1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* AFS fileserver list management. |
3 | * |
4 | * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved. |
5 | * Written by David Howells (dhowells@redhat.com) |
6 | */ |
7 | |
8 | #include <linux/kernel.h> |
9 | #include <linux/slab.h> |
10 | #include "internal.h" |
11 | |
12 | void afs_put_serverlist(struct afs_net *net, struct afs_server_list *slist) |
13 | { |
14 | int i; |
15 | |
16 | if (slist && refcount_dec_and_test(r: &slist->usage)) { |
17 | for (i = 0; i < slist->nr_servers; i++) |
18 | afs_unuse_server(net, slist->servers[i].server, |
19 | afs_server_trace_put_slist); |
20 | kfree(objp: slist); |
21 | } |
22 | } |
23 | |
24 | /* |
25 | * Build a server list from a VLDB record. |
26 | */ |
27 | struct afs_server_list *afs_alloc_server_list(struct afs_cell *cell, |
28 | struct key *key, |
29 | struct afs_vldb_entry *vldb, |
30 | u8 type_mask) |
31 | { |
32 | struct afs_server_list *slist; |
33 | struct afs_server *server; |
34 | int ret = -ENOMEM, nr_servers = 0, i, j; |
35 | |
36 | for (i = 0; i < vldb->nr_servers; i++) |
37 | if (vldb->fs_mask[i] & type_mask) |
38 | nr_servers++; |
39 | |
40 | slist = kzalloc(struct_size(slist, servers, nr_servers), GFP_KERNEL); |
41 | if (!slist) |
42 | goto error; |
43 | |
44 | refcount_set(r: &slist->usage, n: 1); |
45 | rwlock_init(&slist->lock); |
46 | |
47 | for (i = 0; i < AFS_MAXTYPES; i++) |
48 | slist->vids[i] = vldb->vid[i]; |
49 | |
50 | /* Make sure a records exists for each server in the list. */ |
51 | for (i = 0; i < vldb->nr_servers; i++) { |
52 | if (!(vldb->fs_mask[i] & type_mask)) |
53 | continue; |
54 | |
55 | server = afs_lookup_server(cell, key, &vldb->fs_server[i], |
56 | vldb->addr_version[i]); |
57 | if (IS_ERR(ptr: server)) { |
58 | ret = PTR_ERR(ptr: server); |
59 | if (ret == -ENOENT || |
60 | ret == -ENOMEDIUM) |
61 | continue; |
62 | goto error_2; |
63 | } |
64 | |
65 | /* Insertion-sort by UUID */ |
66 | for (j = 0; j < slist->nr_servers; j++) |
67 | if (memcmp(p: &slist->servers[j].server->uuid, |
68 | q: &server->uuid, |
69 | size: sizeof(server->uuid)) >= 0) |
70 | break; |
71 | if (j < slist->nr_servers) { |
72 | if (slist->servers[j].server == server) { |
73 | afs_put_server(cell->net, server, |
74 | afs_server_trace_put_slist_isort); |
75 | continue; |
76 | } |
77 | |
78 | memmove(slist->servers + j + 1, |
79 | slist->servers + j, |
80 | (slist->nr_servers - j) * sizeof(struct afs_server_entry)); |
81 | } |
82 | |
83 | slist->servers[j].server = server; |
84 | slist->nr_servers++; |
85 | } |
86 | |
87 | if (slist->nr_servers == 0) { |
88 | ret = -EDESTADDRREQ; |
89 | goto error_2; |
90 | } |
91 | |
92 | return slist; |
93 | |
94 | error_2: |
95 | afs_put_serverlist(net: cell->net, slist); |
96 | error: |
97 | return ERR_PTR(error: ret); |
98 | } |
99 | |
100 | /* |
101 | * Copy the annotations from an old server list to its potential replacement. |
102 | */ |
103 | bool afs_annotate_server_list(struct afs_server_list *new, |
104 | struct afs_server_list *old) |
105 | { |
106 | struct afs_server *cur; |
107 | int i, j; |
108 | |
109 | if (old->nr_servers != new->nr_servers) |
110 | goto changed; |
111 | |
112 | for (i = 0; i < old->nr_servers; i++) |
113 | if (old->servers[i].server != new->servers[i].server) |
114 | goto changed; |
115 | |
116 | return false; |
117 | |
118 | changed: |
119 | /* Maintain the same preferred server as before if possible. */ |
120 | cur = old->servers[old->preferred].server; |
121 | for (j = 0; j < new->nr_servers; j++) { |
122 | if (new->servers[j].server == cur) { |
123 | new->preferred = j; |
124 | break; |
125 | } |
126 | } |
127 | |
128 | return true; |
129 | } |
130 | |