f2fs: reduce region of f2fs_lock_op covered for better concurrency

In our rename process, region of f2fs_lock_op covered is too big as some of the
code like f2fs_empty_dir/f2fs_find_entry are not needed to protect by this lock.

So in the extreme case like doing checkpoint when we rename old inode to exist
inode in a large directory could cause lower concurrency.

Let's reduce the region of f2fs_lock_op to fix this.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 89b0bd9..1b3cae0 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -387,8 +387,6 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
                        goto out_old;
        }
 
-       f2fs_lock_op(sbi);
-
        if (new_inode) {
 
                err = -ENOTEMPTY;
@@ -401,6 +399,8 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
                if (!new_entry)
                        goto out_dir;
 
+               f2fs_lock_op(sbi);
+
                err = acquire_orphan_inode(sbi);
                if (err)
                        goto put_out_dir;
@@ -429,9 +429,13 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
                update_inode_page(old_inode);
                update_inode_page(new_inode);
        } else {
+               f2fs_lock_op(sbi);
+
                err = f2fs_add_link(new_dentry, old_inode);
-               if (err)
+               if (err) {
+                       f2fs_unlock_op(sbi);
                        goto out_dir;
+               }
 
                if (old_dir_entry) {
                        inc_nlink(new_dir);
@@ -466,6 +470,7 @@ static int f2fs_rename(struct inode *old_dir, struct dentry *old_dentry,
        return 0;
 
 put_out_dir:
+       f2fs_unlock_op(sbi);
        kunmap(new_page);
        f2fs_put_page(new_page, 0);
 out_dir:
@@ -473,7 +478,6 @@ out_dir:
                kunmap(old_dir_page);
                f2fs_put_page(old_dir_page, 0);
        }
-       f2fs_unlock_op(sbi);
 out_old:
        kunmap(old_page);
        f2fs_put_page(old_page, 0);