From 102a0743326a03cd1a1202ceda21e175b7d3575c Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Tue, 20 Feb 2024 01:20:52 +0000
Subject: [PATCH] add new system file
---
kernel/fs/afs/server.c | 473 ++++++++++++++++++++++++++++++----------------------------
1 files changed, 247 insertions(+), 226 deletions(-)
diff --git a/kernel/fs/afs/server.c b/kernel/fs/afs/server.c
index 2c7f621..684a2b0 100644
--- a/kernel/fs/afs/server.c
+++ b/kernel/fs/afs/server.c
@@ -1,32 +1,22 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
/* AFS server record management
*
* Copyright (C) 2002, 2007 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/sched.h>
#include <linux/slab.h>
#include "afs_fs.h"
#include "internal.h"
+#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.
@@ -43,7 +33,7 @@
do {
if (server)
- afs_put_server(net, server);
+ afs_unuse_server_notime(net, server, afs_server_trace_put_find_rsq);
server = NULL;
read_seqbegin_or_lock(&net->fs_addr_lock, &seq);
@@ -81,9 +71,9 @@
}
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));
@@ -94,7 +84,7 @@
}
/*
- * 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)
{
@@ -110,7 +100,7 @@
* changes.
*/
if (server)
- afs_put_server(net, server);
+ afs_unuse_server(net, server, afs_server_trace_put_uuid_rsq);
server = NULL;
read_seqbegin_or_lock(&net->fs_lock, &seq);
@@ -125,7 +115,7 @@
} else if (diff > 0) {
p = p->rb_right;
} else {
- afs_get_server(server);
+ afs_use_server(server, afs_server_trace_get_by_uuid);
break;
}
@@ -140,15 +130,18 @@
}
/*
- * 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 ret = -EEXIST, diff;
+ int diff;
_enter("%p", candidate);
@@ -162,12 +155,30 @@
_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;
@@ -175,6 +186,7 @@
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));
@@ -193,22 +205,22 @@
hlist_add_head_rcu(&server->addr6_link, &net->fs_addresses6);
write_sequnlock(&net->fs_addr_lock);
- ret = 0;
exists:
- afs_get_server(server);
+ afs_get_server(server, afs_server_trace_get_install);
write_sequnlock(&net->fs_lock);
return server;
}
/*
- * 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("");
@@ -216,17 +228,21 @@
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->flags = (1UL << AFS_SERVER_FL_NEW);
- 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, 1, afs_server_trace_alloc);
_leave(" = %p", server);
return server;
@@ -241,48 +257,30 @@
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;
+ struct afs_vl_cursor vc;
+ struct afs_addr_list *alist = NULL;
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;
+ ret = -ERESTARTSYS;
+ if (afs_begin_vlserver_operation(&vc, cell, key)) {
+ while (afs_select_vlserver(&vc)) {
+ if (test_bit(AFS_VLSERVER_FL_IS_YFS, &vc.server->flags))
+ alist = afs_yfsvl_get_endpoints(&vc, uuid);
+ else
+ alist = afs_vl_get_addrs_u(&vc, uuid);
}
+
+ ret = afs_end_vlserver_operation(&vc);
}
-error:
- return ERR_PTR(afs_end_cursor(&ac));
+ return ret < 0 ? ERR_PTR(ret) : alist;
}
/*
* 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;
@@ -290,26 +288,34 @@
_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;
}
@@ -340,33 +346,117 @@
}
/*
+ * Get a reference on a server object.
+ */
+struct afs_server *afs_get_server(struct afs_server *server,
+ enum afs_server_trace reason)
+{
+ 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, r, a, reason);
+ return server;
+}
+
+/*
* Release a reference on a server record.
*/
-void afs_put_server(struct afs_net *net, struct afs_server *server)
+void afs_put_server(struct afs_net *net, struct afs_server *server,
+ enum afs_server_trace reason)
{
unsigned int usage;
if (!server)
return;
- server->put_time = ktime_get_real_seconds();
+ 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);
+}
- usage = atomic_dec_return(&server->usage);
+/*
+ * 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);
- _enter("{%u}", usage);
+ if (active == 0)
+ afs_set_server_timer(net, afs_server_gc_delay);
+ afs_put_server(net, server, reason);
+ }
+}
- if (likely(usage > 0))
- return;
-
- 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->ref),
+ atomic_read(&server->active), afs_server_trace_free);
afs_put_addrlist(rcu_access_pointer(server->addresses));
kfree(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 = {
+ .alist = alist,
+ .index = alist->preferred,
+ .error = 0,
+ };
+
+ afs_fs_give_up_all_callbacks(net, server, &ac, NULL);
}
/*
@@ -374,21 +464,10 @@
*/
static void afs_destroy_server(struct afs_net *net, struct afs_server *server)
{
- struct afs_addr_list *alist = rcu_access_pointer(server->addresses);
- struct afs_addr_cursor ac = {
- .alist = alist,
- .start = alist->index,
- .index = 0,
- .addr = &alist->addrs[alist->index],
- .error = 0,
- };
- _enter("%p", 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);
- call_rcu(&server->rcu, afs_server_rcu);
- afs_dec_servers_outstanding(net);
+ afs_put_server(net, server, afs_server_trace_destroy);
}
/*
@@ -396,31 +475,49 @@
*/
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);
- 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);
}
}
@@ -449,15 +546,19 @@
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);
+ if (purging) {
+ trace_afs_server(server, atomic_read(&server->ref),
+ active, afs_server_trace_purging);
+ if (active != 0)
+ pr_notice("Can't purge s=%08x\n", server->debug_id);
+ }
- 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))
@@ -509,123 +610,41 @@
_enter("");
if (del_timer_sync(&net->fs_timer))
- atomic_dec(&net->servers_outstanding);
+ afs_dec_servers_outstanding(net);
afs_queue_server_manager(net);
_debug("wait");
+ atomic_dec(&net->servers_outstanding);
wait_var_event(&net->servers_outstanding,
!atomic_read(&net->servers_outstanding));
_leave("");
}
/*
- * Probe a fileserver to find its capabilities.
- *
- * TODO: Try service upgrade.
- */
-static bool afs_do_probe_fileserver(struct afs_fs_cursor *fc)
-{
- _enter("");
-
- 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;
- }
- }
-
-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;
- }
-
- 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;
- }
-
- retries++;
- if (retries == 4) {
- fc->ac.error = -ESTALE;
- _leave(" = f [stale]");
- return false;
- }
- _debug("retry");
- goto retry;
-}
-
-/*
* 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("");
- alist = afs_vl_lookup_addrs(fc->vnode->volume->cell, fc->key,
- &server->uuid);
+ trace_afs_server(server, atomic_read(&server->ref), atomic_read(&server->active),
+ afs_server_trace_update);
+
+ alist = afs_vl_lookup_addrs(op->volume->cell, op->key, &server->uuid);
if (IS_ERR(alist)) {
- fc->ac.error = PTR_ERR(alist);
- _leave(" = f [%d]", fc->ac.error);
+ if ((PTR_ERR(alist) == -ERESTARTSYS ||
+ PTR_ERR(alist) == -EINTR) &&
+ (op->flags & AFS_OPERATION_UNINTR) &&
+ server->addresses) {
+ _leave(" = t [intr]");
+ return true;
+ }
+ op->error = PTR_ERR(alist);
+ _leave(" = f [%d]", op->error);
return false;
}
@@ -639,7 +658,6 @@
write_unlock(&server->fs_lock);
}
- server->update_at = ktime_get_real_seconds() + afs_server_update_delay;
afs_put_addrlist(discard);
_leave(" = t");
return true;
@@ -648,10 +666,8 @@
/*
* 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;
@@ -660,24 +676,29 @@
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,
- TASK_INTERRUPTIBLE);
+ (op->flags & AFS_OPERATION_UNINTR) ?
+ TASK_UNINTERRUPTIBLE : TASK_INTERRUPTIBLE);
if (ret == -ERESTARTSYS) {
- fc->ac.error = ret;
+ op->error = ret;
_leave(" = f [intr]");
return false;
}
--
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