- /* We can only use negative dentries if this is stat or lookup,
- for opens and stuff we do need to query server. */
- /* If there is IT_CREAT in intent op set, then we must throw
- away this negative dentry and actually do the request to
- kernel to create whatever needs to be created (if possible)*/
- if (it && (it->it_op & IT_CREAT))
- RETURN(0);
-
- if (d_lustre_invalid(de))
- RETURN(0);
-
- ibits = MDS_INODELOCK_UPDATE;
- rc = ll_have_md_lock(parent, &ibits, LCK_MINMODE);
- GOTO(out_sa, rc);
- }
-
- /* Never execute intents for mount points.
- * Attributes will be fixed up in ll_inode_revalidate_it */
- if (d_mountpoint(de))
- GOTO(out_sa, rc = 1);
-
- exp = ll_i2mdexp(de->d_inode);
-
- OBD_FAIL_TIMEOUT(OBD_FAIL_MDC_REVALIDATE_PAUSE, 5);
- ll_frob_intent(&it, &lookup_it);
- LASSERT(it);
-
- if (it->it_op == IT_LOOKUP && !d_lustre_invalid(de))
- RETURN(1);
-
- if (it->it_op == IT_OPEN) {
- struct inode *inode = de->d_inode;
- struct ll_inode_info *lli = ll_i2info(inode);
- struct obd_client_handle **och_p;
- __u64 ibits;
-
- /*
- * We used to check for MDS_INODELOCK_OPEN here, but in fact
- * just having LOOKUP lock is enough to justify inode is the
- * same. And if inode is the same and we have suitable
- * openhandle, then there is no point in doing another OPEN RPC
- * just to throw away newly received openhandle. There are no
- * security implications too, if file owner or access mode is
- * change, LOOKUP lock is revoked.
- */
-
- if (it->it_flags & FMODE_WRITE)
- och_p = &lli->lli_mds_write_och;
- else if (it->it_flags & FMODE_EXEC)
- och_p = &lli->lli_mds_exec_och;
- else
- och_p = &lli->lli_mds_read_och;
- /* Check for the proper lock. */
- ibits = MDS_INODELOCK_LOOKUP;
- if (!ll_have_md_lock(inode, &ibits, LCK_MINMODE))
- goto do_lock;
- mutex_lock(&lli->lli_och_mutex);
- if (*och_p) { /* Everything is open already, do nothing */
- /* Originally it was idea to do not let them steal our
- * open handle from under us by (*och_usecount)++ here.
- * But in case we have the handle, but we cannot use it
- * due to later checks (e.g. O_CREAT|O_EXCL flags set),
- * nobody would decrement counter increased here. So we
- * just hope the lock won't be invalidated in between.
- * But if it would be, we'll reopen the open request to
- * MDS later during file open path. */
- mutex_unlock(&lli->lli_och_mutex);
- RETURN(1);
- }
- mutex_unlock(&lli->lli_och_mutex);
- }
-
- if (it->it_op == IT_GETATTR) {
- rc = ll_statahead_enter(parent, &de, 0);
- if (rc == 1)
- goto mark;
- else if (rc != -EAGAIN && rc != 0)
- GOTO(out, rc = 0);
- }
-
-do_lock:
- op_data = ll_prep_md_op_data(NULL, parent, de->d_inode,
- de->d_name.name, de->d_name.len,
- 0, LUSTRE_OPC_ANY, NULL);
- if (IS_ERR(op_data))
- RETURN(PTR_ERR(op_data));
-
- if (!IS_POSIXACL(parent) || !exp_connect_umask(exp))
- it->it_create_mode &= ~cfs_curproc_umask();
- it->it_create_mode |= M_CHECK_STALE;
- rc = md_intent_lock(exp, op_data, NULL, 0, it,
- lookup_flags,
- &req, ll_md_blocking_ast, 0);
- it->it_create_mode &= ~M_CHECK_STALE;
- ll_finish_md_op_data(op_data);
-
- /* If req is NULL, then md_intent_lock only tried to do a lock match;
- * if all was well, it will return 1 if it found locks, 0 otherwise. */
- if (req == NULL && rc >= 0) {
- if (!rc)
- goto do_lookup;
- GOTO(out, rc);
- }
-
- if (rc < 0) {
- if (rc != -ESTALE) {
- CDEBUG(D_INFO, "ll_intent_lock: rc %d : it->it_status "
- "%d\n", rc, it->d.lustre.it_status);
- }
- GOTO(out, rc = 0);
- }
-
-revalidate_finish:
- rc = ll_revalidate_it_finish(req, it, de);
- if (rc != 0) {
- if (rc != -ESTALE && rc != -ENOENT)
- ll_intent_release(it);
- GOTO(out, rc = 0);
- }
-
- if ((it->it_op & IT_OPEN) && de->d_inode &&
- !S_ISREG(de->d_inode->i_mode) &&
- !S_ISDIR(de->d_inode->i_mode)) {
- ll_release_openhandle(de, it);
- }
- rc = 1;
-
-out:
- /* We do not free request as it may be reused during following lookup
- * (see comment in mdc/mdc_locks.c::mdc_intent_lock()), request will
- * be freed in ll_lookup_it or in ll_intent_release. But if
- * request was not completed, we need to free it. (bug 5154, 9903) */
- if (req != NULL && !it_disposition(it, DISP_ENQ_COMPLETE))
- ptlrpc_req_finished(req);
- if (rc == 0) {
- /* mdt may grant layout lock for the newly created file, so
- * release the lock to avoid leaking */
- ll_intent_drop_lock(it);
- ll_invalidate_aliases(de->d_inode);
- } else {
- __u64 bits = 0;
- __u64 matched_bits = 0;
-
- CDEBUG(D_DENTRY, "revalidated dentry %.*s (%p) parent %p "
- "inode %p refc %d\n", de->d_name.len,
- de->d_name.name, de, de->d_parent, de->d_inode,
- d_refcount(de));
-
- ll_set_lock_data(exp, de->d_inode, it, &bits);
-
- /* Note: We have to match both LOOKUP and PERM lock
- * here to make sure the dentry is valid and no one
- * changing the permission.
- * But if the client connects < 2.4 server, which will
- * only grant LOOKUP lock, so we can only Match LOOKUP
- * lock for old server */
- if (exp_connect_flags(ll_i2mdexp(de->d_inode)) &&
- OBD_CONNECT_LVB_TYPE)
- matched_bits =
- MDS_INODELOCK_LOOKUP | MDS_INODELOCK_PERM;
- else
- matched_bits = MDS_INODELOCK_LOOKUP;
-
- if (((bits & matched_bits) == matched_bits) &&
- d_lustre_invalid(de))
- d_lustre_revalidate(de);
- ll_lookup_finish_locks(it, de);
- }
-
-mark:
- if (it != NULL && it->it_op == IT_GETATTR && rc > 0)
- ll_statahead_mark(parent, de);
- RETURN(rc);
-
- /*
- * This part is here to combat evil-evil race in real_lookup on 2.6
- * kernels. The race details are: We enter do_lookup() looking for some
- * name, there is nothing in dcache for this name yet and d_lookup()
- * returns NULL. We proceed to real_lookup(), and while we do this,
- * another process does open on the same file we looking up (most simple
- * reproducer), open succeeds and the dentry is added. Now back to
- * us. In real_lookup() we do d_lookup() again and suddenly find the
- * dentry, so we call d_revalidate on it, but there is no lock, so
- * without this code we would return 0, but unpatched real_lookup just
- * returns -ENOENT in such a case instead of retrying the lookup. Once
- * this is dealt with in real_lookup(), all of this ugly mess can go and
- * we can just check locks in ->d_revalidate without doing any RPCs
- * ever.
- */
-do_lookup:
- if (it != &lookup_it) {
- /* MDS_INODELOCK_UPDATE needed for IT_GETATTR case. */
- if (it->it_op == IT_GETATTR)
- lookup_it.it_op = IT_GETATTR;
- ll_lookup_finish_locks(it, de);
- it = &lookup_it;
- }
-
- /* Do real lookup here. */
- op_data = ll_prep_md_op_data(NULL, parent, NULL, de->d_name.name,
- de->d_name.len, 0, (it->it_op & IT_CREAT ?
- LUSTRE_OPC_CREATE :
- LUSTRE_OPC_ANY), NULL);
- if (IS_ERR(op_data))
- RETURN(PTR_ERR(op_data));
-
- rc = md_intent_lock(exp, op_data, NULL, 0, it, 0, &req,
- ll_md_blocking_ast, 0);
- if (rc >= 0) {
- struct mdt_body *mdt_body;
- struct lu_fid fid = {.f_seq = 0, .f_oid = 0, .f_ver = 0};
- mdt_body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
-
- if (de->d_inode)
- fid = *ll_inode2fid(de->d_inode);
-
- /* see if we got same inode, if not - return error */
- if (lu_fid_eq(&fid, &mdt_body->fid1)) {
- ll_finish_md_op_data(op_data);
- op_data = NULL;
- goto revalidate_finish;
- }
- ll_intent_release(it);
- }
- ll_finish_md_op_data(op_data);
- GOTO(out, rc = 0);
-
-out_sa:
- /*
- * For rc == 1 case, should not return directly to prevent losing
- * statahead windows; for rc == 0 case, the "lookup" will be done later.
- */
- if (it != NULL && it->it_op == IT_GETATTR && rc == 1)
- ll_statahead_enter(parent, &de, 1);
- goto mark;
-}
-
-#ifdef HAVE_IOP_ATOMIC_OPEN
-/*
- * Always trust cached dentries. Update statahead window if necessary.
- */
-int ll_revalidate_nd(struct dentry *dentry, unsigned int flags)
-{
- struct inode *parent = dentry->d_parent->d_inode;
- int unplug = 0;
-
- ENTRY;
- CDEBUG(D_VFSTRACE, "VFS Op:name=%s,flags=%u\n",
- dentry->d_name.name, flags);
-
- if (!(flags & (LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE)) &&
- ll_need_statahead(parent, dentry) > 0) {
- if (flags & LOOKUP_RCU)
- RETURN(-ECHILD);
-
- if (dentry->d_inode == NULL)
- unplug = 1;
- do_statahead_enter(parent, &dentry, unplug);
- ll_statahead_mark(parent, dentry);
- }
-
- RETURN(1);
-}
-
-#else /* !HAVE_IOP_ATOMIC_OPEN */
-int ll_revalidate_nd(struct dentry *dentry, struct nameidata *nd)
-{
- int rc;
- ENTRY;
-
-#ifndef HAVE_DCACHE_LOCK
- /* kernel >= 2.6.38 supports rcu-walk, but lustre doesn't. */
- if (nd && (nd->flags & LOOKUP_RCU))
- return -ECHILD;