fixup file permissions if necessary */
 224                 if (fix && (old_mode & S_IALLUGO) != (mode & S_IALLUGO)) {
 225                         CWARN("fixing permissions on %s from %o to %o\n",
 226                               name, old_mode, mode);
 227                         dchild->d_inode->i_mode = (mode & S_IALLUGO) |
 228                                                   (old_mode & ~S_IALLUGO);
 229                         mark_inode_dirty(dchild->d_inode);
 230                 }
 231                 GOTO(out_up, dchild);
 232         }
 233
 234         err = ll_vfs_create(dir->d_inode, dchild, (mode & ~S_IFMT) | S_IFREG,
 235                             NULL);
 236         if (err)
 237                 GOTO(out_err, err);
 238
 239         RETURN(dchild);
 240
 241 out_err:
 242         dput(dchild);
 243         dchild = ERR_PTR(err);
 244 out_up:
 245         return dchild;
 246 }
 247 EXPORT_SYMBOL(simple_mknod);
 248
 249 /* utility to make a directory */
 250 struct dentry *simple_mkdir(struct dentry *dir, struct vfsmount *mnt,
 251                             const char *name, int mode, int fix)
 252 {
 253         struct dentry *dchild;
 254         int err = 0;
 255         ENTRY;
 256
 257         // ASSERT_KERNEL_CTXT("kernel doing mkdir outside kernel context\n");
 258         CDEBUG(D_INODE, "creating directory %.*s\n", (int)strlen(name), name);
 259         dchild = ll_lookup_one_len(name, dir, strlen(name));
 260         if (IS_ERR(dchild))
 261                 GOTO(out_up, dchild);
 262
 263         if (dchild->d_inode) {
 264                 int old_mode = dchild->d_inode->i_mode;
 265                 if (!S_ISDIR(old_mode)) {
 266                         CERROR("found %s (%lu/%u) is mode %o\n", name,
 267                                dchild->d_inode->i_ino,
 268                                dchild->d_inode->i_generation, old_mode);
 269                         GOTO(out_err, err = -ENOTDIR);
 270                 }
 271
 272                 /* Fixup directory permissions if necessary */
 273                 if (fix && (old_mode & S_IALLUGO) != (mode & S_IALLUGO)) {
 274                         CDEBUG(D_CONFIG,
 275                                "fixing permissions on %s from %o to %o\n",
 276                                name, old_mode, mode);
 277                         dchild->d_inode->i_mode = (mode & S_IALLUGO) |
 278                                                   (old_mode & ~S_IALLUGO);
 279                         mark_inode_dirty(dchild->d_inode);
 280                 }
 281                 GOTO(out_up, dchild);
 282         }
 283
 284         err = ll_vfs_mkdir(dir->d_inode, dchild, mnt, mode);
 285         if (err)
 286                 GOTO(out_err, err);
 287
 288         RETURN(dchild);
 289
 290 out_err:
 291         dput(dchild);
 292         dchild = ERR_PTR(err);
 293 out_up:
 294         return dchild;
 295 }
 296 EXPORT_SYMBOL(simple_mkdir);
 297
 298 /* utility to rename a file */
 299 int lustre_rename(struct dentry *dir, struct vfsmount *mnt,
 300                   char *oldname, char *newname)
 301 {
 302         struct dentry *dchild_old, *dchild_new;
 303         int err = 0;
 304         ENTRY;
 305
 306         ASSERT_KERNEL_CTXT("kernel doing rename outside kernel context\n");
 307         CDEBUG(D_INODE, "renaming file %.*s to %.*s\n",
 308                (int)strlen(oldname), oldname, (int)strlen(newname), newname);
 309
 310         dchild_old = ll_lookup_one_len(oldname, dir, strlen(oldname));
 311         if (IS_ERR(dchild_old))
 312                 RETURN(PTR_ERR(dchild_old));
 313
 314         if (!dchild_old->d_inode)
 315                 GOTO(put_old, err = -ENOENT);
 316
 317         dchild_new = ll_lookup_one_len(newname, dir, strlen(newname));
 318         if (IS_ERR(dchild_new))
 319                 GOTO(put_old, err = PTR_ERR(dchild_new));
 320
 321         err = ll_vfs_rename(dir->d_inode, dchild_old, mnt,
 322                             dir->d_inode, dchild_new, mnt);
 323
 324         dput(dchild_new);
 325 put_old:
 326         dput(dchild_old);
 327         RETURN(err);
 328 }
 329 EXPORT_SYMBOL(lustre_rename);
 330
 331 /*
 332  * Read a file from within kernel context.  Prior to calling this
 333  * function we should already have done a push_ctxt().
 334  */
 335 int lustre_fread(struct file *file, void *buf, int len, loff_t *off)
 336 {
 337         ASSERT_KERNEL_CTXT("kernel doing read outside kernel context\n");
 338         if (!file || !file->f_op || !file->f_op->read || !off)
 339                 RETURN(-ENOSYS);
 340
 341         return file->f_op->read(file, buf, len, off);
 342 }
 343 EXPORT_SYMBOL(lustre_fread);
 344
 345 /*
 346  * Write a file from within kernel context.  Prior to calling this
 347  * function we should already have done a push_ctxt().
 348  */
 349 int lustre_fwrite(struct file *file, const void *buf, int len, loff_t *off)
 350 {
 351         ENTRY;
 352         ASSERT_KERNEL_CTXT("kernel doing write outside kernel context\n");
 353         if (!file)
 354                 RETURN(-ENOENT);
 355         if (!file->f_op)
 356                 RETURN(-ENOSYS);
 357         if (!off)
 358                 RETURN(-EINVAL);
 359
 360         if (!file->f_op->write)
 361                 RETURN(-EROFS);
 362
 363         RETURN(file->f_op->write(file, buf, len, off));
 364 }
 365 EXPORT_SYMBOL(lustre_fwrite);
 366
 367 /*
 368  * Sync a file from within kernel context.  Prior to calling this
 369  * function we should already have done a push_ctxt().
 370  */
 371 int lustre_fsync(struct file *file)
 372 {
 373         ENTRY;
 374         ASSERT_KERNEL_CTXT("kernel doing sync outside kernel context\n");
 375         if (!file || !file->f_op || !file->f_op->fsync)
 376                 RETURN(-ENOSYS);
 377
 378         RETURN(cfs_do_fsync(file, 0));
 379 }
 380 EXPORT_SYMBOL(lustre_fsync);
 381
 382 /* Note: dput(dchild) will be called if there is an error */
 383 struct l_file *l_dentry_open(struct lvfs_run_ctxt *ctxt, struct l_dentry *de,
 384                              int flags)
 385 {
 386         mntget(ctxt->pwdmnt);
 387         return ll_dentry_open(de, ctxt->pwdmnt, flags, current_cred());
 388 }
 389 EXPORT_SYMBOL(l_dentry_open);
 390
 391 static int l_filldir(void *__buf, const char *name, int namlen, loff_t offset,
 392                      u64 ino, unsigned int d_type)
 393 {
 394         struct l_linux_dirent *dirent;
 395         struct l_readdir_callback *buf = (struct l_readdir_callback *)__buf;
 396
 397         dirent = buf->lrc_dirent;
 398         if (dirent)
 399                dirent->lld_off = offset;
 400
 401         OBD_ALLOC(dirent, sizeof(*dirent));
 402
 403         if (!dirent)
 404                 return -ENOMEM;
 405
 406         cfs_list_add_tail(&dirent->lld_list, buf->lrc_list);
 407
 408         buf->lrc_dirent = dirent;
 409         dirent->lld_ino = ino;
 410         LASSERT(sizeof(dirent->lld_name) >= namlen + 1);
 411         memcpy(dirent->lld_name, name, namlen);
 412
 413         return 0;
 414 }
 415
 416 long l_readdir(struct file *file, cfs_list_t *dentry_list)
 417 {
 418         struct l_linux_dirent *lastdirent;
 419         struct l_readdir_callback buf;
 420         int error;
 421
 422         buf.lrc_dirent = NULL;
 423         buf.lrc_list = dentry_list;
 424
 425         error = vfs_readdir(file, l_filldir, &buf);
 426         if (error < 0)
 427                 return error;
 428
 429         lastdirent = buf.lrc_dirent;
 430         if (lastdirent)
 431                 lastdirent->lld_off = file->f_pos;
 432
 433         return 0;
 434 }
 435 EXPORT_SYMBOL(l_readdir);
 436
 437 int l_notify_change(struct vfsmount *mnt, struct dentry *dchild,
 438                  struct iattr *newattrs)
 439 {
 440         int rc;
 441
 442         LOCK_INODE_MUTEX(dchild->d_inode);
 443 #ifdef HAVE_SECURITY_PLUG
 444         rc = notify_change(dchild, mnt, newattrs);
 445 #else
 446         rc = notify_change(dchild, newattrs);
 447 #endif
 448         UNLOCK_INODE_MUTEX(dchild->d_inode);
 449         return rc;
 450 }
 451 EXPORT_SYMBOL(l_notify_change);
 452
 453 /* utility to truncate a file */
 454 int simple_truncate(struct dentry *dir, struct vfsmount *mnt,
 455                  char *name, loff_t length)
 456 {
 457         struct dentry *dchild;
 458         struct iattr newattrs;
 459         int err = 0;
 460         ENTRY;
 461
 462         CDEBUG(D_INODE, "truncating file %.*s to %lld\n", (int)strlen(name),
 463                name, (long long)length);
 464         dchild = ll_lookup_one_len(name, dir, strlen(name));
 465         if (IS_ERR(dchild))
 466                 GOTO(out, err = PTR_ERR(dchild));
 467
 468         if (dchild->d_inode) {
 469                 int old_mode = dchild->d_inode->i_mode;
 470                 if (S_ISDIR(old_mode)) {
 471                         CERROR("found %s (%lu/%u) is mode %o\n", name,
 472                                dchild->d_inode->i_ino,
 473                                dchild->d_inode->i_generation, old_mode);
 474                         GOTO(out_dput, err = -EISDIR);
 475                 }
 476
 477                 newattrs.ia_size = length;
 478                 newattrs.ia_valid = ATTR_SIZE;
 479                 err = l_notify_change(mnt, dchild, &newattrs);
 480         }
 481         EXIT;
 482 out_dput:
 483         dput(dchild);
 484 out:
 485         return err;
 486 }
 487 EXPORT_SYMBOL(simple_truncate);
 488
 489 #ifdef LUSTRE_KERNEL_VERSION
 490 int __lvfs_set_rdonly(lvfs_sbdev_type dev, lvfs_sbdev_type jdev)
 491 {
 492 #ifdef HAVE_DEV_SET_RDONLY
 493         if (jdev && (jdev != dev)) {
 494                 CDEBUG(D_IOCTL | D_HA, "set journal dev %lx rdonly\n",
 495                        (long)jdev);
 496                 dev_set_rdonly(jdev);
 497         }
 498         CDEBUG(D_IOCTL | D_HA, "set dev %lx rdonly\n", (long)dev);
 499         dev_set_rdonly(dev);
 500
 501         return 0;
 502 #else
 503         CERROR("DEV %lx CANNOT BE SET READONLY\n", (long)dev);
 504
 505         return -EOPNOTSUPP;
 506 #endif
 507 }
 508 EXPORT_SYMBOL(__lvfs_set_rdonly);
 509
 510 int lvfs_check_rdonly(lvfs_sbdev_type dev)
 511 {
 512 #ifdef HAVE_DEV_SET_RDONLY
 513         return dev_check_rdonly(dev);
 514 #else
 515         return 0;
 516 #endif
 517 }
 518 EXPORT_SYMBOL(lvfs_check_rdonly);
 519
 520 int lvfs_check_io_health(struct obd_device *obd, struct file *file)
 521 {
 522         char *write_page = NULL;
 523         loff_t offset = 0;
 524         int rc = 0;
 525         ENTRY;
 526
 527         OBD_ALLOC(write_page, CFS_PAGE_SIZE);
 528         if (!write_page)
 529                 RETURN(-ENOMEM);
 530
 531         rc = fsfilt_write_record(obd, file, write_page, CFS_PAGE_SIZE, &offset, 1);
 532
 533         OBD_FREE(write_page, CFS_PAGE_SIZE);
 534
 535         CDEBUG(D_INFO, "write 1 page synchronously for checking io rc %d\n",rc);
 536         RETURN(rc);
 537 }
 538 EXPORT_SYMBOL(lvfs_check_io_health);
 539 #endif /* LUSTRE_KERNEL_VERSION */
 540
 541 void obd_update_maxusage()
 542 {
 543         __u64 max1, max2;
 544
 545         max1 = obd_pages_sum();
 546         max2 = obd_memory_sum();
 547
 548         cfs_spin_lock(&obd_updatemax_lock);
 549         if (max1 > obd_max_pages)
 550                 obd_max_pages = max1;
 551         if (max2 > obd_max_alloc)
 552                 obd_max_alloc = max2;
 553         cfs_spin_unlock(&obd_updatemax_lock);
 554
 555 }
 556
 557 __u64 obd_memory_max(void)
 558 {
 559         __u64 ret;
 560
 561         cfs_spin_lock(&obd_updatemax_lock);
 562         ret = obd_max_alloc;
 563         cfs_spin_unlock(&obd_updatemax_lock);
 564
 565         return ret;
 566 }
 567
 568 __u64 obd_pages_max(void)
 569 {
 570         __u64 ret;
 571
 572         cfs_spin_lock(&obd_updatemax_lock);
 573         ret = obd_max_pages;
 574         cfs_spin_unlock(&obd_updatemax_lock);
 575
 576         return ret;
 577 }
 578
 579 EXPORT_SYMBOL(obd_update_maxusage);
 580 EXPORT_SYMBOL(obd_pages_max);
 581 EXPORT_SYMBOL(obd_memory_max);
 582 EXPORT_SYMBOL(obd_memory);
 583
 584 #ifdef LPROCFS
 585 __s64 lprocfs_read_helper(struct lprocfs_counter *lc,
 586                           enum lprocfs_fields_flags field)
 587 {
 588         __s64 ret = 0;
 589         int centry;
 590
 591         if (!lc)
 592                 RETURN(0);
 593         do {
 594                 centry = cfs_atomic_read(&lc->lc_cntl.la_entry);
 595
 596                 switch (field) {
 597                         case LPROCFS_FIELDS_FLAGS_CONFIG:
 598                                 ret = lc->lc_config;
 599                                 break;
 600                         case LPROCFS_FIELDS_FLAGS_SUM:
 601                                 ret = lc->lc_sum + lc->lc_sum_irq;
 602                                 break;
 603                         case LPROCFS_FIELDS_FLAGS_MIN:
 604                                 ret = lc->lc_min;
 605                                 break;
 606                         case LPROCFS_FIELDS_FLAGS_MAX:
 607                                 ret = lc->lc_max;
 608                                 break;
 609                         case LPROCFS_FIELDS_FLAGS_AVG:
 610                                 ret = (lc->lc_max - lc->lc_min)/2;
 611                                 break;
 612                         case LPROCFS_FIELDS_FLAGS_SUMSQUARE:
 613                                 ret = lc->lc_sumsquare;
 614                                 break;
 615                         case LPROCFS_FIELDS_FLAGS_COUNT:
 616                                 ret = lc->lc_count;
 617                                 break;
 618                         default:
 619                                 break;
 620                 };
 621         } while (centry != cfs_atomic_read(&lc->lc_cntl.la_entry) &&
 622                  centry != cfs_atomic_read(&lc->lc_cntl.la_exit));
 623
 624         RETURN(ret);
 625 }
 626 EXPORT_SYMBOL(lprocfs_read_helper);
 627 #endif /* LPROCFS */
 628
 629 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 630 MODULE_DESCRIPTION("Lustre VFS Filesystem Helper v0.1");
 631 MODULE_LICENSE("GPL");