Documentation: fix description of ext4's block_validity mount option

Fix ext4 documentation according to commit 45f1a9c3f63d
("ext4: enable block_validity by default")

Also fix some typos.

[ Further documentation cleanups by tytso ]

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 6c0108eb01372be3c879a43bd99f87305efb3277..3698ed3146e3011b11ed4211a06a7badc2f254cb 100644 (file)
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -351,14 +351,13 @@ nouid32                   Disables 32-bit UIDs and GIDs.  This is for
                        interoperability  with  older kernels which only
                        store and expect 16-bit values.
 
-block_validity         This options allows to enables/disables the in-kernel
+block_validity(*)      These options enable or disable the in-kernel
 noblock_validity       facility for tracking filesystem metadata blocks
-                       within internal data structures. This allows multi-
-                       block allocator and other routines to quickly locate
-                       extents which might overlap with filesystem metadata
-                       blocks. This option is intended for debugging
-                       purposes and since it negatively affects the
-                       performance, it is off by default.
+                       within internal data structures.  This allows multi-
+                       block allocator and other routines to notice
+                       bugs or corrupted allocation bitmaps which cause
+                       blocks to be allocated which overlap with
+                       filesystem metadata blocks.
 
 dioread_lock           Controls whether or not ext4 should use the DIO read
 dioread_nolock         locking. If the dioread_nolock option is specified