fs: check for statfs overflow

Adds a check for an overflow in the filesystem size so if someone is
checking with statfs() on a 16G blocksize hugetlbfs in a 32bit binary that
it will report back EOVERFLOW instead of a size of 0.

Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Jon Tollefson <kniht@linux.vnet.ibm.com>
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/open.c b/fs/open.c
index a99ad09c3197..bb98d2fe809f 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -64,7 +64,8 @@ static int vfs_statfs_native(struct dentry *dentry, struct statfs *buf)
                 memcpy(buf, &st, sizeof(st));
         else {
                 if (sizeof buf->f_blocks == 4) {
-                        if ((st.f_blocks | st.f_bfree | st.f_bavail) &
+                        if ((st.f_blocks | st.f_bfree | st.f_bavail |
+                             st.f_bsize | st.f_frsize) &
                             0xffffffff00000000ULL)
                                 return -EOVERFLOW;
                         /*