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1// SPDX-License-Identifier: GPL-2.02 3#include <linux/quotaops.h>4#include <linux/uuid.h>5 6#include "ext4.h"7#include "xattr.h"8#include "ext4_jbd2.h"9 10static void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,11 const struct fscrypt_name *src)12{13 memset(dst, 0, sizeof(*dst));14 15 dst->usr_fname = src->usr_fname;16 dst->disk_name = src->disk_name;17 dst->hinfo.hash = src->hash;18 dst->hinfo.minor_hash = src->minor_hash;19 dst->crypto_buf = src->crypto_buf;20}21 22int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,23 int lookup, struct ext4_filename *fname)24{25 struct fscrypt_name name;26 int err;27 28 err = fscrypt_setup_filename(dir, iname, lookup, &name);29 if (err)30 return err;31 32 ext4_fname_from_fscrypt_name(fname, &name);33 34 err = ext4_fname_setup_ci_filename(dir, iname, fname);35 if (err)36 ext4_fname_free_filename(fname);37 38 return err;39}40 41int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,42 struct ext4_filename *fname)43{44 struct fscrypt_name name;45 int err;46 47 err = fscrypt_prepare_lookup(dir, dentry, &name);48 if (err)49 return err;50 51 ext4_fname_from_fscrypt_name(fname, &name);52 53 err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);54 if (err)55 ext4_fname_free_filename(fname);56 return err;57}58 59void ext4_fname_free_filename(struct ext4_filename *fname)60{61 struct fscrypt_name name;62 63 name.crypto_buf = fname->crypto_buf;64 fscrypt_free_filename(&name);65 66 fname->crypto_buf.name = NULL;67 fname->usr_fname = NULL;68 fname->disk_name.name = NULL;69 70 ext4_fname_free_ci_filename(fname);71}72 73static bool uuid_is_zero(__u8 u[16])74{75 int i;76 77 for (i = 0; i < 16; i++)78 if (u[i])79 return false;80 return true;81}82 83int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)84{85 struct super_block *sb = file_inode(filp)->i_sb;86 struct ext4_sb_info *sbi = EXT4_SB(sb);87 int err, err2;88 handle_t *handle;89 90 if (!ext4_has_feature_encrypt(sb))91 return -EOPNOTSUPP;92 93 if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {94 err = mnt_want_write_file(filp);95 if (err)96 return err;97 handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);98 if (IS_ERR(handle)) {99 err = PTR_ERR(handle);100 goto pwsalt_err_exit;101 }102 err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,103 EXT4_JTR_NONE);104 if (err)105 goto pwsalt_err_journal;106 lock_buffer(sbi->s_sbh);107 generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);108 ext4_superblock_csum_set(sb);109 unlock_buffer(sbi->s_sbh);110 err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);111pwsalt_err_journal:112 err2 = ext4_journal_stop(handle);113 if (err2 && !err)114 err = err2;115pwsalt_err_exit:116 mnt_drop_write_file(filp);117 if (err)118 return err;119 }120 121 if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))122 return -EFAULT;123 return 0;124}125 126static int ext4_get_context(struct inode *inode, void *ctx, size_t len)127{128 return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,129 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);130}131 132static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,133 void *fs_data)134{135 handle_t *handle = fs_data;136 int res, res2, credits, retries = 0;137 138 /*139 * Encrypting the root directory is not allowed because e2fsck expects140 * lost+found to exist and be unencrypted, and encrypting the root141 * directory would imply encrypting the lost+found directory as well as142 * the filename "lost+found" itself.143 */144 if (inode->i_ino == EXT4_ROOT_INO)145 return -EPERM;146 147 if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))148 return -EINVAL;149 150 if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))151 return -EOPNOTSUPP;152 153 res = ext4_convert_inline_data(inode);154 if (res)155 return res;156 157 /*158 * If a journal handle was specified, then the encryption context is159 * being set on a new inode via inheritance and is part of a larger160 * transaction to create the inode. Otherwise the encryption context is161 * being set on an existing inode in its own transaction. Only in the162 * latter case should the "retry on ENOSPC" logic be used.163 */164 165 if (handle) {166 res = ext4_xattr_set_handle(handle, inode,167 EXT4_XATTR_INDEX_ENCRYPTION,168 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,169 ctx, len, 0);170 if (!res) {171 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);172 ext4_clear_inode_state(inode,173 EXT4_STATE_MAY_INLINE_DATA);174 /*175 * Update inode->i_flags - S_ENCRYPTED will be enabled,176 * S_DAX may be disabled177 */178 ext4_set_inode_flags(inode, false);179 }180 return res;181 }182 183 res = dquot_initialize(inode);184 if (res)185 return res;186retry:187 res = ext4_xattr_set_credits(inode, len, false /* is_create */,188 &credits);189 if (res)190 return res;191 192 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);193 if (IS_ERR(handle))194 return PTR_ERR(handle);195 196 res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,197 EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,198 ctx, len, 0);199 if (!res) {200 ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);201 /*202 * Update inode->i_flags - S_ENCRYPTED will be enabled,203 * S_DAX may be disabled204 */205 ext4_set_inode_flags(inode, false);206 res = ext4_mark_inode_dirty(handle, inode);207 if (res)208 EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");209 }210 res2 = ext4_journal_stop(handle);211 212 if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))213 goto retry;214 if (!res)215 res = res2;216 return res;217}218 219static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)220{221 return EXT4_SB(sb)->s_dummy_enc_policy.policy;222}223 224static bool ext4_has_stable_inodes(struct super_block *sb)225{226 return ext4_has_feature_stable_inodes(sb);227}228 229const struct fscrypt_operations ext4_cryptops = {230 .needs_bounce_pages = 1,231 .has_32bit_inodes = 1,232 .supports_subblock_data_units = 1,233 .legacy_key_prefix = "ext4:",234 .get_context = ext4_get_context,235 .set_context = ext4_set_context,236 .get_dummy_policy = ext4_get_dummy_policy,237 .empty_dir = ext4_empty_dir,238 .has_stable_inodes = ext4_has_stable_inodes,239};240