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/config.h>
  10 #include <linux/completion.h>
  11 #include <linux/kthread.h>
  12 #include <linux/module.h>
  13 #include <linux/sched.h>
  14 #include <linux/spinlock.h>
  15
  16 #include <linux/nfs4.h>
  17 #include <linux/nfs_fs.h>
  18 #include <linux/nfs_xdr.h>
  19
  20 #include "nfs4_fs.h"
  21 #include "delegation.h"
  22
  23 static struct nfs_delegation *nfs_alloc_delegation(void)
  24 {
  25         return (struct nfs_delegation *)kmalloc(sizeof(struct nfs_delegation), GFP_KERNEL);
  26 }
  27
  28 static void nfs_free_delegation(struct nfs_delegation *delegation)
  29 {
  30         if (delegation->cred)
  31                 put_rpccred(delegation->cred);
  32         kfree(delegation);
  33 }
  34
  35 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
  36 {
  37         struct inode *inode = state->inode;
  38         struct file_lock *fl;
  39         int status;
  40
  41         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
  42                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
  43                         continue;
  44                 if ((struct nfs_open_context *)fl->fl_file->private_data != ctx)
  45                         continue;
  46                 status = nfs4_lock_delegation_recall(state, fl);
  47                 if (status >= 0)
  48                         continue;
  49                 switch (status) {
  50                         default:
  51                                 printk(KERN_ERR "%s: unhandled error %d.\n",
  52                                                 __FUNCTION__, status);
  53                         case -NFS4ERR_EXPIRED:
  54                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
  55                         case -NFS4ERR_STALE_CLIENTID:
  56                                 nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs4_state);
  57                                 goto out_err;
  58                 }
  59         }
  60         return 0;
  61 out_err:
  62         return status;
  63 }
  64
  65 static void nfs_delegation_claim_opens(struct inode *inode)
  66 {
  67         struct nfs_inode *nfsi = NFS_I(inode);
  68         struct nfs_open_context *ctx;
  69         struct nfs4_state *state;
  70         int err;
  71
  72 again:
  73         spin_lock(&inode->i_lock);
  74         list_for_each_entry(ctx, &nfsi->open_files, list) {
  75                 state = ctx->state;
  76                 if (state == NULL)
  77                         continue;
  78                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
  79                         continue;
  80                 get_nfs_open_context(ctx);
  81                 spin_unlock(&inode->i_lock);
  82                 err = nfs4_open_delegation_recall(ctx->dentry, state);
  83                 if (err >= 0)
  84                         err = nfs_delegation_claim_locks(ctx, state);
  85                 put_nfs_open_context(ctx);
  86                 if (err != 0)
  87                         return;
  88                 goto again;
  89         }
  90         spin_unlock(&inode->i_lock);
  91 }
  92
  93 /*
  94  * Set up a delegation on an inode
  95  */
  96 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
  97 {
  98         struct nfs_delegation *delegation = NFS_I(inode)->delegation;
  99
 100         if (delegation == NULL)
 101                 return;
 102         memcpy(delegation->stateid.data, res->delegation.data,
 103                         sizeof(delegation->stateid.data));
 104         delegation->type = res->delegation_type;
 105         delegation->maxsize = res->maxsize;
 106         put_rpccred(cred);
 107         delegation->cred = get_rpccred(cred);
 108         delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
 109         NFS_I(inode)->delegation_state = delegation->type;
 110         smp_wmb();
 111 }
 112
 113 /*
 114  * Set up a delegation on an inode
 115  */
 116 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
 117 {
 118         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
 119         struct nfs_inode *nfsi = NFS_I(inode);
 120         struct nfs_delegation *delegation;
 121         int status = 0;
 122
 123         /* Ensure we first revalidate the attributes and page cache! */
 124         if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
 125                 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
 126
 127         delegation = nfs_alloc_delegation();
 128         if (delegation == NULL)
 129                 return -ENOMEM;
 130         memcpy(delegation->stateid.data, res->delegation.data,
 131                         sizeof(delegation->stateid.data));
 132         delegation->type = res->delegation_type;
 133         delegation->maxsize = res->maxsize;
 134         delegation->cred = get_rpccred(cred);
 135         delegation->inode = inode;
 136
 137         spin_lock(&clp->cl_lock);
 138         if (nfsi->delegation == NULL) {
 139                 list_add(&delegation->super_list, &clp->cl_delegations);
 140                 nfsi->delegation = delegation;
 141                 nfsi->delegation_state = delegation->type;
 142                 delegation = NULL;
 143         } else {
 144                 if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
 145                                         sizeof(delegation->stateid)) != 0 ||
 146                                 delegation->type != nfsi->delegation->type) {
 147                         printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
 148                                         __FUNCTION__, NIPQUAD(clp->cl_addr));
 149                         status = -EIO;
 150                 }
 151         }
 152         spin_unlock(&clp->cl_lock);
 153         kfree(delegation);
 154         return status;
 155 }
 156
 157 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
 158 {
 159         int res = 0;
 160
 161         __nfs_revalidate_inode(NFS_SERVER(inode), inode);
 162
 163         res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
 164         nfs_free_delegation(delegation);
 165         return res;
 166 }
 167
 168 /* Sync all data to disk upon delegation return */
 169 static void nfs_msync_inode(struct inode *inode)
 170 {
 171         filemap_fdatawrite(inode->i_mapping);
 172         nfs_wb_all(inode);
 173         filemap_fdatawait(inode->i_mapping);
 174 }
 175
 176 /*
 177  * Basic procedure for returning a delegation to the server
 178  */
 179 int __nfs_inode_return_delegation(struct inode *inode)
 180 {
 181         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
 182         struct nfs_inode *nfsi = NFS_I(inode);
 183         struct nfs_delegation *delegation;
 184         int res = 0;
 185
 186         nfs_msync_inode(inode);
 187         down_read(&clp->cl_sem);
 188         /* Guard against new delegated open calls */
 189         down_write(&nfsi->rwsem);
 190         spin_lock(&clp->cl_lock);
 191         delegation = nfsi->delegation;
 192         if (delegation != NULL) {
 193                 list_del_init(&delegation->super_list);
 194                 nfsi->delegation = NULL;
 195                 nfsi->delegation_state = 0;
 196         }
 197         spin_unlock(&clp->cl_lock);
 198         nfs_delegation_claim_opens(inode);
 199         up_write(&nfsi->rwsem);
 200         up_read(&clp->cl_sem);
 201         nfs_msync_inode(inode);
 202
 203         if (delegation != NULL)
 204                 res = nfs_do_return_delegation(inode, delegation);
 205         return res;
 206 }
 207
 208 /*
 209  * Return all delegations associated to a super block
 210  */
 211 void nfs_return_all_delegations(struct super_block *sb)
 212 {
 213         struct nfs4_client *clp = NFS_SB(sb)->nfs4_state;
 214         struct nfs_delegation *delegation;
 215         struct inode *inode;
 216
 217         if (clp == NULL)
 218                 return;
 219 restart:
 220         spin_lock(&clp->cl_lock);
 221         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 222                 if (delegation->inode->i_sb != sb)
 223                         continue;
 224                 inode = igrab(delegation->inode);
 225                 if (inode == NULL)
 226                         continue;
 227                 spin_unlock(&clp->cl_lock);
 228                 nfs_inode_return_delegation(inode);
 229                 iput(inode);
 230                 goto restart;
 231         }
 232         spin_unlock(&clp->cl_lock);
 233 }
 234
 235 int nfs_do_expire_all_delegations(void *ptr)
 236 {
 237         struct nfs4_client *clp = ptr;
 238         struct nfs_delegation *delegation;
 239         struct inode *inode;
 240         int err = 0;
 241
 242         allow_signal(SIGKILL);
 243 restart:
 244         spin_lock(&clp->cl_lock);
 245         if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
 246                 goto out;
 247         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
 248                 goto out;
 249         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 250                 inode = igrab(delegation->inode);
 251                 if (inode == NULL)
 252                         continue;
 253                 spin_unlock(&clp->cl_lock);
 254                 err = nfs_inode_return_delegation(inode);
 255                 iput(inode);
 256                 if (!err)
 257                         goto restart;
 258         }
 259 out:
 260         spin_unlock(&clp->cl_lock);
 261         nfs4_put_client(clp);
 262         module_put_and_exit(0);
 263 }
 264
 265 void nfs_expire_all_delegations(struct nfs4_client *clp)
 266 {
 267         struct task_struct *task;
 268
 269         __module_get(THIS_MODULE);
 270         atomic_inc(&clp->cl_count);
 271         task = kthread_run(nfs_do_expire_all_delegations, clp,
 272                         "%u.%u.%u.%u-delegreturn",
 273                         NIPQUAD(clp->cl_addr));
 274         if (!IS_ERR(task))
 275                 return;
 276         nfs4_put_client(clp);
 277         module_put(THIS_MODULE);
 278 }
 279
 280 /*
 281  * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
 282  */
 283 void nfs_handle_cb_pathdown(struct nfs4_client *clp)
 284 {
 285         struct nfs_delegation *delegation;
 286         struct inode *inode;
 287
 288         if (clp == NULL)
 289                 return;
 290 restart:
 291         spin_lock(&clp->cl_lock);
 292         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 293                 inode = igrab(delegation->inode);
 294                 if (inode == NULL)
 295                         continue;
 296                 spin_unlock(&clp->cl_lock);
 297                 nfs_inode_return_delegation(inode);
 298                 iput(inode);
 299                 goto restart;
 300         }
 301         spin_unlock(&clp->cl_lock);
 302 }
 303
 304 struct recall_threadargs {
 305         struct inode *inode;
 306         struct nfs4_client *clp;
 307         const nfs4_stateid *stateid;
 308
 309         struct completion started;
 310         int result;
 311 };
 312
 313 static int recall_thread(void *data)
 314 {
 315         struct recall_threadargs *args = (struct recall_threadargs *)data;
 316         struct inode *inode = igrab(args->inode);
 317         struct nfs4_client *clp = NFS_SERVER(inode)->nfs4_state;
 318         struct nfs_inode *nfsi = NFS_I(inode);
 319         struct nfs_delegation *delegation;
 320
 321         daemonize("nfsv4-delegreturn");
 322
 323         nfs_msync_inode(inode);
 324         down_read(&clp->cl_sem);
 325         down_write(&nfsi->rwsem);
 326         spin_lock(&clp->cl_lock);
 327         delegation = nfsi->delegation;
 328         if (delegation != NULL && memcmp(delegation->stateid.data,
 329                                 args->stateid->data,
 330                                 sizeof(delegation->stateid.data)) == 0) {
 331                 list_del_init(&delegation->super_list);
 332                 nfsi->delegation = NULL;
 333                 nfsi->delegation_state = 0;
 334                 args->result = 0;
 335         } else {
 336                 delegation = NULL;
 337                 args->result = -ENOENT;
 338         }
 339         spin_unlock(&clp->cl_lock);
 340         complete(&args->started);
 341         nfs_delegation_claim_opens(inode);
 342         up_write(&nfsi->rwsem);
 343         up_read(&clp->cl_sem);
 344         nfs_msync_inode(inode);
 345
 346         if (delegation != NULL)
 347                 nfs_do_return_delegation(inode, delegation);
 348         iput(inode);
 349         module_put_and_exit(0);
 350 }
 351
 352 /*
 353  * Asynchronous delegation recall!
 354  */
 355 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
 356 {
 357         struct recall_threadargs data = {
 358                 .inode = inode,
 359                 .stateid = stateid,
 360         };
 361         int status;
 362
 363         init_completion(&data.started);
 364         __module_get(THIS_MODULE);
 365         status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
 366         if (status < 0)
 367                 goto out_module_put;
 368         wait_for_completion(&data.started);
 369         return data.result;
 370 out_module_put:
 371         module_put(THIS_MODULE);
 372         return status;
 373 }
 374
 375 /*
 376  * Retrieve the inode associated with a delegation
 377  */
 378 struct inode *nfs_delegation_find_inode(struct nfs4_client *clp, const struct nfs_fh *fhandle)
 379 {
 380         struct nfs_delegation *delegation;
 381         struct inode *res = NULL;
 382         spin_lock(&clp->cl_lock);
 383         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 384                 if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
 385                         res = igrab(delegation->inode);
 386                         break;
 387                 }
 388         }
 389         spin_unlock(&clp->cl_lock);
 390         return res;
 391 }
 392
 393 /*
 394  * Mark all delegations as needing to be reclaimed
 395  */
 396 void nfs_delegation_mark_reclaim(struct nfs4_client *clp)
 397 {
 398         struct nfs_delegation *delegation;
 399         spin_lock(&clp->cl_lock);
 400         list_for_each_entry(delegation, &clp->cl_delegations, super_list)
 401                 delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
 402         spin_unlock(&clp->cl_lock);
 403 }
 404
 405 /*
 406  * Reap all unclaimed delegations after reboot recovery is done
 407  */
 408 void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
 409 {
 410         struct nfs_delegation *delegation, *n;
 411         LIST_HEAD(head);
 412         spin_lock(&clp->cl_lock);
 413         list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
 414                 if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
 415                         continue;
 416                 list_move(&delegation->super_list, &head);
 417                 NFS_I(delegation->inode)->delegation = NULL;
 418                 NFS_I(delegation->inode)->delegation_state = 0;
 419         }
 420         spin_unlock(&clp->cl_lock);
 421         while(!list_empty(&head)) {
 422                 delegation = list_entry(head.next, struct nfs_delegation, super_list);
 423                 list_del(&delegation->super_list);
 424                 nfs_free_delegation(delegation);
 425         }
 426 }