Commit 2ebdef6d authored by Eric Biggers's avatar Eric Biggers

fscrypt: move fscrypt_d_revalidate() to fname.c

fscrypt_d_revalidate() and fscrypt_d_ops really belong in fname.c, since
they're specific to filenames encryption.  crypto.c is for contents
encryption and general fs/crypto/ initialization and utilities.

Link: https://lore.kernel.org/r/20191209204359.228544-1-ebiggers@kernel.orgSigned-off-by: default avatarEric Biggers <ebiggers@google.com>
parent 8a4ab0b8
......@@ -25,8 +25,6 @@
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/ratelimit.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <crypto/skcipher.h>
#include "fscrypt_private.h"
......@@ -286,54 +284,6 @@ int fscrypt_decrypt_block_inplace(const struct inode *inode, struct page *page,
}
EXPORT_SYMBOL(fscrypt_decrypt_block_inplace);
/*
* Validate dentries in encrypted directories to make sure we aren't potentially
* caching stale dentries after a key has been added.
*/
static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
{
struct dentry *dir;
int err;
int valid;
/*
* Plaintext names are always valid, since fscrypt doesn't support
* reverting to ciphertext names without evicting the directory's inode
* -- which implies eviction of the dentries in the directory.
*/
if (!(dentry->d_flags & DCACHE_ENCRYPTED_NAME))
return 1;
/*
* Ciphertext name; valid if the directory's key is still unavailable.
*
* Although fscrypt forbids rename() on ciphertext names, we still must
* use dget_parent() here rather than use ->d_parent directly. That's
* because a corrupted fs image may contain directory hard links, which
* the VFS handles by moving the directory's dentry tree in the dcache
* each time ->lookup() finds the directory and it already has a dentry
* elsewhere. Thus ->d_parent can be changing, and we must safely grab
* a reference to some ->d_parent to prevent it from being freed.
*/
if (flags & LOOKUP_RCU)
return -ECHILD;
dir = dget_parent(dentry);
err = fscrypt_get_encryption_info(d_inode(dir));
valid = !fscrypt_has_encryption_key(d_inode(dir));
dput(dir);
if (err < 0)
return err;
return valid;
}
const struct dentry_operations fscrypt_d_ops = {
.d_revalidate = fscrypt_d_revalidate,
};
/**
* fscrypt_initialize() - allocate major buffers for fs encryption.
* @cop_flags: fscrypt operations flags
......
......@@ -11,6 +11,7 @@
* This has not yet undergone a rigorous security audit.
*/
#include <linux/namei.h>
#include <linux/scatterlist.h>
#include <crypto/skcipher.h>
#include "fscrypt_private.h"
......@@ -400,3 +401,51 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
return ret;
}
EXPORT_SYMBOL(fscrypt_setup_filename);
/*
* Validate dentries in encrypted directories to make sure we aren't potentially
* caching stale dentries after a key has been added.
*/
static int fscrypt_d_revalidate(struct dentry *dentry, unsigned int flags)
{
struct dentry *dir;
int err;
int valid;
/*
* Plaintext names are always valid, since fscrypt doesn't support
* reverting to ciphertext names without evicting the directory's inode
* -- which implies eviction of the dentries in the directory.
*/
if (!(dentry->d_flags & DCACHE_ENCRYPTED_NAME))
return 1;
/*
* Ciphertext name; valid if the directory's key is still unavailable.
*
* Although fscrypt forbids rename() on ciphertext names, we still must
* use dget_parent() here rather than use ->d_parent directly. That's
* because a corrupted fs image may contain directory hard links, which
* the VFS handles by moving the directory's dentry tree in the dcache
* each time ->lookup() finds the directory and it already has a dentry
* elsewhere. Thus ->d_parent can be changing, and we must safely grab
* a reference to some ->d_parent to prevent it from being freed.
*/
if (flags & LOOKUP_RCU)
return -ECHILD;
dir = dget_parent(dentry);
err = fscrypt_get_encryption_info(d_inode(dir));
valid = !fscrypt_has_encryption_key(d_inode(dir));
dput(dir);
if (err < 0)
return err;
return valid;
}
const struct dentry_operations fscrypt_d_ops = {
.d_revalidate = fscrypt_d_revalidate,
};
......@@ -233,7 +233,6 @@ extern int fscrypt_crypt_block(const struct inode *inode,
unsigned int len, unsigned int offs,
gfp_t gfp_flags);
extern struct page *fscrypt_alloc_bounce_page(gfp_t gfp_flags);
extern const struct dentry_operations fscrypt_d_ops;
extern void __printf(3, 4) __cold
fscrypt_msg(const struct inode *inode, const char *level, const char *fmt, ...);
......@@ -265,6 +264,7 @@ extern int fname_encrypt(const struct inode *inode, const struct qstr *iname,
extern bool fscrypt_fname_encrypted_size(const struct inode *inode,
u32 orig_len, u32 max_len,
u32 *encrypted_len_ret);
extern const struct dentry_operations fscrypt_d_ops;
/* hkdf.c */
......
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