fs/afs/volume.h

   1 /* volume.h: 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 _LINUX_AFS_VOLUME_H
  13 #define _LINUX_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
  27 } __attribute__((packed)) afs_vlocation_upd_t;
  28
  29 /*****************************************************************************/
  30 /*
  31  * entry in the cached volume location catalogue
  32  */
  33 struct afs_cache_vlocation
  34 {
  35         uint8_t                 name[64];       /* volume name (lowercase, padded with NULs) */
  36         uint8_t                 nservers;       /* number of entries used in servers[] */
  37         uint8_t                 vidmask;        /* voltype mask for vid[] */
  38         uint8_t                 srvtmask[8];    /* voltype masks for servers[] */
  39 #define AFS_VOL_VTM_RW  0x01 /* R/W version of the volume is available (on this server) */
  40 #define AFS_VOL_VTM_RO  0x02 /* R/O version of the volume is available (on this server) */
  41 #define AFS_VOL_VTM_BAK 0x04 /* backup version of the volume is available (on this server) */
  42
  43         afs_volid_t             vid[3];         /* volume IDs for R/W, R/O and Bak volumes */
  44         struct in_addr          servers[8];     /* fileserver addresses */
  45         time_t                  rtime;          /* last retrieval time */
  46 };
  47
  48 #ifdef AFS_CACHING_SUPPORT
  49 extern struct cachefs_index_def afs_vlocation_cache_index_def;
  50 #endif
  51
  52 /*****************************************************************************/
  53 /*
  54  * volume -> vnode hash table entry
  55  */
  56 struct afs_cache_vhash
  57 {
  58         afs_voltype_t           vtype;          /* which volume variation */
  59         uint8_t                 hash_bucket;    /* which hash bucket this represents */
  60 } __attribute__((packed));
  61
  62 #ifdef AFS_CACHING_SUPPORT
  63 extern struct cachefs_index_def afs_volume_cache_index_def;
  64 #endif
  65
  66 /*****************************************************************************/
  67 /*
  68  * AFS volume location record
  69  */
  70 struct afs_vlocation
  71 {
  72         atomic_t                usage;
  73         struct list_head        link;           /* link in cell volume location list */
  74         struct afs_timer        timeout;        /* decaching timer */
  75         struct afs_cell         *cell;          /* cell to which volume belongs */
  76 #ifdef AFS_CACHING_SUPPORT
  77         struct cachefs_cookie   *cache;         /* caching cookie */
  78 #endif
  79         struct afs_cache_vlocation vldb;        /* volume information DB record */
  80         struct afs_volume       *vols[3];       /* volume access record pointer (index by type) */
  81         rwlock_t                lock;           /* access lock */
  82         unsigned long           read_jif;       /* time at which last read from vlserver */
  83         struct afs_timer        upd_timer;      /* update timer */
  84         struct afs_async_op     upd_op;         /* update operation */
  85         afs_vlocation_upd_t     upd_state;      /* update state */
  86         unsigned short          upd_first_svix; /* first server index during update */
  87         unsigned short          upd_curr_svix;  /* current server index during update */
  88         unsigned short          upd_rej_cnt;    /* ENOMEDIUM count during update */
  89         unsigned short          upd_busy_cnt;   /* EBUSY count during update */
  90         unsigned short          valid;          /* T if valid */
  91 };
  92
  93 extern int afs_vlocation_lookup(struct afs_cell *cell,
  94                                 const char *name,
  95                                 unsigned namesz,
  96                                 struct afs_vlocation **_vlocation);
  97
  98 #define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)
  99
 100 extern void afs_put_vlocation(struct afs_vlocation *vlocation);
 101 extern void afs_vlocation_do_timeout(struct afs_vlocation *vlocation);
 102
 103 /*****************************************************************************/
 104 /*
 105  * AFS volume access record
 106  */
 107 struct afs_volume
 108 {
 109         atomic_t                usage;
 110         struct afs_cell         *cell;          /* cell to which belongs (unrefd ptr) */
 111         struct afs_vlocation    *vlocation;     /* volume location */
 112 #ifdef AFS_CACHING_SUPPORT
 113         struct cachefs_cookie   *cache;         /* caching cookie */
 114 #endif
 115         afs_volid_t             vid;            /* volume ID */
 116         afs_voltype_t           type;           /* type of volume */
 117         char                    type_force;     /* force volume type (suppress R/O -> R/W) */
 118         unsigned short          nservers;       /* number of server slots filled */
 119         unsigned short          rjservers;      /* number of servers discarded due to -ENOMEDIUM */
 120         struct afs_server       *servers[8];    /* servers on which volume resides (ordered) */
 121         struct rw_semaphore     server_sem;     /* lock for accessing current server */
 122 };
 123
 124 extern int afs_volume_lookup(const char *name,
 125                              struct afs_cell *cell,
 126                              int rwpath,
 127                              struct afs_volume **_volume);
 128
 129 #define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)
 130
 131 extern void afs_put_volume(struct afs_volume *volume);
 132
 133 extern int afs_volume_pick_fileserver(struct afs_volume *volume,
 134                                       struct afs_server **_server);
 135
 136 extern int afs_volume_release_fileserver(struct afs_volume *volume,
 137                                          struct afs_server *server,
 138                                          int result);
 139
 140 #endif /* _LINUX_AFS_VOLUME_H */