fscrypt: export fscrypt_d_revalidate()

Dentries that represent no-key names must have a dentry_operations that
includes fscrypt_d_revalidate().  Currently, this is handled by
fscrypt_prepare_lookup() installing fscrypt_d_ops.

However, ceph support for encryption
(https://lore.kernel.org/r/20200914191707.380444-1-jlayton@kernel.org)
can't use fscrypt_d_ops, since ceph already has its own
dentry_operations.

Similarly, ext4 and f2fs support for directories that are both encrypted
and casefolded
(https://lore.kernel.org/r/20200923010151.69506-1-drosen@google.com)
can't use fscrypt_d_ops either, since casefolding requires some dentry
operations too.

To satisfy both users, we need to move the responsibility of installing
the dentry_operations to filesystems.

In preparation for this, export fscrypt_d_revalidate() and give it a
!CONFIG_FS_ENCRYPTION stub.

Reviewed-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20200924054721.187797-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
This commit is contained in:
Eric Biggers 2020-09-23 22:47:21 -07:00
parent 501e43fbea
commit 5b2a828b98
2 changed files with 9 additions and 1 deletions

View File

@ -530,7 +530,7 @@ EXPORT_SYMBOL_GPL(fscrypt_fname_siphash);
* Validate dentries in encrypted directories to make sure we aren't potentially * Validate dentries in encrypted directories to make sure we aren't potentially
* caching stale dentries after a key has been added. * caching stale dentries after a key has been added.
*/ */
static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags) int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
{ {
struct dentry *dir; struct dentry *dir;
int err; int err;
@ -569,6 +569,7 @@ static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
return valid; return valid;
} }
EXPORT_SYMBOL_GPL(fscrypt_d_revalidate);
const struct dentry_operations fscrypt_d_ops = { const struct dentry_operations fscrypt_d_ops = {
.d_revalidate = fscrypt_d_revalidate, .d_revalidate = fscrypt_d_revalidate,

View File

@ -197,6 +197,7 @@ int fscrypt_fname_disk_to_usr(const struct inode *inode,
bool fscrypt_match_name(const struct fscrypt_name *fname, bool fscrypt_match_name(const struct fscrypt_name *fname,
const u8 *de_name, u32 de_name_len); const u8 *de_name, u32 de_name_len);
u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name); u64 fscrypt_fname_siphash(const struct inode *dir, const struct qstr *name);
int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags);
/* bio.c */ /* bio.c */
void fscrypt_decrypt_bio(struct bio *bio); void fscrypt_decrypt_bio(struct bio *bio);
@ -454,6 +455,12 @@ static inline u64 fscrypt_fname_siphash(const struct inode *dir,
return 0; return 0;
} }
static inline int fscrypt_d_revalidate(struct dentry *dentry,
unsigned int flags)
{
return 1;
}
/* bio.c */ /* bio.c */
static inline void fscrypt_decrypt_bio(struct bio *bio) static inline void fscrypt_decrypt_bio(struct bio *bio)
{ {