f2fs: use extent cache to optimize f2fs_reserve_block

In some cases, we only need the block address when we call
f2fs_reserve_block,
other fields of struct dnode_of_data aren't necessary.
We can try extent cache first for such cases in order to speed up the
process.

Signed-off-by: Fan li <fanofcode.li@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index f8f93db..4fabdd4 100644 (file)
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -263,6 +263,19 @@ int f2fs_reserve_block(struct dnode_of_data *dn, pgoff_t index)
        return err;
 }
 
+int f2fs_get_block(struct dnode_of_data *dn, pgoff_t index)
+{
+       struct extent_info ei;
+       struct inode *inode = dn->inode;
+
+       if (f2fs_lookup_extent_cache(inode, index, &ei)) {
+               dn->data_blkaddr = ei.blk + index - ei.fofs;
+               return 0;
+       }
+
+       return f2fs_reserve_block(dn, index);
+}
+
 struct page *get_read_data_page(struct inode *inode, pgoff_t index, int rw)
 {
        struct address_space *mapping = inode->i_mapping;
@@ -1383,7 +1396,8 @@ repeat:
                if (err)
                        goto put_fail;
        }
-       err = f2fs_reserve_block(&dn, index);
+
+       err = f2fs_get_block(&dn, index);
        if (err)
                goto put_fail;
 put_next:

diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 34a524d..09cb365 100644 (file)
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -1768,6 +1768,7 @@ int f2fs_submit_page_bio(struct f2fs_io_info *);
 void f2fs_submit_page_mbio(struct f2fs_io_info *);
 void set_data_blkaddr(struct dnode_of_data *);
 int reserve_new_block(struct dnode_of_data *);
+int f2fs_get_block(struct dnode_of_data *, pgoff_t);
 int f2fs_reserve_block(struct dnode_of_data *, pgoff_t);
 struct page *get_read_data_page(struct inode *, pgoff_t, int);
 struct page *find_data_page(struct inode *, pgoff_t);