Commit e8dfc305 authored by Wu Fengguang's avatar Wu Fengguang
Browse files

writeback: elevate queue_io() into wb_writeback() 



Code refactor for more logical code layout.
No behavior change.

- remove the mis-named __writeback_inodes_sb()

- wb_writeback()/writeback_inodes_wb() will decide when to queue_io()
  before calling __writeback_inodes_wb()

Acked-by: default avatarJan Kara <jack@suse.cz>
Signed-off-by: default avatarWu Fengguang <fengguang.wu@intel.com>
parent f758eeab

fs/fs-writeback.c

+12 −17
Original line number Diff line number Diff line
@@ -580,17 +580,13 @@ static int writeback_sb_inodes(struct super_block *sb, struct bdi_writeback *wb, 
	return 1;

}



void writeback_inodes_wb(struct bdi_writeback *wb,

static void __writeback_inodes_wb(struct bdi_writeback *wb,

				  struct writeback_control *wbc)

{

	int ret = 0;



	if (!wbc->wb_start)

		wbc->wb_start = jiffies; /* livelock avoidance */

	spin_lock(&wb->list_lock);



	if (list_empty(&wb->b_io))

		queue_io(wb, wbc->older_than_this);



	while (!list_empty(&wb->b_io)) {

		struct inode *inode = wb_inode(wb->b_io.prev);
@@ -606,19 +602,16 @@ void writeback_inodes_wb(struct bdi_writeback *wb, 
		if (ret)

			break;

	}

	spin_unlock(&wb->list_lock);

	/* Leave any unwritten inodes on b_io */

}



static void __writeback_inodes_sb(struct super_block *sb,

		struct bdi_writeback *wb, struct writeback_control *wbc)

void writeback_inodes_wb(struct bdi_writeback *wb,

		struct writeback_control *wbc)

{

	WARN_ON(!rwsem_is_locked(&sb->s_umount));



	spin_lock(&wb->list_lock);

	if (list_empty(&wb->b_io))

		queue_io(wb, wbc->older_than_this);

	writeback_sb_inodes(sb, wb, wbc, true);

	__writeback_inodes_wb(wb, wbc);

	spin_unlock(&wb->list_lock);

}
@@ -685,7 +678,7 @@ static long wb_writeback(struct bdi_writeback *wb, 
	 * The intended call sequence for WB_SYNC_ALL writeback is:

	 *

	 *      wb_writeback()

	 *          __writeback_inodes_sb()     <== called only once

	 *          writeback_sb_inodes()       <== called only once

	 *              write_cache_pages()     <== called once for each inode

	 *                   (quickly) tag currently dirty pages

	 *                   (maybe slowly) sync all tagged pages
@@ -694,6 +687,7 @@ static long wb_writeback(struct bdi_writeback *wb, 
		write_chunk = LONG_MAX;



	wbc.wb_start = jiffies; /* livelock avoidance */

	spin_lock(&wb->list_lock);

	for (;;) {

		/*

		 * Stop writeback when nr_pages has been consumed
@@ -730,10 +724,12 @@ static long wb_writeback(struct bdi_writeback *wb, 
		wbc.inodes_written = 0;



		trace_wbc_writeback_start(&wbc, wb->bdi);

		if (list_empty(&wb->b_io))

			queue_io(wb, wbc.older_than_this);

		if (work->sb)

			__writeback_inodes_sb(work->sb, wb, &wbc);

			writeback_sb_inodes(work->sb, wb, &wbc, true);

		else

			writeback_inodes_wb(wb, &wbc);

			__writeback_inodes_wb(wb, &wbc);

		trace_wbc_writeback_written(&wbc, wb->bdi);



		work->nr_pages -= write_chunk - wbc.nr_to_write;
@@ -761,7 +757,6 @@ static long wb_writeback(struct bdi_writeback *wb, 
		 * become available for writeback. Otherwise

		 * we'll just busyloop.

		 */

		spin_lock(&wb->list_lock);

		if (!list_empty(&wb->b_more_io))  {

			inode = wb_inode(wb->b_more_io.prev);

			trace_wbc_writeback_wait(&wbc, wb->bdi);
@@ -769,8 +764,8 @@ static long wb_writeback(struct bdi_writeback *wb, 
			inode_wait_for_writeback(inode, wb);

			spin_unlock(&inode->i_lock);

		}

		spin_unlock(&wb->list_lock);

	}

	spin_unlock(&wb->list_lock);



	return wrote;

}

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