On 2012-09-20 14:47 NeilBrown <neilb@xxxxxxx> Wrote:
>On Thu, 20 Sep 2012 14:34:00 +0800 "Jianpeng Ma" <majianpeng@xxxxxxxxx> wrote:
>
>> In func add_stripe_bio:
>> >> .....
>> >> bip = &sh->dev[dd_idx].toread;
>> >> ......
>> >>spin_unlock_irq(&sh->stripe_lock);
>>
>> >> pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
>> >> (unsigned long long)(*bip)->bi_sector,
>> >> (unsigned long long)sh->sector, dd_idx);
>> After spin_unlock_irq, this thread scheded and toread may become null.
>> So it will be oops.
>>
>> Signed-off-by: Jianpeng Ma <majianpeng@xxxxxxxxx>
>> ---
>> drivers/md/raid5.c | 3 ++-
>> 1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c
>> index adda94d..f172b1e 100644
>> --- a/drivers/md/raid5.c
>> +++ b/drivers/md/raid5.c
>> @@ -2356,6 +2356,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
>> struct bio **bip;
>> struct r5conf *conf = sh->raid_conf;
>> int firstwrite=0;
>> + sector_t sector = bi->bi_sector;
>>
>> pr_debug("adding bi b#%llu to stripe s#%llu\n",
>> (unsigned long long)bi->bi_sector,
>> @@ -2406,7 +2407,7 @@ static int add_stripe_bio(struct stripe_head *sh, struct bio *bi, int dd_idx, in
>> spin_unlock_irq(&sh->stripe_lock);
>>
>> pr_debug("added bi b#%llu to stripe s#%llu, disk %d.\n",
>> - (unsigned long long)(*bip)->bi_sector,
>> + (unsigned long long)sector,
>> (unsigned long long)sh->sector, dd_idx);
>>
>> if (conf->mddev->bitmap && firstwrite) {
>
>
>how about we just move the spin_unlock_irq after the pr_debug??
>
ah! Why are you think ? my method only add a parameter.
BTW, in func handle_failed_stripe:
>>if (!test_bit(R5_Wantfill, &sh->dev[i].flags) &&
>> (!test_bit(R5_Insync, &sh->dev[i].flags) ||
>> test_bit(R5_ReadError, &sh->dev[i].flags))) {
>> bi = sh->dev[i].toread;
>> sh->dev[i].toread = NULL;
>> if (test_and_clear_bit(R5_Overlap, &sh->dev[i].flags))
>> wake_up(&conf->wait_for_overlap);
Why use stripe_lock to protect toread?
Thanks!
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