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