[PATCH 3.16 178/233] fix ufs_isblockset()

[Ben Hutchings]

3.16.48-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Al Viro <v...@zeniv.linux.org.uk>

commit 414cf7186dbec29bd946c138d6b5c09da5955a08 upstream.

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 fs/ufs/util.h | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

--- a/fs/ufs/util.h
+++ b/fs/ufs/util.h
@@ -473,15 +473,19 @@ static inline unsigned _ubh_find_last_ze
 static inline int _ubh_isblockset_(struct ufs_sb_private_info * uspi,
        struct ufs_buffer_head * ubh, unsigned begin, unsigned block)
 {
+       u8 mask;
        switch (uspi->s_fpb) {
        case 8:
                return (*ubh_get_addr (ubh, begin + block) == 0xff);
        case 4:
-               return (*ubh_get_addr (ubh, begin + (block >> 1)) == (0x0f << 
((block & 0x01) << 2)));
+               mask = 0x0f << ((block & 0x01) << 2);
+               return (*ubh_get_addr (ubh, begin + (block >> 1)) & mask) == 
mask;
        case 2:
-               return (*ubh_get_addr (ubh, begin + (block >> 2)) == (0x03 << 
((block & 0x03) << 1)));
+               mask = 0x03 << ((block & 0x03) << 1);
+               return (*ubh_get_addr (ubh, begin + (block >> 2)) & mask) == 
mask;
        case 1:
-               return (*ubh_get_addr (ubh, begin + (block >> 3)) == (0x01 << 
(block & 0x07)));
+               mask = 0x01 << (block & 0x07);
+               return (*ubh_get_addr (ubh, begin + (block >> 3)) & mask) == 
mask;
        }
        return 0;       
 }