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, so at this time
 147  * we will log replays, and process them as if we had not seen them before,
 148  * but we don't bump the sequence in the slot.  Not too worried about it,
 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 int
 156 validate_seqid(struct nfs4_slot_table *tbl, u32 slotid, u32 seqid)
 157 {
 158         struct nfs4_slot *slot;
 159
 160         dprintk("%s enter. slotid %d seqid %d\n",
 161                 __func__, slotid, seqid);
 162
 163         if (slotid > NFS41_BC_MAX_CALLBACKS)
 164                 return htonl(NFS4ERR_BADSLOT);
 165
 166         slot = tbl->slots + slotid;
 167         dprintk("%s slot table seqid: %d\n", __func__, slot->seq_nr);
 168
 169         /* Normal */
 170         if (likely(seqid == slot->seq_nr + 1)) {
 171                 slot->seq_nr++;
 172                 return htonl(NFS4_OK);
 173         }
 174
 175         /* Replay */
 176         if (seqid == slot->seq_nr) {
 177                 dprintk("%s seqid %d is a replay - no DRC available\n",
 178                         __func__, seqid);
 179                 return htonl(NFS4_OK);
 180         }
 181
 182         /* Wraparound */
 183         if (seqid == 1 && (slot->seq_nr + 1) == 0) {
 184                 slot->seq_nr = 1;
 185                 return htonl(NFS4_OK);
 186         }
 187
 188         /* Misordered request */
 189         return htonl(NFS4ERR_SEQ_MISORDERED);
 190 }
 191
 192 /*
 193  * Returns a pointer to a held 'struct nfs_client' that matches the server's
 194  * address, major version number, and session ID.  It is the caller's
 195  * responsibility to release the returned reference.
 196  *
 197  * Returns NULL if there are no connections with sessions, or if no session
 198  * matches the one of interest.
 199  */
 200  static struct nfs_client *find_client_with_session(
 201         const struct sockaddr *addr, u32 nfsversion,
 202         struct nfs4_sessionid *sessionid)
 203 {
 204         struct nfs_client *clp;
 205
 206         clp = nfs_find_client(addr, 4);
 207         if (clp == NULL)
 208                 return NULL;
 209
 210         do {
 211                 struct nfs_client *prev = clp;
 212
 213                 if (clp->cl_session != NULL) {
 214                         if (memcmp(clp->cl_session->sess_id.data,
 215                                         sessionid->data,
 216                                         NFS4_MAX_SESSIONID_LEN) == 0) {
 217                                 /* Returns a held reference to clp */
 218                                 return clp;
 219                         }
 220                 }
 221                 clp = nfs_find_client_next(prev);
 222                 nfs_put_client(prev);
 223         } while (clp != NULL);
 224
 225         return NULL;
 226 }
 227
 228 /*
 229  * For each referring call triple, check the session's slot table for
 230  * a match.  If the slot is in use and the sequence numbers match, the
 231  * client is still waiting for a response to the original request.
 232  */
 233 static bool referring_call_exists(struct nfs_client *clp,
 234                                   uint32_t nrclists,
 235                                   struct referring_call_list *rclists)
 236 {
 237         bool status = 0;
 238         int i, j;
 239         struct nfs4_session *session;
 240         struct nfs4_slot_table *tbl;
 241         struct referring_call_list *rclist;
 242         struct referring_call *ref;
 243
 244         /*
 245          * XXX When client trunking is implemented, this becomes
 246          * a session lookup from within the loop
 247          */
 248         session = clp->cl_session;
 249         tbl = &session->fc_slot_table;
 250
 251         for (i = 0; i < nrclists; i++) {
 252                 rclist = &rclists[i];
 253                 if (memcmp(session->sess_id.data,
 254                            rclist->rcl_sessionid.data,
 255                            NFS4_MAX_SESSIONID_LEN) != 0)
 256                         continue;
 257
 258                 for (j = 0; j < rclist->rcl_nrefcalls; j++) {
 259                         ref = &rclist->rcl_refcalls[j];
 260
 261                         dprintk("%s: sessionid %x:%x:%x:%x sequenceid %u "
 262                                 "slotid %u\n", __func__,
 263                                 ((u32 *)&rclist->rcl_sessionid.data)[0],
 264                                 ((u32 *)&rclist->rcl_sessionid.data)[1],
 265                                 ((u32 *)&rclist->rcl_sessionid.data)[2],
 266                                 ((u32 *)&rclist->rcl_sessionid.data)[3],
 267                                 ref->rc_sequenceid, ref->rc_slotid);
 268
 269                         spin_lock(&tbl->slot_tbl_lock);
 270                         status = (test_bit(ref->rc_slotid, tbl->used_slots) &&
 271                                   tbl->slots[ref->rc_slotid].seq_nr ==
 272                                         ref->rc_sequenceid);
 273                         spin_unlock(&tbl->slot_tbl_lock);
 274                         if (status)
 275                                 goto out;
 276                 }
 277         }
 278
 279 out:
 280         return status;
 281 }
 282
 283 /* FIXME: referring calls should be processed */
 284 unsigned nfs4_callback_sequence(struct cb_sequenceargs *args,
 285                                 struct cb_sequenceres *res)
 286 {
 287         struct nfs_client *clp;
 288         int i, status;
 289
 290         for (i = 0; i < args->csa_nrclists; i++)
 291                 kfree(args->csa_rclists[i].rcl_refcalls);
 292         kfree(args->csa_rclists);
 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,
 300                                 args->csa_slotid, args->csa_sequenceid);
 301         if (status)
 302                 goto out_putclient;
 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         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 315         res->csr_status = status;
 316         return res->csr_status;
 317 }
 318
 319 unsigned nfs4_callback_recallany(struct cb_recallanyargs *args, void *dummy)
 320 {
 321         struct nfs_client *clp;
 322         int status;
 323         fmode_t flags = 0;
 324
 325         status = htonl(NFS4ERR_OP_NOT_IN_SESSION);
 326         clp = nfs_find_client(args->craa_addr, 4);
 327         if (clp == NULL)
 328                 goto out;
 329
 330         dprintk("NFS: RECALL_ANY callback request from %s\n",
 331                 rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
 332
 333         if (test_bit(RCA4_TYPE_MASK_RDATA_DLG, (const unsigned long *)
 334                      &args->craa_type_mask))
 335                 flags = FMODE_READ;
 336         if (test_bit(RCA4_TYPE_MASK_WDATA_DLG, (const unsigned long *)
 337                      &args->craa_type_mask))
 338                 flags |= FMODE_WRITE;
 339
 340         if (flags)
 341                 nfs_expire_all_delegation_types(clp, flags);
 342         status = htonl(NFS4_OK);
 343 out:
 344         dprintk("%s: exit with status = %d\n", __func__, ntohl(status));
 345         return status;
 346 }
 347 #endif /* CONFIG_NFS_V4_1 */