ext4: refactor and move ext4_ioctl_get_encryption_pwsalt()

This patch move code for FS_IOC_GET_ENCRYPTION_PWSALT case into
ext4's crypto.c file, i.e. ext4_ioctl_get_encryption_pwsalt()
and uuid_is_zero(). This is mostly refactoring logic and should
not affect any functionality change.

Suggested-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Ritesh Harjani <ritesh.list@gmail.com>
Link: https://lore.kernel.org/r/5af98b17152a96b245b4f7d2dfb8607fc93e36aa.1652595565.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Ritesh Harjani 2022-05-15 12:07:48 +05:30 committed by Theodore Ts'o
parent 3030b59c85
commit 72f63f4a77
3 changed files with 64 additions and 57 deletions

View File

@ -1,6 +1,7 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/quotaops.h>
#include <linux/uuid.h>
#include "ext4.h"
#include "xattr.h"
@ -71,6 +72,59 @@ void ext4_fname_free_filename(struct ext4_filename *fname)
#endif
}
static bool uuid_is_zero(__u8 u[16])
{
int i;
for (i = 0; i < 16; i++)
if (u[i])
return false;
return true;
}
int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)
{
struct super_block *sb = file_inode(filp)->i_sb;
struct ext4_sb_info *sbi = EXT4_SB(sb);
int err, err2;
handle_t *handle;
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;
if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
err = mnt_want_write_file(filp);
if (err)
return err;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto pwsalt_err_exit;
}
err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
EXT4_JTR_NONE);
if (err)
goto pwsalt_err_journal;
lock_buffer(sbi->s_sbh);
generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
ext4_superblock_csum_set(sb);
unlock_buffer(sbi->s_sbh);
err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
pwsalt_err_journal:
err2 = ext4_journal_stop(handle);
if (err2 && !err)
err = err2;
pwsalt_err_exit:
mnt_drop_write_file(filp);
if (err)
return err;
}
if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))
return -EFAULT;
return 0;
}
static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,

View File

@ -2745,6 +2745,8 @@ int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
void ext4_fname_free_filename(struct ext4_filename *fname);
int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg);
#else /* !CONFIG_FS_ENCRYPTION */
static inline int ext4_fname_setup_filename(struct inode *dir,
const struct qstr *iname,
@ -2777,6 +2779,12 @@ static inline void ext4_fname_free_filename(struct ext4_filename *fname)
fname->cf_name.name = NULL;
#endif
}
static inline int ext4_ioctl_get_encryption_pwsalt(struct file *filp,
void __user *arg)
{
return -EOPNOTSUPP;
}
#endif /* !CONFIG_FS_ENCRYPTION */
/* dir.c */

View File

@ -16,7 +16,6 @@
#include <linux/file.h>
#include <linux/quotaops.h>
#include <linux/random.h>
#include <linux/uuid.h>
#include <linux/uaccess.h>
#include <linux/delay.h>
#include <linux/iversion.h>
@ -504,18 +503,6 @@ journal_err_out:
return err;
}
#ifdef CONFIG_FS_ENCRYPTION
static int uuid_is_zero(__u8 u[16])
{
int i;
for (i = 0; i < 16; i++)
if (u[i])
return 0;
return 1;
}
#endif
/*
* If immutable is set and we are not clearing it, we're not allowed to change
* anything else in the inode. Don't error out if we're only trying to set
@ -1432,51 +1419,9 @@ resizefs_out:
return -EOPNOTSUPP;
return fscrypt_ioctl_set_policy(filp, (const void __user *)arg);
case FS_IOC_GET_ENCRYPTION_PWSALT: {
#ifdef CONFIG_FS_ENCRYPTION
int err, err2;
struct ext4_sb_info *sbi = EXT4_SB(sb);
handle_t *handle;
case FS_IOC_GET_ENCRYPTION_PWSALT:
return ext4_ioctl_get_encryption_pwsalt(filp, (void __user *)arg);
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;
if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
err = mnt_want_write_file(filp);
if (err)
return err;
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
if (IS_ERR(handle)) {
err = PTR_ERR(handle);
goto pwsalt_err_exit;
}
err = ext4_journal_get_write_access(handle, sb,
sbi->s_sbh,
EXT4_JTR_NONE);
if (err)
goto pwsalt_err_journal;
lock_buffer(sbi->s_sbh);
generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
ext4_superblock_csum_set(sb);
unlock_buffer(sbi->s_sbh);
err = ext4_handle_dirty_metadata(handle, NULL,
sbi->s_sbh);
pwsalt_err_journal:
err2 = ext4_journal_stop(handle);
if (err2 && !err)
err = err2;
pwsalt_err_exit:
mnt_drop_write_file(filp);
if (err)
return err;
}
if (copy_to_user((void __user *) arg,
sbi->s_es->s_encrypt_pw_salt, 16))
return -EFAULT;
return 0;
#else
return -EOPNOTSUPP;
#endif
}
case FS_IOC_GET_ENCRYPTION_POLICY:
if (!ext4_has_feature_encrypt(sb))
return -EOPNOTSUPP;