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

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Sat, Jan 13, 2024 at 09:24:45PM +0100, Salvatore Bonaccorso wrote:
> Hi Greg,
> 
> On Sat, Jan 13, 2024 at 09:19:46PM +0100, Greg Kroah-Hartman wrote:
> > On Sat, Jan 13, 2024 at 09:08:50PM +0100, Salvatore Bonaccorso wrote:
> > > 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
> > 
> > I see that, thanks, I'll go fix this up.
> 
> Thanks!
> 
> Please note, the metadata for the commit needs as well some fixup: The
> actual first reporter was here:
> 
> https://lore.kernel.org/stable/ZZhrpNJ3zxMR8wcU@eldamar.lan/raw
> 
> and was "Jitindar Singh, Suraj" <surajjs@amazon.com>. I only reported
> it as regression from the Debian perspective following up on Jitindar
> Singh, Suraj first reporting.
> 
> Sorry did not spotted earlier that reported-by was missing in the
> above.

Added that, and found the original link of the issue reported here and
added that to the commit.

thanks,

greg k-h