io_uring: return locked and pinned page accounting

Locked and pinned memory accounting in io_{,un}account_mem() depends on
having ->sqo_mm, which is NULL after a recent change for non SQPOLL'ed
io_ring. That disables the accounting.

Return ->sqo_mm initialisation back, and do __io_sq_thread_acquire_mm()
based on IORING_SETUP_SQPOLL flag.

Fixes: 8eb06d7e8d ("io_uring: fix missing ->mm on exit")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Pavel Begunkov 2020-07-18 11:31:21 +03:00 committed by Jens Axboe
parent 5dbcad51f7
commit cbcf72148d

View file

@ -981,7 +981,8 @@ static void io_sq_thread_drop_mm(void)
static int __io_sq_thread_acquire_mm(struct io_ring_ctx *ctx)
{
if (!current->mm) {
if (unlikely(!ctx->sqo_mm || !mmget_not_zero(ctx->sqo_mm)))
if (unlikely(!(ctx->flags & IORING_SETUP_SQPOLL) ||
!mmget_not_zero(ctx->sqo_mm)))
return -EFAULT;
kthread_use_mm(ctx->sqo_mm);
}
@ -7259,10 +7260,10 @@ static int io_sq_offload_start(struct io_ring_ctx *ctx,
{
int ret;
if (ctx->flags & IORING_SETUP_SQPOLL) {
mmgrab(current->mm);
ctx->sqo_mm = current->mm;
mmgrab(current->mm);
ctx->sqo_mm = current->mm;
if (ctx->flags & IORING_SETUP_SQPOLL) {
ret = -EPERM;
if (!capable(CAP_SYS_ADMIN))
goto err;