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