/* internal AFS stuff
 *
 * Copyright (C) 2002, 2007 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.
 */

#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/ktime.h>
#include <linux/fs.h>
#include <linux/pagemap.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 <linux/uuid.h>
#include <net/af_rxrpc.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 */
};

enum afs_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,      /* Completed or failed */
};
/*
 * a record of an in-progress RxRPC call
 */
struct afs_call {
        const struct afs_call_type *type;       /* type of call */
        wait_queue_head_t       waitq;          /* processes awaiting completion */
        struct work_struct      async_work;     /* async I/O processor */
        struct work_struct      work;           /* actual work processor */
        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 */
        size_t                  offset;         /* offset into received data store */
        atomic_t                usage;
        enum afs_call_state     state;
        int                     error;          /* error code */
        u32                     abort_code;     /* Remote abort ID or 0 */
        unsigned                request_size;   /* size of request data */
        unsigned                reply_max;      /* maximum size of reply */
        unsigned                first_offset;   /* offset into mapping[first] */
        union {
                unsigned        last_to;        /* amount of mapping[last] */
                unsigned        count2;         /* count used in unmarshalling */
        };
        unsigned char           unmarshall;     /* unmarshalling phase */
        bool                    incoming;       /* T if incoming call */
        bool                    send_pages;     /* T if data from mapping should be sent */
        bool                    need_attention; /* T if RxRPC poked us */
        bool                    async;          /* T if asynchronous */
        u16                     service_id;     /* RxRPC service ID to call */
        __be16                  port;           /* target UDP port */
        u32                     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);

        /* 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);

        /* Work function */
        void (*work)(struct work_struct *work);
};

/*
 * Record of an outstanding read operation on a vnode.
 */
struct afs_read {
        loff_t                  pos;            /* Where to start reading */
        loff_t                  len;            /* How much we're asking for */
        loff_t                  actual_len;     /* How much we're actually getting */
        loff_t                  remain;         /* Amount remaining */
        atomic_t                usage;
        unsigned int            index;          /* Which page we're reading into */
        unsigned int            nr_pages;
        void (*page_done)(struct afs_call *, struct afs_read *);
        struct page             *pages[];
};

/*
 * 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 */
#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;
        time64_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 */
        time64_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;
        time64_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 */
};

/*
 * 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 */
        time64_t                cb_expires;     /* time at which callback expires */
        time64_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 */
};

struct afs_uuid {
        __be32          time_low;                       /* low part of timestamp */
        __be16          time_mid;                       /* mid part of timestamp */
        __be16          time_hi_and_version;            /* high part of timestamp and version  */
        __u8            clock_seq_hi_and_reserved;      /* clock seq hi and variant */
        __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 *);
extern void afs_put_read(struct afs_read *);

/*
 * 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 *,
                                    bool);
extern int afs_fs_give_up_callbacks(struct afs_server *, bool);
extern int afs_fs_fetch_data(struct afs_server *, struct key *,
                             struct afs_vnode *, struct afs_read *, bool);
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 *, bool);
extern int afs_fs_remove(struct afs_server *, struct key *,
                         struct afs_vnode *, const char *, bool, bool);
extern int afs_fs_link(struct afs_server *, struct key *, struct afs_vnode *,
                       struct afs_vnode *, const char *, bool);
extern int afs_fs_symlink(struct afs_server *, struct key *,
                          struct afs_vnode *, const char *, const char *,
                          struct afs_fid *, struct afs_file_status *, bool);
extern int afs_fs_rename(struct afs_server *, struct key *,
                         struct afs_vnode *, const char *,
                         struct afs_vnode *, const char *, bool);
extern int afs_fs_store_data(struct afs_server *, struct afs_writeback *,
                             pgoff_t, pgoff_t, unsigned, unsigned, bool);
extern int afs_fs_setattr(struct afs_server *, struct key *,
                          struct afs_vnode *, struct iattr *, bool);
extern int afs_fs_get_volume_status(struct afs_server *, struct key *,
                                    struct afs_vnode *,
                                    struct afs_volume_status *, bool);
extern int afs_fs_set_lock(struct afs_server *, struct key *,
                           struct afs_vnode *, afs_lock_type_t, bool);
extern int afs_fs_extend_lock(struct afs_server *, struct key *,
                              struct afs_vnode *, bool);
extern int afs_fs_release_lock(struct afs_server *, struct key *,
                               struct afs_vnode *, bool);

/*
 * 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(const struct path *, struct kstat *, u32, unsigned int);
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 void afs_mntpt_kill_timer(void);

/*
 * netdevices.c
 */
extern int afs_get_ipv4_interfaces(struct afs_interface *, size_t, bool);

/*
 * 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 struct socket *afs_socket;
extern atomic_t afs_outstanding_calls;

extern int afs_open_socket(void);
extern void afs_close_socket(void);
extern void afs_put_call(struct afs_call *);
extern int afs_queue_call_work(struct afs_call *);
extern int afs_make_call(struct in_addr *, struct afs_call *, gfp_t, bool);
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_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 *, void *, size_t, bool);

static inline int afs_transfer_reply(struct afs_call *call)
{
        return afs_extract_data(call, call->buffer, call->reply_max, false);
}

/*
 * 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 sockaddr_rxrpc *);
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);

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

/*
 * 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 *,
                                struct afs_read *);
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 *, struct iov_iter *);
extern int afs_writeback_all(struct afs_vnode *);
extern int afs_flush(struct file *, fl_owner_t);
extern int afs_fsync(struct file *, loff_t, loff_t, int);

/*
 * xattr.c
 */
extern const struct xattr_handler *afs_xattr_handlers[];
extern ssize_t afs_listxattr(struct dentry *, char *, size_t);

/*****************************************************************************/
/*
 * debug tracing
 */
#include <trace/events/afs.h>

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 */