mirror of
https://github.com/torvalds/linux.git
synced 2024-11-18 10:01:43 +00:00
6d41807614
The old description for this configuration option was perhaps not completely balanced in terms of describing the tradeoffs of using a default of data=writeback vs. data=ordered. Despite the fact that old description very strongly recomended disabling this feature, all of the major distributions have elected to preserve the existing 'legacy' default, which is a strong hint that it perhaps wasn't telling the whole story. This revised description has been vetted by a number of ext3 developers as being better at informing the user about the tradeoffs of enabling or disabling this configuration feature. Cc: linux-ext4@vger.kernel.org Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Jan Kara <jack@suse.cz>
89 lines
3.4 KiB
Plaintext
89 lines
3.4 KiB
Plaintext
config EXT3_FS
|
|
tristate "Ext3 journalling file system support"
|
|
select JBD
|
|
help
|
|
This is the journalling version of the Second extended file system
|
|
(often called ext3), the de facto standard Linux file system
|
|
(method to organize files on a storage device) for hard disks.
|
|
|
|
The journalling code included in this driver means you do not have
|
|
to run e2fsck (file system checker) on your file systems after a
|
|
crash. The journal keeps track of any changes that were being made
|
|
at the time the system crashed, and can ensure that your file system
|
|
is consistent without the need for a lengthy check.
|
|
|
|
Other than adding the journal to the file system, the on-disk format
|
|
of ext3 is identical to ext2. It is possible to freely switch
|
|
between using the ext3 driver and the ext2 driver, as long as the
|
|
file system has been cleanly unmounted, or e2fsck is run on the file
|
|
system.
|
|
|
|
To add a journal on an existing ext2 file system or change the
|
|
behavior of ext3 file systems, you can use the tune2fs utility ("man
|
|
tune2fs"). To modify attributes of files and directories on ext3
|
|
file systems, use chattr ("man chattr"). You need to be using
|
|
e2fsprogs version 1.20 or later in order to create ext3 journals
|
|
(available at <http://sourceforge.net/projects/e2fsprogs/>).
|
|
|
|
To compile this file system support as a module, choose M here: the
|
|
module will be called ext3.
|
|
|
|
config EXT3_DEFAULTS_TO_ORDERED
|
|
bool "Default to 'data=ordered' in ext3"
|
|
depends on EXT3_FS
|
|
help
|
|
The journal mode options for ext3 have different tradeoffs
|
|
between when data is guaranteed to be on disk and
|
|
performance. The use of "data=writeback" can cause
|
|
unwritten data to appear in files after an system crash or
|
|
power failure, which can be a security issue. However,
|
|
"data=ordered" mode can also result in major performance
|
|
problems, including seconds-long delays before an fsync()
|
|
call returns. For details, see:
|
|
|
|
http://ext4.wiki.kernel.org/index.php/Ext3_data_mode_tradeoffs
|
|
|
|
If you have been historically happy with ext3's performance,
|
|
data=ordered mode will be a safe choice and you should
|
|
answer 'y' here. If you understand the reliability and data
|
|
privacy issues of data=writeback and are willing to make
|
|
that trade off, answer 'n'.
|
|
|
|
config EXT3_FS_XATTR
|
|
bool "Ext3 extended attributes"
|
|
depends on EXT3_FS
|
|
default y
|
|
help
|
|
Extended attributes are name:value pairs associated with inodes by
|
|
the kernel or by users (see the attr(5) manual page, or visit
|
|
<http://acl.bestbits.at/> for details).
|
|
|
|
If unsure, say N.
|
|
|
|
You need this for POSIX ACL support on ext3.
|
|
|
|
config EXT3_FS_POSIX_ACL
|
|
bool "Ext3 POSIX Access Control Lists"
|
|
depends on EXT3_FS_XATTR
|
|
select FS_POSIX_ACL
|
|
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 EXT3_FS_SECURITY
|
|
bool "Ext3 Security Labels"
|
|
depends on EXT3_FS_XATTR
|
|
help
|
|
Security labels support alternative access control models
|
|
implemented by security modules like SELinux. This option
|
|
enables an extended attribute handler for file security
|
|
labels in the ext3 filesystem.
|
|
|
|
If you are not using a security module that requires using
|
|
extended attributes for file security labels, say N.
|