/* SPDX-License-Identifier: GPL-2.0 */
/*
 * linux/fs/nfs/nfs4_fs.h
 *
 * Copyright (C) 2005 Trond Myklebust
 *
 * NFSv4-specific filesystem definitions and declarations
 */

#ifndef __LINUX_FS_NFS_NFS4_FS_H
#define __LINUX_FS_NFS_NFS4_FS_H

#if defined(CONFIG_NFS_V4_2)
#define NFS4_MAX_MINOR_VERSION 2
#elif defined(CONFIG_NFS_V4_1)
#define NFS4_MAX_MINOR_VERSION 1
#else
#define NFS4_MAX_MINOR_VERSION 0
#endif

#if IS_ENABLED(CONFIG_NFS_V4)

#define NFS4_MAX_LOOP_ON_RECOVER (10)

#include <linux/seqlock.h>

struct idmap;

enum nfs4_client_state {
        NFS4CLNT_MANAGER_RUNNING  = 0,
        NFS4CLNT_CHECK_LEASE,
        NFS4CLNT_LEASE_EXPIRED,
        NFS4CLNT_RECLAIM_REBOOT,
        NFS4CLNT_RECLAIM_NOGRACE,
        NFS4CLNT_DELEGRETURN,
        NFS4CLNT_SESSION_RESET,
        NFS4CLNT_LEASE_CONFIRM,
        NFS4CLNT_SERVER_SCOPE_MISMATCH,
        NFS4CLNT_PURGE_STATE,
        NFS4CLNT_BIND_CONN_TO_SESSION,
        NFS4CLNT_MOVED,
        NFS4CLNT_LEASE_MOVED,
        NFS4CLNT_DELEGATION_EXPIRED,
};

#define NFS4_RENEW_TIMEOUT              0x01
#define NFS4_RENEW_DELEGATION_CB        0x02

struct nfs_seqid_counter;
struct nfs4_minor_version_ops {
        u32     minor_version;
        unsigned init_caps;

        int     (*init_client)(struct nfs_client *);
        void    (*shutdown_client)(struct nfs_client *);
        bool    (*match_stateid)(const nfs4_stateid *,
                        const nfs4_stateid *);
        int     (*find_root_sec)(struct nfs_server *, struct nfs_fh *,
                        struct nfs_fsinfo *);
        void    (*free_lock_state)(struct nfs_server *,
                        struct nfs4_lock_state *);
        int     (*test_and_free_expired)(struct nfs_server *,
                        nfs4_stateid *, struct rpc_cred *);
        struct nfs_seqid *
                (*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
        int     (*session_trunk)(struct rpc_clnt *, struct rpc_xprt *, void *);
        const struct rpc_call_ops *call_sync_ops;
        const struct nfs4_state_recovery_ops *reboot_recovery_ops;
        const struct nfs4_state_recovery_ops *nograce_recovery_ops;
        const struct nfs4_state_maintenance_ops *state_renewal_ops;
        const struct nfs4_mig_recovery_ops *mig_recovery_ops;
};

#define NFS_SEQID_CONFIRMED 1
struct nfs_seqid_counter {
        ktime_t create_time;
        int owner_id;
        int flags;
        u32 counter;
        spinlock_t lock;                /* Protects the list */
        struct list_head list;          /* Defines sequence of RPC calls */
        struct rpc_wait_queue   wait;   /* RPC call delay queue */
};

struct nfs_seqid {
        struct nfs_seqid_counter *sequence;
        struct list_head list;
        struct rpc_task *task;
};

static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
{
        if (seqid_mutating_err(-status))
                seqid->flags |= NFS_SEQID_CONFIRMED;
}

/*
 * NFS4 state_owners and lock_owners are simply labels for ordered
 * sequences of RPC calls. Their sole purpose is to provide once-only
 * semantics by allowing the server to identify replayed requests.
 */
struct nfs4_state_owner {
        struct nfs_server    *so_server;
        struct list_head     so_lru;
        unsigned long        so_expires;
        struct rb_node       so_server_node;

        struct rpc_cred      *so_cred;   /* Associated cred */

        spinlock_t           so_lock;
        atomic_t             so_count;
        unsigned long        so_flags;
        struct list_head     so_states;
        struct nfs_seqid_counter so_seqid;
        seqcount_t           so_reclaim_seqcount;
        struct mutex         so_delegreturn_mutex;
};

enum {
        NFS_OWNER_RECLAIM_REBOOT,
        NFS_OWNER_RECLAIM_NOGRACE
};

#define NFS_LOCK_NEW            0
#define NFS_LOCK_RECLAIM        1
#define NFS_LOCK_EXPIRED        2

/*
 * struct nfs4_state maintains the client-side state for a given
 * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
 *
 * OPEN:
 * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
 * we need to know how many files are open for reading or writing on a
 * given inode. This information too is stored here.
 *
 * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
 */

struct nfs4_lock_state {
        struct list_head        ls_locks;       /* Other lock stateids */
        struct nfs4_state *     ls_state;       /* Pointer to open state */
#define NFS_LOCK_INITIALIZED 0
#define NFS_LOCK_LOST        1
        unsigned long           ls_flags;
        struct nfs_seqid_counter        ls_seqid;
        nfs4_stateid            ls_stateid;
        refcount_t              ls_count;
        fl_owner_t              ls_owner;
};

/* bits for nfs4_state->flags */
enum {
        LK_STATE_IN_USE,
        NFS_DELEGATED_STATE,            /* Current stateid is delegation */
        NFS_OPEN_STATE,                 /* OPEN stateid is set */
        NFS_O_RDONLY_STATE,             /* OPEN stateid has read-only state */
        NFS_O_WRONLY_STATE,             /* OPEN stateid has write-only state */
        NFS_O_RDWR_STATE,               /* OPEN stateid has read/write state */
        NFS_STATE_RECLAIM_REBOOT,       /* OPEN stateid server rebooted */
        NFS_STATE_RECLAIM_NOGRACE,      /* OPEN stateid needs to recover state */
        NFS_STATE_POSIX_LOCKS,          /* Posix locks are supported */
        NFS_STATE_RECOVERY_FAILED,      /* OPEN stateid state recovery failed */
        NFS_STATE_MAY_NOTIFY_LOCK,      /* server may CB_NOTIFY_LOCK */
        NFS_STATE_CHANGE_WAIT,          /* A state changing operation is outstanding */
};

struct nfs4_state {
        struct list_head open_states;   /* List of states for the same state_owner */
        struct list_head inode_states;  /* List of states for the same inode */
        struct list_head lock_states;   /* List of subservient lock stateids */

        struct nfs4_state_owner *owner; /* Pointer to the open owner */
        struct inode *inode;            /* Pointer to the inode */

        unsigned long flags;            /* Do we hold any locks? */
        spinlock_t state_lock;          /* Protects the lock_states list */

        seqlock_t seqlock;              /* Protects the stateid/open_stateid */
        nfs4_stateid stateid;           /* Current stateid: may be delegation */
        nfs4_stateid open_stateid;      /* OPEN stateid */

        /* The following 3 fields are protected by owner->so_lock */
        unsigned int n_rdonly;          /* Number of read-only references */
        unsigned int n_wronly;          /* Number of write-only references */
        unsigned int n_rdwr;            /* Number of read/write references */
        fmode_t state;                  /* State on the server (R,W, or RW) */
        atomic_t count;

        wait_queue_head_t waitq;
};


struct nfs4_exception {
        struct nfs4_state *state;
        struct inode *inode;
        nfs4_stateid *stateid;
        long timeout;
        unsigned char delay : 1,
                      recovering : 1,
                      retry : 1;
};

struct nfs4_state_recovery_ops {
        int owner_flag_bit;
        int state_flag_bit;
        int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
        int (*recover_lock)(struct nfs4_state *, struct file_lock *);
        int (*establish_clid)(struct nfs_client *, struct rpc_cred *);
        int (*reclaim_complete)(struct nfs_client *, struct rpc_cred *);
        int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
                struct rpc_cred *);
};

struct nfs4_add_xprt_data {
        struct nfs_client       *clp;
        struct rpc_cred         *cred;
};

struct nfs4_state_maintenance_ops {
        int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned);
        struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *);
        int (*renew_lease)(struct nfs_client *, struct rpc_cred *);
};

struct nfs4_mig_recovery_ops {
        int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
                struct page *, struct rpc_cred *);
        int (*fsid_present)(struct inode *, struct rpc_cred *);
};

extern const struct dentry_operations nfs4_dentry_operations;

/* dir.c */
int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
                    unsigned, umode_t, int *);

/* super.c */
extern struct file_system_type nfs4_fs_type;

/* nfs4namespace.c */
struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
                                         const struct qstr *);
struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
                               struct nfs_fh *, struct nfs_fattr *);
int nfs4_replace_transport(struct nfs_server *server,
                                const struct nfs4_fs_locations *locations);

/* nfs4proc.c */
extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
                          struct rpc_message *, struct nfs4_sequence_args *,
                          struct nfs4_sequence_res *, int);
extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int);
extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, struct rpc_cred *cred);
extern int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred);
extern int nfs4_destroy_clientid(struct nfs_client *clp);
extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *);
extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *);
extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
                                  struct nfs4_fs_locations *, struct page *);
extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
                struct page *page, struct rpc_cred *);
extern int nfs4_proc_fsid_present(struct inode *, struct rpc_cred *);
extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, const struct qstr *,
                            struct nfs_fh *, struct nfs_fattr *);
extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
extern const struct xattr_handler *nfs4_xattr_handlers[];
extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
                const struct nfs_open_context *ctx,
                const struct nfs_lock_context *l_ctx,
                fmode_t fmode);

#if defined(CONFIG_NFS_V4_1)
extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
                struct nfs_fsinfo *fsinfo);
extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
                                  bool sync);
extern int nfs4_detect_session_trunking(struct nfs_client *clp,
                struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);

static inline bool
is_ds_only_client(struct nfs_client *clp)
{
        return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
                EXCHGID4_FLAG_USE_PNFS_DS;
}

static inline bool
is_ds_client(struct nfs_client *clp)
{
        return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
}

static inline bool
_nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
                    struct rpc_clnt **clntp, struct rpc_message *msg)
{
        struct rpc_cred *newcred = NULL;
        rpc_authflavor_t flavor;

        if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
            sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
                /* Using machine creds for cleanup operations
                 * is only relevent if the client credentials
                 * might expire. So don't bother for
                 * RPC_AUTH_UNIX.  If file was only exported to
                 * sec=sys, the PUTFH would fail anyway.
                 */
                if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
                        return false;
        }
        if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
                spin_lock(&clp->cl_lock);
                if (clp->cl_machine_cred != NULL)
                        /* don't call get_rpccred on the machine cred -
                         * a reference will be held for life of clp */
                        newcred = clp->cl_machine_cred;
                spin_unlock(&clp->cl_lock);
                msg->rpc_cred = newcred;

                flavor = clp->cl_rpcclient->cl_auth->au_flavor;
                WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
                             flavor != RPC_AUTH_GSS_KRB5P);
                *clntp = clp->cl_rpcclient;

                return true;
        }
        return false;
}

/*
 * Function responsible for determining if an rpc_message should use the
 * machine cred under SP4_MACH_CRED and if so switching the credential and
 * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
 * Should be called before rpc_call_sync/rpc_call_async.
 */
static inline void
nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
                   struct rpc_clnt **clntp, struct rpc_message *msg)
{
        _nfs4_state_protect(clp, sp4_mode, clntp, msg);
}

/*
 * Special wrapper to nfs4_state_protect for write.
 * If WRITE can use machine cred but COMMIT cannot, make sure all writes
 * that use machine cred use NFS_FILE_SYNC.
 */
static inline void
nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
                         struct rpc_message *msg, struct nfs_pgio_header *hdr)
{
        if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
            !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
                hdr->args.stable = NFS_FILE_SYNC;
}
#else /* CONFIG_NFS_v4_1 */
static inline bool
is_ds_only_client(struct nfs_client *clp)
{
        return false;
}

static inline bool
is_ds_client(struct nfs_client *clp)
{
        return false;
}

static inline void
nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
                   struct rpc_clnt **clntp, struct rpc_message *msg)
{
}

static inline void
nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
                         struct rpc_message *msg, struct nfs_pgio_header *hdr)
{
}
#endif /* CONFIG_NFS_V4_1 */

extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];

extern const u32 nfs4_fattr_bitmap[3];
extern const u32 nfs4_statfs_bitmap[3];
extern const u32 nfs4_pathconf_bitmap[3];
extern const u32 nfs4_fsinfo_bitmap[3];
extern const u32 nfs4_fs_locations_bitmap[3];

void nfs40_shutdown_client(struct nfs_client *);
void nfs41_shutdown_client(struct nfs_client *);
int nfs40_init_client(struct nfs_client *);
int nfs41_init_client(struct nfs_client *);
void nfs4_free_client(struct nfs_client *);

struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);

/* nfs4renewd.c */
extern void nfs4_schedule_state_renewal(struct nfs_client *);
extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
extern void nfs4_kill_renewd(struct nfs_client *);
extern void nfs4_renew_state(struct work_struct *);
extern void nfs4_set_lease_period(struct nfs_client *clp,
                unsigned long lease,
                unsigned long lastrenewed);


/* nfs4state.c */
struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp);
struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp);
int nfs4_discover_server_trunking(struct nfs_client *clp,
                        struct nfs_client **);
int nfs40_discover_server_trunking(struct nfs_client *clp,
                        struct nfs_client **, struct rpc_cred *);
#if defined(CONFIG_NFS_V4_1)
int nfs41_discover_server_trunking(struct nfs_client *clp,
                        struct nfs_client **, struct rpc_cred *);
extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
extern void nfs41_notify_server(struct nfs_client *);
#else
static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
{
}
#endif /* CONFIG_NFS_V4_1 */

extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *, gfp_t);
extern void nfs4_put_state_owner(struct nfs4_state_owner *);
extern void nfs4_purge_state_owners(struct nfs_server *);
extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
extern void nfs4_put_open_state(struct nfs4_state *);
extern void nfs4_close_state(struct nfs4_state *, fmode_t);
extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
extern void nfs_inode_find_state_and_recover(struct inode *inode,
                const nfs4_stateid *stateid);
extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
extern void nfs4_schedule_lease_recovery(struct nfs_client *);
extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
extern void nfs4_schedule_state_manager(struct nfs_client *);
extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
extern void nfs41_handle_server_scope(struct nfs_client *,
                                      struct nfs41_server_scope **);
extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
                const struct nfs_lock_context *, nfs4_stateid *,
                struct rpc_cred **);
extern bool nfs4_refresh_open_stateid(nfs4_stateid *dst,
                struct nfs4_state *state);
extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
                struct nfs4_state *state);

extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
extern void nfs_release_seqid(struct nfs_seqid *seqid);
extern void nfs_free_seqid(struct nfs_seqid *seqid);
extern int nfs4_setup_sequence(struct nfs_client *client,
                                struct nfs4_sequence_args *args,
                                struct nfs4_sequence_res *res,
                                struct rpc_task *task);
extern int nfs4_sequence_done(struct rpc_task *task,
                              struct nfs4_sequence_res *res);

extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);

extern const nfs4_stateid zero_stateid;
extern const nfs4_stateid invalid_stateid;

/* nfs4super.c */
struct nfs_mount_info;
extern struct nfs_subversion nfs_v4;
struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);
extern bool nfs4_disable_idmapping;
extern unsigned short max_session_slots;
extern unsigned short max_session_cb_slots;
extern unsigned short send_implementation_id;
extern bool recover_lost_locks;

#define NFS4_CLIENT_ID_UNIQ_LEN         (64)
extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];

/* nfs4sysctl.c */
#ifdef CONFIG_SYSCTL
int nfs4_register_sysctl(void);
void nfs4_unregister_sysctl(void);
#else
static inline int nfs4_register_sysctl(void)
{
        return 0;
}

static inline void nfs4_unregister_sysctl(void)
{
}
#endif

/* nfs4xdr.c */
extern const struct rpc_procinfo nfs4_procedures[];

struct nfs4_mount_data;

/* callback_xdr.c */
extern const struct svc_version nfs4_callback_version1;
extern const struct svc_version nfs4_callback_version4;

static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
{
        memcpy(dst->data, src->data, sizeof(dst->data));
        dst->type = src->type;
}

static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
{
        if (dst->type != src->type)
                return false;
        return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
}

static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
{
        return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
}

static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
{
        return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
}

static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
{
        return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
}

static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
                const nfs4_stateid *stateid)
{
        return test_bit(NFS_OPEN_STATE, &state->flags) &&
                nfs4_stateid_match_other(&state->open_stateid, stateid);
}

#else

#define nfs4_close_state(a, b) do { } while (0)
#define nfs4_close_sync(a, b) do { } while (0)
#define nfs4_state_protect(a, b, c, d) do { } while (0)
#define nfs4_state_protect_write(a, b, c, d) do { } while (0)

#endif /* CONFIG_NFS_V4 */
#endif /* __LINUX_FS_NFS_NFS4_FS.H */