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![Ritesh Harjani](/assets/img/avatar_default.png)
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>
246 lines
6.1 KiB
C
246 lines
6.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/quotaops.h>
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#include <linux/uuid.h>
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#include "ext4.h"
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#include "xattr.h"
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#include "ext4_jbd2.h"
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static void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
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const struct fscrypt_name *src)
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{
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memset(dst, 0, sizeof(*dst));
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dst->usr_fname = src->usr_fname;
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dst->disk_name = src->disk_name;
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dst->hinfo.hash = src->hash;
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dst->hinfo.minor_hash = src->minor_hash;
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dst->crypto_buf = src->crypto_buf;
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}
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int ext4_fname_setup_filename(struct inode *dir, const struct qstr *iname,
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int lookup, struct ext4_filename *fname)
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{
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struct fscrypt_name name;
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int err;
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err = fscrypt_setup_filename(dir, iname, lookup, &name);
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if (err)
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return err;
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ext4_fname_from_fscrypt_name(fname, &name);
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#if IS_ENABLED(CONFIG_UNICODE)
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err = ext4_fname_setup_ci_filename(dir, iname, fname);
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#endif
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return err;
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}
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int ext4_fname_prepare_lookup(struct inode *dir, struct dentry *dentry,
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struct ext4_filename *fname)
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{
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struct fscrypt_name name;
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int err;
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err = fscrypt_prepare_lookup(dir, dentry, &name);
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if (err)
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return err;
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ext4_fname_from_fscrypt_name(fname, &name);
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#if IS_ENABLED(CONFIG_UNICODE)
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err = ext4_fname_setup_ci_filename(dir, &dentry->d_name, fname);
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#endif
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return err;
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}
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void ext4_fname_free_filename(struct ext4_filename *fname)
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{
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struct fscrypt_name name;
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name.crypto_buf = fname->crypto_buf;
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fscrypt_free_filename(&name);
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fname->crypto_buf.name = NULL;
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fname->usr_fname = NULL;
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fname->disk_name.name = NULL;
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#if IS_ENABLED(CONFIG_UNICODE)
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kfree(fname->cf_name.name);
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fname->cf_name.name = NULL;
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#endif
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}
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static bool uuid_is_zero(__u8 u[16])
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{
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int i;
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for (i = 0; i < 16; i++)
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if (u[i])
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return false;
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return true;
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}
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int ext4_ioctl_get_encryption_pwsalt(struct file *filp, void __user *arg)
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{
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struct super_block *sb = file_inode(filp)->i_sb;
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struct ext4_sb_info *sbi = EXT4_SB(sb);
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int err, err2;
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handle_t *handle;
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if (!ext4_has_feature_encrypt(sb))
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return -EOPNOTSUPP;
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if (uuid_is_zero(sbi->s_es->s_encrypt_pw_salt)) {
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err = mnt_want_write_file(filp);
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if (err)
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return err;
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handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
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if (IS_ERR(handle)) {
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err = PTR_ERR(handle);
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goto pwsalt_err_exit;
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}
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err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
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EXT4_JTR_NONE);
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if (err)
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goto pwsalt_err_journal;
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lock_buffer(sbi->s_sbh);
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generate_random_uuid(sbi->s_es->s_encrypt_pw_salt);
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ext4_superblock_csum_set(sb);
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unlock_buffer(sbi->s_sbh);
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err = ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
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pwsalt_err_journal:
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err2 = ext4_journal_stop(handle);
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if (err2 && !err)
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err = err2;
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pwsalt_err_exit:
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mnt_drop_write_file(filp);
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if (err)
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return err;
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}
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if (copy_to_user(arg, sbi->s_es->s_encrypt_pw_salt, 16))
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return -EFAULT;
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return 0;
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}
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static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
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{
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return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
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EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
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}
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static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
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void *fs_data)
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{
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handle_t *handle = fs_data;
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int res, res2, credits, retries = 0;
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/*
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* Encrypting the root directory is not allowed because e2fsck expects
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* lost+found to exist and be unencrypted, and encrypting the root
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* directory would imply encrypting the lost+found directory as well as
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* the filename "lost+found" itself.
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*/
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if (inode->i_ino == EXT4_ROOT_INO)
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return -EPERM;
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if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
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return -EINVAL;
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if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
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return -EOPNOTSUPP;
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res = ext4_convert_inline_data(inode);
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if (res)
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return res;
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/*
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* If a journal handle was specified, then the encryption context is
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* being set on a new inode via inheritance and is part of a larger
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* transaction to create the inode. Otherwise the encryption context is
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* being set on an existing inode in its own transaction. Only in the
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* latter case should the "retry on ENOSPC" logic be used.
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*/
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if (handle) {
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res = ext4_xattr_set_handle(handle, inode,
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EXT4_XATTR_INDEX_ENCRYPTION,
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EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
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ctx, len, 0);
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if (!res) {
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ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
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ext4_clear_inode_state(inode,
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EXT4_STATE_MAY_INLINE_DATA);
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/*
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* Update inode->i_flags - S_ENCRYPTED will be enabled,
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* S_DAX may be disabled
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*/
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ext4_set_inode_flags(inode, false);
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}
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return res;
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}
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res = dquot_initialize(inode);
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if (res)
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return res;
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retry:
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res = ext4_xattr_set_credits(inode, len, false /* is_create */,
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&credits);
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if (res)
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return res;
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handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
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if (IS_ERR(handle))
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return PTR_ERR(handle);
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res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
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EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
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ctx, len, 0);
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if (!res) {
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ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
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/*
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* Update inode->i_flags - S_ENCRYPTED will be enabled,
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* S_DAX may be disabled
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*/
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ext4_set_inode_flags(inode, false);
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res = ext4_mark_inode_dirty(handle, inode);
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if (res)
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EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
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}
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res2 = ext4_journal_stop(handle);
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if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
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goto retry;
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if (!res)
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res = res2;
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return res;
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}
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static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
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{
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return EXT4_SB(sb)->s_dummy_enc_policy.policy;
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}
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static bool ext4_has_stable_inodes(struct super_block *sb)
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{
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return ext4_has_feature_stable_inodes(sb);
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}
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static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
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int *ino_bits_ret, int *lblk_bits_ret)
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{
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*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
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*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
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}
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const struct fscrypt_operations ext4_cryptops = {
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.key_prefix = "ext4:",
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.get_context = ext4_get_context,
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.set_context = ext4_set_context,
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.get_dummy_policy = ext4_get_dummy_policy,
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.empty_dir = ext4_empty_dir,
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.has_stable_inodes = ext4_has_stable_inodes,
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.get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits,
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};
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