# SPDX-License-Identifier: GPL-2.0-only config NFSD tristate "NFS server support" depends on INET depends on FILE_LOCKING depends on FSNOTIFY select LOCKD select SUNRPC select EXPORTFS select NFS_ACL_SUPPORT if NFSD_V2_ACL select NFS_ACL_SUPPORT if NFSD_V3_ACL depends on MULTIUSER help Choose Y here if you want to allow other computers to access files residing on this system using Sun's Network File System protocol. To compile the NFS server support as a module, choose M here: the module will be called nfsd. You may choose to use a user-space NFS server instead, in which case you can choose N here. To export local file systems using NFS, you also need to install user space programs which can be found in the Linux nfs-utils package, available from http://linux-nfs.org/. More detail about the Linux NFS server implementation is available via the exports(5) man page. Below you can choose which versions of the NFS protocol are available to clients mounting the NFS server on this system. Support for NFS version 3 (RFC 1813) is always available when CONFIG_NFSD is selected. If unsure, say N. config NFSD_V2 bool "NFS server support for NFS version 2 (DEPRECATED)" depends on NFSD default n help NFSv2 (RFC 1094) was the first publicly-released version of NFS. Unless you are hosting ancient (1990's era) NFS clients, you don't need this. If unsure, say N. config NFSD_V2_ACL bool "NFS server support for the NFSv2 ACL protocol extension" depends on NFSD_V2 config NFSD_V3_ACL bool "NFS server support for the NFSv3 ACL protocol extension" depends on NFSD help Solaris NFS servers support an auxiliary NFSv3 ACL protocol that never became an official part of the NFS version 3 protocol. This protocol extension allows applications on NFS clients to manipulate POSIX Access Control Lists on files residing on NFS servers. NFS servers enforce POSIX ACLs on local files whether this protocol is available or not. This option enables support in your system's NFS server for the NFSv3 ACL protocol extension allowing NFS clients to manipulate POSIX ACLs on files exported by your system's NFS server. NFS clients which support the Solaris NFSv3 ACL protocol can then access and modify ACLs on your NFS server. To store ACLs on your NFS server, you also need to enable ACL- related CONFIG options for your local file systems of choice. If unsure, say N. config NFSD_V4 bool "NFS server support for NFS version 4" depends on NFSD && PROC_FS select FS_POSIX_ACL select RPCSEC_GSS_KRB5 select CRYPTO select CRYPTO_MD5 select CRYPTO_SHA256 select GRACE_PERIOD select NFS_V4_2_SSC_HELPER if NFS_V4_2 help This option enables support in your system's NFS server for version 4 of the NFS protocol (RFC 3530). To export files using NFSv4, you need to install additional user space programs which can be found in the Linux nfs-utils package, available from http://linux-nfs.org/. If unsure, say N. config NFSD_PNFS bool config NFSD_BLOCKLAYOUT bool "NFSv4.1 server support for pNFS block layouts" depends on NFSD_V4 && BLOCK select NFSD_PNFS select EXPORTFS_BLOCK_OPS help This option enables support for the exporting pNFS block layouts in the kernel's NFS server. The pNFS block layout enables NFS clients to directly perform I/O to block devices accessible to both the server and the clients. See RFC 5663 for more details. If unsure, say N. config NFSD_SCSILAYOUT bool "NFSv4.1 server support for pNFS SCSI layouts" depends on NFSD_V4 && BLOCK select NFSD_PNFS select EXPORTFS_BLOCK_OPS help This option enables support for the exporting pNFS SCSI layouts in the kernel's NFS server. The pNFS SCSI layout enables NFS clients to directly perform I/O to SCSI devices accessible to both the server and the clients. See draft-ietf-nfsv4-scsi-layout for more details. If unsure, say N. config NFSD_FLEXFILELAYOUT bool "NFSv4.1 server support for pNFS Flex File layouts" depends on NFSD_V4 select NFSD_PNFS help This option enables support for the exporting pNFS Flex File layouts in the kernel's NFS server. The pNFS Flex File layout enables NFS clients to directly perform I/O to NFSv3 devices accessible to both the server and the clients. See draft-ietf-nfsv4-flex-files for more details. Warning, this server implements the bare minimum functionality to be a flex file server - it is for testing the client, not for use in production. If unsure, say N. config NFSD_V4_2_INTER_SSC bool "NFSv4.2 inter server to server COPY" depends on NFSD_V4 && NFS_V4_2 help This option enables support for NFSv4.2 inter server to server copy where the destination server calls the NFSv4.2 client to read the data to copy from the source server. If unsure, say N. config NFSD_V4_SECURITY_LABEL bool "Provide Security Label support for NFSv4 server" depends on NFSD_V4 && SECURITY help Say Y here if you want enable fine-grained security label attribute support for NFS version 4. Security labels allow security modules like SELinux and Smack to label files to facilitate enforcement of their policies. Without this an NFSv4 mount will have the same label on each file. If you do not wish to enable fine-grained security labels SELinux or Smack policies on NFSv4 files, say N. config NFSD_LEGACY_CLIENT_TRACKING bool "Support legacy NFSv4 client tracking methods (DEPRECATED)" depends on NFSD_V4 default y help The NFSv4 server needs to store a small amount of information on stable storage in order to handle state recovery after reboot. Most modern deployments upcall to a userland daemon for this (nfsdcld), but older NFS servers may store information directly in a recoverydir, or spawn a process directly using a usermodehelper upcall. These legacy client tracking methods have proven to be probelmatic and will be removed in the future. Say Y here if you need support for them in the interim.