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Commit 50c8cdb3 authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: introduce nr_pages_to_write for segment alignment 



This patch introduces nr_pages_to_write to align page writes to the segment
or other operational unit size, which can be tuned according to the system
environment.

Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent d3baf95d

fs/f2fs/checkpoint.c

+6 −5
Original line number Diff line number Diff line
@@ -187,18 +187,19 @@ static int f2fs_write_meta_pages(struct address_space *mapping, 
				struct writeback_control *wbc)

{

	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);

	int nrpages = nr_pages_to_skip(sbi, META);

	long written;

	long diff, written;



	/* collect a number of dirty meta pages and write together */

	if (wbc->for_kupdate || get_pages(sbi, F2FS_DIRTY_META) < nrpages)

	if (wbc->for_kupdate ||

		get_pages(sbi, F2FS_DIRTY_META) < nr_pages_to_skip(sbi, META))

		goto skip_write;



	/* if mounting is failed, skip writing node pages */

	mutex_lock(&sbi->cp_mutex);

	written = sync_meta_pages(sbi, META, nrpages);

	diff = nr_pages_to_write(sbi, META, wbc);

	written = sync_meta_pages(sbi, META, wbc->nr_to_write);

	mutex_unlock(&sbi->cp_mutex);

	wbc->nr_to_write -= written;

	wbc->nr_to_write = max((long)0, wbc->nr_to_write - written - diff);

	return 0;



skip_write:

fs/f2fs/data.c

+3 −9
Original line number Diff line number Diff line
@@ -844,8 +844,6 @@ static int f2fs_write_data_page(struct page *page, 
	return AOP_WRITEPAGE_ACTIVATE;

}



#define MAX_DESIRED_PAGES_WP	4096



static int __f2fs_writepage(struct page *page, struct writeback_control *wbc,

			void *data)

{
@@ -862,7 +860,7 @@ static int f2fs_write_data_pages(struct address_space *mapping, 
	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);

	bool locked = false;

	int ret;

	long excess_nrtw = 0, desired_nrtw;

	long diff;



	/* deal with chardevs and other special file */

	if (!mapping->a_ops->writepage)
@@ -872,11 +870,7 @@ static int f2fs_write_data_pages(struct address_space *mapping, 
			get_dirty_dents(inode) < nr_pages_to_skip(sbi, DATA))

		goto skip_write;



	if (wbc->nr_to_write < MAX_DESIRED_PAGES_WP) {

		desired_nrtw = MAX_DESIRED_PAGES_WP;

		excess_nrtw = desired_nrtw - wbc->nr_to_write;

		wbc->nr_to_write = desired_nrtw;

	}

	diff = nr_pages_to_write(sbi, DATA, wbc);



	if (!S_ISDIR(inode->i_mode)) {

		mutex_lock(&sbi->writepages);
@@ -890,7 +884,7 @@ static int f2fs_write_data_pages(struct address_space *mapping, 


	remove_dirty_dir_inode(inode);



	wbc->nr_to_write -= excess_nrtw;

	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);

	return ret;



skip_write:

fs/f2fs/node.c

+3 −5
Original line number Diff line number Diff line
@@ -1202,7 +1202,7 @@ static int f2fs_write_node_pages(struct address_space *mapping, 
			    struct writeback_control *wbc)

{

	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);

	long nr_to_write = wbc->nr_to_write;

	long diff;



	/* balancing f2fs's metadata in background */

	f2fs_balance_fs_bg(sbi);
@@ -1211,12 +1211,10 @@ static int f2fs_write_node_pages(struct address_space *mapping, 
	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))

		goto skip_write;



	/* if mounting is failed, skip writing node pages */

	wbc->nr_to_write = 3 * max_hw_blocks(sbi);

	diff = nr_pages_to_write(sbi, NODE, wbc);

	wbc->sync_mode = WB_SYNC_NONE;

	sync_node_pages(sbi, 0, wbc);

	wbc->nr_to_write = nr_to_write - (3 * max_hw_blocks(sbi) -

						wbc->nr_to_write);

	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);

	return 0;



skip_write:

fs/f2fs/segment.h

+24 −0
Original line number Diff line number Diff line
@@ -683,3 +683,27 @@ static inline int nr_pages_to_skip(struct f2fs_sb_info *sbi, int type) 
	else

		return 0;

}



/*

 * When writing pages, it'd better align nr_to_write for segment size.

 */

static inline long nr_pages_to_write(struct f2fs_sb_info *sbi, int type,

					struct writeback_control *wbc)

{

	long nr_to_write, desired;



	if (wbc->sync_mode != WB_SYNC_NONE)

		return 0;



	nr_to_write = wbc->nr_to_write;



	if (type == DATA)

		desired = 4096;

	else if (type == NODE)

		desired = 3 * max_hw_blocks(sbi);

	else

		desired = MAX_BIO_BLOCKS(max_hw_blocks(sbi));



	wbc->nr_to_write = desired;

	return desired - nr_to_write;

}