lockd: Clean up nlmsvc_lookup_host()
[linux-2.6.git] / fs / lockd / svcshare.c
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
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
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
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  */
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 }