On Sun, Apr 22, 2018 at 01:11:31AM -0700, Nathan Chancellor wrote: > From: Jan Kara <jack@xxxxxxx> > > commit 74dae4278546b897eb81784fdfcce872ddd8b2b8 upstream. > > Competing overwrite DIO in dioread_nolock mode will just overwrite > pointer to io_end in the inode. This may result in data corruption or > extent conversion happening from IO completion interrupt because we > don't properly set buffer_defer_completion() when unlocked DIO races > with locked DIO to unwritten extent. > > Since unlocked DIO doesn't need io_end for anything, just avoid > allocating it and corrupting pointer from inode for locked DIO. > A cleaner fix would be to avoid these games with io_end pointer from the > inode but that requires more intrusive changes so we leave that for > later. > > Cc: stable@xxxxxxxxxxxxxxx > Signed-off-by: Jan Kara <jack@xxxxxxx> > Signed-off-by: Theodore Ts'o <tytso@xxxxxxx> > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > --- > fs/ext4/inode.c | 40 ++++++++++++++++++++-------------------- > 1 file changed, 20 insertions(+), 20 deletions(-) > Both patches now queued up, thanks! greg k-h