Re: [PATCH] xfs: check split_sectors validity before bio_split call

[Hongling Zeng]

在 2026年07月29日 14:52, Christoph Hellwig 写道:
> On Wed, Jul 29, 2026 at 02:31:17PM +0800, Hongling Zeng wrote:
> > Fix by changing the check from !split_sectors to split_sectors <= 0
> > immediately after bio_split_rw_at() and before any arithmetic operations.
> > This prevents both the negative error code propagation and the undefined
> > behavior from left-shifting negative values.
> >
> > When NULL is returned, the caller's while loop naturally terminates,
> > which is the correct behavior for "cannot split" cases.
> >
> > Fixes: 080d01c41d44f ("xfs: implement zoned garbage collection")
> > Cc: <stable@xxxxxxxxxxxxxxx>
> Nothing can actually hit that.  It only happens for invalid flags,
> or unaligned I/O, none of which can happen for GC I/O.
>
> I think checking all cases of the return value is fine, but the fixes
> is a bit bogus, and it really is not stable material.
 Thanks for the review. Updated v2 below - removed Fixes/stable
  tags and reworded as code improvement.