fs/afs/server.h

   1 /* AFS server record
   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 #ifndef AFS_SERVER_H
  13 #define AFS_SERVER_H
  14
  15 #include "types.h"
  16 #include "kafstimod.h"
  17 #include <rxrpc/peer.h>
  18 #include <linux/rwsem.h>
  19
  20 extern spinlock_t afs_server_peer_lock;
  21
  22 /*
  23  * AFS server record
  24  */
  25 struct afs_server {
  26         atomic_t                usage;
  27         struct afs_cell         *cell;          /* cell in which server resides */
  28         struct list_head        link;           /* link in cell's server list */
  29         struct rw_semaphore     sem;            /* access lock */
  30         struct afs_timer        timeout;        /* graveyard timeout */
  31         struct in_addr          addr;           /* server address */
  32         struct rxrpc_peer       *peer;          /* peer record for this server */
  33         struct rxrpc_connection *vlserver;      /* connection to the volume location service */
  34
  35         /* file service access */
  36 #define AFS_SERVER_CONN_LIST_SIZE 2
  37         struct rxrpc_connection *fs_conn[AFS_SERVER_CONN_LIST_SIZE]; /* FS connections */
  38         unsigned                fs_conn_cnt[AFS_SERVER_CONN_LIST_SIZE]; /* per conn call count */
  39         struct list_head        fs_callq;       /* queue of processes waiting to make a call */
  40         spinlock_t              fs_lock;        /* access lock */
  41         int                     fs_state;       /* 0 or reason FS currently marked dead (-errno) */
  42         unsigned                fs_rtt;         /* FS round trip time */
  43         unsigned long           fs_act_jif;     /* time at which last activity occurred */
  44         unsigned long           fs_dead_jif;    /* time at which no longer to be considered dead */
  45
  46         /* callback promise management */
  47         struct list_head        cb_promises;    /* as yet unbroken promises from this server */
  48         spinlock_t              cb_lock;        /* access lock */
  49 };
  50
  51 extern int afs_server_lookup(struct afs_cell *, const struct in_addr *,
  52                              struct afs_server **);
  53
  54 #define afs_get_server(S) do { atomic_inc(&(S)->usage); } while(0)
  55
  56 extern void afs_put_server(struct afs_server *);
  57 extern void afs_server_do_timeout(struct afs_server *);
  58
  59 extern int afs_server_find_by_peer(const struct rxrpc_peer *,
  60                                    struct afs_server **);
  61
  62 extern int afs_server_get_vlconn(struct afs_server *,
  63                                  struct rxrpc_connection **);
  64
  65 static inline
  66 struct afs_server *afs_server_get_from_peer(struct rxrpc_peer *peer)
  67 {
  68         struct afs_server *server;
  69
  70         spin_lock(&afs_server_peer_lock);
  71         server = peer->user;
  72         if (server)
  73                 afs_get_server(server);
  74         spin_unlock(&afs_server_peer_lock);
  75
  76         return server;
  77 }
  78
  79 /*
  80  * AFS server callslot grant record
  81  */
  82 struct afs_server_callslot {
  83         struct list_head        link;           /* link in server's list */
  84         struct task_struct      *task;          /* process waiting to make call */
  85         struct rxrpc_connection *conn;          /* connection to use (or NULL on error) */
  86         short                   nconn;          /* connection slot number (-1 on error) */
  87         char                    ready;          /* T when ready */
  88         int                     errno;          /* error number if nconn==-1 */
  89 };
  90
  91 extern int afs_server_request_callslot(struct afs_server *,
  92                                        struct afs_server_callslot *);
  93
  94 extern void afs_server_release_callslot(struct afs_server *,
  95                                         struct afs_server_callslot *);
  96
  97 #endif /* AFS_SERVER_H */