diff mbox series

[v5,7/8] md: sync blockdev before stopping raid or setting readonly

Message ID 20240201063404.772797-8-linan666@huaweicloud.com
State New
Headers
Series bugfix of MD_CLOSING and clean up md_ioctl() |

Commit Message

Li Nan Feb. 1, 2024, 6:34 a.m. UTC 
  From: Li Nan <linan122@huawei.com>

Commit a05b7ea03d72 ("md: avoid crash when stopping md array races
with closing other open fds.") added sync_block before stopping raid and
setting readonly. Later in commit 260fa034ef7a ("md: avoid deadlock when
dirty buffers during md_stop.") it is moved to ioctl. array_state_store()
was ignored. Add sync blockdev to array_state_store() now.

Signed-off-by: Li Nan <linan122@huawei.com>
---
 drivers/md/md.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Yu Kuai Feb. 2, 2024, 2:12 a.m. UTC | #1 
Hi,

在 2024/02/01 14:34, linan666@huaweicloud.com 写道:
> From: Li Nan <linan122@huawei.com>
> 
> Commit a05b7ea03d72 ("md: avoid crash when stopping md array races
> with closing other open fds.") added sync_block before stopping raid and
> setting readonly. Later in commit 260fa034ef7a ("md: avoid deadlock when
> dirty buffers during md_stop.") it is moved to ioctl. array_state_store()
> was ignored. Add sync blockdev to array_state_store() now.

You're not just adding sync_blockdev() here. Please rewrite the tittle
and commit message.

> 
> Signed-off-by: Li Nan <linan122@huawei.com>
> ---
>   drivers/md/md.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 
> diff --git a/drivers/md/md.c b/drivers/md/md.c
> index 4c7a0225f77d..86becf0015f5 100644
> --- a/drivers/md/md.c
> +++ b/drivers/md/md.c
> @@ -4493,6 +4493,16 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
>   	case broken:		/* cannot be set */
>   	case bad_word:
>   		return -EINVAL;
> +	case clear:
> +	case readonly:
> +	case inactive:
> +	case read_auto:
> +		if (!mddev->pers || !md_is_rdwr(mddev))
> +			break;
> +		err = mddev_set_closing_and_sync_blockdev(mddev);

In this context, mddev->openers should be zero, and such check is in
do_md_stop() and md_set_readonly():

if (atomic_read(&mddev->openers) > !!bdev).

Thanks,
Kuai

> +		if (err)
> +			return err;
> +		break;
>   	default:
>   		break;
>   	}
> @@ -4518,6 +4528,7 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
>   		spin_unlock(&mddev->lock);
>   		return err ?: len;
>   	}
> +
>   	err = mddev_lock(mddev);
>   	if (err)
>   		return err;
> @@ -4592,6 +4603,11 @@ array_state_store(struct mddev *mddev, const char *buf, size_t len)
>   		sysfs_notify_dirent_safe(mddev->sysfs_state);
>   	}
>   	mddev_unlock(mddev);
> +
> +	if (st == readonly || st == read_auto || st == inactive ||
> +	    (err && st == clear))
> +		clear_bit(MD_CLOSING, &mddev->flags);
> +
>   	return err ?: len;
>   }
>   static struct md_sysfs_entry md_array_state =
>
Li Nan Feb. 2, 2024, 9:26 a.m. UTC | #2 
在 2024/2/2 10:12, Yu Kuai 写道:
> Hi,
> 
> 在 2024/02/01 14:34, linan666@huaweicloud.com 写道:
>> From: Li Nan <linan122@huawei.com>
>>
>> Commit a05b7ea03d72 ("md: avoid crash when stopping md array races
>> with closing other open fds.") added sync_block before stopping raid and
>> setting readonly. Later in commit 260fa034ef7a ("md: avoid deadlock when
>> dirty buffers during md_stop.") it is moved to ioctl. array_state_store()
>> was ignored. Add sync blockdev to array_state_store() now.
> 
> You're not just adding sync_blockdev() here. Please rewrite the tittle
> and commit message.
> 
>>
>> Signed-off-by: Li Nan <linan122@huawei.com>
>> ---
>>   drivers/md/md.c | 16 ++++++++++++++++
>>   1 file changed, 16 insertions(+)
>>
>> diff --git a/drivers/md/md.c b/drivers/md/md.c
>> index 4c7a0225f77d..86becf0015f5 100644
>> --- a/drivers/md/md.c
>> +++ b/drivers/md/md.c
>> @@ -4493,6 +4493,16 @@ array_state_store(struct mddev *mddev, const char 
>> *buf, size_t len)
>>       case broken:        /* cannot be set */
>>       case bad_word:
>>           return -EINVAL;
>> +    case clear:
>> +    case readonly:
>> +    case inactive:
>> +    case read_auto:
>> +        if (!mddev->pers || !md_is_rdwr(mddev))
>> +            break;
>> +        err = mddev_set_closing_and_sync_blockdev(mddev);
> 
> In this context, mddev->openers should be zero, and such check is in
> do_md_stop() and md_set_readonly():
> 

Yeah, the checks in do_md_stop() and md_set_readonly() can be removed after
this patch. However, 'mddev->open_metux' is used to protect MD_CLOSING and
'mddev->openers', it can be removed in these functions, too.

I will fix it later. Thanks for your review.

> if (atomic_read(&mddev->openers) > !!bdev).
> 
> Thanks,
> Kuai
>
diff mbox series

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 4c7a0225f77d..86becf0015f5 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -4493,6 +4493,16 @@  array_state_store(struct mddev *mddev, const char *buf, size_t len)
 	case broken:		/* cannot be set */
 	case bad_word:
 		return -EINVAL;
+	case clear:
+	case readonly:
+	case inactive:
+	case read_auto:
+		if (!mddev->pers || !md_is_rdwr(mddev))
+			break;
+		err = mddev_set_closing_and_sync_blockdev(mddev);
+		if (err)
+			return err;
+		break;
 	default:
 		break;
 	}
@@ -4518,6 +4528,7 @@  array_state_store(struct mddev *mddev, const char *buf, size_t len)
 		spin_unlock(&mddev->lock);
 		return err ?: len;
 	}
+
 	err = mddev_lock(mddev);
 	if (err)
 		return err;
@@ -4592,6 +4603,11 @@  array_state_store(struct mddev *mddev, const char *buf, size_t len)
 		sysfs_notify_dirent_safe(mddev->sysfs_state);
 	}
 	mddev_unlock(mddev);
+
+	if (st == readonly || st == read_auto || st == inactive ||
+	    (err && st == clear))
+		clear_bit(MD_CLOSING, &mddev->flags);
+
 	return err ?: len;
 }
 static struct md_sysfs_entry md_array_state =