[PATCH] ext4: 48bit i_file_acl

As we are planning to support 48-bit block numbers for ext4, we need to
support 48-bit block numbers for extended attributes.  In the short term, we
can do this by reuse (on-disk) 16-bit padding (linux2.i_pad1 currently used
only by "hurd") as high order bits for xattr.  This patch basically does that.

Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: Dave Kleikamp <shaggy@austin.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 2b81b13..9db8cff 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -2643,6 +2643,11 @@
 	ei->i_frag_size = raw_inode->i_fsize;
 #endif
 	ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
+	if ((sizeof(sector_t) > 4) &&
+	    (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+	     cpu_to_le32(EXT4_OS_HURD)))
+		ei->i_file_acl |=
+			((__u64)le16_to_cpu(raw_inode->i_file_acl_high)) << 32;
 	if (!S_ISREG(inode->i_mode)) {
 		ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
 	} else {
@@ -2776,6 +2781,11 @@
 	raw_inode->i_frag = ei->i_frag_no;
 	raw_inode->i_fsize = ei->i_frag_size;
 #endif
+	if ((sizeof(sector_t) > 4) &&
+	    (EXT4_SB(inode->i_sb)->s_es->s_creator_os !=
+	     cpu_to_le32(EXT4_OS_HURD)))
+		raw_inode->i_file_acl_high =
+			cpu_to_le16(ei->i_file_acl >> 32);
 	raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
 	if (!S_ISREG(inode->i_mode)) {
 		raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);