lo_rw_aio->call_read_iter-> 1 aops->direct_IO 2 iov_iter_revert lo_rw_aio_complete could happen between 1 and 2, the bio and bvec could be freed before 2, which accesses bvec.
This conflicts with my direcio performance improvement patches, which I'll resend. Signed-off-by: Shaohua Li <[email protected]> --- drivers/block/loop.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index ef83349..153ab3c 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -490,6 +490,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, bvec = __bvec_iter_bvec(bio->bi_io_vec, bio->bi_iter); iov_iter_bvec(&iter, ITER_BVEC | rw, bvec, bio_segments(bio), blk_rq_bytes(cmd->rq)); + bio_inc_remaining(bio); /* * This bio may be started from the middle of the 'bvec' * because of bio splitting, so offset from the bvec must @@ -507,6 +508,7 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd, else ret = call_read_iter(file, &cmd->iocb, &iter); + bio_endio(bio); if (ret != -EIOCBQUEUED) cmd->iocb.ki_complete(&cmd->iocb, ret, 0); return 0; -- 2.9.5
