diff options
| -rw-r--r-- | fs/afs/callback.c | 10 | ||||
| -rw-r--r-- | fs/afs/internal.h | 4 | ||||
| -rw-r--r-- | fs/afs/server.c | 56 |
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)) |