lustre/mds/handler.c

   1 /*
   2  *  linux/mds/handler.c
   3  *
   4  *  Lustre Metadata Server (mds) request handler
   5  *
   6  *  Copyright (C) 2001, 2002 Cluster File Systems, Inc.
   7  *
   8  *  This code is issued under the GNU General Public License.
   9  *  See the file COPYING in this distribution
  10  *
  11  *  by Peter Braam <braam@clusterfs.com>
  12  *
  13  *  This server is single threaded at present (but can easily be multi threaded).
  14  *
  15  */
  16
  17
  18 #define EXPORT_SYMTAB
  19
  20 #include <linux/version.h>
  21 #include <linux/module.h>
  22 #include <linux/fs.h>
  23 #include <linux/stat.h>
  24 #include <linux/locks.h>
  25 #include <linux/ext2_fs.h>
  26 #include <linux/quotaops.h>
  27 #include <asm/unistd.h>
  28 #include <asm/uaccess.h>
  29 #include <linux/obd_support.h>
  30 #include <linux/obd.h>
  31 #include <linux/lustre_lib.h>
  32 #include <linux/lustre_idl.h>
  33 #include <linux/lustre_mds.h>
  34 #include <linux/lustre_net.h>
  35 #include <linux/obd_class.h>
  36
  37 // XXX for testing
  38 static struct mds_obd *MDS;
  39
  40 // XXX make this networked!
  41 static int mds_queue_req(struct ptlrpc_request *req)
  42 {
  43         struct ptlrpc_request *srv_req;
  44
  45         if (!MDS) {
  46                 EXIT;
  47                 return -1;
  48         }
  49
  50         OBD_ALLOC(srv_req, sizeof(*srv_req));
  51         if (!srv_req) {
  52                 EXIT;
  53                 return -ENOMEM;
  54         }
  55
  56         printk("---> MDS at %d %p, incoming req %p, srv_req %p\n",
  57                __LINE__, MDS, req, srv_req);
  58
  59         memset(srv_req, 0, sizeof(*req));
  60
  61         /* move the request buffer */
  62         srv_req->rq_reqbuf = req->rq_reqbuf;
  63         srv_req->rq_reqlen = req->rq_reqlen;
  64         srv_req->rq_obd = MDS;
  65
  66         /* remember where it came from */
  67         srv_req->rq_reply_handle = req;
  68
  69         list_add(&srv_req->rq_list, &MDS->mds_reqs);
  70         wake_up(&MDS->mds_waitq);
  71         return 0;
  72 }
  73
  74 int mds_sendpage(struct ptlrpc_request *req, struct file *file,
  75                     __u64 offset, struct niobuf *dst)
  76 {
  77         int rc;
  78         mm_segment_t oldfs = get_fs();
  79
  80         if (req->rq_peer.peer_nid == 0) {
  81                 /* dst->addr is a user address, but in a different task! */
  82                 set_fs(KERNEL_DS);
  83                 rc = generic_file_read(file, (char *)(long)dst->addr,
  84                                        PAGE_SIZE, &offset);
  85                 set_fs(oldfs);
  86
  87                 if (rc != PAGE_SIZE)
  88                         return -EIO;
  89         } else {
  90                 char *buf;
  91
  92                 OBD_ALLOC(buf, PAGE_SIZE);
  93                 if (!buf)
  94                         return -ENOMEM;
  95
  96                 set_fs(KERNEL_DS);
  97                 rc = generic_file_read(file, buf, PAGE_SIZE, &offset);
  98                 set_fs(oldfs);
  99
 100                 if (rc != PAGE_SIZE) {
 101                         OBD_FREE(buf, PAGE_SIZE);
 102                         return -EIO;
 103                 }
 104
 105                 req->rq_bulkbuf = buf;
 106                 req->rq_bulklen = PAGE_SIZE;
 107                 rc = ptl_send_buf(req, &req->rq_peer, MDS_BULK_PORTAL, 0);
 108                 init_waitqueue_head(&req->rq_wait_for_bulk);
 109                 sleep_on(&req->rq_wait_for_bulk);
 110                 OBD_FREE(buf, PAGE_SIZE);
 111                 req->rq_bulklen = 0; /* FIXME: eek. */
 112         }
 113
 114         return 0;
 115 }
 116
 117 int mds_reply(struct ptlrpc_request *req)
 118 {
 119         struct ptlrpc_request *clnt_req = req->rq_reply_handle;
 120
 121         ENTRY;
 122
 123         if (req->rq_obd->mds_service != NULL) {
 124                 /* This is a request that came from the network via portals. */
 125
 126                 /* FIXME: we need to increment the count of handled events */
 127                 ptl_send_buf(req, &req->rq_peer, MDS_REPLY_PORTAL, 0);
 128         } else {
 129                 /* This is a local request that came from another thread. */
 130
 131                 /* move the reply to the client */
 132                 clnt_req->rq_replen = req->rq_replen;
 133                 clnt_req->rq_repbuf = req->rq_repbuf;
 134                 req->rq_repbuf = NULL;
 135                 req->rq_replen = 0;
 136
 137                 /* free the request buffer */
 138                 OBD_FREE(req->rq_reqbuf, req->rq_reqlen);
 139                 req->rq_reqbuf = NULL;
 140
 141                 /* wake up the client */
 142                 wake_up_interruptible(&clnt_req->rq_wait_for_rep);
 143         }
 144
 145         EXIT;
 146         return 0;
 147 }
 148
 149 int mds_error(struct ptlrpc_request *req)
 150 {
 151         struct ptlrep_hdr *hdr;
 152
 153         ENTRY;
 154
 155         OBD_ALLOC(hdr, sizeof(*hdr));
 156         if (!hdr) {
 157                 EXIT;
 158                 return -ENOMEM;
 159         }
 160
 161         memset(hdr, 0, sizeof(*hdr));
 162
 163         hdr->seqno = req->rq_reqhdr->seqno;
 164         hdr->status = req->rq_status;
 165         hdr->type = MDS_TYPE_ERR;
 166
 167         req->rq_repbuf = (char *)hdr;
 168         req->rq_replen = sizeof(*hdr);
 169
 170         EXIT;
 171         return mds_reply(req);
 172 }
 173
 174 struct dentry *mds_fid2dentry(struct mds_obd *mds, struct ll_fid *fid,
 175                               struct vfsmount **mnt)
 176 {
 177         /* stolen from NFS */
 178         struct super_block *sb = mds->mds_sb;
 179         unsigned long ino = fid->id;
 180         //__u32 generation = fid->generation;
 181         __u32 generation = 0;
 182         struct inode *inode;
 183         struct list_head *lp;
 184         struct dentry *result;
 185
 186         if (ino == 0)
 187                 return ERR_PTR(-ESTALE);
 188
 189         inode = iget(sb, ino);
 190         if (inode == NULL)
 191                 return ERR_PTR(-ENOMEM);
 192
 193         printk("--> mds_fid2dentry: sb %p\n", inode->i_sb);
 194
 195         if (is_bad_inode(inode)
 196             || (generation && inode->i_generation != generation)
 197                 ) {
 198                 /* we didn't find the right inode.. */
 199                 printk(__FUNCTION__
 200                        "bad inode %lu, link: %d ct: %d or version  %u/%u\n",
 201                         inode->i_ino,
 202                         inode->i_nlink, atomic_read(&inode->i_count),
 203                         inode->i_generation,
 204                         generation);
 205                 iput(inode);
 206                 return ERR_PTR(-ESTALE);
 207         }
 208
 209         /* now to find a dentry.
 210          * If possible, get a well-connected one
 211          */
 212         spin_lock(&dcache_lock);
 213         for (lp = inode->i_dentry.next; lp != &inode->i_dentry ; lp=lp->next) {
 214                 result = list_entry(lp,struct dentry, d_alias);
 215                 if (! (result->d_flags & DCACHE_NFSD_DISCONNECTED)) {
 216                         dget_locked(result);
 217                         result->d_vfs_flags |= DCACHE_REFERENCED;
 218                         spin_unlock(&dcache_lock);
 219                         iput(inode);
 220                         return result;
 221                 }
 222         }
 223         spin_unlock(&dcache_lock);
 224         result = d_alloc_root(inode);
 225         if (result == NULL) {
 226                 iput(inode);
 227                 return ERR_PTR(-ENOMEM);
 228         }
 229         result->d_flags |= DCACHE_NFSD_DISCONNECTED;
 230         return result;
 231 }
 232
 233 static inline void mds_get_objid(struct inode *inode, __u64 *id)
 234 {
 235         memcpy(id, &inode->u.ext2_i.i_data, sizeof(*id));
 236 }
 237
 238 int mds_getattr(struct ptlrpc_request *req)
 239 {
 240         struct dentry *de;
 241         struct inode *inode;
 242         struct mds_rep *rep;
 243         int rc;
 244
 245         rc = mds_pack_rep(NULL, 0, NULL, 0, &req->rq_rephdr, &req->rq_rep.mds,
 246                           &req->rq_replen, &req->rq_repbuf);
 247         if (rc) {
 248                 EXIT;
 249                 printk("mds: out of memory\n");
 250                 req->rq_status = -ENOMEM;
 251                 return 0;
 252         }
 253
 254         req->rq_rephdr->seqno = req->rq_reqhdr->seqno;
 255         rep = req->rq_rep.mds;
 256
 257         de = mds_fid2dentry(req->rq_obd, &req->rq_req.mds->fid1, NULL);
 258         if (IS_ERR(de)) {
 259                 EXIT;
 260                 req->rq_rephdr->status = -ENOENT;
 261                 return 0;
 262         }
 263
 264         inode = de->d_inode;
 265         rep->ino = inode->i_ino;
 266         rep->atime = inode->i_atime;
 267         rep->ctime = inode->i_ctime;
 268         rep->mtime = inode->i_mtime;
 269         rep->uid = inode->i_uid;
 270         rep->gid = inode->i_gid;
 271         rep->size = inode->i_size;
 272         rep->mode = inode->i_mode;
 273         rep->nlink = inode->i_nlink;
 274         rep->valid = ~0;
 275         mds_get_objid(inode, &rep->objid);
 276         dput(de);
 277         return 0;
 278 }
 279
 280 int mds_readpage(struct ptlrpc_request *req)
 281 {
 282         struct vfsmount *mnt;
 283         struct dentry *de;
 284         struct file *file;
 285         struct niobuf *niobuf;
 286         struct mds_rep *rep;
 287         int rc;
 288
 289         rc = mds_pack_rep(NULL, 0, NULL, 0, &req->rq_rephdr, &req->rq_rep.mds,
 290                           &req->rq_replen, &req->rq_repbuf);
 291         if (rc) {
 292                 EXIT;
 293                 printk("mds: out of memory\n");
 294                 req->rq_status = -ENOMEM;
 295                 return 0;
 296         }
 297
 298         req->rq_rephdr->seqno = req->rq_reqhdr->seqno;
 299         rep = req->rq_rep.mds;
 300
 301         de = mds_fid2dentry(req->rq_obd, &req->rq_req.mds->fid1, &mnt);
 302         if (IS_ERR(de)) {
 303                 EXIT;
 304                 req->rq_rephdr->status = PTR_ERR(de);
 305                 return 0;
 306         }
 307
 308         printk("mds_readpage: ino %ld\n", de->d_inode->i_ino);
 309
 310         file = dentry_open(de, mnt, O_RDONLY | O_LARGEFILE);
 311         /* note: in case of an error, dentry_open puts dentry */
 312         if (IS_ERR(file)) {
 313                 EXIT;
 314                 req->rq_rephdr->status = PTR_ERR(file);
 315                 return 0;
 316         }
 317
 318         niobuf = mds_req_tgt(req->rq_req.mds);
 319
 320         /* to make this asynchronous make sure that the handling function
 321            doesn't send a reply when this function completes. Instead a
 322            callback function would send the reply */
 323         rc = mds_sendpage(req, file, req->rq_req.mds->size, niobuf);
 324
 325         filp_close(file, 0);
 326         req->rq_rephdr->status = rc;
 327         EXIT;
 328         return 0;
 329 }
 330
 331 int mds_reint(struct ptlrpc_request *req)
 332 {
 333         int rc;
 334         char *buf = mds_req_tgt(req->rq_req.mds);
 335         int len = req->rq_req.mds->tgtlen;
 336         struct mds_update_record rec;
 337
 338         rc = mds_update_unpack(buf, len, &rec);
 339         if (rc) {
 340                 printk(__FUNCTION__ ": invalid record\n");
 341                 req->rq_status = -EINVAL;
 342                 return 0;
 343         }
 344         /* rc will be used to interrupt a for loop over multiple records */
 345         rc = mds_reint_rec(&rec, req);
 346         return 0;
 347 }
 348
 349 //int mds_handle(struct mds_conn *conn, int len, char *buf)
 350 int mds_handle(struct ptlrpc_request *req)
 351 {
 352         int rc;
 353         struct ptlreq_hdr *hdr;
 354
 355         ENTRY;
 356
 357         hdr = (struct ptlreq_hdr *)req->rq_reqbuf;
 358
 359         if (NTOH__u32(hdr->type) != MDS_TYPE_REQ) {
 360                 printk("lustre_mds: wrong packet type sent %d\n",
 361                        NTOH__u32(hdr->type));
 362                 rc = -EINVAL;
 363                 goto out;
 364         }
 365
 366         rc = mds_unpack_req(req->rq_reqbuf, req->rq_reqlen,
 367                             &req->rq_reqhdr, &req->rq_req.mds);
 368         if (rc) {
 369                 printk("lustre_mds: Invalid request\n");
 370                 EXIT;
 371                 goto out;
 372         }
 373
 374         switch (req->rq_reqhdr->opc) {
 375
 376         case MDS_GETATTR:
 377                 CDEBUG(D_INODE, "getattr\n");
 378                 rc = mds_getattr(req);
 379                 break;
 380
 381         case MDS_READPAGE:
 382                 CDEBUG(D_INODE, "readpage\n");
 383                 rc = mds_readpage(req);
 384                 break;
 385
 386         case MDS_REINT:
 387                 CDEBUG(D_INODE, "reint\n");
 388                 rc = mds_reint(req);
 389                 break;
 390
 391         default:
 392                 return mds_error(req);
 393         }
 394
 395 out:
 396         if (rc) {
 397                 printk(__FUNCTION__ ": no header\n");
 398                 return 0;
 399         }
 400
 401         if( req->rq_status) {
 402                 mds_error(req);
 403         } else {
 404                 CDEBUG(D_INODE, "sending reply\n");
 405                 mds_reply(req);
 406         }
 407
 408         return 0;
 409 }
 410
 411
 412 static void mds_timer_run(unsigned long __data)
 413 {
 414         struct task_struct * p = (struct task_struct *) __data;
 415
 416         wake_up_process(p);
 417 }
 418
 419 int mds_main(void *arg)
 420 {
 421         struct mds_obd *mds = (struct mds_obd *) arg;
 422         struct timer_list timer;
 423
 424         lock_kernel();
 425         daemonize();
 426         spin_lock_irq(&current->sigmask_lock);
 427         sigfillset(&current->blocked);
 428         recalc_sigpending(current);
 429         spin_unlock_irq(&current->sigmask_lock);
 430
 431         sprintf(current->comm, "lustre_mds");
 432
 433         /* Set up an interval timer which can be used to trigger a
 434            wakeup after the interval expires */
 435         init_timer(&timer);
 436         timer.data = (unsigned long) current;
 437         timer.function = mds_timer_run;
 438         mds->mds_timer = &timer;
 439
 440         /* Record that the  thread is running */
 441         mds->mds_thread = current;
 442         wake_up(&mds->mds_done_waitq);
 443
 444         printk(KERN_INFO "lustre_mds starting.  Commit interval %d seconds\n",
 445                         mds->mds_interval / HZ);
 446
 447         /* XXX maintain a list of all managed devices: insert here */
 448
 449         /* And now, wait forever for commit wakeup events. */
 450         while (1) {
 451                 int rc;
 452
 453                 if (mds->mds_flags & MDS_UNMOUNT)
 454                         break;
 455
 456                 wake_up(&mds->mds_done_waitq);
 457                 interruptible_sleep_on(&mds->mds_waitq);
 458
 459                 CDEBUG(D_INODE, "lustre_mds wakes\n");
 460                 CDEBUG(D_INODE, "pick up req here and continue\n");
 461
 462                 if (mds->mds_service != NULL) {
 463                         ptl_event_t ev;
 464
 465                         while (1) {
 466                                 struct ptlrpc_request request;
 467                                 struct ptlrpc_service *service;
 468
 469                                 rc = PtlEQGet(mds->mds_service->srv_eq_h, &ev);
 470                                 if (rc != PTL_OK && rc != PTL_EQ_DROPPED)
 471                                         break;
 472
 473                                 service = (struct ptlrpc_service *)ev.mem_desc.user_ptr;
 474
 475                                 /* FIXME: If we move to an event-driven model,
 476                                  * we should put the request on the stack of
 477                                  * mds_handle instead. */
 478                                 memset(&request, 0, sizeof(request));
 479                                 request.rq_reqbuf = ev.mem_desc.start +
 480                                         ev.offset;
 481                                 request.rq_reqlen = ev.mem_desc.length;
 482                                 request.rq_obd = MDS;
 483                                 request.rq_xid = ev.match_bits;
 484
 485                                 request.rq_peer.peer_nid = ev.initiator.nid;
 486                                 /* FIXME: this NI should be the incoming NI.
 487                                  * We don't know how to find that from here. */
 488                                 request.rq_peer.peer_ni =
 489                                         mds->mds_service->srv_self.peer_ni;
 490                                 rc = mds_handle(&request);
 491
 492                                 /* Inform the rpc layer the event has been handled */
 493                                 ptl_received_rpc(service);
 494                         }
 495                 } else {
 496                         struct ptlrpc_request *request;
 497
 498                         if (list_empty(&mds->mds_reqs)) {
 499                                 CDEBUG(D_INODE, "woke because of timer\n");
 500                         } else {
 501                                 request = list_entry(mds->mds_reqs.next,
 502                                                      struct ptlrpc_request,
 503                                                      rq_list);
 504                                 list_del(&request->rq_list);
 505                                 rc = mds_handle(request);
 506                         }
 507                 }
 508         }
 509
 510         del_timer_sync(mds->mds_timer);
 511
 512         /* XXX maintain a list of all managed devices: cleanup here */
 513
 514         mds->mds_thread = NULL;
 515         wake_up(&mds->mds_done_waitq);
 516         printk("lustre_mds: exiting\n");
 517         return 0;
 518 }
 519
 520 static void mds_stop_srv_thread(struct mds_obd *mds)
 521 {
 522         mds->mds_flags |= MDS_UNMOUNT;
 523
 524         while (mds->mds_thread) {
 525                 wake_up(&mds->mds_waitq);
 526                 sleep_on(&mds->mds_done_waitq);
 527         }
 528 }
 529
 530 static void mds_start_srv_thread(struct mds_obd *mds)
 531 {
 532         init_waitqueue_head(&mds->mds_waitq);
 533         init_waitqueue_head(&mds->mds_done_waitq);
 534         kernel_thread(mds_main, (void *)mds,
 535                       CLONE_VM | CLONE_FS | CLONE_FILES);
 536         while (!mds->mds_thread)
 537                 sleep_on(&mds->mds_done_waitq);
 538 }
 539
 540 /* mount the file system (secretly) */
 541 static int mds_setup(struct obd_device *obddev, obd_count len,
 542                         void *buf)
 543
 544 {
 545         struct obd_ioctl_data* data = buf;
 546         struct mds_obd *mds = &obddev->u.mds;
 547         struct vfsmount *mnt;
 548         struct lustre_peer peer;
 549         int err;
 550         ENTRY;
 551
 552
 553         mnt = do_kern_mount(data->ioc_inlbuf2, 0, data->ioc_inlbuf1, NULL);
 554         err = PTR_ERR(mnt);
 555         if (IS_ERR(mnt)) {
 556                 EXIT;
 557                 return err;
 558         }
 559
 560         mds->mds_sb = mnt->mnt_root->d_inode->i_sb;
 561         if (!obddev->u.mds.mds_sb) {
 562                 EXIT;
 563                 return -ENODEV;
 564         }
 565
 566         mds->mds_vfsmnt = mnt;
 567         obddev->u.mds.mds_fstype = strdup(data->ioc_inlbuf2);
 568
 569         mds->mds_ctxt.pwdmnt = mnt;
 570         mds->mds_ctxt.pwd = mnt->mnt_root;
 571         mds->mds_ctxt.fs = KERNEL_DS;
 572         mds->mds_remote_nid = 0;
 573
 574         INIT_LIST_HEAD(&mds->mds_reqs);
 575         mds->mds_thread = NULL;
 576         mds->mds_flags = 0;
 577         mds->mds_interval = 3 * HZ;
 578         MDS = mds;
 579
 580         spin_lock_init(&obddev->u.mds.mds_lock);
 581
 582         err = kportal_uuid_to_peer("self", &peer);
 583         if (err == 0) {
 584                 OBD_ALLOC(mds->mds_service, sizeof(*mds->mds_service));
 585                 if (mds->mds_service == NULL)
 586                         return -ENOMEM;
 587                 mds->mds_service->srv_buf_size = 64 * 1024;
 588                 mds->mds_service->srv_portal = MDS_REQUEST_PORTAL;
 589                 memcpy(&mds->mds_service->srv_self, &peer, sizeof(peer));
 590                 mds->mds_service->srv_wait_queue = &mds->mds_waitq;
 591
 592                 rpc_register_service(mds->mds_service, "self");
 593         }
 594
 595         mds_start_srv_thread(mds);
 596
 597         MOD_INC_USE_COUNT;
 598         EXIT;
 599         return 0;
 600 }
 601
 602 static int mds_cleanup(struct obd_device * obddev)
 603 {
 604         struct super_block *sb;
 605         struct mds_obd *mds = &obddev->u.mds;
 606
 607         ENTRY;
 608
 609         if ( !(obddev->obd_flags & OBD_SET_UP) ) {
 610                 EXIT;
 611                 return 0;
 612         }
 613
 614         if ( !list_empty(&obddev->obd_gen_clients) ) {
 615                 printk(KERN_WARNING __FUNCTION__ ": still has clients!\n");
 616                 EXIT;
 617                 return -EBUSY;
 618         }
 619
 620         MDS = NULL;
 621         mds_stop_srv_thread(mds);
 622         rpc_unregister_service(mds->mds_service);
 623         OBD_FREE(mds->mds_service, sizeof(*mds->mds_service));
 624
 625         sb = mds->mds_sb;
 626         if (!mds->mds_sb){
 627                 EXIT;
 628                 return 0;
 629         }
 630
 631         if (!list_empty(&mds->mds_reqs)) {
 632                 // XXX reply with errors and clean up
 633                 CDEBUG(D_INODE, "Request list not empty!\n");
 634         }
 635
 636         unlock_kernel();
 637         mntput(mds->mds_vfsmnt);
 638         mds->mds_sb = 0;
 639         kfree(mds->mds_fstype);
 640         lock_kernel();
 641
 642         MOD_DEC_USE_COUNT;
 643         EXIT;
 644         return 0;
 645 }
 646
 647 /* use obd ops to offer management infrastructure */
 648 static struct obd_ops mds_obd_ops = {
 649         o_setup:       mds_setup,
 650         o_cleanup:     mds_cleanup,
 651 };
 652
 653 static int __init mds_init(void)
 654 {
 655         obd_register_type(&mds_obd_ops, LUSTRE_MDS_NAME);
 656         return 0;
 657 }
 658
 659 static void __exit mds_exit(void)
 660 {
 661         obd_unregister_type(LUSTRE_MDS_NAME);
 662 }
 663
 664 MODULE_AUTHOR("Peter J. Braam <braam@clusterfs.com>");
 665 MODULE_DESCRIPTION("Lustre Metadata Server (MDS) v0.01");
 666 MODULE_LICENSE("GPL");
 667
 668
 669 // for testing (maybe this stays)
 670 EXPORT_SYMBOL(mds_queue_req);
 671
 672 module_init(mds_init);
 673 module_exit(mds_exit);