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965 lines
24 KiB
965 lines
24 KiB
// SPDX-License-Identifier: GPL-2.0-or-later |
|
/* AFS cell and server record management |
|
* |
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* Copyright (C) 2002, 2017 Red Hat, Inc. All Rights Reserved. |
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* Written by David Howells ([email protected]) |
|
*/ |
|
|
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#include <linux/slab.h> |
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#include <linux/key.h> |
|
#include <linux/ctype.h> |
|
#include <linux/dns_resolver.h> |
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#include <linux/sched.h> |
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#include <linux/inet.h> |
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#include <linux/namei.h> |
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#include <keys/rxrpc-type.h> |
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#include "internal.h" |
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|
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static unsigned __read_mostly afs_cell_gc_delay = 10; |
|
static unsigned __read_mostly afs_cell_min_ttl = 10 * 60; |
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static unsigned __read_mostly afs_cell_max_ttl = 24 * 60 * 60; |
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static atomic_t cell_debug_id; |
|
|
|
static void afs_queue_cell_manager(struct afs_net *); |
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static void afs_manage_cell_work(struct work_struct *); |
|
|
|
static void afs_dec_cells_outstanding(struct afs_net *net) |
|
{ |
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if (atomic_dec_and_test(&net->cells_outstanding)) |
|
wake_up_var(&net->cells_outstanding); |
|
} |
|
|
|
/* |
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* 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) { |
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atomic_inc(&net->cells_outstanding); |
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if (timer_reduce(&net->cells_timer, jiffies + delay * HZ)) |
|
afs_dec_cells_outstanding(net); |
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} else { |
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afs_queue_cell_manager(net); |
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} |
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} |
|
|
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/* |
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* Look up and get an activation reference on a cell record. The caller must |
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* hold net->cells_lock at least read-locked. |
|
*/ |
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static struct afs_cell *afs_find_cell_locked(struct afs_net *net, |
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const char *name, unsigned int namesz, |
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enum afs_cell_trace reason) |
|
{ |
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struct afs_cell *cell = NULL; |
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struct rb_node *p; |
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int n; |
|
|
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_enter("%*.*s", namesz, namesz, name); |
|
|
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if (name && namesz == 0) |
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return ERR_PTR(-EINVAL); |
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if (namesz > AFS_MAXCELLNAME) |
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return ERR_PTR(-ENAMETOOLONG); |
|
|
|
if (!name) { |
|
cell = net->ws_cell; |
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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, |
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min_t(size_t, cell->name_len, namesz)); |
|
if (n == 0) |
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n = cell->name_len - namesz; |
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if (n < 0) |
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p = p->rb_left; |
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else if (n > 0) |
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p = p->rb_right; |
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else |
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goto found; |
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} |
|
|
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return ERR_PTR(-ENOENT); |
|
|
|
found: |
|
return afs_use_cell(cell, reason); |
|
} |
|
|
|
/* |
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* Look up and get an activation reference on a cell record. |
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*/ |
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struct afs_cell *afs_find_cell(struct afs_net *net, |
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const char *name, unsigned int namesz, |
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enum afs_cell_trace reason) |
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{ |
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struct afs_cell *cell; |
|
|
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down_read(&net->cells_lock); |
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cell = afs_find_cell_locked(net, name, namesz, reason); |
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up_read(&net->cells_lock); |
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return cell; |
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} |
|
|
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/* |
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* Set up a cell record and fill in its name, VL server address list and |
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* allocate an anonymous key |
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*/ |
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static struct afs_cell *afs_alloc_cell(struct afs_net *net, |
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const char *name, unsigned int namelen, |
|
const char *addresses) |
|
{ |
|
struct afs_vlserver_list *vllist; |
|
struct afs_cell *cell; |
|
int i, ret; |
|
|
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ASSERT(name); |
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if (namelen == 0) |
|
return ERR_PTR(-EINVAL); |
|
if (namelen > AFS_MAXCELLNAME) { |
|
_leave(" = -ENAMETOOLONG"); |
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return ERR_PTR(-ENAMETOOLONG); |
|
} |
|
|
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/* Prohibit cell names that contain unprintable chars, '/' and '@' or |
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* that begin with a dot. This also precludes "@cell". |
|
*/ |
|
if (name[0] == '.') |
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return ERR_PTR(-EINVAL); |
|
for (i = 0; i < namelen; i++) { |
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char ch = name[i]; |
|
if (!isprint(ch) || ch == '/' || ch == '@') |
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return ERR_PTR(-EINVAL); |
|
} |
|
|
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_enter("%*.*s,%s", namelen, namelen, name, addresses); |
|
|
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cell = kzalloc(sizeof(struct afs_cell), GFP_KERNEL); |
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if (!cell) { |
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_leave(" = -ENOMEM"); |
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return ERR_PTR(-ENOMEM); |
|
} |
|
|
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cell->name = kmalloc(namelen + 1, GFP_KERNEL); |
|
if (!cell->name) { |
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kfree(cell); |
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return ERR_PTR(-ENOMEM); |
|
} |
|
|
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cell->net = net; |
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cell->name_len = namelen; |
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for (i = 0; i < namelen; i++) |
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cell->name[i] = tolower(name[i]); |
|
cell->name[i] = 0; |
|
|
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atomic_set(&cell->ref, 1); |
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atomic_set(&cell->active, 0); |
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INIT_WORK(&cell->manager, afs_manage_cell_work); |
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cell->volumes = RB_ROOT; |
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INIT_HLIST_HEAD(&cell->proc_volumes); |
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seqlock_init(&cell->volume_lock); |
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cell->fs_servers = RB_ROOT; |
|
seqlock_init(&cell->fs_lock); |
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rwlock_init(&cell->vl_servers_lock); |
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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; |
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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(); |
|
} |
|
|
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rcu_assign_pointer(cell->vl_servers, vllist); |
|
|
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cell->dns_source = vllist->source; |
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cell->dns_status = vllist->status; |
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smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ |
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atomic_inc(&net->cells_outstanding); |
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cell->debug_id = atomic_inc_return(&cell_debug_id); |
|
trace_afs_cell(cell->debug_id, 1, 0, afs_cell_trace_alloc); |
|
|
|
_leave(" = %p", cell); |
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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); |
|
} |
|
|
|
/* |
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* afs_lookup_cell - Look up or create a cell record. |
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* @net: The network namespace |
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* @name: The name of the cell. |
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* @namesz: The strlen of the cell name. |
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* @vllist: A colon/comma separated list of numeric IP addresses or NULL. |
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* @excl: T if an error should be given if the cell name already exists. |
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* |
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* 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, |
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const char *name, unsigned int namesz, |
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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 |
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* name, the net namespace and VL server addresses. |
|
* |
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* We also want to do this before we hold any locks as it may involve |
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* upcalling to userspace to make DNS queries. |
|
*/ |
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candidate = afs_alloc_cell(net, name, namesz, vllist); |
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if (IS_ERR(candidate)) { |
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_leave(" = %ld", PTR_ERR(candidate)); |
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return candidate; |
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} |
|
|
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/* Find the insertion point and check to see if someone else added a |
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* cell whilst we were allocating. |
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*/ |
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down_write(&net->cells_lock); |
|
|
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pp = &net->cells.rb_node; |
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parent = NULL; |
|
while (*pp) { |
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parent = *pp; |
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cursor = rb_entry(parent, struct afs_cell, net_node); |
|
|
|
n = strncasecmp(cursor->name, name, |
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min_t(size_t, cursor->name_len, namesz)); |
|
if (n == 0) |
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n = cursor->name_len - namesz; |
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if (n < 0) |
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pp = &(*pp)->rb_left; |
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else if (n > 0) |
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pp = &(*pp)->rb_right; |
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else |
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goto cell_already_exists; |
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} |
|
|
|
cell = candidate; |
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candidate = NULL; |
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atomic_set(&cell->active, 2); |
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trace_afs_cell(cell->debug_id, atomic_read(&cell->ref), 2, afs_cell_trace_insert); |
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rb_link_node_rcu(&cell->net_node, parent, pp); |
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rb_insert_color(&cell->net_node, &net->cells); |
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up_write(&net->cells_lock); |
|
|
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afs_queue_cell(cell, afs_cell_trace_get_queue_new); |
|
|
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wait_for_cell: |
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trace_afs_cell(cell->debug_id, atomic_read(&cell->ref), atomic_read(&cell->active), |
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afs_cell_trace_wait); |
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_debug("wait_for_cell"); |
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wait_var_event(&cell->state, |
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({ |
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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; |
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goto error; |
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} |
|
|
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_leave(" = %p [cell]", cell); |
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return cell; |
|
|
|
cell_already_exists: |
|
_debug("cell exists"); |
|
cell = cursor; |
|
if (excl) { |
|
ret = -EEXIST; |
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} else { |
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afs_use_cell(cursor, afs_cell_trace_use_lookup); |
|
ret = 0; |
|
} |
|
up_write(&net->cells_lock); |
|
if (candidate) |
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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); |
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error_noput: |
|
_leave(" = %d [error]", ret); |
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return ERR_PTR(ret); |
|
} |
|
|
|
/* |
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* set the root cell information |
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* - can be called with a module parameter string |
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* - 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; |
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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); |
|
} |
|
|
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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(""); |
|
}
|
|
|