tmpfs: ZERO_RANGE and COLLAPSE_RANGE not currently supported

commit 13ace4d0d9db40e10ecd66dfda14e297571be813 upstream.

I was well aware of FALLOC_FL_ZERO_RANGE and FALLOC_FL_COLLAPSE_RANGE
support being added to fallocate(); but didn't realize until now that I
had been too stupid to future-proof shmem_fallocate() against new
additions.  -EOPNOTSUPP instead of going on to ordinary fallocation.

Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/mm/shmem.c b/mm/shmem.c
index 9f70e02111c6adcd090d8372ae0405b0f22b9abc..a2801ba8ae2d137d49172452ed4e66798ae68790 100644 (file)
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1728,6 +1728,9 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
        pgoff_t start, index, end;
        int error;
 
+       if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
+               return -EOPNOTSUPP;
+
        mutex_lock(&inode->i_mutex);
 
        if (mode & FALLOC_FL_PUNCH_HOLE) {