ext4: Update documentation about quota mount options
Jan Kara [Tue, 29 Sep 2009 19:59:34 +0000 (15:59 -0400)]
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

Documentation/filesystems/ext4.txt

index 18b5ec8..bf4f4b7 100644 (file)
@@ -282,9 +282,16 @@ 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
                        disks *  RAID chunk size in file system blocks.
-delalloc       (*)     Deferring block allocation until write-out time.
-nodelalloc             Disable delayed allocation. Blocks are allocation
-                       when data is copied from user to page cache.
+
+delalloc       (*)     Defer block allocation until just before ext4
+                       writes out the block(s) in question.  This
+                       allows ext4 to better allocation decisions
+                       more efficiently.
+nodelalloc             Disable delayed allocation.  Blocks are allocated
+                       when the data is copied from userspace to the
+                       page cache, either via the write(2) system call
+                       or when an mmap'ed page which was previously
+                       unallocated is written for the first time.
 
 max_batch_time=usec    Maximum amount of time ext4 should wait for
                        additional filesystem operations to be batch