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         rcu_read_lock();
  41         delegation = rcu_dereference(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         rcu_read_unlock();
  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 __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy)
  66 {
  67         struct nfs_client *clp;
  68         struct inode *inode;
  69         __be32 res;
  70
  71         res = htonl(NFS4ERR_BADHANDLE);
  72         clp = nfs_find_client(args->addr, 4);
  73         if (clp == NULL)
  74                 goto out;
  75
  76         dprintk("NFS: RECALL callback request from %s\n",
  77                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
  78
  79         do {
  80                 struct nfs_client *prev = clp;
  81
  82                 inode = nfs_delegation_find_inode(clp, &args->fh);
  83                 if (inode != NULL) {
  84                         /* Set up a helper thread to actually return the delegation */
  85                         switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
  86                                 case 0:
  87                                         res = 0;
  88                                         break;
  89                                 case -ENOENT:
  90                                         if (res != 0)
  91                                                 res = htonl(NFS4ERR_BAD_STATEID);
  92                                         break;
  93                                 default:
  94                                         res = htonl(NFS4ERR_RESOURCE);
  95                         }
  96                         iput(inode);
  97                 }
  98                 clp = nfs_find_client_next(prev);
  99                 nfs_put_client(prev);
 100         } while (clp != NULL);
 101 out:
 102         dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
 103         return res;
 104 }
 105
 106 int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 107 {
 108         if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
 109                                          sizeof(delegation->stateid.data)) != 0)
 110                 return 0;
 111         return 1;
 112 }
 113
 114 #if defined(CONFIG_NFS_V4_1)
 115
 116 int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 117 {
 118         if (delegation == NULL)
 119                 return 0;
 120
 121         if (stateid->stateid.seqid != 0)
 122                 return 0;
 123         if (memcmp(&delegation->stateid.stateid.other,
 124                    &stateid->stateid.other,
 125                    NFS4_STATEID_OTHER_SIZE))
 126                 return 0;
 127
 128         return 1;
 129 }
 130
 131 /*
 132  * Validate the sequenceID sent by the server.
 133  * Return success if the sequenceID is one more than what we last saw on
 134  * this slot, accounting for wraparound.  Increments the slot's sequence.
 135  *
 136  * We don't yet implement a duplicate request cache, instead we set the
 137  * back channel ca_maxresponsesize_cached to zero. This is OK for now
 138  * since we only currently implement idempotent callbacks anyway.
 139  *
 140  * We have a single slot backchannel at this time, so we don't bother
 141  * checking the used_slots bit array on the table.  The lower layer guarantees
 142  * a single outstanding callback request at a time.
 143  */
 144 static __be32
 145 validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
 146 {
 147         struct nfs4_slot *slot;
 148
 149         dprintk("%s enter. slotid %d seqid %d\n",
 150                 __func__, args->csa_slotid, args->csa_sequenceid);
 151
 152         if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
 153                 return htonl(NFS4ERR_BADSLOT);
 154
 155         slot = tbl->slots + args->csa_slotid;
 156         dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
 157
 158         /* Normal */
 159         if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
 160                 slot->seq_nr++;
 161                 return htonl(NFS4_OK);
 162         }
 163
 164         /* Replay */
 165         if (args->csa_sequenceid == slot->seq_nr) {
 166                 dprintk("%s seqid %d is a replay\n",
 167                         __func__, args->csa_sequenceid);
 168                 /* Signal process_op to set this error on next op */
 169                 if (args->csa_cachethis == 0)
 170                         return htonl(NFS4ERR_RETRY_UNCACHED_REP);
 171
 172                 /* The ca_maxresponsesize_cached is 0 with no DRC */
 173                 else if (args->csa_cachethis == 1)
 174                         return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
 175         }
 176
 177         /* Wraparound */
 178         if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
 179                 slot->seq_nr = 1;
 180                 return htonl(NFS4_OK);
 181         }
 182
 183         /* Misordered request */
 184         return htonl(NFS4ERR_SEQ_MISORDERED);
 185 }
 186
 187 /*
 188  * Returns a pointer to a held 'struct nfs_client' that matches the server's
 189  * address, major version number, and session ID.  It is the caller's
 190  * responsibility to release the returned reference.
 191  *
 192  * Returns NULL if there are no connections with sessions, or if no session
 193  * matches the one of interest.
 194  */
 195  static struct nfs_client *find_client_with_session(
 196         const struct sockaddr *addr, u32 nfsversion,
 197         struct nfs4_sessionid *sessionid)
 198 {
 199         struct nfs_client *clp;
 200
 201         clp = nfs_find_client(addr, 4);
 202         if (clp == NULL)
 203                 return NULL;
 204
 205         do {
 206                 struct nfs_client *prev = clp;
 207
 208                 if (clp->cl_session != NULL) {
 209                         if (memcmp(clp->cl_session->sess_id.data,
 210                                         sessionid->data,
 211                                         NFS4_MAX_SESSIONID_LEN) == 0) {
 212                                 /* Returns a held reference to clp */
 213                                 return clp;
 214                         }
 215                 }
 216                 clp = nfs_find_client_next(prev);
 217                 nfs_put_client(prev);
 218         } while (clp != NULL);
 219
 220         return NULL;
 221 }
 222
 223 /*
 224  * For each referring call triple, check the session's slot table for
 225  * a match.  If the slot is in use and the sequence numbers match, the
 226  * client is still waiting for a response to the original request.
 227  */
 228 static bool referring_call_exists(struct nfs_client *clp,
 229                                   uint32_t nrclists,
 230                                   struct referring_call_list *rclists)
 231 {
 232         bool status = 0;
 233         int i, j;
 234         struct nfs4_session *session;
 235         struct nfs4_slot_table *tbl;
 236         struct referring_call_list *rclist;
 237         struct referring_call *ref;
 238
 239         /*
 240          * XXX When client trunking is implemented, this becomes
 241          * a session lookup from within the loop
 242          */
 243         session = clp->cl_session;
 244         tbl = &session->fc_slot_table;
 245
 246         for (i = 0; i < nrclists; i++) {
 247                 rclist = &rclists[i];
 248                 if (memcmp(session->sess_id.data,
 249                            rclist->rcl_sessionid.data,
 250                            NFS4_MAX_SESSIONID_LEN) != 0)
 251                         continue;
 252
 253                 for (j = 0; j < rclist->rcl_nrefcalls; j++) {
 254                         ref = &rclist->rcl_refcalls[j];
 255
 256                         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
 257                                 "slotid %u\n", __func__,
 258                                 ((u32 *)&rclist->rcl_sessionid.data)[0],
 259                                 ((u32 *)&rclist->rcl_sessionid.data)[1],
 260                                 ((u32 *)&rclist->rcl_sessionid.data)[2],
 261                                 ((u32 *)&rclist->rcl_sessionid.data)[3],
 262                                 ref->rc_sequenceid, ref->rc_slotid);
 263
 264                         spin_lock(&tbl->slot_tbl_lock);
 265                         status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
 266                                   tbl->slots[ref->rc_slotid].seq_nr ==
 267                                         ref->rc_sequenceid);
 268                         spin_unlock(&tbl->slot_tbl_lock);
 269                         if (status)
 270                                 goto out;
 271                 }
 272         }
 273
 274 out:
 275         return status;
 276 }
 277
 278 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
 279                                 struct cb_sequenceres *res)
 280 {
 281         struct nfs_client *clp;
 282         int i;
 283         __be32 status;
 284
 285         status = htonl(NFS4ERR_BADSESSION);
 286         clp = find_client_with_session(args->csa_addr, 4, &args->csa_sessionid);
 287         if (clp == NULL)
 288                 goto out;
 289
 290         status = validate_seqid(&clp->cl_session->bc_slot_table, args);
 291         if (status)
 292                 goto out_putclient;
 293
 294         /*
 295          * Check for pending referring calls.  If a match is found, a
 296          * related callback was received before the response to the original
 297          * call.
 298          */
 299         if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
 300                 status = htonl(NFS4ERR_DELAY);
 301                 goto out_putclient;
 302         }
 303
 304         memcpy(&res->csr_sessionid, &args->csa_sessionid,
 305                sizeof(res->csr_sessionid));
 306         res->csr_sequenceid = args->csa_sequenceid;
 307         res->csr_slotid = args->csa_slotid;
 308         res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 309         res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 310
 311 out_putclient:
 312         nfs_put_client(clp);
 313 out:
 314         for (i = 0; i < args->csa_nrclists; i++)
 315                 kfree(args->csa_rclists[i].rcl_refcalls);
 316         kfree(args->csa_rclists);
 317
 318         if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP))
 319                 res->csr_status = 0;
 320         else
 321                 res->csr_status = status;
 322         dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
 323                 ntohl(status), ntohl(res->csr_status));
 324         return status;
 325 }
 326
 327 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
 328 {
 329         struct nfs_client *clp;
 330         __be32 status;
 331         fmode_t flags = 0;
 332
 333         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 334         clp = nfs_find_client(args->craa_addr, 4);
 335         if (clp == NULL)
 336                 goto out;
 337
 338         dprintk("NFS: RECALL_ANY callback request from %s\n",
 339                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 340
 341         if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
 342                      &args->craa_type_mask))
 343                 flags = FMODE_READ;
 344         if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
 345                      &args->craa_type_mask))
 346                 flags |= FMODE_WRITE;
 347
 348         if (flags)
 349                 nfs_expire_all_delegation_types(clp, flags);
 350         status = htonl(NFS4_OK);
 351 out:
 352         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 353         return status;
 354 }
 355
 356 /* Reduce the fore channel's max_slots to the target value */
 357 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy)
 358 {
 359         struct nfs_client *clp;
 360         struct nfs4_slot_table *fc_tbl;
 361         __be32 status;
 362
 363         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 364         clp = nfs_find_client(args->crsa_addr, 4);
 365         if (clp == NULL)
 366                 goto out;
 367
 368         dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
 369                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR),
 370                 args->crsa_target_max_slots);
 371
 372         fc_tbl = &clp->cl_session->fc_slot_table;
 373
 374         status = htonl(NFS4ERR_BAD_HIGH_SLOT);
 375         if (args->crsa_target_max_slots > fc_tbl->max_slots ||
 376             args->crsa_target_max_slots < 1)
 377                 goto out_putclient;
 378
 379         status = htonl(NFS4_OK);
 380         if (args->crsa_target_max_slots == fc_tbl->max_slots)
 381                 goto out_putclient;
 382
 383         fc_tbl->target_max_slots = args->crsa_target_max_slots;
 384         nfs41_handle_recall_slot(clp);
 385 out_putclient:
 386         nfs_put_client(clp);    /* balance nfs_find_client */
 387 out:
 388         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 389         return status;
 390 }
 391 #endif /* CONFIG_NFS_V4_1 */