Re: [RFC 6/8] ext4: Add an inode flag for atomic writes

Ritesh Harjani
2024-03-08T08:02:49Z

Dave Chinner <david@fromorbit.com> writes:

> On Sat, Mar 02, 2024 at 01:12:03PM +0530, Ritesh Harjani (IBM) wrote:
>> This patch adds an inode atomic writes flag to ext4
>> (EXT4_ATOMICWRITES_FL which uses FS_ATOMICWRITES_FL flag).
>> Also add support for setting of this flag via ioctl.
>>
>> Co-developed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
>> Signed-off-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
>> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
>> ---
>> fs/ext4/ext4.h | 6 ++++++
>> fs/ext4/ioctl.c | 11 +++++++++++
>> 2 files changed, 17 insertions(+)
>>
>> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
>> index 1d2bce26e616..aa7fff2d6f96 100644
>> --- a/fs/ext4/ext4.h
>> +++ b/fs/ext4/ext4.h
>> @@ -495,8 +495,12 @@ struct flex_groups {
>> #define EXT4_EA_INODE_FL 0x00200000 /* Inode used for large EA */
>> /* 0x00400000 was formerly EXT4_EOFBLOCKS_FL */
>>
>> +#define EXT4_ATOMICWRITES_FL FS_ATOMICWRITES_FL /* Inode supports atomic writes */
>> #define EXT4_DAX_FL 0x02000000 /* Inode is DAX */
>
> Tying the on disk format to the kernel user API is a poor choice.
> While the flag bits might have the same value, anything parsing the
> on-disk format should not be required to include kernel syscall API
> header files just to get all the on-disk format definitions it
> needs.

sure. Make sense.
I will hardcode that value.

-ritesh

>
> -Dave.
> --
> Dave Chinner
> david@fromorbit.com