fs/nfsd/nfs4callback.c

   1 /*
   2  *  linux/fs/nfsd/nfs4callback.c
   3  *
   4  *  Copyright (c) 2001 The Regents of the University of Michigan.
   5  *  All rights reserved.
   6  *
   7  *  Kendrick Smith <kmsmith@umich.edu>
   8  *  Andy Adamson <andros@umich.edu>
   9  *
  10  *  Redistribution and use in source and binary forms, with or without
  11  *  modification, are permitted provided that the following conditions
  12  *  are met:
  13  *
  14  *  1. Redistributions of source code must retain the above copyright
  15  *     notice, this list of conditions and the following disclaimer.
  16  *  2. Redistributions in binary form must reproduce the above copyright
  17  *     notice, this list of conditions and the following disclaimer in the
  18  *     documentation and/or other materials provided with the distribution.
  19  *  3. Neither the name of the University nor the names of its
  20  *     contributors may be used to endorse or promote products derived
  21  *     from this software without specific prior written permission.
  22  *
  23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
  24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
  25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
  30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
  31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
  32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  34  */
  35
  36 #include <linux/module.h>
  37 #include <linux/list.h>
  38 #include <linux/inet.h>
  39 #include <linux/errno.h>
  40 #include <linux/delay.h>
  41 #include <linux/sched.h>
  42 #include <linux/kthread.h>
  43 #include <linux/sunrpc/xdr.h>
  44 #include <linux/sunrpc/svc.h>
  45 #include <linux/sunrpc/clnt.h>
  46 #include <linux/nfsd/nfsd.h>
  47 #include <linux/nfsd/state.h>
  48 #include <linux/sunrpc/sched.h>
  49 #include <linux/nfs4.h>
  50
  51 #define NFSDDBG_FACILITY                NFSDDBG_PROC
  52
  53 #define NFSPROC4_CB_NULL 0
  54 #define NFSPROC4_CB_COMPOUND 1
  55
  56 /* declarations */
  57 static const struct rpc_call_ops nfs4_cb_null_ops;
  58
  59 /* Index of predefined Linux callback client operations */
  60
  61 enum {
  62         NFSPROC4_CLNT_CB_NULL = 0,
  63         NFSPROC4_CLNT_CB_RECALL,
  64 };
  65
  66 enum nfs_cb_opnum4 {
  67         OP_CB_RECALL            = 4,
  68 };
  69
  70 #define NFS4_MAXTAGLEN          20
  71
  72 #define NFS4_enc_cb_null_sz             0
  73 #define NFS4_dec_cb_null_sz             0
  74 #define cb_compound_enc_hdr_sz          4
  75 #define cb_compound_dec_hdr_sz          (3 + (NFS4_MAXTAGLEN >> 2))
  76 #define op_enc_sz                       1
  77 #define op_dec_sz                       2
  78 #define enc_nfs4_fh_sz                  (1 + (NFS4_FHSIZE >> 2))
  79 #define enc_stateid_sz                  (NFS4_STATEID_SIZE >> 2)
  80 #define NFS4_enc_cb_recall_sz           (cb_compound_enc_hdr_sz +       \
  81                                         1 + enc_stateid_sz +            \
  82                                         enc_nfs4_fh_sz)
  83
  84 #define NFS4_dec_cb_recall_sz           (cb_compound_dec_hdr_sz  +      \
  85                                         op_dec_sz)
  86
  87 /*
  88 * Generic encode routines from fs/nfs/nfs4xdr.c
  89 */
  90 static inline __be32 *
  91 xdr_writemem(__be32 *p, const void *ptr, int nbytes)
  92 {
  93         int tmp = XDR_QUADLEN(nbytes);
  94         if (!tmp)
  95                 return p;
  96         p[tmp-1] = 0;
  97         memcpy(p, ptr, nbytes);
  98         return p + tmp;
  99 }
 100
 101 #define WRITE32(n)               *p++ = htonl(n)
 102 #define WRITEMEM(ptr,nbytes)     do {                           \
 103         p = xdr_writemem(p, ptr, nbytes);                       \
 104 } while (0)
 105 #define RESERVE_SPACE(nbytes)   do {                            \
 106         p = xdr_reserve_space(xdr, nbytes);                     \
 107         if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
 108         BUG_ON(!p);                                             \
 109 } while (0)
 110
 111 /*
 112  * Generic decode routines from fs/nfs/nfs4xdr.c
 113  */
 114 #define DECODE_TAIL                             \
 115         status = 0;                             \
 116 out:                                            \
 117         return status;                          \
 118 xdr_error:                                      \
 119         dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
 120         status = -EIO;                          \
 121         goto out
 122
 123 #define READ32(x)         (x) = ntohl(*p++)
 124 #define READ64(x)         do {                  \
 125         (x) = (u64)ntohl(*p++) << 32;           \
 126         (x) |= ntohl(*p++);                     \
 127 } while (0)
 128 #define READTIME(x)       do {                  \
 129         p++;                                    \
 130         (x.tv_sec) = ntohl(*p++);               \
 131         (x.tv_nsec) = ntohl(*p++);              \
 132 } while (0)
 133 #define READ_BUF(nbytes)  do { \
 134         p = xdr_inline_decode(xdr, nbytes); \
 135         if (!p) { \
 136                 dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
 137                         __func__, __LINE__); \
 138                 return -EIO; \
 139         } \
 140 } while (0)
 141
 142 struct nfs4_cb_compound_hdr {
 143         int             status;
 144         u32             ident;
 145         u32             nops;
 146         u32             taglen;
 147         char *          tag;
 148 };
 149
 150 static struct {
 151 int stat;
 152 int errno;
 153 } nfs_cb_errtbl[] = {
 154         { NFS4_OK,              0               },
 155         { NFS4ERR_PERM,         EPERM           },
 156         { NFS4ERR_NOENT,        ENOENT          },
 157         { NFS4ERR_IO,           EIO             },
 158         { NFS4ERR_NXIO,         ENXIO           },
 159         { NFS4ERR_ACCESS,       EACCES          },
 160         { NFS4ERR_EXIST,        EEXIST          },
 161         { NFS4ERR_XDEV,         EXDEV           },
 162         { NFS4ERR_NOTDIR,       ENOTDIR         },
 163         { NFS4ERR_ISDIR,        EISDIR          },
 164         { NFS4ERR_INVAL,        EINVAL          },
 165         { NFS4ERR_FBIG,         EFBIG           },
 166         { NFS4ERR_NOSPC,        ENOSPC          },
 167         { NFS4ERR_ROFS,         EROFS           },
 168         { NFS4ERR_MLINK,        EMLINK          },
 169         { NFS4ERR_NAMETOOLONG,  ENAMETOOLONG    },
 170         { NFS4ERR_NOTEMPTY,     ENOTEMPTY       },
 171         { NFS4ERR_DQUOT,        EDQUOT          },
 172         { NFS4ERR_STALE,        ESTALE          },
 173         { NFS4ERR_BADHANDLE,    EBADHANDLE      },
 174         { NFS4ERR_BAD_COOKIE,   EBADCOOKIE      },
 175         { NFS4ERR_NOTSUPP,      ENOTSUPP        },
 176         { NFS4ERR_TOOSMALL,     ETOOSMALL       },
 177         { NFS4ERR_SERVERFAULT,  ESERVERFAULT    },
 178         { NFS4ERR_BADTYPE,      EBADTYPE        },
 179         { NFS4ERR_LOCKED,       EAGAIN          },
 180         { NFS4ERR_RESOURCE,     EREMOTEIO       },
 181         { NFS4ERR_SYMLINK,      ELOOP           },
 182         { NFS4ERR_OP_ILLEGAL,   EOPNOTSUPP      },
 183         { NFS4ERR_DEADLOCK,     EDEADLK         },
 184         { -1,                   EIO             }
 185 };
 186
 187 static int
 188 nfs_cb_stat_to_errno(int stat)
 189 {
 190         int i;
 191         for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
 192                 if (nfs_cb_errtbl[i].stat == stat)
 193                         return nfs_cb_errtbl[i].errno;
 194         }
 195         /* If we cannot translate the error, the recovery routines should
 196         * handle it.
 197         * Note: remaining NFSv4 error codes have values > 10000, so should
 198         * not conflict with native Linux error codes.
 199         */
 200         return stat;
 201 }
 202
 203 /*
 204  * XDR encode
 205  */
 206
 207 static int
 208 encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
 209 {
 210         __be32 * p;
 211
 212         RESERVE_SPACE(16);
 213         WRITE32(0);            /* tag length is always 0 */
 214         WRITE32(NFS4_MINOR_VERSION);
 215         WRITE32(hdr->ident);
 216         WRITE32(hdr->nops);
 217         return 0;
 218 }
 219
 220 static int
 221 encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
 222 {
 223         __be32 *p;
 224         int len = cb_rec->cbr_fhlen;
 225
 226         RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
 227         WRITE32(OP_CB_RECALL);
 228         WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
 229         WRITE32(cb_rec->cbr_trunc);
 230         WRITE32(len);
 231         WRITEMEM(cb_rec->cbr_fhval, len);
 232         return 0;
 233 }
 234
 235 static int
 236 nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
 237 {
 238         struct xdr_stream xdrs, *xdr = &xdrs;
 239
 240         xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
 241         RESERVE_SPACE(0);
 242         return 0;
 243 }
 244
 245 static int
 246 nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
 247 {
 248         struct xdr_stream xdr;
 249         struct nfs4_cb_compound_hdr hdr = {
 250                 .ident = args->cbr_ident,
 251                 .nops   = 1,
 252         };
 253
 254         xdr_init_encode(&xdr, &req->rq_snd_buf, p);
 255         encode_cb_compound_hdr(&xdr, &hdr);
 256         return (encode_cb_recall(&xdr, args));
 257 }
 258
 259
 260 static int
 261 decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
 262         __be32 *p;
 263
 264         READ_BUF(8);
 265         READ32(hdr->status);
 266         READ32(hdr->taglen);
 267         READ_BUF(hdr->taglen + 4);
 268         hdr->tag = (char *)p;
 269         p += XDR_QUADLEN(hdr->taglen);
 270         READ32(hdr->nops);
 271         return 0;
 272 }
 273
 274 static int
 275 decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
 276 {
 277         __be32 *p;
 278         u32 op;
 279         int32_t nfserr;
 280
 281         READ_BUF(8);
 282         READ32(op);
 283         if (op != expected) {
 284                 dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
 285                          " operation %d but we issued a request for %d\n",
 286                          op, expected);
 287                 return -EIO;
 288         }
 289         READ32(nfserr);
 290         if (nfserr != NFS_OK)
 291                 return -nfs_cb_stat_to_errno(nfserr);
 292         return 0;
 293 }
 294
 295 static int
 296 nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
 297 {
 298         return 0;
 299 }
 300
 301 static int
 302 nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
 303 {
 304         struct xdr_stream xdr;
 305         struct nfs4_cb_compound_hdr hdr;
 306         int status;
 307
 308         xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
 309         status = decode_cb_compound_hdr(&xdr, &hdr);
 310         if (status)
 311                 goto out;
 312         status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
 313 out:
 314         return status;
 315 }
 316
 317 /*
 318  * RPC procedure tables
 319  */
 320 #define PROC(proc, call, argtype, restype)                              \
 321 [NFSPROC4_CLNT_##proc] = {                                              \
 322         .p_proc   = NFSPROC4_CB_##call,                                 \
 323         .p_encode = (kxdrproc_t) nfs4_xdr_##argtype,                    \
 324         .p_decode = (kxdrproc_t) nfs4_xdr_##restype,                    \
 325         .p_arglen = NFS4_##argtype##_sz,                                \
 326         .p_replen = NFS4_##restype##_sz,                                \
 327         .p_statidx = NFSPROC4_CB_##call,                                \
 328         .p_name   = #proc,                                              \
 329 }
 330
 331 static struct rpc_procinfo     nfs4_cb_procedures[] = {
 332     PROC(CB_NULL,      NULL,     enc_cb_null,     dec_cb_null),
 333     PROC(CB_RECALL,    COMPOUND,   enc_cb_recall,      dec_cb_recall),
 334 };
 335
 336 static struct rpc_version       nfs_cb_version4 = {
 337         .number                 = 1,
 338         .nrprocs                = ARRAY_SIZE(nfs4_cb_procedures),
 339         .procs                  = nfs4_cb_procedures
 340 };
 341
 342 static struct rpc_version *     nfs_cb_version[] = {
 343         NULL,
 344         &nfs_cb_version4,
 345 };
 346
 347 static struct rpc_program cb_program;
 348
 349 static struct rpc_stat cb_stats = {
 350                 .program        = &cb_program
 351 };
 352
 353 #define NFS4_CALLBACK 0x40000000
 354 static struct rpc_program cb_program = {
 355                 .name           = "nfs4_cb",
 356                 .number         = NFS4_CALLBACK,
 357                 .nrvers         = ARRAY_SIZE(nfs_cb_version),
 358                 .version        = nfs_cb_version,
 359                 .stats          = &cb_stats,
 360 };
 361
 362 /* Reference counting, callback cleanup, etc., all look racy as heck.
 363  * And why is cb_set an atomic? */
 364
 365 static int do_probe_callback(void *data)
 366 {
 367         struct nfs4_client *clp = data;
 368         struct sockaddr_in      addr;
 369         struct nfs4_callback    *cb = &clp->cl_callback;
 370         struct rpc_timeout      timeparms = {
 371                 .to_initval     = (NFSD_LEASE_TIME/4) * HZ,
 372                 .to_retries     = 5,
 373                 .to_maxval      = (NFSD_LEASE_TIME/2) * HZ,
 374                 .to_exponential = 1,
 375         };
 376         struct rpc_create_args args = {
 377                 .protocol       = IPPROTO_TCP,
 378                 .address        = (struct sockaddr *)&addr,
 379                 .addrsize       = sizeof(addr),
 380                 .timeout        = &timeparms,
 381                 .program        = &cb_program,
 382                 .version        = nfs_cb_version[1]->number,
 383                 .authflavor     = RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
 384                 .flags          = (RPC_CLNT_CREATE_NOPING),
 385         };
 386         struct rpc_message msg = {
 387                 .rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
 388                 .rpc_argp       = clp,
 389         };
 390         struct rpc_clnt *client;
 391         int status;
 392
 393         /* Initialize address */
 394         memset(&addr, 0, sizeof(addr));
 395         addr.sin_family = AF_INET;
 396         addr.sin_port = htons(cb->cb_port);
 397         addr.sin_addr.s_addr = htonl(cb->cb_addr);
 398
 399         /* Initialize rpc_stat */
 400         memset(args.program->stats, 0, sizeof(struct rpc_stat));
 401
 402         /* Create RPC client */
 403         client = rpc_create(&args);
 404         if (IS_ERR(client)) {
 405                 dprintk("NFSD: couldn't create callback client\n");
 406                 status = PTR_ERR(client);
 407                 goto out_err;
 408         }
 409
 410         status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
 411
 412         if (status)
 413                 goto out_release_client;
 414
 415         cb->cb_client = client;
 416         atomic_set(&cb->cb_set, 1);
 417         put_nfs4_client(clp);
 418         return 0;
 419 out_release_client:
 420         rpc_shutdown_client(client);
 421 out_err:
 422         dprintk("NFSD: warning: no callback path to client %.*s\n",
 423                 (int)clp->cl_name.len, clp->cl_name.data);
 424         put_nfs4_client(clp);
 425         return status;
 426 }
 427
 428 /*
 429  * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 430  */
 431 void
 432 nfsd4_probe_callback(struct nfs4_client *clp)
 433 {
 434         struct task_struct *t;
 435
 436         BUG_ON(atomic_read(&clp->cl_callback.cb_set));
 437
 438         /* the task holds a reference to the nfs4_client struct */
 439         atomic_inc(&clp->cl_count);
 440
 441         t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
 442
 443         if (IS_ERR(t))
 444                 atomic_dec(&clp->cl_count);
 445
 446         return;
 447 }
 448
 449 /*
 450  * called with dp->dl_count inc'ed.
 451  * nfs4_lock_state() may or may not have been called.
 452  */
 453 void
 454 nfsd4_cb_recall(struct nfs4_delegation *dp)
 455 {
 456         struct nfs4_client *clp = dp->dl_client;
 457         struct rpc_clnt *clnt = clp->cl_callback.cb_client;
 458         struct nfs4_cb_recall *cbr = &dp->dl_recall;
 459         struct rpc_message msg = {
 460                 .rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
 461                 .rpc_argp = cbr,
 462         };
 463         int retries = 1;
 464         int status = 0;
 465
 466         cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
 467         cbr->cbr_dp = dp;
 468
 469         status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 470         while (retries--) {
 471                 switch (status) {
 472                         case -EIO:
 473                                 /* Network partition? */
 474                                 atomic_set(&clp->cl_callback.cb_set, 0);
 475                         case -EBADHANDLE:
 476                         case -NFS4ERR_BAD_STATEID:
 477                                 /* Race: client probably got cb_recall
 478                                  * before open reply granting delegation */
 479                                 break;
 480                         default:
 481                                 goto out_put_cred;
 482                 }
 483                 ssleep(2);
 484                 status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
 485         }
 486 out_put_cred:
 487         /*
 488          * Success or failure, now we're either waiting for lease expiration
 489          * or deleg_return.
 490          */
 491         put_nfs4_client(clp);
 492         nfs4_put_delegation(dp);
 493         return;
 494 }