413 lines
9.1 KiB
C
413 lines
9.1 KiB
C
|
/* AFS cell and server record management
|
||
|
|
*
|
||
|
|
* Copyright (C) 2002 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/module.h>
|
||
|
|
#include <linux/slab.h>
|
||
|
|
#include <linux/key.h>
|
||
|
|
#include <linux/ctype.h>
|
||
|
|
#include <linux/sched.h>
|
||
|
|
#include <keys/rxrpc-type.h>
|
||
|
|
#include "internal.h"
|
||
|
|
|
||
|
|
DECLARE_RWSEM(afs_proc_cells_sem);
|
||
|
|
LIST_HEAD(afs_proc_cells);
|
||
|
|
|
||
|
|
static LIST_HEAD(afs_cells);
|
||
|
|
static DEFINE_RWLOCK(afs_cells_lock);
|
||
|
|
static DECLARE_RWSEM(afs_cells_sem); /* add/remove serialisation */
|
||
|
|
static DECLARE_WAIT_QUEUE_HEAD(afs_cells_freeable_wq);
|
||
|
|
static struct afs_cell *afs_cell_root;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* allocate a cell record and fill in its name, VL server address list and
|
||
|
|
* allocate an anonymous key
|
||
|
|
*/
|
||
|
|
static struct afs_cell *afs_cell_alloc(const char *name, char *vllist)
|
||
|
|
{
|
||
|
|
struct afs_cell *cell;
|
||
|
|
struct key *key;
|
||
|
|
size_t namelen;
|
||
|
|
char keyname[4 + AFS_MAXCELLNAME + 1], *cp, *dp, *next;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
_enter("%s,%s", name, vllist);
|
||
|
|
|
||
|
|
BUG_ON(!name); /* TODO: want to look up "this cell" in the cache */
|
||
|
|
|
||
|
|
namelen = strlen(name);
|
||
|
|
if (namelen > AFS_MAXCELLNAME)
|
||
|
|
return ERR_PTR(-ENAMETOOLONG);
|
||
|
|
|
||
|
|
/* allocate and initialise a cell record */
|
||
|
|
cell = kzalloc(sizeof(struct afs_cell) + namelen + 1, GFP_KERNEL);
|
||
|
|
if (!cell) {
|
||
|
|
_leave(" = -ENOMEM");
|
||
|
|
return ERR_PTR(-ENOMEM);
|
||
|
|
}
|
||
|
|
|
||
|
|
memcpy(cell->name, name, namelen);
|
||
|
|
cell->name[namelen] = 0;
|
||
|
|
|
||
|
|
atomic_set(&cell->usage, 1);
|
||
|
|
INIT_LIST_HEAD(&cell->link);
|
||
|
|
rwlock_init(&cell->servers_lock);
|
||
|
|
INIT_LIST_HEAD(&cell->servers);
|
||
|
|
init_rwsem(&cell->vl_sem);
|
||
|
|
INIT_LIST_HEAD(&cell->vl_list);
|
||
|
|
spin_lock_init(&cell->vl_lock);
|
||
|
|
|
||
|
|
/* fill in the VL server list from the rest of the string */
|
||
|
|
do {
|
||
|
|
unsigned a, b, c, d;
|
||
|
|
|
||
|
|
next = strchr(vllist, ':');
|
||
|
|
if (next)
|
||
|
|
*next++ = 0;
|
||
|
|
|
||
|
|
if (sscanf(vllist, "%u.%u.%u.%u", &a, &b, &c, &d) != 4)
|
||
|
|
goto bad_address;
|
||
|
|
|
||
|
|
if (a > 255 || b > 255 || c > 255 || d > 255)
|
||
|
|
goto bad_address;
|
||
|
|
|
||
|
|
cell->vl_addrs[cell->vl_naddrs++].s_addr =
|
||
|
|
htonl((a << 24) | (b << 16) | (c << 8) | d);
|
||
|
|
|
||
|
|
} while (cell->vl_naddrs < AFS_CELL_MAX_ADDRS && (vllist = next));
|
||
|
|
|
||
|
|
/* create a key to represent an anonymous user */
|
||
|
|
memcpy(keyname, "afs@", 4);
|
||
|
|
dp = keyname + 4;
|
||
|
|
cp = cell->name;
|
||
|
|
do {
|
||
|
|
*dp++ = toupper(*cp);
|
||
|
|
} while (*cp++);
|
||
|
|
|
||
|
|
key = rxrpc_get_null_key(keyname);
|
||
|
|
if (IS_ERR(key)) {
|
||
|
|
_debug("no key");
|
||
|
|
ret = PTR_ERR(key);
|
||
|
|
goto error;
|
||
|
|
}
|
||
|
|
cell->anonymous_key = key;
|
||
|
|
|
||
|
|
_debug("anon key %p{%x}",
|
||
|
|
cell->anonymous_key, key_serial(cell->anonymous_key));
|
||
|
|
|
||
|
|
_leave(" = %p", cell);
|
||
|
|
return cell;
|
||
|
|
|
||
|
|
bad_address:
|
||
|
|
printk(KERN_ERR "kAFS: bad VL server IP address\n");
|
||
|
|
ret = -EINVAL;
|
||
|
|
error:
|
||
|
|
key_put(cell->anonymous_key);
|
||
|
|
kfree(cell);
|
||
|
|
_leave(" = %d", ret);
|
||
|
|
return ERR_PTR(ret);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* create a cell record
|
||
|
|
* - "name" is the name of the cell
|
||
|
|
* - "vllist" is a colon separated list of IP addresses in "a.b.c.d" format
|
||
|
|
*/
|
||
|
|
struct afs_cell *afs_cell_create(const char *name, char *vllist)
|
||
|
|
{
|
||
|
|
struct afs_cell *cell;
|
||
|
|
int ret;
|
||
|
|
|
||
|
|
_enter("%s,%s", name, vllist);
|
||
|
|
|
||
|
|
down_write(&afs_cells_sem);
|
||
|
|
read_lock(&afs_cells_lock);
|
||
|
|
list_for_each_entry(cell, &afs_cells, link) {
|
||
|
|
if (strcasecmp(cell->name, name) == 0)
|
||
|
|
goto duplicate_name;
|
||
|
|
}
|
||
|
|
read_unlock(&afs_cells_lock);
|
||
|
|
|
||
|
|
cell = afs_cell_alloc(name, vllist);
|
||
|
|
if (IS_ERR(cell)) {
|
||
|
|
_leave(" = %ld", PTR_ERR(cell));
|
||
|
|
up_write(&afs_cells_sem);
|
||
|
|
return cell;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* add a proc directory for this cell */
|
||
|
|
ret = afs_proc_cell_setup(cell);
|
||
|
|
if (ret < 0)
|
||
|
|
goto error;
|
||
|
|
|
||
|
|
#ifdef CONFIG_AFS_FSCACHE
|
||
|
|
/* put it up for caching (this never returns an error) */
|
||
|
|
cell->cache = fscache_acquire_cookie(afs_cache_netfs.primary_index,
|
||
|
|
&afs_cell_cache_index_def,
|
||
|
|
cell);
|
||
|
|
#endif
|
||
|
|
|
||
|
|
/* add to the cell lists */
|
||
|
|
write_lock(&afs_cells_lock);
|
||
|
|
list_add_tail(&cell->link, &afs_cells);
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
|
||
|
|
down_write(&afs_proc_cells_sem);
|
||
|
|
list_add_tail(&cell->proc_link, &afs_proc_cells);
|
||
|
|
up_write(&afs_proc_cells_sem);
|
||
|
|
up_write(&afs_cells_sem);
|
||
|
|
|
||
|
|
_leave(" = %p", cell);
|
||
|
|
return cell;
|
||
|
|
|
||
|
|
error:
|
||
|
|
up_write(&afs_cells_sem);
|
||
|
|
key_put(cell->anonymous_key);
|
||
|
|
kfree(cell);
|
||
|
|
_leave(" = %d", ret);
|
||
|
|
return ERR_PTR(ret);
|
||
|
|
|
||
|
|
duplicate_name:
|
||
|
|
read_unlock(&afs_cells_lock);
|
||
|
|
up_write(&afs_cells_sem);
|
||
|
|
return ERR_PTR(-EEXIST);
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* 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(char *rootcell)
|
||
|
|
{
|
||
|
|
struct afs_cell *old_root, *new_root;
|
||
|
|
char *cp;
|
||
|
|
|
||
|
|
_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) {
|
||
|
|
printk(KERN_ERR "kAFS: no VL server IP addresses specified\n");
|
||
|
|
_leave(" = -EINVAL");
|
||
|
|
return -EINVAL;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* allocate a cell record for the root cell */
|
||
|
|
*cp++ = 0;
|
||
|
|
new_root = afs_cell_create(rootcell, cp);
|
||
|
|
if (IS_ERR(new_root)) {
|
||
|
|
_leave(" = %ld", PTR_ERR(new_root));
|
||
|
|
return PTR_ERR(new_root);
|
||
|
|
}
|
||
|
|
|
||
|
|
/* install the new cell */
|
||
|
|
write_lock(&afs_cells_lock);
|
||
|
|
old_root = afs_cell_root;
|
||
|
|
afs_cell_root = new_root;
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
afs_put_cell(old_root);
|
||
|
|
|
||
|
|
_leave(" = 0");
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* lookup a cell record
|
||
|
|
*/
|
||
|
|
struct afs_cell *afs_cell_lookup(const char *name, unsigned namesz)
|
||
|
|
{
|
||
|
|
struct afs_cell *cell;
|
||
|
|
|
||
|
|
_enter("\"%*.*s\",", namesz, namesz, name ? name : "");
|
||
|
|
|
||
|
|
down_read(&afs_cells_sem);
|
||
|
|
read_lock(&afs_cells_lock);
|
||
|
|
|
||
|
|
if (name) {
|
||
|
|
/* if the cell was named, look for it in the cell record list */
|
||
|
|
list_for_each_entry(cell, &afs_cells, link) {
|
||
|
|
if (strncmp(cell->name, name, namesz) == 0) {
|
||
|
|
afs_get_cell(cell);
|
||
|
|
goto found;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
cell = ERR_PTR(-ENOENT);
|
||
|
|
found:
|
||
|
|
;
|
||
|
|
} else {
|
||
|
|
cell = afs_cell_root;
|
||
|
|
if (!cell) {
|
||
|
|
/* this should not happen unless user tries to mount
|
||
|
|
* when root cell is not set. Return an impossibly
|
||
|
|
* bizzare errno to alert the user. Things like
|
||
|
|
* ENOENT might be "more appropriate" but they happen
|
||
|
|
* for other reasons.
|
||
|
|
*/
|
||
|
|
cell = ERR_PTR(-EDESTADDRREQ);
|
||
|
|
} else {
|
||
|
|
afs_get_cell(cell);
|
||
|
|
}
|
||
|
|
|
||
|
|
}
|
||
|
|
|
||
|
|
read_unlock(&afs_cells_lock);
|
||
|
|
up_read(&afs_cells_sem);
|
||
|
|
_leave(" = %p", cell);
|
||
|
|
return cell;
|
||
|
|
}
|
||
|
|
|
||
|
|
#if 0
|
||
|
|
/*
|
||
|
|
* try and get a cell record
|
||
|
|
*/
|
||
|
|
struct afs_cell *afs_get_cell_maybe(struct afs_cell *cell)
|
||
|
|
{
|
||
|
|
write_lock(&afs_cells_lock);
|
||
|
|
|
||
|
|
if (cell && !list_empty(&cell->link))
|
||
|
|
afs_get_cell(cell);
|
||
|
|
else
|
||
|
|
cell = NULL;
|
||
|
|
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
return cell;
|
||
|
|
}
|
||
|
|
#endif /* 0 */
|
||
|
|
|
||
|
|
/*
|
||
|
|
* destroy a cell record
|
||
|
|
*/
|
||
|
|
void afs_put_cell(struct afs_cell *cell)
|
||
|
|
{
|
||
|
|
if (!cell)
|
||
|
|
return;
|
||
|
|
|
||
|
|
_enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name);
|
||
|
|
|
||
|
|
ASSERTCMP(atomic_read(&cell->usage), >, 0);
|
||
|
|
|
||
|
|
/* to prevent a race, the decrement and the dequeue must be effectively
|
||
|
|
* atomic */
|
||
|
|
write_lock(&afs_cells_lock);
|
||
|
|
|
||
|
|
if (likely(!atomic_dec_and_test(&cell->usage))) {
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
_leave("");
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
ASSERT(list_empty(&cell->servers));
|
||
|
|
ASSERT(list_empty(&cell->vl_list));
|
||
|
|
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
|
||
|
|
wake_up(&afs_cells_freeable_wq);
|
||
|
|
|
||
|
|
_leave(" [unused]");
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* destroy a cell record
|
||
|
|
* - must be called with the afs_cells_sem write-locked
|
||
|
|
* - cell->link should have been broken by the caller
|
||
|
|
*/
|
||
|
|
static void afs_cell_destroy(struct afs_cell *cell)
|
||
|
|
{
|
||
|
|
_enter("%p{%d,%s}", cell, atomic_read(&cell->usage), cell->name);
|
||
|
|
|
||
|
|
ASSERTCMP(atomic_read(&cell->usage), >=, 0);
|
||
|
|
ASSERT(list_empty(&cell->link));
|
||
|
|
|
||
|
|
/* wait for everyone to stop using the cell */
|
||
|
|
if (atomic_read(&cell->usage) > 0) {
|
||
|
|
DECLARE_WAITQUEUE(myself, current);
|
||
|
|
|
||
|
|
_debug("wait for cell %s", cell->name);
|
||
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
||
|
|
add_wait_queue(&afs_cells_freeable_wq, &myself);
|
||
|
|
|
||
|
|
while (atomic_read(&cell->usage) > 0) {
|
||
|
|
schedule();
|
||
|
|
set_current_state(TASK_UNINTERRUPTIBLE);
|
||
|
|
}
|
||
|
|
|
||
|
|
remove_wait_queue(&afs_cells_freeable_wq, &myself);
|
||
|
|
set_current_state(TASK_RUNNING);
|
||
|
|
}
|
||
|
|
|
||
|
|
_debug("cell dead");
|
||
|
|
ASSERTCMP(atomic_read(&cell->usage), ==, 0);
|
||
|
|
ASSERT(list_empty(&cell->servers));
|
||
|
|
ASSERT(list_empty(&cell->vl_list));
|
||
|
|
|
||
|
|
afs_proc_cell_remove(cell);
|
||
|
|
|
||
|
|
down_write(&afs_proc_cells_sem);
|
||
|
|
list_del_init(&cell->proc_link);
|
||
|
|
up_write(&afs_proc_cells_sem);
|
||
|
|
|
||
|
|
#ifdef CONFIG_AFS_FSCACHE
|
||
|
|
fscache_relinquish_cookie(cell->cache, 0);
|
||
|
|
#endif
|
||
|
|
key_put(cell->anonymous_key);
|
||
|
|
kfree(cell);
|
||
|
|
|
||
|
|
_leave(" [destroyed]");
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* purge in-memory cell database on module unload or afs_init() failure
|
||
|
|
* - the timeout daemon is stopped before calling this
|
||
|
|
*/
|
||
|
|
void afs_cell_purge(void)
|
||
|
|
{
|
||
|
|
struct afs_cell *cell;
|
||
|
|
|
||
|
|
_enter("");
|
||
|
|
|
||
|
|
afs_put_cell(afs_cell_root);
|
||
|
|
|
||
|
|
down_write(&afs_cells_sem);
|
||
|
|
|
||
|
|
while (!list_empty(&afs_cells)) {
|
||
|
|
cell = NULL;
|
||
|
|
|
||
|
|
/* remove the next cell from the front of the list */
|
||
|
|
write_lock(&afs_cells_lock);
|
||
|
|
|
||
|
|
if (!list_empty(&afs_cells)) {
|
||
|
|
cell = list_entry(afs_cells.next,
|
||
|
|
struct afs_cell, link);
|
||
|
|
list_del_init(&cell->link);
|
||
|
|
}
|
||
|
|
|
||
|
|
write_unlock(&afs_cells_lock);
|
||
|
|
|
||
|
|
if (cell) {
|
||
|
|
_debug("PURGING CELL %s (%d)",
|
||
|
|
cell->name, atomic_read(&cell->usage));
|
||
|
|
|
||
|
|
/* now the cell should be left with no references */
|
||
|
|
afs_cell_destroy(cell);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
up_write(&afs_cells_sem);
|
||
|
|
_leave("");
|
||
|
|
}
|