brd: rename XIP to DAX

Since this is relating to FS_XIP, not KERNEL_XIP, it should be called
DAX instead of XIP.

Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/block/Kconfig b/drivers/block/Kconfig
index 014a1cfc41c5..1b8094d4d7af 100644
--- a/drivers/block/Kconfig
+++ b/drivers/block/Kconfig
@@ -393,14 +393,15 @@ config BLK_DEV_RAM_SIZE
           The default value is 4096 kilobytes. Only change this if you know
           what you are doing.
 
-config BLK_DEV_XIP
-        bool "Support XIP filesystems on RAM block device"
-        depends on BLK_DEV_RAM
+config BLK_DEV_RAM_DAX
+        bool "Support Direct Access (DAX) to RAM block devices"
+        depends on BLK_DEV_RAM && FS_DAX
         default n
         help
-          Support XIP filesystems (such as ext2 with XIP support on) on
-          top of block ram device. This will slightly enlarge the kernel, and
-          will prevent RAM block device backing store memory from being
+          Support filesystems using DAX to access RAM block devices.  This
+          avoids double-buffering data in the page cache before copying it
+          to the block device.  Answering Y will slightly enlarge the kernel,
+          and will prevent RAM block device backing store memory from being
           allocated from highmem (only a problem for highmem systems).
 
 config CDROM_PKTCDVD