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Linux kernel mirror (for testing)
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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * This file contains all the stubs needed when communicating with lockd.
4 * This level of indirection is necessary so we can run nfsd+lockd without
5 * requiring the nfs client to be compiled in/loaded, and vice versa.
6 *
7 * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
8 */
9
10#include <linux/file.h>
11#include <linux/lockd/bind.h>
12#include "nfsd.h"
13#include "vfs.h"
14
15#define NFSDDBG_FACILITY NFSDDBG_LOCKD
16
17#ifdef CONFIG_LOCKD_V4
18#define nlm_stale_fh nlm4_stale_fh
19#define nlm_failed nlm4_failed
20#else
21#define nlm_stale_fh nlm_lck_denied_nolocks
22#define nlm_failed nlm_lck_denied_nolocks
23#endif
24/*
25 * Note: we hold the dentry use count while the file is open.
26 */
27static __be32
28nlm_fopen(struct svc_rqst *rqstp, struct nfs_fh *f, struct file **filp,
29 int mode)
30{
31 __be32 nfserr;
32 int access;
33 struct svc_fh fh;
34
35 /* must initialize before using! but maxsize doesn't matter */
36 fh_init(&fh,0);
37 fh.fh_handle.fh_size = f->size;
38 memcpy(&fh.fh_handle.fh_raw, f->data, f->size);
39 fh.fh_export = NULL;
40
41 /*
42 * Allow BYPASS_GSS as some client implementations use AUTH_SYS
43 * for NLM even when GSS is used for NFS.
44 * Allow OWNER_OVERRIDE as permission might have been changed
45 * after the file was opened.
46 * Pass MAY_NLM so that authentication can be completely bypassed
47 * if NFSEXP_NOAUTHNLM is set. Some older clients use AUTH_NULL
48 * for NLM requests.
49 */
50 access = (mode == O_WRONLY) ? NFSD_MAY_WRITE : NFSD_MAY_READ;
51 access |= NFSD_MAY_NLM | NFSD_MAY_OWNER_OVERRIDE | NFSD_MAY_BYPASS_GSS;
52 nfserr = nfsd_open(rqstp, &fh, S_IFREG, access, filp);
53 fh_put(&fh);
54 /* We return nlm error codes as nlm doesn't know
55 * about nfsd, but nfsd does know about nlm..
56 */
57 switch (nfserr) {
58 case nfs_ok:
59 return 0;
60 case nfserr_jukebox:
61 /* this error can indicate a presence of a conflicting
62 * delegation to an NLM lock request. Options are:
63 * (1) For now, drop this request and make the client
64 * retry. When delegation is returned, client's lock retry
65 * will complete.
66 * (2) NLM4_DENIED as per "spec" signals to the client
67 * that the lock is unavailable now but client can retry.
68 * Linux client implementation does not. It treats
69 * NLM4_DENIED same as NLM4_FAILED and errors the request.
70 * (3) For the future, treat this as blocked lock and try
71 * to callback when the delegation is returned but might
72 * not have a proper lock request to block on.
73 */
74 return nlm_drop_reply;
75 case nfserr_stale:
76 return nlm_stale_fh;
77 default:
78 return nlm_failed;
79 }
80}
81
82static void
83nlm_fclose(struct file *filp)
84{
85 fput(filp);
86}
87
88static const struct nlmsvc_binding nfsd_nlm_ops = {
89 .fopen = nlm_fopen, /* open file for locking */
90 .fclose = nlm_fclose, /* close file */
91};
92
93void
94nfsd_lockd_init(void)
95{
96 dprintk("nfsd: initializing lockd\n");
97 nlmsvc_ops = &nfsd_nlm_ops;
98}
99
100void
101nfsd_lockd_shutdown(void)
102{
103 nlmsvc_ops = NULL;
104}