# Re: \[PATCH\] Monitor: release /proc/mdstat fd when no arrays present

- From: Jes Sorensen \<hidden\>
- Date: 2016-07-21 15:37:41 
- List: linux-raid
- Page: https://ratatoskr.run/linux-raid/2016/07/6632414
- Thread: https://ratatoskr.run/linux-raid/2016/07/6632414/t.md

```text
Tomasz Majchrzak [ref] writes:
> If md kernel module is reloaded, /proc/mdstat cannot be accessed ("cat:
> /proc/mdstat: No such file or directory"). The reason is mdadm monitor
> still holds a file descriptor to previous /proc/mdstat instance. It
> leads to really confusing outcome of the following operations - mdadm
> seems to run without errors, however some udev rules don't get executed
> and new array doesn't work.
>
> Add a check if lseek was successful as it fails if md kernel module has
> been unloaded - close a file descriptor then. The problem is mdadm
> monitor doesn't always do it before next operation takes place. To
> prevent it monitor always releases /proc/mdstat descriptor when there
> are no arrays to be monitored, just in case driver unload happens in a
> moment.
>
> Signed-off-by: Tomasz Majchrzak <redacted>
> Reviewed-by: Artur Paszkiewicz <redacted>
> ---
>  Monitor.c | 2 ++
>  mdstat.c  | 6 +++++-
>  2 files changed, 7 insertions(+), 1 deletion(-)

Looks good, applied!

Thanks,
Jes
```