From: Chuck Lever Subject: [PATCH 1/5] NFS: Update help text for CONFIG_NFS_FS Date: Mon, 04 Feb 2008 19:04:21 -0500 Message-ID: <20080205000421.18602.44285.stgit@manray.1015granger.net> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Cc: linux-nfs@vger.kernel.org To: bfields@citi.umich.edu Return-path: Received: from flpi195.sbcis.sbc.com ([207.115.20.197]:27742 "EHLO flpi195.prodigy.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757139AbYBEAEX (ORCPT ); Mon, 4 Feb 2008 19:04:23 -0500 Sender: linux-nfs-owner@vger.kernel.org List-ID: Refresh the help text for Kconfig items related to the NFS client. Remove obsolete URLs, and make the language consistent among the options. Also move the ROOT_NFS config option next to the options related to the NFS client. Signed-off-by: Chuck Lever --- fs/Kconfig | 136 ++++++++++++++++++++++++++++++------------------------------ 1 files changed, 69 insertions(+), 67 deletions(-) diff --git a/fs/Kconfig b/fs/Kconfig index 987b5d7..5c7f6ee 100644 --- a/fs/Kconfig +++ b/fs/Kconfig @@ -1517,10 +1517,6 @@ config UFS_FS The recently released UFS2 variant (used in FreeBSD 5.x) is READ-ONLY supported. - If you only intend to mount files from some other Unix over the - network using NFS, you don't need the UFS file system support (but - you need NFS file system support obviously). - Note that this option is generally not needed for floppies, since a good portable way to transport files and directories between unixes (and even other operating systems) is given by the tar program ("man @@ -1560,6 +1556,7 @@ menuconfig NETWORK_FILESYSTEMS Say Y here to get to see options for network filesystems and filesystem-related networking code, such as NFS daemon and RPCSEC security modules. + This option alone does not add any kernel code. If you say N, all options in this submenu will be skipped and @@ -1574,44 +1571,35 @@ config NFS_FS select SUNRPC select NFS_ACL_SUPPORT if NFS_V3_ACL help - If you are connected to some other (usually local) Unix computer - (using SLIP, PLIP, PPP or Ethernet) and want to mount files residing - on that computer (the NFS server) using the Network File Sharing - protocol, say Y. "Mounting files" means that the client can access - the files with usual UNIX commands as if they were sitting on the - client's hard disk. For this to work, the server must run the - programs nfsd and mountd (but does not need to have NFS file system - support enabled in its kernel). NFS is explained in the Network - Administrator's Guide, available from - , on its man page: "man - nfs", and in the NFS-HOWTO. - - A superior but less widely used alternative to NFS is provided by - the Coda file system; see "Coda file system support" below. + Say Y here if you want to access files residing on other computers + using the internet standard Network File System protocol. To + compile this file system support as a module, choose M here: the + module will be called nfs. - If you say Y here, you should have said Y to TCP/IP networking also. - This option would enlarge your kernel by about 27 KB. + To mount file systems exported by NFS servers, you also need to + install the user space mount.nfs command which can be found in + the Linux nfs-utils package, available from http://linux-nfs.org/. + Information about using the mount command is available in the + mount(8) man page. More detail about the Linux NFS client + implementation is available via the nfs(5) man page. - To compile this file system support as a module, choose M here: the - module will be called nfs. + Below you can select which versions of the NFS protocol are + available in the kernel to mount NFS servers. Support for NFS + version 2 (RFC 1094) is always available when NFS_FS is selected. - If you are configuring a diskless machine which will mount its root - file system over NFS at boot time, say Y here and to "Kernel - level IP autoconfiguration" above and to "Root file system on NFS" - below. You cannot compile this driver as a module in this case. - There are two packages designed for booting diskless machines over - the net: netboot, available from - , and Etherboot, - available from . + To configure a system which mounts its root file system via NFS at + boot time, say Y here, select "Kernel level IP autoconfiguration" + in the NETWORK menu, and select "Root file system on NFS" below. + You cannot compile this driver as a module in this case. - If you don't know what all this is about, say N. + If unsure, say N. config NFS_V3 bool "Provide NFSv3 client support" depends on NFS_FS help - Say Y here if you want your NFS client to be able to speak version - 3 of the NFS protocol. + This option enables support for version 3 of the NFS protocol + (RFC 1813) in the kernel's NFS client. If unsure, say Y. @@ -1619,9 +1607,21 @@ config NFS_V3_ACL bool "Provide client support for the NFSv3 ACL protocol extension" depends on NFS_V3 help - Implement the NFSv3 ACL protocol extension for manipulating POSIX - Access Control Lists. The server should also be compiled with - the NFSv3 ACL protocol extension; see the CONFIG_NFSD_V3_ACL option. + Some NFS servers support an auxiliary NFSv3 ACL protocol that + Sun added to Solaris but never became an official part of the + NFS version 3 protocol. This nonstandard side-band protocol + allows applications on NFS clients to manipulate POSIX Access + Control Lists on files residing on NFS servers. NFS servers + enforce ACLs on local files whether this protocol is available + or not. + + Say Y here if your NFS server supports the Solaris NFSv3 ACL + protocol and you want your NFS client to allow applications to + access and modify ACLs on files on the server. + + Some NFS servers don't support the Solaris NFSv3 ACL protocol. + You can say N here or specify the "noacl" mount option to prevent + your NFS client from trying to use the NFSv3 ACL protocol. If unsure, say N. @@ -1630,38 +1630,54 @@ config NFS_V4 depends on NFS_FS && EXPERIMENTAL select RPCSEC_GSS_KRB5 help - Say Y here if you want your NFS client to be able to speak the newer - version 4 of the NFS protocol. + This option enables support for version 4 of the NFS protocol + (RFC 3530) in the kernel's NFS client. - Note: Requires auxiliary userspace daemons which may be found on - http://www.citi.umich.edu/projects/nfsv4/ + To mount NFS servers using NFSv4, you also need to install user + space programs which can be found in the Linux nfs-utils package, + available from http://linux-nfs.org/. If unsure, say N. config NFS_DIRECTIO bool "Allow direct I/O on NFS files" depends on NFS_FS + default N help - This option enables applications to perform uncached I/O on files - in NFS file systems using the O_DIRECT open() flag. When O_DIRECT - is set for a file, its data is not cached in the system's page - cache. Data is moved to and from user-level application buffers - directly. Unlike local disk-based file systems, NFS O_DIRECT has - no alignment restrictions. + This option enables support for uncached I/O on files accessed + via an NFS mount point. Applications request direct I/O by + setting the O_DIRECT flag when opening a file. + + When direct I/O is requested, the NFS client moves data to and + from user-level application buffers directly to NFS servers. + Direct I/O on NFS files does not suffer from any I/O or buffer + alignment restrictions, as does direct I/O on files that reside + in local file systems. + + For details, see the open(2) man page. Unless your program is designed to use O_DIRECT properly, you are - much better off allowing the NFS client to manage data caching for - you. Misusing O_DIRECT can cause poor server performance or network - storms. This kernel build option defaults OFF to avoid exposing + better off allowing the NFS client to manage data caching for you. + Misusing O_DIRECT can cause poor server performance or network + storms. This kernel build option defaults to N to avoid exposing system administrators unwittingly to a potentially hazardous feature. - For more details on NFS O_DIRECT, see fs/nfs/direct.c. - - If unsure, say N. This reduces the size of the NFS client, and - causes open() to return EINVAL if a file residing in NFS is + If unsure, say N. This reduces the size of the kernel NFS client, + and causes open(2) to return EINVAL if a file residing in NFS is opened with the O_DIRECT flag. +config ROOT_NFS + bool "Root file system on NFS" + depends on NFS_FS=y && IP_PNP + help + If you want your system to mount its root file system via NFS, say + Y here. This is common practice for managing systems without + local permanent storage. Read + for details. + + Most people say N here. + config NFSD tristate "NFS server support" depends on INET @@ -1738,20 +1754,6 @@ config NFSD_TCP TCP connections usually perform better than the default UDP when the network is lossy or congested. If unsure, say Y. -config ROOT_NFS - bool "Root file system on NFS" - depends on NFS_FS=y && IP_PNP - help - If you want your Linux box to mount its whole root file system (the - one containing the directory /) from some other computer over the - net via NFS (presumably because your box doesn't have a hard disk), - say Y. Read for details. It is - likely that in this case, you also want to say Y to "Kernel level IP - autoconfiguration" so that your box can discover its network address - at boot time. - - Most people say N here. - config LOCKD tristate