aboutsummaryrefslogtreecommitdiff
path: root/fs/lockd/svcshare.c
blob: b9926ce8782e86b7782ab752e61474af35806cca (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
/*
 * linux/fs/lockd/svcshare.c
 *
 * Management of DOS shares.
 *
 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
 */

#include <linux/time.h>
#include <linux/unistd.h>
#include <linux/string.h>
#include <linux/slab.h>

#include <linux/sunrpc/clnt.h>
#include <linux/sunrpc/svc.h>
#include <linux/lockd/lockd.h>
#include <linux/lockd/share.h>

static inline int
nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
{
	return share->s_owner.len == oh->len
	    && !memcmp(share->s_owner.data, oh->data, oh->len);
}

u32
nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share;
	struct xdr_netobj	*oh = &argp->lock.oh;
	u8			*ohdata;

	for (share = file->f_shares; share; share = share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh))
			goto update;
		if ((argp->fsm_access & share->s_mode)
		 || (argp->fsm_mode   & share->s_access ))
			return nlm_lck_denied;
	}

	share = (struct nlm_share *) kmalloc(sizeof(*share) + oh->len,
						GFP_KERNEL);
	if (share == NULL)
		return nlm_lck_denied_nolocks;

	/* Copy owner handle */
	ohdata = (u8 *) (share + 1);
	memcpy(ohdata, oh->data, oh->len);

	share->s_file	    = file;
	share->s_host       = host;
	share->s_owner.data = ohdata;
	share->s_owner.len  = oh->len;
	share->s_next       = file->f_shares;
	file->f_shares      = share;

update:
	share->s_access = argp->fsm_access;
	share->s_mode   = argp->fsm_mode;
	return nlm_granted;
}

/*
 * Delete a share.
 */
u32
nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
			struct nlm_args *argp)
{
	struct nlm_share	*share, **shpp;
	struct xdr_netobj	*oh = &argp->lock.oh;

	for (shpp = &file->f_shares; (share = *shpp) != 0; shpp = &share->s_next) {
		if (share->s_host == host && nlm_cmp_owner(share, oh)) {
			*shpp = share->s_next;
			kfree(share);
			return nlm_granted;
		}
	}

	/* X/Open spec says return success even if there was no
	 * corresponding share. */
	return nlm_granted;
}

/*
 * Traverse all shares for a given file, and delete
 * those owned by the given (type of) host
 */
void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
		nlm_host_match_fn_t match)
{
	struct nlm_share	*share, **shpp;

	shpp = &file->f_shares;
	while ((share = *shpp) !=  NULL) {
		if (match(share->s_host, host)) {
			*shpp = share->s_next;
			kfree(share);
			continue;
		}
		shpp = &share->s_next;
	}
}