Commit 88c9a2ce authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

fork: move copy_io to block/blk-ioc.c 



Move the copying of the I/O context to the block layer as that is where
we can use the proper low-level interfaces.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211126115817.2087431-3-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent e92a559e

block/blk-ioc.c

+27 −0
Original line number Diff line number Diff line
@@ -322,6 +322,33 @@ struct io_context *get_task_io_context(struct task_struct *task, 
	return NULL;

}



int __copy_io(unsigned long clone_flags, struct task_struct *tsk)

{

	struct io_context *ioc = current->io_context;

	struct io_context *new_ioc;



	/*

	 * Share io context with parent, if CLONE_IO is set

	 */

	if (clone_flags & CLONE_IO) {

		get_io_context_active(ioc);



		WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);

		atomic_inc(&ioc->nr_tasks);



		tsk->io_context = ioc;

	} else if (ioprio_valid(ioc->ioprio)) {

		new_ioc = get_task_io_context(tsk, GFP_KERNEL, NUMA_NO_NODE);

		if (unlikely(!new_ioc))

			return -ENOMEM;



		new_ioc->ioprio = ioc->ioprio;

		put_io_context(new_ioc);

	}



	return 0;

}



/**

 * ioc_lookup_icq - lookup io_cq from ioc

 * @ioc: the associated io_context

include/linux/iocontext.h

+13 −10
Original line number Diff line number Diff line
@@ -129,14 +129,6 @@ static inline void get_io_context_active(struct io_context *ioc) 
	atomic_inc(&ioc->active_ref);

}



static inline void ioc_task_link(struct io_context *ioc)

{

	get_io_context_active(ioc);



	WARN_ON_ONCE(atomic_read(&ioc->nr_tasks) <= 0);

	atomic_inc(&ioc->nr_tasks);

}



struct task_struct;

#ifdef CONFIG_BLOCK

void put_io_context(struct io_context *ioc);
@@ -144,10 +136,21 @@ void put_io_context_active(struct io_context *ioc); 
void exit_io_context(struct task_struct *task);

struct io_context *get_task_io_context(struct task_struct *task,

				       gfp_t gfp_flags, int node);

int __copy_io(unsigned long clone_flags, struct task_struct *tsk);

static inline int copy_io(unsigned long clone_flags, struct task_struct *tsk)

{

	if (!current->io_context)

		return 0;

	return __copy_io(clone_flags, tsk);

}

#else

struct io_context;

static inline void put_io_context(struct io_context *ioc) { }

static inline void exit_io_context(struct task_struct *task) { }

#endif

static inline int copy_io(unsigned long clone_flags, struct task_struct *tsk)

{

	return 0;

}

#endif /* CONFIG_BLOCK */



#endif
 
#endif /* IOCONTEXT_H */

kernel/fork.c

+0 −26
Original line number Diff line number Diff line
@@ -1556,32 +1556,6 @@ static int copy_files(unsigned long clone_flags, struct task_struct *tsk) 
	return error;

}



static int copy_io(unsigned long clone_flags, struct task_struct *tsk)

{

#ifdef CONFIG_BLOCK

	struct io_context *ioc = current->io_context;

	struct io_context *new_ioc;



	if (!ioc)

		return 0;

	/*

	 * Share io context with parent, if CLONE_IO is set

	 */

	if (clone_flags & CLONE_IO) {

		ioc_task_link(ioc);

		tsk->io_context = ioc;

	} else if (ioprio_valid(ioc->ioprio)) {

		new_ioc = get_task_io_context(tsk, GFP_KERNEL, NUMA_NO_NODE);

		if (unlikely(!new_ioc))

			return -ENOMEM;



		new_ioc->ioprio = ioc->ioprio;

		put_io_context(new_ioc);

	}

#endif

	return 0;

}



static int copy_sighand(unsigned long clone_flags, struct task_struct *tsk)

{

	struct sighand_struct *sig;