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-rw-r--r--fs/afs/server.c782
1 files changed, 577 insertions, 205 deletions
diff --git a/fs/afs/server.c b/fs/afs/server.c
index c001b1f2455f..1880f1b6a9f1 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -11,317 +11,689 @@
#include <linux/sched.h>
#include <linux/slab.h>
+#include "afs_fs.h"
#include "internal.h"
-static unsigned afs_server_timeout = 10; /* server timeout in seconds */
+static unsigned afs_server_gc_delay = 10; /* Server record timeout in seconds */
+static unsigned afs_server_update_delay = 30; /* Time till VLDB recheck in secs */
-static void afs_reap_server(struct work_struct *);
+static void afs_inc_servers_outstanding(struct afs_net *net)
+{
+ atomic_inc(&net->servers_outstanding);
+}
+
+static void afs_dec_servers_outstanding(struct afs_net *net)
+{
+ if (atomic_dec_and_test(&net->servers_outstanding))
+ wake_up_atomic_t(&net->servers_outstanding);
+}
+
+/*
+ * Find a server by one of its addresses.
+ */
+struct afs_server *afs_find_server(struct afs_net *net,
+ const struct sockaddr_rxrpc *srx)
+{
+ const struct sockaddr_in6 *a = &srx->transport.sin6, *b;
+ const struct afs_addr_list *alist;
+ struct afs_server *server = NULL;
+ unsigned int i;
+ bool ipv6 = true;
+ int seq = 0, diff;
+
+ if (srx->transport.sin6.sin6_addr.s6_addr32[0] == 0 ||
+ srx->transport.sin6.sin6_addr.s6_addr32[1] == 0 ||
+ srx->transport.sin6.sin6_addr.s6_addr32[2] == htonl(0xffff))
+ ipv6 = false;
+
+ rcu_read_lock();
+
+ do {
+ if (server)
+ afs_put_server(net, server);
+ server = NULL;
+ read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
+
+ if (ipv6) {
+ hlist_for_each_entry_rcu(server, &net->fs_addresses6, addr6_link) {
+ alist = rcu_dereference(server->addresses);
+ for (i = alist->nr_ipv4; i < alist->nr_addrs; i++) {
+ b = &alist->addrs[i].transport.sin6;
+ diff = (u16)a->sin6_port - (u16)b->sin6_port;
+ if (diff == 0)
+ diff = memcmp(&a->sin6_addr,
+ &b->sin6_addr,
+ sizeof(struct in6_addr));
+ if (diff == 0)
+ goto found;
+ if (diff < 0) {
+ // TODO: Sort the list
+ //if (i == alist->nr_ipv4)
+ // goto not_found;
+ break;
+ }
+ }
+ }
+ } else {
+ hlist_for_each_entry_rcu(server, &net->fs_addresses4, addr4_link) {
+ alist = rcu_dereference(server->addresses);
+ for (i = 0; i < alist->nr_ipv4; i++) {
+ b = &alist->addrs[i].transport.sin6;
+ diff = (u16)a->sin6_port - (u16)b->sin6_port;
+ if (diff == 0)
+ diff = ((u32)a->sin6_addr.s6_addr32[3] -
+ (u32)b->sin6_addr.s6_addr32[3]);
+ if (diff == 0)
+ goto found;
+ if (diff < 0) {
+ // TODO: Sort the list
+ //if (i == 0)
+ // goto not_found;
+ break;
+ }
+ }
+ }
+ }
+
+ //not_found:
+ server = NULL;
+ found:
+ if (server && !atomic_inc_not_zero(&server->usage))
+ server = NULL;
+
+ } while (need_seqretry(&net->fs_addr_lock, seq));
-/* tree of all the servers, indexed by IP address */
-static struct rb_root afs_servers = RB_ROOT;
-static DEFINE_RWLOCK(afs_servers_lock);
+ done_seqretry(&net->fs_addr_lock, seq);
-/* LRU list of all the servers not currently in use */
-static LIST_HEAD(afs_server_graveyard);
-static DEFINE_SPINLOCK(afs_server_graveyard_lock);
-static DECLARE_DELAYED_WORK(afs_server_reaper, afs_reap_server);
+ rcu_read_unlock();
+ return server;
+}
/*
- * install a server record in the master tree
+ * Look up a server by its UUID
*/
-static int afs_install_server(struct afs_server *server)
+struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uuid)
{
- struct afs_server *xserver;
+ struct afs_server *server = NULL;
+ struct rb_node *p;
+ int diff, seq = 0;
+
+ _enter("%pU", uuid);
+
+ do {
+ /* Unfortunately, rbtree walking doesn't give reliable results
+ * under just the RCU read lock, so we have to check for
+ * changes.
+ */
+ if (server)
+ afs_put_server(net, server);
+ server = NULL;
+
+ read_seqbegin_or_lock(&net->fs_lock, &seq);
+
+ p = net->fs_servers.rb_node;
+ while (p) {
+ server = rb_entry(p, struct afs_server, uuid_rb);
+
+ diff = memcmp(uuid, &server->uuid, sizeof(*uuid));
+ if (diff < 0) {
+ p = p->rb_left;
+ } else if (diff > 0) {
+ p = p->rb_right;
+ } else {
+ afs_get_server(server);
+ break;
+ }
+
+ server = NULL;
+ }
+ } while (need_seqretry(&net->fs_lock, seq));
+
+ done_seqretry(&net->fs_lock, seq);
+
+ _leave(" = %p", server);
+ return server;
+}
+
+/*
+ * Install a server record in the namespace tree
+ */
+static struct afs_server *afs_install_server(struct afs_net *net,
+ struct afs_server *candidate)
+{
+ const struct afs_addr_list *alist;
+ struct afs_server *server;
struct rb_node **pp, *p;
- int ret;
+ int ret = -EEXIST, diff;
- _enter("%p", server);
+ _enter("%p", candidate);
- write_lock(&afs_servers_lock);
+ write_seqlock(&net->fs_lock);
- ret = -EEXIST;
- pp = &afs_servers.rb_node;
+ /* Firstly install the server in the UUID lookup tree */
+ pp = &net->fs_servers.rb_node;
p = NULL;
while (*pp) {
p = *pp;
_debug("- consider %p", p);
- xserver = rb_entry(p, struct afs_server, master_rb);
- if (server->addr.s_addr < xserver->addr.s_addr)
+ server = rb_entry(p, struct afs_server, uuid_rb);
+ diff = memcmp(&candidate->uuid, &server->uuid, sizeof(uuid_t));
+ if (diff < 0)
pp = &(*pp)->rb_left;
- else if (server->addr.s_addr > xserver->addr.s_addr)
+ else if (diff > 0)
pp = &(*pp)->rb_right;
else
- goto error;
+ goto exists;
}
- rb_link_node(&server->master_rb, p, pp);
- rb_insert_color(&server->master_rb, &afs_servers);
+ server = candidate;
+ rb_link_node(&server->uuid_rb, p, pp);
+ rb_insert_color(&server->uuid_rb, &net->fs_servers);
+ hlist_add_head_rcu(&server->proc_link, &net->fs_proc);
+
+ write_seqlock(&net->fs_addr_lock);
+ alist = rcu_dereference_protected(server->addresses,
+ lockdep_is_held(&net->fs_addr_lock.lock));
+
+ /* Secondly, if the server has any IPv4 and/or IPv6 addresses, install
+ * it in the IPv4 and/or IPv6 reverse-map lists.
+ *
+ * TODO: For speed we want to use something other than a flat list
+ * here; even sorting the list in terms of lowest address would help a
+ * bit, but anything we might want to do gets messy and memory
+ * intensive.
+ */
+ if (alist->nr_ipv4 > 0)
+ hlist_add_head_rcu(&server->addr4_link, &net->fs_addresses4);
+ if (alist->nr_addrs > alist->nr_ipv4)
+ hlist_add_head_rcu(&server->addr6_link, &net->fs_addresses6);
+
+ write_sequnlock(&net->fs_addr_lock);
ret = 0;
-error:
- write_unlock(&afs_servers_lock);
- return ret;
+exists:
+ afs_get_server(server);
+ write_sequnlock(&net->fs_lock);
+ return server;
}
/*
* allocate a new server record
*/
-static struct afs_server *afs_alloc_server(struct afs_cell *cell,
- const struct in_addr *addr)
+static struct afs_server *afs_alloc_server(struct afs_net *net,
+ const uuid_t *uuid,
+ struct afs_addr_list *alist)
{
struct afs_server *server;
_enter("");
server = kzalloc(sizeof(struct afs_server), GFP_KERNEL);
- if (server) {
- atomic_set(&server->usage, 1);
- server->cell = cell;
-
- INIT_LIST_HEAD(&server->link);
- INIT_LIST_HEAD(&server->grave);
- init_rwsem(&server->sem);
- spin_lock_init(&server->fs_lock);
- server->fs_vnodes = RB_ROOT;
- server->cb_promises = RB_ROOT;
- spin_lock_init(&server->cb_lock);
- init_waitqueue_head(&server->cb_break_waitq);
- INIT_DELAYED_WORK(&server->cb_break_work,
- afs_dispatch_give_up_callbacks);
-
- memcpy(&server->addr, addr, sizeof(struct in_addr));
- server->addr.s_addr = addr->s_addr;
- _leave(" = %p{%d}", server, atomic_read(&server->usage));
- } else {
- _leave(" = NULL [nomem]");
- }
+ if (!server)
+ goto enomem;
+
+ atomic_set(&server->usage, 1);
+ RCU_INIT_POINTER(server->addresses, alist);
+ server->addr_version = alist->version;
+ server->uuid = *uuid;
+ server->flags = (1UL << AFS_SERVER_FL_NEW);
+ server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
+ rwlock_init(&server->fs_lock);
+ INIT_LIST_HEAD(&server->cb_interests);
+ rwlock_init(&server->cb_break_lock);
+
+ afs_inc_servers_outstanding(net);
+ _leave(" = %p", server);
return server;
+
+enomem:
+ _leave(" = NULL [nomem]");
+ return NULL;
+}
+
+/*
+ * Look up an address record for a server
+ */
+static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
+ struct key *key, const uuid_t *uuid)
+{
+ struct afs_addr_cursor ac;
+ struct afs_addr_list *alist;
+ int ret;
+
+ ret = afs_set_vl_cursor(&ac, cell);
+ if (ret < 0)
+ return ERR_PTR(ret);
+
+ while (afs_iterate_addresses(&ac)) {
+ if (test_bit(ac.index, &ac.alist->yfs))
+ alist = afs_yfsvl_get_endpoints(cell->net, &ac, key, uuid);
+ else
+ alist = afs_vl_get_addrs_u(cell->net, &ac, key, uuid);
+ switch (ac.error) {
+ case 0:
+ afs_end_cursor(&ac);
+ return alist;
+ case -ECONNABORTED:
+ ac.error = afs_abort_to_error(ac.abort_code);
+ goto error;
+ case -ENOMEM:
+ case -ENONET:
+ goto error;
+ case -ENETUNREACH:
+ case -EHOSTUNREACH:
+ case -ECONNREFUSED:
+ break;
+ default:
+ ac.error = -EIO;
+ goto error;
+ }
+ }
+
+error:
+ return ERR_PTR(afs_end_cursor(&ac));
}
/*
- * get an FS-server record for a cell
+ * Get or create a fileserver record.
*/
-struct afs_server *afs_lookup_server(struct afs_cell *cell,
- const struct in_addr *addr)
+struct afs_server *afs_lookup_server(struct afs_cell *cell, struct key *key,
+ const uuid_t *uuid)
{
+ struct afs_addr_list *alist;
struct afs_server *server, *candidate;
- _enter("%p,%pI4", cell, &addr->s_addr);
+ _enter("%p,%pU", cell->net, uuid);
- /* quick scan of the list to see if we already have the server */
- read_lock(&cell->servers_lock);
+ server = afs_find_server_by_uuid(cell->net, uuid);
+ if (server)
+ return server;
- list_for_each_entry(server, &cell->servers, link) {
- if (server->addr.s_addr == addr->s_addr)
- goto found_server_quickly;
- }
- read_unlock(&cell->servers_lock);
+ alist = afs_vl_lookup_addrs(cell, key, uuid);
+ if (IS_ERR(alist))
+ return ERR_CAST(alist);
- candidate = afs_alloc_server(cell, addr);
+ candidate = afs_alloc_server(cell->net, uuid, alist);
if (!candidate) {
- _leave(" = -ENOMEM");
+ afs_put_addrlist(alist);
return ERR_PTR(-ENOMEM);
}
- write_lock(&cell->servers_lock);
-
- /* check the cell's server list again */
- list_for_each_entry(server, &cell->servers, link) {
- if (server->addr.s_addr == addr->s_addr)
- goto found_server;
+ server = afs_install_server(cell->net, candidate);
+ if (server != candidate) {
+ afs_put_addrlist(alist);
+ kfree(candidate);
}
- _debug("new");
- server = candidate;
- if (afs_install_server(server) < 0)
- goto server_in_two_cells;
-
- afs_get_cell(cell);
- list_add_tail(&server->link, &cell->servers);
-
- write_unlock(&cell->servers_lock);
_leave(" = %p{%d}", server, atomic_read(&server->usage));
return server;
+}
- /* found a matching server quickly */
-found_server_quickly:
- _debug("found quickly");
- afs_get_server(server);
- read_unlock(&cell->servers_lock);
-no_longer_unused:
- if (!list_empty(&server->grave)) {
- spin_lock(&afs_server_graveyard_lock);
- list_del_init(&server->grave);
- spin_unlock(&afs_server_graveyard_lock);
+/*
+ * Set the server timer to fire after a given delay, assuming it's not already
+ * set for an earlier time.
+ */
+static void afs_set_server_timer(struct afs_net *net, time64_t delay)
+{
+ if (net->live) {
+ afs_inc_servers_outstanding(net);
+ if (timer_reduce(&net->fs_timer, jiffies + delay * HZ))
+ afs_dec_servers_outstanding(net);
}
- _leave(" = %p{%d}", server, atomic_read(&server->usage));
- return server;
+}
- /* found a matching server on the second pass */
-found_server:
- _debug("found");
- afs_get_server(server);
- write_unlock(&cell->servers_lock);
- kfree(candidate);
- goto no_longer_unused;
-
- /* found a server that seems to be in two cells */
-server_in_two_cells:
- write_unlock(&cell->servers_lock);
- kfree(candidate);
- printk(KERN_NOTICE "kAFS: Server %pI4 appears to be in two cells\n",
- addr);
- _leave(" = -EEXIST");
- return ERR_PTR(-EEXIST);
+/*
+ * Server management timer. We have an increment on fs_outstanding that we
+ * need to pass along to the work item.
+ */
+void afs_servers_timer(struct timer_list *timer)
+{
+ struct afs_net *net = container_of(timer, struct afs_net, fs_timer);
+
+ _enter("");
+ if (!queue_work(afs_wq, &net->fs_manager))
+ afs_dec_servers_outstanding(net);
}
/*
- * look up a server by its IP address
+ * Release a reference on a server record.
*/
-struct afs_server *afs_find_server(const struct sockaddr_rxrpc *srx)
+void afs_put_server(struct afs_net *net, struct afs_server *server)
{
- struct afs_server *server = NULL;
- struct rb_node *p;
- struct in_addr addr = srx->transport.sin.sin_addr;
+ unsigned int usage;
- _enter("{%d,%pI4}", srx->transport.family, &addr.s_addr);
+ if (!server)
+ return;
- if (srx->transport.family != AF_INET) {
- WARN(true, "AFS does not yes support non-IPv4 addresses\n");
- return NULL;
- }
+ server->put_time = ktime_get_real_seconds();
- read_lock(&afs_servers_lock);
+ usage = atomic_dec_return(&server->usage);
- p = afs_servers.rb_node;
- while (p) {
- server = rb_entry(p, struct afs_server, master_rb);
+ _enter("{%u}", usage);
- _debug("- consider %p", p);
+ if (likely(usage > 0))
+ return;
- if (addr.s_addr < server->addr.s_addr) {
- p = p->rb_left;
- } else if (addr.s_addr > server->addr.s_addr) {
- p = p->rb_right;
- } else {
- afs_get_server(server);
- goto found;
- }
- }
+ afs_set_server_timer(net, afs_server_gc_delay);
+}
- server = NULL;
-found:
- read_unlock(&afs_servers_lock);
- ASSERTIFCMP(server, server->addr.s_addr, ==, addr.s_addr);
- _leave(" = %p", server);
- return server;
+static void afs_server_rcu(struct rcu_head *rcu)
+{
+ struct afs_server *server = container_of(rcu, struct afs_server, rcu);
+
+ afs_put_addrlist(server->addresses);
+ kfree(server);
}
/*
- * destroy a server record
- * - removes from the cell list
+ * destroy a dead server
*/
-void afs_put_server(struct afs_server *server)
+static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
{
- if (!server)
- return;
+ struct afs_addr_list *alist = server->addresses;
+ struct afs_addr_cursor ac = {
+ .alist = alist,
+ .addr = &alist->addrs[0],
+ .start = alist->index,
+ .index = alist->index,
+ .error = 0,
+ };
+ _enter("%p", server);
- _enter("%p{%d}", server, atomic_read(&server->usage));
+ afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
+ call_rcu(&server->rcu, afs_server_rcu);
+ afs_dec_servers_outstanding(net);
+}
- _debug("PUT SERVER %d", atomic_read(&server->usage));
+/*
+ * Garbage collect any expired servers.
+ */
+static void afs_gc_servers(struct afs_net *net, struct afs_server *gc_list)
+{
+ struct afs_server *server;
+ bool deleted;
+ int usage;
+
+ while ((server = gc_list)) {
+ gc_list = server->gc_next;
+
+ write_seqlock(&net->fs_lock);
+ usage = 1;
+ deleted = atomic_try_cmpxchg(&server->usage, &usage, 0);
+ if (deleted) {
+ rb_erase(&server->uuid_rb, &net->fs_servers);
+ hlist_del_rcu(&server->proc_link);
+ }
+ write_sequnlock(&net->fs_lock);
- ASSERTCMP(atomic_read(&server->usage), >, 0);
+ if (deleted)
+ afs_destroy_server(net, server);
+ }
+}
- if (likely(!atomic_dec_and_test(&server->usage))) {
- _leave("");
- return;
+/*
+ * Manage the records of servers known to be within a network namespace. This
+ * includes garbage collecting unused servers.
+ *
+ * Note also that we were given an increment on net->servers_outstanding by
+ * whoever queued us that we need to deal with before returning.
+ */
+void afs_manage_servers(struct work_struct *work)
+{
+ struct afs_net *net = container_of(work, struct afs_net, fs_manager);
+ struct afs_server *gc_list = NULL;
+ struct rb_node *cursor;
+ time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX;
+ bool purging = !net->live;
+
+ _enter("");
+
+ /* Trawl the server list looking for servers that have expired from
+ * lack of use.
+ */
+ read_seqlock_excl(&net->fs_lock);
+
+ for (cursor = rb_first(&net->fs_servers); cursor; cursor = rb_next(cursor)) {
+ struct afs_server *server =
+ rb_entry(cursor, struct afs_server, uuid_rb);
+ int usage = atomic_read(&server->usage);
+
+ _debug("manage %pU %u", &server->uuid, usage);
+
+ ASSERTCMP(usage, >=, 1);
+ ASSERTIFCMP(purging, usage, ==, 1);
+
+ if (usage == 1) {
+ time64_t expire_at = server->put_time;
+
+ if (!test_bit(AFS_SERVER_FL_VL_FAIL, &server->flags) &&
+ !test_bit(AFS_SERVER_FL_NOT_FOUND, &server->flags))
+ expire_at += afs_server_gc_delay;
+ if (purging || expire_at <= now) {
+ server->gc_next = gc_list;
+ gc_list = server;
+ } else if (expire_at < next_manage) {
+ next_manage = expire_at;
+ }
+ }
}
- afs_flush_callback_breaks(server);
+ read_sequnlock_excl(&net->fs_lock);
+
+ /* Update the timer on the way out. We have to pass an increment on
+ * servers_outstanding in the namespace that we are in to the timer or
+ * the work scheduler.
+ */
+ if (!purging && next_manage < TIME64_MAX) {
+ now = ktime_get_real_seconds();
- spin_lock(&afs_server_graveyard_lock);
- if (atomic_read(&server->usage) == 0) {
- list_move_tail(&server->grave, &afs_server_graveyard);
- server->time_of_death = ktime_get_real_seconds();
- queue_delayed_work(afs_wq, &afs_server_reaper,
- afs_server_timeout * HZ);
+ if (next_manage - now <= 0) {
+ if (queue_work(afs_wq, &net->fs_manager))
+ afs_inc_servers_outstanding(net);
+ } else {
+ afs_set_server_timer(net, next_manage - now);
+ }
}
- spin_unlock(&afs_server_graveyard_lock);
- _leave(" [dead]");
+
+ afs_gc_servers(net, gc_list);
+
+ afs_dec_servers_outstanding(net);
+ _leave(" [%d]", atomic_read(&net->servers_outstanding));
+}
+
+static void afs_queue_server_manager(struct afs_net *net)
+{
+ afs_inc_servers_outstanding(net);
+ if (!queue_work(afs_wq, &net->fs_manager))
+ afs_dec_servers_outstanding(net);
}
/*
- * destroy a dead server
+ * Purge list of servers.
*/
-static void afs_destroy_server(struct afs_server *server)
+void afs_purge_servers(struct afs_net *net)
{
- _enter("%p", server);
+ _enter("");
- ASSERTIF(server->cb_break_head != server->cb_break_tail,
- delayed_work_pending(&server->cb_break_work));
+ if (del_timer_sync(&net->fs_timer))
+ atomic_dec(&net->servers_outstanding);
- ASSERTCMP(server->fs_vnodes.rb_node, ==, NULL);
- ASSERTCMP(server->cb_promises.rb_node, ==, NULL);
- ASSERTCMP(server->cb_break_head, ==, server->cb_break_tail);
- ASSERTCMP(atomic_read(&server->cb_break_n), ==, 0);
+ afs_queue_server_manager(net);
- afs_put_cell(server->cell);
- kfree(server);
+ _debug("wait");
+ wait_on_atomic_t(&net->servers_outstanding, atomic_t_wait,
+ TASK_UNINTERRUPTIBLE);
+ _leave("");
}
/*
- * reap dead server records
+ * Probe a fileserver to find its capabilities.
+ *
+ * TODO: Try service upgrade.
*/
-static void afs_reap_server(struct work_struct *work)
+static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
{
- LIST_HEAD(corpses);
- struct afs_server *server;
- unsigned long delay, expiry;
- time64_t now;
-
- now = ktime_get_real_seconds();
- spin_lock(&afs_server_graveyard_lock);
-
- while (!list_empty(&afs_server_graveyard)) {
- server = list_entry(afs_server_graveyard.next,
- struct afs_server, grave);
+ _enter("");
- /* the queue is ordered most dead first */
- expiry = server->time_of_death + afs_server_timeout;
- if (expiry > now) {
- delay = (expiry - now) * HZ;
- mod_delayed_work(afs_wq, &afs_server_reaper, delay);
+ fc->ac.addr = NULL;
+ fc->ac.start = READ_ONCE(fc->ac.alist->index);
+ fc->ac.index = fc->ac.start;
+ fc->ac.error = 0;
+ fc->ac.begun = false;
+
+ while (afs_iterate_addresses(&fc->ac)) {
+ afs_fs_get_capabilities(afs_v2net(fc->vnode), fc->cbi->server,
+ &fc->ac, fc->key);
+ switch (fc->ac.error) {
+ case 0:
+ afs_end_cursor(&fc->ac);
+ set_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags);
+ return true;
+ case -ECONNABORTED:
+ fc->ac.error = afs_abort_to_error(fc->ac.abort_code);
+ goto error;
+ case -ENOMEM:
+ case -ENONET:
+ goto error;
+ case -ENETUNREACH:
+ case -EHOSTUNREACH:
+ case -ECONNREFUSED:
+ case -ETIMEDOUT:
+ case -ETIME:
break;
+ default:
+ fc->ac.error = -EIO;
+ goto error;
}
+ }
- write_lock(&server->cell->servers_lock);
- write_lock(&afs_servers_lock);
- if (atomic_read(&server->usage) > 0) {
- list_del_init(&server->grave);
- } else {
- list_move_tail(&server->grave, &corpses);
- list_del_init(&server->link);
- rb_erase(&server->master_rb, &afs_servers);
- }
- write_unlock(&afs_servers_lock);
- write_unlock(&server->cell->servers_lock);
+error:
+ afs_end_cursor(&fc->ac);
+ return false;
+}
+
+/*
+ * If we haven't already, try probing the fileserver to get its capabilities.
+ * We try not to instigate parallel probes, but it's possible that the parallel
+ * probes will fail due to authentication failure when ours would succeed.
+ *
+ * TODO: Try sending an anonymous probe if an authenticated probe fails.
+ */
+bool afs_probe_fileserver(struct afs_fs_cursor *fc)
+{
+ bool success;
+ int ret, retries = 0;
+
+ _enter("");
+
+retry:
+ if (test_bit(AFS_SERVER_FL_PROBED, &fc->cbi->server->flags)) {
+ _leave(" = t");
+ return true;
}
- spin_unlock(&afs_server_graveyard_lock);
+ if (!test_and_set_bit_lock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags)) {
+ success = afs_do_probe_fileserver(fc);
+ clear_bit_unlock(AFS_SERVER_FL_PROBING, &fc->cbi->server->flags);
+ wake_up_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING);
+ _leave(" = t");
+ return success;
+ }
+
+ _debug("wait");
+ ret = wait_on_bit(&fc->cbi->server->flags, AFS_SERVER_FL_PROBING,
+ TASK_INTERRUPTIBLE);
+ if (ret == -ERESTARTSYS) {
+ fc->ac.error = ret;
+ _leave(" = f [%d]", ret);
+ return false;
+ }
- /* now reap the corpses we've extracted */
- while (!list_empty(&corpses)) {
- server = list_entry(corpses.next, struct afs_server, grave);
- list_del(&server->grave);
- afs_destroy_server(server);
+ retries++;
+ if (retries == 4) {
+ fc->ac.error = -ESTALE;
+ _leave(" = f [stale]");
+ return false;
}
+ _debug("retry");
+ goto retry;
}
/*
- * discard all the server records for rmmod
+ * Get an update for a server's address list.
*/
-void __exit afs_purge_servers(void)
+static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
{
- afs_server_timeout = 0;
- mod_delayed_work(afs_wq, &afs_server_reaper, 0);
+ struct afs_addr_list *alist, *discard;
+
+ _enter("");
+
+ alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
+ &server->uuid);
+ if (IS_ERR(alist)) {
+ fc->ac.error = PTR_ERR(alist);
+ _leave(" = f [%d]", fc->ac.error);
+ return false;
+ }
+
+ discard = alist;
+ if (server->addr_version != alist->version) {
+ write_lock(&server->fs_lock);
+ discard = rcu_dereference_protected(server->addresses,
+ lockdep_is_held(&server->fs_lock));
+ rcu_assign_pointer(server->addresses, alist);
+ server->addr_version = alist->version;
+ write_unlock(&server->fs_lock);
+ }
+
+ server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
+ afs_put_addrlist(discard);
+ _leave(" = t");
+ return true;
+}
+
+/*
+ * See if a server's address list needs updating.
+ */
+bool afs_check_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
+{
+ time64_t now = ktime_get_real_seconds();
+ long diff;
+ bool success;
+ int ret, retries = 0;
+
+ _enter("");
+
+ ASSERT(server);
+
+retry:
+ diff = READ_ONCE(server->update_at) - now;
+ if (diff > 0) {
+ _leave(" = t [not now %ld]", diff);
+ return true;
+ }
+
+ if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {
+ success = afs_update_server_record(fc, server);
+ clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);
+ wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);
+ _leave(" = %d", success);
+ return success;
+ }
+
+ ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,
+ TASK_INTERRUPTIBLE);
+ if (ret == -ERESTARTSYS) {
+ fc->ac.error = ret;
+ _leave(" = f [intr]");
+ return false;
+ }
+
+ retries++;
+ if (retries == 4) {
+ _leave(" = f [stale]");
+ ret = -ESTALE;
+ return false;
+ }
+ goto retry;
}