lib/kasprintf.c


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/*
 *  linux/lib/kasprintf.c
 *
 *  Copyright (C) 1991, 1992  Linus Torvalds
 */

#include <stdarg.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/string.h>

/* Simplified asprintf. */
char *kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
{
	unsigned int len;
	char *p;
	va_list aq;

	va_copy(aq, ap);
	len = vsnprintf(NULL, 0, fmt, aq);
	va_end(aq);

	p = kmalloc(len+1, gfp);
	if (!p)
		return NULL;

	vsnprintf(p, len+1, fmt, ap);

	return p;
}
EXPORT_SYMBOL(kvasprintf);

char *kasprintf(gfp_t gfp, const char *fmt, ...)
{
	va_list ap;
	char *p;

	va_start(ap, fmt);
	p = kvasprintf(gfp, fmt, ap);
	va_end(ap);

	return p;
}
EXPORT_SYMBOL(kasprintf);
/*
 * 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

#ifdef CONFIG_NFS_V4

struct idmap;

/*
 * In a seqid-mutating op, this macro controls which error return
 * values trigger incrementation of the seqid.
 *
 * from rfc 3010:
 * The client MUST monotonically increment the sequence number for the
 * CLOSE, LOCK, LOCKU, OPEN, OPEN_CONFIRM, and OPEN_DOWNGRADE
 * operations.  This is true even in the event that the previous
 * operation that used the sequence number received an error.  The only
 * exception to this rule is if the previous operation received one of
 * the following errors: NFSERR_STALE_CLIENTID, NFSERR_STALE_STATEID,
 * NFSERR_BAD_STATEID, NFSERR_BAD_SEQID, NFSERR_BADXDR,
 * NFSERR_RESOURCE, NFSERR_NOFILEHANDLE.
 *
 */
#define seqid_mutating_err(err)       \
(((err) != NFSERR_STALE_CLIENTID) &&  \
 ((err) != NFSERR_STALE_STATEID)  &&  \
 ((err) != NFSERR_BAD_STATEID)    &&  \
 ((err) != NFSERR_BAD_SEQID)      &&  \
 ((err) != NFSERR_BAD_XDR)        &&  \
 ((err) != NFSERR_RESOURCE)       &&  \
 ((err) != NFSERR_NOFILEHANDLE))

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_RECALL_SLOT,
};

enum nfs4_session_state {
	NFS4_SESSION_INITING,
	NFS4_SESSION_DRAINING,
};

struct nfs4_minor_version_ops {
	u32	minor_version;

	int	(*call_sync)(struct nfs_server *server,
			struct rpc_message *msg,
			struct nfs4_sequence_args *args,
			struct nfs4_sequence_res *res,
			int cache_reply);
	int	(*validate_stateid)(struct nfs_delegation *,
			const nfs4_stateid *);
	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;
};

/*
 * struct rpc_sequence ensures that RPC calls are sent in the exact
 * order that they appear on the list.
 */
struct rpc_sequence {
	struct rpc_wait_queue	wait;	/* RPC call delay queue */
	spinlock_t lock;		/* Protects the list */
	struct list_head list;		/* Defines sequence of RPC calls */
};

#define NFS_SEQID_CONFIRMED 1
struct nfs_seqid_counter {
	struct rpc_sequence *sequence;
	int flags;
	u32 counter;
};

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

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

struct nfs_unique_id {
	struct rb_node rb_node;
	__u64 id;
};

/*
 * 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_unique_id so_owner_id;
	struct nfs_server    *so_server;
	struct rb_node	     so_client_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;
	struct rpc_sequence  so_sequence;
};

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_owner {
	unsigned int lo_type;
#define NFS4_ANY_LOCK_TYPE	(0U)
#define NFS4_FLOCK_LOCK_TYPE	(1U << 0)
#define NFS4_POSIX_LOCK_TYPE	(1U << 1)
	union {
		fl_owner_t posix_owner;
		pid_t flock_owner;
	} lo_u;
};

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 1
	int			ls_flags;
	struct nfs_seqid_counter	ls_seqid;
	struct rpc_sequence	ls_sequence;
	struct nfs_unique_id	ls_id;
	nfs4_stateid		ls_stateid;
	atomic_t		ls_count;
	struct nfs4_lock_owner	ls_owner;
};

/* bits for nfs4_state->flags */
enum {
	LK_STATE_IN_USE,
	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
	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 */
};

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;
};


struct nfs4_exception {
	long timeout;
	int retry;
	struct nfs4_state *state;
};

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 *);
	struct rpc_cred * (*get_clid_cred)(struct nfs_client *);
	int (*reclaim_complete)(struct nfs_client *);
};

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

extern const struct dentry_operations nfs4_dentry_operations;