1 files changed, 10 insertions, 0 deletions

diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt
index 1b7f9acbcbbe..104322bf378c 100644
--- a/Documentation/filesystems/ext4.txt
+++ b/Documentation/filesystems/ext4.txt
@@ -375,6 +375,16 @@ dioread_nolock		locking. If the dioread_nolock option is specified
                         Because of the restrictions this options comprises
                         it is off by default (e.g. dioread_lock).
 
+max_dir_size_kb=n       This limits the size of directories so that any
+                        attempt to expand them beyond the specified
+                        limit in kilobytes will cause an ENOSPC error.
+                        This is useful in memory constrained
+                        environments, where a very large directory can
+                        cause severe performance problems or even
+                        provoke the Out Of Memory killer.  (For example,
+                        if there is only 512mb memory available, a 176mb
+                        directory may seriously cramp the system's style.)
+
 i_version               Enable 64-bit inode version support. This option is
                         off by default.