lustre/lvfs/lvfs_linux.c

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