Re: [PATCH v1 1/1] ceph: Fix log output race condition in osd client

[Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>]

On Thu, 2025-09-25 at 09:57 +0200, Simon Buttgereit wrote:
> OSD client logging has a problem in get_osd() and put_osd().
> For one logging output refcount_read() is called twice. If recount
> value changes between both calls logging output is not consistent.
> 
> This patch prints out only the resulting value and adds to the text
> whether it was incremented or decremented.
> 
> Signed-off-by: Simon Buttgereit <simon.buttgereit@tu-ilmenau.de>
> ---
>  net/ceph/osd_client.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
> 
> diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
> index 6664ea73ccf8..9cf91eed8020 100644
> --- a/net/ceph/osd_client.c
> +++ b/net/ceph/osd_client.c
> @@ -1280,8 +1280,7 @@ static struct ceph_osd *create_osd(struct ceph_osd_client *osdc, int onum)
>  static struct ceph_osd *get_osd(struct ceph_osd *osd)
>  {
>  	if (refcount_inc_not_zero(&osd->o_ref)) {
> -		dout("get_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref)-1,
> -		     refcount_read(&osd->o_ref));
> +		dout("get_osd %p; increment refcnt to %d\n", osd, refcount_read(&osd->o_ref));
>  		return osd;
>  	} else {
>  		dout("get_osd %p FAIL\n", osd);
> @@ -1291,8 +1290,7 @@ static struct ceph_osd *get_osd(struct ceph_osd *osd)
>  
>  static void put_osd(struct ceph_osd *osd)
>  {
> -	dout("put_osd %p %d -> %d\n", osd, refcount_read(&osd->o_ref),
> -	     refcount_read(&osd->o_ref) - 1);
> +	dout("put_osd %p; decrement refcnt to %d\n", osd, refcount_read(&osd->o_ref) - 1);
>  	if (refcount_dec_and_test(&osd->o_ref)) {
>  		osd_cleanup(osd);
>  		kfree(osd);

Looks good.

Reviewed-by: Viacheslav Dubeyko <Slava.Dubeyko@ibm.com>

Thanks,
Slava.