namei.c

lustre 1.6.5 source code

                ptlrpc_req_finished(req);
        if (rc == 0) {
                LASSERT(pb->pb_ino);
                I_RELE(pb->pb_ino);
                pb->pb_ino = NULL;
        } else {
                llu_lookup_finish_locks(it, pnode);
        }
        RETURN(rc);
}

static int lookup_it_finish(struct ptlrpc_request *request, int offset,
                            struct lookup_intent *it, void *data)
{
        struct it_cb_data *icbd = data;
        struct pnode *child = icbd->icbd_child;
        struct inode *parent = icbd->icbd_parent;
        struct llu_sb_info *sbi = llu_i2sbi(parent);
        struct inode *inode = NULL;
        int rc;

        /* libsysio require us generate inode right away if success.
         * so if mds created new inode for us we need make sure it
         * succeeded. thus for any error we can't delay to the
         * llu_file_open() time. */
        if (it_disposition(it, DISP_OPEN_CREATE) &&
            it_open_error(DISP_OPEN_CREATE, it)) {
                CDEBUG(D_INODE, "detect mds create error\n");
                return it_open_error(DISP_OPEN_CREATE, it);
        }
        if (it_disposition(it, DISP_OPEN_OPEN) &&
            it_open_error(DISP_OPEN_OPEN, it)) {
                CDEBUG(D_INODE, "detect mds open error\n");
                /* undo which did by mdc_intent_lock */
                if (it_disposition(it, DISP_OPEN_CREATE) &&
                    !it_open_error(DISP_OPEN_CREATE, it)) {
                        LASSERT(request);
                        LASSERT(atomic_read(&request->rq_refcount) > 1);
                        CDEBUG(D_INODE, "dec a ref of req %p\n", request);
                        ptlrpc_req_finished(request);
                }
                return it_open_error(DISP_OPEN_OPEN, it);
        }

        /* NB 1 request reference will be taken away by ll_intent_lock()
         * when I return
         */
        if (!it_disposition(it, DISP_LOOKUP_NEG) || (it->it_op & IT_CREAT)) {
                struct lustre_md md;
                struct llu_inode_info *lli;
                struct intnl_stat *st;
                ENTRY;

                if (it_disposition(it, DISP_OPEN_CREATE))
                        ptlrpc_req_finished(request);

                rc = mdc_req2lustre_md(request, offset, sbi->ll_osc_exp, &md);
                if (rc)
                        RETURN(rc);

                inode = llu_iget(parent->i_fs, &md);
                if (!inode || IS_ERR(inode)) {
                        /* free the lsm if we allocated one above */
                        if (md.lsm != NULL)
                                obd_free_memmd(sbi->ll_osc_exp, &md.lsm);
                        RETURN(inode ? PTR_ERR(inode) : -ENOMEM);
                } else if (md.lsm != NULL &&
                           llu_i2info(inode)->lli_smd != md.lsm) {
                        obd_free_memmd(sbi->ll_osc_exp, &md.lsm);
                }

                lli = llu_i2info(inode);
                st = llu_i2stat(inode);

                /* If this is a stat, get the authoritative file size */
                if (it->it_op == IT_GETATTR && S_ISREG(st->st_mode) &&
                    lli->lli_smd != NULL) {
                        struct lov_stripe_md *lsm = lli->lli_smd;
                        ldlm_error_t rc;

                        LASSERT(lsm->lsm_object_id != 0);

                        /* bug 2334: drop MDS lock before acquiring OST lock */
                        ll_intent_drop_lock(it);

                        rc = llu_glimpse_size(inode);
                        if (rc) {
                                I_RELE(inode);
                                RETURN(rc);
                        }
                }
        } else {
                ENTRY;
        }

        /* intent will be further used in cases of open()/getattr() */
        if (inode && (it->it_op & IT_OPEN))
                LL_SAVE_INTENT(inode, it);

        child->p_base->pb_ino = inode;

        RETURN(0);
}

struct inode *llu_inode_from_lock(struct ldlm_lock *lock)
{
        struct inode *inode;
        lock_res_and_lock(lock);

        if (lock->l_ast_data) {
                inode = (struct inode *)lock->l_ast_data;
                I_REF(inode);
        } else
                inode = NULL;

        unlock_res_and_lock(lock);
        return inode;
}

static int llu_lookup_it(struct inode *parent, struct pnode *pnode,
                         struct lookup_intent *it, int flags)
{
        struct mdc_op_data op_data;
        struct it_cb_data icbd;
        struct ptlrpc_request *req = NULL;
        struct lookup_intent lookup_it = { .it_op = IT_LOOKUP };
        int rc;
        ENTRY;

        if (pnode->p_base->pb_name.len > EXT2_NAME_LEN)
                RETURN(-ENAMETOOLONG);

        if (!it) {
                it = &lookup_it;
                it->it_op_release = ll_intent_release;
        }

        icbd.icbd_child = pnode;
        icbd.icbd_parent = parent;

        llu_prepare_mdc_op_data(&op_data, parent, NULL,
                                pnode->p_base->pb_name.name,
                                pnode->p_base->pb_name.len, flags);

        rc = mdc_intent_lock(llu_i2mdcexp(parent), &op_data, NULL, 0, it,
                             flags, &req, llu_mdc_blocking_ast,
                             LDLM_FL_CANCEL_ON_BLOCK);
        if (rc < 0)
                GOTO(out, rc);

        rc = lookup_it_finish(req, DLM_REPLY_REC_OFF, it, &icbd);
        if (rc != 0) {
                ll_intent_release(it);
                GOTO(out, rc);
        }

        llu_lookup_finish_locks(it, pnode);

 out:
        if (req)
                ptlrpc_req_finished(req);
        return rc;
}

static struct lookup_intent*
translate_lookup_intent(struct intent *intent, const char *path)
{
        struct lookup_intent *it;
        int fmode;

        /* libsysio trick */
        if (!intent || path) {
                CDEBUG(D_VFSTRACE, "not intent needed\n");
                return NULL;
        }

        OBD_ALLOC(it, sizeof(*it));
        LASSERT(it);

        memset(it, 0, sizeof(*it));

        /* libsysio will assign intent like following:
         * NOTE: INT_CREAT has include INT_UPDPARENT
         *
         * open: INT_OPEN [| INT_CREAT]
         * mkdir: INT_CREAT
         * symlink: INT_CREAT
         * unlink: INT_UPDPARENT
         * rmdir: INT_UPDPARENT
         * mknod: INT_CREAT
         * stat: INT_GETATTR
         * setattr: NULL
         *
         * following logic is adjusted for libsysio
         */

        it->it_flags = intent->int_arg2 ? *((int*)intent->int_arg2) : 0;

        if (intent->int_opmask & INT_OPEN) {
                it->it_op |= IT_OPEN;

                /* convert access mode from O_ to FMODE_ */
                if (it->it_flags & O_WRONLY)
                        fmode = FMODE_WRITE;
                else if (it->it_flags & O_RDWR)
                        fmode = FMODE_READ | FMODE_WRITE;
                else
                        fmode = FMODE_READ;
                it->it_flags &= ~O_ACCMODE;
                it->it_flags |= fmode;
        }

        /* XXX libsysio has strange code on intent handling,
         * more check later */
        if (it->it_flags & O_CREAT) {
                it->it_op |= IT_CREAT;
                it->it_create_mode = *((int*)intent->int_arg1);
                /* bug 7278: libsysio hack. For O_EXCL, libsysio depends on
                   this lookup to return negative result, but then there is no
                   way to find out original intent in ll_iop_open(). So we just
                   clear O_EXCL from libsysio flags here to avoid checking
                   for negative result. O_EXCL will be enforced by MDS. */
                *((int*)intent->int_arg2) &= ~O_EXCL;
        }

        if (intent->int_opmask & INT_GETATTR)
                it->it_op |= IT_GETATTR;

        LASSERT(!(intent->int_opmask & INT_SETATTR));

        /* libsysio is different to linux vfs when doing unlink/rmdir,
         * INT_UPDPARENT was passed down during name resolution. Here
         * we treat it as normal lookup, later unlink()/rmdir() will
         * do the actual work */

        /* conform to kernel code, if only IT_LOOKUP was set, don't
         * pass down it */
        if (!it->it_op || it->it_op == IT_LOOKUP) {
                OBD_FREE(it, sizeof(*it));
                it = NULL;
        }
        if (it)
                it->it_op_release = ll_intent_release;

        CDEBUG(D_VFSTRACE, "final intent 0x%x\n", it ? it->it_op : 0);
        return it;
}

int llu_iop_lookup(struct pnode *pnode,
                   struct inode **inop,
                   struct intent *intnt,
                   const char *path)
{
        struct lookup_intent *it;
        int rc;
        ENTRY;

        liblustre_wait_event(0);

        *inop = NULL;

        /* the mount root inode have no name, so don't call
         * remote in this case. but probably we need revalidate
         * it here? FIXME */
        if (pnode->p_mount->mnt_root == pnode) {
                struct inode *i = pnode->p_base->pb_ino;
                *inop = i;
                RETURN(0);
        }

        if (!pnode->p_base->pb_name.len)
                RETURN(-EINVAL);

        it = translate_lookup_intent(intnt, path);

        /* param flags is not used, let it be 0 */
        if (llu_pb_revalidate(pnode, 0, it)) {
                LASSERT(pnode->p_base->pb_ino);
                *inop = pnode->p_base->pb_ino;
                GOTO(out, rc = 0);
        }

        rc = llu_lookup_it(pnode->p_parent->p_base->pb_ino, pnode, it, 0);
        if (!rc) {
                if (!pnode->p_base->pb_ino)
                        rc = -ENOENT;
                else
                        *inop = pnode->p_base->pb_ino;
        }

out:
        liblustre_wait_event(0);
        RETURN(rc);
}