Merge branch 'perf/core' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux...

[pandora-kernel.git] / Documentation / filesystems / ext4.txt

diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 3ae9bc9..232a575 100644 (file)
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -68,12 +68,12 @@ Note: More extensive information for getting started with ext4 can be
     '-o barriers=[0|1]' mount option for both ext3 and ext4 filesystems
     for a fair comparison.  When tuning ext3 for best benchmark numbers,
     it is often worthwhile to try changing the data journaling mode; '-o
-    data=writeback,nobh' can be faster for some workloads.  (Note
-    however that running mounted with data=writeback can potentially
-    leave stale data exposed in recently written files in case of an
-    unclean shutdown, which could be a security exposure in some
-    situations.)  Configuring the filesystem with a large journal can
-    also be helpful for metadata-intensive workloads.
+    data=writeback' can be faster for some workloads.  (Note however that
+    running mounted with data=writeback can potentially leave stale data
+    exposed in recently written files in case of an unclean shutdown,
+    which could be a security exposure in some situations.)  Configuring
+    the filesystem with a large journal can also be helpful for
+    metadata-intensive workloads.
 
 2. Features
 ===========
@@ -272,14 +272,6 @@ grpjquota=<file>   during journal replay. They replace the above
                        package for more details
                        (http://sourceforge.net/projects/linuxquota).
 
-bh             (*)     ext4 associates buffer heads to data pages to
-nobh                   (a) cache disk block mapping information
-                       (b) link pages into transaction to provide
-                           ordering guarantees.
-                       "bh" option forces use of buffer heads.
-                       "nobh" option tries to avoid associating buffer
-                       heads (supported only for "writeback" mode).
-
 stripe=n               Number of filesystem blocks that mballoc will try
                        to use for allocation size and alignment. For RAID5/6
                        systems this should be the number of data
@@ -393,8 +385,7 @@ dioread_nolock              locking. If the dioread_nolock option is specified
                        write and convert the extent to initialized after IO
                        completes. This approach allows ext4 code to avoid
                        using inode mutex, which improves scalability on high
-                       speed storages. However this does not work with nobh
-                       option and the mount will fail. Nor does it work with
+                       speed storages. However this does not work with
                        data journaling and dioread_nolock option will be
                        ignored with kernel warning. Note that dioread_nolock
                        code path is only used for extent-based files.