linux/fs/nfsd/lockd.c
NeilBrown d343fce148 [PATCH] knfsd: Allow lockd to drop replies as appropriate
It is possible for the ->fopen callback from lockd into nfsd to find that an
answer cannot be given straight away (an upcall is needed) and so the request
has to be 'dropped', to be retried later.  That error status is not currently
propagated back.

So:
  Change nlm_fopen to return nlm error codes (rather than a private
  protocol) and define a new nlm_drop_reply code.
  Cause nlm_drop_reply to cause the rpc request to get rpc_drop_reply
  when this error comes back.
  Cause svc_process to drop a request which returns a status of
  rpc_drop_reply.

[akpm@osdl.org: fix warning storm]
Cc: Marc Eshel <eshel@almaden.ibm.com>
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-10-17 08:18:46 -07:00

82 lines
1.7 KiB
C

/*
* linux/fs/nfsd/lockd.c
*
* This file contains all the stubs needed when communicating with lockd.
* This level of indirection is necessary so we can run nfsd+lockd without
* requiring the nfs client to be compiled in/loaded, and vice versa.
*
* Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
*/
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/file.h>
#include <linux/mount.h>
#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/nfsd/nfsd.h>
#include <linux/lockd/bind.h>
#define NFSDDBG_FACILITY NFSDDBG_LOCKD
/*
* Note: we hold the dentry use count while the file is open.
*/
static u32
nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp)
{
u32 nfserr;
struct svc_fh fh;
/* must initialize before using! but maxsize doesn't matter */
fh_init(&fh,0);
fh.fh_handle.fh_size = f->size;
memcpy((char*)&fh.fh_handle.fh_base, f->data, f->size);
fh.fh_export = NULL;
exp_readlock();
nfserr = nfsd_open(rqstp, &fh, S_IFREG, MAY_LOCK, filp);
fh_put(&fh);
rqstp->rq_client = NULL;
exp_readunlock();
/* We return nlm error codes as nlm doesn't know
* about nfsd, but nfsd does know about nlm..
*/
switch (nfserr) {
case nfs_ok:
return 0;
case nfserr_dropit:
return nlm_drop_reply;
#ifdef CONFIG_LOCKD_V4
case nfserr_stale:
return nlm4_stale_fh;
#endif
default:
return nlm_lck_denied;
}
}
static void
nlm_fclose(struct file *filp)
{
fput(filp);
}
static struct nlmsvc_binding nfsd_nlm_ops = {
.fopen = nlm_fopen, /* open file for locking */
.fclose = nlm_fclose, /* close file */
};
void
nfsd_lockd_init(void)
{
dprintk("nfsd: initializing lockd\n");
nlmsvc_ops = &nfsd_nlm_ops;
}
void
nfsd_lockd_shutdown(void)
{
nlmsvc_ops = NULL;
}