From: Sebastian Andrzej Siewior Date: Mon, 16 Feb 2015 18:49:10 +0100 Subject: fs/aio: simple simple work Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.2/older/patches-5.2.17-rt9.tar.xz |BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:768 |in_atomic(): 1, irqs_disabled(): 0, pid: 26, name: rcuos/2 |2 locks held by rcuos/2/26: | #0: (rcu_callback){.+.+..}, at: [] rcu_nocb_kthread+0x1e2/0x380 | #1: (rcu_read_lock_sched){.+.+..}, at: [] percpu_ref_kill_rcu+0xa6/0x1c0 |Preemption disabled at:[] rcu_nocb_kthread+0x263/0x380 |Call Trace: | [] dump_stack+0x4e/0x9c | [] __might_sleep+0xfb/0x170 | [] rt_spin_lock+0x24/0x70 | [] free_ioctx_users+0x30/0x130 | [] percpu_ref_kill_rcu+0x1b4/0x1c0 | [] rcu_nocb_kthread+0x263/0x380 | [] kthread+0xd6/0xf0 | [] ret_from_fork+0x7c/0xb0 replace this preempt_disable() friendly swork. Reported-By: Mike Galbraith Suggested-by: Benjamin LaHaise Signed-off-by: Sebastian Andrzej Siewior --- fs/aio.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/fs/aio.c +++ b/fs/aio.c @@ -127,6 +127,7 @@ struct kioctx { long nr_pages; struct rcu_work free_rwork; /* see free_ioctx() */ + struct work_struct free_work; /* see free_ioctx() */ /* * signals when all in-flight requests are done @@ -612,9 +613,9 @@ static void free_ioctx_reqs(struct percp * and ctx->users has dropped to 0, so we know no more kiocbs can be submitted - * now it's safe to cancel any that need to be. */ -static void free_ioctx_users(struct percpu_ref *ref) +static void free_ioctx_users_work(struct work_struct *work) { - struct kioctx *ctx = container_of(ref, struct kioctx, users); + struct kioctx *ctx = container_of(work, struct kioctx, free_work); struct aio_kiocb *req; spin_lock_irq(&ctx->ctx_lock); @@ -632,6 +633,14 @@ static void free_ioctx_users(struct perc percpu_ref_put(&ctx->reqs); } +static void free_ioctx_users(struct percpu_ref *ref) +{ + struct kioctx *ctx = container_of(ref, struct kioctx, users); + + INIT_WORK(&ctx->free_work, free_ioctx_users_work); + schedule_work(&ctx->free_work); +} + static int ioctx_add_table(struct kioctx *ctx, struct mm_struct *mm) { unsigned i, new_nr;