Re: [PATCH] raid0: fix set_disk_faulty doesn't return -EBUSY

[Mariusz Tkaczyk <mariusz.tkaczyk@linux.intel.com>]

On Tue, 21 Mar 2023 16:56:37 +0800
Wu Guanghao <wuguanghao3@huawei.com> wrote:

> The latest kernel version will not report an error through mdadm
> set_disk_faulty.
> 
> $ lsblk
> sdb                                           8:16   0   10G  0 disk
> └─md0                                         9:0    0 19.9G  0 raid0
> sdc                                           8:32   0   10G  0 disk
> └─md0                                         9:0    0 19.9G  0 raid0
> 
> old kernel:
> ...
> $ mdadm /dev/md0 -f /dev/sdb
> mdadm: set device faulty failed for /dev/sdb:  Device or resource busy
> ...
> 
> latest kernel:
> ...
> $ mdadm /dev/md0 -f /dev/sdb
> mdadm: set /dev/sdb faulty in /dev/md0
> ...
> 
> The old kernel judges whether the Faulty flag is set in rdev->flags,
> and returns -EBUSY if not. And The latest kernel only return -EBUSY
> if the MD_BROKEN flag is set in mddev->flags. raid0 doesn't set error_handler,
> so MD_BROKEN will not be set, it will return 0.
> 
> So if error_handler isn't set for a raid type, also return -EBUSY.
Hi,
Please test with:
https://lore.kernel.org/linux-raid/20230306130317.3418-1-mariusz.tkaczyk@linux.intel.com/

Thanks,
Mariusz

> 
> Fixes: 9631abdbf406 ("md: Set MD_BROKEN for RAID1 and RAID10")
> Signed-off-by: Wu Guanghao <wuguanghao3@huawei.com>
> ---
>  drivers/md/md.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 927a43db5dfb..b1786ff60d97 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -2928,10 +2928,10 @@ state_store(struct md_rdev *rdev, const char *buf,
> size_t len) int err = -EINVAL;
>         bool need_update_sb = false;
> 
> -       if (cmd_match(buf, "faulty") && rdev->mddev->pers) {
> -               md_error(rdev->mddev, rdev);
> +       if (cmd_match(buf, "faulty") && mddev->pers) {
> +               md_error(mddev, rdev);
> 
> -               if (test_bit(MD_BROKEN, &rdev->mddev->flags))
> +               if (!mddev->pers->error_handler || test_bit(MD_BROKEN,
> &mddev->flags)) err = -EBUSY;
>                 else
>                         err = 0;
> @@ -7421,7 +7421,7 @@ static int set_disk_faulty(struct mddev *mddev, dev_t
> dev) err =  -ENODEV;
>         else {
>                 md_error(mddev, rdev);
> -               if (test_bit(MD_BROKEN, &mddev->flags))
> +               if (!mddev->pers->error_handler || test_bit(MD_BROKEN,
> &mddev->flags)) err = -EBUSY;
>         }
>         rcu_read_unlock();
> --
> 2.27.0
> .