[deliverable/linux.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

/* 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_fh.fh_size;

	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_fh.fh_base, 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,
		.pipe_dir_name  = "/nfsd4_cb",
};

/* Reference counting, callback cleanup, etc., all look racy as heck.
 * And why is cb_set an atomic? */

static struct rpc_clnt *setup_callback_client(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_create_args args = {
		.protocol	= IPPROTO_TCP,
		.address	= (struct sockaddr *)&addr,
		.addrsize	= sizeof(addr),
		.timeout	= &timeparms,
		.program	= &cb_program,
		.prognumber	= cb->cb_prog,
		.version	= nfs_cb_version[1]->number,
		.authflavor	= clp->cl_flavor,
		.flags		= (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
		.client_name    = clp->cl_principal,
	};
	struct rpc_clnt *client;

	if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
		return ERR_PTR(-EINVAL);

	/* 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: %ld\n",
			PTR_ERR(client));
	return client;

}

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,
	};
	struct rpc_clnt *client;
	int status;

	client = setup_callback_client(clp);
	if (IS_ERR(client)) {
		status = PTR_ERR(client);
		dprintk("NFSD: couldn't create callback client: %d\n",
								status);
		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: error %d\n",
		(int)clp->cl_name.len, clp->cl_name.data, status);
	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 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.
 */
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
1da177e4 LT	56	/* Index of predefined Linux callback client operations */
	57
	58	enum {
	59	NFSPROC4_CLNT_CB_NULL = 0,
	60	NFSPROC4_CLNT_CB_RECALL,
	61	};
	62
	63	enum nfs_cb_opnum4 {
	64	OP_CB_RECALL = 4,
	65	};
	66
	67	#define NFS4_MAXTAGLEN 20
	68
	69	#define NFS4_enc_cb_null_sz 0
	70	#define NFS4_dec_cb_null_sz 0
	71	#define cb_compound_enc_hdr_sz 4
	72	#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
	73	#define op_enc_sz 1
	74	#define op_dec_sz 2
	75	#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
0ac68d17	76	#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
1da177e4 LT	77	#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
	78	1 + enc_stateid_sz + \
	79	enc_nfs4_fh_sz)
	80
	81	#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
	82	op_dec_sz)
	83
	84	/*
	85	* Generic encode routines from fs/nfs/nfs4xdr.c
	86	*/
f00f328f AV	87	static inline __be32 *
f00f328f AV	88	xdr_writemem(__be32 p, const void ptr, int nbytes)
1da177e4 LT	89	{
	90	int tmp = XDR_QUADLEN(nbytes);
	91	if (!tmp)
	92	return p;
	93	p[tmp-1] = 0;
	94	memcpy(p, ptr, nbytes);
	95	return p + tmp;
	96	}
	97
	98	#define WRITE32(n) *p++ = htonl(n)
	99	#define WRITEMEM(ptr,nbytes) do { \
	100	p = xdr_writemem(p, ptr, nbytes); \
	101	} while (0)
	102	#define RESERVE_SPACE(nbytes) do { \
	103	p = xdr_reserve_space(xdr, nbytes); \
8e24eea7	104	if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
1da177e4 LT	105	BUG_ON(!p); \
	106	} while (0)
	107
	108	/*
	109	* Generic decode routines from fs/nfs/nfs4xdr.c
	110	*/
	111	#define DECODE_TAIL \
	112	status = 0; \
	113	out: \
	114	return status; \
	115	xdr_error: \
	116	dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
	117	status = -EIO; \
	118	goto out
	119
	120	#define READ32(x) (x) = ntohl(*p++)
	121	#define READ64(x) do { \
	122	(x) = (u64)ntohl(*p++) << 32; \
	123	(x) \|= ntohl(*p++); \
	124	} while (0)
	125	#define READTIME(x) do { \
	126	p++; \
	127	(x.tv_sec) = ntohl(*p++); \
	128	(x.tv_nsec) = ntohl(*p++); \
	129	} while (0)
	130	#define READ_BUF(nbytes) do { \
	131	p = xdr_inline_decode(xdr, nbytes); \
	132	if (!p) { \
3e3b4800	133	dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
8e24eea7	134	__func__, __LINE__); \
1da177e4 LT	135	return -EIO; \
	136	} \
	137	} while (0)
	138
	139	struct nfs4_cb_compound_hdr {
	140	int status;
	141	u32 ident;
	142	u32 nops;
	143	u32 taglen;
	144	char * tag;
	145	};
	146
	147	static struct {
	148	int stat;
	149	int errno;
	150	} nfs_cb_errtbl[] = {
	151	{ NFS4_OK, 0 },
	152	{ NFS4ERR_PERM, EPERM },
	153	{ NFS4ERR_NOENT, ENOENT },
	154	{ NFS4ERR_IO, EIO },
	155	{ NFS4ERR_NXIO, ENXIO },
	156	{ NFS4ERR_ACCESS, EACCES },
	157	{ NFS4ERR_EXIST, EEXIST },
	158	{ NFS4ERR_XDEV, EXDEV },
	159	{ NFS4ERR_NOTDIR, ENOTDIR },
	160	{ NFS4ERR_ISDIR, EISDIR },
	161	{ NFS4ERR_INVAL, EINVAL },
	162	{ NFS4ERR_FBIG, EFBIG },
	163	{ NFS4ERR_NOSPC, ENOSPC },
	164	{ NFS4ERR_ROFS, EROFS },
	165	{ NFS4ERR_MLINK, EMLINK },
	166	{ NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
	167	{ NFS4ERR_NOTEMPTY, ENOTEMPTY },
	168	{ NFS4ERR_DQUOT, EDQUOT },
	169	{ NFS4ERR_STALE, ESTALE },
	170	{ NFS4ERR_BADHANDLE, EBADHANDLE },
	171	{ NFS4ERR_BAD_COOKIE, EBADCOOKIE },
	172	{ NFS4ERR_NOTSUPP, ENOTSUPP },
	173	{ NFS4ERR_TOOSMALL, ETOOSMALL },
	174	{ NFS4ERR_SERVERFAULT, ESERVERFAULT },
	175	{ NFS4ERR_BADTYPE, EBADTYPE },
	176	{ NFS4ERR_LOCKED, EAGAIN },
	177	{ NFS4ERR_RESOURCE, EREMOTEIO },
	178	{ NFS4ERR_SYMLINK, ELOOP },
	179	{ NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
	180	{ NFS4ERR_DEADLOCK, EDEADLK },
	181	{ -1, EIO }
	182	};
	183
	184	static int
	185	nfs_cb_stat_to_errno(int stat)
	186	{
	187	int i;
	188	for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
	189	if (nfs_cb_errtbl[i].stat == stat)
	190	return nfs_cb_errtbl[i].errno;
	191	}
	192	/* If we cannot translate the error, the recovery routines should
	193	* handle it.
	194	* Note: remaining NFSv4 error codes have values > 10000, so should
	195	* not conflict with native Linux error codes.
	196	*/
	197	return stat;
	198	}
199
200	/*
201	* XDR encode
202	*/
203
204	static int
205	encode_cb_compound_hdr(struct xdr_stream xdr, struct nfs4_cb_compound_hdr hdr)
206	{
f00f328f	207	__be32 * p;
1da177e4 LT	208
	209	RESERVE_SPACE(16);
	210	WRITE32(0); /* tag length is always 0 */
	211	WRITE32(NFS4_MINOR_VERSION);
	212	WRITE32(hdr->ident);
	213	WRITE32(hdr->nops);
	214	return 0;
	215	}
	216
	217	static int
	218	encode_cb_recall(struct xdr_stream xdr, struct nfs4_cb_recall cb_rec)
	219	{
f00f328f	220	__be32 *p;
6c02eaa1	221	int len = cb_rec->cbr_fh.fh_size;
1da177e4 LT	222
	223	RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
	224	WRITE32(OP_CB_RECALL);
8e407414 BH	225	WRITE32(cb_rec->cbr_stateid.si_generation);
8e407414 BH	226	WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t));
1da177e4 LT	227	WRITE32(cb_rec->cbr_trunc);
1da177e4 LT	228	WRITE32(len);
6c02eaa1	229	WRITEMEM(&cb_rec->cbr_fh.fh_base, len);
1da177e4 LT	230	return 0;
	231	}
	232
	233	static int
f00f328f	234	nfs4_xdr_enc_cb_null(struct rpc_rqst req, __be32 p)
1da177e4 LT	235	{
	236	struct xdr_stream xdrs, *xdr = &xdrs;
	237
	238	xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
	239	RESERVE_SPACE(0);
	240	return 0;
	241	}
	242
	243	static int
f00f328f	244	nfs4_xdr_enc_cb_recall(struct rpc_rqst req, __be32 p, struct nfs4_cb_recall *args)
1da177e4 LT	245	{
	246	struct xdr_stream xdr;
	247	struct nfs4_cb_compound_hdr hdr = {
	248	.ident = args->cbr_ident,
	249	.nops = 1,
	250	};
	251
	252	xdr_init_encode(&xdr, &req->rq_snd_buf, p);
	253	encode_cb_compound_hdr(&xdr, &hdr);
	254	return (encode_cb_recall(&xdr, args));
	255	}
	256
	257
	258	static int
	259	decode_cb_compound_hdr(struct xdr_stream xdr, struct nfs4_cb_compound_hdr hdr){
f00f328f	260	__be32 *p;
1da177e4 LT	261
	262	READ_BUF(8);
	263	READ32(hdr->status);
	264	READ32(hdr->taglen);
	265	READ_BUF(hdr->taglen + 4);
	266	hdr->tag = (char *)p;
	267	p += XDR_QUADLEN(hdr->taglen);
	268	READ32(hdr->nops);
	269	return 0;
	270	}
	271
	272	static int
	273	decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
	274	{
f00f328f	275	__be32 *p;
1da177e4 LT	276	u32 op;
	277	int32_t nfserr;
	278
	279	READ_BUF(8);
	280	READ32(op);
	281	if (op != expected) {
	282	dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
	283	" operation %d but we issued a request for %d\n",
	284	op, expected);
	285	return -EIO;
	286	}
	287	READ32(nfserr);
	288	if (nfserr != NFS_OK)
	289	return -nfs_cb_stat_to_errno(nfserr);
	290	return 0;
	291	}
	292
	293	static int
f00f328f	294	nfs4_xdr_dec_cb_null(struct rpc_rqst req, __be32 p)
1da177e4 LT	295	{
	296	return 0;
	297	}
	298
	299	static int
f00f328f	300	nfs4_xdr_dec_cb_recall(struct rpc_rqst rqstp, __be32 p)
1da177e4 LT	301	{
	302	struct xdr_stream xdr;
	303	struct nfs4_cb_compound_hdr hdr;
	304	int status;
	305
	306	xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
	307	status = decode_cb_compound_hdr(&xdr, &hdr);
	308	if (status)
	309	goto out;
	310	status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
	311	out:
	312	return status;
	313	}
	314
	315	/*
	316	* RPC procedure tables
	317	*/
1da177e4 LT	318	#define PROC(proc, call, argtype, restype) \
	319	[NFSPROC4_CLNT_##proc] = { \
	320	.p_proc = NFSPROC4_CB_##call, \
	321	.p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
	322	.p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
2bea90d4 CL	323	.p_arglen = NFS4_##argtype##_sz, \
2bea90d4 CL	324	.p_replen = NFS4_##restype##_sz, \
cc0175c1 CL	325	.p_statidx = NFSPROC4_CB_##call, \
cc0175c1 CL	326	.p_name = #proc, \
1da177e4 LT	327	}
1da177e4 LT	328
fd39ca9a	329	static struct rpc_procinfo nfs4_cb_procedures[] = {
1da177e4 LT	330	PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
	331	PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
	332	};
	333
fd39ca9a	334	static struct rpc_version nfs_cb_version4 = {
1da177e4	335	.number = 1,
e8c96f8c	336	.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
1da177e4 LT	337	.procs = nfs4_cb_procedures
	338	};
	339
	340	static struct rpc_version * nfs_cb_version[] = {
	341	NULL,
	342	&nfs_cb_version4,
	343	};
	344
ff7d9756 OK	345	static struct rpc_program cb_program;
	346
	347	static struct rpc_stat cb_stats = {
	348	.program = &cb_program
	349	};
	350
	351	#define NFS4_CALLBACK 0x40000000
	352	static struct rpc_program cb_program = {
	353	.name = "nfs4_cb",
	354	.number = NFS4_CALLBACK,
	355	.nrvers = ARRAY_SIZE(nfs_cb_version),
	356	.version = nfs_cb_version,
	357	.stats = &cb_stats,
61054b14	358	.pipe_dir_name = "/nfsd4_cb",
ff7d9756 OK	359	};
ff7d9756 OK	360
2b47eece BF	361	/* Reference counting, callback cleanup, etc., all look racy as heck.
	362	* And why is cb_set an atomic? */
	363
a601caed	364	static struct rpc_clnt setup_callback_client(struct nfs4_client clp)
2b47eece	365	{
1da177e4 LT	366	struct sockaddr_in addr;
1da177e4 LT	367	struct nfs4_callback *cb = &clp->cl_callback;
ae5c7947 CL	368	struct rpc_timeout timeparms = {
	369	.to_initval = (NFSD_LEASE_TIME/4) * HZ,
	370	.to_retries = 5,
	371	.to_maxval = (NFSD_LEASE_TIME/2) * HZ,
	372	.to_exponential = 1,
	373	};
ae5c7947 CL	374	struct rpc_create_args args = {
	375	.protocol = IPPROTO_TCP,
	376	.address = (struct sockaddr *)&addr,
	377	.addrsize = sizeof(addr),
	378	.timeout = &timeparms,
ff7d9756	379	.program = &cb_program,
d5b337b4	380	.prognumber = cb->cb_prog,
ae5c7947	381	.version = nfs_cb_version[1]->number,
61054b14	382	.authflavor = clp->cl_flavor,
b6b6152c	383	.flags = (RPC_CLNT_CREATE_NOPING \| RPC_CLNT_CREATE_QUIET),
608207e8	384	.client_name = clp->cl_principal,
ae5c7947	385	};
63c86716	386	struct rpc_clnt *client;
1da177e4	387
418cd20a	388	if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
a601caed	389	return ERR_PTR(-EINVAL);
608207e8	390
1da177e4 LT	391	/* Initialize address */
	392	memset(&addr, 0, sizeof(addr));
	393	addr.sin_family = AF_INET;
	394	addr.sin_port = htons(cb->cb_port);
	395	addr.sin_addr.s_addr = htonl(cb->cb_addr);
	396
ae5c7947	397	/* Create RPC client */
63c86716	398	client = rpc_create(&args);
a601caed BF	399	if (IS_ERR(client))
	400	dprintk("NFSD: couldn't create callback client: %ld\n",
	401	PTR_ERR(client));
	402	return client;
	403
	404	}
	405
	406	static int do_probe_callback(void *data)
	407	{
	408	struct nfs4_client *clp = data;
	409	struct nfs4_callback *cb = &clp->cl_callback;
	410	struct rpc_message msg = {
	411	.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
	412	.rpc_argp = clp,
	413	};
	414	struct rpc_clnt *client;
	415	int status;
	416
	417	client = setup_callback_client(clp);
63c86716	418	if (IS_ERR(client)) {
63c86716	419	status = PTR_ERR(client);
418cd20a BF	420	dprintk("NFSD: couldn't create callback client: %d\n",
418cd20a BF	421	status);
5b616f5d	422	goto out_err;
1da177e4	423	}
1da177e4	424
63c86716 BF	425	status = rpc_call_sync(client, &msg, RPC_TASK_SOFT);
	426
	427	if (status)
	428	goto out_release_client;
	429
	430	cb->cb_client = client;
	431	atomic_set(&cb->cb_set, 1);
	432	put_nfs4_client(clp);
	433	return 0;
	434	out_release_client:
	435	rpc_shutdown_client(client);
	436	out_err:
418cd20a BF	437	dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
418cd20a BF	438	(int)clp->cl_name.len, clp->cl_name.data, status);
88dd0be3	439	put_nfs4_client(clp);
418cd20a	440	return 0;
63c86716 BF	441	}
	442
	443	/*
	444	* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
	445	*/
	446	void
	447	nfsd4_probe_callback(struct nfs4_client *clp)
	448	{
	449	struct task_struct *t;
	450
	451	BUG_ON(atomic_read(&clp->cl_callback.cb_set));
	452
541e0e09	453	/* the task holds a reference to the nfs4_client struct */
1da177e4 LT	454	atomic_inc(&clp->cl_count);
1da177e4 LT	455
2b47eece	456	t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
1da177e4	457
2b47eece	458	if (IS_ERR(t))
63c86716	459	atomic_dec(&clp->cl_count);
2b47eece	460
1da177e4	461	return;
1da177e4 LT	462	}
1da177e4 LT	463
1da177e4 LT	464	/*
1da177e4 LT	465	* called with dp->dl_count inc'ed.
1da177e4 LT	466	*/
	467	void
	468	nfsd4_cb_recall(struct nfs4_delegation *dp)
	469	{
	470	struct nfs4_client *clp = dp->dl_client;
	471	struct rpc_clnt *clnt = clp->cl_callback.cb_client;
	472	struct nfs4_cb_recall *cbr = &dp->dl_recall;
	473	struct rpc_message msg = {
	474	.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
	475	.rpc_argp = cbr,
	476	};
	477	int retries = 1;
	478	int status = 0;
	479
1da177e4 LT	480	cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
	481	cbr->cbr_dp = dp;
	482
	483	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	484	while (retries--) {
	485	switch (status) {
	486	case -EIO:
	487	/* Network partition? */
404ec117	488	atomic_set(&clp->cl_callback.cb_set, 0);
1da177e4 LT	489	case -EBADHANDLE:
	490	case -NFS4ERR_BAD_STATEID:
	491	/* Race: client probably got cb_recall
	492	* before open reply granting delegation */
	493	break;
	494	default:
	495	goto out_put_cred;
	496	}
	497	ssleep(2);
	498	status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
	499	}
	500	out_put_cred:
404ec117 BF	501	/*
	502	* Success or failure, now we're either waiting for lease expiration
	503	* or deleg_return.
	504	*/
cfdcad4d	505	put_nfs4_client(clp);
1da177e4 LT	506	nfs4_put_delegation(dp);
	507	return;
	508	}