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-rw-r--r--fs/afs/server.c299
1 files changed, 197 insertions, 102 deletions
diff --git a/fs/afs/server.c b/fs/afs/server.c
index 11b90ac7ea30..039e3488511c 100644
--- a/fs/afs/server.c
+++ b/fs/afs/server.c
@@ -12,19 +12,11 @@
#include "protocol_yfs.h"
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 atomic_t afs_server_debug_id;
-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_var(&net->servers_outstanding);
-}
+static struct afs_server *afs_maybe_use_server(struct afs_server *,
+ enum afs_server_trace);
+static void __afs_put_server(struct afs_net *, struct afs_server *);
/*
* Find a server by one of its addresses.
@@ -41,7 +33,7 @@ struct afs_server *afs_find_server(struct afs_net *net,
do {
if (server)
- afs_put_server(net, server, afs_server_trace_put_find_rsq);
+ afs_unuse_server_notime(net, server, afs_server_trace_put_find_rsq);
server = NULL;
read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
@@ -79,9 +71,9 @@ struct afs_server *afs_find_server(struct afs_net *net,
}
server = NULL;
+ continue;
found:
- if (server && !atomic_inc_not_zero(&server->usage))
- server = NULL;
+ server = afs_maybe_use_server(server, afs_server_trace_get_by_addr);
} while (need_seqretry(&net->fs_addr_lock, seq));
@@ -92,7 +84,7 @@ struct afs_server *afs_find_server(struct afs_net *net,
}
/*
- * Look up a server by its UUID
+ * Look up a server by its UUID and mark it active.
*/
struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uuid)
{
@@ -108,7 +100,7 @@ struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uu
* changes.
*/
if (server)
- afs_put_server(net, server, afs_server_trace_put_uuid_rsq);
+ afs_unuse_server(net, server, afs_server_trace_put_uuid_rsq);
server = NULL;
read_seqbegin_or_lock(&net->fs_lock, &seq);
@@ -123,7 +115,7 @@ struct afs_server *afs_find_server_by_uuid(struct afs_net *net, const uuid_t *uu
} else if (diff > 0) {
p = p->rb_right;
} else {
- afs_get_server(server, afs_server_trace_get_by_uuid);
+ afs_use_server(server, afs_server_trace_get_by_uuid);
break;
}
@@ -138,13 +130,16 @@ 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_net *net,
+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;
@@ -160,12 +155,30 @@ static struct afs_server *afs_install_server(struct afs_net *net,
_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;
@@ -173,6 +186,7 @@ static struct afs_server *afs_install_server(struct afs_net *net,
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));
@@ -199,13 +213,14 @@ exists:
}
/*
- * allocate a new server record
+ * Allocate a new server record and mark it active.
*/
-static struct afs_server *afs_alloc_server(struct afs_net *net,
+static struct afs_server *afs_alloc_server(struct afs_cell *cell,
const uuid_t *uuid,
struct afs_addr_list *alist)
{
struct afs_server *server;
+ struct afs_net *net = cell->net;
_enter("");
@@ -213,20 +228,21 @@ static struct afs_server *afs_alloc_server(struct afs_net *net,
if (!server)
goto enomem;
- atomic_set(&server->usage, 1);
+ atomic_set(&server->ref, 1);
+ atomic_set(&server->active, 1);
server->debug_id = atomic_inc_return(&afs_server_debug_id);
RCU_INIT_POINTER(server->addresses, alist);
server->addr_version = alist->version;
server->uuid = *uuid;
- server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
rwlock_init(&server->fs_lock);
- INIT_HLIST_HEAD(&server->cb_volumes);
- rwlock_init(&server->cb_break_lock);
init_waitqueue_head(&server->probe_wq);
+ INIT_LIST_HEAD(&server->probe_link);
spin_lock_init(&server->probe_lock);
+ server->cell = cell;
+ server->rtt = UINT_MAX;
afs_inc_servers_outstanding(net);
- trace_afs_server(server, 1, afs_server_trace_alloc);
+ trace_afs_server(server, 1, 1, afs_server_trace_alloc);
_leave(" = %p", server);
return server;
@@ -264,7 +280,7 @@ static struct afs_addr_list *afs_vl_lookup_addrs(struct afs_cell *cell,
* Get or create a fileserver record.
*/
struct afs_server *afs_lookup_server(struct afs_cell *cell, struct key *key,
- const uuid_t *uuid)
+ const uuid_t *uuid, u32 addr_version)
{
struct afs_addr_list *alist;
struct afs_server *server, *candidate;
@@ -272,26 +288,34 @@ struct afs_server *afs_lookup_server(struct afs_cell *cell, struct key *key,
_enter("%p,%pU", cell->net, uuid);
server = afs_find_server_by_uuid(cell->net, uuid);
- if (server)
+ if (server) {
+ if (server->addr_version != addr_version)
+ set_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);
return server;
+ }
alist = afs_vl_lookup_addrs(cell, key, uuid);
if (IS_ERR(alist))
return ERR_CAST(alist);
- candidate = afs_alloc_server(cell->net, uuid, alist);
+ candidate = afs_alloc_server(cell, uuid, alist);
if (!candidate) {
afs_put_addrlist(alist);
return ERR_PTR(-ENOMEM);
}
- server = afs_install_server(cell->net, candidate);
+ server = afs_install_server(cell, candidate);
if (server != candidate) {
afs_put_addrlist(alist);
kfree(candidate);
+ } else {
+ /* Immediately dispatch an asynchronous probe to each interface
+ * on the fileserver. This will make sure the repeat-probing
+ * service is started.
+ */
+ afs_fs_probe_fileserver(cell->net, server, key, true);
}
- _leave(" = %p{%d}", server, atomic_read(&server->usage));
return server;
}
@@ -327,9 +351,38 @@ void afs_servers_timer(struct timer_list *timer)
struct afs_server *afs_get_server(struct afs_server *server,
enum afs_server_trace reason)
{
- unsigned int u = atomic_inc_return(&server->usage);
+ unsigned int u = atomic_inc_return(&server->ref);
+
+ trace_afs_server(server, u, atomic_read(&server->active), reason);
+ return server;
+}
+
+/*
+ * Try to get a reference on a server object.
+ */
+static struct afs_server *afs_maybe_use_server(struct afs_server *server,
+ enum afs_server_trace reason)
+{
+ unsigned int r = atomic_fetch_add_unless(&server->ref, 1, 0);
+ unsigned int a;
+
+ if (r == 0)
+ return NULL;
+
+ a = atomic_inc_return(&server->active);
+ trace_afs_server(server, r, a, reason);
+ return server;
+}
+
+/*
+ * Get an active count on a server object.
+ */
+struct afs_server *afs_use_server(struct afs_server *server, enum afs_server_trace reason)
+{
+ unsigned int r = atomic_inc_return(&server->ref);
+ unsigned int a = atomic_inc_return(&server->active);
- trace_afs_server(server, u, reason);
+ trace_afs_server(server, r, a, reason);
return server;
}
@@ -344,32 +397,57 @@ void afs_put_server(struct afs_net *net, struct afs_server *server,
if (!server)
return;
- server->put_time = ktime_get_real_seconds();
-
- usage = atomic_dec_return(&server->usage);
+ usage = atomic_dec_return(&server->ref);
+ trace_afs_server(server, usage, atomic_read(&server->active), reason);
+ if (unlikely(usage == 0))
+ __afs_put_server(net, server);
+}
- trace_afs_server(server, usage, reason);
+/*
+ * Drop an active count on a server object without updating the last-unused
+ * time.
+ */
+void afs_unuse_server_notime(struct afs_net *net, struct afs_server *server,
+ enum afs_server_trace reason)
+{
+ if (server) {
+ unsigned int active = atomic_dec_return(&server->active);
- if (likely(usage > 0))
- return;
+ if (active == 0)
+ afs_set_server_timer(net, afs_server_gc_delay);
+ afs_put_server(net, server, reason);
+ }
+}
- afs_set_server_timer(net, afs_server_gc_delay);
+/*
+ * Drop an active count on a server object.
+ */
+void afs_unuse_server(struct afs_net *net, struct afs_server *server,
+ enum afs_server_trace reason)
+{
+ if (server) {
+ server->unuse_time = ktime_get_real_seconds();
+ afs_unuse_server_notime(net, server, reason);
+ }
}
static void afs_server_rcu(struct rcu_head *rcu)
{
struct afs_server *server = container_of(rcu, struct afs_server, rcu);
- trace_afs_server(server, atomic_read(&server->usage),
- afs_server_trace_free);
+ trace_afs_server(server, atomic_read(&server->ref),
+ atomic_read(&server->active), afs_server_trace_free);
afs_put_addrlist(rcu_access_pointer(server->addresses));
kfree(server);
}
-/*
- * destroy a dead server
- */
-static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
+static void __afs_put_server(struct afs_net *net, struct afs_server *server)
+{
+ call_rcu(&server->rcu, afs_server_rcu);
+ afs_dec_servers_outstanding(net);
+}
+
+static void afs_give_up_callbacks(struct afs_net *net, struct afs_server *server)
{
struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
struct afs_addr_cursor ac = {
@@ -378,19 +456,18 @@ static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
.error = 0,
};
- trace_afs_server(server, atomic_read(&server->usage),
- afs_server_trace_give_up_cb);
+ afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
+}
+/*
+ * destroy a dead server
+ */
+static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
+{
if (test_bit(AFS_SERVER_FL_MAY_HAVE_CB, &server->flags))
- afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
+ afs_give_up_callbacks(net, server);
- wait_var_event(&server->probe_outstanding,
- atomic_read(&server->probe_outstanding) == 0);
-
- trace_afs_server(server, atomic_read(&server->usage),
- afs_server_trace_destroy);
- call_rcu(&server->rcu, afs_server_rcu);
- afs_dec_servers_outstanding(net);
+ afs_put_server(net, server, afs_server_trace_destroy);
}
/*
@@ -398,32 +475,49 @@ 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;
- bool deleted;
- int usage;
+ struct afs_server *server, *next, *prev;
+ int active;
while ((server = gc_list)) {
gc_list = server->gc_next;
write_seqlock(&net->fs_lock);
- usage = 1;
- deleted = atomic_try_cmpxchg(&server->usage, &usage, 0);
- trace_afs_server(server, usage, afs_server_trace_gc);
- if (deleted) {
- rb_erase(&server->uuid_rb, &net->fs_servers);
- hlist_del_rcu(&server->proc_link);
- }
- write_sequnlock(&net->fs_lock);
- if (deleted) {
- write_seqlock(&net->fs_addr_lock);
+ active = atomic_read(&server->active);
+ if (active == 0) {
+ trace_afs_server(server, atomic_read(&server->ref),
+ active, afs_server_trace_gc);
+ 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))
hlist_del_rcu(&server->addr4_link);
if (!hlist_unhashed(&server->addr6_link))
hlist_del_rcu(&server->addr6_link);
- write_sequnlock(&net->fs_addr_lock);
- afs_destroy_server(net, server);
}
+ write_sequnlock(&net->fs_lock);
+
+ if (active == 0)
+ afs_destroy_server(net, server);
}
}
@@ -452,15 +546,14 @@ void afs_manage_servers(struct work_struct *work)
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);
+ int active = atomic_read(&server->active);
- _debug("manage %pU %u", &server->uuid, usage);
+ _debug("manage %pU %u", &server->uuid, active);
- ASSERTCMP(usage, >=, 1);
- ASSERTIFCMP(purging, usage, ==, 1);
+ ASSERTIFCMP(purging, active, ==, 0);
- if (usage == 1) {
- time64_t expire_at = server->put_time;
+ if (active == 0) {
+ time64_t expire_at = server->unuse_time;
if (!test_bit(AFS_SERVER_FL_VL_FAIL, &server->flags) &&
!test_bit(AFS_SERVER_FL_NOT_FOUND, &server->flags))
@@ -525,26 +618,27 @@ void afs_purge_servers(struct afs_net *net)
/*
* Get an update for a server's address list.
*/
-static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
+static noinline bool afs_update_server_record(struct afs_operation *op,
+ struct afs_server *server)
{
struct afs_addr_list *alist, *discard;
_enter("");
- trace_afs_server(server, atomic_read(&server->usage), afs_server_trace_update);
+ trace_afs_server(server, atomic_read(&server->ref), atomic_read(&server->active),
+ afs_server_trace_update);
- alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
- &server->uuid);
+ alist = afs_vl_lookup_addrs(op->volume->cell, op->key, &server->uuid);
if (IS_ERR(alist)) {
if ((PTR_ERR(alist) == -ERESTARTSYS ||
PTR_ERR(alist) == -EINTR) &&
- !(fc->flags & AFS_FS_CURSOR_INTR) &&
+ (op->flags & AFS_OPERATION_UNINTR) &&
server->addresses) {
_leave(" = t [intr]");
return true;
}
- fc->error = PTR_ERR(alist);
- _leave(" = f [%d]", fc->error);
+ op->error = PTR_ERR(alist);
+ _leave(" = f [%d]", op->error);
return false;
}
@@ -558,7 +652,6 @@ static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct a
write_unlock(&server->fs_lock);
}
- server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
afs_put_addrlist(discard);
_leave(" = t");
return true;
@@ -567,10 +660,8 @@ static noinline bool afs_update_server_record(struct afs_fs_cursor *fc, struct a
/*
* See if a server's address list needs updating.
*/
-bool afs_check_server_record(struct afs_fs_cursor *fc, struct afs_server *server)
+bool afs_check_server_record(struct afs_operation *op, struct afs_server *server)
{
- time64_t now = ktime_get_real_seconds();
- long diff;
bool success;
int ret, retries = 0;
@@ -579,25 +670,29 @@ bool afs_check_server_record(struct afs_fs_cursor *fc, struct afs_server *server
ASSERT(server);
retry:
- diff = READ_ONCE(server->update_at) - now;
- if (diff > 0) {
- _leave(" = t [not now %ld]", diff);
- return true;
- }
+ if (test_bit(AFS_SERVER_FL_UPDATING, &server->flags))
+ goto wait;
+ if (test_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags))
+ goto update;
+ _leave(" = t [good]");
+ return true;
+update:
if (!test_and_set_bit_lock(AFS_SERVER_FL_UPDATING, &server->flags)) {
- success = afs_update_server_record(fc, server);
+ clear_bit(AFS_SERVER_FL_NEEDS_UPDATE, &server->flags);
+ success = afs_update_server_record(op, server);
clear_bit_unlock(AFS_SERVER_FL_UPDATING, &server->flags);
wake_up_bit(&server->flags, AFS_SERVER_FL_UPDATING);
_leave(" = %d", success);
return success;
}
+wait:
ret = wait_on_bit(&server->flags, AFS_SERVER_FL_UPDATING,
- (fc->flags & AFS_FS_CURSOR_INTR) ?
- TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
+ (op->flags & AFS_OPERATION_UNINTR) ?
+ TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
if (ret == -ERESTARTSYS) {
- fc->error = ret;
+ op->error = ret;
_leave(" = f [intr]");
return false;
}