On 2016/10/17 20:03, Vitaly Wool wrote: > Hi Zhong Jiang, > > On Mon, Oct 17, 2016 at 3:58 AM, zhong jiang <zhongjiang@xxxxxxxxxx> wrote: >> Hi, Vitaly >> >> About the following patch, is it right? >> >> Thanks >> zhongjiang >> On 2016/10/13 12:02, zhongjiang wrote: >>> From: zhong jiang <zhongjiang@xxxxxxxxxx> >>> >>> At present, zhdr->first_num plus bud can exceed the BUDDY_MASK >>> in encode_handle, it will lead to the the caller handle_to_buddy >>> return the error value. >>> >>> The patch fix the issue by changing the BUDDY_MASK to PAGE_MASK, >>> it will be consistent with handle_to_z3fold_header. At the same time, >>> change the BUDDY_MASK to PAGE_MASK in handle_to_buddy is better. > are you seeing problems with the existing code? first_num should wrap around > BUDDY_MASK and this should be ok because it is way bigger than the number > of buddies. > > ~vitaly > > . > first_num plus buddies can exceed the BUDDY_MASK. is it right? (first_num + buddies) & BUDDY_MASK may be a smaller value than first_num. but (handle - zhdr->first_num) & BUDDY_MASK will return incorrect value in handle_to_buddy. Thanks zhongjiang -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
