[PATCH 12/29] ubifs: Implement file open operation

From: Richard Weinberger
Date: Sun Nov 13 2016 - 16:22:08 EST


We need ->open() for files to load the crypto key.
If the no key is present and the file is encrypted,
refuse to open.

Signed-off-by: Richard Weinberger <richard@xxxxxx>
---
fs/ubifs/file.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
index b4fbeefba246..a9c5cc6c0bc5 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -1605,6 +1605,35 @@ static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
return 0;
}

+static int ubifs_file_open(struct inode *inode, struct file *filp)
+{
+ int ret;
+ struct dentry *dir;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+
+ if (ubifs_crypt_is_encrypted(inode)) {
+ ret = fscrypt_get_encryption_info(inode);
+ if (ret)
+ return -EACCES;
+ if (!fscrypt_has_encryption_key(inode))
+ return -ENOKEY;
+ }
+
+ dir = dget_parent(file_dentry(filp));
+ if (ubifs_crypt_is_encrypted(d_inode(dir)) &&
+ !fscrypt_has_permitted_context(d_inode(dir), inode)) {
+ ubifs_err(c, "Inconsistent encryption contexts: %lu/%lu",
+ (unsigned long) d_inode(dir)->i_ino,
+ (unsigned long) inode->i_ino);
+ dput(dir);
+ ubifs_ro_mode(c, -EPERM);
+ return -EPERM;
+ }
+ dput(dir);
+
+ return 0;
+}
+
const struct address_space_operations ubifs_file_address_operations = {
.readpage = ubifs_readpage,
.writepage = ubifs_writepage,
@@ -1647,6 +1676,7 @@ const struct file_operations ubifs_file_operations = {
.unlocked_ioctl = ubifs_ioctl,
.splice_read = generic_file_splice_read,
.splice_write = iter_file_splice_write,
+ .open = ubifs_file_open,
#ifdef CONFIG_COMPAT
.compat_ioctl = ubifs_compat_ioctl,
#endif
--
2.7.3