On Mon, Mar 13, 2023 at 12:33:09PM +0000, Luís Henriques wrote:
> + * The regular open path will use fscrypt_file_open for that, but in the
> + * atomic open a different approach is required.
This should actually be fscrypt_prepare_lookup, not fscrypt_file_open, right?
> +int fscrypt_prepare_atomic_open(struct inode *dir, struct dentry *dentry)
> +{
> + int err;
> +
> + if (!IS_ENCRYPTED(dir))
> + return 0;
> +
> + err = fscrypt_get_encryption_info(dir, true);
> + if (!err && !fscrypt_has_encryption_key(dir)) {
> + spin_lock(&dentry->d_lock);
> + dentry->d_flags |= DCACHE_NOKEY_NAME;
> + spin_unlock(&dentry->d_lock);
> + }
> +
> + return err;
> +}
> +EXPORT_SYMBOL_GPL(fscrypt_prepare_atomic_open);
[...]
> +static inline int fscrypt_prepare_atomic_open(struct inode *dir,
> + struct dentry *dentry)
> +{
> + return -EOPNOTSUPP;
> +}
This has different behavior on unencrypted directories depending on whether
CONFIG_FS_ENCRYPTION is enabled or not. That's bad.
In patch 2, the caller you are introducing has already checked IS_ENCRYPTED().
Also, your kerneldoc comment for fscrypt_prepare_atomic_open() says it is for
*encrypted* directories.
So IMO, just remove the IS_ENCRYPTED() check from the CONFIG_FS_ENCRYPTION
version of fscrypt_prepare_atomic_open().
- Eric
