lkml.org 
[lkml]   [2019]   [Aug]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    From
    Date
    SubjectRe: [PATCH 3/3] xen/blkback: Use refcount_t for refcount
    On Thu, Aug 8, 2019 at 9:35 PM Roger Pau Monné <roger.pau@citrix.com> wrote:
    >
    > On Thu, Aug 08, 2019 at 09:11:00PM +0800, Chuhong Yuan wrote:
    > > Reference counters are preferred to use refcount_t instead of
    > > atomic_t.
    > > This is because the implementation of refcount_t can prevent
    > > overflows and detect possible use-after-free.
    > > So convert atomic_t ref counters to refcount_t.
    >
    > Thanks!
    >
    > I think there are more reference counters in blkback than
    > the one you fixed. There's also an inflight field in xen_blkif_ring,
    > and a pendcnt in pending_req which look like possible candidates to
    > switch to use refcount_t, have you looked into switching those two
    > also?
    >

    It seems that xen_blkif_ring::inflight is 0-based and cannot be directly
    converted to refcount_t.
    This is because the implementation of refcount_t will warn on increasing
    a 0 ref count.
    Therefore I only convert pending_req::pendcnt in v2.

    > Roger.

    \
     
     \ /
      Last update: 2019-08-13 08:10    [W:3.179 / U:0.332 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site