Re: [PATCH 1/2] smb: client: disable directory caching when dir_cache_timeout is zero

[Paulo Alcantara <pc@manguebit.com>]

Henrique Carvalho <henrique.carvalho@suse.com> writes:

> According to the dir_cache_timeout description, setting it to zero
> should disable the caching of directory contents. However, even when
> dir_cache_timeout is zero, some caching related functions are still
> invoked, and the worker thread is initiated, which is unintended
> behavior.
>
> Fix the issue by setting tcon->nohandlecache to true when
> dir_cache_timeout is zero, ensuring that directory handle caching
> is properly disabled.
>
> Clean up the code to reflect this change, to improve consistency,
> and to remove other unnecessary checks.
>
> is_smb1_server() check inside open_cached_dir() can be removed because
> dir caching is only enabled for SMB versions >= 2.0.
>
> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com>
> ---
>  fs/smb/client/cached_dir.c | 12 +++++++-----
>  fs/smb/client/cifsproto.h  |  2 +-
>  fs/smb/client/connect.c    | 10 +++++-----
>  fs/smb/client/misc.c       |  4 ++--
>  4 files changed, 15 insertions(+), 13 deletions(-)

The fix could be simply this:

	diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
	index b227d61a6f20..62a29183c655 100644
	--- a/fs/smb/client/connect.c
	+++ b/fs/smb/client/connect.c
	@@ -2614,7 +2614,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
	 
	 	if (ses->server->dialect >= SMB20_PROT_ID &&
	 	    (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
	-		nohandlecache = ctx->nohandlecache;
	+		nohandlecache = ctx->nohandlecache || !dir_cache_timeout;
	 	else
	 		nohandlecache = true;
	 	tcon = tcon_info_alloc(!nohandlecache, netfs_trace_tcon_ref_new);

and easily backported to -stable kernels that have

        238b351d0935 ("smb3: allow controlling length of time directory entries are cached with dir leases")

And yes, is_smb1_server() check makes no sense as tcon->nohandlecache
would already be set.