[PATCH 09/10] f2fs crypto: sync ext4_lookup and ext4_file_open

From: Jaegeuk Kim
Date: Thu Feb 25 2016 - 14:27:47 EST


This patch tries to catch up with lookup and open policies in ext4.

Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>
---
fs/f2fs/dir.c | 2 +-
fs/f2fs/file.c | 4 ++++
fs/f2fs/namei.c | 23 +++++++++++++++++++++++
3 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index aa06700..31c30dc 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -855,7 +855,7 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)

if (f2fs_encrypted_inode(inode)) {
err = fscrypt_get_encryption_info(inode);
- if (err && err != -EOPNOTSUPP)
+ if (err && err != -ENOKEY && err != -EOPNOTSUPP)
return err;

err = fscrypt_fname_alloc_buffer(inode, F2FS_NAME_LEN, &fstr);
diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
index f326764..533c2dc 100644
--- a/fs/f2fs/file.c
+++ b/fs/f2fs/file.c
@@ -441,6 +441,7 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma)
static int f2fs_file_open(struct inode *inode, struct file *filp)
{
int ret = generic_file_open(inode, filp);
+ struct inode *dir = filp->f_path.dentry->d_parent->d_inode;

if (!ret && f2fs_encrypted_inode(inode)) {
ret = fscrypt_get_encryption_info(inode);
@@ -449,6 +450,9 @@ static int f2fs_file_open(struct inode *inode, struct file *filp)
if (!f2fs_encrypted_inode(inode))
return -ENOKEY;
}
+ if (f2fs_encrypted_inode(dir) &&
+ !fscrypt_has_permitted_context(dir, inode))
+ return -EPERM;
return ret;
}

diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index 748022e..55a7362 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -261,6 +261,21 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
nid_t ino;
int err = 0;

+ if (f2fs_encrypted_inode(dir)) {
+ int res = fscrypt_get_encryption_info(dir);
+
+ /*
+ * DCACHE_ENCRYPTED_WITH_KEY is set if the dentry is
+ * created while the directory was encrypted and we
+ * don't have access to the key.
+ */
+ if (fscrypt_has_encryption_key(dir))
+ fscrypt_set_encrypted_dentry(dentry);
+ fscrypt_set_d_op(dentry);
+ if (res && res != -ENOKEY)
+ return ERR_PTR(res);
+ }
+
if (dentry->d_name.len > F2FS_NAME_LEN)
return ERR_PTR(-ENAMETOOLONG);

@@ -281,6 +296,14 @@ static struct dentry *f2fs_lookup(struct inode *dir, struct dentry *dentry,
if (err)
goto err_out;
}
+ if (!IS_ERR(inode) && f2fs_encrypted_inode(dir) &&
+ (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode)) &&
+ !fscrypt_has_permitted_context(dir, inode)) {
+ bool nokey = f2fs_encrypted_inode(inode) &&
+ !fscrypt_has_encryption_key(inode);
+ iput(inode);
+ return nokey ? ERR_PTR(-ENOKEY) : ERR_PTR(-EPERM);
+ }
return d_splice_alias(inode, dentry);

err_out:
--
2.6.3