[PATCH RFC 3/8] fs/ext4: Disallow encryption if inode is DAX

ira.weiny
2020-04-14T04:01:58Z

From: Ira Weiny <ira.weiny@intel.com>

Encryption and DAX are incompatible. Changing the DAX mode due to a
change in Encryption mode is wrong without a corresponding
address_space_operations update.

Make the 2 options mutually exclusive by returning an error if DAX was
set first.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
fs/ext4/super.c | 10 +---------
1 file changed, 1 insertion(+), 9 deletions(-)

diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0c7c4adb664e..b14863058115 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1325,7 +1325,7 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
if (inode->i_ino == EXT4_ROOT_INO)
return -EPERM;

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

res = ext4_convert_inline_data(inode);
@@ -1349,10 +1349,6 @@ static int ext4_set_context(struct inode *inode, const void *ctx, size_t len,
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);
}
return res;
@@ -1376,10 +1372,6 @@ 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 - S_ENCRYPTED will be enabled,
- * S_DAX may be disabled
- */
ext4_set_inode_flags(inode);
res = ext4_mark_inode_dirty(handle, inode);
if (res)
--
2.25.1