Commit 6f904ff0 authored by Artem Bityutskiy's avatar Artem Bityutskiy Committed by Jens Axboe
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writeback: harmonize writeback threads naming 



The write-back code mixes words "thread" and "task" for the same things. This
is not a big deal, but still an inconsistency.

hch: a convention I tend to use and I've seen in various places
is to always use _task for the storage of the task_struct pointer,
and thread everywhere else.  This especially helps with having
foo_thread for the actual thread and foo_task for a global
variable keeping the task_struct pointer

This patch renames:
* 'bdi_add_default_flusher_task()' -> 'bdi_add_default_flusher_thread()'
* 'bdi_forker_task()'              -> 'bdi_forker_thread()'

because bdi threads are 'bdi_writeback_thread()', so these names are more
consistent.

This patch also amends commentaries and makes them refer the forker and bdi
threads as "thread", not "task".

Also, while on it, make 'bdi_add_default_flusher_thread()' declaration use
'static void' instead of 'void static' and make checkpatch.pl happy.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Signed-off-by: default avatarJens Axboe <jaxboe@fusionio.com>
parent 4aeefdc6

fs/fs-writeback.c

+1 −1
Original line number Diff line number Diff line
@@ -840,7 +840,7 @@ int bdi_writeback_thread(void *data) 


			/*

			 * Longest period of inactivity that we tolerate. If we

			 * see dirty data again later, the task will get

			 * see dirty data again later, the thread will get

			 * recreated automatically.

			 */

			max_idle = max(5UL * 60 * HZ, wait_jiffies);

include/linux/backing-dev.h

+1 −1
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ struct bdi_writeback { 


	unsigned long last_old_flush;		/* last old data flush */



	struct task_struct	*task;		/* writeback task */

	struct task_struct	*task;		/* writeback thread */

	struct list_head	b_dirty;	/* dirty inodes */

	struct list_head	b_io;		/* parked for writeback */

	struct list_head	b_more_io;	/* parked for more writeback */

mm/backing-dev.c

+13 −13
Original line number Diff line number Diff line
@@ -50,7 +50,7 @@ static struct timer_list sync_supers_timer; 
static int bdi_sync_supers(void *);

static void sync_supers_timer_fn(unsigned long);



static void bdi_add_default_flusher_task(struct backing_dev_info *bdi);

static void bdi_add_default_flusher_thread(struct backing_dev_info *bdi);



#ifdef CONFIG_DEBUG_FS

#include <linux/debugfs.h>
@@ -279,10 +279,10 @@ static void bdi_flush_io(struct backing_dev_info *bdi) 
}



/*

 * kupdated() used to do this. We cannot do it from the bdi_forker_task()

 * kupdated() used to do this. We cannot do it from the bdi_forker_thread()

 * or we risk deadlocking on ->s_umount. The longer term solution would be

 * to implement sync_supers_bdi() or similar and simply do it from the

 * bdi writeback tasks individually.

 * bdi writeback thread individually.

 */

static int bdi_sync_supers(void *unused)

{
@@ -318,7 +318,7 @@ static void sync_supers_timer_fn(unsigned long unused) 
	bdi_arm_supers_timer();

}



static int bdi_forker_task(void *ptr)

static int bdi_forker_thread(void *ptr)

{

	struct bdi_writeback *me = ptr;
@@ -354,7 +354,7 @@ static int bdi_forker_task(void *ptr) 
			    !bdi_has_dirty_io(bdi))

				continue;



			bdi_add_default_flusher_task(bdi);

			bdi_add_default_flusher_thread(bdi);

		}



		set_current_state(TASK_INTERRUPTIBLE);
@@ -376,7 +376,7 @@ static int bdi_forker_task(void *ptr) 


		/*

		 * This is our real job - check for pending entries in

		 * bdi_pending_list, and create the tasks that got added

		 * bdi_pending_list, and create the threads that got added

		 */

		bdi = list_entry(bdi_pending_list.next, struct backing_dev_info,

				 bdi_list);
@@ -387,7 +387,7 @@ static int bdi_forker_task(void *ptr) 
		wb->task = kthread_run(bdi_writeback_thread, wb, "flush-%s",

					dev_name(bdi->dev));

		/*

		 * If task creation fails, then readd the bdi to

		 * If thread creation fails, then readd the bdi to

		 * the pending list and force writeout of the bdi

		 * from this forker thread. That will free some memory

		 * and we can try again.
@@ -430,10 +430,10 @@ static void bdi_add_to_pending(struct rcu_head *head) 
}



/*

 * Add the default flusher task that gets created for any bdi

 * Add the default flusher thread that gets created for any bdi

 * that has dirty data pending writeout

 */

void static bdi_add_default_flusher_task(struct backing_dev_info *bdi)

static void bdi_add_default_flusher_thread(struct backing_dev_info *bdi)

{

	if (!bdi_cap_writeback_dirty(bdi))

		return;
@@ -445,10 +445,10 @@ void static bdi_add_default_flusher_task(struct backing_dev_info *bdi) 
	}



	/*

	 * Check with the helper whether to proceed adding a task. Will only

	 * Check with the helper whether to proceed adding a thread. Will only

	 * abort if we two or more simultanous calls to

	 * bdi_add_default_flusher_task() occured, further additions will block

	 * waiting for previous additions to finish.

	 * bdi_add_default_flusher_thread() occured, further additions will

	 * block waiting for previous additions to finish.

	 */

	if (!test_and_set_bit(BDI_pending, &bdi->state)) {

		list_del_rcu(&bdi->bdi_list);
@@ -506,7 +506,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent, 
	if (bdi_cap_flush_forker(bdi)) {

		struct bdi_writeback *wb = &bdi->wb;



		wb->task = kthread_run(bdi_forker_task, wb, "bdi-%s",

		wb->task = kthread_run(bdi_forker_thread, wb, "bdi-%s",

						dev_name(dev));

		if (IS_ERR(wb->task)) {

			wb->task = NULL;

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