fs: Remove ext3 filesystem driver

The functionality of ext3 is fully supported by ext4 driver. Major
distributions (SUSE, RedHat) already use ext4 driver to handle ext3
filesystems for quite some time. There is some ugliness in mm resulting
from jbd cleaning buffers in a dirty page without cleaning page dirty
bit and also support for buffer bouncing in the block layer when stable
pages are required is there only because of jbd. So let's remove the
ext3 driver. This saves us some 28k lines of duplicated code.

Acked-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt
index b971456..5575539 100644
--- a/Documentation/filesystems/ext2.txt
+++ b/Documentation/filesystems/ext2.txt
@@ -360,8 +360,8 @@
 the time of the crash, then there is no guarantee of consistency for
 the blocks in that transaction so they are discarded (which means any
 filesystem changes they represent are also lost).
-Check Documentation/filesystems/ext3.txt if you want to read more about
-ext3 and journaling.
+Check Documentation/filesystems/ext4.txt if you want to read more about
+ext4 and journaling.
 
 References
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