1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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
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
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
38 #include <linux/sched.h>
39 #include <linux/smp_lock.h>
40 #include <linux/quotaops.h>
42 #define DEBUG_SUBSYSTEM S_LLITE
44 #include <obd_support.h>
45 #include <lustre_lite.h>
46 #include <lustre/lustre_idl.h>
47 #include <lustre_dlm.h>
48 #include <lustre_mdc.h>
49 //#include <lustre_ver.h>
50 //#include <lustre_version.h>
52 #include "llite_internal.h"
54 spinlock_t ll_lookup_lock = SPIN_LOCK_UNLOCKED;
56 /* should NOT be called with the dcache lock, see fs/dcache.c */
57 static void ll_release(struct dentry *de)
59 struct ll_dentry_data *lld;
63 if (lld == NULL) { /* NFS copies the de->d_op methods (bug 4655) */
67 #ifndef HAVE_VFS_INTENT_PATCHES
69 ll_intent_release(lld->lld_it);
70 OBD_FREE(lld->lld_it, sizeof(*lld->lld_it));
73 LASSERT(lld->lld_cwd_count == 0);
74 LASSERT(lld->lld_mnt_count == 0);
75 OBD_FREE(de->d_fsdata, sizeof(*lld));
80 /* Compare if two dentries are the same. Don't match if the existing dentry
81 * is marked DCACHE_LUSTRE_INVALID. Returns 1 if different, 0 if the same.
83 * This avoids a race where ll_lookup_it() instantiates a dentry, but we get
84 * an AST before calling d_revalidate_it(). The dentry still exists (marked
85 * INVALID) so d_lookup() matches it, but we have no lock on it (so
86 * lock_match() fails) and we spin around real_lookup(). */
87 int ll_dcompare(struct dentry *parent, struct qstr *d_name, struct qstr *name)
89 struct dentry *dchild;
92 if (d_name->len != name->len)
95 if (memcmp(d_name->name, name->name, name->len))
98 /* XXX: d_name must be in-dentry structure */
99 dchild = container_of(d_name, struct dentry, d_name); /* ugh */
101 CDEBUG(D_DENTRY,"found name %.*s(%p) - flags %d/%x - refc %d\n",
102 name->len, name->name, dchild,
103 d_mountpoint(dchild), dchild->d_flags & DCACHE_LUSTRE_INVALID,
104 atomic_read(&dchild->d_count));
106 /* mountpoint is always valid */
107 if (d_mountpoint(dchild))
110 if (dchild->d_flags & DCACHE_LUSTRE_INVALID)
117 /* should NOT be called with the dcache lock, see fs/dcache.c */
118 static int ll_ddelete(struct dentry *de)
122 #ifndef DCACHE_LUSTRE_INVALID
123 #define DCACHE_LUSTRE_INVALID 0
126 CDEBUG(D_DENTRY, "%s dentry %.*s (%p, parent %p, inode %p) %s%s\n",
127 (de->d_flags & DCACHE_LUSTRE_INVALID ? "deleting" : "keeping"),
128 de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
129 d_unhashed(de) ? "" : "hashed,",
130 list_empty(&de->d_subdirs) ? "" : "subdirs");
131 #if DCACHE_LUSTRE_INVALID == 0
132 #undef DCACHE_LUSTRE_INVALID
138 void ll_set_dd(struct dentry *de)
143 CDEBUG(D_DENTRY, "ldd on dentry %.*s (%p) parent %p inode %p refc %d\n",
144 de->d_name.len, de->d_name.name, de, de->d_parent, de->d_inode,
145 atomic_read(&de->d_count));
147 if (de->d_fsdata == NULL) {
148 struct ll_dentry_data *lld;
151 if (likely(lld != NULL)) {
153 if (likely(de->d_fsdata == NULL))
164 void ll_intent_drop_lock(struct lookup_intent *it)
166 struct lustre_handle *handle;
168 if (it->it_op && it->d.lustre.it_lock_mode) {
169 handle = (struct lustre_handle *)&it->d.lustre.it_lock_handle;
170 CDEBUG(D_DLMTRACE, "releasing lock with cookie "LPX64
171 " from it %p\n", handle->cookie, it);
172 ldlm_lock_decref(handle, it->d.lustre.it_lock_mode);
174 /* bug 494: intent_release may be called multiple times, from
175 * this thread and we don't want to double-decref this lock */
176 it->d.lustre.it_lock_mode = 0;
180 void ll_intent_release(struct lookup_intent *it)
184 CDEBUG(D_INFO, "intent %p released\n", it);
185 ll_intent_drop_lock(it);
186 #ifdef HAVE_VFS_INTENT_PATCHES
188 it->it_op_release = 0;
190 /* We are still holding extra reference on a request, need to free it */
191 if (it_disposition(it, DISP_ENQ_OPEN_REF))
192 ptlrpc_req_finished(it->d.lustre.it_data); /* ll_file_open */
193 if (it_disposition(it, DISP_ENQ_CREATE_REF)) /* create rec */
194 ptlrpc_req_finished(it->d.lustre.it_data);
195 if (it_disposition(it, DISP_ENQ_COMPLETE)) /* saved req from revalidate
197 ptlrpc_req_finished(it->d.lustre.it_data);
199 it->d.lustre.it_disposition = 0;
200 it->d.lustre.it_data = NULL;
204 /* Drop dentry if it is not used already, unhash otherwise.
205 Should be called with dcache lock held!
206 Returns: 1 if dentry was dropped, 0 if unhashed. */
207 int ll_drop_dentry(struct dentry *dentry)
210 if (atomic_read(&dentry->d_count) == 0) {
211 CDEBUG(D_DENTRY, "deleting dentry %.*s (%p) parent %p "
212 "inode %p\n", dentry->d_name.len,
213 dentry->d_name.name, dentry, dentry->d_parent,
217 unlock_dentry(dentry);
218 spin_unlock(&dcache_lock);
219 spin_unlock(&ll_lookup_lock);
221 spin_lock(&ll_lookup_lock);
222 spin_lock(&dcache_lock);
225 /* disconected dentry can not be find without lookup, because we
226 * not need his to unhash or mark invalid. */
227 if (dentry->d_flags & DCACHE_DISCONNECTED) {
228 unlock_dentry(dentry);
232 #ifdef DCACHE_LUSTRE_INVALID
233 if (!(dentry->d_flags & DCACHE_LUSTRE_INVALID)) {
235 if (!d_unhashed(dentry)) {
237 CDEBUG(D_DENTRY, "unhashing dentry %.*s (%p) parent %p "
238 "inode %p refc %d\n", dentry->d_name.len,
239 dentry->d_name.name, dentry, dentry->d_parent,
240 dentry->d_inode, atomic_read(&dentry->d_count));
241 /* actually we don't unhash the dentry, rather just
242 * mark it inaccessible for to __d_lookup(). otherwise
243 * sys_getcwd() could return -ENOENT -bzzz */
244 #ifdef DCACHE_LUSTRE_INVALID
245 dentry->d_flags |= DCACHE_LUSTRE_INVALID;
247 if (!dentry->d_inode || !S_ISDIR(dentry->d_inode->i_mode))
251 unlock_dentry(dentry);
255 void ll_unhash_aliases(struct inode *inode)
257 struct list_head *tmp, *head;
261 CERROR("unexpected NULL inode, tell phil\n");
265 CDEBUG(D_INODE, "marking dentries for ino %lu/%u(%p) invalid\n",
266 inode->i_ino, inode->i_generation, inode);
268 head = &inode->i_dentry;
269 spin_lock(&ll_lookup_lock);
270 spin_lock(&dcache_lock);
273 while ((tmp = tmp->next) != head) {
274 struct dentry *dentry = list_entry(tmp, struct dentry, d_alias);
276 CDEBUG(D_DENTRY, "dentry in drop %.*s (%p) parent %p "
277 "inode %p flags %d\n", dentry->d_name.len,
278 dentry->d_name.name, dentry, dentry->d_parent,
279 dentry->d_inode, dentry->d_flags);
281 if (dentry->d_name.len == 1 && dentry->d_name.name[0] == '/') {
282 CERROR("called on root (?) dentry=%p, inode=%p "
283 "ino=%lu\n", dentry, inode, inode->i_ino);
284 lustre_dump_dentry(dentry, 1);
285 libcfs_debug_dumpstack(NULL);
288 if (ll_drop_dentry(dentry))
291 spin_unlock(&dcache_lock);
292 spin_unlock(&ll_lookup_lock);
297 int ll_revalidate_it_finish(struct ptlrpc_request *request,
298 struct lookup_intent *it,
307 if (it_disposition(it, DISP_LOOKUP_NEG))
310 rc = ll_prep_inode(&de->d_inode, request, NULL);
315 void ll_lookup_finish_locks(struct lookup_intent *it, struct dentry *dentry)
318 LASSERT(dentry != NULL);
320 if (it->d.lustre.it_lock_mode && dentry->d_inode != NULL) {
321 struct inode *inode = dentry->d_inode;
322 struct ll_sb_info *sbi = ll_i2sbi(dentry->d_inode);
324 CDEBUG(D_DLMTRACE, "setting l_data to inode %p (%lu/%u)\n",
325 inode, inode->i_ino, inode->i_generation);
326 md_set_lock_data(sbi->ll_md_exp, &it->d.lustre.it_lock_handle,
330 /* drop lookup or getattr locks immediately */
331 if (it->it_op == IT_LOOKUP || it->it_op == IT_GETATTR) {
332 /* on 2.6 there are situation when several lookups and
333 * revalidations may be requested during single operation.
334 * therefore, we don't release intent here -bzzz */
335 ll_intent_drop_lock(it);
339 void ll_frob_intent(struct lookup_intent **itp, struct lookup_intent *deft)
341 struct lookup_intent *it = *itp;
342 #ifdef HAVE_VFS_INTENT_PATCHES
344 LASSERTF(it->it_magic == INTENT_MAGIC,
345 "%p has bad intent magic: %x\n",
350 if (!it || it->it_op == IT_GETXATTR)
353 #ifdef HAVE_VFS_INTENT_PATCHES
354 it->it_op_release = ll_intent_release;
358 int ll_revalidate_it(struct dentry *de, int lookup_flags,
359 struct lookup_intent *it)
361 struct md_op_data *op_data;
362 struct ptlrpc_request *req = NULL;
363 struct lookup_intent lookup_it = { .it_op = IT_LOOKUP };
364 struct obd_export *exp;
365 struct inode *parent;
369 CDEBUG(D_VFSTRACE, "VFS Op:name=%s,intent=%s\n", de->d_name.name,
372 if (de->d_inode == NULL) {
373 /* We can only use negative dentries if this is stat or lookup,
374 for opens and stuff we do need to query server. */
375 /* If there is IT_CREAT in intent op set, then we must throw
376 away this negative dentry and actually do the request to
377 kernel to create whatever needs to be created (if possible)*/
378 if (it && (it->it_op & IT_CREAT))
381 #ifdef DCACHE_LUSTRE_INVALID
382 if (de->d_flags & DCACHE_LUSTRE_INVALID)
386 rc = ll_have_md_lock(de->d_parent->d_inode,
387 MDS_INODELOCK_UPDATE);
391 /* Never execute intents for mount points.
392 * Attributes will be fixed up in ll_inode_revalidate_it */
393 if (d_mountpoint(de))
394 GOTO(out_sa, rc = 1);
396 /* need to get attributes in case root got changed from other client */
397 if (de == de->d_sb->s_root) {
398 rc = __ll_inode_revalidate_it(de, it, MDS_INODELOCK_LOOKUP);
404 exp = ll_i2mdexp(de->d_inode);
406 OBD_FAIL_TIMEOUT(OBD_FAIL_MDC_REVALIDATE_PAUSE, 5);
407 ll_frob_intent(&it, &lookup_it);
409 parent = de->d_parent->d_inode;
411 op_data = ll_prep_md_op_data(NULL, parent, de->d_inode,
412 de->d_name.name, de->d_name.len,
413 0, LUSTRE_OPC_ANY, NULL);
415 RETURN(PTR_ERR(op_data));
417 if ((it->it_op == IT_OPEN) && de->d_inode) {
418 struct inode *inode = de->d_inode;
419 struct ll_inode_info *lli = ll_i2info(inode);
420 struct obd_client_handle **och_p;
424 * We used to check for MDS_INODELOCK_OPEN here, but in fact
425 * just having LOOKUP lock is enough to justify inode is the
426 * same. And if inode is the same and we have suitable
427 * openhandle, then there is no point in doing another OPEN RPC
428 * just to throw away newly received openhandle. There are no
429 * security implications too, if file owner or access mode is
430 * change, LOOKUP lock is revoked.
434 if (it->it_flags & FMODE_WRITE) {
435 och_p = &lli->lli_mds_write_och;
436 och_usecount = &lli->lli_open_fd_write_count;
437 } else if (it->it_flags & FMODE_EXEC) {
438 och_p = &lli->lli_mds_exec_och;
439 och_usecount = &lli->lli_open_fd_exec_count;
441 och_p = &lli->lli_mds_read_och;
442 och_usecount = &lli->lli_open_fd_read_count;
444 /* Check for the proper lock. */
445 if (!ll_have_md_lock(inode, MDS_INODELOCK_LOOKUP))
447 down(&lli->lli_och_sem);
448 if (*och_p) { /* Everything is open already, do nothing */
449 /*(*och_usecount)++; Do not let them steal our open
450 handle from under us */
451 /* XXX The code above was my original idea, but in case
452 we have the handle, but we cannot use it due to later
453 checks (e.g. O_CREAT|O_EXCL flags set), nobody
454 would decrement counter increased here. So we just
455 hope the lock won't be invalidated in between. But
456 if it would be, we'll reopen the open request to
457 MDS later during file open path */
458 up(&lli->lli_och_sem);
459 ll_finish_md_op_data(op_data);
462 up(&lli->lli_och_sem);
466 if (it->it_op == IT_GETATTR)
467 first = ll_statahead_enter(de->d_parent->d_inode, &de, 0);
470 it->it_create_mode &= ~current->fs->umask;
471 it->it_create_mode |= M_CHECK_STALE;
472 rc = md_intent_lock(exp, op_data, NULL, 0, it,
474 &req, ll_md_blocking_ast, 0);
475 it->it_create_mode &= ~M_CHECK_STALE;
476 ll_finish_md_op_data(op_data);
477 if (it->it_op == IT_GETATTR && !first)
478 /* If there are too many locks on client-side, then some
479 * locks taken by statahead maybe dropped automatically
480 * before the real "revalidate" using them. */
481 ll_statahead_exit(de, req == NULL ? rc : 0);
482 else if (first == -EEXIST)
483 ll_statahead_mark(de);
485 /* If req is NULL, then md_intent_lock only tried to do a lock match;
486 * if all was well, it will return 1 if it found locks, 0 otherwise. */
487 if (req == NULL && rc >= 0) {
495 CDEBUG(D_INFO, "ll_intent_lock: rc %d : it->it_status "
496 "%d\n", rc, it->d.lustre.it_status);
502 rc = ll_revalidate_it_finish(req, it, de);
504 if (rc != -ESTALE && rc != -ENOENT)
505 ll_intent_release(it);
509 if ((it->it_op & IT_OPEN) && de->d_inode &&
510 !S_ISREG(de->d_inode->i_mode) &&
511 !S_ISDIR(de->d_inode->i_mode)) {
512 ll_release_openhandle(de, it);
516 /* unfortunately ll_intent_lock may cause a callback and revoke our
518 spin_lock(&ll_lookup_lock);
519 spin_lock(&dcache_lock);
523 d_rehash_cond(de, 0);
524 spin_unlock(&dcache_lock);
525 spin_unlock(&ll_lookup_lock);
528 /* We do not free request as it may be reused during following lookup
529 * (see comment in mdc/mdc_locks.c::mdc_intent_lock()), request will
530 * be freed in ll_lookup_it or in ll_intent_release. But if
531 * request was not completed, we need to free it. (bug 5154, 9903) */
532 if (req != NULL && !it_disposition(it, DISP_ENQ_COMPLETE))
533 ptlrpc_req_finished(req);
535 #ifdef DCACHE_LUSTRE_INVALID
536 ll_unhash_aliases(de->d_inode);
537 /* done in ll_unhash_aliases()
538 dentry->d_flags |= DCACHE_LUSTRE_INVALID; */
540 /* We do not want d_invalidate to kill all child dentries too */
544 CDEBUG(D_DENTRY, "revalidated dentry %.*s (%p) parent %p "
545 "inode %p refc %d\n", de->d_name.len,
546 de->d_name.name, de, de->d_parent, de->d_inode,
547 atomic_read(&de->d_count));
548 ll_lookup_finish_locks(it, de);
549 #ifdef DCACHE_LUSTRE_INVALID
551 de->d_flags &= ~DCACHE_LUSTRE_INVALID;
558 * This part is here to combat evil-evil race in real_lookup on 2.6
559 * kernels. The race details are: We enter do_lookup() looking for some
560 * name, there is nothing in dcache for this name yet and d_lookup()
561 * returns NULL. We proceed to real_lookup(), and while we do this,
562 * another process does open on the same file we looking up (most simple
563 * reproducer), open succeeds and the dentry is added. Now back to
564 * us. In real_lookup() we do d_lookup() again and suddenly find the
565 * dentry, so we call d_revalidate on it, but there is no lock, so
566 * without this code we would return 0, but unpatched real_lookup just
567 * returns -ENOENT in such a case instead of retrying the lookup. Once
568 * this is dealt with in real_lookup(), all of this ugly mess can go and
569 * we can just check locks in ->d_revalidate without doing any RPCs
573 if (it != &lookup_it) {
574 /* MDS_INODELOCK_UPDATE needed for IT_GETATTR case. */
575 if (it->it_op == IT_GETATTR)
576 lookup_it.it_op = IT_GETATTR;
577 ll_lookup_finish_locks(it, de);
581 /* Do real lookup here. */
582 op_data = ll_prep_md_op_data(NULL, parent, NULL, de->d_name.name,
583 de->d_name.len, 0, (it->it_op & IT_CREAT ?
585 LUSTRE_OPC_ANY), NULL);
587 RETURN(PTR_ERR(op_data));
589 rc = md_intent_lock(exp, op_data, NULL, 0, it, 0, &req,
590 ll_md_blocking_ast, 0);
592 struct mdt_body *mdt_body;
593 struct lu_fid fid = {.f_seq = 0, .f_oid = 0, .f_ver = 0};
594 mdt_body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
597 fid = *ll_inode2fid(de->d_inode);
599 /* see if we got same inode, if not - return error */
600 if (lu_fid_eq(&fid, &mdt_body->fid1)) {
601 ll_finish_md_op_data(op_data);
603 goto revalidate_finish;
605 ll_intent_release(it);
607 ll_finish_md_op_data(op_data);
612 * For rc == 1 case, should not return directly to prevent losing
613 * statahead windows; for rc == 0 case, the "lookup" will be done later.
615 if (it && it->it_op == IT_GETATTR && rc == 1) {
616 first = ll_statahead_enter(de->d_parent->d_inode, &de, 0);
618 ll_statahead_exit(de, 1);
619 else if (first == -EEXIST)
620 ll_statahead_mark(de);
626 /*static*/ void ll_pin(struct dentry *de, struct vfsmount *mnt, int flag)
628 struct inode *inode= de->d_inode;
629 struct ll_sb_info *sbi = ll_i2sbi(inode);
630 struct ll_dentry_data *ldd = ll_d2d(de);
631 struct obd_client_handle *handle;
638 /* Strictly speaking this introduces an additional race: the
639 * increments should wait until the rpc has returned.
640 * However, given that at present the function is void, this
642 if (flag == 1 && (++ldd->lld_mnt_count) > 1) {
648 if (flag == 0 && (++ldd->lld_cwd_count) > 1) {
655 handle = (flag) ? &ldd->lld_mnt_och : &ldd->lld_cwd_och;
656 oc = ll_mdscapa_get(inode);
657 rc = obd_pin(sbi->ll_md_exp, ll_inode2fid(inode), oc, handle, flag);
661 memset(handle, 0, sizeof(*handle));
663 ldd->lld_cwd_count--;
665 ldd->lld_mnt_count--;
673 /*static*/ void ll_unpin(struct dentry *de, struct vfsmount *mnt, int flag)
675 struct ll_sb_info *sbi = ll_i2sbi(de->d_inode);
676 struct ll_dentry_data *ldd = ll_d2d(de);
677 struct obd_client_handle handle;
683 /* Strictly speaking this introduces an additional race: the
684 * increments should wait until the rpc has returned.
685 * However, given that at present the function is void, this
687 handle = (flag) ? ldd->lld_mnt_och : ldd->lld_cwd_och;
688 if (handle.och_magic != OBD_CLIENT_HANDLE_MAGIC) {
689 /* the "pin" failed */
696 count = --ldd->lld_mnt_count;
698 count = --ldd->lld_cwd_count;
706 rc = obd_unpin(sbi->ll_md_exp, &handle, flag);
711 #ifdef HAVE_VFS_INTENT_PATCHES
712 int ll_revalidate_nd(struct dentry *dentry, struct nameidata *nd)
717 if (nd && nd->flags & LOOKUP_LAST && !(nd->flags & LOOKUP_LINK_NOTLAST))
718 rc = ll_revalidate_it(dentry, nd->flags, &nd->intent);
720 rc = ll_revalidate_it(dentry, 0, NULL);
725 int ll_revalidate_nd(struct dentry *dentry, struct nameidata *nd)
730 if (nd && !(nd->flags & (LOOKUP_CONTINUE|LOOKUP_PARENT))) {
731 struct lookup_intent *it;
732 it = ll_convert_intent(&nd->intent.open, nd->flags);
735 if (it->it_op == (IT_OPEN|IT_CREAT))
736 if (nd->intent.open.flags & O_EXCL) {
737 CDEBUG(D_VFSTRACE, "create O_EXCL, returning 0\n");
742 rc = ll_revalidate_it(dentry, nd->flags, it);
744 if (rc && (nd->flags & LOOKUP_OPEN) &&
745 it_disposition(it, DISP_OPEN_OPEN)) {/*Open*/
746 #ifdef HAVE_FILE_IN_STRUCT_INTENT
747 // XXX Code duplication with ll_lookup_nd
748 if (S_ISFIFO(dentry->d_inode->i_mode)) {
749 // We cannot call open here as it would
752 (struct ptlrpc_request *)
753 it->d.lustre.it_data);
755 #if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,17))
756 /* 2.6.1[456] have a bug in open_namei() that forgets to check
757 * nd->intent.open.file for error, so we need to return it as lookup's result
761 nd->intent.open.file->private_data = it;
762 filp = lookup_instantiate_filp(nd, dentry,NULL);
767 nd->intent.open.file->private_data = it;
768 (void)lookup_instantiate_filp(nd, dentry,NULL);
772 ll_release_openhandle(dentry, it);
773 #endif /* HAVE_FILE_IN_STRUCT_INTENT */
775 if (!rc && (nd->flags & LOOKUP_CREATE) &&
776 it_disposition(it, DISP_OPEN_CREATE)) {
777 /* We created something but we may only return
778 * negative dentry here, so save request in dentry,
779 * if lookup will be called later on, it will
780 * pick the request, otherwise it would be freed
782 ll_d2d(dentry)->lld_it = it;
783 it = NULL; /* avoid freeing */
788 ll_intent_release(it);
789 OBD_FREE(it, sizeof(*it));
792 rc = ll_revalidate_it(dentry, 0, NULL);
799 struct dentry_operations ll_d_ops = {
800 .d_revalidate = ll_revalidate_nd,
801 .d_release = ll_release,
802 .d_delete = ll_ddelete,
803 .d_compare = ll_dcompare,