Re: [PATCH 6.1 1/4] cifs: fix flushing folio regression for 6.1 backport

[Salvatore Bonaccorso <carnil@debian.org>]

Hi Greg,

On Sat, Jan 13, 2024 at 10:50:39AM +0100, Greg Kroah-Hartman wrote:
> 6.1-stable review patch.  If anyone has any objections, please let me know.
> 
> ------------------
> 
> filemap_get_folio works differenty in 6.1 vs. later kernels
> (returning NULL in 6.1 instead of an error).  Add
> this minor correction which addresses the regression in the patch:
>   cifs: Fix flushing, invalidation and file size with copy_file_range()
> 
> Suggested-by: David Howells <dhowells@redhat.com>
> Reported-by: Salvatore Bonaccorso <carnil@debian.org>
> Signed-off-by: Steve French <stfrench@microsoft.com>
> Tested-by: Salvatore Bonaccorso <carnil@debian.org>
> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> ---
>  fs/smb/client/cifsfs.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/fs/smb/client/cifsfs.c
> +++ b/fs/smb/client/cifsfs.c
> @@ -1240,7 +1240,7 @@ static int cifs_flush_folio(struct inode
>  	int rc = 0;
>  
>  	folio = filemap_get_folio(inode->i_mapping, index);
> -	if (IS_ERR(folio))
> +	if ((!folio) || (IS_ERR(folio)))
>  		return 0;
>  
>  	size = folio_size(folio);

Note, this one needs to be revisited:

https://lore.kernel.org/stable/ZaLNlyo8cDCpATPm@casper.infradead.org/T/#md6a3f0beceaa886ca0d1e4a47ff5a575340d7e8f

Regards,
Salvatore