fs/afs/volume.h

   1 /* AFS volume management
   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_VOLUME_H
  13 #define AFS_VOLUME_H
  14
  15 #include "types.h"
  16 #include "fsclient.h"
  17 #include "kafstimod.h"
  18 #include "kafsasyncd.h"
  19 #include "cache.h"
  20
  21 typedef enum {
  22         AFS_VLUPD_SLEEP,                /* sleeping waiting for update timer to fire */
  23         AFS_VLUPD_PENDING,              /* on pending queue */
  24         AFS_VLUPD_INPROGRESS,           /* op in progress */
  25         AFS_VLUPD_BUSYSLEEP,            /* sleeping because server returned EBUSY */
  26 } __attribute__((packed)) afs_vlocation_upd_t;
  27
  28 /*
  29  * entry in the cached volume location catalogue
  30  */
  31 struct afs_cache_vlocation {
  32         uint8_t                 name[64];       /* volume name (lowercase, padded with NULs) */
  33         uint8_t                 nservers;       /* number of entries used in servers[] */
  34         uint8_t                 vidmask;        /* voltype mask for vid[] */
  35         uint8_t                 srvtmask[8];    /* voltype masks for servers[] */
  36 #define AFS_VOL_VTM_RW  0x01 /* R/W version of the volume is available (on this server) */
  37 #define AFS_VOL_VTM_RO  0x02 /* R/O version of the volume is available (on this server) */
  38 #define AFS_VOL_VTM_BAK 0x04 /* backup version of the volume is available (on this server) */
  39
  40         afs_volid_t             vid[3];         /* volume IDs for R/W, R/O and Bak volumes */
  41         struct in_addr          servers[8];     /* fileserver addresses */
  42         time_t                  rtime;          /* last retrieval time */
  43 };
  44
  45 #ifdef AFS_CACHING_SUPPORT
  46 extern struct cachefs_index_def afs_vlocation_cache_index_def;
  47 #endif
  48
  49 /*
  50  * volume -> vnode hash table entry
  51  */
  52 struct afs_cache_vhash {
  53         afs_voltype_t           vtype;          /* which volume variation */
  54         uint8_t                 hash_bucket;    /* which hash bucket this represents */
  55 } __attribute__((packed));
  56
  57 #ifdef AFS_CACHING_SUPPORT
  58 extern struct cachefs_index_def afs_volume_cache_index_def;
  59 #endif
  60
  61 /*
  62  * AFS volume location record
  63  */
  64 struct afs_vlocation {
  65         atomic_t                usage;
  66         struct list_head        link;           /* link in cell volume location list */
  67         struct afs_timer        timeout;        /* decaching timer */
  68         struct afs_cell         *cell;          /* cell to which volume belongs */
  69 #ifdef AFS_CACHING_SUPPORT
  70         struct cachefs_cookie   *cache;         /* caching cookie */
  71 #endif
  72         struct afs_cache_vlocation vldb;        /* volume information DB record */
  73         struct afs_volume       *vols[3];       /* volume access record pointer (index by type) */
  74         rwlock_t                lock;           /* access lock */
  75         unsigned long           read_jif;       /* time at which last read from vlserver */
  76         struct afs_timer        upd_timer;      /* update timer */
  77         struct afs_async_op     upd_op;         /* update operation */
  78         afs_vlocation_upd_t     upd_state;      /* update state */
  79         unsigned short          upd_first_svix; /* first server index during update */
  80         unsigned short          upd_curr_svix;  /* current server index during update */
  81         unsigned short          upd_rej_cnt;    /* ENOMEDIUM count during update */
  82         unsigned short          upd_busy_cnt;   /* EBUSY count during update */
  83         unsigned short          valid;          /* T if valid */
  84 };
  85
  86 extern int afs_vlocation_lookup(struct afs_cell *, const char *, unsigned,
  87                                 struct afs_vlocation **);
  88
  89 #define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)
  90
  91 extern void afs_put_vlocation(struct afs_vlocation *);
  92 extern void afs_vlocation_do_timeout(struct afs_vlocation *);
  93
  94 /*
  95  * AFS volume access record
  96  */
  97 struct afs_volume {
  98         atomic_t                usage;
  99         struct afs_cell         *cell;          /* cell to which belongs (unrefd ptr) */
 100         struct afs_vlocation    *vlocation;     /* volume location */
 101 #ifdef AFS_CACHING_SUPPORT
 102         struct cachefs_cookie   *cache;         /* caching cookie */
 103 #endif
 104         afs_volid_t             vid;            /* volume ID */
 105         afs_voltype_t           type;           /* type of volume */
 106         char                    type_force;     /* force volume type (suppress R/O -> R/W) */
 107         unsigned short          nservers;       /* number of server slots filled */
 108         unsigned short          rjservers;      /* number of servers discarded due to -ENOMEDIUM */
 109         struct afs_server       *servers[8];    /* servers on which volume resides (ordered) */
 110         struct rw_semaphore     server_sem;     /* lock for accessing current server */
 111 };
 112
 113 extern int afs_volume_lookup(const char *, struct afs_cell *, int,
 114                              struct afs_volume **);
 115
 116 #define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)
 117
 118 extern void afs_put_volume(struct afs_volume *);
 119
 120 extern int afs_volume_pick_fileserver(struct afs_volume *,
 121                                       struct afs_server **);
 122
 123 extern int afs_volume_release_fileserver(struct afs_volume *,
 124                                          struct afs_server *, int);
 125
 126 #endif /* AFS_VOLUME_H */