Merge remote-tracking branch 'asoc/fix/samsung' into asoc-linus

[mirror_ubuntu-bionic-kernel.git] / drivers / staging / lustre / lustre / llite / namei.c

/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/quotaops.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/security.h>

#define DEBUG_SUBSYSTEM S_LLITE

#include "../include/obd_support.h"
#include "../include/lustre_fid.h"
#include "../include/lustre_lite.h"
#include "../include/lustre_dlm.h"
#include "../include/lustre_ver.h"
#include "llite_internal.h"

static int ll_create_it(struct inode *, struct dentry *,
                        int, struct lookup_intent *);

/* called from iget5_locked->find_inode() under inode_hash_lock spinlock */
static int ll_test_inode(struct inode *inode, void *opaque)
{
        struct ll_inode_info *lli = ll_i2info(inode);
        struct lustre_md     *md = opaque;

        if (unlikely(!(md->body->valid & OBD_MD_FLID))) {
                CERROR("MDS body missing FID\n");
                return 0;
        }

        if (!lu_fid_eq(&lli->lli_fid, &md->body->fid1))
                return 0;

        return 1;
}

static int ll_set_inode(struct inode *inode, void *opaque)
{
        struct ll_inode_info *lli = ll_i2info(inode);
        struct mdt_body *body = ((struct lustre_md *)opaque)->body;

        if (unlikely(!(body->valid & OBD_MD_FLID))) {
                CERROR("MDS body missing FID\n");
                return -EINVAL;
        }

        lli->lli_fid = body->fid1;
        if (unlikely(!(body->valid & OBD_MD_FLTYPE))) {
                CERROR("Can not initialize inode " DFID " without object type: valid = %#llx\n",
                       PFID(&lli->lli_fid), body->valid);
                return -EINVAL;
        }

        inode->i_mode = (inode->i_mode & ~S_IFMT) | (body->mode & S_IFMT);
        if (unlikely(inode->i_mode == 0)) {
                CERROR("Invalid inode "DFID" type\n", PFID(&lli->lli_fid));
                return -EINVAL;
        }

        ll_lli_init(lli);

        return 0;
}


/*
 * Get an inode by inode number (already instantiated by the intent lookup).
 * Returns inode or NULL
 */
struct inode *ll_iget(struct super_block *sb, ino_t hash,
                      struct lustre_md *md)
{
        struct inode     *inode;

        LASSERT(hash != 0);
        inode = iget5_locked(sb, hash, ll_test_inode, ll_set_inode, md);

        if (inode) {
                if (inode->i_state & I_NEW) {
                        int rc = 0;

                        ll_read_inode2(inode, md);
                        if (S_ISREG(inode->i_mode) &&
                            ll_i2info(inode)->lli_clob == NULL) {
                                CDEBUG(D_INODE,
                                        "%s: apply lsm %p to inode "DFID".\n",
                                        ll_get_fsname(sb, NULL, 0), md->lsm,
                                        PFID(ll_inode2fid(inode)));
                                rc = cl_file_inode_init(inode, md);
                        }
                        if (rc != 0) {
                                make_bad_inode(inode);
                                unlock_new_inode(inode);
                                iput(inode);
                                inode = ERR_PTR(rc);
                        } else
                                unlock_new_inode(inode);
                } else if (!(inode->i_state & (I_FREEING | I_CLEAR)))
                        ll_update_inode(inode, md);
                CDEBUG(D_VFSTRACE, "got inode: %p for "DFID"\n",
                       inode, PFID(&md->body->fid1));
        }
        return inode;
}

static void ll_invalidate_negative_children(struct inode *dir)
{
        struct dentry *dentry, *tmp_subdir;
        struct ll_d_hlist_node *p;

        ll_lock_dcache(dir);
        ll_d_hlist_for_each_entry(dentry, p, &dir->i_dentry, d_u.d_alias) {
                spin_lock(&dentry->d_lock);
                if (!list_empty(&dentry->d_subdirs)) {
                        struct dentry *child;

                        list_for_each_entry_safe(child, tmp_subdir,
                                                 &dentry->d_subdirs,
                                                 d_child) {
                                if (child->d_inode == NULL)
                                        d_lustre_invalidate(child, 1);
                        }
                }
                spin_unlock(&dentry->d_lock);
        }
        ll_unlock_dcache(dir);
}

int ll_md_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
                       void *data, int flag)
{
        struct lustre_handle lockh;
        int rc;

        switch (flag) {
        case LDLM_CB_BLOCKING:
                ldlm_lock2handle(lock, &lockh);
                rc = ldlm_cli_cancel(&lockh, LCF_ASYNC);
                if (rc < 0) {
                        CDEBUG(D_INODE, "ldlm_cli_cancel: rc = %d\n", rc);
                        return rc;
                }
                break;
        case LDLM_CB_CANCELING: {
                struct inode *inode = ll_inode_from_resource_lock(lock);
                __u64 bits = lock->l_policy_data.l_inodebits.bits;

                /* Inode is set to lock->l_resource->lr_lvb_inode
                 * for mdc - bug 24555 */
                LASSERT(lock->l_ast_data == NULL);

                if (inode == NULL)
                        break;

                /* Invalidate all dentries associated with this inode */
                LASSERT(lock->l_flags & LDLM_FL_CANCELING);

                if (!fid_res_name_eq(ll_inode2fid(inode),
                                     &lock->l_resource->lr_name)) {
                        LDLM_ERROR(lock, "data mismatch with object "DFID"(%p)",
                                   PFID(ll_inode2fid(inode)), inode);
                        LBUG();
                }

                if (bits & MDS_INODELOCK_XATTR) {
                        ll_xattr_cache_destroy(inode);
                        bits &= ~MDS_INODELOCK_XATTR;
                }

                /* For OPEN locks we differentiate between lock modes
                 * LCK_CR, LCK_CW, LCK_PR - bug 22891 */
                if (bits & MDS_INODELOCK_OPEN)
                        ll_have_md_lock(inode, &bits, lock->l_req_mode);

                if (bits & MDS_INODELOCK_OPEN) {
                        fmode_t fmode;

                        switch (lock->l_req_mode) {
                        case LCK_CW:
                                fmode = FMODE_WRITE;
                                break;
                        case LCK_PR:
                                fmode = FMODE_EXEC;
                                break;
                        case LCK_CR:
                                fmode = FMODE_READ;
                                break;
                        default:
                                LDLM_ERROR(lock, "bad lock mode for OPEN lock");
                                LBUG();
                        }

                        ll_md_real_close(inode, fmode);
                }

                if (bits & (MDS_INODELOCK_LOOKUP | MDS_INODELOCK_UPDATE |
                            MDS_INODELOCK_LAYOUT | MDS_INODELOCK_PERM))
                        ll_have_md_lock(inode, &bits, LCK_MINMODE);

                if (bits & MDS_INODELOCK_LAYOUT) {
                        struct cl_object_conf conf = {
                                .coc_opc = OBJECT_CONF_INVALIDATE,
                                .coc_inode = inode,
                        };

                        rc = ll_layout_conf(inode, &conf);
                        if (rc < 0)
                                CDEBUG(D_INODE, "cannot invalidate layout of "
                                       DFID": rc = %d\n",
                                       PFID(ll_inode2fid(inode)), rc);
                }

                if (bits & MDS_INODELOCK_UPDATE) {
                        struct ll_inode_info *lli = ll_i2info(inode);

                        spin_lock(&lli->lli_lock);
                        lli->lli_flags &= ~LLIF_MDS_SIZE_LOCK;
                        spin_unlock(&lli->lli_lock);
                }

                if ((bits & MDS_INODELOCK_UPDATE) && S_ISDIR(inode->i_mode)) {
                        CDEBUG(D_INODE, "invalidating inode %lu\n",
                               inode->i_ino);
                        truncate_inode_pages(inode->i_mapping, 0);
                        ll_invalidate_negative_children(inode);
                }

                if ((bits & (MDS_INODELOCK_LOOKUP | MDS_INODELOCK_PERM)) &&
                    inode->i_sb->s_root != NULL &&
                    !is_root_inode(inode))
                        ll_invalidate_aliases(inode);

                iput(inode);
                break;
        }
        default:
                LBUG();
        }

        return 0;
}

__u32 ll_i2suppgid(struct inode *i)
{
        if (in_group_p(i->i_gid))
                return (__u32)from_kgid(&init_user_ns, i->i_gid);
        else
                return (__u32)(-1);
}

/* Pack the required supplementary groups into the supplied groups array.
 * If we don't need to use the groups from the target inode(s) then we
 * instead pack one or more groups from the user's supplementary group
 * array in case it might be useful.  Not needed if doing an MDS-side upcall. */
void ll_i2gids(__u32 *suppgids, struct inode *i1, struct inode *i2)
{
#if 0
        int i;
#endif

        LASSERT(i1 != NULL);
        LASSERT(suppgids != NULL);

        suppgids[0] = ll_i2suppgid(i1);

        if (i2)
                suppgids[1] = ll_i2suppgid(i2);
                else
                        suppgids[1] = -1;

#if 0
        for (i = 0; i < current_ngroups; i++) {
                if (suppgids[0] == -1) {
                        if (current_groups[i] != suppgids[1])
                                suppgids[0] = current_groups[i];
                        continue;
                }
                if (suppgids[1] == -1) {
                        if (current_groups[i] != suppgids[0])
                                suppgids[1] = current_groups[i];
                        continue;
                }
                break;
        }
#endif
}

/*
 * try to reuse three types of dentry:
 * 1. unhashed alias, this one is unhashed by d_invalidate (but it may be valid
 *    by concurrent .revalidate).
 * 2. INVALID alias (common case for no valid ldlm lock held, but this flag may
 *    be cleared by others calling d_lustre_revalidate).
 * 3. DISCONNECTED alias.
 */
static struct dentry *ll_find_alias(struct inode *inode, struct dentry *dentry)
{
        struct dentry *alias, *discon_alias, *invalid_alias;
        struct ll_d_hlist_node *p;

        if (ll_d_hlist_empty(&inode->i_dentry))
                return NULL;

        discon_alias = invalid_alias = NULL;

        ll_lock_dcache(inode);
        ll_d_hlist_for_each_entry(alias, p, &inode->i_dentry, d_u.d_alias) {
                LASSERT(alias != dentry);

                spin_lock(&alias->d_lock);
                if (alias->d_flags & DCACHE_DISCONNECTED)
                        /* LASSERT(last_discon == NULL); LU-405, bz 20055 */
                        discon_alias = alias;
                else if (alias->d_parent == dentry->d_parent         &&
                         alias->d_name.hash == dentry->d_name.hash       &&
                         alias->d_name.len == dentry->d_name.len         &&
                         memcmp(alias->d_name.name, dentry->d_name.name,
                                dentry->d_name.len) == 0)
                        invalid_alias = alias;
                spin_unlock(&alias->d_lock);

                if (invalid_alias)
                        break;
        }
        alias = invalid_alias ?: discon_alias ?: NULL;
        if (alias) {
                spin_lock(&alias->d_lock);
                dget_dlock(alias);
                spin_unlock(&alias->d_lock);
        }
        ll_unlock_dcache(inode);

        return alias;
}

/*
 * Similar to d_splice_alias(), but lustre treats invalid alias
 * similar to DCACHE_DISCONNECTED, and tries to use it anyway.
 */
struct dentry *ll_splice_alias(struct inode *inode, struct dentry *de)
{
        struct dentry *new;
        int rc;

        if (inode) {
                new = ll_find_alias(inode, de);
                if (new) {
                        rc = ll_d_init(new);
                        if (rc < 0) {
                                dput(new);
                                return ERR_PTR(rc);
                        }
                        d_move(new, de);
                        iput(inode);
                        CDEBUG(D_DENTRY,
                               "Reuse dentry %p inode %p refc %d flags %#x\n",
                              new, new->d_inode, d_count(new), new->d_flags);
                        return new;
                }
        }
        rc = ll_d_init(de);
        if (rc < 0)
                return ERR_PTR(rc);
        d_add(de, inode);
        CDEBUG(D_DENTRY, "Add dentry %p inode %p refc %d flags %#x\n",
               de, de->d_inode, d_count(de), de->d_flags);
        return de;
}

static int ll_lookup_it_finish(struct ptlrpc_request *request,
                               struct lookup_intent *it,
                               struct inode *parent, struct dentry **de)
{
        struct inode *inode = NULL;
        __u64 bits = 0;
        int rc;

        /* NB 1 request reference will be taken away by ll_intent_lock()
         * when I return */
        CDEBUG(D_DENTRY, "it %p it_disposition %x\n", it,
               it->d.lustre.it_disposition);
        if (!it_disposition(it, DISP_LOOKUP_NEG)) {
                rc = ll_prep_inode(&inode, request, (*de)->d_sb, it);
                if (rc)
                        return rc;

                ll_set_lock_data(ll_i2sbi(parent)->ll_md_exp, inode, it, &bits);

                /* We used to query real size from OSTs here, but actually
                   this is not needed. For stat() calls size would be updated
                   from subsequent do_revalidate()->ll_inode_revalidate_it() in
                   2.4 and
                   vfs_getattr_it->ll_getattr()->ll_inode_revalidate_it() in 2.6
                   Everybody else who needs correct file size would call
                   ll_glimpse_size or some equivalent themselves anyway.
                   Also see bug 7198. */
        }

        /* Only hash *de if it is unhashed (new dentry).
         * Atoimc_open may passing hashed dentries for open.
         */
        if (d_unhashed(*de)) {
                struct dentry *alias;

                alias = ll_splice_alias(inode, *de);
                if (IS_ERR(alias))
                        return PTR_ERR(alias);
                *de = alias;
        } else if (!it_disposition(it, DISP_LOOKUP_NEG)  &&
                   !it_disposition(it, DISP_OPEN_CREATE)) {
                /* With DISP_OPEN_CREATE dentry will
                   instantiated in ll_create_it. */
                LASSERT((*de)->d_inode == NULL);
                d_instantiate(*de, inode);
        }

        if (!it_disposition(it, DISP_LOOKUP_NEG)) {
                /* we have lookup look - unhide dentry */
                if (bits & MDS_INODELOCK_LOOKUP)
                        d_lustre_revalidate(*de);
        } else if (!it_disposition(it, DISP_OPEN_CREATE)) {
                /* If file created on server, don't depend on parent UPDATE
                 * lock to unhide it. It is left hidden and next lookup can
                 * find it in ll_splice_alias.
                 */
                /* Check that parent has UPDATE lock. */
                struct lookup_intent parent_it = {
                                        .it_op = IT_GETATTR,
                                        .d.lustre.it_lock_handle = 0 };

                if (md_revalidate_lock(ll_i2mdexp(parent), &parent_it,
                                       &ll_i2info(parent)->lli_fid, NULL)) {
                        d_lustre_revalidate(*de);
                        ll_intent_release(&parent_it);
                }
        }

        return 0;
}

static struct dentry *ll_lookup_it(struct inode *parent, struct dentry *dentry,
                                   struct lookup_intent *it, int lookup_flags)
{
        struct lookup_intent lookup_it = { .it_op = IT_LOOKUP };
        struct dentry *save = dentry, *retval;
        struct ptlrpc_request *req = NULL;
        struct inode *inode;
        struct md_op_data *op_data;
        __u32 opc;
        int rc;

        if (dentry->d_name.len > ll_i2sbi(parent)->ll_namelen)
                return ERR_PTR(-ENAMETOOLONG);

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),intent=%s\n",
               dentry, parent->i_ino,
               parent->i_generation, parent, LL_IT2STR(it));

        if (d_mountpoint(dentry))
                CERROR("Tell Peter, lookup on mtpt, it %s\n", LL_IT2STR(it));

        if (it == NULL || it->it_op == IT_GETXATTR)
                it = &lookup_it;

        if (it->it_op == IT_GETATTR) {
                rc = ll_statahead_enter(parent, &dentry, 0);
                if (rc == 1) {
                        if (dentry == save)
                                retval = NULL;
                        else
                                retval = dentry;
                        goto out;
                }
        }

        if (it->it_op & IT_CREAT)
                opc = LUSTRE_OPC_CREATE;
        else
                opc = LUSTRE_OPC_ANY;

        op_data = ll_prep_md_op_data(NULL, parent, NULL, dentry->d_name.name,
                                     dentry->d_name.len, lookup_flags, opc,
                                     NULL);
        if (IS_ERR(op_data))
                return (void *)op_data;

        /* enforce umask if acl disabled or MDS doesn't support umask */
        if (!IS_POSIXACL(parent) || !exp_connect_umask(ll_i2mdexp(parent)))
                it->it_create_mode &= ~current_umask();

        rc = md_intent_lock(ll_i2mdexp(parent), op_data, NULL, 0, it,
                            lookup_flags, &req, ll_md_blocking_ast, 0);
        ll_finish_md_op_data(op_data);
        if (rc < 0) {
                retval = ERR_PTR(rc);
                goto out;
        }

        rc = ll_lookup_it_finish(req, it, parent, &dentry);
        if (rc != 0) {
                ll_intent_release(it);
                retval = ERR_PTR(rc);
                goto out;
        }

        inode = dentry->d_inode;
        if ((it->it_op & IT_OPEN) && inode &&
            !S_ISREG(inode->i_mode) &&
            !S_ISDIR(inode->i_mode)) {
                ll_release_openhandle(inode, it);
        }
        ll_lookup_finish_locks(it, inode);

        if (dentry == save)
                retval = NULL;
        else
                retval = dentry;
        goto out;
 out:
        if (req)
                ptlrpc_req_finished(req);
        if (it->it_op == IT_GETATTR && (retval == NULL || retval == dentry))
                ll_statahead_mark(parent, dentry);
        return retval;
}

static struct dentry *ll_lookup_nd(struct inode *parent, struct dentry *dentry,
                                   unsigned int flags)
{
        struct lookup_intent *itp, it = { .it_op = IT_GETATTR };
        struct dentry *de;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),flags=%u\n",
               dentry, parent->i_ino,
               parent->i_generation, parent, flags);

        /* Optimize away (CREATE && !OPEN). Let .create handle the race. */
        if ((flags & LOOKUP_CREATE) && !(flags & LOOKUP_OPEN))
                return NULL;

        if (flags & (LOOKUP_PARENT|LOOKUP_OPEN|LOOKUP_CREATE))
                itp = NULL;
        else
                itp = &it;
        de = ll_lookup_it(parent, dentry, itp, 0);

        if (itp != NULL)
                ll_intent_release(itp);

        return de;
}

/*
 * For cached negative dentry and new dentry, handle lookup/create/open
 * together.
 */
static int ll_atomic_open(struct inode *dir, struct dentry *dentry,
                          struct file *file, unsigned open_flags,
                          umode_t mode, int *opened)
{
        struct lookup_intent *it;
        struct dentry *de;
        long long lookup_flags = LOOKUP_OPEN;
        int rc = 0;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),file %p,open_flags %x,mode %x opened %d\n",
               dentry, dir->i_ino,
               dir->i_generation, dir, file, open_flags, mode, *opened);

        it = kzalloc(sizeof(*it), GFP_NOFS);
        if (!it)
                return -ENOMEM;

        it->it_op = IT_OPEN;
        if (open_flags & O_CREAT) {
                it->it_op |= IT_CREAT;
                lookup_flags |= LOOKUP_CREATE;
        }
        it->it_create_mode = (mode & S_IALLUGO) | S_IFREG;
        it->it_flags = (open_flags & ~O_ACCMODE) | OPEN_FMODE(open_flags);

        /* Dentry added to dcache tree in ll_lookup_it */
        de = ll_lookup_it(dir, dentry, it, lookup_flags);
        if (IS_ERR(de))
                rc = PTR_ERR(de);
        else if (de != NULL)
                dentry = de;

        if (!rc) {
                if (it_disposition(it, DISP_OPEN_CREATE)) {
                        /* Dentry instantiated in ll_create_it. */
                        rc = ll_create_it(dir, dentry, mode, it);
                        if (rc) {
                                /* We dget in ll_splice_alias. */
                                if (de != NULL)
                                        dput(de);
                                goto out_release;
                        }

                        *opened |= FILE_CREATED;
                }
                if (dentry->d_inode && it_disposition(it, DISP_OPEN_OPEN)) {
                        /* Open dentry. */
                        if (S_ISFIFO(dentry->d_inode->i_mode)) {
                                /* We cannot call open here as it would
                                 * deadlock.
                                 */
                                if (it_disposition(it, DISP_ENQ_OPEN_REF))
                                        ptlrpc_req_finished(
                                                       (struct ptlrpc_request *)
                                                          it->d.lustre.it_data);
                                rc = finish_no_open(file, de);
                        } else {
                                file->private_data = it;
                                rc = finish_open(file, dentry, NULL, opened);
                                /* We dget in ll_splice_alias. finish_open takes
                                 * care of dget for fd open.
                                 */
                                if (de != NULL)
                                        dput(de);
                        }
                } else {
                        rc = finish_no_open(file, de);
                }
        }

out_release:
        ll_intent_release(it);
        OBD_FREE(it, sizeof(*it));

        return rc;
}


/* We depend on "mode" being set with the proper file type/umask by now */
static struct inode *ll_create_node(struct inode *dir, struct lookup_intent *it)
{
        struct inode *inode = NULL;
        struct ptlrpc_request *request = NULL;
        struct ll_sb_info *sbi = ll_i2sbi(dir);
        int rc;

        LASSERT(it && it->d.lustre.it_disposition);

        LASSERT(it_disposition(it, DISP_ENQ_CREATE_REF));
        request = it->d.lustre.it_data;
        it_clear_disposition(it, DISP_ENQ_CREATE_REF);
        rc = ll_prep_inode(&inode, request, dir->i_sb, it);
        if (rc) {
                inode = ERR_PTR(rc);
                goto out;
        }

        LASSERT(ll_d_hlist_empty(&inode->i_dentry));

        /* We asked for a lock on the directory, but were granted a
         * lock on the inode.  Since we finally have an inode pointer,
         * stuff it in the lock. */
        CDEBUG(D_DLMTRACE, "setting l_ast_data to inode %p (%lu/%u)\n",
               inode, inode->i_ino, inode->i_generation);
        ll_set_lock_data(sbi->ll_md_exp, inode, it, NULL);
 out:
        ptlrpc_req_finished(request);
        return inode;
}

/*
 * By the time this is called, we already have created the directory cache
 * entry for the new file, but it is so far negative - it has no inode.
 *
 * We defer creating the OBD object(s) until open, to keep the intent and
 * non-intent code paths similar, and also because we do not have the MDS
 * inode number before calling ll_create_node() (which is needed for LOV),
 * so we would need to do yet another RPC to the MDS to store the LOV EA
 * data on the MDS.  If needed, we would pass the PACKED lmm as data and
 * lmm_size in datalen (the MDS still has code which will handle that).
 *
 * If the create succeeds, we fill in the inode information
 * with d_instantiate().
 */
static int ll_create_it(struct inode *dir, struct dentry *dentry, int mode,
                        struct lookup_intent *it)
{
        struct inode *inode;
        int rc = 0;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),intent=%s\n",
               dentry, dir->i_ino,
               dir->i_generation, dir, LL_IT2STR(it));

        rc = it_open_error(DISP_OPEN_CREATE, it);
        if (rc)
                return rc;

        inode = ll_create_node(dir, it);
        if (IS_ERR(inode))
                return PTR_ERR(inode);

        d_instantiate(dentry, inode);
        return 0;
}

static void ll_update_times(struct ptlrpc_request *request,
                            struct inode *inode)
{
        struct mdt_body *body = req_capsule_server_get(&request->rq_pill,
                                                       &RMF_MDT_BODY);

        LASSERT(body);
        if (body->valid & OBD_MD_FLMTIME &&
            body->mtime > LTIME_S(inode->i_mtime)) {
                CDEBUG(D_INODE, "setting ino %lu mtime from %lu to %llu\n",
                       inode->i_ino, LTIME_S(inode->i_mtime), body->mtime);
                LTIME_S(inode->i_mtime) = body->mtime;
        }
        if (body->valid & OBD_MD_FLCTIME &&
            body->ctime > LTIME_S(inode->i_ctime))
                LTIME_S(inode->i_ctime) = body->ctime;
}

static int ll_new_node(struct inode *dir, struct dentry *dentry,
                       const char *tgt, int mode, int rdev,
                       __u32 opc)
{
        struct ptlrpc_request *request = NULL;
        struct md_op_data *op_data;
        struct inode *inode = NULL;
        struct ll_sb_info *sbi = ll_i2sbi(dir);
        int tgt_len = 0;
        int err;

        if (unlikely(tgt != NULL))
                tgt_len = strlen(tgt) + 1;

        op_data = ll_prep_md_op_data(NULL, dir, NULL,
                                     dentry->d_name.name,
                                     dentry->d_name.len,
                                     0, opc, NULL);
        if (IS_ERR(op_data)) {
                err = PTR_ERR(op_data);
                goto err_exit;
        }

        err = md_create(sbi->ll_md_exp, op_data, tgt, tgt_len, mode,
                        from_kuid(&init_user_ns, current_fsuid()),
                        from_kgid(&init_user_ns, current_fsgid()),
                        cfs_curproc_cap_pack(), rdev, &request);
        ll_finish_md_op_data(op_data);
        if (err)
                goto err_exit;

        ll_update_times(request, dir);

        err = ll_prep_inode(&inode, request, dir->i_sb, NULL);
        if (err)
                goto err_exit;

        d_instantiate(dentry, inode);
err_exit:
        ptlrpc_req_finished(request);

        return err;
}

static int ll_mknod(struct inode *dir, struct dentry *dchild,
                    umode_t mode, dev_t rdev)
{
        int err;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p) mode %o dev %x\n",
               dchild, dir->i_ino, dir->i_generation, dir,
               mode, old_encode_dev(rdev));

        if (!IS_POSIXACL(dir) || !exp_connect_umask(ll_i2mdexp(dir)))
                mode &= ~current_umask();

        switch (mode & S_IFMT) {
        case 0:
                mode |= S_IFREG; /* for mode = 0 case, fallthrough */
        case S_IFREG:
        case S_IFCHR:
        case S_IFBLK:
        case S_IFIFO:
        case S_IFSOCK:
                err = ll_new_node(dir, dchild, NULL, mode,
                                  old_encode_dev(rdev),
                                  LUSTRE_OPC_MKNOD);
                break;
        case S_IFDIR:
                err = -EPERM;
                break;
        default:
                err = -EINVAL;
        }

        if (!err)
                ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_MKNOD, 1);

        return err;
}

/*
 * Plain create. Intent create is handled in atomic_open.
 */
static int ll_create_nd(struct inode *dir, struct dentry *dentry,
                        umode_t mode, bool want_excl)
{
        int rc;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),flags=%u, excl=%d\n",
               dentry, dir->i_ino,
               dir->i_generation, dir, mode, want_excl);

        rc = ll_mknod(dir, dentry, mode, 0);

        ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_CREATE, 1);

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd, unhashed %d\n",
               dentry, d_unhashed(dentry));

        return rc;
}

static inline void ll_get_child_fid(struct dentry *child, struct lu_fid *fid)
{
        if (child->d_inode)
                *fid = *ll_inode2fid(child->d_inode);
}

/**
 * Remove dir entry
 **/
int ll_rmdir_entry(struct inode *dir, char *name, int namelen)
{
        struct ptlrpc_request *request = NULL;
        struct md_op_data *op_data;
        int rc;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%.*s,dir=%lu/%u(%p)\n",
               namelen, name, dir->i_ino, dir->i_generation, dir);

        op_data = ll_prep_md_op_data(NULL, dir, NULL, name, strlen(name),
                                     S_IFDIR, LUSTRE_OPC_ANY, NULL);
        if (IS_ERR(op_data))
                return PTR_ERR(op_data);
        op_data->op_cli_flags |= CLI_RM_ENTRY;
        rc = md_unlink(ll_i2sbi(dir)->ll_md_exp, op_data, &request);
        ll_finish_md_op_data(op_data);
        if (rc == 0) {
                ll_update_times(request, dir);
                ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_RMDIR, 1);
        }

        ptlrpc_req_finished(request);
        return rc;
}

int ll_objects_destroy(struct ptlrpc_request *request, struct inode *dir)
{
        struct mdt_body *body;
        struct lov_mds_md *eadata;
        struct lov_stripe_md *lsm = NULL;
        struct obd_trans_info oti = { 0 };
        struct obdo *oa;
        struct obd_capa *oc = NULL;
        int rc;

        /* req is swabbed so this is safe */
        body = req_capsule_server_get(&request->rq_pill, &RMF_MDT_BODY);
        if (!(body->valid & OBD_MD_FLEASIZE))
                return 0;

        if (body->eadatasize == 0) {
                CERROR("OBD_MD_FLEASIZE set but eadatasize zero\n");
                rc = -EPROTO;
                goto out;
        }

        /* The MDS sent back the EA because we unlinked the last reference
         * to this file. Use this EA to unlink the objects on the OST.
         * It's opaque so we don't swab here; we leave it to obd_unpackmd() to
         * check it is complete and sensible. */
        eadata = req_capsule_server_sized_get(&request->rq_pill, &RMF_MDT_MD,
                                              body->eadatasize);
        LASSERT(eadata != NULL);

        rc = obd_unpackmd(ll_i2dtexp(dir), &lsm, eadata, body->eadatasize);
        if (rc < 0) {
                CERROR("obd_unpackmd: %d\n", rc);
                goto out;
        }
        LASSERT(rc >= sizeof(*lsm));

        OBDO_ALLOC(oa);
        if (oa == NULL) {
                rc = -ENOMEM;
                goto out_free_memmd;
        }

        oa->o_oi = lsm->lsm_oi;
        oa->o_mode = body->mode & S_IFMT;
        oa->o_valid = OBD_MD_FLID | OBD_MD_FLTYPE | OBD_MD_FLGROUP;

        if (body->valid & OBD_MD_FLCOOKIE) {
                oa->o_valid |= OBD_MD_FLCOOKIE;
                oti.oti_logcookies =
                        req_capsule_server_sized_get(&request->rq_pill,
                                                     &RMF_LOGCOOKIES,
                                                   sizeof(struct llog_cookie) *
                                                     lsm->lsm_stripe_count);
                if (oti.oti_logcookies == NULL) {
                        oa->o_valid &= ~OBD_MD_FLCOOKIE;
                        body->valid &= ~OBD_MD_FLCOOKIE;
                }
        }

        if (body->valid & OBD_MD_FLOSSCAPA) {
                rc = md_unpack_capa(ll_i2mdexp(dir), request, &RMF_CAPA2, &oc);
                if (rc)
                        goto out_free_memmd;
        }

        rc = obd_destroy(NULL, ll_i2dtexp(dir), oa, lsm, &oti,
                         ll_i2mdexp(dir), oc);
        capa_put(oc);
        if (rc)
                CERROR("obd destroy objid "DOSTID" error %d\n",
                       POSTID(&lsm->lsm_oi), rc);
out_free_memmd:
        obd_free_memmd(ll_i2dtexp(dir), &lsm);
        OBDO_FREE(oa);
out:
        return rc;
}

/* ll_unlink() doesn't update the inode with the new link count.
 * Instead, ll_ddelete() and ll_d_iput() will update it based upon if there
 * is any lock existing. They will recycle dentries and inodes based upon locks
 * too. b=20433 */
static int ll_unlink(struct inode * dir, struct dentry *dentry)
{
        struct ptlrpc_request *request = NULL;
        struct md_op_data *op_data;
        int rc;
        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p)\n",
               dentry, dir->i_ino, dir->i_generation, dir);

        op_data = ll_prep_md_op_data(NULL, dir, NULL,
                                     dentry->d_name.name,
                                     dentry->d_name.len,
                                     0, LUSTRE_OPC_ANY, NULL);
        if (IS_ERR(op_data))
                return PTR_ERR(op_data);

        ll_get_child_fid(dentry, &op_data->op_fid3);
        op_data->op_fid2 = op_data->op_fid3;
        rc = md_unlink(ll_i2sbi(dir)->ll_md_exp, op_data, &request);
        ll_finish_md_op_data(op_data);
        if (rc)
                goto out;

        ll_update_times(request, dir);
        ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_UNLINK, 1);

        rc = ll_objects_destroy(request, dir);
 out:
        ptlrpc_req_finished(request);
        return rc;
}

static int ll_mkdir(struct inode *dir, struct dentry *dentry, ll_umode_t mode)
{
        int err;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p)\n",
               dentry, dir->i_ino, dir->i_generation, dir);

        if (!IS_POSIXACL(dir) || !exp_connect_umask(ll_i2mdexp(dir)))
                mode &= ~current_umask();
        mode = (mode & (S_IRWXUGO|S_ISVTX)) | S_IFDIR;
        err = ll_new_node(dir, dentry, NULL, mode, 0, LUSTRE_OPC_MKDIR);

        if (!err)
                ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_MKDIR, 1);

        return err;
}

static int ll_rmdir(struct inode *dir, struct dentry *dentry)
{
        struct ptlrpc_request *request = NULL;
        struct md_op_data *op_data;
        int rc;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p)\n",
               dentry, dir->i_ino, dir->i_generation, dir);

        op_data = ll_prep_md_op_data(NULL, dir, NULL,
                                     dentry->d_name.name, 
                                     dentry->d_name.len,
                                     S_IFDIR, LUSTRE_OPC_ANY, NULL);
        if (IS_ERR(op_data))
                return PTR_ERR(op_data);

        ll_get_child_fid(dentry, &op_data->op_fid3);
        op_data->op_fid2 = op_data->op_fid3;
        rc = md_unlink(ll_i2sbi(dir)->ll_md_exp, op_data, &request);
        ll_finish_md_op_data(op_data);
        if (rc == 0) {
                ll_update_times(request, dir);
                ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_RMDIR, 1);
        }

        ptlrpc_req_finished(request);
        return rc;
}

static int ll_symlink(struct inode *dir, struct dentry *dentry,
                      const char *oldname)
{
        int err;

        CDEBUG(D_VFSTRACE, "VFS Op:name=%pd,dir=%lu/%u(%p),target=%.*s\n",
               dentry, dir->i_ino, dir->i_generation,
               dir, 3000, oldname);

        err = ll_new_node(dir, dentry, oldname, S_IFLNK | S_IRWXUGO,
                        0, LUSTRE_OPC_SYMLINK);

        if (!err)
                ll_stats_ops_tally(ll_i2sbi(dir), LPROC_LL_SYMLINK, 1);

        return err;
}

static int ll_link(struct dentry *old_dentry, struct inode *dir,
                   struct dentry *new_dentry)
{
        struct inode *src = old_dentry->d_inode;
        struct ll_sb_info *sbi = ll_i2sbi(dir);
        struct ptlrpc_request *request = NULL;
        struct md_op_data *op_data;
        int err;

        CDEBUG(D_VFSTRACE,
               "VFS Op: inode=%lu/%u(%p), dir=%lu/%u(%p), target=%pd\n",
               src->i_ino, src->i_generation, src, dir->i_ino,
               dir->i_generation, dir, new_dentry);

        op_data = ll_prep_md_op_data(NULL, src, dir, new_dentry->d_name.name,
                                     new_dentry->d_name.len,
                                     0, LUSTRE_OPC_ANY, NULL);
        if (IS_ERR(op_data))
                return PTR_ERR(op_data);

        err = md_link(sbi->ll_md_exp, op_data, &request);
        ll_finish_md_op_data(op_data);
        if (err)
                goto out;

        ll_update_times(request, dir);
        ll_stats_ops_tally(sbi, LPROC_LL_LINK, 1);
out:
        ptlrpc_req_finished(request);
        return err;
}

static int ll_rename(struct inode *old_dir, struct dentry *old_dentry,
                     struct inode *new_dir, struct dentry *new_dentry)
{
        struct ptlrpc_request *request = NULL;
        struct ll_sb_info *sbi = ll_i2sbi(old_dir);
        struct md_op_data *op_data;
        int err;

        CDEBUG(D_VFSTRACE,
               "VFS Op:oldname=%pd,src_dir=%lu/%u(%p),newname=%pd,"
               "tgt_dir=%lu/%u(%p)\n", old_dentry,
               old_dir->i_ino, old_dir->i_generation, old_dir, new_dentry,
               new_dir->i_ino, new_dir->i_generation, new_dir);

        op_data = ll_prep_md_op_data(NULL, old_dir, new_dir, NULL, 0, 0,
                                     LUSTRE_OPC_ANY, NULL);
        if (IS_ERR(op_data))
                return PTR_ERR(op_data);

        ll_get_child_fid(old_dentry, &op_data->op_fid3);
        ll_get_child_fid(new_dentry, &op_data->op_fid4);
        err = md_rename(sbi->ll_md_exp, op_data,
                        old_dentry->d_name.name,
                        old_dentry->d_name.len,
                        new_dentry->d_name.name,
                        new_dentry->d_name.len, &request);
        ll_finish_md_op_data(op_data);
        if (!err) {
                ll_update_times(request, old_dir);
                ll_update_times(request, new_dir);
                ll_stats_ops_tally(sbi, LPROC_LL_RENAME, 1);
                err = ll_objects_destroy(request, old_dir);
        }

        ptlrpc_req_finished(request);
        if (!err)
                d_move(old_dentry, new_dentry);
        return err;
}

const struct inode_operations ll_dir_inode_operations = {
        .mknod        = ll_mknod,
        .atomic_open        = ll_atomic_open,
        .lookup      = ll_lookup_nd,
        .create      = ll_create_nd,
        /* We need all these non-raw things for NFSD, to not patch it. */
        .unlink      = ll_unlink,
        .mkdir        = ll_mkdir,
        .rmdir        = ll_rmdir,
        .symlink            = ll_symlink,
        .link          = ll_link,
        .rename      = ll_rename,
        .setattr            = ll_setattr,
        .getattr            = ll_getattr,
        .permission      = ll_inode_permission,
        .setxattr          = ll_setxattr,
        .getxattr          = ll_getxattr,
        .listxattr        = ll_listxattr,
        .removexattr    = ll_removexattr,
        .get_acl            = ll_get_acl,
};

const struct inode_operations ll_special_inode_operations = {
        .setattr        = ll_setattr,
        .getattr        = ll_getattr,
        .permission     = ll_inode_permission,
        .setxattr       = ll_setxattr,
        .getxattr       = ll_getxattr,
        .listxattr      = ll_listxattr,
        .removexattr    = ll_removexattr,
        .get_acl            = ll_get_acl,
};