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ext4: move ext4 crypto code to its own file crypto.c
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This is to cleanup super.c file which has grown quite large.
So, start moving ext4 crypto related code to where it should
be in the first place i.e. fs/ext4/crypto.c

Reviewed-by: Eric Biggers <[email protected]>
Signed-off-by: Ritesh Harjani <[email protected]>
Link: https://lore.kernel.org/r/7d637e093cbc34d727397e8d41a53a1b9ca7d7a4.1652595565.git.ritesh.list@gmail.com
Signed-off-by: Theodore Ts'o <[email protected]>
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riteshharjani authored and tytso committed May 22, 2022
1 parent c069db7 commit b1241c8
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Showing 4 changed files with 131 additions and 122 deletions.
1 change: 1 addition & 0 deletions fs/ext4/Makefile
Original file line number Diff line number Diff line change
Expand Up @@ -17,3 +17,4 @@ ext4-$(CONFIG_EXT4_FS_SECURITY) += xattr_security.o
ext4-inode-test-objs += inode-test.o
obj-$(CONFIG_EXT4_KUNIT_TESTS) += ext4-inode-test.o
ext4-$(CONFIG_FS_VERITY) += verity.o
ext4-$(CONFIG_FS_ENCRYPTION) += crypto.o
127 changes: 127 additions & 0 deletions fs/ext4/crypto.c
Original file line number Diff line number Diff line change
@@ -0,0 +1,127 @@
// SPDX-License-Identifier: GPL-2.0

#include <linux/quotaops.h>

#include "ext4.h"
#include "xattr.h"
#include "ext4_jbd2.h"

static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
}

static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
void *fs_data)
{
handle_t *handle = fs_data;
int res, res2, credits, retries = 0;

/*
* Encrypting the root directory is not allowed because e2fsck expects
* lost+found to exist and be unencrypted, and encrypting the root
* directory would imply encrypting the lost+found directory as well as
* the filename "lost+found" itself.
*/
if (inode->i_ino == EXT4_ROOT_INO)
return -EPERM;

if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
return -EINVAL;

if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
return -EOPNOTSUPP;

res = ext4_convert_inline_data(inode);
if (res)
return res;

/*
* If a journal handle was specified, then the encryption context is
* being set on a new inode via inheritance and is part of a larger
* transaction to create the inode. Otherwise the encryption context is
* being set on an existing inode in its own transaction. Only in the
* latter case should the "retry on ENOSPC" logic be used.
*/

if (handle) {
res = ext4_xattr_set_handle(handle, inode,
EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
ext4_clear_inode_state(inode,
EXT4_STATE_MAY_INLINE_DATA);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
}
return res;
}

res = dquot_initialize(inode);
if (res)
return res;
retry:
res = ext4_xattr_set_credits(inode, len, false /* is_create */,
&credits);
if (res)
return res;

handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
if (IS_ERR(handle))
return PTR_ERR(handle);

res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
}
res2 = ext4_journal_stop(handle);

if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
if (!res)
res = res2;
return res;
}

static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
{
return EXT4_SB(sb)->s_dummy_enc_policy.policy;
}

static bool ext4_has_stable_inodes(struct super_block *sb)
{
return ext4_has_feature_stable_inodes(sb);
}

static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
int *ino_bits_ret, int *lblk_bits_ret)
{
*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
}

const struct fscrypt_operations ext4_cryptops = {
.key_prefix = "ext4:",
.get_context = ext4_get_context,
.set_context = ext4_set_context,
.get_dummy_policy = ext4_get_dummy_policy,
.empty_dir = ext4_empty_dir,
.has_stable_inodes = ext4_has_stable_inodes,
.get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits,
};
3 changes: 3 additions & 0 deletions fs/ext4/ext4.h
Original file line number Diff line number Diff line change
Expand Up @@ -2733,7 +2733,10 @@ extern int ext4_fname_setup_ci_filename(struct inode *dir,
struct ext4_filename *fname);
#endif

/* ext4 encryption related stuff goes here crypto.c */
#ifdef CONFIG_FS_ENCRYPTION
extern const struct fscrypt_operations ext4_cryptops;

static inline void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
const struct fscrypt_name *src)
{
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122 changes: 0 additions & 122 deletions fs/ext4/super.c
Original file line number Diff line number Diff line change
Expand Up @@ -1495,128 +1495,6 @@ static int ext4_nfs_commit_metadata(struct inode *inode)
return ext4_write_inode(inode, &wbc);
}

#ifdef CONFIG_FS_ENCRYPTION
static int ext4_get_context(struct inode *inode, void *ctx, size_t len)
{
return ext4_xattr_get(inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT, ctx, len);
}

static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
void *fs_data)
{
handle_t *handle = fs_data;
int res, res2, credits, retries = 0;

/*
* Encrypting the root directory is not allowed because e2fsck expects
* lost+found to exist and be unencrypted, and encrypting the root
* directory would imply encrypting the lost+found directory as well as
* the filename "lost+found" itself.
*/
if (inode->i_ino == EXT4_ROOT_INO)
return -EPERM;

if (WARN_ON_ONCE(IS_DAX(inode) && i_size_read(inode)))
return -EINVAL;

if (ext4_test_inode_flag(inode, EXT4_INODE_DAX))
return -EOPNOTSUPP;

res = ext4_convert_inline_data(inode);
if (res)
return res;

/*
* If a journal handle was specified, then the encryption context is
* being set on a new inode via inheritance and is part of a larger
* transaction to create the inode. Otherwise the encryption context is
* being set on an existing inode in its own transaction. Only in the
* latter case should the "retry on ENOSPC" logic be used.
*/

if (handle) {
res = ext4_xattr_set_handle(handle, inode,
EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
ext4_clear_inode_state(inode,
EXT4_STATE_MAY_INLINE_DATA);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
}
return res;
}

res = dquot_initialize(inode);
if (res)
return res;
retry:
res = ext4_xattr_set_credits(inode, len, false /* is_create */,
&credits);
if (res)
return res;

handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
if (IS_ERR(handle))
return PTR_ERR(handle);

res = ext4_xattr_set_handle(handle, inode, EXT4_XATTR_INDEX_ENCRYPTION,
EXT4_XATTR_NAME_ENCRYPTION_CONTEXT,
ctx, len, 0);
if (!res) {
ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);
/*
* Update inode->i_flags - S_ENCRYPTED will be enabled,
* S_DAX may be disabled
*/
ext4_set_inode_flags(inode, false);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
EXT4_ERROR_INODE(inode, "Failed to mark inode dirty");
}
res2 = ext4_journal_stop(handle);

if (res == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
goto retry;
if (!res)
res = res2;
return res;
}

static const union fscrypt_policy *ext4_get_dummy_policy(struct super_block *sb)
{
return EXT4_SB(sb)->s_dummy_enc_policy.policy;
}

static bool ext4_has_stable_inodes(struct super_block *sb)
{
return ext4_has_feature_stable_inodes(sb);
}

static void ext4_get_ino_and_lblk_bits(struct super_block *sb,
int *ino_bits_ret, int *lblk_bits_ret)
{
*ino_bits_ret = 8 * sizeof(EXT4_SB(sb)->s_es->s_inodes_count);
*lblk_bits_ret = 8 * sizeof(ext4_lblk_t);
}

static const struct fscrypt_operations ext4_cryptops = {
.key_prefix = "ext4:",
.get_context = ext4_get_context,
.set_context = ext4_set_context,
.get_dummy_policy = ext4_get_dummy_policy,
.empty_dir = ext4_empty_dir,
.has_stable_inodes = ext4_has_stable_inodes,
.get_ino_and_lblk_bits = ext4_get_ino_and_lblk_bits,
};
#endif

#ifdef CONFIG_QUOTA
static const char * const quotatypes[] = INITQFNAMES;
#define QTYPE2NAME(t) (quotatypes[t])
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