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authorEric Biggers <ebiggers@google.com>2017-10-09 22:15:42 +0300
committerTheodore Ts'o <tytso@mit.edu>2017-10-19 02:52:38 +0300
commit94b26f3672a0e41025104c7e46943917544e1c87 (patch)
tree89c19235e098d8f71662a23992c1800a8681b44f /fs/crypto
parent0ea87a9644ebb5c9a3b100585d10533366de3269 (diff)
downloadlinux-94b26f3672a0e41025104c7e46943917544e1c87.tar.xz
fscrypt: new helper function - fscrypt_prepare_rename()
Introduce a helper function which prepares to rename a file into a possibly encrypted directory. It handles loading the encryption keys for the source and target directories if needed, and it handles enforcing that if the target directory (and the source directory for a cross-rename) is encrypted, then the file being moved into the directory has the same encryption policy as its containing directory. Acked-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/crypto')
-rw-r--r--fs/crypto/hooks.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/fs/crypto/hooks.c b/fs/crypto/hooks.c
index 8b90217320dd..822cb78f9b45 100644
--- a/fs/crypto/hooks.c
+++ b/fs/crypto/hooks.c
@@ -62,3 +62,33 @@ int __fscrypt_prepare_link(struct inode *inode, struct inode *dir)
return 0;
}
EXPORT_SYMBOL_GPL(__fscrypt_prepare_link);
+
+int __fscrypt_prepare_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry,
+ unsigned int flags)
+{
+ int err;
+
+ err = fscrypt_require_key(old_dir);
+ if (err)
+ return err;
+
+ err = fscrypt_require_key(new_dir);
+ if (err)
+ return err;
+
+ if (old_dir != new_dir) {
+ if (IS_ENCRYPTED(new_dir) &&
+ !fscrypt_has_permitted_context(new_dir,
+ d_inode(old_dentry)))
+ return -EPERM;
+
+ if ((flags & RENAME_EXCHANGE) &&
+ IS_ENCRYPTED(old_dir) &&
+ !fscrypt_has_permitted_context(old_dir,
+ d_inode(new_dentry)))
+ return -EPERM;
+ }
+ return 0;
+}
+EXPORT_SYMBOL_GPL(__fscrypt_prepare_rename);