ext4: Make sure the MOVE_EXT ioctl can't overwrite append-only files
ext4: Make sure the MOVE_EXT ioctl can't overwrite append-only files

Dan Roseberg has reported a problem with the MOVE_EXT ioctl.  If the
donor file is an append-only file, we should not allow the operation
to proceed, lest we end up overwriting the contents of an append-only
file.

Signed-off-by: "Theodore Ts'o" <4ed386e0495d3e109932df055831d9ec2f824927@mit.edu>
Cc: Dan Rosenberg <eae8df918674d018776356cca2a43d000e4169dc@gmail.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas