fs/afs/cmservice.c

   1 /* AFS Cache Manager Service
   2  *
   3  * Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/init.h>
  14 #include <linux/sched.h>
  15 #include <linux/ip.h>
  16 #include "internal.h"
  17 #include "afs_cm.h"
  18
  19 struct workqueue_struct *afs_cm_workqueue;
  20
  21 static int afs_deliver_cb_init_call_back_state(struct afs_call *,
  22                                                struct sk_buff *, bool);
  23 static int afs_deliver_cb_probe(struct afs_call *, struct sk_buff *, bool);
  24 static int afs_deliver_cb_callback(struct afs_call *, struct sk_buff *, bool);
  25 static void afs_cm_destructor(struct afs_call *);
  26
  27 /*
  28  * CB.CallBack operation type
  29  */
  30 static const struct afs_call_type afs_SRXCBCallBack = {
  31         .deliver        = afs_deliver_cb_callback,
  32         .abort_to_error = afs_abort_to_error,
  33         .destructor     = afs_cm_destructor,
  34 };
  35
  36 /*
  37  * CB.InitCallBackState operation type
  38  */
  39 static const struct afs_call_type afs_SRXCBInitCallBackState = {
  40         .deliver        = afs_deliver_cb_init_call_back_state,
  41         .abort_to_error = afs_abort_to_error,
  42         .destructor     = afs_cm_destructor,
  43 };
  44
  45 /*
  46  * CB.Probe operation type
  47  */
  48 static const struct afs_call_type afs_SRXCBProbe = {
  49         .deliver        = afs_deliver_cb_probe,
  50         .abort_to_error = afs_abort_to_error,
  51         .destructor     = afs_cm_destructor,
  52 };
  53
  54 /*
  55  * route an incoming cache manager call
  56  * - return T if supported, F if not
  57  */
  58 bool afs_cm_incoming_call(struct afs_call *call)
  59 {
  60         u32 operation_id = ntohl(call->operation_ID);
  61
  62         _enter("{CB.OP %u}", operation_id);
  63
  64         switch (operation_id) {
  65         case CBCallBack:
  66                 call->type = &afs_SRXCBCallBack;
  67                 return true;
  68         case CBInitCallBackState:
  69                 call->type = &afs_SRXCBInitCallBackState;
  70                 return true;
  71         case CBProbe:
  72                 call->type = &afs_SRXCBProbe;
  73                 return true;
  74         default:
  75                 return false;
  76         }
  77 }
  78
  79 /*
  80  * clean up a cache manager call
  81  */
  82 static void afs_cm_destructor(struct afs_call *call)
  83 {
  84         _enter("");
  85
  86         afs_put_server(call->server);
  87         call->server = NULL;
  88         kfree(call->buffer);
  89         call->buffer = NULL;
  90 }
  91
  92 /*
  93  * allow the fileserver to see if the cache manager is still alive
  94  */
  95 static void SRXAFSCB_CallBack(struct work_struct *work)
  96 {
  97         struct afs_call *call = container_of(work, struct afs_call, work);
  98
  99         _enter("");
 100
 101         /* be sure to send the reply *before* attempting to spam the AFS server
 102          * with FSFetchStatus requests on the vnodes with broken callbacks lest
 103          * the AFS server get into a vicious cycle of trying to break further
 104          * callbacks because it hadn't received completion of the CBCallBack op
 105          * yet */
 106         afs_send_empty_reply(call);
 107
 108         afs_break_callbacks(call->server, call->count, call->request);
 109         _leave("");
 110 }
 111
 112 /*
 113  * deliver request data to a CB.CallBack call
 114  */
 115 static int afs_deliver_cb_callback(struct afs_call *call, struct sk_buff *skb,
 116                                    bool last)
 117 {
 118         struct afs_callback *cb;
 119         struct afs_server *server;
 120         struct in_addr addr;
 121         __be32 *bp;
 122         u32 tmp;
 123         int ret, loop;
 124
 125         _enter("{%u},{%u},%d", call->unmarshall, skb->len, last);
 126
 127         switch (call->unmarshall) {
 128         case 0:
 129                 call->offset = 0;
 130                 call->unmarshall++;
 131
 132                 /* extract the FID array and its count in two steps */
 133         case 1:
 134                 _debug("extract FID count");
 135                 ret = afs_extract_data(call, skb, last, &call->tmp, 4);
 136                 switch (ret) {
 137                 case 0:         break;
 138                 case -EAGAIN:   return 0;
 139                 default:        return ret;
 140                 }
 141
 142                 call->count = ntohl(call->tmp);
 143                 _debug("FID count: %u", call->count);
 144                 if (call->count > AFSCBMAX)
 145                         return -EBADMSG;
 146
 147                 call->buffer = kmalloc(call->count * 3 * 4, GFP_KERNEL);
 148                 if (!call->buffer)
 149                         return -ENOMEM;
 150                 call->offset = 0;
 151                 call->unmarshall++;
 152
 153         case 2:
 154                 _debug("extract FID array");
 155                 ret = afs_extract_data(call, skb, last, call->buffer,
 156                                        call->count * 3 * 4);
 157                 switch (ret) {
 158                 case 0:         break;
 159                 case -EAGAIN:   return 0;
 160                 default:        return ret;
 161                 }
 162
 163                 _debug("unmarshall FID array");
 164                 call->request = kcalloc(call->count,
 165                                         sizeof(struct afs_callback),
 166                                         GFP_KERNEL);
 167                 if (!call->request)
 168                         return -ENOMEM;
 169
 170                 cb = call->request;
 171                 bp = call->buffer;
 172                 for (loop = call->count; loop > 0; loop--, cb++) {
 173                         cb->fid.vid     = ntohl(*bp++);
 174                         cb->fid.vnode   = ntohl(*bp++);
 175                         cb->fid.unique  = ntohl(*bp++);
 176                         cb->type        = AFSCM_CB_UNTYPED;
 177                 }
 178
 179                 call->offset = 0;
 180                 call->unmarshall++;
 181
 182                 /* extract the callback array and its count in two steps */
 183         case 3:
 184                 _debug("extract CB count");
 185                 ret = afs_extract_data(call, skb, last, &call->tmp, 4);
 186                 switch (ret) {
 187                 case 0:         break;
 188                 case -EAGAIN:   return 0;
 189                 default:        return ret;
 190                 }
 191
 192                 tmp = ntohl(call->tmp);
 193                 _debug("CB count: %u", tmp);
 194                 if (tmp != call->count && tmp != 0)
 195                         return -EBADMSG;
 196                 call->offset = 0;
 197                 call->unmarshall++;
 198                 if (tmp == 0)
 199                         goto empty_cb_array;
 200
 201         case 4:
 202                 _debug("extract CB array");
 203                 ret = afs_extract_data(call, skb, last, call->request,
 204                                        call->count * 3 * 4);
 205                 switch (ret) {
 206                 case 0:         break;
 207                 case -EAGAIN:   return 0;
 208                 default:        return ret;
 209                 }
 210
 211                 _debug("unmarshall CB array");
 212                 cb = call->request;
 213                 bp = call->buffer;
 214                 for (loop = call->count; loop > 0; loop--, cb++) {
 215                         cb->version     = ntohl(*bp++);
 216                         cb->expiry      = ntohl(*bp++);
 217                         cb->type        = ntohl(*bp++);
 218                 }
 219
 220         empty_cb_array:
 221                 call->offset = 0;
 222                 call->unmarshall++;
 223
 224         case 5:
 225                 _debug("trailer");
 226                 if (skb->len != 0)
 227                         return -EBADMSG;
 228                 break;
 229         }
 230
 231         if (!last)
 232                 return 0;
 233
 234         call->state = AFS_CALL_REPLYING;
 235
 236         /* we'll need the file server record as that tells us which set of
 237          * vnodes to operate upon */
 238         memcpy(&addr, &ip_hdr(skb)->saddr, 4);
 239         server = afs_find_server(&addr);
 240         if (!server)
 241                 return -ENOTCONN;
 242         call->server = server;
 243
 244         INIT_WORK(&call->work, SRXAFSCB_CallBack);
 245         schedule_work(&call->work);
 246         return 0;
 247 }
 248
 249 /*
 250  * allow the fileserver to request callback state (re-)initialisation
 251  */
 252 static void SRXAFSCB_InitCallBackState(struct work_struct *work)
 253 {
 254         struct afs_call *call = container_of(work, struct afs_call, work);
 255
 256         _enter("{%p}", call->server);
 257
 258         afs_init_callback_state(call->server);
 259         afs_send_empty_reply(call);
 260         _leave("");
 261 }
 262
 263 /*
 264  * deliver request data to a CB.InitCallBackState call
 265  */
 266 static int afs_deliver_cb_init_call_back_state(struct afs_call *call,
 267                                                struct sk_buff *skb,
 268                                                bool last)
 269 {
 270         struct afs_server *server;
 271         struct in_addr addr;
 272
 273         _enter(",{%u},%d", skb->len, last);
 274
 275         if (skb->len > 0)
 276                 return -EBADMSG;
 277         if (!last)
 278                 return 0;
 279
 280         /* no unmarshalling required */
 281         call->state = AFS_CALL_REPLYING;
 282
 283         /* we'll need the file server record as that tells us which set of
 284          * vnodes to operate upon */
 285         memcpy(&addr, &ip_hdr(skb)->saddr, 4);
 286         server = afs_find_server(&addr);
 287         if (!server)
 288                 return -ENOTCONN;
 289         call->server = server;
 290
 291         INIT_WORK(&call->work, SRXAFSCB_InitCallBackState);
 292         schedule_work(&call->work);
 293         return 0;
 294 }
 295
 296 /*
 297  * allow the fileserver to see if the cache manager is still alive
 298  */
 299 static void SRXAFSCB_Probe(struct work_struct *work)
 300 {
 301         struct afs_call *call = container_of(work, struct afs_call, work);
 302
 303         _enter("");
 304         afs_send_empty_reply(call);
 305         _leave("");
 306 }
 307
 308 /*
 309  * deliver request data to a CB.Probe call
 310  */
 311 static int afs_deliver_cb_probe(struct afs_call *call, struct sk_buff *skb,
 312                                 bool last)
 313 {
 314         _enter(",{%u},%d", skb->len, last);
 315
 316         if (skb->len > 0)
 317                 return -EBADMSG;
 318         if (!last)
 319                 return 0;
 320
 321         /* no unmarshalling required */
 322         call->state = AFS_CALL_REPLYING;
 323
 324         INIT_WORK(&call->work, SRXAFSCB_Probe);
 325         schedule_work(&call->work);
 326         return 0;
 327 }