As call read_mmp_block pass bh_check which value is NULL, then call
sb_getblk to get buffer_head. But mmp_block's buffer_head is already exist
which also is uptodate. Lead to compare the same data.
Signed-off-by: Ye Bin <yebin10@xxxxxxxxxx>
---
fs/ext4/mmp.c | 17 ++++++-----------
1 file changed, 6 insertions(+), 11 deletions(-)
diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c
index 61c765c249b9..8018f6fb6ac2 100644
--- a/fs/ext4/mmp.c
+++ b/fs/ext4/mmp.c
@@ -186,10 +186,7 @@ static int kmmpd(void *data)
*/
diff = jiffies - last_update_time;
if (diff > mmp_check_interval * HZ) {
- struct buffer_head *bh_check = NULL;
- struct mmp_struct *mmp_check;
-
- retval = read_mmp_block(sb, bh_check);
+ retval = read_mmp_block(sb, bh);
if (retval) {
ext4_error_err(sb, -retval,
"error reading MMP data: %d",
@@ -197,20 +194,18 @@ static int kmmpd(void *data)
goto wait_to_exit;
}
- mmp_check = (struct mmp_struct *)(bh_check->b_data);
- if (seq != mmp_check->mmp_seq ||
- memcmp(nodename, mmp_check->mmp_nodename,
- sizeof(mmp->mmp_nodename))) {
- dump_mmp_msg(sb, mmp_check,
+ mmp = (struct mmp_struct *)(bh->b_data);
+ if (seq != le32_to_cpu(mmp->mmp_seq) ||
+ memcmp(nodename, mmp->mmp_nodename,
+ sizeof(nodename))) {
+ dump_mmp_msg(sb, mmp,
"Error while updating MMP info. "
"The filesystem seems to have been"
" multiply mounted.");
ext4_error_err(sb, EBUSY, "abort");
- put_bh(bh_check);
retval = -EBUSY;
goto wait_to_exit;
}
- put_bh(bh_check);
}
/*
--
2.31.1
