f2fs: support ->rename2()

Now new interface ->rename2() is added to VFS, here are related description:
https://lkml.org/lkml/2014/2/7/873
https://lkml.org/lkml/2014/2/7/758

This patch adds function f2fs_rename2() to support ->rename2() including
handling both RENAME_EXCHANGE and RENAME_NOREPLACE flag.

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 1b3cae03c24f04708e74a624bcd4e8342a31c464..27b03776ffd21b8377dd645ba15591c1e783c19e 100644 (file)
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -485,6 +485,169 @@ out:
        return err;
 }
 
+static int f2fs_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
+                            struct inode *new_dir, struct dentry *new_dentry)
+{
+       struct super_block *sb = old_dir->i_sb;
+       struct f2fs_sb_info *sbi = F2FS_SB(sb);
+       struct inode *old_inode = old_dentry->d_inode;
+       struct inode *new_inode = new_dentry->d_inode;
+       struct page *old_dir_page, *new_dir_page;
+       struct page *old_page, *new_page;
+       struct f2fs_dir_entry *old_dir_entry = NULL, *new_dir_entry = NULL;
+       struct f2fs_dir_entry *old_entry, *new_entry;
+       int old_nlink = 0, new_nlink = 0;
+       int err = -ENOENT;
+
+       f2fs_balance_fs(sbi);
+
+       old_entry = f2fs_find_entry(old_dir, &old_dentry->d_name, &old_page);
+       if (!old_entry)
+               goto out;
+
+       new_entry = f2fs_find_entry(new_dir, &new_dentry->d_name, &new_page);
+       if (!new_entry)
+               goto out_old;
+
+       /* prepare for updating ".." directory entry info later */
+       if (old_dir != new_dir) {
+               if (S_ISDIR(old_inode->i_mode)) {
+                       err = -EIO;
+                       old_dir_entry = f2fs_parent_dir(old_inode,
+                                                       &old_dir_page);
+                       if (!old_dir_entry)
+                               goto out_new;
+               }
+
+               if (S_ISDIR(new_inode->i_mode)) {
+                       err = -EIO;
+                       new_dir_entry = f2fs_parent_dir(new_inode,
+                                                       &new_dir_page);
+                       if (!new_dir_entry)
+                               goto out_old_dir;
+               }
+       }
+
+       /*
+        * If cross rename between file and directory those are not
+        * in the same directory, we will inc nlink of file's parent
+        * later, so we should check upper boundary of its nlink.
+        */
+       if ((!old_dir_entry || !new_dir_entry) &&
+                               old_dir_entry != new_dir_entry) {
+               old_nlink = old_dir_entry ? -1 : 1;
+               new_nlink = -old_nlink;
+               err = -EMLINK;
+               if ((old_nlink > 0 && old_inode->i_nlink >= F2FS_LINK_MAX) ||
+                       (new_nlink > 0 && new_inode->i_nlink >= F2FS_LINK_MAX))
+                       goto out_new_dir;
+       }
+
+       f2fs_lock_op(sbi);
+
+       err = update_dent_inode(old_inode, &new_dentry->d_name);
+       if (err)
+               goto out_unlock;
+
+       err = update_dent_inode(new_inode, &old_dentry->d_name);
+       if (err)
+               goto out_undo;
+
+       /* update ".." directory entry info of old dentry */
+       if (old_dir_entry)
+               f2fs_set_link(old_inode, old_dir_entry, old_dir_page, new_dir);
+
+       /* update ".." directory entry info of new dentry */
+       if (new_dir_entry)
+               f2fs_set_link(new_inode, new_dir_entry, new_dir_page, old_dir);
+
+       /* update directory entry info of old dir inode */
+       f2fs_set_link(old_dir, old_entry, old_page, new_inode);
+
+       down_write(&F2FS_I(old_inode)->i_sem);
+       file_lost_pino(old_inode);
+       up_write(&F2FS_I(old_inode)->i_sem);
+
+       update_inode_page(old_inode);
+
+       old_dir->i_ctime = CURRENT_TIME;
+       if (old_nlink) {
+               down_write(&F2FS_I(old_dir)->i_sem);
+               if (old_nlink < 0)
+                       drop_nlink(old_dir);
+               else
+                       inc_nlink(old_dir);
+               up_write(&F2FS_I(old_dir)->i_sem);
+       }
+       mark_inode_dirty(old_dir);
+       update_inode_page(old_dir);
+
+       /* update directory entry info of new dir inode */
+       f2fs_set_link(new_dir, new_entry, new_page, old_inode);
+
+       down_write(&F2FS_I(new_inode)->i_sem);
+       file_lost_pino(new_inode);
+       up_write(&F2FS_I(new_inode)->i_sem);
+
+       update_inode_page(new_inode);
+
+       new_dir->i_ctime = CURRENT_TIME;
+       if (new_nlink) {
+               down_write(&F2FS_I(new_dir)->i_sem);
+               if (new_nlink < 0)
+                       drop_nlink(new_dir);
+               else
+                       inc_nlink(new_dir);
+               up_write(&F2FS_I(new_dir)->i_sem);
+       }
+       mark_inode_dirty(new_dir);
+       update_inode_page(new_dir);
+
+       f2fs_unlock_op(sbi);
+       return 0;
+out_undo:
+       /* Still we may fail to recover name info of f2fs_inode here */
+       update_dent_inode(old_inode, &old_dentry->d_name);
+out_unlock:
+       f2fs_unlock_op(sbi);
+out_new_dir:
+       if (new_dir_entry) {
+               kunmap(new_dir_page);
+               f2fs_put_page(new_dir_page, 0);
+       }
+out_old_dir:
+       if (old_dir_entry) {
+               kunmap(old_dir_page);
+               f2fs_put_page(old_dir_page, 0);
+       }
+out_new:
+       kunmap(new_page);
+       f2fs_put_page(new_page, 0);
+out_old:
+       kunmap(old_page);
+       f2fs_put_page(old_page, 0);
+out:
+       return err;
+}
+
+static int f2fs_rename2(struct inode *old_dir, struct dentry *old_dentry,
+                       struct inode *new_dir, struct dentry *new_dentry,
+                       unsigned int flags)
+{
+       if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE))
+               return -EINVAL;
+
+       if (flags & RENAME_EXCHANGE) {
+               return f2fs_cross_rename(old_dir, old_dentry,
+                                        new_dir, new_dentry);
+       }
+       /*
+        * VFS has already handled the new dentry existence case,
+        * here, we just deal with "RENAME_NOREPLACE" as regular rename.
+        */
+       return f2fs_rename(old_dir, old_dentry, new_dir, new_dentry);
+}
+
 static int f2fs_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode)
 {
        struct f2fs_sb_info *sbi = F2FS_SB(dir->i_sb);
@@ -542,6 +705,7 @@ const struct inode_operations f2fs_dir_inode_operations = {
        .rmdir          = f2fs_rmdir,
        .mknod          = f2fs_mknod,
        .rename         = f2fs_rename,
+       .rename2        = f2fs_rename2,
        .tmpfile        = f2fs_tmpfile,
        .getattr        = f2fs_getattr,
        .setattr        = f2fs_setattr,