From: Josef Bacik <[email protected]> We have fscrypt_file_open() which is meant to be called on files being opened so that their key is loaded when we start reading data from them.
However for btrfs send we are opening the inode directly without a filp, so we need a different helper to make sure we can load the fscrypt context for the inode before reading its contents. Signed-off-by: Josef Bacik <[email protected]> Signed-off-by: Daniel Vacek <[email protected]> --- No changes in v7. v6 changes: * Adapted to fscrypt changes since the last two years. v5: https://lore.kernel.org/linux-btrfs/4a372419c3fe6ad425e1b124c342a054e9d6db23.1706116485.git.jo...@toxicpanda.com/ --- fs/crypto/hooks.c | 38 ++++++++++++++++++++++++++++++++------ include/linux/fscrypt.h | 8 ++++++++ 2 files changed, 40 insertions(+), 6 deletions(-) diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c index a7a8a3f581a0..3142cf106bde 100644 --- a/fs/crypto/hooks.c +++ b/fs/crypto/hooks.c @@ -9,6 +9,37 @@ #include "fscrypt_private.h" +/** + * __fscrypt_file_open() - prepare for filesystem-internal access to a + * possibly-encrypted regular file + * @dir: the inode for the directory via which the file is being accessed + * @inode: the inode being "opened" + * + * This is like fscrypt_file_open(), but instead of taking the 'struct file' + * being opened it takes the parent directory explicitly. This is intended for + * use cases such as "send/receive" which involve the filesystem accessing file + * contents without setting up a 'struct file'. + * + * Return: 0 on success, -ENOKEY if the key is missing, or another -errno code + */ +int __fscrypt_file_open(struct inode *dir, struct inode *inode) +{ + int err; + + err = fscrypt_require_key(inode); + if (err) + return err; + + if (!fscrypt_has_permitted_context(dir, inode)) { + fscrypt_warn(inode, + "Inconsistent encryption context (parent directory: %llu)", + dir->i_ino); + return -EPERM; + } + return 0; +} +EXPORT_SYMBOL_GPL(__fscrypt_file_open); + /** * fscrypt_file_open() - prepare to open a possibly-encrypted regular file * @inode: the inode being opened @@ -60,12 +91,7 @@ int fscrypt_file_open(struct inode *inode, struct file *filp) rcu_read_unlock(); dentry_parent = dget_parent(dentry); - if (!fscrypt_has_permitted_context(d_inode(dentry_parent), inode)) { - fscrypt_warn(inode, - "Inconsistent encryption context (parent directory: %llu)", - d_inode(dentry_parent)->i_ino); - err = -EPERM; - } + err = __fscrypt_file_open(d_inode(dentry_parent), inode); dput(dentry_parent); return err; } diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h index f216f1a78069..dda5b1d32f78 100644 --- a/include/linux/fscrypt.h +++ b/include/linux/fscrypt.h @@ -471,6 +471,7 @@ int fscrypt_zeroout_range(const struct inode *inode, loff_t pos, /* hooks.c */ int fscrypt_file_open(struct inode *inode, struct file *filp); +int __fscrypt_file_open(struct inode *dir, struct inode *inode); int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, struct dentry *dentry); int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry, @@ -818,6 +819,13 @@ static inline int fscrypt_file_open(struct inode *inode, struct file *filp) return 0; } +static inline int __fscrypt_file_open(struct inode *dir, struct inode *inode) +{ + if (IS_ENCRYPTED(inode)) + return -EOPNOTSUPP; + return 0; +} + static inline int __fscrypt_prepare_link(struct inode *inode, struct inode *dir, struct dentry *dentry) { -- 2.53.0
