inode.c

讲述linux的初始化过程

		case 'i':
			strncpy(mnt->codepage.local_name, optarg, 
				SMB_NLS_MAXNAMELEN);
			break;
		case 'c':
			strncpy(mnt->codepage.remote_name, optarg,
				SMB_NLS_MAXNAMELEN);
			break;
		default:
			printk ("smbfs: Unrecognized mount option %s\n",
				optopt);
			return -1;
		}
	}
	mnt->flags = flags;
	return c;
}


static void
smb_put_super(struct super_block *sb)
{
	struct smb_sb_info *server = &(sb->u.smbfs_sb);

	if (server->sock_file) {
		smb_proc_disconnect(server);
		smb_dont_catch_keepalive(server);
		fput(server->sock_file);
	}

	if (server->conn_pid)
	       kill_proc(server->conn_pid, SIGTERM, 1);

	kfree(server->mnt);
	kfree(sb->u.smbfs_sb.temp_buf);
	if (server->packet)
		smb_vfree(server->packet);

	if(sb->u.smbfs_sb.remote_nls) {
		unload_nls(sb->u.smbfs_sb.remote_nls);
		sb->u.smbfs_sb.remote_nls = NULL;
	}
	if(sb->u.smbfs_sb.local_nls) {
		unload_nls(sb->u.smbfs_sb.local_nls);
		sb->u.smbfs_sb.local_nls = NULL;
	}
}

struct super_block *
smb_read_super(struct super_block *sb, void *raw_data, int silent)
{
	struct smb_mount_data_kernel *mnt;
	struct smb_mount_data *oldmnt;
	struct inode *root_inode;
	struct smb_fattr root;
	int ver;

	if (!raw_data)
		goto out_no_data;

	oldmnt = (struct smb_mount_data *) raw_data;
	ver = oldmnt->version;
	if (ver != SMB_MOUNT_OLDVERSION && cpu_to_be32(ver) != SMB_MOUNT_ASCII)
		goto out_wrong_data;

	sb->s_blocksize = 1024;	/* Eh...  Is this correct? */
	sb->s_blocksize_bits = 10;
	sb->s_magic = SMB_SUPER_MAGIC;
	sb->s_flags = 0;
	sb->s_op = &smb_sops;

	sb->u.smbfs_sb.mnt = NULL;
	sb->u.smbfs_sb.sock_file = NULL;
	init_MUTEX(&sb->u.smbfs_sb.sem);
	init_waitqueue_head(&sb->u.smbfs_sb.wait);
	sb->u.smbfs_sb.conn_pid = 0;
	sb->u.smbfs_sb.state = CONN_INVALID; /* no connection yet */
	sb->u.smbfs_sb.generation = 0;
	sb->u.smbfs_sb.packet_size = smb_round_length(SMB_INITIAL_PACKET_SIZE);	
	sb->u.smbfs_sb.packet = smb_vmalloc(sb->u.smbfs_sb.packet_size);
	if (!sb->u.smbfs_sb.packet)
		goto out_no_mem;

	/* Allocate the global temp buffer */
	sb->u.smbfs_sb.temp_buf = kmalloc(2*SMB_MAXPATHLEN + 20, GFP_KERNEL);
	if (!sb->u.smbfs_sb.temp_buf)
		goto out_no_temp;

	/* Setup NLS stuff */
	sb->u.smbfs_sb.remote_nls = NULL;
	sb->u.smbfs_sb.local_nls = NULL;
	sb->u.smbfs_sb.name_buf = sb->u.smbfs_sb.temp_buf + SMB_MAXPATHLEN + 20;

	/* Allocate the mount data structure */
	/* FIXME: merge this with the other malloc and get a whole page? */
	mnt = kmalloc(sizeof(struct smb_mount_data_kernel), GFP_KERNEL);
	if (!mnt)
		goto out_no_mount;
	sb->u.smbfs_sb.mnt = mnt;

	memset(mnt, 0, sizeof(struct smb_mount_data_kernel));
	strncpy(mnt->codepage.local_name, CONFIG_NLS_DEFAULT,
		SMB_NLS_MAXNAMELEN);
	strncpy(mnt->codepage.remote_name, SMB_NLS_REMOTE,
		SMB_NLS_MAXNAMELEN);

	if (ver == SMB_MOUNT_OLDVERSION) {
		mnt->version = oldmnt->version;

		/* FIXME: is this enough to convert uid/gid's ? */
		mnt->mounted_uid = oldmnt->mounted_uid;
		mnt->uid = oldmnt->uid;
		mnt->gid = oldmnt->gid;

		mnt->file_mode =
			oldmnt->file_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
		mnt->dir_mode =
			oldmnt->dir_mode & (S_IRWXU | S_IRWXG | S_IRWXO);
		mnt->file_mode |= S_IFREG;
		mnt->dir_mode  |= S_IFDIR;

		mnt->flags = (oldmnt->file_mode >> 9);
	} else {
		if (parse_options(mnt, raw_data))
			goto out_bad_option;

		mnt->mounted_uid = current->uid;
	}
	smb_setcodepage(&sb->u.smbfs_sb, &mnt->codepage);
	if (!sb->u.smbfs_sb.convert)
		PARANOIA("convert funcptr was NULL!\n");

	/*
	 * Display the enabled options
	 * Note: smb_proc_getattr uses these in 2.4 (but was changed in 2.2)
	 */
	if (mnt->flags & SMB_MOUNT_OLDATTR)
		printk("SMBFS: Using core getattr (Win 95 speedup)\n");
	else if (mnt->flags & SMB_MOUNT_DIRATTR)
		printk("SMBFS: Using dir ff getattr\n");

	/*
	 * Keep the super block locked while we get the root inode.
	 */
	smb_init_root_dirent(&(sb->u.smbfs_sb), &root);
	root_inode = smb_iget(sb, &root);
	if (!root_inode)
		goto out_no_root;

	sb->s_root = d_alloc_root(root_inode);
	if (!sb->s_root)
		goto out_no_root;

	return sb;

out_no_root:
	iput(root_inode);
out_bad_option:
	kfree(sb->u.smbfs_sb.mnt);
out_no_mount:
	kfree(sb->u.smbfs_sb.temp_buf);
out_no_temp:
	smb_vfree(sb->u.smbfs_sb.packet);
out_no_mem:
	if (!sb->u.smbfs_sb.mnt)
		printk(KERN_ERR "smb_read_super: allocation failure\n");
	goto out_fail;
out_wrong_data:
	printk(KERN_ERR "smbfs: mount_data version %d is not supported\n", ver);
	goto out_fail;
out_no_data:
	printk(KERN_ERR "smb_read_super: missing data argument\n");
out_fail:
	return NULL;
}

static int
smb_statfs(struct super_block *sb, struct statfs *buf)
{
	smb_proc_dskattr(sb, buf);

	buf->f_type = SMB_SUPER_MAGIC;
	buf->f_namelen = SMB_MAXPATHLEN;
	return 0;
}

int
smb_notify_change(struct dentry *dentry, struct iattr *attr)
{
	struct inode *inode = dentry->d_inode;
	struct smb_sb_info *server = server_from_dentry(dentry);
	unsigned int mask = (S_IFREG | S_IFDIR | S_IRWXU | S_IRWXG | S_IRWXO);
	int error, changed, refresh = 0;
	struct smb_fattr fattr;

	error = smb_revalidate_inode(dentry);
	if (error)
		goto out;

	if ((error = inode_change_ok(inode, attr)) < 0)
		goto out;

	error = -EPERM;
	if ((attr->ia_valid & ATTR_UID) && (attr->ia_uid != server->mnt->uid))
		goto out;

	if ((attr->ia_valid & ATTR_GID) && (attr->ia_uid != server->mnt->gid))
		goto out;

	if ((attr->ia_valid & ATTR_MODE) && (attr->ia_mode & ~mask))
		goto out;

	if ((attr->ia_valid & ATTR_SIZE) != 0)
	{
		VERBOSE("changing %s/%s, old size=%ld, new size=%ld\n",
			DENTRY_PATH(dentry),
			(long) inode->i_size, (long) attr->ia_size);
		error = smb_open(dentry, O_WRONLY);
		if (error)
			goto out;
		error = smb_proc_trunc(server, inode->u.smbfs_i.fileid,
					 attr->ia_size);
		if (error)
			goto out;
		vmtruncate(inode, attr->ia_size);
		refresh = 1;
	}

	/*
	 * Initialize the fattr and check for changed fields.
	 * Note: CTIME under SMB is creation time rather than
	 * change time, so we don't attempt to change it.
	 */
	smb_get_inode_attr(inode, &fattr);

	changed = 0;
	if ((attr->ia_valid & ATTR_MTIME) != 0)
	{
		fattr.f_mtime = attr->ia_mtime;
		changed = 1;
	}
	if ((attr->ia_valid & ATTR_ATIME) != 0)
	{
		fattr.f_atime = attr->ia_atime;
		/* Earlier protocols don't have an access time */
		if (server->opt.protocol >= SMB_PROTOCOL_LANMAN2)
			changed = 1;
	}
	if (changed)
	{
		error = smb_proc_settime(dentry, &fattr);
		if (error)
			goto out;
		refresh = 1;
	}

	/*
	 * Check for mode changes ... we're extremely limited in
	 * what can be set for SMB servers: just the read-only bit.
	 */
	if ((attr->ia_valid & ATTR_MODE) != 0)
	{
		VERBOSE("%s/%s mode change, old=%x, new=%x\n",
			DENTRY_PATH(dentry), fattr.f_mode, attr->ia_mode);
		changed = 0;
		if (attr->ia_mode & S_IWUSR)
		{
			if (fattr.attr & aRONLY)
			{
				fattr.attr &= ~aRONLY;
				changed = 1;
			}
		} else {
			if (!(fattr.attr & aRONLY))
			{
				fattr.attr |= aRONLY;
				changed = 1;
			}
		}
		if (changed)
		{
			error = smb_proc_setattr(dentry, &fattr);
			if (error)
				goto out;
			refresh = 1;
		}
	}
	error = 0;

out:
	if (refresh)
		smb_refresh_inode(dentry);
	return error;
}

#ifdef DEBUG_SMB_MALLOC
int smb_malloced;
int smb_current_kmalloced;
int smb_current_vmalloced;
#endif

static DECLARE_FSTYPE( smb_fs_type, "smbfs", smb_read_super, 0);

static int __init init_smb_fs(void)
{
	DEBUG1("registering ...\n");

#ifdef DEBUG_SMB_MALLOC
	smb_malloced = 0;
	smb_current_kmalloced = 0;
	smb_current_vmalloced = 0;
#endif

	return register_filesystem(&smb_fs_type);
}

static void __exit exit_smb_fs(void)
{
	DEBUG1("unregistering ...\n");
	unregister_filesystem(&smb_fs_type);
#ifdef DEBUG_SMB_MALLOC
	printk(KERN_DEBUG "smb_malloced: %d\n", smb_malloced);
	printk(KERN_DEBUG "smb_current_kmalloced: %d\n",smb_current_kmalloced);
	printk(KERN_DEBUG "smb_current_vmalloced: %d\n",smb_current_vmalloced);
#endif
}

EXPORT_NO_SYMBOLS;

module_init(init_smb_fs)
module_exit(exit_smb_fs)