[49/90] ext4: Fix time encoding with extra epoch bits

Greg KH
2009-12-11T04:41:12Z

[-- Attachment #1: 0049-ext4-Fix-time-encoding-with-extra-epoch-bits.patch --]
[-- Type: text/plain, Size: 1531 bytes --]

2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
(cherry picked from commit c1fccc0696bcaff6008c11865091f5ec4b0937ab)

"Looking at ext4.h, I think the setting of extra time fields forgets to
mask the epoch bits so the epoch part overwrites nsec part. The second
change is only for coherency (2 -> EXT4_EPOCH_BITS)."

Thanks to Damien Guibouret for pointing out this problem.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---
fs/ext4/ext4.h | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -522,8 +522,8 @@ struct move_extent {
static inline __le32 ext4_encode_extra_time(struct timespec *time)
{
return cpu_to_le32((sizeof(time->tv_sec) > 4 ?
- time->tv_sec >> 32 : 0) |
- ((time->tv_nsec << 2) & EXT4_NSEC_MASK));
+ (time->tv_sec >> 32) & EXT4_EPOCH_MASK : 0) |
+ ((time->tv_nsec << EXT4_EPOCH_BITS) & EXT4_NSEC_MASK));
}

static inline void ext4_decode_extra_time(struct timespec *time, __le32 extra)
@@ -531,7 +531,7 @@ static inline void ext4_decode_extra_tim
if (sizeof(time->tv_sec) > 4)
time->tv_sec |= (__u64)(le32_to_cpu(extra) & EXT4_EPOCH_MASK)
<< 32;
- time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> 2;
+ time->tv_nsec = (le32_to_cpu(extra) & EXT4_NSEC_MASK) >> EXT4_EPOCH_BITS;
}

#define EXT4_INODE_SET_XTIME(xtime, inode, raw_inode) \