Re: [PATCH v2 06/13] sunrpc: add IDs to multipath

[Trond Myklebust <trondmy@hammerspace.com>]

On Thu, 2021-04-15 at 23:52 -0400, Olga Kornievskaia wrote:
> From: Olga Kornievskaia <kolga@netapp.com>
> 
> This is used to uniquely identify sunrpc multipath objects in /sys.
> 
> Signed-off-by: Dan Aloni <dan@kernelim.com>
> ---
>  include/linux/sunrpc/xprtmultipath.h |  4 ++++
>  net/sunrpc/sunrpc_syms.c             |  1 +
>  net/sunrpc/xprtmultipath.c           | 26 ++++++++++++++++++++++++++
>  3 files changed, 31 insertions(+)
> 
> diff --git a/include/linux/sunrpc/xprtmultipath.h
> b/include/linux/sunrpc/xprtmultipath.h
> index c6cce3fbf29d..ef95a6f18ccf 100644
> --- a/include/linux/sunrpc/xprtmultipath.h
> +++ b/include/linux/sunrpc/xprtmultipath.h
> @@ -14,6 +14,7 @@ struct rpc_xprt_switch {
>         spinlock_t              xps_lock;
>         struct kref             xps_kref;
>  
> +       unsigned int            xps_id;
>         unsigned int            xps_nxprts;
>         unsigned int            xps_nactive;
>         atomic_long_t           xps_queuelen;
> @@ -71,4 +72,7 @@ extern struct rpc_xprt *xprt_iter_get_next(struct
> rpc_xprt_iter *xpi);
>  
>  extern bool rpc_xprt_switch_has_addr(struct rpc_xprt_switch *xps,
>                 const struct sockaddr *sap);
> +
> +extern void xprt_multipath_cleanup_ids(void);
> +
>  #endif
> diff --git a/net/sunrpc/sunrpc_syms.c b/net/sunrpc/sunrpc_syms.c
> index b61b74c00483..691c0000e9ea 100644
> --- a/net/sunrpc/sunrpc_syms.c
> +++ b/net/sunrpc/sunrpc_syms.c
> @@ -134,6 +134,7 @@ cleanup_sunrpc(void)
>         rpc_sysfs_exit();
>         rpc_cleanup_clids();
>         xprt_cleanup_ids();
> +       xprt_multipath_cleanup_ids();
>         rpcauth_remove_module();
>         cleanup_socket_xprt();
>         svc_cleanup_xprt_sock();
> diff --git a/net/sunrpc/xprtmultipath.c b/net/sunrpc/xprtmultipath.c
> index 78c075a68c04..b71dd95ad7de 100644
> --- a/net/sunrpc/xprtmultipath.c
> +++ b/net/sunrpc/xprtmultipath.c
> @@ -86,6 +86,30 @@ void rpc_xprt_switch_remove_xprt(struct
> rpc_xprt_switch *xps,
>         xprt_put(xprt);
>  }
>  
> +static DEFINE_IDA(rpc_xprtswitch_ids);
> +
> +void xprt_multipath_cleanup_ids(void)
> +{
> +       ida_destroy(&rpc_xprtswitch_ids);
> +}
> +
> +static int xprt_switch_alloc_id(struct rpc_xprt_switch *xps)
> +{
> +       int id;
> +
> +       id = ida_simple_get(&rpc_xprtswitch_ids, 0, 0, GFP_KERNEL);

This really needs to use the same allocation mode as the caller in
xprt_switch_alloc()

> +       if (id < 0)
> +               return id;
> +
> +       xps->xps_id = id;
> +       return 0;
> +}
> +
> +static void xprt_switch_free_id(struct rpc_xprt_switch *xps)
> +{
> +       ida_simple_remove(&rpc_xprtswitch_ids, xps->xps_id);
> +}
> +
>  /**
>   * xprt_switch_alloc - Allocate a new struct rpc_xprt_switch
>   * @xprt: pointer to struct rpc_xprt
> @@ -103,6 +127,7 @@ struct rpc_xprt_switch *xprt_switch_alloc(struct
> rpc_xprt *xprt,
>         if (xps != NULL) {
>                 spin_lock_init(&xps->xps_lock);
>                 kref_init(&xps->xps_kref);
> +               xprt_switch_alloc_id(xps);
>                 xps->xps_nxprts = xps->xps_nactive = 0;
>                 atomic_long_set(&xps->xps_queuelen, 0);
>                 xps->xps_net = NULL;
> @@ -136,6 +161,7 @@ static void xprt_switch_free(struct kref *kref)
>                         struct rpc_xprt_switch, xps_kref);
>  
>         xprt_switch_free_entries(xps);
> +       xprt_switch_free_id(xps);
>         kfree_rcu(xps, xps_rcu);
>  }
>  

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com