internal.h

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/* internal AFS stuff
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells ([email protected])
 *
 * 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.
 */

#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/skbuff.h>
#include <linux/rxrpc.h>
#include <linux/key.h>
#include <linux/workqueue.h>
#include <linux/sched.h>
#include <linux/fscache.h>
#include <linux/backing-dev.h>

#include "afs.h"
#include "afs_vl.h"

#define AFS_CELL_MAX_ADDRS 15

struct pagevec;
struct afs_call;

typedef enum {
    AFS_VL_NEW,         /* new, uninitialised record */
    AFS_VL_CREATING,        /* creating record */
    AFS_VL_VALID,           /* record is pending */
    AFS_VL_NO_VOLUME,       /* no such volume available */
    AFS_VL_UPDATING,        /* update in progress */
    AFS_VL_VOLUME_DELETED,      /* volume was deleted */
    AFS_VL_UNCERTAIN,       /* uncertain state (update failed) */
} __attribute__((packed)) afs_vlocation_state_t;

struct afs_mount_params {
    bool            rwpath;     /* T if the parent should be considered R/W */
    bool            force;      /* T to force cell type */
    bool            autocell;   /* T if set auto mount operation */
    afs_voltype_t       type;       /* type of volume requested */
    int         volnamesz;  /* size of volume name */
    const char      *volname;   /* name of volume to mount */
    struct afs_cell     *cell;      /* cell in which to find volume */
    struct afs_volume   *volume;    /* volume record */
    struct key      *key;       /* key to use for secure mounting */
};

/*
 * definition of how to wait for the completion of an operation
 */
struct afs_wait_mode {
    /* RxRPC received message notification */
    void (*rx_wakeup)(struct afs_call *call);

    /* synchronous call waiter and call dispatched notification */
    int (*wait)(struct afs_call *call);

    /* asynchronous call completion */
    void (*async_complete)(void *reply, int error);
};

extern const struct afs_wait_mode afs_sync_call;
extern const struct afs_wait_mode afs_async_call;

/*
 * a record of an in-progress RxRPC call
 */
struct afs_call {
    const struct afs_call_type *type;   /* type of call */
    const struct afs_wait_mode *wait_mode;  /* completion wait mode */
    wait_queue_head_t   waitq;      /* processes awaiting completion */
    struct work_struct  async_work; /* asynchronous work processor */
    struct work_struct  work;       /* actual work processor */
    struct sk_buff_head rx_queue;   /* received packets */
    struct rxrpc_call   *rxcall;    /* RxRPC call handle */
    struct key      *key;       /* security for this call */
    struct afs_server   *server;    /* server affected by incoming CM call */
    void            *request;   /* request data (first part) */
    struct address_space    *mapping;   /* page set */
    struct afs_writeback    *wb;        /* writeback being performed */
    void            *buffer;    /* reply receive buffer */
    void            *reply;     /* reply buffer (first part) */
    void            *reply2;    /* reply buffer (second part) */
    void            *reply3;    /* reply buffer (third part) */
    void            *reply4;    /* reply buffer (fourth part) */
    pgoff_t         first;      /* first page in mapping to deal with */
    pgoff_t         last;       /* last page in mapping to deal with */
    enum {                  /* call state */
        AFS_CALL_REQUESTING,    /* request is being sent for outgoing call */
        AFS_CALL_AWAIT_REPLY,   /* awaiting reply to outgoing call */
        AFS_CALL_AWAIT_OP_ID,   /* awaiting op ID on incoming call */
        AFS_CALL_AWAIT_REQUEST, /* awaiting request data on incoming call */
        AFS_CALL_REPLYING,  /* replying to incoming call */
        AFS_CALL_AWAIT_ACK, /* awaiting final ACK of incoming call */
        AFS_CALL_COMPLETE,  /* successfully completed */
        AFS_CALL_BUSY,      /* server was busy */
        AFS_CALL_ABORTED,   /* call was aborted */
        AFS_CALL_ERROR,     /* call failed due to error */
    }           state;
    int         error;      /* error code */
    unsigned        request_size;   /* size of request data */
    unsigned        reply_max;  /* maximum size of reply */
    unsigned        reply_size; /* current size of reply */
    unsigned        first_offset;   /* offset into mapping[first] */
    unsigned        last_to;    /* amount of mapping[last] */
    unsigned        offset;     /* offset into received data store */
    unsigned char       unmarshall; /* unmarshalling phase */
    bool            incoming;   /* T if incoming call */
    bool            send_pages; /* T if data from mapping should be sent */
    u16         service_id; /* RxRPC service ID to call */
    __be16          port;       /* target UDP port */
    __be32          operation_ID;   /* operation ID for an incoming call */
    u32         count;      /* count for use in unmarshalling */
    __be32          tmp;        /* place to extract temporary data */
    afs_dataversion_t   store_version;  /* updated version expected from store */
};

struct afs_call_type {
    const char *name;

    /* deliver request or reply data to an call
     * - returning an error will cause the call to be aborted
     */
    int (*deliver)(struct afs_call *call, struct sk_buff *skb,
               bool last);

    /* map an abort code to an error number */
    int (*abort_to_error)(u32 abort_code);

    /* clean up a call */
    void (*destructor)(struct afs_call *call);
};

/*
 * record of an outstanding writeback on a vnode
 */
struct afs_writeback {
    struct list_head    link;       /* link in vnode->writebacks */
    struct work_struct  writer;     /* work item to perform the writeback */
    struct afs_vnode    *vnode;     /* vnode to which this write applies */
    struct key      *key;       /* owner of this write */
    wait_queue_head_t   waitq;      /* completion and ready wait queue */
    pgoff_t         first;      /* first page in batch */
    pgoff_t         point;      /* last page in current store op */
    pgoff_t         last;       /* last page in batch (inclusive) */
    unsigned        offset_first;   /* offset into first page of start of write */
    unsigned        to_last;    /* offset into last page of end of write */
    int         num_conflicts;  /* count of conflicting writes in list */
    int         usage;
    bool            conflicts;  /* T if has dependent conflicts */
    enum {
        AFS_WBACK_SYNCING,      /* synchronisation being performed */
        AFS_WBACK_PENDING,      /* write pending */
        AFS_WBACK_CONFLICTING,      /* conflicting writes posted */
        AFS_WBACK_WRITING,      /* writing back */
        AFS_WBACK_COMPLETE      /* the writeback record has been unlinked */
    } state __attribute__((packed));
};

/*
 * AFS superblock private data
 * - there's one superblock per volume
 */
struct afs_super_info {
    struct afs_volume   *volume;    /* volume record */
    char            rwparent;   /* T if parent is R/W AFS volume */
};

static inline struct afs_super_info *AFS_FS_S(struct super_block *sb)
{
    return sb->s_fs_info;
}

extern struct file_system_type afs_fs_type;

/*
 * entry in the cached cell catalogue
 */
struct afs_cache_cell {
    char        name[AFS_MAXCELLNAME];  /* cell name (padded with NULs) */
    struct in_addr  vl_servers[15];     /* cached cell VL servers */
};

/*
 * AFS cell record
 */
struct afs_cell {
    atomic_t        usage;
    struct list_head    link;       /* main cell list link */
    struct key      *anonymous_key; /* anonymous user key for this cell */
    struct list_head    proc_link;  /* /proc cell list link */
    struct proc_dir_entry   *proc_dir;  /* /proc dir for this cell */
#ifdef CONFIG_AFS_FSCACHE
    struct fscache_cookie   *cache;     /* caching cookie */
#endif

    /* server record management */
    rwlock_t        servers_lock;   /* active server list lock */
    struct list_head    servers;    /* active server list */

    /* volume location record management */
    struct rw_semaphore vl_sem;     /* volume management serialisation semaphore */
    struct list_head    vl_list;    /* cell's active VL record list */
    spinlock_t      vl_lock;    /* vl_list lock */
    unsigned short      vl_naddrs;  /* number of VL servers in addr list */
    unsigned short      vl_curr_svix;   /* current server index */
    struct in_addr      vl_addrs[AFS_CELL_MAX_ADDRS];   /* cell VL server addresses */

    char            name[0];    /* cell name - must go last */
};

/*
 * entry in the cached volume location catalogue
 */
struct afs_cache_vlocation {
    /* volume name (lowercase, padded with NULs) */
    uint8_t         name[AFS_MAXVOLNAME + 1];

    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 */
};

/*
 * 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));

/*
 * AFS volume location record
 */
struct afs_vlocation {
    atomic_t        usage;
    time_t          time_of_death;  /* time at which put reduced usage to 0 */
    struct list_head    link;       /* link in cell volume location list */
    struct list_head    grave;      /* link in master graveyard list */
    struct list_head    update;     /* link in master update list */
    struct afs_cell     *cell;      /* cell to which volume belongs */
#ifdef CONFIG_AFS_FSCACHE
    struct fscache_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) */
    wait_queue_head_t   waitq;      /* status change waitqueue */
    time_t          update_at;  /* time at which record should be updated */
    spinlock_t      lock;       /* access lock */
    afs_vlocation_state_t   state;      /* volume location state */
    unsigned short      upd_rej_cnt;    /* ENOMEDIUM count during update */
    unsigned short      upd_busy_cnt;   /* EBUSY count during update */
    bool            valid;      /* T if valid */
};

/*
 * AFS fileserver record
 */
struct afs_server {
    atomic_t        usage;
    time_t          time_of_death;  /* time at which put reduced usage to 0 */
    struct in_addr      addr;       /* server address */
    struct afs_cell     *cell;      /* cell in which server resides */
    struct list_head    link;       /* link in cell's server list */
    struct list_head    grave;      /* link in master graveyard list */
    struct rb_node      master_rb;  /* link in master by-addr tree */
    struct rw_semaphore sem;        /* access lock */

    /* file service access */
    struct rb_root      fs_vnodes;  /* vnodes backed by this server (ordered by FID) */
    unsigned long       fs_act_jif; /* time at which last activity occurred */
    unsigned long       fs_dead_jif;    /* time at which no longer to be considered dead */
    spinlock_t      fs_lock;    /* access lock */
    int         fs_state;       /* 0 or reason FS currently marked dead (-errno) */

    /* callback promise management */
    struct rb_root      cb_promises;    /* vnode expiration list (ordered earliest first) */
    struct delayed_work cb_updater; /* callback updater */
    struct delayed_work cb_break_work;  /* collected break dispatcher */
    wait_queue_head_t   cb_break_waitq; /* space available in cb_break waitqueue */
    spinlock_t      cb_lock;    /* access lock */
    struct afs_callback cb_break[64];   /* ring of callbacks awaiting breaking */
    atomic_t        cb_break_n; /* number of pending breaks */
    u8          cb_break_head;  /* head of callback breaking ring */
    u8          cb_break_tail;  /* tail of callback breaking ring */
};

/*
 * 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 CONFIG_AFS_FSCACHE
    struct fscache_cookie   *cache;     /* caching cookie */
#endif
    afs_volid_t     vid;        /* volume ID */
    afs_voltype_t       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 */
    struct backing_dev_info bdi;
};

/*
 * vnode catalogue entry
 */
struct afs_cache_vnode {
    afs_vnodeid_t       vnode_id;   /* vnode ID */
    unsigned        vnode_unique;   /* vnode ID uniquifier */
    afs_dataversion_t   data_version;   /* data version */
};

/*
 * AFS inode private data
 */
struct afs_vnode {
    struct inode        vfs_inode;  /* the VFS's inode record */

    struct afs_volume   *volume;    /* volume on which vnode resides */
    struct afs_server   *server;    /* server currently supplying this file */
    struct afs_fid      fid;        /* the file identifier for this inode */
    struct afs_file_status  status;     /* AFS status info for this file */
#ifdef CONFIG_AFS_FSCACHE
    struct fscache_cookie   *cache;     /* caching cookie */
#endif
    struct afs_permits  *permits;   /* cache of permits so far obtained */
    struct mutex        permits_lock;   /* lock for altering permits list */
    struct mutex        validate_lock;  /* lock for validating this vnode */
    wait_queue_head_t   update_waitq;   /* status fetch waitqueue */
    int         update_cnt; /* number of outstanding ops that will update the
                         * status */
    spinlock_t      writeback_lock; /* lock for writebacks */
    spinlock_t      lock;       /* waitqueue/flags lock */
    unsigned long       flags;
#define AFS_VNODE_CB_BROKEN 0       /* set if vnode's callback was broken */
#define AFS_VNODE_UNSET     1       /* set if vnode attributes not yet set */
#define AFS_VNODE_MODIFIED  2       /* set if vnode's data modified */
#define AFS_VNODE_ZAP_DATA  3       /* set if vnode's data should be invalidated */
#define AFS_VNODE_DELETED   4       /* set if vnode deleted on server */
#define AFS_VNODE_MOUNTPOINT    5       /* set if vnode is a mountpoint symlink */
#define AFS_VNODE_LOCKING   6       /* set if waiting for lock on vnode */
#define AFS_VNODE_READLOCKED    7       /* set if vnode is read-locked on the server */
#define AFS_VNODE_WRITELOCKED   8       /* set if vnode is write-locked on the server */
#define AFS_VNODE_UNLOCKING 9       /* set if vnode is being unlocked on the server */
#define AFS_VNODE_AUTOCELL  10      /* set if Vnode is an auto mount point */
#define AFS_VNODE_PSEUDODIR 11      /* set if Vnode is a pseudo directory */

    long            acl_order;  /* ACL check count (callback break count) */

    struct list_head    writebacks; /* alterations in pagecache that need writing */
    struct list_head    pending_locks;  /* locks waiting to be granted */
    struct list_head    granted_locks;  /* locks granted on this file */
    struct delayed_work lock_work;  /* work to be done in locking */
    struct key      *unlock_key;    /* key to be used in unlocking */

    /* outstanding callback notification on this file */
    struct rb_node      server_rb;  /* link in server->fs_vnodes */
    struct rb_node      cb_promise; /* link in server->cb_promises */
    struct work_struct  cb_broken_work; /* work to be done on callback break */
    time_t          cb_expires; /* time at which callback expires */
    time_t          cb_expires_at;  /* time used to order cb_promise */
    unsigned        cb_version; /* callback version */
    unsigned        cb_expiry;  /* callback expiry time */
    afs_callback_type_t cb_type;    /* type of callback */
    bool            cb_promised;    /* true if promise still holds */
};

/*
 * cached security record for one user's attempt to access a vnode
 */
struct afs_permit {
    struct key      *key;       /* RxRPC ticket holding a security context */
    afs_access_t        access_mask;    /* access mask for this key */
};

/*
 * cache of security records from attempts to access a vnode
 */
struct afs_permits {
    struct rcu_head     rcu;        /* disposal procedure */
    int         count;      /* number of records */
    struct afs_permit   permits[0]; /* the permits so far examined */
};

/*
 * record of one of a system's set of network interfaces
 */
struct afs_interface {
    struct in_addr  address;    /* IPv4 address bound to interface */
    struct in_addr  netmask;    /* netmask applied to address */
    unsigned    mtu;        /* MTU of interface */
};

/*
 * UUID definition [internet draft]
 * - the timestamp is a 60-bit value, split 32/16/12, and goes in 100ns
 *   increments since midnight 15th October 1582
 *   - add AFS_UUID_TO_UNIX_TIME to convert unix time in 100ns units to UUID
 *     time
 * - the clock sequence is a 14-bit counter to avoid duplicate times
 */
struct afs_uuid {
    u32     time_low;           /* low part of timestamp */
    u16     time_mid;           /* mid part of timestamp */
    u16     time_hi_and_version;        /* high part of timestamp and version  */
#define AFS_UUID_TO_UNIX_TIME   0x01b21dd213814000ULL
#define AFS_UUID_TIMEHI_MASK    0x0fff
#define AFS_UUID_VERSION_TIME   0x1000  /* time-based UUID */
#define AFS_UUID_VERSION_NAME   0x3000  /* name-based UUID */
#define AFS_UUID_VERSION_RANDOM 0x4000  /* (pseudo-)random generated UUID */
    u8      clock_seq_hi_and_reserved;  /* clock seq hi and variant */
#define AFS_UUID_CLOCKHI_MASK   0x3f
#define AFS_UUID_VARIANT_STD    0x80
    u8      clock_seq_low;          /* clock seq low */
    u8      node[6];            /* spatially unique node ID (MAC addr) */
};

/*****************************************************************************/
/*
 * cache.c
 */
#ifdef CONFIG_AFS_FSCACHE
extern struct fscache_netfs afs_cache_netfs;
extern struct fscache_cookie_def afs_cell_cache_index_def;
extern struct fscache_cookie_def afs_vlocation_cache_index_def;
extern struct fscache_cookie_def afs_volume_cache_index_def;
extern struct fscache_cookie_def afs_vnode_cache_index_def;
#else
#define afs_cell_cache_index_def    (*(struct fscache_cookie_def *) NULL)
#define afs_vlocation_cache_index_def   (*(struct fscache_cookie_def *) NULL)
#define afs_volume_cache_index_def  (*(struct fscache_cookie_def *) NULL)
#define afs_vnode_cache_index_def   (*(struct fscache_cookie_def *) NULL)
#endif

/*
 * callback.c
 */
extern void afs_init_callback_state(struct afs_server *);
extern void afs_broken_callback_work(struct work_struct *);
extern void afs_break_callbacks(struct afs_server *, size_t,
                struct afs_callback[]);
extern void afs_discard_callback_on_delete(struct afs_vnode *);
extern void afs_give_up_callback(struct afs_vnode *);
extern void afs_dispatch_give_up_callbacks(struct work_struct *);
extern void afs_flush_callback_breaks(struct afs_server *);
extern int __init afs_callback_update_init(void);
extern void afs_callback_update_kill(void);

/*
 * cell.c
 */
extern struct rw_semaphore afs_proc_cells_sem;
extern struct list_head afs_proc_cells;

#define afs_get_cell(C) do { atomic_inc(&(C)->usage); } while(0)
extern int afs_cell_init(char *);
extern struct afs_cell *afs_cell_create(const char *, unsigned, char *, bool);
extern struct afs_cell *afs_cell_lookup(const char *, unsigned, bool);
extern struct afs_cell *afs_grab_cell(struct afs_cell *);
extern void afs_put_cell(struct afs_cell *);
extern void afs_cell_purge(void);

/*
 * cmservice.c
 */
extern bool afs_cm_incoming_call(struct afs_call *);

/*
 * dir.c
 */
extern const struct inode_operations afs_dir_inode_operations;
extern const struct dentry_operations afs_fs_dentry_operations;
extern const struct file_operations afs_dir_file_operations;

/*
 * file.c
 */
extern const struct address_space_operations afs_fs_aops;
extern const struct inode_operations afs_file_inode_operations;
extern const struct file_operations afs_file_operations;

extern int afs_open(struct inode *, struct file *);
extern int afs_release(struct inode *, struct file *);
extern int afs_page_filler(void *, struct page *);

/*
 * flock.c
 */
extern void __exit afs_kill_lock_manager(void);
extern void afs_lock_work(struct work_struct *);
extern void afs_lock_may_be_available(struct afs_vnode *);
extern int afs_lock(struct file *, int, struct file_lock *);
extern int afs_flock(struct file *, int, struct file_lock *);

/*
 * fsclient.c
 */
extern int afs_fs_fetch_file_status(struct afs_server *, struct key *,
                    struct afs_vnode *, struct afs_volsync *,
                    const struct afs_wait_mode *);
extern int afs_fs_give_up_callbacks(struct afs_server *,
                    const struct afs_wait_mode *);
extern int afs_fs_fetch_data(struct afs_server *, struct key *,
                 struct afs_vnode *, off_t, size_t, struct page *,
                 const struct afs_wait_mode *);
extern int afs_fs_create(struct afs_server *, struct key *,
             struct afs_vnode *, const char *, umode_t,
             struct afs_fid *, struct afs_file_status *,
             struct afs_callback *,
             const struct afs_wait_mode *);
extern int afs_fs_remove(struct afs_server *, struct key *,
             struct afs_vnode *, const char *, bool,
             const struct afs_wait_mode *);
extern int afs_fs_link(struct afs_server *, struct key *, struct afs_vnode *,
               struct afs_vnode *, const char *,
               const struct afs_wait_mode *);
extern int afs_fs_symlink(struct afs_server *, struct key *,
              struct afs_vnode *, const char *, const char *,
              struct afs_fid *, struct afs_file_status *,
              const struct afs_wait_mode *);
extern int afs_fs_rename(struct afs_server *, struct key *,
             struct afs_vnode *, const char *,
             struct afs_vnode *, const char *,
             const struct afs_wait_mode *);
extern int afs_fs_store_data(struct afs_server *, struct afs_writeback *,
                 pgoff_t, pgoff_t, unsigned, unsigned,
                 const struct afs_wait_mode *);
extern int afs_fs_setattr(struct afs_server *, struct key *,
              struct afs_vnode *, struct iattr *,
              const struct afs_wait_mode *);
extern int afs_fs_get_volume_status(struct afs_server *, struct key *,
                    struct afs_vnode *,
                    struct afs_volume_status *,
                    const struct afs_wait_mode *);
extern int afs_fs_set_lock(struct afs_server *, struct key *,
               struct afs_vnode *, afs_lock_type_t,
               const struct afs_wait_mode *);
extern int afs_fs_extend_lock(struct afs_server *, struct key *,
                  struct afs_vnode *,
                  const struct afs_wait_mode *);
extern int afs_fs_release_lock(struct afs_server *, struct key *,
                   struct afs_vnode *,
                   const struct afs_wait_mode *);

/*
 * inode.c
 */
extern struct inode *afs_iget_autocell(struct inode *, const char *, int,
                       struct key *);
extern struct inode *afs_iget(struct super_block *, struct key *,
                  struct afs_fid *, struct afs_file_status *,
                  struct afs_callback *);
extern void afs_zap_data(struct afs_vnode *);
extern int afs_validate(struct afs_vnode *, struct key *);
extern int afs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
extern int afs_setattr(struct dentry *, struct iattr *);
extern void afs_evict_inode(struct inode *);
extern int afs_drop_inode(struct inode *);

/*
 * main.c
 */
extern struct workqueue_struct *afs_wq;
extern struct afs_uuid afs_uuid;

/*
 * misc.c
 */
extern int afs_abort_to_error(u32);

/*
 * mntpt.c
 */
extern const struct inode_operations afs_mntpt_inode_operations;
extern const struct inode_operations afs_autocell_inode_operations;
extern const struct file_operations afs_mntpt_file_operations;

extern struct vfsmount *afs_d_automount(struct path *);
extern int afs_mntpt_check_symlink(struct afs_vnode *, struct key *);
extern void afs_mntpt_kill_timer(void);

/*
 * proc.c
 */
extern int afs_proc_init(void);
extern void afs_proc_cleanup(void);
extern int afs_proc_cell_setup(struct afs_cell *);
extern void afs_proc_cell_remove(struct afs_cell *);

/*
 * rxrpc.c
 */
extern int afs_open_socket(void);
extern void afs_close_socket(void);
extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t,
             const struct afs_wait_mode *);
extern struct afs_call *afs_alloc_flat_call(const struct afs_call_type *,
                        size_t, size_t);
extern void afs_flat_call_destructor(struct afs_call *);
extern void afs_transfer_reply(struct afs_call *, struct sk_buff *);
extern void afs_send_empty_reply(struct afs_call *);
extern void afs_send_simple_reply(struct afs_call *, const void *, size_t);
extern int afs_extract_data(struct afs_call *, struct sk_buff *, bool, void *,
                size_t);

/*
 * security.c
 */
extern void afs_clear_permits(struct afs_vnode *);
extern void afs_cache_permit(struct afs_vnode *, struct key *, long);
extern void afs_zap_permits(struct rcu_head *);
extern struct key *afs_request_key(struct afs_cell *);
extern int afs_permission(struct inode *, int);

/*
 * server.c
 */
extern spinlock_t afs_server_peer_lock;

#define afs_get_server(S)                   \
do {                                \
    _debug("GET SERVER %d", atomic_read(&(S)->usage));  \
    atomic_inc(&(S)->usage);                \
} while(0)

extern struct afs_server *afs_lookup_server(struct afs_cell *,
                        const struct in_addr *);
extern struct afs_server *afs_find_server(const struct in_addr *);
extern void afs_put_server(struct afs_server *);
extern void __exit afs_purge_servers(void);

/*
 * super.c
 */
extern int afs_fs_init(void);
extern void afs_fs_exit(void);

/*
 * use-rtnetlink.c
 */
extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);
extern int afs_get_MAC_address(u8 *, size_t);

/*
 * vlclient.c
 */
extern int afs_vl_get_entry_by_name(struct in_addr *, struct key *,
                    const char *, struct afs_cache_vlocation *,
                    const struct afs_wait_mode *);
extern int afs_vl_get_entry_by_id(struct in_addr *, struct key *,
                  afs_volid_t, afs_voltype_t,
                  struct afs_cache_vlocation *,
                  const struct afs_wait_mode *);

/*
 * vlocation.c
 */
#define afs_get_vlocation(V) do { atomic_inc(&(V)->usage); } while(0)

extern int __init afs_vlocation_update_init(void);
extern struct afs_vlocation *afs_vlocation_lookup(struct afs_cell *,
                          struct key *,
                          const char *, size_t);
extern void afs_put_vlocation(struct afs_vlocation *);
extern void afs_vlocation_purge(void);

/*
 * vnode.c
 */
static inline struct afs_vnode *AFS_FS_I(struct inode *inode)
{
    return container_of(inode, struct afs_vnode, vfs_inode);
}

static inline struct inode *AFS_VNODE_TO_I(struct afs_vnode *vnode)
{
    return &vnode->vfs_inode;
}

extern void afs_vnode_finalise_status_update(struct afs_vnode *,
                         struct afs_server *);
extern int afs_vnode_fetch_status(struct afs_vnode *, struct afs_vnode *,
                  struct key *);
extern int afs_vnode_fetch_data(struct afs_vnode *, struct key *,
                off_t, size_t, struct page *);
extern int afs_vnode_create(struct afs_vnode *, struct key *, const char *,
                umode_t, struct afs_fid *, struct afs_file_status *,
                struct afs_callback *, struct afs_server **);
extern int afs_vnode_remove(struct afs_vnode *, struct key *, const char *,
                bool);
extern int afs_vnode_link(struct afs_vnode *, struct afs_vnode *, struct key *,
              const char *);
extern int afs_vnode_symlink(struct afs_vnode *, struct key *, const char *,
                 const char *, struct afs_fid *,
                 struct afs_file_status *, struct afs_server **);
extern int afs_vnode_rename(struct afs_vnode *, struct afs_vnode *,
                struct key *, const char *, const char *);
extern int afs_vnode_store_data(struct afs_writeback *, pgoff_t, pgoff_t,
                unsigned, unsigned);
extern int afs_vnode_setattr(struct afs_vnode *, struct key *, struct iattr *);
extern int afs_vnode_get_volume_status(struct afs_vnode *, struct key *,
                       struct afs_volume_status *);
extern int afs_vnode_set_lock(struct afs_vnode *, struct key *,
                  afs_lock_type_t);
extern int afs_vnode_extend_lock(struct afs_vnode *, struct key *);
extern int afs_vnode_release_lock(struct afs_vnode *, struct key *);

/*
 * volume.c
 */
#define afs_get_volume(V) do { atomic_inc(&(V)->usage); } while(0)

extern void afs_put_volume(struct afs_volume *);
extern struct afs_volume *afs_volume_lookup(struct afs_mount_params *);
extern struct afs_server *afs_volume_pick_fileserver(struct afs_vnode *);
extern int afs_volume_release_fileserver(struct afs_vnode *,
                     struct afs_server *, int);

/*
 * write.c
 */
extern int afs_set_page_dirty(struct page *);
extern void afs_put_writeback(struct afs_writeback *);
extern int afs_write_begin(struct file *file, struct address_space *mapping,
            loff_t pos, unsigned len, unsigned flags,
            struct page **pagep, void **fsdata);
extern int afs_write_end(struct file *file, struct address_space *mapping,
            loff_t pos, unsigned len, unsigned copied,
            struct page *page, void *fsdata);
extern int afs_writepage(struct page *, struct writeback_control *);
extern int afs_writepages(struct address_space *, struct writeback_control *);
extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *);
extern ssize_t afs_file_write(struct kiocb *, const struct iovec *,
                  unsigned long, loff_t);
extern int afs_writeback_all(struct afs_vnode *);
extern int afs_fsync(struct file *, loff_t, loff_t, int);


/*****************************************************************************/
/*
 * debug tracing
 */
extern unsigned afs_debug;

#define dbgprintk(FMT,...) \
    printk("[%-6.6s] "FMT"\n", current->comm ,##__VA_ARGS__)

#define kenter(FMT,...) dbgprintk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
#define kleave(FMT,...) dbgprintk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
#define kdebug(FMT,...) dbgprintk("    "FMT ,##__VA_ARGS__)


#if defined(__KDEBUG)
#define _enter(FMT,...) kenter(FMT,##__VA_ARGS__)
#define _leave(FMT,...) kleave(FMT,##__VA_ARGS__)
#define _debug(FMT,...) kdebug(FMT,##__VA_ARGS__)

#elif defined(CONFIG_AFS_DEBUG)
#define AFS_DEBUG_KENTER    0x01
#define AFS_DEBUG_KLEAVE    0x02
#define AFS_DEBUG_KDEBUG    0x04

#define _enter(FMT,...)                 \
do {                            \
    if (unlikely(afs_debug & AFS_DEBUG_KENTER)) \
        kenter(FMT,##__VA_ARGS__);      \
} while (0)

#define _leave(FMT,...)                 \
do {                            \
    if (unlikely(afs_debug & AFS_DEBUG_KLEAVE)) \
        kleave(FMT,##__VA_ARGS__);      \
} while (0)

#define _debug(FMT,...)                 \
do {                            \
    if (unlikely(afs_debug & AFS_DEBUG_KDEBUG)) \
        kdebug(FMT,##__VA_ARGS__);      \
} while (0)

#else
#define _enter(FMT,...) no_printk("==> %s("FMT")",__func__ ,##__VA_ARGS__)
#define _leave(FMT,...) no_printk("<== %s()"FMT"",__func__ ,##__VA_ARGS__)
#define _debug(FMT,...) no_printk("    "FMT ,##__VA_ARGS__)
#endif

/*
 * debug assertion checking
 */
#if 1 // defined(__KDEBUGALL)

#define ASSERT(X)                       \
do {                                \
    if (unlikely(!(X))) {                   \
        printk(KERN_ERR "\n");              \
        printk(KERN_ERR "AFS: Assertion failed\n"); \
        BUG();                      \
    }                           \
} while(0)

#define ASSERTCMP(X, OP, Y)                     \
do {                                    \
    if (unlikely(!((X) OP (Y)))) {                  \
        printk(KERN_ERR "\n");                  \
        printk(KERN_ERR "AFS: Assertion failed\n");     \
        printk(KERN_ERR "%lu " #OP " %lu is false\n",       \
               (unsigned long)(X), (unsigned long)(Y));     \
        printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",   \
               (unsigned long)(X), (unsigned long)(Y));     \
        BUG();                          \
    }                               \
} while(0)

#define ASSERTRANGE(L, OP1, N, OP2, H)                  \
do {                                    \
    if (unlikely(!((L) OP1 (N)) || !((N) OP2 (H)))) {       \
        printk(KERN_ERR "\n");                  \
        printk(KERN_ERR "AFS: Assertion failed\n");     \
        printk(KERN_ERR "%lu "#OP1" %lu "#OP2" %lu is false\n", \
               (unsigned long)(L), (unsigned long)(N),      \
               (unsigned long)(H));             \
        printk(KERN_ERR "0x%lx "#OP1" 0x%lx "#OP2" 0x%lx is false\n", \
               (unsigned long)(L), (unsigned long)(N),      \
               (unsigned long)(H));             \
        BUG();                          \
    }                               \
} while(0)

#define ASSERTIF(C, X)                      \
do {                                \
    if (unlikely((C) && !(X))) {                \
        printk(KERN_ERR "\n");              \
        printk(KERN_ERR "AFS: Assertion failed\n"); \
        BUG();                      \
    }                           \
} while(0)

#define ASSERTIFCMP(C, X, OP, Y)                    \
do {                                    \
    if (unlikely((C) && !((X) OP (Y)))) {               \
        printk(KERN_ERR "\n");                  \
        printk(KERN_ERR "AFS: Assertion failed\n");     \
        printk(KERN_ERR "%lu " #OP " %lu is false\n",       \
               (unsigned long)(X), (unsigned long)(Y));     \
        printk(KERN_ERR "0x%lx " #OP " 0x%lx is false\n",   \
               (unsigned long)(X), (unsigned long)(Y));     \
        BUG();                          \
    }                               \
} while(0)

#else

#define ASSERT(X)               \
do {                        \
} while(0)

#define ASSERTCMP(X, OP, Y)         \
do {                        \
} while(0)

#define ASSERTRANGE(L, OP1, N, OP2, H)      \
do {                        \
} while(0)

#define ASSERTIF(C, X)              \
do {                        \
} while(0)

#define ASSERTIFCMP(C, X, OP, Y)        \
do {                        \
} while(0)

#endif /* __KDEBUGALL */