Re: [PATCH 3/9] smb: client: sync tcon-level options on remount

[Meetakshi Setiya]

Hi Rajasi,

Some nits:

On Thu, Apr 9, 2026 at 3:03 AM <rajasimandalos@xxxxxxxxx> wrote:
>
> From: Rajasi Mandal <rajasimandal@xxxxxxxxxxxxx>
>
> Several mount options are stored on each cifs_tcon at mount time but
> smb3_reconfigure() only updates cifs_sb->ctx. A remount that changes
> any of these options silently has no effect because the runtime code
> reads from the tcon fields, not from the superblock context.
>
> The affected options and their tcon fields are:
>   retry           -> tcon->retry
>   max_cached_dirs -> tcon->max_cached_dirs
>
> Add smb3_sync_tcon_opts() which walks the tlink_tree under
> tlink_tree_lock and propagates these values from ctx to every tcon
> under tc_lock. Call it from smb3_reconfigure() after the context has
> been updated.
>
> Signed-off-by: Rajasi Mandal <rajasimandal@xxxxxxxxxxxxx>
> ---
>  fs/smb/client/fs_context.c | 31 +++++++++++++++++++++++++++++++
>  1 file changed, 31 insertions(+)
>
> diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
> index e1bf7bad5be6..90e83f07c870 100644
> --- a/fs/smb/client/fs_context.c
> +++ b/fs/smb/client/fs_context.c
> @@ -1307,6 +1307,35 @@ static void smb3_sync_ses_chan_max(struct cifs_ses *ses, unsigned int max_channe
>         spin_unlock(&ses->chan_lock);
>  }
>
> +/*
> + * Synchronize tcon options that are derived from ctx across all tcons
> + * associated with this superblock.  These fields are consulted at runtime
> + * (reconnect, I/O, unlink/rmdir) so remount needs to update the live
> + * tcons in addition to cifs_sb->ctx.
> + */
> +static void smb3_sync_tcon_opts(struct cifs_sb_info *cifs_sb,
> +                               struct smb3_fs_context *ctx)
> +{
> +       struct rb_node *node;
> +
> +       spin_lock(&cifs_sb->tlink_tree_lock);
> +       for (node = rb_first(&cifs_sb->tlink_tree); node; node = rb_next(node)) {
> +               struct tcon_link *tlink;
> +               struct cifs_tcon *tcon;

Maybe declare these outside the loop?

> +
> +               tlink = rb_entry(node, struct tcon_link, tl_rbnode);
> +               tcon = tlink_tcon(tlink);
> +               if (IS_ERR_OR_NULL(tcon))
> +                       continue;
> +
> +               spin_lock(&tcon->tc_lock);
> +               tcon->retry = ctx->retry;
> +               tcon->max_cached_dirs = ctx->max_cached_dirs;

Would be good to add a comment that this will not resize the existing
cached dirents.

> +               spin_unlock(&tcon->tc_lock);
> +       }
> +       spin_unlock(&cifs_sb->tlink_tree_lock);
> +}
> +
>  static int smb3_reconfigure(struct fs_context *fc)
>  {
>         struct smb3_fs_context *ctx = smb3_fc2context(fc);
> @@ -1444,6 +1473,8 @@ static int smb3_reconfigure(struct fs_context *fc)
>         if (!rc)
>                 rc = dfs_cache_remount_fs(cifs_sb);
>  #endif
> +       if (!rc)
> +               smb3_sync_tcon_opts(cifs_sb, cifs_sb->ctx);
>
>         return rc;
>  }
> --
> 2.43.0
>
>

Other than that, it looks good to me.

Thanks

Meetakshi