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_free_delegation(struct nfs_delegation *delegation)
  24 {
  25         if (delegation->cred)
  26                 put_rpccred(delegation->cred);
  27         kfree(delegation);
  28 }
  29
  30 static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state)
  31 {
  32         struct inode *inode = state->inode;
  33         struct file_lock *fl;
  34         int status;
  35
  36         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
  37                 if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
  38                         continue;
  39                 if ((struct nfs_open_context *)fl->fl_file->private_data != ctx)
  40                         continue;
  41                 status = nfs4_lock_delegation_recall(state, fl);
  42                 if (status >= 0)
  43                         continue;
  44                 switch (status) {
  45                         default:
  46                                 printk(KERN_ERR "%s: unhandled error %d.\n",
  47                                                 __FUNCTION__, status);
  48                         case -NFS4ERR_EXPIRED:
  49                                 /* kill_proc(fl->fl_pid, SIGLOST, 1); */
  50                         case -NFS4ERR_STALE_CLIENTID:
  51                                 nfs4_schedule_state_recovery(NFS_SERVER(inode)->nfs_client);
  52                                 goto out_err;
  53                 }
  54         }
  55         return 0;
  56 out_err:
  57         return status;
  58 }
  59
  60 static void nfs_delegation_claim_opens(struct inode *inode)
  61 {
  62         struct nfs_inode *nfsi = NFS_I(inode);
  63         struct nfs_open_context *ctx;
  64         struct nfs4_state *state;
  65         int err;
  66
  67 again:
  68         spin_lock(&inode->i_lock);
  69         list_for_each_entry(ctx, &nfsi->open_files, list) {
  70                 state = ctx->state;
  71                 if (state == NULL)
  72                         continue;
  73                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
  74                         continue;
  75                 get_nfs_open_context(ctx);
  76                 spin_unlock(&inode->i_lock);
  77                 err = nfs4_open_delegation_recall(ctx->dentry, state);
  78                 if (err >= 0)
  79                         err = nfs_delegation_claim_locks(ctx, state);
  80                 put_nfs_open_context(ctx);
  81                 if (err != 0)
  82                         return;
  83                 goto again;
  84         }
  85         spin_unlock(&inode->i_lock);
  86 }
  87
  88 /*
  89  * Set up a delegation on an inode
  90  */
  91 void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
  92 {
  93         struct nfs_delegation *delegation = NFS_I(inode)->delegation;
  94
  95         if (delegation == NULL)
  96                 return;
  97         memcpy(delegation->stateid.data, res->delegation.data,
  98                         sizeof(delegation->stateid.data));
  99         delegation->type = res->delegation_type;
 100         delegation->maxsize = res->maxsize;
 101         put_rpccred(cred);
 102         delegation->cred = get_rpccred(cred);
 103         delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
 104         NFS_I(inode)->delegation_state = delegation->type;
 105         smp_wmb();
 106 }
 107
 108 /*
 109  * Set up a delegation on an inode
 110  */
 111 int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
 112 {
 113         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 114         struct nfs_inode *nfsi = NFS_I(inode);
 115         struct nfs_delegation *delegation;
 116         int status = 0;
 117
 118         /* Ensure we first revalidate the attributes and page cache! */
 119         if ((nfsi->cache_validity & (NFS_INO_REVAL_PAGECACHE|NFS_INO_INVALID_ATTR)))
 120                 __nfs_revalidate_inode(NFS_SERVER(inode), inode);
 121
 122         delegation = kmalloc(sizeof(*delegation), GFP_KERNEL);
 123         if (delegation == NULL)
 124                 return -ENOMEM;
 125         memcpy(delegation->stateid.data, res->delegation.data,
 126                         sizeof(delegation->stateid.data));
 127         delegation->type = res->delegation_type;
 128         delegation->maxsize = res->maxsize;
 129         delegation->change_attr = nfsi->change_attr;
 130         delegation->cred = get_rpccred(cred);
 131         delegation->inode = inode;
 132
 133         spin_lock(&clp->cl_lock);
 134         if (nfsi->delegation == NULL) {
 135                 list_add(&delegation->super_list, &clp->cl_delegations);
 136                 nfsi->delegation = delegation;
 137                 nfsi->delegation_state = delegation->type;
 138                 delegation = NULL;
 139         } else {
 140                 if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
 141                                         sizeof(delegation->stateid)) != 0 ||
 142                                 delegation->type != nfsi->delegation->type) {
 143                         printk("%s: server %u.%u.%u.%u, handed out a duplicate delegation!\n",
 144                                         __FUNCTION__, NIPQUAD(clp->cl_addr.sin_addr));
 145                         status = -EIO;
 146                 }
 147         }
 148         spin_unlock(&clp->cl_lock);
 149         kfree(delegation);
 150         return status;
 151 }
 152
 153 static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation)
 154 {
 155         int res = 0;
 156
 157         res = nfs4_proc_delegreturn(inode, delegation->cred, &delegation->stateid);
 158         nfs_free_delegation(delegation);
 159         return res;
 160 }
 161
 162 /* Sync all data to disk upon delegation return */
 163 static void nfs_msync_inode(struct inode *inode)
 164 {
 165         filemap_fdatawrite(inode->i_mapping);
 166         nfs_wb_all(inode);
 167         filemap_fdatawait(inode->i_mapping);
 168 }
 169
 170 /*
 171  * Basic procedure for returning a delegation to the server
 172  */
 173 int __nfs_inode_return_delegation(struct inode *inode)
 174 {
 175         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 176         struct nfs_inode *nfsi = NFS_I(inode);
 177         struct nfs_delegation *delegation;
 178         int res = 0;
 179
 180         nfs_msync_inode(inode);
 181         down_read(&clp->cl_sem);
 182         /* Guard against new delegated open calls */
 183         down_write(&nfsi->rwsem);
 184         spin_lock(&clp->cl_lock);
 185         delegation = nfsi->delegation;
 186         if (delegation != NULL) {
 187                 list_del_init(&delegation->super_list);
 188                 nfsi->delegation = NULL;
 189                 nfsi->delegation_state = 0;
 190         }
 191         spin_unlock(&clp->cl_lock);
 192         nfs_delegation_claim_opens(inode);
 193         up_write(&nfsi->rwsem);
 194         up_read(&clp->cl_sem);
 195         nfs_msync_inode(inode);
 196
 197         if (delegation != NULL)
 198                 res = nfs_do_return_delegation(inode, delegation);
 199         return res;
 200 }
 201
 202 /*
 203  * Return all delegations associated to a super block
 204  */
 205 void nfs_return_all_delegations(struct super_block *sb)
 206 {
 207         struct nfs_client *clp = NFS_SB(sb)->nfs_client;
 208         struct nfs_delegation *delegation;
 209         struct inode *inode;
 210
 211         if (clp == NULL)
 212                 return;
 213 restart:
 214         spin_lock(&clp->cl_lock);
 215         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 216                 if (delegation->inode->i_sb != sb)
 217                         continue;
 218                 inode = igrab(delegation->inode);
 219                 if (inode == NULL)
 220                         continue;
 221                 spin_unlock(&clp->cl_lock);
 222                 nfs_inode_return_delegation(inode);
 223                 iput(inode);
 224                 goto restart;
 225         }
 226         spin_unlock(&clp->cl_lock);
 227 }
 228
 229 int nfs_do_expire_all_delegations(void *ptr)
 230 {
 231         struct nfs_client *clp = ptr;
 232         struct nfs_delegation *delegation;
 233         struct inode *inode;
 234
 235         allow_signal(SIGKILL);
 236 restart:
 237         spin_lock(&clp->cl_lock);
 238         if (test_bit(NFS4CLNT_STATE_RECOVER, &clp->cl_state) != 0)
 239                 goto out;
 240         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0)
 241                 goto out;
 242         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 243                 inode = igrab(delegation->inode);
 244                 if (inode == NULL)
 245                         continue;
 246                 spin_unlock(&clp->cl_lock);
 247                 nfs_inode_return_delegation(inode);
 248                 iput(inode);
 249                 goto restart;
 250         }
 251 out:
 252         spin_unlock(&clp->cl_lock);
 253         nfs_put_client(clp);
 254         module_put_and_exit(0);
 255 }
 256
 257 void nfs_expire_all_delegations(struct nfs_client *clp)
 258 {
 259         struct task_struct *task;
 260
 261         __module_get(THIS_MODULE);
 262         atomic_inc(&clp->cl_count);
 263         task = kthread_run(nfs_do_expire_all_delegations, clp,
 264                         "%u.%u.%u.%u-delegreturn",
 265                         NIPQUAD(clp->cl_addr.sin_addr));
 266         if (!IS_ERR(task))
 267                 return;
 268         nfs_put_client(clp);
 269         module_put(THIS_MODULE);
 270 }
 271
 272 /*
 273  * Return all delegations following an NFS4ERR_CB_PATH_DOWN error.
 274  */
 275 void nfs_handle_cb_pathdown(struct nfs_client *clp)
 276 {
 277         struct nfs_delegation *delegation;
 278         struct inode *inode;
 279
 280         if (clp == NULL)
 281                 return;
 282 restart:
 283         spin_lock(&clp->cl_lock);
 284         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 285                 inode = igrab(delegation->inode);
 286                 if (inode == NULL)
 287                         continue;
 288                 spin_unlock(&clp->cl_lock);
 289                 nfs_inode_return_delegation(inode);
 290                 iput(inode);
 291                 goto restart;
 292         }
 293         spin_unlock(&clp->cl_lock);
 294 }
 295
 296 struct recall_threadargs {
 297         struct inode *inode;
 298         struct nfs_client *clp;
 299         const nfs4_stateid *stateid;
 300
 301         struct completion started;
 302         int result;
 303 };
 304
 305 static int recall_thread(void *data)
 306 {
 307         struct recall_threadargs *args = (struct recall_threadargs *)data;
 308         struct inode *inode = igrab(args->inode);
 309         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 310         struct nfs_inode *nfsi = NFS_I(inode);
 311         struct nfs_delegation *delegation;
 312
 313         daemonize("nfsv4-delegreturn");
 314
 315         nfs_msync_inode(inode);
 316         down_read(&clp->cl_sem);
 317         down_write(&nfsi->rwsem);
 318         spin_lock(&clp->cl_lock);
 319         delegation = nfsi->delegation;
 320         if (delegation != NULL && memcmp(delegation->stateid.data,
 321                                 args->stateid->data,
 322                                 sizeof(delegation->stateid.data)) == 0) {
 323                 list_del_init(&delegation->super_list);
 324                 nfsi->delegation = NULL;
 325                 nfsi->delegation_state = 0;
 326                 args->result = 0;
 327         } else {
 328                 delegation = NULL;
 329                 args->result = -ENOENT;
 330         }
 331         spin_unlock(&clp->cl_lock);
 332         complete(&args->started);
 333         nfs_delegation_claim_opens(inode);
 334         up_write(&nfsi->rwsem);
 335         up_read(&clp->cl_sem);
 336         nfs_msync_inode(inode);
 337
 338         if (delegation != NULL)
 339                 nfs_do_return_delegation(inode, delegation);
 340         iput(inode);
 341         module_put_and_exit(0);
 342 }
 343
 344 /*
 345  * Asynchronous delegation recall!
 346  */
 347 int nfs_async_inode_return_delegation(struct inode *inode, const nfs4_stateid *stateid)
 348 {
 349         struct recall_threadargs data = {
 350                 .inode = inode,
 351                 .stateid = stateid,
 352         };
 353         int status;
 354
 355         init_completion(&data.started);
 356         __module_get(THIS_MODULE);
 357         status = kernel_thread(recall_thread, &data, CLONE_KERNEL);
 358         if (status < 0)
 359                 goto out_module_put;
 360         wait_for_completion(&data.started);
 361         return data.result;
 362 out_module_put:
 363         module_put(THIS_MODULE);
 364         return status;
 365 }
 366
 367 /*
 368  * Retrieve the inode associated with a delegation
 369  */
 370 struct inode *nfs_delegation_find_inode(struct nfs_client *clp, const struct nfs_fh *fhandle)
 371 {
 372         struct nfs_delegation *delegation;
 373         struct inode *res = NULL;
 374         spin_lock(&clp->cl_lock);
 375         list_for_each_entry(delegation, &clp->cl_delegations, super_list) {
 376                 if (nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
 377                         res = igrab(delegation->inode);
 378                         break;
 379                 }
 380         }
 381         spin_unlock(&clp->cl_lock);
 382         return res;
 383 }
 384
 385 /*
 386  * Mark all delegations as needing to be reclaimed
 387  */
 388 void nfs_delegation_mark_reclaim(struct nfs_client *clp)
 389 {
 390         struct nfs_delegation *delegation;
 391         spin_lock(&clp->cl_lock);
 392         list_for_each_entry(delegation, &clp->cl_delegations, super_list)
 393                 delegation->flags |= NFS_DELEGATION_NEED_RECLAIM;
 394         spin_unlock(&clp->cl_lock);
 395 }
 396
 397 /*
 398  * Reap all unclaimed delegations after reboot recovery is done
 399  */
 400 void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
 401 {
 402         struct nfs_delegation *delegation, *n;
 403         LIST_HEAD(head);
 404         spin_lock(&clp->cl_lock);
 405         list_for_each_entry_safe(delegation, n, &clp->cl_delegations, super_list) {
 406                 if ((delegation->flags & NFS_DELEGATION_NEED_RECLAIM) == 0)
 407                         continue;
 408                 list_move(&delegation->super_list, &head);
 409                 NFS_I(delegation->inode)->delegation = NULL;
 410                 NFS_I(delegation->inode)->delegation_state = 0;
 411         }
 412         spin_unlock(&clp->cl_lock);
 413         while(!list_empty(&head)) {
 414                 delegation = list_entry(head.next, struct nfs_delegation, super_list);
 415                 list_del(&delegation->super_list);
 416                 nfs_free_delegation(delegation);
 417         }
 418 }
 419
 420 int nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
 421 {
 422         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
 423         struct nfs_inode *nfsi = NFS_I(inode);
 424         struct nfs_delegation *delegation;
 425         int res = 0;
 426
 427         if (nfsi->delegation_state == 0)
 428                 return 0;
 429         spin_lock(&clp->cl_lock);
 430         delegation = nfsi->delegation;
 431         if (delegation != NULL) {
 432                 memcpy(dst->data, delegation->stateid.data, sizeof(dst->data));
 433                 res = 1;
 434         }
 435         spin_unlock(&clp->cl_lock);
 436         return res;
 437 }