2008-10-21 02:28:45 +08:00
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config EXT4_FS
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tristate "The Extended 4 (ext4) filesystem"
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select JBD2
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select CRC16
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help
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This is the next generation of the ext3 filesystem.
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Unlike the change from ext2 filesystem to ext3 filesystem,
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the on-disk format of ext4 is not forwards compatible with
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ext3; it is based on extent maps and it supports 48-bit
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physical block numbers. The ext4 filesystem also supports delayed
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allocation, persistent preallocation, high resolution time stamps,
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and a number of other features to improve performance and speed
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up fsck time. For more information, please see the web pages at
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http://ext4.wiki.kernel.org.
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The ext4 filesystem will support mounting an ext3
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filesystem; while there will be some performance gains from
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the delayed allocation and inode table readahead, the best
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performance gains will require enabling ext4 features in the
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2009-01-26 18:12:25 +08:00
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filesystem, or formatting a new filesystem as an ext4
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2008-10-21 02:28:45 +08:00
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filesystem initially.
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To compile this file system support as a module, choose M here. The
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module will be called ext4.
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If unsure, say N.
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config EXT4DEV_COMPAT
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bool "Enable ext4dev compatibility"
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depends on EXT4_FS
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help
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Starting with 2.6.28, the name of the ext4 filesystem was
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renamed from ext4dev to ext4. Unfortunately there are some
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legacy userspace programs (such as klibc's fstype) have
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"ext4dev" hardcoded.
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To enable backwards compatibility so that systems that are
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still expecting to mount ext4 filesystems using ext4dev,
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chose Y here. This feature will go away by 2.6.31, so
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please arrange to get your userspace programs fixed!
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config EXT4_FS_XATTR
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bool "Ext4 extended attributes"
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depends on EXT4_FS
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default y
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help
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Extended attributes are name:value pairs associated with inodes by
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the kernel or by users (see the attr(5) manual page, or visit
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<http://acl.bestbits.at/> for details).
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If unsure, say N.
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You need this for POSIX ACL support on ext4.
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config EXT4_FS_POSIX_ACL
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bool "Ext4 POSIX Access Control Lists"
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depends on EXT4_FS_XATTR
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select FS_POSIX_ACL
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help
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POSIX Access Control Lists (ACLs) support permissions for users and
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groups beyond the owner/group/world scheme.
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To learn more about Access Control Lists, visit the POSIX ACLs for
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Linux website <http://acl.bestbits.at/>.
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If you don't know what Access Control Lists are, say N
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config EXT4_FS_SECURITY
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bool "Ext4 Security Labels"
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depends on EXT4_FS_XATTR
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help
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Security labels support alternative access control models
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implemented by security modules like SELinux. This option
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enables an extended attribute handler for file security
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labels in the ext4 filesystem.
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If you are not using a security module that requires using
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extended attributes for file security labels, say N.
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