From cbcf72148da4af55ea81cfb351ea7c026ff1014f Mon Sep 17 00:00:00 2001 From: Pavel Begunkov Date: Sat, 18 Jul 2020 11:31:21 +0300 Subject: [PATCH] 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: 8eb06d7e8dd85 ("io_uring: fix missing ->mm on exit") Signed-off-by: Pavel Begunkov Signed-off-by: Jens Axboe --- fs/io_uring.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index ba7ce103667b..680b16f71a03 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -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; -- 2.11.0