path: root/fs/nfs/nfs4_fs.h

/* 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,
	NFS4CLNT_RUN_MANAGER,
	NFS4CLNT_RECALL_RUNNING,
	NFS4CLNT_RECALL_ANY_LAYOUT_READ,
	NFS4CLNT_RECALL_ANY_LAYOUT_RW,
};

#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 *, const struct cred *);
	struct nfs_seqid *
		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
	void	(*session_trunk)(struct rpc_clnt *clnt,
			struct rpc_xprt *xprt, void *data);
	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;

	const struct 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_spinlock_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 */
	NFS_CLNT_DST_SSC_COPY_STATE,    /* dst server open state on client*/
	NFS_CLNT_SRC_SSC_COPY_STATE,    /* src server open state on client*/
	NFS_SRV_SSC_COPY_STATE,		/* ssc state on the dst server */
};

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) */
	refcount_t count;

	wait_queue_head_t waitq;
	struct rcu_head rcu_head;
};


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

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 *, const struct cred *);
	int (*reclaim_complete)(struct nfs_client *, const struct cred *);
	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
		const struct cred *);
};

struct nfs4_opendata {
	struct kref kref;
	struct nfs_openargs o_arg;
	struct nfs_openres o_res;
	struct nfs_open_confirmargs c_arg;
	struct nfs_open_confirmres c_res;
	struct nfs4_string owner_name;
	struct nfs4_string group_name;
	struct nfs4_label *a_label;
	struct nfs_fattr f_attr;
	struct nfs4_label *f_label;
	struct dentry *dir;
	struct dentry *dentry;
	struct nfs4_state_owner *owner;
	struct nfs4_state *state;
	struct iattr attrs;
	struct nfs4_layoutget *lgp;
	unsigned long timestamp;
	bool