alistair23-linux/include/linux/sunrpc/xdr.h
Trond Myklebust 88a9fe8cae SUNRPC: Remove the last remnant of the BKL...
Somehow, this escaped the previous purge. There should be no need to keep
any extra locks in the XDR callbacks.

The NFS client XDR code only writes into private objects, whereas all reads
of shared objects are confined to fields that do not change, such as
filehandles...

Ditto for lockd, the NFSv2/v3 client mount code, and rpcbind.

The nfsd XDR code may require the BKL, but since it does a synchronous RPC
call from a thread that already holds the lock, that issue is moot.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2008-12-23 15:21:31 -05:00

211 lines
6.9 KiB
C

/*
* include/linux/sunrpc/xdr.h
*
* Copyright (C) 1995-1997 Olaf Kirch <okir@monad.swb.de>
*/
#ifndef _SUNRPC_XDR_H_
#define _SUNRPC_XDR_H_
#ifdef __KERNEL__
#include <linux/uio.h>
#include <asm/byteorder.h>
#include <linux/scatterlist.h>
#include <linux/smp_lock.h>
/*
* Buffer adjustment
*/
#define XDR_QUADLEN(l) (((l) + 3) >> 2)
/*
* Generic opaque `network object.' At the kernel level, this type
* is used only by lockd.
*/
#define XDR_MAX_NETOBJ 1024
struct xdr_netobj {
unsigned int len;
u8 * data;
};
/*
* This is the generic XDR function. rqstp is either a rpc_rqst (client
* side) or svc_rqst pointer (server side).
* Encode functions always assume there's enough room in the buffer.
*/
typedef int (*kxdrproc_t)(void *rqstp, __be32 *data, void *obj);
/*
* Basic structure for transmission/reception of a client XDR message.
* Features a header (for a linear buffer containing RPC headers
* and the data payload for short messages), and then an array of
* pages.
* The tail iovec allows you to append data after the page array. Its
* main interest is for appending padding to the pages in order to
* satisfy the int_32-alignment requirements in RFC1832.
*
* For the future, we might want to string several of these together
* in a list if anybody wants to make use of NFSv4 COMPOUND
* operations and/or has a need for scatter/gather involving pages.
*/
struct xdr_buf {
struct kvec head[1], /* RPC header + non-page data */
tail[1]; /* Appended after page data */
struct page ** pages; /* Array of contiguous pages */
unsigned int page_base, /* Start of page data */
page_len, /* Length of page data */
flags; /* Flags for data disposition */
#define XDRBUF_READ 0x01 /* target of file read */
#define XDRBUF_WRITE 0x02 /* source of file write */
unsigned int buflen, /* Total length of storage buffer */
len; /* Length of XDR encoded message */
};
/*
* pre-xdr'ed macros.
*/
#define xdr_zero __constant_htonl(0)
#define xdr_one __constant_htonl(1)
#define xdr_two __constant_htonl(2)
#define rpc_success __constant_htonl(RPC_SUCCESS)
#define rpc_prog_unavail __constant_htonl(RPC_PROG_UNAVAIL)
#define rpc_prog_mismatch __constant_htonl(RPC_PROG_MISMATCH)
#define rpc_proc_unavail __constant_htonl(RPC_PROC_UNAVAIL)
#define rpc_garbage_args __constant_htonl(RPC_GARBAGE_ARGS)
#define rpc_system_err __constant_htonl(RPC_SYSTEM_ERR)
#define rpc_drop_reply __constant_htonl(RPC_DROP_REPLY)
#define rpc_auth_ok __constant_htonl(RPC_AUTH_OK)
#define rpc_autherr_badcred __constant_htonl(RPC_AUTH_BADCRED)
#define rpc_autherr_rejectedcred __constant_htonl(RPC_AUTH_REJECTEDCRED)
#define rpc_autherr_badverf __constant_htonl(RPC_AUTH_BADVERF)
#define rpc_autherr_rejectedverf __constant_htonl(RPC_AUTH_REJECTEDVERF)
#define rpc_autherr_tooweak __constant_htonl(RPC_AUTH_TOOWEAK)
#define rpcsec_gsserr_credproblem __constant_htonl(RPCSEC_GSS_CREDPROBLEM)
#define rpcsec_gsserr_ctxproblem __constant_htonl(RPCSEC_GSS_CTXPROBLEM)
#define rpc_autherr_oldseqnum __constant_htonl(101)
/*
* Miscellaneous XDR helper functions
*/
__be32 *xdr_encode_opaque_fixed(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_opaque(__be32 *p, const void *ptr, unsigned int len);
__be32 *xdr_encode_string(__be32 *p, const char *s);
__be32 *xdr_decode_string_inplace(__be32 *p, char **sp, unsigned int *lenp,
unsigned int maxlen);
__be32 *xdr_encode_netobj(__be32 *p, const struct xdr_netobj *);
__be32 *xdr_decode_netobj(__be32 *p, struct xdr_netobj *);
void xdr_encode_pages(struct xdr_buf *, struct page **, unsigned int,
unsigned int);
void xdr_inline_pages(struct xdr_buf *, unsigned int,
struct page **, unsigned int, unsigned int);
static inline __be32 *xdr_encode_array(__be32 *p, const void *s, unsigned int len)
{
return xdr_encode_opaque(p, s, len);
}
/*
* Decode 64bit quantities (NFSv3 support)
*/
static inline __be32 *
xdr_encode_hyper(__be32 *p, __u64 val)
{
*p++ = htonl(val >> 32);
*p++ = htonl(val & 0xFFFFFFFF);
return p;
}
static inline __be32 *
xdr_decode_hyper(__be32 *p, __u64 *valp)
{
*valp = ((__u64) ntohl(*p++)) << 32;
*valp |= ntohl(*p++);
return p;
}
/*
* Adjust kvec to reflect end of xdr'ed data (RPC client XDR)
*/
static inline int
xdr_adjust_iovec(struct kvec *iov, __be32 *p)
{
return iov->iov_len = ((u8 *) p - (u8 *) iov->iov_base);
}
/*
* XDR buffer helper functions
*/
extern void xdr_shift_buf(struct xdr_buf *, size_t);
extern void xdr_buf_from_iov(struct kvec *, struct xdr_buf *);
extern int xdr_buf_subsegment(struct xdr_buf *, struct xdr_buf *, unsigned int, unsigned int);
extern int xdr_buf_read_netobj(struct xdr_buf *, struct xdr_netobj *, unsigned int);
extern int read_bytes_from_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
extern int write_bytes_to_xdr_buf(struct xdr_buf *, unsigned int, void *, unsigned int);
/*
* Helper structure for copying from an sk_buff.
*/
struct xdr_skb_reader {
struct sk_buff *skb;
unsigned int offset;
size_t count;
__wsum csum;
};
typedef size_t (*xdr_skb_read_actor)(struct xdr_skb_reader *desc, void *to, size_t len);
size_t xdr_skb_read_bits(struct xdr_skb_reader *desc, void *to, size_t len);
extern int csum_partial_copy_to_xdr(struct xdr_buf *, struct sk_buff *);
extern ssize_t xdr_partial_copy_from_skb(struct xdr_buf *, unsigned int,
struct xdr_skb_reader *, xdr_skb_read_actor);
extern int xdr_encode_word(struct xdr_buf *, unsigned int, u32);
extern int xdr_decode_word(struct xdr_buf *, unsigned int, u32 *);
struct xdr_array2_desc;
typedef int (*xdr_xcode_elem_t)(struct xdr_array2_desc *desc, void *elem);
struct xdr_array2_desc {
unsigned int elem_size;
unsigned int array_len;
unsigned int array_maxlen;
xdr_xcode_elem_t xcode;
};
extern int xdr_decode_array2(struct xdr_buf *buf, unsigned int base,
struct xdr_array2_desc *desc);
extern int xdr_encode_array2(struct xdr_buf *buf, unsigned int base,
struct xdr_array2_desc *desc);
/*
* Provide some simple tools for XDR buffer overflow-checking etc.
*/
struct xdr_stream {
__be32 *p; /* start of available buffer */
struct xdr_buf *buf; /* XDR buffer to read/write */
__be32 *end; /* end of available buffer space */
struct kvec *iov; /* pointer to the current kvec */
};
extern void xdr_init_encode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
extern __be32 *xdr_reserve_space(struct xdr_stream *xdr, size_t nbytes);
extern void xdr_write_pages(struct xdr_stream *xdr, struct page **pages,
unsigned int base, unsigned int len);
extern void xdr_init_decode(struct xdr_stream *xdr, struct xdr_buf *buf, __be32 *p);
extern __be32 *xdr_inline_decode(struct xdr_stream *xdr, size_t nbytes);
extern void xdr_read_pages(struct xdr_stream *xdr, unsigned int len);
extern void xdr_enter_page(struct xdr_stream *xdr, unsigned int len);
extern int xdr_process_buf(struct xdr_buf *buf, unsigned int offset, unsigned int len, int (*actor)(struct scatterlist *, void *), void *data);
#endif /* __KERNEL__ */
#endif /* _SUNRPC_XDR_H_ */