Commit 2ee6a576 authored by Eric Biggers's avatar Eric Biggers Committed by Theodore Ts'o
Browse files

fs, fscrypt: add an S_ENCRYPTED inode flag 



Introduce a flag S_ENCRYPTED which can be set in ->i_flags to indicate
that the inode is encrypted using the fscrypt (fs/crypto/) mechanism.

Checking this flag will give the same information that
inode->i_sb->s_cop->is_encrypted(inode) currently does, but will be more
efficient.  This will be useful for adding higher-level helper functions
for filesystems to use.  For example we'll be able to replace this:

	if (ext4_encrypted_inode(inode)) {
		ret = fscrypt_get_encryption_info(inode);
		if (ret)
			return ret;
		if (!fscrypt_has_encryption_key(inode))
			return -ENOKEY;
	}

with this:

	ret = fscrypt_require_key(inode);
	if (ret)
		return ret;

... since we'll be able to retain the fast path for unencrypted files as
a single flag check, using an inline function.  This wasn't possible
before because we'd have had to frequently call through the
->i_sb->s_cop->is_encrypted function pointer, even when the encryption
support was disabled or not being used.

Note: we don't define S_ENCRYPTED to 0 if CONFIG_FS_ENCRYPTION is
disabled because we want to continue to return an error if an encrypted
file is accessed without encryption support, rather than pretending that
it is unencrypted.

Reviewed-by: default avatarChao Yu <yuchao0@huawei.com>
Acked-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 734f0d24

fs/ext4/inode.c

+5 −2
Original line number Diff line number Diff line
@@ -4589,10 +4589,13 @@ void ext4_set_inode_flags(struct inode *inode) 
		new_fl |= S_DIRSYNC;

	if (test_opt(inode->i_sb, DAX) && S_ISREG(inode->i_mode) &&

	    !ext4_should_journal_data(inode) && !ext4_has_inline_data(inode) &&

	    !ext4_encrypted_inode(inode))

	    !(flags & EXT4_ENCRYPT_FL))

		new_fl |= S_DAX;

	if (flags & EXT4_ENCRYPT_FL)

		new_fl |= S_ENCRYPTED;

	inode_set_flags(inode, new_fl,

			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX);

			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|S_DAX|

			S_ENCRYPTED);

}



static blkcnt_t ext4_inode_blocks(struct ext4_inode *raw_inode,

fs/ext4/super.c

+6 −2
Original line number Diff line number Diff line
@@ -1181,7 +1181,8 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len, 
			ext4_clear_inode_state(inode,

					EXT4_STATE_MAY_INLINE_DATA);

			/*

			 * Update inode->i_flags - e.g. S_DAX may get disabled

			 * Update inode->i_flags - S_ENCRYPTED will be enabled,

			 * S_DAX may be disabled

			 */

			ext4_set_inode_flags(inode);

		}
@@ -1206,7 +1207,10 @@ retry: 
				    ctx, len, 0);

	if (!res) {

		ext4_set_inode_flag(inode, EXT4_INODE_ENCRYPT);

		/* Update inode->i_flags - e.g. S_DAX may get disabled */

		/*

		 * Update inode->i_flags - S_ENCRYPTED will be enabled,

		 * S_DAX may be disabled

		 */

		ext4_set_inode_flags(inode);

		res = ext4_mark_inode_dirty(handle, inode);

		if (res)

fs/f2fs/f2fs.h

+1 −0
Original line number Diff line number Diff line
@@ -2947,6 +2947,7 @@ static inline void f2fs_set_encrypted_inode(struct inode *inode) 
{

#ifdef CONFIG_F2FS_FS_ENCRYPTION

	file_set_encrypt(inode);

	inode->i_flags |= S_ENCRYPTED;

#endif

}

fs/f2fs/inode.c

+4 −1
Original line number Diff line number Diff line
@@ -43,8 +43,11 @@ void f2fs_set_inode_flags(struct inode *inode) 
		new_fl |= S_NOATIME;

	if (flags & FS_DIRSYNC_FL)

		new_fl |= S_DIRSYNC;

	if (f2fs_encrypted_inode(inode))

		new_fl |= S_ENCRYPTED;

	inode_set_flags(inode, new_fl,

			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);

			S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC|

			S_ENCRYPTED);

}



static void __get_inode_rdev(struct inode *inode, struct f2fs_inode *ri)

fs/ubifs/ioctl.c

+4 −1
Original line number Diff line number Diff line
@@ -38,7 +38,8 @@ void ubifs_set_inode_flags(struct inode *inode) 
{

	unsigned int flags = ubifs_inode(inode)->flags;



	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);

	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC |

			    S_ENCRYPTED);

	if (flags & UBIFS_SYNC_FL)

		inode->i_flags |= S_SYNC;

	if (flags & UBIFS_APPEND_FL)
@@ -47,6 +48,8 @@ void ubifs_set_inode_flags(struct inode *inode) 
		inode->i_flags |= S_IMMUTABLE;

	if (flags & UBIFS_DIRSYNC_FL)

		inode->i_flags |= S_DIRSYNC;

	if (flags & UBIFS_CRYPT_FL)

		inode->i_flags |= S_ENCRYPTED;

}



/*

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