linux/fs/nfs/nfs42xdr.c
Anna Schumaker 1c6dcbe5ce NFS: Implement SEEK
The SEEK operation is used when an application makes an lseek call with
either the SEEK_HOLE or SEEK_DATA flags set.  I fall back on
nfs_file_llseek() if the server does not have SEEK support.

Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2014-09-30 16:24:56 -04:00

99 lines
2.2 KiB
C

/*
* Copyright (c) 2014 Anna Schumaker <Anna.Schumaker@Netapp.com>
*/
#ifndef __LINUX_FS_NFS_NFS4_2XDR_H
#define __LINUX_FS_NFS_NFS4_2XDR_H
#define encode_seek_maxsz (op_encode_hdr_maxsz + \
encode_stateid_maxsz + \
2 /* offset */ + \
1 /* whence */)
#define decode_seek_maxsz (op_decode_hdr_maxsz + \
1 /* eof */ + \
1 /* whence */ + \
2 /* offset */ + \
2 /* length */)
#define NFS4_enc_seek_sz (compound_encode_hdr_maxsz + \
encode_putfh_maxsz + \
encode_seek_maxsz)
#define NFS4_dec_seek_sz (compound_decode_hdr_maxsz + \
decode_putfh_maxsz + \
decode_seek_maxsz)
static void encode_seek(struct xdr_stream *xdr,
struct nfs42_seek_args *args,
struct compound_hdr *hdr)
{
encode_op_hdr(xdr, OP_SEEK, decode_seek_maxsz, hdr);
encode_nfs4_stateid(xdr, &args->sa_stateid);
encode_uint64(xdr, args->sa_offset);
encode_uint32(xdr, args->sa_what);
}
/*
* Encode SEEK request
*/
static void nfs4_xdr_enc_seek(struct rpc_rqst *req,
struct xdr_stream *xdr,
struct nfs42_seek_args *args)
{
struct compound_hdr hdr = {
.minorversion = nfs4_xdr_minorversion(&args->seq_args),
};
encode_compound_hdr(xdr, req, &hdr);
encode_sequence(xdr, &args->seq_args, &hdr);
encode_putfh(xdr, args->sa_fh, &hdr);
encode_seek(xdr, args, &hdr);
encode_nops(&hdr);
}
static int decode_seek(struct xdr_stream *xdr, struct nfs42_seek_res *res)
{
int status;
__be32 *p;
status = decode_op_hdr(xdr, OP_SEEK);
if (status)
return status;
p = xdr_inline_decode(xdr, 4 + 8);
if (unlikely(!p))
goto out_overflow;
res->sr_eof = be32_to_cpup(p++);
p = xdr_decode_hyper(p, &res->sr_offset);
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* Decode SEEK request
*/
static int nfs4_xdr_dec_seek(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
struct nfs42_seek_res *res)
{
struct compound_hdr hdr;
int status;
status = decode_compound_hdr(xdr, &hdr);
if (status)
goto out;
status = decode_sequence(xdr, &res->seq_res, rqstp);
if (status)
goto out;
status = decode_putfh(xdr);
if (status)
goto out;
status = decode_seek(xdr, res);
out:
return status;
}
#endif /* __LINUX_FS_NFS_NFS4_2XDR_H */