On Sat, Jun 24, 2023 at 3:14 AM Rishabh Bhatnagar <risbhat@xxxxxxxxxx> wrote:
>
> From: "Paulo Alcantara (SUSE)" <pc@xxxxxx>
>
> commit 345c1a4a9e09dc5842b7bbb6728a77910db69c52 upstream.
>
> Add helpers for finding TCP connections that are good candidates for
> being used by DFS refresh worker.
>
> Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
> Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
> Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
> Signed-off-by: Rishabh Bhatnagar <risbhat@xxxxxxxxxx>
> ---
> fs/cifs/dfs_cache.c | 44 +++++++++++++++++++++++++++++++-------------
> 1 file changed, 31 insertions(+), 13 deletions(-)
>
> diff --git a/fs/cifs/dfs_cache.c b/fs/cifs/dfs_cache.c
> index 3ca65051b55c..31b3dc09e109 100644
> --- a/fs/cifs/dfs_cache.c
> +++ b/fs/cifs/dfs_cache.c
> @@ -1305,6 +1305,30 @@ static char *get_dfs_root(const char *path)
> return npath;
> }
>
> +static inline void put_tcp_server(struct TCP_Server_Info *server)
> +{
> + cifs_put_tcp_session(server, 0);
> +}
> +
> +static struct TCP_Server_Info *get_tcp_server(struct smb_vol *vol)
> +{
> + struct TCP_Server_Info *server;
> +
> + server = cifs_find_tcp_session(vol);
> + if (IS_ERR_OR_NULL(server))
> + return NULL;
> +
> + spin_lock(&GlobalMid_Lock);
> + if (server->tcpStatus != CifsGood) {
> + spin_unlock(&GlobalMid_Lock);
> + put_tcp_server(server);
> + return NULL;
> + }
> + spin_unlock(&GlobalMid_Lock);
We've moved away from using GlobalMid_Lock for anything other than MIDs.
Please use server->srv_lock instead.
> +
> + return server;
> +}
> +
> /* Find root SMB session out of a DFS link path */
> static struct cifs_ses *find_root_ses(struct vol_info *vi,
> struct cifs_tcon *tcon,
> @@ -1347,13 +1371,8 @@ static struct cifs_ses *find_root_ses(struct vol_info *vi,
> goto out;
> }
>
> - server = cifs_find_tcp_session(&vol);
> - if (IS_ERR_OR_NULL(server)) {
> - ses = ERR_PTR(-EHOSTDOWN);
> - goto out;
> - }
> - if (server->tcpStatus != CifsGood) {
> - cifs_put_tcp_session(server, 0);
> + server = get_tcp_server(&vol);
> + if (!server) {
> ses = ERR_PTR(-EHOSTDOWN);
> goto out;
> }
> @@ -1451,19 +1470,18 @@ static void refresh_cache_worker(struct work_struct *work)
> mutex_lock(&vol_lock);
>
> list_for_each_entry(vi, &vol_list, list) {
> - server = cifs_find_tcp_session(&vi->smb_vol);
> - if (IS_ERR_OR_NULL(server))
> + server = get_tcp_server(&vi->smb_vol);
> + if (!server)
> continue;
> - if (server->tcpStatus != CifsGood)
> - goto next;
> +
> get_tcons(server, &list);
> list_for_each_entry_safe(tcon, ntcon, &list, ulist) {
> refresh_tcon(vi, tcon);
> list_del_init(&tcon->ulist);
> cifs_put_tcon(tcon);
> }
> -next:
> - cifs_put_tcp_session(server, 0);
> +
> + put_tcp_server(server);
> }
> queue_delayed_work(dfscache_wq, &refresh_task, cache_ttl * HZ);
> mutex_unlock(&vol_lock);
> --
> 2.40.1
>
--
Regards,
Shyam
