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 #define __packed __attribute__((packed))
  22
  23 typedef enum {
  24         AFS_VLUPD_SLEEP,                /* sleeping waiting for update timer to fire */
  25         AFS_VLUPD_PENDING,              /* on pending queue */
  26         AFS_VLUPD_INPROGRESS,           /* op in progress */
  27         AFS_VLUPD_BUSYSLEEP,            /* sleeping because server returned EBUSY */
  28
  29 } __attribute__((packed)) afs_vlocation_upd_t;
  30
  31 /*****************************************************************************/
  32 /*
  33  * entry in the cached volume location catalogue
  34  */
  35 struct afs_cache_vlocation
  36 {
  37         uint8_t                 name[64];       /* volume name (lowercase, padded with NULs) */
  38         uint8_t                 nservers;       /* number of entries used in servers[] */
  39         uint8_t                 vidmask;        /* voltype mask for vid[] */
  40         uint8_t                 srvtmask[8];    /* voltype masks for servers[] */
  41 #define AFS_VOL_VTM_RW  0x01 /* R/W version of the volume is available (on this server) */
  42 #define AFS_VOL_VTM_RO  0x02 /* R/O version of the volume is available (on this server) */
  43 #define AFS_VOL_VTM_BAK 0x04 /* backup version of the volume is available (on this server) */
  44
  45         afs_volid_t             vid[3];         /* volume IDs for R/W, R/O and Bak volumes */
  46         struct in_addr          servers[8];     /* fileserver addresses */
  47         time_t                  rtime;          /* last retrieval time */
  48 };
  49
  50 #ifdef AFS_CACHING_SUPPORT
  51 extern struct cachefs_index_def afs_vlocation_cache_index_def;
  52 #endif
  53
  54 /*****************************************************************************/
  55 /*
  56  * volume -> vnode hash table entry
  57  */
  58 struct afs_cache_vhash
  59 {
  60         afs_voltype_t           vtype;          /* which volume variation */
  61         uint8_t                 hash_bucket;    /* which hash bucket this represents */
  62 } __attribute__((packed));
  63
  64 #ifdef AFS_CACHING_SUPPORT
  65 extern struct cachefs_index_def afs_volume_cache_index_def;
  66 #endif
  67
  68 /*****************************************************************************/
  69 /*
  70  * AFS volume location record
  71  */
  72 struct afs_vlocation
  73 {
  74         atomic_t                usage;
  75         struct list_head        link;           /* link in cell volume location list */
  76         struct afs_timer        timeout;        /* decaching timer */
  77         struct afs_cell         *cell;          /* cell to which volume belongs */
  78 #ifdef AFS_CACHING_SUPPORT
  79         struct cachefs_cookie   *cache;         /* caching cookie */
  80 #endif
  81         struct afs_cache_vlocation vldb;        /* volume information DB record */
  82         struct afs_volume       *vols[3];       /* volume access record pointer (index by type) */
  83         rwlock_t                lock;           /* access lock */
  84         unsigned long           read_jif;       /* time at which last read from vlserver */
  85         struct afs_timer        upd_timer;      /* update timer */
  86         struct afs_async_op     upd_op;         /* update operation */
  87         afs_vlocation_upd_t     upd_state;      /* update state */
  88         unsigned short          upd_first_svix; /* first server index during update */
  89         unsigned short          upd_curr_svix;  /* current server index during update */
  90         unsigned short          upd_rej_cnt;    /* ENOMEDIUM count during update */
  91         unsigned short          upd_busy_cnt;   /* EBUSY count during update */
  92         unsigned short          valid;          /* T if valid */
  93 };
  94
  95 extern int afs_vlocation_lookup(struct afs_cell *cell,
  96                                 const char *name,
  97                                 unsigned namesz,
  98                                 struct afs_vlocation **_vlocation);
  99
 100 #define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)
 101
 102 extern void afs_put_vlocation(struct afs_vlocation *vlocation);
 103 extern void afs_vlocation_do_timeout(struct afs_vlocation *vlocation);
 104
 105 /*****************************************************************************/
 106 /*
 107  * AFS volume access record
 108  */
 109 struct afs_volume
 110 {
 111         atomic_t                usage;
 112         struct afs_cell         *cell;          /* cell to which belongs (unrefd ptr) */
 113         struct afs_vlocation    *vlocation;     /* volume location */
 114 #ifdef AFS_CACHING_SUPPORT
 115         struct cachefs_cookie   *cache;         /* caching cookie */
 116 #endif
 117         afs_volid_t             vid;            /* volume ID */
 118         afs_voltype_t __packed  type;           /* type of volume */
 119         char                    type_force;     /* force volume type (suppress R/O -> R/W) */
 120         unsigned short          nservers;       /* number of server slots filled */
 121         unsigned short          rjservers;      /* number of servers discarded due to -ENOMEDIUM */
 122         struct afs_server       *servers[8];    /* servers on which volume resides (ordered) */
 123         struct rw_semaphore     server_sem;     /* lock for accessing current server */
 124 };
 125
 126 extern int afs_volume_lookup(const char *name,
 127                              struct afs_cell *cell,
 128                              int rwpath,
 129                              struct afs_volume **_volume);
 130
 131 #define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)
 132
 133 extern void afs_put_volume(struct afs_volume *volume);
 134
 135 extern int afs_volume_pick_fileserver(struct afs_volume *volume,
 136                                       struct afs_server **_server);
 137
 138 extern int afs_volume_release_fileserver(struct afs_volume *volume,
 139                                          struct afs_server *server,
 140                                          int result);
 141
 142 #endif /* _LINUX_AFS_VOLUME_H */