/*
FUSE: Filesystem in Userspace
Copyright (C) 2001-2006 Miklos Szeredi <miklos@szeredi.hu>
This program can be distributed under the terms of the GNU GPL.
See the file COPYING.
*/
#include "fuse_i.h"
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/file.h>
#include <linux/seq_file.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/parser.h>
#include <linux/statfs.h>
#include <linux/random.h>
MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
MODULE_DESCRIPTION("Filesystem in Userspace");
MODULE_LICENSE("GPL");
static struct kmem_cache *fuse_inode_cachep;
struct list_head fuse_conn_list;
DEFINE_MUTEX(fuse_mutex);
#define FUSE_SUPER_MAGIC 0x65735546
struct fuse_mount_data {
int fd;
unsigned rootmode;
unsigned user_id;
unsigned group_id;
unsigned fd_present : 1;
unsigned rootmode_present : 1;
unsigned user_id_present : 1;
unsigned group_id_present : 1;
unsigned flags;
unsigned max_read;
unsigned blksize;
};
static struct inode *fuse_alloc_inode(struct super_block *sb)
{
struct inode *inode;
struct fuse_inode *fi;
inode = kmem_cache_alloc(fuse_inode_cachep, GFP_KERNEL);
if (!inode)
return NULL;
fi = get_fuse_inode(inode);
fi->i_time = 0;
fi->nodeid = 0;
fi->nlookup = 0;
fi->forget_req = fuse_request_alloc();
if (!fi->forget_req) {
kmem_cache_free(fuse_inode_cachep, inode);
return NULL;
}
return inode;
}
static void fuse_destroy_inode(struct inode *inode)
{
struct fuse_inode *fi = get_fuse_inode(inode);
if (fi->forget_req)
fuse_request_free(fi->forget_req);
kmem_cache_free(fuse_inode_cachep, inode);
}
static void fuse_read_inode(struct inode *inode)
{
/* No op */
}
void fuse_send_forget(struct fuse_conn *fc, struct fuse_req *req,
unsigned long nodeid, u64 nlookup)
{
struct fuse_forget_in *inarg = &req->misc.forget_in;
inarg->nlookup = nlookup;
req->in.h.opcode = FUSE_FORGET;
req->in.h.nodeid = nodeid;
req->in.numargs = 1;
req->in.args[0].size = sizeof(struct fuse_forget_in);
req->in.args[0].value = inarg;
request_send_noreply(fc, req);
}
static void fuse_clear_inode(struct inode *inode)
{
if (inode->i_sb->s_flags & MS_ACTIVE) {
struct fuse_conn *fc = get_fuse_conn(inode);
struct fuse_inode *fi = get_fuse_inode(inode);
fuse_send_forget(fc, fi->forget_req, fi->nodeid, fi->nlookup);
fi->forget_req = NULL;
}
}
static int fuse_remount_fs(struct super_block *sb, int *flags, char *data)
{
if (*flags & MS_MANDLOCK)
return -EINVAL;
return 0;
}
void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr)
{
struct fuse_conn *fc = get_fuse_conn(inode);
if (S_ISREG(inode->i_mode) && i_size_read(inode) != attr->size)
invalidate_inode_pages(inode->i_mapping);
inode->i_ino = attr->ino;
inode->i_mode = (inode->i_mode & S_IFMT) + (attr->mode & 07777);
inode->i_nlink = attr->nlink;
inode->i_uid = attr->uid;
inode->i_gid = attr->gid;
spin_lock(&fc->lock);
i_size_write(inode, attr->size);
spin_unlock(&fc->lock);
inode->i_blocks = attr->blocks;
inode->i_atime.tv_sec = attr->atime;
inode->i_atime.tv_nsec = attr->atimensec;
inode->i_mtime.tv_sec = attr->mtime;
inode->i_mtime.tv_nsec = attr->mtimensec;
inode->i_ctime.tv_sec = attr->ctime;
inode->i_ctime.tv_nsec = attr->ctimensec;
}
static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
{
inode->i_mode = attr->mode & S_IFMT;
inode->i_size = attr->size;
if (S_ISREG(inode->i_mode)) {
fuse_init_common(inode);
fuse_init_file_inode(inode);
} else if (S_ISDIR(inode->i_mode))
fuse_init_dir(inode);
else if (S_ISLNK(inode->i_mode))
fuse_init_symlink(inode);
else if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode) ||
S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) {
fuse_init_common(inode);
init_special_inode(inode, inode->i_mode,
new_decode_dev(attr->rdev));
} else
BUG();
}
static int fuse_inode_eq(struct inode *inode, void *_nodeidp)
{
unsigned long nodeid = *(unsigned long *) _nodeidp;
if (get_node_id(inode) == nodeid)
return 1;
else
return 0;
}
static int fuse_inode_set(struct inode *inode, void *_nodeidp)
{
unsigned long nodeid = *(unsigned long *) _nodeidp;
get_fuse_inode(inode)->nodeid = nodeid;
return 0;
}
struct inode *fuse_iget(struct super_block *sb, unsigned long nodeid,
int generation, struct fuse_attr *attr)
{
struct inode *inode;
struct fuse_inode *fi;
struct fuse_conn *fc = get_fuse_conn_super(sb);
retry:
inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
if (!inode)
return NULL;
if ((inode->i_state & I_NEW)) {
inode->i_flags |= S_NOATIME|S_NOCMTIME;
inode->i_generation = generation;
inode->i_data.backing_dev_info = &fc->bdi;
fuse_init_inode(inode, attr);
unlock_new_inode(inode);
} else if ((inode->i_mode ^ attr->mode) & S_IFMT) {
/* Inode has changed type, any I/O on the old should fail */
make_bad_inode(inode);
iput(inode);
goto retry;
}
fi = get_fuse_inode(inode);
spin_lock(&fc->lock);
fi->nlookup ++;
spin_unlock(&fc->lock);
fuse_change_attributes(inode, attr);
return inode;
}
static void fuse_umount_begin(struct vfsmount *vfsmnt, int flags)
{
if (flags & MNT_FORCE)
fuse_abort_conn(get_fuse_conn_super(vfsmnt->mnt_sb));
}
static void fuse_send_destroy(struct fuse_conn *fc)
{
struct fuse_req *req = fc->destroy_req;
if (req && fc->conn_init) {
fc->destroy_req = NULL;
req->in.h.opcode = FUSE_DESTROY;
req->force = 1;
request_send(fc, req);
fuse_put_request(fc, req);
}
}
static void fuse_put_super(struct super_block *sb)
{
struct fuse_conn *fc = get_fuse_conn_super(sb);
fuse_send_destroy(fc);
spin_lock(&fc->lock);
fc->connected = 0;
fc->blocked = 0;
spin_unlock(&fc->lock);
/* Flush all readers on this fs */
kill_fasync(&fc->fasync, SIGIO, POLL_IN);
wake_up_all(&fc->waitq);
wake_up_all(&fc->blocked_waitq);
mutex_lock(&fuse_mutex);
list_del(&fc->entry);
fuse_ctl_remove_conn(fc);
mutex_unlock(&fuse_mutex);
fuse_conn_put(fc);
}
static void convert_fuse_statfs(struct kstatfs *stbuf, struct fuse_kstatfs *attr)
{
stbuf->f_type = FUSE_SUPER_MAGIC;
stbuf->f_bsize = attr->bsize;
stbuf->f_frsize = attr->frsize;
stbuf->f_blocks = attr->blocks;
stbuf->f_bfree = attr->bfree;
stbuf->f_bavail = attr->bavail;
stbuf->f_files = attr->files;
stbuf->f_ffree = attr->ffree;
stbuf->f_namelen = attr->namelen;
/* fsid is left zero */
}
static int fuse_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
struct fuse_conn *fc = get_fuse_conn_super(sb);
struct fuse_req *req;
struct fuse_statfs_out outarg;
int err;
req = fuse_get_req(fc);
if (IS_ERR(req))
return PTR_ERR(req);
memset(&outarg, 0, sizeof(outarg));
req->in.numargs = 0;
req->in.h.opcode = FUSE_STATFS;
req->in.h.nodeid = get_node_id(dentry->d_inode);
req->out.numargs = 1;
req->out.args[0].size =
fc->minor < 4 ? FUSE_COMPAT_STATFS_SIZE : sizeof(outarg);
req->out.args[0].value = &outarg;
request_send(fc, req);
err = req->out.h.error;
if (!err)
convert_fuse_statfs(buf, &outarg.st);
fuse_put_request(fc, req);
return err;
}
enum {
OPT_FD,
OPT_ROOTMODE,
OPT_USER_ID,
OPT_GROUP_ID,
OPT_DEFAULT_PERMISSIONS,
OPT_ALLOW_OTHER,
OPT_MAX_READ,
OPT_BLKSIZE,
OPT_ERR
};
static match_table_t tokens = {
{OPT_FD, "fd=%u"},
{OPT_ROOTMODE, "rootmode=%o"},
{OPT_USER_ID, "user_id=%u"},
{OPT_GROUP_ID, "group_id=%u"},
{OPT_DEFAULT_PERMISSIONS, "default_permissions"},
{OPT_ALLOW_OTHER, "allow_other"},
{OPT_MAX_READ, "max_read=%u"},
{OPT_BLKSIZE, "blksize=%u"},
{OPT_ERR, NULL}
};
static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
{
char *p;
memset(d, 0, sizeof(struct fuse_mount_data));
d->max_read = ~0;
d->blksize = 512;
while ((p = strsep(&opt, ",")) != NULL) {
int token;
int value;
substring_t args[MAX_OPT_ARGS];
if (!*p)
continue;
token = match_token(p, tokens, args);
switch (token) {
case OPT_FD:
if (match_int(&args[0], &value))
return 0;
d->fd = value;
d->fd_present = 1;
break;
case OPT_ROOTMODE:
if (match_octal(&args[0], &value))
return 0;
d->rootmode = value;
d->rootmode_present = 1;
break;
case OPT_USER_ID:
if (match_int(&args[0], &value))
return 0;
d->user_id = value;
d->user_id_present = 1;
break;
case OPT_GROUP_ID:
if (match_int(&args[0], &value))
return 0;
d->group_id = value;
d->group_id_present = 1;
break;
case OPT_DEFAULT_PERMISSIONS:
d->flags |= FUSE_DEFAULT_PERMISSIONS;
break;
case OPT_ALLOW_OTHER:
d->flags |= FUSE_ALLOW_OTHER;
break;
case OPT_MAX_READ:
if (match_int(&args[0], &value))
return 0;
d->max_read = value;
break;
case OPT_BLKSIZE:
if (!is_bdev || match_int(&args[0], &value))
return 0;
d->blksize = value;
break;
default:
return 0;
}
}
if (!d->fd_present || !d->rootmode_present ||
!d->user_id_present || !d->group_id_present)
return 0;
return 1;
}
static int fuse_show_options(struct seq_file *m, struct vfsmount *mnt)
{
struct fuse_conn *fc = get_fuse_conn_super(mnt->mnt_sb);
seq_printf(m, ",user_id=%u", fc->user_id);
seq_printf(m, ",group_id=%u", fc->group_id);
if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
seq_puts(m, ",default_permissions");
if (fc->flags & FUSE_ALLOW_OTHER)
seq_puts(m, ",allow_other");
if (fc->max_read != ~0)
seq_printf(m, ",max_read=%u", fc->max_read);
return 0;
}
static struct fuse_conn *new_conn(void)
{
struct fuse_conn *fc;
fc = kzalloc(sizeof(*fc), GFP_KERNEL);
if (fc) {
spin_lock_init(&fc->lock);
mutex_init(&fc->inst_mutex);
atomic_set(&fc->count, 1);
init_waitqueue_head(&fc->waitq);
init_waitqueue_head(&fc->blocked_waitq);
INIT_LIST_HEAD(&fc->pending);
INIT_LIST_HEAD(&fc->processing);
INIT_LIST_HEAD(&fc->io);
INIT_LIST_HEAD(&fc->interrupts);
atomic_set(&fc->num_waiting, 0);
fc->bdi.ra_pages = (VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
fc->bdi.unplug_io_fn = default_unplug_io_fn;
fc->reqctr = 0;
fc->blocked = 1;
get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
}
return fc;
}
void fuse_conn_put(struct fuse_conn *fc)
{
if (atomic_dec_and_test(&fc->count)) {
if (fc->destroy_req)
fuse_request_free(fc->destroy_req);
mutex_destroy(&fc->inst_mutex);
kfree(fc);
}
}
struct fuse_conn *fuse_conn_get(struct fuse_conn *fc)
{
atomic_inc(&fc->count);
return fc;
}
static struct inode *get_root_inode(struct super_block *sb, unsigned mode)
{
struct fuse_attr attr;
memset(&attr, 0, sizeof(attr));
attr.mode = mode;
attr.ino = FUSE_ROOT_ID;
return fuse_iget(sb, 1, 0, &attr);
}
static struct super_operations fuse_super_operations = {
.alloc_inode = fuse_alloc_inode,
.destroy_inode = fuse_destroy_inode,
.read_inode = fuse_read_inode,
.clear_inode = fuse_clear_inode,
.remount_fs = fuse_remount_fs,
.put_super = fuse_put_super,
.umount_begin = fuse_umount_begin,
.statfs = fuse_statfs,
.show_options = fuse_show_options,
};
static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req)
{
struct fuse_init_out *arg = &req->misc.init_out;
if (req->out.h.error || arg->major != FUSE_KERNEL_VERSION)
fc->conn_error = 1;
else {
unsigned long ra_pages;
if (arg->minor >= 6) {
ra_pages = arg->max_readahead / PAGE_CACHE_SIZE;
if (arg->flags & FUSE_ASYNC_READ)
fc->async_read = 1;
if (!(arg->flags & FUSE_POSIX_LOCKS))
fc->no_lock = 1;
} else {
ra_pages = fc->max_read / PAGE_CACHE_SIZE;
fc->no_lock = 1;
}
fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages);
fc->minor = arg->minor;
fc->max_write = arg->minor < 5 ? 4096 : arg->max_write;
fc->conn_init = 1;
}
fuse_put_request(fc, req);
fc->blocked = 0;
wake_up_all(&fc->blocked_waitq);
}
static void fuse_send_init(struct fuse_conn *fc, struct fuse_req *req)
{
struct fuse_init_in *arg = &req->misc.init_in;
arg->major = FUSE_KERNEL_VERSION;
arg->minor = FUSE_KERNEL_MINOR_VERSION;
arg->max_readahead = fc->bdi.ra_pages * PAGE_CACHE_SIZE;
arg->flags |= FUSE_ASYNC_READ | FUSE_POSIX_LOCKS;
req->in.h.opcode = FUSE_INIT;
req->in.numargs = 1;
req->in.args[0].size = sizeof(*arg);
req->in.args[0].value = arg;
req->out.numargs = 1;
/* Variable length arguement used for backward compatibility
with interface version < 7.5. Rest of init_out is zeroed
by do_get_request(), so a short reply is not a problem */
req->out.argvar = 1;
req->out.args[0].size = sizeof(struct fuse_init_out);
req->out.args[0].value = &req->misc.init_out;
req->end = process_init_reply;
request_send_background(fc, req);
}
static u64 conn_id(void)
{
static u64 ctr = 1;
return ctr++;
}
static int fuse_fill_super(struct super_block *sb, void *data, int silent)
{
struct fuse_conn *fc;
struct inode *root;
struct fuse_mount_data d;
struct file *file;
struct dentry *root_dentry;
struct fuse_req *init_req;
int err;
int is_bdev = sb->s_bdev != NULL;
if (sb->s_flags & MS_MANDLOCK)
return -EINVAL;
if (!parse_fuse_opt((char *) data, &d, is_bdev))
return -EINVAL;
if (is_bdev) {
#ifdef CONFIG_BLOCK
if (!sb_set_blocksize(sb, d.blksize))
return -EINVAL;
#endif
} else {
sb->s_blocksize = PAGE_CACHE_SIZE;
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
}
sb->s_magic = FUSE_SUPER_MAGIC;
sb->s_op = &fuse_super_operations;
sb->s_maxbytes = MAX_LFS_FILESIZE;
file = fget(d.fd);
if (!file)
return -EINVAL;
if (file->f_op != &fuse_dev_operations)
return -EINVAL;
fc = new_conn();
if (!fc)
return -ENOMEM;
fc->flags = d.flags;
fc->user_id = d.user_id;
fc->group_id = d.group_id;
fc->max_read = d.max_read;
/* Used by get_root_inode() */
sb->s_fs_info = fc;
err = -ENOMEM;
root = get_root_inode(sb, d.rootmode);
if (!root)
goto err;
root_dentry = d_alloc_root(root);
if (!root_dentry) {
iput(root);
goto err;
}
init_req = fuse_request_alloc();
if (!init_req)
goto err_put_root;
if (is_bdev) {
fc->destroy_req = fuse_request_alloc();
if (!fc->destroy_req)
goto err_put_root;
}
mutex_lock(&fuse_mutex);
err = -EINVAL;
if (file->private_data)
goto err_unlock;
fc->id = conn_id();
err = fuse_ctl_add_conn(fc);
if (err)
goto err_unlock;
list_add_tail(&fc->entry, &fuse_conn_list);
sb->s_root = root_dentry;
fc->connected = 1;
file->private_data = fuse_conn_get(fc);
mutex_unlock(&fuse_mutex);
/*
* atomic_dec_and_test() in fput() provides the necessary
* memory barrier for file->private_data to be visible on all
* CPUs after this
*/
fput(file);
fuse_send_init(fc, init_req);
return 0;
err_unlock:
mutex_unlock(&fuse_mutex);
fuse_request_free(init_req);
err_put_root:
dput(root_dentry);
err:
fput(file);
fuse_conn_put(fc);
return err;
}
static int fuse_get_sb(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *raw_data, struct vfsmount *mnt)
{
return get_sb_nodev(fs_type, flags, raw_data, fuse_fill_super, mnt);
}
static struct file_system_type fuse_fs_type = {
.owner = THIS_MODULE,
.name = "fuse",
.get_sb = fuse_get_sb,
.kill_sb = kill_anon_super,
};
#ifdef CONFIG_BLOCK
static int fuse_get_sb_blk(struct file_system_type *fs_type,
int flags, const char *dev_name,
void *raw_data, struct vfsmount *mnt)
{
return get_sb_bdev(fs_type, flags, dev_name, raw_data, fuse_fill_super,
mnt);
}
static struct file_system_type fuseblk_fs_type = {
.owner = THIS_MODULE,
.name = "fuseblk",
.get_sb = fuse_get_sb_blk,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV,
};
static inline int register_fuseblk(void)
{
return register_filesystem(&fuseblk_fs_type);
}
static inline void unregister_fuseblk(void)
{
unregister_filesystem(&fuseblk_fs_type);
}
#else
static inline int register_fuseblk(void)
{
return 0;
}
static inline void unregister_fuseblk(void)
{
}
#endif
static decl_subsys(fuse, NULL, NULL);
static decl_subsys(connections, NULL, NULL);
static void fuse_inode_init_once(void *foo, struct kmem_cache *cachep,
unsigned long flags)
{
struct inode * inode = foo;
if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
SLAB_CTOR_CONSTRUCTOR)
inode_init_once(inode);
}
static int __init fuse_fs_init(void)
{
int err;
err = register_filesystem(&fuse_fs_type);
if (err)
goto out;
err = register_fuseblk();
if (err)
goto out_unreg;
fuse_inode_cachep = kmem_cache_create("fuse_inode",
sizeof(struct fuse_inode),
0, SLAB_HWCACHE_ALIGN,
fuse_inode_init_once, NULL);
err = -ENOMEM;
if (!fuse_inode_cachep)
goto out_unreg2;
return 0;
out_unreg2:
unregister_fuseblk();
out_unreg:
unregister_filesystem(&fuse_fs_type);
out:
return err;
}
static void fuse_fs_cleanup(void)
{
unregister_filesystem(&fuse_fs_type);
unregister_fuseblk();
kmem_cache_destroy(fuse_inode_cachep);
}
static int fuse_sysfs_init(void)
{
int err;
kset_set_kset_s(&fuse_subsys, fs_subsys);
err = subsystem_register(&fuse_subsys);
if (err)
goto out_err;
kset_set_kset_s(&connections_subsys, fuse_subsys);
err = subsystem_register(&connections_subsys);
if (err)
goto out_fuse_unregister;
return 0;
out_fuse_unregister:
subsystem_unregister(&fuse_subsys);
out_err:
return err;
}
static void fuse_sysfs_cleanup(void)
{
subsystem_unregister(&connections_subsys);
subsystem_unregister(&fuse_subsys);
}
static int __init fuse_init(void)
{
int res;
printk("fuse init (API version %i.%i)\n",
FUSE_KERNEL_VERSION, FUSE_KERNEL_MINOR_VERSION);
INIT_LIST_HEAD(&fuse_conn_list);
res = fuse_fs_init();
if (res)
goto err;
res = fuse_dev_init();
if (res)
goto err_fs_cleanup;
res = fuse_sysfs_init();
if (res)
goto err_dev_cleanup;
res = fuse_ctl_init();
if (res)
goto err_sysfs_cleanup;
return 0;
err_sysfs_cleanup:
fuse_sysfs_cleanup();
err_dev_cleanup:
fuse_dev_cleanup();
err_fs_cleanup:
fuse_fs_cleanup();
err:
return res;
}
static void __exit fuse_exit(void)
{
printk(KERN_DEBUG "fuse exit\n");
fuse_ctl_cleanup();
fuse_sysfs_cleanup();
fuse_fs_cleanup();
fuse_dev_cleanup();
}
module_init(fuse_init);
module_exit(fuse_exit);
