1 /*
2 * linux/fs/lockd/svcshare.c
3 *
4 * Management of DOS shares.
5 *
6 * Copyright (C) 1996 Olaf Kirch <okir@monad.swb.de>
7 */
8
9 #include <linux/time.h>
10 #include <linux/unistd.h>
11 #include <linux/string.h>
12 #include <linux/slab.h>
13
14 #include <linux/sunrpc/clnt.h>
15 #include <linux/sunrpc/svc.h>
16 #include <linux/lockd/lockd.h>
17 #include <linux/lockd/share.h>
18
19 static inline int
nlm_cmp_owner(struct nlm_share * share,struct xdr_netobj * oh)20 nlm_cmp_owner(struct nlm_share *share, struct xdr_netobj *oh)
21 {
22 return share->s_owner.len == oh->len
23 && !memcmp(share->s_owner.data, oh->data, oh->len);
24 }
25
26 __be32
nlmsvc_share_file(struct nlm_host * host,struct nlm_file * file,struct nlm_args * argp)27 nlmsvc_share_file(struct nlm_host *host, struct nlm_file *file,
28 struct nlm_args *argp)
29 {
30 struct nlm_share *share;
31 struct xdr_netobj *oh = &argp->lock.oh;
32 u8 *ohdata;
33
34 for (share = file->f_shares; share; share = share->s_next) {
35 if (share->s_host == host && nlm_cmp_owner(share, oh))
36 goto update;
37 if ((argp->fsm_access & share->s_mode)
38 || (argp->fsm_mode & share->s_access ))
39 return nlm_lck_denied;
40 }
41
42 share = kmalloc(sizeof(*share) + oh->len,
43 GFP_KERNEL);
44 if (share == NULL)
45 return nlm_lck_denied_nolocks;
46
47 /* Copy owner handle */
48 ohdata = (u8 *) (share + 1);
49 memcpy(ohdata, oh->data, oh->len);
50
51 share->s_file = file;
52 share->s_host = host;
53 share->s_owner.data = ohdata;
54 share->s_owner.len = oh->len;
55 share->s_next = file->f_shares;
56 file->f_shares = share;
57
58 update:
59 share->s_access = argp->fsm_access;
60 share->s_mode = argp->fsm_mode;
61 return nlm_granted;
62 }
63
64 /*
65 * Delete a share.
66 */
67 __be32
nlmsvc_unshare_file(struct nlm_host * host,struct nlm_file * file,struct nlm_args * argp)68 nlmsvc_unshare_file(struct nlm_host *host, struct nlm_file *file,
69 struct nlm_args *argp)
70 {
71 struct nlm_share *share, **shpp;
72 struct xdr_netobj *oh = &argp->lock.oh;
73
74 for (shpp = &file->f_shares; (share = *shpp) != NULL;
75 shpp = &share->s_next) {
76 if (share->s_host == host && nlm_cmp_owner(share, oh)) {
77 *shpp = share->s_next;
78 kfree(share);
79 return nlm_granted;
80 }
81 }
82
83 /* X/Open spec says return success even if there was no
84 * corresponding share. */
85 return nlm_granted;
86 }
87
88 /*
89 * Traverse all shares for a given file, and delete
90 * those owned by the given (type of) host
91 */
nlmsvc_traverse_shares(struct nlm_host * host,struct nlm_file * file,nlm_host_match_fn_t match)92 void nlmsvc_traverse_shares(struct nlm_host *host, struct nlm_file *file,
93 nlm_host_match_fn_t match)
94 {
95 struct nlm_share *share, **shpp;
96
97 shpp = &file->f_shares;
98 while ((share = *shpp) != NULL) {
99 if (match(share->s_host, host)) {
100 *shpp = share->s_next;
101 kfree(share);
102 continue;
103 }
104 shpp = &share->s_next;
105 }
106 }
107