linux/fs/afs/volume.h

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/* volume.h: AFS volume management
*
* Copyright (C) 2002 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _LINUX_AFS_VOLUME_H
#define _LINUX_AFS_VOLUME_H
#include "types.h"
#include "fsclient.h"
#include "kafstimod.h"
#include "kafsasyncd.h"
#include "cache.h"
#define __packed __attribute__((packed))
typedef enum {
AFS_VLUPD_SLEEP, /* sleeping waiting for update timer to fire */
AFS_VLUPD_PENDING, /* on pending queue */
AFS_VLUPD_INPROGRESS, /* op in progress */
AFS_VLUPD_BUSYSLEEP, /* sleeping because server returned EBUSY */
} __attribute__((packed)) afs_vlocation_upd_t;
/*****************************************************************************/
/*
* entry in the cached volume location catalogue
*/
struct afs_cache_vlocation
{
uint8_t name[64]; /* volume name (lowercase, padded with NULs) */
uint8_t nservers; /* number of entries used in servers[] */
uint8_t vidmask; /* voltype mask for vid[] */
uint8_t srvtmask[8]; /* voltype masks for servers[] */
#define AFS_VOL_VTM_RW 0x01 /* R/W version of the volume is available (on this server) */
#define AFS_VOL_VTM_RO 0x02 /* R/O version of the volume is available (on this server) */
#define AFS_VOL_VTM_BAK 0x04 /* backup version of the volume is available (on this server) */
afs_volid_t vid[3]; /* volume IDs for R/W, R/O and Bak volumes */
struct in_addr servers[8]; /* fileserver addresses */
time_t rtime; /* last retrieval time */
};
#ifdef AFS_CACHING_SUPPORT
extern struct cachefs_index_def afs_vlocation_cache_index_def;
#endif
/*****************************************************************************/
/*
* volume -> vnode hash table entry
*/
struct afs_cache_vhash
{
afs_voltype_t vtype; /* which volume variation */
uint8_t hash_bucket; /* which hash bucket this represents */
} __attribute__((packed));
#ifdef AFS_CACHING_SUPPORT
extern struct cachefs_index_def afs_volume_cache_index_def;
#endif
/*****************************************************************************/
/*
* AFS volume location record
*/
struct afs_vlocation
{
atomic_t usage;
struct list_head link; /* link in cell volume location list */
struct afs_timer timeout; /* decaching timer */
struct afs_cell *cell; /* cell to which volume belongs */
#ifdef AFS_CACHING_SUPPORT
struct cachefs_cookie *cache; /* caching cookie */
#endif
struct afs_cache_vlocation vldb; /* volume information DB record */
struct afs_volume *vols[3]; /* volume access record pointer (index by type) */
rwlock_t lock; /* access lock */
unsigned long read_jif; /* time at which last read from vlserver */
struct afs_timer upd_timer; /* update timer */
struct afs_async_op upd_op; /* update operation */
afs_vlocation_upd_t upd_state; /* update state */
unsigned short upd_first_svix; /* first server index during update */
unsigned short upd_curr_svix; /* current server index during update */
unsigned short upd_rej_cnt; /* ENOMEDIUM count during update */
unsigned short upd_busy_cnt; /* EBUSY count during update */
unsigned short valid; /* T if valid */
};
extern int afs_vlocation_lookup(struct afs_cell *cell,
const char *name,
unsigned namesz,
struct afs_vlocation **_vlocation);
#define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)
extern void afs_put_vlocation(struct afs_vlocation *vlocation);
extern void afs_vlocation_do_timeout(struct afs_vlocation *vlocation);
/*****************************************************************************/
/*
* AFS volume access record
*/
struct afs_volume
{
atomic_t usage;
struct afs_cell *cell; /* cell to which belongs (unrefd ptr) */
struct afs_vlocation *vlocation; /* volume location */
#ifdef AFS_CACHING_SUPPORT
struct cachefs_cookie *cache; /* caching cookie */
#endif
afs_volid_t vid; /* volume ID */
afs_voltype_t __packed type; /* type of volume */
char type_force; /* force volume type (suppress R/O -> R/W) */
unsigned short nservers; /* number of server slots filled */
unsigned short rjservers; /* number of servers discarded due to -ENOMEDIUM */
struct afs_server *servers[8]; /* servers on which volume resides (ordered) */
struct rw_semaphore server_sem; /* lock for accessing current server */
};
extern int afs_volume_lookup(const char *name,
struct afs_cell *cell,
int rwpath,
struct afs_volume **_volume);
#define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)
extern void afs_put_volume(struct afs_volume *volume);
extern int afs_volume_pick_fileserver(struct afs_volume *volume,
struct afs_server **_server);
extern int afs_volume_release_fileserver(struct afs_volume *volume,
struct afs_server *server,
int result);
#endif /* _LINUX_AFS_VOLUME_H */