diff options
Diffstat (limited to 'fs/afs/server_list.c')
-rw-r--r-- | fs/afs/server_list.c | 153 |
1 files changed, 153 insertions, 0 deletions
diff --git a/fs/afs/server_list.c b/fs/afs/server_list.c new file mode 100644 index 000000000000..26bad7032bba --- /dev/null +++ b/fs/afs/server_list.c @@ -0,0 +1,153 @@ +/* AFS fileserver list management. + * + * Copyright (C) 2017 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include <linux/kernel.h> +#include <linux/slab.h> +#include "internal.h" + +void afs_put_serverlist(struct afs_net *net, struct afs_server_list *slist) +{ + int i; + + if (refcount_dec_and_test(&slist->usage)) { + for (i = 0; i < slist->nr_servers; i++) { + afs_put_cb_interest(net, slist->servers[i].cb_interest); + afs_put_server(net, slist->servers[i].server); + } + kfree(slist); + } +} + +/* + * Build a server list from a VLDB record. + */ +struct afs_server_list *afs_alloc_server_list(struct afs_cell *cell, + struct key *key, + struct afs_vldb_entry *vldb, + u8 type_mask) +{ + struct afs_server_list *slist; + struct afs_server *server; + int ret = -ENOMEM, nr_servers = 0, i, j; + + for (i = 0; i < vldb->nr_servers; i++) + if (vldb->fs_mask[i] & type_mask) + nr_servers++; + + slist = kzalloc(sizeof(struct afs_server_list) + + sizeof(struct afs_server_entry) * nr_servers, + GFP_KERNEL); + if (!slist) + goto error; + + refcount_set(&slist->usage, 1); + + /* Make sure a records exists for each server in the list. */ + for (i = 0; i < vldb->nr_servers; i++) { + if (!(vldb->fs_mask[i] & type_mask)) + continue; + + server = afs_lookup_server(cell, key, &vldb->fs_server[i]); + if (IS_ERR(server)) { + ret = PTR_ERR(server); + if (ret == -ENOENT) + continue; + goto error_2; + } + + /* Insertion-sort by server pointer */ + for (j = 0; j < slist->nr_servers; j++) + if (slist->servers[j].server >= server) + break; + if (j < slist->nr_servers) { + if (slist->servers[j].server == server) { + afs_put_server(cell->net, server); + continue; + } + + memmove(slist->servers + j + 1, + slist->servers + j, + (slist->nr_servers - j) * sizeof(struct afs_server_entry)); + } + + slist->servers[j].server = server; + slist->nr_servers++; + } + + if (slist->nr_servers == 0) { + ret = -EDESTADDRREQ; + goto error_2; + } + + return slist; + +error_2: + afs_put_serverlist(cell->net, slist); +error: + return ERR_PTR(ret); +} + +/* + * Copy the annotations from an old server list to its potential replacement. + */ +bool afs_annotate_server_list(struct afs_server_list *new, + struct afs_server_list *old) +{ + struct afs_server *cur; + int i, j; + + if (old->nr_servers != new->nr_servers) + goto changed; + + for (i = 0; i < old->nr_servers; i++) + if (old->servers[i].server != new->servers[i].server) + goto changed; + + return false; + +changed: + /* Maintain the same current server as before if possible. */ + cur = old->servers[old->index].server; + for (j = 0; j < new->nr_servers; j++) { + if (new->servers[j].server == cur) { + new->index = j; + break; + } + } + + /* Keep the old callback interest records where possible so that we + * maintain callback interception. + */ + i = 0; + j = 0; + while (i < old->nr_servers && j < new->nr_servers) { + if (new->servers[j].server == old->servers[i].server) { + struct afs_cb_interest *cbi = old->servers[i].cb_interest; + if (cbi) { + new->servers[j].cb_interest = cbi; + refcount_inc(&cbi->usage); + } + i++; + j++; + continue; + } + + if (new->servers[j].server < old->servers[i].server) { + j++; + continue; + } + + i++; + continue; + } + + return true; +} |