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8b2a464ced
linux/fs/afs/proc.c
David Howells 8b2a464ced afs: Add an address list concept 
Add an RCU replaceable address list structure to hold a list of server
addresses.  The list also holds the

To this end:

 (1) A cell's VL server address list can be loaded directly via insmod or
     echo to /proc/fs/afs/cells or dynamically from a DNS query for AFSDB
     or SRV records.

 (2) Anyone wanting to use a cell's VL server address must wait until the
     cell record comes online and has tried to obtain some addresses.

 (3) An FS server's address list, for the moment, has a single entry that
     is the key to the server list.  This will change in the future when a
     server is instead keyed on its UUID and the VL.GetAddrsU operation is
     used.

 (4) An 'address cursor' concept is introduced to handle iteration through
     the address list.  This is passed to the afs_make_call() as, in the
     future, stuff (such as abort code) that doesn't outlast the call will
     be returned in it.

In the future, we might want to annotate the list with information about
how each address fares.  We might then want to propagate such annotations
over address list replacement.

Whilst we're at it, we allow IPv6 addresses to be specified in
colon-delimited lists by enclosing them in square brackets.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-11-13 15:38:18 +00:00

666 lines
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/* /proc interface for AFS
*
* 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/slab.h>
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include "internal.h"
static inline struct afs_net *afs_proc2net(struct file *f)
{
return &__afs_net;
}
static inline struct afs_net *afs_seq2net(struct seq_file *m)
{
return &__afs_net; // TODO: use seq_file_net(m)
}
static int afs_proc_cells_open(struct inode *inode, struct file *file);
static void *afs_proc_cells_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cells_next(struct seq_file *p, void *v, loff_t *pos);
static void afs_proc_cells_stop(struct seq_file *p, void *v);
static int afs_proc_cells_show(struct seq_file *m, void *v);
static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
size_t size, loff_t *_pos);
static const struct seq_operations afs_proc_cells_ops = {
.start = afs_proc_cells_start,
.next = afs_proc_cells_next,
.stop = afs_proc_cells_stop,
.show = afs_proc_cells_show,
};
static const struct file_operations afs_proc_cells_fops = {
.open = afs_proc_cells_open,
.read = seq_read,
.write = afs_proc_cells_write,
.llseek = seq_lseek,
.release = seq_release,
};
static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
size_t size, loff_t *_pos);
static ssize_t afs_proc_rootcell_write(struct file *file,
const char __user *buf,
size_t size, loff_t *_pos);
static const struct file_operations afs_proc_rootcell_fops = {
.read = afs_proc_rootcell_read,
.write = afs_proc_rootcell_write,
.llseek = no_llseek,
};
static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file);
static void *afs_proc_cell_volumes_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v);
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_volumes_ops = {
.start = afs_proc_cell_volumes_start,
.next = afs_proc_cell_volumes_next,
.stop = afs_proc_cell_volumes_stop,
.show = afs_proc_cell_volumes_show,
};
static const struct file_operations afs_proc_cell_volumes_fops = {
.open = afs_proc_cell_volumes_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int afs_proc_cell_vlservers_open(struct inode *inode,
struct file *file);
static void *afs_proc_cell_vlservers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_vlservers_ops = {
.start = afs_proc_cell_vlservers_start,
.next = afs_proc_cell_vlservers_next,
.stop = afs_proc_cell_vlservers_stop,
.show = afs_proc_cell_vlservers_show,
};
static const struct file_operations afs_proc_cell_vlservers_fops = {
.open = afs_proc_cell_vlservers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int afs_proc_cell_servers_open(struct inode *inode, struct file *file);
static void *afs_proc_cell_servers_start(struct seq_file *p, loff_t *pos);
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
loff_t *pos);
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v);
static int afs_proc_cell_servers_show(struct seq_file *m, void *v);
static const struct seq_operations afs_proc_cell_servers_ops = {
.start = afs_proc_cell_servers_start,
.next = afs_proc_cell_servers_next,
.stop = afs_proc_cell_servers_stop,
.show = afs_proc_cell_servers_show,
};
static const struct file_operations afs_proc_cell_servers_fops = {
.open = afs_proc_cell_servers_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
/*
* initialise the /proc/fs/afs/ directory
*/
int afs_proc_init(struct afs_net *net)
{
_enter("");
net->proc_afs = proc_mkdir("fs/afs", NULL);
if (!net->proc_afs)
goto error_dir;
if (!proc_create("cells", 0644, net->proc_afs, &afs_proc_cells_fops) ||
!proc_create("rootcell", 0644, net->proc_afs, &afs_proc_rootcell_fops))
goto error_tree;
_leave(" = 0");
return 0;
error_tree:
proc_remove(net->proc_afs);
error_dir:
_leave(" = -ENOMEM");
return -ENOMEM;
}
/*
* clean up the /proc/fs/afs/ directory
*/
void afs_proc_cleanup(struct afs_net *net)
{
proc_remove(net->proc_afs);
net->proc_afs = NULL;
}
/*
* open "/proc/fs/afs/cells" which provides a summary of extant cells
*/
static int afs_proc_cells_open(struct inode *inode, struct file *file)
{
struct seq_file *m;
int ret;
ret = seq_open(file, &afs_proc_cells_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = PDE_DATA(inode);
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cells_start(struct seq_file *m, loff_t *_pos)
{
struct afs_net *net = afs_seq2net(m);
rcu_read_lock();
return seq_list_start_head(&net->proc_cells, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cells_next(struct seq_file *m, void *v, loff_t *pos)
{
struct afs_net *net = afs_seq2net(m);
return seq_list_next(v, &net->proc_cells, pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cells_stop(struct seq_file *m, void *v)
{
rcu_read_unlock();
}
/*
* display a header line followed by a load of cell lines
*/
static int afs_proc_cells_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = list_entry(v, struct afs_cell, proc_link);
struct afs_net *net = afs_seq2net(m);
if (v == &net->proc_cells) {
/* display header on line 1 */
seq_puts(m, "USE NAME\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%3u %s\n", atomic_read(&cell->usage), cell->name);
return 0;
}
/*
* handle writes to /proc/fs/afs/cells
* - to add cells: echo "add <cellname> <IP>[:<IP>][:<IP>]"
*/
static ssize_t afs_proc_cells_write(struct file *file, const char __user *buf,
size_t size, loff_t *_pos)
{
struct afs_net *net = afs_proc2net(file);
char *kbuf, *name, *args;
int ret;
/* start by dragging the command into memory */
if (size <= 1 || size >= PAGE_SIZE)
return -EINVAL;
kbuf = memdup_user_nul(buf, size);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
/* trim to first NL */
name = memchr(kbuf, '\n', size);
if (name)
*name = 0;
/* split into command, name and argslist */
name = strchr(kbuf, ' ');
if (!name)
goto inval;
do {
*name++ = 0;
} while(*name == ' ');
if (!*name)
goto inval;
args = strchr(name, ' ');
if (!args)
goto inval;
do {
*args++ = 0;
} while(*args == ' ');
if (!*args)
goto inval;
/* determine command to perform */
_debug("cmd=%s name=%s args=%s", kbuf, name, args);
if (strcmp(kbuf, "add") == 0) {
struct afs_cell *cell;
cell = afs_lookup_cell(net, name, strlen(name), args, true);
if (IS_ERR(cell)) {
ret = PTR_ERR(cell);
goto done;
}
set_bit(AFS_CELL_FL_NO_GC, &cell->flags);
printk("kAFS: Added new cell '%s'\n", name);
} else {
goto inval;
}
ret = size;
done:
kfree(kbuf);
_leave(" = %d", ret);
return ret;
inval:
ret = -EINVAL;
printk("kAFS: Invalid Command on /proc/fs/afs/cells file\n");
goto done;
}
static ssize_t afs_proc_rootcell_read(struct file *file, char __user *buf,
size_t size, loff_t *_pos)
{
return 0;
}
/*
* handle writes to /proc/fs/afs/rootcell
* - to initialize rootcell: echo "cell.name:192.168.231.14"
*/
static ssize_t afs_proc_rootcell_write(struct file *file,
const char __user *buf,
size_t size, loff_t *_pos)
{
struct afs_net *net = afs_proc2net(file);
char *kbuf, *s;
int ret;
/* start by dragging the command into memory */
if (size <= 1 || size >= PAGE_SIZE)
return -EINVAL;
kbuf = memdup_user_nul(buf, size);
if (IS_ERR(kbuf))
return PTR_ERR(kbuf);
/* trim to first NL */
s = memchr(kbuf, '\n', size);
if (s)
*s = 0;
/* determine command to perform */
_debug("rootcell=%s", kbuf);
ret = afs_cell_init(net, kbuf);
if (ret >= 0)
ret = size; /* consume everything, always */
kfree(kbuf);
_leave(" = %d", ret);
return ret;
}
/*
* initialise /proc/fs/afs/<cell>/
*/
int afs_proc_cell_setup(struct afs_net *net, struct afs_cell *cell)
{
struct proc_dir_entry *dir;
_enter("%p{%s},%p", cell, cell->name, net->proc_afs);
dir = proc_mkdir(cell->name, net->proc_afs);
if (!dir)
goto error_dir;
if (!proc_create_data("servers", 0, dir,
&afs_proc_cell_servers_fops, cell) ||
!proc_create_data("vlservers", 0, dir,
&afs_proc_cell_vlservers_fops, cell) ||
!proc_create_data("volumes", 0, dir,
&afs_proc_cell_volumes_fops, cell))
goto error_tree;
_leave(" = 0");
return 0;
error_tree:
remove_proc_subtree(cell->name, net->proc_afs);
error_dir:
_leave(" = -ENOMEM");
return -ENOMEM;
}
/*
* remove /proc/fs/afs/<cell>/
*/
void afs_proc_cell_remove(struct afs_net *net, struct afs_cell *cell)
{
_enter("");
remove_proc_subtree(cell->name, net->proc_afs);
_leave("");
}
/*
* open "/proc/fs/afs/<cell>/volumes" which provides a summary of extant cells
*/
static int afs_proc_cell_volumes_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_volumes_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_volumes_start(struct seq_file *m, loff_t *_pos)
{
struct afs_cell *cell = m->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
/* lock the list against modification */
down_read(&cell->vl_sem);
return seq_list_start_head(&cell->vl_list, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_volumes_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_cell *cell = p->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
return seq_list_next(v, &cell->vl_list, _pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_volumes_stop(struct seq_file *p, void *v)
{
struct afs_cell *cell = p->private;
up_read(&cell->vl_sem);
}
static const char afs_vlocation_states[][4] = {
[AFS_VL_NEW] = "New",
[AFS_VL_CREATING] = "Crt",
[AFS_VL_VALID] = "Val",
[AFS_VL_NO_VOLUME] = "NoV",
[AFS_VL_UPDATING] = "Upd",
[AFS_VL_VOLUME_DELETED] = "Del",
[AFS_VL_UNCERTAIN] = "Unc",
};
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_volumes_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = m->private;
struct afs_vlocation *vlocation =
list_entry(v, struct afs_vlocation, link);
/* display header on line 1 */
if (v == &cell->vl_list) {
seq_puts(m, "USE STT VLID[0] VLID[1] VLID[2] NAME\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%3d %s %08x %08x %08x %s\n",
atomic_read(&vlocation->usage),
afs_vlocation_states[vlocation->state],
vlocation->vldb.vid[0],
vlocation->vldb.vid[1],
vlocation->vldb.vid[2],
vlocation->vldb.name);
return 0;
}
/*
* open "/proc/fs/afs/<cell>/vlservers" which provides a list of volume
* location server
*/
static int afs_proc_cell_vlservers_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_vlservers_ops);
if (ret<0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_vlservers_start(struct seq_file *m, loff_t *_pos)
{
struct afs_addr_list *alist;
struct afs_cell *cell = m->private;
loff_t pos = *_pos;
rcu_read_lock();
alist = rcu_dereference(cell->vl_addrs);
/* allow for the header line */
if (!pos)
return (void *) 1;
pos--;
if (!alist || pos >= alist->nr_addrs)
return NULL;
return alist->addrs + pos;
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_vlservers_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_addr_list *alist;
struct afs_cell *cell = p->private;
loff_t pos;
alist = rcu_dereference(cell->vl_addrs);
pos = *_pos;
(*_pos)++;
if (!alist || pos >= alist->nr_addrs)
return NULL;
return alist->addrs + pos;
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_vlservers_stop(struct seq_file *p, void *v)
{
rcu_read_unlock();
}
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_vlservers_show(struct seq_file *m, void *v)
{
struct sockaddr_rxrpc *addr = v;
/* display header on line 1 */
if (v == (void *)1) {
seq_puts(m, "ADDRESS\n");
return 0;
}
/* display one cell per line on subsequent lines */
seq_printf(m, "%pISp\n", &addr->transport);
return 0;
}
/*
* open "/proc/fs/afs/<cell>/servers" which provides a summary of active
* servers
*/
static int afs_proc_cell_servers_open(struct inode *inode, struct file *file)
{
struct afs_cell *cell;
struct seq_file *m;
int ret;
cell = PDE_DATA(inode);
if (!cell)
return -ENOENT;
ret = seq_open(file, &afs_proc_cell_servers_ops);
if (ret < 0)
return ret;
m = file->private_data;
m->private = cell;
return 0;
}
/*
* set up the iterator to start reading from the cells list and return the
* first item
*/
static void *afs_proc_cell_servers_start(struct seq_file *m, loff_t *_pos)
__acquires(m->private->servers_lock)
{
struct afs_cell *cell = m->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
/* lock the list against modification */
read_lock(&cell->servers_lock);
return seq_list_start_head(&cell->servers, *_pos);
}
/*
* move to next cell in cells list
*/
static void *afs_proc_cell_servers_next(struct seq_file *p, void *v,
loff_t *_pos)
{
struct afs_cell *cell = p->private;
_enter("cell=%p pos=%Ld", cell, *_pos);
return seq_list_next(v, &cell->servers, _pos);
}
/*
* clean up after reading from the cells list
*/
static void afs_proc_cell_servers_stop(struct seq_file *p, void *v)
__releases(p->private->servers_lock)
{
struct afs_cell *cell = p->private;
read_unlock(&cell->servers_lock);
}
/*
* display a header line followed by a load of volume lines
*/
static int afs_proc_cell_servers_show(struct seq_file *m, void *v)
{
struct afs_cell *cell = m->private;
struct afs_server *server = list_entry(v, struct afs_server, link);
char ipaddr[64];
/* display header on line 1 */
if (v == &cell->servers) {
seq_puts(m, "USE ADDR STATE\n");
return 0;
}
/* display one cell per line on subsequent lines */
sprintf(ipaddr, "%pISp", &server->addrs->addrs[0].transport);
seq_printf(m, "%3d %-15s %5d\n",
atomic_read(&server->usage), ipaddr, server->fs_state);
return 0;
}
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