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linux/fs/nfsd/nfs4callback.c

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/*
* 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/xprt.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/slab.h>
#include "nfsd.h"
#include "state.h"
#include "netns.h"
#include "xdr4cb.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,
};
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(struct net *net)
{
struct nfsd_net *nn = net_generic(net, nfsd_net_id);
return max(nn->nfsd4_lease/10, (time_t)1) * HZ;
}
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 rpc_cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
{
if (clp->cl_minorversion == 0) {
return get_rpccred(callback_cred);
} else {
struct rpc_auth *auth = client->cl_auth;
struct auth_cred acred = {};
acred.uid = ses->se_cb_sec.uid;
acred.gid = ses->se_cb_sec.gid;
return auth->au_ops->lookup_cred(client->cl_auth, &acred, 0);
}
}
static struct rpc_clnt *create_backchannel_client(struct rpc_create_args *args)
{
struct rpc_xprt *xprt;
if (args->protocol != XPRT_TRANSPORT_BC_TCP)
return rpc_create(args);
xprt = args->bc_xprt->xpt_bc_xprt;
if (xprt) {
xprt_get(xprt);
return rpc_create_xprt(args, xprt);
}
return rpc_create(args);
}
static int setup_callback_client(struct nfs4_client *clp, struct nfs4_cb_conn *conn, struct nfsd4_session *ses)
{
int maxtime = max_cb_time(clp->net);
struct rpc_timeout timeparms = {
.to_initval = maxtime,
.to_retries = 0,
.to_maxval = maxtime,
};
struct rpc_create_args args = {
.net = clp->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;
struct rpc_cred *cred;
if (clp->cl_minorversion == 0) {
if (!clp->cl_cred.cr_principal &&
(clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5))
return -EINVAL;
args.client_name = clp->cl_cred.cr_principal;
args.prognumber = conn->cb_prog,
args.protocol = XPRT_TRANSPORT_TCP;
args.authflavor = clp->cl_cred.cr_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 = ses->se_cb_sec.flavor;
}
/* Create RPC client */
client = create_backchannel_client(&args);
if (IS_ERR(client)) {
dprintk("NFSD: couldn't create callback client: %ld\n",
PTR_ERR(client));
return PTR_ERR(client);
}
cred = get_backchannel_cred(clp, client, ses);
if (IS_ERR(cred)) {
rpc_shutdown_client(client);
return PTR_ERR(cred);
}
clp->cl_cb_client = client;
clp->cl_cb_cred = cred;
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 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_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)
{
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_client *clp = cb->cb_clp;
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_client *clp = cb->cb_clp;
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 = cb->cb_clp;
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;
put_rpccred(clp->cl_cb_cred);
clp->cl_cb_cred = 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);
}
static 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;
}
cb->cb_msg.rpc_cred = clp->cl_cb_cred;
rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | RPC_TASK_SOFTCONN,
cb->cb_ops, cb);
}
void nfsd4_init_callback(struct nfsd4_callback *cb)
{
INIT_WORK(&cb->cb_work, nfsd4_do_callback_rpc);
}
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_ops = &nfsd4_cb_recall_ops;
INIT_LIST_HEAD(&cb->cb_per_client);
cb->cb_done = true;
run_nfsd4_cb(&dp->dl_recall);
}
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