Commit 9fd99788 authored by Jens Axboe's avatar Jens Axboe
Browse files

io_uring: add task fork hook 



Called when copy_process() is called to copy state to a new child.
Right now this is just a stub, but will be used shortly to properly
handle fork'ing of task based io_uring restrictions.

Reviewed-by: default avatarChristian Brauner (Microsoft) <brauner@kernel.org>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e7f67c2b

include/linux/io_uring.h

+13 −1
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ void __io_uring_free(struct task_struct *tsk); 
void io_uring_unreg_ringfd(void);

const char *io_uring_get_opcode(u8 opcode);

bool io_is_uring_fops(struct file *file);

int __io_uring_fork(struct task_struct *tsk);



static inline void io_uring_files_cancel(void)

{
@@ -25,9 +26,16 @@ static inline void io_uring_task_cancel(void) 
}

static inline void io_uring_free(struct task_struct *tsk)

{

	if (tsk->io_uring)

	if (tsk->io_uring || tsk->io_uring_restrict)

		__io_uring_free(tsk);

}

static inline int io_uring_fork(struct task_struct *tsk)

{

	if (tsk->io_uring_restrict)

		return __io_uring_fork(tsk);



	return 0;

}

#else

static inline void io_uring_task_cancel(void)

{
@@ -46,6 +54,10 @@ static inline bool io_is_uring_fops(struct file *file) 
{

	return false;

}

static inline int io_uring_fork(struct task_struct *tsk)

{

	return 0;

}

#endif



#endif

include/linux/sched.h

+1 −0
Original line number Diff line number Diff line
@@ -1190,6 +1190,7 @@ struct task_struct { 


#ifdef CONFIG_IO_URING

	struct io_uring_task		*io_uring;

	struct io_restriction		*io_uring_restrict;

#endif



	/* Namespaces: */

io_uring/tctx.c

+16 −9
Original line number Diff line number Diff line
@@ -54,6 +54,7 @@ void __io_uring_free(struct task_struct *tsk) 
	 * node is stored in the xarray. Until that gets sorted out, attempt

	 * an iteration here and warn if any entries are found.

	 */

	if (tctx) {

		xa_for_each(&tctx->xa, index, node) {

			WARN_ON_ONCE(1);

			break;
@@ -65,6 +66,7 @@ void __io_uring_free(struct task_struct *tsk) 
		kfree(tctx);

		tsk->io_uring = NULL;

	}

}



__cold int io_uring_alloc_task_context(struct task_struct *task,

				       struct io_ring_ctx *ctx)
@@ -351,3 +353,8 @@ int io_ringfd_unregister(struct io_ring_ctx *ctx, void __user *__arg, 


	return i ? i : ret;

}



int __io_uring_fork(struct task_struct *tsk)

{

	return 0;

}

kernel/fork.c

+6 −0
Original line number Diff line number Diff line
@@ -97,6 +97,7 @@ 
#include <linux/kasan.h>

#include <linux/scs.h>

#include <linux/io_uring.h>

#include <linux/io_uring_types.h>

#include <linux/bpf.h>

#include <linux/stackprotector.h>

#include <linux/user_events.h>
@@ -2129,6 +2130,10 @@ __latent_entropy struct task_struct *copy_process( 


#ifdef CONFIG_IO_URING

	p->io_uring = NULL;

	retval = io_uring_fork(p);

	if (unlikely(retval))

		goto bad_fork_cleanup_delayacct;

	retval = -EAGAIN;

#endif



	p->default_timer_slack_ns = current->timer_slack_ns;
@@ -2525,6 +2530,7 @@ __latent_entropy struct task_struct *copy_process( 
	mpol_put(p->mempolicy);

#endif

bad_fork_cleanup_delayacct:

	io_uring_free(p);

	delayacct_tsk_free(p);

bad_fork_cleanup_count:

	dec_rlimit_ucounts(task_ucounts(p), UCOUNT_RLIMIT_NPROC, 1);