/* SPDX-License-Identifier: GPL-2.0-or-later */
/* internal AFS stuff
 *
 * Copyright (C) 2002, 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 */

#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 <linux/mm_types.h>
#include <linux/dns_resolver.h>
#include <net/net_namespace.h>
#include <net/netns/generic.h>
#include <net/sock.h>
#include <net/af_rxrpc.h>

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

#define AFS_CELL_MAX_ADDRS 15

struct pagevec;
struct afs_call;

/*
 * Partial file-locking emulation mode.  (The problem being that AFS3 only
 * allows whole-file locks and no upgrading/downgrading).
 */
enum afs_flock_mode {
        afs_flock_mode_unset,
        afs_flock_mode_local,   /* Local locking only */
        afs_flock_mode_openafs, /* Don't get server lock for a partial lock */
        afs_flock_mode_strict,  /* Always get a server lock for a partial lock */
        afs_flock_mode_write,   /* Get an exclusive server lock for a partial lock */
};

struct afs_fs_context {
        bool                    force;          /* T to force cell type */
        bool                    autocell;       /* T if set auto mount operation */
        bool                    dyn_root;       /* T if dynamic root */
        bool                    no_cell;        /* T if the source is "none" (for dynroot) */
        enum afs_flock_mode     flock_mode;     /* Partial file-locking emulation mode */
        afs_voltype_t           type;           /* type of volume requested */
        unsigned int            volnamesz;      /* size of volume name */
        const char              *volname;       /* name of volume to mount */
        struct afs_net          *net;           /* the AFS net namespace stuff */
        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_CL_REQUESTING,         /* Client: Request is being sent */
        AFS_CALL_CL_AWAIT_REPLY,        /* Client: Awaiting reply */
        AFS_CALL_CL_PROC_REPLY,         /* Client: rxrpc call complete; processing reply */
        AFS_CALL_SV_AWAIT_OP_ID,        /* Server: Awaiting op ID */
        AFS_CALL_SV_AWAIT_REQUEST,      /* Server: Awaiting request data */
        AFS_CALL_SV_REPLYING,           /* Server: Replying */
        AFS_CALL_SV_AWAIT_ACK,          /* Server: Awaiting final ACK */
        AFS_CALL_COMPLETE,              /* Completed or failed */
};

/*
 * List of server addresses.
 */
struct afs_addr_list {
        struct rcu_head         rcu;
        refcount_t              usage;
        u32                     version;        /* Version */
        unsigned char           max_addrs;
        unsigned char           nr_addrs;
        unsigned char           preferred;      /* Preferred address */
        unsigned char           nr_ipv4;        /* Number of IPv4 addresses */
        enum dns_record_source  source:8;
        enum dns_lookup_status  status:8;
        unsigned long           failed;         /* Mask of addrs that failed locally/ICMP */
        unsigned long           responded;      /* Mask of addrs that responded */
        struct sockaddr_rxrpc   addrs[];
#define AFS_MAX_ADDRESSES ((unsigned int)(sizeof(unsigned long) * 8))
};

/*
 * a record of an in-progress RxRPC call
 */
struct afs_call {
        const struct afs_call_type *type;       /* type of call */
        struct afs_addr_list    *alist;         /* Address is alist[addr_ix] */
        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_net          *net;           /* The network namespace */
        struct afs_server       *server;        /* The fileserver record if fs op (pins ref) */
        struct afs_vlserver     *vlserver;      /* The vlserver record if vl op */
        void                    *request;       /* request data (first part) */
        struct iov_iter         def_iter;       /* Default buffer/data iterator */
        struct iov_iter         *iter;          /* Iterator currently in use */
        union { /* Convenience for ->def_iter */
                struct kvec     kvec[1];
                struct bio_vec  bvec[1];
        };
        void                    *buffer;        /* reply receive buffer */
        union {
                long                    ret0;   /* Value to reply with instead of 0 */
                struct afs_addr_list    *ret_alist;
                struct afs_vldb_entry   *ret_vldb;
                char                    *ret_str;
        };
        struct afs_operation    *op;
        unsigned int            server_index;
        atomic_t                usage;
        enum afs_call_state     state;
        spinlock_t              state_lock;
        int                     error;          /* error code */
        u32                     abort_code;     /* Remote abort ID or 0 */
        unsigned int            max_lifespan;   /* Maximum lifespan to set if not 0 */
        unsigned                request_size;   /* size of request data */
        unsigned                reply_max;      /* maximum size of reply */
        unsigned                count2;         /* count used in unmarshalling */
        unsigned char           unmarshall;     /* unmarshalling phase */
        unsigned char           addr_ix;        /* Address in ->alist */
        bool                    drop_ref;       /* T if need to drop ref for 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 */
        bool                    upgrade;        /* T to request service upgrade */
        bool                    have_reply_time; /* T if have got reply_time */
        bool                    intr;           /* T if interruptible */
        bool                    unmarshalling_error; /* T if an unmarshalling error occurred */
        u16                     service_id;     /* Actual service ID (after upgrade) */
        unsigned int            debug_id;       /* Trace ID */
        u32                     operation_ID;   /* operation ID for an incoming call */
        u32                     count;          /* count for use in unmarshalling */
        union {                                 /* place to extract temporary data */
                struct {
                        __be32  tmp_u;
                        __be32  tmp;
                } __attribute__((packed));
                __be64          tmp64;
        };
        ktime_t                 reply_time;     /* Time of first reply packet */
};

struct afs_call_type {
        const char *name;
        unsigned int op; /* Really enum afs_fs_operation */

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

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

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

        /* Call done function (gets called immediately on success or failure) */
        void (*done)(struct afs_call *call);
};

/*
 * Key available for writeback on a file.
 */
struct afs_wb_key {
        refcount_t              usage;
        struct key              *key;
        struct list_head        vnode_link;     /* Link in vnode->wb_keys */
};

/*
 * AFS open file information record.  Pointed to by file->private_data.
 */
struct afs_file {
        struct key              *key;           /* The key this file was opened with */
        struct afs_wb_key       *wb;            /* Writeback key record for this file */
};

static inline struct key *afs_file_key(struct file *file)
{
        struct afs_file *af = file->private_data;

        return af->key;
}

/*
 * 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 */
        loff_t                  file_size;      /* File size returned by server */
        afs_dataversion_t       data_version;   /* Version number returned by server */
        refcount_t              usage;
        unsigned int            index;          /* Which page we're reading into */
        unsigned int            nr_pages;
        unsigned int            offset;         /* offset into current page */
        struct afs_vnode        *vnode;
        void (*page_done)(struct afs_read *);
        struct page             **pages;
        struct page             *array[];
};

/*
 * AFS superblock private data
 * - there's one superblock per volume
 */
struct afs_super_info {
        struct net              *net_ns;        /* Network namespace */
        struct afs_cell         *cell;          /* The cell in which the volume resides */
        struct afs_volume       *volume;        /* volume record */
        enum afs_flock_mode     flock_mode:8;   /* File locking emulation mode */
        bool                    dyn_root;       /* True if dynamic root */
};

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;

/*
 * Set of substitutes for @sys.
 */
struct afs_sysnames {
#define AFS_NR_SYSNAME 16
        char                    *subs[AFS_NR_SYSNAME];
        refcount_t              usage;
        unsigned short          nr;
        char                    blank[1];
};

/*
 * AFS network namespace record.
 */
struct afs_net {
        struct net              *net;           /* Backpointer to the owning net namespace */
        struct afs_uuid         uuid;
        bool                    live;           /* F if this namespace is being removed */

        /* AF_RXRPC I/O stuff */
        struct socket           *socket;
        struct afs_call         *spare_incoming_call;
        struct work_struct      charge_preallocation_work;
        struct mutex            socket_mutex;
        atomic_t                nr_outstanding_calls;
        atomic_t                nr_superblocks;

        /* Cell database */
        struct rb_root          cells;
        struct afs_cell __rcu   *ws_cell;
        struct work_struct      cells_manager;
        struct timer_list       cells_timer;
        atomic_t                cells_outstanding;
        seqlock_t               cells_lock;
        struct mutex            cells_alias_lock;

        struct mutex            proc_cells_lock;
        struct hlist_head       proc_cells;

        /* Known servers.  Theoretically each fileserver can only be in one
         * cell, but in practice, people create aliases and subsets and there's
         * no easy way to distinguish them.
         */
        seqlock_t               fs_lock;        /* For fs_servers, fs_probe_*, fs_proc */
        struct rb_root          fs_servers;     /* afs_server (by server UUID or address) */
        struct list_head        fs_probe_fast;  /* List of afs_server to probe at 30s intervals */
        struct list_head        fs_probe_slow;  /* List of afs_server to probe at 5m intervals */
        struct hlist_head       fs_proc;        /* procfs servers list */

        struct hlist_head       fs_addresses4;  /* afs_server (by lowest IPv4 addr) */
        struct hlist_head       fs_addresses6;  /* afs_server (by lowest IPv6 addr) */
        seqlock_t               fs_addr_lock;   /* For fs_addresses[46] */

        struct work_struct      fs_manager;
        struct timer_list       fs_timer;

        struct work_struct      fs_prober;
        struct timer_list       fs_probe_timer;
        atomic_t                servers_outstanding;

        /* File locking renewal management */
        struct mutex            lock_manager_mutex;

        /* Misc */
        struct super_block      *dynroot_sb;    /* Dynamic root mount superblock */
        struct proc_dir_entry   *proc_afs;      /* /proc/net/afs directory */
        struct afs_sysnames     *sysnames;
        rwlock_t                sysnames_lock;

        /* Statistics counters */
        atomic_t                n_lookup;       /* Number of lookups done */
        atomic_t                n_reval;        /* Number of dentries needing revalidation */
        atomic_t                n_inval;        /* Number of invalidations by the server */
        atomic_t                n_relpg;        /* Number of invalidations by releasepage */
        atomic_t                n_read_dir;     /* Number of directory pages read */
        atomic_t                n_dir_cr;       /* Number of directory entry creation edits */
        atomic_t                n_dir_rm;       /* Number of directory entry removal edits */
        atomic_t                n_stores;       /* Number of store ops */
        atomic_long_t           n_store_bytes;  /* Number of bytes stored */
        atomic_long_t           n_fetch_bytes;  /* Number of bytes fetched */
        atomic_t                n_fetches;      /* Number of data fetch ops */
};

extern const char afs_init_sysname[];

enum afs_cell_state {
        AFS_CELL_UNSET,
        AFS_CELL_ACTIVATING,
        AFS_CELL_ACTIVE,
        AFS_CELL_DEACTIVATING,
        AFS_CELL_INACTIVE,
        AFS_CELL_FAILED,
};

/*
 * AFS cell record.
 *
 * This is a tricky concept to get right as it is possible to create aliases
 * simply by pointing AFSDB/SRV records for two names at the same set of VL
 * servers; it is also possible to do things like setting up two sets of VL
 * servers, one of which provides a superset of the volumes provided by the
 * other (for internal/external division, for example).
 *
 * Cells only exist in the sense that (a) a cell's name maps to a set of VL
 * servers and (b) a cell's name is used by the client to select the key to use
 * for authentication and encryption.  The cell name is not typically used in
 * the protocol.
 *
 * Two cells are determined to be aliases if they have an explicit alias (YFS
 * only), share any VL servers in common or have at least one volume in common.
 * "In common" means that the address list of the VL servers or the fileservers
 * share at least one endpoint.
 */
struct afs_cell {
        union {
                struct rcu_head rcu;
                struct rb_node  net_node;       /* Node in net->cells */
        };
        struct afs_net          *net;
        struct afs_cell         *alias_of;      /* The cell this is an alias of */
        struct afs_volume       *root_volume;   /* The root.cell volume if there is one */
        struct key              *anonymous_key; /* anonymous user key for this cell */
        struct work_struct      manager;        /* Manager for init/deinit/dns */
        struct hlist_node       proc_link;      /* /proc cell list link */
#ifdef CONFIG_AFS_FSCACHE
        struct fscache_cookie   *cache;         /* caching cookie */
#endif
        time64_t                dns_expiry;     /* Time AFSDB/SRV record expires */
        time64_t                last_inactive;  /* Time of last drop of usage count */
        atomic_t                usage;
        unsigned long           flags;
#define AFS_CELL_FL_NO_GC       0               /* The cell was added manually, don't auto-gc */
#define AFS_CELL_FL_DO_LOOKUP   1               /* DNS lookup requested */
#define AFS_CELL_FL_CHECK_ALIAS 2               /* Need to check for aliases */
        enum afs_cell_state     state;
        short                   error;
        enum dns_record_source  dns_source:8;   /* Latest source of data from lookup */
        enum dns_lookup_status  dns_status:8;   /* Latest status of data from lookup */
        unsigned int            dns_lookup_count; /* Counter of DNS lookups */

        /* The volumes belonging to this cell */
        struct rb_root          volumes;        /* Tree of volumes on this server */
        struct hlist_head       proc_volumes;   /* procfs volume list */
        seqlock_t               volume_lock;    /* For volumes */

        /* Active fileserver interaction state. */
        struct rb_root          fs_servers;     /* afs_server (by server UUID) */
        seqlock_t               fs_lock;        /* For fs_servers  */

        /* VL server list. */
        rwlock_t                vl_servers_lock; /* Lock on vl_servers */
        struct afs_vlserver_list __rcu *vl_servers;

        u8                      name_len;       /* Length of name */
        char                    *name;          /* Cell name, case-flattened and NUL-padded */
};

/*
 * Volume Location server record.
 */
struct afs_vlserver {
        struct rcu_head         rcu;
        struct afs_addr_list    __rcu *addresses; /* List of addresses for this VL server */
        unsigned long           flags;
#define AFS_VLSERVER_FL_PROBED  0               /* The VL server has been probed */
#define AFS_VLSERVER_FL_PROBING 1               /* VL server is being probed */
#define AFS_VLSERVER_FL_IS_YFS  2               /* Server is YFS not AFS */
#define AFS_VLSERVER_FL_RESPONDING 3            /* VL server is responding */
        rwlock_t                lock;           /* Lock on addresses */
        atomic_t                usage;
        unsigned int            rtt;            /* Server's current RTT in uS */

        /* Probe state */
        wait_queue_head_t       probe_wq;
        atomic_t                probe_outstanding;
        spinlock_t              probe_lock;
        struct {
                unsigned int    rtt;            /* RTT in uS */
                u32             abort_code;
                short           error;
                unsigned short  flags;
#define AFS_VLSERVER_PROBE_RESPONDED            0x01 /* At least once response (may be abort) */
#define AFS_VLSERVER_PROBE_IS_YFS               0x02 /* The peer appears to be YFS */
#define AFS_VLSERVER_PROBE_NOT_YFS              0x04 /* The peer appears not to be YFS */
#define AFS_VLSERVER_PROBE_LOCAL_FAILURE        0x08 /* A local failure prevented a probe */
        } probe;

        u16                     port;
        u16                     name_len;       /* Length of name */
        char                    name[];         /* Server name, case-flattened */
};

/*
 * Weighted list of Volume Location servers.
 */
struct afs_vlserver_entry {
        u16                     priority;       /* Preference (as SRV) */
        u16                     weight;         /* Weight (as SRV) */
        enum dns_record_source  source:8;
        enum dns_lookup_status  status:8;
        struct afs_vlserver     *server;
};

struct afs_vlserver_list {
        struct rcu_head         rcu;
        atomic_t                usage;
        u8                      nr_servers;
        u8                      index;          /* Server currently in use */
        u8                      preferred;      /* Preferred server */
        enum dns_record_source  source:8;
        enum dns_lookup_status  status:8;
        rwlock_t                lock;
        struct afs_vlserver_entry servers[];
};

/*
 * Cached VLDB entry.
 *
 * This is pointed to by cell->vldb_entries, indexed by name.
 */
struct afs_vldb_entry {
        afs_volid_t             vid[3];         /* Volume IDs for R/W, R/O and Bak volumes */

        unsigned long           flags;
#define AFS_VLDB_HAS_RW         0               /* - R/W volume exists */
#define AFS_VLDB_HAS_RO         1               /* - R/O volume exists */
#define AFS_VLDB_HAS_BAK        2               /* - Backup volume exists */
#define AFS_VLDB_QUERY_VALID    3               /* - Record is valid */
#define AFS_VLDB_QUERY_ERROR    4               /* - VL server returned error */

        uuid_t                  fs_server[AFS_NMAXNSERVERS];
        u32                     addr_version[AFS_NMAXNSERVERS]; /* Registration change counters */
        u8                      fs_mask[AFS_NMAXNSERVERS];
#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) */
        short                   error;
        u8                      nr_servers;     /* Number of server records */
        u8                      name_len;
        u8                      name[AFS_MAXVOLNAME + 1]; /* NUL-padded volume name */
};

/*
 * Record of fileserver with which we're actively communicating.
 */
struct afs_server {
        struct rcu_head         rcu;
        union {
                uuid_t          uuid;           /* Server ID */
                struct afs_uuid _uuid;
        };

        struct afs_addr_list    __rcu *addresses;
        struct afs_cell         *cell;          /* Cell to which belongs (pins ref) */
        struct rb_node          uuid_rb;        /* Link in net->fs_servers */
        struct afs_server __rcu *uuid_next;     /* Next server with same UUID */
        struct afs_server       *uuid_prev;     /* Previous server with same UUID */
        struct list_head        probe_link;     /* Link in net->fs_probe_list */
        struct hlist_node       addr4_link;     /* Link in net->fs_addresses4 */
        struct hlist_node       addr6_link;     /* Link in net->fs_addresses6 */
        struct hlist_node       proc_link;      /* Link in net->fs_proc */
        struct afs_server       *gc_next;       /* Next server in manager's list */
        time64_t                unuse_time;     /* Time at which last unused */
        unsigned long           flags;
#define AFS_SERVER_FL_RESPONDING 0              /* The server is responding */
#define AFS_SERVER_FL_UPDATING  1
#define AFS_SERVER_FL_NEEDS_UPDATE 2            /* Fileserver address list is out of date */
#define AFS_SERVER_FL_NOT_READY 4               /* The record is not ready for use */
#define AFS_SERVER_FL_NOT_FOUND 5               /* VL server says no such server */
#define AFS_SERVER_FL_VL_FAIL   6               /* Failed to access VL server */
#define AFS_SERVER_FL_MAY_HAVE_CB 8             /* May have callbacks on this fileserver */
#define AFS_SERVER_FL_IS_YFS    16              /* Server is YFS not AFS */
#define AFS_SERVER_FL_NO_IBULK  17              /* Fileserver doesn't support FS.InlineBulkStatus */
#define AFS_SERVER_FL_NO_RM2    18              /* Fileserver doesn't support YFS.RemoveFile2 */
        atomic_t                ref;            /* Object refcount */
        atomic_t                active;         /* Active user count */
        u32                     addr_version;   /* Address list version */
        unsigned int            rtt;            /* Server's current RTT in uS */
        unsigned int            debug_id;       /* Debugging ID for traces */

        /* file service access */
        rwlock_t                fs_lock;        /* access lock */

        /* callback promise management */
        unsigned                cb_s_break;     /* Break-everything counter. */

        /* Probe state */
        unsigned long           probed_at;      /* Time last probe was dispatched (jiffies) */
        wait_queue_head_t       probe_wq;
        atomic_t                probe_outstanding;
        spinlock_t              probe_lock;
        struct {
                unsigned int    rtt;            /* RTT in uS */
                u32             abort_code;
                short           error;
                bool            responded:1;
                bool            is_yfs:1;
                bool            not_yfs:1;
                bool            local_failure:1;
        } probe;
};

/*
 * Replaceable volume server list.
 */
struct afs_server_entry {
        struct afs_server       *server;
};

struct afs_server_list {
        afs_volid_t             vids[AFS_MAXTYPES]; /* Volume IDs */
        refcount_t              usage;
        unsigned char           nr_servers;
        unsigned char           preferred;      /* Preferred server */
        unsigned short          vnovol_mask;    /* Servers to be skipped due to VNOVOL */
        unsigned int            seq;            /* Set to ->servers_seq when installed */
        rwlock_t                lock;
        struct afs_server_entry servers[];
};

/*
 * Live AFS volume management.
 */
struct afs_volume {
        union {
                struct rcu_head rcu;
                afs_volid_t     vid;            /* volume ID */
        };
        atomic_t                usage;
        time64_t                update_at;      /* Time at which to next update */
        struct afs_cell         *cell;          /* Cell to which belongs (pins ref) */
        struct rb_node          cell_node;      /* Link in cell->volumes */
        struct hlist_node       proc_link;      /* Link in cell->proc_volumes */
        struct super_block __rcu *sb;           /* Superblock on which inodes reside */
        unsigned long           flags;
#define AFS_VOLUME_NEEDS_UPDATE 0       /* - T if an update needs performing */
#define AFS_VOLUME_UPDATING     1       /* - T if an update is in progress */
#define AFS_VOLUME_WAIT         2       /* - T if users must wait for update */
#define AFS_VOLUME_DELETED      3       /* - T if volume appears deleted */
#define AFS_VOLUME_OFFLINE      4       /* - T if volume offline notice given */
#define AFS_VOLUME_BUSY         5       /* - T if volume busy notice given */
#define AFS_VOLUME_MAYBE_NO_IBULK 6     /* - T if some servers don't have InlineBulkStatus */
#ifdef CONFIG_AFS_FSCACHE
        struct fscache_cookie   *cache;         /* caching cookie */
#endif
        struct afs_server_list __rcu *servers;  /* List of servers on which volume resides */
        rwlock_t                servers_lock;   /* Lock for ->servers */
        unsigned int            servers_seq;    /* Incremented each time ->servers changes */

        unsigned                cb_v_break;     /* Break-everything counter. */
        rwlock_t                cb_v_break_lock;

        afs_voltype_t           type;           /* type of volume */
        char                    type_force;     /* force volume type (suppress R/O -> R/W) */
        u8                      name_len;
        u8                      name[AFS_MAXVOLNAME + 1]; /* NUL-padded volume name */
};

enum afs_lock_state {
        AFS_VNODE_LOCK_NONE,            /* The vnode has no lock on the server */
        AFS_VNODE_LOCK_WAITING_FOR_CB,  /* We're waiting for the server to break the callback */
        AFS_VNODE_LOCK_SETTING,         /* We're asking the server for a lock */
        AFS_VNODE_LOCK_GRANTED,         /* We have a lock on the server */
        AFS_VNODE_LOCK_EXTENDING,       /* We're extending a lock on the server */
        AFS_VNODE_LOCK_NEED_UNLOCK,     /* We need to unlock on the server */
        AFS_VNODE_LOCK_UNLOCKING,       /* We're telling the server to unlock */
        AFS_VNODE_LOCK_DELETED,         /* The vnode has been deleted whilst we have a lock */
};

/*
 * AFS inode private data.
 *
 * Note that afs_alloc_inode() *must* reset anything that could incorrectly
 * leak from one inode to another.
 */
struct afs_vnode {
        struct inode            vfs_inode;      /* the VFS's inode record */

        struct afs_volume       *volume;        /* volume on which vnode resides */
        struct afs_fid          fid;            /* the file identifier for this inode */
        struct afs_file_status  status;         /* AFS status info for this file */
        afs_dataversion_t       invalid_before; /* Child dentries are invalid before this */
#ifdef CONFIG_AFS_FSCACHE
        struct fscache_cookie   *cache;         /* caching cookie */
#endif
        struct afs_permits __rcu *permit_cache; /* cache of permits so far obtained */
        struct mutex            io_lock;        /* Lock for serialising I/O on this mutex */
        struct rw_semaphore     validate_lock;  /* lock for validating this vnode */
        struct rw_semaphore     rmdir_lock;     /* Lock for rmdir vs sillyrename */
        struct key              *silly_key;     /* Silly rename key */
        spinlock_t              wb_lock;        /* lock for wb_keys */
        spinlock_t              lock;           /* waitqueue/flags lock */
        unsigned long           flags;
#define AFS_VNODE_CB_PROMISED   0               /* Set if vnode has a callback promise */
#define AFS_VNODE_UNSET         1               /* set if vnode attributes not yet set */
#define AFS_VNODE_DIR_VALID     2               /* Set if dir contents are valid */
#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_AUTOCELL      6               /* set if Vnode is an auto mount point */
#define AFS_VNODE_PSEUDODIR     7               /* set if Vnode is a pseudo directory */
#define AFS_VNODE_NEW_CONTENT   8               /* Set if file has new content (create/trunc-0) */
#define AFS_VNODE_SILLY_DELETED 9               /* Set if file has been silly-deleted */

        struct list_head        wb_keys;        /* List of keys available for writeback */
        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              *lock_key;      /* Key to be used in lock ops */
        ktime_t                 locked_at;      /* Time at which lock obtained */
        enum afs_lock_state     lock_state : 8;
        afs_lock_type_t         lock_type : 8;

        /* outstanding callback notification on this file */
        void                    *cb_server;     /* Server with callback/filelock */
        unsigned int            cb_s_break;     /* Mass break counter on ->server */
        unsigned int            cb_v_break;     /* Mass break counter on ->volume */
        unsigned int            cb_break;       /* Break counter on vnode */
        seqlock_t               cb_lock;        /* Lock for ->cb_server, ->status, ->cb_*break */

        time64_t                cb_expires_at;  /* time at which callback expires */
};

static inline struct fscache_cookie *afs_vnode_cache(struct afs_vnode *vnode)
{
#ifdef CONFIG_AFS_FSCACHE
        return vnode->cache;
#else
        return NULL;
#endif
}

/*
 * 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;         /* CallerAccess value for this key */
};

/*
 * Immutable cache of CallerAccess records from attempts to access vnodes.
 * These may be shared between multiple vnodes.
 */
struct afs_permits {
        struct rcu_head         rcu;
        struct hlist_node       hash_node;      /* Link in hash */
        unsigned long           h;              /* Hash value for this permit list */
        refcount_t              usage;
        unsigned short          nr_permits;     /* Number of records */
        bool                    invalidated;    /* Invalidated due to key change */
        struct afs_permit       permits[];      /* List of permits sorted by key pointer */
};

/*
 * Error prioritisation and accumulation.
 */
struct afs_error {
        short   error;                  /* Accumulated error */
        bool    responded;              /* T if server responded */
};

/*
 * Cursor for iterating over a server's address list.
 */
struct afs_addr_cursor {
        struct afs_addr_list    *alist;         /* Current address list (pins ref) */
        unsigned long           tried;          /* Tried addresses */
        signed char             index;          /* Current address */
        bool                    responded;      /* T if the current address responded */
        unsigned short          nr_iterations;  /* Number of address iterations */
        short                   error;
        u32                     abort_code;
};

/*
 * Cursor for iterating over a set of volume location servers.
 */
struct afs_vl_cursor {
        struct afs_addr_cursor  ac;
        struct afs_cell         *cell;          /* The cell we're querying */
        struct afs_vlserver_list *server_list;  /* Current server list (pins ref) */
        struct afs_vlserver     *server;        /* Server on which this resides */
        struct key              *key;           /* Key for the server */
        unsigned long           untried;        /* Bitmask of untried servers */
        short                   index;          /* Current server */
        short                   error;
        unsigned short          flags;
#define AFS_VL_CURSOR_STOP      0x0001          /* Set to cease iteration */
#define AFS_VL_CURSOR_RETRY     0x0002          /* Set to do a retry */
#define AFS_VL_CURSOR_RETRIED   0x0004          /* Set if started a retry */
        unsigned short          nr_iterations;  /* Number of server iterations */
};

/*
 * Fileserver operation methods.
 */
struct afs_operation_ops {
        void (*issue_afs_rpc)(struct afs_operation *op);
        void (*issue_yfs_rpc)(struct afs_operation *op);
        void (*success)(struct afs_operation *op);
        void (*aborted)(struct afs_operation *op);
        void (*edit_dir)(struct afs_operation *op);
        void (*put)(struct afs_operation *op);
};

struct afs_vnode_param {
        struct afs_vnode        *vnode;
        struct afs_fid          fid;            /* Fid to access */
        struct afs_status_cb    scb;            /* Returned status and callback promise */
        afs_dataversion_t       dv_before;      /* Data version before the call */
        unsigned int            cb_break_before; /* cb_break + cb_s_break before the call */
        u8                      dv_delta;       /* Expected change in data version */
        bool                    put_vnode:1;    /* T if we have a ref on the vnode */
        bool                    need_io_lock:1; /* T if we need the I/O lock on this */
        bool                    update_ctime:1; /* Need to update the ctime */
        bool                    set_size:1;     /* Must update i_size */
        bool                    op_unlinked:1;  /* True if file was unlinked by op */
};

/*
 * Fileserver operation wrapper, handling server and address rotation
 * asynchronously.  May make simultaneous calls to multiple servers.
 */
struct afs_operation {
        struct afs_net          *net;           /* Network namespace */
        struct key              *key;           /* Key for the cell */
        const struct afs_call_type *type;       /* Type of call done */
        const struct afs_operation_ops *ops;

        /* Parameters/results for the operation */
        struct afs_volume       *volume;        /* Volume being accessed */
        struct afs_vnode_param  file[2];
        struct afs_vnode_param  *more_files;
        struct afs_volsync      volsync;
        struct dentry           *dentry;        /* Dentry to be altered */
        struct dentry           *dentry_2;      /* Second dentry to be altered */
        struct timespec64       mtime;          /* Modification time to record */
        struct timespec64       ctime;          /* Change time to set */
        short                   nr_files;       /* Number of entries in file[], more_files */
        short                   error;
        unsigned int            debug_id;

        unsigned int            cb_v_break;     /* Volume break counter before op */
        unsigned int            cb_s_break;     /* Server break counter before op */

        union {
                struct {
                        int     which;          /* Which ->file[] to fetch for */
                } fetch_status;
                struct {
                        int     reason;         /* enum afs_edit_dir_reason */
                        mode_t  mode;
                        const char *symlink;
                } create;
                struct {
                        bool    need_rehash;
                } unlink;
                struct {
                        struct dentry *rehash;
                        struct dentry *tmp;
                        bool    new_negative;
                } rename;
                struct {
                        struct afs_read *req;
                } fetch;
                struct {
                        afs_lock_type_t type;
                } lock;
                struct {
                        struct address_space *mapping;  /* Pages being written from */
                        pgoff_t         first;          /* first page in mapping to deal with */
                        pgoff_t         last;           /* last page in mapping to deal with */
                        unsigned        first_offset;   /* offset into mapping[first] */
                        unsigned        last_to;        /* amount of mapping[last] */
                } store;
                struct {
                        struct iattr    *attr;
                        loff_t          old_i_size;
                } setattr;
                struct afs_acl  *acl;
                struct yfs_acl  *yacl;
                struct {
                        struct afs_volume_status vs;
                        struct kstatfs          *buf;
                } volstatus;
        };

        /* Fileserver iteration state */
        struct afs_addr_cursor  ac;
        struct afs_server_list  *server_list;   /* Current server list (pins ref) */
        struct afs_server       *server;        /* Server we're using (ref pinned by server_list) */
        struct afs_call         *call;
        unsigned long           untried;        /* Bitmask of untried servers */
        short                   index;          /* Current server */
        unsigned short          nr_iterations;  /* Number of server iterations */

        unsigned int            flags;
#define AFS_OPERATION_STOP              0x0001  /* Set to cease iteration */
#define AFS_OPERATION_VBUSY             0x0002  /* Set if seen VBUSY */
#define AFS_OPERATION_VMOVED            0x0004  /* Set if seen VMOVED */
#define AFS_OPERATION_VNOVOL            0x0008  /* Set if seen VNOVOL */
#define AFS_OPERATION_CUR_ONLY          0x0010  /* Set if current server only (file lock held) */
#define AFS_OPERATION_NO_VSLEEP         0x0020  /* Set to prevent sleep on VBUSY, VOFFLINE, ... */
#define AFS_OPERATION_UNINTR            0x0040  /* Set if op is uninterruptible */
#define AFS_OPERATION_DOWNGRADE         0x0080  /* Set to retry with downgraded opcode */
#define AFS_OPERATION_LOCK_0            0x0100  /* Set if have io_lock on file[0] */
#define AFS_OPERATION_LOCK_1            0x0200  /* Set if have io_lock on file[1] */
#define AFS_OPERATION_TRIED_ALL         0x0400  /* Set if we've tried all the fileservers */
#define AFS_OPERATION_RETRY_SERVER      0x0800  /* Set if we should retry the current server */
#define AFS_OPERATION_DIR_CONFLICT      0x1000  /* Set if we detected a 3rd-party dir change */
};

/*
 * Cache auxiliary data.
 */
struct afs_vnode_cache_aux {
        u64                     data_version;
} __packed;

#include <trace/events/afs.h>

/*****************************************************************************/
/*
 * addr_list.c
 */
static inline struct afs_addr_list *afs_get_addrlist(struct afs_addr_list *alist)
{
        if (alist)
                refcount_inc(&alist->usage);
        return alist;
}
extern struct afs_addr_list *afs_alloc_addrlist(unsigned int,
                                                unsigned short,
                                                unsigned short);
extern void afs_put_addrlist(struct afs_addr_list *);
extern struct afs_vlserver_list *afs_parse_text_addrs(struct afs_net *,
                                                      const char *, size_t, char,
                                                      unsigned short, unsigned short);
extern struct afs_vlserver_list *afs_dns_query(struct afs_cell *, time64_t *);
extern bool afs_iterate_addresses(struct afs_addr_cursor *);
extern int afs_end_cursor(struct afs_addr_cursor *);

extern void afs_merge_fs_addr4(struct afs_addr_list *, __be32, u16);
extern void afs_merge_fs_addr6(struct afs_addr_list *, __be32 *, u16);

/*
 * 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_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_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_break_callback(struct afs_vnode *, enum afs_cb_break_reason);
extern void afs_break_callback(struct afs_vnode *, enum afs_cb_break_reason);
extern void afs_break_callbacks(struct afs_server *, size_t, struct afs_callback_break *);

static inline unsigned int afs_calc_vnode_cb_break(struct afs_vnode *vnode)
{
        return vnode->cb_break + vnode->cb_v_break;
}

static inline bool afs_cb_is_broken(unsigned int cb_break,
                                    const struct afs_vnode *vnode)
{
        return cb_break != (vnode->cb_break + vnode->volume->cb_v_break);
}

/*
 * cell.c
 */
extern int afs_cell_init(struct afs_net *, const char *);
extern struct afs_cell *afs_lookup_cell_rcu(struct afs_net *, const char *, unsigned);
extern struct afs_cell *afs_lookup_cell(struct afs_net *, const char *, unsigned,
                                        const char *, bool);
extern struct afs_cell *afs_get_cell(struct afs_cell *);
extern void afs_put_cell(struct afs_net *, struct afs_cell *);
extern void afs_manage_cells(struct work_struct *);
extern void afs_cells_timer(struct timer_list *);
extern void __net_exit afs_cell_purge(struct afs_net *);

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

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

extern void afs_d_release(struct dentry *);
extern void afs_check_for_remote_deletion(struct afs_operation *);

/*
 * dir_edit.c
 */
extern void afs_edit_dir_add(struct afs_vnode *, struct qstr *, struct afs_fid *,
                             enum afs_edit_dir_reason);
extern void afs_edit_dir_remove(struct afs_vnode *, struct qstr *, enum afs_edit_dir_reason);

/*
 * dir_silly.c
 */
extern int afs_sillyrename(struct afs_vnode *, struct afs_vnode *,
                           struct dentry *, struct key *);
extern int afs_silly_iput(struct dentry *, struct inode *);

/*
 * dynroot.c
 */
extern const struct inode_operations afs_dynroot_inode_operations;
extern const struct dentry_operations afs_dynroot_dentry_operations;

extern struct inode *afs_try_auto_mntpt(struct dentry *, struct inode *);
extern int afs_dynroot_mkdir(struct afs_net *, struct afs_cell *);
extern void afs_dynroot_rmdir(struct afs_net *, struct afs_cell *);
extern int afs_dynroot_populate(struct super_block *);
extern void afs_dynroot_depopulate(struct super_block *);

/*
 * 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_cache_wb_key(struct afs_vnode *, struct afs_file *);
extern void afs_put_wb_key(struct afs_wb_key *);
extern int afs_open(struct inode *, struct file *);
extern int afs_release(struct inode *, struct file *);
extern int afs_fetch_data(struct afs_vnode *, struct key *, struct afs_read *);
extern int afs_page_filler(void *, struct page *);
extern void afs_put_read(struct afs_read *);

static inline struct afs_read *afs_get_read(struct afs_read *req)
{
        refcount_inc(&req->usage);
        return req;
}

/*
 * flock.c
 */
extern struct workqueue_struct *afs_lock_manager;

extern void afs_lock_op_done(struct afs_call *);
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 void afs_fs_fetch_status(struct afs_operation *);
extern void afs_fs_fetch_data(struct afs_operation *);
extern void afs_fs_create_file(struct afs_operation *);
extern void afs_fs_make_dir(struct afs_operation *);
extern void afs_fs_remove_file(struct afs_operation *);
extern void afs_fs_remove_dir(struct afs_operation *);
extern void afs_fs_link(struct afs_operation *);
extern void afs_fs_symlink(struct afs_operation *);
extern void afs_fs_rename(struct afs_operation *);
extern void afs_fs_store_data(struct afs_operation *);
extern void afs_fs_setattr(struct afs_operation *);
extern void afs_fs_get_volume_status(struct afs_operation *);
extern void afs_fs_set_lock(struct afs_operation *);
extern void afs_fs_extend_lock(struct afs_operation *);
extern void afs_fs_release_lock(struct afs_operation *);
extern int afs_fs_give_up_all_callbacks(struct afs_net *, struct afs_server *,
                                        struct afs_addr_cursor *, struct key *);
extern bool afs_fs_get_capabilities(struct afs_net *, struct afs_server *,
                                    struct afs_addr_cursor *, struct key *);
extern void afs_fs_inline_bulk_status(struct afs_operation *);

struct afs_acl {
        u32     size;
        u8      data[];
};

extern void afs_fs_fetch_acl(struct afs_operation *);
extern void afs_fs_store_acl(struct afs_operation *);

/*
 * fs_operation.c
 */
extern struct afs_operation *afs_alloc_operation(struct key *, struct afs_volume *);
extern int afs_put_operation(struct afs_operation *);
extern bool afs_begin_vnode_operation(struct afs_operation *);
extern void afs_wait_for_operation(struct afs_operation *);
extern int afs_do_sync_operation(struct afs_operation *);

static inline void afs_op_nomem(struct afs_operation *op)
{
        op->error = -ENOMEM;
}

static inline void afs_op_set_vnode(struct afs_operation *op, unsigned int n,
                                    struct afs_vnode *vnode)
{
        op->file[n].vnode = vnode;
        op->file[n].need_io_lock = true;
}

static inline void afs_op_set_fid(struct afs_operation *op, unsigned int n,
                                  const struct afs_fid *fid)
{
        op->file[n].fid = *fid;
}

/*
 * fs_probe.c
 */
extern void afs_fileserver_probe_result(struct afs_call *);
extern void afs_fs_probe_fileserver(struct afs_net *, struct afs_server *, struct key *, bool);
extern int afs_wait_for_fs_probes(struct afs_server_list *, unsigned long);
extern void afs_probe_fileserver(struct afs_net *, struct afs_server *);
extern void afs_fs_probe_dispatcher(struct work_struct *);
extern int afs_wait_for_one_fs_probe(struct afs_server *, bool);
extern void afs_fs_probe_cleanup(struct afs_net *);

/*
 * inode.c
 */
extern const struct afs_operation_ops afs_fetch_status_operation;

extern void afs_vnode_commit_status(struct afs_operation *, struct afs_vnode_param *);
extern int afs_fetch_status(struct afs_vnode *, struct key *, bool, afs_access_t *);
extern int afs_ilookup5_test_by_fid(struct inode *, void *);
extern struct inode *afs_iget_pseudo_dir(struct super_block *, bool);
extern struct inode *afs_iget(struct afs_operation *, struct afs_vnode_param *);
extern struct inode *afs_root_iget(struct super_block *, struct key *);
extern bool afs_check_validity(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 int afs_net_id;

static inline struct afs_net *afs_net(struct net *net)
{
        return net_generic(net, afs_net_id);
}

static inline struct afs_net *afs_sb2net(struct super_block *sb)
{
        return afs_net(AFS_FS_S(sb)->net_ns);
}

static inline struct afs_net *afs_d2net(struct dentry *dentry)
{
        return afs_sb2net(dentry->d_sb);
}

static inline struct afs_net *afs_i2net(struct inode *inode)
{
        return afs_sb2net(inode->i_sb);
}

static inline struct afs_net *afs_v2net(struct afs_vnode *vnode)
{
        return afs_i2net(&vnode->vfs_inode);
}

static inline struct afs_net *afs_sock2net(struct sock *sk)
{
        return net_generic(sock_net(sk), afs_net_id);
}

static inline void __afs_stat(atomic_t *s)
{
        atomic_inc(s);
}

#define afs_stat_v(vnode, n) __afs_stat(&afs_v2net(vnode)->n)

/*
 * misc.c
 */
extern int afs_abort_to_error(u32);
extern void afs_prioritise_error(struct afs_error *, int, 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);

/*
 * proc.c
 */
#ifdef CONFIG_PROC_FS
extern int __net_init afs_proc_init(struct afs_net *);
extern void __net_exit afs_proc_cleanup(struct afs_net *);
extern int afs_proc_cell_setup(struct afs_cell *);
extern void afs_proc_cell_remove(struct afs_cell *);
extern void afs_put_sysnames(struct afs_sysnames *);
#else
static inline int afs_proc_init(struct afs_net *net) { return 0; }
static inline void afs_proc_cleanup(struct afs_net *net) {}
static inline int afs_proc_cell_setup(struct afs_cell *cell) { return 0; }
static inline void afs_proc_cell_remove(struct afs_cell *cell) {}
static inline void afs_put_sysnames(struct afs_sysnames *sysnames) {}
#endif

/*
 * rotate.c
 */
extern bool afs_select_fileserver(struct afs_operation *);
extern void afs_dump_edestaddrreq(const struct afs_operation *);

/*
 * rxrpc.c
 */
extern struct workqueue_struct *afs_async_calls;

extern int __net_init afs_open_socket(struct afs_net *);
extern void __net_exit afs_close_socket(struct afs_net *);
extern void afs_charge_preallocation(struct work_struct *);
extern void afs_put_call(struct afs_call *);
extern void afs_make_call(struct afs_addr_cursor *, struct afs_call *, gfp_t);
extern long afs_wait_for_call_to_complete(struct afs_call *, struct afs_addr_cursor *);
extern struct afs_call *afs_alloc_flat_call(struct afs_net *,
                                            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 *, bool);
extern int afs_protocol_error(struct afs_call *, enum afs_eproto_cause);

static inline void afs_make_op_call(struct afs_operation *op, struct afs_call *call,
                                    gfp_t gfp)
{
        op->call = call;
        op->type = call->type;
        call->op = op;
        call->key = op->key;
        call->intr = !(op->flags & AFS_OPERATION_UNINTR);
        afs_make_call(&op->ac, call, gfp);
}

static inline void afs_extract_begin(struct afs_call *call, void *buf, size_t size)
{
        call->kvec[0].iov_base = buf;
        call->kvec[0].iov_len = size;
        iov_iter_kvec(&call->def_iter, READ, call->kvec, 1, size);
}

static inline void afs_extract_to_tmp(struct afs_call *call)
{
        afs_extract_begin(call, &call->tmp, sizeof(call->tmp));
}

static inline void afs_extract_to_tmp64(struct afs_call *call)
{
        afs_extract_begin(call, &call->tmp64, sizeof(call->tmp64));
}

static inline void afs_extract_discard(struct afs_call *call, size_t size)
{
        iov_iter_discard(&call->def_iter, READ, size);
}

static inline void afs_extract_to_buf(struct afs_call *call, size_t size)
{
        afs_extract_begin(call, call->buffer, size);
}

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

static inline bool afs_check_call_state(struct afs_call *call,
                                        enum afs_call_state state)
{
        return READ_ONCE(call->state) == state;
}

static inline bool afs_set_call_state(struct afs_call *call,
                                      enum afs_call_state from,
                                      enum afs_call_state to)
{
        bool ok = false;

        spin_lock_bh(&call->state_lock);
        if (call->state == from) {
                call->state = to;
                trace_afs_call_state(call, from, to, 0, 0);
                ok = true;
        }
        spin_unlock_bh(&call->state_lock);
        return ok;
}

static inline void afs_set_call_complete(struct afs_call *call,
                                         int error, u32 remote_abort)
{
        enum afs_call_state state;
        bool ok = false;

        spin_lock_bh(&call->state_lock);
        state = call->state;
        if (state != AFS_CALL_COMPLETE) {
                call->abort_code = remote_abort;
                call->error = error;
                call->state = AFS_CALL_COMPLETE;
                trace_afs_call_state(call, state, AFS_CALL_COMPLETE,
                                     error, remote_abort);
                ok = true;
        }
        spin_unlock_bh(&call->state_lock);
        if (ok) {
                trace_afs_call_done(call);

                /* Asynchronous calls have two refs to release - one from the alloc and
                 * one queued with the work item - and we can't just deallocate the
                 * call because the work item may be queued again.
                 */
                if (call->drop_ref)
                        afs_put_call(call);
        }
}

/*
 * security.c
 */
extern void afs_put_permits(struct afs_permits *);
extern void afs_clear_permits(struct afs_vnode *);
extern void afs_cache_permit(struct afs_vnode *, struct key *, unsigned int,
                             struct afs_status_cb *);
extern void afs_zap_permits(struct rcu_head *);
extern struct key *afs_request_key(struct afs_cell *);
extern struct key *afs_request_key_rcu(struct afs_cell *);
extern int afs_check_permit(struct afs_vnode *, struct key *, afs_access_t *);
extern int afs_permission(struct inode *, int);
extern void __exit afs_clean_up_permit_cache(void);

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

extern struct afs_server *afs_find_server(struct afs_net *,
                                          const struct sockaddr_rxrpc *);
extern struct afs_server *afs_find_server_by_uuid(struct afs_net *, const uuid_t *);
extern struct afs_server *afs_lookup_server(struct afs_cell *, struct key *, const uuid_t *, u32);
extern struct afs_server *afs_get_server(struct afs_server *, enum afs_server_trace);
extern struct afs_server *afs_use_server(struct afs_server *, enum afs_server_trace);
extern void afs_unuse_server(struct afs_net *, struct afs_server *, enum afs_server_trace);
extern void afs_unuse_server_notime(struct afs_net *, struct afs_server *, enum afs_server_trace);
extern void afs_put_server(struct afs_net *, struct afs_server *, enum afs_server_trace);
extern void afs_manage_servers(struct work_struct *);
extern void afs_servers_timer(struct timer_list *);
extern void afs_fs_probe_timer(struct timer_list *);
extern void __net_exit afs_purge_servers(struct afs_net *);
extern bool afs_check_server_record(struct afs_operation *, struct afs_server *);

static inline void afs_inc_servers_outstanding(struct afs_net *net)
{
        atomic_inc(&net->servers_outstanding);
}

static inline void afs_dec_servers_outstanding(struct afs_net *net)
{
        if (atomic_dec_and_test(&net->servers_outstanding))
                wake_up_var(&net->servers_outstanding);
}

static inline bool afs_is_probing_server(struct afs_server *server)
{
        return list_empty(&server->probe_link);
}

/*
 * server_list.c
 */
static inline struct afs_server_list *afs_get_serverlist(struct afs_server_list *slist)
{
        refcount_inc(&slist->usage);
        return slist;
}

extern void afs_put_serverlist(struct afs_net *, struct afs_server_list *);
extern struct afs_server_list *afs_alloc_server_list(struct afs_cell *, struct key *,
                                                     struct afs_vldb_entry *,
                                                     u8);
extern bool afs_annotate_server_list(struct afs_server_list *, struct afs_server_list *);

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

/*
 * vlclient.c
 */
extern struct afs_vldb_entry *afs_vl_get_entry_by_name_u(struct afs_vl_cursor *,
                                                         const char *, int);
extern struct afs_addr_list *afs_vl_get_addrs_u(struct afs_vl_cursor *, const uuid_t *);
extern struct afs_call *afs_vl_get_capabilities(struct afs_net *, struct afs_addr_cursor *,
                                                struct key *, struct afs_vlserver *, unsigned int);
extern struct afs_addr_list *afs_yfsvl_get_endpoints(struct afs_vl_cursor *, const uuid_t *);
extern char *afs_yfsvl_get_cell_name(struct afs_vl_cursor *);

/*
 * vl_alias.c
 */
extern int afs_cell_detect_alias(struct afs_cell *, struct key *);

/*
 * vl_probe.c
 */
extern void afs_vlserver_probe_result(struct afs_call *);
extern int afs_send_vl_probes(struct afs_net *, struct key *, struct afs_vlserver_list *);
extern int afs_wait_for_vl_probes(struct afs_vlserver_list *, unsigned long);

/*
 * vl_rotate.c
 */
extern bool afs_begin_vlserver_operation(struct afs_vl_cursor *,
                                         struct afs_cell *, struct key *);
extern bool afs_select_vlserver(struct afs_vl_cursor *);
extern bool afs_select_current_vlserver(struct afs_vl_cursor *);
extern int afs_end_vlserver_operation(struct afs_vl_cursor *);

/*
 * vlserver_list.c
 */
static inline struct afs_vlserver *afs_get_vlserver(struct afs_vlserver *vlserver)
{
        atomic_inc(&vlserver->usage);
        return vlserver;
}

static inline struct afs_vlserver_list *afs_get_vlserverlist(struct afs_vlserver_list *vllist)
{
        if (vllist)
                atomic_inc(&vllist->usage);
        return vllist;
}

extern struct afs_vlserver *afs_alloc_vlserver(const char *, size_t, unsigned short);
extern void afs_put_vlserver(struct afs_net *, struct afs_vlserver *);
extern struct afs_vlserver_list *afs_alloc_vlserver_list(unsigned int);
extern void afs_put_vlserverlist(struct afs_net *, struct afs_vlserver_list *);
extern struct afs_vlserver_list *afs_extract_vlserver_list(struct afs_cell *,
                                                           const void *, size_t);

/*
 * volume.c
 */
extern struct afs_volume *afs_create_volume(struct afs_fs_context *);
extern void afs_activate_volume(struct afs_volume *);
extern void afs_deactivate_volume(struct afs_volume *);
extern struct afs_volume *afs_get_volume(struct afs_volume *, enum afs_volume_trace);
extern void afs_put_volume(struct afs_net *, struct afs_volume *, enum afs_volume_trace);
extern int afs_check_volume_status(struct afs_volume *, struct afs_operation *);

/*
 * write.c
 */
extern int afs_set_page_dirty(struct page *);
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 ssize_t afs_file_write(struct kiocb *, struct iov_iter *);
extern int afs_fsync(struct file *, loff_t, loff_t, int);
extern vm_fault_t afs_page_mkwrite(struct vm_fault *vmf);
extern void afs_prune_wb_keys(struct afs_vnode *);
extern int afs_launder_page(struct page *);

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

/*
 * yfsclient.c
 */
extern void yfs_fs_fetch_data(struct afs_operation *);
extern void yfs_fs_create_file(struct afs_operation *);
extern void yfs_fs_make_dir(struct afs_operation *);
extern void yfs_fs_remove_file2(struct afs_operation *);
extern void yfs_fs_remove_file(struct afs_operation *);
extern void yfs_fs_remove_dir(struct afs_operation *);
extern void yfs_fs_link(struct afs_operation *);
extern void yfs_fs_symlink(struct afs_operation *);
extern void yfs_fs_rename(struct afs_operation *);
extern void yfs_fs_store_data(struct afs_operation *);
extern void yfs_fs_setattr(struct afs_operation *);
extern void yfs_fs_get_volume_status(struct afs_operation *);
extern void yfs_fs_set_lock(struct afs_operation *);
extern void yfs_fs_extend_lock(struct afs_operation *);
extern void yfs_fs_release_lock(struct afs_operation *);
extern void yfs_fs_fetch_status(struct afs_operation *);
extern void yfs_fs_inline_bulk_status(struct afs_operation *);

struct yfs_acl {
        struct afs_acl  *acl;           /* Dir/file/symlink ACL */
        struct afs_acl  *vol_acl;       /* Whole volume ACL */
        u32             inherit_flag;   /* True if ACL is inherited from parent dir */
        u32             num_cleaned;    /* Number of ACEs removed due to subject removal */
        unsigned int    flags;
#define YFS_ACL_WANT_ACL        0x01    /* Set if caller wants ->acl */
#define YFS_ACL_WANT_VOL_ACL    0x02    /* Set if caller wants ->vol_acl */
};

extern void yfs_free_opaque_acl(struct yfs_acl *);
extern void yfs_fs_fetch_opaque_acl(struct afs_operation *);
extern void yfs_fs_store_opaque_acl2(struct afs_operation *);

/*
 * Miscellaneous inline functions.
 */
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;
}

/*
 * Note that a dentry got changed.  We need to set d_fsdata to the data version
 * number derived from the result of the operation.  It doesn't matter if
 * d_fsdata goes backwards as we'll just revalidate.
 */
static inline void afs_update_dentry_version(struct afs_operation *op,
                                             struct afs_vnode_param *dir_vp,
                                             struct dentry *dentry)
{
        if (!op->error)
                dentry->d_fsdata =
                        (void *)(unsigned long)dir_vp->scb.status.data_version;
}

/*
 * Check for a conflicting operation on a directory that we just unlinked from.
 * If someone managed to sneak a link or an unlink in on the file we just
 * unlinked, we won't be able to trust nlink on an AFS file (but not YFS).
 */
static inline void afs_check_dir_conflict(struct afs_operation *op,
                                          struct afs_vnode_param *dvp)
{
        if (dvp->dv_before + dvp->dv_delta != dvp->scb.status.data_version)
                op->flags |= AFS_OPERATION_DIR_CONFLICT;
}

static inline int afs_io_error(struct afs_call *call, enum afs_io_error where)
{
        trace_afs_io_error(call->debug_id, -EIO, where);
        return -EIO;
}

static inline int afs_bad(struct afs_vnode *vnode, enum afs_file_error where)
{
        trace_afs_file_error(vnode, -EIO, where);
        return -EIO;
}

/*****************************************************************************/
/*
 * 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 */