ext4: improve handling of conflicting mount options

[mirror_ubuntu-bionic-kernel.git] / Documentation / filesystems / ext4.txt

diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 232a575a0c4857249edc5aa76a235ce4e258082f..168242b5c045ff6542907dedd11146af6f4e234f 100644 (file)
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -160,7 +160,9 @@ noload                      if the filesystem was not unmounted cleanly,
                        lead to any number of problems.
 
 data=journal           All data are committed into the journal prior to being
-                       written into the main file system.
+                       written into the main file system.  Enabling
+                       this mode will disable delayed allocation and
+                       O_DIRECT support.
 
 data=ordered   (*)     All data are forced directly out to the main file
                        system prior to its metadata being committed to the
@@ -419,8 +421,8 @@ written to the journal first, and then to its final location.
 In the event of a crash, the journal can be replayed, bringing both data and
 metadata into a consistent state.  This mode is the slowest except when data
 needs to be read from and written to disk at the same time where it
-outperforms all others modes.  Currently ext4 does not have delayed
-allocation support if this data journalling mode is selected.
+outperforms all others modes.  Enabling this mode will disable delayed
+allocation and O_DIRECT support.
 
 /proc entries
 =============