[net-next-2.6.git] / fs / nfsd / nfs4callback.c

/*
 *  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), __func__); \
	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", \
			__func__, __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);
	WRITE32(cb_rec->cbr_stateid.si_generation);
	WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_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,
};

static struct rpc_program cb_program;

static struct rpc_stat cb_stats = {
		.program	= &cb_program
};

#define NFS4_CALLBACK 0x40000000
static struct rpc_program cb_program = {
		.name 		= "nfs4_cb",
		.number		= NFS4_CALLBACK,
		.nrvers		= ARRAY_SIZE(nfs_cb_version),
		.version	= nfs_cb_version,
		.stats		= &cb_stats,
};

/* 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 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_create_args args = {
		.protocol	= IPPROTO_TCP,
		.address	= (struct sockaddr *)&addr,
		.addrsize	= sizeof(addr),
		.timeout	= &timeparms,
		.program	= &cb_program,
		.version	= nfs_cb_version[1]->number,
		.authflavor	= RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
	};
	struct rpc_message msg = {
		.rpc_proc       = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
		.rpc_argp       = clp,
	};
	struct rpc_clnt *client;
	int status;

	/* 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);

	/* Create RPC client */
	client = rpc_create(&args);
	if (IS_ERR(client)) {
		dprintk("NFSD: couldn't create callback client\n");
		status = PTR_ERR(client);
		goto out_err;
	}

	status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);

	if (status)
		goto out_release_client;

	cb->cb_client = client;
	atomic_set(&cb->cb_set, 1);
	put_nfs4_client(clp);
	return 0;
out_release_client:
	rpc_shutdown_client(client);
out_err:
	dprintk("NFSD: warning: no callback path to client %.*s\n",
		(int)clp->cl_name.len, clp->cl_name.data);
	put_nfs4_client(clp);
	return status;
}

/*
 * Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
 */
void
nfsd4_probe_callback(struct nfs4_client *clp)
{
	struct task_struct *t;

	BUG_ON(atomic_read(&clp->cl_callback.cb_set));

	/* 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))
		atomic_dec(&clp->cl_count);

	return;
}

/*
 * 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;

	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? */
				atomic_set(&clp->cl_callback.cb_set, 0);
			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:
	/*
	 * Success or failure, now we're either waiting for lease expiration
	 * or deleg_return.
	 */
	put_nfs4_client(clp);
	nfs4_put_delegation(dp);
	return;
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/fs/nfsd/nfs4callback.c
	3	*
	4	* Copyright (c) 2001 The Regents of the University of Michigan.
	5	* All rights reserved.
	6	*
	7	* Kendrick Smith <kmsmith@umich.edu>
	8	* Andy Adamson <andros@umich.edu>
	9	*
	10	* Redistribution and use in source and binary forms, with or without
	11	* modification, are permitted provided that the following conditions
	12	* are met:
	13	*
	14	* 1. Redistributions of source code must retain the above copyright
	15	* notice, this list of conditions and the following disclaimer.
	16	* 2. Redistributions in binary form must reproduce the above copyright
	17	* notice, this list of conditions and the following disclaimer in the
	18	* documentation and/or other materials provided with the distribution.
	19	* 3. Neither the name of the University nor the names of its
	20	* contributors may be used to endorse or promote products derived
	21	* from this software without specific prior written permission.
	22	*
	23	* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
	24	* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
	25	* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
	26	* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	27	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
	28	* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
	29	* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
	30	* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
	31	* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
	32	* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
	33	* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	34	*/
	35
1da177e4 LT	36	#include <linux/module.h>
	37	#include <linux/list.h>
	38	#include <linux/inet.h>
	39	#include <linux/errno.h>
	40	#include <linux/delay.h>
e8edc6e0	41	#include <linux/sched.h>
2b47eece	42	#include <linux/kthread.h>
1da177e4 LT	43	#include <linux/sunrpc/xdr.h>
	44	#include <linux/sunrpc/svc.h>
	45	#include <linux/sunrpc/clnt.h>
	46	#include <linux/nfsd/nfsd.h>
	47	#include <linux/nfsd/state.h>
	48	#include <linux/sunrpc/sched.h>
	49	#include <linux/nfs4.h>
	50
	51	#define NFSDDBG_FACILITY NFSDDBG_PROC
	52
	53	#define NFSPROC4_CB_NULL 0
	54	#define NFSPROC4_CB_COMPOUND 1
	55
	56	/* declarations */
963d8fe5	57	static const struct rpc_call_ops nfs4_cb_null_ops;
1da177e4 LT	58
	59	/* Index of predefined Linux callback client operations */
	60
	61	enum {
	62	NFSPROC4_CLNT_CB_NULL = 0,
	63	NFSPROC4_CLNT_CB_RECALL,
	64	};
	65
	66	enum nfs_cb_opnum4 {
	67	OP_CB_RECALL = 4,
	68	};
	69
	70	#define NFS4_MAXTAGLEN 20
	71
	72	#define NFS4_enc_cb_null_sz 0
	73	#define NFS4_dec_cb_null_sz 0
	74	#define cb_compound_enc_hdr_sz 4
	75	#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
	76	#define op_enc_sz 1
	77	#define op_dec_sz 2
	78	#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
0ac68d17	79	#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
1da177e4 LT	80	#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
	81	1 + enc_stateid_sz + \
	82	enc_nfs4_fh_sz)
	83
	84	#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
	85	op_dec_sz)
	86
	87	/*
	88	* Generic encode routines from fs/nfs/nfs4xdr.c
	89	*/
f00f328f AV	90	static inline __be32 *
f00f328f AV	91	xdr_writemem(__be32 p, const void ptr, int nbytes)
1da177e4 LT	92	{
	93	int tmp = XDR_QUADLEN(nbytes);
	94	if (!tmp)
	95	return p;
	96	p[tmp-1] = 0;
	97	memcpy(p, ptr, nbytes);
	98	return p + tmp;
	99	}
	100
	101	#define WRITE32(n) *p++ = htonl(n)
	102	#define WRITEMEM(ptr,nbytes) do { \
	103	p = xdr_writemem(p, ptr, nbytes); \
	104	} while (0)
	105	#define RESERVE_SPACE(nbytes) do { \
	106	p = xdr_reserve_space(xdr, nbytes); \
8e24eea7	107	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
1da177e4 LT	108	BUG_ON(!p); \
	109	} while (0)
	110
	111	/*
	112	* Generic decode routines from fs/nfs/nfs4xdr.c
	113	*/
	114	#define DECODE_TAIL \
	115	status = 0; \
	116	out: \
	117	return status; \
	118	xdr_error: \
	119	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
	120	status = -EIO; \
	121	goto out
	122
	123	#define READ32(x) (x) = ntohl(*p++)
	124	#define READ64(x) do { \
	125	(x) = (u64)ntohl(*p++) << 32; \
	126	(x) \|= ntohl(*p++); \
	127	} while (0)
	128	#define READTIME(x) do { \
	129	p++; \
	130	(x.tv_sec) = ntohl(*p++); \
	131	(x.tv_nsec) = ntohl(*p++); \
	132	} while (0)
	133	#define READ_BUF(nbytes) do { \
	134	p = xdr_inline_decode(xdr, nbytes); \
	135	if (!p) { \
3e3b4800	136	dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
8e24eea7	137	__func__, __LINE__); \
1da177e4 LT	138	return -EIO; \
	139	} \
	140	} while (0)
	141
	142	struct nfs4_cb_compound_hdr {
	143	int status;
	144	u32 ident;
	145	u32 nops;
	146	u32 taglen;
	147	char * tag;
	148	};
	149
	150	static struct {
	151	int stat;
	152	int errno;
	153	} nfs_cb_errtbl[] = {
	154	{ NFS4_OK, 0 },
	155	{ NFS4ERR_PERM, EPERM },
	156	{ NFS4ERR_NOENT, ENOENT },
	157	{ NFS4ERR_IO, EIO },
	158	{ NFS4ERR_NXIO, ENXIO },
	159	{ NFS4ERR_ACCESS, EACCES },
	160	{ NFS4ERR_EXIST, EEXIST },
	161	{ NFS4ERR_XDEV, EXDEV },
	162	{ NFS4ERR_NOTDIR, ENOTDIR },
	163	{ NFS4ERR_ISDIR, EISDIR },
	164	{ NFS4ERR_INVAL, EINVAL },
	165	{ NFS4ERR_FBIG, EFBIG },
	166	{ NFS4ERR_NOSPC, ENOSPC },
	167	{ NFS4ERR_ROFS, EROFS },
	168	{ NFS4ERR_MLINK, EMLINK },
	169	{ NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
	170	{ NFS4ERR_NOTEMPTY, ENOTEMPTY },
	171	{ NFS4ERR_DQUOT, EDQUOT },
	172	{ NFS4ERR_STALE, ESTALE },
	173	{ NFS4ERR_BADHANDLE, EBADHANDLE },
	174	{ NFS4ERR_BAD_COOKIE, EBADCOOKIE },
	175	{ NFS4ERR_NOTSUPP, ENOTSUPP },
	176	{ NFS4ERR_TOOSMALL, ETOOSMALL },
	177	{ NFS4ERR_SERVERFAULT, ESERVERFAULT },
	178	{ NFS4ERR_BADTYPE, EBADTYPE },
	179	{ NFS4ERR_LOCKED, EAGAIN },
	180	{ NFS4ERR_RESOURCE, EREMOTEIO },
	181	{ NFS4ERR_SYMLINK, ELOOP },
	182	{ NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
	183	{ NFS4ERR_DEADLOCK, EDEADLK },
	184	{ -1, EIO }
	185	};
	186
	187	static int
	188	nfs_cb_stat_to_errno(int stat)
	189	{
	190	int i;
	191	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
	192	if (nfs_cb_errtbl[i].stat == stat)
	193	return nfs_cb_errtbl[i].errno;
	194	}
	195	/* If we cannot translate the error, the recovery routines should
	196	* handle it.
	197	* Note: remaining NFSv4 error codes have values > 10000, so should
	198	* not conflict with native Linux error codes.
	199	*/
	200	return stat;
	201	}
202
203	/*
204	* XDR encode
205	*/
206
207	static int
208	encode_cb_compound_hdr(struct xdr_stream xdr, struct nfs4_cb_compound_hdr hdr)
209	{
f00f328f	210	__be32 * p;
1da177e4 LT	211
	212	RESERVE_SPACE(16);
	213	WRITE32(0); /* tag length is always 0 */
	214	WRITE32(NFS4_MINOR_VERSION);
	215	WRITE32(hdr->ident);
	216	WRITE32(hdr->nops);
	217	return 0;
	218	}
	219
	220	static int
	221	encode_cb_recall(struct xdr_stream xdr, struct nfs4_cb_recall cb_rec)
	222	{
f00f328f	223	__be32 *p;
1da177e4 LT	224	int len = cb_rec->cbr_fhlen;
	225
	226	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
	227	WRITE32(OP_CB_RECALL);
8e407414 BH	228	WRITE32(cb_rec->cbr_stateid.si_generation);
8e407414 BH	229	WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t));
1da177e4 LT	230	WRITE32(cb_rec->cbr_trunc);
	231	WRITE32(len);
	232	WRITEMEM(cb_rec->cbr_fhval, len);
	233	return 0;
	234	}
	235
	236	static int
f00f328f	237	nfs4_xdr_enc_cb_null(struct rpc_rqst req, __be32 p)
1da177e4 LT	238	{
	239	struct xdr_stream xdrs, *xdr = &xdrs;
	240
	241	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
	242	RESERVE_SPACE(0);
	243	return 0;
	244	}
	245
	246	static int
f00f328f	247	nfs4_xdr_enc_cb_recall(struct rpc_rqst req, __be32 p, struct nfs4_cb_recall *args)
1da177e4 LT	248	{
	249	struct xdr_stream xdr;
	250	struct nfs4_cb_compound_hdr hdr = {
	251	.ident = args->cbr_ident,
	252	.nops = 1,
	253	};
	254
	255	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	256	encode_cb_compound_hdr(&xdr, &hdr);
	257	return (encode_cb_recall(&xdr, args));
	258	}
	259
	260
	261	static int
	262	decode_cb_compound_hdr(struct xdr_stream xdr, struct nfs4_cb_compound_hdr hdr){
f00f328f	263	__be32 *p;
1da177e4 LT	264
	265	READ_BUF(8);
	266	READ32(hdr->status);
	267	READ32(hdr->taglen);
	268	READ_BUF(hdr->taglen + 4);
	269	hdr->tag = (char *)p;
	270	p += XDR_QUADLEN(hdr->taglen);
	271	READ32(hdr->nops);
	272	return 0;
	273	}
	274
	275	static int
	276	decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
	277	{
f00f328f	278	__be32 *p;
1da177e4 LT	279	u32 op;
	280	int32_t nfserr;
	281
	282	READ_BUF(8);
	283	READ32(op);
	284	if (op != expected) {
	285	dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
	286	" operation %d but we issued a request for %d\n",
	287	op, expected);
	288	return -EIO;
	289	}
	290	READ32(nfserr);
	291	if (nfserr != NFS_OK)
	292	return -nfs_cb_stat_to_errno(nfserr);
	293	return 0;
	294	}
	295
	296	static int
f00f328f	297	nfs4_xdr_dec_cb_null(struct rpc_rqst req, __be32 p)
1da177e4 LT	298	{
	299	return 0;
	300	}
	301
	302	static int
f00f328f	303	nfs4_xdr_dec_cb_recall(struct rpc_rqst rqstp, __be32 p)
1da177e4 LT	304	{
	305	struct xdr_stream xdr;
	306	struct nfs4_cb_compound_hdr hdr;
	307	int status;
	308
	309	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	310	status = decode_cb_compound_hdr(&xdr, &hdr);
	311	if (status)
	312	goto out;
	313	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
	314	out:
	315	return status;
	316	}
	317
	318	/*
	319	* RPC procedure tables
	320	*/
1da177e4 LT	321	#define PROC(proc, call, argtype, restype) \
	322	[NFSPROC4_CLNT_##proc] = { \
	323	.p_proc = NFSPROC4_CB_##call, \
	324	.p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
	325	.p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
2bea90d4 CL	326	.p_arglen = NFS4_##argtype##_sz, \
2bea90d4 CL	327	.p_replen = NFS4_##restype##_sz, \
cc0175c1 CL	328	.p_statidx = NFSPROC4_CB_##call, \
cc0175c1 CL	329	.p_name = #proc, \
1da177e4 LT	330	}
1da177e4 LT	331
fd39ca9a	332	static struct rpc_procinfo nfs4_cb_procedures[] = {
1da177e4 LT	333	PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
	334	PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
	335	};
	336
fd39ca9a	337	static struct rpc_version nfs_cb_version4 = {
1da177e4	338	.number = 1,
e8c96f8c	339	.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
1da177e4 LT	340	.procs = nfs4_cb_procedures
	341	};
	342
	343	static struct rpc_version * nfs_cb_version[] = {
	344	NULL,
	345	&nfs_cb_version4,
	346	};
	347
ff7d9756 OK	348	static struct rpc_program cb_program;
	349
	350	static struct rpc_stat cb_stats = {
	351	.program = &cb_program
	352	};
	353
	354	#define NFS4_CALLBACK 0x40000000
	355	static struct rpc_program cb_program = {
	356	.name = "nfs4_cb",
	357	.number = NFS4_CALLBACK,
	358	.nrvers = ARRAY_SIZE(nfs_cb_version),
	359	.version = nfs_cb_version,
	360	.stats = &cb_stats,
	361	};
	362
2b47eece BF	363	/* Reference counting, callback cleanup, etc., all look racy as heck.
	364	* And why is cb_set an atomic? */
	365
	366	static int do_probe_callback(void *data)
	367	{
	368	struct nfs4_client *clp = data;
1da177e4 LT	369	struct sockaddr_in addr;
1da177e4 LT	370	struct nfs4_callback *cb = &clp->cl_callback;
ae5c7947 CL	371	struct rpc_timeout timeparms = {
	372	.to_initval = (NFSD_LEASE_TIME/4) * HZ,
	373	.to_retries = 5,
	374	.to_maxval = (NFSD_LEASE_TIME/2) * HZ,
	375	.to_exponential = 1,
	376	};
ae5c7947 CL	377	struct rpc_create_args args = {
	378	.protocol = IPPROTO_TCP,
	379	.address = (struct sockaddr *)&addr,
	380	.addrsize = sizeof(addr),
	381	.timeout = &timeparms,
ff7d9756	382	.program = &cb_program,
ae5c7947	383	.version = nfs_cb_version[1]->number,
63c86716	384	.authflavor = RPC_AUTH_UNIX, /* XXX: need AUTH_GSS... */
b6b6152c	385	.flags = (RPC_CLNT_CREATE_NOPING \| RPC_CLNT_CREATE_QUIET),
ae5c7947	386	};
63c86716 BF	387	struct rpc_message msg = {
	388	.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
	389	.rpc_argp = clp,
	390	};
	391	struct rpc_clnt *client;
	392	int status;
1da177e4 LT	393
	394	/* Initialize address */
	395	memset(&addr, 0, sizeof(addr));
	396	addr.sin_family = AF_INET;
	397	addr.sin_port = htons(cb->cb_port);
	398	addr.sin_addr.s_addr = htonl(cb->cb_addr);
	399
ae5c7947	400	/* Create RPC client */
63c86716 BF	401	client = rpc_create(&args);
63c86716 BF	402	if (IS_ERR(client)) {
1da177e4	403	dprintk("NFSD: couldn't create callback client\n");
63c86716	404	status = PTR_ERR(client);
5b616f5d	405	goto out_err;
1da177e4	406	}
1da177e4	407
63c86716 BF	408	status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
	409
	410	if (status)
	411	goto out_release_client;
	412
	413	cb->cb_client = client;
	414	atomic_set(&cb->cb_set, 1);
	415	put_nfs4_client(clp);
	416	return 0;
	417	out_release_client:
	418	rpc_shutdown_client(client);
	419	out_err:
63c86716 BF	420	dprintk("NFSD: warning: no callback path to client %.*s\n",
63c86716 BF	421	(int)clp->cl_name.len, clp->cl_name.data);
88dd0be3	422	put_nfs4_client(clp);
63c86716 BF	423	return status;
	424	}
	425
	426	/*
	427	* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
	428	*/
	429	void
	430	nfsd4_probe_callback(struct nfs4_client *clp)
	431	{
	432	struct task_struct *t;
	433
	434	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
	435
541e0e09	436	/* the task holds a reference to the nfs4_client struct */
1da177e4 LT	437	atomic_inc(&clp->cl_count);
1da177e4 LT	438
2b47eece	439	t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
1da177e4	440
2b47eece	441	if (IS_ERR(t))
63c86716	442	atomic_dec(&clp->cl_count);
2b47eece	443
1da177e4	444	return;
1da177e4 LT	445	}
1da177e4 LT	446
1da177e4 LT	447	/*
	448	* called with dp->dl_count inc'ed.
	449	* nfs4_lock_state() may or may not have been called.
	450	*/
	451	void
	452	nfsd4_cb_recall(struct nfs4_delegation *dp)
	453	{
	454	struct nfs4_client *clp = dp->dl_client;
	455	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
	456	struct nfs4_cb_recall *cbr = &dp->dl_recall;
	457	struct rpc_message msg = {
	458	.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
	459	.rpc_argp = cbr,
	460	};
	461	int retries = 1;
	462	int status = 0;
	463
1da177e4 LT	464	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
	465	cbr->cbr_dp = dp;
	466
	467	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	468	while (retries--) {
	469	switch (status) {
	470	case -EIO:
	471	/* Network partition? */
404ec117	472	atomic_set(&clp->cl_callback.cb_set, 0);
1da177e4 LT	473	case -EBADHANDLE:
	474	case -NFS4ERR_BAD_STATEID:
	475	/* Race: client probably got cb_recall
	476	* before open reply granting delegation */
	477	break;
	478	default:
	479	goto out_put_cred;
	480	}
	481	ssleep(2);
	482	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	483	}
	484	out_put_cred:
404ec117 BF	485	/*
	486	* Success or failure, now we're either waiting for lease expiration
	487	* or deleg_return.
	488	*/
cfdcad4d	489	put_nfs4_client(clp);
1da177e4 LT	490	nfs4_put_delegation(dp);
	491	return;
	492	}