FEX-Emu/linux
1
0
Fork 0
mirror of https://github.com/FEX-Emu/linux.git synced 2025-01-01 06:42:31 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity
ecdd03b791
linux/fs/nfsd/nfs4callback.c
J. Bruce Fields ecdd03b791 nfsd4: create rpc callback client from server thread 
The code is a little simpler, and it should be easier to avoid races, if
we just do all rpc client creation/destruction from nfsd or laundromat
threads and do only the rpc calls themselves asynchronously.  The rpc
creation doesn't involve any significant waiting (it doesn't call the
client, for example), so there's no reason not to do this.

Also don't bother destroying the client on failure of the rpc null
probe.  We may want to retry the probe later anyway.

Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
2009-04-29 16:44:53 -04:00

511 lines
14 KiB
C
Raw Blame History

/*
* linux/fs/nfsd/nfs4callback.c
*
* Copyright (c) 2001 The Regents of the University of Michigan.
* All rights reserved.
*
* Kendrick Smith <kmsmith@umich.edu>
* Andy Adamson <andros@umich.edu>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
* BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/module.h>
#include <linux/list.h>
#include <linux/inet.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/sched.h>
#include <linux/kthread.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/clnt.h>
#include <linux/nfsd/nfsd.h>
#include <linux/nfsd/state.h>
#include <linux/sunrpc/sched.h>
#include <linux/nfs4.h>
#define NFSDDBG_FACILITY NFSDDBG_PROC
#define NFSPROC4_CB_NULL 0
#define NFSPROC4_CB_COMPOUND 1
/* Index of predefined Linux callback client operations */
enum {
NFSPROC4_CLNT_CB_NULL = 0,
NFSPROC4_CLNT_CB_RECALL,
};
enum nfs_cb_opnum4 {
OP_CB_RECALL = 4,
};
#define NFS4_MAXTAGLEN 20
#define NFS4_enc_cb_null_sz 0
#define NFS4_dec_cb_null_sz 0
#define cb_compound_enc_hdr_sz 4
#define cb_compound_dec_hdr_sz (3 + (NFS4_MAXTAGLEN >> 2))
#define op_enc_sz 1
#define op_dec_sz 2
#define enc_nfs4_fh_sz (1 + (NFS4_FHSIZE >> 2))
#define enc_stateid_sz (NFS4_STATEID_SIZE >> 2)
#define NFS4_enc_cb_recall_sz (cb_compound_enc_hdr_sz + \
1 + enc_stateid_sz + \
enc_nfs4_fh_sz)
#define NFS4_dec_cb_recall_sz (cb_compound_dec_hdr_sz + \
op_dec_sz)
/*
* Generic encode routines from fs/nfs/nfs4xdr.c
*/
static inline __be32 *
xdr_writemem(__be32 *p, const void *ptr, int nbytes)
{
int tmp = XDR_QUADLEN(nbytes);
if (!tmp)
return p;
p[tmp-1] = 0;
memcpy(p, ptr, nbytes);
return p + tmp;
}
#define WRITE32(n) *p++ = htonl(n)
#define WRITEMEM(ptr,nbytes) do { \
p = xdr_writemem(p, ptr, nbytes); \
} while (0)
#define RESERVE_SPACE(nbytes) do { \
p = xdr_reserve_space(xdr, nbytes); \
if (!p) dprintk("NFSD: RESERVE_SPACE(%d) failed in function %s\n", (int) (nbytes), __func__); \
BUG_ON(!p); \
} while (0)
/*
* Generic decode routines from fs/nfs/nfs4xdr.c
*/
#define DECODE_TAIL \
status = 0; \
out: \
return status; \
xdr_error: \
dprintk("NFSD: xdr error! (%s:%d)\n", __FILE__, __LINE__); \
status = -EIO; \
goto out
#define READ32(x) (x) = ntohl(*p++)
#define READ64(x) do { \
(x) = (u64)ntohl(*p++) << 32; \
(x) |= ntohl(*p++); \
} while (0)
#define READTIME(x) do { \
p++; \
(x.tv_sec) = ntohl(*p++); \
(x.tv_nsec) = ntohl(*p++); \
} while (0)
#define READ_BUF(nbytes) do { \
p = xdr_inline_decode(xdr, nbytes); \
if (!p) { \
dprintk("NFSD: %s: reply buffer overflowed in line %d.\n", \
__func__, __LINE__); \
return -EIO; \
} \
} while (0)
struct nfs4_cb_compound_hdr {
int status;
u32 ident;
u32 nops;
u32 taglen;
char * tag;
};
static struct {
int stat;
int errno;
} nfs_cb_errtbl[] = {
{ NFS4_OK, 0 },
{ NFS4ERR_PERM, EPERM },
{ NFS4ERR_NOENT, ENOENT },
{ NFS4ERR_IO, EIO },
{ NFS4ERR_NXIO, ENXIO },
{ NFS4ERR_ACCESS, EACCES },
{ NFS4ERR_EXIST, EEXIST },
{ NFS4ERR_XDEV, EXDEV },
{ NFS4ERR_NOTDIR, ENOTDIR },
{ NFS4ERR_ISDIR, EISDIR },
{ NFS4ERR_INVAL, EINVAL },
{ NFS4ERR_FBIG, EFBIG },
{ NFS4ERR_NOSPC, ENOSPC },
{ NFS4ERR_ROFS, EROFS },
{ NFS4ERR_MLINK, EMLINK },
{ NFS4ERR_NAMETOOLONG, ENAMETOOLONG },
{ NFS4ERR_NOTEMPTY, ENOTEMPTY },
{ NFS4ERR_DQUOT, EDQUOT },
{ NFS4ERR_STALE, ESTALE },
{ NFS4ERR_BADHANDLE, EBADHANDLE },
{ NFS4ERR_BAD_COOKIE, EBADCOOKIE },
{ NFS4ERR_NOTSUPP, ENOTSUPP },
{ NFS4ERR_TOOSMALL, ETOOSMALL },
{ NFS4ERR_SERVERFAULT, ESERVERFAULT },
{ NFS4ERR_BADTYPE, EBADTYPE },
{ NFS4ERR_LOCKED, EAGAIN },
{ NFS4ERR_RESOURCE, EREMOTEIO },
{ NFS4ERR_SYMLINK, ELOOP },
{ NFS4ERR_OP_ILLEGAL, EOPNOTSUPP },
{ NFS4ERR_DEADLOCK, EDEADLK },
{ -1, EIO }
};
static int
nfs_cb_stat_to_errno(int stat)
{
int i;
for (i = 0; nfs_cb_errtbl[i].stat != -1; i++) {
if (nfs_cb_errtbl[i].stat == stat)
return nfs_cb_errtbl[i].errno;
}
/* If we cannot translate the error, the recovery routines should
* handle it.
* Note: remaining NFSv4 error codes have values > 10000, so should
* not conflict with native Linux error codes.
*/
return stat;
}
/*
* XDR encode
*/
static int
encode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr)
{
__be32 * p;
RESERVE_SPACE(16);
WRITE32(0); /* tag length is always 0 */
WRITE32(NFS4_MINOR_VERSION);
WRITE32(hdr->ident);
WRITE32(hdr->nops);
return 0;
}
static int
encode_cb_recall(struct xdr_stream *xdr, struct nfs4_cb_recall *cb_rec)
{
__be32 *p;
int len = cb_rec->cbr_fh.fh_size;
RESERVE_SPACE(12+sizeof(cb_rec->cbr_stateid) + len);
WRITE32(OP_CB_RECALL);
WRITE32(cb_rec->cbr_stateid.si_generation);
WRITEMEM(&cb_rec->cbr_stateid.si_opaque, sizeof(stateid_opaque_t));
WRITE32(cb_rec->cbr_trunc);
WRITE32(len);
WRITEMEM(&cb_rec->cbr_fh.fh_base, len);
return 0;
}
static int
nfs4_xdr_enc_cb_null(struct rpc_rqst *req, __be32 *p)
{
struct xdr_stream xdrs, *xdr = &xdrs;
xdr_init_encode(&xdrs, &req->rq_snd_buf, p);
RESERVE_SPACE(0);
return 0;
}
static int
nfs4_xdr_enc_cb_recall(struct rpc_rqst *req, __be32 *p, struct nfs4_cb_recall *args)
{
struct xdr_stream xdr;
struct nfs4_cb_compound_hdr hdr = {
.ident = args->cbr_ident,
.nops = 1,
};
xdr_init_encode(&xdr, &req->rq_snd_buf, p);
encode_cb_compound_hdr(&xdr, &hdr);
return (encode_cb_recall(&xdr, args));
}
static int
decode_cb_compound_hdr(struct xdr_stream *xdr, struct nfs4_cb_compound_hdr *hdr){
__be32 *p;
READ_BUF(8);
READ32(hdr->status);
READ32(hdr->taglen);
READ_BUF(hdr->taglen + 4);
hdr->tag = (char *)p;
p += XDR_QUADLEN(hdr->taglen);
READ32(hdr->nops);
return 0;
}
static int
decode_cb_op_hdr(struct xdr_stream *xdr, enum nfs_opnum4 expected)
{
__be32 *p;
u32 op;
int32_t nfserr;
READ_BUF(8);
READ32(op);
if (op != expected) {
dprintk("NFSD: decode_cb_op_hdr: Callback server returned "
" operation %d but we issued a request for %d\n",
op, expected);
return -EIO;
}
READ32(nfserr);
if (nfserr != NFS_OK)
return -nfs_cb_stat_to_errno(nfserr);
return 0;
}
static int
nfs4_xdr_dec_cb_null(struct rpc_rqst *req, __be32 *p)
{
return 0;
}
static int
nfs4_xdr_dec_cb_recall(struct rpc_rqst *rqstp, __be32 *p)
{
struct xdr_stream xdr;
struct nfs4_cb_compound_hdr hdr;
int status;
xdr_init_decode(&xdr, &rqstp->rq_rcv_buf, p);
status = decode_cb_compound_hdr(&xdr, &hdr);
if (status)
goto out;
status = decode_cb_op_hdr(&xdr, OP_CB_RECALL);
out:
return status;
}
/*
* RPC procedure tables
*/
#define PROC(proc, call, argtype, restype) \
[NFSPROC4_CLNT_##proc] = { \
.p_proc = NFSPROC4_CB_##call, \
.p_encode = (kxdrproc_t) nfs4_xdr_##argtype, \
.p_decode = (kxdrproc_t) nfs4_xdr_##restype, \
.p_arglen = NFS4_##argtype##_sz, \
.p_replen = NFS4_##restype##_sz, \
.p_statidx = NFSPROC4_CB_##call, \
.p_name = #proc, \
}
static struct rpc_procinfo nfs4_cb_procedures[] = {
PROC(CB_NULL, NULL, enc_cb_null, dec_cb_null),
PROC(CB_RECALL, COMPOUND, enc_cb_recall, dec_cb_recall),
};
static struct rpc_version nfs_cb_version4 = {
.number = 1,
.nrprocs = ARRAY_SIZE(nfs4_cb_procedures),
.procs = nfs4_cb_procedures
};
static struct rpc_version * nfs_cb_version[] = {
NULL,
&nfs_cb_version4,
};
static struct rpc_program cb_program;
static struct rpc_stat cb_stats = {
.program = &cb_program
};
#define NFS4_CALLBACK 0x40000000
static struct rpc_program cb_program = {
.name = "nfs4_cb",
.number = NFS4_CALLBACK,
.nrvers = ARRAY_SIZE(nfs_cb_version),
.version = nfs_cb_version,
.stats = &cb_stats,
.pipe_dir_name = "/nfsd4_cb",
};
static int max_cb_time(void)
{
return max(NFSD_LEASE_TIME/10, (time_t)1) * HZ;
}
/* Reference counting, callback cleanup, etc., all look racy as heck.
* And why is cb_set an atomic? */
int setup_callback_client(struct nfs4_client *clp)
{
struct sockaddr_in addr;
struct nfs4_callback *cb = &clp->cl_callback;
struct rpc_timeout timeparms = {
.to_initval = max_cb_time(),
.to_retries = 0,
};
struct rpc_create_args args = {
.protocol = IPPROTO_TCP,
.address = (struct sockaddr *)&addr,
.addrsize = sizeof(addr),
.timeout = &timeparms,
.program = &cb_program,
.prognumber = cb->cb_prog,
.version = nfs_cb_version[1]->number,
.authflavor = clp->cl_flavor,
.flags = (RPC_CLNT_CREATE_NOPING | RPC_CLNT_CREATE_QUIET),
.client_name = clp->cl_principal,
};
struct rpc_clnt *client;
if (!clp->cl_principal && (clp->cl_flavor >= RPC_AUTH_GSS_KRB5))
return -EINVAL;
/* Initialize address */
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(cb->cb_port);
addr.sin_addr.s_addr = htonl(cb->cb_addr);
/* Create RPC client */
client = rpc_create(&args);
if (IS_ERR(client)) {
dprintk("NFSD: couldn't create callback client: %ld\n",
PTR_ERR(client));
return PTR_ERR(client);
}
cb->cb_client = client;
return 0;
}
static void warn_no_callback_path(struct nfs4_client *clp, int reason)
{
dprintk("NFSD: warning: no callback path to client %.*s: error %d\n",
(int)clp->cl_name.len, clp->cl_name.data, reason);
}
static int do_probe_callback(void *data)
{
struct nfs4_client *clp = data;
struct nfs4_callback *cb = &clp->cl_callback;
struct rpc_message msg = {
.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_NULL],
.rpc_argp = clp,
};
int status;
status = rpc_call_sync(cb->cb_client, &msg, RPC_TASK_SOFT);
if (status)
warn_no_callback_path(clp, status);
else
atomic_set(&cb->cb_set, 1);
put_nfs4_client(clp);
return 0;
}
/*
* Set up the callback client and put a NFSPROC4_CB_NULL on the wire...
*/
void
nfsd4_probe_callback(struct nfs4_client *clp)
{
struct task_struct *t;
int status;
BUG_ON(atomic_read(&clp->cl_callback.cb_set));
status = setup_callback_client(clp);
if (status) {
warn_no_callback_path(clp, status);
return;
}
/* the task holds a reference to the nfs4_client struct */
atomic_inc(&clp->cl_count);
t = kthread_run(do_probe_callback, clp, "nfs4_cb_probe");
if (IS_ERR(t))
atomic_dec(&clp->cl_count);
return;
}
/*
* called with dp->dl_count inc'ed.
*/
void
nfsd4_cb_recall(struct nfs4_delegation *dp)
{
struct nfs4_client *clp = dp->dl_client;
struct rpc_clnt *clnt = clp->cl_callback.cb_client;
struct nfs4_cb_recall *cbr = &dp->dl_recall;
struct rpc_message msg = {
.rpc_proc = &nfs4_cb_procedures[NFSPROC4_CLNT_CB_RECALL],
.rpc_argp = cbr,
};
int retries = 1;
int status = 0;
cbr->cbr_trunc = 0; /* XXX need to implement truncate optimization */
cbr->cbr_dp = dp;
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
while (retries--) {
switch (status) {
case -EIO:
/* Network partition? */
atomic_set(&clp->cl_callback.cb_set, 0);
case -EBADHANDLE:
case -NFS4ERR_BAD_STATEID:
/* Race: client probably got cb_recall
* before open reply granting delegation */
break;
default:
goto out_put_cred;
}
ssleep(2);
status = rpc_call_sync(clnt, &msg, RPC_TASK_SOFT);
}
out_put_cred:
/*
* Success or failure, now we're either waiting for lease expiration
* or deleg_return.
*/
put_nfs4_client(clp);
nfs4_put_delegation(dp);
return;
}
Reference in New Issue View Git Blame Copy Permalink