[PATCH] fscrypt: remove fscrypt_operations::max_namelen

[PATCH] fscrypt: remove fscrypt_operations::max_namelen

[Eric Biggers]

From: Eric Biggers <ebiggers@google.com>

The max_namelen field is unnecessary, as it is set to 255 (NAME_MAX) on
all filesystems that support fscrypt (or plan to support fscrypt).  For
simplicity, just use NAME_MAX directly instead.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 fs/crypto/fname.c       | 3 +--
 fs/ext4/super.c         | 1 -
 fs/f2fs/super.c         | 1 -
 fs/ubifs/crypto.c       | 1 -
 include/linux/fscrypt.h | 3 ---
 5 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/fs/crypto/fname.c b/fs/crypto/fname.c
index eb538c28df940..a9be4bc74a94a 100644
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -429,8 +429,7 @@ int fscrypt_setup_filename(struct inode *dir, const struct qstr *iname,
 
 	if (fscrypt_has_encryption_key(dir)) {
 		if (!fscrypt_fname_encrypted_size(&dir->i_crypt_info->ci_policy,
-						  iname->len,
-						  dir->i_sb->s_cop->max_namelen,
+						  iname->len, NAME_MAX,
 						  &fname->crypto_buf.len))
 			return -ENAMETOOLONG;
 		fname->crypto_buf.name = kmalloc(fname->crypto_buf.len,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 136940af00b88..47212d7c02b84 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1566,7 +1566,6 @@ static const struct fscrypt_operations ext4_cryptops = {
 	.set_context		= ext4_set_context,
 	.get_dummy_policy	= ext4_get_dummy_policy,
 	.empty_dir		= ext4_empty_dir,
-	.max_namelen		= EXT4_NAME_LEN,
 	.has_stable_inodes	= ext4_has_stable_inodes,
 	.get_ino_and_lblk_bits	= ext4_get_ino_and_lblk_bits,
 };
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 78ebc306ee2b5..cf049a042482b 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2976,7 +2976,6 @@ static const struct fscrypt_operations f2fs_cryptops = {
 	.set_context		= f2fs_set_context,
 	.get_dummy_policy	= f2fs_get_dummy_policy,
 	.empty_dir		= f2fs_empty_dir,
-	.max_namelen		= F2FS_NAME_LEN,
 	.has_stable_inodes	= f2fs_has_stable_inodes,
 	.get_ino_and_lblk_bits	= f2fs_get_ino_and_lblk_bits,
 	.get_num_devices	= f2fs_get_num_devices,
diff --git a/fs/ubifs/crypto.c b/fs/ubifs/crypto.c
index 22be7aeb96c4f..c57b46a352d8f 100644
--- a/fs/ubifs/crypto.c
+++ b/fs/ubifs/crypto.c
@@ -82,5 +82,4 @@ const struct fscrypt_operations ubifs_crypt_operations = {
 	.get_context		= ubifs_crypt_get_context,
 	.set_context		= ubifs_crypt_set_context,
 	.empty_dir		= ubifs_crypt_empty_dir,
-	.max_namelen		= UBIFS_MAX_NLEN,
 };
diff --git a/include/linux/fscrypt.h b/include/linux/fscrypt.h
index e912ed9141d9d..91ea9477e9bd2 100644
--- a/include/linux/fscrypt.h
+++ b/include/linux/fscrypt.h
@@ -118,9 +118,6 @@ struct fscrypt_operations {
 	 */
 	bool (*empty_dir)(struct inode *inode);
 
-	/* The filesystem's maximum ciphertext filename length, in bytes */
-	unsigned int max_namelen;
-
 	/*
 	 * Check whether the filesystem's inode numbers and UUID are stable,
 	 * meaning that they will never be changed even by offline operations
-- 
2.33.0

Re: [PATCH] fscrypt: remove fscrypt_operations::max_namelen

[Eric Biggers]

On Thu, Sep 09, 2021 at 11:45:13AM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> The max_namelen field is unnecessary, as it is set to 255 (NAME_MAX) on
> all filesystems that support fscrypt (or plan to support fscrypt).  For
> simplicity, just use NAME_MAX directly instead.
> 
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  fs/crypto/fname.c       | 3 +--
>  fs/ext4/super.c         | 1 -
>  fs/f2fs/super.c         | 1 -
>  fs/ubifs/crypto.c       | 1 -
>  include/linux/fscrypt.h | 3 ---
>  5 files changed, 1 insertion(+), 8 deletions(-)

Applied to fscrypt.git#master for 5.16.

- Eric