>On Thu, 28 Feb 2013 15:51:01 +0800 majianpeng <majianpeng@xxxxxxxxx> wrote:
>
>> For badsector,it took two steps:rewrite and reread.So for
>> write-operation,it make no sense to rewrite after write-operation.
>
>Please please please please please try to explain yourself better.
>
Sorry for that.
>This patch doesn't make any sense. The write succeeded. We set the MadeGood
>flag so that later code will remove the block from the bad-block list.
>There will be no re-read or re-write.
>
For a striep which contain badsector is doing write-operation.
In analyse_stripe, it check badsector and set R5_ReadError.
write--->MadeGood->clear badblock log. But it can't clear R5_ReadError flag.
So it will exec those code in func handle_stripe:
> /* If the failed drives are just a ReadError, then we might need
> * to progress the repair/check process
> */
> if (s.failed <= conf->max_degraded && !conf->mddev->ro)
> for (i = 0; i < s.failed; i++) {
> struct r5dev *dev = &sh->dev[s.failed_num[i]];
> if (test_bit(R5_ReadError, &dev->flags)
> && !test_bit(R5_LOCKED, &dev->flags)
> && test_bit(R5_UPTODATE, &dev->flags)
> ) {
> if (!test_bit(R5_ReWrite, &dev->flags)) {
> set_bit(R5_Wantwrite, &dev->flags);
> set_bit(R5_ReWrite, &dev->flags);
> set_bit(R5_LOCKED, &dev->flags);
> s.locked++;
> } else {
> /* let's read it back */
> set_bit(R5_Wantread, &dev->flags);
> set_bit(R5_LOCKED, &dev->flags);
> s.locked++;
> }
> }
> }
But the flag ReWrite can't set. So it do write-operatoin again.Then do read-operation.
Thanks!
Jianpeng Ma
>NeilBrown
>
>
>>
>> Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
>> ---
>> drivers/md/raid5.c | 4 +++-
>> 1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index 19d77a0..59c0569 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -1921,8 +1921,10 @@ static void raid5_end_write_request(struct bio *bi, int error)
>> &rdev->mddev->recovery);
>> } else if (is_badblock(rdev, sh->sector,
>> STRIPE_SECTORS,
>> - &first_bad, &bad_sectors))
>> + &first_bad, &bad_sectors)) {
>> set_bit(R5_MadeGood, &sh->dev[i].flags);
>> + set_bit(R5_ReWrite, &sh->dev[i].flags);
>> + }
>> }
>> rdev_dec_pending(rdev, conf->mddev);
>>
>
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