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

Meetakshi Setiya
2026-04-17T14:29:55Z

Hi Rajasi,

Some nits:

On Thu, Apr 9, 2026 at 3:03 AM <rajasimandalos@gmail.com> wrote:
>
> From: Rajasi Mandal <rajasimandal@microsoft.com>
>
> 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@microsoft.com>
> ---
> 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