super.c

linux 内核源代码

	if (server->flags & NFS_MOUNT_UNSHARED)
		compare_super = NULL;

	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
	}

	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

	if (!s->s_root) {
		/* initial superblock/root creation */
		nfs_clone_super(s, data->sb);
	}

	mntroot = nfs_get_root(s, data->fh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}
	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
		dput(mntroot);
		error = -ESTALE;
		goto error_splat_super;
	}

	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;

	dprintk("<-- nfs_xdev_get_sb() = 0\n");
	return 0;

out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs_xdev_get_sb() = %d [error]\n", error);
	return error;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs_xdev_get_sb() = %d [splat]\n", error);
	return error;
}

#ifdef CONFIG_NFS_V4

/*
 * Finish setting up a cloned NFS4 superblock
 */
static void nfs4_clone_super(struct super_block *sb,
			    const struct super_block *old_sb)
{
	sb->s_blocksize_bits = old_sb->s_blocksize_bits;
	sb->s_blocksize = old_sb->s_blocksize;
	sb->s_maxbytes = old_sb->s_maxbytes;
	sb->s_time_gran = 1;
	sb->s_op = old_sb->s_op;
 	nfs_initialise_sb(sb);
}

/*
 * Set up an NFS4 superblock
 */
static void nfs4_fill_super(struct super_block *sb)
{
	sb->s_time_gran = 1;
	sb->s_op = &nfs4_sops;
	nfs_initialise_sb(sb);
}

/*
 * Validate NFSv4 mount options
 */
static int nfs4_validate_mount_data(void *options,
				    struct nfs_parsed_mount_data *args,
				    const char *dev_name)
{
	struct nfs4_mount_data *data = (struct nfs4_mount_data *)options;
	char *c;

	memset(args, 0, sizeof(*args));

	if (data == NULL)
		goto out_no_data;

	args->rsize		= NFS_MAX_FILE_IO_SIZE;
	args->wsize		= NFS_MAX_FILE_IO_SIZE;
	args->timeo		= 600;
	args->retrans		= 2;
	args->acregmin		= 3;
	args->acregmax		= 60;
	args->acdirmin		= 30;
	args->acdirmax		= 60;
	args->nfs_server.protocol = XPRT_TRANSPORT_TCP;

	switch (data->version) {
	case 1:
		if (data->host_addrlen != sizeof(args->nfs_server.address))
			goto out_no_address;
		if (copy_from_user(&args->nfs_server.address,
				   data->host_addr,
				   sizeof(args->nfs_server.address)))
			return -EFAULT;
		if (args->nfs_server.address.sin_port == 0)
			args->nfs_server.address.sin_port = htons(NFS_PORT);
		if (!nfs_verify_server_address((struct sockaddr *)
						&args->nfs_server.address))
			goto out_no_address;

		switch (data->auth_flavourlen) {
		case 0:
			args->auth_flavors[0] = RPC_AUTH_UNIX;
			break;
		case 1:
			if (copy_from_user(&args->auth_flavors[0],
					   data->auth_flavours,
					   sizeof(args->auth_flavors[0])))
				return -EFAULT;
			break;
		default:
			goto out_inval_auth;
		}

		c = strndup_user(data->hostname.data, NFS4_MAXNAMLEN);
		if (IS_ERR(c))
			return PTR_ERR(c);
		args->nfs_server.hostname = c;

		c = strndup_user(data->mnt_path.data, NFS4_MAXPATHLEN);
		if (IS_ERR(c))
			return PTR_ERR(c);
		args->nfs_server.export_path = c;
		dfprintk(MOUNT, "NFS: MNTPATH: '%s'\n", c);

		c = strndup_user(data->client_addr.data, 16);
		if (IS_ERR(c))
			return PTR_ERR(c);
		args->client_address = c;

		/*
		 * Translate to nfs_parsed_mount_data, which nfs4_fill_super
		 * can deal with.
		 */

		args->flags	= data->flags & NFS4_MOUNT_FLAGMASK;
		args->rsize	= data->rsize;
		args->wsize	= data->wsize;
		args->timeo	= data->timeo;
		args->retrans	= data->retrans;
		args->acregmin	= data->acregmin;
		args->acregmax	= data->acregmax;
		args->acdirmin	= data->acdirmin;
		args->acdirmax	= data->acdirmax;
		args->nfs_server.protocol = data->proto;

		break;
	default: {
		unsigned int len;

		if (nfs_parse_mount_options((char *)options, args) == 0)
			return -EINVAL;

		if (!nfs_verify_server_address((struct sockaddr *)
						&args->nfs_server.address))
			return -EINVAL;

		switch (args->auth_flavor_len) {
		case 0:
			args->auth_flavors[0] = RPC_AUTH_UNIX;
			break;
		case 1:
			break;
		default:
			goto out_inval_auth;
		}

		/*
		 * Split "dev_name" into "hostname:mntpath".
		 */
		c = strchr(dev_name, ':');
		if (c == NULL)
			return -EINVAL;
		/* while calculating len, pretend ':' is '\0' */
		len = c - dev_name;
		if (len > NFS4_MAXNAMLEN)
			return -ENAMETOOLONG;
		args->nfs_server.hostname = kzalloc(len, GFP_KERNEL);
		if (args->nfs_server.hostname == NULL)
			return -ENOMEM;
		strncpy(args->nfs_server.hostname, dev_name, len - 1);

		c++;			/* step over the ':' */
		len = strlen(c);
		if (len > NFS4_MAXPATHLEN)
			return -ENAMETOOLONG;
		args->nfs_server.export_path = kzalloc(len + 1, GFP_KERNEL);
		if (args->nfs_server.export_path == NULL)
			return -ENOMEM;
		strncpy(args->nfs_server.export_path, c, len);

		dprintk("MNTPATH: %s\n", args->nfs_server.export_path);

		if (args->client_address == NULL)
			goto out_no_client_address;

		break;
		}
	}

	return 0;

out_no_data:
	dfprintk(MOUNT, "NFS4: mount program didn't pass any mount data\n");
	return -EINVAL;

out_inval_auth:
	dfprintk(MOUNT, "NFS4: Invalid number of RPC auth flavours %d\n",
		 data->auth_flavourlen);
	return -EINVAL;

out_no_address:
	dfprintk(MOUNT, "NFS4: mount program didn't pass remote address\n");
	return -EINVAL;

out_no_client_address:
	dfprintk(MOUNT, "NFS4: mount program didn't pass callback address\n");
	return -EINVAL;
}

/*
 * Get the superblock for an NFS4 mountpoint
 */
static int nfs4_get_sb(struct file_system_type *fs_type,
	int flags, const char *dev_name, void *raw_data, struct vfsmount *mnt)
{
	struct nfs_parsed_mount_data data;
	struct super_block *s;
	struct nfs_server *server;
	struct nfs_fh mntfh;
	struct dentry *mntroot;
	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
	struct nfs_sb_mountdata sb_mntdata = {
		.mntflags = flags,
	};
	int error;

	/* Validate the mount data */
	error = nfs4_validate_mount_data(raw_data, &data, dev_name);
	if (error < 0)
		goto out;

	/* Get a volume representation */
	server = nfs4_create_server(&data, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out;
	}
	sb_mntdata.server = server;

	if (server->flags & NFS4_MOUNT_UNSHARED)
		compare_super = NULL;

	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(fs_type, compare_super, nfs_set_super, &sb_mntdata);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_free;
	}

	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

	if (!s->s_root) {
		/* initial superblock/root creation */
		nfs4_fill_super(s);
	}

	mntroot = nfs4_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}

	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;
	error = 0;

out:
	kfree(data.client_address);
	kfree(data.nfs_server.export_path);
	kfree(data.nfs_server.hostname);
	return error;

out_free:
	nfs_free_server(server);
	goto out;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	goto out;
}

static void nfs4_kill_super(struct super_block *sb)
{
	struct nfs_server *server = NFS_SB(sb);

	nfs_return_all_delegations(sb);
	kill_anon_super(sb);

	nfs4_renewd_prepare_shutdown(server);
	nfs_free_server(server);
}

/*
 * Clone an NFS4 server record on xdev traversal (FSID-change)
 */
static int nfs4_xdev_get_sb(struct file_system_type *fs_type, int flags,
			    const char *dev_name, void *raw_data,
			    struct vfsmount *mnt)
{
	struct nfs_clone_mount *data = raw_data;
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
	struct nfs_sb_mountdata sb_mntdata = {
		.mntflags = flags,
	};
	int error;

	dprintk("--> nfs4_xdev_get_sb()\n");

	/* create a new volume representation */
	server = nfs_clone_server(NFS_SB(data->sb), data->fh, data->fattr);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
	}
	sb_mntdata.server = server;

	if (server->flags & NFS4_MOUNT_UNSHARED)
		compare_super = NULL;

	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
	}

	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

	if (!s->s_root) {
		/* initial superblock/root creation */
		nfs4_clone_super(s, data->sb);
	}

	mntroot = nfs4_get_root(s, data->fh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}
	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
		dput(mntroot);
		error = -ESTALE;
		goto error_splat_super;
	}

	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;

	dprintk("<-- nfs4_xdev_get_sb() = 0\n");
	return 0;

out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs4_xdev_get_sb() = %d [error]\n", error);
	return error;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs4_xdev_get_sb() = %d [splat]\n", error);
	return error;
}

/*
 * Create an NFS4 server record on referral traversal
 */
static int nfs4_referral_get_sb(struct file_system_type *fs_type, int flags,
				const char *dev_name, void *raw_data,
				struct vfsmount *mnt)
{
	struct nfs_clone_mount *data = raw_data;
	struct super_block *s;
	struct nfs_server *server;
	struct dentry *mntroot;
	struct nfs_fh mntfh;
	int (*compare_super)(struct super_block *, void *) = nfs_compare_super;
	struct nfs_sb_mountdata sb_mntdata = {
		.mntflags = flags,
	};
	int error;

	dprintk("--> nfs4_referral_get_sb()\n");

	/* create a new volume representation */
	server = nfs4_create_referral_server(data, &mntfh);
	if (IS_ERR(server)) {
		error = PTR_ERR(server);
		goto out_err_noserver;
	}
	sb_mntdata.server = server;

	if (server->flags & NFS4_MOUNT_UNSHARED)
		compare_super = NULL;

	/* Get a superblock - note that we may end up sharing one that already exists */
	s = sget(&nfs_fs_type, compare_super, nfs_set_super, &sb_mntdata);
	if (IS_ERR(s)) {
		error = PTR_ERR(s);
		goto out_err_nosb;
	}

	if (s->s_fs_info != server) {
		nfs_free_server(server);
		server = NULL;
	}

	if (!s->s_root) {
		/* initial superblock/root creation */
		nfs4_fill_super(s);
	}

	mntroot = nfs4_get_root(s, &mntfh);
	if (IS_ERR(mntroot)) {
		error = PTR_ERR(mntroot);
		goto error_splat_super;
	}
	if (mntroot->d_inode->i_op != NFS_SB(s)->nfs_client->rpc_ops->dir_inode_ops) {
		dput(mntroot);
		error = -ESTALE;
		goto error_splat_super;
	}

	s->s_flags |= MS_ACTIVE;
	mnt->mnt_sb = s;
	mnt->mnt_root = mntroot;

	dprintk("<-- nfs4_referral_get_sb() = 0\n");
	return 0;

out_err_nosb:
	nfs_free_server(server);
out_err_noserver:
	dprintk("<-- nfs4_referral_get_sb() = %d [error]\n", error);
	return error;

error_splat_super:
	up_write(&s->s_umount);
	deactivate_super(s);
	dprintk("<-- nfs4_referral_get_sb() = %d [splat]\n", error);
	return error;
}

#endif /* CONFIG_NFS_V4 */