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-rw-r--r--fs/afs/callback.c10
-rw-r--r--fs/afs/internal.h4
-rw-r--r--fs/afs/server.c56
3 files changed, 59 insertions, 11 deletions
diff --git a/fs/afs/callback.c b/fs/afs/callback.c
index b4cb9bb63f0a..7d9b23d981bf 100644
--- a/fs/afs/callback.c
+++ b/fs/afs/callback.c
@@ -21,11 +21,17 @@
#include "internal.h"
/*
- * allow the fileserver to request callback state (re-)initialisation
+ * Allow the fileserver to request callback state (re-)initialisation.
+ * Unfortunately, UUIDs are not guaranteed unique.
*/
void afs_init_callback_state(struct afs_server *server)
{
- server->cb_s_break++;
+ rcu_read_lock();
+ do {
+ server->cb_s_break++;
+ server = rcu_dereference(server->uuid_next);
+ } while (0);
+ rcu_read_unlock();
}
/*
diff --git a/fs/afs/internal.h b/fs/afs/internal.h
index c64c2b47ece7..e0dc14d4d8b9 100644
--- a/fs/afs/internal.h
+++ b/fs/afs/internal.h
@@ -486,7 +486,9 @@ struct afs_server {
struct afs_addr_list __rcu *addresses;
struct afs_cell *cell; /* Cell to which belongs (pins ref) */
- struct rb_node uuid_rb; /* Link in cell->fs_servers */
+ struct rb_node uuid_rb; /* Link in net->fs_servers */
+ struct afs_server __rcu *uuid_next; /* Next server with same UUID */
+ struct afs_server *uuid_prev; /* Previous server with same UUID */
struct list_head probe_link; /* Link in net->fs_probe_list */
struct hlist_node addr4_link; /* Link in net->fs_addresses4 */
struct hlist_node addr6_link; /* Link in net->fs_addresses6 */
diff --git a/fs/afs/server.c b/fs/afs/server.c
index c51039a077cd..88593ffcb54e 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -130,13 +130,15 @@ struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uu
}
/*
- * Install a server record in the namespace tree
+ * Install a server record in the namespace tree. If there's a clash, we stick
+ * it into a list anchored on whichever afs_server struct is actually in the
+ * tree.
*/
static struct afs_server *afs_install_server(struct afs_cell *cell,
struct afs_server *candidate)
{
const struct afs_addr_list *alist;
- struct afs_server *server;
+ struct afs_server *server, *next;
struct afs_net *net = cell->net;
struct rb_node **pp, *p;
int diff;
@@ -153,12 +155,30 @@ static struct afs_server *afs_install_server(struct afs_cell *cell,
_debug("- consider %p", p);
server = rb_entry(p, struct afs_server, uuid_rb);
diff = memcmp(&candidate->uuid, &server->uuid, sizeof(uuid_t));
- if (diff < 0)
+ if (diff < 0) {
pp = &(*pp)->rb_left;
- else if (diff > 0)
+ } else if (diff > 0) {
pp = &(*pp)->rb_right;
- else
- goto exists;
+ } else {
+ if (server->cell == cell)
+ goto exists;
+
+ /* We have the same UUID representing servers in
+ * different cells. Append the new server to the list.
+ */
+ for (;;) {
+ next = rcu_dereference_protected(
+ server->uuid_next,
+ lockdep_is_held(&net->fs_lock.lock));
+ if (!next)
+ break;
+ server = next;
+ }
+ rcu_assign_pointer(server->uuid_next, candidate);
+ candidate->uuid_prev = server;
+ server = candidate;
+ goto added_dup;
+ }
}
server = candidate;
@@ -166,6 +186,7 @@ static struct afs_server *afs_install_server(struct afs_cell *cell,
rb_insert_color(&server->uuid_rb, &net->fs_servers);
hlist_add_head_rcu(&server->proc_link, &net->fs_proc);
+added_dup:
write_seqlock(&net->fs_addr_lock);
alist = rcu_dereference_protected(server->addresses,
lockdep_is_held(&net->fs_addr_lock.lock));
@@ -453,7 +474,7 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
*/
static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
{
- struct afs_server *server;
+ struct afs_server *server, *next, *prev;
int active;
while ((server = gc_list)) {
@@ -465,7 +486,26 @@ static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
if (active == 0) {
trace_afs_server(server, atomic_read(&server->ref),
active, afs_server_trace_gc);
- rb_erase(&server->uuid_rb, &net->fs_servers);
+ next = rcu_dereference_protected(
+ server->uuid_next, lockdep_is_held(&net->fs_lock.lock));
+ prev = server->uuid_prev;
+ if (!prev) {
+ /* The one at the front is in the tree */
+ if (!next) {
+ rb_erase(&server->uuid_rb, &net->fs_servers);
+ } else {
+ rb_replace_node_rcu(&server->uuid_rb,
+ &next->uuid_rb,
+ &net->fs_servers);
+ next->uuid_prev = NULL;
+ }
+ } else {
+ /* This server is not at the front */
+ rcu_assign_pointer(prev->uuid_next, next);
+ if (next)
+ next->uuid_prev = prev;
+ }
+
list_del(&server->probe_link);
hlist_del_rcu(&server->proc_link);
if (!hlist_unhashed(&server->addr4_link))