[v6.18-rcX PATCH 0/3] nfs/localio: fixes for recent misaligned DIO changes

[Mike Snitzer <snitzer@kernel.org>]

Hi,

These changes are needed to fix v6.18-rc1 commit c817248fc831
("nfs/localio: add proper O_DIRECT support for READ and WRITE").

This patchset fixes the KASAN use-after-free bug that was reported here:
https://lore.kernel.org/linux-nfs/aPSvi5Yr2lGOh5Jh@dell-per750-06-vm-07.rhts.eng.pek2.redhat.com/

I still contend there wasn't an actual problem but these changes bring
more control to the misaligned DIO IO completion by marshalling it
through the use of a refcount.

With the additional minimal memory barriers associated with atomic_t
methods the KASAN splat no longer occurs.

Also, removed "dead code" to handle ENOTBLK that shouldn't ever be
seen by NFS, and backfill misaligned DIO short read support.

Thanks,
Mike

Mike Snitzer (3):
  nfs/localio: remove unecessary ENOTBLK handling in DIO WRITE support
  nfs/localio: add refcounting for each iocb IO associated with NFS pgio header
  nfs/localio: backfill missing partial read support for misaligned DIO

 fs/nfs/localio.c | 149 +++++++++++++++++++++++++++++------------------
 1 file changed, 91 insertions(+), 58 deletions(-)

-- 
2.44.0