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,
  21                              struct cb_getattrres *res,
  22                              struct cb_process_state *cps)
  23 {
  24         struct nfs_delegation *delegation;
  25         struct nfs_inode *nfsi;
  26         struct inode *inode;
  27
  28         res->status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
  29         if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
  30                 goto out;
  31
  32         res->bitmap[0] = res->bitmap[1] = 0;
  33         res->status = htonl(NFS4ERR_BADHANDLE);
  34
  35         dprintk("NFS: GETATTR callback request from %s\n",
  36                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
  37
  38         inode = nfs_delegation_find_inode(cps->clp, &args->fh);
  39         if (inode == NULL)
  40                 goto out;
  41         nfsi = NFS_I(inode);
  42         rcu_read_lock();
  43         delegation = rcu_dereference(nfsi->delegation);
  44         if (delegation == NULL || (delegation->type & FMODE_WRITE) == 0)
  45                 goto out_iput;
  46         res->size = i_size_read(inode);
  47         res->change_attr = delegation->change_attr;
  48         if (nfsi->npages != 0)
  49                 res->change_attr++;
  50         res->ctime = inode->i_ctime;
  51         res->mtime = inode->i_mtime;
  52         res->bitmap[0] = (FATTR4_WORD0_CHANGE|FATTR4_WORD0_SIZE) &
  53                 args->bitmap[0];
  54         res->bitmap[1] = (FATTR4_WORD1_TIME_METADATA|FATTR4_WORD1_TIME_MODIFY) &
  55                 args->bitmap[1];
  56         res->status = 0;
  57 out_iput:
  58         rcu_read_unlock();
  59         iput(inode);
  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                             struct cb_process_state *cps)
  67 {
  68         struct inode *inode;
  69         __be32 res;
  70
  71         res = htonl(NFS4ERR_OP_NOT_IN_SESSION);
  72         if (!cps->clp) /* Always set for v4.0. Set in cb_sequence for v4.1 */
  73                 goto out;
  74
  75         dprintk("NFS: RECALL callback request from %s\n",
  76                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
  77
  78         res = htonl(NFS4ERR_BADHANDLE);
  79         inode = nfs_delegation_find_inode(cps->clp, &args->fh);
  80         if (inode == NULL)
  81                 goto out;
  82         /* Set up a helper thread to actually return the delegation */
  83         switch (nfs_async_inode_return_delegation(inode, &args->stateid)) {
  84         case 0:
  85                 res = 0;
  86                 break;
  87         case -ENOENT:
  88                 if (res != 0)
  89                         res = htonl(NFS4ERR_BAD_STATEID);
  90                 break;
  91         default:
  92                 res = htonl(NFS4ERR_RESOURCE);
  93         }
  94         iput(inode);
  95 out:
  96         dprintk("%s: exit with status = %d\n", __func__, ntohl(res));
  97         return res;
  98 }
  99
 100 int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 101 {
 102         if (delegation == NULL || memcmp(delegation->stateid.data, stateid->data,
 103                                          sizeof(delegation->stateid.data)) != 0)
 104                 return 0;
 105         return 1;
 106 }
 107
 108 #if defined(CONFIG_NFS_V4_1)
 109
 110 int nfs41_validate_delegation_stateid(struct nfs_delegation *delegation, const nfs4_stateid *stateid)
 111 {
 112         if (delegation == NULL)
 113                 return 0;
 114
 115         if (stateid->stateid.seqid != 0)
 116                 return 0;
 117         if (memcmp(&delegation->stateid.stateid.other,
 118                    &stateid->stateid.other,
 119                    NFS4_STATEID_OTHER_SIZE))
 120                 return 0;
 121
 122         return 1;
 123 }
 124
 125 /*
 126  * Validate the sequenceID sent by the server.
 127  * Return success if the sequenceID is one more than what we last saw on
 128  * this slot, accounting for wraparound.  Increments the slot's sequence.
 129  *
 130  * We don't yet implement a duplicate request cache, instead we set the
 131  * back channel ca_maxresponsesize_cached to zero. This is OK for now
 132  * since we only currently implement idempotent callbacks anyway.
 133  *
 134  * We have a single slot backchannel at this time, so we don't bother
 135  * checking the used_slots bit array on the table.  The lower layer guarantees
 136  * a single outstanding callback request at a time.
 137  */
 138 static __be32
 139 validate_seqid(struct nfs4_slot_table *tbl, struct cb_sequenceargs * args)
 140 {
 141         struct nfs4_slot *slot;
 142
 143         dprintk("%s enter. slotid %d seqid %d\n",
 144                 __func__, args->csa_slotid, args->csa_sequenceid);
 145
 146         if (args->csa_slotid > NFS41_BC_MAX_CALLBACKS)
 147                 return htonl(NFS4ERR_BADSLOT);
 148
 149         slot = tbl->slots + args->csa_slotid;
 150         dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
 151
 152         /* Normal */
 153         if (likely(args->csa_sequenceid == slot->seq_nr + 1)) {
 154                 slot->seq_nr++;
 155                 return htonl(NFS4_OK);
 156         }
 157
 158         /* Replay */
 159         if (args->csa_sequenceid == slot->seq_nr) {
 160                 dprintk("%s seqid %d is a replay\n",
 161                         __func__, args->csa_sequenceid);
 162                 /* Signal process_op to set this error on next op */
 163                 if (args->csa_cachethis == 0)
 164                         return htonl(NFS4ERR_RETRY_UNCACHED_REP);
 165
 166                 /* The ca_maxresponsesize_cached is 0 with no DRC */
 167                 else if (args->csa_cachethis == 1)
 168                         return htonl(NFS4ERR_REP_TOO_BIG_TO_CACHE);
 169         }
 170
 171         /* Wraparound */
 172         if (args->csa_sequenceid == 1 && (slot->seq_nr + 1) == 0) {
 173                 slot->seq_nr = 1;
 174                 return htonl(NFS4_OK);
 175         }
 176
 177         /* Misordered request */
 178         return htonl(NFS4ERR_SEQ_MISORDERED);
 179 }
 180
 181 /*
 182  * For each referring call triple, check the session's slot table for
 183  * a match.  If the slot is in use and the sequence numbers match, the
 184  * client is still waiting for a response to the original request.
 185  */
 186 static bool referring_call_exists(struct nfs_client *clp,
 187                                   uint32_t nrclists,
 188                                   struct referring_call_list *rclists)
 189 {
 190         bool status = 0;
 191         int i, j;
 192         struct nfs4_session *session;
 193         struct nfs4_slot_table *tbl;
 194         struct referring_call_list *rclist;
 195         struct referring_call *ref;
 196
 197         /*
 198          * XXX When client trunking is implemented, this becomes
 199          * a session lookup from within the loop
 200          */
 201         session = clp->cl_session;
 202         tbl = &session->fc_slot_table;
 203
 204         for (i = 0; i < nrclists; i++) {
 205                 rclist = &rclists[i];
 206                 if (memcmp(session->sess_id.data,
 207                            rclist->rcl_sessionid.data,
 208                            NFS4_MAX_SESSIONID_LEN) != 0)
 209                         continue;
 210
 211                 for (j = 0; j < rclist->rcl_nrefcalls; j++) {
 212                         ref = &rclist->rcl_refcalls[j];
 213
 214                         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
 215                                 "slotid %u\n", __func__,
 216                                 ((u32 *)&rclist->rcl_sessionid.data)[0],
 217                                 ((u32 *)&rclist->rcl_sessionid.data)[1],
 218                                 ((u32 *)&rclist->rcl_sessionid.data)[2],
 219                                 ((u32 *)&rclist->rcl_sessionid.data)[3],
 220                                 ref->rc_sequenceid, ref->rc_slotid);
 221
 222                         spin_lock(&tbl->slot_tbl_lock);
 223                         status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
 224                                   tbl->slots[ref->rc_slotid].seq_nr ==
 225                                         ref->rc_sequenceid);
 226                         spin_unlock(&tbl->slot_tbl_lock);
 227                         if (status)
 228                                 goto out;
 229                 }
 230         }
 231
 232 out:
 233         return status;
 234 }
 235
 236 __be32 nfs4_callback_sequence(struct cb_sequenceargs *args,
 237                               struct cb_sequenceres *res,
 238                               struct cb_process_state *cps)
 239 {
 240         struct nfs_client *clp;
 241         int i;
 242         __be32 status;
 243
 244         cps->clp = NULL;
 245
 246         status = htonl(NFS4ERR_BADSESSION);
 247         /* Incoming session must match the callback session */
 248         if (memcmp(&args->csa_sessionid, cps->svc_sid, NFS4_MAX_SESSIONID_LEN))
 249                 goto out;
 250
 251         clp = nfs4_find_client_sessionid(args->csa_addr,
 252                                          &args->csa_sessionid, 1);
 253         if (clp == NULL)
 254                 goto out;
 255
 256         /* state manager is resetting the session */
 257         if (test_bit(NFS4_SESSION_DRAINING, &clp->cl_session->session_state)) {
 258                 status = NFS4ERR_DELAY;
 259                 goto out;
 260         }
 261
 262         status = validate_seqid(&clp->cl_session->bc_slot_table, args);
 263         if (status)
 264                 goto out;
 265
 266         /*
 267          * Check for pending referring calls.  If a match is found, a
 268          * related callback was received before the response to the original
 269          * call.
 270          */
 271         if (referring_call_exists(clp, args->csa_nrclists, args->csa_rclists)) {
 272                 status = htonl(NFS4ERR_DELAY);
 273                 goto out;
 274         }
 275
 276         memcpy(&res->csr_sessionid, &args->csa_sessionid,
 277                sizeof(res->csr_sessionid));
 278         res->csr_sequenceid = args->csa_sequenceid;
 279         res->csr_slotid = args->csa_slotid;
 280         res->csr_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 281         res->csr_target_highestslotid = NFS41_BC_MAX_CALLBACKS - 1;
 282         nfs4_cb_take_slot(clp);
 283         cps->clp = clp; /* put in nfs4_callback_compound */
 284
 285 out:
 286         for (i = 0; i < args->csa_nrclists; i++)
 287                 kfree(args->csa_rclists[i].rcl_refcalls);
 288         kfree(args->csa_rclists);
 289
 290         if (status == htonl(NFS4ERR_RETRY_UNCACHED_REP)) {
 291                 cps->drc_status = status;
 292                 status = 0;
 293         } else
 294                 res->csr_status = status;
 295
 296         dprintk("%s: exit with status = %d res->csr_status %d\n", __func__,
 297                 ntohl(status), ntohl(res->csr_status));
 298         return status;
 299 }
 300
 301 __be32 nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy,
 302                                struct cb_process_state *cps)
 303 {
 304         __be32 status;
 305         fmode_t flags = 0;
 306
 307         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 308         if (!cps->clp) /* set in cb_sequence */
 309                 goto out;
 310
 311         dprintk("NFS: RECALL_ANY callback request from %s\n",
 312                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 313
 314         if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
 315                      &args->craa_type_mask))
 316                 flags = FMODE_READ;
 317         if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
 318                      &args->craa_type_mask))
 319                 flags |= FMODE_WRITE;
 320
 321         if (flags)
 322                 nfs_expire_all_delegation_types(cps->clp, flags);
 323         status = htonl(NFS4_OK);
 324 out:
 325         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 326         return status;
 327 }
 328
 329 /* Reduce the fore channel's max_slots to the target value */
 330 __be32 nfs4_callback_recallslot(struct cb_recallslotargs *args, void *dummy,
 331                                 struct cb_process_state *cps)
 332 {
 333         struct nfs4_slot_table *fc_tbl;
 334         __be32 status;
 335
 336         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 337         if (!cps->clp) /* set in cb_sequence */
 338                 goto out;
 339
 340         dprintk("NFS: CB_RECALL_SLOT request from %s target max slots %d\n",
 341                 rpc_peeraddr2str(cps->clp->cl_rpcclient, RPC_DISPLAY_ADDR),
 342                 args->crsa_target_max_slots);
 343
 344         fc_tbl = &cps->clp->cl_session->fc_slot_table;
 345
 346         status = htonl(NFS4ERR_BAD_HIGH_SLOT);
 347         if (args->crsa_target_max_slots > fc_tbl->max_slots ||
 348             args->crsa_target_max_slots < 1)
 349                 goto out;
 350
 351         status = htonl(NFS4_OK);
 352         if (args->crsa_target_max_slots == fc_tbl->max_slots)
 353                 goto out;
 354
 355         fc_tbl->target_max_slots = args->crsa_target_max_slots;
 356         nfs41_handle_recall_slot(cps->clp);
 357 out:
 358         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 359         return status;
 360 }
 361 #endif /* CONFIG_NFS_V4_1 */