ext4: do not iput inode under running transaction in ext4_rename()

In ext4_rename(), when RENAME_WHITEOUT failed to add new entry into
directory, it ends up dropping new created whiteout inode under the
running transaction. After commit <9b88f9fb0d2> ("ext4: Do not iput inode
under running transaction"), we follow the assumptions that evict() does
not get called from a transaction context but in ext4_rename() it breaks
this suggestion. Although it's not a real problem, better to obey it, so
this patch add inode to orphan list and stop transaction before final
iput().

Signed-off-by: zhangyi (F) <yi.zhang@huawei.com>
Link: https://lore.kernel.org/r/20210303131703.330415-2-yi.zhang@huawei.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c
index 4aae59d552887dc272f7896872e8a5ce2e10e9f8..1fe8370dbf0b9a45bb64e0f1503cfb88617f2d2d 100644 (file)
--- a/fs/ext4/namei.c
+++ b/fs/ext4/namei.c
@@ -3799,14 +3799,14 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
         */
        retval = -ENOENT;
        if (!old.bh || le32_to_cpu(old.de->inode) != old.inode->i_ino)
-               goto end_rename;
+               goto release_bh;
 
        new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
                                 &new.de, &new.inlined);
        if (IS_ERR(new.bh)) {
                retval = PTR_ERR(new.bh);
                new.bh = NULL;
-               goto end_rename;
+               goto release_bh;
        }
        if (new.bh) {
                if (!new.inode) {
@@ -3823,15 +3823,13 @@ static int ext4_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
                handle = ext4_journal_start(old.dir, EXT4_HT_DIR, credits);
                if (IS_ERR(handle)) {
                        retval = PTR_ERR(handle);
-                       handle = NULL;
-                       goto end_rename;
+                       goto release_bh;
                }
        } else {
                whiteout = ext4_whiteout_for_rename(mnt_userns, &old, credits, &handle);
                if (IS_ERR(whiteout)) {
                        retval = PTR_ERR(whiteout);
-                       whiteout = NULL;
-                       goto end_rename;
+                       goto release_bh;
                }
        }
 
@@ -3965,16 +3963,18 @@ end_rename:
                        ext4_resetent(handle, &old,
                                      old.inode->i_ino, old_file_type);
                        drop_nlink(whiteout);
+                       ext4_orphan_add(handle, whiteout);
                }
                unlock_new_inode(whiteout);
+               ext4_journal_stop(handle);
                iput(whiteout);
-
+       } else {
+               ext4_journal_stop(handle);
        }
+release_bh:
        brelse(old.dir_bh);
        brelse(old.bh);
        brelse(new.bh);
-       if (handle)
-               ext4_journal_stop(handle);
        return retval;
 }