kernel-ark/fs/xfs/Kconfig
David Howells 9361401eb7 [PATCH] BLOCK: Make it possible to disable the block layer [try #6]
Make it possible to disable the block layer.  Not all embedded devices require
it, some can make do with just JFFS2, NFS, ramfs, etc - none of which require
the block layer to be present.

This patch does the following:

 (*) Introduces CONFIG_BLOCK to disable the block layer, buffering and blockdev
     support.

 (*) Adds dependencies on CONFIG_BLOCK to any configuration item that controls
     an item that uses the block layer.  This includes:

     (*) Block I/O tracing.

     (*) Disk partition code.

     (*) All filesystems that are block based, eg: Ext3, ReiserFS, ISOFS.

     (*) The SCSI layer.  As far as I can tell, even SCSI chardevs use the
     	 block layer to do scheduling.  Some drivers that use SCSI facilities -
     	 such as USB storage - end up disabled indirectly from this.

     (*) Various block-based device drivers, such as IDE and the old CDROM
     	 drivers.

     (*) MTD blockdev handling and FTL.

     (*) JFFS - which uses set_bdev_super(), something it could avoid doing by
     	 taking a leaf out of JFFS2's book.

 (*) Makes most of the contents of linux/blkdev.h, linux/buffer_head.h and
     linux/elevator.h contingent on CONFIG_BLOCK being set.  sector_div() is,
     however, still used in places, and so is still available.

 (*) Also made contingent are the contents of linux/mpage.h, linux/genhd.h and
     parts of linux/fs.h.

 (*) Makes a number of files in fs/ contingent on CONFIG_BLOCK.

 (*) Makes mm/bounce.c (bounce buffering) contingent on CONFIG_BLOCK.

 (*) set_page_dirty() doesn't call __set_page_dirty_buffers() if CONFIG_BLOCK
     is not enabled.

 (*) fs/no-block.c is created to hold out-of-line stubs and things that are
     required when CONFIG_BLOCK is not set:

     (*) Default blockdev file operations (to give error ENODEV on opening).

 (*) Makes some /proc changes:

     (*) /proc/devices does not list any blockdevs.

     (*) /proc/diskstats and /proc/partitions are contingent on CONFIG_BLOCK.

 (*) Makes some compat ioctl handling contingent on CONFIG_BLOCK.

 (*) If CONFIG_BLOCK is not defined, makes sys_quotactl() return -ENODEV if
     given command other than Q_SYNC or if a special device is specified.

 (*) In init/do_mounts.c, no reference is made to the blockdev routines if
     CONFIG_BLOCK is not defined.  This does not prohibit NFS roots or JFFS2.

 (*) The bdflush, ioprio_set and ioprio_get syscalls can now be absent (return
     error ENOSYS by way of cond_syscall if so).

 (*) The seclvl_bd_claim() and seclvl_bd_release() security calls do nothing if
     CONFIG_BLOCK is not set, since they can't then happen.

Signed-Off-By: David Howells <dhowells@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2006-09-30 20:52:31 +02:00

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config XFS_FS
tristate "XFS filesystem support"
depends on BLOCK
help
XFS is a high performance journaling filesystem which originated
on the SGI IRIX platform. It is completely multi-threaded, can
support large files and large filesystems, extended attributes,
variable block sizes, is extent based, and makes extensive use of
Btrees (directories, extents, free space) to aid both performance
and scalability.
Refer to the documentation at <http://oss.sgi.com/projects/xfs/>
for complete details. This implementation is on-disk compatible
with the IRIX version of XFS.
To compile this file system support as a module, choose M here: the
module will be called xfs. Be aware, however, that if the file
system of your root partition is compiled as a module, you'll need
to use an initial ramdisk (initrd) to boot.
config XFS_QUOTA
bool "XFS Quota support"
depends on XFS_FS
help
If you say Y here, you will be able to set limits for disk usage on
a per user and/or a per group basis under XFS. XFS considers quota
information as filesystem metadata and uses journaling to provide a
higher level guarantee of consistency. The on-disk data format for
quota is also compatible with the IRIX version of XFS, allowing a
filesystem to be migrated between Linux and IRIX without any need
for conversion.
If unsure, say N. More comprehensive documentation can be found in
README.quota in the xfsprogs package. XFS quota can be used either
with or without the generic quota support enabled (CONFIG_QUOTA) -
they are completely independent subsystems.
config XFS_SECURITY
bool "XFS Security Label support"
depends on XFS_FS
help
Security labels support alternative access control models
implemented by security modules like SELinux. This option
enables an extended attribute namespace for inode security
labels in the XFS filesystem.
If you are not using a security module that requires using
extended attributes for inode security labels, say N.
config XFS_POSIX_ACL
bool "XFS POSIX ACL support"
depends on XFS_FS
help
POSIX Access Control Lists (ACLs) support permissions for users and
groups beyond the owner/group/world scheme.
To learn more about Access Control Lists, visit the POSIX ACLs for
Linux website <http://acl.bestbits.at/>.
If you don't know what Access Control Lists are, say N.
config XFS_RT
bool "XFS Realtime subvolume support"
depends on XFS_FS
help
If you say Y here you will be able to mount and use XFS filesystems
which contain a realtime subvolume. The realtime subvolume is a
separate area of disk space where only file data is stored. It was
originally designed to provide deterministic data rates suitable
for media streaming applications, but is also useful as a generic
mechanism for ensuring data and metadata/log I/Os are completely
separated. Regular file I/Os are isolated to a separate device
from all other requests, and this can be done quite transparently
to applications via the inherit-realtime directory inode flag.
See the xfs man page in section 5 for additional information.
If unsure, say N.