On Mar 25, 2020, at 3:37 AM, Harshad Shirwadkar <harshadshirwadkar@gmail.com> wrote:
> 
> This patch makes ext4_find_entry and related routines to return
> logical block address of the dirent block. This logical block address
> is used in the directory shrinking code to perform reverse lookup and
> verify that the lookup was successful.
> 
> Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
> ---
> fs/ext4/namei.c | 54 +++++++++++++++++++++++++++++--------------------
> 1 file changed, 32 insertions(+), 22 deletions(-)

Would it make sense to add the "lblk" field to struct ext4_renament,
rather than adding an extra argument for all of these functions?

Otherwise, the patch looks OK.

Reviewed-by: Andreas Dilger <adilger@dilger.ca>

> static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
> -			       int force_reread)
> +			       int force_reread, ext4_lblk_t lblk)
> {
> 	int retval;
> 	/*
> @@ -3593,7 +3600,8 @@ static void ext4_rename_delete(handle_t *handle, struct ext4_renament *ent,
> 		retval = ext4_find_delete_entry(handle, ent->dir,
> 						&ent->dentry->d_name);
> 	} else {
> -		retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh);
> +		retval = ext4_delete_entry(handle, ent->dir, ent->de, ent->bh,
> +					   lblk);
> 		if (retval == -ENOENT) {
> 			retval = ext4_find_delete_entry(handle, ent->dir,
> 							&ent->dentry->d_name);
> @@ -3679,6 +3687,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> 	struct inode *whiteout = NULL;
> 	int credits;
> 	u8 old_file_type;
> +	ext4_lblk_t lblk;
> 
> 	if (new.inode && new.inode->i_nlink == 0) {
> 		EXT4_ERROR_INODE(new.inode,
> @@ -3706,7 +3715,8 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> 			return retval;
> 	}
> 
> -	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL);
> +	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name, &old.de, NULL,
> +				 &lblk);
> 	if (IS_ERR(old.bh))
> 		return PTR_ERR(old.bh);
> 	/*
> @@ -3720,7 +3730,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> 		goto end_rename;
> 
> 	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
> -				 &new.de, &new.inlined);
> +				 &new.de, &new.inlined, NULL);
> 	if (IS_ERR(new.bh)) {
> 		retval = PTR_ERR(new.bh);
> 		new.bh = NULL;
> @@ -3817,7 +3827,7 @@ static int ext4_rename(struct inode *old_dir, struct dentry *old_dentry,
> 		/*
> 		 * ok, that's it
> 		 */
> -		ext4_rename_delete(handle, &old, force_reread);
> +		ext4_rename_delete(handle, &old, force_reread, lblk);
> 	}
> 
> 	if (new.inode) {
> @@ -3900,7 +3910,7 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
> 		return retval;
> 
> 	old.bh = ext4_find_entry(old.dir, &old.dentry->d_name,
> -				 &old.de, &old.inlined);
> +				 &old.de, &old.inlined, NULL);
> 	if (IS_ERR(old.bh))
> 		return PTR_ERR(old.bh);
> 	/*
> @@ -3914,7 +3924,7 @@ static int ext4_cross_rename(struct inode *old_dir, struct dentry *old_dentry,
> 		goto end_rename;
> 
> 	new.bh = ext4_find_entry(new.dir, &new.dentry->d_name,
> -				 &new.de, &new.inlined);
> +				 &new.de, &new.inlined, NULL);
> 	if (IS_ERR(new.bh)) {
> 		retval = PTR_ERR(new.bh);
> 		new.bh = NULL;
> --
> 2.25.1.696.g5e7596f4ac-goog
> 


Cheers, Andreas