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.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c
index 10cbee9dc3d1266b1ee53fb54276a34e587b704a..c5360b743fec7388bc045829a2f96135da3d6f31 100644 (file)
--- a/fs/f2fs/node.c
+++ b/fs/f2fs/node.c
@@ -847,32 +847,13 @@ fail:
        return ERR_PTR(err);
 }
 
-static int read_node_page(struct page *page, int type)
-{
-       struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
-       struct node_info ni;
-
-       get_node_info(sbi, page->index, &ni);
-
-       if (ni.blk_addr == NULL_ADDR) {
-               f2fs_put_page(page, 1);
-               return -ENOENT;
-       }
-
-       if (PageUptodate(page)) {
-               unlock_page(page);
-               return 0;
-       }
-
-       return f2fs_readpage(sbi, page, ni.blk_addr, type);
-}
-
 /*
  * Readahead a node page
  */
 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
 {
        struct address_space *mapping = sbi->node_inode->i_mapping;
+       struct node_info ni;
        struct page *apage;
 
        apage = find_get_page(mapping, nid);
@@ -886,22 +867,40 @@ void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
        if (!apage)
                return;
 
-       if (read_node_page(apage, READA) == 0)
+       get_node_info(sbi, nid, &ni);
+
+       if (ni.blk_addr == NULL_ADDR || PageUptodate(apage)) {
+               f2fs_put_page(apage, 1);
+               return;
+       }
+
+       if (f2fs_readpage(sbi, apage, ni.blk_addr, READA) == 0)
                f2fs_put_page(apage, 0);
        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;
+       struct node_info ni;
+       int err;
 
        page = grab_cache_page(mapping, nid);
        if (!page)
                return ERR_PTR(-ENOMEM);
 
-       err = read_node_page(page, READ_SYNC);
+       get_node_info(sbi, nid, &ni);
+
+       if (ni.blk_addr == NULL_ADDR) {
+               f2fs_put_page(page, 1);
+               return ERR_PTR(-ENOENT);
+       }
+
+       if (PageUptodate(page))
+               goto got_it;
+
+       err = f2fs_readpage(sbi, page, ni.blk_addr, READ_SYNC);
        if (err)
                return ERR_PTR(err);
 
@@ -910,6 +909,7 @@ struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
                f2fs_put_page(page, 1);
                return ERR_PTR(-EIO);
        }
+got_it:
        BUG_ON(nid != nid_of_node(page));
        mark_page_accessed(page);
        return page;
@@ -923,6 +923,7 @@ 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;
+       struct node_info ni;
        int i, end;
        int err = 0;
        nid_t nid;
@@ -936,10 +937,18 @@ 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))
+
+       get_node_info(sbi, nid, &ni);
+
+       if (ni.blk_addr == NULL_ADDR) {
+               f2fs_put_page(page, 1);
+               return ERR_PTR(-ENOENT);
+       }
+
+       if (PageUptodate(page))
                goto page_hit;
 
-       err = read_node_page(page, READ_SYNC);
+       err = f2fs_readpage(sbi, page, ni.blk_addr, READ_SYNC);
        if (err)
                return ERR_PTR(err);
 
@@ -956,7 +965,7 @@ 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);
        }