1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* AFS fileserver list management.
4 * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved.
5 * Written by David Howells (dhowells@redhat.com)
8 #include <linux/kernel.h>
9 #include <linux/slab.h>
12 void afs_put_serverlist(struct afs_net *net, struct afs_server_list *slist)
16 if (slist && refcount_dec_and_test(&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_rcu(slist, rcu);
25 * Build a server list from a VLDB record.
27 struct afs_server_list *afs_alloc_server_list(struct afs_volume *volume,
29 struct afs_vldb_entry *vldb)
31 struct afs_server_list *slist;
32 struct afs_server *server;
33 unsigned int type_mask = 1 << volume->type;
34 bool use_newrepsites = false;
35 int ret = -ENOMEM, nr_servers = 0, newrep = 0, i, j, usable = 0;
37 /* Work out if we're going to restrict to NEWREPSITE-marked servers or
38 * not. If at least one site is marked as NEWREPSITE, then it's likely
39 * that "vos release" is busy updating RO sites. We cut over from one
40 * to the other when >=50% of the sites have been updated. Sites that
41 * are in the process of being updated are marked DONTUSE.
43 for (i = 0; i < vldb->nr_servers; i++) {
44 if (!(vldb->fs_mask[i] & type_mask))
47 if (vldb->vlsf_flags[i] & AFS_VLSF_DONTUSE)
50 if (vldb->vlsf_flags[i] & AFS_VLSF_NEWREPSITE)
54 slist = kzalloc(struct_size(slist, servers, nr_servers), GFP_KERNEL);
59 if (newrep < usable / 2) {
60 slist->ro_replicating = AFS_RO_REPLICATING_USE_OLD;
62 slist->ro_replicating = AFS_RO_REPLICATING_USE_NEW;
63 use_newrepsites = true;
67 refcount_set(&slist->usage, 1);
68 rwlock_init(&slist->lock);
70 /* Make sure a records exists for each server in the list. */
71 for (i = 0; i < vldb->nr_servers; i++) {
72 unsigned long se_flags = 0;
73 bool newrepsite = vldb->vlsf_flags[i] & AFS_VLSF_NEWREPSITE;
75 if (!(vldb->fs_mask[i] & type_mask))
77 if (vldb->vlsf_flags[i] & AFS_VLSF_DONTUSE)
78 __set_bit(AFS_SE_EXCLUDED, &se_flags);
79 if (newrep && (newrepsite ^ use_newrepsites))
80 __set_bit(AFS_SE_EXCLUDED, &se_flags);
82 server = afs_lookup_server(volume->cell, key, &vldb->fs_server[i],
83 vldb->addr_version[i]);
85 ret = PTR_ERR(server);
92 /* Insertion-sort by UUID */
93 for (j = 0; j < slist->nr_servers; j++)
94 if (memcmp(&slist->servers[j].server->uuid,
96 sizeof(server->uuid)) >= 0)
98 if (j < slist->nr_servers) {
99 if (slist->servers[j].server == server) {
100 afs_put_server(volume->cell->net, server,
101 afs_server_trace_put_slist_isort);
105 memmove(slist->servers + j + 1,
107 (slist->nr_servers - j) * sizeof(struct afs_server_entry));
110 slist->servers[j].server = server;
111 slist->servers[j].volume = volume;
112 slist->servers[j].flags = se_flags;
113 slist->servers[j].cb_expires_at = AFS_NO_CB_PROMISE;
117 if (slist->nr_servers == 0) {
125 afs_put_serverlist(volume->cell->net, slist);
131 * Copy the annotations from an old server list to its potential replacement.
133 bool afs_annotate_server_list(struct afs_server_list *new,
134 struct afs_server_list *old)
136 unsigned long mask = 1UL << AFS_SE_EXCLUDED;
139 if (old->nr_servers != new->nr_servers ||
140 old->ro_replicating != new->ro_replicating)
143 for (i = 0; i < old->nr_servers; i++) {
144 if (old->servers[i].server != new->servers[i].server)
146 if ((old->servers[i].flags & mask) != (new->servers[i].flags & mask))
155 * Attach a volume to the servers it is going to use.
157 void afs_attach_volume_to_servers(struct afs_volume *volume, struct afs_server_list *slist)
159 struct afs_server_entry *se, *pe;
160 struct afs_server *server;
164 down_write(&volume->cell->vs_lock);
166 for (i = 0; i < slist->nr_servers; i++) {
167 se = &slist->servers[i];
170 list_for_each(p, &server->volumes) {
171 pe = list_entry(p, struct afs_server_entry, slink);
172 if (volume->vid <= pe->volume->vid)
175 list_add_tail(&se->slink, p);
178 slist->attached = true;
179 up_write(&volume->cell->vs_lock);
183 * Reattach a volume to the servers it is going to use when server list is
184 * replaced. We try to switch the attachment points to avoid rewalking the
187 void afs_reattach_volume_to_servers(struct afs_volume *volume, struct afs_server_list *new,
188 struct afs_server_list *old)
190 unsigned int n = 0, o = 0;
192 down_write(&volume->cell->vs_lock);
194 while (n < new->nr_servers || o < old->nr_servers) {
195 struct afs_server_entry *pn = n < new->nr_servers ? &new->servers[n] : NULL;
196 struct afs_server_entry *po = o < old->nr_servers ? &old->servers[o] : NULL;
197 struct afs_server_entry *s;
201 if (pn && po && pn->server == po->server) {
202 pn->cb_expires_at = po->cb_expires_at;
203 list_replace(&po->slink, &pn->slink);
210 diff = memcmp(&pn->server->uuid, &po->server->uuid,
211 sizeof(pn->server->uuid));
216 list_for_each(p, &pn->server->volumes) {
217 s = list_entry(p, struct afs_server_entry, slink);
218 if (volume->vid <= s->volume->vid)
221 list_add_tail(&pn->slink, p);
224 list_del(&po->slink);
229 up_write(&volume->cell->vs_lock);
233 * Detach a volume from the servers it has been using.
235 void afs_detach_volume_from_servers(struct afs_volume *volume, struct afs_server_list *slist)
239 if (!slist->attached)
242 down_write(&volume->cell->vs_lock);
244 for (i = 0; i < slist->nr_servers; i++)
245 list_del(&slist->servers[i].slink);
247 slist->attached = false;
248 up_write(&volume->cell->vs_lock);