linux/fs/nfsd/nfs4callback.c
Linus Torvalds aeba12b26c nfsd-6.2 supplement:
- Address numerous reports of refcount underflows in NFSD's filecache
 - Address a UAF in callback setup error handling
 - Address a UAF during server-to-server copy
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Merge tag 'nfsd-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux

Pull more nfsd updates from Chuck Lever:
 "This contains a number of crasher fixes that were not ready for the
  initial pull request last week.

  In particular, Jeff's patch attempts to address reference count
  underflows in NFSD's filecache, which have been very difficult to
  track down because there is no reliable reproducer.

  Common failure modes:
      https://bugzilla.kernel.org/show_bug.cgi?id=216691#c11
      https://bugzilla.kernel.org/show_bug.cgi?id=216674#c6
      https://bugzilla.redhat.com/show_bug.cgi?id=2138605

  The race windows were found by inspection and the clean-ups appear
  sensible and pass regression testing, so we include them here in the
  hope that they address the problem. However we remain vigilant because
  we don't have 100% certainty yet that the problem is fully addressed.

  Summary:

   - Address numerous reports of refcount underflows in NFSD's filecache

   - Address a UAF in callback setup error handling

   - Address a UAF during server-to-server copy"

* tag 'nfsd-6.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/cel/linux:
  NFSD: fix use-after-free in __nfs42_ssc_open()
  nfsd: under NFSv4.1, fix double svc_xprt_put on rpc_create failure
  nfsd: rework refcounting in filecache
2022-12-19 09:10:33 -06:00

1466 lines
36 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/xprt.h>
#include <linux/sunrpc/svc_xprt.h>
#include <linux/slab.h>
#include "nfsd.h"
#include "state.h"
#include "netns.h"
#include "trace.h"
#include "xdr4cb.h"
#include "xdr4.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 */
struct nfs4_cb_compound_hdr {
/* args */
u32 ident; /* minorversion 0 only */
u32 nops;
__be32 *nops_p;
u32 minorversion;
/* res */
int status;
};
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"
*/
static void encode_uint32(struct xdr_stream *xdr, u32 n)
{
WARN_ON_ONCE(xdr_stream_encode_u32(xdr, n) < 0);
}
static void encode_bitmap4(struct xdr_stream *xdr, const __u32 *bitmap,
size_t len)
{
WARN_ON_ONCE(xdr_stream_encode_uint32_array(xdr, bitmap, len) < 0);
}
/*
* 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_OFFLOAD = 15,
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_raw, 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_cb_opnum4 expected, int *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 = nfs_cb_stat_to_errno(be32_to_cpup(p));
return 0;
out_overflow:
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;
p += XDR_QUADLEN(length);
hdr->nops = be32_to_cpup(p);
return 0;
out_overflow:
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_stid.sc_file->fi_fhandle);
hdr->nops++;
}
/*
* CB_RECALLANY4args
*
* struct CB_RECALLANY4args {
* uint32_t craa_objects_to_keep;
* bitmap4 craa_type_mask;
* };
*/
static void
encode_cb_recallany4args(struct xdr_stream *xdr,
struct nfs4_cb_compound_hdr *hdr, struct nfsd4_cb_recall_any *ra)
{
encode_nfs_cb_opnum4(xdr, OP_CB_RECALL_ANY);
encode_uint32(xdr, ra->ra_keep);
encode_bitmap4(xdr, ra->ra_bmval, ARRAY_SIZE(ra->ra_bmval));
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;
int status = -ESERVERFAULT;
__be32 *p;
u32 dummy;
/*
* 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;
if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
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:
cb->cb_seq_status = status;
return status;
out_overflow:
status = -EIO;
goto out;
}
static int decode_cb_sequence4res(struct xdr_stream *xdr,
struct nfsd4_callback *cb)
{
int status;
if (cb->cb_clp->cl_minorversion == 0)
return 0;
status = decode_cb_op_status(xdr, OP_CB_SEQUENCE, &cb->cb_seq_status);
if (unlikely(status || cb->cb_seq_status))
return status;
return decode_cb_sequence4resok(xdr, cb);
}
/*
* 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,
const 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 void *data)
{
const struct nfsd4_callback *cb = data;
const struct nfs4_delegation *dp = cb_to_delegation(cb);
struct nfs4_cb_compound_hdr hdr = {
.ident = cb->cb_clp->cl_cb_ident,
.minorversion = cb->cb_clp->cl_minorversion,
};
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
encode_cb_recall4args(xdr, dp, &hdr);
encode_cb_nops(&hdr);
}
/*
* 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
*/
static void
nfs4_xdr_enc_cb_recall_any(struct rpc_rqst *req,
struct xdr_stream *xdr, const void *data)
{
const struct nfsd4_callback *cb = data;
struct nfsd4_cb_recall_any *ra;
struct nfs4_cb_compound_hdr hdr = {
.ident = cb->cb_clp->cl_cb_ident,
.minorversion = cb->cb_clp->cl_minorversion,
};
ra = container_of(cb, struct nfsd4_cb_recall_any, ra_cb);
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
encode_cb_recallany4args(xdr, &hdr, ra);
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,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
return status;
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status || cb->cb_seq_status))
return status;
return decode_cb_op_status(xdr, OP_CB_RECALL, &cb->cb_status);
}
/*
* 20.6. Operation 8: CB_RECALL_ANY - Keep Any N Recallable Objects
*/
static int
nfs4_xdr_dec_cb_recall_any(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
return status;
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status || cb->cb_seq_status))
return status;
status = decode_cb_op_status(xdr, OP_CB_RECALL_ANY, &cb->cb_status);
return status;
}
#ifdef CONFIG_NFSD_PNFS
/*
* CB_LAYOUTRECALL4args
*
* struct layoutrecall_file4 {
* nfs_fh4 lor_fh;
* offset4 lor_offset;
* length4 lor_length;
* stateid4 lor_stateid;
* };
*
* union layoutrecall4 switch(layoutrecall_type4 lor_recalltype) {
* case LAYOUTRECALL4_FILE:
* layoutrecall_file4 lor_layout;
* case LAYOUTRECALL4_FSID:
* fsid4 lor_fsid;
* case LAYOUTRECALL4_ALL:
* void;
* };
*
* struct CB_LAYOUTRECALL4args {
* layouttype4 clora_type;
* layoutiomode4 clora_iomode;
* bool clora_changed;
* layoutrecall4 clora_recall;
* };
*/
static void encode_cb_layout4args(struct xdr_stream *xdr,
const struct nfs4_layout_stateid *ls,
struct nfs4_cb_compound_hdr *hdr)
{
__be32 *p;
BUG_ON(hdr->minorversion == 0);
p = xdr_reserve_space(xdr, 5 * 4);
*p++ = cpu_to_be32(OP_CB_LAYOUTRECALL);
*p++ = cpu_to_be32(ls->ls_layout_type);
*p++ = cpu_to_be32(IOMODE_ANY);
*p++ = cpu_to_be32(1);
*p = cpu_to_be32(RETURN_FILE);
encode_nfs_fh4(xdr, &ls->ls_stid.sc_file->fi_fhandle);
p = xdr_reserve_space(xdr, 2 * 8);
p = xdr_encode_hyper(p, 0);
xdr_encode_hyper(p, NFS4_MAX_UINT64);
encode_stateid4(xdr, &ls->ls_recall_sid);
hdr->nops++;
}
static void nfs4_xdr_enc_cb_layout(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfsd4_callback *cb = data;
const struct nfs4_layout_stateid *ls =
container_of(cb, struct nfs4_layout_stateid, ls_recall);
struct nfs4_cb_compound_hdr hdr = {
.ident = 0,
.minorversion = cb->cb_clp->cl_minorversion,
};
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
encode_cb_layout4args(xdr, ls, &hdr);
encode_cb_nops(&hdr);
}
static int nfs4_xdr_dec_cb_layout(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
return status;
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status || cb->cb_seq_status))
return status;
return decode_cb_op_status(xdr, OP_CB_LAYOUTRECALL, &cb->cb_status);
}
#endif /* CONFIG_NFSD_PNFS */
static void encode_stateowner(struct xdr_stream *xdr, struct nfs4_stateowner *so)
{
__be32 *p;
p = xdr_reserve_space(xdr, 8 + 4 + so->so_owner.len);
p = xdr_encode_opaque_fixed(p, &so->so_client->cl_clientid, 8);
xdr_encode_opaque(p, so->so_owner.data, so->so_owner.len);
}
static void nfs4_xdr_enc_cb_notify_lock(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfsd4_callback *cb = data;
const struct nfsd4_blocked_lock *nbl =
container_of(cb, struct nfsd4_blocked_lock, nbl_cb);
struct nfs4_lockowner *lo = (struct nfs4_lockowner *)nbl->nbl_lock.fl_owner;
struct nfs4_cb_compound_hdr hdr = {
.ident = 0,
.minorversion = cb->cb_clp->cl_minorversion,
};
__be32 *p;
BUG_ON(hdr.minorversion == 0);
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
p = xdr_reserve_space(xdr, 4);
*p = cpu_to_be32(OP_CB_NOTIFY_LOCK);
encode_nfs_fh4(xdr, &nbl->nbl_fh);
encode_stateowner(xdr, &lo->lo_owner);
hdr.nops++;
encode_cb_nops(&hdr);
}
static int nfs4_xdr_dec_cb_notify_lock(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
return status;
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status || cb->cb_seq_status))
return status;
return decode_cb_op_status(xdr, OP_CB_NOTIFY_LOCK, &cb->cb_status);
}
/*
* struct write_response4 {
* stateid4 wr_callback_id<1>;
* length4 wr_count;
* stable_how4 wr_committed;
* verifier4 wr_writeverf;
* };
* union offload_info4 switch (nfsstat4 coa_status) {
* case NFS4_OK:
* write_response4 coa_resok4;
* default:
* length4 coa_bytes_copied;
* };
* struct CB_OFFLOAD4args {
* nfs_fh4 coa_fh;
* stateid4 coa_stateid;
* offload_info4 coa_offload_info;
* };
*/
static void encode_offload_info4(struct xdr_stream *xdr,
const struct nfsd4_cb_offload *cbo)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = cbo->co_nfserr;
switch (cbo->co_nfserr) {
case nfs_ok:
p = xdr_reserve_space(xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
p = xdr_encode_empty_array(p);
p = xdr_encode_hyper(p, cbo->co_res.wr_bytes_written);
*p++ = cpu_to_be32(cbo->co_res.wr_stable_how);
p = xdr_encode_opaque_fixed(p, cbo->co_res.wr_verifier.data,
NFS4_VERIFIER_SIZE);
break;
default:
p = xdr_reserve_space(xdr, 8);
/* We always return success if bytes were written */
p = xdr_encode_hyper(p, 0);
}
}
static void encode_cb_offload4args(struct xdr_stream *xdr,
const struct nfsd4_cb_offload *cbo,
struct nfs4_cb_compound_hdr *hdr)
{
__be32 *p;
p = xdr_reserve_space(xdr, 4);
*p = cpu_to_be32(OP_CB_OFFLOAD);
encode_nfs_fh4(xdr, &cbo->co_fh);
encode_stateid4(xdr, &cbo->co_res.cb_stateid);
encode_offload_info4(xdr, cbo);
hdr->nops++;
}
static void nfs4_xdr_enc_cb_offload(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfsd4_callback *cb = data;
const struct nfsd4_cb_offload *cbo =
container_of(cb, struct nfsd4_cb_offload, co_cb);
struct nfs4_cb_compound_hdr hdr = {
.ident = 0,
.minorversion = cb->cb_clp->cl_minorversion,
};
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
encode_cb_offload4args(xdr, cbo, &hdr);
encode_cb_nops(&hdr);
}
static int nfs4_xdr_dec_cb_offload(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
status = decode_cb_compound4res(xdr, &hdr);
if (unlikely(status))
return status;
status = decode_cb_sequence4res(xdr, cb);
if (unlikely(status || cb->cb_seq_status))
return status;
return decode_cb_op_status(xdr, OP_CB_OFFLOAD, &cb->cb_status);
}
/*
* RPC procedure tables
*/
#define PROC(proc, call, argtype, restype) \
[NFSPROC4_CLNT_##proc] = { \
.p_proc = NFSPROC4_CB_##call, \
.p_encode = nfs4_xdr_enc_##argtype, \
.p_decode = 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 const struct rpc_procinfo nfs4_cb_procedures[] = {
PROC(CB_NULL, NULL, cb_null, cb_null),
PROC(CB_RECALL, COMPOUND, cb_recall, cb_recall),
#ifdef CONFIG_NFSD_PNFS
PROC(CB_LAYOUT, COMPOUND, cb_layout, cb_layout),
#endif
PROC(CB_NOTIFY_LOCK, COMPOUND, cb_notify_lock, cb_notify_lock),
PROC(CB_OFFLOAD, COMPOUND, cb_offload, cb_offload),
PROC(CB_RECALL_ANY, COMPOUND, cb_recall_any, cb_recall_any),
};
static unsigned int nfs4_cb_counts[ARRAY_SIZE(nfs4_cb_procedures)];
static const 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,
.counts = nfs4_cb_counts,
};
static const struct rpc_version *nfs_cb_version[2] = {
[1] = &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);
/*
* nfsd4_lease is set to at most one hour in __nfsd4_write_time,
* so we can use 32-bit math on it. Warn if that assumption
* ever stops being true.
*/
if (WARN_ON_ONCE(nn->nfsd4_lease > 3600))
return 360 * HZ;
return max(((u32)nn->nfsd4_lease)/10, 1u) * HZ;
}
static struct workqueue_struct *callback_wq;
static bool nfsd4_queue_cb(struct nfsd4_callback *cb)
{
return queue_work(callback_wq, &cb->cb_work);
}
static void nfsd41_cb_inflight_begin(struct nfs4_client *clp)
{
atomic_inc(&clp->cl_cb_inflight);
}
static void nfsd41_cb_inflight_end(struct nfs4_client *clp)
{
if (atomic_dec_and_test(&clp->cl_cb_inflight))
wake_up_var(&clp->cl_cb_inflight);
}
static void nfsd41_cb_inflight_wait_complete(struct nfs4_client *clp)
{
wait_var_event(&clp->cl_cb_inflight,
!atomic_read(&clp->cl_cb_inflight));
}
static const struct cred *get_backchannel_cred(struct nfs4_client *clp, struct rpc_clnt *client, struct nfsd4_session *ses)
{
if (clp->cl_minorversion == 0) {
client->cl_principal = clp->cl_cred.cr_targ_princ ?
clp->cl_cred.cr_targ_princ : "nfs";
return get_cred(rpc_machine_cred());
} else {
struct cred *kcred;
kcred = prepare_kernel_cred(&init_task);
if (!kcred)
return NULL;
kcred->uid = ses->se_cb_sec.uid;
kcred->gid = ses->se_cb_sec.gid;
return kcred;
}
}
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 = 1,
.flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
.cred = current_cred(),
};
struct rpc_clnt *client;
const struct cred *cred;
if (clp->cl_minorversion == 0) {
if (!clp->cl_cred.cr_principal &&
(clp->cl_cred.cr_flavor >= RPC_AUTH_GSS_KRB5)) {
trace_nfsd_cb_setup_err(clp, -EINVAL);
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_session = ses;
args.bc_xprt = conn->cb_xprt;
args.prognumber = clp->cl_cb_session->se_cb_prog;
args.protocol = conn->cb_xprt->xpt_class->xcl_ident |
XPRT_TRANSPORT_BC;
args.authflavor = ses->se_cb_sec.flavor;
}
/* Create RPC client */
client = rpc_create(&args);
if (IS_ERR(client)) {
trace_nfsd_cb_setup_err(clp, PTR_ERR(client));
return PTR_ERR(client);
}
cred = get_backchannel_cred(clp, client, ses);
if (!cred) {
trace_nfsd_cb_setup_err(clp, -ENOMEM);
rpc_shutdown_client(client);
return -ENOMEM;
}
if (clp->cl_minorversion != 0)
clp->cl_cb_conn.cb_xprt = conn->cb_xprt;
clp->cl_cb_client = client;
clp->cl_cb_cred = cred;
rcu_read_lock();
trace_nfsd_cb_setup(clp, rpc_peeraddr2str(client, RPC_DISPLAY_NETID),
args.authflavor);
rcu_read_unlock();
return 0;
}
static void nfsd4_mark_cb_state(struct nfs4_client *clp, int newstate)
{
if (clp->cl_cb_state != newstate) {
clp->cl_cb_state = newstate;
trace_nfsd_cb_state(clp);
}
}
static void nfsd4_mark_cb_down(struct nfs4_client *clp, int reason)
{
if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
return;
nfsd4_mark_cb_state(clp, NFSD4_CB_DOWN);
}
static void nfsd4_mark_cb_fault(struct nfs4_client *clp, int reason)
{
if (test_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags))
return;
nfsd4_mark_cb_state(clp, NFSD4_CB_FAULT);
}
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
nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
}
static void nfsd4_cb_probe_release(void *calldata)
{
struct nfs4_client *clp = container_of(calldata, struct nfs4_client, cl_cb_null);
nfsd41_cb_inflight_end(clp);
}
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,
.rpc_release = nfsd4_cb_probe_release,
};
/*
* 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)
{
trace_nfsd_cb_probe(clp);
nfsd4_mark_cb_state(clp, NFSD4_CB_UNKNOWN);
set_bit(NFSD4_CLIENT_CB_UPDATE, &clp->cl_flags);
nfsd4_run_cb(&clp->cl_cb_null);
}
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)
{
nfsd4_mark_cb_state(clp, 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 nfsd4_callback *cb, struct rpc_task *task)
{
struct nfs4_client *clp = cb->cb_clp;
if (!cb->cb_holds_slot &&
test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
/* Race breaker */
if (test_and_set_bit(0, &clp->cl_cb_slot_busy) != 0) {
dprintk("%s slot is busy\n", __func__);
return false;
}
rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
}
cb->cb_holds_slot = true;
return true;
}
static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
if (cb->cb_holds_slot) {
cb->cb_holds_slot = false;
clear_bit(0, &clp->cl_cb_slot_busy);
rpc_wake_up_next(&clp->cl_cb_waitq);
}
}
static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
nfsd41_cb_release_slot(cb);
if (cb->cb_ops && cb->cb_ops->release)
cb->cb_ops->release(cb);
nfsd41_cb_inflight_end(clp);
}
/*
* 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_seq_status is only set in decode_cb_sequence4res,
* and so will remain 1 if an rpc level failure occurs.
*/
cb->cb_seq_status = 1;
cb->cb_status = 0;
if (minorversion && !nfsd41_cb_get_slot(cb, task))
return;
rpc_call_start(task);
}
static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
struct nfsd4_session *session = clp->cl_cb_session;
bool ret = true;
if (!clp->cl_minorversion) {
/*
* If the backchannel connection was shut down while this
* task was queued, we need to resubmit it after setting up
* a new backchannel connection.
*
* Note that if we lost our callback connection permanently
* the submission code will error out, so we don't need to
* handle that case here.
*/
if (RPC_SIGNALLED(task))
goto need_restart;
return true;
}
if (!cb->cb_holds_slot)
goto need_restart;
switch (cb->cb_seq_status) {
case 0:
/*
* No need for lock, access serialized in nfsd4_cb_prepare
*
* RFC5661 20.9.3
* If CB_SEQUENCE returns an error, then the state of the slot
* (sequence ID, cached reply) MUST NOT change.
*/
++session->se_cb_seq_nr;
break;
case -ESERVERFAULT:
++session->se_cb_seq_nr;
fallthrough;
case 1:
case -NFS4ERR_BADSESSION:
nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
ret = false;
break;
case -NFS4ERR_DELAY:
if (!rpc_restart_call(task))
goto out;
rpc_delay(task, 2 * HZ);
return false;
case -NFS4ERR_BADSLOT:
goto retry_nowait;
case -NFS4ERR_SEQ_MISORDERED:
if (session->se_cb_seq_nr != 1) {
session->se_cb_seq_nr = 1;
goto retry_nowait;
}
break;
default:
nfsd4_mark_cb_fault(cb->cb_clp, cb->cb_seq_status);
dprintk("%s: unprocessed error %d\n", __func__,
cb->cb_seq_status);
}
nfsd41_cb_release_slot(cb);
dprintk("%s: freed slot, new seqid=%d\n", __func__,
clp->cl_cb_session->se_cb_seq_nr);
if (RPC_SIGNALLED(task))
goto need_restart;
out:
return ret;
retry_nowait:
if (rpc_restart_call_prepare(task))
ret = false;
goto out;
need_restart:
if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
task->tk_status = 0;
cb->cb_need_restart = true;
}
return false;
}
static void nfsd4_cb_done(struct rpc_task *task, void *calldata)
{
struct nfsd4_callback *cb = calldata;
struct nfs4_client *clp = cb->cb_clp;
if (!nfsd4_cb_sequence_done(task, cb))
return;
if (cb->cb_status) {
WARN_ON_ONCE(task->tk_status);
task->tk_status = cb->cb_status;
}
switch (cb->cb_ops->done(cb, task)) {
case 0:
task->tk_status = 0;
rpc_restart_call_prepare(task);
return;
case 1:
switch (task->tk_status) {
case -EIO:
case -ETIMEDOUT:
case -EACCES:
nfsd4_mark_cb_down(clp, task->tk_status);
}
break;
default:
BUG();
}
}
static void nfsd4_cb_release(void *calldata)
{
struct nfsd4_callback *cb = calldata;
if (cb->cb_need_restart)
nfsd4_queue_cb(cb);
else
nfsd41_destroy_cb(cb);
}
static const struct rpc_call_ops nfsd4_cb_ops = {
.rpc_call_prepare = nfsd4_cb_prepare,
.rpc_call_done = nfsd4_cb_done,
.rpc_release = nfsd4_cb_release,
};
int nfsd4_create_callback_queue(void)
{
callback_wq = alloc_ordered_workqueue("nfsd4_callbacks", 0);
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)
{
if (clp->cl_cb_state != NFSD4_CB_UNKNOWN)
trace_nfsd_cb_shutdown(clp);
set_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags);
/*
* Note this won't actually result in a null callback;
* instead, nfsd4_run_cb_null() will detect the killed
* client, destroy the rpc client, and stop:
*/
nfsd4_run_cb(&clp->cl_cb_null);
flush_workqueue(callback_wq);
nfsd41_cb_inflight_wait_complete(clp);
}
/* 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;
}
/*
* Note there isn't a lot of locking in this code; instead we depend on
* the fact that it is run from the callback_wq, which won't run two
* work items at once. So, for example, callback_wq handles all access
* of cl_cb_client and all calls to rpc_create or rpc_shutdown_client.
*/
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_cred(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);
if (c)
svc_xprt_put(c->cn_xprt);
return;
}
}
static void
nfsd4_run_cb_work(struct work_struct *work)
{
struct nfsd4_callback *cb =
container_of(work, struct nfsd4_callback, cb_work);
struct nfs4_client *clp = cb->cb_clp;
struct rpc_clnt *clnt;
int flags;
if (cb->cb_need_restart) {
cb->cb_need_restart = false;
} else {
if (cb->cb_ops && cb->cb_ops->prepare)
cb->cb_ops->prepare(cb);
}
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: */
nfsd41_destroy_cb(cb);
return;
}
/*
* Don't send probe messages for 4.1 or later.
*/
if (!cb->cb_ops && clp->cl_minorversion) {
nfsd4_mark_cb_state(clp, NFSD4_CB_UP);
nfsd41_destroy_cb(cb);
return;
}
cb->cb_msg.rpc_cred = clp->cl_cb_cred;
flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
}
void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op)
{
cb->cb_clp = clp;
cb->cb_msg.rpc_proc = &nfs4_cb_procedures[op];
cb->cb_msg.rpc_argp = cb;
cb->cb_msg.rpc_resp = cb;
cb->cb_ops = ops;
INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
cb->cb_seq_status = 1;
cb->cb_status = 0;
cb->cb_need_restart = false;
cb->cb_holds_slot = false;
}
/**
* nfsd4_run_cb - queue up a callback job to run
* @cb: callback to queue
*
* Kick off a callback to do its thing. Returns false if it was already
* on a queue, true otherwise.
*/
bool nfsd4_run_cb(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
bool queued;
nfsd41_cb_inflight_begin(clp);
queued = nfsd4_queue_cb(cb);
if (!queued)
nfsd41_cb_inflight_end(clp);
return queued;
}