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Commit 56ae674c authored by Jaegeuk Kim's avatar Jaegeuk Kim
Browse files

f2fs: remove redundant lock_page calls 



In get_node_page, we do not need to call lock_page all the time.

If the node page is cached as uptodate,

1. grab_cache_page locks the page,
2. read_node_page unlocks the page, and
3. lock_page is called for further process.

Let's avoid this.

Reviewed-by: default avatarNamjae Jeon <namjae.jeon@samsung.com>
Signed-off-by: default avatarJaegeuk Kim <jaegeuk.kim@samsung.com>
parent 53cf9522

fs/f2fs/node.c

+25 −15
Original line number Diff line number Diff line
@@ -847,6 +847,12 @@ struct page *new_node_page(struct dnode_of_data *dn, unsigned int ofs) 
	return ERR_PTR(err);

}



/*

 * Caller should do after getting the following values.

 * 0: f2fs_put_page(page, 0)

 * LOCKED_PAGE: f2fs_put_page(page, 1)

 * error: nothing

 */

static int read_node_page(struct page *page, int type)

{

	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
@@ -859,10 +865,8 @@ static int read_node_page(struct page *page, int type) 
		return -ENOENT;

	}



	if (PageUptodate(page)) {

		unlock_page(page);

		return 0;

	}

	if (PageUptodate(page))

		return LOCKED_PAGE;



	return f2fs_readpage(sbi, page, ni.blk_addr, type);

}
@@ -874,6 +878,7 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid) 
{

	struct address_space *mapping = sbi->node_inode->i_mapping;

	struct page *apage;

	int err;



	apage = find_get_page(mapping, nid);

	if (apage && PageUptodate(apage)) {
@@ -886,30 +891,36 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid) 
	if (!apage)

		return;



	if (read_node_page(apage, READA) == 0)

	err = read_node_page(apage, READA);

	if (err == 0)

		f2fs_put_page(apage, 0);

	else if (err == LOCKED_PAGE)

		f2fs_put_page(apage, 1);

	return;

}



struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)

{

	int err;

	struct page *page;

	struct address_space *mapping = sbi->node_inode->i_mapping;

	struct page *page;

	int err;



	page = grab_cache_page(mapping, nid);

	if (!page)

		return ERR_PTR(-ENOMEM);



	err = read_node_page(page, READ_SYNC);

	if (err)

	if (err < 0)

		return ERR_PTR(err);

	else if (err == LOCKED_PAGE)

		goto got_it;



	lock_page(page);

	if (!PageUptodate(page)) {

		f2fs_put_page(page, 1);

		return ERR_PTR(-EIO);

	}

got_it:

	BUG_ON(nid != nid_of_node(page));

	mark_page_accessed(page);

	return page;
@@ -923,10 +934,9 @@ struct page *get_node_page_ra(struct page *parent, int start) 
{

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

	struct address_space *mapping = sbi->node_inode->i_mapping;

	int i, end;

	int err = 0;

	nid_t nid;

	struct page *page;

	int err, i, end;

	nid_t nid;



	/* First, try getting the desired direct node. */

	nid = get_nid(parent, start, false);
@@ -936,12 +946,12 @@ struct page *get_node_page_ra(struct page *parent, int start) 
	page = grab_cache_page(mapping, nid);

	if (!page)

		return ERR_PTR(-ENOMEM);

	else if (PageUptodate(page))

		goto page_hit;



	err = read_node_page(page, READ_SYNC);

	if (err)

	if (err < 0)

		return ERR_PTR(err);

	else if (err == LOCKED_PAGE)

		goto page_hit;



	/* Then, try readahead for siblings of the desired node */

	end = start + MAX_RA_NODE;
@@ -956,7 +966,7 @@ struct page *get_node_page_ra(struct page *parent, int start) 
	lock_page(page);



page_hit:

	if (PageError(page)) {

	if (!PageUptodate(page)) {

		f2fs_put_page(page, 1);

		return ERR_PTR(-EIO);

	}

fs/f2fs/node.h

+3 −0
Original line number Diff line number Diff line
@@ -29,6 +29,9 @@ 
/* vector size for gang look-up from nat cache that consists of radix tree */

#define NATVEC_SIZE	64



/* return value for read_node_page */

#define LOCKED_PAGE	1



/*

 * For node information

 */