| Message ID | 8c40d7b6897875be8f908ca4aabf280c2f15b8d4.1691505882.git.sweettea-kernel@dorminy.me (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fscrypt: add extent encryption | expand |
On Tue, Aug 08, 2023 at 01:08:24PM -0400, Sweet Tea Dorminy wrote: > Since per-extent infos are not tied to inodes, an ino-based policy > cannot access the inode's i_ino to get the necessary information. > Instead, this adds an optional fscrypt_operation pointer to get the ino > equivalent for an extent, adds a wrapper to get the ino for an info, and > uses this wrapper everywhere where the ci's inode's i_ino is currently > accessed. > > Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> > --- > fs/crypto/fscrypt_private.h | 18 ++++++++++++++++++ > fs/crypto/keyring.c | 8 ++++---- > fs/crypto/keysetup.c | 6 +++--- > include/linux/fscrypt.h | 9 +++++++++ > 4 files changed, 34 insertions(+), 7 deletions(-) > > diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h > index 1244797cd8a9..4fe79b774f1f 100644 > --- a/fs/crypto/fscrypt_private.h > +++ b/fs/crypto/fscrypt_private.h > @@ -332,6 +332,24 @@ static inline bool fscrypt_uses_extent_encryption(const struct inode *inode) > return false; > } > > +/** > + * fscrypt_get_info_ino() - get the ino or ino equivalent for an info > + * > + * @ci: the fscrypt_info in question > + * > + * Return: For inode-based encryption, this will return the info's inode's ino. > + * For extent-based encryption, this will return the extent's ino equivalent > + * or 0 if it is not implemented. > + */ > +static inline u64 fscrypt_get_info_ino(const struct fscrypt_info *ci) > +{ > + if (ci->ci_inode) > + return ci->ci_inode->i_ino; > + if (!ci->ci_sb->s_cop->get_extent_ino_equivalent) > + return 0; > + return ci->ci_sb->s_cop->get_extent_ino_equivalent(ci->ci_info_ptr); > +} > + > /* crypto.c */ > extern struct kmem_cache *fscrypt_info_cachep; > int fscrypt_initialize(struct super_block *sb); > diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c > index 7cbb1fd872ac..53e37b8a822c 100644 > --- a/fs/crypto/keyring.c > +++ b/fs/crypto/keyring.c > @@ -914,12 +914,12 @@ static int check_for_busy_inodes(struct super_block *sb, > } > > { > - /* select an example file to show for debugging purposes */ > - struct inode *inode = > + /* select an example info to show for debugging purposes */ > + struct fscrypt_info *ci = > list_first_entry(&mk->mk_decrypted_inodes, > struct fscrypt_info, > - ci_master_key_link)->ci_inode; > - ino = inode->i_ino; > + ci_master_key_link); > + ino = fscrypt_get_info_ino(ci); > } > spin_unlock(&mk->mk_decrypted_inodes_lock); > > diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c > index c72f9015ed35..32e62cc57708 100644 > --- a/fs/crypto/keysetup.c > +++ b/fs/crypto/keysetup.c > @@ -380,10 +380,10 @@ int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, > void fscrypt_hash_inode_number(struct fscrypt_info *ci, > const struct fscrypt_master_key *mk) > { > - WARN_ON_ONCE(ci->ci_inode->i_ino == 0); > + WARN_ON_ONCE(fscrypt_get_info_ino(ci) == 0); > WARN_ON_ONCE(!mk->mk_ino_hash_key_initialized); > > - ci->ci_hashed_ino = (u32)siphash_1u64(ci->ci_inode->i_ino, > + ci->ci_hashed_ino = (u32)siphash_1u64(fscrypt_get_info_ino(ci), > &mk->mk_ino_hash_key); > } > > @@ -705,7 +705,7 @@ fscrypt_setup_encryption_info(struct inode *inode, > if (res) > goto out; > > - if (inode->i_ino) > + if (fscrypt_get_info_ino(crypt_info)) > fscrypt_hash_inode_number(crypt_info, mk); > } > > diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h > index c895b12737a1..2a64e7a71a53 100644 > --- a/include/linux/fscrypt.h > +++ b/include/linux/fscrypt.h > @@ -160,6 +160,15 @@ struct fscrypt_operations { > void (*get_ino_and_lblk_bits)(struct super_block *sb, > int *ino_bits_ret, int *lblk_bits_ret); > > + /* > + * Get the inode number equivalent for filesystems using per-extent > + * encryption keys. > + * > + * This function only needs to be implemented if support for one of the > + * FSCRYPT_POLICY_FLAG_IV_INO_* flags is needed. > + */ > + u64 (*get_extent_ino_equivalent)(struct fscrypt_info **info_ptr); > + I went and looked at your tree and nobody actually uses this. I understand wanting to add something for future expansion, but we're just sort of adding things and hoping they'll be useful one day. I think it's best to leave this off and if somebody needs it they can add it later. Thanks, Josef
diff --git a/fs/crypto/fscrypt_private.h b/fs/crypto/fscrypt_private.h index 1244797cd8a9..4fe79b774f1f 100644 --- a/fs/crypto/fscrypt_private.h +++ b/fs/crypto/fscrypt_private.h @@ -332,6 +332,24 @@ static inline bool fscrypt_uses_extent_encryption(const struct inode *inode) return false; } +/** + * fscrypt_get_info_ino() - get the ino or ino equivalent for an info + * + * @ci: the fscrypt_info in question + * + * Return: For inode-based encryption, this will return the info's inode's ino. + * For extent-based encryption, this will return the extent's ino equivalent + * or 0 if it is not implemented. + */ +static inline u64 fscrypt_get_info_ino(const struct fscrypt_info *ci) +{ + if (ci->ci_inode) + return ci->ci_inode->i_ino; + if (!ci->ci_sb->s_cop->get_extent_ino_equivalent) + return 0; + return ci->ci_sb->s_cop->get_extent_ino_equivalent(ci->ci_info_ptr); +} + /* crypto.c */ extern struct kmem_cache *fscrypt_info_cachep; int fscrypt_initialize(struct super_block *sb); diff --git a/fs/crypto/keyring.c b/fs/crypto/keyring.c index 7cbb1fd872ac..53e37b8a822c 100644 --- a/fs/crypto/keyring.c +++ b/fs/crypto/keyring.c @@ -914,12 +914,12 @@ static int check_for_busy_inodes(struct super_block *sb, } { - /* select an example file to show for debugging purposes */ - struct inode *inode = + /* select an example info to show for debugging purposes */ + struct fscrypt_info *ci = list_first_entry(&mk->mk_decrypted_inodes, struct fscrypt_info, - ci_master_key_link)->ci_inode; - ino = inode->i_ino; + ci_master_key_link); + ino = fscrypt_get_info_ino(ci); } spin_unlock(&mk->mk_decrypted_inodes_lock); diff --git a/fs/crypto/keysetup.c b/fs/crypto/keysetup.c index c72f9015ed35..32e62cc57708 100644 --- a/fs/crypto/keysetup.c +++ b/fs/crypto/keysetup.c @@ -380,10 +380,10 @@ int fscrypt_derive_dirhash_key(struct fscrypt_info *ci, void fscrypt_hash_inode_number(struct fscrypt_info *ci, const struct fscrypt_master_key *mk) { - WARN_ON_ONCE(ci->ci_inode->i_ino == 0); + WARN_ON_ONCE(fscrypt_get_info_ino(ci) == 0); WARN_ON_ONCE(!mk->mk_ino_hash_key_initialized); - ci->ci_hashed_ino = (u32)siphash_1u64(ci->ci_inode->i_ino, + ci->ci_hashed_ino = (u32)siphash_1u64(fscrypt_get_info_ino(ci), &mk->mk_ino_hash_key); } @@ -705,7 +705,7 @@ fscrypt_setup_encryption_info(struct inode *inode, if (res) goto out; - if (inode->i_ino) + if (fscrypt_get_info_ino(crypt_info)) fscrypt_hash_inode_number(crypt_info, mk); } diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index c895b12737a1..2a64e7a71a53 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -160,6 +160,15 @@ struct fscrypt_operations { void (*get_ino_and_lblk_bits)(struct super_block *sb, int *ino_bits_ret, int *lblk_bits_ret); + /* + * Get the inode number equivalent for filesystems using per-extent + * encryption keys. + * + * This function only needs to be implemented if support for one of the + * FSCRYPT_POLICY_FLAG_IV_INO_* flags is needed. + */ + u64 (*get_extent_ino_equivalent)(struct fscrypt_info **info_ptr); + /* * Return an array of pointers to the block devices to which the * filesystem may write encrypted file contents, NULL if the filesystem
Since per-extent infos are not tied to inodes, an ino-based policy cannot access the inode's i_ino to get the necessary information. Instead, this adds an optional fscrypt_operation pointer to get the ino equivalent for an extent, adds a wrapper to get the ino for an info, and uses this wrapper everywhere where the ci's inode's i_ino is currently accessed. Signed-off-by: Sweet Tea Dorminy <sweettea-kernel@dorminy.me> --- fs/crypto/fscrypt_private.h | 18 ++++++++++++++++++ fs/crypto/keyring.c | 8 ++++---- fs/crypto/keysetup.c | 6 +++--- include/linux/fscrypt.h | 9 +++++++++ 4 files changed, 34 insertions(+), 7 deletions(-)