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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
23typedef 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 */
35struct 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
51extern struct cachefs_index_def afs_vlocation_cache_index_def;
52#endif
53
54/*****************************************************************************/
55/*
56 * volume -> vnode hash table entry
57 */
58struct 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
65extern struct cachefs_index_def afs_volume_cache_index_def;
66#endif
67
68/*****************************************************************************/
69/*
70 * AFS volume location record
71 */
72struct 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
95extern 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
102extern void afs_put_vlocation(struct afs_vlocation *vlocation);
103extern void afs_vlocation_do_timeout(struct afs_vlocation *vlocation);
104
105/*****************************************************************************/
106/*
107 * AFS volume access record
108 */
109struct 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
126extern 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
133extern void afs_put_volume(struct afs_volume *volume);
134
135extern int afs_volume_pick_fileserver(struct afs_volume *volume,
136 struct afs_server **_server);
137
138extern int afs_volume_release_fileserver(struct afs_volume *volume,
139 struct afs_server *server,
140 int result);
141
142#endif /* _LINUX_AFS_VOLUME_H */