fs/nfs/delegation.c

   1 /*
   2  * linux/fs/nfs/delegation.c
   3  *
   4  * Copyright (C) 2004 Trond Myklebust
   5  *
   6  * NFS file delegation management
   7  *
   8  */
   9 #include <linux/completion.h>
  10 #include <linux/kthread.h>
  11 #include <linux/module.h>
  12 #include <linux/sched.h>
  13 #include <linux/spinlock.h>
  14
  15 #include <linux/nfs4.h>
  16 #include <linux/nfs_fs.h>
  17 #include <linux/nfs_xdr.h>
  18
  19 #include "nfs4_fs.h"
  20 #include "delegation.h"
  21 #include "internal.h"
  22
  23 static void nfs_do_free_delegation(struct nfs_delegation *delegation)
  24 {
  25         kfree(delegation);
  26 }
  27
  28 static void nfs_free_delegation_callback(struct rcu_head *head)
  29 {
  30         struct nfs_delegation *delegation = container_of(head, struct nfs_delegation, rcu);
  31
  32         nfs_do_free_delegation(delegation);
  33 }
  34
  35 static void nfs_free_delegation(struct nfs_delegation *delegation)
  36 {
  37         struct rpc_cred *cred;
  38
  39         cred = rcu_dereference(delegation->cred);
  40         rcu_assign_pointer(delegation->cred, NULL);
  41         call_rcu(&delegation->rcu, nfs_free_delegation_callback);
  42         if (cred)
  43                 put_rpccred(cred);
  44 }
  45
  46 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
  47 {
  48         struct inode *inode = state->inode;
  49         struct file_lock *fl;
  50         int status;
  51
  52 <<<<<<< HEAD:fs/nfs/delegation.c
  53         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
  54 =======
  55         for (fl = inode->i_flock; fl != NULL; fl = fl->fl_next) {
  56 >>>>>>> 264e3e889d86e552b4191d69bb60f4f3b383135a:fs/nfs/delegation.c
  57                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
  58                         continue;
  59                 if (nfs_file_open_context(fl->fl_file) != ctx)
  60                         continue;
  61                 status = nfs4_lock_delegation_recall(state, fl);
  62                 if (status >= 0)
  63                         continue;
  64                 switch (status) {
  65                         default:
  66                                 printk(KERN_ERR "%s: unhandled error %d.\n",
  67                                                 __FUNCTION__, status);
  68                         case -NFS4ERR_EXPIRED:
  69                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
  70                         case -NFS4ERR_STALE_CLIENTID:
  71                                 nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
  72                                 goto out_err;
  73                 }
  74         }
  75         return 0;
  76 out_err:
  77         return status;
  78 }
  79
  80 static void nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
  81 {
  82         struct nfs_inode *nfsi = NFS_I(inode);
  83         struct nfs_open_context *ctx;
  84         struct nfs4_state *state;
  85         int err;
  86
  87 again:
  88         spin_lock(&inode->i_lock);
  89         list_for_each_entry(ctx, &nfsi->open_files, list) {
  90                 state = ctx->state;
  91                 if (state == NULL)
  92                         continue;
  93                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
  94                         continue;
  95                 if (memcmp(state->stateid.data, stateid->data, sizeof(state->stateid.data)) != 0)
  96                         continue;
  97                 get_nfs_open_context(ctx);
  98                 spin_unlock(&inode->i_lock);
  99                 err = nfs4_open_delegation_recall(ctx, state, stateid);
 100                 if (err >= 0)
 101                         err = nfs_delegation_claim_locks(ctx, state);
 102                 put_nfs_open_context(ctx);
 103                 if (err != 0)
 104                         return;
 105                 goto again;
 106         }
 107         spin_unlock(&inode->i_lock);
 108 }
 109
 110 /*
 111  * Set up a delegation on an inode
 112  */
 113 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
 114 {
 115         struct nfs_delegation *delegation = NFS_I(inode)->delegation;
 116         struct rpc_cred *oldcred;
 117
 118         if (delegation == NULL)
 119                 return;
 120         memcpy(delegation->stateid.data, res->delegation.data,
 121                         sizeof(delegation->stateid.data));
 122         delegation->type = res->delegation_type;
 123         delegation->maxsize = res->maxsize;
 124         oldcred = delegation->cred;
 125         delegation->cred = get_rpccred(cred);
 126         delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
 127         NFS_I(inode)->delegation_state = delegation->type;
 128         smp_wmb();
 129         put_rpccred(oldcred);
 130 }
 131
 132 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
 133 {
 134         int res = 0;
 135
 136         res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid, issync);
 137         nfs_free_delegation(delegation);
 138         return res;
 139 }
 140
 141 static struct nfs_delegation *nfs_detach_delegation_locked(struct nfs_inode *nfsi, const nfs4_stateid *stateid)
 142 {
 143         struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
 144
 145         if (delegation == NULL)
 146                 goto nomatch;
 147         if (stateid != NULL && memcmp(delegation->stateid.data, stateid->data,
 148                                 sizeof(delegation->stateid.data)) != 0)
 149                 goto nomatch;
 150         list_del_rcu(&delegation->super_list);
 151         nfsi->delegation_state = 0;
 152         rcu_assign_pointer(nfsi->delegation, NULL);
 153         return delegation;
 154 nomatch:
 155         return NULL;
 156 }
 157
 158 /*
 159  * Set up a delegation on an inode
 160  */
 161 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
 162 {
 163         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 164         struct nfs_inode *nfsi = NFS_I(inode);
 165         struct nfs_delegation *delegation;
 166         struct nfs_delegation *freeme = NULL;
 167         int status = 0;
 168
 169         delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
 170         if (delegation == NULL)
 171                 return -ENOMEM;
 172         memcpy(delegation->stateid.data, res->delegation.data,
 173                         sizeof(delegation->stateid.data));
 174         delegation->type = res->delegation_type;
 175         delegation->maxsize = res->maxsize;
 176         delegation->change_attr = nfsi->change_attr;
 177         delegation->cred = get_rpccred(cred);
 178         delegation->inode = inode;
 179
 180         spin_lock(&clp->cl_lock);
 181         if (rcu_dereference(nfsi->delegation) != NULL) {
 182                 if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
 183                                         sizeof(delegation->stateid)) == 0 &&
 184                                 delegation->type == nfsi->delegation->type) {
 185                         goto out;
 186                 }
 187                 /*
 188                  * Deal with broken servers that hand out two
 189                  * delegations for the same file.
 190                  */
 191                 dfprintk(FILE, "%s: server %s handed out "
 192                                 "a duplicate delegation!\n",
 193                                 __FUNCTION__, clp->cl_hostname);
 194                 if (delegation->type <= nfsi->delegation->type) {
 195                         freeme = delegation;
 196                         delegation = NULL;
 197                         goto out;
 198                 }
 199                 freeme = nfs_detach_delegation_locked(nfsi, NULL);
 200         }
 201         list_add_rcu(&delegation->super_list, &clp->cl_delegations);
 202         nfsi->delegation_state = delegation->type;
 203         rcu_assign_pointer(nfsi->delegation, delegation);
 204         delegation = NULL;
 205
 206         /* Ensure we revalidate the attributes and page cache! */
 207         spin_lock(&inode->i_lock);
 208         nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
 209         spin_unlock(&inode->i_lock);
 210
 211 out:
 212         spin_unlock(&clp->cl_lock);
 213         if (delegation != NULL)
 214                 nfs_free_delegation(delegation);
 215         if (freeme != NULL)
 216                 nfs_do_return_delegation(inode, freeme, 0);
 217         return status;
 218 }
 219
 220 /* Sync all data to disk upon delegation return */
 221 static void nfs_msync_inode(struct inode *inode)
 222 {
 223         filemap_fdatawrite(inode->i_mapping);
 224         nfs_wb_all(inode);
 225         filemap_fdatawait(inode->i_mapping);
 226 }
 227
 228 /*
 229  * Basic procedure for returning a delegation to the server
 230  */
 231 static int __nfs_inode_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
 232 {
 233         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 234         struct nfs_inode *nfsi = NFS_I(inode);
 235
 236         nfs_msync_inode(inode);
 237         down_read(&clp->cl_sem);
 238         /* Guard against new delegated open calls */
 239         down_write(&nfsi->rwsem);
 240         nfs_delegation_claim_opens(inode, &delegation->stateid);
 241         up_write(&nfsi->rwsem);
 242         up_read(&clp->cl_sem);
 243         nfs_msync_inode(inode);
 244
 245         return nfs_do_return_delegation(inode, delegation, 1);
 246 }
 247
 248 /*
 249  * This function returns the delegation without reclaiming opens
 250  * or protecting against delegation reclaims.
 251  * It is therefore really only safe to be called from
 252  * nfs4_clear_inode()
 253  */
 254 void nfs_inode_return_delegation_noreclaim(struct inode *inode)
 255 {
 256         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 257         struct nfs_inode *nfsi = NFS_I(inode);
 258         struct nfs_delegation *delegation;
 259
 260         if (rcu_dereference(nfsi->delegation) != NULL) {
 261                 spin_lock(&clp->cl_lock);
 262                 delegation = nfs_detach_delegation_locked(nfsi, NULL);
 263                 spin_unlock(&clp->cl_lock);
 264                 if (delegation != NULL)
 265                         nfs_do_return_delegation(inode, delegation, 0);
 266         }
 267 }
 268
 269 int nfs_inode_return_delegation(struct inode *inode)
 270 {
 271         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 272         struct nfs_inode *nfsi = NFS_I(inode);
 273         struct nfs_delegation *delegation;
 274         int err = 0;
 275
 276         if (rcu_dereference(nfsi->delegation) != NULL) {
 277                 spin_lock(&clp->cl_lock);
 278                 delegation = nfs_detach_delegation_locked(nfsi, NULL);
 279                 spin_unlock(&clp->cl_lock);
 280                 if (delegation != NULL)
 281                         err = __nfs_inode_return_delegation(inode, delegation);
 282         }
 283         return err;
 284 }
 285
 286 /*
 287  * Return all delegations associated to a super block
 288  */
 289 void nfs_return_all_delegations(struct super_block *sb)
 290 {
 291         struct nfs_client *clp = NFS_SB(sb)->nfs_client;
 292         struct nfs_delegation *delegation;
 293         struct inode *inode;
 294
 295         if (clp == NULL)
 296                 return;
 297 restart:
 298         rcu_read_lock();
 299         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
 300                 if (delegation->inode->i_sb != sb)
 301                         continue;
 302                 inode = igrab(delegation->inode);
 303                 if (inode == NULL)
 304                         continue;
 305                 spin_lock(&clp->cl_lock);
 306                 delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
 307                 spin_unlock(&clp->cl_lock);
 308                 rcu_read_unlock();
 309                 if (delegation != NULL)
 310                         __nfs_inode_return_delegation(inode, delegation);
 311                 iput(inode);
 312                 goto restart;
 313         }
 314         rcu_read_unlock();
 315 }
 316
 317 static int nfs_do_expire_all_delegations(void *ptr)
 318 {
 319         struct nfs_client *clp = ptr;
 320         struct nfs_delegation *delegation;
 321         struct inode *inode;
 322
 323         allow_signal(SIGKILL);
 324 restart:
 325         if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
 326                 goto out;
 327         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
 328                 goto out;
 329         rcu_read_lock();
 330         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
 331                 inode = igrab(delegation->inode);
 332                 if (inode == NULL)
 333                         continue;
 334                 spin_lock(&clp->cl_lock);
 335                 delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
 336                 spin_unlock(&clp->cl_lock);
 337                 rcu_read_unlock();
 338                 if (delegation)
 339                         __nfs_inode_return_delegation(inode, delegation);
 340                 iput(inode);
 341                 goto restart;
 342         }
 343         rcu_read_unlock();
 344 out:
 345         nfs_put_client(clp);
 346         module_put_and_exit(0);
 347 }
 348
 349 void nfs_expire_all_delegations(struct nfs_client *clp)
 350 {
 351         struct task_struct *task;
 352
 353         __module_get(THIS_MODULE);
 354         atomic_inc(&clp->cl_count);
 355         task = kthread_run(nfs_do_expire_all_delegations, clp,
 356                                 "%s-delegreturn",
 357                                 rpc_peeraddr2str(clp->cl_rpcclient,
 358                                                         RPC_DISPLAY_ADDR));
 359         if (!IS_ERR(task))
 360                 return;
 361         nfs_put_client(clp);
 362         module_put(THIS_MODULE);
 363 }
 364
 365 /*
 366  * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
 367  */
 368 void nfs_handle_cb_pathdown(struct nfs_client *clp)
 369 {
 370         struct nfs_delegation *delegation;
 371         struct inode *inode;
 372
 373         if (clp == NULL)
 374                 return;
 375 restart:
 376         rcu_read_lock();
 377         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
 378                 inode = igrab(delegation->inode);
 379                 if (inode == NULL)
 380                         continue;
 381                 spin_lock(&clp->cl_lock);
 382                 delegation = nfs_detach_delegation_locked(NFS_I(inode), NULL);
 383                 spin_unlock(&clp->cl_lock);
 384                 rcu_read_unlock();
 385                 if (delegation != NULL)
 386                         __nfs_inode_return_delegation(inode, delegation);
 387                 iput(inode);
 388                 goto restart;
 389         }
 390         rcu_read_unlock();
 391 }
 392
 393 struct recall_threadargs {
 394         struct inode *inode;
 395         struct nfs_client *clp;
 396         const nfs4_stateid *stateid;
 397
 398         struct completion started;
 399         int result;
 400 };
 401
 402 static int recall_thread(void *data)
 403 {
 404         struct recall_threadargs *args = (struct recall_threadargs *)data;
 405         struct inode *inode = igrab(args->inode);
 406         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 407         struct nfs_inode *nfsi = NFS_I(inode);
 408         struct nfs_delegation *delegation;
 409
 410         daemonize("nfsv4-delegreturn");
 411
 412         nfs_msync_inode(inode);
 413         down_read(&clp->cl_sem);
 414         down_write(&nfsi->rwsem);
 415         spin_lock(&clp->cl_lock);
 416         delegation = nfs_detach_delegation_locked(nfsi, args->stateid);
 417         if (delegation != NULL)
 418                 args->result = 0;
 419         else
 420                 args->result = -ENOENT;
 421         spin_unlock(&clp->cl_lock);
 422         complete(&args->started);
 423         nfs_delegation_claim_opens(inode, args->stateid);
 424         up_write(&nfsi->rwsem);
 425         up_read(&clp->cl_sem);
 426         nfs_msync_inode(inode);
 427
 428         if (delegation != NULL)
 429                 nfs_do_return_delegation(inode, delegation, 1);
 430         iput(inode);
 431         module_put_and_exit(0);
 432 }
 433
 434 /*
 435  * Asynchronous delegation recall!
 436  */
 437 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
 438 {
 439         struct recall_threadargs data = {
 440                 .inode = inode,
 441                 .stateid = stateid,
 442         };
 443         int status;
 444
 445         init_completion(&data.started);
 446         __module_get(THIS_MODULE);
 447         status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
 448         if (status < 0)
 449                 goto out_module_put;
 450         wait_for_completion(&data.started);
 451         return data.result;
 452 out_module_put:
 453         module_put(THIS_MODULE);
 454         return status;
 455 }
 456
 457 /*
 458  * Retrieve the inode associated with a delegation
 459  */
 460 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
 461 {
 462         struct nfs_delegation *delegation;
 463         struct inode *res = NULL;
 464         rcu_read_lock();
 465         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
 466                 if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
 467                         res = igrab(delegation->inode);
 468                         break;
 469                 }
 470         }
 471         rcu_read_unlock();
 472         return res;
 473 }
 474
 475 /*
 476  * Mark all delegations as needing to be reclaimed
 477  */
 478 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
 479 {
 480         struct nfs_delegation *delegation;
 481         rcu_read_lock();
 482         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list)
 483                 delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
 484         rcu_read_unlock();
 485 }
 486
 487 /*
 488  * Reap all unclaimed delegations after reboot recovery is done
 489  */
 490 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 491 {
 492         struct nfs_delegation *delegation;
 493 restart:
 494         rcu_read_lock();
 495         list_for_each_entry_rcu(delegation, &clp->cl_delegations, super_list) {
 496                 if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
 497                         continue;
 498                 spin_lock(&clp->cl_lock);
 499                 delegation = nfs_detach_delegation_locked(NFS_I(delegation->inode), NULL);
 500                 spin_unlock(&clp->cl_lock);
 501                 rcu_read_unlock();
 502                 if (delegation != NULL)
 503                         nfs_free_delegation(delegation);
 504                 goto restart;
 505         }
 506         rcu_read_unlock();
 507 }
 508
 509 int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
 510 {
 511         struct nfs_inode *nfsi = NFS_I(inode);
 512         struct nfs_delegation *delegation;
 513         int ret = 0;
 514
 515         rcu_read_lock();
 516         delegation = rcu_dereference(nfsi->delegation);
 517         if (delegation != NULL) {
 518                 memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
 519                 ret = 1;
 520         }
 521         rcu_read_unlock();
 522         return ret;
 523 }