/*
* 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/nfs4.h>
#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 "stats.h"
#include "trace.h"
#include "xdr4cb.h"
#include "xdr4.h"
#include "nfs4xdr_gen.h"
#define NFSDDBG_FACILITY NFSDDBG_PROC
#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)
{
xdr_stream_encode_uint32_array(xdr, bitmap, len);
}
static int decode_cb_fattr4(struct xdr_stream *xdr, uint32_t *bitmap,
struct nfs4_cb_fattr *fattr)
{
fattr->ncf_cb_change = 0;
fattr->ncf_cb_fsize = 0;
fattr->ncf_cb_atime.tv_sec = 0;
fattr->ncf_cb_atime.tv_nsec = 0;
fattr->ncf_cb_mtime.tv_sec = 0;
fattr->ncf_cb_mtime.tv_nsec = 0;
if (bitmap[0] & FATTR4_WORD0_CHANGE)
if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_change) < 0)
return -EIO;
if (bitmap[0] & FATTR4_WORD0_SIZE)
if (xdr_stream_decode_u64(xdr, &fattr->ncf_cb_fsize) < 0)
return -EIO;
if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_ACCESS) {
fattr4_time_deleg_access access;
if (!xdrgen_decode_fattr4_time_deleg_access(xdr, &access))
return -EIO;
if (access.nseconds >= NSEC_PER_SEC)
return -EIO;
fattr->ncf_cb_atime.tv_sec = access.seconds;
fattr->ncf_cb_atime.tv_nsec = access.nseconds;
}
if (bitmap[2] & FATTR4_WORD2_TIME_DELEG_MODIFY) {
fattr4_time_deleg_modify modify;
if (!xdrgen_decode_fattr4_time_deleg_modify(xdr, &modify))
return -EIO;
if (modify.nseconds >= NSEC_PER_SEC)
return -EIO;
fattr->ncf_cb_mtime.tv_sec = modify.seconds;
fattr->ncf_cb_mtime.tv_nsec = modify.nseconds;
}
return 0;
}
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, XDR_UNIT);
if (unlikely(p == NULL))
goto out_overflow;
hdr->status = be32_to_cpup(p);
/* Ignore the tag */
if (xdr_stream_decode_u32(xdr, &length) < 0)
goto out_overflow;
if (xdr_inline_decode(xdr, length) == NULL)
goto out_overflow;
if (xdr_stream_decode_u32(xdr, &hdr->nops) < 0)
goto out_overflow;
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_GETATTR4args
* struct CB_GETATTR4args {
* nfs_fh4 fh;
* bitmap4 attr_request;
* };
*
* The size and change attributes are the only one
* guaranteed to be serviced by the client.
*/
static void
encode_cb_getattr4args(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr,
struct nfs4_cb_fattr *fattr)
{
struct nfs4_delegation *dp = container_of(fattr, struct nfs4_delegation, dl_cb_fattr);
struct knfsd_fh *fh = &dp->dl_stid.sc_file->fi_fhandle;
struct nfs4_cb_fattr *ncf = &dp->dl_cb_fattr;
u32 bmap_size = 1;
u32 bmap[3];
bmap[0] = FATTR4_WORD0_SIZE;
if (!ncf->ncf_file_modified)
bmap[0] |= FATTR4_WORD0_CHANGE;
if (deleg_attrs_deleg(dp->dl_type)) {
bmap[1] = 0;
bmap[2] = FATTR4_WORD2_TIME_DELEG_ACCESS | FATTR4_WORD2_TIME_DELEG_MODIFY;
bmap_size = 3;
}
encode_nfs_cb_opnum4(xdr, OP_CB_GETATTR);
encode_nfs_fh4(xdr, fh);
encode_bitmap4(xdr, bmap, bmap_size);
hdr->nops++;
}
static u32 highest_slotid(struct nfsd4_session *ses)
{
u32 idx;
spin_lock(&ses->se_lock);
idx = fls(~ses->se_cb_slot_avail);
if (idx > 0)
--idx;
idx = max(idx, ses->se_cb_highest_slot);
spin_unlock(&ses->se_lock);
return idx;
}
static void
encode_referring_call4(struct xdr_stream *xdr,
const struct nfsd4_referring_call *rc)
{
encode_uint32(xdr, rc->rc_sequenceid);
encode_uint32(xdr, rc->rc_slotid);
}
static void
encode_referring_call_list4(struct xdr_stream *xdr,
const struct nfsd4_referring_call_list *rcl)
{
struct nfsd4_referring_call *rc;
__be32 *p;
p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN);
xdr_encode_opaque_fixed(p, rcl->rcl_sessionid.data,
NFS4_MAX_SESSIONID_LEN);
encode_uint32(xdr, rcl->__nr_referring_calls);
list_for_each_entry(rc, &rcl->rcl_referring_calls, __list)
encode_referring_call4(xdr, rc);
}
/*
* 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;
struct nfsd4_referring_call_list *rcl;
__be32 *p;
if (hdr->minorversion == 0)
return;
rcu_read_lock();
session = rcu_dereference(cb->cb_clp->cl_cb_session);
if (!session) {
rcu_read_unlock();
return;
}
encode_nfs_cb_opnum4(xdr, OP_CB_SEQUENCE);
encode_sessionid4(xdr, session);
p = xdr_reserve_space(xdr, XDR_UNIT * 4);
*p++ = cpu_to_be32(session->se_cb_seq_nr[cb->cb_held_slot]); /* csa_sequenceid */
*p++ = cpu_to_be32(cb->cb_held_slot); /* csa_slotid */
*p++ = cpu_to_be32(highest_slotid(session)); /* csa_highest_slotid */
*p++ = xdr_zero; /* csa_cachethis */
/* csa_referring_call_lists */
encode_uint32(xdr, cb->cb_nr_referring_call_list);
list_for_each_entry(rcl, &cb->cb_referring_call_list, __list)
encode_referring_call_list4(xdr, rcl);
hdr->nops++;
rcu_read_unlock();
}
static void update_cb_slot_table(struct nfsd4_session *ses, u32 target)
{
/* No need to do anything if nothing changed */
if (likely(target == READ_ONCE(ses->se_cb_highest_slot)))
return;
spin_lock(&ses->se_lock);
if (target > ses->se_cb_highest_slot) {
int i;
target = min(target, NFSD_BC_SLOT_TABLE_SIZE - 1);
/*
* Growing the slot table. Reset any new sequences to 1.
*
* NB: There is some debate about whether the RFC requires this,
* but the Linux client expects it.
*/
for (i = ses->se_cb_highest_slot + 1; i <= target; ++i)
ses->se_cb_seq_nr[i] = 1;
}
ses->se_cb_highest_slot = target;
spin_unlock(&ses->se_lock);
}
/*
* 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;
int status = -ESERVERFAULT;
__be32 *p;
u32 seqid, slotid, target;
rcu_read_lock();
session = rcu_dereference(cb->cb_clp->cl_cb_session);
if (!session) {
rcu_read_unlock();
cb->cb_seq_status = -NFS4ERR_BADSESSION;
return -NFS4ERR_BADSESSION;
}
/*
* 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)) {
rcu_read_unlock();
goto out_overflow;
}
if (memcmp(p, session->se_sessionid.data, NFS4_MAX_SESSIONID_LEN)) {
dprintk("NFS: %s Invalid session id\n", __func__);
rcu_read_unlock();
goto out;
}
p += XDR_QUADLEN(NFS4_MAX_SESSIONID_LEN);
seqid = be32_to_cpup(p++);
if (seqid != session->se_cb_seq_nr[cb->cb_held_slot]) {
dprintk("NFS: %s Invalid sequence number\n", __func__);
rcu_read_unlock();
goto out;
}
slotid = be32_to_cpup(p++);
if (slotid != cb->cb_held_slot) {
dprintk("NFS: %s Invalid slotid\n", __func__);
rcu_read_unlock();
goto out;
}
p++; // ignore current highest slot value
target = be32_to_cpup(p++);
update_cb_slot_table(session, target);
rcu_read_unlock();
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);
}
/*
* 20.1. Operation 3: CB_GETATTR - Get Attributes
*/
static void nfs4_xdr_enc_cb_getattr(struct rpc_rqst *req,
struct xdr_stream *xdr, const void *data)
{
const struct nfsd4_callback *cb = data;
struct nfs4_cb_fattr *ncf =
container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
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_getattr4args(xdr, &hdr, ncf);
encode_cb_nops(&hdr);
}
/*
* 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;
}
/*
* 20.1. Operation 3: CB_GETATTR - Get Attributes
*/
static int nfs4_xdr_dec_cb_getattr(struct rpc_rqst *rqstp,
struct xdr_stream *xdr,
void *data)
{
struct nfsd4_callback *cb = data;
struct nfs4_cb_compound_hdr hdr;
int status;
u32 bitmap[3] = {0};
u32 attrlen, maxlen;
struct nfs4_cb_fattr *ncf =
container_of(cb, struct nfs4_cb_fattr, ncf_getattr);
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_GETATTR, &cb->cb_status);
if (unlikely(status || cb->cb_status))
return status;
if (xdr_stream_decode_uint32_array(xdr, bitmap, 3) < 0)
return -EIO;
if (xdr_stream_decode_u32(xdr, &attrlen) < 0)
return -EIO;
maxlen = sizeof(ncf->ncf_cb_change) + sizeof(ncf->ncf_cb_fsize);
if (bitmap[2] != 0)
maxlen += (sizeof(ncf->ncf_cb_mtime.tv_sec) +
sizeof(ncf->ncf_cb_mtime.tv_nsec)) * 2;
if (attrlen > maxlen)
return -EIO;
status = decode_cb_fattr4(xdr, bitmap, ncf);
return status;
}
/*
* 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(struct rpc_rqst *req,
struct xdr_stream *xdr,
const void *data)
{
const struct nfsd4_callback *cb = data;
struct nfsd4_cb_notify *ncn = container_of(cb, struct nfsd4_cb_notify, ncn_cb);
struct nfs4_delegation *dp = container_of(ncn, struct nfs4_delegation, dl_cb_notify);
struct nfs4_cb_compound_hdr hdr = {
.ident = 0,
.minorversion = cb->cb_clp->cl_minorversion,
};
struct CB_NOTIFY4args args;
unsigned int start;
WARN_ON_ONCE(hdr.minorversion == 0);
encode_cb_compound4args(xdr, &hdr);
encode_cb_sequence4args(xdr, cb, &hdr);
/*
* nfsd4_cb_notify_prepare() sized the payload against a single page,
* but did not account for the compound, sequence, stateid, and
* filehandle encoded here. If the variable-length encode overflows the
* backchannel send buffer, roll back to before the operation so that a
* truncated CB_NOTIFY is never placed on the wire.
*/
start = xdr_stream_pos(xdr);
if (xdr_stream_encode_u32(xdr, OP_CB_NOTIFY) < 0)
goto out_err;
args.cna_stateid.seqid = dp->dl_stid.sc_stateid.si_generation;
memcpy(&args.cna_stateid.other, &dp->dl_stid.sc_stateid.si_opaque,
ARRAY_SIZE(args.cna_stateid.other));
args.cna_fh.len = dp->dl_stid.sc_file->fi_fhandle.fh_size;
args.cna_fh.data = dp->dl_stid.sc_file->fi_fhandle.fh_raw;
args.cna_changes.count = ncn->ncn_nf_cnt;
args.cna_changes.element = ncn->ncn_nf;
if (!xdrgen_encode_CB_NOTIFY4args(xdr, &args))
goto out_err;
hdr.nops++;
encode_cb_nops(&hdr);
return;
out_err:
/*
* Drop the CB_NOTIFY op and emit a valid CB_SEQUENCE-only compound so
* the client still advances its slot. Flag the failure so the done
* handler recalls the delegation and the missed notification is not
* silently lost. The flag is written here in the transmit path and read
* in the done handler; the two are serialized phases of the same
* rpc_task, so no additional barrier is needed.
*/
ncn->ncn_encode_err = true;
xdr_truncate_encode(xdr, start);
encode_cb_nops(&hdr);
}
static int nfs4_xdr_dec_cb_notify(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, &cb->cb_status);
}
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.c.flc_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_CLNT_##proc, \
.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, COMPOUND, cb_notify, cb_notify),
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),
PROC(CB_GETATTR, COMPOUND, cb_getattr, cb_getattr),
};
#define NFS4_CB_PROGRAM 0x40000000
#define NFS4_CB_VERSION 1
struct nfsd_net_cb {
struct rpc_version version4;
const struct rpc_version *versions[NFS4_CB_VERSION + 1];
struct rpc_program program;
struct rpc_stat stat;
};
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 bool nfsd4_queue_cb(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
trace_nfsd_cb_queue(clp, cb);
return queue_work(clp->cl_callback_wq, &cb->cb_work);
}
static void nfsd4_requeue_cb(struct rpc_task *task, struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
if (!test_bit(NFSD4_CLIENT_CB_KILL, &clp->cl_flags)) {
trace_nfsd_cb_restart(clp, cb);
task->tk_status = 0;
set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags);
}
}
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)
{
atomic_dec_and_wake_up(&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->fsuid = ses->se_cb_sec.uid;
kcred->fsgid = 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)
{
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
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,
.version = NFS4_CB_VERSION,
.flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
.cred = current_cred(),
};
struct rpc_clnt *client;
const struct cred *cred;
args.program = &nn->nfsd_cb->program;
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 || !ses)
return -EINVAL;
args.bc_xprt = conn->cb_xprt;
args.prognumber = ses->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;
rcu_assign_pointer(clp->cl_cb_session, ses);
}
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_new_state(clp);
}
}
static void nfsd4_mark_cb_down(struct nfs4_client *clp)
{
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)
{
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);
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(clp->cl_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);
}
static int grab_slot(struct nfsd4_session *ses)
{
int idx;
spin_lock(&ses->se_lock);
idx = ffs(ses->se_cb_slot_avail) - 1;
if (idx < 0 || idx > ses->se_cb_highest_slot) {
spin_unlock(&ses->se_lock);
return -1;
}
/* clear the bit for the slot */
ses->se_cb_slot_avail &= ~BIT(idx);
spin_unlock(&ses->se_lock);
return idx;
}
/*
* 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;
struct nfsd4_session *ses;
if (cb->cb_held_slot >= 0)
return true;
rcu_read_lock();
ses = rcu_dereference(clp->cl_cb_session);
if (!ses) {
rcu_read_unlock();
rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
return false;
}
cb->cb_held_slot = grab_slot(ses);
if (cb->cb_held_slot < 0) {
rcu_read_unlock();
rpc_sleep_on(&clp->cl_cb_waitq, task, NULL);
/* Race breaker */
rcu_read_lock();
ses = rcu_dereference(clp->cl_cb_session);
if (ses)
cb->cb_held_slot = grab_slot(ses);
rcu_read_unlock();
if (cb->cb_held_slot < 0)
return false;
rpc_wake_up_queued_task(&clp->cl_cb_waitq, task);
} else {
rcu_read_unlock();
}
return true;
}
static void nfsd41_cb_release_slot(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
struct nfsd4_session *ses;
if (cb->cb_held_slot >= 0) {
rcu_read_lock();
ses = rcu_dereference(clp->cl_cb_session);
if (ses) {
spin_lock(&ses->se_lock);
ses->se_cb_slot_avail |= BIT(cb->cb_held_slot);
spin_unlock(&ses->se_lock);
}
rcu_read_unlock();
cb->cb_held_slot = -1;
rpc_wake_up_next(&clp->cl_cb_waitq);
}
}
static void nfsd41_destroy_cb(struct nfsd4_callback *cb)
{
struct nfs4_client *clp = cb->cb_clp;
trace_nfsd_cb_destroy(clp, cb);
nfsd41_cb_release_slot(cb);
if (test_bit(NFSD4_CALLBACK_WAKE, &cb->cb_flags))
clear_and_wake_up_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags);
else
clear_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags);
/*
* Order the clear of NFSD4_CALLBACK_RUNNING above before the ->release()
* callback below. A release op may re-check producer-side state to decide
* whether to requeue itself (see nfsd4_cb_notify_release()), and that
* check must not be reordered ahead of the clear. The plain clear_bit()
* path carries no ordering; clear_and_wake_up_bit() already issues this
* barrier internally, so the extra one is harmless there.
*/
smp_mb__after_atomic();
if (cb->cb_ops && cb->cb_ops->release)
cb->cb_ops->release(cb);
nfsd41_cb_inflight_end(clp);
}
/**
* nfsd41_cb_referring_call - add a referring call to a callback operation
* @cb: context of callback to add the rc to
* @sessionid: referring call's session ID
* @slotid: referring call's session slot index
* @seqno: referring call's slot sequence number
*
* Caller serializes access to @cb.
*
* NB: If memory allocation fails, the referring call is not added.
*/
void nfsd41_cb_referring_call(struct nfsd4_callback *cb,
struct nfs4_sessionid *sessionid,
u32 slotid, u32 seqno)
{
struct nfsd4_referring_call_list *rcl;
struct nfsd4_referring_call *rc;
bool found;
might_sleep();
found = false;
list_for_each_entry(rcl, &cb->cb_referring_call_list, __list) {
if (!memcmp(rcl->rcl_sessionid.data, sessionid->data,
NFS4_MAX_SESSIONID_LEN)) {
found = true;
break;
}
}
if (!found) {
rcl = kmalloc_obj(*rcl);
if (!rcl)
return;
memcpy(rcl->rcl_sessionid.data, sessionid->data,
NFS4_MAX_SESSIONID_LEN);
rcl->__nr_referring_calls = 0;
INIT_LIST_HEAD(&rcl->rcl_referring_calls);
list_add(&rcl->__list, &cb->cb_referring_call_list);
cb->cb_nr_referring_call_list++;
}
found = false;
list_for_each_entry(rc, &rcl->rcl_referring_calls, __list) {
if (rc->rc_sequenceid == seqno && rc->rc_slotid == slotid) {
found = true;
break;
}
}
if (!found) {
rc = kmalloc_obj(*rc);
if (!rc)
goto out;
rc->rc_sequenceid = seqno;
rc->rc_slotid = slotid;
rcl->__nr_referring_calls++;
list_add(&rc->__list, &rcl->rcl_referring_calls);
}
out:
if (!rcl->__nr_referring_calls) {
cb->cb_nr_referring_call_list--;
list_del(&rcl->__list);
kfree(rcl);
}
}
/**
* nfsd41_cb_destroy_referring_call_list - release referring call info
* @cb: context of a callback that has completed
*
* Callers who allocate referring calls using nfsd41_cb_referring_call() must
* release those resources by calling nfsd41_cb_destroy_referring_call_list.
*
* Caller serializes access to @cb.
*/
void nfsd41_cb_destroy_referring_call_list(struct nfsd4_callback *cb)
{
struct nfsd4_referring_call_list *rcl;
struct nfsd4_referring_call *rc;
while (!list_empty(&cb->cb_referring_call_list)) {
rcl = list_first_entry(&cb->cb_referring_call_list,
struct nfsd4_referring_call_list,
__list);
while (!list_empty(&rcl->rcl_referring_calls)) {
rc = list_first_entry(&rcl->rcl_referring_calls,
struct nfsd4_referring_call,
__list);
list_del(&rc->__list);
kfree(rc);
}
list_del(&rcl->__list);
kfree(rcl);
}
}
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.
*/
trace_nfsd_cb_rpc_prepare(clp);
cb->cb_seq_status = 1;
cb->cb_status = 0;
if (minorversion) {
if (!rcu_access_pointer(clp->cl_cb_session)) {
rpc_exit(task, -EIO);
return;
}
if (!nfsd41_cb_get_slot(cb, task))
return;
}
rpc_call_start(task);
}
/* Returns true if CB_COMPOUND processing should continue */
static bool nfsd4_cb_sequence_done(struct rpc_task *task, struct nfsd4_callback *cb)
{
struct nfsd4_session *session;
bool ret = false;
if (cb->cb_held_slot < 0)
goto requeue;
rcu_read_lock();
session = rcu_dereference(cb->cb_clp->cl_cb_session);
if (!session) {
rcu_read_unlock();
goto requeue;
}
/* This is the operation status code for CB_SEQUENCE */
trace_nfsd_cb_seq_status(task, cb, session);
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[cb->cb_held_slot];
ret = true;
break;
case -ESERVERFAULT:
/*
* Call succeeded, but the session, slot index, or slot
* sequence number in the response do not match the same
* in the server's call. The sequence information is thus
* untrustworthy.
*/
nfsd4_mark_cb_fault(cb->cb_clp);
break;
case 1:
/*
* cb_seq_status remains 1 if an RPC Reply was never
* received. NFSD can't know if the client processed
* the CB_SEQUENCE operation. Ask the client to send a
* DESTROY_SESSION to recover.
*/
fallthrough;
case -NFS4ERR_BADSESSION:
nfsd4_mark_cb_fault(cb->cb_clp);
rcu_read_unlock();
goto requeue;
case -NFS4ERR_DELAY:
cb->cb_seq_status = 1;
if (RPC_SIGNALLED(task) || !rpc_restart_call(task)) {
rcu_read_unlock();
goto requeue;
}
rpc_delay(task, 2 * HZ);
rcu_read_unlock();
return false;
case -NFS4ERR_SEQ_MISORDERED:
case -NFS4ERR_BADSLOT:
/*
* A SEQ_MISORDERED or BADSLOT error means that the client and
* server are out of sync as to the backchannel parameters. Mark
* the backchannel faulty and restart the RPC, but leak the slot
* so that it's no longer used.
*/
nfsd4_mark_cb_fault(cb->cb_clp);
cb->cb_held_slot = -1;
rcu_read_unlock();
goto retry_nowait;
default:
nfsd4_mark_cb_fault(cb->cb_clp);
}
trace_nfsd_cb_free_slot(task, cb, session);
rcu_read_unlock();
nfsd41_cb_release_slot(cb);
return ret;
retry_nowait:
/*
* RPC_SIGNALLED() means that the rpc_client is being torn down and
* (possibly) recreated. Requeue the call in that case.
*/
if (!RPC_SIGNALLED(task)) {
if (rpc_restart_call_prepare(task))
return false;
}
requeue:
nfsd41_cb_release_slot(cb);
nfsd4_requeue_cb(task, cb);
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;
trace_nfsd_cb_rpc_done(clp);
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))
nfsd4_requeue_cb(task, cb);
} else if (!nfsd4_cb_sequence_done(task, cb)) {
return;
}
if (cb->cb_status) {
WARN_ONCE(task->tk_status,
"cb_status=%d tk_status=%d cb_opcode=%d",
cb->cb_status, task->tk_status, cb->cb_ops->opcode);
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);
}
break;
default:
BUG();
}
}
static void nfsd4_cb_release(void *calldata)
{
struct nfsd4_callback *cb = calldata;
trace_nfsd_cb_rpc_release(cb->cb_clp);
if (test_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags))
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,
};
/* 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(clp->cl_callback_wq);
nfsd41_cb_inflight_wait_complete(clp);
}
static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
{
struct nfsd4_session *s;
struct nfsd4_conn *c;
lockdep_assert_held(&clp->cl_lock);
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 clp->cl_callback_wq, which won't run two
* work items at once. So, for example, clp->cl_callback_wq handles all
* access of cl_cb_client, and all calls to rpc_create or
* rpc_shutdown_client.
*
* cl_cb_session is written only from cl_callback_wq (via
* rcu_assign_pointer) and read from rpciod under rcu_read_lock (via
* rcu_dereference) by encode_cb_sequence4args(), decode_cb_sequence4resok(),
* nfsd4_cb_sequence_done(), and the cb-slot helpers. Sessions are freed
* with kfree_rcu() so that rpciod readers in an RCU read-side critical
* section never dereference a freed session.
*/
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;
trace_nfsd_cb_bc_update(clp, cb);
/*
* This is either an update, or the client dying; in either case,
* kill the old client:
*/
if (clp->cl_cb_client) {
trace_nfsd_cb_bc_shutdown(clp, cb);
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:
*/
WARN_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);
if (c)
svc_xprt_put(c->cn_xprt);
rcu_assign_pointer(clp->cl_cb_session, ses);
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, ret;
trace_nfsd_cb_start(clp);
if (clp->cl_flags & NFSD4_CLIENT_CB_FLAG_MASK)
nfsd4_process_cb_update(cb);
clnt = clp->cl_cb_client;
if (!clnt || clp->cl_state == NFSD4_COURTESY) {
/*
* Callback channel broken, client killed or
* nfs4_client in courtesy state; 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;
}
if (!test_and_clear_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags)) {
if (cb->cb_ops && cb->cb_ops->prepare)
if (!cb->cb_ops->prepare(cb)) {
nfsd41_destroy_cb(cb);
return;
}
}
cb->cb_msg.rpc_cred = clp->cl_cb_cred;
flags = clp->cl_minorversion ? RPC_TASK_NOCONNECT : RPC_TASK_SOFTCONN;
ret = rpc_call_async(clnt, &cb->cb_msg, RPC_TASK_SOFT | flags,
cb->cb_ops ? &nfsd4_cb_ops : &nfsd4_cb_probe_ops, cb);
if (ret != 0) {
set_bit(NFSD4_CALLBACK_REQUEUE, &cb->cb_flags);
nfsd4_queue_cb(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_flags = 0;
cb->cb_ops = ops;
INIT_WORK(&cb->cb_work, nfsd4_run_cb_work);
cb->cb_status = 0;
cb->cb_held_slot = -1;
cb->cb_nr_referring_call_list = 0;
INIT_LIST_HEAD(&cb->cb_referring_call_list);
}
/**
* 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;
struct nfsd_net *nn = net_generic(clp->net, nfsd_net_id);
const struct nfsd4_callback_ops *ops = cb->cb_ops;
u32 minorversion = clp->cl_minorversion;
bool queued;
nfsd41_cb_inflight_begin(clp);
queued = nfsd4_queue_cb(cb);
if (queued) {
if (ops) {
nfsd_stats_cb_op_inc(nn, ops->opcode);
/*
* Minorversion > 0 callbacks prepend a CB_SEQUENCE op
* (see encode_cb_sequence4args()); count it like the
* forechannel counts SEQUENCE, so it isn't perpetually
* reported as zero. CB_NULL probes (ops == NULL) carry
* no CB_SEQUENCE -- and on 4.1+ they are dropped without
* sending any RPC (see nfsd4_run_cb_work()) -- so they
* must not be counted here.
*/
if (minorversion > 0)
nfsd_stats_cb_op_inc(nn, OP_CB_SEQUENCE);
}
} else {
nfsd41_cb_inflight_end(clp);
}
return queued;
}
/**
* nfsd_net_cb_shutdown - release per-netns callback RPC program resources
* @nn: NFS server network namespace
*
* Frees resources allocated by nfsd_net_cb_init().
*/
void nfsd_net_cb_shutdown(struct nfsd_net *nn)
{
struct nfsd_net_cb *cb = nn->nfsd_cb;
if (cb) {
kfree(cb->version4.counts);
kfree(cb);
nn->nfsd_cb = NULL;
}
}
/**
* nfsd_net_cb_init - initialize per-netns callback RPC program
* @nn: NFS server network namespace
*
* Sets up the callback RPC program, version table, procedure
* counts, and statistics structure for @nn. Caller must release
* these resources using nfsd_net_cb_shutdown().
*
* Return: 0 on success, or -ENOMEM if allocation fails.
*/
int nfsd_net_cb_init(struct nfsd_net *nn)
{
struct nfsd_net_cb *cb;
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
if (!cb)
return -ENOMEM;
cb->version4.counts = kzalloc_objs(unsigned int,
ARRAY_SIZE(nfs4_cb_procedures), GFP_KERNEL);
if (!cb->version4.counts) {
kfree(cb);
return -ENOMEM;
}
/*
* 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.
*/
cb->version4.number = NFS4_CB_VERSION;
cb->version4.nrprocs = ARRAY_SIZE(nfs4_cb_procedures);
cb->version4.procs = nfs4_cb_procedures;
cb->versions[NFS4_CB_VERSION] = &cb->version4;
cb->program.name = "nfs4_cb";
cb->program.number = NFS4_CB_PROGRAM;
cb->program.nrvers = ARRAY_SIZE(cb->versions);
cb->program.version = &cb->versions[0];
cb->program.pipe_dir_name = "nfsd4_cb";
cb->program.stats = &cb->stat;
cb->stat.program = &cb->program;
nn->nfsd_cb = cb;
return 0;
}
