alistair23-linux/fs/nfs/mount_clnt.c
Trond Myklebust fdcb45777a NFS: Fix the mapping of the NFSERR_SERVERFAULT error
It was recently pointed out that the NFSERR_SERVERFAULT error, which is
designed to inform the user of a serious internal error on the server, was
being mapped to an error value that is internal to the kernel.

This patch maps it to the error EREMOTEIO, which is exported to userland
through errno.h.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Cc: stable@kernel.org
2010-02-09 14:29:29 -05:00

532 lines
12 KiB
C

/*
* In-kernel MOUNT protocol client
*
* Copyright (C) 1997, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/socket.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/uio.h>
#include <linux/net.h>
#include <linux/in.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs_fs.h>
#include "internal.h"
#ifdef RPC_DEBUG
# define NFSDBG_FACILITY NFSDBG_MOUNT
#endif
/*
* Defined by RFC 1094, section A.3; and RFC 1813, section 5.1.4
*/
#define MNTPATHLEN (1024)
/*
* XDR data type sizes
*/
#define encode_dirpath_sz (1 + XDR_QUADLEN(MNTPATHLEN))
#define MNT_status_sz (1)
#define MNT_fhs_status_sz (1)
#define MNT_fhandle_sz XDR_QUADLEN(NFS2_FHSIZE)
#define MNT_fhandle3_sz (1 + XDR_QUADLEN(NFS3_FHSIZE))
#define MNT_authflav3_sz (1 + NFS_MAX_SECFLAVORS)
/*
* XDR argument and result sizes
*/
#define MNT_enc_dirpath_sz encode_dirpath_sz
#define MNT_dec_mountres_sz (MNT_status_sz + MNT_fhandle_sz)
#define MNT_dec_mountres3_sz (MNT_status_sz + MNT_fhandle_sz + \
MNT_authflav3_sz)
/*
* Defined by RFC 1094, section A.5
*/
enum {
MOUNTPROC_NULL = 0,
MOUNTPROC_MNT = 1,
MOUNTPROC_DUMP = 2,
MOUNTPROC_UMNT = 3,
MOUNTPROC_UMNTALL = 4,
MOUNTPROC_EXPORT = 5,
};
/*
* Defined by RFC 1813, section 5.2
*/
enum {
MOUNTPROC3_NULL = 0,
MOUNTPROC3_MNT = 1,
MOUNTPROC3_DUMP = 2,
MOUNTPROC3_UMNT = 3,
MOUNTPROC3_UMNTALL = 4,
MOUNTPROC3_EXPORT = 5,
};
static struct rpc_program mnt_program;
/*
* Defined by OpenGroup XNFS Version 3W, chapter 8
*/
enum mountstat {
MNT_OK = 0,
MNT_EPERM = 1,
MNT_ENOENT = 2,
MNT_EACCES = 13,
MNT_EINVAL = 22,
};
static struct {
u32 status;
int errno;
} mnt_errtbl[] = {
{ .status = MNT_OK, .errno = 0, },
{ .status = MNT_EPERM, .errno = -EPERM, },
{ .status = MNT_ENOENT, .errno = -ENOENT, },
{ .status = MNT_EACCES, .errno = -EACCES, },
{ .status = MNT_EINVAL, .errno = -EINVAL, },
};
/*
* Defined by RFC 1813, section 5.1.5
*/
enum mountstat3 {
MNT3_OK = 0, /* no error */
MNT3ERR_PERM = 1, /* Not owner */
MNT3ERR_NOENT = 2, /* No such file or directory */
MNT3ERR_IO = 5, /* I/O error */
MNT3ERR_ACCES = 13, /* Permission denied */
MNT3ERR_NOTDIR = 20, /* Not a directory */
MNT3ERR_INVAL = 22, /* Invalid argument */
MNT3ERR_NAMETOOLONG = 63, /* Filename too long */
MNT3ERR_NOTSUPP = 10004, /* Operation not supported */
MNT3ERR_SERVERFAULT = 10006, /* A failure on the server */
};
static struct {
u32 status;
int errno;
} mnt3_errtbl[] = {
{ .status = MNT3_OK, .errno = 0, },
{ .status = MNT3ERR_PERM, .errno = -EPERM, },
{ .status = MNT3ERR_NOENT, .errno = -ENOENT, },
{ .status = MNT3ERR_IO, .errno = -EIO, },
{ .status = MNT3ERR_ACCES, .errno = -EACCES, },
{ .status = MNT3ERR_NOTDIR, .errno = -ENOTDIR, },
{ .status = MNT3ERR_INVAL, .errno = -EINVAL, },
{ .status = MNT3ERR_NAMETOOLONG, .errno = -ENAMETOOLONG, },
{ .status = MNT3ERR_NOTSUPP, .errno = -ENOTSUPP, },
{ .status = MNT3ERR_SERVERFAULT, .errno = -EREMOTEIO, },
};
struct mountres {
int errno;
struct nfs_fh *fh;
unsigned int *auth_count;
rpc_authflavor_t *auth_flavors;
};
struct mnt_fhstatus {
u32 status;
struct nfs_fh *fh;
};
/**
* nfs_mount - Obtain an NFS file handle for the given host and path
* @info: pointer to mount request arguments
*
* Uses default timeout parameters specified by underlying transport.
*/
int nfs_mount(struct nfs_mount_request *info)
{
struct mountres result = {
.fh = info->fh,
.auth_count = info->auth_flav_len,
.auth_flavors = info->auth_flavs,
};
struct rpc_message msg = {
.rpc_argp = info->dirpath,
.rpc_resp = &result,
};
struct rpc_create_args args = {
.protocol = info->protocol,
.address = info->sap,
.addrsize = info->salen,
.servername = info->hostname,
.program = &mnt_program,
.version = info->version,
.authflavor = RPC_AUTH_UNIX,
};
struct rpc_clnt *mnt_clnt;
int status;
dprintk("NFS: sending MNT request for %s:%s\n",
(info->hostname ? info->hostname : "server"),
info->dirpath);
if (info->noresvport)
args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
mnt_clnt = rpc_create(&args);
if (IS_ERR(mnt_clnt))
goto out_clnt_err;
if (info->version == NFS_MNT3_VERSION)
msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC3_MNT];
else
msg.rpc_proc = &mnt_clnt->cl_procinfo[MOUNTPROC_MNT];
status = rpc_call_sync(mnt_clnt, &msg, 0);
rpc_shutdown_client(mnt_clnt);
if (status < 0)
goto out_call_err;
if (result.errno != 0)
goto out_mnt_err;
dprintk("NFS: MNT request succeeded\n");
status = 0;
out:
return status;
out_clnt_err:
status = PTR_ERR(mnt_clnt);
dprintk("NFS: failed to create MNT RPC client, status=%d\n", status);
goto out;
out_call_err:
dprintk("NFS: MNT request failed, status=%d\n", status);
goto out;
out_mnt_err:
dprintk("NFS: MNT server returned result %d\n", result.errno);
status = result.errno;
goto out;
}
/**
* nfs_umount - Notify a server that we have unmounted this export
* @info: pointer to umount request arguments
*
* MOUNTPROC_UMNT is advisory, so we set a short timeout, and always
* use UDP.
*/
void nfs_umount(const struct nfs_mount_request *info)
{
static const struct rpc_timeout nfs_umnt_timeout = {
.to_initval = 1 * HZ,
.to_maxval = 3 * HZ,
.to_retries = 2,
};
struct rpc_create_args args = {
.protocol = IPPROTO_UDP,
.address = info->sap,
.addrsize = info->salen,
.timeout = &nfs_umnt_timeout,
.servername = info->hostname,
.program = &mnt_program,
.version = info->version,
.authflavor = RPC_AUTH_UNIX,
.flags = RPC_CLNT_CREATE_NOPING,
};
struct mountres result;
struct rpc_message msg = {
.rpc_argp = info->dirpath,
.rpc_resp = &result,
};
struct rpc_clnt *clnt;
int status;
if (info->noresvport)
args.flags |= RPC_CLNT_CREATE_NONPRIVPORT;
clnt = rpc_create(&args);
if (unlikely(IS_ERR(clnt)))
goto out_clnt_err;
dprintk("NFS: sending UMNT request for %s:%s\n",
(info->hostname ? info->hostname : "server"), info->dirpath);
if (info->version == NFS_MNT3_VERSION)
msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC3_UMNT];
else
msg.rpc_proc = &clnt->cl_procinfo[MOUNTPROC_UMNT];
status = rpc_call_sync(clnt, &msg, 0);
rpc_shutdown_client(clnt);
if (unlikely(status < 0))
goto out_call_err;
return;
out_clnt_err:
dprintk("NFS: failed to create UMNT RPC client, status=%ld\n",
PTR_ERR(clnt));
return;
out_call_err:
dprintk("NFS: UMNT request failed, status=%d\n", status);
}
/*
* XDR encode/decode functions for MOUNT
*/
static int encode_mntdirpath(struct xdr_stream *xdr, const char *pathname)
{
const u32 pathname_len = strlen(pathname);
__be32 *p;
if (unlikely(pathname_len > MNTPATHLEN))
return -EIO;
p = xdr_reserve_space(xdr, sizeof(u32) + pathname_len);
if (unlikely(p == NULL))
return -EIO;
xdr_encode_opaque(p, pathname, pathname_len);
return 0;
}
static int mnt_enc_dirpath(struct rpc_rqst *req, __be32 *p,
const char *dirpath)
{
struct xdr_stream xdr;
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
return encode_mntdirpath(&xdr, dirpath);
}
/*
* RFC 1094: "A non-zero status indicates some sort of error. In this
* case, the status is a UNIX error number." This can be problematic
* if the server and client use different errno values for the same
* error.
*
* However, the OpenGroup XNFS spec provides a simple mapping that is
* independent of local errno values on the server and the client.
*/
static int decode_status(struct xdr_stream *xdr, struct mountres *res)
{
unsigned int i;
u32 status;
__be32 *p;
p = xdr_inline_decode(xdr, sizeof(status));
if (unlikely(p == NULL))
return -EIO;
status = ntohl(*p);
for (i = 0; i < ARRAY_SIZE(mnt_errtbl); i++) {
if (mnt_errtbl[i].status == status) {
res->errno = mnt_errtbl[i].errno;
return 0;
}
}
dprintk("NFS: unrecognized MNT status code: %u\n", status);
res->errno = -EACCES;
return 0;
}
static int decode_fhandle(struct xdr_stream *xdr, struct mountres *res)
{
struct nfs_fh *fh = res->fh;
__be32 *p;
p = xdr_inline_decode(xdr, NFS2_FHSIZE);
if (unlikely(p == NULL))
return -EIO;
fh->size = NFS2_FHSIZE;
memcpy(fh->data, p, NFS2_FHSIZE);
return 0;
}
static int mnt_dec_mountres(struct rpc_rqst *req, __be32 *p,
struct mountres *res)
{
struct xdr_stream xdr;
int status;
xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
status = decode_status(&xdr, res);
if (unlikely(status != 0 || res->errno != 0))
return status;
return decode_fhandle(&xdr, res);
}
static int decode_fhs_status(struct xdr_stream *xdr, struct mountres *res)
{
unsigned int i;
u32 status;
__be32 *p;
p = xdr_inline_decode(xdr, sizeof(status));
if (unlikely(p == NULL))
return -EIO;
status = ntohl(*p);
for (i = 0; i < ARRAY_SIZE(mnt3_errtbl); i++) {
if (mnt3_errtbl[i].status == status) {
res->errno = mnt3_errtbl[i].errno;
return 0;
}
}
dprintk("NFS: unrecognized MNT3 status code: %u\n", status);
res->errno = -EACCES;
return 0;
}
static int decode_fhandle3(struct xdr_stream *xdr, struct mountres *res)
{
struct nfs_fh *fh = res->fh;
u32 size;
__be32 *p;
p = xdr_inline_decode(xdr, sizeof(size));
if (unlikely(p == NULL))
return -EIO;
size = ntohl(*p++);
if (size > NFS3_FHSIZE || size == 0)
return -EIO;
p = xdr_inline_decode(xdr, size);
if (unlikely(p == NULL))
return -EIO;
fh->size = size;
memcpy(fh->data, p, size);
return 0;
}
static int decode_auth_flavors(struct xdr_stream *xdr, struct mountres *res)
{
rpc_authflavor_t *flavors = res->auth_flavors;
unsigned int *count = res->auth_count;
u32 entries, i;
__be32 *p;
if (*count == 0)
return 0;
p = xdr_inline_decode(xdr, sizeof(entries));
if (unlikely(p == NULL))
return -EIO;
entries = ntohl(*p);
dprintk("NFS: received %u auth flavors\n", entries);
if (entries > NFS_MAX_SECFLAVORS)
entries = NFS_MAX_SECFLAVORS;
p = xdr_inline_decode(xdr, sizeof(u32) * entries);
if (unlikely(p == NULL))
return -EIO;
if (entries > *count)
entries = *count;
for (i = 0; i < entries; i++) {
flavors[i] = ntohl(*p++);
dprintk("NFS:\tflavor %u: %d\n", i, flavors[i]);
}
*count = i;
return 0;
}
static int mnt_dec_mountres3(struct rpc_rqst *req, __be32 *p,
struct mountres *res)
{
struct xdr_stream xdr;
int status;
xdr_init_decode(&xdr, &req->rq_rcv_buf, p);
status = decode_fhs_status(&xdr, res);
if (unlikely(status != 0 || res->errno != 0))
return status;
status = decode_fhandle3(&xdr, res);
if (unlikely(status != 0)) {
res->errno = -EBADHANDLE;
return 0;
}
return decode_auth_flavors(&xdr, res);
}
static struct rpc_procinfo mnt_procedures[] = {
[MOUNTPROC_MNT] = {
.p_proc = MOUNTPROC_MNT,
.p_encode = (kxdrproc_t)mnt_enc_dirpath,
.p_decode = (kxdrproc_t)mnt_dec_mountres,
.p_arglen = MNT_enc_dirpath_sz,
.p_replen = MNT_dec_mountres_sz,
.p_statidx = MOUNTPROC_MNT,
.p_name = "MOUNT",
},
[MOUNTPROC_UMNT] = {
.p_proc = MOUNTPROC_UMNT,
.p_encode = (kxdrproc_t)mnt_enc_dirpath,
.p_arglen = MNT_enc_dirpath_sz,
.p_statidx = MOUNTPROC_UMNT,
.p_name = "UMOUNT",
},
};
static struct rpc_procinfo mnt3_procedures[] = {
[MOUNTPROC3_MNT] = {
.p_proc = MOUNTPROC3_MNT,
.p_encode = (kxdrproc_t)mnt_enc_dirpath,
.p_decode = (kxdrproc_t)mnt_dec_mountres3,
.p_arglen = MNT_enc_dirpath_sz,
.p_replen = MNT_dec_mountres3_sz,
.p_statidx = MOUNTPROC3_MNT,
.p_name = "MOUNT",
},
[MOUNTPROC3_UMNT] = {
.p_proc = MOUNTPROC3_UMNT,
.p_encode = (kxdrproc_t)mnt_enc_dirpath,
.p_arglen = MNT_enc_dirpath_sz,
.p_statidx = MOUNTPROC3_UMNT,
.p_name = "UMOUNT",
},
};
static struct rpc_version mnt_version1 = {
.number = 1,
.nrprocs = 2,
.procs = mnt_procedures,
};
static struct rpc_version mnt_version3 = {
.number = 3,
.nrprocs = 2,
.procs = mnt3_procedures,
};
static struct rpc_version *mnt_version[] = {
NULL,
&mnt_version1,
NULL,
&mnt_version3,
};
static struct rpc_stat mnt_stats;
static struct rpc_program mnt_program = {
.name = "mount",
.number = NFS_MNT_PROGRAM,
.nrvers = ARRAY_SIZE(mnt_version),
.version = mnt_version,
.stats = &mnt_stats,
};