[PATCHv2 1/3] ext4: Move ext4 crypto code to its own file crypto.c

Ritesh Harjani
2022-05-14T17:23:06Z

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

Signed-off-by: Ritesh Harjani <ritesh.list@gmail.com>
---
fs/ext4/Makefile | 1 +
fs/ext4/crypto.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++
fs/ext4/ext4.h | 3 ++
fs/ext4/super.c | 122 ---------------------------------------------
4 files changed, 131 insertions(+), 122 deletions(-)
create mode 100644 fs/ext4/crypto.c

diff --git a/fs/ext4/Makefile b/fs/ext4/Makefile
index 7d89142e1421..72206a292676 100644
--- a/fs/ext4/Makefile
+++ b/fs/ext4/Makefile
@@ -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
diff --git a/fs/ext4/crypto.c b/fs/ext4/crypto.c
new file mode 100644
index 000000000000..e5413c0970ee
--- /dev/null
+++ b/fs/ext4/crypto.c
@@ -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,
+};
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index a743b1e3b89e..9100f0ba4a52 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -2731,6 +2731,9 @@ extern int ext4_fname_setup_ci_filename(struct inode *dir,
struct ext4_filename *fname);
#endif

+/* ext4 encryption related stuff goes here crypto.c */
+extern const struct fscrypt_operations ext4_cryptops;
+
#ifdef CONFIG_FS_ENCRYPTION
static inline void ext4_fname_from_fscrypt_name(struct ext4_filename *dst,
const struct fscrypt_name *src)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 1847b46af808..e6cfd338712c 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1492,128 +1492,6 @@ 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])
--
2.31.1