remove useless mnt_want_write call in xfs_write

When mnt_want_write was introduced a call to it was added around
xfs_ichgtime, but there is no need for this because a file can't be open
read/write on a r/o mount, and a mount can't degrade r/o while we still
have files open for writing.  As the mnt_want_write changes were never
merged into the CVS tree this patch is for mainline only.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Niv Sardi <xaiki@sgi.com>

1 files changed, 1 insertions, 9 deletions

diff --git a/fs/xfs/linux-2.6/xfs_lrw.c b/fs/xfs/linux-2.6/xfs_lrw.c
index 4959c8744997..59b7d5f9e64a 100644
--- a/fs/xfs/linux-2.6/xfs_lrw.c
+++ b/fs/xfs/linux-2.6/xfs_lrw.c
@@ -51,7 +51,6 @@
 #include "xfs_vnodeops.h"
 
 #include <linux/capability.h>
-#include <linux/mount.h>
 #include <linux/writeback.h>
 
 
@@ -668,15 +667,8 @@ start:
         if (new_size > xip->i_size)
                 xip->i_new_size = new_size;
 
-        /*
-         * We're not supposed to change timestamps in readonly-mounted
-         * filesystems.  Throw it away if anyone asks us.
-         */
-        if (likely(!(ioflags & IO_INVIS) &&
-                   !mnt_want_write(file->f_path.mnt))) {
+        if (likely(!(ioflags & IO_INVIS)))
                 xfs_ichgtime(xip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
-                mnt_drop_write(file->f_path.mnt);
-        }
 
         /*
          * If the offset is beyond the size of the file, we have a couple