[PATCH 3.16 178/233] fix ufs_isblockset()

From: Ben Hutchings
Date: Sat Sep 09 2017 - 19:06:48 EST


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

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

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 414cf7186dbec29bd946c138d6b5c09da5955a08 upstream.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
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;
}