ENOTEMPTY on "rm -rf" for snapshot and subvolume

Hi Everyone,

Recently i created a snapshot of an existing volume which had
some amount of data.
Now that after creating the snapshot i have tried deleting the
same snapshot. But i am
getting ENOTEMPTY for "rmdir". But when i see the actual files
inside are deleted
not the parent directory.

From the code it looks like

if (inode->i_size > BTRFS_EMPTY_DIR_SIZE ||
inode->i_ino == BTRFS_FIRST_FREE_OBJECTID)
return -ENOTEMPTY;

Why would "unlink" succeeds for the files inside the
directory?, yet returning ENOTEMPTY

This looks odd after this, i went ahead and tried deleting the
the existing volume itself
same result.

So i was wondering if at all this is supposed to work this way,
do i need to use "btrfs"
commands to delete subvolumes always? and their relative snapshots?.

But either in that case too returning ENOTEMPTY does confuse a
user a lot. Isn't it valid
just by returning EPERM will explain a lot to users saying that
this is a snapshot of a
subvolume or a parent subvolume which is not supposed to be
deleted this way.

Quoted 7 lines

Quoted 6 lines

But either in that case too returning ENOTEMPTY does confuse a
user a lot. Isn't it valid
just by returning EPERM will explain a lot to users saying that
this is a snapshot of a
subvolume or a parent subvolume which is not supposed to be
deleted this way.

Good point, eperm might be more intuitive.

-chris