Jens Axboe
d8e9fd2cc7
BugLink: https://bugs.launchpad.net/bugs/2114239 commit b13ee668e8280ca5b07f8ce2846b9957a8a10853 upstream. blkdev_read_iter() has a few odd checks, like gating the position and count adjustment on whether or not the result is bigger-than-or-equal to zero (where bigger than makes more sense), and not checking the return value of blkdev_direct_IO() before doing an iov_iter_revert(). The latter can lead to attempting to revert with a negative value, which when passed to iov_iter_revert() as an unsigned value will lead to throwing a WARN_ON() because unroll is bigger than MAX_RW_COUNT. Be sane and don't revert for -EIOCBQUEUED, like what is done in other spots. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Noah Wager <noah.wager@canonical.com> Signed-off-by: Mehmet Basaran <mehmet.basaran@canonical.com>