From: Filipe Manana <fdmanana@suse.com>
Date: Thu, 20 Jan 2022 11:00:07 +0000
Subject: [PATCH] btrfs: pass the dentry to btrfs_log_new_name() instead of the
 inode
Git-commit: d5f5bd546552a94eefd68c42f40f778c40a89d2c
Patch-mainline: v5.18-rc1
References: bsc#1207263

In the next patch in the series, there will be the need to access the old
name, and its length, of an inode when logging the inode during a rename.
So instead of passing the inode to btrfs_log_new_name() pass the dentry,
because from the dentry we can get the inode, the name and its length.

This will avoid passing 3 new parameters to btrfs_log_new_name() in the
next patch - the name, its length and an index number. This way we end
up passing only 1 new parameter, the index number.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 fs/btrfs/inode.c    |  8 ++++----
 fs/btrfs/tree-log.c | 19 +++++++++++++++----
 fs/btrfs/tree-log.h |  2 +-
 3 files changed, 20 insertions(+), 9 deletions(-)

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5c7aeb588313..8a172e76aadb 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -6531,7 +6531,7 @@ static int btrfs_link(struct dentry *old_dentry, struct inode *dir,
 				goto fail;
 		}
 		d_instantiate(dentry, inode);
-		btrfs_log_new_name(trans, BTRFS_I(inode), NULL, parent);
+		btrfs_log_new_name(trans, old_dentry, NULL, parent);
 	}
 
 fail:
@@ -9211,13 +9211,13 @@ static int btrfs_rename_exchange(struct inode *old_dir,
 		BTRFS_I(new_inode)->dir_index = new_idx;
 
 	if (root_log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
+		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
 				   new_dentry->d_parent);
 		btrfs_end_log_trans(root);
 		root_log_pinned = false;
 	}
 	if (dest_log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(new_inode), BTRFS_I(new_dir),
+		btrfs_log_new_name(trans, new_dentry, BTRFS_I(new_dir),
 				   old_dentry->d_parent);
 		btrfs_end_log_trans(dest);
 		dest_log_pinned = false;
@@ -9498,7 +9498,7 @@ static int btrfs_rename(struct user_namespace *mnt_userns,
 		BTRFS_I(old_inode)->dir_index = index;
 
 	if (log_pinned) {
-		btrfs_log_new_name(trans, BTRFS_I(old_inode), BTRFS_I(old_dir),
+		btrfs_log_new_name(trans, old_dentry, BTRFS_I(old_dir),
 				   new_dentry->d_parent);
 		btrfs_end_log_trans(root);
 		log_pinned = false;
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 2f4f34924c69..0bb0b0439615 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -6788,14 +6788,25 @@ void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
 	mutex_unlock(&dir->log_mutex);
 }
 
-/*
- * Call this after adding a new name for a file and it will properly
- * update the log to reflect the new name.
+/**
+ * Update the log after adding a new name for an inode.
+ *
+ * @trans:              Transaction handle.
+ * @old_dentry:         The dentry associated with the old name and the old
+ *                      parent directory.
+ * @old_dir:            The inode of the previous parent directory for the case
+ *                      of a rename. For a link operation, it must be NULL.
+ * @parent:             The dentry associated with the directory under which the
+ *                      new name is located.
+ *
+ * Call this after adding a new name for an inode, as a result of a link or
+ * rename operation, and it will properly update the log to reflect the new name.
  */
 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
-			struct btrfs_inode *inode, struct btrfs_inode *old_dir,
+			struct dentry *old_dentry, struct btrfs_inode *old_dir,
 			struct dentry *parent)
 {
+	struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
 	struct btrfs_log_ctx ctx;
 
 	/*
diff --git a/fs/btrfs/tree-log.h b/fs/btrfs/tree-log.h
index f6811c3df38a..e69411f308ed 100644
--- a/fs/btrfs/tree-log.h
+++ b/fs/btrfs/tree-log.h
@@ -86,7 +86,7 @@ void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
 void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
 				   struct btrfs_inode *dir);
 void btrfs_log_new_name(struct btrfs_trans_handle *trans,
-			struct btrfs_inode *inode, struct btrfs_inode *old_dir,
+			struct dentry *old_dentry, struct btrfs_inode *old_dir,
 			struct dentry *parent);
 
 #endif
-- 
2.26.2