Messages in this thread | | | Date | Mon, 26 Oct 2020 17:35:46 +0100 | From | David Sterba <> | Subject | Re: [PATCH 6/7] btrfs: Promote to unsigned long long before shifting |
| |
On Sun, Oct 04, 2020 at 07:04:27PM +0100, Matthew Wilcox (Oracle) wrote: > On 32-bit systems, this shift will overflow for files larger than 4GB. > > Cc: stable@vger.kernel.org > Fixes: 53b381b3abeb ("Btrfs: RAID5 and RAID6") > Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> > --- > fs/btrfs/raid56.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/btrfs/raid56.c b/fs/btrfs/raid56.c > index 255490f42b5d..5ee0a53301bd 100644 > --- a/fs/btrfs/raid56.c > +++ b/fs/btrfs/raid56.c > @@ -1089,7 +1089,7 @@ static int rbio_add_io_page(struct btrfs_raid_bio *rbio, > u64 disk_start; > > stripe = &rbio->bbio->stripes[stripe_nr]; > - disk_start = stripe->physical + (page_index << PAGE_SHIFT); > + disk_start = stripe->physical + ((loff_t)page_index << PAGE_SHIFT);
It seems that this patch is mechanical replacement. If you check the callers, the page_index is passed from an int that iterates over bits set in an unsigned long (bitmap). The result won't overflow.
| |