[PATCH v2 02/11] fs, fscrypt: add an S_ENCRYPTED inode flag
Eric Biggers
ebiggers3 at gmail.com
Mon Oct 9 12:15:35 PDT 2017
From: Eric Biggers <ebiggers at google.com>
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: Chao Yu <yuchao0 at huawei.com>
Acked-by: Dave Chinner <dchinner at redhat.com>
Signed-off-by: Eric Biggers <ebiggers at google.com>
---
fs/ext4/inode.c | 7 +++++--
fs/ext4/super.c | 8 ++++++--
fs/f2fs/f2fs.h | 1 +
fs/f2fs/inode.c | 5 ++++-
fs/ubifs/ioctl.c | 5 ++++-
fs/ubifs/xattr.c | 1 +
include/linux/fs.h | 2 ++
7 files changed, 23 insertions(+), 6 deletions(-)
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 31db875bc7a1..d5a471939fbc 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -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,
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index b104096fce9e..dcfb19539871 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -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 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
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)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index fc53aebaf3ae..34d6e9ae8422 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -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
}
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index 50c88e37ed66..53fb08810ee9 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -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)
diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
index fdc311246807..0164bcc827f8 100644
--- a/fs/ubifs/ioctl.c
+++ b/fs/ubifs/ioctl.c
@@ -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;
}
/*
diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index c13eae819cbc..5ddc89d564fd 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -170,6 +170,7 @@ static int create_xattr(struct ubifs_info *c, struct inode *host,
err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
if (err)
goto out_cancel;
+ ubifs_set_inode_flags(host);
mutex_unlock(&host_ui->ui_mutex);
ubifs_release_budget(c, &req);
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 13dab191a23e..3efd5ded21c9 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1853,6 +1853,7 @@ struct super_operations {
#else
#define S_DAX 0 /* Make all the DAX code disappear */
#endif
+#define S_ENCRYPTED 16384 /* Encrypted file (using fs/crypto/) */
/*
* Note that nosuid etc flags are inode-specific: setting some file-system
@@ -1892,6 +1893,7 @@ static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags
#define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT)
#define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC)
#define IS_DAX(inode) ((inode)->i_flags & S_DAX)
+#define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED)
#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \
(inode)->i_rdev == WHITEOUT_DEV)
--
2.14.2.920.gcf0c67979c-goog
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