linux/fs/nfsd/nfs4callback.c
J. Bruce Fields 4ca1f872cd nfsd4: use auth_unix unconditionally on backchannel
This isn't actually correct, but it works with the Linux client, and
agrees with the behavior we used to have before commit 80fc015bdf.

Later patches will implement the spec-mandated behavior (which is to use
the security parameters explicitly given by the client in create_session
or backchannel_ctl).

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2012-03-28 19:14:36 -04:00

1038 lines
26 KiB
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/sunrpc/clnt.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/slab.h>
#include "nfsd.h"
#include "state.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
static void nfsd4_mark_cb_fault(struct nfs4_client *, int reason);
#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,
NFSPROC4_CLNT_CB_SEQUENCE,
};
#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 sessionid_sz (NFS4_MAX_SESSIONID_LEN >> 2)
#define cb_sequence_enc_sz (sessionid_sz + 4 + \
1 /* no referring calls list yet */)
#define cb_sequence_dec_sz (op_dec_sz + sessionid_sz + 4)
#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 + \
cb_sequence_enc_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
cb_sequence_dec_sz + \
op_dec_sz)
struct nfs4_cb_compound_hdr {
/* args */
u32 ident; /* minorversion 0 only */
u32 nops;
__be32 *nops_p;
u32 minorversion;
/* res */
int status;
};
/*
* Handle decode buffer overflows out-of-line.
*/
static void print_overflow_msg(const char *func, const struct xdr_stream *xdr)
{
dprintk("NFS: %s prematurely hit the end of our receive buffer. "
"Remaining buffer length is %tu words.\n",
func, xdr->end - xdr->p);
}
static __be32 *xdr_encode_empty_array(__be32 *p)
{
*p++ = xdr_zero;
return p;
}
/*
* Encode/decode NFSv4 CB basic data types
*
* Basic NFSv4 callback data types are defined in section 15 of RFC
* 3530: "Network File System (NFS) version 4 Protocol" and section
* 20 of RFC 5661: "Network File System (NFS) Version 4 Minor Version
* 1 Protocol"
*/
/*
* nfs_cb_opnum4
*
* enum nfs_cb_opnum4 {
* OP_CB_GETATTR = 3,
* ...
* };
*/
enum nfs_cb_opnum4 {
OP_CB_GETATTR = 3,
OP_CB_RECALL = 4,
OP_CB_LAYOUTRECALL = 5,
OP_CB_NOTIFY = 6,
OP_CB_PUSH_DELEG = 7,
OP_CB_RECALL_ANY = 8,
OP_CB_RECALLABLE_OBJ_AVAIL = 9,
OP_CB_RECALL_SLOT = 10,
OP_CB_SEQUENCE = 11,
OP_CB_WANTS_CANCELLED = 12,
OP_CB_NOTIFY_LOCK = 13,
OP_CB_NOTIFY_DEVICEID = 14,
OP_CB_ILLEGAL = 10044
};
static void encode_nfs_cb_opnum4(struct xdr_stream *xdr, enum nfs_cb_opnum4 op)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = cpu_to_be32(op);
}
/*
* nfs_fh4
*
* typedef opaque nfs_fh4<NFS4_FHSIZE>;
*/
static void encode_nfs_fh4(struct xdr_stream *xdr, const struct knfsd_fh *fh)
{
u32 length = fh->fh_size;
__be32 *p;
BUG_ON(length > NFS4_FHSIZE);
p = xdr_reserve_space(xdr, 4 + length);
xdr_encode_opaque(p, &fh->fh_base, length);
}
/*
* stateid4
*
* struct stateid4 {
* uint32_t seqid;
* opaque other[12];
* };
*/
static void encode_stateid4(struct xdr_stream *xdr, const stateid_t *sid)
{
__be32 *p;
p = xdr_reserve_space(xdr, NFS4_STATEID_SIZE);
*p++ = cpu_to_be32(sid->si_generation);
xdr_encode_opaque_fixed(p, &sid->si_opaque, NFS4_STATEID_OTHER_SIZE);
}
/*
* sessionid4
*
* typedef opaque sessionid4[NFS4_SESSIONID_SIZE];
*/
static void encode_sessionid4(struct xdr_stream *xdr,
const struct nfsd4_session *session)
{
__be32 *p;
p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
xdr_encode_opaque_fixed(p, session->se_sessionid.data,
NFS4_MAX_SESSIONID_LEN);
}
/*
* nfsstat4
*/
static const 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 }
};
/*
* 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.
*/
static int nfs_cb_stat_to_errno(int status)
{
int i;
for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
if (nfs_cb_errtbl[i].stat == status)
return nfs_cb_errtbl[i].errno;
}
dprintk("NFSD: Unrecognized NFS CB status value: %u\n", status);
return -status;
}
static int decode_cb_op_status(struct xdr_stream *xdr, enum nfs_opnum4 expected,
enum nfsstat4 *status)
{
__be32 *p;
u32 op;
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
goto out_overflow;
op = be32_to_cpup(p++);
if (unlikely(op != expected))
goto out_unexpected;
*status = be32_to_cpup(p);
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
out_unexpected:
dprintk("NFSD: Callback server returned operation %d but "
"we issued a request for %d\n", op, expected);
return -EIO;
}
/*
* CB_COMPOUND4args
*
* struct CB_COMPOUND4args {
* utf8str_cs tag;
* uint32_t minorversion;
* uint32_t callback_ident;
* nfs_cb_argop4 argarray<>;
* };
*/
static void encode_cb_compound4args(struct xdr_stream *xdr,
struct nfs4_cb_compound_hdr *hdr)
{
__be32 * p;
p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4);
p = xdr_encode_empty_array(p); /* empty tag */
*p++ = cpu_to_be32(hdr->minorversion);
*p++ = cpu_to_be32(hdr->ident);
hdr->nops_p = p;
*p = cpu_to_be32(hdr->nops); /* argarray element count */
}
/*
* Update argarray element count
*/
static void encode_cb_nops(struct nfs4_cb_compound_hdr *hdr)
{
BUG_ON(hdr->nops > NFS4_MAX_BACK_CHANNEL_OPS);
*hdr->nops_p = cpu_to_be32(hdr->nops);
}
/*
* CB_COMPOUND4res
*
* struct CB_COMPOUND4res {
* nfsstat4 status;
* utf8str_cs tag;
* nfs_cb_resop4 resarray<>;
* };
*/
static int decode_cb_compound4res(struct xdr_stream *xdr,
struct nfs4_cb_compound_hdr *hdr)
{
u32 length;
__be32 *p;
p = xdr_inline_decode(xdr, 4 + 4);
if (unlikely(p == NULL))
goto out_overflow;
hdr->status = be32_to_cpup(p++);
/* Ignore the tag */
length = be32_to_cpup(p++);
p = xdr_inline_decode(xdr, length + 4);
if (unlikely(p == NULL))
goto out_overflow;
hdr->nops = be32_to_cpup(p);
return 0;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
/*
* CB_RECALL4args
*
* struct CB_RECALL4args {
* stateid4 stateid;
* bool truncate;
* nfs_fh4 fh;
* };
*/
static void encode_cb_recall4args(struct xdr_stream *xdr,
const struct nfs4_delegation *dp,
struct nfs4_cb_compound_hdr *hdr)
{
__be32 *p;
encode_nfs_cb_opnum4(xdr, OP_CB_RECALL);
encode_stateid4(xdr, &dp->dl_stid.sc_stateid);
p = xdr_reserve_space(xdr, 4);
*p++ = xdr_zero; /* truncate */
encode_nfs_fh4(xdr, &dp->dl_fh);
hdr->nops++;
}
/*
* CB_SEQUENCE4args
*
* struct CB_SEQUENCE4args {
* sessionid4 csa_sessionid;
* sequenceid4 csa_sequenceid;
* slotid4 csa_slotid;
* slotid4 csa_highest_slotid;
* bool csa_cachethis;
* referring_call_list4 csa_referring_call_lists<>;
* };
*/
static void encode_cb_sequence4args(struct xdr_stream *xdr,
const struct nfsd4_callback *cb,
struct nfs4_cb_compound_hdr *hdr)
{
struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
__be32 *p;
if (hdr->minorversion == 0)
return;
encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
encode_sessionid4(xdr, session);
p = xdr_reserve_space(xdr, 4 + 4 + 4 + 4 + 4);
*p++ = cpu_to_be32(session->se_cb_seq_nr); /* csa_sequenceid */
*p++ = xdr_zero; /* csa_slotid */
*p++ = xdr_zero; /* csa_highest_slotid */
*p++ = xdr_zero; /* csa_cachethis */
xdr_encode_empty_array(p); /* csa_referring_call_lists */
hdr->nops++;
}
/*
* CB_SEQUENCE4resok
*
* struct CB_SEQUENCE4resok {
* sessionid4 csr_sessionid;
* sequenceid4 csr_sequenceid;
* slotid4 csr_slotid;
* slotid4 csr_highest_slotid;
* slotid4 csr_target_highest_slotid;
* };
*
* union CB_SEQUENCE4res switch (nfsstat4 csr_status) {
* case NFS4_OK:
* CB_SEQUENCE4resok csr_resok4;
* default:
* void;
* };
*
* Our current back channel implmentation supports a single backchannel
* with a single slot.
*/
static int decode_cb_sequence4resok(struct xdr_stream *xdr,
struct nfsd4_callback *cb)
{
struct nfsd4_session *session = cb->cb_clp->cl_cb_session;
struct nfs4_sessionid id;
int status;
__be32 *p;
u32 dummy;
status = -ESERVERFAULT;
/*
* If the server returns different values for sessionID, slotID or
* sequence number, the server is looney tunes.
*/
p = xdr_inline_decode(xdr, NFS4_MAX_SESSIONID_LEN + 4 + 4 + 4 + 4);
if (unlikely(p == NULL))
goto out_overflow;
memcpy(id.data, p, NFS4_MAX_SESSIONID_LEN);
if (memcmp(id.data, session->se_sessionid.data,
NFS4_MAX_SESSIONID_LEN) != 0) {
dprintk("NFS: %s Invalid session id\n", __func__);
goto out;
}
p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
dummy = be32_to_cpup(p++);
if (dummy != session->se_cb_seq_nr) {
dprintk("NFS: %s Invalid sequence number\n", __func__);
goto out;
}
dummy = be32_to_cpup(p++);
if (dummy != 0) {
dprintk("NFS: %s Invalid slotid\n", __func__);
goto out;
}
/*
* FIXME: process highest slotid and target highest slotid
*/
status = 0;
out:
if (status)
nfsd4_mark_cb_fault(cb->cb_clp, status);
return status;
out_overflow:
print_overflow_msg(__func__, xdr);
return -EIO;
}
static int decode_cb_sequence4res(struct xdr_stream *xdr,
struct nfsd4_callback *cb)
{
enum nfsstat4 nfserr;
int status;
if (cb->cb_minorversion == 0)
return 0;
status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &nfserr);
if (unlikely(status))
goto out;
if (unlikely(nfserr != NFS4_OK))
goto out_default;
status = decode_cb_sequence4resok(xdr, cb);
out:
return status;
out_default:
return nfs_cb_stat_to_errno(nfserr);
}
/*
* NFSv4.0 and NFSv4.1 XDR encode functions
*
* NFSv4.0 callback argument types are defined in section 15 of RFC
* 3530: "Network File System (NFS) version 4 Protocol" and section 20
* of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
* Protocol".
*/
/*
* NB: Without this zero space reservation, callbacks over krb5p fail
*/
static void nfs4_xdr_enc_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
void *__unused)
{
xdr_reserve_space(xdr, 0);
}
/*
* 20.2. Operation 4: CB_RECALL - Recall a Delegation
*/
static void nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, struct xdr_stream *xdr,
const struct nfsd4_callback *cb)
{
const struct nfs4_delegation *args = cb->cb_op;
struct nfs4_cb_compound_hdr hdr = {
.ident = cb->cb_clp->cl_cb_ident,
.minorversion = cb->cb_minorversion,
};
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
encode_cb_recall4args(xdr, args, &hdr);
encode_cb_nops(&hdr);
}
/*
* NFSv4.0 and NFSv4.1 XDR decode functions
*
* NFSv4.0 callback result types are defined in section 15 of RFC
* 3530: "Network File System (NFS) version 4 Protocol" and section 20
* of RFC 5661: "Network File System (NFS) Version 4 Minor Version 1
* Protocol".
*/
static int nfs4_xdr_dec_cb_null(struct rpc_rqst *req, struct xdr_stream *xdr,
void *__unused)
{
return 0;
}
/*
* 20.2. Operation 4: CB_RECALL - Recall a Delegation
*/
static int nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
struct nfsd4_callback *cb)
{
struct nfs4_cb_compound_hdr hdr;
enum nfsstat4 nfserr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
goto out;
if (cb != NULL) {
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status))
goto out;
}
status = decode_cb_op_status(xdr, OP_CB_RECALL, &nfserr);
if (unlikely(status))
goto out;
if (unlikely(nfserr != NFS4_OK))
status = nfs_cb_stat_to_errno(nfserr);
out:
return status;
}
/*
* RPC procedure tables
*/
#define PROC(proc, call, argtype, restype) \
[NFSPROC4_CLNT_##proc] = { \
.p_proc = NFSPROC4_CB_##call, \
.p_encode = (kxdreproc_t)nfs4_xdr_enc_##argtype, \
.p_decode = (kxdrdproc_t)nfs4_xdr_dec_##restype, \
.p_arglen = NFS4_enc_##argtype##_sz, \
.p_replen = NFS4_dec_##restype##_sz, \
.p_statidx = NFSPROC4_CB_##call, \
.p_name = #proc, \
}
static struct rpc_procinfo nfs4_cb_procedures[] = {
PROC(CB_NULL, NULL, cb_null, cb_null),
PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
};
static struct rpc_version nfs_cb_version4 = {
/*
* Note on the callback rpc program version number: despite language in rfc
* 5661 section 18.36.3 requiring servers to use 4 in this field, the
* official xdr descriptions for both 4.0 and 4.1 specify version 1, and
* in practice that appears to be what implementations use. The section
* 18.36.3 language is expected to be fixed in an erratum.
*/
.number = 1,
.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
.procs = nfs4_cb_procedures
};
static const struct rpc_version *nfs_cb_version[] = {
&nfs_cb_version4,
};
static const struct rpc_program cb_program;
static struct rpc_stat cb_stats = {
.program = &cb_program
};
#define NFS4_CALLBACK 0x40000000
static const 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",
};
static int max_cb_time(void)
{
return max(nfsd4_lease/10, (time_t)1) * HZ;
}
static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
{
struct rpc_timeout timeparms = {
.to_initval = max_cb_time(),
.to_retries = 0,
};
struct rpc_create_args args = {
.net = &init_net,
.address = (struct sockaddr *) &conn->cb_addr,
.addrsize = conn->cb_addrlen,
.saddress = (struct sockaddr *) &conn->cb_saddr,
.timeout = &timeparms,
.program = &cb_program,
.version = 0,
.flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
};
struct rpc_clnt *client;
if (clp->cl_minorversion == 0) {
if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
return -EINVAL;
args.client_name = clp->cl_principal;
args.prognumber = conn->cb_prog,
args.protocol = XPRT_TRANSPORT_TCP;
args.authflavor = clp->cl_flavor;
clp->cl_cb_ident = conn->cb_ident;
} else {
if (!conn->cb_xprt)
return -EINVAL;
clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
clp->cl_cb_session = ses;
args.bc_xprt = conn->cb_xprt;
args.prognumber = clp->cl_cb_session->se_cb_prog;
args.protocol = XPRT_TRANSPORT_BC_TCP;
args.authflavor = RPC_AUTH_UNIX;
}
/* Create RPC client */
client = rpc_create(&args);
if (IS_ERR(client)) {
dprintk("NFSD: couldn't create callback client: %ld\n",
PTR_ERR(client));
return PTR_ERR(client);
}
clp->cl_cb_client = client;
return 0;
}
static void warn_no_callback_path(struct nfs4_client *clp, int reason)
{
dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
(int)clp->cl_name.len, clp->cl_name.data, reason);
}
static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
{
clp->cl_cb_state = NFSD4_CB_DOWN;
warn_no_callback_path(clp, reason);
}
static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
{
clp->cl_cb_state = NFSD4_CB_FAULT;
warn_no_callback_path(clp, reason);
}
static void nfsd4_cb_probe_done(struct rpc_task *task, void *calldata)
{
struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
if (task->tk_status)
nfsd4_mark_cb_down(clp, task->tk_status);
else
clp->cl_cb_state = NFSD4_CB_UP;
}
static const struct rpc_call_ops nfsd4_cb_probe_ops = {
/* XXX: release method to ensure we set the cb channel down if
* necessary on early failure? */
.rpc_call_done = nfsd4_cb_probe_done,
};
static struct rpc_cred *callback_cred;
int set_callback_cred(void)
{
if (callback_cred)
return 0;
callback_cred = rpc_lookup_machine_cred("nfs");
if (!callback_cred)
return -ENOMEM;
return 0;
}
static struct workqueue_struct *callback_wq;
static void run_nfsd4_cb(struct nfsd4_callback *cb)
{
queue_work(callback_wq, &cb->cb_work);
}
static void do_probe_callback(struct nfs4_client *clp)
{
struct nfsd4_callback *cb = &clp->cl_cb_null;
cb->cb_op = NULL;
cb->cb_clp = clp;
cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL];
cb->cb_msg.rpc_argp = NULL;
cb->cb_msg.rpc_resp = NULL;
cb->cb_msg.rpc_cred = callback_cred;
cb->cb_ops = &nfsd4_cb_probe_ops;
run_nfsd4_cb(cb);
}
/*
* Poke the callback thread to process any updates to the callback
* parameters, and send a null probe.
*/
void nfsd4_probe_callback(struct nfs4_client *clp)
{
/* XXX: atomicity? Also, should we be using cl_flags? */
clp->cl_cb_state = NFSD4_CB_UNKNOWN;
set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
do_probe_callback(clp);
}
void nfsd4_probe_callback_sync(struct nfs4_client *clp)
{
nfsd4_probe_callback(clp);
flush_workqueue(callback_wq);
}
void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *conn)
{
clp->cl_cb_state = NFSD4_CB_UNKNOWN;
spin_lock(&clp->cl_lock);
memcpy(&clp->cl_cb_conn, conn, sizeof(struct nfs4_cb_conn));
spin_unlock(&clp->cl_lock);
}
/*
* There's currently a single callback channel slot.
* If the slot is available, then mark it busy. Otherwise, set the
* thread for sleeping on the callback RPC wait queue.
*/
static bool nfsd41_cb_get_slot(struct nfs4_client *clp, struct rpc_task *task)
{
if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
dprintk("%s slot is busy\n", __func__);
return false;
}
return true;
}
/*
* TODO: cb_sequence should support referring call lists, cachethis, multiple
* slots, and mark callback channel down on communication errors.
*/
static void nfsd4_cb_prepare(struct rpc_task *task, void *calldata)
{
struct nfsd4_callback *cb = calldata;
struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
struct nfs4_client *clp = dp->dl_stid.sc_client;
u32 minorversion = clp->cl_minorversion;
cb->cb_minorversion = minorversion;
if (minorversion) {
if (!nfsd41_cb_get_slot(clp, task))
return;
}
spin_lock(&clp->cl_lock);
if (list_empty(&cb->cb_per_client)) {
/* This is the first call, not a restart */
cb->cb_done = false;
list_add(&cb->cb_per_client, &clp->cl_callbacks);
}
spin_unlock(&clp->cl_lock);
rpc_call_start(task);
}
static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
{
struct nfsd4_callback *cb = calldata;
struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
struct nfs4_client *clp = dp->dl_stid.sc_client;
dprintk("%s: minorversion=%d\n", __func__,
clp->cl_minorversion);
if (clp->cl_minorversion) {
/* No need for lock, access serialized in nfsd4_cb_prepare */
++clp->cl_cb_session->se_cb_seq_nr;
clear_bit(0, &clp->cl_cb_slot_busy);
rpc_wake_up_next(&clp->cl_cb_waitq);
dprintk("%s: freed slot, new seqid=%d\n", __func__,
clp->cl_cb_session->se_cb_seq_nr);
/* We're done looking into the sequence information */
task->tk_msg.rpc_resp = NULL;
}
}
static void nfsd4_cb_recall_done(struct rpc_task *task, void *calldata)
{
struct nfsd4_callback *cb = calldata;
struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
struct nfs4_client *clp = dp->dl_stid.sc_client;
struct rpc_clnt *current_rpc_client = clp->cl_cb_client;
nfsd4_cb_done(task, calldata);
if (current_rpc_client != task->tk_client) {
/* We're shutting down or changing cl_cb_client; leave
* it to nfsd4_process_cb_update to restart the call if
* necessary. */
return;
}
if (cb->cb_done)
return;
switch (task->tk_status) {
case 0:
cb->cb_done = true;
return;
case -EBADHANDLE:
case -NFS4ERR_BAD_STATEID:
/* Race: client probably got cb_recall
* before open reply granting delegation */
break;
default:
/* Network partition? */
nfsd4_mark_cb_down(clp, task->tk_status);
}
if (dp->dl_retries--) {
rpc_delay(task, 2*HZ);
task->tk_status = 0;
rpc_restart_call_prepare(task);
return;
}
nfsd4_mark_cb_down(clp, task->tk_status);
cb->cb_done = true;
}
static void nfsd4_cb_recall_release(void *calldata)
{
struct nfsd4_callback *cb = calldata;
struct nfs4_client *clp = cb->cb_clp;
struct nfs4_delegation *dp = container_of(cb, struct nfs4_delegation, dl_recall);
if (cb->cb_done) {
spin_lock(&clp->cl_lock);
list_del(&cb->cb_per_client);
spin_unlock(&clp->cl_lock);
nfs4_put_delegation(dp);
}
}
static const struct rpc_call_ops nfsd4_cb_recall_ops = {
.rpc_call_prepare = nfsd4_cb_prepare,
.rpc_call_done = nfsd4_cb_recall_done,
.rpc_release = nfsd4_cb_recall_release,
};
int nfsd4_create_callback_queue(void)
{
callback_wq = create_singlethread_workqueue("nfsd4_callbacks");
if (!callback_wq)
return -ENOMEM;
return 0;
}
void nfsd4_destroy_callback_queue(void)
{
destroy_workqueue(callback_wq);
}
/* must be called under the state lock */
void nfsd4_shutdown_callback(struct nfs4_client *clp)
{
set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
/*
* Note this won't actually result in a null callback;
* instead, nfsd4_do_callback_rpc() will detect the killed
* client, destroy the rpc client, and stop:
*/
do_probe_callback(clp);
flush_workqueue(callback_wq);
}
static void nfsd4_release_cb(struct nfsd4_callback *cb)
{
if (cb->cb_ops->rpc_release)
cb->cb_ops->rpc_release(cb);
}
/* requires cl_lock: */
static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
{
struct nfsd4_session *s;
struct nfsd4_conn *c;
list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
list_for_each_entry(c, &s->se_conns, cn_persession) {
if (c->cn_flags & NFS4_CDFC4_BACK)
return c;
}
}
return NULL;
}
static void nfsd4_process_cb_update(struct nfsd4_callback *cb)
{
struct nfs4_cb_conn conn;
struct nfs4_client *clp = cb->cb_clp;
struct nfsd4_session *ses = NULL;
struct nfsd4_conn *c;
int err;
/*
* This is either an update, or the client dying; in either case,
* kill the old client:
*/
if (clp->cl_cb_client) {
rpc_shutdown_client(clp->cl_cb_client);
clp->cl_cb_client = NULL;
}
if (clp->cl_cb_conn.cb_xprt) {
svc_xprt_put(clp->cl_cb_conn.cb_xprt);
clp->cl_cb_conn.cb_xprt = NULL;
}
if (test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags))
return;
spin_lock(&clp->cl_lock);
/*
* Only serialized callback code is allowed to clear these
* flags; main nfsd code can only set them:
*/
BUG_ON(!(clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK));
clear_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
memcpy(&conn, &cb->cb_clp->cl_cb_conn, sizeof(struct nfs4_cb_conn));
c = __nfsd4_find_backchannel(clp);
if (c) {
svc_xprt_get(c->cn_xprt);
conn.cb_xprt = c->cn_xprt;
ses = c->cn_session;
}
spin_unlock(&clp->cl_lock);
err = setup_callback_client(clp, &conn, ses);
if (err) {
nfsd4_mark_cb_down(clp, err);
return;
}
/* Yay, the callback channel's back! Restart any callbacks: */
list_for_each_entry(cb, &clp->cl_callbacks, cb_per_client)
run_nfsd4_cb(cb);
}
void nfsd4_do_callback_rpc(struct work_struct *w)
{
struct nfsd4_callback *cb = container_of(w, struct nfsd4_callback, cb_work);
struct nfs4_client *clp = cb->cb_clp;
struct rpc_clnt *clnt;
if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
nfsd4_process_cb_update(cb);
clnt = clp->cl_cb_client;
if (!clnt) {
/* Callback channel broken, or client killed; give up: */
nfsd4_release_cb(cb);
return;
}
rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
cb->cb_ops, cb);
}
void nfsd4_cb_recall(struct nfs4_delegation *dp)
{
struct nfsd4_callback *cb = &dp->dl_recall;
struct nfs4_client *clp = dp->dl_stid.sc_client;
dp->dl_retries = 1;
cb->cb_op = dp;
cb->cb_clp = clp;
cb->cb_msg.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL];
cb->cb_msg.rpc_argp = cb;
cb->cb_msg.rpc_resp = cb;
cb->cb_msg.rpc_cred = callback_cred;
cb->cb_ops = &nfsd4_cb_recall_ops;
dp->dl_retries = 1;
INIT_LIST_HEAD(&cb->cb_per_client);
cb->cb_done = true;
run_nfsd4_cb(&dp->dl_recall);
}