ACK: [PATCH 0/1] [SRU][O/gcp] Fix switching IO scheduler to "none"

[Magali Lemes]

On 07/10/2024 11:46, Paolo Pisati wrote:
> BugLink: https://bugs.launchpad.net/bugs/2083845
> 
> [Impact]
> With Oracular linux-gcp kernel version 6.11.0-1002.2, running the google-guest-agent causes an error. The guest-agent sets the I/O scheduler to 'none', causing errors such as below:
> 
> ```
> 2024-10-07T09:24:03.262548+00:00 oracular-old-gga-test google_guest_agent[1125]: panic: invalid return from write: got 256 from a write of 4
> ```
> 
> With strace, we can also see that the return value of write is unexpected:
> 
> [pid 3127] write(7, "none", 4) = 256
> 
> [Fix]
> 
> Fix commit is e3accac1a976e65491a9b9fba82ce8ddbd3d2389 ("block: Fix elv_iosched_local_module handling of "none" scheduler").
> 
> [How to test]
> 
> Apply the fix, rebuild the kernel and try to change scheduler in sysfs, e.g.:
> 
> # echo "none" > /sys/devices/virtual/block/loop1/queue/scheduler
> # echo $?
> 0
> 
> [Regression potential]
> 
> Upstream clean cherry-pick, already part of v6.11.2.
> 

Acked-by: Magali Lemes <magali.lemes at canonical.com>

> Damien Le Moal (1):
>    block: Fix elv_iosched_local_module handling of "none" scheduler
> 
>   block/elevator.c | 4 +++-
>   1 file changed, 3 insertions(+), 1 deletion(-)
>