[PATCH] jbd2: enable building of jbd2 and have ext4 use it rather than jbd
Reworked from a patch by Mingming Cao and Randy Dunlap
Signed-off-By: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/Kconfig b/fs/Kconfig
index ac9ba1c..db4d133 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -143,24 +143,24 @@
config EXT4DEV_FS
tristate "Ext4dev/ext4 extended fs support development (EXPERIMENTAL)"
depends on EXPERIMENTAL
- select JBD
- help
+ select JBD2
+ help
Ext4dev is a predecessor filesystem of the next generation
extended fs ext4, based on ext3 filesystem code. It will be
renamed ext4 fs later, once ext4dev is mature and stabilized.
- Unlike the change from ext2 filesystem to ext3 filesystem,
- the on-disk format of ext4dev is not the same as ext3 any more:
+ Unlike the change from ext2 filesystem to ext3 filesystem,
+ the on-disk format of ext4dev is not the same as ext3 any more:
it is based on extent maps and it supports 48-bit physical block
- numbers. These combined on-disk format changes will allow
+ numbers. These combined on-disk format changes will allow
ext4dev/ext4 to handle more than 16 TB filesystem volumes --
a hard limit that ext3 cannot overcome without changing the
- on-disk format.
+ on-disk format.
Other than extent maps and 48-bit block numbers, ext4dev also is
- likely to have other new features such as persistent preallocation,
+ likely to have other new features such as persistent preallocation,
high resolution time stamps, and larger file support etc. These
- features will be added to ext4dev gradually.
+ features will be added to ext4dev gradually.
To compile this file system support as a module, choose M here. The
module will be called ext4dev. Be aware, however, that the filesystem
@@ -239,6 +239,38 @@
generated. To turn debugging off again, do
"echo 0 > /proc/sys/fs/jbd-debug".
+config JBD2
+ tristate
+ help
+ This is a generic journaling layer for block devices that support
+ both 32-bit and 64-bit block numbers. It is currently used by
+ the ext4dev/ext4 filesystem, but it could also be used to add
+ journal support to other file systems or block devices such
+ as RAID or LVM.
+
+ If you are using ext4dev/ext4, you need to say Y here. If you are not
+ using ext4dev/ext4 then you will probably want to say N.
+
+ To compile this device as a module, choose M here. The module will be
+ called jbd2. If you are compiling ext4dev/ext4 into the kernel,
+ you cannot compile this code as a module.
+
+config JBD2_DEBUG
+ bool "JBD2 (ext4dev/ext4) debugging support"
+ depends on JBD2
+ help
+ If you are using the ext4dev/ext4 journaled file system (or
+ potentially any other filesystem/device using JBD2), this option
+ allows you to enable debugging output while the system is running,
+ in order to help track down any problems you are having.
+ By default, the debugging output will be turned off.
+
+ If you select Y here, then you will be able to turn on debugging
+ with "echo N > /proc/sys/fs/jbd2-debug", where N is a number between
+ 1 and 5. The higher the number, the more debugging output is
+ generated. To turn debugging off again, do
+ "echo 0 > /proc/sys/fs/jbd2-debug".
+
config FS_MBCACHE
# Meta block cache for Extended Attributes (ext2/ext3/ext4)
tristate