original development tree for Linux kernel GTP module; now long in mainline.
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/*
* Super block/filesystem wide operations
*
* Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
* Michael Callahan <callahan@maths.ox.ac.uk>
*
* Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
* Copyright (C) Carnegie Mellon University
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/stat.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/file.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/pid_namespace.h>
#include <asm/uaccess.h>
#include <linux/fs.h>
#include <linux/vmalloc.h>
#include <linux/coda.h>
#include <linux/coda_psdev.h>
#include "coda_linux.h"
#include "coda_cache.h"
#include "coda_int.h"
/* VFS super_block ops */
static void coda_evict_inode(struct inode *);
static void coda_put_super(struct super_block *);
static int coda_statfs(struct dentry *dentry, struct kstatfs *buf);
static struct kmem_cache * coda_inode_cachep;
static struct inode *coda_alloc_inode(struct super_block *sb)
{
struct coda_inode_info *ei;
ei = kmem_cache_alloc(coda_inode_cachep, GFP_KERNEL);
if (!ei)
return NULL;
memset(&ei->c_fid, 0, sizeof(struct CodaFid));
ei->c_flags = 0;
ei->c_uid = GLOBAL_ROOT_UID;
ei->c_cached_perm = 0;
spin_lock_init(&ei->c_lock);
return &ei->vfs_inode;
}
static void coda_i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
kmem_cache_free(coda_inode_cachep, ITOC(inode));
}
static void coda_destroy_inode(struct inode *inode)
{
call_rcu(&inode->i_rcu, coda_i_callback);
}
static void init_once(void *foo)
{
struct coda_inode_info *ei = (struct coda_inode_info *) foo;
inode_init_once(&ei->vfs_inode);
}
int coda_init_inodecache(void)
{
coda_inode_cachep = kmem_cache_create("coda_inode_cache",
sizeof(struct coda_inode_info),
0, SLAB_RECLAIM_ACCOUNT|SLAB_MEM_SPREAD,
init_once);
if (coda_inode_cachep == NULL)
return -ENOMEM;
return 0;
}
void coda_destroy_inodecache(void)
{
/*
* Make sure all delayed rcu free inodes are flushed before we
* destroy cache.
*/
rcu_barrier();
kmem_cache_destroy(coda_inode_cachep);
}
static int coda_remount(struct super_block *sb, int *flags, char *data)
{
*flags |= MS_NOATIME;
return 0;
}
/* exported operations */
static const struct super_operations coda_super_operations =
{
.alloc_inode = coda_alloc_inode,
.destroy_inode = coda_destroy_inode,
.evict_inode = coda_evict_inode,
.put_super = coda_put_super,
.statfs = coda_statfs,
.remount_fs = coda_remount,
};
static int get_device_index(struct coda_mount_data *data)
{
struct fd f;
struct inode *inode;
int idx;
if (data == NULL) {
printk("coda_read_super: Bad mount data\n");
return -1;
}
if (data->version != CODA_MOUNT_VERSION) {
printk("coda_read_super: Bad mount version\n");
return -1;
}
f = fdget(data->fd);
if (!f.file)
goto Ebadf;
inode = file_inode(f.file);
if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
fdput(f);
goto Ebadf;
}
idx = iminor(inode);
fdput(f);
if (idx < 0 || idx >= MAX_CODADEVS) {
printk("coda_read_super: Bad minor number\n");
return -1;
}
return idx;
Ebadf:
printk("coda_read_super: Bad file\n");
return -1;
}
static int coda_fill_super(struct super_block *sb, void *data, int silent)
{
struct inode *root = NULL;
struct venus_comm *vc;
struct CodaFid fid;
int error;
int idx;
if (task_active_pid_ns(current) != &init_pid_ns)
return -EINVAL;
idx = get_device_index((struct coda_mount_data *) data);
/* Ignore errors in data, for backward compatibility */
if(idx == -1)
idx = 0;
printk(KERN_INFO "coda_read_super: device index: %i\n", idx);
vc = &coda_comms[idx];
mutex_lock(&vc->vc_mutex);
if (!vc->vc_inuse) {
printk("coda_read_super: No pseudo device\n");
error = -EINVAL;
goto unlock_out;
}
if (vc->vc_sb) {
printk("coda_read_super: Device already mounted\n");
error = -EBUSY;
goto unlock_out;
}
error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
if (error)
goto unlock_out;
vc->vc_sb = sb;
mutex_unlock(&vc->vc_mutex);
sb->s_fs_info = vc;
sb->s_flags |= MS_NOATIME;
sb->s_blocksize = 4096; /* XXXXX what do we put here?? */
sb->s_blocksize_bits = 12;
sb->s_magic = CODA_SUPER_MAGIC;
sb->s_op = &coda_super_operations;
sb->s_d_op = &coda_dentry_operations;
sb->s_bdi = &vc->bdi;
/* get root fid from Venus: this needs the root inode */
error = venus_rootfid(sb, &fid);
if ( error ) {
printk("coda_read_super: coda_get_rootfid failed with %d\n",
error);
goto error;
}
printk("coda_read_super: rootfid is %s\n", coda_f2s(&fid));
/* make root inode */
root = coda_cnode_make(&fid, sb);
if (IS_ERR(root)) {
error = PTR_ERR(root);
printk("Failure of coda_cnode_make for root: error %d\n", error);
goto error;
}
printk("coda_read_super: rootinode is %ld dev %s\n",
root->i_ino, root->i_sb->s_id);
sb->s_root = d_make_root(root);
if (!sb->s_root) {
error = -EINVAL;
goto error;
}
return 0;
error:
mutex_lock(&vc->vc_mutex);
bdi_destroy(&vc->bdi);
vc->vc_sb = NULL;
sb->s_fs_info = NULL;
unlock_out:
mutex_unlock(&vc->vc_mutex);
return error;
}
static void coda_put_super(struct super_block *sb)
{
struct venus_comm *vcp = coda_vcp(sb);
mutex_lock(&vcp->vc_mutex);
bdi_destroy(&vcp->bdi);
vcp->vc_sb = NULL;
sb->s_fs_info = NULL;
mutex_unlock(&vcp->vc_mutex);
printk("Coda: Bye bye.\n");
}
static void coda_evict_inode(struct inode *inode)
{
truncate_inode_pages(&inode->i_data, 0);
clear_inode(inode);
coda_cache_clear_inode(inode);
}
int coda_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat)
{
int err = coda_revalidate_inode(dentry);
if (!err)
generic_fillattr(dentry->d_inode, stat);
return err;
}
int coda_setattr(struct dentry *de, struct iattr *iattr)
{
struct inode *inode = de->d_inode;
struct coda_vattr vattr;
int error;
memset(&vattr, 0, sizeof(vattr));
inode->i_ctime = CURRENT_TIME_SEC;
coda_iattr_to_vattr(iattr, &vattr);
vattr.va_type = C_VNON; /* cannot set type */
/* Venus is responsible for truncating the container-file!!! */
error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);
if (!error) {
coda_vattr_to_iattr(inode, &vattr);
coda_cache_clear_inode(inode);
}
return error;
}
const struct inode_operations coda_file_inode_operations = {
.permission = coda_permission,
.getattr = coda_getattr,
.setattr = coda_setattr,
};
static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int error;
error = venus_statfs(dentry, buf);
if (error) {
/* fake something like AFS does */
buf->f_blocks = 9000000;
buf->f_bfree = 9000000;
buf->f_bavail = 9000000;
buf->f_files = 9000000;
buf->f_ffree = 9000000;
}
/* and fill in the rest */
buf->f_type = CODA_SUPER_MAGIC;
buf->f_bsize = 4096;
buf->f_namelen = CODA_MAXNAMLEN;
return 0;
}
/* init_coda: used by filesystems.c to register coda */
static struct dentry *coda_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_nodev(fs_type, flags, data, coda_fill_super);
}
struct file_system_type coda_fs_type = {
.owner = THIS_MODULE,
.name = "coda",
.mount = coda_mount,
.kill_sb = kill_anon_super,
.fs_flags = FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("coda");