Eugen Hristev <[email protected]> writes:
> int ext4_fname_setup_ci_filename(struct inode *dir, const struct qstr *iname,
> struct ext4_filename *name)
> {
> @@ -1503,20 +1451,35 @@ static bool ext4_match(struct inode *parent,
> #if IS_ENABLED(CONFIG_UNICODE)
> if (IS_CASEFOLDED(parent) &&
> (!IS_ENCRYPTED(parent) || fscrypt_has_encryption_key(parent))) {
> - if (fname->cf_name.name) {
> - if (IS_ENCRYPTED(parent)) {
> - if (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
> - fname->hinfo.minor_hash !=
> - EXT4_DIRENT_MINOR_HASH(de)) {
> + int ret;
>
> - return false;
> - }
> - }
> - return !ext4_ci_compare(parent, &fname->cf_name,
> - de->name, de->name_len, true);
> + /*
> + * Just checking IS_ENCRYPTED(parent) below is not
> + * sufficient to decide whether one can use the hash for
> + * skipping the string comparison, because the key might
> + * have been added right after
> + * ext4_fname_setup_ci_filename(). In this case, a hash
> + * mismatch will be a false negative. Therefore, make
> + * sure cf_name was properly initialized before
> + * considering the calculated hash.
> + */
> + if (IS_ENCRYPTED(parent) && fname->cf_name.name &&
> + (fname->hinfo.hash != EXT4_DIRENT_HASH(de) ||
> + fname->hinfo.minor_hash != EXT4_DIRENT_MINOR_HASH(de)))
> + return false;
> +
> + ret = generic_ci_match(parent, fname->usr_fname,
> + &fname->cf_name, de->name,
> + de->name_len);
> + if (ret < 0) {
> + /*
> + * Treat comparison errors as not a match. The
> + * only case where it happens is on a disk
> + * corruption or ENOMEM.
> + */
> + return false;
A minor problem with splitting the series as you did is that "ext4: Log
error when lookup of encoded dentry fails" conflicts with this change
and you get a merge conflict if it is applied in the wrong order.
--
Gabriel Krisman Bertazi