[PATCH 5.9 552/757] ext4: disallow modifying DAX inode flag if inline_data has been set

[Greg Kroah-Hartman]

From: Xiao Yang <yangx.jy@xxxxxxxxxxxxxx>

[ Upstream commit aa2f77920b743c44e02e2dc8474bbf8bd30007a2 ]

inline_data is mutually exclusive to DAX so enabling both of them triggers
the following issue:
------------------------------------------
# mkfs.ext4 -F -O inline_data /dev/pmem1
...
# mount /dev/pmem1 /mnt
# echo 'test' >/mnt/file
# lsattr -l /mnt/file
/mnt/file                    Inline_Data
# xfs_io -c "chattr +x" /mnt/file
# xfs_io -c "lsattr -v" /mnt/file
[dax] /mnt/file
# umount /mnt
# mount /dev/pmem1 /mnt
# cat /mnt/file
cat: /mnt/file: Numerical result out of range
------------------------------------------

Fixes: b383a73f2b83 ("fs/ext4: Introduce DAX inode flag")
Signed-off-by: Xiao Yang <yangx.jy@xxxxxxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Reviewed-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Reviewed-by: Andreas Dilger <adilger@xxxxxxxxx>
Link: https://lore.kernel.org/r/20200828084330.15776-1-yangx.jy@xxxxxxxxxxxxxx
Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 fs/ext4/ext4.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 523e00d7b3924..69187b6205b2b 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -492,7 +492,7 @@ struct flex_groups {
 
 /* Flags which are mutually exclusive to DAX */
 #define EXT4_DAX_MUT_EXCL (EXT4_VERITY_FL | EXT4_ENCRYPT_FL |\
-			   EXT4_JOURNAL_DATA_FL)
+			   EXT4_JOURNAL_DATA_FL | EXT4_INLINE_DATA_FL)
 
 /* Mask out flags that are inappropriate for the given type of inode. */
 static inline __u32 ext4_mask_flags(umode_t mode, __u32 flags)
-- 
2.25.1