fs/nfs/callback_proc.c

   1 /*
   2  * linux/fs/nfs/callback_proc.c
   3  *
   4  * Copyright (C) 2004 Trond Myklebust
   5  *
   6  * NFSv4 callback procedures
   7  */
   8 #include <linux/nfs4.h>
   9 #include <linux/nfs_fs.h>
  10 #include <linux/slab.h>
  11 #include "nfs4_fs.h"
  12 #include "callback.h"
  13 #include "delegation.h"
  14 #include "internal.h"
  15
  16 #ifdef NFS_DEBUG
  17 #define NFSDBG_FACILITY NFSDBG_CALLBACK
  18 #endif
  19
  20 __be32 nfs4_callback_getattr(struct cb_getattrargs *args, struct cb_getattrres *res)
  21 {
  22         struct nfs_client *clp;
  23         struct nfs_delegation *delegation;
  24         struct nfs_inode *nfsi;
  25         struct inode *inode;
  26
  27         res->bitmap[0] = res->bitmap[1] = 0;
  28         res->status = htonl(NFS4ERR_BADHANDLE);
  29         clp = nfs_find_client(args->addr, 4);
  30         if (clp == NULL)
  31                 goto out;
  32
  33         dprintk("NFS: GETATTR callback request from %s\n",
  34                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
  35
  36         inode = nfs_delegation_find_inode(clp, &args->fh);
  37         if (inode == NULL)
  38                 goto out_putclient;
  39         nfsi = NFS_I(inode);
  40         down_read(&nfsi->rwsem);
  41         delegation = nfsi->delegation;
  42         if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
  43                 goto out_iput;
  44         res->size = i_size_read(inode);
  45         res->change_attr = delegation->change_attr;
  46         if (nfsi->npages != 0)
  47                 res->change_attr++;
  48         res->ctime = inode->i_ctime;
  49         res->mtime = inode->i_mtime;
  50         res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
  51                 args->bitmap[0];
  52         res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
  53                 args->bitmap[1];
  54         res->status = 0;
  55 out_iput:
  56         up_read(&nfsi->rwsem);
  57         iput(inode);
  58 out_putclient:
  59         nfs_put_client(clp);
  60 out:
  61         dprintk("%s: exit with status = %d\n", __func__, ntohl(res->status));
  62         return res->status;
  63 }
  64
  65 static int (*nfs_validate_delegation_stateid(struct nfs_client *clp))(struct nfs_delegation *, const nfs4_stateid *)
  66 {
  67 #if defined(CONFIG_NFS_V4_1)
  68         if (clp->cl_minorversion > 0)
  69                 return nfs41_validate_delegation_stateid;
  70 #endif
  71         return nfs4_validate_delegation_stateid;
  72 }
  73
  74
  75 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
  76 {
  77         struct nfs_client *clp;
  78         struct inode *inode;
  79         __be32 res;
  80
  81         res = htonl(NFS4ERR_BADHANDLE);
  82         clp = nfs_find_client(args->addr, 4);
  83         if (clp == NULL)
  84                 goto out;
  85
  86         dprintk("NFS: RECALL callback request from %s\n",
  87                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
  88
  89         do {
  90                 struct nfs_client *prev = clp;
  91
  92                 inode = nfs_delegation_find_inode(clp, &args->fh);
  93                 if (inode != NULL) {
  94                         /* Set up a helper thread to actually return the delegation */
  95                         switch (nfs_async_inode_return_delegation(inode, &args->stateid,
  96                                                                   nfs_validate_delegation_stateid(clp))) {
  97                                 case 0:
  98                                         res = 0;
  99                                         break;
 100                                 case -ENOENT:
 101                                         if (res != 0)
 102                                                 res = htonl(NFS4ERR_BAD_STATEID);
 103                                         break;
 104                                 default:
 105                                         res = htonl(NFS4ERR_RESOURCE);
 106                         }
 107                         iput(inode);
 108                 }
 109                 clp = nfs_find_client_next(prev);
 110                 nfs_put_client(prev);
 111         } while (clp != NULL);
 112 out:
 113         dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
 114         return res;
 115 }
 116
 117 int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 118 {
 119         if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
 120                                          sizeof(delegation->stateid.data)) != 0)
 121                 return 0;
 122         return 1;
 123 }
 124
 125 #if defined(CONFIG_NFS_V4_1)
 126
 127 int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 128 {
 129         if (delegation == NULL)
 130                 return 0;
 131
 132         /* seqid is 4-bytes long */
 133         if (((u32 *) &stateid->data)[0] != 0)
 134                 return 0;
 135         if (memcmp(&delegation->stateid.data[4], &stateid->data[4],
 136                    sizeof(stateid->data)-4))
 137                 return 0;
 138
 139         return 1;
 140 }
 141
 142 /*
 143  * Validate the sequenceID sent by the server.
 144  * Return success if the sequenceID is one more than what we last saw on
 145  * this slot, accounting for wraparound.  Increments the slot's sequence.
 146  *
 147  * We don't yet implement a duplicate request cache, instead we set the
 148  * back channel ca_maxresponsesize_cached to zero. This is OK for now
 149  * since we only currently implement idempotent callbacks anyway.
 150  *
 151  * We have a single slot backchannel at this time, so we don't bother
 152  * checking the used_slots bit array on the table.  The lower layer guarantees
 153  * a single outstanding callback request at a time.
 154  */
 155 static __be32
 156 validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
 157 {
 158         struct nfs4_slot *slot;
 159
 160         dprintk("%s enter. slotid %d seqid %d\n",
 161                 __func__, args->csa_slotid, args->csa_sequenceid);
 162
 163         if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
 164                 return htonl(NFS4ERR_BADSLOT);
 165
 166         slot = tbl->slots + args->csa_slotid;
 167         dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
 168
 169         /* Normal */
 170         if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
 171                 slot->seq_nr++;
 172                 return htonl(NFS4_OK);
 173         }
 174
 175         /* Replay */
 176         if (args->csa_sequenceid == slot->seq_nr) {
 177                 dprintk("%s seqid %d is a replay\n",
 178                         __func__, args->csa_sequenceid);
 179                 /* Signal process_op to set this error on next op */
 180                 if (args->csa_cachethis == 0)
 181                         return htonl(NFS4ERR_RETRY_UNCACHED_REP);
 182
 183                 /* The ca_maxresponsesize_cached is 0 with no DRC */
 184                 else if (args->csa_cachethis == 1)
 185                         return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
 186         }
 187
 188         /* Wraparound */
 189         if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
 190                 slot->seq_nr = 1;
 191                 return htonl(NFS4_OK);
 192         }
 193
 194         /* Misordered request */
 195         return htonl(NFS4ERR_SEQ_MISORDERED);
 196 }
 197
 198 /*
 199  * Returns a pointer to a held 'struct nfs_client' that matches the server's
 200  * address, major version number, and session ID.  It is the caller's
 201  * responsibility to release the returned reference.
 202  *
 203  * Returns NULL if there are no connections with sessions, or if no session
 204  * matches the one of interest.
 205  */
 206  static struct nfs_client *find_client_with_session(
 207         const struct sockaddr *addr, u32 nfsversion,
 208         struct nfs4_sessionid *sessionid)
 209 {
 210         struct nfs_client *clp;
 211
 212         clp = nfs_find_client(addr, 4);
 213         if (clp == NULL)
 214                 return NULL;
 215
 216         do {
 217                 struct nfs_client *prev = clp;
 218
 219                 if (clp->cl_session != NULL) {
 220                         if (memcmp(clp->cl_session->sess_id.data,
 221                                         sessionid->data,
 222                                         NFS4_MAX_SESSIONID_LEN) == 0) {
 223                                 /* Returns a held reference to clp */
 224                                 return clp;
 225                         }
 226                 }
 227                 clp = nfs_find_client_next(prev);
 228                 nfs_put_client(prev);
 229         } while (clp != NULL);
 230
 231         return NULL;
 232 }
 233
 234 /*
 235  * For each referring call triple, check the session's slot table for
 236  * a match.  If the slot is in use and the sequence numbers match, the
 237  * client is still waiting for a response to the original request.
 238  */
 239 static bool referring_call_exists(struct nfs_client *clp,
 240                                   uint32_t nrclists,
 241                                   struct referring_call_list *rclists)
 242 {
 243         bool status = 0;
 244         int i, j;
 245         struct nfs4_session *session;
 246         struct nfs4_slot_table *tbl;
 247         struct referring_call_list *rclist;
 248         struct referring_call *ref;
 249
 250         /*
 251          * XXX When client trunking is implemented, this becomes
 252          * a session lookup from within the loop
 253          */
 254         session = clp->cl_session;
 255         tbl = &session->fc_slot_table;
 256
 257         for (i = 0; i < nrclists; i++) {
 258                 rclist = &rclists[i];
 259                 if (memcmp(session->sess_id.data,
 260                            rclist->rcl_sessionid.data,
 261                            NFS4_MAX_SESSIONID_LEN) != 0)
 262                         continue;
 263
 264                 for (j = 0; j < rclist->rcl_nrefcalls; j++) {
 265                         ref = &rclist->rcl_refcalls[j];
 266
 267                         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
 268                                 "slotid %u\n", __func__,
 269                                 ((u32 *)&rclist->rcl_sessionid.data)[0],
 270                                 ((u32 *)&rclist->rcl_sessionid.data)[1],
 271                                 ((u32 *)&rclist->rcl_sessionid.data)[2],
 272                                 ((u32 *)&rclist->rcl_sessionid.data)[3],
 273                                 ref->rc_sequenceid, ref->rc_slotid);
 274
 275                         spin_lock(&tbl->slot_tbl_lock);
 276                         status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
 277                                   tbl->slots[ref->rc_slotid].seq_nr ==
 278                                         ref->rc_sequenceid);
 279                         spin_unlock(&tbl->slot_tbl_lock);
 280                         if (status)
 281                                 goto out;
 282                 }
 283         }
 284
 285 out:
 286         return status;
 287 }
 288
 289 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
 290                                 struct cb_sequenceres *res)
 291 {
 292         struct nfs_client *clp;
 293         int i;
 294         __be32 status;
 295
 296         status = htonl(NFS4ERR_BADSESSION);
 297         clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid);
 298         if (clp == NULL)
 299                 goto out;
 300
 301         status = validate_seqid(&clp->cl_session->bc_slot_table, args);
 302         if (status)
 303                 goto out_putclient;
 304
 305         /*
 306          * Check for pending referring calls.  If a match is found, a
 307          * related callback was received before the response to the original
 308          * call.
 309          */
 310         if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
 311                 status = htonl(NFS4ERR_DELAY);
 312                 goto out_putclient;
 313         }
 314
 315         memcpy(&res->csr_sessionid, &args->csa_sessionid,
 316                sizeof(res->csr_sessionid));
 317         res->csr_sequenceid = args->csa_sequenceid;
 318         res->csr_slotid = args->csa_slotid;
 319         res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 320         res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 321
 322 out_putclient:
 323         nfs_put_client(clp);
 324 out:
 325         for (i = 0; i < args->csa_nrclists; i++)
 326                 kfree(args->csa_rclists[i].rcl_refcalls);
 327         kfree(args->csa_rclists);
 328
 329         if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP))
 330                 res->csr_status = 0;
 331         else
 332                 res->csr_status = status;
 333         dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
 334                 ntohl(status), ntohl(res->csr_status));
 335         return status;
 336 }
 337
 338 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
 339 {
 340         struct nfs_client *clp;
 341         __be32 status;
 342         fmode_t flags = 0;
 343
 344         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 345         clp = nfs_find_client(args->craa_addr, 4);
 346         if (clp == NULL)
 347                 goto out;
 348
 349         dprintk("NFS: RECALL_ANY callback request from %s\n",
 350                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 351
 352         if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
 353                      &args->craa_type_mask))
 354                 flags = FMODE_READ;
 355         if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
 356                      &args->craa_type_mask))
 357                 flags |= FMODE_WRITE;
 358
 359         if (flags)
 360                 nfs_expire_all_delegation_types(clp, flags);
 361         status = htonl(NFS4_OK);
 362 out:
 363         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 364         return status;
 365 }
 366
 367 /* Reduce the fore channel's max_slots to the target value */
 368 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy)
 369 {
 370         struct nfs_client *clp;
 371         struct nfs4_slot_table *fc_tbl;
 372         __be32 status;
 373
 374         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 375         clp = nfs_find_client(args->crsa_addr, 4);
 376         if (clp == NULL)
 377                 goto out;
 378
 379         dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
 380                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
 381                 args->crsa_target_max_slots);
 382
 383         fc_tbl = &clp->cl_session->fc_slot_table;
 384
 385         status = htonl(NFS4ERR_BAD_HIGH_SLOT);
 386         if (args->crsa_target_max_slots > fc_tbl->max_slots ||
 387             args->crsa_target_max_slots < 1)
 388                 goto out_putclient;
 389
 390         status = htonl(NFS4_OK);
 391         if (args->crsa_target_max_slots == fc_tbl->max_slots)
 392                 goto out_putclient;
 393
 394         fc_tbl->target_max_slots = args->crsa_target_max_slots;
 395         nfs41_handle_recall_slot(clp);
 396 out_putclient:
 397         nfs_put_client(clp);    /* balance nfs_find_client */
 398 out:
 399         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 400         return status;
 401 }
 402 #endif /* CONFIG_NFS_V4_1 */