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/* AFS superblock handling
*
* Copyright (c) 2002, 2007, 2018 Red Hat, Inc. All rights reserved.
*
* This software may be freely redistributed under the terms of the
* GNU General Public License.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Authors: David Howells <dhowells@redhat.com>
* David Woodhouse <dwmw2@infradead.org>
*
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mount.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/fs_parser.h>
#include <linux/statfs.h>
#include <linux/sched.h>
#include <linux/nsproxy.h>
#include <linux/magic.h>
#include <net/net_namespace.h>
#include "internal.h"
static void afs_i_init_once(void *foo);
static void afs_kill_super(struct super_block *sb);
static struct inode *afs_alloc_inode(struct super_block *sb);
static void afs_destroy_inode(struct inode *inode);
static void afs_free_inode(struct inode *inode);
static int afs_statfs(struct dentry *dentry, struct kstatfs *buf);
static int afs_show_devname(struct seq_file *m, struct dentry *root);
static int afs_show_options(struct seq_file *m, struct dentry *root);
static int afs_init_fs_context(struct fs_context *fc);
static const struct fs_parameter_description afs_fs_parameters;
struct file_system_type afs_fs_type = {
.owner = THIS_MODULE,
.name = "afs",
.init_fs_context = afs_init_fs_context,
.parameters = &afs_fs_parameters,
.kill_sb = afs_kill_super,
.fs_flags = FS_RENAME_DOES_D_MOVE,
};
MODULE_ALIAS_FS("afs");
int afs_net_id;
static const struct super_operations afs_super_ops = {
.statfs = afs_statfs,
.alloc_inode = afs_alloc_inode,
.drop_inode = afs_drop_inode,
.destroy_inode = afs_destroy_inode,
.free_inode = afs_free_inode,
.evict_inode = afs_evict_inode,
.show_devname = afs_show_devname,
.show_options = afs_show_options,
};
static struct kmem_cache *afs_inode_cachep;
static atomic_t afs_count_active_inodes;
enum afs_param {
Opt_autocell,
Opt_dyn,
Opt_flock,
Opt_source,
};
static const struct fs_parameter_spec afs_param_specs[] = {
fsparam_flag ("autocell", Opt_autocell),
fsparam_flag ("dyn", Opt_dyn),
fsparam_enum ("flock", Opt_flock),
fsparam_string("source", Opt_source),
{}
};
static const struct fs_parameter_enum afs_param_enums[] = {
{ Opt_flock, "local", afs_flock_mode_local },
{ Opt_flock, "openafs", afs_flock_mode_openafs },
{ Opt_flock, "strict", afs_flock_mode_strict },
{ Opt_flock, "write", afs_flock_mode_write },
{}
};
static const struct fs_parameter_description afs_fs_parameters = {
.name = "kAFS",
.specs = afs_param_specs,
.enums = afs_param_enums,
};
/*
* initialise the filesystem
*/
int __init afs_fs_init(void)
{
int ret;
_enter("");
/* create ourselves an inode cache */
atomic_set(&afs_count_active_inodes, 0);
ret = -ENOMEM;
afs_inode_cachep = kmem_cache_create("afs_inode_cache",
sizeof(struct afs_vnode),
0,
SLAB_HWCACHE_ALIGN|SLAB_ACCOUNT,
afs_i_init_once);
if (!afs_inode_cachep) {
printk(KERN_NOTICE "kAFS: Failed to allocate inode cache\n");
return ret;
}
/* now export our filesystem to lesser mortals */
ret = register_filesystem(&afs_fs_type);
if (ret < 0) {
kmem_cache_destroy(afs_inode_cachep);
_leave(" = %d", ret);
return ret;
}
_leave(" = 0");
return 0;
}
/*
* clean up the filesystem
*/
void afs_fs_exit(void)
{
_enter("");
afs_mntpt_kill_timer();
unregister_filesystem(&afs_fs_type);
if (atomic_read(&afs_count_active_inodes) != 0) {
printk("kAFS: %d active inode objects still present\n",
atomic_read(&afs_count_active_inodes));
BUG();
}
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(afs_inode_cachep);
_leave("");
}
/*
* Display the mount device name in /proc/mounts.
*/
static int afs_show_devname(struct seq_file *m, struct dentry *root)
{
struct afs_super_info *as = AFS_FS_S(root->d_sb);
struct afs_volume *volume = as->volume;
struct afs_cell *cell = as->cell;
const char *suf = "";
char pref = '%';
if (as->dyn_root) {
seq_puts(m, "none");
return 0;
}
switch (volume->type) {
case AFSVL_RWVOL:
break;
case AFSVL_ROVOL:
pref = '#';
if (volume->type_force)
suf = ".readonly";
break;
case AFSVL_BACKVOL:
pref = '#';
suf = ".backup";
break;
}
seq_printf(m, "%c%s:%s%s", pref, cell->name, volume->name, suf);
return 0;
}
/*
* Display the mount options in /proc/mounts.
*/
static int afs_show_options(struct seq_file *m, struct dentry *root)
{
struct afs_super_info *as = AFS_FS_S(root->d_sb);
const char *p = NULL;
if (as->dyn_root)
seq_puts(m, ",dyn");
if (test_bit(AFS_VNODE_AUTOCELL, &AFS_FS_I(d_inode(root))->flags))
seq_puts(m, ",autocell");
switch (as->flock_mode) {
case afs_flock_mode_unset: break;
case afs_flock_mode_local: p
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