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linux/fs/nfsd/nfs4callback.c
J. Bruce Fields cfdcad4da1 knfsd: nfsv4 delegation recall should take reference on client 
It's not enough to take a reference on the delegation object itself; we
need to ensure that the rpc_client won't go away just as we're about to
make an rpc call.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2007-10-09 18:31:57 -04:00

493 lines
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/*
* linux/fs/nfsd/nfs4callback.c
*
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* Kendrick Smith <kmsmith@umich.edu>
* Andy Adamson <andros@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/module.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/state.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs4.h>
#define NFSDDBG_FACILITY NFSDDBG_PROC
#define NFSPROC4_CB_NULL 0
#define NFSPROC4_CB_COMPOUND 1
/* declarations */
static const struct rpc_call_ops nfs4_cb_null_ops;
/* Index of predefined Linux callback client operations */
enum {
NFSPROC4_CLNT_CB_NULL = 0,
NFSPROC4_CLNT_CB_RECALL,
};
enum nfs_cb_opnum4 {
OP_CB_RECALL = 4,
};
#define NFS4_MAXTAGLEN 20
#define NFS4_enc_cb_null_sz 0
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
op_dec_sz)
/*
* Generic encode routines from fs/nfs/nfs4xdr.c
*/
static inline __be32 *
xdr_writemem(__be32 *p, const void *ptr, int nbytes)
{
int tmp = XDR_QUADLEN(nbytes);
if (!tmp)
return p;
p[tmp-1] = 0;
memcpy(p, ptr, nbytes);
return p + tmp;
}
#define WRITE32(n) *p++ = htonl(n)
#define WRITEMEM(ptr,nbytes) do { \
p = xdr_writemem(p, ptr, nbytes); \
} while (0)
#define RESERVE_SPACE(nbytes) do { \
p = xdr_reserve_space(xdr, nbytes); \
if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __FUNCTION__); \
BUG_ON(!p); \
} while (0)
/*
* Generic decode routines from fs/nfs/nfs4xdr.c
*/
#define DECODE_TAIL \
status = 0; \
out: \
return status; \
xdr_error: \
dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
status = -EIO; \
goto out
#define READ32(x) (x) = ntohl(*p++)
#define READ64(x) do { \
(x) = (u64)ntohl(*p++) << 32; \
(x) |= ntohl(*p++); \
} while (0)
#define READTIME(x) do { \
p++; \
(x.tv_sec) = ntohl(*p++); \
(x.tv_nsec) = ntohl(*p++); \
} while (0)
#define READ_BUF(nbytes) do { \
p = xdr_inline_decode(xdr, nbytes); \
if (!p) { \
dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
__FUNCTION__, __LINE__); \
return -EIO; \
} \
} while (0)
struct nfs4_cb_compound_hdr {
int status;
u32 ident;
u32 nops;
u32 taglen;
char * tag;
};
static struct {
int stat;
int errno;
} nfs_cb_errtbl[] = {
{ NFS4_OK, 0 },
{ NFS4ERR_PERM, EPERM },
{ NFS4ERR_NOENT, ENOENT },
{ NFS4ERR_IO, EIO },
{ NFS4ERR_NXIO, ENXIO },
{ NFS4ERR_ACCESS, EACCES },
{ NFS4ERR_EXIST, EEXIST },
{ NFS4ERR_XDEV, EXDEV },
{ NFS4ERR_NOTDIR, ENOTDIR },
{ NFS4ERR_ISDIR, EISDIR },
{ NFS4ERR_INVAL, EINVAL },
{ NFS4ERR_FBIG, EFBIG },
{ NFS4ERR_NOSPC, ENOSPC },
{ NFS4ERR_ROFS, EROFS },
{ NFS4ERR_MLINK, EMLINK },
{ NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
{ NFS4ERR_NOTEMPTY, ENOTEMPTY },
{ NFS4ERR_DQUOT, EDQUOT },
{ NFS4ERR_STALE, ESTALE },
{ NFS4ERR_BADHANDLE, EBADHANDLE },
{ NFS4ERR_BAD_COOKIE, EBADCOOKIE },
{ NFS4ERR_NOTSUPP, ENOTSUPP },
{ NFS4ERR_TOOSMALL, ETOOSMALL },
{ NFS4ERR_SERVERFAULT, ESERVERFAULT },
{ NFS4ERR_BADTYPE, EBADTYPE },
{ NFS4ERR_LOCKED, EAGAIN },
{ NFS4ERR_RESOURCE, EREMOTEIO },
{ NFS4ERR_SYMLINK, ELOOP },
{ NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
{ NFS4ERR_DEADLOCK, EDEADLK },
{ -1, EIO }
};
static int
nfs_cb_stat_to_errno(int stat)
{
int i;
for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
if (nfs_cb_errtbl[i].stat == stat)
return nfs_cb_errtbl[i].errno;
}
/* If we cannot translate the error, the recovery routines should
* handle it.
* Note: remaining NFSv4 error codes have values > 10000, so should
* not conflict with native Linux error codes.
*/
return stat;
}
/*
* XDR encode
*/
static int
encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
{
__be32 * p;
RESERVE_SPACE(16);
WRITE32(0); /* tag length is always 0 */
WRITE32(NFS4_MINOR_VERSION);
WRITE32(hdr->ident);
WRITE32(hdr->nops);
return 0;
}
static int
encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
{
__be32 *p;
int len = cb_rec->cbr_fhlen;
RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
WRITE32(OP_CB_RECALL);
WRITEMEM(&cb_rec->cbr_stateid, sizeof(stateid_t));
WRITE32(cb_rec->cbr_trunc);
WRITE32(len);
WRITEMEM(cb_rec->cbr_fhval, len);
return 0;
}
static int
nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
{
struct xdr_stream xdrs, *xdr = &xdrs;
xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
RESERVE_SPACE(0);
return 0;
}
static int
nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
{
struct xdr_stream xdr;
struct nfs4_cb_compound_hdr hdr = {
.ident = args->cbr_ident,
.nops = 1,
};
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
encode_cb_compound_hdr(&xdr, &hdr);
return (encode_cb_recall(&xdr, args));
}
static int
decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
__be32 *p;
READ_BUF(8);
READ32(hdr->status);
READ32(hdr->taglen);
READ_BUF(hdr->taglen + 4);
hdr->tag = (char *)p;
p += XDR_QUADLEN(hdr->taglen);
READ32(hdr->nops);
return 0;
}
static int
decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
{
__be32 *p;
u32 op;
int32_t nfserr;
READ_BUF(8);
READ32(op);
if (op != expected) {
dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
" operation %d but we issued a request for %d\n",
op, expected);
return -EIO;
}
READ32(nfserr);
if (nfserr != NFS_OK)
return -nfs_cb_stat_to_errno(nfserr);
return 0;
}
static int
nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
{
return 0;
}
static int
nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
{
struct xdr_stream xdr;
struct nfs4_cb_compound_hdr hdr;
int status;
xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
status = decode_cb_compound_hdr(&xdr, &hdr);
if (status)
goto out;
status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
out:
return status;
}
/*
* RPC procedure tables
*/
#define PROC(proc, call, argtype, restype) \
[NFSPROC4_CLNT_##proc] = { \
.p_proc = NFSPROC4_CB_##call, \
.p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
.p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
.p_arglen = NFS4_##argtype##_sz, \
.p_replen = NFS4_##restype##_sz, \
.p_statidx = NFSPROC4_CB_##call, \
.p_name = #proc, \
}
static struct rpc_procinfo nfs4_cb_procedures[] = {
PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
};
static struct rpc_version nfs_cb_version4 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
.procs = nfs4_cb_procedures
};
static struct rpc_version * nfs_cb_version[] = {
NULL,
&nfs_cb_version4,
};
/* Reference counting, callback cleanup, etc., all look racy as heck.
* And why is cb_set an atomic? */
static int do_probe_callback(void *data)
{
struct nfs4_client *clp = data;
struct nfs4_callback *cb = &clp->cl_callback;
struct rpc_message msg = {
.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
.rpc_argp = clp,
};
int status;
status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
if (status) {
rpc_shutdown_client(cb->cb_client);
cb->cb_client = NULL;
} else
atomic_set(&cb->cb_set, 1);
put_nfs4_client(clp);
return 0;
}
/*
* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
*/
void
nfsd4_probe_callback(struct nfs4_client *clp)
{
struct sockaddr_in addr;
struct nfs4_callback *cb = &clp->cl_callback;
struct rpc_timeout timeparms = {
.to_initval = (NFSD_LEASE_TIME/4) * HZ,
.to_retries = 5,
.to_maxval = (NFSD_LEASE_TIME/2) * HZ,
.to_exponential = 1,
};
struct rpc_program * program = &cb->cb_program;
struct rpc_create_args args = {
.protocol = IPPROTO_TCP,
.address = (struct sockaddr *)&addr,
.addrsize = sizeof(addr),
.timeout = &timeparms,
.program = program,
.version = nfs_cb_version[1]->number,
.authflavor = RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
.flags = (RPC_CLNT_CREATE_NOPING),
};
struct task_struct *t;
if (atomic_read(&cb->cb_set))
return;
/* Initialize address */
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(cb->cb_port);
addr.sin_addr.s_addr = htonl(cb->cb_addr);
/* Initialize rpc_program */
program->name = "nfs4_cb";
program->number = cb->cb_prog;
program->nrvers = ARRAY_SIZE(nfs_cb_version);
program->version = nfs_cb_version;
program->stats = &cb->cb_stat;
/* Initialize rpc_stat */
memset(program->stats, 0, sizeof(cb->cb_stat));
program->stats->program = program;
/* Create RPC client */
cb->cb_client = rpc_create(&args);
if (IS_ERR(cb->cb_client)) {
dprintk("NFSD: couldn't create callback client\n");
goto out_err;
}
/* the task holds a reference to the nfs4_client struct */
atomic_inc(&clp->cl_count);
t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
if (IS_ERR(t))
goto out_release_clp;
return;
out_release_clp:
atomic_dec(&clp->cl_count);
rpc_shutdown_client(cb->cb_client);
out_err:
cb->cb_client = NULL;
dprintk("NFSD: warning: no callback path to client %.*s\n",
(int)clp->cl_name.len, clp->cl_name.data);
}
/*
* called with dp->dl_count inc'ed.
* nfs4_lock_state() may or may not have been called.
*/
void
nfsd4_cb_recall(struct nfs4_delegation *dp)
{
struct nfs4_client *clp = dp->dl_client;
struct rpc_clnt *clnt = clp->cl_callback.cb_client;
struct nfs4_cb_recall *cbr = &dp->dl_recall;
struct rpc_message msg = {
.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
.rpc_argp = cbr,
};
int retries = 1;
int status = 0;
if ((!atomic_read(&clp->cl_callback.cb_set)) || !clnt)
return;
cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
cbr->cbr_dp = dp;
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
while (retries--) {
switch (status) {
case -EIO:
/* Network partition? */
case -EBADHANDLE:
case -NFS4ERR_BAD_STATEID:
/* Race: client probably got cb_recall
* before open reply granting delegation */
break;
default:
goto out_put_cred;
}
ssleep(2);
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
}
out_put_cred:
if (status == -EIO)
atomic_set(&clp->cl_callback.cb_set, 0);
/* Success or failure, now we're either waiting for lease expiration
* or deleg_return. */
dprintk("NFSD: nfs4_cb_recall: dp %p dl_flock %p dl_count %d\n",dp, dp->dl_flock, atomic_read(&dp->dl_count));
put_nfs4_client(clp);
nfs4_put_delegation(dp);
return;
}
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