// SPDX-License-Identifier: GPL-2.0-or-later
|
/* AFS cell and server record management
|
*
|
* Copyright (C) 2002, 2017 Red Hat, Inc. All Rights Reserved.
|
* Written by David Howells (dhowells@redhat.com)
|
*/
|
|
#include <linux/slab.h>
|
#include <linux/key.h>
|
#include <linux/ctype.h>
|
#include <linux/dns_resolver.h>
|
#include <linux/sched.h>
|
#include <linux/inet.h>
|
#include <linux/namei.h>
|
#include <keys/rxrpc-type.h>
|
#include "internal.h"
|
|
static unsigned __read_mostly afs_cell_gc_delay = 10;
|
static unsigned __read_mostly afs_cell_min_ttl = 10 * 60;
|
static unsigned __read_mostly afs_cell_max_ttl = 24 * 60 * 60;
|
static atomic_t cell_debug_id;
|
|
static void afs_queue_cell_manager(struct afs_net *);
|
static void afs_manage_cell_work(struct work_struct *);
|
|
static void afs_dec_cells_outstanding(struct afs_net *net)
|
{
|
if (atomic_dec_and_test(&net->cells_outstanding))
|
wake_up_var(&net->cells_outstanding);
|
}
|
|
/*
|
* Set the cell timer to fire after a given delay, assuming it's not already
|
* set for an earlier time.
|
*/
|
static void afs_set_cell_timer(struct afs_net *net, time64_t delay)
|
{
|
if (net->live) {
|
atomic_inc(&net->cells_outstanding);
|
if (timer_reduce(&net->cells_timer, jiffies + delay * HZ))
|
afs_dec_cells_outstanding(net);
|
} else {
|
afs_queue_cell_manager(net);
|
}
|
}
|
|
/*
|
* Look up and get an activation reference on a cell record. The caller must
|
* hold net->cells_lock at least read-locked.
|
*/
|
static struct afs_cell *afs_find_cell_locked(struct afs_net *net,
|
const char *name, unsigned int namesz,
|
enum afs_cell_trace reason)
|
{
|
struct afs_cell *cell = NULL;
|
struct rb_node *p;
|
int n;
|
|
_enter("%*.*s", namesz, namesz, name);
|
|
if (name && namesz == 0)
|
return ERR_PTR(-EINVAL);
|
if (namesz > AFS_MAXCELLNAME)
|
return ERR_PTR(-ENAMETOOLONG);
|
|
if (!name) {
|
cell = net->ws_cell;
|
if (!cell)
|
return ERR_PTR(-EDESTADDRREQ);
|
goto found;
|
}
|
|
p = net->cells.rb_node;
|
while (p) {
|
cell = rb_entry(p, struct afs_cell, net_node);
|
|
n = strncasecmp(cell->name, name,
|
min_t(size_t, cell->name_len, namesz));
|
if (n == 0)
|
n = cell->name_len - namesz;
|
if (n < 0)
|
p = p->rb_left;
|
else if (n > 0)
|
p = p->rb_right;
|
else
|
goto found;
|
}
|
|
return ERR_PTR(-ENOENT);
|
|
found:
|
return afs_use_cell(cell, reason);
|
}
|
|
/*
|
* Look up and get an activation reference on a cell record.
|
*/
|
struct afs_cell *afs_find_cell(struct afs_net *net,
|
const char *name, unsigned int namesz,
|
enum afs_cell_trace reason)
|
{
|
struct afs_cell *cell;
|
|
down_read(&net->cells_lock);
|
cell = afs_find_cell_locked(net, name, namesz, reason);
|
up_read(&net->cells_lock);
|
return cell;
|
}
|
|
/*
|
* Set up a cell record and fill in its name, VL server address list and
|
* allocate an anonymous key
|
*/
|
static struct afs_cell *afs_alloc_cell(struct afs_net *net,
|
const char *name, unsigned int namelen,
|
const char *addresses)
|
{
|
struct afs_vlserver_list *vllist;
|
struct afs_cell *cell;
|
int i, ret;
|
|
ASSERT(name);
|
if (namelen == 0)
|
return ERR_PTR(-EINVAL);
|
if (namelen > AFS_MAXCELLNAME) {
|
_leave(" = -ENAMETOOLONG");
|
return ERR_PTR(-ENAMETOOLONG);
|
}
|
|
/* Prohibit cell names that contain unprintable chars, '/' and '@' or
|
* that begin with a dot. This also precludes "@cell".
|
*/
|
if (name[0] == '.')
|
return ERR_PTR(-EINVAL);
|
for (i = 0; i < namelen; i++) {
|
char ch = name[i];
|
if (!isprint(ch) || ch == '/' || ch == '@')
|
return ERR_PTR(-EINVAL);
|
}
|
|
_enter("%*.*s,%s", namelen, namelen, name, addresses);
|
|
cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL);
|
if (!cell) {
|
_leave(" = -ENOMEM");
|
return ERR_PTR(-ENOMEM);
|
}
|
|
cell->name = kmalloc(namelen + 1, GFP_KERNEL);
|
if (!cell->name) {
|
kfree(cell);
|
return ERR_PTR(-ENOMEM);
|
}
|
|
cell->net = net;
|
cell->name_len = namelen;
|
for (i = 0; i < namelen; i++)
|
cell->name[i] = tolower(name[i]);
|
cell->name[i] = 0;
|
|
atomic_set(&cell->ref, 1);
|
atomic_set(&cell->active, 0);
|
INIT_WORK(&cell->manager, afs_manage_cell_work);
|
cell->volumes = RB_ROOT;
|
INIT_HLIST_HEAD(&cell->proc_volumes);
|
seqlock_init(&cell->volume_lock);
|
cell->fs_servers = RB_ROOT;
|
seqlock_init(&cell->fs_lock);
|
rwlock_init(&cell->vl_servers_lock);
|
cell->flags = (1 << AFS_CELL_FL_CHECK_ALIAS);
|
|
/* Provide a VL server list, filling it in if we were given a list of
|
* addresses to use.
|
*/
|
if (addresses) {
|
vllist = afs_parse_text_addrs(net,
|
addresses, strlen(addresses), ':',
|
VL_SERVICE, AFS_VL_PORT);
|
if (IS_ERR(vllist)) {
|
ret = PTR_ERR(vllist);
|
goto parse_failed;
|
}
|
|
vllist->source = DNS_RECORD_FROM_CONFIG;
|
vllist->status = DNS_LOOKUP_NOT_DONE;
|
cell->dns_expiry = TIME64_MAX;
|
} else {
|
ret = -ENOMEM;
|
vllist = afs_alloc_vlserver_list(0);
|
if (!vllist)
|
goto error;
|
vllist->source = DNS_RECORD_UNAVAILABLE;
|
vllist->status = DNS_LOOKUP_NOT_DONE;
|
cell->dns_expiry = ktime_get_real_seconds();
|
}
|
|
rcu_assign_pointer(cell->vl_servers, vllist);
|
|
cell->dns_source = vllist->source;
|
cell->dns_status = vllist->status;
|
smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */
|
atomic_inc(&net->cells_outstanding);
|
cell->debug_id = atomic_inc_return(&cell_debug_id);
|
trace_afs_cell(cell->debug_id, 1, 0, afs_cell_trace_alloc);
|
|
_leave(" = %p", cell);
|
return cell;
|
|
parse_failed:
|
if (ret == -EINVAL)
|
printk(KERN_ERR "kAFS: bad VL server IP address\n");
|
error:
|
kfree(cell->name);
|
kfree(cell);
|
_leave(" = %d", ret);
|
return ERR_PTR(ret);
|
}
|
|
/*
|
* afs_lookup_cell - Look up or create a cell record.
|
* @net: The network namespace
|
* @name: The name of the cell.
|
* @namesz: The strlen of the cell name.
|
* @vllist: A colon/comma separated list of numeric IP addresses or NULL.
|
* @excl: T if an error should be given if the cell name already exists.
|
*
|
* Look up a cell record by name and query the DNS for VL server addresses if
|
* needed. Note that that actual DNS query is punted off to the manager thread
|
* so that this function can return immediately if interrupted whilst allowing
|
* cell records to be shared even if not yet fully constructed.
|
*/
|
struct afs_cell *afs_lookup_cell(struct afs_net *net,
|
const char *name, unsigned int namesz,
|
const char *vllist, bool excl)
|
{
|
struct afs_cell *cell, *candidate, *cursor;
|
struct rb_node *parent, **pp;
|
enum afs_cell_state state;
|
int ret, n;
|
|
_enter("%s,%s", name, vllist);
|
|
if (!excl) {
|
cell = afs_find_cell(net, name, namesz, afs_cell_trace_use_lookup);
|
if (!IS_ERR(cell))
|
goto wait_for_cell;
|
}
|
|
/* Assume we're probably going to create a cell and preallocate and
|
* mostly set up a candidate record. We can then use this to stash the
|
* name, the net namespace and VL server addresses.
|
*
|
* We also want to do this before we hold any locks as it may involve
|
* upcalling to userspace to make DNS queries.
|
*/
|
candidate = afs_alloc_cell(net, name, namesz, vllist);
|
if (IS_ERR(candidate)) {
|
_leave(" = %ld", PTR_ERR(candidate));
|
return candidate;
|
}
|
|
/* Find the insertion point and check to see if someone else added a
|
* cell whilst we were allocating.
|
*/
|
down_write(&net->cells_lock);
|
|
pp = &net->cells.rb_node;
|
parent = NULL;
|
while (*pp) {
|
parent = *pp;
|
cursor = rb_entry(parent, struct afs_cell, net_node);
|
|
n = strncasecmp(cursor->name, name,
|
min_t(size_t, cursor->name_len, namesz));
|
if (n == 0)
|
n = cursor->name_len - namesz;
|
if (n < 0)
|
pp = &(*pp)->rb_left;
|
else if (n > 0)
|
pp = &(*pp)->rb_right;
|
else
|
goto cell_already_exists;
|
}
|
|
cell = candidate;
|
candidate = NULL;
|
atomic_set(&cell->active, 2);
|
trace_afs_cell(cell->debug_id, atomic_read(&cell->ref), 2, afs_cell_trace_insert);
|
rb_link_node_rcu(&cell->net_node, parent, pp);
|
rb_insert_color(&cell->net_node, &net->cells);
|
up_write(&net->cells_lock);
|
|
afs_queue_cell(cell, afs_cell_trace_get_queue_new);
|
|
wait_for_cell:
|
trace_afs_cell(cell->debug_id, atomic_read(&cell->ref), atomic_read(&cell->active),
|
afs_cell_trace_wait);
|
_debug("wait_for_cell");
|
wait_var_event(&cell->state,
|
({
|
state = smp_load_acquire(&cell->state); /* vs error */
|
state == AFS_CELL_ACTIVE || state == AFS_CELL_REMOVED;
|
}));
|
|
/* Check the state obtained from the wait check. */
|
if (state == AFS_CELL_REMOVED) {
|
ret = cell->error;
|
goto error;
|
}
|
|
_leave(" = %p [cell]", cell);
|
return cell;
|
|
cell_already_exists:
|
_debug("cell exists");
|
cell = cursor;
|
if (excl) {
|
ret = -EEXIST;
|
} else {
|
afs_use_cell(cursor, afs_cell_trace_use_lookup);
|
ret = 0;
|
}
|
up_write(&net->cells_lock);
|
if (candidate)
|
afs_put_cell(candidate, afs_cell_trace_put_candidate);
|
if (ret == 0)
|
goto wait_for_cell;
|
goto error_noput;
|
error:
|
afs_unuse_cell(net, cell, afs_cell_trace_unuse_lookup);
|
error_noput:
|
_leave(" = %d [error]", ret);
|
return ERR_PTR(ret);
|
}
|
|
/*
|
* set the root cell information
|
* - can be called with a module parameter string
|
* - can be called from a write to /proc/fs/afs/rootcell
|
*/
|
int afs_cell_init(struct afs_net *net, const char *rootcell)
|
{
|
struct afs_cell *old_root, *new_root;
|
const char *cp, *vllist;
|
size_t len;
|
|
_enter("");
|
|
if (!rootcell) {
|
/* module is loaded with no parameters, or built statically.
|
* - in the future we might initialize cell DB here.
|
*/
|
_leave(" = 0 [no root]");
|
return 0;
|
}
|
|
cp = strchr(rootcell, ':');
|
if (!cp) {
|
_debug("kAFS: no VL server IP addresses specified");
|
vllist = NULL;
|
len = strlen(rootcell);
|
} else {
|
vllist = cp + 1;
|
len = cp - rootcell;
|
}
|
|
/* allocate a cell record for the root cell */
|
new_root = afs_lookup_cell(net, rootcell, len, vllist, false);
|
if (IS_ERR(new_root)) {
|
_leave(" = %ld", PTR_ERR(new_root));
|
return PTR_ERR(new_root);
|
}
|
|
if (!test_and_set_bit(AFS_CELL_FL_NO_GC, &new_root->flags))
|
afs_use_cell(new_root, afs_cell_trace_use_pin);
|
|
/* install the new cell */
|
down_write(&net->cells_lock);
|
afs_see_cell(new_root, afs_cell_trace_see_ws);
|
old_root = net->ws_cell;
|
net->ws_cell = new_root;
|
up_write(&net->cells_lock);
|
|
afs_unuse_cell(net, old_root, afs_cell_trace_unuse_ws);
|
_leave(" = 0");
|
return 0;
|
}
|
|
/*
|
* Update a cell's VL server address list from the DNS.
|
*/
|
static int afs_update_cell(struct afs_cell *cell)
|
{
|
struct afs_vlserver_list *vllist, *old = NULL, *p;
|
unsigned int min_ttl = READ_ONCE(afs_cell_min_ttl);
|
unsigned int max_ttl = READ_ONCE(afs_cell_max_ttl);
|
time64_t now, expiry = 0;
|
int ret = 0;
|
|
_enter("%s", cell->name);
|
|
vllist = afs_dns_query(cell, &expiry);
|
if (IS_ERR(vllist)) {
|
ret = PTR_ERR(vllist);
|
|
_debug("%s: fail %d", cell->name, ret);
|
if (ret == -ENOMEM)
|
goto out_wake;
|
|
ret = -ENOMEM;
|
vllist = afs_alloc_vlserver_list(0);
|
if (!vllist)
|
goto out_wake;
|
|
switch (ret) {
|
case -ENODATA:
|
case -EDESTADDRREQ:
|
vllist->status = DNS_LOOKUP_GOT_NOT_FOUND;
|
break;
|
case -EAGAIN:
|
case -ECONNREFUSED:
|
vllist->status = DNS_LOOKUP_GOT_TEMP_FAILURE;
|
break;
|
default:
|
vllist->status = DNS_LOOKUP_GOT_LOCAL_FAILURE;
|
break;
|
}
|
}
|
|
_debug("%s: got list %d %d", cell->name, vllist->source, vllist->status);
|
cell->dns_status = vllist->status;
|
|
now = ktime_get_real_seconds();
|
if (min_ttl > max_ttl)
|
max_ttl = min_ttl;
|
if (expiry < now + min_ttl)
|
expiry = now + min_ttl;
|
else if (expiry > now + max_ttl)
|
expiry = now + max_ttl;
|
|
_debug("%s: status %d", cell->name, vllist->status);
|
if (vllist->source == DNS_RECORD_UNAVAILABLE) {
|
switch (vllist->status) {
|
case DNS_LOOKUP_GOT_NOT_FOUND:
|
/* The DNS said that the cell does not exist or there
|
* weren't any addresses to be had.
|
*/
|
cell->dns_expiry = expiry;
|
break;
|
|
case DNS_LOOKUP_BAD:
|
case DNS_LOOKUP_GOT_LOCAL_FAILURE:
|
case DNS_LOOKUP_GOT_TEMP_FAILURE:
|
case DNS_LOOKUP_GOT_NS_FAILURE:
|
default:
|
cell->dns_expiry = now + 10;
|
break;
|
}
|
} else {
|
cell->dns_expiry = expiry;
|
}
|
|
/* Replace the VL server list if the new record has servers or the old
|
* record doesn't.
|
*/
|
write_lock(&cell->vl_servers_lock);
|
p = rcu_dereference_protected(cell->vl_servers, true);
|
if (vllist->nr_servers > 0 || p->nr_servers == 0) {
|
rcu_assign_pointer(cell->vl_servers, vllist);
|
cell->dns_source = vllist->source;
|
old = p;
|
}
|
write_unlock(&cell->vl_servers_lock);
|
afs_put_vlserverlist(cell->net, old);
|
|
out_wake:
|
smp_store_release(&cell->dns_lookup_count,
|
cell->dns_lookup_count + 1); /* vs source/status */
|
wake_up_var(&cell->dns_lookup_count);
|
_leave(" = %d", ret);
|
return ret;
|
}
|
|
/*
|
* Destroy a cell record
|
*/
|
static void afs_cell_destroy(struct rcu_head *rcu)
|
{
|
struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu);
|
struct afs_net *net = cell->net;
|
int u;
|
|
_enter("%p{%s}", cell, cell->name);
|
|
u = atomic_read(&cell->ref);
|
ASSERTCMP(u, ==, 0);
|
trace_afs_cell(cell->debug_id, u, atomic_read(&cell->active), afs_cell_trace_free);
|
|
afs_put_vlserverlist(net, rcu_access_pointer(cell->vl_servers));
|
afs_unuse_cell(net, cell->alias_of, afs_cell_trace_unuse_alias);
|
key_put(cell->anonymous_key);
|
kfree(cell->name);
|
kfree(cell);
|
|
afs_dec_cells_outstanding(net);
|
_leave(" [destroyed]");
|
}
|
|
/*
|
* Queue the cell manager.
|
*/
|
static void afs_queue_cell_manager(struct afs_net *net)
|
{
|
int outstanding = atomic_inc_return(&net->cells_outstanding);
|
|
_enter("%d", outstanding);
|
|
if (!queue_work(afs_wq, &net->cells_manager))
|
afs_dec_cells_outstanding(net);
|
}
|
|
/*
|
* Cell management timer. We have an increment on cells_outstanding that we
|
* need to pass along to the work item.
|
*/
|
void afs_cells_timer(struct timer_list *timer)
|
{
|
struct afs_net *net = container_of(timer, struct afs_net, cells_timer);
|
|
_enter("");
|
if (!queue_work(afs_wq, &net->cells_manager))
|
afs_dec_cells_outstanding(net);
|
}
|
|
/*
|
* Get a reference on a cell record.
|
*/
|
struct afs_cell *afs_get_cell(struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
int u;
|
|
if (atomic_read(&cell->ref) <= 0)
|
BUG();
|
|
u = atomic_inc_return(&cell->ref);
|
trace_afs_cell(cell->debug_id, u, atomic_read(&cell->active), reason);
|
return cell;
|
}
|
|
/*
|
* Drop a reference on a cell record.
|
*/
|
void afs_put_cell(struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
if (cell) {
|
unsigned int debug_id = cell->debug_id;
|
unsigned int u, a;
|
|
a = atomic_read(&cell->active);
|
u = atomic_dec_return(&cell->ref);
|
trace_afs_cell(debug_id, u, a, reason);
|
if (u == 0) {
|
a = atomic_read(&cell->active);
|
WARN(a != 0, "Cell active count %u > 0\n", a);
|
call_rcu(&cell->rcu, afs_cell_destroy);
|
}
|
}
|
}
|
|
/*
|
* Note a cell becoming more active.
|
*/
|
struct afs_cell *afs_use_cell(struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
int u, a;
|
|
if (atomic_read(&cell->ref) <= 0)
|
BUG();
|
|
u = atomic_read(&cell->ref);
|
a = atomic_inc_return(&cell->active);
|
trace_afs_cell(cell->debug_id, u, a, reason);
|
return cell;
|
}
|
|
/*
|
* Record a cell becoming less active. When the active counter reaches 1, it
|
* is scheduled for destruction, but may get reactivated.
|
*/
|
void afs_unuse_cell(struct afs_net *net, struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
unsigned int debug_id;
|
time64_t now, expire_delay;
|
int u, a;
|
|
if (!cell)
|
return;
|
|
_enter("%s", cell->name);
|
|
now = ktime_get_real_seconds();
|
cell->last_inactive = now;
|
expire_delay = 0;
|
if (cell->vl_servers->nr_servers)
|
expire_delay = afs_cell_gc_delay;
|
|
debug_id = cell->debug_id;
|
u = atomic_read(&cell->ref);
|
a = atomic_dec_return(&cell->active);
|
trace_afs_cell(debug_id, u, a, reason);
|
WARN_ON(a == 0);
|
if (a == 1)
|
/* 'cell' may now be garbage collected. */
|
afs_set_cell_timer(net, expire_delay);
|
}
|
|
/*
|
* Note that a cell has been seen.
|
*/
|
void afs_see_cell(struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
int u, a;
|
|
u = atomic_read(&cell->ref);
|
a = atomic_read(&cell->active);
|
trace_afs_cell(cell->debug_id, u, a, reason);
|
}
|
|
/*
|
* Queue a cell for management, giving the workqueue a ref to hold.
|
*/
|
void afs_queue_cell(struct afs_cell *cell, enum afs_cell_trace reason)
|
{
|
afs_get_cell(cell, reason);
|
if (!queue_work(afs_wq, &cell->manager))
|
afs_put_cell(cell, afs_cell_trace_put_queue_fail);
|
}
|
|
/*
|
* Allocate a key to use as a placeholder for anonymous user security.
|
*/
|
static int afs_alloc_anon_key(struct afs_cell *cell)
|
{
|
struct key *key;
|
char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp;
|
|
/* Create a key to represent an anonymous user. */
|
memcpy(keyname, "afs@", 4);
|
dp = keyname + 4;
|
cp = cell->name;
|
do {
|
*dp++ = tolower(*cp);
|
} while (*cp++);
|
|
key = rxrpc_get_null_key(keyname);
|
if (IS_ERR(key))
|
return PTR_ERR(key);
|
|
cell->anonymous_key = key;
|
|
_debug("anon key %p{%x}",
|
cell->anonymous_key, key_serial(cell->anonymous_key));
|
return 0;
|
}
|
|
/*
|
* Activate a cell.
|
*/
|
static int afs_activate_cell(struct afs_net *net, struct afs_cell *cell)
|
{
|
struct hlist_node **p;
|
struct afs_cell *pcell;
|
int ret;
|
|
if (!cell->anonymous_key) {
|
ret = afs_alloc_anon_key(cell);
|
if (ret < 0)
|
return ret;
|
}
|
|
#ifdef CONFIG_AFS_FSCACHE
|
cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index,
|
&afs_cell_cache_index_def,
|
cell->name, strlen(cell->name),
|
NULL, 0,
|
cell, 0, true);
|
#endif
|
ret = afs_proc_cell_setup(cell);
|
if (ret < 0)
|
return ret;
|
|
mutex_lock(&net->proc_cells_lock);
|
for (p = &net->proc_cells.first; *p; p = &(*p)->next) {
|
pcell = hlist_entry(*p, struct afs_cell, proc_link);
|
if (strcmp(cell->name, pcell->name) < 0)
|
break;
|
}
|
|
cell->proc_link.pprev = p;
|
cell->proc_link.next = *p;
|
rcu_assign_pointer(*p, &cell->proc_link.next);
|
if (cell->proc_link.next)
|
cell->proc_link.next->pprev = &cell->proc_link.next;
|
|
afs_dynroot_mkdir(net, cell);
|
mutex_unlock(&net->proc_cells_lock);
|
return 0;
|
}
|
|
/*
|
* Deactivate a cell.
|
*/
|
static void afs_deactivate_cell(struct afs_net *net, struct afs_cell *cell)
|
{
|
_enter("%s", cell->name);
|
|
afs_proc_cell_remove(cell);
|
|
mutex_lock(&net->proc_cells_lock);
|
hlist_del_rcu(&cell->proc_link);
|
afs_dynroot_rmdir(net, cell);
|
mutex_unlock(&net->proc_cells_lock);
|
|
#ifdef CONFIG_AFS_FSCACHE
|
fscache_relinquish_cookie(cell->cache, NULL, false);
|
cell->cache = NULL;
|
#endif
|
|
_leave("");
|
}
|
|
/*
|
* Manage a cell record, initialising and destroying it, maintaining its DNS
|
* records.
|
*/
|
static void afs_manage_cell(struct afs_cell *cell)
|
{
|
struct afs_net *net = cell->net;
|
int ret, active;
|
|
_enter("%s", cell->name);
|
|
again:
|
_debug("state %u", cell->state);
|
switch (cell->state) {
|
case AFS_CELL_INACTIVE:
|
case AFS_CELL_FAILED:
|
down_write(&net->cells_lock);
|
active = 1;
|
if (atomic_try_cmpxchg_relaxed(&cell->active, &active, 0)) {
|
rb_erase(&cell->net_node, &net->cells);
|
trace_afs_cell(cell->debug_id, atomic_read(&cell->ref), 0,
|
afs_cell_trace_unuse_delete);
|
smp_store_release(&cell->state, AFS_CELL_REMOVED);
|
}
|
up_write(&net->cells_lock);
|
if (cell->state == AFS_CELL_REMOVED) {
|
wake_up_var(&cell->state);
|
goto final_destruction;
|
}
|
if (cell->state == AFS_CELL_FAILED)
|
goto done;
|
smp_store_release(&cell->state, AFS_CELL_UNSET);
|
wake_up_var(&cell->state);
|
goto again;
|
|
case AFS_CELL_UNSET:
|
smp_store_release(&cell->state, AFS_CELL_ACTIVATING);
|
wake_up_var(&cell->state);
|
goto again;
|
|
case AFS_CELL_ACTIVATING:
|
ret = afs_activate_cell(net, cell);
|
if (ret < 0)
|
goto activation_failed;
|
|
smp_store_release(&cell->state, AFS_CELL_ACTIVE);
|
wake_up_var(&cell->state);
|
goto again;
|
|
case AFS_CELL_ACTIVE:
|
if (atomic_read(&cell->active) > 1) {
|
if (test_and_clear_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags)) {
|
ret = afs_update_cell(cell);
|
if (ret < 0)
|
cell->error = ret;
|
}
|
goto done;
|
}
|
smp_store_release(&cell->state, AFS_CELL_DEACTIVATING);
|
wake_up_var(&cell->state);
|
goto again;
|
|
case AFS_CELL_DEACTIVATING:
|
if (atomic_read(&cell->active) > 1)
|
goto reverse_deactivation;
|
afs_deactivate_cell(net, cell);
|
smp_store_release(&cell->state, AFS_CELL_INACTIVE);
|
wake_up_var(&cell->state);
|
goto again;
|
|
case AFS_CELL_REMOVED:
|
goto done;
|
|
default:
|
break;
|
}
|
_debug("bad state %u", cell->state);
|
BUG(); /* Unhandled state */
|
|
activation_failed:
|
cell->error = ret;
|
afs_deactivate_cell(net, cell);
|
|
smp_store_release(&cell->state, AFS_CELL_FAILED); /* vs error */
|
wake_up_var(&cell->state);
|
goto again;
|
|
reverse_deactivation:
|
smp_store_release(&cell->state, AFS_CELL_ACTIVE);
|
wake_up_var(&cell->state);
|
_leave(" [deact->act]");
|
return;
|
|
done:
|
_leave(" [done %u]", cell->state);
|
return;
|
|
final_destruction:
|
/* The root volume is pinning the cell */
|
afs_put_volume(cell->net, cell->root_volume, afs_volume_trace_put_cell_root);
|
cell->root_volume = NULL;
|
afs_put_cell(cell, afs_cell_trace_put_destroy);
|
}
|
|
static void afs_manage_cell_work(struct work_struct *work)
|
{
|
struct afs_cell *cell = container_of(work, struct afs_cell, manager);
|
|
afs_manage_cell(cell);
|
afs_put_cell(cell, afs_cell_trace_put_queue_work);
|
}
|
|
/*
|
* Manage the records of cells known to a network namespace. This includes
|
* updating the DNS records and garbage collecting unused cells that were
|
* automatically added.
|
*
|
* Note that constructed cell records may only be removed from net->cells by
|
* this work item, so it is safe for this work item to stash a cursor pointing
|
* into the tree and then return to caller (provided it skips cells that are
|
* still under construction).
|
*
|
* Note also that we were given an increment on net->cells_outstanding by
|
* whoever queued us that we need to deal with before returning.
|
*/
|
void afs_manage_cells(struct work_struct *work)
|
{
|
struct afs_net *net = container_of(work, struct afs_net, cells_manager);
|
struct rb_node *cursor;
|
time64_t now = ktime_get_real_seconds(), next_manage = TIME64_MAX;
|
bool purging = !net->live;
|
|
_enter("");
|
|
/* Trawl the cell database looking for cells that have expired from
|
* lack of use and cells whose DNS results have expired and dispatch
|
* their managers.
|
*/
|
down_read(&net->cells_lock);
|
|
for (cursor = rb_first(&net->cells); cursor; cursor = rb_next(cursor)) {
|
struct afs_cell *cell =
|
rb_entry(cursor, struct afs_cell, net_node);
|
unsigned active;
|
bool sched_cell = false;
|
|
active = atomic_read(&cell->active);
|
trace_afs_cell(cell->debug_id, atomic_read(&cell->ref),
|
active, afs_cell_trace_manage);
|
|
ASSERTCMP(active, >=, 1);
|
|
if (purging) {
|
if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags)) {
|
active = atomic_dec_return(&cell->active);
|
trace_afs_cell(cell->debug_id, atomic_read(&cell->ref),
|
active, afs_cell_trace_unuse_pin);
|
}
|
}
|
|
if (active == 1) {
|
struct afs_vlserver_list *vllist;
|
time64_t expire_at = cell->last_inactive;
|
|
read_lock(&cell->vl_servers_lock);
|
vllist = rcu_dereference_protected(
|
cell->vl_servers,
|
lockdep_is_held(&cell->vl_servers_lock));
|
if (vllist->nr_servers > 0)
|
expire_at += afs_cell_gc_delay;
|
read_unlock(&cell->vl_servers_lock);
|
if (purging || expire_at <= now)
|
sched_cell = true;
|
else if (expire_at < next_manage)
|
next_manage = expire_at;
|
}
|
|
if (!purging) {
|
if (test_bit(AFS_CELL_FL_DO_LOOKUP, &cell->flags))
|
sched_cell = true;
|
}
|
|
if (sched_cell)
|
afs_queue_cell(cell, afs_cell_trace_get_queue_manage);
|
}
|
|
up_read(&net->cells_lock);
|
|
/* Update the timer on the way out. We have to pass an increment on
|
* cells_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();
|
|
if (next_manage - now <= 0) {
|
if (queue_work(afs_wq, &net->cells_manager))
|
atomic_inc(&net->cells_outstanding);
|
} else {
|
afs_set_cell_timer(net, next_manage - now);
|
}
|
}
|
|
afs_dec_cells_outstanding(net);
|
_leave(" [%d]", atomic_read(&net->cells_outstanding));
|
}
|
|
/*
|
* Purge in-memory cell database.
|
*/
|
void afs_cell_purge(struct afs_net *net)
|
{
|
struct afs_cell *ws;
|
|
_enter("");
|
|
down_write(&net->cells_lock);
|
ws = net->ws_cell;
|
net->ws_cell = NULL;
|
up_write(&net->cells_lock);
|
afs_unuse_cell(net, ws, afs_cell_trace_unuse_ws);
|
|
_debug("del timer");
|
if (del_timer_sync(&net->cells_timer))
|
atomic_dec(&net->cells_outstanding);
|
|
_debug("kick mgr");
|
afs_queue_cell_manager(net);
|
|
_debug("wait");
|
wait_var_event(&net->cells_outstanding,
|
!atomic_read(&net->cells_outstanding));
|
_leave("");
|
}
|
