linux/fs/lockd/xdr.c
Chuck Lever 2bea90d43a SUNRPC: RPC buffer size estimates are too large
The RPC buffer size estimation logic in net/sunrpc/clnt.c always
significantly overestimates the requirements for the buffer size.
A little instrumentation demonstrated that in fact rpc_malloc was never
allocating the buffer from the mempool, but almost always called kmalloc.

To compute the size of the RPC buffer more precisely, split p_bufsiz into
two fields; one for the argument size, and one for the result size.

Then, compute the sum of the exact call and reply header sizes, and split
the RPC buffer precisely between the two.  That should keep almost all RPC
buffers within the 2KiB buffer mempool limit.

And, we can finally be rid of RPC_SLACK_SPACE!

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2007-04-30 22:17:10 -07:00

640 lines
14 KiB
C

/*
* linux/fs/lockd/xdr.c
*
* XDR support for lockd and the lock client.
*
* Copyright (C) 1995, 1996 Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/utsname.h>
#include <linux/nfs.h>
#include <linux/sunrpc/xdr.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/sunrpc/stats.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/sm_inter.h>
#define NLMDBG_FACILITY NLMDBG_XDR
static inline loff_t
s32_to_loff_t(__s32 offset)
{
return (loff_t)offset;
}
static inline __s32
loff_t_to_s32(loff_t offset)
{
__s32 res;
if (offset >= NLM_OFFSET_MAX)
res = NLM_OFFSET_MAX;
else if (offset <= -NLM_OFFSET_MAX)
res = -NLM_OFFSET_MAX;
else
res = offset;
return res;
}
/*
* XDR functions for basic NLM types
*/
static __be32 *nlm_decode_cookie(__be32 *p, struct nlm_cookie *c)
{
unsigned int len;
len = ntohl(*p++);
if(len==0)
{
c->len=4;
memset(c->data, 0, 4); /* hockeypux brain damage */
}
else if(len<=NLM_MAXCOOKIELEN)
{
c->len=len;
memcpy(c->data, p, len);
p+=XDR_QUADLEN(len);
}
else
{
printk(KERN_NOTICE
"lockd: bad cookie size %d (only cookies under %d bytes are supported.)\n", len, NLM_MAXCOOKIELEN);
return NULL;
}
return p;
}
static inline __be32 *
nlm_encode_cookie(__be32 *p, struct nlm_cookie *c)
{
*p++ = htonl(c->len);
memcpy(p, c->data, c->len);
p+=XDR_QUADLEN(c->len);
return p;
}
static __be32 *
nlm_decode_fh(__be32 *p, struct nfs_fh *f)
{
unsigned int len;
if ((len = ntohl(*p++)) != NFS2_FHSIZE) {
printk(KERN_NOTICE
"lockd: bad fhandle size %d (should be %d)\n",
len, NFS2_FHSIZE);
return NULL;
}
f->size = NFS2_FHSIZE;
memset(f->data, 0, sizeof(f->data));
memcpy(f->data, p, NFS2_FHSIZE);
return p + XDR_QUADLEN(NFS2_FHSIZE);
}
static inline __be32 *
nlm_encode_fh(__be32 *p, struct nfs_fh *f)
{
*p++ = htonl(NFS2_FHSIZE);
memcpy(p, f->data, NFS2_FHSIZE);
return p + XDR_QUADLEN(NFS2_FHSIZE);
}
/*
* Encode and decode owner handle
*/
static inline __be32 *
nlm_decode_oh(__be32 *p, struct xdr_netobj *oh)
{
return xdr_decode_netobj(p, oh);
}
static inline __be32 *
nlm_encode_oh(__be32 *p, struct xdr_netobj *oh)
{
return xdr_encode_netobj(p, oh);
}
static __be32 *
nlm_decode_lock(__be32 *p, struct nlm_lock *lock)
{
struct file_lock *fl = &lock->fl;
s32 start, len, end;
if (!(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len,
NLM_MAXSTRLEN))
|| !(p = nlm_decode_fh(p, &lock->fh))
|| !(p = nlm_decode_oh(p, &lock->oh)))
return NULL;
lock->svid = ntohl(*p++);
locks_init_lock(fl);
fl->fl_owner = current->files;
fl->fl_pid = (pid_t)lock->svid;
fl->fl_flags = FL_POSIX;
fl->fl_type = F_RDLCK; /* as good as anything else */
start = ntohl(*p++);
len = ntohl(*p++);
end = start + len - 1;
fl->fl_start = s32_to_loff_t(start);
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = s32_to_loff_t(end);
return p;
}
/*
* Encode a lock as part of an NLM call
*/
static __be32 *
nlm_encode_lock(__be32 *p, struct nlm_lock *lock)
{
struct file_lock *fl = &lock->fl;
__s32 start, len;
if (!(p = xdr_encode_string(p, lock->caller))
|| !(p = nlm_encode_fh(p, &lock->fh))
|| !(p = nlm_encode_oh(p, &lock->oh)))
return NULL;
if (fl->fl_start > NLM_OFFSET_MAX
|| (fl->fl_end > NLM_OFFSET_MAX && fl->fl_end != OFFSET_MAX))
return NULL;
start = loff_t_to_s32(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
len = 0;
else
len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
*p++ = htonl(lock->svid);
*p++ = htonl(start);
*p++ = htonl(len);
return p;
}
/*
* Encode result of a TEST/TEST_MSG call
*/
static __be32 *
nlm_encode_testres(__be32 *p, struct nlm_res *resp)
{
s32 start, len;
if (!(p = nlm_encode_cookie(p, &resp->cookie)))
return NULL;
*p++ = resp->status;
if (resp->status == nlm_lck_denied) {
struct file_lock *fl = &resp->lock.fl;
*p++ = (fl->fl_type == F_RDLCK)? xdr_zero : xdr_one;
*p++ = htonl(resp->lock.svid);
/* Encode owner handle. */
if (!(p = xdr_encode_netobj(p, &resp->lock.oh)))
return NULL;
start = loff_t_to_s32(fl->fl_start);
if (fl->fl_end == OFFSET_MAX)
len = 0;
else
len = loff_t_to_s32(fl->fl_end - fl->fl_start + 1);
*p++ = htonl(start);
*p++ = htonl(len);
}
return p;
}
/*
* First, the server side XDR functions
*/
int
nlmsvc_decode_testargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm_decode_cookie(p, &argp->cookie)))
return 0;
exclusive = ntohl(*p++);
if (!(p = nlm_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_encode_testres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_encode_testres(p, resp)))
return 0;
return xdr_ressize_check(rqstp, p);
}
int
nlmsvc_decode_lockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm_decode_cookie(p, &argp->cookie)))
return 0;
argp->block = ntohl(*p++);
exclusive = ntohl(*p++);
if (!(p = nlm_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
argp->reclaim = ntohl(*p++);
argp->state = ntohl(*p++);
argp->monitor = 1; /* monitor client by default */
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_cancargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
u32 exclusive;
if (!(p = nlm_decode_cookie(p, &argp->cookie)))
return 0;
argp->block = ntohl(*p++);
exclusive = ntohl(*p++);
if (!(p = nlm_decode_lock(p, &argp->lock)))
return 0;
if (exclusive)
argp->lock.fl.fl_type = F_WRLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_unlockargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
if (!(p = nlm_decode_cookie(p, &argp->cookie))
|| !(p = nlm_decode_lock(p, &argp->lock)))
return 0;
argp->lock.fl.fl_type = F_UNLCK;
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_shareargs(struct svc_rqst *rqstp, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
memset(lock, 0, sizeof(*lock));
locks_init_lock(&lock->fl);
lock->svid = ~(u32) 0;
lock->fl.fl_pid = (pid_t)lock->svid;
if (!(p = nlm_decode_cookie(p, &argp->cookie))
|| !(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len, NLM_MAXSTRLEN))
|| !(p = nlm_decode_fh(p, &lock->fh))
|| !(p = nlm_decode_oh(p, &lock->oh)))
return 0;
argp->fsm_mode = ntohl(*p++);
argp->fsm_access = ntohl(*p++);
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_encode_shareres(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_encode_cookie(p, &resp->cookie)))
return 0;
*p++ = resp->status;
*p++ = xdr_zero; /* sequence argument */
return xdr_ressize_check(rqstp, p);
}
int
nlmsvc_encode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_encode_cookie(p, &resp->cookie)))
return 0;
*p++ = resp->status;
return xdr_ressize_check(rqstp, p);
}
int
nlmsvc_decode_notify(struct svc_rqst *rqstp, __be32 *p, struct nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = xdr_decode_string_inplace(p, &lock->caller,
&lock->len, NLM_MAXSTRLEN)))
return 0;
argp->state = ntohl(*p++);
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_reboot(struct svc_rqst *rqstp, __be32 *p, struct nlm_reboot *argp)
{
if (!(p = xdr_decode_string_inplace(p, &argp->mon, &argp->len, SM_MAXSTRLEN)))
return 0;
argp->state = ntohl(*p++);
/* Preserve the address in network byte order */
argp->addr = *p++;
argp->vers = *p++;
argp->proto = *p++;
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_res(struct svc_rqst *rqstp, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_decode_cookie(p, &resp->cookie)))
return 0;
resp->status = *p++;
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_decode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_argsize_check(rqstp, p);
}
int
nlmsvc_encode_void(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
return xdr_ressize_check(rqstp, p);
}
/*
* Now, the client side XDR functions
*/
#ifdef NLMCLNT_SUPPORT_SHARES
static int
nlmclt_decode_void(struct rpc_rqst *req, u32 *p, void *ptr)
{
return 0;
}
#endif
static int
nlmclt_encode_testargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = nlm_encode_cookie(p, &argp->cookie)))
return -EIO;
*p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
if (!(p = nlm_encode_lock(p, lock)))
return -EIO;
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_decode_testres(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_decode_cookie(p, &resp->cookie)))
return -EIO;
resp->status = *p++;
if (resp->status == nlm_lck_denied) {
struct file_lock *fl = &resp->lock.fl;
u32 excl;
s32 start, len, end;
memset(&resp->lock, 0, sizeof(resp->lock));
locks_init_lock(fl);
excl = ntohl(*p++);
resp->lock.svid = ntohl(*p++);
fl->fl_pid = (pid_t)resp->lock.svid;
if (!(p = nlm_decode_oh(p, &resp->lock.oh)))
return -EIO;
fl->fl_flags = FL_POSIX;
fl->fl_type = excl? F_WRLCK : F_RDLCK;
start = ntohl(*p++);
len = ntohl(*p++);
end = start + len - 1;
fl->fl_start = s32_to_loff_t(start);
if (len == 0 || end < 0)
fl->fl_end = OFFSET_MAX;
else
fl->fl_end = s32_to_loff_t(end);
}
return 0;
}
static int
nlmclt_encode_lockargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = nlm_encode_cookie(p, &argp->cookie)))
return -EIO;
*p++ = argp->block? xdr_one : xdr_zero;
*p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
if (!(p = nlm_encode_lock(p, lock)))
return -EIO;
*p++ = argp->reclaim? xdr_one : xdr_zero;
*p++ = htonl(argp->state);
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_encode_cancargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = nlm_encode_cookie(p, &argp->cookie)))
return -EIO;
*p++ = argp->block? xdr_one : xdr_zero;
*p++ = (lock->fl.fl_type == F_WRLCK)? xdr_one : xdr_zero;
if (!(p = nlm_encode_lock(p, lock)))
return -EIO;
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_encode_unlockargs(struct rpc_rqst *req, __be32 *p, nlm_args *argp)
{
struct nlm_lock *lock = &argp->lock;
if (!(p = nlm_encode_cookie(p, &argp->cookie)))
return -EIO;
if (!(p = nlm_encode_lock(p, lock)))
return -EIO;
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_encode_res(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_encode_cookie(p, &resp->cookie)))
return -EIO;
*p++ = resp->status;
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_encode_testres(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_encode_testres(p, resp)))
return -EIO;
req->rq_slen = xdr_adjust_iovec(req->rq_svec, p);
return 0;
}
static int
nlmclt_decode_res(struct rpc_rqst *req, __be32 *p, struct nlm_res *resp)
{
if (!(p = nlm_decode_cookie(p, &resp->cookie)))
return -EIO;
resp->status = *p++;
return 0;
}
#if (NLMCLNT_OHSIZE > XDR_MAX_NETOBJ)
# error "NLM host name cannot be larger than XDR_MAX_NETOBJ!"
#endif
/*
* Buffer requirements for NLM
*/
#define NLM_void_sz 0
#define NLM_cookie_sz 1+XDR_QUADLEN(NLM_MAXCOOKIELEN)
#define NLM_caller_sz 1+XDR_QUADLEN(NLMCLNT_OHSIZE)
#define NLM_owner_sz 1+XDR_QUADLEN(NLMCLNT_OHSIZE)
#define NLM_fhandle_sz 1+XDR_QUADLEN(NFS2_FHSIZE)
#define NLM_lock_sz 3+NLM_caller_sz+NLM_owner_sz+NLM_fhandle_sz
#define NLM_holder_sz 4+NLM_owner_sz
#define NLM_testargs_sz NLM_cookie_sz+1+NLM_lock_sz
#define NLM_lockargs_sz NLM_cookie_sz+4+NLM_lock_sz
#define NLM_cancargs_sz NLM_cookie_sz+2+NLM_lock_sz
#define NLM_unlockargs_sz NLM_cookie_sz+NLM_lock_sz
#define NLM_testres_sz NLM_cookie_sz+1+NLM_holder_sz
#define NLM_res_sz NLM_cookie_sz+1
#define NLM_norep_sz 0
/*
* For NLM, a void procedure really returns nothing
*/
#define nlmclt_decode_norep NULL
#define PROC(proc, argtype, restype) \
[NLMPROC_##proc] = { \
.p_proc = NLMPROC_##proc, \
.p_encode = (kxdrproc_t) nlmclt_encode_##argtype, \
.p_decode = (kxdrproc_t) nlmclt_decode_##restype, \
.p_arglen = NLM_##argtype##_sz, \
.p_replen = NLM_##restype##_sz, \
.p_statidx = NLMPROC_##proc, \
.p_name = #proc, \
}
static struct rpc_procinfo nlm_procedures[] = {
PROC(TEST, testargs, testres),
PROC(LOCK, lockargs, res),
PROC(CANCEL, cancargs, res),
PROC(UNLOCK, unlockargs, res),
PROC(GRANTED, testargs, res),
PROC(TEST_MSG, testargs, norep),
PROC(LOCK_MSG, lockargs, norep),
PROC(CANCEL_MSG, cancargs, norep),
PROC(UNLOCK_MSG, unlockargs, norep),
PROC(GRANTED_MSG, testargs, norep),
PROC(TEST_RES, testres, norep),
PROC(LOCK_RES, res, norep),
PROC(CANCEL_RES, res, norep),
PROC(UNLOCK_RES, res, norep),
PROC(GRANTED_RES, res, norep),
#ifdef NLMCLNT_SUPPORT_SHARES
PROC(SHARE, shareargs, shareres),
PROC(UNSHARE, shareargs, shareres),
PROC(NM_LOCK, lockargs, res),
PROC(FREE_ALL, notify, void),
#endif
};
static struct rpc_version nlm_version1 = {
.number = 1,
.nrprocs = 16,
.procs = nlm_procedures,
};
static struct rpc_version nlm_version3 = {
.number = 3,
.nrprocs = 24,
.procs = nlm_procedures,
};
#ifdef CONFIG_LOCKD_V4
extern struct rpc_version nlm_version4;
#endif
static struct rpc_version * nlm_versions[] = {
[1] = &nlm_version1,
[3] = &nlm_version3,
#ifdef CONFIG_LOCKD_V4
[4] = &nlm_version4,
#endif
};
static struct rpc_stat nlm_stats;
struct rpc_program nlm_program = {
.name = "lockd",
.number = NLM_PROGRAM,
.nrvers = ARRAY_SIZE(nlm_versions),
.version = nlm_versions,
.stats = &nlm_stats,
};
#ifdef RPC_DEBUG
const char *nlmdbg_cookie2a(const struct nlm_cookie *cookie)
{
/*
* We can get away with a static buffer because we're only
* called with BKL held.
*/
static char buf[2*NLM_MAXCOOKIELEN+1];
int i;
int len = sizeof(buf);
char *p = buf;
len--; /* allow for trailing \0 */
if (len < 3)
return "???";
for (i = 0 ; i < cookie->len ; i++) {
if (len < 2) {
strcpy(p-3, "...");
break;
}
sprintf(p, "%02x", cookie->data[i]);
p += 2;
len -= 2;
}
*p = '\0';
return buf;
}
#endif