mirror of https://gitee.com/openkylin/linux.git
775 lines
18 KiB
C
775 lines
18 KiB
C
/* AFS cell and server record management
|
|
*
|
|
* Copyright (C) 2002, 2017 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/slab.h>
|
|
#include <linux/key.h>
|
|
#include <linux/ctype.h>
|
|
#include <linux/dns_resolver.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/inet.h>
|
|
#include <keys/rxrpc-type.h>
|
|
#include "internal.h"
|
|
|
|
static unsigned __read_mostly afs_cell_gc_delay = 10;
|
|
|
|
static void afs_manage_cell(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);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Look up and get an activation reference on a cell record under RCU
|
|
* conditions. The caller must hold the RCU read lock.
|
|
*/
|
|
struct afs_cell *afs_lookup_cell_rcu(struct afs_net *net,
|
|
const char *name, unsigned int namesz)
|
|
{
|
|
struct afs_cell *cell = NULL;
|
|
struct rb_node *p;
|
|
int n, seq = 0, ret = 0;
|
|
|
|
_enter("%*.*s", namesz, namesz, name);
|
|
|
|
if (name && namesz == 0)
|
|
return ERR_PTR(-EINVAL);
|
|
if (namesz > AFS_MAXCELLNAME)
|
|
return ERR_PTR(-ENAMETOOLONG);
|
|
|
|
do {
|
|
/* Unfortunately, rbtree walking doesn't give reliable results
|
|
* under just the RCU read lock, so we have to check for
|
|
* changes.
|
|
*/
|
|
if (cell)
|
|
afs_put_cell(net, cell);
|
|
cell = NULL;
|
|
ret = -ENOENT;
|
|
|
|
read_seqbegin_or_lock(&net->cells_lock, &seq);
|
|
|
|
if (!name) {
|
|
cell = rcu_dereference_raw(net->ws_cell);
|
|
if (cell) {
|
|
afs_get_cell(cell);
|
|
break;
|
|
}
|
|
ret = -EDESTADDRREQ;
|
|
continue;
|
|
}
|
|
|
|
p = rcu_dereference_raw(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 = rcu_dereference_raw(p->rb_left);
|
|
} else if (n > 0) {
|
|
p = rcu_dereference_raw(p->rb_right);
|
|
} else {
|
|
if (atomic_inc_not_zero(&cell->usage)) {
|
|
ret = 0;
|
|
break;
|
|
}
|
|
/* We want to repeat the search, this time with
|
|
* the lock properly locked.
|
|
*/
|
|
}
|
|
cell = NULL;
|
|
}
|
|
|
|
} while (need_seqretry(&net->cells_lock, seq));
|
|
|
|
done_seqretry(&net->cells_lock, seq);
|
|
|
|
return ret == 0 ? cell : ERR_PTR(ret);
|
|
}
|
|
|
|
/*
|
|
* 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 *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);
|
|
}
|
|
if (namelen == 5 && memcmp(name, "@cell", 5) == 0)
|
|
return ERR_PTR(-EINVAL);
|
|
|
|
_enter("%*.*s,%s", namelen, namelen, name, vllist);
|
|
|
|
cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL);
|
|
if (!cell) {
|
|
_leave(" = -ENOMEM");
|
|
return ERR_PTR(-ENOMEM);
|
|
}
|
|
|
|
cell->net = net;
|
|
cell->name_len = namelen;
|
|
for (i = 0; i < namelen; i++)
|
|
cell->name[i] = tolower(name[i]);
|
|
|
|
atomic_set(&cell->usage, 2);
|
|
INIT_WORK(&cell->manager, afs_manage_cell);
|
|
cell->flags = ((1 << AFS_CELL_FL_NOT_READY) |
|
|
(1 << AFS_CELL_FL_NO_LOOKUP_YET));
|
|
INIT_LIST_HEAD(&cell->proc_volumes);
|
|
rwlock_init(&cell->proc_lock);
|
|
rwlock_init(&cell->vl_addrs_lock);
|
|
|
|
/* Fill in the VL server list if we were given a list of addresses to
|
|
* use.
|
|
*/
|
|
if (vllist) {
|
|
struct afs_addr_list *alist;
|
|
|
|
alist = afs_parse_text_addrs(vllist, strlen(vllist), ':',
|
|
VL_SERVICE, AFS_VL_PORT);
|
|
if (IS_ERR(alist)) {
|
|
ret = PTR_ERR(alist);
|
|
goto parse_failed;
|
|
}
|
|
|
|
rcu_assign_pointer(cell->vl_addrs, alist);
|
|
cell->dns_expiry = TIME64_MAX;
|
|
}
|
|
|
|
_leave(" = %p", cell);
|
|
return cell;
|
|
|
|
parse_failed:
|
|
if (ret == -EINVAL)
|
|
printk(KERN_ERR "kAFS: bad VL server IP address\n");
|
|
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;
|
|
int ret, n;
|
|
|
|
_enter("%s,%s", name, vllist);
|
|
|
|
if (!excl) {
|
|
rcu_read_lock();
|
|
cell = afs_lookup_cell_rcu(net, name, namesz);
|
|
rcu_read_unlock();
|
|
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.
|
|
*/
|
|
write_seqlock(&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;
|
|
rb_link_node_rcu(&cell->net_node, parent, pp);
|
|
rb_insert_color(&cell->net_node, &net->cells);
|
|
atomic_inc(&net->cells_outstanding);
|
|
write_sequnlock(&net->cells_lock);
|
|
|
|
queue_work(afs_wq, &cell->manager);
|
|
|
|
wait_for_cell:
|
|
_debug("wait_for_cell");
|
|
ret = wait_on_bit(&cell->flags, AFS_CELL_FL_NOT_READY, TASK_INTERRUPTIBLE);
|
|
smp_rmb();
|
|
|
|
switch (READ_ONCE(cell->state)) {
|
|
case AFS_CELL_FAILED:
|
|
ret = cell->error;
|
|
goto error;
|
|
default:
|
|
_debug("weird %u %d", cell->state, cell->error);
|
|
goto error;
|
|
case AFS_CELL_ACTIVE:
|
|
break;
|
|
}
|
|
|
|
_leave(" = %p [cell]", cell);
|
|
return cell;
|
|
|
|
cell_already_exists:
|
|
_debug("cell exists");
|
|
cell = cursor;
|
|
if (excl) {
|
|
ret = -EEXIST;
|
|
} else {
|
|
afs_get_cell(cursor);
|
|
ret = 0;
|
|
}
|
|
write_sequnlock(&net->cells_lock);
|
|
kfree(candidate);
|
|
if (ret == 0)
|
|
goto wait_for_cell;
|
|
goto error_noput;
|
|
error:
|
|
afs_put_cell(net, cell);
|
|
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_get_cell(new_root);
|
|
|
|
/* install the new cell */
|
|
write_seqlock(&net->cells_lock);
|
|
old_root = net->ws_cell;
|
|
net->ws_cell = new_root;
|
|
write_sequnlock(&net->cells_lock);
|
|
|
|
afs_put_cell(net, old_root);
|
|
_leave(" = 0");
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Update a cell's VL server address list from the DNS.
|
|
*/
|
|
static void afs_update_cell(struct afs_cell *cell)
|
|
{
|
|
struct afs_addr_list *alist, *old;
|
|
time64_t now, expiry;
|
|
|
|
_enter("%s", cell->name);
|
|
|
|
alist = afs_dns_query(cell, &expiry);
|
|
if (IS_ERR(alist)) {
|
|
switch (PTR_ERR(alist)) {
|
|
case -ENODATA:
|
|
/* The DNS said that the cell does not exist */
|
|
set_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
|
|
clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
|
|
cell->dns_expiry = ktime_get_real_seconds() + 61;
|
|
break;
|
|
|
|
case -EAGAIN:
|
|
case -ECONNREFUSED:
|
|
default:
|
|
set_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
|
|
cell->dns_expiry = ktime_get_real_seconds() + 10;
|
|
break;
|
|
}
|
|
|
|
cell->error = -EDESTADDRREQ;
|
|
} else {
|
|
clear_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags);
|
|
clear_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags);
|
|
|
|
/* Exclusion on changing vl_addrs is achieved by a
|
|
* non-reentrant work item.
|
|
*/
|
|
old = rcu_dereference_protected(cell->vl_addrs, true);
|
|
rcu_assign_pointer(cell->vl_addrs, alist);
|
|
cell->dns_expiry = expiry;
|
|
|
|
if (old)
|
|
afs_put_addrlist(old);
|
|
}
|
|
|
|
if (test_and_clear_bit(AFS_CELL_FL_NO_LOOKUP_YET, &cell->flags))
|
|
wake_up_bit(&cell->flags, AFS_CELL_FL_NO_LOOKUP_YET);
|
|
|
|
now = ktime_get_real_seconds();
|
|
afs_set_cell_timer(cell->net, cell->dns_expiry - now);
|
|
_leave("");
|
|
}
|
|
|
|
/*
|
|
* Destroy a cell record
|
|
*/
|
|
static void afs_cell_destroy(struct rcu_head *rcu)
|
|
{
|
|
struct afs_cell *cell = container_of(rcu, struct afs_cell, rcu);
|
|
|
|
_enter("%p{%s}", cell, cell->name);
|
|
|
|
ASSERTCMP(atomic_read(&cell->usage), ==, 0);
|
|
|
|
afs_put_addrlist(rcu_access_pointer(cell->vl_addrs));
|
|
key_put(cell->anonymous_key);
|
|
kfree(cell);
|
|
|
|
_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)
|
|
{
|
|
atomic_inc(&cell->usage);
|
|
return cell;
|
|
}
|
|
|
|
/*
|
|
* Drop a reference on a cell record.
|
|
*/
|
|
void afs_put_cell(struct afs_net *net, struct afs_cell *cell)
|
|
{
|
|
time64_t now, expire_delay;
|
|
|
|
if (!cell)
|
|
return;
|
|
|
|
_enter("%s", cell->name);
|
|
|
|
now = ktime_get_real_seconds();
|
|
cell->last_inactive = now;
|
|
expire_delay = 0;
|
|
if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
|
|
!test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
|
|
expire_delay = afs_cell_gc_delay;
|
|
|
|
if (atomic_dec_return(&cell->usage) > 1)
|
|
return;
|
|
|
|
/* 'cell' may now be garbage collected. */
|
|
afs_set_cell_timer(net, expire_delay);
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
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(net, cell);
|
|
if (ret < 0)
|
|
return ret;
|
|
spin_lock(&net->proc_cells_lock);
|
|
list_add_tail(&cell->proc_link, &net->proc_cells);
|
|
spin_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(net, cell);
|
|
|
|
spin_lock(&net->proc_cells_lock);
|
|
list_del_init(&cell->proc_link);
|
|
spin_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 work_struct *work)
|
|
{
|
|
struct afs_cell *cell = container_of(work, struct afs_cell, manager);
|
|
struct afs_net *net = cell->net;
|
|
bool deleted;
|
|
int ret, usage;
|
|
|
|
_enter("%s", cell->name);
|
|
|
|
again:
|
|
_debug("state %u", cell->state);
|
|
switch (cell->state) {
|
|
case AFS_CELL_INACTIVE:
|
|
case AFS_CELL_FAILED:
|
|
write_seqlock(&net->cells_lock);
|
|
usage = 1;
|
|
deleted = atomic_try_cmpxchg_relaxed(&cell->usage, &usage, 0);
|
|
if (deleted)
|
|
rb_erase(&cell->net_node, &net->cells);
|
|
write_sequnlock(&net->cells_lock);
|
|
if (deleted)
|
|
goto final_destruction;
|
|
if (cell->state == AFS_CELL_FAILED)
|
|
goto done;
|
|
cell->state = AFS_CELL_UNSET;
|
|
goto again;
|
|
|
|
case AFS_CELL_UNSET:
|
|
cell->state = AFS_CELL_ACTIVATING;
|
|
goto again;
|
|
|
|
case AFS_CELL_ACTIVATING:
|
|
ret = afs_activate_cell(net, cell);
|
|
if (ret < 0)
|
|
goto activation_failed;
|
|
|
|
cell->state = AFS_CELL_ACTIVE;
|
|
smp_wmb();
|
|
clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
|
|
wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
|
|
goto again;
|
|
|
|
case AFS_CELL_ACTIVE:
|
|
if (atomic_read(&cell->usage) > 1) {
|
|
time64_t now = ktime_get_real_seconds();
|
|
if (cell->dns_expiry <= now && net->live)
|
|
afs_update_cell(cell);
|
|
goto done;
|
|
}
|
|
cell->state = AFS_CELL_DEACTIVATING;
|
|
goto again;
|
|
|
|
case AFS_CELL_DEACTIVATING:
|
|
set_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
|
|
if (atomic_read(&cell->usage) > 1)
|
|
goto reverse_deactivation;
|
|
afs_deactivate_cell(net, cell);
|
|
cell->state = AFS_CELL_INACTIVE;
|
|
goto again;
|
|
|
|
default:
|
|
break;
|
|
}
|
|
_debug("bad state %u", cell->state);
|
|
BUG(); /* Unhandled state */
|
|
|
|
activation_failed:
|
|
cell->error = ret;
|
|
afs_deactivate_cell(net, cell);
|
|
|
|
cell->state = AFS_CELL_FAILED;
|
|
smp_wmb();
|
|
if (test_and_clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags))
|
|
wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
|
|
goto again;
|
|
|
|
reverse_deactivation:
|
|
cell->state = AFS_CELL_ACTIVE;
|
|
smp_wmb();
|
|
clear_bit(AFS_CELL_FL_NOT_READY, &cell->flags);
|
|
wake_up_bit(&cell->flags, AFS_CELL_FL_NOT_READY);
|
|
_leave(" [deact->act]");
|
|
return;
|
|
|
|
done:
|
|
_leave(" [done %u]", cell->state);
|
|
return;
|
|
|
|
final_destruction:
|
|
call_rcu(&cell->rcu, afs_cell_destroy);
|
|
afs_dec_cells_outstanding(net);
|
|
_leave(" [destruct %d]", atomic_read(&net->cells_outstanding));
|
|
}
|
|
|
|
/*
|
|
* 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.
|
|
*/
|
|
read_seqlock_excl(&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 usage;
|
|
bool sched_cell = false;
|
|
|
|
usage = atomic_read(&cell->usage);
|
|
_debug("manage %s %u", cell->name, usage);
|
|
|
|
ASSERTCMP(usage, >=, 1);
|
|
|
|
if (purging) {
|
|
if (test_and_clear_bit(AFS_CELL_FL_NO_GC, &cell->flags))
|
|
usage = atomic_dec_return(&cell->usage);
|
|
ASSERTCMP(usage, ==, 1);
|
|
}
|
|
|
|
if (usage == 1) {
|
|
time64_t expire_at = cell->last_inactive;
|
|
|
|
if (!test_bit(AFS_CELL_FL_DNS_FAIL, &cell->flags) &&
|
|
!test_bit(AFS_CELL_FL_NOT_FOUND, &cell->flags))
|
|
expire_at += afs_cell_gc_delay;
|
|
if (purging || expire_at <= now)
|
|
sched_cell = true;
|
|
else if (expire_at < next_manage)
|
|
next_manage = expire_at;
|
|
}
|
|
|
|
if (!purging) {
|
|
if (cell->dns_expiry <= now)
|
|
sched_cell = true;
|
|
else if (cell->dns_expiry <= next_manage)
|
|
next_manage = cell->dns_expiry;
|
|
}
|
|
|
|
if (sched_cell)
|
|
queue_work(afs_wq, &cell->manager);
|
|
}
|
|
|
|
read_sequnlock_excl(&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("");
|
|
|
|
write_seqlock(&net->cells_lock);
|
|
ws = net->ws_cell;
|
|
net->ws_cell = NULL;
|
|
write_sequnlock(&net->cells_lock);
|
|
afs_put_cell(net, 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("");
|
|
}
|