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linux/fs/nfs/nfs2xdr.c
Trond Myklebust 9ed5af268e SUNRPC: Clean up the handling of page padding in rpc_prepare_reply_pages() 
rpc_prepare_reply_pages() currently expects the 'hdrsize' argument to
contain the length of the data that we expect to want placed in the head
kvec plus a count of 1 word of padding that is placed after the page data.
This is very confusing when trying to read the code, and sometimes leads
to callers adding an arbitrary value of '1' just in order to satisfy the
requirement (whether or not the page data actually needs such padding).

This patch aims to clarify the code by changing the 'hdrsize' argument
to remove that 1 word of padding. This means we need to subtract the
padding from all the existing callers.

Fixes: 02ef04e432 ("NFS: Account for XDR pad of buf->pages")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-12-02 14:05:53 -05:00

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// SPDX-License-Identifier: GPL-2.0
/*
* linux/fs/nfs/nfs2xdr.c
*
* XDR functions to encode/decode NFS RPC arguments and results.
*
* Copyright (C) 1992, 1993, 1994 Rick Sladkey
* Copyright (C) 1996 Olaf Kirch
* 04 Aug 1998 Ion Badulescu <ionut@cs.columbia.edu>
* FIFO's need special handling in NFSv2
*/
#include <linux/param.h>
#include <linux/time.h>
#include <linux/mm.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/in.h>
#include <linux/pagemap.h>
#include <linux/proc_fs.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfs.h>
#include <linux/nfs2.h>
#include <linux/nfs_fs.h>
#include "nfstrace.h"
#include "internal.h"
#define NFSDBG_FACILITY NFSDBG_XDR
/* Mapping from NFS error code to "errno" error code. */
#define errno_NFSERR_IO EIO
/*
* Declare the space requirements for NFS arguments and replies as
* number of 32bit-words
*/
#define NFS_pagepad_sz (1) /* Page padding */
#define NFS_fhandle_sz (8)
#define NFS_sattr_sz (8)
#define NFS_filename_sz (1+(NFS2_MAXNAMLEN>>2))
#define NFS_path_sz (1+(NFS2_MAXPATHLEN>>2))
#define NFS_fattr_sz (17)
#define NFS_info_sz (5)
#define NFS_entry_sz (NFS_filename_sz+3)
#define NFS_diropargs_sz (NFS_fhandle_sz+NFS_filename_sz)
#define NFS_removeargs_sz (NFS_fhandle_sz+NFS_filename_sz)
#define NFS_sattrargs_sz (NFS_fhandle_sz+NFS_sattr_sz)
#define NFS_readlinkargs_sz (NFS_fhandle_sz)
#define NFS_readargs_sz (NFS_fhandle_sz+3)
#define NFS_writeargs_sz (NFS_fhandle_sz+4)
#define NFS_createargs_sz (NFS_diropargs_sz+NFS_sattr_sz)
#define NFS_renameargs_sz (NFS_diropargs_sz+NFS_diropargs_sz)
#define NFS_linkargs_sz (NFS_fhandle_sz+NFS_diropargs_sz)
#define NFS_symlinkargs_sz (NFS_diropargs_sz+1+NFS_sattr_sz)
#define NFS_readdirargs_sz (NFS_fhandle_sz+2)
#define NFS_attrstat_sz (1+NFS_fattr_sz)
#define NFS_diropres_sz (1+NFS_fhandle_sz+NFS_fattr_sz)
#define NFS_readlinkres_sz (2+NFS_pagepad_sz)
#define NFS_readres_sz (1+NFS_fattr_sz+1+NFS_pagepad_sz)
#define NFS_writeres_sz (NFS_attrstat_sz)
#define NFS_stat_sz (1)
#define NFS_readdirres_sz (1+NFS_pagepad_sz)
#define NFS_statfsres_sz (1+NFS_info_sz)
static int nfs_stat_to_errno(enum nfs_stat);
/*
* Encode/decode NFSv2 basic data types
*
* Basic NFSv2 data types are defined in section 2.3 of RFC 1094:
* "NFS: Network File System Protocol Specification".
*
* Not all basic data types have their own encoding and decoding
* functions. For run-time efficiency, some data types are encoded
* or decoded inline.
*/
static struct user_namespace *rpc_userns(const struct rpc_clnt *clnt)
{
if (clnt && clnt->cl_cred)
return clnt->cl_cred->user_ns;
return &init_user_ns;
}
static struct user_namespace *rpc_rqst_userns(const struct rpc_rqst *rqstp)
{
if (rqstp->rq_task)
return rpc_userns(rqstp->rq_task->tk_client);
return &init_user_ns;
}
/*
* typedef opaque nfsdata<>;
*/
static int decode_nfsdata(struct xdr_stream *xdr, struct nfs_pgio_res *result)
{
u32 recvd, count;
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EIO;
count = be32_to_cpup(p);
recvd = xdr_read_pages(xdr, count);
if (unlikely(count > recvd))
goto out_cheating;
out:
result->eof = 0; /* NFSv2 does not pass EOF flag on the wire. */
result->count = count;
return count;
out_cheating:
dprintk("NFS: server cheating in read result: "
"count %u > recvd %u\n", count, recvd);
count = recvd;
goto out;
}
/*
* enum stat {
* NFS_OK = 0,
* NFSERR_PERM = 1,
* NFSERR_NOENT = 2,
* NFSERR_IO = 5,
* NFSERR_NXIO = 6,
* NFSERR_ACCES = 13,
* NFSERR_EXIST = 17,
* NFSERR_NODEV = 19,
* NFSERR_NOTDIR = 20,
* NFSERR_ISDIR = 21,
* NFSERR_FBIG = 27,
* NFSERR_NOSPC = 28,
* NFSERR_ROFS = 30,
* NFSERR_NAMETOOLONG = 63,
* NFSERR_NOTEMPTY = 66,
* NFSERR_DQUOT = 69,
* NFSERR_STALE = 70,
* NFSERR_WFLUSH = 99
* };
*/
static int decode_stat(struct xdr_stream *xdr, enum nfs_stat *status)
{
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EIO;
if (unlikely(*p != cpu_to_be32(NFS_OK)))
goto out_status;
*status = 0;
return 0;
out_status:
*status = be32_to_cpup(p);
trace_nfs_xdr_status(xdr, (int)*status);
return 0;
}
/*
* 2.3.2. ftype
*
* enum ftype {
* NFNON = 0,
* NFREG = 1,
* NFDIR = 2,
* NFBLK = 3,
* NFCHR = 4,
* NFLNK = 5
* };
*
*/
static __be32 *xdr_decode_ftype(__be32 *p, u32 *type)
{
*type = be32_to_cpup(p++);
if (unlikely(*type > NF2FIFO))
*type = NFBAD;
return p;
}
/*
* 2.3.3. fhandle
*
* typedef opaque fhandle[FHSIZE];
*/
static void encode_fhandle(struct xdr_stream *xdr, const struct nfs_fh *fh)
{
__be32 *p;
p = xdr_reserve_space(xdr, NFS2_FHSIZE);
memcpy(p, fh->data, NFS2_FHSIZE);
}
static int decode_fhandle(struct xdr_stream *xdr, struct nfs_fh *fh)
{
__be32 *p;
p = xdr_inline_decode(xdr, NFS2_FHSIZE);
if (unlikely(!p))
return -EIO;
fh->size = NFS2_FHSIZE;
memcpy(fh->data, p, NFS2_FHSIZE);
return 0;
}
/*
* 2.3.4. timeval
*
* struct timeval {
* unsigned int seconds;
* unsigned int useconds;
* };
*/
static __be32 *xdr_encode_time(__be32 *p, const struct timespec64 *timep)
{
*p++ = cpu_to_be32((u32)timep->tv_sec);
if (timep->tv_nsec != 0)
*p++ = cpu_to_be32(timep->tv_nsec / NSEC_PER_USEC);
else
*p++ = cpu_to_be32(0);
return p;
}
/*
* Passing the invalid value useconds=1000000 is a Sun convention for
* "set to current server time". It's needed to make permissions checks
* for the "touch" program across v2 mounts to Solaris and Irix servers
* work correctly. See description of sattr in section 6.1 of "NFS
* Illustrated" by Brent Callaghan, Addison-Wesley, ISBN 0-201-32750-5.
*/
static __be32 *xdr_encode_current_server_time(__be32 *p,
const struct timespec64 *timep)
{
*p++ = cpu_to_be32(timep->tv_sec);
*p++ = cpu_to_be32(1000000);
return p;
}
static __be32 *xdr_decode_time(__be32 *p, struct timespec64 *timep)
{
timep->tv_sec = be32_to_cpup(p++);
timep->tv_nsec = be32_to_cpup(p++) * NSEC_PER_USEC;
return p;
}
/*
* 2.3.5. fattr
*
* struct fattr {
* ftype type;
* unsigned int mode;
* unsigned int nlink;
* unsigned int uid;
* unsigned int gid;
* unsigned int size;
* unsigned int blocksize;
* unsigned int rdev;
* unsigned int blocks;
* unsigned int fsid;
* unsigned int fileid;
* timeval atime;
* timeval mtime;
* timeval ctime;
* };
*
*/
static int decode_fattr(struct xdr_stream *xdr, struct nfs_fattr *fattr,
struct user_namespace *userns)
{
u32 rdev, type;
__be32 *p;
p = xdr_inline_decode(xdr, NFS_fattr_sz << 2);
if (unlikely(!p))
return -EIO;
fattr->valid |= NFS_ATTR_FATTR_V2;
p = xdr_decode_ftype(p, &type);
fattr->mode = be32_to_cpup(p++);
fattr->nlink = be32_to_cpup(p++);
fattr->uid = make_kuid(userns, be32_to_cpup(p++));
if (!uid_valid(fattr->uid))
goto out_uid;
fattr->gid = make_kgid(userns, be32_to_cpup(p++));
if (!gid_valid(fattr->gid))
goto out_gid;
fattr->size = be32_to_cpup(p++);
fattr->du.nfs2.blocksize = be32_to_cpup(p++);
rdev = be32_to_cpup(p++);
fattr->rdev = new_decode_dev(rdev);
if (type == (u32)NFCHR && rdev == (u32)NFS2_FIFO_DEV) {
fattr->mode = (fattr->mode & ~S_IFMT) | S_IFIFO;
fattr->rdev = 0;
}
fattr->du.nfs2.blocks = be32_to_cpup(p++);
fattr->fsid.major = be32_to_cpup(p++);
fattr->fsid.minor = 0;
fattr->fileid = be32_to_cpup(p++);
p = xdr_decode_time(p, &fattr->atime);
p = xdr_decode_time(p, &fattr->mtime);
xdr_decode_time(p, &fattr->ctime);
fattr->change_attr = nfs_timespec_to_change_attr(&fattr->ctime);
return 0;
out_uid:
dprintk("NFS: returned invalid uid\n");
return -EINVAL;
out_gid:
dprintk("NFS: returned invalid gid\n");
return -EINVAL;
}
/*
* 2.3.6. sattr
*
* struct sattr {
* unsigned int mode;
* unsigned int uid;
* unsigned int gid;
* unsigned int size;
* timeval atime;
* timeval mtime;
* };
*/
#define NFS2_SATTR_NOT_SET (0xffffffff)
static __be32 *xdr_time_not_set(__be32 *p)
{
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
return p;
}
static void encode_sattr(struct xdr_stream *xdr, const struct iattr *attr,
struct user_namespace *userns)
{
__be32 *p;
p = xdr_reserve_space(xdr, NFS_sattr_sz << 2);
if (attr->ia_valid & ATTR_MODE)
*p++ = cpu_to_be32(attr->ia_mode);
else
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
if (attr->ia_valid & ATTR_UID)
*p++ = cpu_to_be32(from_kuid_munged(userns, attr->ia_uid));
else
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
if (attr->ia_valid & ATTR_GID)
*p++ = cpu_to_be32(from_kgid_munged(userns, attr->ia_gid));
else
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
if (attr->ia_valid & ATTR_SIZE)
*p++ = cpu_to_be32((u32)attr->ia_size);
else
*p++ = cpu_to_be32(NFS2_SATTR_NOT_SET);
if (attr->ia_valid & ATTR_ATIME_SET)
p = xdr_encode_time(p, &attr->ia_atime);
else if (attr->ia_valid & ATTR_ATIME)
p = xdr_encode_current_server_time(p, &attr->ia_atime);
else
p = xdr_time_not_set(p);
if (attr->ia_valid & ATTR_MTIME_SET)
xdr_encode_time(p, &attr->ia_mtime);
else if (attr->ia_valid & ATTR_MTIME)
xdr_encode_current_server_time(p, &attr->ia_mtime);
else
xdr_time_not_set(p);
}
/*
* 2.3.7. filename
*
* typedef string filename<MAXNAMLEN>;
*/
static void encode_filename(struct xdr_stream *xdr,
const char *name, u32 length)
{
__be32 *p;
WARN_ON_ONCE(length > NFS2_MAXNAMLEN);
p = xdr_reserve_space(xdr, 4 + length);
xdr_encode_opaque(p, name, length);
}
static int decode_filename_inline(struct xdr_stream *xdr,
const char **name, u32 *length)
{
__be32 *p;
u32 count;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EIO;
count = be32_to_cpup(p);
if (count > NFS3_MAXNAMLEN)
goto out_nametoolong;
p = xdr_inline_decode(xdr, count);
if (unlikely(!p))
return -EIO;
*name = (const char *)p;
*length = count;
return 0;
out_nametoolong:
dprintk("NFS: returned filename too long: %u\n", count);
return -ENAMETOOLONG;
}
/*
* 2.3.8. path
*
* typedef string path<MAXPATHLEN>;
*/
static void encode_path(struct xdr_stream *xdr, struct page **pages, u32 length)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = cpu_to_be32(length);
xdr_write_pages(xdr, pages, 0, length);
}
static int decode_path(struct xdr_stream *xdr)
{
u32 length, recvd;
__be32 *p;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EIO;
length = be32_to_cpup(p);
if (unlikely(length >= xdr->buf->page_len || length > NFS_MAXPATHLEN))
goto out_size;
recvd = xdr_read_pages(xdr, length);
if (unlikely(length > recvd))
goto out_cheating;
xdr_terminate_string(xdr->buf, length);
return 0;
out_size:
dprintk("NFS: returned pathname too long: %u\n", length);
return -ENAMETOOLONG;
out_cheating:
dprintk("NFS: server cheating in pathname result: "
"length %u > received %u\n", length, recvd);
return -EIO;
}
/*
* 2.3.9. attrstat
*
* union attrstat switch (stat status) {
* case NFS_OK:
* fattr attributes;
* default:
* void;
* };
*/
static int decode_attrstat(struct xdr_stream *xdr, struct nfs_fattr *result,
__u32 *op_status,
struct user_namespace *userns)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (op_status)
*op_status = status;
if (status != NFS_OK)
goto out_default;
error = decode_fattr(xdr, result, userns);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
/*
* 2.3.10. diropargs
*
* struct diropargs {
* fhandle dir;
* filename name;
* };
*/
static void encode_diropargs(struct xdr_stream *xdr, const struct nfs_fh *fh,
const char *name, u32 length)
{
encode_fhandle(xdr, fh);
encode_filename(xdr, name, length);
}
/*
* 2.3.11. diropres
*
* union diropres switch (stat status) {
* case NFS_OK:
* struct {
* fhandle file;
* fattr attributes;
* } diropok;
* default:
* void;
* };
*/
static int decode_diropok(struct xdr_stream *xdr, struct nfs_diropok *result,
struct user_namespace *userns)
{
int error;
error = decode_fhandle(xdr, result->fh);
if (unlikely(error))
goto out;
error = decode_fattr(xdr, result->fattr, userns);
out:
return error;
}
static int decode_diropres(struct xdr_stream *xdr, struct nfs_diropok *result,
struct user_namespace *userns)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (status != NFS_OK)
goto out_default;
error = decode_diropok(xdr, result, userns);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
/*
* NFSv2 XDR encode functions
*
* NFSv2 argument types are defined in section 2.2 of RFC 1094:
* "NFS: Network File System Protocol Specification".
*/
static void nfs2_xdr_enc_fhandle(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_fh *fh = data;
encode_fhandle(xdr, fh);
}
/*
* 2.2.3. sattrargs
*
* struct sattrargs {
* fhandle file;
* sattr attributes;
* };
*/
static void nfs2_xdr_enc_sattrargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_sattrargs *args = data;
encode_fhandle(xdr, args->fh);
encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
}
static void nfs2_xdr_enc_diropargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_diropargs *args = data;
encode_diropargs(xdr, args->fh, args->name, args->len);
}
static void nfs2_xdr_enc_readlinkargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_readlinkargs *args = data;
encode_fhandle(xdr, args->fh);
rpc_prepare_reply_pages(req, args->pages, args->pgbase, args->pglen,
NFS_readlinkres_sz - NFS_pagepad_sz);
}
/*
* 2.2.7. readargs
*
* struct readargs {
* fhandle file;
* unsigned offset;
* unsigned count;
* unsigned totalcount;
* };
*/
static void encode_readargs(struct xdr_stream *xdr,
const struct nfs_pgio_args *args)
{
u32 offset = args->offset;
u32 count = args->count;
__be32 *p;
encode_fhandle(xdr, args->fh);
p = xdr_reserve_space(xdr, 4 + 4 + 4);
*p++ = cpu_to_be32(offset);
*p++ = cpu_to_be32(count);
*p = cpu_to_be32(count);
}
static void nfs2_xdr_enc_readargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_pgio_args *args = data;
encode_readargs(xdr, args);
rpc_prepare_reply_pages(req, args->pages, args->pgbase, args->count,
NFS_readres_sz - NFS_pagepad_sz);
req->rq_rcv_buf.flags |= XDRBUF_READ;
}
/*
* 2.2.9. writeargs
*
* struct writeargs {
* fhandle file;
* unsigned beginoffset;
* unsigned offset;
* unsigned totalcount;
* nfsdata data;
* };
*/
static void encode_writeargs(struct xdr_stream *xdr,
const struct nfs_pgio_args *args)
{
u32 offset = args->offset;
u32 count = args->count;
__be32 *p;
encode_fhandle(xdr, args->fh);
p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
*p++ = cpu_to_be32(offset);
*p++ = cpu_to_be32(offset);
*p++ = cpu_to_be32(count);
/* nfsdata */
*p = cpu_to_be32(count);
xdr_write_pages(xdr, args->pages, args->pgbase, count);
}
static void nfs2_xdr_enc_writeargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_pgio_args *args = data;
encode_writeargs(xdr, args);
xdr->buf->flags |= XDRBUF_WRITE;
}
/*
* 2.2.10. createargs
*
* struct createargs {
* diropargs where;
* sattr attributes;
* };
*/
static void nfs2_xdr_enc_createargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_createargs *args = data;
encode_diropargs(xdr, args->fh, args->name, args->len);
encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
}
static void nfs2_xdr_enc_removeargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_removeargs *args = data;
encode_diropargs(xdr, args->fh, args->name.name, args->name.len);
}
/*
* 2.2.12. renameargs
*
* struct renameargs {
* diropargs from;
* diropargs to;
* };
*/
static void nfs2_xdr_enc_renameargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_renameargs *args = data;
const struct qstr *old = args->old_name;
const struct qstr *new = args->new_name;
encode_diropargs(xdr, args->old_dir, old->name, old->len);
encode_diropargs(xdr, args->new_dir, new->name, new->len);
}
/*
* 2.2.13. linkargs
*
* struct linkargs {
* fhandle from;
* diropargs to;
* };
*/
static void nfs2_xdr_enc_linkargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_linkargs *args = data;
encode_fhandle(xdr, args->fromfh);
encode_diropargs(xdr, args->tofh, args->toname, args->tolen);
}
/*
* 2.2.14. symlinkargs
*
* struct symlinkargs {
* diropargs from;
* path to;
* sattr attributes;
* };
*/
static void nfs2_xdr_enc_symlinkargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_symlinkargs *args = data;
encode_diropargs(xdr, args->fromfh, args->fromname, args->fromlen);
encode_path(xdr, args->pages, args->pathlen);
encode_sattr(xdr, args->sattr, rpc_rqst_userns(req));
}
/*
* 2.2.17. readdirargs
*
* struct readdirargs {
* fhandle dir;
* nfscookie cookie;
* unsigned count;
* };
*/
static void encode_readdirargs(struct xdr_stream *xdr,
const struct nfs_readdirargs *args)
{
__be32 *p;
encode_fhandle(xdr, args->fh);
p = xdr_reserve_space(xdr, 4 + 4);
*p++ = cpu_to_be32(args->cookie);
*p = cpu_to_be32(args->count);
}
static void nfs2_xdr_enc_readdirargs(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfs_readdirargs *args = data;
encode_readdirargs(xdr, args);
rpc_prepare_reply_pages(req, args->pages, 0, args->count,
NFS_readdirres_sz - NFS_pagepad_sz);
}
/*
* NFSv2 XDR decode functions
*
* NFSv2 result types are defined in section 2.2 of RFC 1094:
* "NFS: Network File System Protocol Specification".
*/
static int nfs2_xdr_dec_stat(struct rpc_rqst *req, struct xdr_stream *xdr,
void *__unused)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (status != NFS_OK)
goto out_default;
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
static int nfs2_xdr_dec_attrstat(struct rpc_rqst *req, struct xdr_stream *xdr,
void *result)
{
return decode_attrstat(xdr, result, NULL, rpc_rqst_userns(req));
}
static int nfs2_xdr_dec_diropres(struct rpc_rqst *req, struct xdr_stream *xdr,
void *result)
{
return decode_diropres(xdr, result, rpc_rqst_userns(req));
}
/*
* 2.2.6. readlinkres
*
* union readlinkres switch (stat status) {
* case NFS_OK:
* path data;
* default:
* void;
* };
*/
static int nfs2_xdr_dec_readlinkres(struct rpc_rqst *req,
struct xdr_stream *xdr, void *__unused)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (status != NFS_OK)
goto out_default;
error = decode_path(xdr);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
/*
* 2.2.7. readres
*
* union readres switch (stat status) {
* case NFS_OK:
* fattr attributes;
* nfsdata data;
* default:
* void;
* };
*/
static int nfs2_xdr_dec_readres(struct rpc_rqst *req, struct xdr_stream *xdr,
void *data)
{
struct nfs_pgio_res *result = data;
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
result->op_status = status;
if (status != NFS_OK)
goto out_default;
error = decode_fattr(xdr, result->fattr, rpc_rqst_userns(req));
if (unlikely(error))
goto out;
error = decode_nfsdata(xdr, result);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
static int nfs2_xdr_dec_writeres(struct rpc_rqst *req, struct xdr_stream *xdr,
void *data)
{
struct nfs_pgio_res *result = data;
/* All NFSv2 writes are "file sync" writes */
result->verf->committed = NFS_FILE_SYNC;
return decode_attrstat(xdr, result->fattr, &result->op_status,
rpc_rqst_userns(req));
}
/**
* nfs2_decode_dirent - Decode a single NFSv2 directory entry stored in
* the local page cache.
* @xdr: XDR stream where entry resides
* @entry: buffer to fill in with entry data
* @plus: boolean indicating whether this should be a readdirplus entry
*
* Returns zero if successful, otherwise a negative errno value is
* returned.
*
* This function is not invoked during READDIR reply decoding, but
* rather whenever an application invokes the getdents(2) system call
* on a directory already in our cache.
*
* 2.2.17. entry
*
* struct entry {
* unsigned fileid;
* filename name;
* nfscookie cookie;
* entry *nextentry;
* };
*/
int nfs2_decode_dirent(struct xdr_stream *xdr, struct nfs_entry *entry,
bool plus)
{
__be32 *p;
int error;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EAGAIN;
if (*p++ == xdr_zero) {
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EAGAIN;
if (*p++ == xdr_zero)
return -EAGAIN;
entry->eof = 1;
return -EBADCOOKIE;
}
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EAGAIN;
entry->ino = be32_to_cpup(p);
error = decode_filename_inline(xdr, &entry->name, &entry->len);
if (unlikely(error))
return error;
/*
* The type (size and byte order) of nfscookie isn't defined in
* RFC 1094. This implementation assumes that it's an XDR uint32.
*/
entry->prev_cookie = entry->cookie;
p = xdr_inline_decode(xdr, 4);
if (unlikely(!p))
return -EAGAIN;
entry->cookie = be32_to_cpup(p);
entry->d_type = DT_UNKNOWN;
return 0;
}
/*
* 2.2.17. readdirres
*
* union readdirres switch (stat status) {
* case NFS_OK:
* struct {
* entry *entries;
* bool eof;
* } readdirok;
* default:
* void;
* };
*
* Read the directory contents into the page cache, but don't
* touch them. The actual decoding is done by nfs2_decode_dirent()
* during subsequent nfs_readdir() calls.
*/
static int decode_readdirok(struct xdr_stream *xdr)
{
return xdr_read_pages(xdr, xdr->buf->page_len);
}
static int nfs2_xdr_dec_readdirres(struct rpc_rqst *req,
struct xdr_stream *xdr, void *__unused)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (status != NFS_OK)
goto out_default;
error = decode_readdirok(xdr);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
/*
* 2.2.18. statfsres
*
* union statfsres (stat status) {
* case NFS_OK:
* struct {
* unsigned tsize;
* unsigned bsize;
* unsigned blocks;
* unsigned bfree;
* unsigned bavail;
* } info;
* default:
* void;
* };
*/
static int decode_info(struct xdr_stream *xdr, struct nfs2_fsstat *result)
{
__be32 *p;
p = xdr_inline_decode(xdr, NFS_info_sz << 2);
if (unlikely(!p))
return -EIO;
result->tsize = be32_to_cpup(p++);
result->bsize = be32_to_cpup(p++);
result->blocks = be32_to_cpup(p++);
result->bfree = be32_to_cpup(p++);
result->bavail = be32_to_cpup(p);
return 0;
}
static int nfs2_xdr_dec_statfsres(struct rpc_rqst *req, struct xdr_stream *xdr,
void *result)
{
enum nfs_stat status;
int error;
error = decode_stat(xdr, &status);
if (unlikely(error))
goto out;
if (status != NFS_OK)
goto out_default;
error = decode_info(xdr, result);
out:
return error;
out_default:
return nfs_stat_to_errno(status);
}
/*
* We need to translate between nfs status return values and
* the local errno values which may not be the same.
*/
static const struct {
int stat;
int errno;
} nfs_errtbl[] = {
{ NFS_OK, 0 },
{ NFSERR_PERM, -EPERM },
{ NFSERR_NOENT, -ENOENT },
{ NFSERR_IO, -errno_NFSERR_IO},
{ NFSERR_NXIO, -ENXIO },
/* { NFSERR_EAGAIN, -EAGAIN }, */
{ NFSERR_ACCES, -EACCES },
{ NFSERR_EXIST, -EEXIST },
{ NFSERR_XDEV, -EXDEV },
{ NFSERR_NODEV, -ENODEV },
{ NFSERR_NOTDIR, -ENOTDIR },
{ NFSERR_ISDIR, -EISDIR },
{ NFSERR_INVAL, -EINVAL },
{ NFSERR_FBIG, -EFBIG },
{ NFSERR_NOSPC, -ENOSPC },
{ NFSERR_ROFS, -EROFS },
{ NFSERR_MLINK, -EMLINK },
{ NFSERR_NAMETOOLONG, -ENAMETOOLONG },
{ NFSERR_NOTEMPTY, -ENOTEMPTY },
{ NFSERR_DQUOT, -EDQUOT },
{ NFSERR_STALE, -ESTALE },
{ NFSERR_REMOTE, -EREMOTE },
#ifdef EWFLUSH
{ NFSERR_WFLUSH, -EWFLUSH },
#endif
{ NFSERR_BADHANDLE, -EBADHANDLE },
{ NFSERR_NOT_SYNC, -ENOTSYNC },
{ NFSERR_BAD_COOKIE, -EBADCOOKIE },
{ NFSERR_NOTSUPP, -ENOTSUPP },
{ NFSERR_TOOSMALL, -ETOOSMALL },
{ NFSERR_SERVERFAULT, -EREMOTEIO },
{ NFSERR_BADTYPE, -EBADTYPE },
{ NFSERR_JUKEBOX, -EJUKEBOX },
{ -1, -EIO }
};
/**
* nfs_stat_to_errno - convert an NFS status code to a local errno
* @status: NFS status code to convert
*
* Returns a local errno value, or -EIO if the NFS status code is
* not recognized. This function is used jointly by NFSv2 and NFSv3.
*/
static int nfs_stat_to_errno(enum nfs_stat status)
{
int i;
for (i = 0; nfs_errtbl[i].stat != -1; i++) {
if (nfs_errtbl[i].stat == (int)status)
return nfs_errtbl[i].errno;
}
dprintk("NFS: Unrecognized nfs status value: %u\n", status);
return nfs_errtbl[i].errno;
}
#define PROC(proc, argtype, restype, timer) \
[NFSPROC_##proc] = { \
.p_proc = NFSPROC_##proc, \
.p_encode = nfs2_xdr_enc_##argtype, \
.p_decode = nfs2_xdr_dec_##restype, \
.p_arglen = NFS_##argtype##_sz, \
.p_replen = NFS_##restype##_sz, \
.p_timer = timer, \
.p_statidx = NFSPROC_##proc, \
.p_name = #proc, \
}
const struct rpc_procinfo nfs_procedures[] = {
PROC(GETATTR, fhandle, attrstat, 1),
PROC(SETATTR, sattrargs, attrstat, 0),
PROC(LOOKUP, diropargs, diropres, 2),
PROC(READLINK, readlinkargs, readlinkres, 3),
PROC(READ, readargs, readres, 3),
PROC(WRITE, writeargs, writeres, 4),
PROC(CREATE, createargs, diropres, 0),
PROC(REMOVE, removeargs, stat, 0),
PROC(RENAME, renameargs, stat, 0),
PROC(LINK, linkargs, stat, 0),
PROC(SYMLINK, symlinkargs, stat, 0),
PROC(MKDIR, createargs, diropres, 0),
PROC(RMDIR, diropargs, stat, 0),
PROC(READDIR, readdirargs, readdirres, 3),
PROC(STATFS, fhandle, statfsres, 0),
};
static unsigned int nfs_version2_counts[ARRAY_SIZE(nfs_procedures)];
const struct rpc_version nfs_version2 = {
.number = 2,
.nrprocs = ARRAY_SIZE(nfs_procedures),
.procs = nfs_procedures,
.counts = nfs_version2_counts,
};
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